Ciprofloxacin and Azithromycin Susceptibility in Salmonella Causing Bloodstream Infection in a Tertiary Care Hospital in South India

Abstract

Enteric fever is a major health concern worldwide, especially in tropical countries. Enteric fever caused by Salmonella enterica is a gastrointestinal tract disease to begin with and later involving many systems,. After the advent of multidrug resistant Salmonellae, ciprofloxacin became the focus of its treatment. Azithromycin is widely being used for the prevention and treatment of Enteric fever. Of late, there are reports in literature to support that Salmonella have regained susceptibility to Ampicillin, Cotrimaxazole and Chloramphenicol. Therefore, this study undertaken aims to find out the antimicrobial susceptibility of Salmonella isolates to conventional drugs like Ampicillin, Cotrimaxazole and Chloramphenicol and find out susceptibility pattern of Ciprofloxacin that is over used for treatment of enteric fever and Azithromycin, most often used in children. As there is no disc diffusion method as per CLSI 2019 guidelines to detect the susceptibility to ciprofloxacin, ciprofloxacin resistance was determined by minimum inhibitory concentration(MIC)by E-test.Kirby-Bauer disk diffusion technique was used to monitor Azithromycin resistance among Salmonella entericaserovarTyphi as per CLSI 2019 guidelines. METHODS:The Prospective study was conducted over a period of 8 months (May 2019- December 2019) with the clinical samples yielding the growth of Salmonella from blood. These strains were screened for Ciprofloxacin susceptibility by E-test. Azithromycin,Ampicillin, Co-Trimaxazole and Chloramphenicol susceptibility were detected by Kirby-Bauer disc diffusion technique. RESULTS: Of the 80 isolates that were screened, 52 (65%) were resistant, 24 (30%) were intermediate susceptible and remaining 4(5%) were sensitive to ciprofloxacin by MIC detection. 69 (86.25%) of the isolates were sensitive and 11 (13.75%) were resistant to Azithromycin by disc diffusion technique. All isolates (100%)were found to be susceptible to Ampicillin, Co-Trimaxazole and Chloramphenicol CONCLUSION:The current study shows a high prevalence of resistance to ciprofloxacin in Salmonella species isolated in and around Mysuru district in southern India. Detection of ciprofloxacin resistance by the Kirby Bauer disk diffusion method is less effective, so it is advised that MIC of ciprofloxacin must be regularly done in the diagnostic laboratories for all strains. The findings from our study also showed low level resistance (13.75%) to Azithromycin. It is advised that Azithromycin can be used as a therapeutic agent only if it is reported to be sensitive by the susceptibility test. Conventional agents like Ampicillin, Co-Trimaxazole and Chloramphenicol can be reconsidered for treatment of Enteric fever.