Publications by authors named "Mason V Reichard"

55 Publications

Detection of Trichinella murrelli and Trichinella pseudospiralis in bobcats (Lynx rufus) from Oklahoma.

Vet Parasitol Reg Stud Reports 2021 Jul 14;25:100609. Epub 2021 Jul 14.

Department of Infectious Diseases, Unit of Foodborne and Neglected Parasitic Diseases, Istituto Superiore di Sanità, Rome, Italy.

Trichinella spp. infect wild carnivores throughout the world. We determined the prevalence and mean infection intensity of Trichinella spp. in bobcats (Lynx rufus) from 41 counties in Oklahoma (USA). Tongues from 306 bobcats were examined using artificial tissue digestion. The prevalence (95% confidence interval) of Trichinella spp. was 5.9% (3.7%-9.2%) in which 18 of the 301 bobcats were infected. Bobcats infected with Trichinella spp. were detected in 10 of the 41 (24.4%; 13.7%-39.5%) counties sampled. Although variable, a statistically significant difference was not detected in the prevalence of Trichinella spp. among counties where bobcats were collected. The mean (standard deviation) and median (range) infection intensity of Trichinella sp. larvae were 30.9 (39.8) and 9.6 (0.6-119.9) larvae per gram of tissue examined. Genotyping results demonstrated that 17 bobcats were infected with T. murrelliand one bobcat was infected with T. pseudospiralis. This is the first report of T. pseudospiralis in bobcats and in Oklahoma. These data suggest the bobcat, as an obligate carnivore, is likely an important host in maintaining T. murrelli sylvatic cycles in Oklahoma.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.vprsr.2021.100609DOI Listing
July 2021

Ticks infesting dogs and cats in North America: Biology, geographic distribution, and pathogen transmission.

Vet Parasitol 2021 Jun 19;294:109392. Epub 2021 Feb 19.

Department of Veterinary Pathobiology, College of Veterinary Medicine, Oklahoma State University, Stillwater, Oklahoma, 74078, United States.

A diverse array of ixodid and argasid ticks infest dogs and cats in North America, resulting in skin lesions, blood loss, and disease. The ticks most commonly found on pets in this region are hard ticks of the genera Amblyomma, Dermacentor, Ixodes, and Rhipicephalus, as well as the more recently established Haemaphysalis longicornis. Soft tick genera, especially Otobius and Ornithodoros, are also reported from pets in some regions. In this review, we provide a summary of the complex and diverse life histories, distinct morphologies, and questing and feeding behaviors of the more common ticks of dogs and cats in North America with a focus on recent changes in geographic distribution. We also review pathogens of dogs and cats associated with the different tick species, some of which can cause serious, potentially fatal disease, and describe the zoonotic risk posed by ticks of pets. Understanding the natural history of ticks and the maintenance cycles responsible for providing an ongoing source of tick-borne infections is critical to effectively combatting the challenges ticks pose to the health of pets and people.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.vetpar.2021.109392DOI Listing
June 2021

Corrigendum to "A probe-based droplet digital polymerase chain reaction assay for early detection of feline acute cytauxzoonosis" [Vet. Parasitol. 292 (2021) 109413].

Vet Parasitol 2021 May 17;293:109428. Epub 2021 Apr 17.

Department of Veterinary Pathobiology, College of Veterinary Medicine, Oklahoma State University, 250 McElroy Hall, Stillwater, OK, 74078, USA. Electronic address:

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.vetpar.2021.109428DOI Listing
May 2021

A probe-based droplet digital polymerase chain reaction assay for early detection of feline acute cytauxzoonosis.

Vet Parasitol 2021 Apr 15;292:109413. Epub 2021 Mar 15.

Department of Veterinary Pathobiology, College of Veterinary Medicine, Oklahoma State University, 250 McElroy Hall, Stillwater, OK, 74078, USA. Electronic address:

Cytauxzoonosis is a tick-borne disease of domestic cats with high mortality and narrow therapeutic window, particularly in the southcentral and southeastern United States. The causative agent is the apicomplexan protozoal parasite Cytauxzoon felis and is primarily transmitted by Amblyomma americanum, the lone star tick. Currently there is no vaccine available to prevent cytauxzoonosis and treatment is often ineffective if not initiated early enough in the course of disease. Early diagnosis and therapeutic intervention are therefore crucial for the survival of infected cats. Several methods are available for diagnosis of cytauxzoonosis, with PCR being the most sensitive. However, current PCR assays, which employ double-stranded DNA intercalating dyes to detect C. felis infection, have inherent limitations such as the potential for false positive detection of non-specific amplification products and inability to provide absolute quantification of parasite load. The objective of this study was to develop a probe-based droplet digital PCR (ddPCR) assay capable of detection and quantification of C. felis load over time and during treatment. The C. felis ddPCR assay was able to (i) reliably detect and quantify C. felis DNA in clinical blood samples from cats with acute cytauxzoonosis and (ii) monitor clinical parasite load in response to anti-protozoal treatment through absolute quantification of C. felis DNA over time. When tested on blood samples from cats with experimental C. felis infection, the assay was able to detect infection in cats as early as 24 h prior to the development of clinical signs. In addition, we demonstrate that this probe-based design can be utilized in traditional real-time PCR systems, with similar detection capabilities as compared to ddPCR. The C. felis probe-based ddPCR was also able to detect infection in samples with lower parasite loads when compared to existing nested PCR assays, although these results were not significant due to small sample size. To the author's knowledge, this is the first reported probe-based ddPCR assay to detect Cytauxzoon felis infection in domestic cats.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.vetpar.2021.109413DOI Listing
April 2021

Species Distribution Model of Trichinella Species in Cougars (Puma concolor) for the Southwestern Region of Colorado, USA.

J Wildl Dis 2021 01;57(1):211-214

Department of Veterinary Pathobiology, Center for Veterinary Health Sciences, Oklahoma State University, 250 McElroy Hall, Stillwater, Oklahoma 74078, USA.

