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1.
Vet Med Sci ; 8(5): 2005-2011, 2022 09.
Article in English | MEDLINE | ID: mdl-35809056

ABSTRACT

BACKGROUND: Toxoplasma gondii is a widespread zoonotic protozoan parasite capable of infecting all warm-blooded animals. Although the genotypes of T. gondii in pigs have been reported worldwide, there is no information on the genotypes and diversity of T. gondii in pigs in Grenada, West Indies. OBJECTIVES: The aims of the present study were to isolate, genotype and determine the diversity of T. gondii genotypes in pigs. METHODS: We carried out a modified agglutination test (MAT) on blood from 149 pig hearts collected from a local meat market. Myocardial tissue homogenate from pigs that tested positive for T. gondii was homogenized and inoculated into mice for isolation of the parasite. We collected mouse tissues and extracted DNA for genotyping based on 11 polymerase chain reaction-restriction fragment length polymorphism markers (SAG1, SAG2, alt. SAG2, SAG 3, BTUB, GRA6, L358, PK1, C22-8, C 29-2 and Apico). RESULTS: Out of the 149 pig hearts, 31 (20.8%) tested positive for T. gondii on MAT. Bioassays in mice yielded 12 isolates designated TgpgGr1 to TgpgGr12. Molecular characterisation of T. gondii revealed four genotypes as follows: ToxoDB #2-clonal type III (seven isolates); ToxoDB #7 (three isolates); ToxoDB #13 (one isolate); ToxoDB #30 (1 isolate). Overall, ToxoDB #2 was the most common (58%). Toxo database (DB) # 13, which causes interstitial pneumonia in affected mice, has also been reported. CONCLUSION: The genetic diversity of T. gondii in pigs in Grenada is lower than that in other surrounding Caribbean areas.


Subject(s)
Rodent Diseases , Swine Diseases , Toxoplasma , Toxoplasmosis, Animal , Animals , Antibodies, Protozoan/genetics , Genotype , Grenada , Mice , Swine , Swine Diseases/epidemiology , Toxoplasma/genetics , Toxoplasmosis, Animal/parasitology
2.
Ticks Tick Borne Dis ; 12(4): 101727, 2021 07.
Article in English | MEDLINE | ID: mdl-33865177

ABSTRACT

Anaplasma platys is a tick-transmitted rickettsial pathogen, which is known to be the etiologic agent for cyclic thrombocytopenia in its primary canine host. Infections with this pathogen are also reported in cats, cattle and people. Similarly, Ehrlichia canis is another tick-borne rickettsial pathogen responsible for canine monocytic ehrlichiosis and is also reported to cause infections in people. We describe infections in dogs with these two pathogens on the Caribbean island of Grenada, West Indies by detection using molecular methods. We utilized a 16S rRNA gene-based PCR assay to detect both Ehrlichia and Anaplasma species by screening 155 canine blood samples from asymptomatic dogs. We found 18.7 % of the dogs to be positive for A. platys and 16.8 % for E. canis. Samples that tested positive for A. platys were further assessed by sequence analysis targeting 16S rRNA, 23S rRNA, citrate synthase (gltA) and heat shock protein (groEL) genes. Phylogenetic analysis revealed high correlation of A. platys 16S rRNA and gltA gene sequences with the geographic origins, while 23S rRNA and groEL gene sequences clustered independent of the geographic origins. This study represents an important step in defining the widespread distribution of active rickettsial infections in Caribbean dogs with no apparent clinical signs, thus posing a high risk for canine health and to a lesser extent to humans, as most dogs in the Caribbean are free-roaming.


Subject(s)
Anaplasma/isolation & purification , Anaplasmosis/epidemiology , Dog Diseases/epidemiology , Ehrlichia canis/isolation & purification , Ehrlichiosis/veterinary , Anaplasma/enzymology , Anaplasma/genetics , Anaplasmosis/microbiology , Animals , Bacterial Proteins/analysis , Chaperonin 60/analysis , Citrate (si)-Synthase/analysis , Dog Diseases/microbiology , Dogs , Ehrlichia canis/enzymology , Ehrlichia canis/genetics , Ehrlichiosis/epidemiology , Ehrlichiosis/microbiology , Grenada/epidemiology , Prevalence , RNA, Bacterial/analysis , RNA, Ribosomal, 16S/analysis , RNA, Ribosomal, 23S/analysis
3.
Pathogens ; 10(2)2021 Feb 10.
Article in English | MEDLINE | ID: mdl-33578784

