Prevalence of Metallo-β-lactamases Encoding Genes Among Pseudomonas aeruginosa Strains Isolated From the Bedridden Patients in the Intensive Care Units

Abstract

Background:Pseudomonas aeruginosa is one of the most important agents causing nosocomial infections worldwide. Multidrug resistance of isolated bacteria from nosocomial infections makes it difficult and sometimes impossible to treat. Objectives: The aim of the present study was to investigate the antibiotic resistance and association between blaIMP and blaVIM genes with resistance to meropenem and imipenem among P. aeruginosa strains isolated from Iranian patients in ICU wards of Hamadan, IR Iran. Patients and Methods:In this cross-sectional study, 100 P. aeruginosa strains were isolated from bedridden patients in ICU wards of three university hospitals during five months in 2012. Isolates were confirmed at species level using biochemical tests. Their susceptibility to 18 antibiotics was assessed using Kirby-Bauer disc diffusion method. The minimum inhibitory concentration (MIC) was determined by E-test method. Single PCR was used for detecting blaVIM, and blaIMP genes. Results: The highest resistance rates of the isolates to ampicillin/sulbactam, tigecycline, and cefotaxime were 95%, 76%, and 67%, respectively. The lowest resistance rates were observed by colistin sulfate (96%), piperacillin/tazobactam (81%), amikacin (77%), aztreonam (77%), meropenem (76%), imipenem (76%), cefepime (76%), piperacillin (74%), ceftazidime (74%), gentamycin (72%), tobramycin (73%), and levofloxacin (70%) . E-test illustrated that 24% of the isolates were resistant to imipenem (MIC: 32 µg/mL). In contrary to blaVIM gene that was not detected in any isolate, blaIMP gene was detected in 4% of the isolates. No statistically significant association was observed between resistance rates to imipenem and meropenem with aforementioned genes. Conclusions: Prevalence of P. aeruginosa strains drug resistance in our areas was very high and alerting, but the other antibiotics were effective enough to be used in treatment of the infection. Overall, low resistance rate in this region was probably resulted from low prevalence of metallo-β-lactamases producing strains. Permanent monitoring of changes in P. aeruginosa resistance would help to determine national priorities for local intervention efforts.

Phenotypic and Molecular Detection of IMP and SPM Metallo-Beta-Lactamases in Clinical Isolates of Carbapenem Resistant Pseudomonas aeruginosa

“…However, not only the sputum isolates of this study were resistant to all antibiotics tested, but also 11 (42.3%) of them were detected as MDR. On the other hand, our clinical isolates had a relatively low resistance rate (< 40%) against all antibiotics tested, except gentamicin, as well as other Iranian studies (3,16). However, the studies conducted by Radan et al in 2016, and Mirsalehian et al in 2017, reported the higher antibiotic resistance rate (5,13), may be due to the type of samples, as all isolates collected from burn sections.…”

Pseudomonas aeruginosa-producing Metallo-β-lactamases (VIM, IMP, SME, and AIM) in the Clinical Isolates of Intensive Care Units, a University Hospital in Isfahan, Iran

“…Nosocomial outbreaks caused by MBL-producing P. aeruginosa have been reported in different hospital units of our country such as many countries worldwide. [ 10 11 ] Carbapenemases that hydrolyze carbapenems and make them inactive have been progressively reported in Asia and Europe, Canada, and the United States. [ 12 ]…”

Retrospective Study on the Prevalence and Antibiotic Resistance Pattern of Staphylococcus Aureus and Staphylococcus Epidermidis Among Patients Suspicious of Bacteremia During 2006 - 2011

“…As prevalence of infectious diseases have been decreasing during last decades (13), but the drug resistance became an important issue regarding the treatment of such diseases (7,8,14,15). Drug resistance in Staphylococcus spp.…”