Comparison of the Glaesserella parasuis Virulence in Mice and Piglets

Abstract

In this study, we compared the virulence of the most common serovars of Glaesserella parasuis in China, serovars 4, 5, 12, and 13 (36 strains in total) in BALB/c mice and piglets. In mice, the median lethal doses (LD50s) of the four serovars were roughly 9.80 × 107–4.60 × 109 CFU, 2.10 × 108–8.85 × 109 CFU, 4.81 × 107–7.01 × 109 CFU, and 1.75 × 108–8.45 × 108 CFU, respectively. Serovar 13 showed the strongest virulence, followed by serovar 4, serovar 12, and serovar 5, but a significant difference in virulence was only observed between serovars 5 and 13. The virulence of strains of the same serovars differed significantly in piglets. Virulent and attenuated strains were present in all serovars, but serovar 5 was the most virulent in piglets, followed by serovars 13, 4, and 12. A significant difference in virulence was observed between serovars 5 and 4 and between serovars 5 and 12. However, the virulence of serovars 5 and 13 did not differ significantly. This comprehensive analysis of G. parasuis virulence in mice and piglets demonstrated that: (1) the order of virulence of the four domestic epidemic serovars (from strongest to weakest) in piglets was serovars 5, 13, 4, and 12; (2) both virulent and attenuated strains were present in all serovars, so virulence did not necessarily correlate with serovar; (3) Although G. parasuis was fatal in BALB/c mice, its virulence is inconsistent with that in piglets, indicating that BALB/c mice are inadequate as an alternative model of G. parasuis infection.

Secondary Highly Pathogenic Porcine Reproductive and Respiratory Syndrome Virus (HP-PRRSV2) Infection Augments Inflammatory Responses, Clinical Outcomes, and Pathogen Load in Glaesserella-parasuis-Infected Piglets

“…Although single infections with bacteria or viruses alone can induce respiratory infections in pigs, coinfection with various pathogens is very common [ 28 , 71 ]. A Gps infection initiates an innate immune response and induces the production of inflammatory cytokines [ 72 , 73 ]. HP-PRRSV2 targets the immune system of pigs, impairing immune defense against pathogenic microbes and increasing host susceptibility to primary and secondary pathogens [ 64 , 74 ].…”

Severe Inflammation Caused by Coinfection of PCV2 and Glaesserella parasuis Is Associated with Pyroptosis via Noncanonical Inflammasome Pathway

“…BALB/c mice and RAW264.7 cells are the common and convenient models for studying PCV2 infection [27,33]. Despite BALB/c mice being regarded as an inadequate model for virulence of serovar 5 strain of G. parasuis [34], the fact does not affect the relevance of the reported data because the mechanism was studied, which may be independent from the virulence of G. parasuis. In this study, the results of BALB/c mice infected with PCV2 and G. parasuis demonstrated that PCV2 and G. parasuis have synergistic interactions in pathology and PCV2 infection can increase G. parasuis propagation in the lungs.…”

Integrated Analysis of Long Non-Coding RNA Expression Profiles in Glaesserella parasuis-Induced Meningitis: New Insight into Pathogenesis

“…To date, 15 serotypes of G. parasuis have been identified based on the Kielstein-Rapp-Gabrielson serotyping scheme [3]. Serotype 5 is the most prevalent serotype, and can be used as a virulence marker for G. parasuis infection [4]. Previous research has reported that G. parasuis can invade the central nervous system through the blood-brain barrier (BBB), resulting in meningitis [5].…”