62 results on '"Awang RA"'
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2. Assessing the impact of systemic conditions on periodontal health in Malaysian population: a retrospective study.
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Arshad S, Awang RA, Rahman NA, Hassan A, Ahmad WMAW, Mohamed RN, Basha S, and Karobari MI
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- Humans, Malaysia epidemiology, Retrospective Studies, Male, Female, Middle Aged, Adult, Risk Factors, Aged, Periodontal Diseases epidemiology, Age Factors, Periodontitis epidemiology
- Abstract
Background: Periodontal diseases, including gingivitis and periodontitis, are among the most prevalent oral health issues globally. They compromise the supportive structures of teeth and are influenced by both local and systemic factors. This study aimed to systematically assess the impact of systemic conditions on periodontal health in Malaysian population, addressing the gap in understanding these factors as potential risk factors., Methods: A retrospective, non-interventional study was conducted using medical records from Hospital Universiti Sains Malaysia, Kelantan, from September 2019 to December 2022. The study included patients with periodontitis and systemic conditions. Data were analyzed using descriptive statistics, chi-squared tests, Fisher's exact tests, Mann-Whitney U tests, Kruskal-Wallis tests, Spearman's correlation, and logistic regression., Results: Out of 600 records, 274 patients were included. The cohort was 51.8% male, with a median age of 51 years. Malays accounted for 92.3% of the sample. Hypertension and diabetes mellitus were the most common comorbid conditions. Severe periodontitis was significantly associated with age (45-64 years, p = 0.018) and Malay ethnicity (p = 0.011). Logistic regression revealed that age and ethnicity were significant predictors of periodontitis severity, with Malays being 12.5 times more likely to develop severe periodontitis., Conclusion: Systemic conditions significantly influence periodontitis development and progression. Age and ethnicity are crucial predictors of periodontitis severity in the Malaysian population. Comprehensive risk assessment tools are necessary to incorporate a broader spectrum of risk factors for better management and prevention., (© 2024. The Author(s).)
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- 2024
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3. Bioinformatics Analysis and Spatiotemporal Distribution of the fliC Gene and Its Protein Isolated from Escherichia coli-Infected Patients in Eastern Algeria.
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Harrar A, Hamat RA, and Hamidechi MA
- Abstract
Background: The fliC locus in Escherichia coli primarily encodes flagellar (H) antigens. Exploring fliC sequence diversity will shed light on the mechanisms of bacterial pathogenicity. This study examined the presence of fliC mutant strains of E. coli in infected patients from different age groups, sexes and sample types in eastern Algerian provinces over a span of 2 years., Methods: This retrospective, cross-sectional study involved three provinces in eastern Algeria: i) Bordj Bou Arreridj, ii) Setif and iii) Batna. A total of 75 E. coli isolates were obtained from the University State Hospital Centre. Two types of analyses were conducted: i) a bioinformatics analysis of the protein sequences translated from the fliC genes, specifically the fliC flagellar sequences and ii) a multifactorial statistical analysis (multiple correspondence analysis [MCA]) of the population of infected patients, considering various parameters. The fliC protein sequences were aligned using the Multiple Alignment using Fast Fourier Transform (MAFFT) programme. The alignment results were then visualised using the MView programme. Finally, a phylogenetic tree was constructed using the maximum likelihood algorithm in MEGA 11 software., Results: Bioinformatics analysis highlighted the strong conservation of the structures of the fliC protein sequences, especially at the two N- and C-terminal ends, and strong variability in the central zone. This remarkable fliC intersequence similarity is corroborated by the presence of protein motifs identified in the PROSITE protein motif database., Conclusion: fliC mutations in E. coli were not detected in the clinical samples of patients from hospitals in the three Algerian Provinces. Our analysis revealed that all the samples exhibited characteristics of wild-type virulent bacteria without mutations. A multicentre study is warranted for epidemiological surveillance of fliC mutant strains for future preventive measures., Competing Interests: Conflict of interest: None., (© Penerbit Universiti Sains Malaysia, 2024.)
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- 2024
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4. Validity and Reliability of a Questionnaire on the Knowledge, Attitudes, Perceptions and Practices toward Food Poisoning among Malaysian Secondary School Students: A Pilot Study.
- Author
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Ramu P, Osman M, Abdul Mutalib NA, Aljaberi MA, Lee KH, Lin CY, and Hamat RA
- Abstract
Children in school settings are at risk of contracting food poisoning due to inadequate food safety practices and safe eating behaviors. This research aimed to develop a valid and reliable questionnaire on the knowledge, attitudes, perceptions, and practices (KAP
2 ) toward food poisoning and its prevention among secondary school students. The questionnaire was developed by considering the Health Belief Model (HBM). A pilot study using a cross-sectional survey was conducted in Tangkak, Johor, among 30 selected students using a convenience sampling method. A pre-test was conducted on 15 secondary school students aged 13-17 years old prior to the pilot study, and they were excluded from the pilot study. The constructed knowledge was assessed using the difficulty and discrimination indices. Meanwhile, the reliability of the attitude, practice, and perception components in the questionnaire were assessed using Cronbach's alpha. Regarding knowledge (34 items), the difficulty index showed that most items ( n = 28) were easy, while one was difficult, and the remaining five were within an acceptable range. In addition, the discrimination index of the knowledge component (34 items) showed that twenty-two, three, and one had good, acceptable, and excellent ranges, respectively. Only eight items had a low discrimination power. All items of the attitude and practice components (10 items for each) showed a corrected item-total correlation value of >0.30. Only four out of twenty-one items of the perception component showed an unacceptable range of <0.30. However, following a discussion with the experts, all items were retained. With the incorporation of the HBM, the 75-item adapted food poisoning KAP2 questionnaire is valid and reliable. It can be utilized to measure and generate food poisoning KAP2 among secondary school students in Malaysia.- Published
- 2023
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5. Phage Therapy as an Alternative Treatment Modality for Resistant Staphylococcus aureus Infections.
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Atshan SS, Hamat RA, Aljaberi MA, Chen JS, Huang SW, Lin CY, Mullins BJ, and Kicic A
- Abstract
The production and use of antibiotics increased significantly after the Second World War due to their effectiveness against bacterial infections. However, bacterial resistance also emerged and has now become an important global issue. Those most in need are typically high-risk and include individuals who experience burns and other wounds, as well as those with pulmonary infections caused by antibiotic-resistant bacteria, such as Pseudomonas aeruginosa , Acinetobacter sp, and Staphylococci . With investment to develop new antibiotics waning, finding and developing alternative therapeutic strategies to tackle this issue is imperative. One option remerging in popularity is bacteriophage (phage) therapy. This review focuses on Staphylococcus aureus and how it has developed resistance to antibiotics. It also discusses the potential of phage therapy in this setting and its appropriateness in high-risk people, such as those with cystic fibrosis, where it typically forms a biofilm.
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- 2023
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6. A cross-sectional study on the impact of the COVID-19 pandemic on psychological outcomes: Multiple indicators and multiple causes modeling.
- Author
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Aljaberi MA, Alareqe NA, Alsalahi A, Qasem MA, Noman S, Uzir MUH, Mohammed LA, Fares ZEA, Lin CY, Abdallah AM, Hamat RA, and Mohd Rani MD
- Subjects
- Humans, Pandemics, Cross-Sectional Studies, SARS-CoV-2, Depression epidemiology, Depression psychology, Anxiety epidemiology, Anxiety psychology, COVID-19 epidemiology, Sleep Initiation and Maintenance Disorders epidemiology
- Abstract
Although the psychological impact of coronavirus disease 2019 (COVID-19) has been evaluated in the literature, further research is needed, particularly on post-traumatic stress disorder (PTSD) and psychological outcomes, is needed. This study aims to investigate the effect of the COVID-19 pandemic on psychological outcomes (depression, anxiety, and insomnia). A cross-sectional study using an online survey was conducted using the following instruments: Impact of Event Scale-Revised (IES-R), Patient Health Questionnaire-9 (PHQ-9), Generalized Anxiety Disorder (GAD-7), and Insomnia Severity Index (ISI). Confirmatory factor analysis (CFA), structural equation model (SEM), multiple indicators and multiple causes (MIMIC) modeling, and differential item functioning (DIF) were performed to analyze the collected data. According to the results, participants with PTSD (n = 360) showed a higher level of depression, anxiety, and insomnia than those without PTSD (n = 639). Among the participants, 36.5% experienced moderate to severe symptoms of depression, and 32.6% had mild depressive symptoms. Moreover, 23.7% of participants experienced moderate to severe anxiety symptoms, and 33.1% had mild anxiety symptoms. In addition, 51.5% of participants experienced symptoms of insomnia. In conclusion, the PTSD caused by COVID-19 is significantly associated with depression, anxiety, and insomnia at the level of latent constructs and observed variables., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2022 Aljaberi et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)
- Published
- 2022
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7. Effects on the Titanium Implant Surface by Different Hygiene Instrumentations: A Narrative Review.
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Yen Nee W, Raja Awang RA, and Hassan A
- Abstract
Peri-implant disease is usually caused by the accumulation of dental biofilm around the implant, and this biofilm can irradiate the gingiva tissue, which leads to inflammation and, more severely, to a deterioration of the bone structure. There is a concern regarding the removal of biofilm from the implant surface by using different hygiene instruments. Some hygiene instruments may have some effect on the dental implant surface, resulting in roughening or damage to the implant surfaces. This study reviewed the effects of titanium implant surfaces on different hygiene instruments. A literature search was conducted from PubMed, ScienceDirect, and Scopus databases for articles published from 1992 to 2021. A total of 19 full-text papers with keywords of interest that met all the eligibility criteria were selected. Surface roughness was evaluated with a scanning electron microscope and also using a profilometer, laser scanning, scanning probe, and atomic force microscopes. A metal curette produced a roughened surface on the titanium implant, but a plastic curette did not alter the surface. Instrumentation with rubber cups left the surface unchanged and appeared to smoothen the surface, whereas the air-powder abrasive instrumentation altered the surface with the presence of micro pits and pores. A conventional metal ultrasonic scaler showed significant surface topographical changes and scratches on both titanium surfaces, as a diode laser, light-emitting diode (LED), and laser treatment did not show any alteration on the rough and smooth titanium surfaces. Thus, a non-metallic instrument such as a plastic curette, rubber cups, and novel technology including diode laser, LED, and laser treatment is appropriate and can be used for debridement on smooth and machined titanium implant surfaces as well as sandblasted and acid-etched (SLA), titanium plasma-sprayed (TPS), and resorbable blasted media (RBM) surfaces. The use of metallic instruments should be avoided, and it is not recommended., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2022, Yen Nee et al.)
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- 2022
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8. Sero-prevalence of malaria and the knowledge, attitudes and practices relating to the prevention of malaria among indigenous people living in the central forest spine in Peninsular Malaysia: a mixed-methods study.
