Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 27
Filter
1.
Ecohealth ; 21(1): 71-82, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38727761

ABSTRACT

Mycobacterium bovis, a member of the Mycobacterium tuberculosis complex (MTC) and non-tuberculous Mycobacteria (NTM), may infect wild and domestic mammals, including humans. Although cattle are the main hosts and spreaders of M. bovis, many wildlife hosts play an important role worldwide. In Argentina, wild boar and domestic pigs are considered important links in mammalian tuberculosis (mTB) transmission. The aim of this work was to investigate the presence of M. bovis in wild pigs from different regions of Argentina, to characterize isolates of M. bovis obtained, and to compare those with other previously found in vertebrate hosts. A total of 311 samples from wild pigs were obtained, and bacteriological culture, molecular identification and genotyping were performed, obtaining 63 isolates (34 MTC and 29 NTM). Twelve M. bovis spoligotypes were detected. Our findings suggest that wild pigs have a prominent role as reservoirs of mTB in Argentina, based on an estimated prevalence of 11.2 ± 1.8% (95% CI 8.0-14.8) for MTC and the frequency distribution of spoligotypes shared by cattle (75%), domestic pigs (58%) and wildlife (50%). Argentina has a typical scenario where cattle and pigs are farm-raised extensively, sharing the environment with wildlife, creating conditions for effective transmission of mTB in the wildlife-livestock-human interface.


Subject(s)
Animals, Wild , Mycobacterium bovis , Swine Diseases , Tuberculosis , Animals , Argentina/epidemiology , Animals, Wild/microbiology , Tuberculosis/epidemiology , Tuberculosis/veterinary , Tuberculosis/microbiology , Mycobacterium bovis/isolation & purification , Mycobacterium bovis/genetics , Swine , Swine Diseases/microbiology , Swine Diseases/epidemiology , Sus scrofa/microbiology , Disease Reservoirs/microbiology , Disease Reservoirs/veterinary , Prevalence , Genotype
2.
Antiviral Res ; 225: 105858, 2024 May.
Article in English | MEDLINE | ID: mdl-38490342

ABSTRACT

Chikungunya virus (CHIKV) is a mosquito-borne virus transmitted by Aedes mosquitoes. While there are no antiviral therapies currently available to treat CHIKV infections, several licensed oral drugs have shown significant anti-CHIKV activity in cells and in mouse models. However, the efficacy in mosquitoes has not yet been assessed. Such cross-species antiviral activity could be favorable, since virus inhibition in the mosquito vector might prevent further transmission to vertebrate hosts. Here, we explored the antiviral effect of ß-d-N4-hydroxycytidine (NHC, EIDD-1931), the active metabolite of molnupiravir, on CHIKV replication in Aedes aegypti mosquitoes. Antiviral assays in mosquito cells and in ex vivo cultured mosquito guts showed that NHC had significant antiviral activity against CHIKV. Exposure to a clinically relevant concentration of NHC did not affect Ae. aegypti lifespan when delivered via a bloodmeal, but it slightly reduced the number of eggs developed in the ovaries. When mosquitoes were exposed to a blood meal containing both CHIKV and NHC, the compound did not significantly reduce virus infection and dissemination in the mosquitoes. This was confirmed by modelling and could be explained by pharmacokinetic analysis, which revealed that by 6 h post-blood-feeding, 90% of NHC had been cleared from the mosquito bodies. Our data show that NHC inhibited CHIKV replication in mosquito cells and gut tissue, but not in vivo when mosquitoes were provided with a CHIKV-infectious bloodmeal spiked with NHC. The pipeline presented in this study offers a suitable approach to identify anti-arboviral drugs that may impede replication in mosquitoes.


Subject(s)
Aedes , Chikungunya Fever , Chikungunya virus , Cytidine/analogs & derivatives , Animals , Mice , Chikungunya virus/physiology , Virus Replication , Antiviral Agents
3.
Front Vet Sci ; 11: 1346514, 2024.
Article in English | MEDLINE | ID: mdl-38420209

