Current research in parasitology & vector-borne diseases最新文献

{"title":"Infectivity of symptomatic Plasmodium vivax cases to different generations of wild-caught and laboratory-adapted Anopheles arabiensis using a membrane feeding assay, Ethiopia","authors":"Tenaye Ayele ,&nbsp;Biniam Wondale ,&nbsp;Girum Tamiru ,&nbsp;Nigatu Eligo ,&nbsp;Bernt Lindtjørn ,&nbsp;Fekadu Massebo","doi":"10.1016/j.crpvbd.2023.100137","DOIUrl":"https://doi.org/10.1016/j.crpvbd.2023.100137","url":null,"abstract":"<div><p>When measuring human to mosquito transmission of <em>Plasmodium</em> spp., laboratory-adapted (colony) mosquitoes can be utilized. To connect transmission studies to the local epidemiology, it can be important to comprehend the relationship between infectivity in laboratory-adapted (colony) and wild-caught (wild) mosquitoes of the same species. Microscopically confirmed <em>Plasmodium vivax</em> cases were recruited from health facilities in Arba Minch town, and a nested polymerase chain reaction (nPCR) was used for subsequent confirmation. We performed paired membrane-feeding assays using colony <em>An. arabiensis</em> and three generations of wild origin <em>An. arabiensis</em>. <em>Anopheles arabiensis</em> aged 3–6 days were fed after being starved for 8–14 h. Microscopically, the oocyst development was evaluated at day 7 after feeding. Circumsporozoite proteins (CSPs) assay was carried out by enzyme-linked immunosorbent assay (ELISA). In 19 paired feeding experiments, the feeding efficiency was more than doubled in colony (median: 62.5%; interquartile range, IQR: 35–78%) than in wild mosquitoes (median: 28.5%; IQR: 17.5–40%; <em>P</em> &lt; 0.001). Among the 19 <em>P. vivax</em> gametocyte-positive blood samples, 63.2% (<em>n</em> = 12) were infective to wild <em>An. arabiensis</em> and 73.7% (<em>n</em> = 14) were infective to colony <em>An. arabiensis</em>. The median infection rate was twice as high (26%) in the colony than in the wild (13%) <em>An. arabiensis</em>, although the difference was marginally insignificant (<em>P</em> = 0.06). Although the observed difference was not statistically significant (<em>P</em> = 0.19), the median number of oocysts per midgut was more than twice as high (17.8/midgut) in colony than in wild (7.2/midgut) <em>An. arabiensis</em>. The median feeding efficiency was 26.5% (IQR: 18–37%) in F1, 29.3% (IQR: 28–40%) in F2 and 31.2% (IQR: 30–37%) in F3 generations of wild <em>An. arabiensis</em>. Also, no significant difference was observed in oocyst infection rate and load between generations of wild <em>An. arabiensis</em>. CSP rate of <em>P. vivax</em> was 3.1% (3/97; 95% CI: 0.6–8.8%) in wild and 3.6% (3/84; 95% CI: 0.7–10.1%) in colony <em>An. arabiensis</em>. The results of the present study revealed that oocyst infection and load/midgut, and CSP rate were roughly comparable, indicating that colony mosquitoes can be employed for infectivity studies, while larger sample sizes may be necessary in future studies.</p></div>","PeriodicalId":94311,"journal":{"name":"Current research in parasitology & vector-borne diseases","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49778373","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Plague mitigation for prairie dog and black-footed ferret conservation: Degree and duration of flea control with 0.005% fipronil grain bait","authors":"David A. Eads ,&nbsp;Travis M. Livieri ,&nbsp;Phillip Dobesh ,&nbsp;John P. Hughes ,&nbsp;Jason Fly ,&nbsp;Holly Redmond ,&nbsp;Eddie Childers ,&nbsp;Matthew S. Schwarz ,&nbsp;Dean E. Biggins","doi":"10.1016/j.crpvbd.2023.100124","DOIUrl":"10.1016/j.crpvbd.2023.100124","url":null,"abstract":"<div><p>Sylvatic plague, a primarily flea-borne zoonosis, is a significant threat to prairie dogs (<em>Cynomys</em> spp., PDs) and their specialized predators, endangered black-footed ferrets (<em>Mustela nigripes</em>, BFFs). Host-fed fipronil baits have proven effective in controlling fleas on PDs for the purposes of plague mitigation and BFF conservation. Currently, annual treatments are the norm. We tested the long-term efficacy of fipronil bait treatments with black-tailed PDs (<em>C. ludovicianus</em>, BTPDs) and BFFs in South