- Author
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Kader Maideen SF, Rashid A, Ahmad NI, Zahari SNA, and Hamat RA
- Subjects
- Adult, Cross-Sectional Studies, Forests, Humans, Indigenous Peoples, Malaysia epidemiology, Middle Aged, Prevalence, Surveys and Questionnaires, Health Knowledge, Attitudes, Practice, Malaria epidemiology, Malaria prevention & control
- Abstract
Background: Malaria is still a major public health threat in some parts of the world. Many countries are targeting to achieve malaria free status country. This study aimed to determine the sero-prevalence of malaria and the knowledge, attitudes and practices relating to the prevention of malaria among the indigenous adults living in the central forest spine in Peninsular Malaysia., Methods: A mixed method study was conducted in indigenous settlements in 2020. Blood film for malaria parasite (BFMP) was used to diagnose malaria in this study. A structured questionnaire was used to collect data from the participants. For the qualitative data, in-depth interviews were conducted and data was collected until data saturation was reached. Multiple linear regression was used to determine the predictors after adjusting for confounders. A p-value of < 0.05 is considered as statistically significant. Meaningful statements from the in-depth interviews were assigned to the relevant codes using NVivo version 12 software., Results: A total of 284 indigenous people participated in the study. The prevalence of malaria in this study was 0%. Those in the middle age group between 25 and 41 years and tested positive for malaria previously were significantly more likely to have better knowledge and attitude scores. Significant correlations were also observed between knowledge-attitude and knowledge-practice. For the qualitative results, most of the respondents were unsure of monkey malaria, but all were aware of human malaria., Conclusion: The present study highlighted the absence of malaria in the study population and relatively good knowledge, attitudes and practices relating to the prevention of malaria., (© 2022. The Author(s).)
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- 2022
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9. Exploring Factors Affecting Graduate Students' Satisfaction toward E-Learning in the Era of the COVID-19 Crisis.
- Author
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Mohammed LA, Aljaberi MA, Amidi A, Abdulsalam R, Lin CY, Hamat RA, and Abdallah AM
- Abstract
Background: Shifting the educational system from a traditional to an online context during COVID-19 necessitated several considerations to assure students' satisfaction with e-learning., Aim: This study aims to explore the factors influencing students' satisfaction with e-learning during the COVID-19 crisis. In particular, it tests multiple mediations, student factors, and system quality between students' satisfaction and each course evaluation and instructor's performance., Methodology: In this cross-sectional study, 258 undergraduate and postgraduate students enrolled in online courses at multiple Malaysian universities were recruited using non-probabilistic purposive sampling. Data were collected using a questionnaire that assessed four factors that influenced students' satisfaction with e-learning during the COVID-19 crisis (i.e., instructor performance, course evaluation, student factors, and system quality) and analyzed using the partial least squares route structural equation modelling (PLS-SEM)., Results: The results indicated that the four factors were significantly associated with students' satisfaction with e-learning during COVID-19. Student factors and system quality were the most factors predicting students' satisfaction with e-learning. Findings indicate statistically significant relationships between the instructor's performance, student factors, course evaluation, and system quality on students' satisfaction. Furthermore, the results depict that both course evaluation and system quality serially mediate the relationship between instructors' performance and students' satisfaction., Conclusion: This study finds that improving and enhancing student factors and system quality is critical for students' satisfaction with e-learning. Furthermore, e-learning platforms should contain new advances of computer-mediated technologies that enable collaboration, which is a critical factor in the success of e-learning systems.
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- 2022
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10. Diagnostic Accuracy of Centor Score for Diagnosis of Group A Streptococcal Pharyngitis among Adults in Primary Care Clinics in Malaysia.
- Author
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Muthanna A, Shamsuddin NH, Abdul Rashid A, Ghazali SS, Hamat RA, Mawardi M, Salim HS, and Zakariah SZ
- Abstract
Background: Pharyngitis is a common presentation seen in general practice, but it is difficult to differentiate whether its etiology is viral or bacterial. The Centor score gives an approximation of the etiology of the pharyngitis, which informs physicians of the need to prescribe antibiotics. This study aimed to assess the validity of the Centor score in diagnosing Group A streptococcal (GAS) pharyngitis amongst adults in Malaysia., Methods: This cross-sectional study was conducted to compare the clinical criteria of the Centor score to the gold standard throat swab culture results amongst 215 adults presenting with sore throat in primary care clinics. The participants were adult patients who complained of sore throat and visited the three public primary care clinics in Sepang, Malaysia. The convenience sampling method was used. The throat swabs were analysed for β-haemolytic streptococci. Demographic and clinical data, including the Centor score, were analysed in relation to the pathogen., Results: Pharyngitis was diagnosed in 130 (60.5%) of the participants. Six isolates (2.4%) were identified as GAS pharyngitis. Both Centor scores 3 and 4 had a sensitivity of 50%, and specificities of 97.6% and 100%, respectively., Conclusion: A Centor score < 3 is favourable for excluding a diagnosis of GAS pharyngitis. Centor scores 3 and 4 require further examination to confirm a diagnosis of GAS pharyngitis., Competing Interests: Conflict of Interest None., (© Penerbit Universiti Sains Malaysia, 2022.)
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- 2022
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11. Corrigendum: Stem Cell Therapy in Dengue Virus-Infected BALB/C Mice Improves Hepatic Injury.
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Sakinah S, Priya SP, Mok PL, Munisvaradass R, Teh SW, Sun Z, Alzahrani B, Bakar FA, Chee HY, Hamat RA, He G, Xiong C, Joseph N, Tong JB, Wu X, Maniam M, Samrot AV, Higuchi A, and Kumar SS
- Abstract
[This corrects the article DOI: 10.3389/fcell.2021.637270.]., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The reviewer RR declared a shared affiliation, with no collaboration, with one of the authors, AH, to the handling editor at the time of the review., (Copyright © 2022 Sakinah, Priya, Mok, Munisvaradass, Teh, Sun, Alzahrani, Bakar, Chee, Hamat, He, Xiong, Joseph, Tong, Wu, Maniam, Samrot, Higuchi and Kumar.)
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- 2022
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12. Antibiotic Prescribing Patterns for Patients with Pharyngitis in Malaysian Public Primary Care Clinics.
- Author
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Muthanna A, Zakariah SZ, Abdul Rashid A, Ghazali SS, Hamat RA, Mawardi M, Salim HS, and Shamsuddin NH
- Abstract
Background: Over-prescription of antibiotics for upper respiratory tract infection (URTI) is a continuing problem in Malaysia, leading to increased antimicrobial resistance and unnecessary cost incurred for treatment. In a patient presenting with a sore throat, it is recommended to only prescribe antibiotics to group A streptococcus (GAS) pharyngitis confirmed by a throat culture, rapid antigen test or in patients with a Centor score of 4., Methods: This cross-sectional study assessed the proportion of antibiotics prescribed and antimicrobial susceptibility patterns of GAS pharyngitis in the Malaysian primary care setting. Two-hundred and fifteen adult patients presenting with sore throat were recruited in three primary care clinics. Demographic data and clinical information were collected and analysed. Centor scores were calculated according to the clinical information and throat swabs were collected from all participants for GAS identification., Results: Only six throat swabs isolated GAS and indicated for antimicrobial treatment (2.8%). However, 48 participants (22.3%) were prescribed antibiotics out of which only four (8.3%) patients with isolated GAS, including three (6.2%) patients who clinically had a Centor score of 4 and one patient with a score of 3. Amoxicillin and erythromycin were the most commonly prescribed antibiotics (58.3% and 25% of all antibiotics, respectively)., Conclusion: There is a high proportion of antibiotic prescriptions which were not indicated in patients with sore throat in this study. This may reflect a common practice of antibiotic overuse for sore throat in primary care settings in Malaysia. Concerted interventions to reduce the inappropriate prescribing of antibiotics are urgently needed., Competing Interests: Conflicts of Interest None., (© Penerbit Universiti Sains Malaysia, 2022.)
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- 2022
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13. Temporomandibular Joint Disorders: Is there a Need for Additional Subspeciality in Dentistry?
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Arshad S, Awang RA, and Malik S
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- Dentistry, Humans, Temporomandibular Joint, Temporomandibular Joint Disorders diagnosis, Temporomandibular Joint Disorders therapy
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- 2021
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14. Efficacy of Interventional Programs in Reducing Acculturative Stress and Enhancing Adjustment of International Students to the New Host Educational Environment: A Systematic Review and Meta-Analysis.
- Author
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Aljaberi MA, Alsalahi A, Juni MH, Noman S, Al-Tammemi AB, and Hamat RA
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- Humans, Students
- Abstract
This review aimed to systematically outline and meta-analyze the efficacy of psychoeducational, cultural orientation, socio-cultural, and peer-pairing programs in reducing acculturative stress and enhancing adjustment among international students worldwide. The consulted databases were PubMed, Scopus, Web of Science, ScienceDirect, EBSCO, and ProQuest. Eligibility criteria allowed the inclusion of randomized controlled trials (RCTs) and quasi-experimental trials without applying language, country, publication type or time restrictions. The quality of the eligible studies was appraised by the RoB2 tool of Cochrane for RCTs and JBI critical appraisal tools for quasi-experimental trials. Data items were collected based on PICO acronym by two investigators and reviewed for accuracy by a third one. The evidence was narratively synthesized and validated by proceeding with a random model meta-analysis using Cochrane RevMan software(Version 5.4). The quality of the pooled evidence from meta-analysis was assessed using the tool of GRADE. Out of 29,975 retrieved records, 14 studies (six RCTs and eight quasi-experimental trials) were included. The psychoeducational program significantly reduced acculturative stress and enhanced adjustment. In contrast, cultural orientation and peer-pairing programs significantly enhanced adjustment, but could not reduce acculturative stress. In meta-analysis, acculturative stress was significantly reduced in the psychoeducational intervention versus controls [overall pooled size effect = -3.89 (95% CI: -5.42, -2.53) at p < 0.001]. Similarly, adjustment was significantly enhanced in the psychoeducation and socio-cultural interventions versus control [overall pooled size effect = 3.10 (95% CI: 2.35, 3.85) at p < 0.001]. In conclusion, the psychoeducational program demonstrated superior efficacy in reducing acculturative stress and enhancing adjustment compared to the other interventional programs. However, socio-cultural programs have still been effective in enhancing adjustment. This systematic review is registered in PROSPERO (CRD42018104211).
- Published
- 2021
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15. The Role of Subinhibitory Concentrations of Daptomycin and Tigecycline in Modulating Virulence in Staphylococcus aureus .
