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Background: Pseudomonas aeruginosa is an important pathogen in healthcare settings that poses significant challenges due to its ability to rapidly develop antibiotic resistance. Its propensity to form biofilms and adapt to host defenses makes it even more difficult to treat, leading to prolonged and debilitating illnesses. So, it is vital to prioritize efforts to develop new strategies for treating infections caused by this pathogen. In the present work, morphological and biological characteristics of vB_PaeS_TUMS_P6 (P6), a lytic phage against P. aeruginosa, belonging to the genus Luzseptimavirus were fully described. Methods: P. aeruginosa ATCC 27853 was used for propagation and biological characterization of P6. Its morphology was assessed using transmission electron microscopy (TEM). Adsorption rate assay, one-step growth curve analysis and time-kill experiment were analyzed. Host Range of P6, as well as pH and thermal stability were also determined. Results: The results showed that it was of classic podovirus morphology and had a short latent period. It could kill bacteria at multiplicity of infection as low as 0.01 and also infect some multidrug-resistant clinical isolates. Stability data suggested that P6 remained stable in various temperatures and pH levels, which is a beneficial characteristic for phage therapy in different situations. Conclusion: This study presents promising data supporting the future use of P6 as a candidate for phage therapy.

Introduction: Pseudomonas aeruginosa isolates producing metallo-β-lactamase have caused nosocomial outbreaks, severe infections, and ineffective carbapenem therapy worldwide since 1991. Due to their prevalence, hospital infection control techniques are difficult. This study aimed to find out the prevalence of metallo-β-lactamase among P. aeruginosa isolates from two tertiary care hospitals in Kathmandu. Methods: A descriptive cross-sectional study was conducted at the Department of Microbiology and Department of Pathology of two tertiary care centres in Kathmandu from 7 December 2021 to 6 April 2023, after receiving ethical approval from the Ethical Review Board. Isolated strains were identified and tested for antibiotic susceptibility by modified Kirby-Bauer Methods. Metallo-β-lactamase presence was confirmed using an imipenem-imipenem/ ethylenediaminetetraacetic acid disc. A convenience sampling method was used. The point estimate was calculated at 95% Confidence Interval. Results: Among 255, Pseudomanas aeruginosa isolates, the distribution of metallo-β-lactamase-producing Pseudomanas aeruginosa was 103 (40.39%) (34.32-46.69 at 95% Confidence Interval). Multidrug resistance categories included multidrug resistance 74 (71.80%), extensively drug resistance 32 (31.10%), P. aeruginosa difficult-to-treat 16 (15.53%) and carbapenem-resistant P. aeruginosa was determined to be 82 (79.60%). Conclusions: The study found a high prevalence of metallo-β-lactamase-producing Pseudomanas aeruginosa isolates, requiring early identification, infection control measures, and an all-inclusive antimicrobial therapy protocol to reduce their spread in medical settings.

Background and Objective: Cervical cancer is the fourth most common cancer in the world. The most important issue in cancer treatment is the destruction of cancer cells in the presence of normal cells. For this reason, it is necessary to use natural resources such as plants to treat cancer. The aim of this study is to evaluate the antibacterial effects of the ethanolic extract of Alhagi maurorum on Staphylococcus aureus and Pseudomonas aeruginosa and cytotoxicity on HeLa cervical cancer cell line. Methods: In this experimental study, first the ethanolic extract of Alhagi maurorum was prepared, and then the two standard strains of Staphylococcus aureus (ATCC: 25923) and Pseudomonas aeruginosa (ATCC: 27853) were lyophilized by culturing in nutrient medium. In order to confirm the standard strains, biochemical tests were performed. Microdilution method was used to determine the minimum inhibitory concentration and after obtaining the minimum inhibitory concentration, the minimum bactericidal concentration was evaluated. Furthermore, the effects of the cytotoxicity of the extract at concentrations of 0.1, 10, 50, 100, 500 and 1000 μg/ml was evaluated on the HeLa cell line in a period of 48 hours using the MTT method and comparing its toxicity with the cisplatin group (positive control group). Findings: Ethanol extract of Alhagi maurorum at a concentration of 50 μg/ml reduced the growth of cancer cells, and in the statistical comparison, 50, 500 and 1000 μg concentrations revealed significant differences (p

