|1804-1||ETIOLOGY AND RESISTANCE PATTERNS OF MASTITIS-CAUSING AGENTS IN GOATS|
|Autores:||Wellington Dias Lopes Júnior (CCA/UFPB - Centro de Ciências Agrárias/Universidade Federal da Paraíba) ; Candice Maria Gomes de Leon (CCA/UFPB - Centro de Ciências Agrárias/Universidade Federal da Paraíba) ; Francisca Geovânia Canafístula de Sousa (CCA/UFPB - Centro de Ciências Agrárias/Universidade Federal da Paraíba) ; Angélica Soares de Mendonca Lopes (CCA/UFPB - Centro de Ciências Agrárias/Universidade Federal da Paraíba) ; Camila Pereira da Silva (CCA/UFPB - Centro de Ciências Agrárias/Universidade Federal da Paraíba) ; Celso José Bruno de Oliveira (CCA/UFPB - Centro de Ciências Agrárias/Universidade Federal da Paraíba) |
The aim of this study to assess the antimicrobial resistance patterns of microorganisms associated with caprine subclinical mastitis in semiarid Paraiba, Northeastern Brazil. Microbial isolating was performed by conventional bacteriology using aseptically milk samples. Antimicrobial susceptibility tests were performed by the disk diffusion method and by microdilution using a semiautomatic system (Autoscan 4, Siemens) in order to determine the minimum inhibitory concentration (MIC) of the tested antimicrobials. Clinical mastitis was detected in 2 animals only (0.7%). Considering the microbiological isolating as the gold standard for subclinical mastitis diagnosis, 56 (10%) half udders and 43 (15%) lactating goats were considered positive for subclinical mastitis. Only staphylococci organisms were identified as mastitis-causing agents in the investigated animals. Out of the 44 isolates cultured from the milk samples, the majority of them were coagulase negative staphylococci (n=33) belonging to the following species: S. epidermidis (15), S. schleiferi (4), S. lugdunensis (4), S. haemolyticus (3), S. xylosus (2), S. simulans (2), S. cohnii (2) and S. sciuri (1), as only 11 isolates were coagulase positive staphylococci: S. intermedius (4), S. aureus (4), and S. hyicus (3). Microorganisms associated with mastitis showed high levels of resistance against beta-lactams, mainly ampicillin and penicillin G (75% and 77%, respectively), according to the results by the disk-diffusion method. High resistance against teracycline (45%) was also observed. Pan-susceptibility was reported for gentamicin, neomycin, chloramphenicol, and cephalothin. Multidrug resistance was observed in 12 (27%) isolates, mainly in coagulase negative staphylococci. The results from the microdilution method corroborated the main findings observed by the disk-diffusion method. However, the microdilution method indicated a higher resistance rate of staphylococci against certain antimicrobials, particularly gentamicin (18%). This is very important considering gentamicin is widely used in Brazil to either treat clinical and subclinical mastitis or prevent the infection before lactations. There was no significant association between the synthesis of coagulase by staphylococci and antimicrobial resistance.
Acknowledgements: CNPq for financial support/fellowship and Capes for fellowship.
Palavras-chave: antimicrobial susceptibility test, caprine mastitis, MIC, subclinical mastitis