Prevalence of SHV, TEM, CTX-M and OXA-48 β-Lactamase Genes in Clinical Isolates of Pseudomonas aeruginosa in Bandar-Abbas, Iran

Abstract

Background Pseudomonas aeruginosa is an aerobic gram-negative bacillus that is the cause of a range of opportunistic infections in humans. P. aeruginosa is one of the most important pathogenic bacteria in the development of nosocomial infections such as pneumonia associated with intensive care unit (ICU) ventilator, bacteremia, urinary tract infections, and infection in people with severe and septic burns (1, 2). Infections caused by P. aeruginosa are often severe and lifethreatening. P. aeruginosa infection is difficult to control and eliminate because it has intrinsic resistance to many antimicrobial agents (3). The rapid increase of extendedspectrum beta-lactamase (ESBL)-producing isolates of P. aeruginosa is a health risk. Many isolates of P. aeruginosa are susceptible to cephalosporins and carbapenems; however, this bacterium has acquired resistance to these antibiotics. P. aeruginosa resistance mechanisms include ß-lactamase production, efflux pumps and changes in outer membrane proteins. Multi-drug resistant (MDR) strain of P. aeruginosa is able to produce a wide range of beta-lactamase enzymes. According to Ambler classification, beta-lactamases are divided into four groups based on their structures (A-D). P. aeruginosa resistance to cephalosporins, monobactam and carbapenems may be acquired by ESBL enzymes (4,5). The prevalence of resistance to carbapenems among P. aeruginosa isolates is a common challenge facing the successful treatment of the life-threatening and permanent infections due to this bacterium (6,7). Proper and up-to-date information about the antibiotic resistance of clinical isolates of P. aeruginosa is essential for the treatment of the infections caused by these strains. The aim of this study was to investigate the presence of bla SHV , bla TEM , bla CTX-M and bla OXA-48 beta-lactamase genes in the clinical isolates of P. aeruginosa in Bandar Abbas, Iran. Materials and Methods In this descriptive study, 96 P. aeruginosa strains isolated from wound patients hospitalized in Bandar Abbas Hospital from May to December 2017 were studied. Identification of these isolates was confirmed using Gram staining and biochemical tests including catalase and oxidase tests, fermentation in oxidation-fermentation

Detection of extended spectrum beta-lactamase genes in Pseudomonas aeruginosa isolated from patients in rural Eastern Cape Province, South Africa

“…Several researchers have reported on the concurrence of different β-lactamase genes found in the same strains 38 , 39 . The most common ESBL combination in this study was a combination of bla TEM + bla SHV (40.5%) contrary to Chen et al 31 , who reported the commonest to be bla SHV + bla CTX-M .…”

Prevalence, Antimicrobial Resistance, and Molecular Description of Pseudomonas aeruginosa Isolated from Meat and Meat Products

“…In another Iranian survey, Bahrami et al [47] described that blaCTX-M, blaSHV, blaTEM, and blaOXA were the most frequent antibiotic resistance genes detected in 23.95%, 23.08%, 57.29%, and 12.5% of P. aeruginosa strains, respectively. A survey on camel meat [48] showed that the total distribution of ESBL-producing P. aeruginosa was 45%, and blaCTX-M (38.00%), blaSHV (33.30%), and blaTEM (28.50%) were the most commonly detected antibiotic resistance genes. Extended-spectrum b-lactamases are encoded by bla plasmid-mediated genes, particularly blaCTX-M, blaSHV, blaTEM, blaVEB, and blaOXA, which have extended the substratum specificity toward cefotaxime, ceftazidime, and ceftriaxone [49].…”

Insights into Carbapenem Resistance in Vibrio Species: Current Status and Future Perspectives

“…Carbapenems are characterized by the distinctive carbapenem structure (see red structure in Figure 1 ) that comprises the β-lactam ring. This unique combination in their molecular structure makes this group of antibiotics exceptionally stable when confronted by β-lactamases [ 36 ], mediated by either the TEM, SHV, CTX, or OXA genes [ 37 ]. Due to the steric hindrance conferred by the 6-α-1R-hydroxyethyl moiety (see blue structure in Figure 1 ) at the β-lactamase binding site [ 38 , 39 ], carbapenems are significantly more stable and more effective than other β-lactams such as penicillin and cephalosporins [ 40 , 41 ].…”