Background: Insecticide resistance in Anopheles gambiae threatens malaria control. This study evaluated biosynthesized silver nanoparticles (AgNPs) derived from the endophytic fungus Aspergillus niger for their effects on mosquito feeding behavior, resistance-associated gene expression, and permethrin susceptibility. Methods: AgNPs were biosynthesized using cell-free extracellular metabolites of an A. niger isolate and characterized by ultraviolet–visible spectroscopy, transmission electron microscopy (TEM), dynamic light scattering, zeta-potential analysis, and Fourier-transform infrared spectroscopy. The nanoparticles were predominantly spherical, with mean TEM and hydrodynamic diameters of 25.6 ± 4.2 and 28.3 ± 5.1 nm, respectively, a polydispersity index of 0.21, and a zeta potential of −32.4 ± 2.8 mV. Adult A. gambiae were exposed to 0.1, 0.5, and 1.0 mg/L AgNPs. Results: AgNP exposure significantly and concentration-dependently delayed host-seeking, reduced feeding success and blood-meal volume, and decreased responsiveness to a standardized human-odor stimulus ( p < 0.001). Expression of the resistance-associated genes Cyp6m2 , Cyp6p3 , and Ace1 decreased by up to 71%, 66%, and 59%, respectively ( p < 0.001). Permethrin-induced mortality increased from 45.8 ± 5.1% in controls to 89.3 ± 4.2% at the highest AgNP concentration, indicating enhanced permethrin-associated mortality but not restoration of full susceptibility. Conclusions: Biosynthesized AgNPs altered behavioral and selected molecular endpoints and enhanced permethrin-associated mortality in resistant A. gambiae under controlled laboratory conditions. These findings provide laboratory-scale evidence supporting further investigation of fungal-derived AgNPs as potential adjuncts to vector control. However, operational effectiveness, environmental persistence, nontarget effects, ecological safety, and effects on malaria transmission were not evaluated and require validation in mechanistic, semifield, ecological, and field studies.
Background: A rapid and easy-to-use diagnostic tool is essential for the accurate diagnosis of malaria. Recombinase polymerase amplification (RPA) is well suited for on-site detection due to its rapid turnaround, high sensitivity, and operation at low temperatures. However, result visualization commonly relies on fluorescence probes, which require specialized equipment, or lateral flow strips, which add to the overall assay cost. Methods: In this study, we developed a hydroxynaphthol blue (HNB)-based RPA assay for the visual detection of Plasmodium knowlesi . As well, we attempted to performed RPA without DNA isolation via a commercial kit. This method utilizes a simple DNA preparation method involving dilution and heat treatment of whole blood, eliminating the need for commercial DNA extraction kits. The entire extraction process was completed in less than 10 mins. Within 20 mins of incubation at 37°C, amplification was confirmed by a visible color change, enabling simple, equipment-free interpretation. Results: The assay demonstrated high analytical sensitivity, with a limit of detection of 0.005 parasites/µL. No cross-reactivity was observed with other Plasmodium species, indicating high specificity of the HNB-RPA assay. Conclusions: This assay provides a rapid, sensitive, and cost-effective diagnostic approach, suitable for resource-limited and field settings.
Background: Utilizing Wolbachia for mosquito biocontrol requires baseline understanding of natural infection dynamics, lineage diversity, and host-symbiont phylogenetic concordance across native vector populations. Methods: We collected 2,167 adult mosquitoes ( Anopheles , Culex , Aedes , and Mansonia ) across five districts in central India (Madhya Pradesh and Chhattisgarh). Specimens were screened in 263 genus-level pools via wsp PCR. Positive pools were brought to individuals level, typed across three different loci ( ftsZ , gltA , and GroEL ) of Wolbachia spp., and validated by mosquito barcoding ( cox1 , ITS2). Maximum likelihood phylogenies were constructed for all six loci both for Wolbachia (four) and mosquitoes (two). Results: Overall, 27 pools (10.26%) and 49 individuals (21.21%) were wsp -positive that includes 17 Anopheles , 18 Culex , 9 Aedes , and 5 Mansonia . Culicines exhibited robust multilocus amplification, whereas all 17 Anopheles failed to amplify at ftsZ , gltA , and GroEL . Phylogenetic trees of the mosquito-host cox1 and ITS2 resolved all four genera and five wsp -positive Anopheles species into monophyletic clades with 84–100% bootstrap support. In Wolbachia phylogenies, culicine isolates clustered in Supergroup B ( w Pip), with ftsZ and gltA trees resolving Mansonia symbionts into a well-supported, distinct lineage (95–97% bootstrap). Crucially, the wsp tree revealed that four An. annularis sequences formed a monophyletic clade (89–98% bootstrap), clustering with the bat-fly endosymbiont Penicillidia jenynsii rather than mosquito-adapted strains. Primary malaria vectors ( An. culicifacies and An. fluviatilis ) tested negative for Wolbachia . Conclusions: Phylogenetic divergence and housekeeping gene dropout indicate that wsp detection in wild Anopheles represents transient or horizontal acquisition rather than stable intracellular endosymbiosis. Multilocus phylogenetic validation is critical prior to deploying symbiont-based biocontrol.
Onchocerca lupi is a zoonotic nematode primarily affecting dogs, rarely causing human ocular infections. This report presents a rare case of human ocular O. lupi infection from Türkiye with a distinct clinical feature. A 19-year-old woman presented with a 2-week history of redness in her right eye. Examination revealed a subconjunctival nodule in the superotemporal quadrant. Orbital MRI showed a heterogeneous hypointense lesion in the right upper eyelid. Following an excisional biopsy and topical treatment, symptoms partially regressed, and the patient was monitored. One year later, she returned with recurrent hyperemia and mucopurulent discharge. During a conjunctival swab collection, a subconjunctival nematode was observed and extracted. Microscopic analysis confirmed adult O. lupi morphology, showing a multilayered cuticle with undulating annular ridges. This case contributes valuable insights into the literature regarding recurrent nodular presentation and delayed spontaneous extrusion.
Background: Cat-associated pathogens transmitted by arthropods are of global public and veterinary health importance. Cats, as well as dogs, have historically coexisted with humans in rural and urban environments. However, studies on microorganisms associated with cats are much less extensive than those on dogs. Materials and Methods: Therefore, the present study aims to document natural infections of Anaplasma , Bartonella , Ehrlichia , and Rickettsia in cats ( Felis catus ) using PCR in northeastern Mexico. Blood samples were collected from cats with the support of the Canine and Feline Control Centers and veterinary clinics. Specific pathogens were amplified by PCR, and some positive samples were sequenced. Results: A total of 250 cats were obtained from three municipalities in Nuevo Leon, Mexico. Specific PCR testing showed that 33.6% (84/250) cats tested positive for at least one of the pathogens. The overall natural pathogen infection rates were Ehrlichia with 20.8% (52/250), followed by Anaplasma with 8% (20/250), Bartonella with 3.2% (8/250), and Rickettsia with 1.6% (4/250). Phylogenetic analysis placed the Bartonella sequence within a well-supported B. quintana clade . The partial 16S rRNA sequence obtained from Ehrlichia was conservatively classified as Ehrlichia sp. closely related to E. chaffeensis . Conclusion: These findings document exposure or infection of cats with multiple arthropod-borne bacteria and support continued molecular surveillance using additional discriminatory loci.
