scholarly journals Molecular Analysis of Canine Filaria and Its Wolbachia Endosymbionts in Domestic Dogs Collected from Two Animal University Hospitals in Bangkok Metropolitan Region, Thailand

Pathogens ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 114 ◽  
Author(s):  
Hathaithip Satjawongvanit ◽  
Atchara Phumee ◽  
Sonthaya Tiawsirisup ◽  
Sivapong Sungpradit ◽  
Narisa Brownell ◽  
...  

Canine filariasis is caused by several nematode species, such as Dirofilaria immitis, Dirofilaria repens, Brugia pahangi, Brugia malayi, and Acanthocheilonema reconditum. Zoonotic filariasis is one of the world’s neglected tropical diseases. Since 2000, the World Health Organization (WHO) has promoted a global filarial eradication program to eliminate filariasis by 2020. Apart from vector control strategies, the infection control of reservoir hosts is necessary for more effective filariasis control. In addition, many studies have reported that Wolbachia is necessary for the development, reproduction, and survival of the filarial nematode. Consequently, the use of antibiotics to kill Wolbachia in nematodes has now become an alternative strategy to control filariasis. Previously, a case of subconjunctival dirofilariasis caused by Dirofilaria spp. has been reported in a woman who resides in the center of Bangkok, Thailand. Therefore, our study aimed to principally demonstrate the presence of filarial nematodes and Wolbachia bacteria in blood collected from domestic dogs from the Bangkok Metropolitan Region, Thailand. A total of 57 blood samples from dogs with suspected dirofilariasis who had visited veterinary clinics in Bangkok were collected. The investigations for the presence of microfilaria were carried out by using both microscopic and molecular examinations. PCR was used as the molecular detection method for the filarial nematodes based on the COI and ITS1 regions. The demonstration of Wolbachia was performed using PCR to amplify the FtsZ gene. All positive samples by PCR were then cloned and sequenced. The results showed that the filarial nematodes were detected in 16 samples (28.07%) using microscopic examinations. The molecular detection of filarial species using COI-PCR revealed that 50 samples (87.72%) were positive; these consisted of 33 (57.89%), 13 (22.81%), and 4 (7.02%) samples for D. immitis, B. pahangi, and B. malayi, respectively. While the ITS1-PCR showed that 41 samples (71.93%) were positive—30 samples (52.63%) were identified as containing D. immitis and 11 samples (19.30%) were identified to have B. pahangi, whereas B. malayi was not detected. Forty-seven samples (82.45%) were positive for Wolbachia DNA and the phylogenetic tree of all positive Wolbachia was classified into the supergroup C clade. This study has established fundamental data on filariasis associated with Wolbachia infection in domestic dogs in the Bangkok Metropolitan Region. An extensive survey of dog blood samples would provide valuable epidemiologic data on potential zoonotic filariasis in Thailand. In addition, this information could be used for the future development of more effective prevention and control strategies for canine filariasis in Thailand.

2020 ◽  
Vol 5 ◽  
pp. 45 ◽  
Author(s):  
Hugo C. Turner ◽  
Michael D. French ◽  
Antonio Montresor ◽  
Charles H. King ◽  
David Rollinson ◽  
...  

Background: Schistosomiasis is one of the most prevalent neglected tropical diseases (NTDs) with an estimated 229 million people requiring preventive treatment worldwide. Recommendations for preventive chemotherapy strategies have been made by the World Health Organization (WHO) whereby the frequency of treatment is determined by the settings prevalence. Despite recent progress, many countries still need to scale up treatment and important questions remain regarding optimal control strategies. This paper presents a systematic review of the economic evaluations of human schistosomiasis interventions. Methods: A systematic review of the literature was conducted on 22nd August 2019 using the PubMed (MEDLINE) and ISI Web of Science electronic databases. The focus was economic evaluations of schistosomiasis interventions, such as cost-effectiveness and cost-benefit analyses. No date or language stipulations were applied to the searches. Results: We identified 53 relevant health economic analyses of schistosomiasis interventions. Most studies related to Schistosoma japonicum followed by S. haematobium. Several studies also included other NTDs. In Africa, most studies evaluated preventive chemotherapy, whereas in China they mostly evaluated programmes using a combination of interventions (such as chemotherapy, snail control and health education). There was wide variation in the methodology and epidemiological settings investigated. A range of effectiveness metrics were used by the different studies. Conclusions: Due to the variation across the identified studies, it was not possible to make definitive policy recommendations. Although, in general, the current WHO recommended preventive chemotherapy approach to control schistosomiasis was found to be cost-effective. This finding has important implications for policymakers, advocacy groups and potential funders. However, there are several important inconsistencies and research gaps (such as how the health benefits of interventions are quantified) that need to be addressed to identify the resources required to achieve schistosomiasis control and elimination.