ABSTRACT

Introduction: Non-tuberculous Mycobacteria (NTM) are mainly environmental but can cause opportunistic infections and diseases in humans and animals. Livestock and wild animals can be infected with NTM. In Argentina, there are native wild species facing conservation risks, and they are the focus of protection and reintroduction projects designed to preserve biodiversity in various ecoregions. The aim of this study was to report the presence of NTM in samples collected from four endangered native wild species from nine Argentine provinces, as part of their pre-release health assessment. Methods: A total of 165 samples from giant anteater, peccary, tapir and pampas deer were obtained, these included either bronchoalveolar or endotracheal lavages, or oropharyngeal, nasopharyngeal or tracheal swabs. Bacteriological culture followed by molecular identification and sequencing were performed. Results: A total of 27 NTM were detected, including Mycobacterium avium subsp. hominissuis, M. intracellulare, M. terrae, M. gordonense, M. kumamotonense, M. fortuitum, M. saskatchewanense, and M. genavense. Results revealed a 16,36% NTM recovery rate, with the giant anteater showing the highest prevalence among the mammals under study. Discussion: In Argentina, due to extensive production systems, the interaction between domestic and wild species sharing the same environment is frequent, increasing the exposure of all the species to these NTM. In this way, the transmission of infectious agents from one to another is feasible. Moreover, NTMs might interfere with the diagnosis of bovine tuberculosis and paratuberculosis. These findings emphasize the importance of active health surveillance in conservation programs. It highlights the need to address NTM epidemiology in wildlife and its impact on conservation and public health.

4.
Eur J Med Chem ; 264: 116010, 2024 Jan 15.
Article in English | MEDLINE | ID: mdl-38104375

ABSTRACT

The worldwide re-emerge of the Chikungunya virus (CHIKV), the high morbidity associated with it, and the lack of an available vaccine or antiviral treatment make the development of a potent CHIKV-inhibitor highly desirable. Therefore, an extensive lead optimization was performed based on the previously reported CHVB compound 1b and the reported synthesis route was optimized - improving the overall yield in remarkably shorter synthesis and work-up time. Hundred analogues were designed, synthesized, and investigated for their antiviral activity, physiochemistry, and toxicological profile. An extensive structure-activity relationship study (SAR) was performed, which focused mainly on the combination of scaffold changes and revealed the key chemical features for potent anti-CHIKV inhibition. Further, a thorough ADMET investigation of the compounds was carried out: the compounds were screened for their aqueous solubility, lipophilicity, their toxicity in CaCo-2 cells, and possible hERG channel interactions. Additionally, 55 analogues were assessed for their metabolic stability in human liver microsomes (HLMs), leading to a structure-metabolism relationship study (SMR). The compounds showed an excellent safety profile, favourable physicochemical characteristics, and the required metabolic stability. A cross-resistance study confirmed the viral capping machinery (nsP1) to be the viral target of these compounds. This study identified 31b and 34 as potent, safe, and stable lead compounds for further development as selective CHIKV inhibitors. Finally, the collected insight led to a successful scaffold hop (64b) for future antiviral research studies.


Subject(s)
Chikungunya Fever , Chikungunya virus , Humans , Caco-2 Cells , Antiviral Agents/chemistry , Pyrimidines/pharmacology , Chikungunya Fever/drug therapy , Virus Replication
5.
Matern Child Nutr ; : e13571, 2023 Dec 28.
Article in English | MEDLINE | ID: mdl-38155486

ABSTRACT

With multiple food fortification frameworks, countries can find it challenging to determine optimal methods for planning and implementing food fortification programmes to combat vitamin and mineral deficiencies, especially without additional technical support. To address this challenge, this study aimed to review existing frameworks to determine consistencies, differences, strengths, and weaknesses across the frameworks, and based on the review findings, formulate an enhanced and streamlined fortification framework. Nineteen frameworks were ultimately examined following a comprehensive literature review and key informant interviews. Generally, the reviewed frameworks amply describe motives and methods for the determination of fortification need and feasibility, industry engagement/quality assurance and quality control, and impact evaluations/surveillance. However, there was limited inclusion or discussion throughout the reviewed frameworks around harmonization of fortification with existing micronutrient interventions; fortification policy and/or strategy; enforcement, incentives, and penalties to ensure producer compliance with industry standards; and periodic fortification programme review and reassessment. The findings were used to develop a comprehensive Fortification Blueprint that aims to provide structured guidance and a library of tools and resources to fortification programme managers and key stakeholders to ensure optimal and sustainable programme design.

