Congresso Brasileiro de Microbiologia 2023

Congresso Brasileiro de Microbiologia 2023

Resumo: 43-2

43-2

PHENOTYPIC CHARACTERIZATION OF ANTIMICROBIAL RESISTANCE AND VIRULENCE FACTORS IN GRAM-NEGATIVE BACTERIA FROM WESTERN SANTA CATARINA, BRAZIL.

Autores:

Edilson do Carmo Marins Júnior (UNIVASF - Universidade Federal do Vale do São Francisco) ; Samily Aquino de Sá Oliveira (UNIVASF - Universidade Federal do Vale do São Francisco) ; Renata de Faria Silva Souza (UNIVASF - Universidade Federal do Vale do São Francisco) ; Alisson Teixeira da Silva (UNIVASF - Universidade Federal do Vale do São Francisco) ; Jônatas José da Silva (UNIVASF - Universidade Federal do Vale do São Francisco) ; Emanuelly Santos Vasconcelos (UNIVASF - Universidade Federal do Vale do São Francisco) ; Lilian Kolling Girardini (UNOESC - Universidade do Oeste de Santa Catarina) ; Mateus Matiuzzi da Costa (UNIVASF - Universidade Federal do Vale do São Francisco)

Resumo:

One Health encompasses the interconnectedness of human, animal, and environmental health. Antimicrobial resistance (AMR) is a critical concern in this context due to its implications across various domains. Understanding the virulence factors carried and expressed by gram-negative bacteria and their impact on ecosystems is essential. This study aimed to phenotypically characterize the resistance profile and virulence factors of gram-negative bacteria from Western Santa Catarina. Thirty-four isolates from hospitalized human patients, animals, environment, and food sources were selected. The isolates were identified using Gram staining and biochemical tests. Susceptibility testing to azithromycin, ciprofloxacin, chloramphenicol, meropenem, and sulfamethoxazole + trimethoprim was performed using disk diffusion. Classification of Multi-Drug Resistance (MDR) was done using the Multiple Antimicrobial Resistance Index (MAR). Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of meropenem were evaluated for 12 selected isolates using broth microdilution. Biofilm formation at the solid-liquid interface was assessed through the crystal violet adherence test, and liquid-air interface biofilm formation was evaluated with ethanol precipitation. The Cartwheel method was employed to detect active efflux pumps. Resistance was observed in 65.71% of the isolates to sulfamethoxazole + trimethoprim, 54.28% to meropenem, 45.71% to chloramphenicol, and 37.14% to azithromycin and ciprofloxacin. Twenty isolates were classified as MDR (MAR > 0.2). All animal and environmental isolates (n=4) were susceptible to meropenem, with MIC values of 0.5 μg/mL, while human-derived isolates (n=8) exhibited MIC values up to 64 times higher than the cutoff (4 μg/mL). Regarding biofilm production at the solid-liquid interface, 71% of isolates were weak producers, and 26% were moderate producers, with only one isolate considered non-producer. For liquid-air interface biofilm, 12% formed a small film, and 88% formed a moderate film. Six isolates were positive for active efflux pumps. The results demonstrate that virulence profiles, including antimicrobial resistance, biofilm production, and active efflux pumps, enhance the survival and infection potential of these microorganisms in the environment and food sources. These findings underscore the alarming use of antimicrobials as animal additives, leading to the selection of resistant bacteria and posing risks to animal populations and consumers of animal-origin foods. Furthermore, they emphasize the need for antimicrobial alternatives, promoting prudent antimicrobial use and implementing stricter control strategies for animal supplementation.

Palavras-chave:

Bacterial multidrug resistance, Animal production, Zoonoses, Antibiotic therapy

Agência de fomento:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) - Finance Code 001, Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) and Fundação de Amparo à Ciência e Tecnologia do Estado de Pernambuco (FACEPE).