Calf Rotavirus Research Articles

Passive immunity to bovine rotavirus in newborn calves fed colostrum supplements from cows immunized with recombinant SA11 rotavirus core-like particle (CLP) or virus-like particle (VLP) vaccines

Heterotypic passive immunity to IND (P[5]G6) bovine rotavirus (BRV) was evaluated. Three groups of calves ( n = 5 per group) were fed 1% pooled colostrum supplements (birth to 7 days of age) from BRV seropositive cows vaccinated with recombinant SA11(P[2]G3) rotavirus-like particles (VLPs), recombinant SA11 rotavirus core-like particles (CLPs), or inactivated SA11 rotavirus (SA11). Control calves ( n = 5 per group) received either pooled colostrum from unvaccinated (BRV field exposure seropositive) control cows, or no colostrum. IgG1 antibody titers to IND BRV for the pooled colostrum were: 1048576 (VLP); 1048576 (CLP); 262144 (SA11); and 16384 (control colostrum). Elevated titers of BRV neutralizing (VN) antibodies were present in VLP colostrum (98 000), and SA11 colostrum (25 000), but not in CLP colostrum (1400), compared to colostrum from nonvaccinates (2081). Calves were orally inoculated with virulent IND BRV at 2 days of age and challenged at post-inoculation day (PID) 21. Calves were monitored daily for diarrhea and faecal BRV shedding through PID 10 and post-challenge day (PCD) 10. After colostrum feeding, the IgG1 antibody titers were highest in serum and faeces of calves fed VLP and CLP colostrum, but VN and IgA antibodies were highest in calves fed VLP colostrum. After BRV inoculation, calves fed colostrum from vaccinated cows had significantly fewer days of BRV-associated diarrhea and BRV shedding than control calves. All calves fed VLP colostrum were protected from diarrhea after BRV inoculation; two calves shed BRV. In the CLP colostrum group, one calf developed BRV-associated diarrhea and all calves shed virus. In the SA11 colostrum group, three calves developed BRV-associated diarrhea and four calves shed virus. BRV-associated diarrhea and shedding occurred in 9 of 10 control calves. Active IgM antibody responses occurred in faeces and/or serum of most calves after BRV inoculation. However, the highest active antibody responses (IgM and IgG1 in serum, and IgM, IgG1 or IgA in faeces) after BRV inoculation were in calves fed control or no colostrum, in association with clinical diarrhea in most of these calves. After challenge at PID 21, BRV-associated diarrhea and shedding were of short duration or absent, in all groups. These results demonstrate the efficacy of colostrum from VLP vaccinated cows to provide heterologous, passive protection against BRV diarrhea and shedding in calves. In comparison, calves fed CLP or SA11 colostrum were only partially protected against BRV diarrhea or shedding.

Field evaluation of chicken egg yolk immunoglobulins specific for bovine rotavirus in neonatal calves.

The oral efficacy of chicken egg yolk immunoglobulins (yIg) specific for bovine rotavirus (BRV) serotypes G6 and G10 in protecting neonatal calves was examined in a herd of cattle under field conditions. In one of the three trials, yIg-treated calves tested under high relative humidity (RH) showed a significantly increased mean body weight (P < 0.05) and a decrease in number of calves shedding high titer of BRV (G6) in stool compared to control calves (P < 0.01), suggesting that our yIg product was effective in a field condition with an epidemic outbreak of BRV diarrhea.

Persistence of a single electropherotype and serotype (G6P5) of bovine rotavirus in calves on a closed dairy farm from 1990 to 1993

SUMMARY A virologic survey was conducted on calves with diarrhea associated with bovine rotavirus (brv) on a closed dairy farm. The brv was detected from 32 of 219 (14.6%) fecal specimens repeatedly collected from 56 calves born during the years 1992-1993, regardless of whether they had diarrhea. Most of the 32 strains were isolated from fecal specimens obtained from 2- to 6-week-old calves. After electrophoresis of double-stranded viral rna from the 32 strains, genomic rna migration patterns were similar to those of the predominant brv strains isolated at the same farm during the years 1990-1991. All representative strains were identified as G serotype 6 (G6) and P type 5 (P5) by results of the virus-neutralization test and polymerase chain reaction procedure. Thus, brv had no change in genomic rna electropherotypes and serologic antigenicities in a closed dairy herd over a period of several years.

