Parasitology最新文献

In the ecologically diverse metropolitan area of Seoul, raccoon dogs (Nyctereutes procyonoides) coexist with humans and domestic animals, creating opportunities for vector-borne parasite transmission. Climate-driven shifts in mosquito populations may further enhance these risks, highlighting the need to monitor Dirofilaria immitis in urban wildlife for veterinary and public health. Among 51 raccoon dogs examined, D. immitis was identified in the pulmonary arteries and right ventricle of 13 animals (25.5%) by necropsy, with worm burdens ranging from 2 to 9. Lung tissue PCR revealed 4 additional subclinical infections, resulting in a final confirmed prevalence of 17 positives (33.3%). In contrast, whole-blood PCR detected only 11 positives (21.6%), all confirmed by necropsy, indicating higher sensitivity of lung tissue PCR. Phylogenetic analysis of cytochrome c oxidase subunit 1 sequences showed all isolates clustered with reference D. immitis across Asia and Europe, and haplotype analysis revealed low genetic diversity among Korean isolates. Wolbachia 16S ribosomal RNA sequences from raccoon dogs consistently grouped in supergroup C, confirming their association with D. immitis. These findings confirm natural infections of D. immitis and Wolbachia in wild raccoon dogs and highlight their potential role as urban wildlife reservoirs, while lung tissue-based molecular detection offers synergistic advantages for detecting subclinical infections and improving estimates of heartworm occurrence.

Infectious diseases result from multiple interactions among microbes and hosts, but community ecology approaches are rarely applied. Manipulation of vector populations provides a unique opportunity to test the importance of vectors in infection cycles while also observing changes in pathogen community diversity and species interactions. Yet for many vector-borne infections in wildlife, a biological vector has not been experimentally verified, and few manipulative studies have been performed. Using a captive colony of fruit bats in Ghana, we conducted the first study to experimentally test the role of bat flies as vectors of Bartonella species. We observed changes in the Bartonella bacteria community over time following the decline of bat flies and again after their subsequent restocking. Reduced transmission rates led to microbial community changes attributed to ecological drift and potential species sorting through interspecific competition mediated by host immunity. We demonstrate that forces maintaining diversity in communities of free-living macroorganisms act in similar ways in communities of symbiotic microorganisms, both within and among hosts.

Pentanchids (Elasmobranchii) are among the most species-rich groups of chondrichthyans. In the North Atlantic Ocean, the Icelandic catshark [Apristurus laurussonii (Saemundsson)], white ghost catshark (Apristurus aphyodes Nakaya & Stehmann), and mouse catshark [Galeus murinus (Collett)] are commonly found in deepwater habitats. However, information on their parasite communities remains scarce. This study provides the first comprehensive characterization of the metazoan parasite communities of the 3 pentanchid species. In total, 56 specimens were collected in Icelandic waters at depths of 466-1322 m between 2023 and 2024 and examined using standardized parasitological protocols, including morphological and molecular methods. Infection patterns were assessed in relation to size, maturity, body condition and capture area of hosts. Parasite intensities in all sharks ranged from 2 to 227 individuals, comprising 15 different taxa and resulting in 27 new parasite-host records, some of which likely representing new species. Eight out of 9 commonly found parasites did not display a high degree of host-specificity, indicating similar feeding habits, niche preferences, and trophic position of these sympatric species. Nonetheless, multivariate analyses revealed significant differences in the structure and composition of their parasite assemblages, with some parasites representing indicator species and occurring more abundantly and frequently in a certain deepwater catshark species. In addition, significant small-scale geographic differences were detected. At a broader geographical scale, North Atlantic pentanchids showed higher parasite richness and diversity, and lower dominance compared to standardized data from Mediterranean counterparts. Ecological factors underlying these patterns on host-parasite dynamics in (deepwater) cat sharks are discussed.