6.
PLoS Negl Trop Dis ; 17(9): e0011649, 2023 09.
Article in English | MEDLINE | ID: mdl-37729233

ABSTRACT

BACKGROUND: West Nile virus (WNV) and Usutu virus (USUV) are emerging arthropod-borne viruses (arboviruses) in Europe transmitted by Culex mosquitoes. In Belgium, it is currently unknown which Culex species are competent vectors for WNV or USUV and if these mosquitoes carry Wolbachia, an endosymbiotic bacterium that can block arbovirus transmission. The aims of our study were to measure the vector competence of Belgian Culex mosquitoes to WNV and USUV and determine if a naturally acquired Wolbachia infection can influence virus transmission. METHODOLOGY/PRINCIPAL FINDINGS: Female Culex mosquitoes were captured from urban and peri-urban sites in Leuven, Belgium and offered an infectious bloodmeal containing WNV lineage 2, USUV European (EU) lineage 3, or USUV African (AF) lineage 3. Blood-fed females were incubated for 14 days at 25°C after which the body, head, and saliva were collected to measure infection, dissemination, and transmission rates as well as transmission efficiency. Mosquito species were identified by qRT-PCR or Sanger sequencing, the presence of infectious virus in mosquitoes was confirmed by plaque assays, and viral genome copies were quantified by qRT-PCR. Culex pipiens pipiens were able to transmit WNV (4.3% transmission efficiency, n = 2/47) but not USUV (EU lineage: n = 0/56; AF lineage: n = 0/37). In contrast, Culex modestus were able to transmit USUV (AF lineage: 20% transmission efficiency, n = 1/5) but not WNV (n = 0/6). We found that the presence or absence of Wolbachia was species-dependent and did not associate with virus transmission. CONCLUSIONS/SIGNIFICANCE: This is the first report that Belgian Culex mosquitoes can transmit both WNV and USUV, forewarning the risk of human transmission. More research is needed to understand the potential influence of Wolbachia on arbovirus transmission in Culex modestus mosquitoes.


Subject(s)
Arboviruses , Culex , Culicidae , Flavivirus , West Nile Fever , West Nile virus , Animals , Female , Humans , West Nile virus/genetics , Belgium , Flavivirus/genetics , Mosquito Vectors
7.
Microbiol Spectr ; : e0519522, 2023 Aug 04.
Article in English | MEDLINE | ID: mdl-37540021

ABSTRACT

Aedes aegypti mosquitoes can transmit several arboviruses, including chikungunya virus (CHIKV), dengue virus (DENV), and Zika virus (ZIKV). When blood-feeding on a virus-infected human, the mosquito ingests the virus into the midgut (stomach), where it replicates and must overcome the midgut barrier to disseminate to other organs and ultimately be transmitted via the saliva. Current tools to study mosquito-borne viruses (MBVs) include 2D-cell culture systems and in vivo mosquito infection models, which offer great advantages, yet have some limitations. Here, we describe a long-term ex vivo culture of Ae. aegypti guts. Cultured guts were metabolically active for 7 d in a 96-well plate at 28°C and were permissive to ZIKV, DENV, Ross River virus, and CHIKV. Ex vivo guts from Culex pipiens mosquitoes were found to be permissive to Usutu virus. Immunofluorescence staining confirmed viral protein synthesis in CHIKV-infected guts of Ae. aegypti. Furthermore, fluorescence microscopy revealed replication and spread of a reporter DENV in specific regions of the midgut. In addition, two known antiviral molecules, ß-d-N4-hydroxycytidine and 7-deaza-2'-C-methyladenosine, were able to inhibit CHIKV and ZIKV replication, respectively, in the ex vivo model. Together, our results show that ex vivo guts can be efficiently infected with mosquito-borne alpha- and flaviviruses and employed to evaluate antiviral drugs. Furthermore, the setup can be extended to other mosquito species. Ex vivo gut cultures could thus be a new model to study MBVs, offering the advantage of reduced biosafety measures compared to infecting living mosquitoes. IMPORTANCE Mosquito-borne viruses (MBVs) are a significant global health threat since they can cause severe diseases in humans, such as hemorrhagic fever, encephalitis, and chronic arthritis. MBVs rely on the mosquito vector to infect new hosts and perpetuate virus transmission. No therapeutics are currently available. The study of arbovirus infection in the mosquito vector can greatly contribute to elucidating strategies for controlling arbovirus transmission. This work investigated the infection of guts from Aedes aegypti mosquitoes in an ex vivo platform. We found several MBVs capable of replicating in the gut tissue, including viruses of major health importance, such as dengue, chikungunya, and Zika viruses. In addition, antiviral compounds reduced arbovirus infection in the cultured gut tissue. Overall, the gut model emerges as a useful tool for diverse applications such as studying tissue-specific responses to virus infection and screening potential anti-arboviral molecules.

