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To better understand host-phage interactions and the genetic bases of phage resistance in a model system relevant to potential phage therapy, we isolated several spontaneous mutants of the USA300 S. aureus clinical isolate NRS384 that were resistant to phage K. Six of these had a single missense mutation in the host rpoC gene, which encodes the RNA polymerase β' subunit. To examine the hypothesis that mutations in the host RNA polymerase affect the transcription of phage genes, we performed RNA-seq analysis on total RNA samples collected from NRS384 wild-type (WT) and rpoC G17D mutant cultures infected with phage K, at different timepoints after infection. Infection of the WT host led to a steady increase of phage transcription relative to the host. Our analysis allowed us to define 53 transcriptional units and to categorize genes based on their temporal expression patterns. Predicted promoter sequences defined by conserved -35, -10, and, in some cases, extended -10 elements, were found upstream of early and middle genes. However, in many cases, sequences upstream of late genes did not contain clear, complete, canonical promoter sequences, suggesting that factors in addition to host RNA polymerase are required for their expression. Infection of the rpoC G17D mutant host led to a transcriptional pattern that was similar to that of the WT at early timepoints. However, beginning at 20 min after infection, transcription of late genes (such as phage structural genes and host lysis genes) was severely reduced. Our data indicate that the rpoC G17D mutation prevents the expression of phage late genes, resulting in a failed infection cycle for phage K. In addition to illuminating the global transcriptional landscape of phage K throughout the infection cycle, this study will inform our investigations into the basis of phage K's control of its transcriptional program as well as mechanisms of phage resistance.

In a study of antibiotic resistance in Staphylococcus aureus, specific cell wall mutants were previously generated for the peptidoglycan biosynthesis gene murF , by the insertion of an integrative plasmid. A collection of 30 independent mutants was obtained, and all harbored a variable number of copies of the inserted plasmid, arranged in tandem in the chromosome. Of the 30 mutants, only 3, F9, F20 and F26, with a lower number of plasmid copies, showed an altered peptidoglycan structure, lower resistance to β-lactams and a different loss-of-function mutation in rho gene, that encodes a transcription termination factor. The rho mutations were found to correlate with the level of oxacillin resistance, since genetic complementation with rho gene reestablished the resistance and cell wall parental profile in F9, F20 and F26 strains. Furthermore, complementation with rho resulted in the amplification of the number of plasmid tandem repeats, suggesting that Rho enabled events of recombination that favored a rearrangement in the chromosome in the region of the impaired murF gene. Although the full mechanism of reversion of the cell wall damage was not fully elucidated, we showed that Rho is involved in the recombination process that mediates the tandem amplification of exogeneous DNA fragments inserted into the chromosome. IMPORTANCE The cell wall of bacteria, namely, peptidoglycan, is the target of several antibiotic classes such as β-lactams. Staphylococcus aureus is well known for its capacity to adapt to antibiotic stress and develop resistance strategies, namely, to β-lactams. In this context, the construction of cell wall mutants provides useful models to study the development of such resistance mechanisms. Here, we characterized a collection of independent mutants, impaired in the same peptidoglycan biosynthetic step, obtained through the insertion of a plasmid in the coding region of murF gene. S. aureus demonstrated the capacity to overcome the cell wall damage by amplifying the copy number of the inserted plasmid, through an undescribed mechanism that involves the Rho transcription termination factor.

Staphylococcus aureus (S. aureus) is an important pathogen causing various limited or systemic infections. Methicillin resistant S. aureus (MRSA) in particular presents a major clinical and public health problem. Toxic shock syndrome toxin-1 (TSST-1) encoded by the gene tst is an important virulence factor of tst positive S. aureus, leading to multi-organ malfunction. However, the mechanism of TSST-1 in pathogenesis is only partly clear. In this study, we investigated the prevalence of the tst gene in clinical isolates of S. aureus. Then, animal experiments were performed to further evaluate the influence of the presence of the tst gene associated Staphylococcus aureus Pathogenicity Island (SaPI) on body weight, serum cytokine concentrations and the bacterial load in different organs. In addition, macrophages were used to analyze the secretion of cytokines in vitro and bacterial survival in the cytoplasm. Finally, pathological analysis was carried out to evaluate organ tissue impairment. The results demonstrated that the prevalence of tst gene was approximately 17.8% of the bacterial strains examined. BALB/c mice infected with tst gene associated SaPI positive isolates exhibited a severe loss of body weight and a high bacterial load in the liver, heart, kidney and spleen. Pathological analysis demonstrated that tissue impairment was more severe after infection with tst gene associated SaPI positive isolates. Moreover, the secretion of IL-6, IL-2 and IL17A by macrophages infected with tst gene associated SaPI positive isolates clearly increased. Notably, IL-6 secretion in BALB/c mice infected with tst gene associated SaPI positive isolates was higher than that in BALB/c mice infected with negative ones. Together, these results indicated that the tst gene associated SaPI may play a critical role in the pathological process of infection via a direct and persistent toxic function, and by promoting the secretion of inflammatory cytokines that indirectly induce immune suppression., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

We report for the first time an oxacillin-susceptible mecA-positive Staphylococcus aureus (OS-MRSA) associated with a processed food product in Europe. One isolate (MRSA-ST5-type V SCCmec) was found in cheese among 600 food samples confiscated from air passengers from international flights in Vienna Airport (Austria). Type V SCCmec strains do not harbor functional mecI-mecR1 genes and in such strains mecA expression is regulated by the bla system (blaI-blaR1-blaZ). It has been recently reported that malfunctions in the bla system lead to the constitutive expression of mecA. The OS-MRSA reported in this study harbored the bla system on a plasmid and one deletion occurred in the blaR1 gene causing a frameshift variant that lead to an incomplete BlaR1 protein. This finding highlights the potential role of food as a neglected route of dissemination of emerging MRSA variants., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Objectives: Nosocomial infections caused by methicillin resistant Staphylococcus aureus (MRSA) and emergence of vancomycin resistant S. aureus (VRSA) have led to great concern in healthcare settings worldwide. Methods: A total of 100 S. aureus clinical isolates from hospitalized patients were investigated for antimicrobial susceptibility, the presence of resistance ( mecA , vanA , and vanB ) and virulence ( hlaA , fnbpA , cna , clfA , tsst-1 , eta , and spa ) encoding genes, and molecular typing based on polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) of spa gene. Results: All isolates were resistant to one or more antibiotics, with the most frequent resistance found against amoxicillin (69%). A total of 46 isolates were MRSA, and 40% of isolates were multidrug resistant (MDR). Of all S. aureus isolates, two isolates were confirmed as VRSA and four isolates confirmed as vancomycin intermediate S. aureus (VISA). The frequency of clfA , cna , tsst-1 , and eta genes among MRSA isolates was significantly higher than methicillin sensitive S. aureus (MSSA). The significant correlation between MDR isolates and the carriage of multiple virulence genes was seen. All MDR isolates carried at least four virulence genes. Furthermore, biofilm formation in MRSA isolates was significantly higher than MSSA. The spa gene PCR products generated 4 major and 10 minor types. After digestion of spa amplicons with Hin dIII restriction enzyme, 10 different patterns ranging 174-938 bp were detected. S2b and S2a subtypes were detected frequently in MRSA isolates. Conclusions: It seems that the appropriate surveillance and control measures are essential to prevent the emergence and transmission of MRSA and VRSA strains in our country.

Background: Staphylococcus aureus is one of the major pathogens of public health importance responsible for various forms of infection. Development of resistance to commonly used antimicrobials limited treatment options against infections due to this pathogen. Antimicrobial resistance profile of Staphylococcus aureus isolated from patients with surgical site infection and ear infection and corresponding nasal swab was investigated in Tikur Anbessa Specialized Hospital (TASH), Addis Ababa, Ethiopia., Methods: Wound and corresponding nasal swabs from patients with surgical site infection from general surgery ward (n = 14), orthopedic ward (n = 21) and those with otitis media (n = 59) from Ear Nose and Throat (ENT) ward were cultured for S. aureus isolation according to standard procedures from December 2013 to June 2014. Isolates were investigated for susceptibility to panel of 17 antimicrobials using Kirby Bauer disc diffusion assay. Susceptibility to methicillin was phenotypically determined based on sensitivity of isolates to cefoxitin and oxacillin., Results: A total of 79 S. aureus isolates were recovered from 54(57.4%) of patients. The isolates were resistant to ampicillin (100%), oxacillin and cefoxitin (68.4%, each), clindamycin (63.3%), cephalothin (59.5%), tetracycline (57%), sulfamethoxazole + trimethoprim and bacitracin (53.2%, each), and erythromycin (51.9%). Resistance to two or more antimicrobials was recorded in 74 (95%) of the isolates, while resistance to 3 or more antimicrobials was detected in 65(82.3%) of the isolates. Fifty-four (68.4%) of the isolates were methicillin resistant S. aureus (MRSA). Rate of occurrence of MRSA was more common among isolates from surgical wards (p < 0.001) compared to those from ENT ward. High level of multi-drug resistance (MDR) was detected more commonly among isolates from orthopedic ward than those from general surgical ward and patients with ear infection (p < 0.001). One of the isolate cultured from wound swab of a patient with surgical site infection from orthopedic ward was resistant to all of the 17 antimicrobials tested., Conclusion: S. aureus isolates from patients in TASH exhibited resistance to majority of antimicrobials commonly employed for the treatment of staphylococcal infections which calls for urgent need of prudent use of antimicrobials and the need for implementation of effective infection control practices to hamper spread of MDR S. aureus.

