Prevalence of OXA-Type β-Lactamases AmongAcinetobacter baumanniiIsolates from Northwest of Iran

Abstract

Carbapenems have been considered as last line antibiotics for treatment of multidrug-resistant (MDR) Acinetobacter baumannii but carbapenem resistant A. baumannii has been increased during the last decade in many parts of the world. OXA-type β-lactamase enzymes are the most common cause of carbapenem resistance in A. baumannii and presence of ISAba1 in upstream of these genes may increase the expression of these OXA genes. The aim of this study was to determine, for the first time, the antibiotic resistance pattern and prevalence of OXA type β-lactamases among nosocomial A. baumannii isolates from northwest of Iran. A total of 100 A. baumannii isolates were recovered from hospitalized patients in a university hospital in northwest of Iran. Sixty-two percent of isolates were resistant to imipenem. All isolates carried bla(OXA-51)-like gene. Among imipenem resistant isolates, 88.7% carried bla(OXA-23)-like, 1.6% carried bla(OXA-40)-like, and 3.2% had bla(OXA-58)-like resistance genes. Ninety percent of isolates contained ISAba1 element and in 74.2% of imipenem resistant isolates, ISAba1 was located in upstream of bla(OXA-23)-like. The results of this study demonstrated high prevalence of OXA-type carbapenemase among MDR A. bumanii in the Northwest of Iran.

Antimicrobial Resistance Patterns and Prevalence of blaPER-1 and blaVEB-1 Genes Among ESBL-producing Pseudomonas aeruginosa Isolates in West of Iran

“…PCR amplifications were done using specific primers for the β-lactamases PER-1, and VEB-1 genes, as described previously (17). PCR was performed for all ESBL-producers which their resistance to cephalosporins and phenotypic was identified by confirmatory tests.…”

“…PCR was performed for all ESBL-producers which their resistance to cephalosporins and phenotypic was identified by confirmatory tests. DNA was extracted by the boiling method as previously described (17). The DNA amplification program consisted of an initial denaturation (94 °C, 5 minutes) followed by 35 cycles of denaturation (94 °C, 60 seconds), annealing (50 °C for PER-1 and 55 °C for VEB-1, 60 seconds), extension (72 °C, 45 seconds) and a single final extension for 5 minutes at 72 °C.…”

Acinetobacter baumannii strains isolated from patients in intensive care units in Goiânia, Brazil: Molecular and drug susceptibility profiles

“…Resistance to carbapenem increases significantly when OXA genes are juxtaposed next to insertion elements with promoter functions, the most effective of which is the insertion sequence element of A . baumannii (IS Aba1 ) [11,16,17]. Biofilm formation is another important feature of A .…”

Growing OXA-23 type strains among carbapenem-resistant Acinetobacter baumannii and tigecycline as an alternate combination therapy

“…In our study only one (2.2%) of the strains carried OXA-58. From a neighboring country, Sonrabi et al (25) blaOXA-24, blaOXA-40, and blaOXA-143, which have importance in the epidemiology of Acinetobacter and antimicrobial resistance, have been kept out of the scope of our study. This can be considered as a limitation of our analysis.…”