dog and cat assay data sheet

"Strep zoo" in dogs (hemorrhagic streptococcal pneumonia)

Test code: B0019 - Qualitative detection of Streptococcus equi subspecies zooepidemicus by polymerase chain reaction. This assay detects and differentiates subspecies equi and subspecies zooepidemicus.

Streptococcus equi subsp. equi is the etiological agent of strangles and is responsible for nearly 30% of all reported equine infections worldwide (Chanter, 1997). The very closely related organism Streptococcus zooepidemicus (S. equi subsp. zooepidemicus) has also been found to be a significant cause of equine lower airway disease, foal pneumonia, endometritis, and abortion (Chanter, 1997). In dogs, S. zooepidemicus is associated with hemorrhagic streptococcal pneumonia (HSP) in dogs ([Garnett et al., 1982). The HSP syndrome is a severe infection, in which sudden death can occur without any prior clinical signs. In general, dogs with higher S. equi subsp. zooepidemicus scores of infection were more likely to have severe alveolar damage (Chalker et al., 2003).

In the past, identification of S. equi bacteria usually relied on culture of the bacteria, but this technique is slow and not very sensitive. A recent study (Newton, 2000) has shown that repeated nasopharyngeal swabbing and culture of Streptococcus equi could not detect the development of healthy carriers in more than 50% of equine strangles outbreaks. S. equi was sometimes not detected by culture of nasopharyngeal swabs from carriers for up to 2 or 3 months before nasal shedding resumed sporadically. The study found that PCR was a more sensitive technique for detecting S. equi on swabs: many more known positive swabs were detected using PCR than using culture (56 of 61 swabs positive by PCR vs. 18 of 61 swabs positive by culture). Similar results were obtained for equine guttural pouch samples from 12 established carriers (PCR 76% vs. culture 59%). PCR also allows differentiation of the two subspecies, equi and zooepidemicus.

Utilities:

• Confirm the disease causing agent
• Ensure that dog populations are free of Streptococcus zoopidemicus
• Early prevention of spread of Strep zoo among a group of dogs
• Minimize human exposure to Strep zoo
• Safety monitoring of biological products and vaccines that derive from susceptible animals

References:
Chalker, V.J., Brooks, H.W. and Brownlie, J. (2003) The association of Streptococcus equi subsp. zooepidemicus with canine infectious respiratory disease. Vet Microbiol. 95:149-156.
Chanter, N. (1997) Streptococci and enterococci as animal pathogens. J. Appl. Microbiol. Symp. Suppl. 83:100S-109S.
Garnett, N.L., Eydelloth, R.S., Swindle, M.M., Vonderfecht, S.L., Strandberg, J.D. and Luzarraga, M.B. (1982) Hemorrhagic streptococcal pneumonia in newly procured research dogs. J. Am. Vet. Med. Assoc. 181:1371–1374.
Newton, J.R., Verheyen, K., Talbot, N.C., Timoney, J.F., Wood, J.L., Lakhani, K.H. and Chanter, N. (2000) Control of strangles outbreaks by isolation of guttural pouch carriers identified using PCR and culture of Streptococcus equi. Equine Vet J. 32:515-526.

Canine specimen requirement: Nasopharyngeal swab, or 0.5 ml whole blood in EDTA (purple top) or ACD (yellow top) tube.

For specimen types other than those listed here, please call to confirm specimen acceptability and shipping instructions.

For all specimen types, if there will be a delay in shipping, or during very warm weather, refrigerate specimens until shipped and ship with a cold pack unless more stringent shipping requirements are specified. Frozen specimens should be shipped so as to remain frozen in transit. See shipping instructions for more information.

Turnaround time: 2 business days

Methodology: Qualitative PCR

Normal range: Nondetected