Molecular detection of enteric viruses from diarrheic calves in Egypt

Abstract

Neonatal calf diarrhea (NCD) is a major cause of morbidity, mortality and economic losses in the beef and dairy industries. This study was conducted to investigate the existence of enteric viruses in two Egyptian farms with a history of recurrent diarrhea. Fecal samples were collected from 25 diarrheic calves. RNA was extracted and tested by reverse transcription polymerase chain reaction (RT-PCR) for the presence of rotavirus, norovirus, astrovirus, torovirus, coronavirus and bovine viral diarrhea virus. Overall, 76 % (19/25) of samples tested positive for one or more viruses. Rota-, noro- and astroviruses were detected in 48 %, 24 % and 32 % of tested samples, respectively. About 37 % (7/19) of positive samples had two different viruses. One-month-old calves were the group most vulnerable to infections. Based on phylogenetic analysis, bovine rotaviruses were of genotypes G6 and G10, bovine noroviruses were in GIII.2, and bovine astroviruses were in the BAstV lineage 1. Astrovirus sequences showed a high level nucleotide sequence similarity with the Brazilian BAstV sequences available in GenBank. We believe this is the first report of bovine norovirus and bovine astrovirus circulating among calves in Egypt. Further epidemiological studies are recommended to investigate their presence on a wider scale, to predict their association with NCD, and to design appropriate diagnostic and control methods.

Phylogeny of bovine norovirus in Egypt based on VP2 gene

“…The results of this study confirm those of Mohamed et al [17], who found the detection rates of BNoV at 24% in Egyptian cattle as compared to 27.6% in this study. The results of both studies collectively indicate the endemic nature of BNoV infection in Egyptian cattle.…”

“…The results of both studies collectively indicate the endemic nature of BNoV infection in Egyptian cattle. The detected BNoV strains were genetically-related to BNoV-GIII.2 genotype (Newbury2-like), either based on BNoV-RdRp [17] or based on BNoV-VP2 (this study). BNoV-GIII.2 has a worldwide distribution, unlike BNoV-GIII.1 [23].…”

“…Accordingly, its impact on livestock industries is unknown. In Africa, the reports of BNoV-infections came only from Egypt and Tunisia [17,22].…”

“…In Egypt, few data are available on the newly emerging enteric viruses of cattle, including BNoV. Only one study described BNoV infection in two cattle farms in Egypt [17]. The present study was conducted to (i) report the existence of BNoV among diarrheic calves in Sharkia province of Egypt and (ii) to study the phylogenesis of these BNoV strains on the basis of VP2 gene.…”

Molecular characterization of group A rotavirus from rhesus macaques ( Macaca mulatta ) at human–wildlife interfaces in Bangladesh

“…The wide host breadth of RVA strains indicated the potential of RVAs for interspecies transmission. Only one G10 strain was identified in the study, this strain is uncommon in human (Do et al, ; Luchs & Timenetsky Mdo, ) but are frequently found in animals, particularly in cattle, pigs and lambs (Ennima et al, ; Komoto et al, ; Madadgar, Nazaktabar, Keivanfar, Zahraei Salehi, & Lotfollah Zadeh, ; Mohamed, Mansour, El‐Araby, Mor, & Goyal, ; Rajendran & Kang, ). G10P[15] is an unusual combination but has previously been reported in a calf in India (Rajendran & Kang, ).…”