Objective: The objective of this study was to determine the prevalence of methicillin-resistant Staphylococcus aureus and antimicrobial susceptibility patterns among janitors working at Mekelle University, Tigray, Northern Ethiopia., Result: The overall prevalence of S. aureus and MRSA in the present study were 17.97% (69/384) and 6.25% (24/384) respectively. Although not statistically significant, the prevalence of MRSA among janitors working in the medical area (9.7%, 10/103) was two times higher than the non-medical area (4.9%, 14/281). Janitors who had more service year and who were unable to read and write were found with high isolates of MRSA. Nasal carriage of MRSA among janitors who work in the hospital and who were hospitalized in the last 3 months and those who had exposure to wastes and body fluids were 13 (37.1%) and 10 (38.5%) respectively. Majority of the isolates of S. aureus were sensitive to ciprofloxacin (67; 97%), doxycycline (56; 81%), erythromycin (54; 78%), chloramphenicol (50; 72.5%) and cefoxitin (45; 65.2%). Sixty-seven of the 69 (97%) were resistant to penicillin. Of the 69 isolates of S. aureus, 22 (31.9%) showed multidrug resistant. Fourteen were resistant to three antimicrobials, 2 were resistant to four antimicrobials, and 7 were resistant to five antimicrobials.

Objective: To determine antibiotic susceptibility pattern of S. aureus isolates from clinical specimens collected from patients at Kenyatta National Hospital from March 2014-February 2016, and to determine the prevalence and quarterly trends of MRSA throughout the study period., Results: A total of 944 S. aureus isolates were analyzed. High sensitivity of S. aureus was observed for quinupristin/dalfopristin (100%), tigecycline (98.2), imipenem (98%), nitrofurantoin (97.6%), linezolid (97.3%), teicoplanin (97.1%) and vancomycin (95.1%). High resistance was recorded against penicillin G (91.9%), trimethoprim/sulfamethoxazole (56.9%) and tetracycline (33.2%). MRSA prevalence among the patients at KNH was 27.8%. Highest proportion (80%) of MRSA was in burns unit. Both MRSA and MSSA were highly susceptible to quinupristin/dalfopristin, tigecycline, linezolid, nitrofurantoin, ampicillin/sulbactam and vancomycin and showed high resistance to commonly used antibiotics such as gentamycin, erythromycin, levofloxacin and tetracycline. A majority of isolates were from pus specimen (68%).

Most Staphylococcus aureus infections occur in previously colonized persons who also act as reservoirs for continued dissemination. This study aimed to investigate the carriage of antimicrobial resistance and virulence markers in S. aureus isolates associated with nasal colonization. The study was conducted from December 2013-April 2014. Nasal swabs were collected and questionnaires administered to 97 medical students in Riyadh Saudi Arabia. Bacterial culture, identification and antimicrobial susceptibility testing were performed by conventional methods and chromogenic agar was used for methicillin resistant S. aureus (MRSA) screening. Molecular characterization of isolates was carried out using the StaphyType DNA microarray. Thirty two students (43%) had S. aureus nasal carriage (MSSA = 31; MRSA = 1). Seventeen clonal complexes (CC) were identified namely: CC15-MSSA (n = 5), CC1-MSSA-SCCfus (n = 4), CC8-MSSA (n = 3), CC22-MSSA (n = 3), CC25-MSSA (n = 3), CC101-MSSA (n = 2). Other CC found as single isolates were CC5-MSSA, CC6-MSSA, CC30-MSSA, CC45-MSSA, CC96-MSSA, CC188-MSSA, CC398-MSSA, CC942-MSSA/PVL+, CC1290-MSSA, ST2482-MSSA, CC80-MRSA-IV/PVL+. The CC1-SCCfus isolates harbored the Staphylococcal cassette chromosome (SCC) with ccrA-1; ccrB-1 and ccrB-3 genes plus the putative fusidic acid resistance marker Q6GD50. One MSSA isolate was genotyped as coagulase negative Staphylococcus spp with an irregular composite SCCmec element. Majority of the isolates harbored various virulence genes including the hemolysin, enterotoxin, and exfoliative genes as well as various adhesive protein producing genes. Although there was low carriage of MRSA, the MSSA isolates harbored various resistance and virulence genes including those usually seen in MRSA isolates. The presence of isolates with incomplete SCCmec elements plus putative resistance and virulence genes is of concern., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

We compared 3 real-time PCR assays: off-label use of 2 commercial assays (BD-GeneOhm™ MRSA assay for methicillin-resistant Staphylococcus aureus [MRSA] detection and BD-GeneOhm StaphSR™ for MRSA and methicillin-susceptible S. aureus detection) and an in-house real-time PCR assay for detection of total S. aureus from clinical specimens. Testing was performed on 200 distinct specimens. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated using culture as the gold standard. The prevalence of S. aureus in the samples was 44.5%, and MRSA was 20%. For total S. aureus, the StaphSR-PCR and the in-house PCR assays had a sensitivity and specificity of 94.4% and 96.4% and 93.3% and 99.1%, respectively. For MRSA detection, the StaphSR and the BD GeneOhm assay had a sensitivity and specificity of 92.5% and 98.8% and 92.5% and 96.3%, respectively. This study demonstrates the potential use of tests like the StaphSR-PCR assay for rapid detection of S. aureus and MRSA directly from clinical specimens; however, culture follow-up would be needed to identify other potential pathogens in the specimen., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Objective: To provide an inclusive blend of extant meta-analyses on the burden of Staphylococcus (S.) aureus and its resistant strains across diverse study populations, settings, and temporal contexts. Methods: The study has adopted PRISMA 2020-based guides and registered its protocol on Open Science Framework with an extensive literature search. Study quality was assessed by QUOROM and AMSTAR techniques. Data analysis included parsing of study-level statistical power, assessment of primary study overlap, pooling of meta-analysis results, subgroup and temporal analysis. Results: Totally 41 studies (64 meta-analyses) were selected by the inclusion criteria. The summary meta-analysis revealed global prevalence rates for S. aureus [24.8%, 95%C1 0.248(0.204-0.293), I2 = 93%], methicillin resistant S. aureus (MRSA) [5.8%, 95% CI 0.058(0.044-0.073), I2 = 92%], vancomycin intermediate S. aureus [1.7%, 95%C1 0.017(0.013–0.021), I2 = 36.4%], heterogeneous vancomycin intermediate S. aureus [5.2%, 95% CI 0.052(0.038–0.056), I2 = 36.4%], community-associated methicillin-resistant S. aureus [19.9%, 95%C1 0.199(-0.170–0.568), I2 = 96.67%), livestock-associated-MRSA [13.6%, 95% CI 0.136(-0.028–0.243), I2 = 97.7%], and mupirocin resistant S. aureus [7.6%, 95% CI 0.076(0.062–0.090), 12 = 0%]. Temporal analysis revealed that the burden community-associated methicillin-resistant S. aureus notably increased from 1.3% in 2003 to 39.0% in 2014. Coagulase-negative staphylococci rose from 23.2% in 2021 to 29.8% in 2022. Vancomycin resistant S. aureus peaked at 9.0% in 2018, declining to 2.6% in 2020. Livestock-associated-MRSA significantly increased to 19.0% in 2020. MRSA fluctuated, peaking at 52.7% in 2012 and 31.0% in 2022. Conclusions: The study reveals a considerable global prevalence of S. aureus at 24.8%. Regional differences were apparent, with Africa facing a high burden of MRSA at 40.8% of S. aureus and temporal trends exposed a dynamic state. [ABSTRACT FROM AUTHOR]