Dakota, USA. During 2018–2020, we provided BTPDs on 21 sites with grain bait formula, laced with 0.005% fipronil (50 ​mg/kg); 18 non-treated sites functioned as baselines. In 2020–2022, we live-trapped, anesthetized, and combed BTPDs for fleas. Flea control was significant for at least 639–885 days. Flea abundance on the treated sites was &lt; 0.5 fleas/BTPD for ∼750 days. During 2020–2022, we sampled BFFs for fleas on 4 BTPD colonies treated with fipronil grain bait and 8 non-treated colonies. Flea control was significant with BFFs, but flea abundance began to rebound within ∼240 days post-treatment. When feasible, the combination of insecticide treatments, such as fipronil baits, and BFF vaccination against plague provide a “two-pronged” protection approach for these endangered carnivores. If fipronil bait treatments are less effective with predatory BFFs than PDs, as found herein, the “two-pronged” approach might be used to protect BFFs and biennial fipronil bait treatments might be used to protect PDs. If BFF vaccination is not possible, or few BFFs can be vaccinated, annual fipronil bait treatments might be used as a precaution to protect BFFs. Flea densities might be surveyed to determine when/where more frequent treatments seem useful.</p></div>","PeriodicalId":94311,"journal":{"name":"Current research in parasitology & vector-borne diseases","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10250916/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9618621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integrating vector control within an emerging agricultural system in a region of climate vulnerability in southern Malawi: A focus on malaria, schistosomiasis, and arboviral diseases","authors":"Christopher M. Jones ,&nbsp;Anne L. Wilson ,&nbsp;Michelle C. Stanton ,&nbsp;J. Russell Stothard ,&nbsp;Federica Guglielmo ,&nbsp;James Chirombo ,&nbsp;Lindiwe Mafuleka ,&nbsp;Rose Oronje ,&nbsp;Themba Mzilahowa","doi":"10.1016/j.crpvbd.2023.100133","DOIUrl":"10.1016/j.crpvbd.2023.100133","url":null,"abstract":"<div><p>Infectious diseases are emerging at an unprecedented rate while food production intensifies to keep pace with population growth. Large-scale irrigation schemes have the potential to permanently transform the landscape with health, nutritional and socio-economic benefits; yet, this also leads to a shift in land-use patterns that can promote endemic and invasive insect vectors and pathogens. The balance between ensuring food security and preventing emerging infectious disease is a necessity; yet the impact of irrigation on vector-borne diseases at the epidemiological, entomological and economic level is uncertain and depends on the geographical and climatological context. Here, we highlight the risk factors and challenges facing vector-borne disease surveillance and control in an emerging agricultural ecosystem in the lower Shire Valley region of southern Malawi. A phased large scale irrigation programme (The Shire Valley Transformation Project, SVTP) promises to transform over 40,000 ha into viable and resilient farmland, yet the valley is endemic for malaria and schistosomiasis and experiences frequent extreme flooding events following tropical cyclones. The latter exacerbate vector-borne disease risk while simultaneously making any empirical assessment of that risk a significant hurdle. We propose that the SVTP provides a unique opportunity to take a One Health approach at mitigating vector-borne disease risk while maintaining agricultural output. A long-term and multi-disciplinary approach with buy-in from multiple stakeholders will be needed to achieve this goal.