Detection of ESBLs and MDR in pseudomonas aeruginosa in a tertiary-care teaching hospital

Background: Pseudomonas aeruginosa is characterized as an important nosocomial pathogen with increasing antimicrobial resistance. The multidrug-resistant (MDR) phenotype in P. aeruginosa is increasing worldwide. The purpose of this study was to evaluate the prevalence of antibiotic susceptibility, ESBLs (Extended spectrum beta lactamases) producing and multidrug resistant (MDR) P. aeruginosa, isolated from clinical specimens of patients and environment of hospital. Patients and methods: This descriptive study was carried out on 76 isolates of P. aeruginosa from a 500-bed tertiarycare general teaching hospital in Kashan, Iran in 2010. Susceptibility testing according to the CLSI (Clinical Laboratory Standards Institute) recommended to eight antipseudomonal agents was performed. ESBLs producing strains were confirmed by double disk diffusion method. Multidrug-resistant isolates were defined as those resistant to three or more classes of antipseudomonal agents. Results: The highest resistance rates from the isolated P. aeruginosa were shown against piperacillin, imipenem, cefotaxime, ceftriaxone, gentamicin, ceftazidime, aztreonam, and ciprofloxacin, respectively. Seven isolates (9.2) were ESBL producers. More than 30 of the isolates were resistant to at least three classes of antibiotics, and 13 of MDR strains were resistant to all eight tested classes of antimicrobials. Among the total isolates, 6.6 were susceptible to all studied agents, and 9.2 were resistant to a single agent. The isolated bacteria from the tracheal samples showed the highest MDR rate. Conclusion: Prevalence of P. aeruginosa producing ESBL and MDR strains from our clinical samples and environment is still low. © 2011 IDTMRC, Infectious Diseases and Tropical Medicine Research Center

Detection of GES-2, a class a Beta-lactamase produced by pseudomonas aeruginosa in a teaching hospital in Iran

Background: Guiana Extended-Spectrum (GES-2) as one of the Extended-spectrum β-lactamases (ESBLs), produced by Pseudomonas aeruginosa, is able to compromise the efectiveness of imipenem and tends to be geographically limited. Objectives: The aim of this study was to detect the spread of GES-2 β-lactamase gene among ESBL- producing P. aeruginosa isolates in a teaching hospital in Kashan, Iran. Materials and Methods: Detection of β-lactamase gene blaGES-2 in eight ESBL producing isolates of P. aeruginosa collected from 100 clinical and environmental specimens was performed by PCR method. The susceptibility of the isolates to eight antibacterial agents was determined by disk diffusion method. ESBL production of the isolates was detected by double disk synergy test. DNA sequencing and aligning with the reference sequence were performed using BLAST and CLUSTAL W for selected PCR products of the blaGES-2 gene. Results: A total of 100 environmental and clinical isolates of P. aeruginosa were collected. Eight of the isolates were found to be ESBL positive. The highest resistance rate was detected for piperacillin (75), while the lowest resistance rate was for ciprofoxacin (12.5). Fifty percent of the isolates (four out of eight) were imipenem-susceptible and MDR. The blaGES-2 gene was detected in all ESBL-producing isolates. Sequencing of both forward and reverse strands of the blaGES-2 gene were identified by BLASTn search as the ATP-binding cassette (ABC) transporter permease, partial cds, clone G-1 P. aeruginosa (Accession no. AB591379.1). Conclusions: According to the present data, this is the frst report on the presence of blaGES-2 gene of ESBL-producing P. aeruginosa from teaching hospitals of Iran. Fifty percent of the blaGES-2 positive P. aeruginosa isolates were multi-drug resistance (MDR). © 2013, Ahvaz Jundishapur University of Medical Sciences

Detection and characterization of multidrug resistance and extended-spectrum-beta-lactamase-producing (ESBL s) pseudomonas aeruginosa isolates in teaching hospital

Pseudomonas aeruginosa is the most common pathogen causing nosocomial infections. The objective of this study was to investigate the extended-spectrum-beta-lactamase (ESBLs) producing and multidrug resistance of hospital isolates of P. aeruginosa and to determine the presence of several resistance genes. A total of 86 isolates of P. aeruginosa were collected from teaching hospital in Kashan, Iran. Susceptibility to eight antimicrobial agents was performed by disk diffusion method. ESBL-phenotypic detection was carried out by double-disk synergy test; and the presence of the genes encoding of bla(TEM), bla(SHV), bla(CTX-M), bla(OXA) and bla(GES)-like genes was studied by polymerase chain reaction. The prevalence of ESBLs was 8.1. The presence of genes encoding ESBLs was confirmed in seven isolates, comprising seven bla(GES-2), one bla(SHV-1), one bla(SHV-5) and one bla(CTX-M-1) genes. P. aeruginosa demonstrated the highest resistance rate to piperacillin (38.4), 67.5 of isolates were sensitive to imipenem whereas 32.5 were MDR (resistant to three or more classes of antibiotics). A multidrug-resistant (MDR) phenotype occurred frequently in P. aeruginosa. bla(GES-2), which compromises the efficacy of imipenem detected in all of seven ESBLproducing P. aeruginosa strains. Proper infection control practices and barriers are essential to prevent spreading and outbreaks of ESBL-producing and MDR P. aeruginosa in our teaching hospital. © 2011 Academic Journals

Frequency of extended-spectrum beta-lactamase (ESBL) multidrug-resistance produced by Pseudomonas aeruginosa isolated from clinical and environmental specimens in Kashan Shahid Beheshti hospital during 2010-11

Background: Pseudomonas aeruginosa is among the most important nosocomial bacterial infections with innate resistance to many antibiotics. This study was designed to evaluate the frequency of extended-spectrum beta-lactamase (ESBL) multidrug-resistance produced by P. aeruginosa isolated from clinical and environmental specimens in Kashan Shahid Beheshti hospital. Materials and Methods: This descriptive study was conducted on clinical isolates (n=76) of P. aeruginosa from Kashan Shahid Beheshti hospital during 2010-11. Antibiotic susceptibility testing for eight antimicrobial agents was carried out according to the clinical and laboratory standards institute (CLSI) guidelines and ESBL-producing strains were confirmed using double-disk diffusion test. MDR-isolates were defined as those resistant to three or more classes of antibiotics. Results: Among all P. aeruginosa isolates, the highest resistance was seen for piperacillin, imipenem, cefotaxime, ceftriaxone, gentamicin, ceftazidime, aztreonam and ciprofloxacin, respectively. Seven strains (9.2) were ESBL-positive. Twenty-seven percent of the isolates were resistant to at least three classes of antibiotics 8 out of 14 tracheal discharges 4 out of 9 wound and 2 out of 3 blood samples were MDR. Conclusion: The study emphasizes the high frequency of MDR-P. aeruginosa in clinical and environmental specimens isolated from this hospital. Imipenem resistance in MDR-P. aeruginosa isolates is also high in this study. This calls for strict infection control measures to prevent further microbial spread