ABSTRACT

Infections with tick-borne pathogens belonging to Anaplasma/Ehrlichia in various vertebrate hosts are a persistent problem resulting in nonspecific clinical signs during early infection. Diagnosis of single and multi-infections with these pathogens, causing diseases in companion/agricultural animals and people, remains a challenge. Traditional methods of diagnosis, such as microscopy and serology, have low sensitivity and specificity. Polymerase chain reaction (PCR) assays are widely used to detect early-phase infections, since these have high sensitivity and specificity. We report the development and validation of an assay involving PCR followed by magnetic capture method using species-specific oligonucleotides to detect six Anaplasma/Ehrlichia species pathogens in canine, bovine, caprine, and ovine blood samples. Overall, the assay application to 455 samples detected 30.1% (137/455) positives for one or more out of six screened pathogens. Single-pathogen infections were observed in 94.9% (130/137) of the positive samples, while co-infections were detected in 5.1% (7/137). Anaplasma marginale infection in cattle had the highest detection rate (34.4%), followed by canines positive for Anaplasma platys (16.4%) and Ehrlichia canis (13.9%). The assay aided in documenting the first molecular evidence for A. marginale in cattle and small ruminants and Ehrlichia chaffeensis and Ehrlichia ewingii in dogs in the Caribbean island of Grenada.

4.
Infect Immun ; 88(10)2020 09 18.
Article in English | MEDLINE | ID: mdl-32747600

ABSTRACT

Ehrlichia chaffeensis, a tick-transmitted obligate intracellular rickettsial agent, causes human monocytic ehrlichiosis. In recent reports, we described substantial advances in developing random and targeted gene disruption methods to investigate the functions of E. chaffeensis genes. We reported earlier that the Himar1 transposon-based random mutagenesis is a valuable tool in defining E. chaffeensis genes critical for its persistent growth in vivo in reservoir and incidental hosts. The method also aided in extending studies focused on vaccine development and immunity. Here, we describe the generation and mapping of 55 new mutations. To define the critical nature of the bacterial genes, infection experiments were carried out in the canine host with pools of mutant organisms. Infection evaluation in the physiologically relevant host by molecular assays and by xenodiagnoses allowed the identification of many proteins critical for the pathogen's persistent in vivo growth. Genes encoding proteins involved in biotin biosynthesis, protein synthesis and fatty acid biosynthesis, DNA repair, electron transfer, and a component of a multidrug resistance (MDR) efflux pump were concluded to be essential for the pathogen's in vivo growth. Three known immunodominant membrane proteins, i.e., two 28-kDa outer membrane proteins (P28/OMP) and a 120-kDa surface protein, were also recognized as necessary for the pathogen's obligate intracellular life cycle. The discovery of many E. chaffeensis proteins crucial for its continuous in vivo growth will serve as a major resource for investigations aimed at defining pathogenesis and developing novel therapeutics for this and related pathogens of the rickettsial family Anaplasmataceae.


Subject(s)
Ehrlichia chaffeensis/genetics , Ehrlichiosis/microbiology , Genes, Bacterial , Animals , Bacterial Proteins/genetics , Cell Line , Dogs , Ehrlichia chaffeensis/growth & development , Ehrlichia chaffeensis/pathogenicity , Ehrlichiosis/transmission , Gene Library , Genome, Bacterial/genetics , Macrophages/microbiology , Mutagenesis, Insertional , Mutation , Ticks , Transcription, Genetic , Virulence/genetics
5.
Infect Immun ; 87(2)2019 02.
Article in English | MEDLINE | ID: mdl-30396898

