Actinobacillus pleuropneumoniae

Test code: B0099 - Ultrasensitive qualitative detection of Actinobacillus pleuropneumoniae by real time polymerase chain reaction.

Actinobacillus pleuropneumoniae, previously known as Haemophilus pleuropneumoniae, causes respiratory infection of swine. There are at least twelve different strains, some of which are non-pathogenic, but others can cause severe disease symptoms. Strains 1, 5, 9, 11 and 12 are highly virulent, while strains 3 and 6 cause mild disease symptoms. The organism shows affinity for the tonsils and respiratory tract of infected animals. The incubation period is usually very short, from as little as 12 hours to 3 days. Infected animals can spread the bacteria through respiratory aerosols, and the bacteria can survive in discharges, serum, and tissues for up to 5 days.

The major threat of this bacterial infection is that some pigs can carry the bacteria without any clinical signs. Young piglets with poorly developed immune system are particularly susceptible to infection. Once piglets are infected, rapid onset of pneumonia can occur and may result in hemorrhagic pneumonia. Prior to death or just after death, it is common to see blood coming from the nasal cavity of pigs. Postmortem examination can reveal characteristic lesions: large areas of hemorrhage in the dorsal lobes of the lungs. Lesions of this type and location do not commonly result from other infections - most other microbial infections cause lesions in the lower lung lobes, or throughout the lungs without hemorrhage.

The ability to detect these bacteria in subclinically infected herds is essential for control of the disease. Serology, and both standard and immunomagnetic separation-based (IMS) bacterial isolation methods, have sometimes been used for this purpose. Serological monitoring is cheap but it has limitations: infected pigs may be serologically negative, and sometimes, inconclusive serological results may be observed in the absence of clinical signs or pathological lesions. Culture identification of the organism or antigen detection by immunological methods usually has very low sensitivity. However, molecular detection by PCR is rapid, sensitive and specific, and is an important alternative to traditional methods in identifying these bacteria (Frey, J., 2003).

Utilities:

• Help confirm the disease causing agent
• Help ensure that swine herds are free of Actinobacillus pleuropneumoniae bacteria
• Early prevention of spread of the bacteria among a herd
• Minimize human exposure to the bacteria

References:
Frey, J. (2003) Detection, identification, and subtyping of Actinobacillus pleuropneumoniae. Methods Mol. Biol. 216:87-95.

Specimen requirements: Nasopharyngeal swab, or environmental swab, or 0.2 ml whole blood in EDTA (purple top) tube, or 0.2 ml serum, or 0.2 ml fresh, frozen or fixed tissue.

Contact Zoologix if advice is needed to determine an appropriate specimen type for a specific diagnostic application. For specimen types not listed here, please contact Zoologix 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 real time PCR

Normal range: Nondetected