- Author
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Atshan SS, Hamat RA, Coolen MJL, Dykes G, Sekawi Z, Mullins BJ, Than LTL, Abduljaleel SA, and Kicic A
- Abstract
Staphylococcus aureus ( S. aureus ) infections are notoriously complicated by the ability of the organism to grow in biofilms and are difficult to eradicate with antimicrobial therapy. The purpose of the current study was to clarify the influence of sub-inhibitory concentrations (sub-MICs) of daptomycin and tigecycline antibiotics on biofilm adhesion factors and exoproteins expressions by S. aureus clinical isolates. Six clinical isolates representing positive biofilm S. aureus clones (3 methicillin-sensitive S. aureus (MSSA) and 3 methicillin-resistant S. aureus (MRSA)) were grown with sub-MICs (0.5 MIC) of two antibiotics (daptomycin and tigecycline) for 12 h of incubation. RNA extracted from culture pellets was used via relative quantitative real-time-PCR (qRT-PCR) to determine expression of specific adhesion ( fnbA , fnbB , clfA , clfB , fib , ebps , cna , eno ) and biofilm ( icaADBC ) genes. To examine the effect of sub-MIC of these antibiotics on the expression of extracellular proteins, samples from the culture supernatants of six isolates were collected after 12 h of treatment with or without tigecycline in order to profile protein production via 2D gel sodium dodecyl sulfate-polyacrylamide gel electrophoresis (2D gel-SDS-PAGE). Sub-MIC treatment of all clinical MRSA and MSSA strains with daptomycin or tigecycline dramatically induced or suppressed fnbA , fnbB , clfA , clfB , fib , ebps , cna , eno , and icaADBC gene expression. Furthermore, sub-MIC use of tigecycline significantly reduced the total number of separated protein spots across all the isolates, as well as decreasing production of certain individual proteins. Collectively, this study showed very different responses in terms of both gene expression and protein secretion across the various isolates. In addition, our results suggest that sub-MIC usage of daptomycin and tigecycline could signal virulence induction by S. aureus via the regulation of biofilm adhesion factor genes and exoproteins. If translating findings to the clinical treatment of S. aureus , the therapeutic regimen should be adapted depending on antibiotic, the virulence factor and strain type.
- Published
- 2021
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16. Perceived Severity and Susceptibility towards Leptospirosis Infection in Malaysia.
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Sukeri S, Zahiruddin WM, Shafei MN, Hamat RA, Osman M, Jamaluddin TZMT, and Daud AB
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- Health Behavior, Health Knowledge, Attitudes, Practice, Humans, Malaysia epidemiology, Severity of Illness Index, Disease Susceptibility, Ecosystem, Leptospirosis etiology
- Abstract
Background: Perceived severity and susceptibility refers to one's belief of the seriousness and the risk of contracting a specific disease. It is an essential study in public health as it assists in the understanding of the motivating factors towards disease prevention. This qualitative study aimed to explore perceived severity and susceptibility towards leptospirosis infection among respondents in two states of Malaysia., Methods: Focus group discussions using the phenomenology approach was conducted involving 72 respondents in Selangor and Kelantan. Data were examined using content analysis., Results: Respondents perceived leptospirosis infection as severe due to its poor disease prognosis and complications. However, some rated it less severe when compared with other chronic diseases such as cancer and AIDS. Their perceptions were influenced by their knowledge about the disease, media portrayal and frequency of health campaigns by the government. All respondents believed they were not susceptible to the disease., Conclusion: The low perceived susceptibility of leptospirosis infection is a matter of concern as it may contribute to respondents' lack of motivation towards preventing the disease. The study findings may provide the basis for health promotional activities designed to heighten public perceived threat towards leptospirosis infection and thereby improving preventive health behaviors for avoiding leptospirosis.
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- 2020
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17. High Level Aminoglycoside Resistance And Distribution Of The Resistance Genes In Enterococcus faecalis And Enterococcus faecium From Teaching Hospital In Malaysia.
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Moussa AA, Md Nordin AF, Hamat RA, and Jasni AS
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Background: Enterococcus faecium and Enterococcus faecalis are among the predominant species causing hospital-acquired infections. Currently, enterococcal infections are treated using combination therapy of an aminoglycoside with cell-wall active agents, which led to high level aminoglycoside resistance (HLAR) and vancomycin resistance (VRE) among enterococci. The aim of this study was to determine the prevalence of HLAR and the distribution of the resistance genes among clinical E. faecalis and E. faecium isolates in Malaysia., Materials and Methods: Seventy-five enterococci isolates recovered from different clinical sources were re-identified by subculturing on selective medium, Gram staining, biochemical profiling (API 20 Strep), and 16s rRNA sequencing. Antimicrobial susceptibility testing (AST) was performed using Kirby-Bauer disc diffusion, E-test, and broth microdilution methods. PCR amplification was used to detect the presence of aminoglycoside modifying enzyme (AME) genes [ aac(6')-Ie-aph(2")-Ia, aph(2")-Ib, aph(2")-Ic, aph(2")-Id, aph(3')-IIIa ]. Descriptive data analysis was used to analyze the antibiotic susceptibility profiles and the distribution of HLAR genes., Results: The majority of the isolates recovered from the clinical samples are E. faecalis (66.7%), with the highest recovery from the pus. The prevalence of HLGR (51%) is higher when compared to HLSR (45-49%). Analysis of the resistance genes showed that bifunctional genes aac(6')-Ie-aph(2")-Ia and aph(3')-IIIa contributed to the HLAR E. faecalis and E. faecium . The other AME genes [ aph(2")-Ib, aph(2")-Ic, aph(2")-Id ] were not detected in this study., Conclusion: This study provides the first prevalence data on HLAR and the distribution of the AME genes among E. faecalis and E. faecium isolates from Malaysia. These highlight the need for continued antibiotic surveillance to minimize its emergence and further dissemination., Competing Interests: The authors declare that there is no competing interest regarding the publication of this paper., (© 2019 Moussa et al.)
- Published
- 2019
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18. Antibiotic Susceptibility Patterns, Biofilm Formation and esp Gene among Clinical Enterococci: Is There Any Association?
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Weng PL, Ramli R, and Hamat RA
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- Bacterial Proteins metabolism, Cross-Sectional Studies, Enterococcus faecalis genetics, Enterococcus faecium genetics, Malaysia, Membrane Proteins metabolism, Microbial Sensitivity Tests, Anti-Bacterial Agents pharmacology, Bacterial Proteins genetics, Biofilms, Enterococcus faecalis physiology, Enterococcus faecium physiology, Membrane Proteins genetics
- Abstract
Enterococci are commonly found in humans, animals and environments. Their highly adaptive mechanisms are related to several virulent determinants and their ability to resist antibiotics. Data on the relationship between the esp gene, biofilm formation and antibiotic susceptibility profiles may differ between countries. This cross-sectional study was conducted to determine the proportion of esp gene and biofilm formation among Enterococcus faecalis and Enterococcus faecium clinical isolates. We also investigated the possible association between the esp gene with antibiotic susceptibility patterns and biofilm formation. The isolates were collected from clinical samples and identified using biochemical tests and 16SRNA. Antibiotic susceptibility patterns and a biofilm assay were conducted according to the established guidelines. Molecular detection by PCR was used to identify the esp gene using established primers. In total, 52 and 28 of E. faecalis and E. faecium were identified, respectively. E. faecium exhibited higher resistance rates compared to E. faecalis as follows: piperacillin/tazobactam (100% versus 1.9%), ampicillin (92.8% versus 1.9%), high-level gentamicin resistance (HLGR) (89.3% versus 25.0%) and penicillin (82.1% versus 7.7%). E. faecium produced more biofilms than E. faecalis (59.3% versus 49.0%). E. faecium acquired the esp gene more frequently than E. faecalis (78.6% versus 46.2%). Interestingly, the associations between ampicillin and tazobactam/piperacillin resistance with the esp gene were statistically significant ( X
2 = 4.581, p = 0.027; and X2 = 6.276, p = 0.012, respectively). Our results demonstrate that E. faecium exhibits high rates of antimicrobial resistance, esp gene acquisition and biofilm formation. These peculiar traits of E. faecium may have implications for the management of enterococcal infections in hospitals. Thus, concerted efforts by all parties in establishing appropriate treatment and effective control measures are warranted in future.- Published
- 2019
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19. Leptospirosis and its prevention: knowledge, attitude and practice of urban community in Selangor, Malaysia.
- Author
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Abdullah NM, Mohammad WMZW, Shafei MN, Sukeri S, Idris Z, Arifin WN, Nozmi N, Saudi SNS, Samsudin S, Zainudin AW, Hamat RA, Ibrahim R, Masri SN, Saliluddin SM, Daud A, Osman M, and Jamaluddin TZMT
- Subjects
- Adult, Cross-Sectional Studies, Female, Health Behavior, Humans, Leptospirosis prevention & control, Logistic Models, Malaysia, Male, Middle Aged, Surveys and Questionnaires, Health Knowledge, Attitudes, Practice, Leptospirosis psychology, Urban Population
- Abstract
Background: Leptospirosis is still endemic in Malaysia and has been prevalent in Selangor where cases have been underreported. Primarily, this was due to lack of awareness in the urban community in this region. This study determined the knowledge, attitude and preventive practice (KAP) of leptospirosis, and identified the significant predictors influencing KAP among urban community in Hulu Langat, Selangor., Methods: This cross-sectional study was conducted from 2015 to 2017 using validated questionnaire. Sampling methods included multistage cluster sampling, followed by simple random sampling to obtain 315 respondents. Descriptive analysis was performed to determine the KAP while χ
2 and the subsequent logistic regression analysis were carried out to identify associations and predictors between variables., Results: Respondents were mainly Malaysian Bumiputra with a mean (Standard Deviation (SD)) age of 32.5 (13.0) years. Of 315 respondents, 80.3% (n = 253) had poor knowledge, 87.0% (n = 274) had good attitude, and 81.3% (n = 256) showed unacceptable practice towards leptospirosis and its prevention. Regression analysis identified age as the sole predictor influencing good knowledge (AOR 2.388; 95% CI = 1.298, 4.396; p = 0.005). Education level (AOR 2.197; 95% CI = 1.109, 4.352; p = 0.024) was also noted as the significant predictor influencing the overall practice., Conclusions: The urban community in Selangor showed a positive attitude in waste management despite having little knowledge regarding the disease itself. The study also discovered inadequacy in preventive practice, hence marking the importance of the proper integration of knowledge and attitude into forming an acceptable practice to reduce transmission of Leptospira among urban population in Malaysia.- Published
- 2019
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20. Bioactive 2-(Methyldithio)Pyridine-3-Carbonitrile from Persian Shallot ( Allium stipitatum Regel.) Exerts Broad-Spectrum Antimicrobial Activity.
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Karunanidhi A, Ghaznavi-Rad E, Jeevajothi Nathan J, Joseph N, Chigurupati S, Mohd Fauzi F, Pichika MR, Hamat RA, Lung LTT, van Belkum A, and Neela V
- Subjects
- Anti-Bacterial Agents pharmacology, Candida drug effects, Chemical Fractionation, Microbial Sensitivity Tests, Molecular Structure, Nitriles chemistry, Nitriles isolation & purification, Phytochemicals analysis, Pyridines isolation & purification, Pyridines pharmacology, Anti-Bacterial Agents chemistry, Methicillin-Resistant Staphylococcus aureus drug effects, Pyridines chemistry, Shallots chemistry
- Abstract
Antibiotic resistance is a problem that continues to challenge the healthcare sector, especially in clinically significant pathogens like methicillin-resistant Staphylococcus aureus (MRSA). Herein is described the isolation and structure elucidation of a bioactive compound from Allium stipitatum with antimicrobial activity. Crude Allium stipitatum dichloromethane extract (ASDE) was subjected to systematic purification by chromatographic procedures to afford various bioactive fractions. A fraction that exhibited anti-MRSA activity (4 µg·mL
-1 ) was further characterized to determine the structure. The structure of the compound was elucidated as 2-(methyldithio)pyridine-3-carbonitrile (2-Medpy-3-CN). The 2-Medpy-3-CN compound, which was screened for antimicrobial activity, exhibited minimum inhibitory concentrations (MICs) in the range of 0.5 to >64 µg·mL-1 for tested bacterial species and 0.25 to 2 µg·mL-1 for Candida spp. Further studies are important to confirm the drug target and mechanism of action.- Published
- 2019
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21. Seroprevalence and distribution of leptospirosis serovars among wet market workers in northeastern, Malaysia: a cross sectional study.
