Ecology of Catarina virus (family Arenaviridae) in southern Texas, 2001-2004.
ABSTRACT: A total of 3941 rodents were captured during a 46-month prospective (mark-recapture) study on the ecology of Catarina virus in southern Texas. Antibody reactive against Catarina virus was found in 73 (11.9%) of 611 southern plains woodrats (Neotoma micropus) and none of 3330 other rodents; strains of Catarina virus were isolated from 6 antibody-negative and 9 antibody-positive southern plains woodrats; and the infections in at least 3 southern plains woodrats were chronic. These results affirm the notion that the southern plains woodrat is the principal host of Catarina virus and suggest that Catarina virus infection is highly specific to N. micropus.
Project description:The southern plains woodrat (Neotoma micropus) is the principal host of Catarina virus in southern Texas and a natural host of other North American Tacaribe serocomplex viruses. The objectives of this study were to increase our knowledge of the genetic diversity among Tacaribe serocomplex viruses associated with N. micropus and to define better the natural host relationships of these viruses. Pairwise comparisons of complete glycoprotein precursor gene sequences and complete nucleocapsid protein gene sequences revealed a high level of genetic diversity among Tacaribe serocomplex viruses associated with N. micropus in western Oklahoma, southern New Mexico, and northern and southern Texas. Collectively, the results of Bayesian analyses of nucleotide sequences and pairwise comparisons of amino acid sequences confirmed that the arenaviruses associated with N. micropus in Oklahoma and New Mexico should be included in the Whitewater Arroyo species complex, and indicated that that the arenaviruses associated with N. micropus in northern Texas are strains of a novel arenaviral species--tentatively named "Middle Pease River virus". Together, the results of assays for arenavirus and assays for anti-arenavirus antibody in 54 southern plains woodrats and 325 other rodents captured at 2 localities suggested that the southern plains woodrat is the principal host of Middle Pease River virus in northern Texas.
Project description:Trypanosoma cruzi, the causative agent of Chagas' disease, is an important public health and veterinary pathogen. Although human cases are rare in the United States, infections in wildlife, and in some areas domestic dogs, are common. In 2008 and 2010, we investigated T. cruzi prevalence in possible vertebrate reservoirs in southern Texas, with an emphasis on southern plains woodrats (Neotoma micropus). Infection status was determined using a combination of culture isolation, polymerase chain reaction (PCR), and serologic testing. Based on PCR and/or culture, T. cruzi was detected in 35 of 104 (34%) woodrats, 3 of 4 (75%) striped skunks (Mephitis mephitis), 12 of 20 (60%) raccoons (Procyon lotor), and 5 of 28 (18%) other rodents including a hispid cotton rat (Sigmodon hispidus), rock squirrel (Otospermophilus variegatus), black rat (Rattus rattus), and two house mice (Mus musculus). Additionally, another Trypanosoma species was detected in 41 woodrats, of which 27 were co-infected with T. cruzi. Genetic characterization of T. cruzi revealed that raccoon, rock squirrel, and cotton rat isolates were genotype TcIV, while woodrats and skunks were infected with TcI and TcIV. Based on the Chagas Stat-Pak assay, antibodies were detected in 27 woodrats (26%), 13 raccoons (65%), 4 skunks (100%), and 5 other rodents (18%) (two white-ankled mice [Peromyscus pectoralis laceianus], two house mice, and a rock squirrel). Seroprevalence based on indirect immunofluorescence antibody testing was higher for both woodrats (37%) and raccoons (90%), compared with the Chagas Stat-Pak. This is the first report of T. cruzi in a hispid cotton rat, black rat, rock squirrel, and white-ankled mouse. These data indicate that based on culture and PCR testing, the prevalence of T. cruzi in woodrats is comparable with other common reservoirs (i.e., raccoons and opossums) in the United States. However, unlike raccoons and opossums, which tend to be infected with a particular genotype, southern plains woodrats were infected with TcI and TcIV at near equal frequencies.
Project description:The objective of this study was to advance our knowledge of the epizootiology of Bear Canyon virus and other Tacaribe serocomplex viruses (Arenaviridae) associated with wild rodents in California. Antibody (immunoglobulin G [IgG]) to a Tacaribe serocomplex virus was found in 145 (3.6%) of 3977 neotomine rodents (Cricetidae: Neotominae) captured in six counties in southern California. The majority (122 or 84.1%) of the 145 antibody-positive rodents were big-eared woodrats (Neotoma macrotis) or California mice (Peromyscus californicus). The 23 other antibody-positive rodents included a white-throated woodrat (N. albigula), desert woodrat (N. lepida), Bryant's woodrats (N. bryanti), brush mice (P. boylii), cactus mice (P. eremicus), and deer mice (P. maniculatus). Analyses of viral nucleocapsid protein gene sequence data indicated that Bear Canyon virus is associated with N. macrotis and/or P. californicus in Santa Barbara County, Los Angeles County, Orange County, and western Riverside County. Together, analyses of field data and antibody prevalence data indicated that N. macrotis is the principal host of Bear Canyon virus. Last, the analyses of viral nucleocapsid protein gene sequence data suggested that the Tacaribe serocomplex virus associated with N. albigula and N. lepida in eastern Riverside County represents a novel species (tentatively named "Palo Verde virus") in the genus Arenavirus.
