Molecular characterization of class 1, 2 and 3 integrons in clinical multi-drug resistant Klebsiella pneumoniae isolates

Abstract

Background The aim of this study was to characterize class 1,2 and 3 integrons in clinical MDR Klebsiella pneumoniae isolates in Kashan, Iran. Methods One hundred-eighty one Klebsiella pneumoniae were recovered from clinical specimens during November 2013 to October 2014. Antimicrobial susceptibility patterns were determined by disk diffusion method according to the Clinical and Laboratory Standards Institute (CLSI) guidelines for detection of MDR strains. Of the 181 Klebsiella pneumoniae, 146 (80.7%) of isolates were isolated from nosocomial infected patients and 150 (82.9%) identified as MDR isolates. The PCR amplification was used to show presence of class 1, 2 and 3 integrons among MDR strains. The PCR method and sequencing were used for evaluation of cassette content of integrons. Results Of the MDR K. pneumoniae isolates, 150 (100%) and 55 (36.7%) carried intI1 and intI2 genes, respectively. None of the MDR Klebsiella pneumoniae isolates carried class 3 integrons. Amplification of conserved segment (CS) of class 1 and class 2 integrons revealed 10 different arrays including: No. cassette; dfrA5 , dfrA30 ; aadA2 ; aadA2 , dfrA12 ; dfrA17 , aadA5 , aadA4 ; dfrA5 , dfrA30 , aadA2 ; dfrA5 , dfrA30 , aadA2 , dfrA12, dfrA5 , dfrA30 , dfrA17 , aadA5 , aadA4 ; aadA2 , aadA2 , dfrA12 ; dfrA5 , dfrA30 , aadA2 , aadA2 , dfrA12 and 4 arrays including: No. cassette; aadA1 ; dfrA1-sat1 ; aadA1 , dfrA1-sat1 , respectively. Conclusions The finding of present study revealed a high prevalence of integrons especially class 1 among MDR K. pneumoniae isolates from nosocomial infections in Kashan, which led to rapid extension of MDR strains.

Genotyping and Virulence Analysis of Drug Resistant Clinical Klebsiella pneumoniae Isolates in Egypt

“…Finally, forty-nine (98%) out of our 50 K. pneumoniae isolates were positive for the intI1 gene. Lower percentages (74%, 69%, and 53%) were reported by Derakhshan et al, Zaki et al, and Liao et al; in contrast, all (100%) isolates of Firoozeh et al in Iran were positive for this gene 7,9,22,25 .…”

“…Nonetheless, Derakhshan et al in Iran and Liao et al in China reported that 1% and 2% of their isolates, respectively, were positive for class 2 integrons 9,25 . In addition, Firoozeh et al in Iran reported that 37% of their isolates were positive for this gene 7 . Similarly, none of our isolates was positive for intI3; this finding matches the results reported by Derakhshan et al, Zaki et al and Firoozeh et al 7,9,22 . Significant correlations were found between the intI1 gene and resistance to aztreonam and ceftriaxone (p-value ≤ 0.05).…”

“…More than one hundred and thirty different cassettes that confer resistance against important antibiotic classes e.g. : ß-lactams, fluoroquinolones, aminoglycosides, and macrolides have been discovered 7 . The polysaccharide capsule is an important factor for bacterial virulence.…”

Characterization and Plasmid Profile of Resistant Klebsiella pneumoniae Isolates in Patients with Urinary Tract Infection in Nasarawa State, Nigeria

“…Pathogenicity of MDR Klebsiella pneumoniae has been attributed to the possession and production of resistance genes, virulence genes, integrons, production of toxins (Li et al, 2013;Firoozeh et al, 2019). Extended Spectrum Beta-Lactamases genes from isolated resistant Klebsiella pneumoniae include TEM, SHV, and CTX-M.…”

Integron activity accelerates the evolution of antibiotic resistance

“…Five classes of MIs have been described but the class 1 integron is, by far, the most prevalent and clinically relevant. The first multidrug resistance plasmids that were isolated in the 1950s carried class 1 mobile integrons (Liebert et al, 1999;Mitsuhashi et al, 1961;Rownd et al, 1966;Stokes & Hall, 1989), and recent surveys have shown that class 1 integrons are found in a substantial fraction of isolates of E. coli (Halaji et al, 2020;Rao et al, 2006;Yu et al, 2003), K. pneumoniae (Firoozeh et al, 2019;Li et al, 2013), P. aeruginosa (Oliver et al, 2015;Ruiz-Martínez et al, 2011), and A. baumanii (Chen et al, 2015;Turton et al, 2005).…”