Abstract:
Mastitis is a cow disease usually signalized by
irritation, swelling, and soreness of the udder. It is characterized by physical, chemical, and biological changes
in the udder and milk. The aim of this study was to detect
and characterize pathogens causing subclinical mastitis
(SCM) from the milk of dairy cows of small-scale farmers
through culture and molecular techniques. Milk was collected from 32 cows belonging to 8 small-scale farmers around Harrismith District, South Africa. The results showed
that screening of SCM by California mastitis test and somatic
cell counts (SCC) was 21.87 and 25%, respectively. Culture
methods revealed the presence of Staphylococcus aureus at
93% followed by Streptococci spp. and Escherichia coli at
36.4 and 13.3%, respectively. The PCR could only detect
E. coli, while single-molecule real-time sequencing showed
a total of 2 phyla, 5 families, 7 genera, and 131 species.
Clostridiaceae was the most abundant family, while
Romboutsia was the most abundant genus followed by
Turicibacter spp. The present study has documented the
occurrence of SCM causing pathogens in milk collected
from cows of small-scale farmers in Harrismith, indicating
that SCM may be present at higher levels than expected.