ABSTRACT

Rocky Mountain spotted fever (RMSF) is a potentially fatal tick-borne disease in people and dogs. RMSF is reported in the United States and several countries in North, Central, and South America. The causative agent of this disease, Rickettsia rickettsii, is transmitted by several species of ticks, including Dermacentor andersoni, Rhipicephalus sanguineus, and Amblyomma americanum RMSF clinical signs generally include fever, headache, nausea, vomiting, muscle pain, lack of appetite, and rash. If untreated, it can quickly progress into a life-threatening illness in people and dogs, with high fatality rates ranging from 30 to 80%. While RMSF has been known for over a century, recent epidemiological data suggest that the numbers of documented cases and the fatality rates remain high in people, particularly during the last two decades in parts of North America. Currently, there are no vaccines available to prevent RMSF in either dogs or people. In this study, we investigated the efficacies of two experimental vaccines, a subunit vaccine containing two recombinant outer membrane proteins as recombinant antigens (RCA) and a whole-cell inactivated antigen vaccine (WCA), in conferring protection against virulent R. rickettsii infection challenge in a newly established canine model for RMSF. Dogs vaccinated with WCA were protected from RMSF, whereas those receiving RCA developed disease similar to that of nonvaccinated R. rickettsii-infected dogs. WCA also reduced the pathogen loads to nearly undetected levels in the blood, lungs, liver, spleen, and brain and induced bacterial antigen-specific immune responses. This study provides the first evidence of the protective ability of WCA against RMSF in dogs.


Subject(s)
Antigens, Bacterial/immunology , Dog Diseases , Rickettsia rickettsii/immunology , Rickettsial Vaccines/immunology , Rocky Mountain Spotted Fever , Animals , Bacterial Outer Membrane Proteins/immunology , Dog Diseases/immunology , Dog Diseases/microbiology , Dog Diseases/prevention & control , Dogs , Recombinant Proteins/immunology , Rocky Mountain Spotted Fever/immunology , Rocky Mountain Spotted Fever/prevention & control , Rocky Mountain Spotted Fever/veterinary
6.
Vet World ; 12(12): 2070-2075, 2019 Dec.
Article in English | MEDLINE | ID: mdl-32095061

ABSTRACT

BACKGROUND AND AIM: There is currently no published information on the prevalence and antimicrobial susceptibility patterns of commensal Escherichia coli in dogs of Grenada origin. Monitoring antimicrobial resistance helps in the empirical selection of antibiotics. This study determined the occurrence of E. coli including the O157:H7 serotype in feces of non-diarrheic dogs of Grenada origin and the antibiotic resistance pattern of the E. coli isolates. MATERIALS AND METHODS: Fecal samples from 142 of the 144 (98.6%) dogs were culture positive for E. coli. Selection of up to three colonies from each of the 142 E. coli-positive samples yielded a total of 402 E. coli isolates, which were analyzed for the presence of non-sorbitol fermenting colonies, and O157-agglutination. RESULTS: Of the 402 E. coli isolates, 30 (7.5%) were non-sorbitol fermenters. However, none of the 402 isolates gave a positive reaction (O157:H7) to the E. coli O157:H7 latex kit. Antimicrobial susceptibility tests against 12 antibiotics revealed low resistance rates to all the tested antibiotics except for tetracycline (Te) (23.4%), cephalothin (CF) (13.2%), and ampicillin (AM) (7.7%). Thirty-nine out of the 402 (9.7%), E. coli isolates were resistant to two or more antibiotics of different classes. CONCLUSION: This is the first report of isolation and antimicrobial susceptibilities of commensal E. coli from non-diarrheic dogs in Grenada. Some of the isolates (39/402 isolates, 9.7%) were resistant to multiple antibiotics. This study showed that presently, dogs in Grenada should not be considered a reservoir for the E. coli O157:H7 serotype and for multiple antibiotic-resistant E. coli strains. Among the 402 E. coli isolates, the resistance rate to drugs other than Te, CF, and AM was very low.

7.
PLoS One ; 12(2): e0169011, 2017.
Article in English | MEDLINE | ID: mdl-28199317

ABSTRACT

Accurate detection of filarial parasites in humans is essential for the implementation and evaluation of mass drug administration programs to control onchocerciasis and lymphatic filariasis. Determining the infection levels in vector populations is also important for assessing transmission, deciding when drug treatments may be terminated and for monitoring recrudescence. Immunological methods to detect infection in humans are available, however, cross-reactivity issues have been reported. Nucleic acid-based molecular assays offer high levels of specificity and sensitivity, and can be used to detect infection in both humans and vectors. In this study we developed loop-mediated isothermal amplification (LAMP) tests to detect three different filarial DNAs in human and insect samples using pH sensitive dyes for enhanced visual detection of amplification. Furthermore, reactions were performed in a portable, non-instrumented nucleic acid amplification (NINA) device that provides a stable heat source for LAMP. The efficacy of several strand displacing DNA polymerases were evaluated in combination with neutral red or phenol red dyes. Colorimetric NINA-LAMP assays targeting Brugia Hha I repeat, Onchocerca volvulus GST1a and Wuchereria bancrofti LDR each exhibit species-specificity and are also highly sensitive, detecting DNA equivalent to 1/10-1/5000th of one microfilaria. Reaction times varied depending on whether a single copy gene (70 minutes, O. volvulus) or repetitive DNA (40 min, B. malayi and W. bancrofti) was employed as a biomarker. The NINA heater can be used to detect multiple infections simultaneously. The accuracy, simplicity and versatility of the technology suggests that colorimetric NINA-LAMP assays are ideally suited for monitoring the success of filariasis control programs.


