Jiangsu Institute of Parasitic Diseases

Half of the world's population is at risk of malaria infection, and artemisinin (ART) turns out to be a powerful medicine for malaria control. The rapid emergence and global spread of resistance to ART have led to a significantly increasing clinical treatment failure rate worldwide. A critical limitation of ART is its extremely short blood half-life (~1 h), which results in rapid declines in plasma drug concentrations below therapeutic thresholds. Some parasites may switch into a "dormant" form, which is less sensitive to ART, resulting in recrudescence following treatment. Thus, developing a sustained-release formulation provides a promising solution to prolong the in vivo half-life of ART. Additionally, its relatively low solubility restricts its in vivo bioavailability, primarily due to the limited dissolution and absorption of the compound in aqueous biological environments. In this study, we prepared a zein-based sustained-release formulation of ART for oral and intraperitoneal administration. Our results indicate that this zein-based sustained release nanoformulation not only significantly improves ART's water solubility (a key barrier to its bioavailability) but also extends its in vivo half-life via controlled drug release. Importantly, the prolonged half-life ensures sustained therapeutic ART concentrations, directly enhancing the formulation's ability against ART-resistant P. falciparum strains. Collectively, these results highlight the formulation's substantial potential for clinical application in improving ART-based antimalarial therapy.

The endophytic Streptomyces sp. PRh3 (PRh3), isolated from Dongxiang wild rice (DXWR), exhibited impaired biosynthetic capacity in the laboratory. To address this defect, rifampicin-based ribosome engineering was first applied to PRh3 to generate PRh3-r55, which acquired a characteristic H473Y rifampicin-resistant mutation in rpoB to activate the production of two β-carboline alkaloids JBIR-133 and JBIR-134. Then the biosynthetic gene cluster (BGC) ksl was introduced into PRh3-r55 for heterologous expression, generating PRh3-r55K. This combined approach achieved a synergistic effect, enabling the strain to produce not only the expected JBIR-133, JBIR-134, and kitasetaline, but also a novel sulfur-containing molecule, novkitasetaline. Structural elucidation identified novkitasetaline as a unique tryptamine-substituted kitasetaline derivative at the C-3 position of its pyridine ring. Notably, this structural modification conferred significant antimalarial activity to novkitasetaline, rendering it active against drug-sensitive Plasmodium falciparum 3D7 (IC50 = 32.65 ± 2.93 μM) and three other drug-resistant P. falciparum strains: K13C580Y, Dd2, and HB3 (IC50 = 45.98 ± 4.17~59.67 ± 3.15 μM), primarily by disrupting late-stage parasite development. These efforts not only identified a promising antimalarial lead compound but also demonstrated that combining ribosome engineering with heterologous expression is an effective strategy for discovering bioactive natural products from Streptomyces.

Before adopting a new hematology analyzer in clinical laboratories, evaluating its platelet counting performance is critical. To assess the analytical performance of impedance (PLT-I), hybrid (PLT-H), and optical (PLT-O) platelet counts on the novel Mindray BC-7800 (BC-7800) and to compare platelet parameters obtained from the BC-7800 and Sysmex XN-3000 (XN-3000), including PLT-I, PLT-O, and PLT-F (optical fluorescent platelet count using oxazine dye), against the international reference method (IRM) in specimens with platelet interferences. Analytical parameters of the BC-7800, including limit of blank, linearity, reproducibility, and carryover, were evaluated. Interference testing included 126 specimens with red blood cell (RBC) microcytosis and 21 specimens from patients with blasts. Diagnostic performance against the IRM was assessed at platelet transfusion thresholds of 10 × 103/µL and 20 × 103/µL. The BC-7800 met acceptable criteria for most basic parameters, except within-run precision for PLT-I and PLT-H in some thrombocytopenic specimens. In RBC microcytosis, all methods showed strong correlations with the IRM, though PLT-I exhibited proportional bias. In leukemia specimens, PLT-O from the BC-7800 and PLT-F from the XN-3000 showed the strongest agreement with the IRM, while PLT-H and PLT-O from the XN-3000 exhibited systematic bias. Specificity and positive predictive value were excellent across all methods. Sensitivity, negative predictive value, and accuracy were highest for PLT-O from the BC-7800 and PLT-F. The BC-7800 demonstrated reliable platelet analysis, particularly with PLT-O in thrombocytopenic and interference-prone specimens. PLT-H and optical fluorescent platelet methods showed strong reliability in specimens with RBC microcytosis, while PLT-O from the BC-7800 and PLT-F offered the highest accuracy for guiding platelet transfusion decisions.