Little information exists on the occurrence of Trichinella spp. in cougars (Puma concolor) throughout North and South America. However, species distribution models (SDM) can be used to predict suitable habitat for elusive species with limited occurrence data. In 2018, we used existing occurrence data to estimate the suitable habitat and ecological drivers of Trichinella species in cougars from the southwestern region of Colorado, US from winter months. Environmental layers were constructed and an SDM was then created for the southwestern region of Colorado. The final model (area under the curve=0.73) found areas of suitable habitat for Trichinella spp. to be associated with lower elevation, lower temperature, and higher proportions of evergreen needleleaf forests and grasslands. These results might indicate potential transmission hotspots for Trichinella spp. in the southwestern region of Colorado for where cougars are consuming infected hosts and where cougars can transmit to other hosts, including humans. However, due to limited occurrence data, more suitable habitat likely exists.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.7589/JWD-D-20-00055DOI Listing
January 2021

Recent reports of winter tick, Dermacentor albipictus, from dogs and cats in North America.

Vet Parasitol Reg Stud Reports 2020 12 2;22:100490. Epub 2020 Nov 2.

Department of Veterinary Pathobiology, College of Veterinary Medicine, Oklahoma State University, Stillwater, OK, USA.

Dermacentor albipictus, a common one-host tick of large animals in North America, is most often reported from moose (Alces alces) and is rarely implicated as a parasite of cats and dogs. From 2018 to 2020, 4 dogs and 4 cats from United States and 3 dogs from Canada were infested with D. albipictus. The specimens were collected and submitted to university diagnostic specialists by veterinary clinics in Indiana, Kentucky, Minnesota, Colorado, Wyoming, Utah, Alberta, and British Columbia between the months of October to February (United States) and April to June (Canada). Six adults and five nymphal D. albipictus were collected in the United States while three adults were collected from pets in Canada, and most often a single D. albipictus was present. Identification of specimens collected in the United States were confirmed by amplification and sequencing of 16S rRNA and ITS-2 gene fragments. Rickettsia spp. were not detected in any D. albipictus collected in the United States by 17 kDa-based PCR. As tick populations continue to increase and expand in North America, correct identification of ticks collected from pets is critical to accurately track the progression and spread of ticks and tick-borne diseases.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.vprsr.2020.100490DOI Listing
December 2020

Seroprevalence, DNA isolation, and genetic characterization of Toxoplasma gondii from black bear (Ursus americanus) sera collected in Eastern Oklahoma.

Parasitol Res 2020 Mar 21;119(3):1109-1115. Epub 2020 Feb 21.

Department of Veterinary Pathobiology, Oklahoma State University, Stillwater, OK, 74078, USA.

Black bears (Ursus americanus) are commonly exposed to Toxoplasma gondii. However, there are no reports of exposure or infection with T. gondii in black bears from Oklahoma. The purpose of our project was to determine the seroprevalence of T. gondii antibodies in black bears collected in Oklahoma. Additionally, since only serum was available from these bears, we sought to determine if DNA extraction and PCR amplification for T. gondii was possible on serum samples from bears with positive titers. Seroprevalence was determined using modified agglutination test (MAT). Serum was collected from 44 live-trapped bears in southeastern Oklahoma; 32 (73% ± 58-84%) had antibodies against T. gondii. Seroprevalence in adult bears (85% ± 67-95%) was significantly higher (p = 0.028) than yearlings (33.0% ± 56-80%). Adult bears were 3.4 times more likely to have antibodies to T. gondii than yearlings. From the bears with positive titers, T. gondii DNA was detected in 12 of the 32 seropositive samples by PCR of the B1 gene, with two of the samples showing variation in two nucleotide positions when compared with available sequences. Multilocus PCR-RFLP genotyping of these 12 samples revealed three ToxoDB genotypes, including #2 (type III, haplogroup 3), #4 (type XII, haplogroup 12), and #74 (haplogroup 12). To the best of our knowledge, this is the first report of T. gondii seroprevalence in black bears from Oklahoma. Our results indicate that exposure and infection with T. gondii in black bears from Oklahoma is common.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00436-019-06535-zDOI Listing
March 2020

Transmission of Cytauxzoon felis to domestic cats by Amblyomma americanum nymphs.

Parasit Vectors 2019 Jan 11;12(1):28. Epub 2019 Jan 11.

Department of Veterinary Pathobiology, Oklahoma State University Center for Veterinary Health Sciences, Stillwater, OK, 74078, USA.

Background: Successful Cytauxzoon felis transmission studies have occurred using Amblyomma americanum adults acquisition-fed as nymphs on an experimentally infected domestic cat or Dermacentor variabilis adults fed as nymphs on a splenectomized bobcat. Here, we evaluated A. americanum and D. variabilis nymphs acquisition-fed as larvae on a C. felis-infected carrier domestic cat for competence to transmit the protozoan parasite as nymphs to naïve, healthy domestic cats.

Methods: Amblyomma americanum and D. variabilis larvae were applied to a chronically infected, parasitemic C. felis donor cat (Felis catus) and allowed to feed to repletion. Engorged larvae were collected and held through ecdysis. Three cats were each infested with 66 A. americanum or 66 D. variabilis emerged nymphs. Cytauxzoon felis infections in principal cats were determined by clinical signs and detection of circulating parasite by blood smear and PCR evaluation.

Results: Clinical signs of cytauxzoonosis were observed in cats infested with A. americanum nymphs beginning 12-15 days post-infestation (dpi). The same cats were PCR positive on 12-14 dpi; piroplasms were evident in blood smears at 16 dpi, and macrophage schizonts were observed in stained spleen impression smears in two animals at necropsy. Cats infested with acquisition-fed D. variabilis nymphs remained clinically normal and did not develop detectable parasitemia over the course of the study as determined by blood smear and PCR.

Conclusions: Cytauxzoon felis was successfully transmitted to domestic cats by A. americanum nymphs acquisition-fed as larvae on the donor cat. However, we were not able to transmit C. felis to healthy domestic cats with D. variabilis nymphs that were simultaneously acquisition-fed on the same donor cat. Results from this study suggest that larval and nymphal A. americanum likely play important roles in natural transmission cycles of C. felis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s13071-018-3276-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6330474PMC
January 2019

Identification of antigens via protein microarray and assessment of expression library immunization against cytauxzoonosis.

Clin Proteomics 2018 29;15:44. Epub 2018 Dec 29.

1College of Veterinary Medicine, North Carolina State University, Research Building Room 464, 1060 William Moore Drive, Raleigh, NC 27607 USA.