Subject(s)
Aedes/parasitology , DNA, Helminth/genetics , Elephantiasis, Filarial , Nucleic Acid Amplification Techniques/methods , Onchocerca volvulus/genetics , Onchocerciasis , Simuliidae/parasitology , Wuchereria bancrofti/genetics , Animals , Colorimetry , Elephantiasis, Filarial/diagnosis , Elephantiasis, Filarial/genetics , Humans , Onchocerciasis/diagnosis , Onchocerciasis/genetics
8.
Mol Biochem Parasitol ; 210(1-2): 10-12, 2016.
Article in English | MEDLINE | ID: mdl-27473357

ABSTRACT

Accurate, simple and affordable diagnostics are needed to detect Onchocerca volvulus infection in humans. A newly developed colorimetric loop-mediated isothermal amplification (LAMP) assay was compared to PCR and skin snip analysis for diagnosis of onchocerciasis. The robustness and simplicity of the assay indicates that it may be a useful field tool for surveillance in endemic countries.


Subject(s)
Nucleic Acid Amplification Techniques , Onchocerca volvulus/genetics , Onchocerciasis/diagnosis , Onchocerciasis/parasitology , Polymerase Chain Reaction , Skin/parasitology , Animals , Humans , Polymerase Chain Reaction/methods , Reproducibility of Results , Sensitivity and Specificity
9.
Trends Parasitol ; 31(8): 391-400, 2015 Aug.
Article in English | MEDLINE | ID: mdl-25978936

ABSTRACT

Filarial parasites are tissue-dwelling nematodes responsible for some of the most important neglected tropical diseases. All are transmitted by blood-sucking arthropod. Onchocerciasis and lymphatic filariasis in particular are the cause of much disfigurement and morbidity. Accurate parasite detection is essential for the success of filariasis control programs. The current toolbox for diagnosis and surveillance is limited because many of the available tools suffer from lack of sensitivity and specificity, and/or are cost-prohibitive. We review the methods currently in use and discuss the prospects for developing new molecular diagnostic (MDx) tools based on nucleic acid detection. We briefly describe recent developments in isothermal nucleic acid amplification and detection, and focus on emerging technologies that are field-deployable or suitable for low-resource settings.


Subject(s)
Filariasis/diagnosis , Filariasis/prevention & control , Molecular Diagnostic Techniques/trends , Population Surveillance , Animals , Filariasis/parasitology , Humans , Immunologic Tests , Molecular Diagnostic Techniques/standards , Nucleic Acid Amplification Techniques
10.
PLoS One ; 9(10): e108927, 2014.
Article in English | MEDLINE | ID: mdl-25299656

ABSTRACT

Onchocerciasis is a debilitating neglected tropical disease caused by infection with the filarial parasite Onchocerca volvulus. Adult worms live in subcutaneous tissues and produce large numbers of microfilariae that migrate to the skin and eyes. The disease is spread by black flies of the genus Simulium following ingestion of microfilariae that develop into infective stage larvae in the insect. Currently, transmission is monitored by capture and dissection of black flies and microscopic examination of parasites, or using the polymerase chain reaction to determine the presence of parasite DNA in pools of black flies. In this study we identified a new DNA biomarker, encoding O. volvulus glutathione S-transferase 1a (OvGST1a), to detect O. volvulus infection in vector black flies. We developed an OvGST1a-based loop-mediated isothermal amplification (LAMP) assay where amplification of specific target DNA is detectable using turbidity or by a hydroxy naphthol blue color change. The results indicated that the assay is sensitive and rapid, capable of detecting DNA equivalent to less than one microfilaria within 60 minutes. The test is highly specific for the human parasite, as no cross-reaction was detected using DNA from the closely related and sympatric cattle parasite Onchocerca ochengi. The test has the potential to be developed further as a field tool for use in the surveillance of transmission before and after implementation of mass drug administration programs for onchocerciasis.


