title: Comparison of three typing assays for nicotinamide adenine dinucleotide-independent Actinobacillus pleuropneumoniae.
abstract: Three tests for typing clinical isolates of Actinobacillus pleuropneumoniae biovar 2 were compared: 1) standard coagglutination with type-specific antisera against serovars 1-12 of biovar 1 of A. pleuropneumoniae; 2) a previously described polymerase chain reaction system for detecting the apx genes encoding the ApxI, ApxII, and ApxIII toxins in A. pleuropneumoniae; and 3) a restriction fragment length polymorphism analysis of the transferrin-binding protein B gene. The panel of strains tested included 112 field isolates of biovar 2 recovered from pigs between 1979 and 2007 in Italy and Spain, and reference strains for all described serovars of both biovars. The values of Simpson index of diversity obtained for the 3 methods were 0.68, 0.20, and 0.60, respectively. Coagglutination assays identified the field isolates as belonging to serovars 2 (9 strains), 4 (13 strains), 7 (61 strains), 9 (17 strains), and 11 (1 strain). Eleven strains were not typeable, and cross-reactivity was observed between serovars 2 and 4, 4 and 7, and 9 and 11. Isolates of A. pleuropneumoniae biovar 2 displayed 2 apx patterns: ApxII(+) (94 strains) and ApxI(+)/ApxII(+) (18 strains). The restriction fragment length polymorphism analysis assigned the strains tested to 3 different patterns. This method distinguished between biovar 2 reference strains and field strains that could not be identified by other methods, thus constituting a useful complementary test for the typing of A. pleuropneumoniae biovar 2.
authors: Diagnostic Laboratory, Laboratorios HIPRA S.A., Paratge Arbusset s/n, Girona 17170, Spain. jmg@hipra.com
authors: Jaime
authors: J
authors: Maldonado
authors: Mónica
authors: M
authors: Blanco
authors: Eva
authors: E
authors: Martínez
authors: Jesús
authors: J
authors: Navas
mesh_terms: D000189:Actinobacillus Infections / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary; D016977:Actinobacillus pleuropneumoniae / Q000145:classification* / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D000942:Antigens, Bacterial; D001427:Bacterial Toxins / Q000378:metabolism; D015373:Bacterial Typing Techniques / Q000379:methods / Q000662:veterinary*; D004269:DNA, Bacterial / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D007558:Italy / Q000453:epidemiology; D009243:NAD / Q000378:metabolism*; D016133:Polymerase Chain Reaction / Q000379:methods / Q000662:veterinary; D012150:Polymorphism, Restriction Fragment Length; D015203:Reproducibility of Results; D013030:Spain / Q000453:epidemiology; D013552:Swine; D013553:Swine Diseases / Q000453:epidemiology / Q000382:microbiology
chemical_list: D000942:Antigens, Bacterial; D001427:Bacterial Toxins; D004269:DNA, Bacterial; D009243:NAD