Chemical insecticides have been the primary method of mosquito control, but in recent years, mosquitoes have become resistant to these compounds. Metarhizium fungi are emerging as promising alternatives and can kill mosquitoes with a small number of spores. It was previously shown that caterpillars affected by fungal infections can attract mosquitoes. However, the mechanisms and potential applications of this attraction are lacking. Here we show that Metarhizium-colonized insect cadavers release the volatile longifolene to attract and infect healthy insects, facilitating spore dispersal. We identified the responsible odorant receptors in Drosophila melanogaster and Aedes albopictus. The virulent mosquito pathogen Metarhizium pingshaense was engineered to express pine longifolene synthase to produce a large amount of longifolene on media. The transgenic spores effectively attracted and killed male and female A. albopictus, Anopheles sinensis and Culex pipiens. Attraction of wild-caught mosquitoes was not impacted by human presence, but mosquito-attracting flowering plants competed with transgenic M. pingshaense for attractiveness, although mortality remained over 90%. This study uncovered an active spore dispersal mechanism in broad-host-range entomopathogenic Metarhizium, enhancing mosquito control efficacy.

Background: TIM-1-positive regulatory B cells (TIM-1+Bregs) are important modulators of immune responses and influence the liver’s immune microenvironment. However, their role in hepatic alveolar echinococcosis (HAE) is not well understood. This study

Asian hepatointestinal schistosomiasis due to Schistosomajaponicum is prevalent in the Philippines and in Indonesia, while it is close to elimination in China. The second Asian schistosome, S.mekongi, is found in Cambodia and Laos. The main pathology caused by both species is liver fibrosis, which can cause significant morbidity and mortality, mainly due to portal hypertension leading to bleeding from esophageal varices. Ultrasonography was introduced several decades ago as a safe, fast, non-invasive, and relatively inexpensive technique for assessing chronic schistosomiasis-related hepatic pathology in the clinical and field settings. A standardized ultrasound protocol had been established by experts at a WHO-chaired meeting in Cairo, Egypt, in 1990. The peculiarities of sonomorphologic abnormalities caused by S.japonicum and S.mekongi were not sufficiently covered in the Cairo protocol and not addressed at all in the subsequent WHO chaired meeting in Niamey 1996. At a follow-up WHO-chaired meeting in Phnom Pehnh, Cambodia, in 2002, an attempt was made to develop a protocol for Asian schistosomiasis, but a protocol resulting from this meeting has never been published. Although several studies investigated the use of ultrasonography to assess S.japonicum- and S.mekongi-related sonomorphological morbidity across endemic areas the lack of a standardized protocol hampered the characterization of sonomorphologic abnormalities with regard to progression, reversibility, prognosis, and correlation to morbidity. In addition, the comparison of data from different endemic areas and populations remained difficult. Therefore, a WHO-chiared expert meeting took place in Basel, Switzerland in September 2024 with the aim to establish a standardized ultrasound protocol for reporting the pathology caused by S.japonicum and S.mekongi. The proposed protocol is described in this article.Graphical Supplementary InformationThe online version contains supplementary material available at 10.1186/s40249-025-01349-x.

