Antimicrobial resistance studies in staphylococci and streptococci isolated from cows with mastitis in Argentina.

Autor: Crespi E; Universidad de Buenos Aires, Facultad de Ciencias Veterinarias, Cátedra de Microbiología, Av. Chorroarín 280, Buenos Aires C1427CWO, Argentina., Pereyra AM; Universidad de Buenos Aires, Facultad de Ciencias Veterinarias, Cátedra de Microbiología, Av. Chorroarín 280, Buenos Aires C1427CWO, Argentina., Puigdevall T; Universidad de Buenos Aires, Facultad de Ciencias Veterinarias, Cátedra de Microbiología, Av. Chorroarín 280, Buenos Aires C1427CWO, Argentina., Rumi MV; Universidad de Buenos Aires, Facultad de Ciencias Veterinarias, Cátedra de Microbiología, Av. Chorroarín 280, Buenos Aires C1427CWO, Argentina., Testorelli MF; Universidad de Buenos Aires, Facultad de Ciencias Veterinarias, Cátedra de Microbiología, Av. Chorroarín 280, Buenos Aires C1427CWO, Argentina., Caggiano N; Universidad de Buenos Aires, Facultad de Ciencias Veterinarias, Cátedra de Fisiología Animal, Av. Chorroarín 280, Buenos Aires C1427CWO, Argentina., Gulone L; Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Cátedra de Microbiología, Junín 954, Buenos Aires C1113AAD, Argentina., Mollerach M; Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Cátedra de Microbiología, Junín 954, Buenos Aires C1113AAD, Argentina., Gentilini ER; Universidad de Buenos Aires, Facultad de Ciencias Veterinarias, Cátedra de Microbiología, Av. Chorroarín 280, Buenos Aires C1427CWO, Argentina., Srednik ME; Universidad de Buenos Aires, Facultad de Ciencias Veterinarias, Cátedra de Microbiología, Av. Chorroarín 280, Buenos Aires C1427CWO, Argentina. maru_sred@fvet.uba.ar.
Jazyk: angličtina
Zdroj: Journal of veterinary science [J Vet Sci] 2022 Nov; Vol. 23 (6), pp. e12.
DOI: 10.4142/jvs.21062
Abstrakt: Background: Staphylococcus aureus and Streptococcus agalactiae are the main cause of clinical mastitis in dairy cattle in Argentina, whereas coagulase-negative staphylococci (CNS) and environmental streptococci are the main cause of subclinical mastitis. Bacteria isolated from infected animals show increasing antimicrobial resistance.
Objectives: This study aims to determine the antimicrobial resistance of staphylococci and streptococci isolated from milk with mastitis, and to genotypically characterize the methicillin-resistant (MR) staphylococci.
Methods: Isolation was performed on blood agar and identification was based on biochemical reactions. Antimicrobial susceptibility was according to the Clinical and Laboratory Standards Institute guidelines. The antimicrobial resistance genes, SCC mec type and spa type were detected by the polymerase chain reaction method.
Results: We isolated a total of 185 staphylococci and 28 streptococci from 148 milk samples. Among the staphylococcal isolates, 154 were identified as CNS and 31 as S. aureus . Among the 154 CNS, 24.6% (n = 38) were resistant to penicillin, 14.9% (n = 23) to erythromycin, 17.5% (n = 27) to clindamycin, 6.5% (n = 10) to cefoxitin and oxacillin. Among the S. aureus isolates, 16.1% (n = 5) were resistant to penicillin, 3.2% (n = 1) to cefoxitin and oxacillin (MRSA). Six MR isolates (5 CNS and 1 MRSA) were positive to the mecA gene, and presented the SCC mec IVa. The MRSA strain presented the sequence type 83 and the spa type 002. Among the 28 streptococcal isolates, 14.3% (n = 4) were resistant to penicillin, 10.7% (n = 3) to erythromycin and 14.3% (n = 4) to clindamycin.
Conclusions: The present findings of this study indicate a development of antimicrobial resistance in main bacteria isolated from cows with mastitis in Argentina.
Competing Interests: The authors declare no conflicts of interest.
(© 2022 The Korean Society of Veterinary Science.)
Databáze: MEDLINE