Background: Staphylococcus aureus is a Gram-positive cocci commonly inhabiting the nasal cavity as a commensal. Methicillin-resistant type of Staphylococcus aureus results in invasive infections that are difficult to treat with regular antibiotics. This study helps us determine the prevalence of MRSA among healthcare workers who pose a potential risk of being the carriers of the MRSA strains, leading to infections in hospital patients. Materials & Methods: A descriptive cross-sectional study was conducted six months (January-June 2023) at a Tertiary care hospital, Ananthapuramu. A total of 100 nasal swabs from healthcare workers were collected, and Staphylococcus aureus was isolated and identified using standard conventional culture methods and biochemical tests. The isolated Staphylococcus aureus was tested for the presence of MRSA by using a cefoxitin (30 µg) disc in Muller Hinton Agar Medium by Kirby-Bauer disk diffusion method according to Clinical Laboratory Standards Institute (CLSI) guidelines. Results: Out of 100 samples, 14(14%) samples were positive for nasal carriage of Staphylococcus aureus, and 4 (4%) isolates were positive for MRSA. The prevalence of MRSA was 4% in our study among the healthcare workers. Conclusion: The study revealed the prevalence of Methicillin-Resistant Staphylococcus aureus in nasal carriers among healthcare workers as 4%, which may threaten the spread of MRSA among patients admitted to the hospital. Thus, the present study helps us highlight the need to regularly screen carriers in apparently asymptomatic healthcare workers to prevent nosocomial infections. [ABSTRACT FROM AUTHOR]

Staphylococcus aureus bacteria, especially Methicillin Resistant Staphylococcus aureus (MRSA), is one of the main causes of antibiotic resistance. MRSA is a bacteria that is resistant to the β-lactam class of penicillin antibiotics. MRSA infections can cause a variety of health problems, including skin infections, pneumonia, and bacteremia. This problem requires alternative resources that can be an option. Propolis from the stingless bee species Tetragonula laeviceps can be a potential alternative for treating MRSA infections. This research is classified as a true experiment with a posttest control group design. The concentration of propolis ethanol extract tested was 20%; 10%; 5%; 2.5%; 1.25%; and 0.625% in the diffusion and dilution methods. These two methods provide assessment output in the form of inhibition zone diameter, minimum inhibition concentration, and minimum bactericidal concentration. The data obtained will be tested statistically using One-way Anova and Fisher's exact tests. Test results show that the ethanol extract of Tetragonula laeviceps propolis has an antimicrobial effect against MRSA bacteria. The diffusion test showed that the average diameter of the inhibition zone formed by the ethanol extract of propolis successively from a concentration of 20% to 1,25% with six repetitions was 12.7 ± 1.23 mm; 11.36 ± 0.67 mm; 10.24 ± 0.61 mm; 7.59 ± 1.69 mm; and 6.5 ± 1.14 mm. From these averages, the One-Way Anova test revealed a statistically significant difference in the diameter of the inhibition zone (F(7,40) = [ 192.79], p = 0.000). [ABSTRACT FROM AUTHOR]

Food sold in healthcare facilities and environments are underestimated as sources of exposure of customers to potential pathogens. In the current study, we investigated the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in selected food items sold in two hospitals located in Benin City, Edo State, South-South Nigeria. A total of 100 food samples were obtained from food vendors and screened by pour plate method for the presence of heterotrophic bacterial and Staphylococcus aureus. Their antibiotic sensitivity patterns were determined by disc diffusion method and the presence of toxigenic and pathogenic genes by polymerase chain reaction and gel electrophoresis. Majority of the food samples investigated harbored Staphylococcus aureus, with varying levels of antibiotics resistance pattern. Only 5 of the isolates were observed to be methicillin resistant, with only one harboring the mecA gene. The results of this study are an indication that methicillin resistant Staphylococcus aureus could be a source of contaminant in ready-to-eat food sold in hospital facilities, and effort must be taken to prevent the occurrence of diseases arising from their presence. [ABSTRACT FROM AUTHOR]

Background:Azadirachta indica has been used against a few disease in traditional medicine and have long history of use, and their use is worldwide in both developing and devolved countries, also have multiple health benefits. This study aimed to evaluate the antibacterial activity of Neem leaves extract against standard bacterial strain and only one drug resistant strain of important human pathogenic bacteria by using in vitro methods. Methods: This study aimed to evaluate the antimicrobial effects of Azadirachta indica (Neem) leaves extracts against selected pathogens. The present study was carried out to screen and evaluate antimicrobial activity of leaves of Azadirhta indica (Neem)methanol and petroleum ether extracts. Azadirchta indica extracts were tested against standard strains of S. aureus ATCC 6538, E. coli ATCC 25922, P. aeroginosa ATCC 9027, K. pneumonia ATCC 700603, and S. typhimurium ATCC 14028. The effeminacy of the extracts was studied and determined by applying different concentration of extracts on the selected bacterial strains and synthetic antimicrobial discs were used as positive control by using disc diffusion method. Results: With the statistical test analysis the comparison done showed that, no significant different between the two extracts used, and Staphylococcus aureus and Methicillin resistant staphylococcus aureus were the only bacteria susceptibly affected by this Neem extracts used. Conclusions: The result obtained indicate the leaves extracts of Neem plant have enormous antimicrobial effect, and may be exploited for the treatment of various infectious diseases

Nosocomial infections are proving to be a menace for the whole health care system, with methicillin resistant Staphylococcus aureus (MRSA) being a very notorious causative agent. Along with the role of mecA gene producing penicillin-binding protein (PBP2a), production of beta-lactamase enzyme by Staphylococcus aureus makes the organism resistant to all ß-lactam agents. This study aims at phenotypic detection of methicillin resistance and ß-Lactamase production in all S. aureus isolates by Cefoxitin disk diffusion test and Penicillin zone-edge test, respectively. In this prospective crosssectional study, samples were obtained from patients admitted to different departments and were processed according to the standard laboratory protocols. As per the CLSI guidelines, phenotypic detection of resistance to methicillin was done by Cefoxitin Disk Diffusion test, whereas production of beta-lactamase enzyme was phenotypically detected by penicillin zone edge test. Among 179 isolates of S. aureus, 116 (64.8%) were MRSA, whereas the remaining 63 (35.2%) isolates were methicillin-sensitive Staphylococcus aureus (MSS A). Staphylococcus aureus infection among ICU and non-ICU patients were found to be 24(13%) and 155(86.6%) respectively. Among 24 ICU patients, 19 had MRSA infection, whereas among 155 non-ICU patients, 97 had MRSA infection. Out of 63 MSS A isolates, only 2 (3.17%) were found to be sensitive to Penicillin by Zone-edge test, 04 isolates showed presence of ß-lactamase production, while remaining 57 isolates were resistant to Penicillin. At the same time, several class of antibiotics were found to be ineffective against these MRSA isolates. Cases of methicillin-resistant and b-lactamase producing Staphylococcus aureus infections are on the rise in our hospital settings. [ABSTRACT FROM AUTHOR]

Background: Azadirachta indica has been used against a few disease in traditional medicine and have long history of use, and their use is worldwide in both developing and devolved countries, also have multiple health benefits. Objectives: This study aimed to evaluate the antibacterial activity of Neem leaves extract against standard bacterial strain and only one drug resistant strain of important human pathogenic bacteria by using in vitro methods. Methods: This study aimed to evaluate the antimicrobial effects of Azadirachta indica (Neem) leaves extracts against selected pathogens. The present study was carried out to screen and evaluate antimicrobial activity of leaves of Azadirhta indica (Neem)methanol and petroleum ether extracts. Azadirchta indica extracts were tested against standard strains of S. aureus ATCC 6538, E. coli ATCC 25922, P. aeroginosa ATCC 9027, K. pneumonia ATCC 700603, and S. typhimurium ATCC 14028. The effeminacy of the extracts was studied and determined by applying different concentration of extracts on the selected bacterial strains and synthetic antimicrobial discs were used as positive control by using disc diffusion method. Results: With the statistical test analysis the comparison done showed that, no significant different between the two extracts used, and Staphylococcus aureus and Methicillin resistant staphylococcus aureus were the only bacteria susceptibly affected by this Neem extracts used. Conclusions: The result obtained indicate the leaves extracts of Neem plant have enormous antimicrobial effect, and may be exploited for the treatment of various infectious diseases. [ABSTRACT FROM AUTHOR]

Occurrence of Staphylococcus aureus in children with osteomyelitis. This study was conducted at K. M. M. C. & Hospital, Mathura (UP). A total of 60 patients with osteomyelitis contributed to this study from October 2017 to October 2019. Patients with known immunodeficiency syndromes were excluded. Specimen collections were meticulously performed to avoid contamination which was accomplished by needle aspiration or surgical sampling. Staphylococcus aureus was recovered in more than half of the cases of osteomyelitis in both infants and children. Amikacin, Clindamycin and Cefazolin were effective in such cases. The distal end of the femur and upper-end tibia were the most common sites of infection where boys were more infected than girls. The haematogenous route was the main cause of the transmission of osteomyelitis in children. Principally Staphylococcus aureus causes the majority of cases of osteomyelitis in children followed by H. influenza, Group B Streptococcus, P. aeruginosa, E. coli and Serratia marcescens.

