Ticks transmit a wide diversity of pathogens to a great variety of hosts, including humans. We conducted a tick surveillance study in northwestern Spain between 2014 and 2019. Ticks were removed from people and identified. Tick numbers, species, development stages, the timeline, seasonal and geographical distribution and epidemiological characteristics of people bitten by ticks were studied. We collected ticks from 8143 people. Nymphs of I. ricinus were the most frequently collected. Rhipicephalus bursa, R. sanguineus s.l., Hy. marginatum, Hy. lusitanicum, D. marginatus, D. reticulatus and H. punctata were also found, with adults as the main stage. The number of collected Hyalomma spp. and R. bursa has been progressively increasing over time. Although bites occurred throughout the year, the highest number of incidents was reported from April to July. The distribution patterns of the tick species were different between the north and the south of the region, which was related to cases detected in humans of the pathogens they carried. Adult men were more likely to be bitten by ticks than women. Ticks were most frequently removed from adults from the lower limbs, while for children, they were mainly attached to the head. Epidemiological surveillance is essential given the increase in tick populations in recent years, mainly of species potentially carrying pathogens causing emerging diseases in Spain, such as Crimean–Congo hemorrhagic fever (CCFH).

Summary: Plasmid conjugation is a major horizontal gene transfer mechanism. The acquisition of a plasmid may cause a perturbation of the cell functions in addition to provide advantageous properties for the recipient cell, such as the gaining of antibiotic resistances. The interplay between plasmid and chromosomal functions has been studied using the IncHI1 plasmid R27. Plasmids of the incompatibility group HI1, isolated from several Gram‐negative pathogens, are associated with the spread of multidrug resistance. Their conjugation is tightly regulated by temperature, being repressed at temperatures within the host (37°C). In this report, we described that at permissive temperature, when conjugation of plasmid R27 is prompted, a reduction in the motility of the cells is observed. This reduction is mediated by the plasmid‐encoded regulators TrhR/TrhY, which together with HtdA form a plasmid‐borne regulatory circuit controlling R27 conjugation. TrhR/TrhY, required to induce R27 conjugation, is responsible for the downregulation of the flagella synthesis and the consequent decrease in motility. TrhR/TrhY repress, direct or indirectly, the expression of the specific flagellar sigma subunit FliA and, consequently, the expression of all genes located bellow in the flagellar expression cascade.

Toxoplasma gondii is a pathogenic protozoan parasite that infects the nucleated cells of warm-blooded hosts leading to an infectious zoonotic disease known as toxoplasmosis. The infection outcomes might be severe and fatal in patients with immunodeficiency, diabetes, and pregnant women and infants. The One Health approach to toxoplasmosis highlights that the health of humans is closely related to the health of animals and our common environment. The presence of drug resistance and side effects, the further improvement of sensitivity and specificity of serodiagnostic tools and the potentiality of vaccine candidates to induce the host immune response are considered as justifiable reasons for the identification of novel targets for the better management of toxoplasmosis. Thus, the identification of new critical proteins in the proteome of Toxoplasma parasites can also be helpful in designing and test more effective drugs, vaccines, and diagnostic tools. Accordingly, in this study we present important proteins found in the proteome of the life cycle-specific stages of Toxoplasma parasites that are potential diagnostic or vaccine candidates. The current study might help to understand the complexity of these parasites and provide a possible source of strategies and biomolecules that can be further evaluated in the pathobiology of Toxoplasma parasites and for diagnostics and vaccine trials against this disease.

