High prevalence of extended-spectrum β-lactamase-producing pathogens: results of a surveillance study in two hospitals in Ujjain, India

Ashish Pathak^1,2, Yogyata Marothi³, Vandana Kekre⁴, Kalpana Mahadik⁵, Ragini Macaden⁶, Cecilia Stålsby Lundborg<sup>1

1</sup>Division of Global Health, Department of Public Health Sciences, Karolinska Institutet, Stockholm, Sweden; ²Department of Pediatrics, ³Department of Microbiology, ⁴Department of Medicine, ⁵Department of Obstetrics and Gynecology, RD Gardi Medical College, Ujjain, India; ⁶St Johns Research Institute, Bangalore, India

Background: Recent reports of the rapid evolution of bacterial resistance in India require urgent antibiotic stewardship programs. This study aimed to define the magnitude and pattern of resistance of bacterial pathogens to guide empirical therapy.
Methods: We prospectively collected consecutive, clinically significant, and nonduplicate bacterial isolates from each patient from two hospitals in Ujjain, India. The antibiotic susceptibility of the bacteria was tested using a disc diffusion method as recommended by the Clinical and Laboratory Standards Institute.
Results: A total of 716 pathogens were isolated from 2568 patients (median age, 25 years; range, 0 days to 92 years). Gram-negative infections were predominant (62%). The isolated pathogens included Staphylococcus aureus (n = 221; 31%), Escherichia coli (n = 149; 21%), Pseudomonas aeruginosa (n = 127; 18%), and Klebsiella pneumoniae (n = 107; 15%). Common diagnoses included abscesses (56%), urinary tract infections (14%), blood stream infections (10%), pneumonia (10%), and vaginal infections (10%). In E. coli isolates, 69% (95% confidence interval [CI] 61.6–76.6) were extended-spectrum β-lactamase (ESBL) producers and 41% (95% CI 31.6–50.5) of K. pneumoniae isolates were ESBL producers. These isolates had a high resistance to fluoroquinolones and β-lactams, except for imipenem and piperacillin-tazobactam. Salmonella typhi remained sensitive to third-generation cephalosporins. Methicillin-resistant S. aureus (MRSA) constituted 30% of all S. aureus isolates and showed resistance to ciprofloxacin (81%), cotrimoxazole (76%), and levofloxacin (60%).
Conclusion: Our results showed a high prevalence of ESBL among Gram-negative bacterial isolates and a high prevalence of MRSA among S. aureus isolates. Carbapenems provided the broadest coverage for Gram-negative bacteria, while glycopeptides were the most effective against MRSA; however, both classes of drugs need to be used judiciously. This study will help in planning future antibiotic stewardship programs.

Keywords: antibiotic susceptibility, surveillance, extended-spectrum β-lactamases, India