Antigenic variants rabies virus

This may not be the complete list of references from this article. National Center for Biotechnology Information , U. Can J Comp Med. Copyright and License information Disclaimer. Copyright notice. This article has been cited by other articles in PMC.

Abstract Street rabies virus isolated from 51 specimens from Ontario, Quebec, Manitoba and the Northwest Territories have been typed by a panel of 36 antinucleocapsid monoclonal antibodies.

Wiktor TJ, Koprowski H. Antigenic variants of rabies virus. J Exp Med. Americas, abstr. The retrospective and prospective analysis of viral isolates from humans and wild and domestic animals with specific monoclonal antibodies MAbs provides data regarding the most likely reservoir species involved in rabies transmission and dissemination 12 , 15 , 23 , Here we report the results for viral isolates that were characterized with a panel of eight MAbs in order to determine the reservoirs and their distribution in Mexico.

We studied brain samples that were positive by the fluorescent antibody test used for routine diagnosis 9 , which came from the following animals: 85 cows, 79 dogs, 40 humans, 15 skunks, 7 cats, 6 insectivorous bats, 5 pigs, 4 horses, 3 foxes, 2 bobcats, 2 coyotes, 2 goats, 2 sheep, 1 donkey, and 1 vampire bat. Samples were collected between and from 27 out of the 32 Mexican states, mostly during implementation of rabies focus control measures. Mammalogists identified the species of wild animals foxes, skunks, and bats.

The specimens were incorporated into the mammal collection of the Laboratorio de Cordados Terrestres under the direction of Ticul Alvares-Solorzano. On average four mice were used per sample. Mice died from rabies in an average time of 3 weeks, and brain samples were subjected to a semiquantitative fluorescent antibody test. The remaining samples were subjected to subsequent passages in mouse brain until reaching the level of antigen focus formation mentioned above 12 , Instead of prototype strains, previously identified V1 and V10 rabies viruses were used as reactivity controls for MAbs.

In some assays, an anti-mouse immunoglobulin G IgG was added to positive impressions to rule out cross-reactions with this reagent. Louis, Mo. Slides were rinsed carefully, impression by impression, with alternating phosphate-buffered saline 0. The slides were rinsed again with phosphate-buffered saline and water as indicated above. The slides were finally rinsed with water and dried at room temperature.

A drop of buffered glycerol was added on each tissue impression. Brain tissues in which V1 and V10 were previously propagated were mixed homogeneously and used as a positive control for the MAbs in each assay. With this panel it is possible to define 11 reaction patterns, each of which is strongly associated with a different reservoir species 12 ; nevertheless, the V1 pattern, specific for dogs and mongooses, has also been reported for isolates from coyotes, foxes, and skunks, variants which are not closely related, by genetic studies, to that of dogs 11 , 12 , 23 , We analyzed specimens, which comprised samples from nine species belonging to nonreservoir hosts and samples from six species of reservoir hosts.

The number of variants found per species was higher in nonreservoir hosts than in reservoir hosts. Additionally, in nonreservoir specimens, the higher the number of samples and the wider the territory that they encompassed, the higher the number of variants that were found.

Symbols indicate species from which rabies virus was isolated as follows: human figure, humans; club, dogs; pen point, foxes; six-pointed asterisk, skunks; cross with rounded tips, coyotes; horned circle, cows; teardrop, cats; heart, pigs; star inside circle, humans, cows, and dogs; ship's wheel, humans and pigs; yin-yang symbol, humans, dogs, and cats; lightning bolt, humans and cows.

Larger symbols represent higher numbers of cases. Symbols represent isolation of rabies virus variants from different hosts as follows: flower, V11 isolated from Desmodus rotundus ; eight-pointed star, V9 isolated from T.

Interestingly, there was no evidence of V1 in dogs in the northern states. Nevertheless, samples of V1 were isolated from wild animals, cattle, or humans, with the exception of Tamaulipas and Durango. V8 and V10 were isolated from skunks and nonreservoir hosts. V8 was found in the central states, and the major subspecies of skunk identified was Spilogale putorius leucoparia 1.

V10 samples were limited to the south of the Baja California peninsula, with Spilogale putorius lucasana 17 being the only skunk subspecies involved.

No new V8 and V10 rabies cases have been detected so far among hog-nosed-skunks and cows, respectively, but V8 is still being isolated in the region from S. It is important to note that the cow involved in the isolation of V10 was raised in the state of Puebla. Distribution of rabies virus variants V7, V8, and V10 isolated from foxes, skunks, and other species. Symbols: arrowheads pointing up and down, V8 isolated from S.

V7 was isolated from gray foxes Urocyon cineroargenteus in Zacatecas and Sonora as well as from other wild species such as coyotes Canis latrans and bobcats Lynx rufus along the Sierra Madre Occidental within the boundaries of the northern states of Sonora and Sinaloa, respectively.

V3 was also found in Estado de Mexico. V5 was found in the center of the country and in Michoacan, a subtropical state of western Mexico. V11 was the only variant that could be isolated from a vampire bat Desmodus rotundus in the state of Chiapas.