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Rahman MHAA, Hairon SM, Hamat RA, Jamaluddin TZMT, Shafei MN, Idris N, Osman M, Sukeri S, Wahab ZA, Mohammad WMZW, Idris Z, and Daud A
- Subjects
- Adolescent, Adult, Aged, Animals, Cross-Sectional Studies, Female, Humans, Leptospirosis blood, Malaysia epidemiology, Male, Middle Aged, Occupational Diseases blood, Occupational Diseases epidemiology, Seroepidemiologic Studies, Serogroup, Young Adult, Zoonoses blood, Zoonoses epidemiology, Antibodies, Bacterial blood, Farmers statistics & numerical data, Food Handling statistics & numerical data, Leptospira classification, Leptospira immunology, Leptospirosis epidemiology
- Abstract
Background: Leptospirosis is a zoonotic disease associated with occupations which exposed workers to environments contaminated with urine of infected animals. The objective of this study was to determine the seroprevalence of leptospirosis among wet market workers in Kelantan., Methods: A cross sectional study was conducted in two main wet markets in Kelantan and 232 wet market workers were randomly selected. Blood samples were analysed for microscopic agglutination test (MAT) against 20 live leptospirosis reference serovars. MAT titres of 1:100 or more were considered as seropositive., Results: It was found that the overall seroprevalence for leptospirosis among the respondents was 33.6% (95% CI = 27.5, 39.7). The samples were tested positive against serovars Melaka (IMR LEP 1), Terengganu (IMR LEP 115), Sarawak (IMR LEP 175), Copenhageni (IMR LEP 803/11), Hardjobovis (IMR LEP 27), Australis, Autumnalis, Bataviae, Canicola, Grippotyphosa, Hardjoprajitno, Icterohaemorrhagiae, Javanica, Pyrogenes, Terrasovi, Djasiman, Patoc and Pomona. The predominant serovars was Autumnalis (18.2%)., Conclusion: Wet markets workers were at risk for leptospirosis infection evidenced by high seroprevalence of leptospirosis in this study. Further research need to be conducted to determine factors that favours infection in this groups.
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- 2018
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22. Clinical Screening Tools to Diagnose Group A Streptococcal Pharyngotonsillitis in Primary Care Clinics to Improve Prescribing Habits.
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Muthanna A, Salim HS, Hamat RA, Shamsuddin NH, and Zakariah SZ
- Abstract
This review highlights the clinical scoring tools used for the management of acute pharyngotonsillitis in primary care clinics. It will include the prevalence of group A pharyngotonsillitis among children and adults worldwide and the selective tests employed for diagnosing group A streptococcal pharyngotonsillitis. Pharyngotonsillitis is one of the common reasons for visits to primary care clinics worldwide, and physicians tend to prescribe antibiotics according to the clinical symptoms, which leads to overprescribing antibiotics. This in turn may lead to serious health impacts and severe reactions and may promote antibiotic resistance. These significantly add on to the health care costs. The available information from health organisations and previous studies has indicated the need to manage the diagnosis of pharyngotonsillitis to improve prescribing habits in primary care clinics., Competing Interests: Conflicts of Interest None.
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- 2018
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23. Modulatory and regenerative potential of transplanted bone marrow-derived mesenchymal stem cells on rifampicin-induced kidney toxicity.
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Danjuma L, Mok PL, Higuchi A, Hamat RA, Teh SW, Koh AE, Munusamy MA, Arulselvan P, Rajan M, Nambi A, Swamy KB, Vijayaraman K, Murugan K, Natarajaseenivasan K, and Subbiah SK
- Abstract
Introduction: Anti-tuberculosis agent rifampicin is extensively used for its effectiveness. Possible complications of tuberculosis and prolonged rifampicin treatment include kidney damage; these conditions can lead to reduced efficiency of the affected kidney and consequently to other diseases. Bone marrow-derived mesenchymal stem cells (BMMSCs) can be used in conjunction with rifampicin to avert kidney damage; because of its regenerative and differentiating potentials into kidney cells. This research was designed to assess the modulatory and regenerative potentials of MSCs in averting kidney damage due to rifampicin-induced kidney toxicity in Wistar rats and their progenies. BMMSCs used in this research were characterized according to the guidelines of International Society for Cellular Therapy., Methods: The rats (male and female) were divided into three experimental groups, as follows: Group 1: control rats (4 males & 4 females); Group 2: rats treated with rifampicin only (4 males & 4 females); and Group 3: rats treated with rifampicin plus MSCs (4 males & 4 females). Therapeutic doses of rifampicin (9 mg/kg/day for 3-months) and MSCs infusions (twice/month for 3-months) were administered orally and intravenously respectively. At the end of the three months, the animals were bred together to determine if the effects would carry over to the next generation. Following breeding, the rats were sacrificed to harvest serum for biochemical analysis and the kidneys were also harvested for histological analysis and quantification of the glomeruli size, for the adult rats and their progenies., Results: The results showed some level of alterations in the biochemical indicators and histopathological damage in the rats that received rifampicin treatment alone, while the control and stem cells treated group showed apparently normal to nearly normal levels of both bio-indicators and normal histological architecture., Conclusions: Intravenous administration of MSCs yielded sensible development, as seen from biochemical indicators, histology and the quantitative cell analysis, hence implying the modulatory and regenerative properties of MSCs.
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- 2018
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24. The 'Checkmate' for Iron Between Human Host and Invading Bacteria: Chess Game Analogy.
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Kalidasan V, Joseph N, Kumar S, Hamat RA, and Neela VK
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Iron is an essential nutrient for all living organisms with critical roles in many biological processes. The mammalian host maintains the iron requirements by dietary intake, while the invading pathogenic bacteria compete with the host to obtain those absorbed irons. In order to limit the iron uptake by the bacteria, the human host employs numerous iron binding proteins and withholding defense mechanisms that capture iron from the microbial invaders. To counteract, the bacteria cope with the iron limitation imposed by the host by expressing various iron acquisition systems, allowing them to achieve effective iron homeostasis. The armamentarium used by the human host and invading bacteria, leads to the dilemma of who wins the ultimate war for iron., Competing Interests: Compliance of Ethical StandardsThe authors declare that they have no competing interests.
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- 2018
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25. A qualitative exploration of the misconceptions, knowledge gaps and constructs of leptospirosis among rural and urban communities in Malaysia.
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Sukeri S, Idris Z, Zahiruddin WM, Shafei MN, Idris N, Hamat RA, Jamaluddin TZT, Osman M, Wahab ZA, and Daud A
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- Animals, Health Behavior, Humans, Malaysia epidemiology, Qualitative Research, Rats, Rural Population statistics & numerical data, Leptospirosis epidemiology
- Abstract
This qualitative study aimed to explore the misconceptions, knowledge gaps and constructs of leptospirosis among 72 respondents from rural and urban districts in two states of Malaysia. We conducted focus group discussions and data were examined using thematic analyses. The layman term of 'rat urine disease' contributed the most to the misconceptions regarding leptospirosis. There were gaps in the knowledge among urban and rural respondents in the two states, with the majority of subjects demonstrating a poor understanding of the disease. Construction of knowledge about leptospirosis relied mostly on the information provided by mass and social media; reading materials; word-of-mouth publicity; observations; experiences; and knowledge sharing among families, friends, and communities. The study findings may provide the foundation for the development of educational materials that may reduce the gaps in knowledge, and thereby improve health literacy and enhance preventive health behaviours for avoiding leptospirosis., Competing Interests: The authors have declared that no competing interests exist.
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- 2018
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26. Antibacterial and Antibiofilm Activities of Nonpolar Extracts of Allium stipitatum Regel. against Multidrug Resistant Bacteria.
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Karunanidhi A, Ghaznavi-Rad E, Hamat RA, Pichika MR, Lung LTT, Mohd Fauzi F, Chigurupati S, van Belkum A, and Neela V
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- Acinetobacter baumannii drug effects, Bacteria, Biofilms, Microbial Sensitivity Tests, Staphylococcus aureus, Stenotrophomonas maltophilia drug effects, Allium chemistry, Anti-Bacterial Agents pharmacology, Methicillin-Resistant Staphylococcus aureus drug effects, Plant Extracts pharmacology
- Abstract
The present study assessed the in vitro antibacterial and antibiofilm potential of hexane (ASHE) and dichloromethane (ASDE) extracts of Allium stipitatum (Persian shallot) against planktonic cells and biofilm structures of clinically significant antibiotic resistant pathogens, with a special emphasis on methicillin-sensitive Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA), and emerging pathogens, Acinetobacter baumannii and Stenotrophomonas maltophilia . Antibacterial activities were determined through disk diffusion, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), time-kill kinetics, and electron microscopy. Antibiofilm activity was assessed by XTT [2,3- bis (2-methoxy-4-nitro-5-sulfo-phenyl)-2H-tetrazolium-5-carboxanilide] reduction assay and by confocal laser scanning microscopy (CLSM). The zone of inhibition ranged from 13 to 33 mm, while the MICs and MBCs ranged from 16 to 1024 μ g mL
-1 . Both ASHE and ASDE completely eradicated overnight cultures of the test microorganisms, including antibiotic resistant strains. Time-kill studies showed that the extracts were strongly bactericidal against planktonic cultures of S. aureus , MRSA, Acinetobacter baumannii, and S. maltophilia as early as 4 hours postinoculation (hpi). ASHE and ASDE were shown to inhibit preformed biofilms of the four biofilm phenotypes tested. Our results demonstrate the potential therapeutic application of ASHE and ASDE to inhibit the growth of gram-positive and gram-negative biofilms of clinical significance and warrant further investigation of the potential of A. stipitatum bulbs against biofilm-related drug resistance.- Published
- 2018
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27. Leptospirosis Health Intervention Module Effect on Knowledge, Attitude, Belief, and Practice among Wet Market Workers in Northeastern Malaysia: An Intervention Study.
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Rahman MHAA, Hairon SM, Hamat RA, Jamaluddin TZMT, Shafei MN, Idris N, Osman M, Sukeri S, Wahab ZA, Mohammad WMZW, Idris Z, and Daud A
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- Adult, Awareness, Female, Humans, Malaysia epidemiology, Male, Middle Aged, Socioeconomic Factors, Food Handling, Health Education organization & administration, Health Knowledge, Attitudes, Practice, Leptospirosis epidemiology
- Abstract
Leptospirosis is an infectious disease which can be prevented by increasing awareness and promoting preventive health behaviours among high risk groups including wet market workers. Thus, the aim of this study was to determine the effectiveness of Leptospirosis Health Intervention Program (LHIP) in improving knowledge, attitude, belief and practice towards leptospirosis among wet market workers in Kelantan. This intervention study was conducted in two main wet markets in Kelantan involving 116 participants in each control and intervention groups. The health education intervention was based on Leptospirosis Health Intervention Module. The knowledge, attitude, belief and practice scores were measured before and six weeks after the intervention to examine the effect of the program. The results showed that knowledge ( p < 0.001), attitude ( p = 0.001), belief ( p < 0.001) and practice ( p < 0.001) scores changes were significantly higher in the intervention group compared to the control group. The adjusted mean differences were 12.93 (95% CI: 8.47, 17.39) for knowledge, 5.55 (95% CI: 2.28, 8.81) for attitude, 7.21 (95% CI: 3.43, 10.99) for belief and 7.35 (95% CI: 3.64, 11.05) for practice scores. Leptospirosis Health Intervention Program was an effective health educational tools to improve awareness and preventive behaviours among risk groups such as wet market workers.