</p></div>","PeriodicalId":94311,"journal":{"name":"Current research in parasitology & vector-borne diseases","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10412864/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9990491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficacy and safety of Felpreva®, a spot-on formulation for cats containing emodepside, praziquantel and tigolaner against experimental infestation with the Australian paralysis tick Ixodes holocyclus","authors":"Florian Roeber ,&nbsp;Chrissie Jackson ,&nbsp;Michael Chambers ,&nbsp;Veronica Smith ,&nbsp;Jane Hume ,&nbsp;Katrin Blazejak ,&nbsp;Norbert Mencke","doi":"10.1016/j.crpvbd.2023.100123","DOIUrl":"https://doi.org/10.1016/j.crpvbd.2023.100123","url":null,"abstract":"<div><p>The Australian paralysis tick <em>Ixodes holocyclus</em> continues to be a serious threat to companion animals along Australia’s east coast. The tick produces a potent neurotoxin which causes a rapidly ascending flaccid paralysis, which if left untreated, can result in the death of the animal. There is currently only a limited number of products registered in Australia for the treatment and control of paralysis ticks in cats. Felpreva® is an effective spot-on combination containing emodepside, praziquantel and tigolaner. To investigate the therapeutic and long-term persistent efficacy of Felpreva® (2.04% w/v emodepside, 8.14% w/v praziquantel and 9.79% w/v tigolaner) against experimental infestation with <em>I. holocyclus</em> in cats, two studies were undertaken. Fifty cats were included in the studies on study Day -17. These cats were immunized against paralysis tick holocyclotoxin prior to the study commencing. Immunity to holocyclotoxin was confirmed with a tick carrying capacity (TCC) test conducted prior to treatment. Cats were treated once on Day 0. Group 1 cats were treated with the placebo formulation and Group 2 cats were treated with Felpreva®. Cats were infested on Days -14 (tick carrying capacity test), 0, 28, 56, 70, 84 and 91 (weeks 4, 8, 10, 12 and 13). Ticks were counted on cats 24 h, 48 h and 72 ​h post-treatment and infestation, except during the tick carrying capacity test when they were counted approximately 72 ​h post-infestation only. The 24-h and 48-h assessments were conducted without removing the ticks. The ticks were assessed, removed and discarded at the 72-h assessment time-points. Significant differences in total live tick counts at ∼24 h, ∼48 h and ∼72 ​h post-infestation were observed between the treatment and control group. Differences were significant (<em>P</em> ​&lt; ​0.05 to ​&lt; ​0.001) in all instances. Treatment efficacies of 98.1–100% were observed ∼72 ​h post-infestation through to 13 weeks (94 days) post-treatment. These results show that a single application of Felpreva® provides effective treatment and control against induced infestation with paralysis ticks for 13 weeks.</p></div>","PeriodicalId":94311,"journal":{"name":"Current research in parasitology & vector-borne diseases","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49791524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Larviciding intervention targeting malaria vectors also affects Culex mosquito distribution in the city of Yaoundé, Cameroon","authors":"Abdou Talipouo ,&nbsp;Patricia Doumbe-Belisse ,&nbsp;Carmène S. Ngadjeu ,&nbsp;Landre Djamouko-Djonkam ,&nbsp;Elysée Nchoutpouen ,&nbsp;Roland Bamou ,&nbsp;Nadège Sonhafouo-Chiana ,&nbsp;Audrey Paul Marie Mayi ,&nbsp;Gisèle Aurélie Dadji Foko ,&nbsp;Parfait Awono-Ambene ,&nbsp;Sévilor Kekeunou ,&nbsp;Charles S. Wondji ,&nbsp;Christophe Antonio-Nkondjio","doi":"10.1016/j.crpvbd.2023.100136","DOIUrl":"https://doi.org/10.1016/j.crpvbd.2023.100136","url":null,"abstract":"<div><p>Although <em>Culex</em> species are considered to be equally affected by control measures targeting malaria vectors, there is still not enough evidence of the impact of interventions such as larviciding on the distribution of these mosquito species. The present study assessed the impact of a larviciding trial targeting malaria vectors on <em>Culex</em> mosquito species in the city of Yaoundé, Cameroon. A cluster randomized trial comparing 13 treated clusters and 13 untreated clusters was implemented. Data were collected at baseline and during the larviciding intervention, from March 2017 to November 2020. The microbial larvicide VectoMax G was applied once every 2 weeks in the intervention areas. Adult mosquitoes were collected using CDC light traps in both intervention and non-intervention areas and compared between arms. Globally, larviciding intervention was associated with 69% reduction in aquatic habitats with <em>Culex</em> larvae and 36.65% reduction of adult <em>Culex</em> densities in houses. Adult <em>Culex</em> densities were reduced both indoors (35.26%) and outdoors (42.37%). No change in the composition of <em>Culex</em> species was recorded. The study suggests a high impact of larviciding on <em>Culex</em> mosquito species distribution. The impact of the intervention can be improved if typical <em>Culex</em> breeding habitats including pit latrines are targeted.