Feeding-Induced Changes of Bacteriolytic Activity and the Pattern of Bacteriolytic Compounds in the Stomach and Small Intestine of the Haematophagous Bug Triatoma infestans (Klug, 1834) (Reduviidae, Triatominae)

Intestinal homeostasis mechanisms of the haematophagous triatomines regulate the development of mutualistic symbionts and other gut bacteria. Investigating antimicrobial compounds of these insects, we have determined spectrophotometrically that the bacteriolytic activity is between pH 3 and pH 9 using homogenates of fifth instar Triatoma infestans stomachs and small intestines from unfed bugs and up to 50 days after feeding. The activity against Gram-positive Micrococcus luteus was strongest at pH 4 and pH 7 and was higher in the stomach than in the small intestine. Symbiotic Rhodococcus triatomae were not lysed. Lysis of Gram-negative Escherichia coli showed a maximum at pH 7 in the stomach and at pH 5 in the small intestine. Bacteriolytic activity against both M. luteus and E. coli was reduced 24 h after feeding, then increased, and at 50 days after feeding was strongly reduced. In zymographs, the activity against M. luteus was mainly correlated to proteins of about 16 kDa. At different periods of time after feeding, seven bands of lysis appeared between 15 and 40 kDa and more bands using extracts of the small intestine than those of the stomach. This is the first proof for the synthesis of antibacterial proteins of 22–40 kDa in triatomines.

A Novel Gonadotropic Microsporidian Parasite (Microsporidium clinchi n. sp.) Infecting a Declining Population of Pheasantshell Mussels (Actinonaias pectorosa) (Unioinidae) from the Clinch River, USA

Freshwater mussels of the order Unionida are among the most endangered animal groups globally, but the causes of their population decline are often enigmatic, with little known about the role of disease. In 2018, we collected wild adult pheasantshell (Actinonaias pectorosa) and mucket (Actinonaias ligamentina) during an epidemiologic survey investigating an ongoing mussel mass mortality event in the Clinch River, Virginia and Tennessee, USA. Histopathology and transmission electron microscopy showed a novel microsporidian parasite primarily infecting the ovary of pheasantshell. Sequencing of the small subunit rRNA gene produced a 1333 bp sequence with the greatest similarity to Pseudonosema cristatellae (AF484694.1; 86.36%; e-value = 0), a microsporidium infecting the freshwater bryozoan (Cristatella mucedo). Microsporidia were observed in 65% (17/26) of the examined female pheasantshell (A. pectorosa) and in no (0/2) female muckets (A. ligamentina) and occurred at mortality and non-mortality sites. Our findings indicate that a novel parasite, Microsporidium clinchi n. sp., is present in pheasantshell in the Clinch River, and while likely not a cause of mass mortality, could reduce fecundity and recruitment in this declining population and threaten the success of reintroductions. Surveillance of M. clinchi n. sp. and evaluation of broodstock and their progeny for microsporidia would therefore be prudent.

Low Malaria Transmission in Rosso, an Irrigated Rice-Growing Area in Mauritania

The construction of dams along the Senegal River resulted in an increase in irrigated land areas and changes in the epidemiology and transmission of water-related diseases. The objective of this study was to update epidemiological data on malaria in Rosso, one of the major Mauritanian cities along the Senegal River. Febrile patients (n = 318) were screened for malaria using a rapid diagnostic test (RDT) for malaria and microscopic examination of blood smears. Diagnosis was later confirmed by polymerase chain reaction (PCR). The mean age of 318 febrile patients was 25.1 (range 1–80 years). Only 7 (2.2%) and 2 (0.6%) had a positive RDT and thick smear, respectively. PCR confirmed the diagnosis in two Plasmodium vivax-infected patients. Most participants (198/318, 62.3%) had no recent travel history outside Rosso. The majority of the febrile patients (90%, 284/311) owned at least one insecticide-treated net (ITN). The frequency of the use of ITNs was not significantly associated with season (rainy vs. dry seasons; p = 0.9) or with the number of ITNs per household (rs = 0.07; n = 285; p = 0.19). Of 285 individuals with ITNs, only two (0.7%) with no travel history were PCR-positive for malaria. Despite the presence of mosquito breeding sites related to rice irrigation, malaria transmission in Rosso remained very low, possibly due to the high coverage and frequent use of bed nets. Regular entomological surveillance for possible changes in the prevalence of Anopheles mosquito species and their behavioural aspects should be implemented.

