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1.
PLoS One ; 19(6): e0305064, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38837973

RESUMO

Artemisinin resistance threatens malaria control and elimination efforts globally. Recent studies have reported the emergence of Plasmodium falciparum parasites tolerant to artemisinin agents in sub-Saharan Africa, including Uganda. The current study assessed the day 3 parasite clearance and its correlation with P. falciparum K13 propeller gene (pfkelch13) mutations in P. falciparum parasites isolated from patients with uncomplicated malaria under artemether-lumefantrine (AL) treatment. This study enrolled 100 P. falciparum-positive patients to whom AL was prescribed between 09/September/2022 and 06/November/2022. Blood samples were collected in EDTA tubes before treatment initiation (day 0) and on day 3. Parasitemia was assessed by microscopy from blood smears and quantitative polymerase chain reaction (qPCR) from the DNA extracted. The day 0 parasite K13 gene was sequenced using Sanger sequencing. Sequence data were analysed using MEGA version 11 software. The data were analysed using STATA version 15, and the Mann‒Whitney U test was used to compare PCR parasite clearance on day 3 using the comparative CT value method and pfkelch13 mutations. The prevalence of day 3 parasitaemia was 24% (24/100) by microscopy and 63% (63/100) by qPCR from the AL-treated patients. P. falciparum K13-propeller gene polymorphism was detected in 18.8% (15/80) of the day 0 DNA samples. The K13 mutations found were C469Y, 12.5% (10/80); A675V, 2.5% (2/80); A569S, 1.25%, (1/80), A578S, 1.25%, (1/80) and; F491S, 1.25%, (1/80) a new allele not reported anywhere. The C469Y mutation, compared to the wild-type, was associated with delayed parasite clearance p = 0.0278, Hodges-Lehmann estimation 3.2108 on the log scale, (95%CI 1.7076, 4.4730). There was a high prevalence of day 3 P. falciparum among malaria patients treated using artemether-lumefantrine. We conclude the presence of the K13 mutation associated with artemisinin resistance by P. falciparum in Adjumani district, Uganda, necessitates regular surveillance of the effectiveness and efficacy of artemether-lumefantrine in the country.


Assuntos
Antimaláricos , Combinação Arteméter e Lumefantrina , Malária Falciparum , Mutação , Parasitemia , Plasmodium falciparum , Humanos , Plasmodium falciparum/genética , Plasmodium falciparum/efeitos dos fármacos , Combinação Arteméter e Lumefantrina/uso terapêutico , Uganda/epidemiologia , Malária Falciparum/tratamento farmacológico , Malária Falciparum/parasitologia , Malária Falciparum/epidemiologia , Antimaláricos/uso terapêutico , Masculino , Feminino , Parasitemia/tratamento farmacológico , Parasitemia/parasitologia , Parasitemia/epidemiologia , Proteínas de Protozoários/genética , Adulto , Criança , Adolescente , Pré-Escolar , Adulto Jovem , Resistência a Medicamentos/genética , Artemisininas/uso terapêutico , Pessoa de Meia-Idade
2.
medRxiv ; 2024 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-38712186

RESUMO

Artemisinin resistance threatens malaria control and elimination efforts globally. Recent studies have reported the emergence of Plasmodium falciparum parasites tolerant to artemisinin agents in sub-Saharan Africa, including Uganda. The current study assessed the day 3 parasite clearance and its correlation with P. falciparum K13 propeller gene (pfkelch13) mutations in P. falciparum parasites isolated from patients with uncomplicated malaria under artemether-lumefantrine (AL) treatment. This study enrolled 100 P. falciparum-positive patients to whom AL was prescribed between 09/September/2022 and 06/November/2022. Blood samples were collected in EDTA tubes before treatment initiation (day 0) and on day 3. Parasitemia was assessed by microscopy from blood smears and quantitative polymerase chain reaction (qPCR) from the DNA extracted. The day 0 parasite K13 gene was sequenced using Sanger sequencing. Sequence data were analysed using MEGA version 11 software. The data were analysed using STATA version 15, and the Mann‒Whitney U test was used to compare PCR parasite clearance on day 3 using the comparative CT value method and pfkelch13 mutations. The prevalence of day 3 parasitaemia was 24% (24/100) by microscopy and 63% (63/100) by qPCR from the AL-treated patients. P. falciparum K13-propeller gene polymorphism was detected in 18.8% (15/80) of the day 0 DNA samples. The K13 mutations found were C469Y, 12.5% (10/80); A675V, 2.5% (2/80); A569S, 1.25%, (1/80), A578S, 1.25%, (1/80) and; F491S, 1.25%, (1/80) a new allele not reported anywhere. The C469Y mutation, compared to the wild-type, was associated with delayed parasite clearance p=0.0278, Hodges-Lehmann estimation 3.2108 on the log scale, (95%CI 1.7076, 4.4730). There was a high prevalence of day 3 P. falciparum among malaria patients treated using artemether-lumefantrine. We conclude that the K13 mutation associated with artemisinin resistance by P. falciparum is present in Adjumani district, Uganda. This necessitates regular surveillance of the effectiveness and efficacy of artemether-lumefantrine in the country.