Contamination of meat and meat products with pathogenic and spoilage microorganisms is one of the most important challenges facing the meat industry that results in a range of human health problems and economic losses. This work aimed to identify the occurrence of Pseudomonas spp. especially Pseudomonas aeruginosa (P. aeruginosa) in some processed and ready-to-eat meat products in Sohag governorate. A total of 200 random meat product samples; minced beef meat, luncheon, burger, and sausage (50 of each) were purchased from different markets in Sohag governorate, Egypt over a period of 12 months from November 2020 to October 2021. Pseudomonas spp. was suspected in 32 (15%) of the meat products examined samples using the colony morphology on Cetrimide agar, represented as follows; 30%, 18%, 6%, and 10% in minced beef meat, luncheon burger, and sausage, respectively. Using the morphological and biochemical methods, P. aeruginosa was suspected in 12 isolates (37.5%) with an incidence of 12/200 (6%) of the total examined samples. The PCR results revealed that only 8/12 (66.7%) of the suspected isolates encoded the 16S rDNA gene of P. aeruginosa with an incidence of 4% of the total examined samples, 4 (50%) of which were detected in the minced beef meat samples, 2 (25%) in the sausage samples while in the luncheon and burger P. aeruginosa was identified in only 1 sample (12.5%) for each.

In this project, we employed ethanolic (EMI) and aqueous (AMI) extracts of mango (Mangifera indica L., Anacardiaceae) fruit seeds as a modulator of antibiotic resistance against multidrug-resistant (MDR) Pseudomonas aeruginosa and Acinetobacter baumannii to evaluate natural compounds isolated from by-products or waste of edible plants. We also investigated the effect of these extracts alone and in combination with standard classes of antibiotics in the desired strains. M. indica seeds were processed and exploited using ethanol and water. The minimum inhibitory concentrations (MICs) of clinical isolates were examined against EMI and AMI extracts, followed by seven antibiotics of ceftazidime, ciprofloxacin, penicillin, amikacin, meropenem, ampicillin, and colistin. The checkerboard method evaluated the synergistic action between mango kernel extract (EMI) and seven antibiotics. EMI extract significantly revealed antimicrobial properties against MDR A. baumannii and P. aeruginosa with synergistic effects with the applied antibiotics. The considerable antibacterial efficacy of ethanolic extract of M. indica seeds can have great curative value as antibacterial drugs against infections caused by MDR P.aeruginosa and A. baumannii.

The effect of chronic irradiation of Pseudomonas aeruginosa (P. aeruginosa) phytopathogenic strain IMV 9096 and saprophytic strain IMV 8614 at a dose rate of 0.19 µGy/s of γ-radiation in the dose field of 137Cs on the immunomodulatory properties of their lipopolysaccharide (LPS) has been investigated. It was shown that in the wild-type seedlings of Arabidopsis thaliana (A. thaliana) Col-0 pre-treatment with LPS 9096, isolated from both irradiated and non-irradiated bacterial culture, caused an increased harmful effect 2.8 - 5.6 fold when plants were then infected with bacteria of this strain. Seedling damage was more pronounced with the use of LPS, isolated from bacteria exposed to chronic radiation. In seedlings of mutant jin1 with impaired jasmonate signaling pre-treatment of LPS 9096 caused attenuation of the damage at 20 - 45 % when infected with P. aeruginosa 9096. Pre-treatment of Arabidopsis seeds with bacterial LPS 8614, obtained from both irradiated and non-irradiated P. aeruginosa 8614 cultures, had a non-significant effect (± 15 % over control). In mutant plants, jin1 pre-treatment of seeds with LPS 8614 led to increased damage when infected with P. aeruginosa IMV 9096 at 30 - 60 %. It was found that chronic irradiation of bacteria changes the immunomodulatory properties of their LPS and the effect depends on the bacterial strain. This effect is mediated by jasmonate and salicylate signaling systems.