Sequence Analysis of Pigeon, Turkey, and Chicken Rotavirus VP8* Identifies Rotavirus 993/83, Isolated from Calf Feces, as a Pigeon Rotavirus

Partial-length gene 4 cDNA encompassing the VP8* portion of VP4 from chicken rotavirus (RV) Ch-1, turkey RV Ty-1 and Ty-3, and pigeon RV PO-13 was sequenced and compared to RV 993/83 isolated from a calf with diarrhea. Ninety-six percent amino acid sequence identity was seen between VP8* from calf RV 993/83 and pigeon RV PO-13, while only 77 to 83% identity was seen in comparison with turkey and chicken RV VP8* sequences. Phylogenetic tree analysis places all avian RV (including calf isolate 993/83) on a branch at the bottom of the VP8* tree. When tested with three neutralizing monoclonal antibodies raised against pigeon RV PO-13, RV 993/83 and Ty-1 share three, Ch-1 shares two, and Ty-3 shares one neutralizing epitope(s) on VP4 with pigeon RV PO-13.

Passive protection against bovine rotavirus in calves by specific immunoglobulins from chicken egg yolk.

The efficacy of chicken egg yolk immunoglobulins (yIg) from hens immunized with bovine rotavirus (BRV) serotype G6 (strain Shimane) or serotype G10 (strain KK-3) for protection against homologous BRV in calves was investigated. A significant protection by anti-BRV yIg having 6400 neutralizing antibody titer per dose could be achieved in calves (P < 0.01).

A Unique VP4 Gene Allele Carried by an Unusual Bovine Rotavirus Strain, 993/83

The VP4 protein of an unusual group A calf rotavirus strain, 993/83 (serotype G7 and subgroup non-I and non-II), was determined to contain 770 amino acids, shorter than any other VP4 proteins sequenced to date. The 993/83 VP4 exhibited only 55-62% amino acid identity to the VP4s of the representatives of 12 distinct P serotypes, suggesting that 993/83 VP4 represents a new P serotype.

Rotavirus 993/83, isolated from calf faeces, closely resembles an avian rotavirus.

Polypeptides from purified virions of the calf rotavirus (RV) isolate 993/83 and those from the pigeon RV isolate PO-13 comigrated on SDS-polyacrylamide gels. Two polypeptides of 45K and 47K were detected at the position of VP6. Both proteins behaved like authentic VP6 protein with EDTA and heat treatment. RV 993/83 and PO-13 showed identical one-dimensional peptide maps for VP2, and the 45K and 47K proteins. More than 70% of sera from German cattle older than 1 year showed neutralizing serum antibodies to RV 993/83 and RV PO-13.

Cell culture propagation of calf rotavirus and detection of rotavirus specific antibody in colostrum and milk of cows and buffaloes

A bovine rotavirus was adapted to serial propagation in Madin Darby bovine kidney (MDBK) cells. Virus of cell culture origin when examined by electron microscopy exhibited characteristic rotavirus morphology and had a typical RNA electropherotype on polyacrylamide gel electrophoresis. Mean IgG concentration in the first colostral whey was 62.80 +/- 6.56 mg/ml in cows and 104.40 +/- 31.12 mg/ml and 2.52 +/- 0.28 mg/ml respectively. The geometric mean neutralising antibody titre against bovine rotavirus in the first colostral whey was 279 in cows and 139 in buffaloes. It declined to 10 and 13 (respectively) by the tenth day.

The Finest Ultrastructural Details of the Inner Layer of Rotavirus Revealed by Minimal Electron Doses

The inner layer of human and calf rotavirus ultrastructure was analyzed using minimal doses in transmission electron microscopy. The morphological unit of spontaneously disrupted virions has the aspect of a flower-like structure, and its petals are hexagonally arranged and have a central pin hole. The similar flower appearance can be observed in complete virions and in rotavirus tube structures produced in aged samples of rotavirus kept for more than a year.

Protection against bovine rotaviruses in newborn calves by continuous feeding of immune colostrum.

Three pregnant cows were inoculated intramuscularly with inactivated vaccine to bovine rotavirus (BRV) serotype 1 (BRV-1) and serotype 2 (BRV-2). Serum neutralizing antibody (NA) titers against both serotypes increased significantly after immunization. NA titers of colostrum obtained from immunized cows against BRV-1 and BRV-2 were 29286 and 38109, respectively, which were significantly higher than those from non-immunized control cows. Nine and 6 colostrum deprived calves were orally challenged with BRV-1 and BRV-2, respectively, and monitored for clinical manifestation and viral shedding. Five calves of them, 3 with BRV-1 and 2 with BRV-2, received 2 l of milk replacer supplemented with 10% immune colostrum 2 hr before challenge and twice daily for the first 5 days after challenge. Other 10 calves, 6 with BRV-1 and 4 with BRV-2, were fed only milk replacer as controls. All control calves developed severe diarrhea and shed a large amount of BRV in feces, beginning from 24 to 48 hr after challenge inoculation. On the contrary, all calves but one fed colostrum supplement remained clinically healthy after challenge, and BRV was not detected in their feces during feeding immune colostrum. The possibility that continuous feeding of immune colostrum is capable of preventing newborn calves from diarrhea associated with BRV and viral shedding was suggested.

