The efficacy of antibiotics against salmonella enterica in diarrheic calves
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Abstract
This study investigated the prevalence of Salmonella enterica in diarrheic buffalo calves and assessed the antimicrobial sensitivity and therapeutic efficacy of various antibiotics against the pathogen. A total of 120 faecal samples were collected randomly from Hyderabad, of which 55 (45.83%) were found to be positive for S. enterica. The samples were categorized based on their consistency, with watery samples having the highest prevalence rate (57.5%), followed by loose (42.5%) and semisolid (37.5%) samples. Male calves had a higher prevalence rate (58.33%) compared to females (33.33%). Confirmation tests (methyl red and citrate) identified the pathogen as S. enterica and yielded negative results for indole, Voges-Proskauer, and urease tests. Antimicrobial susceptibility testing was performed using various antibiotics. Amoxicillin and gentamycin were found to be highly effective against S. enterica, while ciprofloxacin and enrofloxacin were moderately effective. Azithromycin, chloramphenicol, erythromycin, tetracycline, ampicillin, streptomycin, and neomycin were found to be highly pathogen sensitive. Gentamycin and amoxicillin were assessed for therapeutic efficacy using the antimicrobial susceptibility test. Amoxicillin achieved 100% effectiveness on the 4th day, and gentamycin on the 5th day. These antibiotics significantly increased mean platelet count (p<0.05) but decreased Hb concentration, total erythrocyte count, and total leukocyte count (p<0.05) on the 2nd-5th post-treatment days. Salmonella enterica is prevalent in diarrheic buffalo calves, particularly in male calves, in Hyderabad. While amoxicillin and gentamycin are highly effective against the pathogen, they may adversely affect blood parameters. These findings suggest the need for appropriate antibiotic selection and careful monitoring of the health of diarrheic calves.
Keywords: Antibiotics; Diarrhea; Salmonella enterica; Therapeutic effects