Subject(s)
Insect Vectors/genetics , Nucleic Acid Amplification Techniques/methods , Onchocerca volvulus/genetics , Onchocerciasis/diagnosis , Simuliidae/genetics , Animals , Base Sequence , Cattle , Cattle Diseases/parasitology , Glutathione Transferase/genetics , Humans , Larva/genetics , Microfilariae/genetics , Molecular Sequence Data , Onchocerciasis/parasitology , Sequence Alignment
11.
PLoS One ; 9(9): e107727, 2014.
Article in English | MEDLINE | ID: mdl-25226276

ABSTRACT

Human babesiosis is caused by one of several babesial species transmitted by ixodid ticks that have distinct geographical distributions based on the presence of competent animal hosts. The pathology of babesiosis, like malaria, is a consequence of the parasitaemia which develops through the cyclical replication of Babesia parasites in a patient's red blood cells, though symptoms typically are nonspecific. We have identified the gene encoding Rhoptry-Associated Protein -1 (RAP-1) from a human isolate of B. divergens, Rouen1987 and characterized its protein product at the molecular and cellular level. Consistent with other Babesia RAP-1 homologues, BdRAP-1 is expressed as a 46 kDa protein in the parasite rhoptries, suggesting a possible role in red cell invasion. Native BdRAP-1 binds to an unidentified red cell receptor(s) that appears to be non-sialylated and non-proteinacious in nature, but we do not find significant reduction in growth with anti-rRAP1 antibodies in vitro, highlighting the possibility the B. divergens is able to use alternative pathways for invasion, or there is an alternative, complementary, role for BdRAP-1 during the invasion process. As it is the parasite's ability to recognize and then invade host cells which is central to clinical disease, characterising and understanding the role of Babesia-derived proteins involved in these steps are of great interest for the development of an effective prophylaxis.


Subject(s)
Babesia/genetics , Babesia/metabolism , Babesiosis/parasitology , Protozoan Proteins/genetics , Protozoan Proteins/metabolism , Amino Acid Sequence , Animals , Babesia/immunology , Babesiosis/immunology , Cattle , Cloning, Molecular , Erythrocytes/parasitology , Gene Expression , Immunodominant Epitopes/immunology , Molecular Sequence Data , Molecular Weight , Protein Binding , Protozoan Proteins/chemistry , Protozoan Proteins/immunology , Receptors, Cell Surface/metabolism , Recombinant Fusion Proteins/chemistry , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/immunology , Recombinant Fusion Proteins/metabolism , Sequence Alignment , Sequence Analysis, DNA
12.
Transfusion ; 54(3): 585-91, 2014 Mar.
Article in English | MEDLINE | ID: mdl-23888882

ABSTRACT

BACKGROUND: Babesia represents one of the major infectious threats to the blood supply since clinically silent infections in humans are common and these can be life-threatening in certain recipients. It is important to understand the effect of blood storage conditions on the viability of Babesia as this will impact the occurrence and severity of transfusion-transmitted babesiosis. STUDY DESIGN AND METHODS: Babesia divergens was introduced into blood bags containing leukoreduced red blood cells (RBCs) and stored at 4°C for 0 to 31 days. Samples were withdrawn for assessment of the presence, morphology, and viability of parasites. Blood smears were made immediately on removal from blood bags at different time intervals and evaluated by blood film microscopy. RBCs withdrawn from the bags were also cultured for 8 days using conditions optimal for parasite reproduction and growth to allow assessment of parasite viability. RESULTS: After 24 hours of storage at 4°C, there was a substantial reduction of parasitemia in the blood bags, which was maintained throughout storage. This decrease was accompanied by a change in morphology of parasites, with the number of altered parasites increasing through the period of storage. However, viability was maintained through 31 days of cold storage with a lag in achieving exponential growth seen in the parasites subjected to longer periods of refrigeration. CONCLUSION: Refrigeration of B. divergens leads to an alteration of parasite morphology and a decrease in parasite numbers. However, there are sufficient parasites that are robust enough to survive 31 days of storage at 4°C and yield high end-point parasitemia.