ObjectiveTo investigate the prevalence, antimicrobial susceptibility, and enterotoxin gene of Staphylococcus aureus (S. aureus) isolates in ready-to-eat (RTE) foods in Guangzhou from 2008 to 2019.MethodsRTE food samples were randomly collected from retail outlets and supermarkets in 11 districts of Guangzhou and the isolation and identification of S. aureus were performed. All isolated S. aureus were tested for antimicrobial susceptibility, enterotoxin genes and multilocus sequence typing (MLST). Methicillin resistant S. aureus (MRSA) isolates were further characterized by staphylococcal cassette chromosome mec (SCCmec) typing.ResultsA total of 157 S. aureus isolates(11.22%) were detected from 1 399 RTE food samples in Guangzhou from 2009 to 2018. The prevalence of S. aureus in cooked pork samples was significantly higher than those in non-meat samples (17.95% vs 9.43%, P

Staphylococcus aureus is a common mastitis pathogen in dairy cows, and methicillin-resistant S. aureus (MRSA) has been found in dairy farms all over the world. The study carried out on bovines from three governorates in Egypt, with the goal of determining the prevalence of MRSA in positive milk samples of subclinical mastitis, performing an antibiotic susceptibility test against MRSA isolates and determining the risk factors associated with MRSA. A total of 350 quarter milk samples (n = 200 mixed breed cow; n = 150 water buffalo) were collected and examined for subclinical mastitis using the California mastitis test (CMT) before being exposed to standard microbiological procedures for S. aureus isolation. The disc diffusion method was used to phenotypically analyse the positive S. aureus isolates for MRSA, which was verified by a PCR assay targeting the mecA gene. According to the findings of the study, 41.4% (145/350) milk samples were positive based on CMT, while 35.7% (125/350) of positive samples identified as MRSA based on PCR assay. However, the obtained results revealed non-significant disparity between cattle and buffalo and all predicted risk factors were strongly associated with prevalence of subclinical mastitis. The in-vitro antibiotic susceptibility test revealed that cefoxitin was completely resistant, whereas linezolid, ciprofloxacin, and trimethoprim + sulphamethoxazole were sensitive against the MRSA isolates. The relevance of S. aureus to public health, as well as the development of resistance to antibiotics like methicillin, needs ongoing testing of antimicrobial medications against MRSA isolates. [ABSTRACT FROM AUTHOR]

Occurrence of Staphylococcus aureus in children with osteomyelitis. This study was conducted at K. M. M. C. & Hospital, Mathura (UP). A total of 60 patients with osteomyelitis contributed to this study from October 2017 to October 2019. Patients with known immunodeficiency syndromes were excluded. Specimen collections were meticulously performed to avoid contamination which was accomplished by needle aspiration or surgical sampling. Staphylococcus aureus was recovered in more than half of the cases of osteomyelitis in both infants and children. Amikacin, Clindamycin and Cefazolin were effective in such cases. The distal end of the femur and upper-end tibia were the most common sites of infection where boys were more infected than girls. The haematogenous route was the main cause of the transmission of osteomyelitis in children. Principally Staphylococcus aureus causes the majority of cases of osteomyelitis in children followed by H. influenza, Group B Streptococcus, P. aeruginosa, E. coli and Serratia marcescens. [ABSTRACT FROM AUTHOR]

Abstract Background This is the first review of literature and synthesis of data on community onset methicillin resistant Staphylococcus aureus (CO-MRSA) infections in Australia. Incidence of CO-MRSA varies considerably in Australia, depending on geographic and demographic factors. Methods Data for the rates of MRSA infections were collected from articles identified using PubMed, Scopus, the grey literature and data from State and Federal Government Surveillance Systems. We synthesized data and developed a framework for how data was selected, collated, linked, organized and interpreted. Results The results of our literature search demonstrates considerable gaps in the reporting of CO-MRSA in Australia. Consequently, total incidences were under reported; however the available data suggests the incidence varied between 44 (Tasmania) and 388 (southern Northern Territory) cases per 100,000 person years. Hospitalised cases of CO-MRSA varied between 3.8 (regional Victoria) and 329 (southern Northern Territory). Taking the median percentage of infections by site for all regions available, skin and soft tissue infections (SSTIs) consisted of 56% of hospitalized CO-MRSA, compared with bacteremias, which represented 14%. No region had a complete data set of CO-MRSA infections treated in out-patient settings and so incidences were underestimates. Nevertheless, estimates of the incidence of CO-MRSA treated outside hospitals varied between 11.3 (Melbourne) and 285 (Northern Territory) per 100,000 person-years. These infections were chiefly SSTIs, although urinary tract infections were also noted. Incidences of CO-MRSA blood-stream infections and outpatient skin and soft tissue infections have been increasing with time, except in Tasmania. CO-MRSA is observed to affect people living in remote areas and areas of socioeconomic disadvantage disproportionately. Conclusions We generated the first estimates of the incidence of CO-MRSA infections in Australia and identified stark regional differences in the nature and frequency of infections. Critically, we demonstrate that there has been a lack of consistency in reporting CO-MRSA and a general dearth of data. The only government in Australia that requires reporting of CO-MRSA is the Tasmanian, where the infection was least prevalent. Some regions of Australia have very high incidences of CO-MRSA. To improve surveillance and inform effective interventions, we recommend a standardized national reporting system in Australia that reports infections at a range of infection sites, has broad geographic coverage and consistent use of terminology. We have identified limitations in the available data that hinder understanding the prevalence of CO-MRSA.

Despite increased pre and postoperative care including screening procedures, improvement in the operating room environment, and controlled prophylactic antibiotic therapy, the health burden of Surgical Site Infections (SSIs) in India is far more escalated than that in developed countries. SSIs ranging from superficial skin infection to life threatening septicemia affect one third of the patient population undergoing surgery, thereby contributing to morbidity and mortality. One of the most dominant bacterial species that causes SSIs is Staphylococcus aureus, wherein Methicillin Resistant S.aureus (MRSA) alone contributes to a significant increase in both the cost and the length of hospitalisation along with an increased mortality rate among patients with SSIs. The rising resistance pattern among pathogens coupled with the concerns over the tolerance and safety of currently available agents against MRSA limits treatment options available for patients with SSIs. Levonadifloxacin and its oral prodrug alalevonadifloxacin are novel benzoquinolizine anti-MRSA agents which have recently been approved in India to tackle gram positive 'super-bugs'. Herein, the aim of this review article was to collate the possible factors contributing toward SSIs, its implications on health and economy, antibiotic resistance, possible preventive measures, and the need for new antimicrobial agents. [ABSTRACT FROM AUTHOR]

Antimicrobial peptides (AMPs) are promising candidates as new anti-biofilm agents to cope with biofilm-related infections. To date, numerous studies have evaluated the efficacy of AMPs as anti-biofilm agents. However, studies related to the mechanism of their anti-biofilm action are still lacking. Similar to other antibiotics, AMPs also require greater quantity and time to kill bacteria embedded in the biofilm, as compared to killing planktonic cells. This study has been conducted as an attempt to elucidate reasons of this negligible anti-biofilm activity of AMPs. We found that AMPs (100 µg/mL) processed with methicillin resistant Staphylococcus aureus (MRSA) biofilms were degraded into fragments over time, with significantly reduced antimicrobial activity due to exposure to aureolysin, an extracellular protease known to regulate the biofilm growth cycle of S. aureus. As such, it was determined that AMPs encounter resistance of aureolysin during their action on S. aureus biofilm. [ABSTRACT FROM AUTHOR]

Toxins produced by bacteria can result into various systemic manifestations through the release of cytokines which leads to changes at the molecular level. This index case of an 18 years old adult immuno-competent male patient, presented with high grade ongoing fever for 3 days, had wound on left arm in deltoid region. there were diffuse maculo-papular rash predominantly in both palms feet and trunk, erythematous and blanchable on examination. Patient was treated with inj. Piperacillin- Tazobactam and Linezolid, i.v. fluids and nor-adrenaline infusion. Patient was diagnosed with concurrent Staphylococcal Scalded Skin Syndrome (SSSS) and Toxic Shock Syndrome (TSS). The two syndromes are caused by different toxins produced by different strains of Staphylococcus aureus. The source of infection was a pus discharging sinus on left arm. The findings were proven on skin biopsy and met the case definition criteria of TSS. He is currently asymptomatic after the treatment being given against Methicillin-resistant Staphylococcus aureus (MRSA) isolated from the pus. It is therefore possible for a single strain of bacteria being capable of producing different toxins, resulting in two different clinical syndromes having a concurrent presentation.