3.
Animals (Basel) ; 13(18)2023 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-37760244

RESUMO

Tick-borne diseases (TBDs) massively impact bovine production. In endemic countries, animals are often subclinically infected, showing no signs of the illness. Anemia is a hallmark of TBDs, but there is inadequate information on its presence in infected Thai cattle. In the present study, 265 cattle from four provinces in Thailand were surveyed to identify tick-borne pathogens (TBPs) and to evaluate the changes in the packed cell volume (PCV) values associated with detection. Microscopy and polymerase chain reaction (PCR) were also compared for TBP detection. Babesia/Theileria/Hepatozoon was detected in 33.58% (89/265) of the cattle samples. Specifically, Babesia bovis (9/265), B. bigemina (12/265), Theileria orientalis (62/265), and Anaplasma marginale (50/265) were identified using species-specific assays. Significant decreases in the mean PCV levels were observed in cattle that were positive for at least one TBP (p < 0.001), Babesia/Theileria/Hepatozoon (p < 0.001), T. orientalis (p < 0.001), and A. marginale (p = 0.049). The results of PCR and microscopy for the detection of TBPs suggested slight and fair agreement between the two detection tools. The present findings contribute to a better understanding of TBDs in the field and shall facilitate the formulation of effective control for TBDs in Thailand.

4.
Parasit Vectors ; 16(1): 224, 2023 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-37415211

RESUMO

A meeting, sponsored by the Bill and Melinda Gates Foundation (BMGF) and organised by Clinglobal, was held at The International Livestock Research Institute (ILRI) in Nairobi, Kenya, from 19th - to 21st October 2022. The meeting assembled a unique group of experts on tick control in Africa. Academia, international agencies (FAO and ILRI), the private Animal Health sector and government veterinary services were represented. The significant outcomes included: (i) a shared commitment to standardisation and improvement of acaricide resistance bioassay protocols, particularly the widely used larval packet test (LPT); (ii) development of novel molecular assays for detecting acaricide resistance; (3) creation of platforms for disseminating acaricide resistance data to farmers, veterinary service providers and veterinary authorities to enable more rational evidence-based control of livestock ticks. Implementation of enhanced control will be facilitated by several recently established networks focused on control of parasites in Africa and globally, whose activities were presented at the meeting. These include a newly launched community of practice on management of livestock ticks, coordinated by FAO, an African module of the World Association for the Advancement of Veterinary Parasitology (WAAVP-AN) and the MAHABA (Managing Animal Health and Acaricides for a Better Africa) initiative of Elanco Animal Health.


Assuntos
Acaricidas , Doenças dos Bovinos , Rhipicephalus , Infestações por Carrapato , Doenças Transmitidas por Carrapatos , Animais , Bovinos , Acaricidas/farmacologia , Quênia/epidemiologia , Doenças Transmitidas por Carrapatos/epidemiologia , Doenças Transmitidas por Carrapatos/prevenção & controle , Doenças Transmitidas por Carrapatos/veterinária , Doenças dos Bovinos/diagnóstico , Doenças dos Bovinos/tratamento farmacológico , Doenças dos Bovinos/epidemiologia , Infestações por Carrapato/epidemiologia , Infestações por Carrapato/prevenção & controle , Infestações por Carrapato/veterinária
5.
Microorganisms ; 10(12)2022 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-36557637

RESUMO

We previously reported the emergence of amitraz-resistant Rhipicephalus (Boophilus) decoloratus ticks in the western region of Uganda. This study characterized the octopamine/tyramine receptor gene (OCT/Tyr) of amitraz-resistant and -susceptible R. (B.) decoloratus ticks from four regions of Uganda. The OCT/Tyr gene was amplified from genomic DNA of 17 R. (B.) decoloratus larval populations of known susceptibility to amitraz. The amplicons were purified, cloned and sequenced to determine mutations in the partial coding region of the OCT/Tyr gene. The amplified R. (B.) decoloratus OCT/Tyr gene was 91-100% identical to the R. (B.) microplus OCT/Tyr gene. Up to 24 single nucleotide polymorphisms (SNPs) were found in the OCT/Tyr gene from ticks obtained from high acaricide pressure areas, compared to 8 from the low acaricide pressure areas. A total of eight amino acid mutations were recorded in the partial OCT/Tyr gene from ticks from the western region, and four of them were associated with amitraz-resistant tick populations. The amino acid mutations M1G, L16F, D41G and V72A were associated with phenotypic resistance to amitraz with no specific pattern. Phylogenetic analysis revealed that the OCT/Tyr gene sequence from this study clustered into two distinct groups that separated the genotype from high acaricide pressure areas from the susceptible populations. In conclusion, this study is the first to characterize the R. (B.) decoloratus OCT/Tyr receptor gene and reports four novel amino acid mutations associated with phenotypic amitraz resistance in Uganda. However, lack of mutations in the ORF of the OCT/Tyr gene fragment for some of the amitraz-resistant R. (B.) decoloratus ticks could suggest that other mechanisms of resistance may be responsible for amitraz resistance, hence the need for further investigation.