Background: Cytauxzoonosis is a disease of felids in North America caused by the tick-transmitted apicomplexan parasite . Cytauxzoonosis is particularly virulent for domestic cats, but no vaccine currently exists. The parasite cannot be cultivated in vitro, presenting a significant limitation for vaccine development.

Methods: Recent sequencing of the genome has identified over 4300 putative protein-encoding genes. From this pool we constructed a protein microarray containing 673 putative proteins. This microarray was probed with sera from -infected and naïve cats to identify differentially reactive antigens which were incorporated into two expression library vaccines, one polyvalent and one monovalent. We assessed the efficacy of these vaccines to prevent of infection and/or disease in a tick-challenge model.

Results: Probing of the protein microarray resulted in identification of 30 differentially reactive antigens that were incorporated into the two expression library vaccines. However, expression library immunization failed to prevent infection or disease in cats challenged with .

Conclusions: Protein microarray facilitated high-throughput identification of novel antigens, substantially increasing the pool of characterized antigens. These antigens should be considered for development of vaccines, diagnostics, and therapeutics.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s12014-018-9218-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6310948PMC
December 2018

Efficacy of a topical formulation of selamectin plus sarolaner against induced infestations of Amblyomma americanum on cats and prevention of Cytauxzoon felis transmission.

Vet Parasitol 2019 Jun 11;270 Suppl 1:S31-S37. Epub 2018 Nov 11.

Zoetis, Veterinary Medicine Research and Development, Kalamazoo, MI 49007, USA.

Cytauxzoonosis, caused by infection with Cytauxzoon felis, is the most severe tick-borne disease of cats. The purpose of our study was to determine the efficacy of selamectin (6.0 mg/kg) plus sarolaner (1.0 mg/kg) formulated in combination (Revolution® Plus / Stronghold Plus, Zoetis) applied topically once a month on cats for three months against induced infestations of Amblyomma americanum adults and to evaluate the effectiveness of the product in preventing the transmission of C. felis. This study was conducted in two phases. Sixteen cats were dosed with selamectin/sarolaner or a placebo (vehicle control) on Days 0, 28, and 56. In phase 1, each cat was infested with 50 (±5) unfed adult A. americanum on Day 4 and tick counts were conducted on Day 6 (48 h post infestation) and Day 7 (72 h post infestation) to evaluate acaricidal efficacy. In phase 2, to confirm acaricidal efficacy and evaluate prevention of C. felis transmission, each cat was infested on Day 60 with 50 (±5) adult A. americanum acquisition fed as nymphs on two C. felis-infected donor cats. Tick counts were conducted on Day 62 (48 h post infestation) and Day 63 (72 h post infestation). Blood samples were collected on Days -9, 60, 70, 76, and 90 and tested for infection with C. felis. Placebo cats were adequately infested on all count days, with least squares (geometric) mean live tick counts ranging from 34.0 (28.8) to 46.1 (46.0). Treatment reduced the least squares (geometric) mean counts compared to placebo by 27.1 (32.1)% and 90.4 (96.8)% on Days 6 and 7, respectively. The corresponding percent reductions were 56.4 (60.6)% and 94.7 (97.3)% on Days 62 and 63, respectively. Least squares mean counts were significantly lower in the treated group compared with the placebo group on all count days (P ≤ 0.0286). All cats were negative for C. felis by PCR prior to study start. In phase 2, seven cats in the control group and no cats in the selamectin/sarolaner group became infected with C. felis (P = 0.0017). Topical treatment with selamectin/sarolaner was >90% effective in reducing A. americanum tick counts 72 h after infestation and prevented the transmission of C. felis from infected ticks following the third of three monthly treatments. Revolution Plus / Stronghold Plus offers an option for the control of A. americanum infestations on cats and for preventing the transmission of C. felis to cats.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.vetpar.2018.10.018DOI Listing
June 2019

Genetic variability of cloned Cytauxzoon felis ribosomal RNA ITS1 and ITS2 genomic regions from domestic cats with varied clinical outcomes from five states.

Vet Parasitol 2017 Sep 3;244:136-143. Epub 2017 Aug 3.

Department of Veterinary Pathobiology, Texas A&M University, College Station, TX 77843-4467, USA. Electronic address:

Cytauxzoon felis is a tick-borne hemoparasite that causes cytauxzoonosis in domestic cats in the United States. Historically, feline cytauxzoonosis was reported to be nearly always fatal. However, increasing evidence of cats surviving acute infection and/or harboring a chronic, subclinical infection has suggested the existence of different C. felis strains that may vary in pathogenicity. In this study, the intraspecific variation of the C. felis first and second ribosomal RNA internal transcribed spacer (ITS1, ITS2) regions was assessed for any clinical outcome or geographic associations. Sequence data were obtained for 122C. felis ITS1 and ITS2 clones from 41 domestic cat blood samples from Arkansas, Kansas, Missouri, Oklahoma, and Texas. Seven previously reported ITS1 region sequences were found, and a previously undescribed 23-bp insert was detected in cloned ITS1 sequences from a domestic cat in Missouri and two cats in Oklahoma. Four previously reported ITS2 region sequences were identified, and a 40-bp insert similar to that previously reported in C. felis of a domestic cat from Arkansas and pumas was detected in 18 cloned C. felis sequences from 12 domestic cats. One clone contained both the 23-bp insert and 40-bp insert within the ITS1 and ITS2 regions, respectively. Combined ITS1 and ITS2 sequence genotypes revealed that C. felis sequences from 27 cats (72/122 clones) corresponded to four previously described genotypes, ITSa, ITSc, ITSd, and ITSn. Five clones with the novel 23-bp insert from three cat isolates represented two new genotypes, ITSaa and ITSbb. Genotypes ITScc, ITSdd, ITSee, ITSff, ITSgg, and ITShh denoted 13 clones that matched prior sequences but had no previously assigned genotype. Genotypes ITSii through ITStt comprised 32 clones that were similar to, but did not exactly match, previously described genotypes. Twenty-five cats had C. felis infections with multiple ITS genotypes. Considerable C. felis genetic diversity was revealed with no significant geographic or clinical outcome associations.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.vetpar.2017.08.002DOI Listing
September 2017

Pilot Study to Assess the Efficacy of Ivermectin and Fenbendazole for Treating Captive-Born Olive Baboons () Coinfected with and .