Background: Pseudomonas aeruginosa (P. aeruginosa) is a gram negative bacteria that is known to cause nosocomial infections. Carbapenem is used to treat the damage caused by P. aeruginosa, however it is becoming resistant to carbapenems because of the production of β-lactamases. The objectives of the study were to systematically review the prevalence of blaNDM-1 in carbapenem-resistant Pseudomonas aeruginosa (CRPA) and to review and analyze the clinical sources as well as the antibiotic resistance profile of CRPA carrying blaNDM-1. Methods: The researchers systematically searched PubMed, ScienceDirect, and Google Scholar. Studies that met the inclusion criteria were included in the review. In assessing the methodological quality of the included studies, the JBI Critical Appraisal Checklist for Studies Reporting Prevalence Data and the JBI Critical Appraisal Checklist for Case Reports were used. Results: A total of nine studies were included in which eight were cross-sectional studies and one was a case report. The highest prevalence rate reported was 54.55% in blaNDM-1 positive CRPA isolates among the cross-sectional studies. The three most frequent sources of clinical isolates of CRPA carrying blaNDM-1 include urine, wound discharge, and tissue, among the included studies. Lastly, this review showed that among the included studies, CRPA isolates carrying blaNDM-1 were most resistant to ceftazidime and gentamicin. Conclusions: There is varying prevalence of blaNDM-1 in CRPA in different countries. Urine, wound discharge, and tissue specimens being the most frequent sources of CRPA isolates carrying blaNDM-1 poses a challenge that must be given attention by the infection control committee, thus the need for proper handling and processing of clinical specimens. Resistance to ceftazidime and gentamicin among the CRPA isolates carrying blaNDM-1highlights the growing challenge of successfully treating infections caused by this bacteria. This challenge reminds us of the importance and purpose of antibiotic stewardship that emphasizes the improvement of proper antibiotic prescription by the physicians and proper antibiotic use by the patients that can help in preventing harm and antibiotic resistance. Doi: 10.28991/SciMedJ-2021-0304-9 Full Text: PDF

Introduction: Carbapenems resistance due to metallo-beta-lactamase production in Pseudomonas aeruginosa is a major concern which is increasing globally resulting in limited therapeutic choices. This study aimed to find out the prevalence of Pseudomonas aeruginosa isolates among clinical samples showing growth of a tertiary care centre. Methods: A descriptive cross-sectional study was conducted on various clinical samples which showed growth in the Department of Microbiology of a tertiary care centre between 1 September 2020 to 28 February 2021 after receiving ethical approval from the Institutional Review Committee (Reference number: 03-G/020). Convenience sampling was done. All timely received clinical specimens were inoculated and incubated at 37°C for 48 hours and identified by standard microbiological techniques. Point estimate and 95% Confidence Interval were calculated. Results: Among 1049 clinical samples showing growth, 68 (6.48%) (4.99-7.97, 95% Confidence Interval) Pseudomonas aeruginosa were isolated. Among them, 6 (8.82%) were found to be metallo-beta-lactamase positive. Conclusions: The prevalence of Pseudomonas aeruginosa was similar to the studies done in similar settings. As metallo-beta-lactamase production was detected among isolated species which can be spread very rapidly and may develop a problematic scenario in treatment procedures, regular surveillance along with judicious use of carbapenems should precede.

In this review, we draw attention and discuss the risk factors and causes of the development of oral squamous cell carcinoma (OSCC) focusing on oral microbiota. Recently, a breakthrough in the study of cancer has been the discovery of the relationship between the presence of certain types of bacteria and the development of cancer in the human body. Studies have shown that, Porphyromonas gingivalis (P. gingivalis) bacteria that is responsible for the destructive processes in the oral cavity, could play an important role in the development of OSCC. In our continuing search for bacteria that causes oral squamous cell carcinoma, we came across the Pseudomona aeruginosa, which due to its metabolite properties, may play important role in carcinogenesis of oral cancer. One possible mechanism is the ability of Pseudomonas to synthesize nitric oxide (NO) that modulates different cancer-related appearances such as apoptosis, cell cycle, angiogenesis, invasion, and metastasis. We think that P. aeruginosa increases the concentration of NO by converting salivary nitrite to nitric oxide, and this is how it contributes to NO-related carcinogenesis. Early diagnosis and treatment of periodontitis are very important not only for patients’ oral health, but also for the prevention of OSCC development. Screening test for OSCC based on determination of salivary NO levels could be appealing and may prove to be useful assay for diagnosis and early detection of disease progression in oral cancer.

