Trends in antibiotic resistance among major bacterial pathogens isolated from blood cultures tested at a large private laboratory network in India, 2008–2014

Objective There have been no long-term studies on trends in antibiotic resistance (ABR) on a national scale in India. Using a private laboratory network, the ABR patterns of organisms most commonly associated with bacteremia, obtained from patients across India between 2008 and 2014, were examined. Methods A retrospective study of patient blood cultures collected over a 7-year period (January 1, 2008–December 31, 2014) was conducted. Data on the microorganism(s) identified and their antimicrobial susceptibility were obtained from SRL Diagnostics (Mumbai, India). Results Of 135 268 blood cultures, 18 695 (14%) had at least one identified pathogen. In addition to continual high rates of methicillin-resistant Staphylococcus aureus (MRSA; approximately 44.2%), high resistance to nalidixic acid among Salmonella Typhi (98%) was observed, and carbapenem resistance increased in both Escherichia coli (7.8% to 11.5%; p = 0.332) and Klebsiella pneumoniae (41.5% to 56.6%; p < 0.001). Carbapenem resistance was also stable and high for both Acinetobacter species (approximately 69.6%) and Pseudomonas aeruginosa (approximately 49%). Resistance was also detected to colistin in the Gram-negatives and to vancomycin and linezolid in S. aureus. Conclusion Increasing resistance to antibiotics of last-resort, particularly among Gram-negatives, suggests an urgent need for new antibiotics and improved antimicrobial stewardship programs in India.