8.
PLoS One ; 18(1): e0280737, 2023.
Article in English | MEDLINE | ID: mdl-36701326

ABSTRACT

OBJECTIVE: Disorganised and chaotic home environments may hinder the adoption of healthy lifestyle behaviours and contribute to excessive weight gain among adolescents. We examined whether self-reported level of chaos within the family home environment is associated with lifestyle behaviours and obesity in adolescent girls and boys. METHODS: Cross-sectional data from the 3rd wave of the Québec Adipose and Lifestyle Investigation in Youth (QUALITY) study were analyzed. The sample consisted of n = 377 White adolescents with a history of parental obesity. Home environment chaos was measured using the Confusion, Hubbub, and Order Scale (CHAOS) analyzed both continuously and dichotomized as high vs. low chaos. Body Mass Index z-scores (zBMI) were computed using WHO standards from measured weight and height. Physical activity (7-day accelerometry), vegetable and fruit intake (three 24-hour diet recalls), and leisure screen time and sleep duration (questionnaire) were assessed. Sex-specific linear regression models were used to estimate associations between level of family home environment chaos, lifestyle behaviours and zBMI. RESULTS: The overall level of chaos was low in our study sample, with higher reported levels among girls compared to boys. Among girls, high (vs low) chaos was associated with shorter sleep duration (hours/day) (B = - 0.44, 95% CI: -0.75, -0.14). No associations were observed for other lifestyle behaviours or for zBMI. CONCLUSION: In this sample of adolescents with a parental history of obesity, higher household chaos was not associated with obesity or lifestyle behaviours, except for sleep duration among girls. Replication of findings in more diverse samples is indicated.


Subject(s)
Obesity , Pediatric Obesity , Male , Female , Humans , Adolescent , Cross-Sectional Studies , Obesity/etiology , Diet , Life Style , Body Mass Index
9.
mBio ; 13(5): e0102122, 2022 10 26.
Article in English | MEDLINE | ID: mdl-36069449

ABSTRACT

Mosquitoes are important vectors for many arboviruses. It is becoming increasingly clear that various symbiotic microorganisms (including bacteria and insect-specific viruses; ISVs) in mosquitoes have the potential to modulate the ability of mosquitoes to transmit arboviruses. In this study, we compared the bacteriome and virome (both eukaryotic viruses and bacteriophages) of female adult Aedes aegypti and Culex quinquefasciatus mosquitoes fed with sucrose/water, blood, or blood spiked with Zika virus (ZIKV) or West Nile virus (WNV), respectively. Furthermore, we investigated associations between the microbiota and vector competence. We show that the influence of arboviruses on the mosquito microbiome-and vice versa-is distinct for each combination of arbovirus/mosquito species. The presence of ZIKV resulted in a temporarily increased Aedes ISV diversity. However, this effect was distinct for different ISVs: some ISVs decreased following the blood meal (Aedes aegypti totivirus), whereas other ISVs increased only when the blood contained ZIKV (Guadeloupe mosquito virus). Also, the diversity of the Aedes bacteriome depended on the diet and the presence of ZIKV, with a lower diversity observed for mosquitoes receiving blood without ZIKV. In Cx. quinquefasciatus, some ISVs increased in WNV-infected mosquitoes (Guadeloupe Culex tymo-like virus). Particularly, the presence of Wenzhou sobemo-like virus 3 (WSLV3) was associated with the absence of infectious WNV in mosquito heads, suggesting that WSLV3 might affect vector competence for WNV. Distinct profiles of bacteriophages were identified in Culex mosquitoes depending on diet, despite the lack of clear changes in the bacteriome. Overall, our data demonstrate a complex three-way interaction among arboviruses, resident microbiota, and the host, which is distinct for different arbovirus-mosquito combinations. A better understanding of these interactions may lead to the identification of microbiota able to suppress the ability of arbovirus transmission to humans, and hence improved arbovirus control measures. IMPORTANCE In this study, we first utilized the single mosquito microbiome analysis, demonstrating a complex three-way interaction among arboviruses, resident microbiota, and the host, which is distinct for different arbovirus-mosquito combinations. Some of the previously described "core virus" increased in the mosquitos receiving viral blood meal, like Guadeloupe mosquito virus and Guadeloupe Culex tymo-like virus, suggesting their potential roles in ZIKV and WNV infection. Notably, Wenzhou sobemo-like virus 3 was associated with the absence of infectious WNV in heads of Culex mosquitoes, which might affect vector competence for WNV. A better understanding of these interactions will lead to the identification of microbiota able to suppress the ability of arbovirus transmission to humans, and hence improved arbovirus control measures.


Subject(s)
Aedes , Arboviruses , Culex , Microbiota , Viruses , West Nile virus , Zika Virus Infection , Zika Virus , Humans , Animals , Female , Mosquito Vectors , Bacteria , Sucrose , Water
10.
J Med Entomol ; 59(6): 2072-2079, 2022 11 16.
Article in English | MEDLINE | ID: mdl-36130161

