Short communication: Bovine mastitis caused by a multidrug-resistant, mcr-1-positive (colistin-resistant), extended-spectrum ß-lactamase-producing Escherichia coli clone on a Greek dairy farm.
J Dairy Sci
; 103(1): 852-857, 2020 Jan.
Article
en En
| MEDLINE
| ID: mdl-31733863
ABSTRACT
We performed a survey aimed at analyzing milk samples collected from cows with mastitis for the presence of extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli. Single-quarter mastitic milk samples obtained from 400 cows in 23 Greek dairy herds with a history of E. coli mastitis were processed for the selective isolation of ESBL-producing E. coli. The antimicrobial susceptibility of the ESBL-producing isolates was analyzed using agar disk diffusion, and minimum inhibitory concentrations of colistin were determined by broth microdilution. We used PCR followed by DNA sequencing to characterize the ß-lactamases and mcr-1 (colistin resistance) genes, and for phylotyping and multilocus sequence typing. We found a total of 89/400 (22.25%) E. coli isolates from 12/23 (52%) farms. Six isolates originating from 6 cows on a single farm were ESBL producers and were resistant to cefquinome, amoxicillin-clavulanic acid, aztreonam, ampicillin, and colistin. Five of these isolates were resistant to trimethoprim-sulfamethoxazole, and 5 to streptomycin. The 6 ESBL producers were mcr-1-positive and carried blaTEM-1 genes; 3 also carried blaCTX-M genes, and 3 carried blaSHV genes. All of the ESBL producers belonged to phylogroup A, multilocus sequence type ST666 (n = 5), or a single locus variant of ST666 (n = 1). To our knowledge, this is the first report of endemic bovine mastitis caused by mcr-1-positive, ESBL-producing E. coli. These results highlight the value of active surveillance of antimicrobial resistance not commonly tested by diagnostic laboratories for the early detection of novel resistant strains.
Palabras clave
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Colistina
/
Escherichia coli
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Infecciones por Escherichia coli
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Mastitis Bovina
Tipo de estudio:
Screening_studies
Límite:
Animals
País/Región como asunto:
Europa
Idioma:
En
Revista:
J Dairy Sci
Año:
2020
Tipo del documento:
Article
País de afiliación:
Grecia