J Am Assoc Lab Anim Sci 2017 Jan;56(1):52-56

Comparative Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA.

In this study, we evaluated the efficacy of combined treatment with ivermectin and fenbendazole (IVM-FBZ) for treating captive olive baboons (Papio anubis) infected with Strongyloides fülleborni and Trichuris trichiura, 2 common nematode parasites of these NHP. Infected baboons were treated for a total of 9 wk with ivermectin (400 μg/kg IM twice weekly) and fenbendazole (50 mg/kg PO once daily for 3 d; 3 rounds of treatment, 21 d apart). Five baboons naturally infected with both S. fülleborni and T. trichiura (n = 4) or S. fülleborni alone (n = 1) received the combination therapy; an additional baboon infected with both parasites served as a nontreated control. The efficacy of IVM-FBZ was measured as the reduction in fecal egg counts of S. fülleborni and T. trichiura as determined by quantitative fecal flotation examination after treatment of baboons with IVM-FBZ. All baboons treated with IVM-FBZ stopped shedding S. fülleborni and T. trichiura eggs by 8 d after treatment and remained negative for at least 161 d. The nontreated control baboon shed S. fülleborni and T. trichiura eggs throughout the study period. Our results indicate that the IVM-FBZ regimen was efficacious for treating olive baboons infected with S. fülleborni and T. trichiura.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5250495PMC
January 2017

Immunologic detection of Giardia duodenalis in a specific pathogen-free captive olive baboon ( Papio cynocephalus anubis) colony.

J Vet Diagn Invest 2017 Nov 28;29(6):916-919. Epub 2017 Jul 28.

Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (Saleh, Zajac).

Several commercial Giardia immunoassays were evaluated in baboons for sensitivity and specificity as well as ease of use in a large specific pathogen-free (SPF) colony. An additional objective was to identify the assemblage(s) of Giardia duodenalis present in this baboon colony. A direct immunofluorescent antibody test (IFAT) was used as the reference test. Tests evaluated were a patient-side rapid test for dogs and cats, a human rapid test, and a well-plate ELISA designed for use with humans. Test sensitivities and specificities were compared using the McNemar paired t-test and were further evaluated for agreement using an unweighted Cohen kappa statistic. When compared to the IFAT reference, both human tests were more sensitive than the veterinary test. Based on PCR and sequencing of the G. duodenalis small-subunit ribosomal RNA and glutamate dehydrogenase loci, assemblage AI was present in this baboon colony. We found that 10 of the 110 (9%) baboons in this SPF colony were infected with a zoonotic strain of G. duodenalis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1177/1040638717721580DOI Listing
November 2017

Prevalence of infection in healthy free-roaming cats in north-central Oklahoma and central Iowa.

JFMS Open Rep 2016 Jan-Jun;2(1):2055116916655174. Epub 2016 Jun 14.

Department of Veterinary Pathobiology, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK, USA.

Cytauxzoonosis is a tick-borne disease of cats, and Oklahoma (OK), USA, is considered an enzootic state. To determine the prevalence of , blood was collected from free-roaming cats, as they are frequently exposed to tick vectors. Our objective was to determine the prevalence of infection in free-roaming cats in north-central Oklahoma and central Iowa (IA). Infection with was determined using DNA extracted from blood and PCR amplification. Blood was collected from 380 free-roaming cats between January and April in 2014 in OK. DNA from was detected in 3/380 (0.8%; 95% confidential interval [CI] 0.22-2.3%). In IA, 292 blood samples were collected between 2012 and 2014. No -infected cats were detected (0; 95% CI 0-0%). The prevalence of (0.8%) in north-central OK reported herein was lower than the previously reported 3.4% in domestic cats in OK. Our study supports that the prevalence in a given enzootic area can vary by location and from the pool of cats sampled. None of 291 (0%) cats were infected with in central IA. To date, only one case of cytauxzoonosis in a domestic cat has been reported in IA. It is important to monitor cats for infections in northern US states, as geographic distribution of expands northward. As free-roaming cats have more contact with the tick vectors of , this population allows us to monitor the expansion of distribution.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1177/2055116916655174DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5362915PMC
June 2016

Prevalence of Alaria infection in companion animals in north central Oklahoma from 2006 through 2015 and detection in wildlife.

J Am Vet Med Assoc 2017 Apr;250(8):881-886

OBJECTIVE To determine the prevalence of Alaria infection in cats and dogs in north central Oklahoma over various periods and investigate whether wild animal species in this region were also infected. DESIGN Combined cross-sectional study and case series. SAMPLE Results of parasitological testing of fecal samples from 5,417 client-owned dogs and 1,246 client-owned cats (2006 through 2014); fecal samples from 837 shelter or rescue dogs and 331 shelter or rescue cats (2013 and 2014) and 268 feral cats (2015); tongue or jowl samples from cadavers of 43 wild pigs, 3 opossums, and 1 raccoon; and intestinal tract segments from cadavers of 48 cats and 5 coyotes. PROCEDURES Various parasite recovery techniques were performed to detect various Alaria stages in samples. Recovered adult trematodes and mesocercariae were used for PCR assay and sequencing of the 28S rRNA gene. RESULTS Prevalence of Alaria infection was significantly higher in feral cats (9.0%) than in shelter or rescue cats (0.6%) and client-owned cats (1.4%) and in shelter or rescue dogs (1.8%) than in client-owned dogs (0.2%). Mesocercariae were recovered from tissue samples from 11 (26%) wild pigs and 1 opossum. Amplicon sequences from adult trematodes and mesocercariae were 100% identical to each other and 99% homologous to GenBank sequences of Alaria alata and Alaria mustelae. CONCLUSIONS AND CLINICAL RELEVANCE Prevalence of Alaria infection in the study area has increased in dogs and cats since 1990, when infections were rare. Prevalence in wild pigs was similar to that in Eurasia, where A alata is considered an emerging zoonotic parasite.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.2460/javma.250.8.881DOI Listing
April 2017

Minimum transmission time of Cytauxzoon felis by Amblyomma americanum to domestic cats in relation to duration of infestation, and investigation of ingestion of infected ticks as a potential route of transmission.

J Feline Med Surg 2018 02 2;20(2):67-72. Epub 2017 Feb 2.

