Mahyar Porbaran1, Hamed Tahmasebi2, MohammadReza Arabestani3. 1. Department of Microbiology, Faculty of Basic Sciences, Islamic Azad University, Hamedan Branch, Hamedan, Iran. 2. School of Medicine, Shahroud University of Medical Sciences, Shahroud, Iran. 3. Microbiology Department, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran.
Abstract
BACKGROUND: The iron/siderophore uptake system (IUS) involved in the Acinetobacter baumannii pathogenicity. However, IUS's role in antibiotic resistance and the production of β-lactamase enzymes of A. baumannii are unclear. This study aimed to investigate the relationship between the production of β-lactamase enzymes and IUS regulatory genes in clinical isolates of A. baumannii. Methods. A. baumannii isolates were collected from clinical isolates using biochemical tests. The antibiotic resistance patterns and β-lactamase-producing strains were identified using the disk diffusion method (DDM). Also, IUS genes were detected by the polymerase chain reaction (PCR) method. RESULTS: Seventy-two (72) A. baumannii isolates were collected from a different clinical specimen. Gentamicin-resistant strains (43%) had the highest frequency, and aztreonam-resistant strains (12.5%) had the lowest frequency. Also, the distribution of AmpC and MBL producing isolates were 27.7% and 35%, respectively. Moreover, the frequencies of basD, bauA, pld, paaE, entA, feoB, hemO, and tonB genes were as follows: 12.5%, 15.2%, 11.1%, 15.2%, 19.4%, 16.6%, 23.6%, and 6.9%. Further, a strong correlation was observed between the abundance of β-lactamase-producing strains and IUS genes. CONCLUSIONS: Based on our knowledge from this study, the association between β-lactamase production and IUS genes in A. baumannii plays an essential role in the emergence of drug-resistant strains.
BACKGROUND: The iron/siderophore uptake system (IUS) involved in the Acinetobacter baumannii pathogenicity. However, IUS's role in antibiotic resistance and the production of β-lactamase enzymes of A. baumannii are unclear. This study aimed to investigate the relationship between the production of β-lactamase enzymes and IUS regulatory genes in clinical isolates of A. baumannii. Methods. A. baumannii isolates were collected from clinical isolates using biochemical tests. The antibiotic resistance patterns and β-lactamase-producing strains were identified using the disk diffusion method (DDM). Also, IUS genes were detected by the polymerase chain reaction (PCR) method. RESULTS: Seventy-two (72) A. baumannii isolates were collected from a different clinical specimen. Gentamicin-resistant strains (43%) had the highest frequency, and aztreonam-resistant strains (12.5%) had the lowest frequency. Also, the distribution of AmpC and MBL producing isolates were 27.7% and 35%, respectively. Moreover, the frequencies of basD, bauA, pld, paaE, entA, feoB, hemO, and tonB genes were as follows: 12.5%, 15.2%, 11.1%, 15.2%, 19.4%, 16.6%, 23.6%, and 6.9%. Further, a strong correlation was observed between the abundance of β-lactamase-producing strains and IUS genes. CONCLUSIONS: Based on our knowledge from this study, the association between β-lactamase production and IUS genes in A. baumannii plays an essential role in the emergence of drug-resistant strains.
Authors: S Jasemi; M Douraghi; H Adibhesami; H Zeraati; M Rahbar; M A Boroumand; A Aliramezani; S Ghourchian; M Mohammadzadeh Journal: Lett Appl Microbiol Date: 2016-11-02 Impact factor: 2.858