Protection between different serotypes of bovine rotavirus in gnotobiotic calves: specificity of serum antibody and coproantibody responses.

In a previous study, different U.S. isolates of bovine rotavirus were studied for their serotypes and cross-protective properties (G. N. Woode, N. E. Kelso, T. F. Simpson, S. K. Gaul, L. E. Evans, and L. Babiuk, J. Clin. Microbiol. 18:358-364, 1983). Three viruses belonging to two different serotype groups were used as vaccines in gnotobiotic calves, which were subsequently challenged with B641 or B223, representing the two bovine serotypes. In the present work, the experiments were repeated with more calves and the specificity of their antibody responses was measured and compared with the results of the protection studies. Protection between different serotypes occurred under both homologous and heterologous conditions but was not directly serotype dependent. B223 virus showed both homologous and heterologous protection against B223 and B641 challenge viruses. This was a one-way reaction, as B641 did not induce protection against B223. Neonatal calf diarrhea virus vaccine produced neither homologous (against B641) nor heterologous (against B223) protection. The plaque reduction neutralization titers of serum antibody and coproantibody did not predict a state of protection against the challenge virus. Calves vaccinated with neonatal calf diarrhea virus or B641 developed neutralizing antibodies to their respective heterologous challenge viruses but were not protected. After challenge, the boosted coproantibody plaque reduction neutralization response to the original vaccine virus was greater than that to the challenge virus.

Detection of Rotavirus from Stools by Latex Agglutination Test

AbstractsLatex agglutination (LA) reagents were prepared using antisera against human rotaviruses (Wa and S2 strains). A commercially available LA test (Rotalex) using antisera against calf rotavirus was also used. Semititrations of rotavirus antigens were compared by three LA tests on 110 stools of children with acute gastroenteritis which had been previously determined rotavirus‐positive by electron microscopy and polyacrylamide gel electrophoresis of genome RNA. LA tests showed diversity of subgroups. The three LA tests reported in this study are concluded to be useful for clinical application in spite of a few exceptions in semititration.

Rotavirus Survival in Raw and Treated Waters and Its Health Implications

Rotaviruses are among the major causes of acute gastroenteritis in man as well as a variety of animals. Although not much is known about the mechanisms of transmission of these viruses in nature, fecally-contaminated water appears to play a role in this regard. This study was, therefore, aimed at determining how well rotaviruses could survive in water. Calf rotavirus (strain C-486) grown in MA-104 cells was used as a model in this study. Samples of raw (RW) and municipally-treated tap water (TW) from the Ottawa River (Ontario, Canada) were contaminated with the virus to give a final concentration of approximately 5.0 × 104 plaque forming units (PFU)/ml. The virus-contaminated water samples were held either at 4°C or 20°C in the dark for a total of 64 days. In TW held at 4°C, there was no significant drop in the virus titre even after 64 days, whereas, at 20°C the titre was reduced by nearly 2-logl0 over the same period. In RW a 3-10gl0 drop in PFU occurred in 16 and 32 days at 20°C and 4°C, respectively. These data indicate that rotaviruses could survive long enough in the water environment to give water a considerable potential as a vehicle for their spread.

Comparison of bovine, simian and human rotavirus structural glycoproteins.

The structural glycoproteins of calf (BDV 486), human (Wa) and simian (SA11) rotaviruses were compared for sensitivity to endoglycosidase (Endo) H. The calf and human virus glycoproteins were reduced by approximately 5000 molecular weight in two equal stages. The simian rotavirus glycoprotein sustained only one 2500 molecular weight decrease. The effect of the host cell on the viral oligosaccharide composition was examined. Endo H digests of calf rotavirus 82-124 extracted from stool and its progeny propagated and [35S]methionine-labelled in MA104 cells were compared. Endo H had the same effects on the glycoproteins, indicating that the nature of the host cell does not affect the oligosaccharide composition of the virus glycoproteins.

Oligosaccharide composition of calf rotavirus.

The oligosaccharides of the structural glycoprotein (VP7) of calf rotavirus were characterized. The precursor of VP7 produced in infected cells in the presence of tunicamycin migrated on SDS-polyacrylamide gels with an apparent molecular weight 6000 less than the glycosylated glycoprotein. Endoglycosidase (Endo) H digestion of the mature virus resulted in a decrease of 5000 in the molecular weight of VP7 in two discrete stages. Analysis of Endo H-treated, 3H-labelled digestion products of VP7 on Bio-Gel P-4 identified an oligosaccharide of molecular weight 1350 as the predominant form. Further treatment of the digest with mannosidase and analysis on Bio-Gel P-2 columns indicated that the oligosaccharide was digested into a free mannose and an oligosaccharide of molecular weight 400 in the ratio of 6:1. This indicates that the oligosaccharides of VP7 consist of four N-linked (Man)7 residues, two of which occupy more exposed and two more cryptic positions in the VP7 molecule.

