Submitted to: Journal of Clinical Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/21/1998
Publication Date: N/A
Interpretive Summary: Bordetella bronchiseptica and toxigenic Pasteurella multocida are the etiologic agents of swine atrophic rhinitis and primary bronchopneumonia in piglets. Moderate and severe outbreaks are of considerable economic importance as they are often accompanied by reduced growth rate and inefficient feed conversion. Methods currently used for identification of B. bronchiseptica and toxigenic P. multocida from diagnostic samples are time-consuming, suffer from a lack of sensitivity, and are based, in part, on subjective observations. Here we describe the use of two nucleic acid probes for fast and easy detection of these organisms. A two-color development procedure permits the use of a single sample for their simultaneoueous detection and provides results that are easy to interpret. When present, colonies of B. bronchiseptica turn pink and colonies of toxigenic P. multocida turn purple. Comparison of this technique to results from conventional identification methods indicates that it has superior sensitivity and comparable specificity. This technique has wide application for diagnostic and experimental studies.
Technical Abstract: Bordetella bronchiseptica and toxigenic Pasteurella multocida are the etiologic agents of swine atrophic rhinitis. Methods currently used for their identification are time-consuming and suffer from a lack of sensitivity. We describe a colony lift-hybridization assay for detection of B. bronchiseptica and toxigenic P. multocida that can be performed on a single colony lift derived from a primary isolation plate, without the need for pure subcultures of suspect bacteria. Membranes are hybridized simultaneously to probes derived from the B. bronchiseptica alcA gene and the P. multocida toxA gene. A multicolor development procedure permits sequential detection of bound probes. The assay was tested on 83 primary isolation plates generated from nasal swabs of swine with clinical signs of atrophic rhinitis. Comparison of the results from the colony lift- hybridization assay with those from conventional testing, based on a combination of colony morphology, biochemical reactions, mouse lethality, and ELISA, indicated that the colony life assay has superior sensitvity and comparabel specificity. This technique has wide application for diagnostic and experimental studies.