The causative agent of Chagas disease (Trypanosoma cruzi) is transmitted to mammals, including humans, mainly by insect vectors of the subfamily Triatominae (Hemiptera: Reduviidae). Also known as “kissing bugs”, the subfamily currently includes 159 species in 18 genera and five tribes. Although the majority of the species are distributed in the Americas, here we present the first comprehensive compilation of Non-American triatomine occurrences to complement the American triatomine information, representing together the most complete and integrated database available to date at a global scale. The data (396 records) corresponds to 16 species of the genera Linschosteus and Triatoma from Africa, Asia and Oceania between the years 1926 and 2022, including verified records with associated geographic coordinates, collection dates, and ecological information. Data were gathered through a systematic review of published literature and colleague-provided data, validated through expert consultation. The most important novelties refer to (i) temporal and geographical Non-American species records updates, (ii) current records of T. rubrofasciata found hundreds of kilometers inland (opposite to the historical data only in port areas), and (iii) geographical records of the two last described species of Triatoma (T. atrata and T. picta). This resource aims to support global surveillance efforts by offering evidence of potential vector presence in non-endemic vectorial transmission regions. The dataset may inform ecological niche modeling, risk assessment, and public health strategies, contributing to a broader understanding of the global distribution of vectors and to entomological surveillance implicated in Chagas disease outside the Americas.

Schistosomiasis remains a critical public health challenge in endemic regions, particularly among school-aged children. Despite global efforts, conventional health education approaches show limited success in translating knowledge into sustained practices change. This study evaluates the efficacy of two innovative educational approaches—curriculum-integrated infiltration and stepwise progressive approaches—compared to traditional methods in enhancing schistosomiasis-related knowledge, attitudes, and practices (KAP) among students. A school-based intervention was conducted in Duchang County’s Zhouxi township, with is an area afferted by schistosomiasis in China. Sixth-grade students (n ≈ 300) were divided into three groups: a traditional intervention group receiving standard WHO-aligned lectures, an infiltration group with cross-disciplinary curriculum integration, and a stepwise group with modular, tiered content. KAP outcomes were assessed via validated questionnaires at baseline and post-intervention. Both intervention groups demonstrated significant knowledge gains compared to traditional intervention (post-intervention accuracy: infiltration 89.67%, stepwise 91.10%, traditional intervention 86.50%; P < 0.001). Practices knowledge showed the most significant improvement (41.47% increase in the infiltration group vs. 22.38% in traditional intervention). The stepwise approaches achieved the highest overall accuracy (91.10%) but showed no statistically significant advantage over the infiltration approach (P > 0.05). Attitudinal improvements were consistent across groups, with high baseline rates limiting further gains (post-intervention: 95.60–96.68%). Curriculum-integrated and stepwise approaches effectively address the knowledge-practices gap in schistosomiasis education. The infiltration strategy, requiring minimal resources, is ideal for practices reinforcement in low-resource settings, while the stepwise approach suits rapid knowledge dissemination in well-resourced areas. These findings advocate for context-adaptive, multisectoral frameworks to optimize school-based interventions, aligning with WHO goals for neglected tropical disease elimination.

BackgroundNaegleria fowleri, a pathogenic free-living amoeba, causes primary amoebic meningoencephalitis (PAM), a rare but devastating disease with acute onset, rapid progression, and > 95% mortality. Despite its rarity, the catastrophic outcomes associated with this infection underscore the critical importance of prevention. In this report, we present a rare pediatric fatality caused by PAM in China, highlighting the challenges of diagnosis and treatment.Case presentationA 6-year-old child from Lushan County, Henan Province, developed persistent high fever, headache, vomiting, and altered mental status on December 5, 2024. After receiving ineffective local treatment, the child was transferred to the Eastern District of Henan Children’s Hospital on December 7 for further evaluation and management. Upon admission, cerebrospinal fluid was collected for laboratory analysis, and antimicrobial therapy, including amphotericin B, fluconazole, and rifampicin, was promptly initiated. Despite these interventions, the patient’s condition deteriorated rapidly, and the child succumbed to the infection on December 9.ConclusionsClinical and laboratory findings strongly suggest that the child was infected with N. fowleri, resulting in PAM. Epidemiological investigation suggests possible exposure at a public bathhouse. Given the survival characteristics of the N. fowleri and potential habitat expansion due to global warming, this sporadic case underscores PAM's lethal potential. With mortality exceeding 95%, early recognition and prompt intervention are crucial. Clinicians should maintain high suspicion for PAM in patients with compatible symptoms, especially in regions with warm freshwater exposure.Supplementary InformationThe online version contains supplementary material available at 10.1186/s40249-025-01347-z.