1 Department of Veterinary Pathobiology, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK, USA.

Objectives The objectives of the present study were to determine the duration of infestation by Amblyomma americanum necessary for transmission of Cytauxzoon felis to domestic cats and to determine if ingestion of C felis-infected A americanum by cats is a route of transmission. Methods Forty-nine cats were assigned to one of seven groups, with seven cats per group. Cats were infested with A americanum adults, acquisition fed as nymphs on a cytauxzoonosis survivor cat, for 12 h (group 1), 18 h (group 2), 24 h (group 3), 36 h (group 4), 48 h (group 5) and to repletion (group 7; control). Cats in group 6 were fed C felis-infected ticks. Thumb counts were performed at the end of the duration of infestation for groups 1-5 and at 48 h for the control group. For group 6, 50 live C felis-infected adult A americanum were mixed with food and fed to each of the cats. Transmission of C felis was determined by examining blood of cats by DNA extraction followed by PCR. Results Of 50 ticks placed on each cat (groups 1-5 and 7), the arithmetic mean attachment ± SEM ranged from 46.9 ± 1.9 in group 3 to 49.3 ± 0.3 in group 1. In group 6, the average number ± SEM of ticks ingested was 46.5 ± 2.3. One cat in group 5 that had been infested for 48 h became infected with C felis. None of the cats in group 6 (ingestion) became infected with C felis. Six of 7 (85.7%) cats in group 7, the control group, became infected with C felis. Conclusions and relevance Our results indicate that transmission of C felis to domestic cats can happen as quickly as >36 h but ⩽48 h of exposure to A americanum infected with C felis and that ingestion of C felis-infected A americanum is not a likely route of transmission.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1177/1098612X17691172DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5788073PMC
February 2018

Increased detection of Dirofilaria immitis antigen in cats after heat pretreatment of samples.

J Feline Med Surg 2017 Oct 30;19(10):1013-1016. Epub 2016 Sep 30.

1 Department of Veterinary Pathobiology, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK, USA.

Objectives To determine whether pretreating diagnostic samples with heat increases the detection of Dirofilaria immitis antigen in adult cats, we evaluated feline serum and plasma samples collected in heartworm-endemic areas of the southern United States. Methods Commercial microtiter well assays for detection of D immitis antigen were used to evaluate serum or plasma samples from 385 shelter and free-roaming cats from the southcentral and southeastern United States before and after heat treatment; commercial antibody tests were performed on a subset of samples. Results Prior to sample heat treatment, 1/220 (0.5%) shelter cats and 4/165 (2.4%) free-roaming cats had detectable D immitis antigen. After heat pretreatment, the detection rate increased to 13/220 (5.9%) and 13/165 (7.9%), respectively. Antibody reactive to D immitis was significantly more common ( P <0.001) in the serum of cats that were antigen positive after heat treatment (10/13; 76.9%) than serum from cats that remained antigen negative after heat treatment (22/163; 13.5%). Conclusions and relevance Heat pretreatment of feline samples increased antigen detection by commercial assays for D immitis and improved overall concordance of antigen and antibody test results in antigen-positive samples in this population. Although further work to investigate the specificity of D immitis antigen assays when using pre-treated samples is warranted, this approach may be useful in the diagnosis of heartworm infection in individual cats and may increase the accuracy of surveys based on antigen detection.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1177/1098612X16670562DOI Listing
October 2017

Ectoparasites of free-roaming domestic cats in the central United States.

Vet Parasitol 2016 Sep 31;228:17-22. Epub 2016 Jul 31.

Department of Veterinary Pathobiology, Center for Veterinary Health Sciences, Oklahoma State University, 250 McElroy Hall Stillwater, OK 74078, USA. Electronic address:

Free-roaming domestic cat (Felis catus) populations serve as a valuable resource for studying ectoparasite prevalence. While they share a similar environment as owned cats, free-roaming cats do not receive routine veterinary care or ectoparasiticide application, giving insight into parasite risks for owned animals. We examined up to 673 infested cats presented to a trap-neuter-return (TNR) clinic in the central United States. Ectoparasite prevalences on cats were as follows: fleas (71.6%), ticks (18.7%), Felicola subrostratus (1.0%), Cheyletiella blakei (0.9%), and Otodectes cynotis (19.3%). Fleas, ticks, and O. cynotis were found in all months sampled. A total of 1117 fleas were recovered from 322 infested cats. The predominate flea recovered from cats was Ctenocephalides felis (97.2%) followed by Pulex spp. (2.8%), Cediopsylla simplex (0.6%), and Nosopsyllus fasciatus (0.6%). A total of 373 ticks were recovered from 126 infested cats. The predominate tick species was Amblyomma americanum (65.9%) followed by Ixodes scapularis (32.5%), Dermacentor variabilis (10.3%), and Rhipicephalus sanguineus (0.8%). Immature tick stages accounted for 54.7% of all ticks found, highlighting an under-appreciated source of tick burden on domestic cats. The results of this study emphasize the importance of year-round use of ectoparasiticides with both insecticidal and acaricidal activity on domestic cats.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.vetpar.2016.07.034DOI Listing
September 2016

PCR amplification of a multi-copy mitochondrial gene (cox3) improves detection of Cytauxzoon felis infection as compared to a ribosomal gene (18S).

Vet Parasitol 2016 Jul 8;225:123-30. Epub 2016 Jun 8.

North Carolina State University, College of Veterinary Medicine, 1060 William Moore Dr., Raleigh, NC 27607, United States. Electronic address:

Cytauxzoon felis is a tick-transmitted protozoan parasite that infects felids. Clinical disease caused by acute C. felis infection rapidly progresses in domestic cats, leading to high morbidity and mortality. Accurately diagnosing cytauxzoonosis as soon as possible during acute infection would allow for earlier initiation of antiprotozoal therapy which could lead to higher survival rates. Molecular detection of parasite rRNA genes (18S) by PCR has previously been shown to be a sensitive method of diagnosing C. felis infections. Based on evidence from related apicomplexan species, we hypothesized that C. felis mitochondrial genes would exist at higher copy numbers than 18S and would be a more sensitive diagnostic target. In this study we have designed a PCR assay targeting the C. felis mitochondrial gene cytochrome c oxidase subunit III (cox3). Herein we demonstrate that (1) the cox3 PCR can detect as low as 1 copy of DNA target and can detect C. felis in samples with known mitochondrial sequence heterogeneity, (2) cox3 copy number is increased relative to 18S in blood and tissue samples from acutely infected cats, and (3) the cox3 PCR is more sensitive than 18S PCR for detection of C. felis during early infections.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.vetpar.2016.06.013DOI Listing
July 2016

High prevalence of Trichinella pseudospiralis in Florida panthers (Puma concolor coryi).