6.
Pathogens ; 11(10)2022 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-36297166

RESUMO

Goats are key livestock animals and goat raising is an income-generating venture for smallholder farmers, supporting agricultural development in many parts of the world. However, goat production is often limited by various factors, such as tick-borne diseases. Goat piroplasmosis is a disease caused by apicomplexan parasites Babesia spp. and Theileria spp., while anaplasmosis is caused by bacterial Anaplasma spp. In the Philippines, the presence of Babesia, Theileria, and Anaplasma has not been reported in goats. In this study, DNA obtained from goats were molecularly screened for Babesia/Theileria and Anaplasma. Of 396, 77.02% (305/396) and 38.64% (153/396) were positive for piroplasma and Anaplasma using PCR assays targeting the 18S rRNA and 16S rRNA genes, respectively. Similarly, Babesia ovis was detected in six samples (1.52%). Representative Babesia/Theileria sequences shared 89.97-97.74% identity with each other and were most closely related to T. orientalis, T. annulata, and Theileria spp. Meanwhile, Anaplasma 16SrRNA sequences were related to A. odocoilei, A. platys, and A. phagocytophilum. This is the first molecular identification of B. ovis, Theileria spp., and Anaplasma spp. in goats from the Philippines.

7.
Front Vet Sci ; 8: 762107, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34912876

RESUMO

In the present study, we screened 502 natural product compounds against the in vitro growth of Babesia (B.) bovis. Then, the novel and potent identified compounds were further evaluated for their in vitro efficacies using viability and cytotoxicity assays. The in vivo inhibitory effects of the selected compounds were evaluated using B. microti "rodent strain" in mice model. Three potent compounds, namely, Rottlerin (RL), Narasin (NR), Lasalocid acid (LA), exhibited the lowest IC50 (half-maximal inhibitory concentration) as follows: 5.45 ± 1.20 µM for RL, 1.86 ± 0.66 µM for NR, and 3.56 ± 1.41 µM for LA. The viability result revealed the ability of RL and LA to prevent the regrowth of treated parasite at 4 × IC50 and 2 × IC50, respectively, while 4 × IC50 of NR was sufficient to stop the regrowth of parasite. The hematology parameters of B. microti in vivo were different in the NR-treated groups as compared to the infected/untreated group. Interestingly, intraperitoneal administration of NR exhibiting inhibition in the growth of B. microti in mice was similar to that observed after administration of the commonly used antibabesial drug, diminazene aceturate (DA) (76.57% for DA, 74.73% for NR). Our findings indicate the richness of natural product compounds by novel potent antibabesial candidates, and the identified potent compounds, especially NR, might be used for the treatment of animal babesiosis.

8.
Scientifica (Cairo) ; 2021: 3258059, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34589246

RESUMO

The dynamics of extended-spectrum ß-lactamase- (ESBL-) and AmpC ß-lactamase-producing bacteria (which are deadly groups of antimicrobial-resistant bacteria) have not been well understood in developing countries. This raises major concerns to antimicrobial resistance (AMR) control. We investigated the prevalence and factors linked to the fecal carriage of ESBL- or AmpC-producing Escherichia coli (ESBL-/AmpC-EC) in commercial chickens. Cloacal swabs from 400 birds were sampled and submitted to the Central Diagnostic Laboratory for ESBL-/AmpC-EC screening by culture methods using MacConkey agar supplemented with cefotaxime. Epidemiological data were collected using a structured questionnaire and plausible risk factor analyses prepared by R software using X 2 test and logistic regression modeling. Results showed that the prevalence of ESBL-/AmpC-EC was 17.5%. Univariable screening hypothesized that carriage was probably influenced by a type of commercial chicken, geographical location, age group, flock size, and housing system (p < 0.05). Modeling exposed that broiler birds were at a higher risk of being ESBL-/AmpC-EC carriers (COR = 9.82, CI = 3.85-25.07). Birds from Wakiso Town Council (COR = 4.89, CI = 2.04-11.72) and flocks of 700-1200 birds were also at a higher risk of harboring ESBL-/AmpC-EC (COR = 2.41, CI = 1.11-5.23). Birds aged 4 months and below were more susceptible to ESBL-/AmpC-EC carriage compared with those aged 1 month and below being 6.33 times (CI = 1.65-24.35) likely to be carriers. The occurrence of ESBL-/AmpC-EC in flocks suggests possible treatment failures while managing colibacillosis. Consequently, injudicious antimicrobial use should be replaced with an accurate diagnosis by bacterial culture and sensitivity testing so as to circumvent AMR emergence, spread, and associated losses.

