Comparison of Haemophilus parasuis reference strains and field isolates by using random amplified polymorphic DNA and protein profiles

Abstract

BackgroundHaemophilus parasuis is the causative agent of Glässer’s disease and is a pathogen of swine in high-health status herds. Reports on serotyping of field strains from outbreaks describe that approximately 30% of them are nontypeable and therefore cannot be traced. Molecular typing methods have been used as alternatives to serotyping. This study was done to compare random amplified polymorphic DNA (RAPD) profiles and whole cell protein (WCP) lysate profiles as methods for distinguishing H. parasuis reference strains and field isolates.ResultsThe DNA and WCP lysate profiles of 15 reference strains and 31 field isolates of H. parasuis were analyzed using the Dice and neighbor joining algorithms. The results revealed unique and reproducible DNA and protein profiles among the reference strains and field isolates studied. Simpson’s index of diversity showed significant discrimination between isolates when three 10mer primers were combined for the RAPD method and also when both the RAPD and WCP lysate typing methods were combined.ConclusionsThe RAPD profiles seen among the reference strains and field isolates did not appear to change over time which may reflect a lack of DNA mutations in the genes of the samples. The recent field isolates had different WCP lysate profiles than the reference strains, possibly because the number of passages of the type strains may affect their protein expression.

Peer Review #2 of "Association between iscR-based phylogeny, serovars and potential virulence markers of Haemophilus parasuis (v0.1)"

“…Results of current study on correlation between population structure and virulence were contradictory. H.parasuis strains in some sub-groups tend to be virulent (Ruiz et al, 2001;Olvera et al, 2006a;Olvera et al, 2006b;Wang et al, 2016), while no association between population structure and clinical virulence was found in others (Zehr et al, 2012;Boerlin et al, 2013;Howell et al, 2014). No strong correlation between clinical phenotype and iscR-based phylogeny or PVMs profiles was observed in this study.…”

The Epidemiologic and Pharmacodynamic Cutoff Values of Tilmicosin against Haemophilus parasuis

“…Haemophilus parasuis , a Gram-negative bacterium of the Pasteurella group of organisms, is a respiratory pathogens of pigs ( Fu et al, 2013 ; Luan et al, 2013 ). It is mainly responsible for Glässer’s disease, which is characterized by polyserositis, arthritis, and meningitis ( Guo et al, 2011 ; Mullins et al, 2013 ; Moleres et al, 2015 ) and has caused large economic losses in the worldwide pig industry in recent years ( Vilalta et al, 2012 ; Zehr et al, 2012 ).…”

Association betweeniscR-based phylogeny, serovars and potential virulence markers ofHaemophilus parasuis

“…Results of current study on correlation between population structure and virulence were contradictory. H. parasuis strains in some sub-groups tend to be virulent (Ruiz et al, 2001; Olvera, Calsamiglia & Aragon, 2006a; Olvera, Cerda-Cuellar & Aragon, 2006b; Wang et al, 2016), while no association between population structure and clinical virulence was found in others (Zehr, Lavrov & Tabatabai, 2012; Boerlin et al, 2013; Howell et al, 2014). No strong correlation between clinical phenotype and iscR -based phylogeny or PVMs profiles was observed in this study.…”