Acta tropica最新文献

{"title":"West Nile virus in adults and larvae of Culiseta longiareolata and Culex hortensis (Diptera: Culicidae) captured in Hamedan, western Iran","authors":"","doi":"10.1016/j.actatropica.2024.107434","DOIUrl":"10.1016/j.actatropica.2024.107434","url":null,"abstract":"<div><div>West Nile virus (WNV) is an emerging arbovirus transmitted by mosquitoes. Although it is considered the most widespread mosquito-borne arbovirus in Iran, vectors of this zoonotic pathogen remain unknown in many regions. This study aimed to assess the presence of WNV in mosquitoes collected in the western city of Hamedan in 2022. Adult mosquitoes were captured using light traps, and mosquito larvae were collected by dipping technique from 45 diverse habitats, including urban, suburban, and rural sites. Specimens were identified and pooled into 69 batches based on their species for viral RNA extraction and Real-Time PCR. In total, 3243 mosquitoes (2209 larvae and 1034 adults) were captured and identified as <em>Culiseta longiareolata, Culex hortensis, Anopheles maculipennis</em> s.l., <em>Culex theileri, Culex pipiens, Anopheles claviger</em>, and <em>Anopheles superpictus</em> s.l. in decreasing order. Molecular screening revealed seven WNV-positive pools of <em>Culiseta longiareolata</em> and <em>Culex hortensis</em> in rural (<em>n</em> = 5) and urban areas (<em>n</em> = 2). Detection of WNV RNA indicates active circulation in mosquitoes and risk of transmission to humans and animals in Hamadan. These findings identify putative vectors in Hamadan, though vectors likely vary regionally in Iran. Further surveillance is needed to elucidate local WNV epidemiology and transmission dynamics fully. Nonetheless, this study provides important baseline evidence of WNV activity to guide prevention strategies in this area.</div></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142446098","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Frequency of chloroquine-resistant haplotype of Plasmodium falciparum (CVIET) in Ibadan, Southwest Nigeria 17 years post-chloroquine withdrawal","authors":"","doi":"10.1016/j.actatropica.2024.107435","DOIUrl":"10.1016/j.actatropica.2024.107435","url":null,"abstract":"<div><div>The replacement of chloroquine with artemisinin-based combination therapies (ACTs) for over a decade has had varying impacts on the ability of the malaria parasite to sustain its chloroquine resistance prowess in different malaria-endemic regions. We evaluated the frequency of <em>Plasmodium falciparum</em> chloroquine resistance transporter (<em>Pf</em>CRT) mutations in Ibadan, Nigeria 17 years after the replacement of chloroquine with ACTs for malaria treatment. Fragments of <em>Pf</em>CRT gene from genomic DNA of microscopically confirmed <em>P. falciparum</em>-infected patients were amplified and sequenced. There were 19% CVIET mutant and 81% CVMNK wild-type haplotypes on residues 72–76. A220S change were found in 16.7% of samples occurring concurrently with the CVIET haplotype, while a Q271E mutation occurred in a <em>Pf</em>CRT wild-type isolate. The reduced prevalence of the <em>Pf</em>CRT mutant alleles in this study compared to previous reports suggests a gradual disappearance of chloroquine-resistant malaria parasites following reduced drug pressure. It may also be a result of fitness demand on the parasites in attempts to evolve resistance against the current first-line regimen. However, evaluating the prevalence of other chloroquine resistance markers such as <em>Plasmodium falciparum</em> multidrug resistance 1 gene mutations in this population, and a more robust sample size will help to consolidate these findings.</div></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142455626","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigating Sortase A inhibitory potential of herbal compounds using integrated computational and biochemical approaches","authors":"","doi":"10.1016/j.actatropica.2024.107430","DOIUrl":"10.1016/j.actatropica.2024.107430","url":null,"abstract":"<div><div>Multi-drug resistance in bacteria is emerging as a major global health challenge, causing substantial harm in terms of mortality, morbidity, and financial strain on healthcare systems. These bacteria are constantly acquiring new virulence factors and drug-resistance mechanisms, which highlights the critical need for innovative antimicrobial medicines and identification of new therapeutic targets, such as Sortase A (EfSrtA_ΔN59). EfSrtA_ΔN59, a transpeptidase significant for the adhesion and virulence of <em>Enterococcus faecalis</em> (<em>E. faecalis</em>), presents an attractive target for disrupting biofilm formation—a key factor in persistent infections. This study investigates the inhibitory effects of two natural flavonoids- Rutin Trihydrate and Quercetin, on EfSrtA_ΔN59 and biofilm formation in <em>E. faecalis</em>. With <em>in vitro</em> enzymatic assays and biofilm quantification techniques, we demonstrate that both compounds significantly attenuate EfSrtA_ΔN59 activity, thereby hindering bacterial biofilm formation. Rutin Trihydrate and Quercetin exhibited strong binding affinities to the EfSrtA_ΔN59 enzyme, as confirmed by molecular docking and MD simulation studies. This was further substantiated by a notable reduction in biofilm biomass in bacterial cultures treated with these compounds. These findings highlight the potential of Rutin Trihydrate and Quercetin as promising candidates for the development of novel anti-virulence therapies aimed at mitigating <em>E. faecalis</em> infections, thereby offering a compelling alternative to traditional antibiotics.