Aparajita Chatterjee,1 Shipra Rai,1 Vasudeva Guddattu,2 Chiranjay Mukhopadhyay,3 Kavitha Saravu1,4 1Department of Medicine, Kasturba Medical College, Manipal Academy of Higher Education (MAHE), Manipal, Madhav Nagar, Karnataka, India; 2Department of Statistics, Prasanna School of Public Health, Manipal Academy of Higher Education (MAHE), Manipal, Madhav Nagar, Karnataka, India; 3Department of Microbiology, Kasturba Medical College Manipal Academy of Higher Education (MAHE), Manipal, Madhav Nagar, Karnataka, India; 4Manipal McGill Center for Infectious Diseases, Prasanna School of Public Health, Manipal Academy of Higher Education (MAHE), Manipal, Madhav Nagar, Karnataka, India Purpose: To determine morbidity and mortality of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive S. aureus (MSSA) infections in a tertiary health care facility.Methods: A cohort study among hospitalized adult patients with culture proven MRSA or MSSA monoinfection were recruited in a tertiary referral center in South India from November 2011 to December 2012.Results: Of total 551 subjects, 284 (52%) had MRSA and 267 (48%) MSSA infection. A total of 184 (65%) subjects had health care-associated MRSA (HA-MRSA) and 100 (35%) community-associated MRSA (CA-MRSA). Chronic kidney disease and recent antibiotic use had significant association with MRSA. MRSA patients had significant respiratory infection (OR 2.24 [1.04, 5.16]) and bacteremia (OR 2.24 [10.40, 5.16]), relative to MSSA. MSSA group had better survival function compared to MRSA group (P=0.028). Median duration of ICU stays were 5 days (IQR 4, 8) and 2 days (IQR 2, 2) in MRSA and MSSA, respectively. Complications such as acute kidney injury, sepsis, multiorgan dysfunction, need for supportive measures were more in the MRSA group.Conclusion: MRSA imposes a huge burden in Indian scenario and HA-MRSA remains the main culprit. Patients with history of chronic kidney disease and recent use of antibiotics were found to be at a higher risk. Patients with MRSA infections tend to have poorer outcomes in terms of longer hospital stay, greater complications, and mortality. Keywords: methicillin-resistant Staphylococcus aureus, Staphylococcus aureus, risk factors, outcome, mortality, India, prognosis, impact, morbidity

Introduction: Methicillin-Resistant Staphylococcus aureus (MRSA) infection is a major global healthcare problem, the prevalence of which varies from 25-50% in India. It is known to cause Skin and Soft tissue Infections (SSI), endovascular infections, endocarditis, pneumonia, septic arthritis, osteomyelitis, and sepsis. Vancomycin is the drug of choice for treating severe MRSA infections. Ceftaroline, a fifth-generation cephalosporin has been approved by the United States Food and Drug Administration (US FDA) for treating acute bacterial SSI caused by susceptible micro-organisms including MRSA, Community acquired respiratory tract infection, MRSA bacteremia and endocarditis. Aim: To assess the susceptibility of clinical isolates of S. aureus to ceftaroline, in a Tertiary Care Hospital. Materials and Methods: This prospective study was conducted in the Department of Microbiology of a Tertiary Care Hospital over a period of two months from June 2019 to July 2019. S.aureus isolates from various clinical samples were screened for methicillin resistance by disc diffusion method using cefoxitin disc and ceftaroline susceptibility of these isolates was assessed by E-strip method. The isolates were classified as ceftaroline susceptible, Susceptibility Dose Dependent (SDD) and ceftaroline resistant respectively as per CLSI guidelines. A descriptive analysis of the data was done and the results were presented as frequencies and percentages. Results: All the S.aureus isolates were found to be susceptible to ceftaroline. Methicillin Sensitive Staphylococcus aureus (MSSA) isolates had lower Minimum Inhibitory Concentration (MIC) when compared to MRSA. The highest MIC among MRSA was 0.5 μg/mL. Conclusion: Ceftaroline can be considered as an effective alternative for treatment of infections caused by MRSA. [ABSTRACT FROM AUTHOR]

Introduction: Surgical site infection (SSI) is one of the most common hospitals acquired infection. The present study describes resistogram of bacterial pathogens in SSIs in the hospitals in and around Sangli, Maharashtra, India. Materials and Methods: The resistogram pattern was studied by modified Kirby-Bauer disc diffusion method. Results: A total of 1491 pus samples from patients clinically diagnosed of SSIs were processed and 911 isolates were obtained. The most common Gram-positive isolates were Staphylococcus aureus(53.92%), coagulase-negative Staphylococci (31.17%), Enterococcus (10.58%), and Streptococcus pyogens (4.31%); while Gram-negative isolates were Escherichia coli (33.16%), Klebsiella spp. (28.92%), Citrobacter species (4.98%), Pseudomonas aeruginosa (12.96%), Acinetobacter species (1.99%), Proteus mirabilis (10.97%), and Proteus vulgaris (6.98%). The frequency of methicillin-resistant S. aureus (MRSA) was 28% whereas the frequency of methicillin sensitive S. aureus was 72%. The MRSA showed multidrug resistance pattern. Conclusion: Twenty-eight percent are MRSA which showed multidrug resistance pattern. While most of the Gram-positive isolates were resistance toward the amoxicillin/clavulanate, gentamicin, and ceftriaxone. Most of the Gram-negative isolates were resistant to ampicillin, ciprofloxacin and ceftriaxone. [ABSTRACT FROM AUTHOR]

Objectives: Methicillin resistant Staphylococcus aureus (MRSA) nasal carriage often precedes infection. This work aims to genetically profile MRSA carriage of resistant genes (mecA, blaZ and tetM) and certain virulence genes (nuc, pvl, spa and scn). Methods: Phenotypically confirmed Staphylococcus aureus were Screened for oxacillin resistance and assessed for ß-lactamase production. Further confirmation of identity was performed by multiplex PCR of the 16SrRNA, mecA, tetM, pvl, nuc, spa and scn genes. DNA gel fingerprint analysis was carried out and the bands were clustered in a dendrogram. Results: The study analysed 81 Staphylococcus aureus isolates for Methicillin resistance out of which 38 (46.9%) were MRSA. The DNA extraction method was effective for all MRSA isolates evaluated. All phenotypic MRSA isolates (100%) were positive for the S. aureus specific 16SrRNA gene confirming that these isolates were S. aureus strains. The nuc gene was detected in 19/38 (50%) of the MRSA isolates, blaZ gene in 14/38 (36.8%) and tetM in 18/38 (47.4%). Conclusions: The need for improved vigilance to recognize MRSA strains cannot be overemphasized. If MRSA control is not tracked, these strains will increase exponentially. [ABSTRACT FROM AUTHOR]

The assessment of MDRO infection and colonization should include the identification of known carriers, the detection of hospital-specific and healthcare-associated acquisition, an estimation of the burden of serious infection, an understanding of the reservoir affecting the transmission of MDROs, and an evaluation of the effect of intervention. Several strategies can be used to obtain data that aid in this assessment. We have defined and categorized the recommended metrics for each of these aspects of measuring MDRO infection and colonization, for use by healthcare facilities. © 2008 by The Society for Healthcare Epidemiology of America. All rights reserved.

BackgroundPatients with newly acquired methicillin-resistant Staphylococcus aureus (MRSA) have significant risks of short-term morbidity and mortality due to this pathogen. We were interested in assessing whether long-term carriers have persistent risks of disease and whether all carriers, regardless of the duration of carriage, should be considered to be reasonable candidates for interventions to reduce the risk of infection.MethodsWe conducted a single-center retrospective cohort study to evaluate the risk of subsequent MRSA infection and death among patients known to have harbored MRSA for at least 1 year (i.e., prevalent carriers).ResultsAmong 281 prevalent carriers, 65 (23%) developed a total of 96 discrete and unrelated MRSA infections in the year after their identification as prevalent carriers. The most common infections were pneumonia (accounting for 39% of MRSA infections), soft-tissue infection (14%), and central venous catheter infection (14%). Twenty-four percent of all infections involved bacteremia. Thirty-eight MRSA infections occurred during a new hospitalization, and 32 (84%) of these infections were the reason for admission to the hospital. MRSA contributed to 14 deaths, with 6 of these deaths deemed to be attributable to MRSA. Harboring MRSA for 1 year are at high risk for subsequent MRSA morbidity and mortality and should be considered to be targets for intervention, in addition to individuals who have newly acquired this pathogen.

