Detection of mastitis-associated bacteria can be accomplished by culturing or by molecular techniques. On the other hand, rapid and inexpensive methods to enumerate bacterial load without culturing can be better achieved by molecular methods. Staphylococcus aureus and Escherichia coli are the predominant bacterial pathogens associated with bovine mastitis. Here, we describe the application of conventional PCR for the limit of detection (LOD) of genomic DNA of S. aureus and E. coli based on single-copy genes. The selected genes were thermonuclease (nuc), aureolysin (aur), and staphopain A (scpA) for S. aureus and β-D-glucuronidase A (uidA), cytochrome d oxidase (cyd), and rodA (a gene affecting cell shape and methicillin sensitivity) for E. coli. The LOD was 5.3, 15.9, and 143 pg for aur, nuc, and scpA genes, corresponding to S. aureus genomic copies of 1.75 × 10(3), 5.16 × 10(3), and 4.71 × 10(4), respectively. The LOD was 0.45, 12.3 and 109 pg for uidA, rodA and cyd genes, corresponding to E. coli genome copies of 8.91 × 10(1), 2.43 × 10(3), and 2.16 × 10(4), respectively. Application of uidA and aur PCRs to field strains revealed that as low as approximately 100 genome copies of E. coli and 1000-10,000 copies of S. aureus could be detected. This study is the first to report LOD of genomic DNA using conventional PCR for aur and scpA genes of S. aureus, and rodA and cyd genes of E. coli. The results should be useful for developing assays to assess bacterial load in milk and to determine the load that contributes to subclinical or clinical mastitis.
A questionnaire based study on various clinical complications related to different body systems of pigs with special reference to respiratory system has been carried out in fifty different pig farms of Hassan district, Karnataka state during the period from April 2019 to March 2020. The clinical problems related to digestive system were in the highest order (96%) followed by systemic/ fever (80%), skin problems (64%). The problems related to the respiratory system like coughing, laboured breathing, nasal discharge, and dryness of snout etc, (46%), reproductive problems (38%), endoparasites (28%), urinary system (12%). The complications related to nervous system (10%) was also observed. The respiratory problems appeared at considerable levels. Further detailed analysis related to the respiratory diseases caused by the various agents along with the managemental and environmental factors is warranted for the future studies to know the major factors involved in inducing the respiratory problems in pigs of the study area.
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