Citrobacter freundii is an opportunistic pathogen in animals and humans. The current study aimed to isolate C. freundii from the intestines of common carp (Cyprinus carpio) and test their antibiotic susceptibility. For this purpose, 70 specimens of intestine were gathered from fish farms in Mosul city from October 2022 to February 2023. Initially, the samples were inoculated in Tryptone soya broth (TSB) and then cultured on both TSA and MacConkey agar. The suspected single colonies were streaked on the eosin methylene blue (EMB) and Salmonella Shigella agar. All suspected isolates were confirmed by manually prepared biochemical tests and the VITEK®2 compact, and then their sensitivity was determined against eight antibiotics. According to the cultural characteristics, biochemical tests, and VITEK®2 compact, 18 (12.6%) isolates out of 70 samples were C. freundii. All isolates were highly susceptible to ciprofloxacin, amikacin, and gentamicin, moderately sensitive to tetracycline, ceftriaxone, highly resistant to amoxicillin and Cefixime, and low resistance to tobramycin. The presence of C. freundii in aquaculture represents many facets of challenges, with implications for public health, environmental stability, and the economic causes of fish farming.
Hamad et al. (Sat,) studied this question.