Presença de bactérias do gênero Pseudomonas sp. com resistência a antibióticos em peixes comercializados no mercado dos peixes do Mucuripe, Fortaleza/CE

Abstract

Studies carried out in the Northeast of Brazil highlight the socio economic importance of the commercialization of fish found in fairs and markets. These studies address the presence of pathogens, especially of the genus Pseudomonas sp., in the microbiota of fish, which are responsible for secondary infections, cases of food spoilage and poisoning. The research focused on verifying the presence of bacteria of the genus Pseudomonas sp. with resistance to antimicrobials in specimens of Pargos fish (Lutjanus purpureus) from the Mucuripe Fish Market, Fortaleza/CE. Quantification, isolation, identification and antimicrobial susceptibility testing methods were used. Five specimens were collected over five continuous weeks from July to August 2023. Microbiological analyses were carried out on the skin, gills and intestines. For presumptive quantification, the Most Probable Number (MPN) technique was used in Asparagine Broth. The MPN values ranged from 750 to >110,000 MPN/mL for the mucus from the skin and gills; and >11,000 to >110,000 MPN/g for the intestine. The presence of the Pseudomonas genus was confirmed on selective Cetrimide Agar medium. A total of 130 strains were isolated, 44 from skin mucus, 41 from the gills and 45 from the intestine. The morphology was confirmed (rods) and the occurrence of Gram (Gram negative). 112 strains went on to biochemical tests, 39 from skin mucus, 34 from gills and 39 from the intestine. For the skin mucus, 31 (27.7%) strains performed for the genus Pseudomonas sp., 4 (3.6%) for the species Pseudomonas aeruginosa and 4 (3.6%) for the Phylum Pseudomonadota. For the gills, 34 (30.4%) strains performed for the genus Pseudomonas and there was no identification for the species P. aeruginosa or for the Phylum Pseudomonadota. For the intestine, 31 (27.7%) strains performed for the genus Pseudomonas sp. 3 (2.7%) for the species P. aeruginosa and 5 (4.5%) for the Phylum Pseudomonadota. The disk diffusion test was used to perform the antibiogram. The following commercial disks with antimicrobials for clinical and veterinary use were selected: Amoxicillin (AMO 10 μg), Cefotaxime (CTX 30 μg); Chloramphenicol (CLO 30 μg) and Tetracycline (TET 30 μg). Evaluation of the susceptibility of the strains to different antimicrobials showed that the strains isolated from skin mucus demonstrated 100% resistance to amoxicillin, while no strain was resistant to chloramphenicol at this specific site. The results highlight the importance of preventive measures to contain the spread of these microorganisms.