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

• This study examined long-term trends in antibiotic resistance on a national scale in India.
• Colistin-resistant Klebsiella pneumoniae and Escherichia coli strains have emerged in India.
• In 2014, the prevalence of carbapenem-resistant E. coli was11.5%, the highest reported to date globally.

SummaryObjectiveThere 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.MethodsA 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).ResultsOf 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.ConclusionIncreasing resistance to antibiotics of last-resort, particularly among Gram-negatives, suggests an urgent need for new antibiotics and improved antimicrobial stewardship programs in India.