Phenotypic and genotypic detection of metallo-β-lactamases in A. baumanii isolates obtained from clinical samples in Shahrekord, southwest Iran

Abstract

Objective Acinetobacter baumanii is a pathogenic bacterium that is the cause of many nosocomial infections. This study aimed to determine metallo-β-lactamases (MBL) produced by the A. baumanii isolates obtained from clinical samples in Shahrekord, southwest Iran. Results A total of 100 A. baumanii were isolated from 250 clinical samples between June 2013 and June 2014. Then, the isolates were identified by biochemical tests, and MBL screening was conducted by the phenotypic tests modified Hodge, EDTA-disk synergy (EDS), combined disk (CD) and AmpC disc after antibiotic sensitivity test. Using PCR technique the bla genes were detected. Eighty-five (85%) isolates were resistant to meropenem and imipenem. Phenotypic tests showed that out of the 100 isolates, 46, 59, 50, 65 and 65 isolates were positive: AmpC disk, CD, EDS, Modified Hodge and E-test MBL respectively. Gene detection by PCR showed that 23 isolates carried the VIM-1 gene and only three isolates carried the IMP-1 gene. The prevalence of metallo-β-lactamases isolates containing A. baumanii is increasing. Furthermore, the coexistence of various carbapenemases is dominantly act as a major problem. Continuous monitoring of the infections related to these bacteria should be considered to plan an alternative and new therapeutic strategies.

Molecular Identification of Carbapenem Resistance Acinetobacter baumannii causing Ventilator-Associated Pneumonia Isolated from Intensive Care Unit of Tertiary Care Hospital

“…In this study, carbapenem mediated resistance was mainly found due to class B and class D carbapenemase. Among class B bla IMP and bla VIM the results are in concordance with other studies, 23,24 while in some studies [25][26][27][28] lower percentage of isolates harbouring bla IMP gene was observed. These variations were found due to change in pattern of resistance over different years and geographical difference within the countries over a period.…”

Detection of Multidrug-Resistant Acinetobacter baumannii among Gram-Negative Bacteria Isolated from Clinical Samples

“…Acinetobacter baumannii is an important opportunistic pathogen causing about 80% of clinical infections of the 21 st century (Odewale, Adefioye, Ojo, Adewumi, & Olowe, 2016;Almasaudi, 2018;Khaledi et al, 2019), and several nosocomial infections such as ventilator-associated infection (VAP), burn and wound infections leading to significant morbidity and mortality particularly in immunocompromised patients as well as those admitted in intensive care units (Basri et al, 2015;Azimi, Talebi, Pourshafie, Owlia, & Lari, 2015;Asif, Alvi, & Rehman, 2018). Report showed that, the A. baumannii has been isolated from blood, sputum, skin, pleural fluid, and urine samples, usually in device associated infections (Mayasari & Siregar, 2015).…”

Investigating the Presence of Efflux Pump Genes adeI and adeJ in Clinical Antibiotic-Resistant Isolates of Acinetobacter baumannii

“…Acinetobacter baumannii possesses many properties that might lead to drug resistance. The main resistance mechanisms include the production of antimicrobial inactivating enzymes, such as beta-lactamases and amino-glycosidase (8,9), changing the target position and reducing membrane permeability, biofilm formation, and high expression of efflux pumps, particularly those with resistance nodulation cell division (RND) transporters (8,10,11).…”