ABSTRACT

The emergence of West Nile virus and Usutu virus in Europe poses a significant risk to public health. In the absence of efficient antiviral therapy or vaccine candidates, the only strategy to control these arboviruses is to target the Culex (Diptera: Culicidae) mosquito vector. However, the selection pressure caused by exposure to insecticides for vector control or agricultural pest control can lead to insecticide resistance, thereby reducing the efficacy of insecticide-based vector control interventions. In Culex mosquitoes, two of the most common amino acid substitutions associated with insecticide resistance are the kdr L1014F in voltage gated sodium channels and G119S in acetylcholinesterase. In this study, Culex pipiens biotype pipiens, Culex torrentium, and Culex modestus were sampled from 2019 to 2021 in three distinct environmental habitats (urban, peri-urban, and agricultural) in and around the city of Leuven, Belgium. Individual mosquitoes were screened for two mutations resulting in L1014F and G119S amino acid substitutions. Both mutations were observed in Cx. pipiens and Cx. modestus but not in Cx. torrentium mosquitoes across the four collection sites. Furthermore, multi-resistance or cross-resistance in Cx. pipiens could be a threat in these areas, as both mutations were observed at low frequencies. These results provide the first report of kdr L1014F and ace-1 G119S resistance mutations in Cx. pipiens and Cx. modestus mosquitoes from Belgium, highlighting the importance of mosquito surveillance to design effective arbovirus outbreak control strategies.


Subject(s)
Culex , Culicidae , Insecticides , Pyrethrins , Animals , Pyrethrins/pharmacology , Belgium , Organophosphates/pharmacology , Acetylcholinesterase/genetics , Insecticide Resistance/genetics , Insecticides/pharmacology , Mosquito Vectors/genetics , Mutation
11.
ACS Omega ; 7(23): 19640-19647, 2022 Jun 14.
Article in English | MEDLINE | ID: mdl-35721970

ABSTRACT

Silicon carbide (SiC) has become an extraordinary photonic material. Achieving reproducible self-formation of silicon quantum dots (SiQDs) within SiC matrices could be beneficial for producing electroluminescent devices operating at high power, high temperatures, or high voltages. In this work, we use a remote plasma-enhanced chemical vapor deposition system to grow SiC thin films. We identified that a particular combination of 20 sccm of CH4 and a range of 58-100 sccm of H2 mass flow with 600 °C annealing allows the abundant and reproducible self-formation of SiQDs within the SiC films. These SiQDs dramatically increase the photoluminescence-integrated intensity of our SiC films. The photoluminescence of our SiQDs shows a normal distribution with positive skewness and well-defined intensity maxima in blue regions of the electromagnetic spectrum (439-465 nm) and is clearly perceptible to the naked eye.

12.
Mol Ther Methods Clin Dev ; 25: 215-224, 2022 Jun 09.
Article in English | MEDLINE | ID: mdl-35313504

ABSTRACT

New platforms are needed for the design of novel prophylactic vaccines and advanced immune therapies. Live-attenuated yellow fever vaccine YF17D serves as a vector for several licensed vaccines and platform for novel candidates. On the basis of YF17D, we developed an exceptionally potent COVID-19 vaccine candidate called YF-S0. However, use of such live RNA viruses raises safety concerns, such as adverse events linked to original YF17D (yellow fever vaccine-associated neurotropic disease [YEL-AND] and yellow fever vaccine-associated viscerotropic disease [YEL-AVD]). In this study, we investigated the biodistribution and shedding of YF-S0 in hamsters. Likewise, we introduced hamsters deficient in signal transducer and activator of transcription 2 (STAT2) signaling as a new preclinical model of YEL-AND/AVD. Compared with YF17D, YF-S0 showed improved safety with limited dissemination to brain and visceral tissues, absent or low viremia, and no shedding of infectious virus. Considering that yellow fever virus is transmitted by Aedes mosquitoes, any inadvertent exposure to the live recombinant vector via mosquito bites is to be excluded. The transmission risk of YF-S0 was hence compared with readily transmitting YF-Asibi strain and non-transmitting YF17D vaccine, with no evidence for productive infection of mosquitoes. The overall favorable safety profile of YF-S0 is expected to translate to other vaccines based on the same YF17D platform.

