High Predatory Capacity of a Novel Arthrobotrys oligospora Variety on the Ovine Gastrointestinal Nematode Haemonchus contortus (Rhabditomorpha: Trichostrongylidae)

With the worldwide development of anthelmintic resistance, new alternative approaches for controlling gastrointestinal nematodes in sheep are urgently required. In this work, we identified and characterized native nematode-trapping fungi. We collected seven isolates of fungi with the capacity to form adhesive, three-dimensional networks as the main mechanism to capture, kill, and consume nematodes. The nematode-trapping fungi were classified into two groups; the first group includes the R2-13 strain, showing faster growth, abundant aerial hyphae, scarce conidia production, bigger conidia, and it formed a clade with Arthrobotrys oligospora sensu stricto. The second comprises the A6, A12, A13, R2-1, R2-6, and R2-14 strains, showing a growth adhering to the culture medium, forming little aerial hyphae, smaller conidia, and these formed a sister clade to A. oligospora. Except for the R2-6 strain, conidia production was induced by light. In all the strains, the predatory capacity against the sheep gastrointestinal nematode Haemonchus contortus was greater than 58% compared with the control group. The A6 and A13 strains were the most active against the infective H. contortus third instar (L3) larvae, with an average capture capacity of 91%. Altogether, our results support evidence for a novel A. oligospora variety with high nematode-trapping activity and promissory in helminthic controlThis research was funded by FONDEC-UAQ-2019 (Fondo para el desarrollo del Conocimiento—Universidad Autónoma de Querétaro, FNB202002) to E.U.E.N.S

The nematode Caenorhabditis elegans as a model to assess the anthelmintic potential from plant extracts

"Los nematodos parásitos afectan la productividad pecuaria, dando lugar a pérdidas económicas considerables. Sin embargo, son pocos los antihelmínticos disponibles en el mercado y la resistencia de los parásitos a los existentes va en incremento, por lo que su control es actualmente ineficiente. En este sentido, la búsqueda de nuevas estrategias para controlar la parasitosis es una necesidad actual. Una posibilidad para el control estriba en la investigación de metabolitos derivados de plantas, ya que el conocimiento sobre su uso tradicional es un referente de inicio. Sin embargo, la eficacia antihelmíntica, así como los mecanismos de acción de plantas con uso tradicional como anti-parasitarios, poco se han investigado científicamente, y en la mayoría de los casos se desconocen los compuestos activos responsables del efecto anti-parasitario. Una de las limitantes del estudio experimental del potencial antihelmíntico es la dificultad de trabajar con modelos parásitos. En este sentido, el nematodo de vida libre C. elegans es un modelo útil para entender el mecanismo de acción de drogas antihelmínticas. Por un lado, este nematodo se puede mantener y manipular en laboratorio con facilidad; por otro, comparte características fisiológicas y homología genética con nematodos parásitos, lo que permite comparaciones válidas. En esta revisión se pretende mostrar el potencial de la búsqueda de compuestos activos derivados de plantas tradicionalmente utilizadas como anti-parasitarios como punto de partida en el desarrollo de nuevos fármacos antihelmínticos, así como resaltar las ventajas que C. elegans proporciona para entender los mecanismos de acción de nuevos compuestos.""Parasitic nematodes affect livestock productivity, leading to economic losses. Despite their importance, few anthelmintics have been developed and several parasites have developed resistance to them, rendering control of parasitic infections very inefficient. In this sense, the search for new strategies to control parasitic nematodes is timely and relevant. One possibility is to conduct research on metabolites derived from plants with anthelmintic potential, since knowledge about its traditional use is a good starting point. However, the anthelmintic efficacy and mechanisms of action of plants traditionally used, have been scarcely investigated, and the bioactive compounds responsible for the effects remain mostly unknown. One of the limitations that experimental studies on potential anthelmintic face is the difficulty of working with parasite models. In this respect, the free-living nematode C. elegans is a useful tool for understanding the mechanism of action of anthelmintic drugs as well as mechanisms of resistance. First, C. elegans can be maintained and easily manipulated in the laboratory; in addition, C. elegans shares physiological characteristics and has genetic homology with nematode parasites, allowing valid comparisons. This review aims to underscore the potential of finding active compounds derived from plants traditionally used as anthelmintic as a starting point in the development of new drugs, as well as highlight the benefits that C. elegans provides for understanding mechanisms of action of novel anthelmintic.

A Systematic Review on the Role of Wildlife as Carriers and Spreaders of <i>Campylobacter</i> spp.

Campylobacter spp. are important zoonotic pathogens and can cause one of the main bacterial diarrheal diseases worldwide. Research in the context of infection arising from transmission from other humans and other vertebrates has been extensive. A large fraction of these investigations has focused on domestic animals; however, there are also a number of publications which either totally, or at least in part, consider the role of wild or feral animals as carriers or spreaders of Campylobacter spp. Here, we carry out a systematic review to explore the role played by wild vertebrates as sources of Campylobacter spp. with a compilation of prevalence data for more than 150 species including reptiles, mammals and birds. We found that numerous vertebrate species can act as carriers of Campylobacter species, but we also found that some host specificity may exist, reducing the risk of spread from wildlife to domestic animals or humans

Prevalence of fleas and gastrointestinal parasites in free-roaming cats in central Mexico.

