Publication:

Antibiotic sensitivity profile and resistance of microorganisms isolated from south Indian population, a hospital based study at Velappanchavady, Chennai, India

Background Increasing rates of antibiotic drug resistance has been noted in recent times and this adversely affects the prognosis and outcomes of patients. There is a greater need for local resistance prevalence data in order to guide empirical prescription and to identify areas in which medical need for newer antimicrobial agents is greater.

Methods A prospective hospital based observational study was carried out to determine antibiotic sensitivity profile and resistance pattern of microorganisms. Samples were collected from urinary tract infections, while cultures from blood stream infections, sputum samples and Serology. Antibiotic susceptibility was determined by the standard disc diffusion method. Data interpretation was based on CLSI, 2017 guidelines for antimicrobial susceptibility testing.

Results The predominant isolates from the samples were, Staphylococcus aureus (16.7%) 67, K. pneumoniae (11.5%) 46, E. coli (29.4%) 118, P. aeruginosa (6%) 24. Escherichia coli, the most common causative organism showed high resistance to commonly used drugs such as Ampicillin (60.1%) 71, Amoxicillin (53.4%) 63, Amoxicillin-clavulanic acid (44.1%) 52 and Nalidixic acid (53.4%) 63. E. coli was found to be most sensitive to Amikacin (51.7%) 61, Piperacillin (69.5%) 82, Norfloxacin (61.9%) 73, Meropenem (76.3%) 90 and Imipenem (68.6%) 81. Klebsiella was most sensitive to 30 (65.2%) ofloxacin, 31 (67.4%) ciprofloxacin followed by 24 (52.2%) ceftriaxone and least sensitive to 7 (15.2%) Amoxicillin and 12 (26.1%) Ampicillin.

Conclusions Among commonly used antibiotics resistance to Penicillins (Ampicillin, Amoxicillin) was highest. Resistance to Fluoroquinolones (Ciprofloxacin) was seen in majority of the patients. Among broad spectrum antibiotics Imipenem, Meropenem resistance was seen in lesser proportion of the patients.