13.
Public Health Nutr ; 24(14): 4417-4429, 2021 10.
Article in English | MEDLINE | ID: mdl-34218842

ABSTRACT

OBJECTIVE: This study aimed to examine in Colombian rural households the association between different severity levels of household food insecurity and the presence of the double burden of malnutrition (SCOWT), defined as the coexistence of a stunted child under 5 years of age and an overweight or obese (OWOB) mother. DESIGN: A secondary data analysis was conducted using cross-sectional data from the Colombian National Nutritional Survey (ENSIN) 2015. Household food insecurity status was assessed by using the Latin-American and Caribbean Food Security Scale (ELCSA). The household SCOWT status (child stunting and OWOB mother) was determined using anthropometric data from a mother and her child. SETTING: Rural Colombia. PARTICIPANTS: Totally, 2·350 mother-child pairs living in the same household. RESULTS: Sixty-two per cent of the households were food-insecure and SCOWT was present in 7·8 % of the households. Moderate (OR: 2·39, 95 % CI (1·36, 4·21)) and severe (OR: 1·86, 95 % CI (1·10, 3·15)) food insecurity was associated with SCOWT in an unadjusted logistic regression. Only moderate food insecurity remained significantly associated with SCOWT in a multivariate logistic regression (adjusted OR: 2·41, 95 % CI (1·24, 4·68)). CONCLUSIONS: Colombian rural areas are not exempt from the worldwide concern of increasing OWOB rates while stunting is still persistent. These results highlight the need of implementing double-duty rural actions targeting the most vulnerable households to SCOWT, particularly in terms of overcoming food insecurity beyond hunger satisfaction to prevent all forms of malnutrition.


Subject(s)
Food Insecurity , Malnutrition , Colombia/epidemiology , Cross-Sectional Studies , Female , Food Supply , Humans , Malnutrition/epidemiology , Nutritional Status , Prevalence , Socioeconomic Factors
14.
Malar J ; 20(1): 225, 2021 May 19.
Article in English | MEDLINE | ID: mdl-34011373

ABSTRACT

BACKGROUND: Loop-mediated isothermal amplification (LAMP) for malaria diagnosis at the point of care (POC) depends on the detection capacity of synthesized nucleic acids and the specificity of the amplification target. To improve malaria diagnosis, new colorimetric LAMP tests were developed using multicopy targets for Plasmodium vivax and Plasmodium falciparum detection. METHODS: The cytochrome oxidase I (COX1) mitochondrial gene and the non-coding sequence Pvr47 for P. vivax, and the sub-telomeric sequence of erythrocyte membrane protein 1 (EMP1) and the non-coding sequence Pfr364 for P. falciparum were targeted to design new LAMP primers. The limit of detection (LOD) of each colorimetric LAMP was established and assessed with DNA extracted by mini spin column kit and the Boil & Spin method from 28 microscopy infections, 101 malaria submicroscopic infections detected by real-time PCR only, and 183 negatives infections by both microscopy and PCR. RESULTS: The LODs for the colorimetric LAMPs were estimated between 2.4 to 3.7 parasites/µL of whole blood. For P. vivax detection, the colorimetric LAMP using the COX1 target showed a better performance than the Pvr47 target, whereas the Pfr364 target was the most specific for P. falciparum detection. All microscopic infections of P. vivax were detected by PvCOX1-LAMP using the mini spin column kit DNA extraction method and 81% (17/21) were detected using Boil & Spin sample preparation. Moreover, all microscopic infections of P. falciparum were detected by Pfr364-LAMP using both sample preparation methods. In total, PvCOX1-LAMP and Pfr364-LAMP detected 80.2% (81 samples) of the submicroscopic infections using the DNA extraction method by mini spin column kit, while 36.6% (37 samples) were detected using the Boil & Spin sample preparation method. CONCLUSION: The colorimetric LAMPs with multicopy targets using the COX1 target for P. vivax and the Pfr364 for P. falciparum have a high potential to improve POC malaria diagnosis detecting a greater number of submicroscopic Plasmodium infections.


Subject(s)
Colorimetry/methods , Malaria, Falciparum/diagnosis , Malaria, Vivax/diagnosis , Molecular Diagnostic Techniques/methods , Nucleic Acid Amplification Techniques/methods , Plasmodium falciparum/isolation & purification , Plasmodium vivax/isolation & purification , Electron Transport Complex IV/analysis , Plasmodium falciparum/enzymology , Plasmodium vivax/enzymology , Protozoan Proteins/analysis
15.
Microorganisms ; 9(5)2021 Apr 27.
Article in English | MEDLINE | ID: mdl-33925738

ABSTRACT

Favipiravir (T-705) is a broad-spectrum antiviral drug that inhibits RNA viruses after intracellular conversion into its active form, T-705 ribofuranosyl 5'-triphosphate. We previously showed that T-705 is able to significantly inhibit the replication of chikungunya virus (CHIKV), an arbovirus transmitted by Aedes mosquitoes, in mammalian cells and in mouse models. In contrast, the effect of T-705 on CHIKV infection and replication in the mosquito vector is unknown. Since the antiviral activity of T-705 has been shown to be cell line-dependent, we studied here its antiviral efficacy in Aedes-derived mosquito cells and in Aedes aegypti mosquitoes. Interestingly, T-705 was devoid of anti-CHIKV activity in mosquito cells, despite being effective against CHIKV in Vero cells. By investigating the metabolic activation profile, we showed that, unlike Vero cells, mosquito cells were not able to convert T-705 into its active form. To explore whether alternative metabolization pathways might exist in vivo, Aedes aegypti mosquitoes were infected with CHIKV and administered T-705 via an artificial blood meal. Virus titrations of whole mosquitoes showed that T-705 was not able to reduce CHIKV infection in mosquitoes. Combined, these in vitro and in vivo data indicate that T-705 lacks antiviral activity in mosquitoes due to inadequate metabolic activation in this animal species.