Parasitic diseases represent a significant global public health concern. Two clinically important parasites of high prevalence rates are Trichinella spiralis and Strongyloides stercoralis. However, the limitations of currently used nematocidal drugs highlight the urgent need for novel treatment approaches. The present study investigated the in vitro nematocidal activity of methanol extracts from Amphipterygium adstringens, Artemisia ludoviciana, Cymbopogon citratus, Heterotheca inuloides, Jatropha dioica, Justicia spicigera, Larrea tridentata, Mimosa tenuiflora, Psacalium decompositum, Ruta chalepensis, Semialarium mexicanum, and Smilax aspera against T. spiralis L1 and S. venezuelensis L3 (model for S. stercoralis). Most of the plants showed antiparasitic activity, but R. chalepensis crude methanol extract showed the most potent nematocidal activity against both parasites, with a mean lethal concentration (LC₅₀) of 28.2 µg/mL and a selectivity index (SI) of 22.4 for T. spiralis and an LC₅₀ of 244.8 µg/mL and SI of 2.58 for S. venezuelensis. This extract was further separated into n-hexane, chloroform, and methanol partitions by continuous Soxhlet extractions. The n-hexane partition demonstrated the strongest activity against both parasites, with an LC₅₀ of 147.6 µg/mL and an SI of 7.77 against T. spiralis and an LC₅₀ of 39.2 µg/mL and an SI of 3.77 against S. venezuelensis. LC-MS/MS analysis identified coumarins as the main chemical class (53%), and chalepin represented this partition’s most abundant compound (29.9%). Overall, this study confirmed the antiparasitic potential of medicinal plants commonly used in Mexico. In addition, it highlights the possibility of obtaining bioactive compounds from plants like R. chalepensis, or the other plants evaluated in this study, as novel treatments against parasitic diseases.

Background: Schistosomiasis impacts over 230 million people globally, with 251.4 million needing treatment. The disease causes intestinal and urinary symptoms, such as hepatic fibrosis, hepatomegaly, splenomegaly, and bladder calcifications. While praziquantel (PZQ) is the primary treatment, its effectiveness against juvenile stages (schistosomula) is limited, highlighting the need for new therapeutic agents, repurposed drugs, or reformulated compounds. Existing microscopy methods for assessing schistosomula viability are labor-intensive, subjective, and time-consuming. Methods: An artificial intelligence (AI)-assisted culture system using YOLOv5 was developed to evaluate compounds against Schistosoma mansoni schistosomula. The AI model, based on object detection, was trained on 4390 images distinguishing between healthy and damaged schistosomula. The system was externally validated against human counters, and a small-scale assay was performed to demonstrate its potential for larger-scale assays in the future. Results: The AI model exhibited high accuracy, achieving a mean average precision (mAP) of 0.966 (96.6%) and effectively differentiating between healthy and damaged schistosomula. External validation demonstrated significantly improved accuracy and counting time compared to human counters. A small-scale assay was conducted to validate the system, identifying 28 potential compounds with schistosomicidal activity against schistosomula in vitro and providing their preliminary LC₅₀ values. Conclusions: This AI-powered method significantly improves accuracy and time efficiency compared to traditional microscopy. It enables the evaluation of compounds for potential schistosomiasis drugs without the need for dyes or specialized equipment, facilitating more efficient drug assessment.

Ticks drive a wide diversity of pathogens to a great variety of hosts, including humans. We conducted a tick surveillance study in northwestern Spain between 2014 and 2019. Ticks were removed from people and were identified. Tick numbers, species, development stages, evolution over time, seasonal and geographical distribution, and epidemiological characteristics of people bitten by ticks were studied. We collected ticks from 8143 people. Nymphs of Ixodes ricinus were the most frequently collected. Rhipicephalus bursa, Rhipicephalus sanguineus sensu lato (s.l), Hyalomma marginatum, Hyalomma lusitanicum, Dermacentor marginatus, Dermacentor reticulatus and Haemaphysalis punctata were also found, with adults as the main stage. Hyalomma spp. and R. bursa have been progressively increasing over time. Although bites occurred throughout the year, the highest number of incidents were reported from April to July. The distribution patterns of the tick species were different between the north and the south of the region, which was related to cases detected in humans of the pathogens they carried. Adult men were more likely to be bitten by ticks than women. Ticks were most frequently removed from adults from the lower limbs, while for children they were mainly attached to the head. Epidemiological surveillance is essential given the increase in tick populations in recent years, mainly of species potentially carrying pathogens causing emerging diseases in Spain, such as the Crimean Congo Hemorraghic Fever (CCFH).