</div></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142455630","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The value of nomogram analysis in prediction of cerebral spread of hepatic alveolar echinococcosis","authors":"","doi":"10.1016/j.actatropica.2024.107429","DOIUrl":"10.1016/j.actatropica.2024.107429","url":null,"abstract":"<div><h3>Background</h3><div>The prognosis after brain metastasis of alveolar echinococcosis is inferior, but there is currently no effective method to predict brain metastasis.</div></div><div><h3>Purpose</h3><div>To explore the value of a nomogram constructed based on a CT plain scan and enhanced imaging features combined with clinical indicators in predicting brain metastasis of hepatic alveolar echinococcosis (HAE).</div></div><div><h3>Materials and Methods</h3><div>The imaging characteristics and clinical indicators of 116 patients diagnosed with HAE in the Affiliated Hospital of Qinghai University from 2015 to 2022 were retrospectively collected. The data were randomly divided into a training set and a validation set according to 7:3, and the difference between the two groups was analyzed. Binary logistic regression analysis was used to obtain independent predictors of brain metastasis in HAE, and a prediction model was constructed based on this and expressed in the form of a nomogram. Receiver operating characteristic (ROC) curve and calibration curve (CRC) were used to evaluate model performance, and decision curve analysis (DCA) was used to assess the clinical value of the predictive model.</div></div><div><h3>Result</h3><div>A total of 116 HAE patients were included (average age 38.07±15.09 years old, 54 males and 62 females, 81 patients (70 %) in the training set, and 35 patients (30 %) in the validation set). There was no statistically significant difference between CT plain scan and enhanced imaging features combined with clinical indicators between the training set and the validation set (<em>p</em> &gt; 0.05). After statistical analysis, it was found that whether there is invasion of the inferior vena cava, whether there is invasion of the hepatic artery, and whether there is metastasis to other organs are independent predictors of brain metastasis in HAE. A prediction model was built based on these three variables. The area under the ROC curve (AUC), cutoff value, sensitivity, and specificity of the training set and validation set were 0.922 and 0.886, 0.6934 and 0.6643, 75.00 and 84.62, 94.34 and 81.82, respectively. CRC shows good consistency between the predicted probability and the actual value of the sample. DCA showed that the clinical value of the model was high.</div></div><div><h3>Conclusion</h3><div>The nomogram constructed based on imaging features combined with clinical indicators can effectively predict whether HAE will develop brain metastasis, which is helpful for clinicians to quickly screen out high-risk patients with HAE developing brain metastases, evaluate patient prognosis, and is more conducive to the realization of individualized and precise medical decisions.</div></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142455631","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prevalence and genetic diversity of Giardia duodenalis in sheep from large-scale farms in Southern Xinjiang, China","authors":"","doi":"10.1016/j.actatropica.2024.107428","DOIUrl":"10.1016/j.actatropica.2024.107428","url":null,"abstract":"<div><div><em>Giardia duodenalis</em> is a significant zoonotic parasite. In this study, 767 fresh fecal samples were collected randomly from six large-scale sheep farms in Southern Xinjiang, China. Initially, <em>G. duodenalis</em> was screened using PCR at the SSU rRNA gene. Positive samples then underwent PCR amplification at the <em>bg, gdh</em>, and <em>tpi</em> genes. The prevalence of <em>G. duodenalis</em> in sheep was 17.5% (134/767), with the highest prevalence observed in the 3–6 months age group at 26.8% (56/209) and the lowest in the over 12 months age group at 6.8% (14/205). Among the 134 positive samples, only Assemblage E was identified. A total of 106, 92, and 98 sequences of <em>G. duodenalis</em> were obtained at the <em>gdh, tpi</em>, and <em>bg</em> genes, respectively. Fourteen isolates of <em>G. duodenalis</em> were successfully amplified at all three genes, resulting in nine <em>G. duodenalis</em> multilocus genotypes (MLG) named MLG E1-MLG E14, indicating high genetic diversity. In conclusion, <em>G. duodenalis</em> infection in sheep from large-scale farms is common in Southern Xinjiang, China, showing geographical regional distributions and genetic diversity.