Vector-Borne Pathogens in Ticks and Fleas of Client-Owned Dogs in Metro Manila, Philippines

Rhipicephalus sanguineus s.l. and Ctenocephalides felis are considered the most prevalent ectoparasites of dogs in the Philippines. Vector-borne pathogens (VBPs) in these ectoparasites pose health risks to humans and animals. This study aimed to confirm the morphological and molecular identity of tick and flea species parasitising dogs in Metro Manila (Philippines) and molecularly investigate the possible presence of Bartonella spp., Rickettsia spp., Ehrlichia canis, and Anaplasma platys DNA. Ticks (n = 58) and fleas (n = 52) on dogs from three veterinary clinics in Metro Manila were collected and identified morphologically and molecularly via amplification and sequencing of cytochrome c oxidase I (cox1). Aliquots of ectoparasite DNA underwent real-time polymerase chain reaction (qPCR) screening for VBPs. All ticks were R. linnaei (formerly R. sanguineus s.l. “tropical lineage”), while all fleas were C. felis from clade 6 of the tropical II cluster/“Cairns” clade known from Australia. DNA of B. clarridgeiae was detected in 10% of fleas. DNA of R. felis was detected in 10% of fleas and in 3.8% of ticks. DNA of E. canis and A. platys was not detected. This study confirmed the presence of ticks and fleas as frequent ectoparasites on dogs and VBP presence emphasises the importance of preventative actions for animal health and welfare.

Molecular Survey of Anaplasmataceae Agents and Coxiellaceae in Non-Hematophagous Bats and Associated Ectoparasites from Brazil

The Anaplasmataceae family (order Rickettsiales) encompasses obligately intracellular bacteria of the genera Anaplasma, Ehrlichia, and Neorickettsia. Together with Coxiella burnetii (Coxiellaceae family, order Legionellales), these bacteria represent important causative agents of diseases in humans and animals. The scarcity of studies that investigated the occurrence of these agents in bats and their associated ectoparasites, emphasizes the need to achieve a better understanding of the role of these animals in the maintenance of such bacteria. Herein, 418 samples (133 blood, 135 spleen, and 150 ectoparasites) are collected from 135 non-hematophagous bats belonging to 12 species in a periurban area of Campo Grande city, Mato Grosso do Sul state, midwestern Brazil. In the results, 1.65% (7/418), 12.04% (50/418), and 13.63% (57/418) of samples are positive in PCR assays for Anaplasma spp. (16S rRNA gene), Ehrlichia spp. (dsb gene), and Neorickettsia spp. (16S rRNA gene), respectively. Anaplasma spp. and Neorickettsia spp. are detected in one (5.26%) Ornithodoros hasei tick larva. Ehrlichia spp. is detected in 14% of bat flies (represented by Megistopoda aranea, Trichobius costalimai, and Strebla hertigi), 6% of tick larvae (O. hasei), 12% of Spinturnicidae mites (represented by Periglischrus sp., P. torrealbai, and P. acutisternus), and 38% of Macronyssidae mites (Steatonyssuss sp.). The obtained sequences are observed to be similar to Anaplasma phagocytophilum (97.42–97.6% identified), Ehrlichia minasensis (96.73–100% identified), Neorickettsia risticii (96.7–100% identified), and Neorickettsia findlayensis (95.07–100% identified) by BLASTn analyses, and closely related to Ehrlichia ruminantium by phylogenetic analyses based on the gltA gene. No bat samples (blood/spleen) are positive in the qPCR assay for C. burnetii based on the IS1111 gene. The present work shows, for the first time, the occurrence of Anaplasmataceae in bats and associated ectoparasites (ticks, mites, and bat flies) from Brazil.

Larvicidal Effect of Vitex ovata Thunb. (Lamiales: Lamiaceae) Leaf Extract towards Aedes (Stegomyia) aegypti (Linnaeus, 1762) (Diptera: Culicidae)

According to the WHO there are more than 700,000 deaths every year involving vector-borne diseases such as malaria, dengue, Chagas disease, yellow fever and Japanese encephalitis. Aedes aegypti, the principal vector of the dengue virus, is of great concern in various parts of the world, especially in tropical and subtropical countries. Vector control through insecticide application is one of the best ways to control the disease’s transmission. Thus, insecticide resistance in Ae. aegypti poses a significant threat to public health worldwide. The use of plant natural product-based insecticides that are less harmful to the environment, and without known resistance development, constitutes an alternative to chemical insecticides. Given this, a methanolic extract from Vitex ovata plants was prepared and tested for its larvicidal effect against Ae. aegypti. A susceptibility test on Ae. aegypti larvae was conducted using the standard WHO method. Results showed that the methanolic extract of V. ovata had larvicidal activity against Ae. aegypti with LC50 values of 2114 mg/L, and achieved 84% mortality with the highest concentration at 10,000 mg/L. This study showed that the crude extract of V. ovata bioactive molecules could be potentially developed as biolarvicides for Aedes mosquito vector control. This study recommends future research on using different solvents in the isolation of active ingredients from V. ovata, identification of phytochemicals with larvicidal properties, a toxicity study and lastly, an evaluation of the effectiveness of controlling Aedes in small-scale field trials for environmentally safe botanical insecticide intervention.