16.
mSphere ; 6(2)2021 04 21.
Article in English | MEDLINE | ID: mdl-33883261

ABSTRACT

Culex modestus mosquitoes are considered potential transmission vectors of West Nile virus and Usutu virus. Their presence has been reported across several European countries, including one larva detected in Belgium in 2018. In this study, mosquitoes were collected in the city of Leuven and surrounding areas in the summers of 2019 and 2020. Species identification was performed based on morphological features and partial sequences of the mitochondrial cytochrome oxidase subunit I (COI) gene. The 107 mosquitoes collected in 2019 belonged to eight mosquito species, Culex pipiens (24.3%), Cx. modestus (48.6%), Cx. torrentium (0.9%), Culiseta annulata (0.9%), Culiseta morsitans (0.9%), Aedes sticticus (14.0%), Aedes cinereus (9.3%), and Anopheles plumbeus (0.9%), suggesting the presence of an established Cx. modestus population in Belgium. The collection of Cx. modestus mosquitoes at the same locations in 2020 confirmed their establishment in the region. Haplotype network analysis of the COI sequences for Cx. modestus showed that the Belgian population is rather diverse, suggesting that it may have been established in Belgium for some time. The Belgian Cx. modestus population was most closely related to populations from the United Kingdom and Germany. Characterization of the virome of the collected mosquitoes resulted in the identification of at least 33 eukaryotic viral species. Nine (nearly) complete genomes belonging to 6 viral species were identified, all of which were closely related to known viruses. In conclusion, here, we report the presence of Cx. modestus in the surrounding areas of Leuven, Belgium. As this species is considered to be a vector of several arboviruses, the implementation of vector surveillance programs to monitor this species is recommended.IMPORTANCECulex modestus mosquitoes are considered to be a potential "bridge" vector, being able to transmit pathogens between birds as well as from birds to mammals, including humans. In Belgium, this mosquito species was considered absent until the finding of one larva in 2018 and subsequent evidence of a large population in 2019 to 2020 described here. We collected mosquitoes in the summers of 2019 and 2020 in the city of Leuven and surrounding areas. The mosquito species was identified by morphological and molecular methods, demonstrating the presence of Cx. modestus in this region. The ability of mosquitoes to transmit pathogens can depend on several factors, one of them being their natural virus composition. Therefore, we identified the mosquito-specific viruses harbored by Belgian mosquitoes. As Cx. modestus is able to transmit viruses such as West Nile virus and Usutu virus, the establishment of this mosquito species may increase the risk of virus transmission in the region. It is thus advisable to implement mosquito surveillance programs to monitor this species.


Subject(s)
Culex/virology , Mosquito Vectors/virology , Virome/genetics , Viruses/genetics , Animals , Belgium , Culex/classification , Flavivirus/physiology , Seasons , Viruses/classification , Viruses/isolation & purification , West Nile virus/physiology
17.
Pathogens ; 9(12)2020 Dec 09.
Article in English | MEDLINE | ID: mdl-33317119

ABSTRACT

Anaplasma marginale, a well-known cattle pathogen of tropical and subtropical world regions, has been previously molecularly characterized in a giant anteater (Myrmecophaga tridactyla) from Corrientes, Argentina. Ticks or other hematophagous arthropod involved in the wild transmission cycle remained unknown. The aim of the present study was to analyze the simultaneous occurrence of A. marginale in blood samples and ticks from giant anteaters from Corrientes in order to investigate if ticks could be relevant in the transmission among these mammals. Blood samples from 50 giant anteaters collected in different years and 26 ticks Amblyomma dubitatum and A. sculptum were studied through the molecular amplification of two unequivocal species-specific genes from A. marginale: msp5 and msp1ß. Twenty five giant anteaters and tick organs (salivary glands, gut and oviduct) from 11 ticks tested positive to the A. marginale DNA amplification. The further molecular characterization through MSP1a tandem repeats analysis revealed the presence of genotypes circulating among giant anteaters that had been previously identified in cattle blood samples from the same geographical region. These results confirm the presence of A. marginale in giant anteaters in Corrientes and suggests that A. dubitatum and A. sculptum ticks could be involved in the transmission among giant anteaters. Future studies will determine the role of these tick species in the wild transmission cycle in the study area and the eventual connection with the domestic cycle.

