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D S Postle

Publications and source records attributed to D S Postle.

11 recordsLinked to original sources
PubMed1978

Induced staphylococcal infections in the bovine mammary gland.

In a study to develop and define a practical model of bovine mastitis caused by Staphylococcus aureus, induced infections were attempted in 203 bovine mammary glands of 41 cows, using 12 strains of S aureus. Approximately 100 colony-forming units of S aureus in saline solution were injected after milking, and milk samples were collected daily from test glands for 14 days to monitor the progress of infections and inflammatory responses. Relationships were examined for cow-related factors and for various characteristics of the strains of S aureus used to the development of a persistent intramammary infection. A dairy cow that was useful in this model was defined as follows: (1) the 2nd to 7th month in the 1st to 5th lactation; (2) producing milk from all mammary glands that contained less than 6 x 10(5) somatic cells/ml; and (3) having mammary glands that were free of any primary mastitis pathogen, as well as micrococci and Corynebacterium bovis. From the present study, it was not possible to define clearly a strain of S aureus which would be useful in the model, but 5 strains of S aureus were identified as being capable of producing persistent subacute infections with a high degree of repeatability.

Animals↗
PubMed1976

Observations on bacteriologic isolation from pairs of quarter-milk samples.

Observations are reported on the agreement of bacteriologic isolation between 11,917 pairs of quarter-milk samples collected as either duplicate samples (both samples collected during 1 farm visit) or consecutive samples (2 samples collected at different milkings). Better agreement was found for duplicate samples (95.5%) than for consecutive samples (88.5% for interval of 2 to 7 days and 81.3% for interval of 8 to 16 days). From these observations, it was estimated that for diagnosing an intramammary infection, the examination of a single quarter-milk sample would be expected to have an error of approximately 3%.

Animals↗