Parasit Vectors 2015 Feb 4;8:67. Epub 2015 Feb 4.

Department of Infectious, Parasitic and Immunomediated Diseases, Istituto Superiore di Sanità, viale Regina Elena 299, Rome, 00161, Italy.

Background: Parasites of the genus Trichinella are zoonotic nematodes common in carnivores throughout the world. We determined the prevalence and species of Trichinella infections in Florida panthers (Puma concolor coryi).

Methods: Tongues from Florida panthers were collected at necropsy and examined by pepsin-HCl artificial digestion for infection with Trichinella spp. DNA was extracted from larvae and multiplex PCR using Trichinella species-specific primers was used to genotype the worms.

Results: Trichinella spp. larvae were detected in 24 of 112 (21.4%; 14.6%-30.3%) panthers. Sixteen of the panthers (14.3%) were infected with T. pseudospiralis, 1 (0.9%) was infected with T. spiralis, and 2 (1.8%) had mixed infections of T. pseudospiralis and T. spiralis. Trichinella spp. larvae from 5 panthers were not identified at the species level due to degraded DNA.

Conclusions: This is the highest prevalence of T. pseudospiralis detected in North America up to now and suggests the Florida panther is a key mammalian reservoir of this parasite in southern Florida. Trichinella pseudospiralis can infect both mammals and birds indicating the source of infection for Florida panthers could be broader than believed; however, birds represent a small percentage (0.01%) of the cat's diet. Since wild pigs (Sus scrofa) can be parasitized by both T. pseudospiralis and T. spiralis and these swine can comprise a large portion (~40%) of a panther's diet in Florida, we believe that Florida panthers acquired these zoonotic parasites from feeding on wild pigs.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s13071-015-0674-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4324651PMC
February 2015

Prevalence of Cytauxzoon felis infection in healthy cats from enzootic areas in Arkansas, Missouri, and Oklahoma.

Parasit Vectors 2015 Jan 8;8:13. Epub 2015 Jan 8.

Department of Veterinary Pathobiology, Oklahoma State University, Stillwater, OK, USA.

Background: Infection with Cytauxzoon felis in domestic cats can cause fever, lethargy, depression, inappetence, icterus, and often death. With a high mortality rate, cytauxzoonosis was historically considered a fatal disease. Within the last 15 years, cats with or without treatment have been recognized as chronically infected survivors of C. felis infection. Our objective was to determine the prevalence of C. felis in healthy domestic cats from Arkansas, Missouri, and Oklahoma.

Methods: Infection with C. felis was determined using DNA extracted from anticoagulated whole blood and PCR amplification using C. felis-specific primers. Chi-square, Fisher's exact tests, and odds ratios were used to compare proportions of cats infected with C. felis.

Results: Blood samples were collected from 902 healthy domestic cats between October 2008 and April 2012. DNA from Cytauxzoon felis was detected in 56 of 902 (6.2%; 95% confidence interval, 4.7-7.9) samples. The highest prevalence of C. felis infection (15.5%; 10.3-21.7) was observed in cats from Arkansas, followed by cats from Missouri (12.9%; 6.1-24.0), and cats from Oklahoma (3.4%; 2.2-5.1). Cats sampled in Arkansas and Missouri were 5.1 and 4.2, respectively, times more likely to be chronically infected with C. felis than cats from Oklahoma.

Conclusions: Infection with C. felis is common in domestic cats through Arkansas, Missouri, and Oklahoma. The high prevalence of C. felis reported herein suggests that infected domestic cats are likely reservoirs of infection for naive felines. The high prevalence of C. felis substantiates the importance for the use of approved acaricides on cats to prevent cytauxzoonosis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s13071-014-0618-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4297400PMC
January 2015

Pre-treatment with heat facilitates detection of antigen of Dirofilaria immitis in canine samples.

Vet Parasitol 2014 Jun 18;203(1-2):250-2. Epub 2014 Jan 18.

Department of Veterinary Pathobiology, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK, United States.

Diagnosis of Dirofilaria immitis infection in dogs is largely dependent on detection of antigen in canine serum, plasma, or whole blood, but antigen may be bound in immune complexes and thus not detected. To develop a model for antigen blocking, we mixed serum from a microfilaremic, antigen-positive dog with that of a hypergammaglobulinemic dog not currently infected with D. immitis and converted the positive sample to antigen-negative; detection of antigen was restored when the mixed sample was heat-treated, presumably due to disruption of antigen/antibody complexes. A blood sample was also evaluated from a dog that was microfilaremic and for which microfilariae were identified as D. immitis by morphologic examination. Antigen of D. immitis was not detected in this sample prior to heating but the sample was strongly positive after heat treatment of whole blood. Taken together, our results indicate that blood samples from some dogs may contain factors that inhibit detection of antigen of D. immitis, and that heat treatment of these samples prior to testing could improve the sensitivity of these assays in some patients.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.vetpar.2014.01.007DOI Listing
June 2014

Prevalence of antibodies to spotted fever group Rickettsia spp. and Ehrlichia spp. in coyotes (Canis latrans) in Oklahoma and Texas, USA.

J Wildl Dis 2013 Jul;49(3):670-3

Department of Veterinary Pathobiology, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, Oklahoma 74078, USA.