9.
Ticks Tick Borne Dis ; 12(5): 101784, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34280696

RESUMO

Common vector-borne diseases of horses include equine piroplasmosis (EP) caused by Babesia caballi and Theileria equi, and equine granulocytic anaplasmosis (EGA) caused by Anaplasma phagocytophilum. Equine piroplasmosis leads to severe health issues in horses and restrictions on the movement of horses internationally. Anaplasma phagocytophilum causes an acute febrile illness in horses and is also of zoonotic importance. In the present study, blood samples were collected from 152 Turkish racehorses from three different provinces (Izmir, Gaziantep, and Konya) of Turkey to investigate the prevalence of EP and EGA. Standard and nested polymerase chain reactions were performed to identify equine piroplasms and A. phagocytophilum, respectively. PCR primers targeting Babesia spp. 18S rRNA, B. caballi BC48, T. equi EMA-1, and A. phagocytophilum 16S rRNA genes were used for molecular diagnosis. Following the cloning and subsequent sequencing of PCR-positive samples, a total of 15 (9.9%) horses were found to be infected with at least one pathogen. Theileria equi and A. phagocytophilum were found in 3.3% (5/152) and 6.6% (10/152) of the samples, respectively. Although B. caballi specimens were not detected in any of the samples, a positive signal was detected for the Babesia genus-specific 18S rRNA PCR. Subsequent sequencing of this signal revealed 100% identity to Babesia ovis. This is the first detection of B. ovis DNA in racehorses in Turkey to the best of our knowledge. Additionally, this study also reports the first molecular identification of A. phagocytophilum in Turkish racehorses. Based on this report, it is recommended that future epidemiological studies on horses also take B. ovis, a parasite usually found in sheep, into consideration and that further detailed studies be conducted to unravel the transmission pathways and potential clinical effects of B. ovis in horses.


Assuntos
Anaplasma phagocytophilum/isolamento & purificação , Anaplasmose/epidemiologia , Ehrlichiose/veterinária , Doenças dos Cavalos/epidemiologia , Piroplasmida/isolamento & purificação , Infecções por Protozoários/epidemiologia , Anaplasmose/microbiologia , Animais , DNA de Protozoário/análise , Ehrlichiose/epidemiologia , Ehrlichiose/microbiologia , Feminino , Doenças dos Cavalos/microbiologia , Doenças dos Cavalos/parasitologia , Cavalos , Masculino , Prevalência , Infecções por Protozoários/parasitologia , Turquia/epidemiologia
10.
Ticks Tick Borne Dis ; 12(5): 101772, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34214889

RESUMO

In Uganda, ticks and tick-borne diseases (TBDs) pose a big challenge to farmers. They reduce cattle productivity and cause severe economic damage. Several studies have documented the prevalence of tick-borne pathogens in cattle; however, their genetic characteristics and the role of wildlife-livestock interaction in the epidemiology of the TBDs are not well documented. This study assessed the prevalence and genetic diversity of various tick-borne pathogens (TBPs) as well as the risk factors associated with the occurrence of TBPs in blood samples of 208 randomly selected cattle from 16 farms located around Queen Elizabeth National Park (QENP) in Kasese District in western Uganda. Farming practices, disease challenges, and the level of wildlife-livestock interactions were assessed by a questionnaire survey amongst farm owners. Polymerase chain reaction (PCR) assays revealed that 62.9% (131/208) cattle samples were positive for one or more pathogens. Using specific PCR assays, we detected Theileria spp., Theileria parva, Anaplasma marginale, Anaplasma platys-like, and Babesia bigemina at 50.5%, 27.9%, 19.2%, 11.5% and 8.7%, respectively. We also confirmed the infection of samples by Theileria velifera and Theileria mutans after sequencing the Theileria spp. 18S rRNA gene. The risk factors associated with the occurrence of TBPs included communal grazing, herd size, age, and proximity to QENP. Phylogenetic analysis of the T. parva p104 gene showed a high identity to the previous isolates from Uganda and other East African countries and clustered closer to the buffalo (Syncerus caffer) isolates, suggesting a possible cross-species transmission. The sequences of A. marginale groEL and B. bigemina RAP-1a formed well-supported clades with high identities to the previous isolates identified from central and eastern Uganda. The isolates obtained from A. phagocytophilum 16S rRNA gene sequences showed relationship with A. platys-like, Anaplasma sp., uncultured Anaplasma species and A. phagocytophilum isolates from Africa, Asia, Europe, and the USA. The findings of the present study showed that TBDs are still a burden to farmers and that management practices in this area may increase the transmission of pathogens between livestock and wildlife.


