Detection of Human Torovirus Like Particles and Adenovirus Type F in Children Attending to Babylon Maternity and Children Hospital

Abstract

Toroviruses are enteric viruses belonging to the Nidovirales order that infect different animal species and human . Torovirus-like particales (TVLPs) that are immunologically related to BRV have been reported as etiological agents of gastroenteritis in humans.

The lack of “in vitro” culture systems for toroviruses, except  for the prototype Berne virus or BEV, isolated originally from an infected horse, has hampered their study and the development of diagnostic assays. This  study  describes a real time RT-PCR method to detect  human  torovirus- like particles  (TVLPs) RNA in clinical  stool  samples using primers corresponding to the gene coding for  the nucleocapsid protein which are conserved in all (TVLPs) strains known to date. During this study, the CT value  measured  during real-time PCR analysis was used as an indication of the viral load found in the stool  sample . The assay was evaluated with 72 stool samples from children attending the Babylon maternity and children hospital. Fifty tow out of 72 (72.2%) children were shedding virus at  the time of sample collection, indicating a high incidence of TVLPs  infection  in Babylon Province. This  is the first study  attempted  for   estimating  the presence of TVLPs  in Iraq. The real time RT-PCR assay described in this study  provides a rapid, highly sensitive, specific and reliable detection and quantization  method enabling future TVLPs  epidemiological studies. In addition to that  the study included the development of real-time PCR assays for the detection of group F Adenovirus in 250 stool samples of pediatric subjects  exhibiting symptoms of diarrhea and/ or vomiting  which  were examined. PCR results of 10 positive Adenovirus group F diarrheic stool samples were confirmed by electron microscopy  examination which gave clear positive Adenovirus appearance . Till now there was no successful virus  culture growth for  isolation of diarrhegenic type 40 and 41 grow in routine cell culture . The result of this study by real time reverse transcription  – PCR  assay reflected in 72 .2 % and 58 % torovirus and adenovirus group F respectively. The genotyping results of adenoviruses(genotype 40 and 41)  highlight the significance of rapid molecular methods for the routine screening of stool samples in diagnostic laboratories to provide rapid and efficient methods .

Keywords: Human Torovirus, Adenovirus, RT-PCR, Electron Microscopy.