</p></div>","PeriodicalId":94311,"journal":{"name":"Current research in parasitology & vector-borne diseases","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49791531","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Extracellular vesicles of the liver fluke Opisthorchis felineus stimulate the angiogenesis of human umbilical vein endothelial cells","authors":"Dmitry V. Ponomarev ,&nbsp;Ekaterina A. Lishai ,&nbsp;Anna V. Kovner ,&nbsp;Maria V. Kharkova ,&nbsp;Oxana Zaparina ,&nbsp;Yaroslav K. Kapuschak ,&nbsp;Viatcheslav A. Mordvinov ,&nbsp;Maria Y. Pakharukova","doi":"10.1016/j.crpvbd.2023.100153","DOIUrl":"https://doi.org/10.1016/j.crpvbd.2023.100153","url":null,"abstract":"<div><p>The liver fluke <em>Opisthorchis felineus</em> is a clinically important food-borne parasite of humans. Infection with <em>O. felineus</em> in mammals is associated with liver morbidities such as periductal fibrosis, bile duct neoplasia, and chronic inflammation. Previously we have shown that excretory-secretory products (ESP) can stimulate the healing of skin wounds in mice, which may be due to stimulated angiogenesis and extracellular matrix remodeling. However, there are no studies analyzing the angiogenic character of <em>O. felineus</em>, and its effects on angiogenesis, vascularity, and vascular endothelium. The aim of this study was to evaluate the capacity of ESP and extracellular vesicles (EVs) of <em>O. felineus</em> to stimulate angiogenesis and the formation of pseudo-capillaries <em>in vitro.</em> We also aimed at the assessment of the angiogenesis during the infection <em>in vivo</em>, and estimation of the endothelial cell type abundances from heterogeneous bulk liver transcriptome between uninfected and infected animals with single-cell information. The study revealed significant alterations in vascularity in the hamster liver and significant involvement of portal endothelial cells at the transcriptome level. We also demonstrated that the ESP and EVs of <em>O. felineus</em> have the capacity to stimulate the formation of pseudo-capillaries <em>in vitro</em>. Both ESP and EVs appeared to have similar effects on all four parameters, increasing node formation and total master segments length, and significantly decreasing total isolated branches length and number of isolated segments of pseudo-capillaries. The liver flukes manipulate the hostʼs angiogenic response, a fact that has been related to the pathogenesis caused by these parasites. Understanding these pathogenic mechanisms may uncover new therapeutic targets to relieve or prevent the most severe complications of opisthorchiasis.</p></div>","PeriodicalId":94311,"journal":{"name":"Current research in parasitology & vector-borne diseases","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2667114X23000419/pdfft?md5=8ee2b8130c4f0337505362a48c6a6399&pid=1-s2.0-S2667114X23000419-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134832382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatial repellents: The current roadmap to global recommendation of spatial repellents for public health use","authors":"Nicole L. Achee ,&nbsp;T. Alex Perkins ,&nbsp;Sean M. Moore ,&nbsp;Fang Liu ,&nbsp;Issaka Sagara ,&nbsp;Suzanne Van Hulle ,&nbsp;Eric O. Ochomo ,&nbsp;John E. Gimnig ,&nbsp;Hasitha A. Tissera ,&nbsp;Steven A. Harvey ,&nbsp;April Monroe ,&nbsp;Amy C. Morrison ,&nbsp;Thomas W. Scott ,&nbsp;Robert C. Reiner Jr. ,&nbsp;John P. Grieco","doi":"10.1016/j.crpvbd.2022.100107","DOIUrl":"10.1016/j.crpvbd.2022.100107","url":null,"abstract":"<div><p>Spatial repellent (SR) products are envisioned to complement existing vector control methods through the continual release of volatile active ingredients (AI) providing: (i) protection against day-time and early-evening biting; (ii) protection in