Coyotes (Canis latrans) are commonly infested with ticks, including Amblyomma americanum, the predominant vector of Ehrlichia chaffeensis and Ehrlichia ewingii; Dermacentor variabilis, an important vector of Rickettsia rickettsii; and Amblyomma maculatum, a major vector of Rickettsia parkeri, a spotted fever group (SFG) Rickettsia. To determine the degree to which coyotes are infected with or exposed to tick-borne bacterial disease agents, serum samples collected from coyotes in Oklahoma and Texas were tested for antibodies reactive to R. rickettsii, Ehrlichia canis, E. chaffeensis, E. ewingii, Borrelia burgdorferi, and Anaplasma phagocytophilum by indirect fluorescent antibody (IFA) testing or enzyme-linked immunosorbent assay (ELISA). Of the coyotes tested, 60% (46/77) and 64% (47/74) had antibodies reactive to R. rickettsii and E. chaffeensis, respectively, on IFA. Additionally, 5% (4/77) had antibodies reactive to E. canis, but not B. burgdorferi or A. phagocytophilum, on SNAP(®) 4Dx(®) ELISA; subsequent serologic analysis by plate ELISA using species-specific peptides revealed antibodies to E. ewingii, E. canis, and E. chaffeensis in 46% (23/50), 18% (9/50), and 4% (2/50) of serum samples, respectively. Taken together, these data indicate that coyotes in this region are commonly exposed to SFG Rickettsia and E. ewingii and that further consideration of coyotes as a component of the maintenance cycle for these pathogens may be warranted.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.7589/2012-08-215DOI Listing
July 2013

Efficacy of an imidacloprid 10 % / flumethrin 4.5 % collar (Seresto®, Bayer) for preventing the transmission of Cytauxzoon felis to domestic cats by Amblyomma americanum.

Parasitol Res 2013 Aug;112 Suppl 1:11-20

Department of Veterinary Pathobiology, Center for Veterinary Health Science, Oklahoma State University, Stillwater, OK 74078, USA.

Infection of Cytauxzoon felis in domestic cats produces a severe disease characterised by fever, lethargy, inappetence, anorexia, depression, dehydration, icterus and often death. Transmission of C. felis to cats is dependent on being fed upon by infected Amblyomma americanum (lone star ticks). The purpose of the present study was to determine if application of a 10 % imidacloprid/4.5 % flumethrin collar (Seresto®, Bayer) on cats prevents transmission of C. felis by repelling ticks. Twenty cats were randomised to either a treated (n = 10) or non-treated control group (n = 10) based on their susceptibility to ticks. Cats of high, medium and low tick susceptibility were represented in both groups. Treated cats were fitted with 10 % imidacloprid/4.5 % flumethrin collars on study day 0 and both groups were then infested with C. felis-infected A. americanum on study day 30. Tick thumb counts were performed at 24 and 48 hours post infestation. Transmission of C. felis was determined by examining blood of cats by DNA extraction followed by PCR amplification with piroplasm-specific primers. Ticks did not attach to any of the 10 % imidacloprid/4.5 % flumethrin- treated cats. However, ticks attached and fed on all the non-treated control cats. The geometric mean number of ticks attached to the non-treated control cats at 24 and 48 hours was 15.3 and 14.2, respectively. Cytauxzoon felis was transmitted to 9 of 10 (90 %) non-treated control cats; C. felis was not transmitted to any of the treated cats. Transmission of C. felis to the non-treated cats was first detected between 8 and 16 days post infestation. Our results indicate that application of the 10 % imidacloprid/4.5 % flumethrin collar to cats prevented ticks from attaching, feeding and transmitting C. felis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00436-013-3277-7DOI Listing
August 2013

Clarifying Prehistoric Parasitism from a Complementary Morphological and Molecular Approach.

J Archaeol Sci 2013 Jul;40(7):3060-3066

University of Oklahoma, Department of Anthropology, 455 West Lindsey, Dale Hall Tower 521, Norman, OK 73019.

This paper reports an approach to the identification of prehistoric parasitic infection, which integrates traditional morphological methods with molecular methods. The approach includes the strengths of each method while mitigating the limitations. Demonstrating the efficacy of this approach, we provide a case study from a 1,400 year old desiccated fecal sample from La Cueva de los Muertos Chiquitos, archaeological site, near Rio Zape, Durango, Mexico. Traditionally prepared microscope slides were processed via microscopy and tentative ascarids were identified. Information regarding the parasites' developmental stage was recorded. DNA was then extracted directly from the slide material. From this DNA extract, a small segment of the 18S ribosomal RNA gene variant that is specific to , and its phylogenetically close relatives, was targeted for PCR amplification and sequencing. Phylogenetic analysis of the DNA sequence best matched a member of physalopterids, rather than ascarids, with a single exception of a match to . Subsequent extractions, amplifications and sequencing of the original rehydrated coprolite material confirmed these results. The sequence represented a phylogenetic anomaly and subsequent analysis determined the sequence was an error in the BLAST database, likely attributable to misidentification of juvenile specimens prior to sequencing and submission. are a difficult genus to identify morphologically and can carry major health burdens. They may be underreported in humans, in part, because of morphological similarities to the more common human parasites belonging to ascarids. We conclude that integrating traditional morphological methods with molecular methods can help resolve this issue, in both contemporary and prehistoric populations.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jas.2013.03.010DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3640563PMC
July 2013

Potential ecological distribution of Cytauxzoon felis in domestic cats in Oklahoma, Missouri, and Arkansas.

Vet Parasitol 2013 Feb 17;192(1-3):104-10. Epub 2012 Oct 17.

Department of Zoology, Oklahoma State University, Stillwater, OK 74078, USA.

The ecological distribution of Cytauxzoon felis, an often-fatal tick-borne apicomplexan that infects domestic cats, has not been evaluated or identified despite its continued emergence. Infection of C. felis is characterized by lethargy, icterus, fever, anorexia, anemia, and death. The natural vertebrate reservoir of C. felis is the bobcat (Lynx rufus). To determine the possible distribution of C. felis in three states where infection is common (Oklahoma, Missouri, and Arkansas), two separate approaches to ecological niche modeling were implemented. First, a model relating several different climatic layers to geographic locations where cases of C. felis infection were confirmed in domestic cats was developed to predict the possible distribution of the parasite. The second model incorporated occurrences of bobcats with environmental layers and land cover suitable for tick vectors to identify areas of overlap where C. felis transmission was likely. Results of both models indicated a high probability of C. felis from central Oklahoma to south-central Missouri. However, other predicted areas of C. felis occurrence varied between the two modeling approaches. Modeling the vertebrate reservoir and the tick vector predicted a broader possible distribution compared to modeling cases of C. felis infection in domestic cats. Our results suggest that C. felis is likely to extend beyond areas predicted by case modeling due to the presence of both the vector and reservoir.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.vetpar.2012.10.008DOI Listing
February 2013

Genetic diversity of Hepatozoon spp. in coyotes from the south-central United States.

