RESUMO
Purpose: Salmonella Enteritidis (SE) and Salmonella Typhimurium (STM) are the serovars most frequently associated with human illness. Ciprofloxacin is most widely used to manage cases in adults. The present study aimed to evaluate the in vitro antibacterial activity of leading brands of ciprofloxacin (tablets) marketed in Bishoftu city against SE and STM serovars, and field isolates of Salmonella (non-serotyped) from dairy milk in central Ethiopia. Methods: Five most widely prescribed ciprofloxacin brands (A-E) were subjected to in vitro efficacy evaluation against Salmonella isolates by using the disc diffusion method. The zone of inhibition (ZI) of the tested brands was compared with the standard disc and interpreted as susceptible, intermediate, and resistant. Results: Out of 27 replicates (SE, STM, and field Salmonella isolates each = 9) tested for efficacy, the result revealed the mean ZI of the brands varies for all tested isolates (p < 0.05). The highest mean was recorded for Brand E (24.7±0.71, 24.3±0.50, and 19.5±2.69) and lowest for Brand A (22.0±0.87, 21.0±0.87, and 10.7±1.4) for field Salmonella isolates, STM and SE, respectively. All SE were resistant to four brands (Brand A-D) whereas 67% and 33% of them were resistant and intermediate to Brand E, respectively. Similarly, 33% of STM were resistant to Brand A while all the STM were intermediate to other brands. Furthermore, all non-serotyped field isolates of Salmonella were intermediate to all five tested ciprofloxacin brands with variable ranges of mean of ZI (p<0.05). Conclusion: The study revealed that Brand E was found to have relatively better efficacy against SE than other brands. The current study warrants a need for periodic surveillance of both the quality and efficacy of antibiotics to improve patient well-being and minimize the risk of antimicrobial resistance.
