Changes

*Oxidase-negative

*Oxidase-negative

===Detections & Differentiation===

===Detection & Differentiation===

The most simple method of detection is to gram stain a sample, usually puss, and to then visualise the distinctive clusters under a microscope. This provides a basic identification of the type of bacteria, however occasionally it is necessary to identify the species that causing the infection. This can be done using various techniques based on the different characteristics of the species. Growing cultures on blood agar will enable identification of haemolytic vs. non haemolytic species. PCR is the most specific method of determining the species of bacteria but requires laboratory analysis of samples.

The most simple method of detection is to gram stain a sample, usually puss, and to then visualise the distinctive clusters under a microscope. This provides a basic identification of the type of bacteria, however occasionally it is necessary to identify the species that causing the infection. This can be done using various techniques based on the different characteristics of the species. Selective agar such as blood, for haemolysin producing species such as ''S. aureus'' and ''S. intermedius'' as well as non haemolytic species such as ''S. hyicus''. MacConkey agar can be used to identify. PCR is the most specific method of determining the species of bacteria but requires laboratory analysis of samples and is only usually used in research.

*Coagulase-negative strains vary in ability to cause haemolysis

*Coagulase-negative strains vary in ability to cause haemolysis

*Slide test to detect bound coagulase (clumping factor) on surface of bacteria; bacteria clump within 1-2 minutes

*Slide test to detect bound coagulase (clumping factor) on surface of bacteria; bacteria clump within 1-2 minutes

*Tube test detects free coagulase, secreted by bactera; positive result indicated by clot formation in tube following 24-hour incubation; free coagulase converts prothrombin to thrombin which converts fibrinogen to fibrin

*Tube test detects free coagulase, secreted by bactera; positive result indicated by clot formation in tube following 24-hour incubation; free coagulase converts prothrombin to thrombin which converts fibrinogen to fibrin

===Pathogenesis and pathogenicity===

===Pathogenesis and pathogenicity===