Antimicrobial Resistance Frequency in CarbapenemaseProducing and Biofilm Forming Clinical Klebsiella pneumoniae Isolatesin Northwest of Iran

Background and Aim : Klebsiella pneumoniae is an opportunistic bacterium, which is globallyrecognized for its high prevalence and antimicrobial resistance. Carbapenemase production andbiofilm formation are critical resistance and pathogenesis mechanisms in K. pneumoniae. Thisstudy evaluated the prevalence of three prevalent carbapenemase related genes and four frequentbiofilm related genes in K. pneumoniae isolates regarding drug resistance in Zanjan, Iran.Methods : In this cross-sectional study, ۱۰۴ clinical K. pneumoniae samples were collected fromeducational hospitals, Zanjan, Iran. Isolate identification and confirmation were done usingstandard biochemical tests and PCR. Disk diffusion antibiotic susceptibility testing was performedaccording to NCCLS guidelines. Phenotypic confirmatory test for ESBL producing isolaterecognition was performed according to CLSI guidelines. Minimal inhibitory concentrations weremeasured with ETEST. Biofilm formation degree was evaluated using Stepanovic’s microtiterplate colorimetric method. Multiplex-PCR was performed to detect the presence of carbapenemaseproduction genes blaVIM, blaNDM, and blaOXA-۴۸ and biofilm related genes LuxS, Fimh۱, wza,and mrkD. Statistical analysis of the results was performed using SPSS ۱۹.Results : The highest resistance rate was against ampicillin (۱۰۰.۰%) followed by cefotaxime(۷۲.۱%). Among the ۱۰۴ K. pneumoniae isolates, ۵۲ (۵۰.۰%), and ۳۱ (۲۹.۸%) strains weredetermined as MDR and XDR, respectively. Moreover, ۲۱ (۴۰.۴%) strains were determined asESBL producing. Among a total number of ۵۰ slime producing K. pneumoniae strains, ۷ (۱۴.۰%),۱۵ (۳۰.۰%), and ۲۸ (۵۶.۰%) strains exhibited high, moderate, and weak levels of biofilmformation, respectively. A number of ۴۱ (۷۸.۸%) strains were susceptible to colistin, and ۱۰(۱۹.۲%) were resistant. Chi-square exact (Fisher exact for luxS) demonstrated insignificantdifference between strong and moderate biofilm production related genes.Conclusion : The study demonstrated increased rate of carbapenemase production and biofilmformation in K. pneumoniae strains in the region, highlighting the importance of properly updatedantimicrobial prescription guidelines regarding epidemiological data.

کلیدواژه ها:

Beta-lactamases ، Biofilm ، Drug resistance ، Klebsiella pneumoniae