Assuntos
Doenças dos Bovinos/epidemiologia , Doenças Transmitidas por Carrapatos/veterinária , Animais , Bovinos , Doenças dos Bovinos/microbiologia , Doenças dos Bovinos/parasitologia , Variação Genética , Parques Recreativos , Prevalência , Doenças Transmitidas por Carrapatos/epidemiologia , Doenças Transmitidas por Carrapatos/microbiologia , Doenças Transmitidas por Carrapatos/parasitologia , Uganda/epidemiologia
11.
Int J Vet Sci Med ; 9(1): 11-21, 2021 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-34104644

RESUMO

There are increasing reports of antimicrobial treatment failures for bacterial diseases of poultry in Uganda. The paucity of data on antimicrobial resistance (AMR) of pathogenic bacteria in Uganda is a major setback to AMR control. This study investigated the occurrence of fowl typhoid, colibacillosis, and AMR in associated pathogens from 2012 to 2018. Laboratory records from the Central Diagnostic Laboratory (CDL), a National Veterinary Diagnostic Facility located at Makerere University, were reviewed. Archived isolates of the causative bacteria for the two diseases were also evaluated for AMR. The frequencies of the two disease conditions, their clinical and necropsy presentations and the demographic data of the diagnostic samples were summarized from the records. Archived bacterial isolates were revived before antimicrobial susceptibility testing. This was done on Mueller Hinton agar using the disk diffusion method, against 16 antimicrobials of medical and veterinary importance according to the Clinical Laboratory Standards Institute guidelines. A total of 697 poultry cases were presented for bacteriological investigations in the review period. Colibacillosis and salmonellosis had prevalence rates of 39.7% (277/697) and 16.2% (113/697), respectively. A total of 63 and 92 isolates of Escherichia coli and Salmonella spp., respectively, were archived but 43 (68.3%) E. coli and 47 (51.1%) Salmonella spp. isolates were recovered and evaluated for AMR. Multidrug resistance was more frequent in E. coli (38; 88.4%) than salmonellae (25; 53.2%), (p < 0.001). The high prevalence of colibacillosis, salmonellosis and the AMR of associated pathogens warrants immediate institution of appropriate disease control measures.

12.
Acta Parasitol ; 66(4): 1458-1465, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34043120

RESUMO

PURPOSE: Bovine babesiosis causes morbidity in tropical and subtropical countries worldwide. The present study aimed to determine the seroprevalence of Babesia bigemina and B. bovis in cattle and water buffaloes in Menoufia province, where the second-highest population of bovines in Lower Egypt are raised. MATERIALS AND METHODS: A total of 506 blood samples were collected from cattle (N = 262) and water buffaloes (N = 244) in Menoufia province, Egypt. Seroprevalences of B. bigemina and B. bovis in the samples were determined using recombinant Babesia antigen-specific enzyme-linked immunosorbent assays (ELISA). RESULTS: In cattle, the seroprevalences of B. bigemina and B. bovis were 41.60 and 38.17% (37.40 and 35.88% for IgM and 9.54 and 6.11% for IgG), respectively, whereas those of water buffaloes were 35.66 and 31.97% (27.87 and 21.72% for IgM and 15.16 and 15.16% for IgG), respectively. Statistically significant changes in the seroprevalences of the two infective agents were recorded on the basis of region and season of sample collection. CONCLUSION: In conclusion, babesiosis is frequent and presents a threat of an epidemic among bovines in Menoufia province. In turn, control of bovine babesiosis is required because of its potential to detrimentally affect milk and meat production in Menoufia province.


Assuntos
Babesia bovis , Babesia , Babesiose , Doenças dos Bovinos , Animais , Babesia/genética , Babesiose/epidemiologia , Búfalos , Bovinos , Doenças dos Bovinos/epidemiologia , Egito/epidemiologia , Reação em Cadeia da Polimerase , Estudos Soroepidemiológicos
13.
Front Microbiol ; 12: 619335, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33776955

RESUMO

Toxoplasmosis is a zoonotic parasitic disease caused by the obligate intracellular protozoa Toxoplasma gondii, which threatens a range of warm-blooded mammals including humans. To date, it remains a challenge to find safe and effective drug treatment or vaccine against toxoplasmosis. In this study, our results found that the development of a mutant strain based on gene disruption of dense granule protein 9 (gra9) in type II PLK strain decreased parasite replication in vivo, severely attenuated virulence in mice, and significantly reduced the formation of cysts in animals. Hence, we developed an immunization scheme to evaluate the protective immunity of the attenuated strain of Δgra9 in type II PLK parasite as a live attenuated vaccine against toxoplasmosis in the mouse model. Δgra9 vaccination-induced full immune responses characterized by significantly high levels of pro-inflammatory cytokine interferon gamma (IFN-γ) and interleukin-12 (IL-12), maintained the high T. gondii-specific immunoglobulin G (IgG) level, and mixed high IgG1/IgG2a levels. Their levels provided the complete protective immunity which is a combination of cellular and humoral immunity in mouse models against further infections of lethal doses of type I RH, type II PLK wild-type tachyzoites, or type II PLK cysts. Results showed that Δgra9 vaccination proved its immunogenicity and potency conferring 100% protection against acute and chronic T. gondii challenges. Together, Δgra9 vaccination provided safe and efficient immune protection against challenging parasites, suggesting that PLK:Δgra9 is a potentially promising live attenuated vaccine candidate.