ObjectivesTo evaluate the adequacy of discharge room cleaning and the impact of a cleaning intervention on the presence of methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) on environmental surfaces in intensive care unit (ICU) rooms.DesignProspective environmental study.Setting and sampleConvenience sample of ICU rooms in an academic hospital. METHODS AND INTERVENTION: The intervention consisted of (1) a change from the use of pour bottles to bucket immersion for applying disinfectant to cleaning cloths, (2) an educational campaign, and (3) feedback regarding adequacy of discharge cleaning. Cleaning of 15 surfaces was evaluated by inspecting for removal of a preapplied mark, visible only with an ultraviolet lamp ("black light"). Six surfaces were cultured for MRSA or VRE contamination. Outcomes of mark removal and culture positivity were evaluated by chi(2) testing and generalized linear mixed models, clustering by room.ResultsThe black-light mark was removed from 44% of surfaces at baseline, compared with 71% during the intervention (P < .001). The intervention increased the likelihood of removal of black-light marks after discharge cleaning (odds ratio, 4.4; P < .001), controlling for ICU type (medical vs surgical) and type of surface. The intervention reduced the likelihood of an environmental culture positive for MRSA or VRE (proportion of cultures positive, 45% at baseline vs 27% during the intervention; adjusted odds ratio, 0.4; P = .02). Broad, flat surfaces were more likely to be cleaned than were doorknobs and sink or toilet handles.ConclusionsIncreasing the volume of disinfectant applied to environmental surfaces, providing education for Environmental Services staff, and instituting feedback with a black-light marker improved cleaning and reduced the frequency of MRSA and VRE contamination.

Invasive disease following methicillin-resistant Staphylococcus aureus (MRSA) detection is common, regardless of whether initial detection involves colonization or infection. We assessed the genetic relatedness of isolates obtained > or =2 weeks apart representing either repeated infections or colonization-infection sets to determine if infections are likely to be caused by previously harbored strains. We found that MRSA infection following initial colonization or infection is caused by the same strain in most cases, suggesting that a single successful attempt at decolonization may prevent the majority of later infection.

Legislation aimed at controlling antimicrobial-resistant pathogens through the use of active surveillance cultures to screen hospitalized patients has been introduced in at least 2 US states. In response to the proposed legislation, the Society for Healthcare Epidemiology of America (SHEA) and the Association of Professionals in Infection Control and Epidemiology (APIC) have developed this joint position statement. Both organizations are dedicated to combating healthcare-associated infections with a wide array of methods, including the use of active surveillance cultures in appropriate circumstances. This position statement reviews the proposed legislation and the rationale for use of active surveillance cultures, examines the scientific evidence supporting the use of this strategy, and discusses a number of unresolved issues surrounding legislation mandating use of active surveillance cultures. The following 5 consensus points are offered. (1) Although reducing the burden of antimicrobial-resistant pathogens, including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE), is of preeminent importance, APIC and SHEA do not support legislation to mandate use of active surveillance cultures to screen for MRSA, VRE, or other antimicrobial-resistant pathogens. (2) SHEA and APIC support the continued development, validation, and application of efficacious and cost-effective strategies for the prevention of infections caused by MRSA, VRE, and other antimicrobial-resistant and antimicrobial-susceptible pathogens. (3) APIC and SHEA welcome efforts by healthcare consumers, together with private, local, state, and federal policy makers, to focus attention on and formulate solutions for the growing problem of antimicrobial resistance and healthcare-associated infections. (4) SHEA and APIC support ongoing additional research to determine and optimize the appropriateness, utility, feasibility, and cost-effectiveness of using active surveillance cultures to screen both lower-risk and high-risk populations. (5) APIC and SHEA support stronger collaboration between state and local public health authorities and institutional infection prevention and control experts.

BackgroundRoutine culturing of patients in intensive care units (ICUs) for methicillin-resistant Staphylococcus aureus (MRSA) identifies unrecognized carriers and facilitates timely isolation. However, the benefit of surveillance in detecting prevalent and incident carriers likely varies among ICUs. In addition, many assessments underestimate the incidence of acquisition by including prevalent carriers in the at-risk population.MethodsWe performed a retrospective cohort study using accurate at-risk populations to evaluate the range of benefit of admission and weekly surveillance cultures in detecting otherwise unrecognized MRSA in 12 ICUs in 5 states.ResultsWe assessed 142 ICU-months. Among the 12 ICUs, the admission prevalence of imported MRSA was 5%-21%, with admission surveillance providing 30%-135% increases in rates of detection. The monthly hospital-associated incidence was 2%-6%, with weekly surveillance providing 7%-157% increases in detection. The common practice of reporting incidence using the total number of patients or total patient-days underestimated incidence by one-third. Surgical ICUs had lower MRSA importation but higher MRSA incidence. Overall, routine surveillance prevented the misclassification of 17% (unit range, 11%-29%) of "incident" carriers, compared with clinical cultures, and increased precaution days by 18% (unit range, 11%-91%).ConclusionsRoutine surveillance significantly increases the detection of MRSA, but this benefit is not uniform across ICUs, even with high compliance and the use of correct denominators.

BackgroundSerial interventions are often used to reduce the risk of health care-associated methicillin-resistant Staphylococcus aureus (MRSA) infections. To our knowledge, the relative impact of these interventions has not previously been ascertained.MethodsWe conducted a retrospective study of 4 major infection control interventions using an interrupted time series design to evaluate their impact on MRSA bacteremia in an 800-bed hospital with 8 intensive care units (ICUs). Interventions were introduced 1 at a time during a 9-year period and involved the promotion of compliance with maximal sterile barrier precautions during central venous catheter placement, the institution of alcohol-based hand rubs for hand disinfection, the introduction of a hand hygiene campaign, and the institution of routine nares surveillance cultures for MRSA in all ICUs for patients on ICU admission and weekly thereafter while in the ICU. Positive cultures resulted in the initiation of contact isolation precautions. Using segmented regression analyses, we evaluated changes in monthly incidence and prevalence of MRSA bacteremia from their predicted values. Methicillin-susceptible Staphylococcus aureus bacteremia was monitored as a control.ResultsRoutine surveillance cultures and subsequent contact isolation precautions resulted in substantial reductions in MRSA bacteremia in both ICUs and non-ICUs. In 16 months, the incidence density of MRSA bacteremia decreased by 75% in ICUs (P=.007) and by 40% in non-ICUs (P=.008), leading to a 67% hospital-wide reduction in the incidence density of MRSA bacteremia (P=.002). Methicillin-susceptible S. aureus bacteremia rates remained stable during this time. The other interventions were not associated with a statistically significant change in MRSA bacteremia.ConclusionsRoutine surveillance for MRSA in ICUs allowed earlier initiation of contact isolation precautions and was associated with large and statistically significant reductions in the incidence of MRSA bacteremia in the ICUs and hospital wide. In contrast, no similar decrease was attributable to the other infection control interventions.

BackgroundEnvironmental contamination with methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) occurs during the care of patients harboring these organisms and may increase the risk of transmission to subsequent room occupants.MethodsTwenty-month retrospective cohort study of patients admitted to 8 intensive care units performing routine admission and weekly screening for MRSA and VRE. We assessed the relative odds of acquisition among patients admitted to rooms in which the most recent occupants were MRSA positive or VRE positive, compared with patients admitted to other rooms.ResultsOf 11 528 intensive care unit room stays, 10 151 occupants were eligible to acquire MRSA, and 10 349 were eligible to acquire VRE. Among patients whose prior room occupant was MRSA positive, 3.9% acquired MRSA, compared with 2.9% of patients whose prior room occupant was MRSA negative (adjusted odds ratio, 1.4; P = .04). VRE, Among patients whose prior room occupant was VRE positive, these values were 4.5% and 2.8% respectively (adjusted odds ratio, 1.4; P = .02). These excess risks accounted for 5.1% of all incident MRSA cases and 6.8% of all incident VRE cases, with a population attributable risk among exposed patients of less than 2% for either organism. Acquisition was significantly associated with longer post-intensive care unit length of stay.ConclusionsAdmission to a room previously occupied by an MRSA-positive patient or a VRE-positive patient significantly increased the odds of acquisition for MRSA and VRE. However, this route of transmission was a minor contributor to overall transmission. The effect of current cleaning practices in reducing the risk to the observed levels and the potential for further reduction are unknown.

