Anti-Microbial Susceptibility Patterns of Enterobacteriaceae Isolated From A Tertiary Care Unit In Gujarat

摘要

Objectives: Present study was undertaken to assess antibiotic susceptibility patterns of Enterobacteriaceae at a tertiary care hospital in Gujarat, India. Methods: Out of 276 culture positive samples, 154 samples of Enterbacteriaceae were examined and 11 different types of specimen were collected. Microbial sensitivity testing was done using disk diffusion test with Escherichia coli NCTC 10418 as per CLSI guidelines. Results: Highest Enterobacteriacae infections were found in urine followed by pus and sputum. Enterobacteriacae species demonstrated marked resistance against monotherapy of penicillins and cephalosporins. Combination of ampicillin, amoxicillin and third generation cephalosporins with sulbactam and monotherapy of amikacin showed higher sensitivity to Enterobacteriacae infections but maximum sensitivity was shown by carbapenems. Conclusions: Urinary tract infection was the most common hospital acquired infection. Co-administration of ?-lactamase inhibitor markedly expanded the anti-microbial sensitivity of penicillins and cephalosporins. Use of amikacin and carbapenems should be restricted to severe nosocomial infections to avoid rapid emergence of resistant strains. Introduction The development of antibiotic resistance can be viewed as a global problem in microbial genetic ecology. It is a very complex problem to contemplate, let alone solve, due to the geographic scale, the variety of environmental factors, and the enormous number and diversity of microbial participants. Extended spectrum β-lactamases (ESbLs) continue to be a major problem in clinical setups worldwide, conferring resistance against extended spectrum cephalosporins. Increasing resistance to third and fourth generation cephalosporins has become a cause of concern especially amongst Enterobacteriaceae family which is one of the main cause of nosocomial infections. ESbLs are the derivatives of common b-lactamases (TEM and SHV b-lactamases) that have undergone one or more amino acid substitutions near the active site of the enzyme, thus increasing their affinity and the hydrolytic activity against third generation cephalosporins and monobactams. Extensive use of newer generation cephalosporins has been the strong factor for the evolution of newer b-lactamases such as ESbLs. ESbLs are encoded by transferable conjugative plasmids, which often code resistance determinants to other antimicrobial agents such as aminoglycosides. These conjugative plasmids are responsible for the dissemination of resistance to other members of gram negative bacteria in hospitals and in the community ( 1,2,3,4 ).Bacterial infection is the most common cause for hospital visits. In almost all cases of nosocomial infection, there is a need to start treatment before the final microbiological results are available. Area-specific monitoring studies aimed to gain knowledge about the type of pathogens responsible for specific infection and their resistance patterns may help the clinicians to choose the correct empirical treatment. Hence, this study was undertaken to find out the antibiotic susceptibility pattern of the isolated pathogenic Enterobacteriaceae from various specimens from hospital acquired infections. Materials and methods Our study group comprised of patients who were clinical suspects of bacterial infection or who had undergone various surgical procedures. Project was undertaken at Rajasthan Hospitals, Ahmedabad, Gujarat, India. A protocol was designed and all the information pertaining to the patient's name, age, sex and culture susceptibility etc. were recorded on individual basis. Collected specimen comprised of urine, pus, sputum, endotracheal secretion (ET), blood, bile, broncho-alveolar lavage (BAL), semen, body tissues and various body fluids. All the samples were collected by standard procedures in aseptic closed containers and extensive care was taken to avoid contamination such as in case of urine sample, standard “clean-catch” method was adopted. Specimen wa