Studies on isolation and susceptibility to antibiotics of the pathogens involved in SCUD etiology of aquatic turtles

Abstract

The objectives of this study were to isolate and identify the bacteria present in the shell and plastron ulcers in a group of infected turtles compared with healthy turtles, and antibiotic susceptibility testing of bacterial species identified in order to recommend the appropriate treatment. A total number of 32 red-eared slider (Trachemys scripta elegans) with specific septicemic cutaneous ulcerative disease (SCUD) lesions were sampled from the shell and plastron, compared with 8 healthy turtles. Cotton swabs were used for sampling, and the inoculation was carried out on blood agar, XLD, MacConkey and SDA plates. Biochemical characterization used API Biomerieux 20 system. Susceptibility to antibiotics was evaluated using Kirby Bauer disk diffusion method on Mueller-Hinton agar. In the samples from turtles with lesions, predominantly Gram-negative bacteria were isolated, in particular Citrobacter freundii – 16 turtles, Escherichia coli – 13 turtles, Klebsiella – 10 turtles, Serratia – 9 turtles, Shigella – 8 turtles, Salmonella – 6 turtles, plus Gram positive bacteria such as Staphylococcus – 18 turtles, Micrococcus – 11 turtles and Bacillus – 9 turtles. Regarding the group of 8 healthy turtles ratio was significantly in favor of Gram positive, with Staphylococcus – 7 turtles, Micrococcus 6 and Bacillus 4 samples. Regarding the inhibition area diameter for infected turtles, the most efficient antibiotic was Doxycycline with the average value of 15.15 mm, Enrofloxacin with 14.95 mm and Florfenicol with 14.8 mm. Lower efficiency was observed for Ceftriaxone with 4.05mm and Colistin with 7.01 mm.