Buffaloes are the second largest source of milk.
Mastitis is a major impediment for milk production, but not much information is available about bubaline
mastitis, especially subclinical
mastitis. The aim of this study was to (a) investigate the application of various tests for the diagnosis of bubaline subclinical
mastitis, (b) identify the major bacteria associated with it, and (c) evaluate the antibiotic resistance pattern of the bacteria. To this end, 190 quarter milk samples were collected from 57 domesticated dairy buffaloes from organized (64 samples) and unorganized (126 samples) sectors. Of these, 48.4%, 40.0%, 45.8%, 61.1%, and 61.6% were positive for subclinical
mastitis by somatic cell count, electrical conductivity, California
mastitis test,
bromothymol blue test, and N-acetyl
glucosaminidase test, respectively. As compared to the gold standard of somatic cell count, California
mastitis test performed the best. However, a combination of the two methods was found to be the best option. Microbiological evaluation, both by biochemical methods as well as by monoplex and multiplex polymerase chain reaction, revealed that
coagulase-negative staphylococci were the most predominant (64.8%) bacteria, followed by streptococci (18.1%), Escherichia coli (9.8%) and Staphylococcus aureus (7.3%). Most of the pathogens were resistant to multiple
antibiotics, especially to β-
lactam antibiotics. We propose that California
mastitis test be combined with somatic cell count for diagnosis of subclinical
mastitis in domestic dairy buffaloes. Further, our results reveal high resistance of the associated bacteria to the β-
lactam class of
antibiotics, and a possible major role of
coagulase-negative staphylococci in causing the disease in India.