Subject(s)
Babesia/isolation & purification , Blood Preservation/standards , Cold Temperature , Cryopreservation/standards , Erythrocytes/parasitology , Blood Component Transfusion
13.
Parasite ; 20: 24, 2013.
Article in English | MEDLINE | ID: mdl-23815966

ABSTRACT

Understanding the evolutionary relationships of Trypanosoma (Duttonella) vivax genotypes between West Africa and Southern Africa can provide information on the epidemiology and control of trypanosomosis. Cattle blood samples from Zambia and Ghana were screened for T. vivax infection using specie-specific PCR and sequencing analysis. Substantial polymorphism was obtained from phylogenetic analysis of sequences of cathepsin L-like catalytic domains. T. vivax from Ghana clustered together with West African and South American sequences, while T. vivax from Zambia formed one distinct clade and clustered with East African and Southern African sequences. This study suggests existence of distinct genetic diversity between T. vivax genotypes from West Africa and Zambia as per their geographical origins.


Subject(s)
Cathepsin L/genetics , Cattle Diseases/parasitology , Genetic Variation , Trypanosoma vivax/genetics , Trypanosomiasis, African/veterinary , Animals , Base Sequence , Cattle , Cluster Analysis , DNA, Protozoan/chemistry , Genotype , Ghana , Molecular Sequence Data , Phylogeny , Trypanosoma vivax/classification , Trypanosomiasis, African/parasitology , Zambia
14.
J Vet Med Sci ; 75(11): 1463-70, 2013 Nov.
Article in English | MEDLINE | ID: mdl-23856760

ABSTRACT

In the present study, we screened blood DNA samples obtained from cattle bred in Brazil (n=164) and Ghana (n=80) for Babesia bovis using a diagnostic PCR assay and found prevalences of 14.6% and 46.3%, respectively. Subsequently, the genetic diversity of B. bovis in Thailand, Brazil and Ghana was analyzed, based on the DNA sequence of merozoite surface antigen-1 (MSA-1). In Thailand, MSA-1 sequences were relatively conserved and found in a single clade of the phylogram, while Brazilian MSA-1 sequences showed high genetic diversity and were dispersed across three different clades. In contrast, the sequences from Ghanaian samples were detected in two different clades, one of which contained only a single Ghanaian sequence. The identities among the MSA-1 sequences from Thailand, Brazil and Ghana were 99.0-100%, 57.5-99.4% and 60.3-100%, respectively, while the similarities among the deduced MSA-1 amino acid sequences within the respective countries were 98.4-100%, 59.4-99.7% and 58.7-100%, respectively. These observations suggested that the genetic diversity of B. bovis based on MSA-1 sequences was higher in Brazil and Ghana than in Thailand. The current data highlight the importance of conducting extensive studies on the genetic diversity of B. bovis before designing immune control strategies in each surveyed country.


Subject(s)
Babesia bovis/genetics , Babesiosis/parasitology , Cattle Diseases/parasitology , Genetic Variation/genetics , Phylogeny , Animals , Babesiosis/epidemiology , Base Sequence , Brazil/epidemiology , Cattle , Cattle Diseases/epidemiology , DNA, Protozoan/chemistry , DNA, Protozoan/genetics , Ghana , Merozoite Surface Protein 1/chemistry , Merozoite Surface Protein 1/genetics , Molecular Sequence Data , Polymerase Chain Reaction/veterinary , Prevalence , Protozoan Proteins/chemistry , Protozoan Proteins/genetics , Sequence Alignment , Sequence Analysis, DNA , Thailand/epidemiology
16.
J Vet Med Sci ; 75(2): 211-4, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23037864

ABSTRACT

Babesia ovata is a tick-transmitted hemoprotozoan parasite that infects cattle. In our study, bovine blood samples (n=2,034) were collected from 10 different countries (Brazil, China, Ghana, Japan, Mongolia, the Philippines, South Africa, Sri Lanka, Thailand and Vietnam) and DNA extracted. The DNA samples were screened using an established and specific polymerase chain reaction (PCR) assay targeting the Apical membrane antigen 1 (AMA-1) gene. Parasite DNA was detected among samples collected from Japan, Mongolia and Thailand. Sequence analyses confirmed that the PCR assay detected only B. ovata AMA-1, and that amplicons from different geographical locations were conserved. Our findings highlight the importance of designing adequate strategies to control B. ovata infection in Japan, Mongolia, and Thailand.


