Genotypic identification of methicillin resistance and virulence factors in Staphylococcus spp. from bovine mastitis milk

• Published in: Comparative clinical pathology Vol. 26; no. 6; pp. 1355 - 1361
• Main Authors: Patel, Khushal, Joshi, Chaitanya, Nauriyal, Devendra, Kunjadiya, Anju
• Format: Journal Article
• Language: English
• Published: London Springer London 01-11-2017; Springer Nature B.V
• Subjects: Antibiotics; California mastitis test; Cattle; Hematology; Mannitol; Mastitis; Medicine; Medicine & Public Health; Methicillin; Milk; Oncology; Original Article; Pathology; rRNA 16S; Staphylococcus; Virulence factors; Mastitis; Antibacterial resistance; Resistance genes; Virulence; Staphylococcus; MRSA
• ISSN: 1618-5641; 1618-565X
• DOI: 10.1007/s00580-017-2540-1

The aim of this study was the genotypic characterization of methicillin resistance and virulence of
Staphylococcus
spp. from bovine mastitis cases. The study was designed to collect milk samples from 120 animals (90 lactating cows and 30 buffaloes) and screened using California mastitis test and somatic cell counts.
Staphylococci
were isolated on Baird-Parker, mannitol salt and identified based on their physiologically and species-specific biochemical tests. Antibiotic resistivity assay was performed using standard antibiotic disc diffusion technique for screening. On the basis of antibiograms, 26 strains were selected. Selective isolates were identified based on 16S rDNA gene sequencing. Virulence genes associated with
Staphylococcus
sp. viz.
coa
,
ccr
,
sar
,
spa
,
clf
A,
ica
complex,
fnb
A, and
mec
A were amplified on screened isolates. A total of 26 isolates,
S. aureus
,
S. pasteuri
,
S. hominis
,
Micrococcus
sp., and
Macrococcus
sp. were selected on the basis of all in vitro assay and their 16S rDNA sequences were submitted to NCBI, GenBank under the accession number KX821621 to KX821646. Out of 26 studied typed isolates, 19, 15, 14, 21, 6, 25, and 22 isolates give amplification for
mec
A,
coa
,
spa
,
clf
A,
ccr
,
ica
,
fnb
A, and
sar
genes, respectively. Four
S. aureus
possessed all virulence genes. Presence of methicillin resistance
Staphylococci
having virulence genes revealed that mastitis is a major concern nowadays affecting animal health, milk quality, and yield. Further genomic study of these isolates will provide broad new insights on virulence.