Studies evaluating the risk of methicillin-resistant Staphylococcus aureus (MRSA)-associated sequelae in colonized or infected inpatients have not extended follow-up into the period after discharge from the hospital. We determined the 18-month risk of MRSA infection among 209 adult patients newly identified as harboring MRSA. Twenty-nine percent of patients (60 patients) developed subsequent MRSA infections (90 infections). These infections were often severe. Twenty-eight percent of infections (25 of 90) involved bacteremia, and 56% (50 of 90) involved pneumonia, soft tissue infection, osteomyelitis, or septic arthritis. Eighty percent of patients (48 of 60) with subsequent MRSA infection developed the infection at a new site, and 49% of new MRSA infections (44 of 90) first became manifest after discharge from the hospital. Accurate assessment of the risk of MRSA-associated sequelae requires prolonged follow-up after discharge.

Using whole-genome sequencing, we identified a community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) sequence type (ST) 398 type V (5C2&5) isolate (typically found in China) in Australia in 2017. This CA-MRSA ST398 variant was highly virulent, similar to other related CA-MRSAs of ST398. This strain should be monitored to prevent more widespread dissemination.

Drug discovery process includes screening of potential compounds to propose as drug and identification of potential targets to be inhibited in order to combat disease prognosis. A combined approach of phytochemistry and bioinformatics is used to deal with drug discovery against antimicrobial resistance by identifying potential targets and candidate drugs. The work includes evaluation of antimicrobial activity of terpenoid-based plant extracts against antibiotic resistant microorganisms. The study was conducted to explain possible new perspective of drug discovery. Phytocompounds from herbal medicinal plants Bacopa monnieri and Andrographis paniculata were employed. Phytochemical tests were performed for both the plants to screen the presence of phytocompounds. Antimicrobial activities of the crude extracts of two medicinal plants (Bacopa monnieri and Andrographis paniculata) were screened. Best reported zone of inhibition observed with Andrographis paniculata was 1.5 cm in Pseudomonas aeruginosa and 1.0 cm in Bacillus subtilis. The least inhibition was shown by Bacopa monnieri , i.e. 0.7 cm in Pseudomonas aeruginosa and 0.6 cm in Bacillus subtilis. In silico analysis of phytochemicals is studied against multidrug resistant (MDR) strains of methicillin resistant Staphylococcus aureus using computer-aided drug discovery. Identification of target proteins was performed using database mining. Subsequently, molecular docking was done to depict the interaction of chosen terpenoid (Bacoside, Bacopa saponin, andrographin and β-sitosterol) against the identified target proteins (PDB entry 2X4K & 2IHY) of MRSA. Andrographin and bacoside has more specificity towards the target protein identified for Staphylococcus aureus. This justifies them as potential compound with antimicrobial property. This study concludes the antimicrobial property of medicinal extracts of Bacopa monnieri and Andrographis paniculata against methicillin resistance Staphylococcus aureus and establishes the interaction of current phytochemicals involved in antimicrobial activity through an in-silico approach to reduce the cost incurred in experimental efforts. • Identification of antimicrobial terpenoid compounds of herbal medicinal plants Bacopa monnieri and Andrographis paniculata. • In-silico Drug discovery approach from medicinal plant extracts. • Biochemical tests of herbal plant extracts. • Target identification from methicillin resistant Staphylococcus aureus (MRSA). • Molecular docking to identify the interaction between identified targets and screened ligands. [ABSTRACT FROM AUTHOR]

Staphylococcus aureus and Mycobacterium tuberculosis are major causative agents responsible for serious nosocomial and community-acquired infections impacting healthcare systems globally. Over several decades, these pathogens have developed resistance to multiple antibiotics significantly affecting morbidity and mortality. Thus, these recalcitrant pathogens are amongst the most formidable microbial pathogens for which international healthcare agencies have mandated active identification and development of new antibacterial agents for chemotherapeutic intervention. In our present work, a series of new quinazolin-4(3 H)-one derivatives were designed, synthesized and evaluated for their antibacterial activity against ESKAP pathogens and pathogenic mycobacteria. The experiments revealed that 4'c , 4'e , 4'f and 4'h displayed selective and potent inhibitory activity against Staphylococcus aureus with MIC values ranging from 0.03-0.25 μ g/mL. Furthermore, compounds 4'c and 4'e were found to be benign to Vero cells (CC 50 = >5 μ g/mL) and displayed promising selectivity index (SI) > 167 and > 83.4 respectively. Additionally, 4'c and 4'e demonstrated equipotent MIC against multiple drug-resistant strains of S. aureus including VRSA, concentration dependent bactericidal activity against S. aureus and synergized with FDA approved drugs. Moreover, compound 4′c exhibited more potent activity in reducing the biofilm and exhibited a PAE of ∼2 h at 10X MIC which is comparable to levofloxacin and vancomycin. In vivo efficacy of 4'c in murine neutropenic thigh infection model revealed that 4'c caused a similar reduction in cfu as vancomycin. Gratifyingly, compounds 4d , 4e , 9a , 9b , 14a , 4'e and 4'f also exhibited anti-mycobacterial activity with MIC values in the range of 2-16 μ g/mL. In addition, the compounds were found to be less toxic to Vero cells (CC 50 = 12.5->100 μ g/mL), thus displaying a favourable selectivity index. The interesting results obtained here suggest the potential utilization of these new quinazolin-4(3 H)-one derivatives as promising antibacterial agents for treating MDR-Staphylococcal and mycobacterial infections. Image 1 • Series of new quinazolin-4(3 H)-one derivatives were designed, synthesized and evaluated for antibacterial activity. • 4'c , 4'e , 4'f and 4'h displayed selective and potent inhibitory activity against Staphylococcus aureus. • 4'c and 4'e were found to be non-toxic to Vero cells and displayed promising SI. • 4'c and 4'e demonstrated equipotent MIC against multiple drug-resistant strains of S. aureus , concentration dependent bactericidal activity against S. aureus and synergized with tested drugs. • 4′c exhibited more potent activity in reducing the biofilm and exhibited a PAE of ∼2 h at 10X MIC and also exhibited similar in vivo efficacy as Vancomycin. [ABSTRACT FROM AUTHOR]

Background Staphylococci are a group of bacteria that cause diseases ranging from minor skin infections to lifethreatening bacteremia. Biofilm formation was determined by a number of methods and is available to detect the capability of staphylococci to colonize the biomedical devices. The icaA and icaD have been reported to play a significant role in biofilm formation. Objective To achieve and detect the molecular basis of adhesion properties in respect to methicillin resistant Staphylococcus aureus. Methods Clinical samples were taken from Burn patients; identified and Methicillin susceptibility was tested. The genes icaA and icaD were amplified in methicillin resistant Staphylococcus aureus and the polymerase chain reaction products were sequenced and aligned with the previous recorded sequences online. Results There was a great correlation between the presence of icaD genes and the slime production. Methicillin resistant Staphylococcus aureus did not reveal any correlation between icaA and icaD and slime layer production; nonetheless, a correlation was noticed between icaD alone and a biofilm production Conclusion The present findings indicated that methicillin resistant Staphylococcus aureus was able to form biofilm. None of the methicillin resistant Staphylococcus aureus isolates harboured icaA; while 100% of them contained icaD. [ABSTRACT FROM AUTHOR]

S. aureus is a common commensal of the skin and mucosal membranes of humans, with estimates of 20% (range from 12% to 30%) of healthy people are persistent S. aureus nasal carriers, 30% (range from 16% to 70%) are intermittent carriers, and 50% (range from 16% to 69%) are non-carriers. The aim of this article is to explore the factors associated with Methicillin Resistant StaphylococcusAureus carriage among food handlers. Across sectional study was done to involve 200 persons who are handling foods in 40 restaurants in Duhok city in the study. MethicillinResistant Staphylococcus Aureus was detect among 27% of studied population. Methicillin Resistant Staphylococcus Aureus carrier rate showed a significant association with skin and soft tissue infections, health facilities visits and certain jobs of food handlers. Age, duration of work in the restaurants, personal protective measures and antibiotic use showed no significant association with the prevalence of MRSA. MethicillinResistant StaphylococcusAureus carrier rate was higher among food handlers working in popular restaurants when compared to other restaurants. Ongoing screening of all persons who handled foods is crucial to detect and treat those are MRSA carrier as one of major public health issues. [ABSTRACT FROM AUTHOR]