14.
Parasitol Int ; 81: 102260, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33264674

RESUMO

The inhibitory efficacies of pyronaridine tetraphosphate (PYR), when used in combination with two novel and potent antibabesial drugs; clofazimine (CF), and MMV396693 were evaluated in the current study against the growth of Babesia bovis, B. caballi, and B. gibsoni in vitro and B. microti in mice. The in vitro study against the selected parasites was performed using combination of PYR with either CF or MMV396693 in ratios ranged from 0.75:0.75 to 0.25:0.25. Combined application of PYR/MMV396693 revealed additive and indifferent interactions against the in vitro growth of all screened Babesia parasites. PYR in combination with CF, achieved indifferent and antagonistic interactions with all used concentration ratios against the in vitro growth of B. bovis and B. caballi. Treatment with PYR-CF combination therapy caused significant inhibition (P < 0.05) of the fluorescence values at days 12, 14, 16, 18, and 22 p.i. in comparison with control mice. Of note, treatment with combination therapy exhibited inhibition in the growth of B. microti (23.16%) greater than those caused by PYR alone. In summary, the obtained results highlight the improvement in the in vivo antibabesial efficacy of PYR when used in combination with CF rather than using PYR alone but such inhibition is still lower than those caused by either DA or CF monotherapies.


Assuntos
Antiprotozoários/farmacologia , Babesia/efeitos dos fármacos , Babesiose/tratamento farmacológico , Naftiridinas/farmacologia , Animais , Modelos Animais de Doenças , Feminino , Camundongos , Camundongos Endogâmicos BALB C
15.
Pathogens ; 11(1)2021 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-35055979

RESUMO

In this study, cattle farms located in Oudalan and Séno, two provinces in the Sahel region, northern Burkina Faso, were surveyed. Cattle owners were interviewed, cattle were examined for tick infestation, and ticks as well as blood samples were collected during the dry season (October). Blood DNA samples were tested for Babesia and Theileria infections using nested PCRs and sequencing. A total of 22 herds, 174 Zebu cattle were investigated at 6 different sites. Overall, 76 cattle (43.7 %) from 18 farms (81.8%) were found infested with ticks. Cattle in Séno, adult cattle (>5 years) and those owned by the Fulani ethnic group were significantly (p < 0.05) more likely to be tick-infested. A total of 144 adult ticks belonging to five species namely: Hyalomma impeltatum, Hyalomma impressum, Hyalomma rufipes, Rhipicephalus evertsi evertsi, and Rhipicephalus guilhoni were collected from the animals. Piroplasms were detected in the blood DNA of 23 (13.2%) cattle. The cattle in Séno and adult cattle were significantly more likely to be piroplasm-positive. Five pathogens diversely distributed were identified. Theileria mutans (12/174), Babesia bigemina (5/174), Theileria annulata (3/174), and Theileria velifera (3/174) were detected for the first time in northern Burkina Faso, whereas Babesia occultans (1/174) was found for the first time in cattle in West Africa. The analysis of the sequences, including B. bigemina RAP-1a, T. annulata Tams1 genes, and the 18S rRNA genes of all the five protozoa, revealed identities ranging from 98.4 to 100% with previously published sequences. Phylogenetic analysis based on the 18S rRNA gene sequences located north Burkina Faso piroplasms in the same clade as isolates from Africa and other regions of the world. Notably, T. mutans sequences were distributed in two clades: the T. mutans Intona strain clade and the Theileria sp. (strain MSD)/ Theileria sp. B15a clade, suggesting the presence of at least two strains in the area. These findings indicate that the control of ticks and tick-borne diseases should be taken into account in strategies to improve animal health in the Sahel region.

16.
Pathogens ; 9(11)2020 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-33121172

RESUMO

Ticks and tick-borne diseases are major impediments to livestock production. To date, there have been several studies on the prevalence of tick-borne pathogens (TBPs) in cattle, but very few studies have documented TBPs in goats in Uganda. In this study, polymerase chain reaction assays and sequence analysis of different molecular markers were used to assess the presence and genetic characteristics of TBPs in 201 goats from Kasese district in western Uganda. The risk factors associated with TBP infections were also analyzed. We detected Theileria spp. (13.4%), Anaplasma phagocytophilum (10.9%), Anaplasma ovis (5.5%), Babesia ovis (5.5%), and Ehrlichia ruminantium (0.5%). The sequences of B. ovis ssu rRNA and A. ovismsp4 genes showed some degree of diversity among the parasite isolates in this study. The E. ruminantium pCS20 sequence formed a well-supported clade with isolates from Amblyomma variegatum ticks from Uganda. Wildlife interaction, sampling location, low body condition score, tick infestation, and herd size were significantly associated with TBP infections in the goats. The findings in this study provide important information on the epidemiology of tick-borne pathogens in Uganda, and show that goats could be potential reservoirs for tick-borne pathogens.