2020 ◽  
Vol 5 ◽  
pp. 45
Author(s):  
Hugo C. Turner ◽  
Michael D. French ◽  
Antonio Montresor ◽  
Charles H. King ◽  
David Rollinson ◽  
...  

Background: Schistosomiasis is one of the most prevalent neglected tropical diseases (NTDs) with an estimated 229 million people requiring preventive treatment worldwide. Recommendations for preventive chemotherapy strategies have been made by the World Health Organization (WHO) whereby the frequency of treatment is determined by the settings prevalence. Despite recent progress, many countries still need to scale up treatment and important questions remain regarding optimal control strategies. This paper presents a systematic review of the economic evaluations of human schistosomiasis interventions. Methods: A systematic review of the literature was conducted on 22nd August 2019 using the PubMed (MEDLINE) and ISI Web of Science electronic databases. The focus was economic evaluations of schistosomiasis interventions, such as cost-effectiveness and cost-benefit analyses. No date or language stipulations were applied to the searches. Results: We identified 53 relevant health economic analyses of schistosomiasis interventions. Most studies related to Schistosoma japonicum followed by S. haematobium. Several studies also included other NTDs. In Africa, most studies evaluated preventive chemotherapy, whereas in China they mostly evaluated programmes using a combination of interventions (such as chemotherapy, snail control and health education). There was wide variation in the methodology and epidemiological settings investigated. A range of effectiveness metrics were used by the different studies. Conclusions: Due to the variation across the identified studies, it was not possible to make definitive policy recommendations. Although, in general, the current WHO recommended preventive chemotherapy approach to control schistosomiasis was found to be cost-effective. This finding has important implications for policymakers, advocacy groups and potential funders. However, there are several important inconsistencies and research gaps (such as how the health benefits of interventions are quantified) that need to be addressed to identify the resources required to achieve schistosomiasis control and elimination.


2020 ◽  
Vol 27 ◽  
Author(s):  
Kush K. Maheshwari ◽  
Debasish Bandyopadhyay

Background: Neglected tropical diseases (NTDs) affect a huge population of the world and majority of the victims belong to the poor community of the developing countries. Until now, the World Health Organization (WHO) has identified 20 tropical diseases as NTDs that must be addressed with high priority. However, many heterocyclic scaffolds have demonstrated potent therapeutic activity against several NTDs. Objective: There are three major objectives: (1) To discuss the causes, symptoms, and current status of all the 20 NTDs; (2) To explore the available heterocyclic drugs, and their mechanism of actions (if known) that are being used to treat NTDs; (3) To develop general awareness on NTDs among the medicinal/health research community and beyond. Methods: The 20 NTDs have been discussed according to their alphabetic orders along with the possible heterocyclic remedies. Current status of treatment with an emphasis on the heterocyclic drugs (commercially available and investigational) has been outlined. In addition, brief discussion of the impacts of NTDs on socio-economic condition is included. Results: NTDs are often difficult to diagnose and the problem is worsened by the unhealthy hygiene, improper awareness, and inadequate healthcare in the developing countries where these diseases primarily affect poor people. The statistics include duration of suffering, numbers affected, and access to healthcare and medication. The mechanism of actions of various heterocyclic drugs, if reported, have been briefly summarized. Conclusion: Scientists and pharmaceutical corporations should allocate more resources to reveal the in-depth mechanism of actions of many heterocyclic drugs that are currently being used for the treatment of NTDs. Analysis of current heterocyclic compounds and development of new medications can help in the fight to reduce/remove the devastating effects of NTDs. An opinion-based concise review has been presented. Based on available literature, this is the first effect to present all the 20 NTDs and related heterocyclic compounds under the same umbrella.