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- 2018
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28. Development and validation of a new knowledge, attitude, belief and practice questionnaire on leptospirosis in Malaysia.
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Zahiruddin WM, Arifin WN, Mohd-Nazri S, Sukeri S, Zawaha I, Bakar RA, Hamat RA, Malina O, Jamaludin TZMT, Pathman A, Mas-Harithulfadhli-Agus AR, Norazlin I, Suhailah BS, Saudi SNS, Abdullah NM, Nozmi N, Zainuddin AW, and Aziah D
- Subjects
- Adult, Factor Analysis, Statistical, Female, Humans, Malaysia, Middle Aged, Psychometrics, Reproducibility of Results, Health Knowledge, Attitudes, Practice, Leptospirosis psychology, Surveys and Questionnaires
- Abstract
Background: In Malaysia, leptospirosis is considered an endemic disease, with sporadic outbreaks following rainy or flood seasons. The objective of this study was to develop and validate a new knowledge, attitude, belief and practice (KABP) questionnaire on leptospirosis for use in urban and rural populations in Malaysia., Methods: The questionnaire comprised development and validation stages. The development phase encompassed a literature review, expert panel review, focus-group testing, and evaluation. The validation phase consisted of exploratory and confirmatory parts to verify the psychometric properties of the questionnaire. A total of 214 and 759 participants were recruited from two Malaysian states, Kelantan and Selangor respectively, for the validation phase. The participants comprised urban and rural communities with a high reported incidence of leptospirosis. The knowledge section of the validation phase utilized item response theory (IRT) analysis. The attitude and belief sections utilized exploratory factor analysis (EFA) and confirmatory factor analysis (CFA)., Results: The development phase resulted in a questionnaire that included four main sections: knowledge, attitude, belief, and practice. In the exploratory phase, as shown by the IRT analysis of knowledge about leptospirosis, the difficulty and discrimination values of the items were acceptable, with the exception of two items. Based on the EFA, the psychometric properties of the attitude, belief, and practice sections were poor. Thus, these sections were revised, and no further factor analysis of the practice section was conducted. In the confirmatory stage, the difficulty and discrimination values of the items in the knowledge section remained within the acceptable range. The CFA of the attitude section resulted in a good-fitting two-factor model. The CFA of the belief section retained low number of items, although the analysis resulted in a good fit in the final three-factor model., Conclusions: Based on the IRT analysis and factor analytic evidence, the knowledge and attitude sections of the KABP questionnaire on leptospirosis were psychometrically valid. However, the psychometric properties of the belief section were unsatisfactory, despite being revised after the initial validation study. Further development of this section is warranted in future studies.
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- 2018
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29. Genomic plasticity between human and mycobacterial DNA: A review.
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Danjuma L, Ling MP, Hamat RA, Higuchi A, Alarfaj AA, Marlina, Benelli G, Arulselvan P, Rajan M, and Kumar Subbiah S
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- Antitubercular Agents therapeutic use, Cell Death, DNA Methylation, DNA, Bacterial biosynthesis, Drug Resistance, Bacterial genetics, Epigenesis, Genetic, Host-Pathogen Interactions, Humans, Latent Tuberculosis drug therapy, Latent Tuberculosis immunology, Microbial Viability, Mycobacterium tuberculosis drug effects, Mycobacterium tuberculosis immunology, Mycobacterium tuberculosis pathogenicity, Stem Cells immunology, Stem Cells microbiology, DNA Replication, DNA, Bacterial genetics, Gene Expression Regulation, Bacterial, Genome, Bacterial, Latent Tuberculosis genetics, Latent Tuberculosis microbiology, Mycobacterium tuberculosis genetics
- Abstract
Mycobacterium tuberculosis has a remarkable ability of long-term persistence despite vigorous host immunity and prolonged therapy. The bacteria persist in secure niches such as the mesenchymal stem cells in the bone marrow and reactivate the disease, leading to therapeutic failure. Many bacterial cells can remain latent within a diseased tissue so that their genetic material can be incorporated into the genetic material of the host tissue. This incorporated genetic material reproduces in a manner similar to that of cellular DNA. After the cell division, the incorporated gene is reproduced normally and distributed proportionately between the two progeny. This inherent adoption of long-term persistence and incorporating the bacterial genetic material into that of the host tissue remains and is considered imperative for microbial advancement and chemotherapeutic resistance; moreover, new evidence indicates that the bacteria might pass on genetic material to the host DNA sequence. Several studies focused on the survival mechanism of M. tuberculosis in the host immune system with the aim of helping the efforts to discover new drugs and vaccines against tuberculosis. This review explored the mechanisms through which this bacterium affects the expression of human genes. The first part of the review summarizes the current knowledge about the interactions between microbes and host microenvironment, with special reference to the M. tuberculosis neglected persistence in immune cells and stem cells. Then, we focused on how bacteria can affect human genes and their expression. Furthermore, we analyzed the literature base on the process of cell death during tuberculosis infection, giving particular emphasis to gene methylation as an inherited process in the neutralization of possibly injurious gene components in the genome. The final section discusses recent advances related to the M. tuberculosis interaction with host epigenetic circuitry., (Copyright © 2017 Elsevier Ltd. All rights reserved.)
- Published
- 2017
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30. 3D modelling of the pathogenic Leptospira protein LipL32: A bioinformatics approach.
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Kumaran SK, Bakar MFA, Mohd-Padil H, Mat-Sharani S, Sakinah S, Poorani K, Alsaeedy H, Peli A, Wei TS, Ling MP, Hamat RA, Neela VK, Higuchi A, Alarfaj AA, Rajan M, Benelli G, Arulselvan P, and Kumar SS
- Subjects
- Antigens, Bacterial immunology, Bacterial Outer Membrane Proteins immunology, Computational Biology, Leptospira genetics, Lipoproteins immunology, Antigens, Bacterial chemistry, Bacterial Outer Membrane Proteins chemistry, Leptospira immunology, Leptospirosis immunology, Lipoproteins chemistry, Models, Molecular
- Abstract
Leptospirosis is a widespread zoonotic disease caused by pathogenic Leptospira species (Leptospiraceae). LipL32 is an abundant lipoprotein from the outer membrane proteins (OMPs) group, highly conserved among pathogenic and intermediate Leptospira species. Several studies used LipL32 as a specific gene to identify the presence of leptospires. This research was aimed to study the characteristics of LipL32 protein gene code, to fill the knowledge gap concerning the most appropriate gene that can be used as antigen to detect the Leptospira. Here, we investigated the features of LipL32 in fourteen Leptospira pathogenic strains based on comparative analyses of their primary, secondary structures and 3D modeling using a bioinformatics approach. Furthermore, the physicochemical properties of LipL32 in different strains were studied, shedding light on the identity of signal peptides, as well as on the secondary and tertiary structure of the LipL32 protein, supported by 3D modelling assays. The results showed that the LipL32 gene was present in all the fourteen pathogenic Leptospira strains used in this study, with limited diversity in terms of sequence conservation, hydrophobic group, hydrophilic group and number of turns (random coil). Overall, these results add basic knowledge to the characteristics of LipL32 protein, contributing to the identification of potential antigen candidates in future research, in order to ensure prompt and reliable detection of pathogenic Leptospira species., (Copyright © 2017 Elsevier B.V. All rights reserved.)
- Published
- 2017
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31. Phylogenetic Analysis of Giardia lamblia Human Genotypes in Fars Province, Southern Iran.
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Rayani M, Hatam G, Unyah NZ, Ashrafmansori A, Abdullah WO, and Hamat RA
- Abstract
Background: This study is the first phylogenetic genotype analysis of Giardia lamblia in Iran. The main objective was to determine genotyping and identify the sub-assemblages of Giardia lamblia isolates involved in the transmission of giardiasis in Fars Province, south of Iran, in 2012., Methods: Forty G. lamblia isolates were collected from the patient's fecal samples with gastrointestinal discomfort referred to the health centers and hospitals in Shiraz, Fars Province, south of Iran. Purification of G. lamblia cysts from fecal samples and DNA extraction were performed using monolayer of sucrose density gradient and Phenol-Chloroform-Isoamylalcohol (PCI) respectively. Semi-nested PCR and sequence analysis were then performed using the primers (GDHeF, GDHiF, and GDHiR) which amplified a 432-bp fragment of Giardia glutamate dehydrogenase ( gdh ) gene. Phylogenetic analysis was carried out using a neighbor-joining tree composed of the nucleotide sequences of G. lamblia isolates obtained in this study and the known sequences isolates published in GenBank., Results: G. lamblia sub-assemblage AII was the most prevalent genotype with 80% of the cases and 20% of the cases belong to sub-assemblage BIII and BIV based on the DNA sequence of the gdh . G. lamblia isolates at Fars Province were widely distributed within assemblage A cluster (sub-assemblage AII) and the remaining isolates were dispersed throughout the assemblage B cluster (sub-assemblage BIII and BIV)., Conclusion: PCR Sequencing and phylogenetic analysis was a proper molecular method for genotyping and discriminating of the of G. lamblia sub-assemblages in fecal samples, using the glutamate dehydrogenase gene that suggests a human contamination origin of giardiasis., Competing Interests: Conflict of Interests The authors declare that there is no conflict of interests.
- Published
- 2017
32. Efficiency of newly formulated camptothecin with β-cyclodextrin-EDTA-Fe 3 O 4 nanoparticle-conjugated nanocarriers as an anti-colon cancer (HT29) drug.