• A biosurfactant (BS) was isolated from human Lactobacillus gasseri BC9. • BS inhibited biofilms of methicillin resistant S. aureus (MRSA) strains. • BS loaded in liposomes (BS-LP) enhanced the antibiofilm activity. • Lyophilized matrices containing BS-LP were formulated for topical application. Staphylococcus aureus is the major causative agent of skin and soft tissue infections, whose prevention and treatment have become more difficult due to the emergence of antibiotic-resistant strains. In this regard, the development of an effective treatment represents a challenge that can be overcome by delivering new antibiofilm agents with appropriate nanocarriers. In this study, a biosurfactant (BS) isolated from Lactobacillus gasseri BC9 and subsequently loaded in liposomes (LP), was evaluated for its ability to prevent the development and to eradicate the biofilm of different methicillin resistant S. aureus (MRSA) strains. BS from L. gasseri BC9 was not cytotoxic and was able to prevent formation and to eradicate the biofilm of different MRSA strains. BS loaded liposomes (BS-LP) presented a mean diameter (lower than 200 nm) suitable for topical administration and a low polydispersity index (lower than 0.2) that were maintained over time for up 28 days. Notably, BS-LP showed higher ability than free BS to inhibit S. aureus biofilm formation and eradication. BS-LP were loaded in lyophilized matrices able to quickly dissolve (dissolution time lower than 5 s) upon contact with exudate, thus allowing vesicle reconstitution. In conclusion, in this work, we demonstrated the antibiofilm activity of Lactobacillus -derived BS and BS-LP against clinically relevant MRSA strains. Furthermore, the affordable production of lyophilized matrices containing BS-LP for local prevention of cutaneous infections was established. [ABSTRACT FROM AUTHOR]

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Objective: To undertake the first detailed genomic analysis of methicillin-resistant Staphylococcus aureus (MRSA) isolated in Sri Lanka. Methods: A prospective observational study was performed on 94 MRSA isolates collected over a 4 months period from the Anuradhapura Teaching Hospital, Sri Lanka. Screening for mec A, mec C, and the Panton-Valentine leucocidin (PVL)-associated lukS-PV/lukF-PV genes and molecular characterization by spa typing was undertaken. Whole genome sequencing (WGS) and phylogenetic analysis was performed on selected multilocus sequence type (MLST) clonal complex 5 (CC5) isolates from Sri Lanka, England, Australia, and Argentina. Results: All 94 MRSA harbored the mecA gene. Nineteen spa types belonging to nine MLST clonal complexes were identified. Where origin of the sample was recorded, most isolates were from skin and soft tissue infections (70/91; 76.9%), with fewer causing bacteremia (16/91; 17.6%), empyema (3/91; 3.3%) and osteomyelitis (2/91; 2.2%). Sixty two (65.9%) isolates were PVL positive with the majority (56 isolates; 90.3%) belonging to a dominant CC5 lineage. This lineage, PVL-positive ST5-MRSA-IVc, was associated with both community and hospital-onset infections. Based on WGS, representative PVL-positive ST5-MRSA-IVc isolates from Sri Lanka, England and Australia formed a single phylogenetic clade, suggesting wide geographical circulation. Conclusions: We present the most detailed genomic analysis of MRSA isolated in Sri Lanka to date. The analysis identified a PVL-positive ST5-MRSA-IVc that is prevalent among MRSA causing clinical infections in Sri Lanka. Furthermore, this clone was also found among isolates from the United Kingdom and Australia. [ABSTRACT FROM AUTHOR]

Introduction: The versatility of Staphylococcus aureus has been transformed as "Methicillin resistant Staphylococcus aureus". The most challenging are the disastrous virulence patterns being expressed due to the selection pressure of antibiotics. For assessing the prevalence of methicillin resistant Staphylococcus aureus; screening by cefoxitin disc (30µg) diffusion method is still a realistic approach among conventional phenotypic methods, being applied in most of the laboratories. This reliable and feasible technique contributes significantly for MRSA detection. Objective: To evaluate the prevalence and identify the sensitivity pattern of methicillin resistant Staphylococcus aureus isolates from different clinical specimens in a tertiary care hospital. Study Design: Descriptive study. Setting: Pathology Department, Microbiology Laboratory, PGMI. Period: January 2015 to December 2015. Materials & Methods: A total 713 clinical isolates of Staphylococcus aureus were processed. Identification and confirmation of Staphylococcus aureus was done by colony morphology on blood agar, gram stain, catalase, coagulase and DNA-ase tests. Screening for methicillin resistance was done using cefoxitin disc (30µg, OXOID); while different antibiotic discs were used to assess the sensitivity profile by Modified Kirby-Bauer Disc Diffusion method according to CLSI guidelines (2016). Results: Out of 713 Staphylococcus aureus isolates, 92 (12.90%) isolates were labelled as methicillin resistant by cefoxitin disc diffusion test. Out of 92 MRSA isolates, 57 (14.65%) were recovered from male patients and 35 (10.80%) from female patients. While, 60 (65.22%) MRSA isolates showed hemolysis on blood agar. Among 92 MRSA isolates, 41 (44.57%) were recovered from pus specimen. Resistance to trimethoprim/sulfamethoxazole was highest (65.22%) after penicillin (100%); while all the MRSA isolates were 100% sensitive to both vancomycin and linezolid. Conclusion: The prevalence of MRSA in hospital care settings is of great clinical concern. To combat this public health threat effectively, continuous surveillance of healthcare associated infections, along with local antibiotic sensitivity pattern of MRSA; as well as formulation of a definite antibiotic policy is required. [ABSTRACT FROM AUTHOR]

Resistance to methicillin in methicillin resistant Staphylococcus aureus (MRSA) is dependent on mecA gene located on staphylococcal cassette chromosome (SCC). Both SCCmec type and Panton-Valentine leukocidin (PVL) affect S. aureus pathogenicity. Aim of this study was to investigate the prevalence of SCCmecA types and pvl genes among MRSA isolates from inpatients. During this cross-sectional study on 100 clinical isolates, following antibiotic susceptibility test, screening of mecA and pvl genes, as well as SCCmec typing, was done in a multiplex PCR technique. From the studied samples, 58 isolates were recognized as MRSA. The frequency of mecA and pvl was 58% and 4%, respectively. All of the MRSA were resistant to cefoxitin and had the highest sensitivity to chloramphenicol. The majority (77.5%) of MRSA was originated from wound samples. The SCCmec III was the most frequent type (22.4%) in these samples. The pvl positive isolates were from SCCmec IVb and V, thus meaning they are from CA-MRSA. These results show a high prevalence of MRSA in the studied region and a widespread prevalence of SCCmec I-V types. Furthermore, high prevalence of SCCmec III indicates the prevalence of multidrug resistant MRSA. This finding is a serious alarm for medical health care practitioners for the correct use of antibiotics in order to limit the spread of multidrug resistant strains. In addition, with regard to life threatening infections caused by pvl harbouring strains, early diagnosis and treatment of infections caused by these isolates should be mandatory. [ABSTRACT FROM AUTHOR]

Introduction and aim: Staphylococcus aureus is a significant opportunistic pathogen possessing highly variable genome, causing thus wide range of infections. An important location where this pathogen may occur in healthy individuals includes not only organs such as skin, pharynx, nasal mucosa, etc., but also oral cavity. The main objective of our study was to find out whether various oral cavity conditions such as periodontitis, fixed and removable dental prostheses and stomatological diseases with indications for extraction influence the level of oral cavity colonization by the Staphylococcus aureus, as well as to define the frequency of occurence of methicillin-resistant strains of this microorganism in stomatological patients. Methods: The examined collection consisted of 96 patients, who attended dental services LUXDENT, Ltd., in Nitra from June 2014 to January 2015. Patients were divided into the groups studied, i.e., the group of patients with 1. periodontitis, 2. dental diseases with indications for extraction, 3. fixed or removable prosthetic restorations and 4. control group. Microbiological samples were obtained by sterile swabs from oral and nasal cavity of subjects included into study and delivered to the laboratory within 24 h. At the laboratory, samples were processed by standard methods for isolation and identification of Staphylococcus aureus and confirmed by polymerase chain reaction, in which the specific region of nuc gene, characteristic for Staphylococcus aureus was amplified. Methicillin-resistant strains of Staphylococcus aureus were identified using disc difusion method according to the methodology of the European Committee on Antimicrobial Susceptibility Testing [8]. Results: The presence of S. aureus was found in 35 samples (20.2%) out of 173 examined samples (oral and nasal cavity swabs), while 31 of those samples were methicillin-sensitive (88.58%) and four of them were methicillin-resistant (11.42%). There was a statistically important difference between the occurrence of the microorganism in nose and mouth (p < 0,05) indicating a more frequent occurrence in the nasal cavity. The presence of the microorganism in both nasal and oral cavities simultaneously was discovered only in three out of 96 patients (3.12%). When comparing the group of patients with fixed and removable prostheses to other groups, the occurrence of microorganism studied was significantly higher (p < 0,05). Conclusions: Our results indicate that the oral cavity may be an important site of Staphylococcus aureus colonisation and the conditions in the oral cavity, e.g., fixed and removable restorations may promote oral carriage of this microorganism.