The First Description of Setaria Tundra (Issaitshikoff & Rajewskaya, 1928) in Roe Deer from Croatia

Dirofilaria sp. and Blood Meal Analysis in Mosquitoes Collected in Vojvodina and Mačva, and the First Report of Setaria tundra (Issaitshikoff & Rajewskaya, 1928) in Serbia

Dirofilaria immitis and D. repens are the two most widespread and important species of mosquito-borne nematodes, posing a significant threat to veterinary health and particularly affecting canines and felines. While D. immitis causes cardiopulmonary dirofilariasis, D. repens causes subcutaneous infections in dogs and other carnivores. Despite the extensive knowledge on these parasites, little is known about their natural vectors in Serbia. The parasite Setaria tundra, known to infect deer, has not yet been detected in Serbia but has been documented in neighboring countries. Thus, the aim of this study was to (i) further map out Dirofilaria sp. hotspots in the Vojvodina Province and detect S. tundra for the first time, (ii) detect positive mosquito species that can provide insights into how the nematodes spread in Serbia, and (iii) analyze the blood-fed female mosquitoes of species found to be infected, in order to identify the potential source of parasite infection. A total of 2902 female mosquitoes were collected across 73 locations during 2021 and 2022. Molecular biology methods, based on conventional PCR, were used to analyze non-blood-fed (2521 specimens) and blood-fed (381 specimens) female mosquitos, in order to detect filarial nematode presence and identify blood-meal sources, respectively. When the parasite genome was detected, the amplicon (cox1 gene, 650 bp fragment) was sent for Sanger sequencing, further confirming the presence of nematodes and species assignation. D. immitis was detected in three Culex pipiens mosquitoes collected in Zrenjanin (August 2021) and Glogonj and Svetozar Miletić (both in July 2021). Additionally, Setaria tundra was detected in Aedes vexans collected in Iđoš (mid-August 2021) and Aedes caspius, which was collected in Mali Iđoš (end of July 2021). This work identifies two new locations where D. immitis occurs in Vojvodina, and is the first report of S. tundra in Serbian territory. Blood-meal analysis provided insights into the preferences of mosquitoes that were positive for Dirofilaria sp. and S. tundra.

Helminth fauna in roe deer (Capreolus capreolus Linnaeus, 1758) in the province of Grosseto (central Italy)

Helminth infection was analysed at necropsy and coprology in a total of 54 roe deer from the province of Grosseto (central Italy) between 2018 - 2020. Age and sex data were recorded for each deer for a total of 31 adults (23 females, 8 males) and 23 juveniles (11 females, 12 males). The results on the small intestine (51 samples) highlighted that nematodes belonging to the species Trichostrongylus colubriformis were the most prevalent parasite (41.2 %), followed by the cestode Moniezia expansa (7.8 %). The large intestine results (52 samples) showed Trichuris spp. (53.8 %), Oesophagostomum venulosum (50 %) and Chabertia ovina (26.9 %). In the abomasum, only Ostertagia ostertagi (17.9 %) was found. Of the 34 samples analysed by bronchopulmonary, only the lung of an adult female was positive for Dictyocaulus spp. In two livers out of 33 samples analysed, nematodes of the species Setaria tundra were found on the surface. Copropositivity was observed in 45 of the 52 faecal samples analysed. The results of the present study indicate that the roe deer is host to several species of parasites, which are also common in other cervids and domestic ruminants. Statistical testing highlighted a significant difference between mean intensities in males and females.

Setaria cervi (Filarioidea, Onchocercidae) undressing in ungulates: altered morphology of developmental stages, their molecular detection and complete sequence cox1 gene

This work introduces new morphological and molecular information on the filaroid nematode Setaria cervi (Rudolphi, 1819) obtained from 13 infected game ungulates out of 96 dissected. The hosts comprised the following: a single moose (Alces alces), ten red deer (Cervus elaphus) and two sika deer (Cervus nippon) originating from the western and northern regions of the Czech Republic. Based on the complete sequences of the gene encoding mitochondrial cytochrome c oxidase subunit 1 (cox1), all 20 females and four males belonged to the species S. cervi. We detected three developmental female stages (adult fertile females, juvenile L5 females and L4 female larvae) differing in size and some morphological traits as the subtle structure of peribuccal crown and shape and features of tail knob. Such differences were described in detail for the first time. The phylogenetic relationships within the family Onchocercidae have been evaluated using new information on the cox1 sequence of S. cervi (maximum likelihood method, GTR + I + G model). In accordance with the latest phylogenetic studies, the present analysis confirmed the ancient separation of the subclass Setariinae from the remaining two onchocercid lineages Dirofilariinae and Onchocerinae.