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Krishnan P, Rajan M, Kumari S, Sakinah S, Priya SP, Amira F, Danjuma L, Pooi Ling M, Fakurazi S, Arulselvan P, Higuchi A, Arumugam R, Alarfaj AA, Munusamy MA, Hamat RA, Benelli G, Murugan K, and Kumar SS
- Subjects
- Antineoplastic Agents, Phytogenic pharmacology, Apoptosis drug effects, Camptothecin pharmacology, Colonic Neoplasms metabolism, Edetic Acid chemistry, Ferric Compounds chemistry, G1 Phase drug effects, HT29 Cells, Humans, beta-Cyclodextrins chemistry, Antineoplastic Agents, Phytogenic chemistry, Camptothecin chemistry, Nanoconjugates chemistry
- Abstract
Camptothecin (CPT) is an anti-cancer drug that effectively treats various cancers, including colon cancer. However, poor solubility and other drawbacks have restricted its chemotherapeutic potential. To overcome these restrictions, CPT was encapsulated in CEF (cyclodextrin-EDTA-FE
3 O4 ), a composite nanoparticle of magnetic iron oxide (Fe3 O4 ), and β-cyclodextrin was cross-linked with ethylenediaminetetraacetic acid (EDTA). This formulation improved CPT's solubility and bioavailability for cancer cells. The use of magnetically responsive anti-cancer formulation is highly advantageous in cancer chemotherapy. The chemical characterisation of CPT-CEF was studied here. The ability of this nano-compound to induce apoptosis in HT29 colon cancer cells and A549 lung cancer cells was evaluated. The dose-dependent cytotoxicity of CPT-CEF was shown using MTT. Propidium iodide and Annexin V staining, mitochondrial membrane depolarisation (JC-1 dye), and caspase-3 activity were assayed to detect apoptosis in CPT-CEF-treated cancer cells. Cell cycle analysis also showed G1 phase arrest, which indicated possible synergistic effects of the nano-carrier. These study results show that CPT-CEF causes a dose-dependent cell viability reduction in HT29 and A549 cells and induces apoptosis in colon cancer cells via caspase-3 activation. These data strongly suggest that CPT could be used as a major nanocarrier for CPT to effectively treat colon cancer.- Published
- 2017
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33. Micro-anatomical changes in major blood vessel caused by dengue virus (serotype 2) infection.
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Priya SP, Sakinah S, Ling MP, Chee HY, Higuchi A, Hamat RA, Neela VK, Alarfaj AA, Munusamy MA, Hatamleh AA, Al-Sabri AE, Abdulaziz Al-Suwailem IA, Rajan M, Benelli G, Marlina, and Kumar SS
- Subjects
- Animals, Endothelial Cells virology, Mice, Mice, Inbred BALB C, Serogroup, Dengue pathology, Dengue virology, Dengue Virus classification, Endothelial Cells pathology
- Abstract
Dengue virus (DENV) has emerged as a major economic concern in developing countries, with 2.5 billion people believed to be at risk. Vascular endothelial cells (ECs) lining the circulatory system from heart to end vessels perform crucial functions in the human body, by aiding gas exchange in lungs, gaseous, nutritional and its waste exchange in all tissues, including the blood brain barrier, filtration of fluid in the glomeruli, neutrophil recruitment, hormone trafficking, as well as maintenance of blood vessel tone and hemostasis. These functions can be deregulated during DENV infection. In this study, BALB/c mice infected with DENV serotype 2 were analyzed histologically for changes in major blood vessels in response to DENV infection. In the uninfected mouse model, blood vessels showed normal architecture with intact endothelial monolayer, tunica media, and tunica adventitia. In the infected mouse model, DENV distorted the endothelium lining and disturbed the smooth muscle, elastic laminae and their supporting tissues causing vascular structural disarrangement. This may explain the severe pathological illness in DENV-infected individuals. The overall DENV-induced damages on the endothelial and it's supporting tissues and the dysregulated immune reactions initiated by the host were discussed., (Copyright © 2017. Published by Elsevier B.V.)
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- 2017
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34. Assessing the Knowledge Level, Attitudes, Risky Behaviors and Preventive Practices on Sexually Transmitted Diseases among University Students as Future Healthcare Providers in the Central Zone of Malaysia: A Cross-Sectional Study.
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Folasayo AT, Oluwasegun AJ, Samsudin S, Saudi SN, Osman M, and Hamat RA
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- Adolescent, Adult, Age Factors, Condoms statistics & numerical data, Cross-Sectional Studies, Female, Health Personnel, Humans, Malaysia, Male, Odds Ratio, Risk-Taking, Sex Factors, Sex Work statistics & numerical data, Socioeconomic Factors, Students statistics & numerical data, Surveys and Questionnaires, Young Adult, Health Knowledge, Attitudes, Practice, Sexual Behavior statistics & numerical data, Sexually Transmitted Diseases prevention & control, Students, Health Occupations statistics & numerical data, Universities
- Abstract
This study was done to assess the knowledge, attitudes, risky behaviors and preventive practices related to sexually-transmitted diseases (STDs) among health and non-health sciences university students as future healthcare providers in Malaysia. A total of 700 health and non-health sciences university students (255 male; 445 female) aged between 17 and 30 years were surveyed by using a self-administered questionnaire. The majority (86.6%) had heard of STDs, and 50.4% knew STDs could present without symptoms. HIV remains the best known STD (83.6%) by the students, while chlamydia (26%) and trichomoniasis (21.0%) were rarely known. Gender, age group, educational level and faculty type were strongly associated with knowledge level ( p -values < 0.05). Most of them (88.8%) were aware that STD screening was important while use of condoms was protective (63.8%). The majority of them strongly felt that treatment should be sought immediately if they (85.5%) and their partners (87.4%) have symptoms. Among the sexually-active students, 66.7% and 18% had sexual intercourse with multiple partners and commercial sex workers, while 17.4% and 9.4% took alcohol and drugs before having sex, respectively. By logistic regression analysis, students aged 24-30 years old (an odds ratio (AOR) = 0.57, 95% confidence interval (CI) = 0.377-0.859) and faculty type (AOR = 5.69, 95% CI = 4.019-8.057) were the significant predictors for the knowledge level. Knowledge on the non-HIV causes of STDs is still lacking, and the risky behavior practiced by the sexually-active students in this study is alarming. There is a need to revisit the existing STD education curriculum in both schools and universities so that appropriate intervention on STDs can be implemented.
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- 2017
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35. Impact of dengue virus (serotype DENV-2) infection on liver of BALB/c mice: A histopathological analysis.
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Sakinah S, Priya SP, Kumari S, Amira F, K P, Alsaeedy H, Ling MP, Chee HY, Higuchi A, Alarfaj AA, Munusamy MA, Murugan K, Taib CN, Arulselvan P, Rajan M, Neela VK, Hamat RA, Benelli G, and Kumar SS
- Subjects
- Animals, Dengue pathology, Disease Models, Animal, Hepatocytes pathology, Humans, Liver virology, Mice, Serogroup, Dengue virology, Dengue Virus pathogenicity, Hepatocytes virology, Liver pathology
- Abstract
In this research, we characterized the histopathological impact of dengue virus (serotype DENV-2) infection in livers of BALB/c mice. The mice were infected with different doses of DENV-2 via intraperitoneal injection and liver tissues were processed for histological analyses and variation was documented. In the BALB/c mouse model, typical liver tissues showed regular hepatocyte architecture, with normal endothelial cells surrounding sinusoid capillary. Based on histopathological observations, the liver sections of BALB/c mice infected by DENV-2 exhibited a loss of cell integrity, with a widening of the sinusoidal spaces. There were marked increases in the infiltration of mononuclear cells. The areas of hemorrhage and micro- and macrovesicular steatosis were noted. Necrosis and apoptosis were abundantly present. The hallmark of viral infection, i.e., cytopathic effects, included intracellular edema and vacuole formation, cumulatively led to sinusoidal and lobular collapse in the liver. The histopathological studies on autopsy specimens of fatal human DENV cases are important to shed light on tissue damage for preventive and treatment modalities, in order to manage future DENV infections. In this framework, the method present here on BALB/c mouse model may be used to study not only the effects of infections by other DENV serotypes, but also to investigate the effects of novel drugs, such as recently developed nano-formulations, and the relative recovery ability with intact immune functions of host., (Copyright © 2016 Elsevier Ltd. All rights reserved.)
- Published
- 2017
- Full Text
- View/download PDF
36. The effect of periodontal scaling and root polishing on serum IL-17E concentrations and the IL-17A:IL-17E ratio.
- Author
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Nile CJ, Apatzidou DA, Awang RA, Riggio MP, Kinane DF, and Lappin DF
- Subjects
- Adult, Biomarkers blood, Debridement, Enzyme-Linked Immunosorbent Assay, Female, Humans, Male, Periodontal Index, Chronic Periodontitis therapy, Dental Scaling, Interleukin-17 blood, Root Planing
- Abstract
Objectives: The serum IL-17A:IL-17E ratio has previously been demonstrated to be a clinical marker of periodontitis. The aim of this study was to determine the effects of non-surgical periodontal treatment on the serum IL-17A:IL-17E ratio., Materials and Methods: Forty chronic periodontitis patients completed this study and received periodontal treatment comprising scaling and root planing plus ultrasonic debridement. Clinical data were recorded at baseline, 6 weeks (R1) after treatment completion (full-mouth or quadrant-scaling and root planing) and 25 weeks after baseline (R2). Serum samples were taken at each time point and cytokines concentrations determined by ELISA., Results: Following treatment, statistically significant reductions were noted in clinical parameters. However, IL-17A and IL-17E concentrations were significantly greater than baseline values before- and after-adjusting for smoking. The IL-17A:IL-17E ratio was lower at R1 and R2. Serum IL-6 and TNF levels were significantly lower at R1 only. Also exclusively at R1, serum IL-17A and IL-17E correlated positively with clinical parameters, while the IL-17A:IL-17E ratio correlated negatively with probing pocket depth and clinical attachment., Conclusion: Increased serum IL-17E and a reduced IL-17A:IL-17E ratio may be indicative and/or a consequence of periodontal therapy. Therefore, the role of IL-17E in periodontal disease progression and the healing process is worthy of further investigation., Clinical Relevance: IL-17E may be a valuable biomarker to monitor the healing process following periodontal treatment as increased IL-17E levels and a reduced IL-17A:IL-17E ratio could reflect clinical improvements post-therapy. Therefore, monitoring serum IL-17E might be useful to identify individuals who require additional periodontal treatment.
- Published
- 2016
- Full Text
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37. Evaluation of Modified Laboratory Processes for Isolation of Bacteria and Fungi in Continuous Ambulatory Peritoneal Dialysis Patients with Peritonitis.
- Author
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Ahmadi S, Amin-Nordin S, Neela VK, Hamat RA, Goh BL, Nor LA, and Azman AZ
- Subjects
- Cohort Studies, Humans, Clinical Laboratory Techniques, Kidney Failure, Chronic therapy, Peritoneal Dialysis, Continuous Ambulatory adverse effects, Peritonitis microbiology
- Published
- 2015
- Full Text
- View/download PDF
38. The Influence of Glycated Hemoglobin on the Cross Susceptibility Between Type 1 Diabetes Mellitus and Periodontal Disease.
