Frequency of PER, VEB, SHV, TEM and CTX-M Genes in Resistant Strains of Pseudomonas aeruginosa Producing Extended Spectrum β-Lactamases

Abstract

Background:Pseudomonas aeruginosa is the most common pathogen causing nosocomial infections. Resistance of P. aeruginosa strains to broad-spectrum cephalosporins may be mediated by extended-spectrum β-lactamases (ESBLs).Objectives:We intended to investigate the prevalence of ESBLs and antimicrobial susceptibilities of P. aeruginosa isolated from patients in Zahedan, Iran.Materials and Methods:In this cross-sectional study, during 2012–2013, 116 P. aeruginosa isolates were collected from a teaching hospital in Zahedan, Iran. Susceptibility to eight antimicrobial agents was carried out by disk diffusion method. The ESBL producing strains were detected by combination disk test (CDT). ESBL positive isolates as well as other isolates showing minimum inhibitory concentrations (MICs) ≥ 4 μg/mL for ceftazidime, cefotaxime, ceftriaxone and aztreonam, were screened for the presence of the genes encoding blaTEM, blaSHV, blaPER-1 and blaVEB-1, by polymerase chain reaction (PCR).Results:Ciprofloxacin and piperacillin were the most efficient antipseudomonal agents. The results disclosed that 19 (16.37%) of the isolates were multidrug resistant and 8 (6.89%) were ESBL-positive. Of the 116 isolates, 30 (25.86%) were resistant to at least one of the antibiotics ceftazidime, ceftriaxone, cefotaxime or aztreonam and among these 30 (100%), 4 (13.3%), 2 (6.6%) and 2 (6.6%), amplified blaTEM, blaVEB-1, blaPER-1 and blaSHV, respectively. From the 30 TEM-positive isolates, 22 were ESBL-negative. Sequencing of the ESBL genes verified the accuracy of the PCR products.Conclusions:According to our results, blaTEM-116 was the most frequent isolated ESBL gene among the P. aeruginosa strains isolated from patients.

Molecular Detection and Sequencing of SHV Gene Encoding for Extended-Spectrum Β-Lactamases Produced by Multidrug Resistance Some of the Gram-Negative Bacteria

“…This result was similar to those observed by Toupkanlou, et al, [34] who reported the prevalence rate is 36%. In contrast to our study, a study by Ghaima and Abdulhassan [35] detection the prevalence of ESBL-SHV gene in P. aeruginosa was 52.3%, Bahmani and Ramazanzadeh [36] detected that the prevalence of ESBL-SHV gene in P. aeruginosa was 10.57% and in a study by Bokaeian et al, [37] blaSHV was 6.6%, and Chika and Agbakoba [38] was 43.5%.…”

Application of six multiplex PCR's among 200 clinical isolates of Pseudomonas aeruginosa for the detection of 20 drug resistance encoding genes

“…We designed primers for the selected genes found to be most prevalent among clinical studies as well as our own observation from NGS based study and other reports [12–21]. Multiplex PCR Primer designed against drug resistance gene include Group‐1; (ESBL‐MBL) blaTem, blaOXA, blaCTX‐M‐15, blaVim) Group‐2, (blaGes, blaVeb and DIM and AmpC) Efflux pump genes‐ Group‐3 (MexA,B‐oprM); Group‐4 (MexC,D‐oprJ); Group‐5 (Mex X,Y‐oprN) Group‐6 (oprD, nfxB, MexR) primers were purchased from Eurofins Genomics India Pvt Ltd, Bangalore, India.…”

Distribution of Ambler Class A Β-lactamase Genes and Evaluation of Resistance Patterns in Multi-Drug and Extensively-Drug Resistant P. aeruginosa Clinical Isolates

“…In our study, 80% of the XDR strains were isolated from tracheal specimens, 5/ Enayatzadeh and colleagues found a significant, positive association between presence of the β-lactamase genes, especially the bla TEM-1 and bla SHV-1 and resistance to β-lactam antibiotics, which signifies the need for new treatment strategies. methods such as PCR have been suggested to be more sensitive (34). Furthermore, we detected significant associations between presence of the βlactamase genes and resistance to β-lactam antibiotics.…”