ABSTRACT Background and Objectives: Pseudomonas aeruginosa is an opportunistic pathogen resistant to various antibiotics. The aim of the present study was to study resistant patterns in clinical isolates of P. aeruginosa, classify them into pandrug resistance (PDR), extensive drug resistance (XDR) and multidrug resistance (MDR) groups, and identify extended-spectrum β-lactamase (ESBL)-positive isolates using the phenotypic and genotypic methods. Methods: This cross-sectional study was conducted on 161 P. aeruginosa isolates collected from the city of Isfahan, Iran. Antibiotic susceptibility tests were performed using 11 antimicrobial agents. ESBL-positive strains were identified using the phenotypic and genotypic methods. Results: The highest level of antibiotic resistance was observed against ceftazidime (77.64%). None of the isolates was resistant to polymyxin B. In the phenotypic method, 64 isolates (39.75%) were found as ESLB-positive, whereas 132 isolates (81.98%) were ESBL-positive in the genotypic method. The number of ESBL-positive isolates in the genotypic method was significantly higher than in the phenotypic method. The frequency of XDR and MDR isolates was 50.93% and 27.32%, respectively. None of the isolates was PDR. The frequency of the blaTEM gene was significantly higher than other genes (P

Abstract Background: Pseudomonas aeruginosa is an opportunistic gram-negative bacterium that is a major cause of nosocomial infections such as severe burns. Curcumin is the main component of turmeric (Curcuma longa) that has anti-cancer and anti-inflammatory effects. The aim of this study was to evaluate antibacterial effect of curcumin in ciprofloxacin resistant isolates of Pseudomonas aeruginosa through mexC and mexD gene expression. Materials and Methods: In this descriptive-analytical study, Pseudomonas aeruginosa strains were obtained from hospitals and laboratories in Guilan province. After disc difusion and MIC tests, four ciprofloxacin resistant strains of Pseudomonas aeruginosa were treated by ciprofloxacin (1/2MIC) only (control sample) and in the combination with curcumin encapsulated in micelle nanoparticles (test sample). After 24h, RNA extraction and cDNA synthesis was performed. Then, the expression of mexC and mexD genes was evaluated quantitatively by Real-time PCR method in curcumin treated and un-treated cells Results: This study showed that combination of ciprofloxacin (1/2 MIC) with curcumin encapsulated in micelle nanoparticles led to approximately 50% of growth inhibition in Pseudomonas aeruginosa. In treated cells with curcumin and ciprofloxacin compared to treated cells with ciprofloxacin alone, mexC and mexD genes were significantly (p0.65 fold in three isolates and >0.1 fold in four isolates, respectively. Conclusion: Our results suggested that curcumin encapsulated in micelle nanoparticles combined with 1/2 MIC value of ciprofloxacin inhibits the growth of Pseudomonas aeruginosa through reducing mexC and mexD expression.

ABSTRACT Background and Objectives: Nowadays, the prevalence of multidrug-resistant pathogens such as Pseudomonas aeruginosa is increasing worldwide. Many studies have been seeking new treatment strategies to treat infections caused by these microorganisms. Silver nanoparticles (AgNPs) along with L-arginine have significant antimicrobial effects and could be used as alternatives for ineffective drugs. Methods: In this study, the antibacterial activity of AgNPs, L-arginine and various concentrations of AgNPs along with L-arginine (12.5 and 25 mg/ml) were investigated against P. aeruginosa PAO1 using the broth macrodilution method. Results: Minimum inhibitory concentration of AgNPs, L-arginine and AgNPs combined with 25 and 12.5 mg/ml L-arginine was 15.6 μg/ml, 25 mg/ml, 1.9 μg/ml and 3.9 μg/ml, respectively. Minimum bactericidal concentration of AgNPs, L-arginine and AgNPs combined with 25 and 12.5 mg/ml L-arginine was 31.2 μg/ml, 50 mg/ml, 3.9 μg/ml and 7.8 μg/ml, respectively. Conclusion: Our study suggests that AgNPs along with L-arginine can be used as an alternative antibacterial agent against P. aeruginosa, and might be useful for treatment of wound infections. Keywords: Nanoparticles, Arginine, Anti-Bacterial Agents, Pseudomonas aeruginosa.

A garantia do fornecimento de uma água de qualidade destinada ao consumo humano é uma questão relevante para a saúde pública, sobretudo quando a água ofertada é dependente de meios alternativos, como os chamados caminhões-pipa. Entretanto, a grande preocupação quanto a esse tipo de transporte de água está relacionada aos diversos riscos de contaminações que podem ocorrer. Assim, o presente estudo teve como objetivo avaliar a qualidade bacteriológica da água para consumo direto (ingestão) comercializada por caminhões-pipa, destinada ao abastecimento da cidade de Caruaru-PE. Foram analisadas 10 amostras, obtidas de cinco caminhões-pipa, por meio da Técnica dos Tubos Múltiplos, para a identificação de Pseudomonas aeruginosa e do grupo coliforme e, da técnica pour plate, para a contagem de bactérias heterotróficas. Os resultados revelaram a presença dos grupos bacterianos testados na maioria das amostras analisadas. Foi verificado que o tempo era um fator que contribuia para o aumento do índice de contaminação. Conclui-se que esse tipo de comércio acaba fornecendo uma água que não atende aos requisitos de potabilidade e com um alto risco de contaminação, sendo imprópria para o consumo humano.

