Dissemination of Pseudomonas aeruginosa Producing blaIMP1, blaVIM2, blaSIM1, blaSPM1 in Shiraz, Iran

Abstract

Background: Metallo-β-lactamase (MBL) producing Pseudomonas aeruginosa is responsible for many important nosocomial outbreaks including pneumonia and septicemia. Various studies have reported the separation of P. aeruginosa producing MBLs enzymes resulted in increases in multiple traditional antibiotics resistance including carbapenems, cephalosporins and penicillins. Objectives: In this study, based on the standard phenotypic and genotypic methods, we examined the MBLs possible production of a P. aeruginosa isolate. The main objective was exploring the dissemination of resistant MBL P. aeruginosa in south-west of Iran, Shiraz. Materials and Methods: During a six-month period-from October 2011 to March 2012-240 P. aeruginosa isolates, collected from four teaching hospitals in Shiraz located in southwest of Iran, were examined. The isolates were mainly collected from wound, urine, and sputum. Minimum inhibitory concentration (MIC) ≥4 µg/mL to imipenem was determined by micro-dilution broth. Identification of P. aeruginosa with MBL was detected using double disk synergy test (DDST) and polymerase chain reaction (PCR) using specific primers for blaIMP1, blaVIM2, blaSIM1, blaSPM1. All laboratory procedures was according to clinical and laboratory standards institute (CLSI) recommendations. Results: From 240 P. aeruginosa isolates, 82 (34.16%) isolates were imipenem-resistant (minimum inhibitory concentration (MIC) ≥4 µg/ mL). Among these imipenem-resistant isolates, 19 (23.3%) MBL-producing P. aeruginosa isolates were screened using DDST. A specific PCR test confirmed the presence of 18 (21.95%) P. aeruginosa producing blaIMP1 and blaVIM2. Conclusions: Beside our study, the detection of MBL genes were reported in a few studies conducted in Iran. The spread of detected MBLs producing P. aeruginosa were unprecedented in the region due to the lack of independent related researches or the novel incidence of these genes. This detection must be noted by associated clinical and health care services.

Metallo-beta-Lactamase VIM-1, SPM-1, and IMP-1 Genes Among Clinical Pseudomonas aeruginosa Species Isolated in Zahedan, Iran

“…The results of the above mentioned researches are nearly consistent with those of the present study indicating that VIM-1 is the predominant MBL in Iran. Another research showed that 34 out of 111 (43%) species isolated carried VIM gene ( 6 , 26 ) and their results are not consistent with those of the current study. It can be said that the prevalence of MBL in the species isolated from that hospital was more than expected.…”

“…Metallo-beta-lactamase-generative P. aeruginosa species were reported for the first time in Japan in 1991. However, these species are reported worldwide as well as Iran, in which isolation of multidrug-resistant P. aeruginosa species has reached a critical point ( 6 ). Metallo-beta-lactamases (MBLs) such as VIM, IMP, and SPM, which belong to group B of Ambler classification, cause hydrolysis of a variety of beta lactams except monobactam (aztreonam) ( 7 ).…”

Detection and Genetic Characterization of Metallo-β-Lactamase IMP-1 and VIM-2 in Pseudomonas aeruginosa Strains From Different Hospitals in Kermanshah, Iran

“…In another study, from 240 P. aeruginosa isolates, 34.16% were imipenem-resistant, and 23.3% were screened as MBL-positive strains using the double-disk synergy test. Additionally, a specific polymerase chain reaction (PCR) test confirmed the presence of 8 (9.75%) and 10 (12.19%) IMP-1 and VIM-2 types, respectively ( 18 ).…”

Detection of blaSPM-1 Metallo-β-Lactamase Gene in Imipenem-Resistant Pseudomonas aeruginosa Strains Isolated From Hospitalized Patients in Isfahan Hospitals

“…These enzymes were categorized to three subgroups including 3a, 3b and 3c enzymes. Enzymes of the 3a subgroup were distinguished from the other two by their broad-spectrum activity; 3b enzymes revealed special avidity to carbapenems; and 3c enzymes were associated with poor hydrolyzing activity (8)(9)(10). Chelators such as EDTA in vitro and other chelators (e.g.…”

“…Metallo-β-lactamase-producing P. aeruginosa isolates were first reported in Japan in 1991, and since then have been detected in various countries (9). In addition to the detection of VIM in Verona, Italy and SPM MBL in Sao Paolo, Brazil, other MBLs have been identified (10,11). The production of MBLs is important because several outbreaks caused by MBL-producing strains have been reported (12).…”