17.
Animals (Basel) ; 10(9)2020 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-32927890

RESUMO

Hemoplasmas (hemotropic mycoplasmas) are small pleomorphic bacteria that parasitize the surface of red blood cells of several mammalian species including cattle, goats, and humans, causing infectious anemia. However, studies on hemoplasmas have been neglected and to date, there are no studies on bovine and caprine hemoplasmas in Uganda or the entire East African region. In this study, a polymerase chain reaction (PCR) assay targeting the 16S rRNA gene was used to investigate the presence of hemoplasma in 409 samples (cattle = 208; goats = 201) collected from Kasese district, western Uganda. Results showed that 32.2% (67/208) of cattle samples and 43.8% (88/201) of goat samples were positive for hemoplasmas. Sequencing analysis identified Candidatus Mycoplasma haemobos and Mycoplasma wenyonii in cattle, while Candidatus Mycoplasma erythrocervae and Mycoplasma ovis were identified in goats. Statistical analysis showed that goats were at a higher risk of infection with hemoplasmas compared with cattle. To the best of our knowledge, this is the first molecular evidence of hemoplasmas in bovine and caprine animals in Uganda and the entire east African region.

18.
Ticks Tick Borne Dis ; 11(5): 101478, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32723638

RESUMO

Ticks carry and transmit a wide range of pathogens (bacteria, viruses, and protozoa) that are of importance to humans and animals globally. However, information about the tick-borne pathogens harbored by ticks in the Xinjiang Uygur Autonomous Region (XUAR), northwestern China, is scarce. This study investigated the occurrence of tick species of domestic animals and tick-borne pathogens by using morphological molecular identification and sequence analysis in Turpan, Qitai, Altay, Hejing, Nileke, and Zhaosu counties (XUAR). A total of 5822 adult ticks (females and males) from 12 tick species were identified from 5 animal species (cattle, goats, sheep, camels, and horses) in 6 counties in the XUAR. Collected tick species included Dermacentor marginatus (24.7 %), Dermacentor nuttalli (20.8 %), Hyalomma anatolicum (13.7 %), Dermacentor niveus (13.1 %), Haemaphysalis punctata (10.7 %), Dermacentor silvarum (7.1 %), Dermacentor pavlovskyi (3.9 %), Hyalomma asiaticum (2.2 %), Rhipicephalus pumilio (1.9 %), Rhipicephalus sanguineus sensu lato (0.7 %), Rhipicephalus turanicus (0.6 %), and Hyalomma asiaticum kozlovi (0.6 %). Furthermore, 750 partially engorged adult ticks (females and males), including H. anatolicum (250), D. nuttalli (250), and D. marginatus (250), were individually separated according to species and sampling site, used for DNA extraction, and then screened for tick-borne pathogens. The most common pathogen was Rickettsia raoultii (36.80 %), followed by Brucella sp. (26.2 %), Anaplasma ovis (22.4 %), Babesia caballi (14.8 %), Theileria equi (8.7 %), and Theileria ovis (8.5 %). The sequencing of 6 genes showed a 96-100 % nucleotide identity between the sequences in this study and those deposited in GenBank. This study provides a scientific reference for the prevention and control of tick-borne diseases in the XUAR.


Assuntos
Anaplasma ovis/isolamento & purificação , Babesia/isolamento & purificação , Brucella/isolamento & purificação , Ixodidae/microbiologia , Ixodidae/parasitologia , Rickettsia/isolamento & purificação , Theileria/isolamento & purificação , Animais , Camelus/parasitologia , Bovinos/parasitologia , China , Feminino , Cabras/parasitologia , Cavalos/parasitologia , Masculino , Carneiro Doméstico/parasitologia , Especificidade da Espécie
19.
Ticks Tick Borne Dis ; 11(5): 101466, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32723655

