Detection of blaSHV-1 for ESBL production among clinical strains of Escherichia coli Sanmugam Kayalvili1, Dr. Gopinath P2 1BDS 2nd year, Saveetha Dental College, Saveetha University, Chennai 2 Senior Lecturer, Department of Microbiology, Saveetha Dental College, Saveetha University, Chennai Corresponding Author E-mail:
Online published on 12 January, 2017. Abstract Plasmid-mediated β-lactamase gene is SHV-1 (sulfhydryl variable), which is chromosomally encoded in the majority of isolates of K. pneumoniae but is usually plasmid-mediated in E. coli. Over the years, many new βlactam antibiotics have been developed; however, with each new class of antibiotic, a new β-lactamase emerged that caused resistance to that particular class of antibiotic. Presumably, the selective pressure imposed by the use and overuse of new antibiotics in the treatment of patients has resulted in the emergence for new variants of βlactamase enzymes. A sum of 20 urinary isolates of E. coli were subjected to antibiotic susceptibility testing and detected for blaSHV-1 gene by PCR. We found increased percentage of isolates were shown to be resistant to different antibiotics and 70% of them were resistant to imipenem drug. 20% of them were harboring blaSHV-1 gene by PCR. Since ESBL-positive isolates show false susceptibility to expanded-spectrum cephalosporins in standard phenotypic test, it is difficult to relay on it. Specific detection methods recommended by CLSI have to be adopted. Those isolates need to be confirmed by multiplex PCR with sets of resistance genes for ESBLs are recommended where the availability and resources are available for prompt and accurate therapy. Top Keywords E. coli, blaSHV-1, ESBL, PCR. Top |