Effect of saliva stabilisers on detection of PRRSv in oral fluid by qPCR

Abstract

This study evaluated the effect of extraction-amplification methods, storage temperature and saliva stabilisers on detection of porcine reproductive and respiratory syndrome virus (PRRSV) RNA by quantitative reverse transcriptase real-time PCR (qRT-PCR) in porcine oral fluid. The diagnostic performance of different extraction-amplification methods was examined using a dilution series of oral fluid spiked with PRRSV. To determine RNA stability, porcine oral fluid, with or without commercially available saliva stabilisers, was spiked with PRRSV, stored at 4°C or room temperature and tested for the presence of PRRSV RNA by qRT-PCR. PRRSV RNA could be detected in oral fluid using all extraction-amplification combinations, but the limit of detection varied amongst different combinations. Storage temperature and saliva stabilisers had an effect on the stability of PRRSV RNA, which could only be detected for 7days when PRRSV spiked oral fluid was kept at 4°C or stabilised at room temperature with a commercial mRNA stabiliser.

Copyright © 2013 Elsevier Ltd. All rights reserved.

Decorte I, Van der Stede Y, Nauwynck H, De Regge N, Cay A B. Effect of saliva stabilisers on detection of porcine reproductive and respiratory syndrome virus in oral fluid by quantitative reverse transcriptase real-time PCR. The veterinary journal 2013 [in press].

In vitro inactivation of PRRSv and PRv by acidic electrolyzed water

Abstract

Slightly acidic electrolyzed water (SAEW, pH 5.0-6.5) is a novel disinfectant with environmentally friendly broad spectrum microbial decontamination properties which could have significant utility on farm. Two of the most important pathogenic viruses in pigs are porcine reproductive and respiratory syndrome virus (PRRSV) and pseudorabies virus (PRV). The aim of this study was to evaluate the viricidal effectiveness of SAEW against PRRSV and PRV in vitro under different available chlorine concentrations (ACCs, 30, 50 and 70mg/L), treatment times (5, 10 and 15min) and temperatures (4, 20, 40 and 60°C), respectively. SAEW had a strong viricidal activity against both PRRSV and PRV. This activity increased with increasing ACC, treatment time and temperature. PRRSV and PRV titres of 7.0log₁₀TCID₅₀/mL and 5.9log₁₀TCID₅₀/mL, respectively, were completely inactivated by SAEW at an ACC of ⩾50mg/L for 10min even though SAEW had no negative effect on the host cells. SAEW thus shows promise as a disinfectant for use on pig farms to reduce the spread of both PRRSV and PRV, and to limit the morbidity associated with those viruses.

Copyright © 2013 Elsevier Ltd. All rights reserved.

Hao X, Shen Z, Wang J, Zhang Q, Li B, Wang C, Cao W. In vitro inactivation of porcine reproductive and respiratory syndrome virus and pseudorabies virus by slightly acidic electrolyzed water. The veterinary journal 2013 [in press].

Effects on boar semen quality after infection with PRRSv: a case report

Abstract

ABSTRACT: The effect of porcine reproductive and respiratory syndrome virus (PRRSV) on semen quality was examined in a group of 11 spontaneously infected boars in a commercial boar stud. Semen samples were collected 4 weeks prior to 4 weeks post-infection (wpi). Infection with PRRSV of the European genotype subtype 1 (EU-1) was verified by specific quantitative real-time polymerase chain reaction (RT-PCR) in 36% of the serum samples. All boars seroconverted before 4 wpi and remained in normal condition throughout the study. Comparison of the percentage of morphologically intact spermatozoa revealed an increase of acrosome-defective spermatozoa (P = 0.012) between -4 and 4 wpi. Significant deleterious effects on semen quality were detected for membrane integrity when semen had been stored for 2 days after sampling. Analysis of sperm subpopulations in a thermoresistance test on day 7 after sampling revealed alterations in the percentage of circular, progressively motile spermatozoa (P = 0.013), in the percentage of non-linear, progressively motile spermatozoa (P = 0.01), and on the amplitude of lateral sperm head displacement (P = 0.047). There was no difference in the incidence of mitochondrially active spermatozoa (P = 0.075). Investigation of routine production data between pre- and post-infection status showed no differences on ejaculate volume (P = 0.417), sperm concentration (P = 0.788), and percentage of motile spermatozoa (P = 0.321). This case report provides insights into a potential control strategy for PRRSV outbreaks in boar studs.

PMID:

 

23442207

 

[PubMed - as supplied by publisher]

Schulze M, Revilla-FernÃndez S, Schmoll F, Grossfeld R, Griessler A. Effects on boar semen quality after infection with porcine reproductive and respiratory syndrome virus: a case report. Acta Veterinaria Scandinavica 2013;55(1):16-16.