Project description:From 2008 to 2010, southern plains woodrats (Neotoma micropus) from southern Texas, were examined for parasites and selected pathogens. Eight helminth species were recovered from 97 woodrats including, Trichuris neotomae from 78 (prevalence = 80%), Ascarops sp. from 42 (43%), Nematodirus neotoma from 31 (32%), Raillietina sp. from nine (9%), Taenia taeniaeformis larvae from eight (8%), and an unidentified spiurid, a Scaphiostomum sp. and a Zonorchis sp. each from a single woodrat. Besnotia neotomofelis was detected in three (3%) woodrats and microfilaria were detected in seven (7%). Polymerase chain reaction (PCR) testing of blood samples from 104 woodrats detected a novel Babesia sp. in one (1%) and Hepatozoon sp. in 17 (16%) woodrats. Partial 18S rRNA gene sequence of the Babesia was 94% similar to B. conradae. Histologic examination of tissues detected intestinal coccidia in seven of 104 (7%), Sarcocystis neotomafelis in 26 (25%), Hepatozoon sp. in 21 (20%), and Dunnifilaria meningica in four (4%) woodrats. Three woodrats (5%) were seropositive for Toxoplasma gondii. Ectoparasites recovered included fleas (Orchopeas sexdentatus and O. neotomae), ticks (Ixodes woodi and Ornithodoros turicata), mites (Trombicula sp. and Ornithonyssus (Bdellonyssus) bacoti) and bot flies (Cuterebra sp.). The only difference in prevalence related to gender was for N. neotoma (males > females, p = 0.029). Prevalence of T. neotomae and all intestinal parasites combined was significantly higher in adults compared with juveniles (p = 0.0068 and p =0.0004), respectively. Lesions or clinical signs were associated with Cuterebra and B. neotomofelis. Collectively, these data indicate that woodrats from southern Texas harbor several parasites of veterinary and/or medical importance.
Project description:The purpose of this study was to extend our knowledge of the geographic distribution and genetic diversity of the arenavirus(es) associated with Neotoma species (woodrats) in the southwestern United States. Infectious arenavirus was recovered from 14 (3.3%) of 425 woodrats. The virus-positive species included N. albigula in New Mexico and Oklahoma, N. cinerea in Utah, N. mexicana in New Mexico and Utah, and N. micropus in Texas. Analyses of viral nucleocapsid protein gene sequence data indicated that all the isolates were strains of the Whitewater Arroyo virus, an arenavirus previously known only from northwestern New Mexico. Analyses of the sequence data also indicated that there can be substantial genetic diversity among strains of Whitewater Arroyo virus from conspecific woodrats collected from different localities and substantial genetic diversity among strains from different woodrat species collected from the same locality.
Project description:Bayesian analyses of glycoprotein precursor and nucleocapsid protein gene sequences indicated that arenaviruses naturally associated with white-throated woodrats in central Arizona are phylogenetically closely related to the Whitewater Arroyo virus prototype strain AV 9310135, which originally was isolated from a white-throated woodrat captured in northwestern New Mexico. Pairwise comparisons of glycoprotein precursor and nucleocapsid protein amino acid sequences revealed extensive diversity among arenaviruses isolated from white-throated woodrats captured in different counties in central Arizona and extensive diversity between these viruses and Whitewater Arroyo virus strain AV 9310135. It was concluded that the viruses isolated from the white-throated woodrats captured in Arizona represent 2 novel species (Big Brushy Tank virus and Tonto Creek virus) and that these species should be included with Whitewater Arroyo virus in a species complex within the Tacaribe serocomplex (family Arenaviridae, genus Arenavirus).