2020 ◽  
Vol 14 (2) ◽  
pp. 134-144 ◽  
Author(s):  
Matthew P. Ameh ◽  
Mamman Mohammed ◽  
Yusuf P. Ofemile ◽  
Magaji G. Mohammed ◽  
Ada Gabriel ◽  
...  

Background: The World Health Organization included snakebite envenomation among Neglected Tropical Diseases in 2017. The importance of natural products from plants is enormous, given that most prescribed drugs originate from plants. Among this is Mucuna pruriens and Mimosa pudica, with many registered patents asserting their health benefits. Objective: This study investigated the in vitro neutralizing effects of Mucuna pruriens seed and Mimosa pudica root extracts on venoms of Naja nigricollis and Bitis arietans. Methods: In mice, the LD50 and phytochemical analysis of M. pruriens and M. pudica plant extracts were carried out prior to the evaluation of their haemolytic and fibrinolytic effect. Their effects on the activities of phospholipase A2 (PLA2) were also assessed. Results: At a concentration of 50 mg/ml, both plant extracts were found to neutralize the fibrinolytic activity of N. nigricollis, but 400 mg/ml was required to neutralize the fibrinolytic activity of B. arietans. In haemolytic studies, 50 mg/ml concentration of M. pruriens extract suppressed haemolysis caused by N. nigricollis venom by 70% but at the same concentration, M. pudica extract reduced haemolysis by 49.4%. M. pruriens, at 50 mg/ml concentration, only inhibited phospholipase A2 activity by 7.7% but higher concentrations up to 400mg/ml had no effect against the venom of N. nigricollis; at 200 mg/ml. M. pudica extract inhibited PLA2 activity by 23%. Conclusion: The results suggest that M. pruriens and M. pudica may be considered as promising antivenom agents for people living in a snake-bite prone environment.


Biomolecules ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 458
Author(s):  
Emmanuel Broni ◽  
Samuel K. Kwofie ◽  
Seth O. Asiedu ◽  
Whelton A. Miller ◽  
Michael D. Wilson

The huge burden of leishmaniasis caused by the trypanosomatid protozoan parasite Leishmania is well known. This illness was included in the list of neglected tropical diseases targeted for elimination by the World Health Organization. However, the increasing evidence of resistance to existing antimonial drugs has made the eradication of the disease difficult to achieve, thus warranting the search for new drug targets. We report here studies that used computational methods to identify inhibitors of receptors from natural products. The cell division cycle-2-related kinase 12 (CRK12) receptor is a plausible drug target against Leishmania donovani. This study modelled the 3D molecular structure of the L. donovani CRK12 (LdCRK12) and screened for small molecules with potential inhibitory activity from African flora. An integrated library of 7722 African natural product-derived compounds and known inhibitors were screened against the LdCRK12 using AutoDock Vina after performing energy minimization with GROMACS 2018. Four natural products, namely sesamin (NANPDB1649), methyl ellagic acid (NANPDB1406), stylopine (NANPDB2581), and sennecicannabine (NANPDB6446) were found to be potential LdCRK12 inhibitory molecules. The molecular docking studies revealed two compounds NANPDB1406 and NANPDB2581 with binding affinities of −9.5 and −9.2 kcal/mol, respectively, against LdCRK12 which were higher than those of the known inhibitors and drugs, including GSK3186899, amphotericin B, miltefosine, and paromomycin. All the four compounds were predicted to have inhibitory constant (Ki) values ranging from 0.108 to 0.587 μM. NANPDB2581, NANPDB1649 and NANPDB1406 were also predicted as antileishmanial with Pa and Pi values of 0.415 and 0.043, 0.391 and 0.052, and 0.351 and 0.071, respectively. Molecular dynamics simulations coupled with molecular mechanics Poisson–Boltzmann surface area (MM/PBSA) computations reinforced their good binding mechanisms. Most compounds were observed to bind in the ATP binding pocket of the kinase domain. Lys488 was predicted as a key residue critical for ligand binding in the ATP binding pocket of the LdCRK12. The molecules were pharmacologically profiled as druglike with inconsequential toxicity. The identified molecules have scaffolds that could form the backbone for fragment-based drug design of novel leishmanicides but warrant further studies to evaluate their therapeutic potential.


