Genotyping and molecular characterization of clinical isolates from a single hospital in Southwestern Iran.

() is a pathogen responsible for nosocomial infections among the hospitalized patients. The aim of this study was to investigate genotyping and molecular characterization and to examine the biofilm formation ability of isolates. In total, 70 isolates were collected from patients admitted to Imam Khomeini Hospital in Ahvaz, Southwestern Iran. Minimum inhibitory concentrations (MIC) test was performed using Vitek 2 system. The presence of genes encoding metallo-β-lactamases, oxacillinases, and integrase and the biofilm formation ability were then evaluated. Multiple locus variable-number tandem repeat (VNTR) analysis (MLVA) typing and multiplex PCR were performed to determine the genetic relationships. The bla-like gene had the highest prevalence. The frequency of genes encoding , , and among MDR isolates were 12 (17.1%), 18 (25.7%), and 22 (31.4%), respectively. Moreover, 46 isolates (75.4%) harbored class I integron and 10 isolates (16.39%) carried class II integron. The number of weak, moderate and strong biofilm-producing isolates were 3 (4.3%), 7 (10%), and 55 (78.5%), respectively. The results showed that 70 isolates were grouped into 12 distinct MLVA types with five clusters and four singleton genotypes. In addition, 25 (35.7%) isolates were assigned to international clone (IC) variants, 37 (52.8%) isolates belonged to group 1 (IC II), and 8  (11.4%) isolates belonged to group 2 (IC I). Our findings revealed that the population structure of the isolates was genetically diverse. More focus on genetic variation and antibiotic resistance of isolates are recommended.