Project description:The results of analyses of glycoprotein precursor and nucleocapsid protein gene sequences indicated that an arenavirus isolated from a Mexican woodrat (Neotoma mexicana) captured in Arizona is a strain of a novel species (proposed name Skinner Tank virus) and that arenaviruses isolated from Mexican woodrats captured in Colorado, New Mexico, and Utah are strains of Whitewater Arroyo virus or species phylogenetically closely related to Whitewater Arroyo virus. Pairwise comparisons of glycoprotein precursor sequences and nucleocapsid protein sequences revealed a high level of divergence among the viruses isolated from the Mexican woodrats captured in Colorado, New Mexico, and Utah and the Whitewater Arroyo virus prototype strain AV 9310135, which originally was isolated from a white-throated woodrat (Neotoma albigula) captured in New Mexico. Conceptually, the viruses from Colorado, New Mexico, and Utah and strain AV 9310135 could be grouped together in a species complex in the family Arenaviridae, genus Arenavirus.
Project description:Besnoitia darlingi, B. neotomofelis and B. oryctofelisi are closely related coccidian parasites with cats as definitive hosts. While B. darlingi uses opossums as intermediate hosts, B. neotomofelis and B. oryctofelisi have been described in Southern Plains woodrats (Neotoma micropus) from the USA and in domestic rabbits from Argentina, respectively. A comparison of the Internal Transcribed Spacer-1 (ITS-1) region of the ribosomal DNA (rDNA) of these Besnoitia spp. showed only a few differences. The present study aimed at developing a real-time PCR to detect B. darlingi, B. neotomofelis and B. oryctofelisi in tissues of intermediate and in faeces of definitive hosts in order to support studies of these organisms' epidemiology and pathogenesis. The established PCR was based on primer regions distinct from the ITS-1 sequences of ungulate Besnoitia spp. and made use of a Besnoitia universal probe. To monitor inhibition, a heterologous internal control was established based on the enhanced green fluorescent protein gene. The real-time PCR reacted with B. darlingi, B. neotomofelis and B. oryctofelisi, while the novel PCR did not recognize ungulate Besnoitia spp. (B. besnoiti, B. bennetti, B. tarandi). DNA of Apicomplexa ascribed to other Besnoitia-related genera, including other gut parasites of cats (Cryptosporidium parvum, Giardia duodenalis, Tritrichomonas foetus), was not recognized. The real-time PCR had an analytic sensitivity of less than 1 tachyzoite per reaction. In feline faeces spiked with B. darlingi oocysts, the limit of detection was a DNA amount equivalent to 1 oocyst per PCR reaction. In B. darlingi infected ?-interferon knock-out mice, the lung was identified as the predilection organ. In conclusion, this real-time PCR should advance further studies on these parasites and may inspire research on related species, not only in the Americas, but also in other parts of the world.
Project description:Two hundred twenty-two individuals of the southern plains woodrat (Neotoma micropus) were captured from 198 excavated middens at 10 discrete collecting sites from a single population in south-central Texas. Field data, mitochondrial D-loop haplotypes, and polymorphic microsatellite loci (5-7) were used to determine genetic patterns in parentage, relatedness, and mating strategy. Microsatellite loci were highly polymorphic (average observed heterozygosity = 0.859) and were used to construct genotypes that were unique for each individual (probability of identical genotypes: 1 in 2,104,567). Results indicated a high frequency of multiple paternity (6 of 9 litters), evidence of repeat mating between the same 2 individuals, and no indication of male dominance at any collection site. Examination of these data suggested a promiscuous mating system. Within a site, average relatedness between adult females was similar to that between adult males. A higher level of cohabitation from that previously documented was recorded and finer-scale analyses revealed high levels of relatedness between most cohabiting individuals. Taken with results from other studies of mating behaviors of N. micropus, our results suggest that mating and social behavior of this species are likely influenced by population density.
Project description:A new species of Brachycephalus (Anura: Brachycephalidae) is described from the Atlantic Forest of northeastern state of Santa Catarina, southern Brazil. Nine specimens (eight adults and a juvenile) were collected from the leaf litter of montane forests 790-835 m above sea level (a.s.l.). The new species is a member of the pernix group by its bufoniform shape and the absence of dermal co-ossification and is distinguished from all its congeners by a combination of its general coloration (dorsal region of head, dorsum, legs, arms, and flanks light, brownish green to dark, olive green, with darker region in the middle of the dorsum and a white line along the vertebral column in most specimens) and by its smooth dorsum. The geographical distribution of the new species is highly reduced (extent of occurrence estimated as 25.04 ha, or possibly 34.37 ha). In addition, its habitat has experienced some level of degradation, raising concerns about the future conservation of the species. Preliminary density estimates suggest one calling individual every 3-4 m2 at 815-835 m a.s.l. and every 100 m2 at 790 m a.s.l. Together with the recently described B. boticario and B. fuscolineatus, the new species is among the southernmost species of Brachycephalus known to date.