Parasitologia, Volume 2, Issue 1 (March 2022) – 5 articles

Despite the major impact of Blastocystis sp. in terms of prevalence in human and animal populations and the risk of zoonotic transmission, no epidemiological survey has yet been conducted in cattle herds in France. The aim of this study was thus to assess the prevalence and molecular diversity of Blastocystis sp. and associated factors in dairy cattle from the north of France. A total of 1581 fecal samples were collected from 1246 animals reared in 20 farms. Molecular detection of the protozoan was performed by real-time PCR and indicated an overall prevalence of Blastocystis sp. reaching 54.8% in the study population. Important inter-herd variation (from 22.2% to 76.5%) of Blastocystis sp. prevalence was also reported. Sequence analysis of 159 positive samples highlighted a very large predominance of ST10 (36/159) and ST14 (64/159), and ST2 was only found in 2 samples. Mixed subtype infections were common, representing 35.8% of sequenced samples (57/159). A putative correlation between Blastocystis sp. colonization and various animal and herd characteristics or feed intake was subsequently investigated. The protozoan was less prevalent in cows that have recently calved but Blastocystis sp. carriage was not significantly related to age. Blastocystis sp. colonization also decreased with high beet pulp and pasture grass consumption and increased with corn silage intake. Finally, the only significant association between Blastocystis sp. STs and animal and herd characteristics was the number of lactations of cows, with a predominance of ST14 in cows that calved once only. Full article

This review describes the current research status regarding the implementation of predatory fungi in the biological control approach of bird gastrointestinal (GI) parasitosis. The main GI parasites of Galliformes (e.g., broilers, layers, peacocks, pheasants) and Ratites (e.g., ostriches, emus, rheas) are addressed, as well as their impact on farms, zoos, and private collections. The main characteristics regarding biocontrol with predatory fungi are briefly described, such as their mode of action and efficacy against GI parasites of different animal hosts. The state of the art regarding the use of predatory fungi in birds is reviewed here by describing all associated articles already published in the main databases, techniques, and their main findings. Ovicidal fungi such as Pochonia chlamydosporia, Metarhizium spp. and Acremonium spp., and larvicidal fungi, namely Duddingtonia flagrans, Arthrobotrys spp. and Monacrosporium thaumasium, have shown promising predacious activity against ascarid eggs and nematode larvae from chickens and ostriches, both in vitro and in vivo, also revealing tolerance to the GI passage in chickens and maintenance of predacious capacity. Further studies are needed to understand the fungi–parasite–host gut microbiota interactions and target other avian GI parasitic species, such as nematodes, coccidia, cestodes, and trematodes. Full article

Lymphatic filariasis (LF) is an important tropical disease that affects over a billion people in more than 80 countries and approximately 40 million people are currently suffering from severe disfigurement and disability. A diagnostic tool is the principal impact factor to determine the infection status of lymphatic filariasis. The purpose of the present study was to investigate nucleic acid of Wuchereria bancrofti as well as antifilarial IgG4 in a Myanmar immigrant community living along the Moei River, a natural border between Mae Sot, Tak province Thailand and Myawaddy, Myanmar which is an endemic area of bancroftian filariasis. Blood was collected from 300 Myanmar immigrants in Mae Sot district, Tak Province. The nucleic acid of W. bancrofti was assessed in the study population using our recent published miniPCR-Duplex Lateral Flow dipstick (DLFD) platform as well as the standard PCR technique. The antifilarial IgG4 was detected in the study population using the developed ELISA which used BmSxp protein as antigen. The miniPCR-DLFD method delivered results comparable to the standard PCR technique and it enables convenient and rapid visual detection of the parasite nucleic acid. Furthermore, the ELISA using BmSxp antigen demonstrated a sensitivity, specificity, and positive and negative predictive values of 98.1%, 98.9%, 96.3%, and 99.4% respectively. The W. bancrofti nucleic acid and antifilarial IgG4 were detected in 1.6% (5/300), and 2% (6/300) of the study population, accordingly. The results of this study also revealed important epidemiological data about LF on the Thai–Myanmar border. Full article

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. Full article

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. Full article