Perfil de resistência aos antimicrobianos de Escherichia coli isoladas de urina de cães e gatos

Abstract

Urinary tract infections (UTI) are characterized by bacterial proliferation in the urethra, bladder, ureters and kidneys. Escherichia coli (E. coli) is a gram negative bacteria, non-sporulated, flagellate, bacillary which is considered one of the most common agents of urinary tract infections, with highly resistant strains: multidrug-resistant bacteria (MDR). Bacterial resistance has been reported as major problem of animal and human health due to the widespread use of antibiotics. Domestic animals are pointed out as reservoirs of resistant bacteria and E. coli is one of the main antimicrobial resistance spreaders. The objective of this study was to characterize the resistance profile of E. coli in urine samples from dogs and cats in Cuiabá-MT. Materials, Methods & Results: Isolates from urine samples of domestic animals (dog and cat) were received and processed at Microbiology Laboratory of the UFMT Veterinary Hospital in 2020. The samples were seeded in Blood and MacConkey Agar, incubated for 24 hours at 37ºC and after growth were characterized morphologically and biochemically. For antimicrobial susceptibility test agar diffusion method was performed, following the guidelines of the CLSI (Institute of Clinical and Laboratory Standards). The antimicrobial classes were tested: carbapenems (imipenem and meropenem), penicillins (amoxicillin + clavulanic acid), cephalosporins (ceftriaxone), aminoglycosides (gentamicin), quinolones (ciprofloxacin and enrofloxacin) and phenicol (chloramphenicol). Isolates were classified according to their resistance profile. 365 urines were processed and E. coli was found in 33 (9%) urine samples, 22 from dogs and 11 from cats. From the 33 isolates, 16 (48.5%) showed multi-resistance characteristics. The antibiotic with the highest frequency of resistance was cephalexin (22/33), followed by ciprofloxacin (19/33) and enrofloxacin (17/33). Discussion: Currently, the spread of broad-spectrum cephalosporin-resistant Enterobacteriaceae is quite worrying, especially in E. coli (ESCR-E.coli) which is already found worldwide in dogs and cats, including Brazil. Cephalexin considered the first choice drug was also ineffective in other works. Second-generation quinolones have good action against gram-negative bacteria, however in this study, as in others, had little efficacy. Studies relate the resistance to this antimicrobial class to wide use in veterinary medicine, especially enrofloxacin for exclusive use in animals. Quinolone resistance has already been reported in animal and human strains, and the emergence of E. coli strains resistant to these antimicrobials in this and others studies suggests that E. coli is a major spreader of quinolone resistance. The results of antimicrobial susceptibility testing shows that imipenem, meropenem, amoxicillin + acid. clavulanic and chloramphenicol were drugs with the best efficacy. Multidrug resistance found in high percentage in this study (48.5%) alert to the possibility of the spread of resistance genes to environment and human population as well as the importance of pets animals in this issue. Bacterial resistance among dogs and cats is believed to have received little attention despite the frequent use of antibiotics to treat infections in companion animals. In veterinary medicine, treatment with antimicrobials is not always easy, due to the difficulty of a quick diagnosis and high therapy costs, but the high percentage of antibiotic resistance presented in this study and the global situation, isolation and antimicrobial sensitivity testing are necessary.