Genotyping of Haemophilus parasuis isolated from northwest China using PCR-RFLP based on the ompA gene.
Outer membrane proteins (OMPs) are the major virulent factors of Haemophilus parasuis. PCR-RFLP targeting the ompA gene was conducted to investigate the possibility of genotyping H. parasuis in this study. Fifteen reference strains and 49 isolates from pig farms in northwest China were genotyped by PCR-RFLP with a pair of specific primers. The results indicated that both the 15 reference strains and 49 isolates could be classified into 8 different genotypes by PCR-RFLP, respectively. Seven genotypes including AA, BB, BA, CA, BC, BD and CD existed simultaneously in the reference strains and isolates, but genotype CB only existed in the isolated strains. Interestingly, genotypes BA, CD and CA were only found in diseased pigs and accounted for 38.8%, 22.4% and 18.4% of the isolates, respectively. On the other hand, strains isolated from apparently healthy pigs were classified into genotypes AA, BB, BC and CB. However, the virulent reference serovar 1 strain has an AA genotype, and the fact that nearly all strains from the healthy pigs belonged to serovars classed as virulent suggests that these genotypes might also include virulent strains; therefore, further validation with more field strains is needed. The capability of the RFLP-PCR method based on the ompA gene for genotyping H. parasuis isolates indicates that this method may be a useful tool for epidemiological study.
Key Laboratory of Grazing Animal Diseases of Ministry of Agriculture, Key Laboratory of Animal Virology of Ministry of Agriculture, State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China.
Yue-Feng
YF
Chu
Peng-Chen
PC
Gao
Ping
P
Zhao
Yin
Y
He
Nian-Zhang
NZ
Zhang
Yong-Sheng
YS
Liu
Ji-Xing
JX
Liu
Zhong-Xin
ZX
Lu
D000818:Animals; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D002681:China / Q000453:epidemiology; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D005838:Genotype; D006192:Haemophilus Infections / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D044137:Haemophilus parasuis / Q000235:genetics* / Q000302:isolation & purification; D016133:Polymerase Chain Reaction / Q000379:methods / Q000662:veterinary; D012150:Polymorphism, Restriction Fragment Length; D013552:Swine; D013553:Swine Diseases / Q000453:epidemiology / Q000382:microbiology*
D001425:Bacterial Outer Membrane Proteins; C078167:OMPA outer membrane proteins