Correlation of multi-drug resistance, integron and blaESBL gene carriage with genetic fingerprints of extended-spectrum β-lactamase producing Klebsiella pneumoniae

Background: Some genetic and phenotypic variables are associated among distinct microbial populations. Objectives: The associations between multi-drug resistance (MDR) phenotypes, prevalence of antibiotic resistance integrons (ARIs), bla_SHV, bla_TEM and bla_CTX-M gene carriage and genetic fingerprints of random amplified polymorphic DNA (RAPD), confirmed by pulsed field gel electrophoresis (PFGE), were investigated among extended-spectrum β-lactamases (ESBL)-producing nosocomial isolates of Klebsiella pneumoniae. Materials and Methods: Susceptibility of 35 ESBL-producing K. pneumoniae nosocomial isolates to 22 antimicrobial agents was determined. Integron carriage was detected using specific primers for intI1, intI2 and intI3 genes by PCR. Results: All isolates were resistant to piperacillin and susceptible to imipenem. MDR phenotype was observed in 91.4% of the isolates. Class 1 integrons were detected in 21 (60%) and class 2 integrons in 3 (8.57%) of the isolates. Two of the isolates carried both classes and none harbored class 3 integrons. Significant correlations were observed between resistance to aminoglycosides, fluoroquinolones and sulfonamides, and between genotype groups with carriage of ARIs, MDR phenotype and bla_SHV gene carriage. ARI carriage was also significantly associated with MDR phenotype. Conclusions: Our findings suggest the possible co-carriage of some bla_SHV genes and ARIs on the same plasmids harboring the MDR genes. Possible role of integrons in dissemination of ESBL-encoding bla_SHV genes among ESBL-producing K. pneumoniae nosocomial isolates may be inferred.