Quinolone resistance among enteric fever isolates in a tertiary care hospital

Introduction: Enteric fever is an important public health problem in developing countries like India. Antibiotics are still the main stay in the treatment of enteric fever, but enteric fever Salmonellae have developed drug resistance and this has further hampered the process of reducing the mortality and morbidity associated with this disease. Materials and Methods: Phenotypically and serologically confirmed enteric fever Salmonellae were subjected for antimicrobial susceptibility testing by Kirby Bauer disc diffusion testing. Results: 8.77% of samples received for blood culture yielded the growth of enteric fever Salmonellae, 31 S.Paratyphi A and 25 S.Typhi were isolated. S.Paratyphi A isolates are on the rise. Male to female ratio was 3:1, more commonly isolated in the first 3 decades. Seasonal variation was observed with majority of them isolated between July to September. Mean time for positive blood culture was 3-5 days.83.3% of the isolates were resistant to Nalidixic acid. Conclusion: Enteric fever continues to be a major public health problem around Mysore. During monsoon months the number of Enteric fever cases increases. Young adults are more commonly susceptible. The Enteric fever Salmonellae in this region have regained susceptibility to Ampicillin, Trimethoprim/Sulfmethoxazole and Chloramphenicol indicating the disappearance of MDR cases. Ciprofloxacin resistance is not very common in this region. Nalidixic acid is not a good screening test for detection of quinolone resistance.