Hora and Ali, IJPSR, 2012; Vol. 3(9): 3331-3336 ISSN: 0975-8232 Available online on www.ijpsr.com 3331 IJPSR (2012), Vol. 3, Issue 09 (Research Article) Received on 24 May, 2012; received in revised form 07 July, 2012; accepted 27 August, 2012 A STUDY OF RELATIONSHIP BETWEEN ANTIBIOTIC RESISTANCE AND MOLECULAR CHARACTERISTICS OF ESCHERICHIA COLI ISOLATES OBTAINED FROM DIFFERENT HUMAN CLINICAL SPECIMENS AGAINST MULTIPLE ANTIBIOTIC RESISTANCE (MAR) INDEX IN BAREILLY (INDIA) REGION Sandhya Hora* and Ziledar Ali Central Research Laboratory, Department of Biochemistry, Shri Ram Murti Samarak-Institute of Medical Sciences, Nainital Road, Bareilly-243202, Uttar Pradesh, India ABSTRACT To analyse the situation of antibiotic resistance, a total of 77 E. coli isolates from urine, pus, sputum and endo-tracheal aspirate were screened for their antibiograms for antibiotic resistance, multiple antibiotic resistance (MAR) index for evaluating the spread of resistance and plasmid profiles for the presence and characterization of plasmids. Very high resistance level (>90%) was detected against ampicillin, amoxicillin, ceftazidime, norfloxacin, tetracycline while imipenem and amikacin recorded the least resistance levels of 2.3% and 13.9% respectively among the isolates. An increased resistance to amoxicillin, tetracycline, cotrimoxazole and norfloxacin were observed in this geographical area which however displayed a lower resistance in other countries. The MAR index varied considerably, the lowest was 0.18 and the highest was 0.89. Plasmids of 10 size ranges were detected in the isolates. Some isolates possessed single sized plasmid while other possessed multiple plasmids. Isolates with high multi- antibiotic resistance profiles were found to possess multiple plasmids. This study shows that regular antimicrobial sensitivity surveillance is necessary and acquisition of plasmid could greatly contribute in the antibiotic resistance and poses a significant risk of the spread of microbial resistance in this community. INTRODUCTION: Escherichia coli is a multi-talented, very adaptive, enteric gram-negative bacillus, which belongs to the family Enterobacteriaeceae. Most strains of E. coli live as commensal, many perhaps all are opportunistic pathogens of humans. E. coli is one of the main causes of both nosocomial and community acquired infections in humans. The organism is therefore of clinical importance and can be isolated from various clinical specimens. It is one of the organisms most frequently isolated from blood 1, 2, 3 . E. coli has now been established as etiological agents of human gastroenteritis, enteric fever, septicemia, localized infections and diarrhea disease of humans 4 . The antibiotic susceptibility of bacterial isolates is not constant but dynamic and varies with time and environment 5 . Indeed, high resistance rate to several antimicrobial agents have been observed in commensal bacteria in developing countries 6 . Keywords: E. coli, Antibiogram, plasmid profile, ESBL, Multiple Antibiotic Resistance Index Correspondence to Author: Sandhya Hora, Research Assistant, 202, Faculty Residence, SRMS-CET, Bareilly-243202, Uttar Pradesh, India E-mail: sandhya.hora@gmail.com QUICK RESPONSE CODE IJPSR: ICV- 4.57 Website: www.ijpsr.com