2021 ◽  
Vol 9 (6) ◽  
pp. 1163
Author(s):  
Eduarda Alexandra Gonçalves de Oliveira Moura ◽  
Daniela Gomes da Silva ◽  
Caio Henrique Turco ◽  
Thainara Vitoria Carnevalli Sanches ◽  
Gabriel Yuri Storino ◽  
...  

Since the occurrence of swine salmonellosis has increased over time and control strategies other than biosecurity are highly recommended, the present study aimed to evaluate the efficacy of vaccination with Salmonella Choleraesuis and Salmonella Typhimurium bacterins in pigs. Two experimental groups were formed: G1, animals immunized with two doses of a commercial vaccine (n = 20); G2, control group (n = 20). After vaccination, all pigs were orally challenged (D0) with 108 CFU of Salmonella Typhimurium and evaluated for 40 days. Every 10 days after D0, five piglets from each experimental group were euthanized and submitted to the necroscopic examination, when organ samples were collected. Blood samples and rectal swabs were collected before the first dose of the vaccine (D−42), before the second dose (D−21), before the challenge (D0), and thereafter, every three days until D39. Blood count, serum IgG measurement by ELISA, and the excretion of Salmonella Typhimurium in feces were evaluated. While the results from blood count and serum IgG concentration did not differ, the detection and excretion of Salmonella between G1 and G2 differed (p < 0.05). Therefore, it was observed that this vaccine partially protected the animals against experimental infection with Salmonella Typhimurium, reducing the excretion of bacteria in feces.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Runglawan Chawengkirttikul ◽  
Witchuta Junsiri ◽  
Amaya Watthanadirek ◽  
Napassorn Poolsawat ◽  
Sutthida Minsakorn ◽  
...  

AbstractLeucocytozoon sabrazesi is the intracellular protozoa of leucocytozoonosis, which is transmitted by the insect vectors and affects chickens in most subtropical and tropical regions of the globe, except South America, and causing enormous economic losses due to decreasing meat yield and egg production. In this study, L. sabrazesi gametocytes have been observed in the blood smears, and molecular methods have been used to analyse the occurrence and genetic diversity of L. sabrazesi in blood samples from 313 chickens raised in northern, western and southern parts of Thailand. The nested polymerase chain reaction (nested PCR) assay based on the cytb gene revealed that 80.51% (252/313) chickens were positive of L. sabrazesi. The phylogenetic analysis indicated that L. sabrazesi cytb gene is conserved in Thailand, showed 2 clades and 2 subclades with similarity ranged from 89.5 to 100%. The diversity analysis showed 13 and 18 haplotypes of the sequences from Thailand and from other countries, respectively. The entropy analyses of nucleic acid sequences showed 26 high entropy peaks with values ranging from 0.24493 to 1.21056, while those of amino acid sequences exhibited 5 high entropy peaks with values ranging from 0.39267 to 0.97012. The results; therefore, indicate a high molecular occurrence of L. sabrazesi in chicken blood samples with the associated factors that is statistically significant (p < 0.05). Hence, our results could be used to improve the immunodiagnostic methods and to find appropriate preventive control strategies or vaccination programs against leucocytozoonosis in order to mitigate or eliminate the harmful impact of this infection on chicken industry.


2019 ◽  
Vol 29 (Supplement_4) ◽  
Author(s):  
A A Gobir ◽  
C L Ejembi ◽  
A A Aliyu ◽  
M B Garba ◽  
C J C Igboanusi ◽  
...  

Abstract Background Lassa fever disease (LFD) is a viral haemorrhagic fever that is endemic in some West african countries where an estimated 300,000 to 500,000 cases and 5000 deaths occur yearly. The World Health Organization described it as a global health threat. At community level, its prevention relies on promoting good “community hygiene”. This study was conducted to assess practice of community hygiene measures against LFD and its associated factors. Methods A cross-sectional, community based descriptive study conducted during a LFD epidemic in a a rural community of Nigeria. An interviewer-administered questionnaire was used to collect data from 556 adult respondents, selected using systematic random sampling technique. Data was analyzed using SPSS. Results A majority of the respondents were females (52.9%). Educational attainment was significantly associated with safe food storage at the multivariate level (aOR= 1.31, 95% CI: 1.10-1.54,P= 0.002) while having a good knowledge of LFD was a significant predictor of maintaining good housing standards (aOR= 3.73, 95% CI: 1.09-12.80,P=0.036). Conclusions Predictors of practice of community hygiene against LFD include education and having an excellent knowledge of LFD. To improve community hygiene practices in the community, there is need for a comprehensive LFD behavior change communication intervention. Key messages Cubing the global threat of LFD depends on its effective prevention in endemic West African communities. This study shows that such preventive measures are poor and there is need for more response to address the problem.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Arthur K. S. Ng’etich ◽  
Kuku Voyi ◽  
Clifford M. Mutero