Effects of Methanolic Extract from Turmeric (Curcuma longa) against the In Vitro Multiplication of Several Babesia Species and Theileria equi

Anti-piroplasm drugs currently on the market have proven toxicity to the host and parasite resistance. Plants are possible sources of novel drugs. Subsequently, a novel strategy should be used to find new anti-piroplasm agents that are both effective and safe. In the present study, we have evaluated the effect of turmeric (Curcuma longa) methanolic extract on the in vitro growth of Babesia (B.) bovis, B. divergens, B. caballi, and Theileria (T.) equi. The in vitro inhibitory effectiveness of turmeric was assessed using a fluorescence test. The enhancement in the in vitro inhibitory efficacy of turmeric when administrated in combination with diminazene aceturate (DA) was investigated using in vitro cultures of different piroplasm parasites. Turmeric reduced the in vitro growth of B. bovis, B. divergens, T. equi, and B. caballi with IC50 values of 0.830 0.078, 0.375 0.055, 1.405 0.575, and 0.720 0.090 mg/mL, respectively. An amount of 1 mg/mL turmeric for B. bovis, 0.5 mg/mL turmeric for B. divergens, 1 mg/mL turmeric for T. equi, and 0.5 mg/mL turmeric for B. caballi exhibited 73.43%, 80.065%, 73.47%, and 47.375% inhibitions in the growth of the parasites, respectively. When turmeric was combined with DA, its in vitro inhibitory impact on bovine Babesia and equine Babesia/Theileria parasites was amplified. These findings show that a methanolic extract of turmeric could be a promising medicinal plant for the treatment of babesiosis, especially when administered in conjunction with DA.

The Diagnosis, Treatment, Surveillance and Control of Cystic Echinococcosis in the Province of Rio Negro: The “One-Health” Model

Cystic Echinococcosis (CE) is an endemo-epidemic disease in the Rio Negro Province, República Argentina. Due to the number of cases, the length of hospital stays after surgery and its associated mortality, it is a serious public health problem that generates high costs for the health system. Oriented towards its control, primary prevention activities have been carried out since 1980, based on the deworming of dogs and the vaccination of lambs; secondary prevention has consisted in the actively search for cases through serological or ultrasonographic screening; and tertiary prevention has been based on timely treatment, either by surgery or by medical treatment with albendazole. All these prevention activities have been carried out under the concept and strategies of the “One Health” model, through both inter-institutional and interdisciplinary work, as well as with the support, commitment and critical participation of the community. As a result, an important drop has been observed in the prevalence of CE in humans and in its lethality (0.5% in 1997–2020, no deaths in the last two years); moreover, an important decrease has been observed in costs to the health system, due to the reduction of hospitalizations and the number of surgeries.

Recent Advances in the Control of Helminths of Domestic Animals by Helminthophagous Fungi

This review describes the advances acquired and proven in the use of helminthophagous fungi in the control of gastrointestinal helminth parasites in domestic animals. Old and well-known premises about parasitic epidemiology and the factors that can interfere with the best performance of biological control are mentioned. Some of the most promising fungi are Duddingtonia flagrans from the predatory fungi group and Pochonia chamydosporia and Mucor circinelloides from the ovicidal fungi group. These fungi produce resistance spores called chlamidospores. Bioverm® and BioWorma®, based on the fungus D. flagrans, are available as commercial. Biotechnological products such as nanoparticles and obtaining primary and secondary metabolites have already been obtained from these fungi. Because they have different mechanisms of action, ovicidal and predatory fungi, when used together, can present a complementary and synergistic action in the biological control of helminths. Therefore, future research in the search for new formulations, the association of fungi from different groups, extraction of new molecules, and nanoparticles of these fungi in the control of helminths in various domestic animals are desired.

Micro-Epidemiological Investigation of Echinococcus multilocularis in Wild Hosts from an Endemic Area of Southwestern Hungary

Echinococcus multilocularis is a tapeworm causing severe zoonotic disease in temperate Europe. Between 2018 and 2020, 68 golden jackals and 94 red foxes were investigated to determine the prevalence of E. multilocularis infection and its driving factors. The overall prevalence (golden jackal: 41.2%; red fox: 12.5%) significantly differed, whereas the mean intensities did not. The spatial scan statistics revealed three significant clusters of E. multilocularis infection. The binary logistic and ordinal regression results revealed that the golden jackal is more likely to become infected than the red fox, and the probability of infection level was also higher in jackals. Our findings highlight the golden jackal’s role, which could be as important as the red fox in the spread of this severe zoonotic agent. This micro-epidemiological approach can advance the knowledge on local drivers which facilitate the spread of E. multilocularis and could cause a relevant public health problem on the continent.