Viral interference between H9N2-low pathogenic avian influenza virus and avian infectious bronchitis virus vaccine strain H120 in vivo.

The interaction between a low pathogenic avian influenza virus (A/CK/TUN/145/2012), a H9N2 Tunisian isolate, and a vaccine strain (H120) of avian infectious bronchitis, administered simultaneously or sequentially three days apart to chicks during 20 days, was evaluated using ELISA antibody levels, quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analyses and histopathology examination. First, the in vivo replication interference of avian influenza virus (AIV) and infectious bronchitis virus (IBV) was evaluated using qRT-PCR to detect accurately either AIV or IBV genomes or viral copy numbers during dual infections. Second, we have determined the amount of specific antibodies in sera of chick's infected with AIV alone, IBV alone, mixed AIV + IBV, IBV then AIV or AIV IBV 3 days later using an ELISA test.

Viral interference between low pathogenic avian influenza H9N2 and avian infectious bronchitis viruses in vitro and in ovo.

Background: Low pathogenic avian influenza (LPAI) H9N2 and infectious bronchitis virus (IBV) are important pathogens of poultry, causing important economic losses for the sector. Replication interference between these two viruses was described using cell cultures (CC) and embryonated chicken eggs (ECE). Chicken embryo lung (CEL) and ECE were simultaneously or sequentially infected with IBV vaccine strain (H120) and LPAIV-H9N2 (A/Ck/TUN/145/2012) to evaluate viral interactionsin vitro and in ovo, respectively.

A multiplex real-time RT-PCR for simultaneous detection of four most common avian respiratory viruses.

A one-step multiplex real-time reverse transcription-PCR (rRT-PCR) assay was developed for simultaneous detection and quantification of four avian respiratory viruses: avian influenza virus (AIV), infectious bronchitis virus (IBV), Newcastle disease virus (NDV) and infectious laryngotracheitis virus (ILTV). In comparison with the singleplex rRT-PCR, the specificity, the sensitivity and the reproducibility of the new assay were evaluated and validated using 70 clinical samples. The optimal cutoff point, the corresponding limit of quantification (LoQ) and the limit of detection (LoD) were statistical established based on receiver operating characteristic (ROC) curve analysis.

A novel method for detection of H9N2 influenza viruses by an aptamer-real time-PCR.

H9N2 Influenza subtype has emerged in Tunisia causing epidemics in poultry and resulting in major economic losses. New mutations in their hemagglutinin and neuraminidase proteins were acquired, suggesting their potential to directly infect humans. Effective surveillance tools should be implemented to help prevent potential spillover of the virus across species.

Accurate Detection of Avian Respiratory Viruses by Use of Multiplex PCR-Based Luminex Suspension Microarray Assay.

A novel oligonucleotide suspension microarray (Luminex microsphere system) was developed for the rapid detection of avian respiratory viruses of major clinical importance. This test was optimized and validated with 70 clinical samples. The developed tool was accurate for high-throughput detection and differentiation of the most important avian respiratory viruses: avian influenza virus (AIV), Newcastle disease virus (NDV), infection bronchitis virus (IBV), and infectious laryngotracheitis virus (ILTV) in single- and mixed-virus infections.