- Author
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Lappin DF, Robertson D, Hodge P, Treagus D, Awang RA, Ramage G, and Nile CJ
- Subjects
- Case-Control Studies, Diabetes Mellitus, Type 1 complications, Humans, Interleukin-6 metabolism, Porphyromonas gingivalis, Chemokines metabolism, Cytokines metabolism, Diabetes Mellitus, Type 1 metabolism, Glycated Hemoglobin physiology, Periodontal Diseases complications
- Abstract
Background: Periodontal disease is a major complication of type 1 diabetes mellitus (T1DM). The aim of the present study is to investigate the relationship between glycated hemoglobin and circulating levels of interleukin (IL)-6, IL-8, and C-X-C motif chemokine ligand 5 (CXCL5) in non-smoking patients suffering from T1DM, with and without periodontitis. In addition, to determine the effect of advanced glycation end products (AGE) in the presence and absence of Porphyromonas gingivalis lipopolysaccharide (LPS) on IL-6, IL-8, and CXCL5 expression by THP-1 monocytes and OKF6/TERT-2 cells., Methods: There were 104 participants in the study: 19 healthy volunteers, 23 patients with periodontitis, 28 patients with T1DM, and 34 patients with T1DM and periodontitis. Levels of blood glucose/glycated hemoglobin (International Federation of Clinical Chemistry [IFCC]) were determined by high-performance liquid chromatography. Levels of IL-6, IL-8, and CXCL5 in plasma were determined by enzyme-linked immunosorbent assay (ELISA). In vitro stimulation of OKF6/TERT-2 cells and THP-1 monocytes was performed with combinations of AGE and P. gingivalis LPS. Changes in expression of IL-6, IL-8, and CXCL5 were monitored by ELISA and real-time polymerase chain reaction., Results: Patients with diabetes and periodontitis had higher plasma levels of IL-8 than patients with periodontitis alone. Plasma levels of IL-8 correlated significantly with IFCC units, clinical probing depth, and attachment loss. AGE and LPS, alone or in combination, stimulated IL-6, IL-8, and CXCL5 expression in both OKF6/TERT-2 cells and THP-1 monocytes., Conclusions: Elevated plasma levels of IL-8 potentially contribute to the cross-susceptibility between periodontitis and T1DM. P. gingivalis LPS and AGE in combination caused significantly greater expression of IL-6, IL-8, and CXCL5 from THP-1 monocytes and OKF6/TERT-2 cells than LPS alone.
- Published
- 2015
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39. IL-33 Exacerbates Periodontal Disease through Induction of RANKL.
- Author
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Malcolm J, Awang RA, Oliver-Bell J, Butcher JP, Campbell L, Adrados Planell A, Lappin DF, Fukada SY, Nile CJ, Liew FY, and Culshaw S
- Subjects
- Alveolar Bone Loss immunology, Alveolar Bone Loss microbiology, Alveolar Bone Loss pathology, Alveolar Process pathology, Animals, Antibodies, Bacterial blood, B-Lymphocytes immunology, Bacteroidaceae Infections immunology, Chronic Periodontitis microbiology, Disease Models, Animal, Female, Gingiva immunology, Humans, Immunoglobulin G blood, Interleukin-1 Receptor-Like 1 Protein, Interleukin-33, Interleukins analysis, Interleukins antagonists & inhibitors, Interleukins pharmacology, Lymph Nodes immunology, Lymphocytes immunology, Maxilla pathology, Mice, Mice, Inbred BALB C, Osteoprotegerin pharmacology, Porphyromonas gingivalis immunology, Receptors, Cell Surface analysis, Receptors, Interleukin antagonists & inhibitors, T-Lymphocytes immunology, Chronic Periodontitis immunology, Interleukins immunology, RANK Ligand immunology
- Abstract
Cytokines mediate the balance between protective and destructive immunity in periodontitis. We sought to investigate the role of IL-33 in periodontitis. The expression of IL-33 in gingival tissue from healthy controls (n = 10) and patients with chronic periodontitis (n = 17) was investigated. Based on a murine model of periodontal disease, the function of IL-33 was determined first by administration of exogenous IL-33 and second by inhibition of IL-33 signaling using mice deficient in the IL-33 receptor ST2. Alveolar bone level, serum antibody, and lymphocyte responses were assessed in the murine model. Expression of IL-33 and ST2 was elevated in gingival tissues from patients with chronic periodontitis as compared with healthy tissues (P < 0.05). Similarly, Il33 expression was higher in periodontal tissues of Porphyromonas gingivalis-infected mice as compared with sham-infected controls (P < 0.05). IL-33 treatment of P. gingivalis-infected mice significantly exacerbated alveolar bone loss when compared with infection or IL-33 treatment alone (P < 0.001). Conversely, P. gingivalis infection-induced alveolar bone loss was attenuated in mice lacking ST2. The percentages of T and B lymphocytes expressing nuclear factor κB ligand (RANKL) in the gingival tissues and T lymphocytes expressing RANKL in the cervical draining lymph nodes were higher in IL-33-treated P. gingivalis-infected mice versus phosphate buffered saline-treated P. gingivalis-infected controls (all P < 0.001). Targeting the RANKL pathway by osteoprotegerin administration abrogated periodontal bone destruction in P. gingivalis-infected, IL-33-treated mice. These data demonstrate a previously unrecognized role for IL-33 in exacerbating bone loss in a RANKL-dependent manner in the context of bacterial infection and suggest that this pathway may be amenable to manipulation as a novel therapeutic target in periodontitis., (© International & American Associations for Dental Research 2015.)
- Published
- 2015
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- View/download PDF
40. The mazEF toxin-antitoxin system as an attractive target in clinical isolates of Enterococcus faecium and Enterococcus faecalis.
- Author
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Soheili S, Ghafourian S, Sekawi Z, Neela VK, Sadeghifard N, Taherikalani M, Khosravi A, Ramli R, and Hamat RA
- Subjects
- Enterococcus faecalis isolation & purification, Enterococcus faecalis pathogenicity, Enterococcus faecium isolation & purification, Enterococcus faecium pathogenicity, Gene Expression Regulation, Bacterial, Humans, Plasmids genetics, Virulence Factors, Antitoxins genetics, Bacterial Toxins genetics, Enterococcus faecalis genetics, Enterococcus faecium genetics
- Abstract
The toxin-antitoxin (TA) system is a regulatory system where two sets of genes encode the toxin and its corresponding antitoxin. In this study, the prevalence of TA systems in independently isolated clinical isolates of Enterococcus faecium and Enterococcus faecalis was determined, the dominant TA system was identified, different virulence genes in E. faecium and E. faecalis were surveyed, the level of expression of the virulence and TA genes in normal and stress conditions was determined, and finally their associations with the TA genes were defined. Remarkably, the analysis demonstrated higBA and mazEF in all clinical isolates, and their locations were on chromosomes and plasmids, respectively. On the other hand, a quantitative analysis of TA and virulence genes revealed that the expression level in both genes is different under normal and stress conditions. The results obtained by anti-mazF peptide nucleic acids demonstrated that the expression level of virulence genes had decreased. These findings demonstrate an association between TA systems and virulence factors. The mazEF on the plasmids and the higBA TA genes on the chromosomes of all E. faecium and E. faecalis strains were dominant. Additionally, there was a decrease in the expression of virulence genes in the presence of anti-mazF peptide nucleic acids. Therefore, it is suggested that mazEF TA systems are potent and sensitive targets in all E. faecium and E. faecalis strains.
- Published
- 2015
- Full Text
- View/download PDF
41. Erratum to: Clinical associations between IL-17 family cytokines and periodontitis and potential differential roles for IL-17A and IL-17E in periodontal immunity.
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Awang RA, Lappin DF, MacPherson A, Riggio M, Robertson D, Hodge P, Ramage G, Culshaw S, Preshaw PM, Taylor J, and Nile C
- Published
- 2015
- Full Text
- View/download PDF
42. Recent developments in β-cell differentiation of pluripotent stem cells induced by small and large molecules.
- Author
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Kumar SS, Alarfaj AA, Munusamy MA, Singh AJ, Peng IC, Priya SP, Hamat RA, and Higuchi A
- Subjects
- Animals, Clinical Trials as Topic, Gene Expression Regulation, Humans, Induced Pluripotent Stem Cells, Insulin-Secreting Cells metabolism, Pluripotent Stem Cells metabolism, Signal Transduction, Time Factors, Cell Differentiation drug effects, Insulin-Secreting Cells cytology, Pluripotent Stem Cells cytology, Pluripotent Stem Cells drug effects
- Abstract
Human pluripotent stem cells, including human embryonic stem cells (hESCs) and human induced pluripotent stem cells (hiPSCs), hold promise as novel therapeutic tools for diabetes treatment because of their self-renewal capacity and ability to differentiate into beta (β)-cells. Small and large molecules play important roles in each stage of β-cell differentiation from both hESCs and hiPSCs. The small and large molecules that are described in this review have significantly advanced efforts to cure diabetic disease. Lately, effective protocols have been implemented to induce hESCs and human mesenchymal stem cells (hMSCs) to differentiate into functional β-cells. Several small molecules, proteins, and growth factors promote pancreatic differentiation from hESCs and hMSCs. These small molecules (e.g., cyclopamine, wortmannin, retinoic acid, and sodium butyrate) and large molecules (e.g. activin A, betacellulin, bone morphogentic protein (BMP4), epidermal growth factor (EGF), fibroblast growth factor (FGF), keratinocyte growth factor (KGF), hepatocyte growth factor (HGF), noggin, transforming growth factor (TGF-α), and WNT3A) are thought to contribute from the initial stages of definitive endoderm formation to the final stages of maturation of functional endocrine cells. We discuss the importance of such small and large molecules in uniquely optimized protocols of β-cell differentiation from stem cells. A global understanding of various small and large molecules and their functions will help to establish an efficient protocol for β-cell differentiation.
- Published
- 2014
- Full Text
- View/download PDF
43. Clinical associations between IL-17 family cytokines and periodontitis and potential differential roles for IL-17A and IL-17E in periodontal immunity.
- Author
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Awang RA, Lappin DF, MacPherson A, Riggio M, Robertson D, Hodge P, Ramage G, Culshaw S, Preshaw PM, Taylor J, and Nile C
- Subjects
- Adult, Biofilms, Biomarkers blood, Case-Control Studies, Coculture Techniques, Enzyme-Linked Immunosorbent Assay, Female, Gingival Crevicular Fluid immunology, Humans, Keratinocytes cytology, Male, Middle Aged, Porphyromonas gingivalis metabolism, Cytokines metabolism, Gene Expression Regulation, Interleukin-17 metabolism, Periodontitis immunology, Periodontitis metabolism
- Abstract
Objective: IL-17A is implicated in periodontitis pathogenesis. The roles of IL-17B-IL-17F and IL-17A/F are unknown. This study aimed to determine clinical associations between IL-17 family cytokines and periodontitis and to investigate the biological roles of IL-17A and IL-17E using in vitro model systems., Materials and Methods: Samples from 97 patients with periodontitis and 77 healthy volunteers were used in the study. Serum, saliva and gingival crevicular fluid (GCF) levels of IL-17 family cytokines were measured by ELISA. Oral keratinocytes were stimulated with a P. gingivalis biofilm, or IL-17A, in the presence and absence of IL-17E and the expression of IL-8 and CXCL5 were investigated by ELISA and real-time-PCR. NF-κB phosphorylation in similar experiments was also measured using a cell-based ELISA., Results: Serum, saliva and GCF IL-17A levels were higher in periodontitis patients and correlated positively with clinical parameters of attachment loss, pocket depth and bleeding on probing. Serum IL-17E levels were lower in periodontitis patients and the serum IL-17A:IL-17E ratio correlated positively with clinical parameters. In vitro, IL-17E inhibited Porphyromonas gingivalis and IL-17A induced expression of chemokines by reducing phosphorylation of the NF-κB p65 subunit., Conclusions: Serum IL-17A:IL-17E may be a marker of disease severity. IL-17E may have opposing roles to IL-17A in periodontitis pathogenesis. IL-17E can negatively regulate IL-17A and periodontal pathogen induced expression of chemokines by oral keratinocytes.