The prevalence of fleas and gastrointestinal parasites in free-roaming and domestic cats in central Mexico was evaluated. Three hundred and fifty eight cats captured in the street or brought in by owners to the Animal Control Center Unit, a unit of State Government, from June 2010 to May 2011, were included in the study. All cats were examined for the presence of fleas and gastrointestinal worms. One-hundred and ninety (53%) cats were infested with at least one flea species. Single infestations were observed in 106 (30%) cats and mixed infestations in 84 (23%) cats. Four species of fleas were recovered: Ctenocephalides felis in 53% of the cats, C. canis in 18%, Echidnophaga gallinacea in 7% and Pulex irritans in 1%. One-hundred and sixty three (45%) cats were infected with one or more species of gastrointestinal parasites: 48 (13%) with nematodes, 145 (40%) with cestodes, and one animal presented Moniliformis moniliformis. Prevalences and mean intensity of infection were: Physaloptera praeputialis 7 and 18; T. cati 3 and 2; Ancylostoma tubaeforme 2.5 and 2; Toxascaris leonina 0.5 and 2; Dipylidium caninum 36 and 32; Taenia taeniformis 4 and 3 and Moniliformis moniliformis 0.3 and 106, respectively. There was significant association (P<0.01), between season and ectoparasites load, more fleas were obtained in the summer and autumn than in the winter and spring; however, no statistical difference was observed for endoparasites load (P>0.05). The correlation between the total number of ectoparasites and endoparasites was not significant (r = 0.089, P = 0.094)

Gap Analysis of the Habitat Interface of Ticks and Wildlife in Mexico

Mexico is a highly diverse country where ticks and tick-borne diseases (TBD) directly impact the health of humans and domestic and wild animals. Ticks of the genera Rhipicephalus spp., Amblyomma spp., and Ixodes spp. represent the most important species in terms of host parasitism and geographical distribution in the country, although information on other genera is either limited or null. In addition, information regarding the influence of global warming on the increase in tick populations is scarce or nonexistent, despite climate conditions being the most important factors that determine tick distribution. In order to aid in the management of ticks and the risks of TBD in humans and domestic animals in Mexico, an analysis was conducted of the gaps in information on ticks with the purpose of updating the available knowledge of these ectoparasites and adapting the existing diagnostic tools for potential distribution analysis of TBD in wildlife. These tools will help to determine the epidemiological role of wildlife in the human&ndash;domestic animal interface in anthropized environments in Mexico

Immunization of cattle with a Rhipicephalus microplus chitinase peptide containing predicted B-cell epitopes reduces tick biological fitness

Rhipicephalus microplus, the cattle fever tick, is the most important ectoparasite impacting the livestock industry worldwide. Overreliance on chemical treatments for tick control has led to the emergence of acaricide-resistant ticks and environmental contamination. An immunological strategy based on vaccines offers an alternative approach to tick control. To develop novel tick vaccines, it is crucial to identify and evaluate antigens capable of generating protection in cattle. Chitinases are enzymes that degrade older chitin at the time of moulting, therefore allowing interstadial metamorphosis. In this study, 1 R. microplus chitinase was identified and its capacity to reduce fitness in ticks fed on immunized cattle was evaluated. First, the predicted amino acid sequence was determined in 4 isolates and their similarity was analysed by bioinformatics. Four peptides containing predicted B-cell epitopes were designed. The immunogenicity of each peptide was assessed by inoculating 2 cattle, 4 times at 21 days intervals, and the antibody response was verified by indirect ELISA. A challenge experiment was conducted with those peptides that were immunogenic. The chitinase gene was successfully amplified and sequenced, enabling comparison with reference strains. Notably, a 99.32% identity and 99.84% similarity were ascertained among the sequences. Furthermore, native protein recognition was demonstrated through western blot assays. Chitinase peptide 3 reduced the weight and oviposition of engorged ticks, as well as larvae viability, exhibiting a 71% efficacy. Therefore, chitinase 3 emerges as a viable vaccine candidate, holding promise for its integration into a multiantigenic vaccine against R. microplus

Immunomolecular Characterization of MIC-1, a Novel Antigen in Babesia bigemina, Which Contains Conserved and Immunodominant B-Cell Epitopes that Induce Neutralizing Antibodies

Babesia bigemina is one of the most prevalent species causing bovine babesiosis around the world. Antigens involved in host cell invasion are vaccine targets for this disease but are largely unknown in this species. The invasion process of Babesia spp. into erythrocytes involves membrane proteins from the apical complex. A protein stored in the micronemes, called Micronemal Protein 1 (MIC-1), contains a sialic acid binding domain that participates in the invasion process of host cells and is a vaccine candidate in other apicomplexan parasites. It is not known if there is a homologous gene for mic-1 in B. bigemina. Therefore, the aim of this study was to characterize the mic-1 gene homologue in Babesia bigemina. A gene was found with a microneme adhesive repeat (MAR) domain in the predicted amino acid sequence. Transcription was determined by reverse transcription polymerase chain reaction (RT-PCR). Subsequently, antibodies against peptides containing conserved B-cell epitopes were used to confirm the expression of MIC-1 in intraerythrocytic merozoites. The presence of anti MIC-1 antibodies in cattle naturally infected with B. bigemina was determined and up to 97.4% of the cattle sera (113 out of 116) identified MIC-1 using enzyme-linked immunosorbent assay (ELISA) methods. Finally, antibodies against MIC-1 were able to block 70% merozoite invasion in-vitro

Prevalence of unique and mixed helminth infection recovered in domestic and stray cats in central Mexico.

<p>Prevalence of unique and mixed helminth infection recovered in domestic and stray cats in central Mexico.</p