</div></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142405901","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bothrops atrox snake venom decreased MHC-II and CD86 expression in bone marrow-derived dendritic cells","authors":"","doi":"10.1016/j.actatropica.2024.107426","DOIUrl":"10.1016/j.actatropica.2024.107426","url":null,"abstract":"<div><div>The effect of Bothrops atrox venom (BaV) on the maturation of bone marrow-derived dendritic cells (BMDCs) from mice was investigated, with a focus on selected cell markers, TAP1 expression, and the release of pro-inflammatory cytokines during this process. The objective was to evaluate BaV's impact on dendritic cell (DC) function, as DCs are pivotal in antigen presentation and responsible for initiating the immune response mediated by naïve T cells, as well as regulating the immune system. Bone marrow cells were obtained from Swiss mice, and hematopoietic precursors were differentiated into BMDCs using GM-CSF and IL-4. On the 7th day, BaV and LPS were introduced into the culture, and the cells were analyzed 24 h later. BaV's ability to stimulate BMDC maturation was assessed through the analysis of surface marker expression. The findings demonstrated that BMDCs are highly influenced by culture environment factors, such as GM-CSF and IL-4, and are sensitive to additional stimuli like LPS and BaV. Mature DCs exhibited elevated levels of critical markers for T cell activation, such as MHC-II, CD80, and CD86, displaying specific phenotypic characteristics. However, the observed reduction in MHC-II and CD86 expression following BaV exposure suggests a substantial impact on the immunological activation capacity of these cells, potentially interfering with the adaptive immune response. Furthermore, the selective release of cytokines, such as IL-6, but not TNF-α or IL-1β, indicates differentiated modulation of inflammatory responses by DCs under various stimulation conditions.</div></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142405899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"New Techniques and Tools for Mosquito Control.","authors":"Rui-De Xue, Tong-Yan Zhao, Chun-Xiao Li","doi":"10.1016/j.actatropica.2024.107425","DOIUrl":"10.1016/j.actatropica.2024.107425","url":null,"abstract":"","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142399094","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Adaptation and Carry Over Effects of Extreme Sporadic Heat Stress in Culex Mosquitoes.","authors":"","doi":"10.1016/j.actatropica.2024.107417","DOIUrl":"10.1016/j.actatropica.2024.107417","url":null,"abstract":"<div><div>Mosquitoes, as temperature-sensitive ectothermic vectors, exhibit temperature-dependence. This study investigates <em>Culex pipiens pallens (Cx. pallens</em>) responses to abrupt temperature increases and their implications on mosquito physiology.</div><div>First instar larvae (24hr post hatching) and newly enclosed adults (24hr post emergence) were separately exposed to heat shock regimes of 33°C, 37°C, and 42°C for 3 days alongside a control temperature of 27°C. Results showed that mortality was triggered at 42°C within a day. Adult male mosquitoes were less tolerant to all temperatures than larvae and adult females (<em>p &lt; 0.05</em>). Exposing larvae to constant temperatures for 3 days significantly decreased larvae's development time, growth rate and adult emergence (<em>p</em> &lt; <em>0.05</em>). Reproductive fitness was significantly reduced (<em>p &lt; 0.05</em>) in males emerging from larvae exposed to 37°C. Life table parameters showed significant increased mortality rate, kill power and decreased life expectancy at the embryonic stage (<em>p &lt; 0.05</em>). Furthermore, heatwaves deactivated the Transient receptor protein ankyrin 1 at 37°C (<em>p</em> &lt; <em>0.05</em>) in larvae but not adults. Calmodium, Heat shock protein 90, and small heat shock protein expression were significantly decreased in larvae at 37°C (<em>p &lt; 0.05</em>) as compared to larvae raised at 33°C and 27°C.</div><div>In conclusion, we classified the heat waves into three categories: adaptable (33°C), critical (37°C), and fatal (42°C). Prolonged exposure of <em>Culex pallens</em> larvae to extreme heat affects the male reproductive output. These findings may serve as an important reference for forecasting vector and pest dynamics and used to tailor mosquito prevention and control measures.