Background: Pseudomonas aeruginosa has recently emerged as one of the main causes of nosocomial infections in the intensive care unit due to vast antibiotic resistance potency. The aim of this study was to investigate the antimicrobial resistance pattern and evaluation of the frequency of beta-lactamase genes in Pseudomonas aeruginosa strains. Methods: Generally, 42 P. aeruginosa strains were collected from different clinical specimens. The phenotypic and genotypic tests such as disc diffusion, Modified Hodge test and molecular detection of blaIMP, blaIMP1, blaVIM2, and blaKPC genes were performed. Results:According to the results, by disk diffusion method 33 (78.58%) to Cefotaxime, 31 (73.8%) of strains were resistant to Ceftriaxone, and 31 (73.8%) to Co-trimoxazole, while the lowest resistance was observed in case of Polymyxin B 3 (7.15%). On the other hand 4 (9.52%) of strains were recognized as MHT positive. Moreover, 26 (61.9%) of isolates were detected as multi drug resistance strains. In addition, 2 (4.7%) of isolates harbored blaIMP, 2 (4.7%) blaIMP1 and 10 (23.8%) blaVIM2 genes, whereas the blaKPC gene was not reported. Conclusion: According to the results, the prevalence of beta-lactamase genes and antibiotic resistance pattern in patients with high levels of hospitalization is essential. Therefore, it is necessary to identify the strains containing β-lactamase genes for better control and treatment.

Background: Pseudomonas aeruginosa ( P. aeruginosa ) and Staphylococcus aureus ( S. aureus ) are well defined as food poisoning pathogens that are highly resistant and need continuous studies., Aim: The purpose of the work was to examine phenotypic and genotypic characteristics of both P. aeruginosa and S. aureus , and treatment trials with medicinal plants., Methods: Samples were examined for isolation of P. aeruginosa and S. aureus on selective media followed by biochemical confirmation, biofilm formation, genes detection , and expression of P. aeruginosa pslA biofilm gene was performed by quantitative real-time polymerase chain reaction after treatment with 0.312 mg/ml Moringa oleifera aqueous extract as a minimum inhibitory concentration., Results: The highest isolation rate of P. aeruginosa was 20% from both raw milk and Kariesh cheese, followed by 16% and 12% from ice cream and processed cheese, respectively, while the highest isolation rate of S. aureus was 36% from raw milk followed by 28% in ice cream and 16% in both Kariesh cheese and processed cheese. 30% of P. aeruginosa isolates were biofilm producers, while only 21% of S. aureus isolates were able to produce biofilm. The P. aeruginosa isolates harbor virulence-associated genes nan1 , exoS , toxA , and pslA at 100%, 80%, 40%, and 40%, respectively. Staphylococcus aureus SEs genes were examined in S. aureus strains, where SEA and SEB genes were detected with 60%, but no isolate harbored SEC , SED , or SEE . The significant fold change of P. aeruginosa pslA expression was 0.40332 after treatment with M. oleifera aqueous extract., Conclusion: Pseudomonas aeruginosa and S. aureus harbor dangerous virulence genes that cause food poisoning, but M. oleifera extract could minimize their action., Competing Interests: The authors declare that there is no conflict of interest.