Induction of cross-reactive serum neutralizing antibody to human rotavirus in calves after in utero administration of bovine rotavirus.

Sera from calves infected in utero or postnatally with bovine rotavirus NCDV or postnatally with human rotavirus D (serotype 1) were tested by plaque reduction neutralization assay for antibody to bovine rotavirus and to three serotypes of human rotavirus. Homologous antibody developed in all animals, but antibody to heterologous rotaviruses developed mainly in animals exposed in utero to bovine rotavirus. The development of heterologous antibody may explain the immunological implications for cross-protection, previously observed between bovine and human rotavirus in experimentally infected calves.

The isolation of rotavirus from calves, foals, dogs and cats in New Zealand.

The incidence of rotaviruses in calves, foals, dogs and cats in the Dunedin urban and rural areas was investigated using electron microscopy and enzyme-linked immunosorbent assays. Of the 283 faecal specimens examined, 26% were positive for rotavirus. Comparison of the genetic electropherotypes was made by separating the viral dsRNA segments using polyacrylamide gel electrophoresis. It is possible that rotavirus infection is a zoonotic disease.

Human rotavirus detection by agglutination of antibody-coated erythrocytes.

We sensitized sheep erythrocytes (SRBC) with antibodies against human rotavirus strain Wa (SRBC-antiWa) and antibodies against calf rotavirus strain NCDV (SRBC-antiNCDV). These were readily agglutinated in the presence of homologous antigens, i.e., human rotavirus and calf rotavirus. By the hemagglutination of SRBC-antiWa and SRBC-antiNCDV (reverse passive hemagglutination [RPHA]), titration of rotavirus in extracts from feces of children suffering from diarrhea (61 specimens) was carried out. We found that the ratio of titers determined with SRBC-antiWa and SRBC-antiNCDV varied remarkably from specimen to specimen. This indicated that the antigenic determinants on human rotavirus in patients feces cross-react with antibodies against NCDV to varying extents. To express the cross-reactivity of human rotavirus with antibodies to NCDV, we propose a Wa/NCDV rotavirus index which can be calculated from the RPHA titer with SRBC-antiWa and SRBC-antiNCDV as follows: Wa/NCDV rotavirus index = (antiWa-RPHA titer of specimen/antiWa-RPHA titer of NCDV)/(antiNCDV-RPHA titer of specimen/antiNCDV-RPHA titer of NCDV).

Rotavirus and reovirus stability in microorganism-free distilled and wastewaters

Survival of calf rotavirus and reovirus under controlled laboratory conditions in microorganism-free, distilled and wastewater at 8 and 26°C was examined by periodic measurement of cytopathic effects (CPE) and indirect fluorescent antibody (IFA) assays. Five samples of both water-types were collected and inoculated with the two viruses. Three samples of each type of water were divided into two bottles, one per virus, for incubation at 8°C. Two samples were used at 26°C, one per trial. In the absence of light and shaking at 26°C, 7–13 days were required for a loss of 90% infectivity for rotavirus and reovirus, while at 8°C, averages were 80 days for rotavirus and 260 days for reovirus. Virus infectivity remained for more than 30 days at 26°C and 400 days at 8°C. Rates of decline were 10–100 times greater at 26 than at 8°C, but at both temperatures, the MPN log 10 rate of decline of infectivity was linear.

Immunity to rotavirus in conventional neonatal calves.

The local and systemic humoral immune responses to rotavirus were studied in six conventional neonatal calves. Attenuated bovine rotavirus was administered either orally or directly into an isolated intestinal loop. The parameters monitored were neutralizing rotavirus antibody in serum, immunofluorescent and neutralizing rotavirus antibody in intestinal loop washings, and rotavirus antibody-producing cells in intestinal mucosa. An antibody response was observed in the serum and intestinal secretions from one calf only. Viral replication was not detected in the isolated intestinal loop. Rotavirus antibody-producing cells were found in the intestinal mucosa of five calves. Double staining revealed that most of these cells produced antibody of the immunoglobulin A class. The conclusions were: (i) a previously described system to detect rotavirus antibody-producing cells can be used to study immune responses in neonatal calves, (ii) the class or subclass of antibody in rotavirus antibody-producing cells can be determined by double immunofluorescent staining, (iii) neonatal calves respond to rotavirus inoculation with a local immunoglobulin A response, and (iv) most of the rotavirus antibody-producing cells are located in the mucosa of the proximal small intestine.