</div></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142387157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Global prevalence of Cryptosporidium andersoni in dairy cattle: A systematic review and meta-analysis","authors":"","doi":"10.1016/j.actatropica.2024.107427","DOIUrl":"10.1016/j.actatropica.2024.107427","url":null,"abstract":"<div><div><em>Cryptosporidium</em> spp. are apicomplexan parasites commonly found in the gastrointestinal tracts of humans and in a wide range of animals. Infection is prevalent in dairy cattle and results in diarrhea and increased mortality with significant production losses. <em>Cryptosporidium andersoni</em> is commonly seen in asymptomatic adult cattle and has been associated with gastritis, reduced milk yield, and poor weight gain. However, a meta-analysis of <em>C. andersoni</em> infection in dairy cattle globally has not yet been published. We searched databases for studies on the global prevalence of <em>C. andersoni</em> infection in dairy cattle published from January 1, 2000, to December 31, 2022. The prevalence of <em>C. andersoni</em> infection in dairy cattle was estimated using a random effects model. In total, 86 publications from 30 countries were included in the final quantitative analysis. The global prevalence of <em>C. andersoni</em> in dairy cattle was 4.7 % (95 % confidence interval [CI]: 4.5–4.9 %, 2,554/54,627). European dairy cattle had the highest rate of <em>C. andersoni</em> infection at 8.8 % (961/10,944). A univariate meta-regression analysis indicated that the age of cattle (<em>P</em> = 0.002) and sample collection year (<em>P</em> = 0.025) might be sources of heterogeneity. This systematic review suggests that globally, dairy cattle exhibit a low level of <em>C. andersoni</em> infection; however, the geographical distribution of infection is extensive. <em>C. andersoni</em> mainly infects the stomach of cattle and causes no obvious clinical symptoms after infection but is thought to be responsible for reduced milk production. Therefore, subclinical <em>Cryptosporidium</em> infection in dairy cattle is easily overlooked. Cattle with subclinical infections can produce feces containing oocysts that are inadvertently not safely handled, which can then infect healthy dairy cattle and even cause <em>Cryptosporidium</em> infection in dairy cattle breeders. Therefore, prevention of <em>C. andersoni</em> transmission in asymptomatic cattle is an important issue that should not be neglected.</div></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142405900","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phylogenetics and species delimitation of the recluse spider, Loxosceles rufescens (Araneae: Sicariidae) populations invading Bangkok, Thailand","authors":"","doi":"10.1016/j.actatropica.2024.107424","DOIUrl":"10.1016/j.actatropica.2024.107424","url":null,"abstract":"<div><div>The Mediterranean recluse spider, <em>Loxosceles rufescens</em>, has been discovered for the first time inhabiting human dwellings in Bangkok, Thailand. Expeditions across 39 localities revealed five establishments with <em>L. rufescens</em> populations. The highest density was recorded in a storage house on Yaowarat Road, located in the heart of Bangkok's Chinatown, where 315 individuals were found, including adults, juveniles, and spiderlings. This medically significant spider's presence in such a densely populated urban area raises concerns about potential envenomation risks. Thirteen specimens of <em>L. rufescens</em> were extracted for DNA and sequenced for molecular phylogenetic analyses. COI and ITS2 markers were used to investigate relationships within <em>L. rufescens</em> and across available <em>Loxosceles</em> species sequences. Results indicate COI is superior for resolving species-level genetic clusters compared to ITS2. Surprisingly, <em>L. rufescens</em> individuals from the same house were found in significantly distant COI lineages, suggesting mtDNA may not be suitable for studying intra-specific phylogeography in this case. Species delimitation methods ABGD and ASAP demonstrated promising results for both COI and ITS2, while bPTP and GMYC tended to overestimate species numbers. ITS2 exhibited high sequence similarity in <em>L. rufescens</em>, suggesting potential utility as a barcoding marker for identification of this globally distributed species. Genetic distance analyses revealed a potential barcoding gap (K2P) of 8–9 % for COI and &lt;2 % for ITS2 in <em>Loxosceles</em>. This study contributes valuable sequence data for the medically important genus <em>Loxosceles</em> and highlights the need for integrative approaches in understanding its evolution and spread. The findings have important implications for pest management strategies and public health in urban environments.</div></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142379866","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}