Antimicrobial susceptibility pattern of blood isolates from a teaching hospital in north India

Bloodstream infections are associated with significant patient morbidity and mortality worldwide. In this study, we examined antimicrobial susceptibility patterns by reviewing the data on 5,704 blood samples that were collected from patients with fever/sepsis admitted to Government Medical College and Hospital, Chandigarh, India, over a period of 1 year from August 2003 to July 2004. Among the 567 qualifying samples, Pseudomonas aeruginosa (19.75%), Escherichia coli (15.17%), Klebsiella pneumoniae (14.99%), and Salmonella enterica serovar Typhi (12.87%) were the most frequently isolated Gram-negative bacteria other than Citrobacter, Acinetobacter, Proteus, and Enterobacter spp. collectively accounting for 80.96% of the isolates. Staphylococus aureus (13.86%) and Enterococcus feacalis (2.35%) were most frequently isolated Gram-positive bacteria other than other Streptococcus and Staphylococcus spp. collectively accounting for 18% of the isolates. Among the antibiotics used for susceptibility testing of Gram-negative isolates, amikacin showed higher activity (76.61%) against Enterobacteriaceae and ciprofloxacin (65.17%) against non-fermenters. However, cefoperazone + sulbactum showed the highest activity (82.66%) among all Gram-negative isolates. For Gram-positive isolates, vancomycin (100%), ciprofloxacin (89.74%) showed the highest activity against Staphylococcus spp. Combinations of antibiotics are often prescribed as emperic therapy for bacteremia, especially for Gram-negative pathogens. Hence the antibiotic susceptibility patterns of blood isolates reported here may be a useful guide for physicians initiating emperic therapy with antibiotics.