Subject(s)
Babesia/classification , Babesia/isolation & purification , Babesiosis/veterinary , Polymerase Chain Reaction/veterinary , Africa/epidemiology , Animals , Asia/epidemiology , Babesia/genetics , Babesiosis/epidemiology , Babesiosis/parasitology , Cattle , Phylogeny , Seroepidemiologic Studies , South America/epidemiology
17.
Parasit Vectors ; 5: 217, 2012 Oct 01.
Article in English | MEDLINE | ID: mdl-23025330

ABSTRACT

BACKGROUND: African trypanosomes are extracellular protozoan parasites that are transmitted between mammalian hosts by the bite of an infected tsetse fly. Human African Trypanosomiasis (HAT) or sleeping sickness is caused by Trypanosoma brucei rhodesiense or T. brucei gambiense, while African Animal Trypanosomiasis (AAT) is caused mainly by T. vivax, T. congolense, T. simiae,T. evansi and T. brucei brucei. Trypanosomiasis is of public health importance in humans and is also the major constraint for livestock productivity in sub-Saharan African countries. Scanty information exists about the trypanosomiasis status in Ghana especially regarding molecular epidemiology. Therefore, this study intended to apply molecular tools to identify and characterize trypanosomes in Ghana. METHODS: A total of 219 tsetse flies, 248 pigs and 146 cattle blood samples were collected from Adidome and Koforidua regions in Ghana in 2010. Initial PCR assays were conducted using the internal transcribed spacer one (ITS1) of ribosomal DNA (rDNA) primers, which can detect most of the pathogenic trypanosome species and T. vivax-specific cathepsin L-like gene primers. In addition, species- or subgroup-specific PCRs were performed for T. b. rhodesiense, T. b. gambiense, T. evansi and three subgroups of T. congolense. RESULTS: The overall prevalence of trypanosomes were 17.4% (38/219), 57.5% (84/146) and 28.6% (71/248) in tsetse flies, cattle and pigs, respectively. T. congolense subgroup-specific PCR revealed that T. congolense Savannah (52.6%) and T. congolense Forest (66.0%) were the endemic subgroups in Ghana with 18.6% being mixed infections. T. evansi was detected in a single tsetse fly. Human infective trypanosomes were not detected in the tested samples. CONCLUSION: Our results showed that there is a high prevalence of parasites in both tsetse flies and livestock in the study areas in Ghana. This enhances the need to strengthen control policies and institute measures that help prevent the spread of the parasites.


Subject(s)
Cattle Diseases/epidemiology , Cattle Diseases/parasitology , Swine Diseases/epidemiology , Swine Diseases/parasitology , Trypanosoma/classification , Trypanosoma/genetics , Trypanosomiasis/veterinary , Animals , Cattle , DNA, Protozoan/chemistry , DNA, Protozoan/genetics , DNA, Ribosomal Spacer/chemistry , DNA, Ribosomal Spacer/genetics , Ghana/epidemiology , Molecular Epidemiology , Molecular Sequence Data , Prevalence , Sequence Analysis, DNA , Swine , Trypanosoma/isolation & purification , Trypanosomiasis/epidemiology , Tsetse Flies/parasitology
18.
PLoS Negl Trop Dis ; 5(4): e1001, 2011 Apr 05.
Article in English | MEDLINE | ID: mdl-21483707

ABSTRACT

Rabies virus (RABV) is enzootic throughout Africa, with the domestic dog (Canis familiaris) being the principal vector. Dog rabies is estimated to cause 24,000 human deaths per year in Africa, however, this estimate is still considered to be conservative. Two sub-Saharan African RABV lineages have been detected in West Africa. Lineage 2 is present throughout West Africa, whereas Africa 1a dominates in northern and eastern Africa, but has been detected in Nigeria and Gabon, and Africa 1b was previously absent from West Africa. We confirmed the presence of RABV in a cohort of 76 brain samples obtained from rabid animals in Ghana collected over an eighteen-month period (2007-2009). Phylogenetic analysis of the sequences obtained confirmed all viruses to be RABV, belonging to lineages previously detected in sub-Saharan Africa. However, unlike earlier reported studies that suggested a single lineage (Africa 2) circulates in West Africa, we identified viruses belonging to the Africa 2 lineage and both Africa 1 (a and b) sub-lineages. Phylogeographic Bayesian Markov chain Monte Carlo analysis of a 405 bp fragment of the RABV nucleoprotein gene from the 76 new sequences derived from Ghanaian animals suggest that within the Africa 2 lineage three clades co-circulate with their origins in other West African countries. Africa 1a is probably a western extension of a clade circulating in central Africa and the Africa 1b virus a probable recent introduction from eastern Africa. We also developed and tested a novel reverse-transcription loop-mediated isothermal amplification (RT-LAMP) assay for the detection of RABV in African laboratories. This RT-LAMP was shown to detect both Africa 1 and 2 viruses, including its adaptation to a lateral flow device format for product visualization. These data suggest that RABV epidemiology is more complex than previously thought in West Africa and that there have been repeated introductions of RABV into Ghana. This analysis highlights the potential problems of individual developing nations implementing rabies control programmes in the absence of a regional programme.