J Parasitol 2013 Apr 27;99(2):375-8. Epub 2012 Aug 27.

Department of Veterinary Pathobiology, Center for Veterinary Health Sciences, Stillwater, Oklahoma 74078, USA.

To better define the strains and species of Hepatozoon that infect coyotes in the south-central United States, whole blood and muscle samples were collected from 44 coyotes from 6 locations in Oklahoma and Texas. Samples were evaluated by a nested polymerase chain reaction (PCR) using primers amplifying a variable region of the apicomplexan 18S rRNA gene as well as histopathology (muscle only) for presence of tissue cysts. Hepatozoon spp. infections were identified in 79.5% (35/44) of coyotes tested including 27 of 44 (61.4%) whole blood samples and 17 of 44 (38.6%) muscle samples tested by PCR and 23 of 44 (52.3%) muscle samples evaluated by histological examination. Analysis revealed 19 distinct sequences comprising 3 major clusters of Hepatozoon spp., i.e., 1 most closely related to Hepatozoon americanum, another most closely related to Hepatozoon canis , and the third an intermediate between the 2 groups. The diversity of Hepatozoon spp. in wild canids appears greater than previously recognized and warrants further investigation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1645/GE-3104.1DOI Listing
April 2013

Biology of Francisella tularensis subspecies holarctica live vaccine strain in the tick vector Dermacentor variabilis.

PLoS One 2012 18;7(4):e35441. Epub 2012 Apr 18.

Department of Veterinary Pathobiology, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, Oklahoma, United States of America.

Background: The γ-proteobacterium Francisella tularensis is the etiologic agent of seasonal tick-transmitted tularemia epizootics in rodents and rabbits and of incidental infections in humans. The biology of F. tularensis in its tick vectors has not been fully described, particularly with respect to its quanta and duration of colonization, tissue dissemination, and transovarial transmission. A systematic study of the colonization of Dermacentor variabilis by the F. tularensis subsp. holarctica live vaccine strain (LVS) was undertaken to better understand whether D. variabilis may serve as an inter-epizootic reservoir for F. tularensis.

Methodology/principal Findings: Colony-reared larva, nymph, and adult D. variabilis were artificially fed LVS via glass capillary tubes fitted over the tick mouthparts, and the level of colonization determined by microbial culture. Larvae and nymphs were initially colonized with 8.8 ± 0.8 × 10(1) and 1.1 ± 0.03 × 10(3) CFU/tick, respectively. Post-molting, a significant increase in colonization of both molted nymphs and adults occurred, and LVS persisted in 42% of molted adult ticks at 126 days post-capillary tube feeding. In adult ticks, LVS initially colonized the gut, disseminated to hemolymph and salivary glands by 21 days, and persisted up to 165 days. LVS was detected in the salivary secretions of adult ticks after four days post intra-hemocoelic inoculation, and LVS recovered from salivary gland was infectious to mice with an infectious dose 50% of 3 CFU. LVS in gravid female ticks colonized via the intra-hemocoelic route disseminated to the ovaries and then to the oocytes, but the pathogen was not recovered from the subsequently-hatched larvae.

Conclusions/significance: This study demonstrates that D. variabilis can be efficiently colonized with F. tularensis using artificial methods. The persistence of F. tularensis in D. variabilis suggests that this tick species may be involved in the maintenance of enzootic foci of tularemia in the central United States.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0035441PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3329428PMC
November 2012

Detection of Dirofilaria immitis and Ehrlichia species in coyotes (Canis latrans), from rural Oklahoma and Texas.

Vector Borne Zoonotic Dis 2012 Jul 26;12(7):619-21. Epub 2012 Mar 26.

Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, Oklahoma 74078, USA.

There is a lack of knowledge regarding the prevalence of Dirofilaria immitis and Ehrlichia spp. in coyotes in Oklahoma and Texas. Documenting the prevalence of these vector-borne disease agents in coyotes from Oklahoma and Texas underscores the importance of wild canids as reservoir hosts that infect companion animals and humans. To learn more about the sylvatic cycle of D. immitis and Ehrlichia spp. in coyotes from Oklahoma and Texas, we tested for infection with and exposure to, respectively, these disease agents. Coyote carcasses were collected opportunistically from animal control experts and hunters in seven counties in Oklahoma and Texas from January to March, 2010. Serum samples from 77 coyotes were tested with a commercial ELISA test. Five (6.5%) coyotes had D. immitis antigens, and four (5.2%) had antibodies to Ehrlichia spp. The overall prevalence of D. immitis was low relative to studies from the eastern United States. Little is known about the prevalence of Ehrlichia spp. throughout the United States, but coyotes from rural Oklahoma in the current study had a higher exposure rate than those reported from California, and a lower rate than data from an earlier study from Oklahoma.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1089/vbz.2011.0815DOI Listing
July 2012

Phylogeny and evolution of the Piroplasmida as inferred from 18S rRNA sequences.

Int J Parasitol 2012 Apr 13;42(4):353-63. Epub 2012 Mar 13.

Department of Zoology, Oklahoma State University, Stillwater, OK 74078, USA.

The order Piroplasmida consists of several genera of tick-borne parasites that infect mammals, and to a lesser extent birds, and are therefore of medical and economic importance. Despite their importance, considerable confusion exists concerning the relationship among piroplasmid species, specifically concerning the number of genera and the intergeneric relationships. To examine evolutionary relationships among piroplasmids, we conducted phylogenetic analyses of 192 18S rDNA sequences from the genera Theileria, Babesia and Cytauxzoon. Our analyses revealed eight clades potentially representing distinct genera, and we distinguish the Duncani Group and Microti Group as genetically distinct groups of species requiring detailed analysis of morphology and life-history to allow formal generic description. The piroplasmid phylogeny revealed considerable host diversity and limited host specificity, suggesting piroplasmids have undergone frequent host switches during their evolution. Our analyses provide the first reported evolutionary timescale for piroplasmids independent of the assumption of parasite-host cospeciation, which is invalid for piroplasmids. Evolutionary rate analyses revealed considerable substitution rate heterogeneity, which we attribute to host switching and diversification. Finally, we call for a comprehensive phylogenetic, morphological and life-history analysis for these medically relevant taxa to resolve relationships and understand host specificity.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ijpara.2012.02.005DOI Listing
April 2012
-->