Detection of Actinobacillus pleuropneumoniae by PCR on field strains from healthy and diseased pigs

• Published in: Current microbiology 2003-06, Vol.46 (6), p.443-447
• Main Authors: SILENE KLEIN, Catia, PIFFER, Itamar Antonio, CERONI DA SILVA, Sérgio, SCHRANK, Augusto, BURIN FAVERO, Maria Bernardete, SILVEIRA SCHRANK, Irene
• Format: Article
• Language: English
• Subjects: Actinobacillus Infections - diagnosis; Actinobacillus Infections - microbiology; Actinobacillus Infections - veterinary; Actinobacillus pleuropneumoniae - genetics; Actinobacillus pleuropneumoniae - isolation & purification; Action of physical and chemical agents; Animal diseases; Animals; Bacteriology; Biological and medical sciences; Blotting, Southern - veterinary; Deoxyribonucleic acid; DNA; DNA, Bacterial - chemistry; DNA, Bacterial - genetics; Fundamental and applied biological sciences. Psychology; Hogs; Hybridization; Microbiology; Miscellaneous; Pleuropneumonia, Contagious - diagnosis; Pleuropneumonia, Contagious - microbiology; Polymerase chain reaction; Polymerase Chain Reaction - methods; Polymerase Chain Reaction - veterinary; Sensitivity and Specificity; Sequence Analysis, DNA; Serotyping - veterinary; Swine; Swine - microbiology; Swine Diseases; Virology
• ISSN: 0343-8651; 1432-0991
• DOI: 10.1007/s00284-002-3890-7

We investigated whether primers able to specifically amplify a 0.7-kb DNA fragment from the conserved cpx genes could be applied to analyze A. pleuropneumoniae field isolates. The specific cpx primers were tested on 120 strains of A. pleuropneumoniae and other NAD-dependent field isolates from healthy and diseased animals to analyze A. pleuropneumoniae isolates from pigs in Brazil. We found that PCR and hybridization were able to discriminate between isolates of A. pleuropneumoniae and other bacteria. The 0.7-kb cpx DNA fragments were amplified from all 63 A. pleuropneumoniae isolates from herds with clinical symptoms and were isolated from lesions of acute cases of swine pleuropneumonia, both serotypable and nonserotypable. The PCR was also applied to 57 field isolates obtained from animals of apparently healthy herds, and the amplified cpx product was present in four serotypable and only two out of eleven A. pleuropneumoniae nonserotypable isolates. All nonserotypable A. pleuropneumoniae isolates revealed the apxA amplification pattern compatible with previously known serotypes. Some nonserotypable isolates might represent a population of isolates that originally were serotypable but lost the ability to react with serotype-specific antisera or might belong to novel serotypes. The PCR method applied is highly sensitive for serotypable A. pleuropneumoniae strains and for nonserotypable strains isolated from acute cases of swine pleuropneumoniae in Brazil.