Background: Dracocephalum kotschyi Boiss. is known as a native medicinal plant of Iran., Objective: In this study, aqueous extract of D. kotschyi was used to synthesize ZnO-NPs. To produce ZnO-NPs, aerial parts of D. kotschyi were powdered and then macerated for obtaining aqueous extract, after that, aqueous extract was used to reduse zinc nitrate to ZnO-NPs., Methods: To confirm nanoparticles synthesis, SEM, TEM, UV-Vis, FTIR, and XRD were used. The synthesized ZnO-NPs were studied for antimicrobial activities by microdilution method for calculating MIC and MBC. Analysis of ZnO-NPs confirmed successful synthesis by extract of D. kotschyi., Results: The sizes of ZnO-NPs were estimated 50-200 nm in diameter. Antibacterial and antifungal experiments showed potent activities against Staphylococos aureus , Pseudomonas aeruginosa and Candida albicans. The results of the studies showed that the nanoparticles synthesized with the aqueous extract of D. kotschyi have a much greater antimicrobial effect than the aqueous extract of D. kotschyi and zinc nanoparticles, each alone (MIC values 3.7 to 7.5 mg/ml)., Conclusion: The noteworthy point is that the inhibitory rate of synthesized zinc oxide nanoparticles is higher compared to broad-spectrum antibiotics, such as chloramphenicol (MIC values 15 mg/ml). Determining the therapeutic and toxic dose of this product for humans requires further investigation and clinical trials., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

AbstractINTRODUCTION:Chamomile ( Chamaemelum nobile ) is widely used throughout the world, and has anti-inflammatory, deodorant, bacteriostatic, antimicrobial, carminative, sedative, antiseptic, anti-catarrhal, and spasmolytic properties. Because of the increasing incidence of drug-resistant bacteria, the development of natural antibacterial sources such as medical herbs for the treatment of infectious diseases is necessary. Extracts from different plant parts such as the leaves, flowers, fruit, and bark of Combretum albiflorum, Laurus nobilis , and Sonchus oleraceus were found to possess anti-quorum sensing (QS) activities. In this study, we evaluated the effect of C. nobile against Pseudomonas aeruginosa biofilm formationMETHODS:The P. aeruginosa samples were isolated from patients with different types of infection, including wound infection, septicemia, and urinary tract infection. The flowers of C. nobile were dried and the extract was removed using a rotary device and then dissolved in dimethyl sulfoxide at pH 7.4. The microdilution method was used to evaluate the minimum inhibitory concentration (MIC) of this extract on P. aeruginosa , and biofilm inhibition was assayed.RESULTS:Eighty percent of the isolated samples (16/20) could form a biofilm, and most of these were isolated from wound infections. The biofilm inhibitory concentration of the C. nobile extract was 6.25-25mg/ml, whereas the MIC was 12.5-50mg/ml.CONCLUSIONS:The anti-QS property of C. nobile may play an important role in its antibacterial activity, thus offering an additional strategy in the fight against bacterial infections. However, molecular investigation is required to explore the exact mechanisms of the antibacterial action and functions of this phytocompound.

In order to develop more potent and novel antibacterial agents, a Schiff base derived from tyrosine and benzaldehyde was prepared along with its Cu(II), Pd(II) and Pt(II) complexes. Formation and purity of the ligand L-1 was determined by 1H NMR and elemental analysis along with other analytical techniques like FTIR, UV-Vis spectroscopies, XRD and TGA/DSC analysis. The chemical structures of the prepared Schiff base-metal complexes were suggested depending upon the results obtained from FTIR, UV-Visible spectroscopy, XRD, 1H NMR, CHN and TGA/DSC analyses. Analytical data revealed that the Schiff base ligand L-1, can coordinate in the bidentate manner with the metal ions via N and O atoms resulting in the formation of Cu(II), Pd(II) and Pt(II) complexes with 1:2 stoichiometry. Thermal analysis results explained the general decomposition pattern of the prepared compounds and the presence of water molecule in the prepared ligand and its complexes. The crystalline nature of the compounds was confirmed by the powder XRD analysis except for the platinum complex, which was amorphous. The in vitro antibacterial activity of the uncomplexed ligand L-1 and its complexes (Cu(II), Pd(II) and Pt(II)) was also evaluated against gram positive bacterium, Bacillus subtilis and gram negative bacterium, Pseudomonas aeruginosa by the well-diffusion method. Antibacterial activity of the prepared Schiff base ligand L-1 and its complexes was determined in terms of inhibition zones. [ABSTRACT FROM AUTHOR]