enclosed/semi-enclosed and peri-domestic spaces; (iii) various formulations to fit context-specific applications; and (iv) increased coverage over traditional control methods. SR product AIs also have demonstrated effect against insecticide-resistant vectors linked to malaria and <em>Aedes-</em>borne virus (ABV) transmission. Over the past two decades, key stakeholders, including World Health Organization (WHO) representatives, have met to discuss the role of SRs in reducing arthropod-borne diseases based on existing evidence. A key focus has been to establish a critical development path for SRs, including scientific, regulatory and social parameters that would constitute an outline for a SR target product profile, i.e. optimum product characteristics. The principal gap is the lack of epidemiological data demonstrating SR public health impact across a range of different ecological and epidemiological settings, to inform a WHO policy recommendation. Here we describe in brief trials that are designed to fulfill evidence needs for WHO assessment and initial projections of SR cost-effectiveness against malaria and dengue.</p></div>","PeriodicalId":94311,"journal":{"name":"Current research in parasitology & vector-borne diseases","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9801085/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10524444","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Immediate and long-term efficacy of Felpreva®, a new spot-on formulation containing tigolaner, emodepside and praziquantel, applied as a single application to cats artificially infested with the cat flea Ctenocephalides felis","authors":"Norbert Mencke ,&nbsp;Katrin Blazejak ,&nbsp;Gabriele Petry ,&nbsp;Hannah Hamburg ,&nbsp;Hannah Ringeisen ,&nbsp;Tanja N. Knoppe ,&nbsp;Alta Viljoen ,&nbsp;Ashley Smith ,&nbsp;Jennifer Spruill","doi":"10.1016/j.crpvbd.2023.100122","DOIUrl":"https://doi.org/10.1016/j.crpvbd.2023.100122","url":null,"abstract":"<div><p>Five studies (two dose determination, two dose confirmation, and one speed of flea kill study) were conducted to assess the immediate (therapeutic) efficacy and long-term persistent (preventive) efficacy of a single spot-on application containing the novel acaricide and insecticide tigolaner in combination with emodepside and praziquantel (Felpreva®, Vetoquinol S.A. Lure, France) applied to cats artificially infested with <em>Ctenocephalides felis</em>. Eight cats per group were randomly allocated to 0, 1×, 1.3× and 2× of the minimum dose (14.5 ​mg/kg body weight) of tigolaner (dose determination studies) or randomly allocated to 0 and 1× of the dosage (dose confirmation studies). Onset of efficacy was assessed in a speed of flea kill study on an existing flea infestation 8, 12 and 24 ​h after treatment and reassessed after monthly flea reinfestation until 13 weeks post-treatment. Efficacy was calculated according to the Abbott formula using arithmetic means. Efficacy was claimed when (i) control groups were adequately infested (flea retention ≥ 50%) at each time-point in the studies; (ii) flea counts in treated groups were significantly lower (<em>P</em> ​≤ ​0.05) than flea counts in control groups; and (iii) calculated efficacy was ≥ 90% (speed of flea kill study) and ≥ 95% (dose determination and dose confirmation studies). Tigolaner at 14.5 ​mg/kg body weight was 100% effective against fleas on Day 1 (immediate, therapeutic efficacy) in both, dose determination and dose confirmation studies. The long-term persistent efficacy in week 13 ranged between 96.3% and 100%. Fleas were rapidly killed within 12 ​h after treatment (100% flea reduction, immediate efficacy). New flea infestations were successfully prevented for 8 weeks (98.9–100% flea reduction) within 8 ​h after reinfestation, and at week 13 (96.3% flea reduction) within 24 ​h after reinfestation.