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 135268 blood cultures, 18695 (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.