Variations in the levels of acute-phase proteins and lactoferrin in serum and milk during bovine subclinical mastitis.

Variations in the levels of acute phase proteins and lactoferrin in serum and milk for diagnosis of subclinical mastitis in dairy cows are described in this research paper. Milking animals from two organized dairy farms in Kerala, India, were screened by California Mastitis Test (CMT), Electrical Conductivity test (EC) and Somatic Cell Count (SCC) test to identify animals affected with sub clinical mastitis (SCM). The concentrations of acute phase proteins (APP) Haptoglobin (Hp), C- reactive protein (CRP), Albumin, Lactoferrin (Lf) and α- 1 acid glycoprotein (AGP) in milk and Hp, Albumin, Serum Amyloid A (SAA) and CRP in the serum of 40 normal cows and 40 cows affected with sub clinical mastitis were assessed. Solid phase ELISA was employed for assessment of all parameters except the albumin levels, for which spectrophotometry was used. The values of Hp in milk; and SAA, AGP and Lf in serum, were significantly elevated in the group with sub clinical mastitis. Such variations were found to be independent of the specific bacterial organism causing the disease. These results show that significant variations exist in the levels of acute phase proteins Hp, AGP and Lf in milk, and SAA in serum of animals affected with subclinical bovine mastitis that are not affected by specific bacterial etiology.

Genotypic and phenotypic ß-lactam resistance and presence of PVL gene in Staphylococci from dry bovine udder.

Dairy cows affected with subclinical mastitis can be sources of virulent, antimicrobial-resistant Staphylococci to humans because of the excretion of the bacteria through their milk. This study focussed on the phenotypic and genotypic antibiotic resistance patterns of Staphylococci isolated from dairy cows in early dry period. Among 96 isolates of Gram positive cocci from 157 cows, 76 were identified as Coagulase Negative Staphylococci and the remaining 20 were Staphylococcus aureus. Typical amplicons of coagulase gene were obtained for all 20 samples of S. aureus with three major coagulase types being identified as giving 627 bp (40%), 910 bp (35%) and 710 bp (25%) long PCR products. The groEL gene was amplified in PCR of all 76 isolates of Coagulase Negative Staphylococci, and incubation of PCR products with restriction enzyme PvuII yielded three distinct PCR-RFLP fragment patterns bearing resemblance to S. chromogenes and S. hyicus. Highest sensitivity of Coagulase Negative Staphylococci was noted for Azithromycin (92.5%) and the least to Tetracyclines (76.3%), whereas for S. aureus, it was Cefoperazone (95%) and Azithromycin (72.2%) respectively. Phenotypic resistance to Oxacillin (25 isolates), and Cefoxitin (11 isolates) was detected by dilution method with a commercial strip (Ezy MICTM). Genotypic resistance to ß-Lactam antibiotics was found in 65 (34 with mecA gene and 31 with blaZ gene) isolates. Eighteen isolates possessed both the genes, with the PVL gene for virulence being detected in five of them. Nine isolates which had mecA gene were phenotypically susceptible to oxacillin while phenotypic resistance to oxacillin was observed in seven isolates that did not have either mecA or blaZ gene. This is the first report of persistent Staphylococcal infections possessing PVL gene and high level of genotypic resistance to ß-Lactam antibiotics in small- holder dairy cattle from India.

Epidemiology of bovine viral diarrhoea among tropical small holder dairy units in Kerala, India.

Prevalence of bovine viral diarrhoea among 385 dairy cattle reared under a small holder system in Trichur District of Kerala State in India was determined through an ELISA targeting antibodies against p80-p125 non-structural protein of the virus. Prevalence was 24.7% among the total population, but was higher (52%) when 85 animals having infertility problems alone were considered. Significant serum biochemistry differences between animals could be noticed only in total protein, globulin and phosphorous, all of which were low in seropositive animals. All animals which were seronegative for antibodies were screened by another ELISA targeting the E(rns) protein of the viral nucleocapsid to detect persistently infected (PI) animals. The single, positive animal had only a transient period of antigens in the blood, indicating absence of PI animals in the study population. High prevalence of the disease in isolated small holder units even in the absence of PI animals is discussed in view of identifying the common source of infection and initiating control measures.