Background: These days, the antibiotic resistance of Pseudomonas aeruginosa isolates to imipenem has significantly increased. Therefore the study of resistance to imipenem in this organism to imipenem in determining the appropriate treatment is crucial and necessary. The goal of this study is to compare three phenotypic methods of E-test, disk diffusion and micro broth dilution in the study of resistance to imipenem in clinical isolates of P. aeruginosa. Methods: Within a 6-month interval, 120 clinical specimens were collected and evaluated. All isolates were identified as P. aeruginosa by standard biochemical tests and amplification of 16S rRNA gene. Three phenotypic methods of E-test, disk diffusion, and micro broth dilution were used to determine imipenem resistance in P. aeruginosa isolates. Results: Of the 96 P. aeruginosa isolates studied for their resistance to imipenem by the use of E-test, disk diffusion and micro broth dilution methods, 38.5% of the strains in micro broth dilution method and 33.3% in the two methods of E-test and disk diffusion were resistant to imipenem. The rate of sensitivity and specificity of disk diffusion and E-test methods were 100%, 90.1%, and they were 100% and 83.1% for micro broth dilution, respectively. Conclusion: With regard to the results obtained from the comparison of the three methods 100% agreement were observed among the antimicrobial susceptibility results obtained by the E-test and disk diffusion methods (P ≥ 0.05). Therefore, the use of disk diffusion method can be an appropriate replacement for E-test method with regard to its being easy and cost-effective.

Aims: To develop a method for rapid detection of bacteria via bacteriophage amplification coupled with exogenous fluorochromic stains. Methods and Results: A method for the rapid detection of bacteria was developed which consisted of exposing the sample suspected to contain target cells to host-specific phage. After at least one infection cycle, bacteria known to be infected by the phage (helper cells) were added and the number of nascent phage particles was estimated using the Live/Dead BacLight Bacterial Viability kit. Using Pseudomonas aeruginosa, it was shown that the dead helper cell population following phage infection was proportional to the initial number of target cells present in the original sample. Approximately 1 × 101 CFU per ml of P. aeruginosa could be detected within 4 h without the need for enrichment. Conclusions: The phage lytic amplification assay coupled with exogenous fluorochromic stains was able to detect approx. 1 × 101 CFU per ml of the target bacterium within 4 h. Significance and Impact of the Study: A method to detect low number of bacterial cells in a sample within 4 h without the need for enrichment was developed. [ABSTRACT FROM AUTHOR]

Provides information on a medical case of a severe Pseudomonas aeruginosa infection in a healthy infant where ecthyma gangrenosum was helpful for diagnosis. Therapeutic applications of oral antibiotics and dopamine; Findings of otoscopic examination and physical examination; Purpose of urine and stool cultures.

Pseudomonas aeruginosaisolates (n = 183), collected from bacteraemic patients hospitalised in São Paulo Hospital (Brazil) during 2000–2001, were screened for susceptibility to antimicrobial agents. The polymyxins were the most active compounds (100% susceptibility), followed by amikacin and cefepime (59.0%), meropenem (57.4%), and imipenem and gentamicin (55.2%). Imipenem-resistant isolates were ribotyped and screened for production of metallo-β-lactamases (MBLs) by PCR with primers forblaIMP,blaVIM andblaSPM. MBL production was detected in 36 isolates (19.7% of the entire collection; 43.9% of the imipenem-resistant isolates) and the MBLs included SPM-1-like (55.6%), VIM-2-like (30.6%) and IMP-1-like (8.3%) enzymes. [ABSTRACT FROM AUTHOR]

SummaryPseudomonas aeruginosa can cause ulcerative bacterial keratitis. A feature of keratitis is the rapid infiltration of the avascular corneal stroma by neutrophils. KC is a potent neutrophil chemokine. The present study used a mouse model of ocular infection to assess the relationship between KC and inflammation in the cornea in response to challenge with a strain of P. aeruginosa causing keratitis. Low levels of KC mRNA and protein were detected by in situ hybridization and ELISA, respectively, in unchallenged corneas. Dramatically increased numbers of KC mRNA+ cells were present in P. aeruginosa strain 6294-challenged corneas. Expression of KC mRNA was found to be up-regulated in the corneal epithelium in response to wounding alone. The KC mRNA+ cells were located in the epithelium and corresponding to infiltrating neutrophils cells in the stroma. Quantification of KC protein at different time points showed peak levels at 8 h of bacterial challenge. These results suggest that KC may be involved with the regulation of leucocyte infiltration early during bacterial keratitis. [ABSTRACT FROM AUTHOR]