V4 was isolated from one specimen of T. Nine out of 11 antigenic rabies virus variants previously reported in the United States were found within Mexico 10 , 11 , 12 , 14 , V4, V7, V8, V9, V10, and V11 were directly isolated from their natural wild reservoirs; V1 was isolated from dogs; and V3 and V5 were obtained from nonreservoir hosts. More than one antigenic variant was usually observed for nonreservoir hosts, even in species with low numbers of samples, such as pigs and horses.

These results support previous findings that show the high susceptibility of mammals to any rabies virus 26 , 29 , The high number of samples obtained from humans, cows, and dogs underlines the priority that these species have for the national program for the control of rabies.

Furthermore, they show the diversity of variants found in nonreservoir species and thus an approximate estimate of the potential risk of humans acquiring rabies from the specific reservoirs of the variants found. The detection of variants transmitted by reservoirs other than dogs allowed for notification of the national program of zoonosis to search for other wild reservoir species.

Besides the high number of rabid dogs, we could identify several samples from rabid skunks and insectivorous bats. The geographic distribution of rabies virus variants within Mexico is shown in Fig. V1 has been concentrated in the central region of the country and correlates with a higher density of human and dog populations; the data also suggest that it is enzootic in the region because of its persistence over time.

The presence of V1 in several southern states during and could be related either to trade activities or to an undetected region of enzooticity for dogs. In contrast, in the north of the country V1 was isolated mainly from wild species and livestock. This finding could be related to the domestic dog-coyote enzootic cycle identified by sequence analysis of the V1 nucleoprotein gene isolated from samples from coyotes and dogs 22 , 27 , Alternatively, the presence of V1 in the northern states could be explained by the occurrence of a variant with a phylogenetic relationship with V1 rabies virus isolated from some skunks in California, Arkansas, and Wisconsin and foxes in Texas 11 , 27 , which is phylogenetically distant from V1 of dogs and coyotes V8 showed a wide distribution in central Mexico and was isolated from S.

These data indicate that these variants are also enzootic and that their main reservoir is not the striped skunk Mephitis mephitis , as in the United States 7 , V8 and V10 have differences at the genetic level; the phylogenetic tree suggested by other studies 11 , 20 grouped both variants in different lineages, implying that they diverged long ago or are only distantly related.

Thus, our data, along with those of previous studies 11 , 20 , show that in Mexico there are at least two independent skunk rabies foci that perhaps diverged long ago 11 , V7 was isolated for the first time in Mexico from two gray foxes U. V7 was also isolated from one bobcat L. Regarding aerial reservoirs, isolation rates and distribution of the vampire bat-associated rabies virus variants V11, V3, and V5 found in this study correlate with the relative population densities and distribution of the three vampire bat species found in Mexico 2 , 13 , 17 , It is not clear whether Desmodus rotundus is the major reservoir 14 , 32 for the three variants found V11, V3, and V5 or if Diphylla ecaudata and Diaemus youngi could also be infected and thus also play a role in the enzootic maintenance of the variants.

The hypothesis of the involvement of the latter species and of Desmodus rotundus in the enzootic maintenance of rabies virus might not be likely if the feeding behavior of Diphylla ecaudata and Diaemus youngi were considered. However, the lack of data available about feeding preferences in rabid vampire bats strengthens our hypothesis. The fact that V5 was found only in one pig and one dog probably means that the natural reservoir of this variant could have low population densities, low rabies rates, and restricted distribution in the country, data that are in agreement with the ecology of Diaemus youngi 17 , Rabies in the colonial insectivorous bat T.

In Mexico, just one case of V9 rabies attributed to T. In the present study six rabid T. Given the migratory behavior of this species, the identification of a rabies virus antigenic variant is not enough to determine whether the rabid T.

A different situation prevailed in the central region in the state of Puebla, where V4 and V9 were almost simultaneously detected. This study globally shows that rabies virus antigenic typing allowed determination of rabid reservoirs and their distribution in Mexico, which will probably enable better prevention and control of the illness in humans and in the reservoir hosts. Villalpando for their support in identifying wild animals; our colleagues working at the National Network of Public Health Rabies Laboratories as well as the epidemiologists and personnel of the rabies control program in Mexico for providing all samples; the Ministry of Agriculture, Livestock and Food Protection for providing some specimens from wild animals and cattle; Dolores Correa InDRE for encouraging this work; and our collaborators Jorge Romero, Beatriz Escamilla, Juan Manuel Campos, Irma Padilla, Ofelia Hernandez, and Lidia Crecencio for their generous hard work and help.

National Center for Biotechnology Information , U. Journal List J Clin Microbiol v. J Clin Microbiol. Author information Article notes Copyright and License information Disclaimer. Phone: , ext. Fax: E-mail: moc. This article has been cited by other articles in PMC. Abstract Rabies remains a public health problem in the Americas because of the great diversity of wild reservoirs that maintain the virus in nature.

Viral propagation. Antigenic characterization of rabies virus. RESULTS We analyzed specimens, which comprised samples from nine species belonging to nonreservoir hosts and samples from six species of reservoir hosts. The results of this study clearly indicate that the selection of vaccine strains and the methods used to evaluate the potency of rabies vaccines need to be revised. Sign In or Create an Account. Advanced Search. User Tools. Sign In. Skip Nav Destination Article Navigation.

Article July 01 This Site. Google Scholar. H Koprowski H Koprowski. Author and Article Information. TJ Wiktor.