International Journal of Current Microbiology and Applied Sciences
ISSN: 2319-7706 Volume 2 Number 8 (2013) pp. 196-205 
Detection and molecular characterization of extended spectrum of beta lactamase (ESBL) producing Escherichia coli 
Sulochana Somasundaram1* , K.R.Gowthami1 , A.Helen 1 , P.Srilekha2 and M.Sivanandam1 
1Sri Venkateswara College of Engineering, Sriperumbudur, Tamil Nadu, India. 2Sooriya Hospital, Chennai, Tamil Nadu, India *Corresponding author e-mail: 
xtended spectrum beta - lactamases (ESBLs) are on the rise in hospital settings across the globe. Hence it is necessary to know the prevalence of ESBL so as to formulate a policy of empirical therapy in high risk units. The aim of the study is to assess the prevalence of ESBL positive strains isolated from the clinical samples from the intensive care unit patients of Sooriya hospital, Chennai, India and to analyze the presence of TEM gene and its Molecular characterization. A total of 100 non repetitive E.coli isolates were obtained during the period from February to November 2011 from clinical samples (urine, pus and blood) of intensive care unit patients. Standard biochemical tests were performed to confirm the organism. Antimicrobial assay was performed for all isolates by Antibiotic susceptibility testing by Kirby Bauer method, and the production of ESBL was determined by the Double Disc Synergy Test (DDST). PCR was used to demonstrate the presence of TEM gene. The isolates producing TEM gene were typed using the Restriction Fragment Length Polymorphism (RFLP).Out of 100 clinical samples 10 samples were potential ESBL producers. The presence of TEM gene was confirmed by PCR. In RFLP analysis, restriction cleavage by XbaI reveals six different banding patterns for the samples indicating six different source of origin. We conclude from this study that the clinical samples showed 10% ESBL. The analysis of TEM gene by PCR and RFLP typing showed the prevalence of ESBL from six different origin. 
E.coli; ESBL; Betalactamases; Double Disc Synergy Test; PCR ; RFLP; Multidrug resistant E.coli.