- Published
- 2014
- Full Text
- View/download PDF
44. Methicillin-susceptible and -resistant Staphylococcus aureus with high-level antiseptic and low-level mupirocin resistance in Malaysia.
- Author
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Ghasemzadeh-Moghaddam H, van Belkum A, Hamat RA, van Wamel W, and Neela V
- Subjects
- Bacterial Proteins genetics, Bacterial Proteins metabolism, Benzalkonium Compounds pharmacology, Benzethonium pharmacology, Chlorhexidine analogs & derivatives, Chlorhexidine pharmacology, Gene Expression, Genotype, Humans, Malaysia epidemiology, Membrane Transport Proteins genetics, Membrane Transport Proteins metabolism, Methicillin-Resistant Staphylococcus aureus isolation & purification, Methicillin-Resistant Staphylococcus aureus metabolism, Microbial Sensitivity Tests, Nuclear Proteins genetics, Nuclear Proteins metabolism, Prevalence, Staphylococcal Infections drug therapy, Staphylococcal Infections microbiology, Tertiary Healthcare, Anti-Bacterial Agents pharmacology, Anti-Infective Agents, Local pharmacology, Methicillin-Resistant Staphylococcus aureus drug effects, Methicillin-Resistant Staphylococcus aureus genetics, Mupirocin pharmacology, Staphylococcal Infections epidemiology
- Abstract
The prevalence and spread of mupirocin and antiseptic resistance among colonizing and infectious Staphylococcus aureus were determined. S. aureus isolated from anterior nares and infection sites of patients hospitalized in the largest tertiary care referral hospital in Malaysia was investigated for mupirocin and antiseptic susceptibility testing, and for PCR detection of mupA, qacA/B, and smr genes. Twelve isolates showed resistance to mupirocin by disk diffusion, of which 10 (3.8%) harbored the mupA gene. Minimum inhibitory concentrations (MICs) ranged from 64 to 768 μg/ml for mupA positive and below 46 μg/ml for negative isolates. The mupA was more common among ST239 isolates (70%). The qacA/B was carried in 67 out of 95 methicillin-resistant Staphylococcus aureus (MRSA) (70.5%) and 3 out of 164 methicillin-susceptible Staphylococcus aureus (MSSA) (1.8%), while smr was carried in 6 out of 95 MRSA (6.3%) strains. MICs ranged from 3.9 to 15.6 μg/ml for benzethonium chloride (BTC) and benzalkonium chloride (BKC), and from 10.3 to 20.7 μg/ml for chlorhexidine digluconate (CHG). Isolates with qacA/B and smr or qacA/B alone showed higher MIC (20.7 μg/ml for CHG and 15.6 μg/ml for BTC and BKC) than the isolates that lacked antiseptic resistance genes (10.3 μg/ml for CHG and 3.9 μg/ml for BTC and BKC). In 16 cases, ST239 was isolated from the infection site and the nares simultaneously, and shared identical resistance patterns (qacAB or qacAB+smr), suggesting possible endogenous infection. Spread of low-level mupirocin resistance expressing ST239 MRSA and high-level resistance expressing emerging ST1, co-existing with antiseptic-resistant genes showing elevated MICs, should be monitored for effective infection control.
- Published
- 2014
- Full Text
- View/download PDF
45. PDMS nanocomposites for heat transfer enhancement in microfluidic platforms.
- Author
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Yi P, Awang RA, Rowe WS, Kalantar-zadeh K, and Khoshmanesh K
- Abstract
Increasing the thermal conductivity of PDMS (polydimethylsiloxane) based microfluidics is an important issue for the thermal management of hot spots produced by embedding electronic circuits in such systems. This paper presents a solution for enhancing the thermal conductivity of such PDMS based microfluidics by introducing thermally conductive alumina (Al2O3) nanoparticles, forming PDMS/Al2O3 nanocomposites. The materials are fully characterized for different concentrations of Al2O3 in PDMS for experiments which are conducted at different flow rates. Our results suggest that incorporation of Al2O3 nanoparticles at 10% w/w in the PDMS based nanocomposite significantly enhances the heat conduction from hot spots by enhancing the thermal conductivity, while maintaining the flexibility and decreasing the specific heat capacity of the developed materials. This proof-of-concept study offers potential for a practical solution for the cooling of future embedded electronic systems.
- Published
- 2014
- Full Text
- View/download PDF
46. The alpha 7 nicotinic receptor agonist PHA-543613 hydrochloride inhibits Porphyromonas gingivalis-induced expression of interleukin-8 by oral keratinocytes.
- Author
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Macpherson A, Zoheir N, Awang RA, Culshaw S, Ramage G, Lappin DF, and Nile CJ
- Subjects
- Acetylcholine immunology, Animals, Bridged Bicyclo Compounds, Heterocyclic pharmacology, Bungarotoxins pharmacology, CHO Cells, Cricetulus, Humans, Keratinocytes drug effects, Lipopolysaccharides, Mouth Mucosa cytology, Periodontal Diseases genetics, Periodontal Diseases immunology, Porphyromonas gingivalis, Quinuclidines pharmacology, RNA, Messenger metabolism, STAT3 Transcription Factor immunology, Transcription Factor RelA immunology, alpha7 Nicotinic Acetylcholine Receptor agonists, alpha7 Nicotinic Acetylcholine Receptor antagonists & inhibitors, alpha7 Nicotinic Acetylcholine Receptor genetics, Interleukin-8 immunology, Keratinocytes immunology, alpha7 Nicotinic Acetylcholine Receptor immunology
- Abstract
Objective: The alpha 7 nicotinic receptor (α7nAChR) is expressed by oral keratinocytes. α7nAChR activation mediates anti-inflammatory responses. The objective of this study was to determine if α7nAChR activation inhibited pathogen-induced interleukin-8 (IL-8) expression by oral keratinocytes., Materials and Methods: Periodontal tissue expression of α7nAChR was determined by real-time PCR. OKF6/TERT-2 oral keratinocytes were exposed to Porphyromonas gingivalis in the presence and absence of a α7nAChR agonist (PHA-543613 hydrochloride) alone or after pre-exposure to a specific α7nAChR antagonist (α-bungarotoxin). Interleukin-8 (IL-8) expression was measured by ELISA and real-time PCR. Phosphorylation of the NF-κB p65 subunit was determined using an NF-κB p65 profiler assay and STAT-3 activation by STAT-3 in-cell ELISA. The release of ACh from oral keratinocytes in response to P. gingivalis lipopolysaccharide was determined using a GeneBLAzer M3 CHO-K1-bla cell reporter assay., Results: Expression of α7nAChR mRNA was elevated in diseased periodontal tissue. PHA-543613 hydrochloride inhibited P. gingivalis-induced expression of IL-8 at the transcriptional level. This effect was abolished when cells were pre-exposed to a specific α7nAChR antagonist, α-bungarotoxin. PHA-543613 hydrochloride downregulated NF-κB signalling through reduced phosphorylation of the NF-κB p65-subunit. In addition, PHA-543613 hydrochloride promoted STAT-3 signalling by maintenance of phosphorylation. Furthermore, oral keratinocytes upregulated ACh release in response to P. gingivalis lipopolysaccharide., Conclusion: These data suggest that α7nAChR plays a role in regulating the innate immune responses of oral keratinocytes.
- Published
- 2014
- Full Text
- View/download PDF
47. The mazEF toxin-antitoxin system as a novel antibacterial target in Acinetobacter baumannii.
- Author
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Ghafourian S, Good L, Sekawi Z, Hamat RA, Soheili S, Sadeghifard N, and Neela V
- Subjects
- Acinetobacter baumannii genetics, Antitoxins genetics, Bacterial Toxins genetics, Humans, Reverse Transcriptase Polymerase Chain Reaction, Transcription, Genetic, Acinetobacter baumannii metabolism, Antitoxins metabolism, Bacterial Toxins metabolism
- Abstract
Although analysis of toxin-antitoxin (TA) systems can be instructive, to date, there is no information on the prevalence and identity of TA systems based on a large panel of Acinetobacter baumannii clinical isolates. The aim of the current study was to screen for functional TA systems among clinical isolates of A. baumannii and to identify the systems' locations. For this purpose, we screened 85 A. baumannii isolates collected from different clinical sources for the presence of the mazEF, relBE and higBA TA genes. The results revealed that the genes coding for the mazEF TA system were commonly present in all clinical isolates of A. baumannii. Reverse transcriptase-polymerase chain reaction analysis showed that transcripts were produced in the clinical isolates. Our findings showed that TA genes are prevalent, harboured by chromosomes and transcribed within A. baumannii. Hence, activation of the toxin proteins in the mazEF TA system should be investigated further as an effective antibacterial strategy against this bacterium.
- Published
- 2014
- Full Text
- View/download PDF
48. Extracellular enzyme profiling of Stenotrophomonas maltophilia clinical isolates.
- Author
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Thomas R, Hamat RA, and Neela V
- Subjects
- Cross Infection microbiology, Environmental Microbiology, Humans, Stenotrophomonas maltophilia isolation & purification, Bacterial Proteins analysis, Enzymes analysis, Gram-Negative Bacterial Infections microbiology, Stenotrophomonas maltophilia enzymology, Virulence Factors analysis
- Published
- 2014
- Full Text
- View/download PDF
49. Wide distribution of virulence genes among Enterococcus faecium and Enterococcus faecalis clinical isolates.
- Author
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Soheili S, Ghafourian S, Sekawi Z, Neela V, Sadeghifard N, Ramli R, and Hamat RA
- Subjects
- Enterococcus faecalis isolation & purification, Enterococcus faecalis pathogenicity, Enterococcus faecium isolation & purification, Enterococcus faecium pathogenicity, Genes, Bacterial, Humans, Virulence, Enterococcus faecalis genetics, Enterococcus faecium genetics, Gram-Positive Bacterial Infections microbiology, Virulence Factors genetics
- Abstract
Enterococcus, a Gram-positive facultative anaerobic cocci belonging to the lactic acid bacteria of the phylum Firmicutes, is known to be able to resist a wide range of hostile conditions such as different pH levels, high concentration of NaCl (6.5%), and the extended temperatures between 5(°)C and 65(°)C. Despite being the third most common nosocomial pathogen, our understanding on its virulence factors is still poorly understood. The current study was aimed to determine the prevalence of different virulence genes in Enterococcus faecalis and Enterococcus faecium. For this purpose, 79 clinical isolates of Malaysian enterococci were evaluated for the presence of virulence genes. pilB, fms8, efaAfm, and sgrA genes are prevalent in all clinical isolates. In conclusion, the pathogenicity of E. faecalis and E. faecium could be associated with different virulence factors and these genes are widely distributed among the enterococcal species.
- Published
- 2014
- Full Text
- View/download PDF
50. Stenotrophomonas maltophilia: pathogenesis model using Caenorhabditis elegans.
- Author
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Thomas R, Hamat RA, and Neela V
- Subjects
- Animals, Biological Assay, Survival Analysis, Caenorhabditis elegans microbiology, Disease Models, Animal, Stenotrophomonas maltophilia pathogenicity
- Published
- 2013
- Full Text
- View/download PDF
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