Subject(s)
Rabies virus/classification , Rabies virus/genetics , Rabies/veterinary , Animals , Brain/virology , Dogs , Genotype , Ghana/epidemiology , Molecular Diagnostic Techniques/methods , Molecular Sequence Data , Nucleic Acid Amplification Techniques/methods , Phylogeny , Phylogeography , RNA, Viral/genetics , Rabies/epidemiology , Rabies/virology , Rabies virus/isolation & purification , Sequence Analysis, DNA
19.
Parasitol Res ; 105(1): 249-54, 2009 Jul.
Article in English | MEDLINE | ID: mdl-19294421

ABSTRACT

A truncated fragment of the gene encoding the 200-kDa protein (P200) of Babesia bigemina was cloned into a plasmid vector, pGEX-4 T-1 and expressed in Escherichia coli as a glutathione-S-transferase fused protein. An indirect enzyme-linked immunosorbent assay (ELISA) using the rp200/CT detected specific antibodies in cattle experimentally infected with B. bigemina. Furthermore, the antigen did not cross-react with antibodies to Babesia bovis, a closely related Babesia parasite indicating that rp200/CT is a specific antigen for the diagnosis of B. bigemina infection. Additionally, ELISA using p200/CT and polymerase chain reaction were conducted on serum and corresponding DNA samples obtained from field cattle to evaluate the diagnostic utility of the p200/CT antigen. Results from the current study suggest that p200/CT ELISA is a sensitive and specific method for improved serodiagnosis of B. bigemina infection.


Subject(s)
Antibodies, Protozoan/blood , Antigens, Protozoan , Babesia/chemistry , Babesiosis/veterinary , Cattle Diseases/diagnosis , Animals , Antigens, Protozoan/genetics , Babesia/genetics , Babesiosis/diagnosis , Cattle , Cloning, Molecular , Cross Reactions , Enzyme-Linked Immunosorbent Assay/methods , Escherichia coli/genetics , Gene Expression , Recombinant Fusion Proteins/genetics , Sensitivity and Specificity
20.
Am J Trop Med Hyg ; 78(1): 117-21, 2008 Jan.
Article in English | MEDLINE | ID: mdl-18187794

ABSTRACT

With the objective of developing a simpler diagnostic alternative, a rapid immunochromatographic test (BoiICT) was constructed for the simultaneous detection of Babesia bovis- and Babesia bigemina-specific antibodies using B. bovis recombinant merozoite surface antigen-2c and B. bigemina recombinant rhoptry-associated protein-1. The BoiICT selectively detected specific antibodies to B. bovis and B. bigemina. All sera from cattle infected with other protozoan parasites (i.e., Cryptosporidium parvum, Neospora caninum, and Theileria orientalis) showed negative results in the BoiICT. The relative sensitivity and specificity for detecting antibody to B. bovis were 96.7% (29 of 30) and 91.3% (73 of 80), respectively. The relative sensitivity and specificity for detecting antibody to B. bigemina were 96.7% (29 of 30) and 92.5% (74 of 80), respectively. These findings indicate that the BoiICT is useful for fast field diagnostic assessment of bovine babesioses without any laboratory equipment.


Subject(s)
Babesia/immunology , Babesiosis/veterinary , Cattle Diseases/diagnosis , Animals , Antigens, Protozoan/analysis , Babesia/classification , Babesia bovis/immunology , Babesiosis/diagnosis , Cattle , Cattle Diseases/blood , Cattle Diseases/parasitology , Enzyme-Linked Immunosorbent Assay/veterinary , Predictive Value of Tests , Reagent Kits, Diagnostic/veterinary , Sensitivity and Specificity , Serologic Tests/veterinary
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