</p></div>","PeriodicalId":94311,"journal":{"name":"Current research in parasitology & vector-borne diseases","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49710255","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Acanthamoeba keratitis: Molecular typing of Acanthamoeba species directly from ocular tissue","authors":"Lisa Connelly ,&nbsp;Deepa Anijeet ,&nbsp;Derek Tole ,&nbsp;Claire L. Alexander","doi":"10.1016/j.crpvbd.2023.100141","DOIUrl":"https://doi.org/10.1016/j.crpvbd.2023.100141","url":null,"abstract":"<div><p>This report explores the molecular profiling of <em>Acanthamoeba</em> spp. from individuals in the UK suffering from a debilitating, sight-threatening disease of the cornea known as <em>Acanthamoeba</em> keratitis (AK). Seventy ocular samples from individuals undergoing investigations for AK were sent to the Scottish Microbiology Reference Laboratories (SMiRL), Glasgow during 2017–2019, and subjected to DNA extraction followed by in-depth molecular typing using a nested PCR/bi-directional sequencing approach. Of the 70 samples tested, 40 were PCR-positive. Of these, 32 were successfully sequenced and assigned to two of 23 existing genotypes termed T1 to T23. Molecular profiling of the 32 samples highlighted two genotypes, namely T3 (<em>n</em> = 3) and T4 (<em>n</em> = 29). For those 29 samples identified as the T4 genotype, a sub-genotype (T4A-T4H) was recorded: T4A (<em>n</em> = 18); T4B (<em>n</em> = 5); T4C (<em>n</em> = 1); T4E (<em>n</em> = 4); and T4F (<em>n</em> = 1). This study highlights that the T4 genotype and T4A subtype are the predominant molecular variants to cause ocular disease in the UK. Gaining in-depth information on the molecular profiling of <em>Acanthamoeba</em> spp. is essential to increase our understanding of the source(s) of infection, transmission pathways, and potential associations with clinical outcomes for this rare, yet potentially debilitating ocular disease.</p></div>","PeriodicalId":94311,"journal":{"name":"Current research in parasitology & vector-borne diseases","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49791525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Novel insights on the genetic population structure of human-infecting Cyclospora spp. and evidence for rapid subtype selection among isolates from the USA","authors":"David K. Jacobson,&nbsp;Anna C. Peterson,&nbsp;Yvonne Qvarnstrom,&nbsp;Joel L.N. Barratt","doi":"10.1016/j.crpvbd.2023.100145","DOIUrl":"https://doi.org/10.1016/j.crpvbd.2023.100145","url":null,"abstract":"<div><p>Human-infecting <em>Cyclospora</em> was recently characterized as three species, two of which (<em>C. cayetanensis</em> and <em>C. ashfordi</em>) are currently responsible for all known human infections in the USA, yet much remains unknown about the genetic structure within these two species. Here, we investigate <em>Cyclospora</em> genotyping data from 2018 through 2022 to ascertain if there are temporal patterns in the genetic structure of <em>Cyclospora</em> parasites that cause infections in US residents from year to year. First, we investigate three levels of genetic characterization: species, subpopulation, and strain, to elucidate annual trends in <em>Cyclospora</em> infections. Next, we determine if shifts in genetic diversity can be linked to any of the eight loci used in our <em>Cyclospora</em> genotyping approach. We observed fluctuations in the abundance of <em>Cyclospora</em> types at the species and subpopulation levels, but no significant temporal trends were identified; however, we found recurrent and sporadic strains within both <em>C. ashfordi</em> and <em>C. cayetanensis</em>. We also uncovered major shifts in the mitochondrial genotypes in both species, where there was a universal increase in abundance of a specific mitochondrial genotype that was relatively abundant in 2018 but reached near fixation (was observed in over 96% of isolates) in <em>C. ashfordi</em> by 2022. Similarly, this allele jumped from 29% to 82% relative abundance of isolates belonging to <em>C. cayetanensis</em>. Overall, our analysis uncovers previously unknown temporal-genetic patterns in US <em>Cyclospora</em> types from 2018 through 2022 and is an important step to presenting a clearer picture of the factors influencing cyclosporiasis outbreaks in the USA.</p></div>","PeriodicalId":94311,"journal":{"name":"Current research in parasitology & vector-borne diseases","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49791529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}