Iranian Journal of Medical Sciences

Document Type: Original Article(s)


1 Departments of Microbiology, Faculty of Life Sciences and Technology, Shahid Beheshti University, Tehran, Iran

2 Research Center for Food Hygiene and Safety, Shahid Sadoughi University of Medical Sciences, Yazd, Iran


Background: 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.
Methods: 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).
Results: 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.
Conclusion: 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.