18.
Viruses ; 12(9)2020 08 31.
Article in English | MEDLINE | ID: mdl-32878245

ABSTRACT

Arthropod-borne viruses contribute significantly to global mortality and morbidity in humans and animals. These viruses are mainly transmitted between susceptible vertebrate hosts by hematophagous arthropod vectors, especially mosquitoes. Recently, there has been substantial attention for a novel group of viruses, referred to as insect-specific viruses (ISVs) which are exclusively maintained in mosquito populations. Recent discoveries of novel insect-specific viruses over the past years generated a great interest not only in their potential use as vaccine and diagnostic platforms but also as novel biological control agents due to their ability to modulate arbovirus transmission. While arboviruses infect both vertebrate and invertebrate hosts, the replication of insect-specific viruses is restricted in vertebrates at multiple stages of virus replication. The vertebrate restriction factors include the genetic elements of ISVs (structural and non-structural genes and the untranslated terminal regions), vertebrate host factors (agonists and antagonists), and the temperature-dependent microenvironment. A better understanding of these bottlenecks is thus warranted. In this review, we explore these factors and the complex interplay between ISVs and their hosts contributing to this host restriction phenomenon.


Subject(s)
Arboviruses/physiology , Arthropods/virology , Insect Viruses/physiology , Virus Diseases/virology , Animals , Arboviruses/classification , Arboviruses/genetics , Arboviruses/isolation & purification , Arthropods/classification , Arthropods/physiology , Host Specificity , Humans , Insect Viruses/classification , Insect Viruses/genetics , Insect Viruses/isolation & purification , Virus Diseases/transmission
19.
J Exp Zool A Ecol Integr Physiol ; 333(3): 181-193, 2020 03.
Article in English | MEDLINE | ID: mdl-31904197

ABSTRACT

Different hypotheses have been proposed to explain the adaptive value of matrotrophy, which is the postfertilization maternal provisioning to developing embryos. The Trexler-DeAngelis model proposes that matrotrophy provides fitness advantages when food abundance is high and availability is constant. If food availability is low or unpredictable, prefertilization maternal provisioning (lecithotrophy) should be favored over matrotrophy. In this study, we tested this model in two fish species from the family Poeciliidae, Poeciliopsis gracilis and P. infans, using field and laboratory data. In the field study, we explored the effects of population, season, and food abundance on the degree of matrotrophy. In P. infans, we found evidence that supports this model: In the population where food abundance decreased during the dry season, females reduced the amount of postfertilization provisioning and thus exhibited a more lecithotrophic strategy. In P. gracilis, we observed patterns that were partially consistent with this model: Food abundance decreased during the wet season in three populations of this species, but only in one of these populations, females exhibited less postfertilization nutrient transfer during this season. In the laboratory study, we tested the effects of constant, fluctuating, and low food availability on the relative amounts of pre- and postfertilization provisioning of P. infans. Our laboratory results also support the Trexler-DeAngelis model because both low and fluctuating food regimes promoted a more lecithotrophic strategy. Together, our findings indicate that the benefits of matrotrophy are more likely to occur when females have constant access to food sources.


Subject(s)
Animal Nutritional Physiological Phenomena , Cyprinodontiformes/physiology , Viviparity, Nonmammalian/physiology , Animals , Embryo, Nonmammalian , Female , Nutritional Status/physiology , Seasons
20.
Int J Pediatr Otorhinolaryngol ; 126: 109604, 2019 Nov.
Article in English | MEDLINE | ID: mdl-31369973

ABSTRACT

This case series aims to determine the optimal surgical approach for pediatric laryngeal saccular cysts. A retrospective chart review of patients who underwent surgical treatment for laryngeal saccular cysts was completed; 5 patients were diagnosed and surgically treated. Treatment approaches included aspiration, supraglottoplasty, injection of bleomycin, endoscopic subtotal resection (marsupialization with the laser or endoscopic instrumentation of the cyst), endoscopic extended subtotal excision (subtotal resection plus removal of false vocal fold with lasering or coblation of the inner cyst wall), and transcervical approaches for resection. Based on our outcomes, an endoscopic extended subtotal resection of the cyst will achieve the best outcomes for cysts confined to the larynx or for Type 1 cysts. A transcervical approach for resection of the cyst will achieve the best outcomes for Type 2 cysts that extend into the neck or are extralaryngeal.


Subject(s)
Cysts/surgery , Endoscopy , Laryngeal Diseases/surgery , Humans , Infant , Infant, Newborn , Laser Therapy , Lasers, Gas , Male , Retrospective Studies
SELECTION OF CITATIONS
SEARCH DETAIL
...