This paper examines the histology of rat lungs following intestinal immunization with killed mucoid Pseudom onus aeruginosa and subsequent pulmonary challenge with live P. aeruginosaa The lungs of non-immune challenged rats developed a confluent haemorrhagic pneumonitis with degeneration and sloughing of the mucosa of the airways; perivascular infiltration with mononuclear cells was apparent 1-2 h post-challenge; some neutrophils were present by 2 h post-challenge; by 12 h post-challenge oedema and intra-alveolar haemorrhage were prominent and Gram-negative organisms were seen in large quantities. In contrast, immunized challenged animals showed a pronounced neutrophilic response 1-2 h post-challenge; by 12 h post-challenge patchy abscesses were apparent with resolving inflammation and no organisms visible. The findings suggest that intestinal immunization prevents the development of fatal P. aeruginosa infections in the lung by accelerating the recruitment of polymorphonuclear neutrophils. [ABSTRACT FROM AUTHOR]

The aliphatic amidase (acylamide amidohydrolase; EC 3.5.1.4) from Pseudomonas aeruginosa is a hexameric enzyme composed of six identical subunits with a molecular weight of ∼38 kDa. Since microbial amidases are very important enzymes in industrial biocatalysis, the structural characterization of this enzyme will help in the design of novel catalytic activities of commercial interest. The present study reports the successful crystallization of the wild-type amidase from P. aeruginosa. Native crystals were obtained and a complete data set was collected at 1.4 Å resolution, although the crystals showed diffraction to 1.25 Å resolution. The crystals were found to belong to space group P6322, with unit-cell parameters a = b = 102.60, c = 151.71 Å, and contain one molecule in the asymmetric unit. [ABSTRACT FROM AUTHOR]

Introduction: Nowadays, the co-infection of different classes of pathogens is a major concern. The objective of this study was to develop a successful therapy for keratitis caused by the co-infection of Candida sp. with Pseudomonas sp, which is difficult to cure. The study is based on a 47 years old male farmer showing redness and watering in the right eye for 15-days. ; Methods: The microbiological examination was performed to isolate the causative organisms, i.e. Pseudomonas aeruginosa and Candida albicans. They were cultured separately along with their co-culture and treated with ciprofloxacin and amphotericin B during the growing stage to predict a definite cure. ; Results: Scanning electron microscope (SEM) results confirmed the inter-specific interaction between the two different types of microorganisms. Amphotericin-B and Ciprofloxacin showed the least MIC value for both organisms in co-culture. ; Conclusion: Treatment with Amphotericin-B and 5% ciprofloxacin effectively hindered the growth of Pseudomonas aeruginosa and Candida albicans, the co-infection of which caused keratitis. This therapy may be successfully implied for such cases of co-infection in the future., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Pubic osteomyelitis is a rare disease usually results from various gynecologic and urologic surgeries. We present a-78 year old-woman admitted to the Infectious Department of Imam Khomeini Hospital in June 2014 with pubic osteomyelitis caused by pseudomonas aeruginosa followed by hysterectomy., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)

The objective of this study was to investigate the effects of P. aeruginosa PAO1 cellular and soluble culture fractions on human mesenchymal stem cells (MSCs) death signaling pathways and cytokine profile. The bone marrow isolated MSCs, incubated for different periods of time with one of the three P. aeruginosa PAO1 culture fractions, i.e. low density whole cultures, heat inactivated bacterial cultures sediments and sterile supernatants, were submitted to the following assays: i) fluorescence microscopy evaluation of cellular morphology and viability; ii) bax, caspase 9, relA and bcl-2 genes expression analysis by qRT-PCR; and iii) quantification of the level of IL-1β, IL-6, IL-8 and IL-10 cytokines released in the MSCs supernatants determined by ELISA. Results were statistically analyzed using the GraphPad In Stat software. The PAO1 whole cultures exhibited the most relevant influences, impacting on MSCs morphology and viability, interfering with apoptotic pathways and significantly stimulating the production of IL-1β and IL-10, while decreasing the production of IL-6 and IL-8. The culture supernatants increased the production of IL-1β and reduced the secretion of all other tested cytokines, while heat-inactivated bacterial cells significantly stimulated both IL-1β and IL-10 production. These data could suggest that in vivo, the fate of P. aeruginosa infection depends on the proportion between different bacterial culture fractions (i.e. the number of viable bacterial cells, the number of dead cells and the amount of bacterial soluble products accumulated locally) that could be influenced by the initial infective dose, by the host defense mechanisms, and also by the administered antimicrobial treatment that may thus interfere with the evolution and magnitude of the induced lesions., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)