RESUMO

Due to the specific plateau climate, a variety of unique animals live in the Qinghai-Tibetan Plateau Area (QTPA) including yaks (Bos grunniens), Tibetan sheep (Ovis aries) and Bactrian camels (Camelus bactrianus). However, information on tick-borne diseases (TBDs) in the QTPA and on the molecular characteristics of tick-borne pathogens (TBPs) in the area is limited. Therefore, the aim of this study was to investigate Anaplasma spp., Babesia spp., Theileria spp., Borrelia burgdorferi sensu lato and Rickettsia spp. infecting yaks, Tibetan sheep and camels in this area. A total of 276 animals were screened. Overall, 84.5% (164/194) of yaks, 58% (23/40) of Tibetan sheep, and 38% (16/42) of camels tested positive for at least one pathogen. Theileria spp., Anaplasma ovis and spotted fever group (SFG) Rickettsia spp. were detected as TBPs in the current study with overall infection rates of 10.9% (30/276), 8.3% (23/276) and 62.9% (171/276), respectively. Further study revealed that 1.5% (3/194) of the yaks were infected with Theileria sp. OT3, 1.5% (3/194) with T. luwenshuni, 6.2% (12/194) with T. uilenbergi, 1.1% (2/194) with T. ovis and 82% (159/194) with SFG Rickettsia spp. It was also shown that 58% (23/40) of the Tibetan sheep were infected with A. ovis and 15% (6/40) with T. ovis. Among the camels, 10% (4/42) were infected with T. equi, while 29% (12/42) were positive for Rickettsia spp. Sequence analysis revealed that the Rickettsia spp. infecting yaks and camels were Rickettsia raoultii and Rickettsia slovaca. To the best of our knowledge, this study reports the first detection and characterization of these pathogens in yaks, Tibetan sheep and camels in the country, except for T. luwenshuni infections in yaks.


Assuntos
Anaplasmose/epidemiologia , Babesiose/epidemiologia , Camelus , Doença de Lyme/veterinária , Infecções por Rickettsia/veterinária , Theileriose/epidemiologia , Doenças Transmitidas por Carrapatos/epidemiologia , Anaplasma/isolamento & purificação , Anaplasmose/microbiologia , Animais , Babesia/isolamento & purificação , Babesiose/parasitologia , Grupo Borrelia Burgdorferi/isolamento & purificação , Bovinos , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/microbiologia , Doença de Lyme/epidemiologia , Doença de Lyme/microbiologia , Prevalência , Rickettsia/isolamento & purificação , Infecções por Rickettsia/epidemiologia , Infecções por Rickettsia/microbiologia , Ovinos , Doenças dos Ovinos/epidemiologia , Doenças dos Ovinos/microbiologia , Carneiro Doméstico , Theileria/isolamento & purificação , Theileriose/parasitologia , Tibet/epidemiologia , Doenças Transmitidas por Carrapatos/microbiologia , Doenças Transmitidas por Carrapatos/parasitologia
20.
Acta Trop ; 211: 105598, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32592686

RESUMO

Tick-borne diseases (TBDs) are serious constraints to livestock production in Tanzania and other tropical and subtropical countries and impact the livelihoods of resource-poor farming communities in the region. In Tanzania, detailed studies on tick-borne pathogens (TBPs) in cattle using sensitive molecular detection methods are scarce. The objective of this study was to investigate the occurrence and species composition of bovine TBPs in cattle kept in Zanzibar Island. A total of 236 blood samples were randomly collected in cattle population in June and July 2019. We used polymerase chain reaction (PCR) and gene sequencing to detect and identify pathogens. PCR screening of all 236 samples revealed that 64.5% of animals were infected by TBPs, including Theileria parva (34.3%), T. mutans (38.1%), T. taurotragi (30.9%), Anaplasma marginale (10.2%), Babesia bigemina (5.1%), T. velifera (3.4%) and B. bovis (2.1%). Overall a total of 86 animals (36.4%) were co-infected with up to five pathogens including T. parva, T. mutans, T. taurotragi, A. marginale and B. bigemina. The pathogens mostly involved in the co-infection were T. parva, T. taurotragi and T. mutans. Sequence analysis indicated that T. parva p104 and B. bigemina RAP1a genes are diverse among the sampled animals in Zanzibar Island, with 99.64%-100% and 99.51%-100% nucleotide sequence identity value respectively. In contrast, the A. marginale MSP-5, T. mutans 18S rRNA V4 region and B. bovis SBP-2 genes are conserved, with 100%, 99.05%-100% and 99.66%-100% nucleotide sequence identity values respectively. The phylogenetic analyses revealed that T. parva p104 and B. bigemina RAP1a gene sequences showed significant differences of genotypes, as they appear in different clades. Meanwhile, A. marginale MSP-5, T. mutans 18S rRNA V4 region and B. bovis SBP-2 gene sequences appear in the same clade with other sequences extracted from the NCBI GenBank. The epidemiological findings revealed in this study will provide important information on tick-borne diseases in Tanzania and will be used as scientific basis for planning future control strategies.


Assuntos
Anaplasmose/parasitologia , Vetores Aracnídeos/parasitologia , Theileriose/parasitologia , Doenças Transmitidas por Carrapatos/veterinária , Carrapatos/parasitologia , Anaplasma/genética , Anaplasma/isolamento & purificação , Anaplasmose/epidemiologia , Animais , Babesia/genética , Babesia/isolamento & purificação , Bovinos , Variação Genética , Filogenia , Reação em Cadeia da Polimerase , Tanzânia/epidemiologia , Theileria/genética , Theileria/isolamento & purificação , Theileriose/epidemiologia , Doenças Transmitidas por Carrapatos/diagnóstico , Doenças Transmitidas por Carrapatos/parasitologia
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