title: Detection of Ambler class A, B and D ß-lactamases among Pseudomonas aeruginosa and Acinetobacter baumannii clinical isolates from burn patients.
abstract: In this study, we evaluated the existence of classes A, B and D ß-lactamases among Pseudomonas aeruginosa (P.aeruginosa) and Acinetobacter baumannii (A.baumannii) strains isolated from burn patients in Tehran during the years 2012 and 2013. From these strains, the frequency of MBL (metallo-beta-lactamase) and ESBL (extended-spectrum beta-lactamase) producers were evaluated using CDDT (Combined Disk Diffusion Tests). The prevalence of some related genes, including blaIMP, blaVIM, blaSPM, blaKPC, blaGIM, blaDIM, blaBIC, blaOXA-48, blaCTX-M-15 and blaNDM genes, was evaluated using PCR and sequencing methods. Of the 75 non-fermenter isolates, 47 P.aeruginosa and 28 A.baumannii were isolated and identified. A high rate of resistance to common antibiotics was detected among A.baumannii isolates in particular, showing 100% resistance to 9 tested antibiotics. CDDT showed that 21 (28%) and 25 (34.25%) of the non-fermenter isolates were ESBL and MBL producers respectively. The prevalence of blaCTX-M-15 and blaIMP genes among the 75 non-fermenter isolates was 7 (9.3%) and 1 (1.3%), respectively. Fortunately, no other genes were detected in either of the non-fermenters. The mortality rate due to MBL-producing isolates was 5 (20%). This study showed specific resistance genes exist among some MBL and ESBL gram-negative non-fermenters which were isolated from burn patients in Tehran.
authors.affiliation: Microbiology Department, Medical school, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: M
authors.initials: M
authors.lastname: Hakemi Vala
authors.affiliation: Microbiology Department, Medical school, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: M
authors.initials: M
authors.lastname: Hallajzadeh
authors.affiliation: Microbiology Department, Medical school, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: A
authors.initials: A
authors.lastname: Hashemi
authors.affiliation: Microbiology Department, Medical school, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: H
authors.initials: H
authors.lastname: Goudarzi
authors.affiliation: Department of Microbiology, Islamic Azad University, North Tehran Branch,Tehran, Iran.
authors.forename: M
authors.initials: M
authors.lastname: Tarhani
authors.affiliation: Shahid Motahari burn hospital, Tehran, Iran.
authors.forename: M
authors.initials: M
authors.lastname: Sattarzadeh Tabrizi
authors.affiliation: Shahid Motahari burn hospital, Tehran, Iran.
authors.forename: F
authors.initials: F
authors.lastname: Bazmi
keywords: Acinetobacter baumannii; BLSE; MBL; Pseudomonas aeruginosa; patients brûlés