Abstract Background Effective surveillance and response systems are vital to achievement of disease control and elimination goals. Kenya adopted the revised guidelines of the integrated disease surveillance and response system in 2012. Previous assessments of surveillance system core and support functions in Africa are limited to notifiable diseases with minimal attention given to neglected tropical diseases amenable to preventive chemotherapy (PC-NTDs). The study aimed to assess surveillance system core and support functions relating to PC-NTDs in Kenya. Methods A mixed method cross-sectional survey was adapted involving 192 health facility workers, 50 community-level health workers and 44 sub-national level health personnel. Data was collected using modified World Health Organization generic questionnaires, observation checklists and interview schedules. Descriptive summaries, tests of associations using Pearson’s Chi-square or Fisher’s exact tests and mixed effects regression models were used to analyse quantitative data. Qualitative data derived from interviews with study participants were coded and analysed thematically. Results Surveillance core and support functions in relation to PC-NTDs were assessed in comparison to an indicator performance target of 80%. Optimal performance reported on specimen handling (84%; 100%), reports submission (100%; 100%) and data analysis (84%; 80%) at the sub-county and county levels respectively. Facilities achieved the threshold on reports submission (84%), reporting deadlines (88%) and feedback (80%). However, low performance reported on case definitions availability (60%), case registers (19%), functional laboratories (52%) and data analysis (58%). Having well-equipped laboratories (3.07, 95% CI: 1.36, 6.94), PC-NTDs provision in reporting forms (3.20, 95% CI: 1.44, 7.10) and surveillance training (4.15, 95% CI: 2.30, 7.48) were associated with higher odds of functional surveillance systems. Challenges facing surveillance activities implementation revealed through qualitative data were in relation to surveillance guidelines and reporting tools, data analysis, feedback, supervisory activities, training and resource provision. Conclusion There was evidence of low-performing surveillance functions regarding PC-NTDs especially at the peripheral surveillance levels. Case detection, registration and confirmation, reporting, data analysis and feedback performed sub-optimally at the facility and community levels. Additionally, support functions including standards and guidelines, supervision, training and resources were particularly weak at the sub-national level. Improved PC-NTDs surveillance performance sub-nationally requires strengthened capacities.


2011 ◽  
Vol 77 (13) ◽  
pp. 4669-4675 ◽  
Author(s):  
Dawn C. Bisi ◽  
David J. Lampe

ABSTRACTThe insect-vectored disease malaria is a major world health problem. New control strategies are needed to supplement the current use of insecticides and medications. A genetic approach can be used to inhibit development of malaria parasites (Plasmodiumspp.) in the mosquito host. We hypothesized thatPantoea agglomerans, a bacterial symbiont ofAnophelesmosquitoes, could be engineered to express and secrete anti-Plasmodiumeffector proteins, a strategy termed paratransgenesis. To this end, plasmids that include thepelBorhlyAsecretion signals from the genes of related species (pectate lyase fromErwinia carotovoraand hemolysin A fromEscherichia coli, respectively) were created and tested for their efficacy in secreting known anti-Plasmodiumeffector proteins (SM1, anti-Pbs21, and PLA2) inP. agglomeransandE. coli.P. agglomeranssuccessfully secreted HlyA fusions of anti-Pbs21 and PLA2, and these strains are under evaluation for anti-Plasmodiumactivity in infected mosquitoes. Varied expression and/or secretion of the effector proteins was observed, suggesting that the individual characteristics of a particular effector may require empirical testing of several secretion signals. Importantly, those strains that secreted efficiently grew as well as wild-type strains under laboratory conditions and, thus, may be expected to be competitive with the native microbiota in the environment of the mosquito midgut.


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