No abstract

No abstract

No abstract

Strains isolated from the skin and the upper respiratory tract of chickens and from bovine udders showed characteristics typical for Staphylococcus epidermidis biotype 2, but produced a heat‐resistant nuclease (DNase) and reacted in the tube coagulase test. The strains were physiologically, biochemically and serologically indistinguishable from Staphylococcus hyicus strains isolated from swine. However, in contrast to S. hyicus, they appeared to be devoid of pathogenicity when tested in colostrum deprived piglets. The poultry strains occur frequently as skin inhabitants.

Antibodies to the staphylococcal antigens peptidoglycan, P-ribitol teichoic acid, and lipoteichoic acid, as well as to the peptidoglycan epitopes L-Lys-D-Ala-D-Ala, L-Lys-D-Ala, and pentaglycine, were found over a wide range of concentrations in sera from both blood donors and patients with verified or suspected staphylococcal infections. The patient group was heterogeneous with regard to both age and type of staphylococcal infections, being representative for sera sent to our laboratory. In single-antigen assays antibodies to pentaglycine had the highest predictive positive value (67%), although only 32% of the patients had elevated levels of such antibodies. Combinations of test antigens could yield positive predictive values as high as 100%, but then the fraction of positive sera was low. Indeed, the fraction of patient sera which was positive in multiple-antigen tests never exceeded 61%. The clinical usefulness of these seroassays for identifying Staphylococcus aureus as a causative agent was limited, owing to the considerable overlap in the range of antibody concentrations between patient and blood donor sera.

A comparison has been made between the bacteriophage and serological methods for identifying types among coagulase-positive staphylococci. In only a few cases was one particular serotype clearly related to a particular phage-type, and in several cases single ‘types’ recognized by one method contained several different ‘types’ when tested by the second method. Nevertheless, when sets of strains isolated in the investigation of epidemics or of the nose and skin carrier state of particular individuals were tested by the two methods, consistent results were obtained: an individual combination of phage-type and serotype appeared to be stable.The principal advantages of phage-typing are the facts that it is able to recognize more types than the serological method, and that the distinctions between the types are based on a greater number of different reactions. The advantages of the serological method are the smaller number of untypable strains and its greater technical simplicity.Thanks are due to Miss Joan Rippon, Ph.D., for assistance in the analysis of the phage-typing results.

No abstract

No abstract