Sindhu N.,CCS Haryana Agricultural University |
Sharma A.,CCS Haryana Agricultural University |
Sharma A.,Veterinary College Central Laboratory |
Jain V.K.,CCS Haryana Agricultural University
Indian Journal of Animal Sciences | Year: 2010
The present study aimed to diagnose Staphylococcus aureus from mastitic milk samples of crossbred cows using genus specific PCR assay based on gap gene (encoding glyceraldehyde -3-phosphate dehydrogenase) and species specific PCR assay based on aroA gene (encoding 5-enolpyruvylshikimate-3-phosphate synthase). For internal control, a set of universal primers were included. Out of 770 milk samples tested, 50.74 and 52.21% samples were diagnosed to be positive for Staphylococcus spp. by cultural examination and gap gene based genus specific PCR, whereas as many as 41.91% and 43.38% samples were found positive for Staphylococcus aureus by bacteriological examination and aroA. gene based species specific PCR respectively. The assay could also detect the "no growth" milk samples. Using this rapid, sensitive and specific method, staphylococcal isolates can be differentiated at the subspecies or strain level within 6-8 h and it can contribute to an increased understanding of mastitis epidemiology and control options for overall increase in lifetime productivity of crossbred cattle.
Sharma A.,Veterinary College Central Laboratory
Buffalo Bulletin | Year: 2010
The study was conducted to detect Staphylococcus aureus directly in mastitic milk of Murrah buffaloes using coagulase gene based specific polymerase chain reaction assay. Out of 628 samples, a total of 140 samples were found positive with four amplified products of size 960 bp, 870 bp, 740 bp and 610 bp in 8.57 percent, 19.28 percent, 29.29 percent and 42.85 percent of the milk samples, respectively. On PCR examination of Staphylococcus aureus found positive by bacteriological examination and biochemical tests, similar amplified products were observed in 9.37 percent, 21.09 percent, 32.03 percent and 37.5 percent of culture isolates (n=128) respectively. Ubiquitous PCR assay with amplified product of size 108 bp was used as an internal control for detection of Staphylococcus aureus. By this assay, nonviable Staphylococcus aureus could also be detected in milk samples of animals treated with antibiotics The study revealed that several coagulase gene types are responsible for genetic heterogeneity among Staphylococcus aureus isolated from mastitis cases in buffaloes and predominance of these amplified products shows significant variation over time paving way for understanding of epidemiology of mastitis in a particular location.