Shweta Mishra
Banaras Hindu University, India
Title: Genetic profiling of clinical isolates of Citrobacter freundii expressing blaAmpC gene in a tertiary referral hospital of northern India
Biography
Biography: Shweta Mishra
Abstract
The common mechanism of resistance of Citrobacter freundii to β-lactam antibiotics is the presences of plasmid mediated blaAmpC. In this study we evaluate the emergence of ampC gene among clinical isolates of C. freundii isolated from urine of symptomatic UTI patients and also to assess mobile genetic elements. A total of 30 consecutive, clinical isolates of C. freundii were investigated for the presence of AmpC β-lactamase. Molecular characterization was studied by mPCR for gene of AmpC including the coproduction of other β-lactamase. Presence of integron was detected using integrase gene primers. Presence of integron to blaAmpC gene along with gene cassettes identified using specific primers. Genetic location on insertion sequence was also seen. A total of 16 isolates were phenotypically positive for AmpC. On performing their genotypic characterization, 5 isolates were found to be positive for blaCMY-2, 3 isolates having blaDHA-2 whereas one isolates coproducing blaCMY-2 and blaDHA-2. In which some AmpC positive isolates were coexisting blaNDM, blaIMP, blaVIM family of MBL and blaCTXM, blaSHV of ESBL. Among them 8 were harboring class 1 integron, linkage between integron and blaCMY-2 has been detected. Investigation of gene-cassettes revealed the presence of dihydrofolate reductase (dhfr) and aminoglycoside 6'-N-acetyltransferase (aac 6') genes and presence of CMY-2 gene on ISEcp1 were also seen. The study showed that these genes have high ability to cross species barrier with ease and integrated other resistance genes. Eventually, AmpC gene highlights the potential risk in hospital environment. Thus the attainment of AmpC genes by C. freundii restricts therapeutic alternatives for combating infections.