Associations between management factors and seroprevalence of Mycobacterium avium subsp. paratuberculosis in dromedary camels.

Johne's disease is a chronic infectious granulomatous enteritis caused by Mycobacterium avium subsp. paratuberculosis (MAP) and mainly infect wild and domestic animals. Although MAP infection has been reported worldwide, observational studies on MAP in camels are very scarce. The objective of the present investigation was to determine the herd- and camel-level seroprevalences and management factors associated with MAP seroprevalence in dromedary camels in the Eastern Province, Saudi Arabia. A cross-sectional study with two-stage random sampling was conducted. Serum samples from 391 camels in 67 herds were collected and tested for the presence of MAP antibodies using a commercial indirect ELISA test. The average MAP herd- and camel-level seroprevalences were 40.3% (95% CI: 29.10 - 52.60%) and 16.1% (95% CI: 12.78 - 20.11%), respectively. The herd-level factors showed a greater risk of MAP seropositivity in medium (36 - 75) and larger (>75) size herds compared with small (<36) herds. Furthermore, the risk of MAP seropositivity decreased in herds with calving pens compared to herds without calving pens. The camel-level factors indicated a decrease in seroprevalence of MAP with the age of camels. The present study revealed a high prevalence of MAP in dromedary camels in Eastern Province, Saudi Arabia. The herd-level risk factors for MAP seroprevalence identified in this study will provide the baseline data for developing and implementing a comprehensive control program for MAP in Saudi Arabia.

Evaluation of three different concentration and extraction methods for recovery efficiency of human adenovirus and human rotavirus virus A.

Routine wastewater treatment plants (WWTPs) effluents monitoring is essential because of enteric viruses' low infectious dose beyond molecular detectability. In current study methods for concentration and extraction, inter-method compatibility and recovery efficiency of spiked human adenovirus (HAdV) and human rotavirus A (RVA) were evaluated. For virus concentration, polyethylene glycol precipitation (PEG), charged membrane-based adsorption/elution (CMAE), and glass wool-based concentration (GW) methods were used. Nucleic acid was extracted by PowerViral™ Environmental RNA/DNA Isolation (POW), ZymoBIOMICS™ RNA extraction (ZYMO) and Wizard® Genomic DNA Purification (WGDP) and samples were analyzed by Real-Time PCR. CMAE method yielded significantly higher concentrations for both ARQ (Armored-RNA Quant) and RVA compared to PEG (P =  0.001 and 0.003) and GW (P <  0.0001). Highest HAdV concentration was obtained by PEG (P =  0.001 and < 0.0001) in relation to CMAE and GW. ZYMO yielded a significantly higher ARQ and RVA concentrations (P =  0.03 and 0.0057), whereas significantly higher concentration was obtained by POW for HAdV (P =  0.032). CMAE × ZYMO achieved the highest recovery efficiencies for ARQ (69.77 %) and RVA (64.25, respectively, while PEG × POW present efficiency of 9.7 % for HAdV. These findings provide guidance for understanding of method-related biases for viral recovery efficiency.