Prevalence of Extended-Spectrum β-lactamase and Integron Gene Carriage in Multidrug-Resistant Klebsiella Species Isolated from Outpatients in Yazd, Iran

Community-acquired infections by multidrug-resistant (MDR), extended-spectrum β-lactamase (ESBL) producing Klebsiella species (Klebsiella spp.) is of major concern worldwide. Antibiotic resistance, production of extended-spectrum β-lactamases (ESBLs), and carbapenemases, as well as the presence of classes 1, 2, and 3 integrons in outpatient isolates of Klebsiella collected from Yazd central laboratory, Yazd, Iran. We collected 250 Klebsiella isolates from Yazd central laboratory between August 2015 and October 2017. Antibiotic susceptibility was determined against 18 antibiotics by disc diffusion, and multidrug-resistant isolates were tested for ESBL production by the phenotypic confirmatory test according to CLSI 2017 protocols. The amplification of β-lactamase genes blaSHV, blaTEM, blaCTX-M, blaOXA-48, blaKPC, and blaNDM, classes 1, 2, and 3 integrase genes, was carried out using specific primers and polymerase chain reaction (PCR). Of the 250 Klebsiella outpatient isolates, 3.6% were K. oxytoca and the rest were K. pneumoniae. Disc diffusion showed that 21 (8.4%) isolates were MDR, 19 (90.4%) of which were ESBL producers including one K. oxytoca. The most prevalent β-lactamase gene was blaSHV followed by blaTEM and blaCTX-M, but blaOXA-48, blaKPC, and blaNDM were not detected. Class 1 integron was detected in 18 out of 21 MDR isolates (85.7%), but classes 2 and 3 were not observed. Two isolates were resistant to carbapenems and harbored blaSHV, blaTEM, and blaCTX-M, as well as class 1 integron. ESBL production and the presence of multiple β-lactamase genes in MDR community isolates of Klebsiella spp. can have significant implications in terms of the spread of these opportunistic pathogens.