Search

Background: Dictyocaulosis is a parasitic disease caused by pulmonary nematodes from genus Dictyocaulus affecting various ungulate hosts. It can cause verminous bronchopneumonia and for heavily infected individuals, fatal outcomes can occur. Case presentation: The study describes the case of a male European bison which died three months after relocation from Slovakia to one of the reintroduction areas in Nucșoara village, Făgăraș Mountains, Romania. Necropsy revealed the presence of pulmonary nematodes in the respiratory tract. Morphology and molecular diagnosis was performed and Dictyocaulus viviparus was identified. Conclusion: Rigorous health monitoring is essential to assure the success of reintroduction programs, understanding and preventing infectious diseases and limiting their impact on population health. [ABSTRACT FROM AUTHOR]

Background: Fleas are important hematophagous insects, infesting mammals and birds with a worldwide distribution. Fleas of medical importance have been reported from various carnivores worldwide, such as felids, canids, or mustelids. Romania hosts a wide carnivore diversity, but very little is known about flea species that parasitize these animals in Romania. This study aimed to provide a better understanding of the fleas' diversity and their distribution in a relatively large and diverse number of wild carnivore hosts from Romania. Methods: From 2013 to 2021, 282 carcasses of wild carnivores from different locations in Romania were collected and examined for the presence of ectoparasites. All collected fleas were morphologically identified using specific keys and descriptions. An analysis of the co-occurrence networks was performed. Results: A total of 11 flea species were identified: Pulex irritans (41.09%), Paraceras melis (20.11%), Ctenocephalides felis (7.33%), Ctenocephalides canis (7.83%), Monopsyllus sciurorum (11.11%), Chaetopsylla trichosa (21.96%), Chaetopsylla homoea (5.5%), Chaetopsylla tuberculaticeps (100%), Chaetopsylla rothschildi (13.33%), Chaetopsylla sp. (14.34%), Chaetopsylla globiceps (5.12%), Echidnophaga gallinacea (10%). The statistical analyses showed a significant difference between the infestation of Martes foina with females being more frequently infected than males (66% versus 33%). Paraceras melis infesting Meles meles had a significantly higher prevalence in female badgers than in males (× 2 = 7.7977, P < 0.01) and higher intensities of infestations in males than in females (t = 1.871, P < 0.05). Conclusions: This is the first large-scale study investigating the distribution and diversity of flea species infesting wild carnivores in Romania. Three flea species were identified for the first time in Romania (E. gallinacea, C. homoea, and C. tuberculaticeps). [ABSTRACT FROM AUTHOR]

Background: Thelaziosis is a neglected vector-borne disease caused by parasitic nematode worms of the genus Thelazia which affects various hosts. Limited attention has been given to ungulate-associated Thelazia species. Current diagnosis of thelaziosis and the identification/differentiation of species heavily relies on morphological features. Therefore, we conducted an epidemiological study in Romanian cattle, with the aim to obtain morphological and molecular data that can be used for species identification. Methods: The eyes of 705 slaughtered cattle were sampled and subjected to morphological identification, morphometric analysis, and molecular characterization. PCR amplification and sequence analysis were performed based on the cytochromec oxidase subunit 1 (COI) gene. Statistical tests assessed the correlations between infection parameters and ecological or biogeographical factors. A novel PCR method was developed based on the consensus sequence from each species. Specific forward primers were designed for each of the three species, and a reverse primer (COIintR) was used for all reactions. A consensus thermal profile was established by gradient PCR amplification of each species separately. Results: Of the sampled cattle, 19.3% were infected with Thelazia spp. Prevalence varied significantly with ecogeographical factors. A total of 585 Thelazia nematodes were recovered, with T. rhodesi being the most abundant, followed by T. skrjabini and T. gulosa. Morphometric and molecular analyses supported the morphological identification, yielding unique sequences for each species. From the 59 T. rhodesi specimens sequenced, 29 unique sequences were obtained, with a 99.1–99.85% nucleotide identity to the only other COI sequence present in GenBank®. All nine T. gulosa isolates were unique (99.37–100% nucleotide identity to other sequences), while T. skrjabini specimens displayed 98.47–100% nucleotide identity to the sole available sequence. Conclusions: Bovine thelaziosis is prevalent in Romania, raising concerns for animal welfare and potential economic impacts. Infected cattle grazing alongside vulnerable wild ruminants, such as the European bison, may affect conservation efforts. Our newly developed multiplex PCR shows promise as a valuable surveillance tool, enabling the detection of occult infections in apparently healthy animals through lachrymal secretion testing. [ABSTRACT FROM AUTHOR]

Background: Toxoplasma gondii is a protozoan parasite that infects a large spectrum of warm-blooded animals, including humans. Small rodents and insectivores play an important role in the epidemiology of T. gondii and may serve as a source of infection for both, domestic and wild definitive felid hosts. Factors influencing the occurrence of T. gondii in wild small mammals are unknown, despite the fact that many intermediate host species are identified. We have used small mammals (Rodentia and Lipotyphla) captured over two years in various habitats, both in urbanised and in natural landscapes. We assessed the importance of land-use, season and host ecology on T. gondii infection. Results: We examined 471 individuals belonging to 20 small mammal species, collected at 63 locations spread over wide altitude, habitat and land-use ranges from Romania. Heart tissue samples were individually analysed by PCR targeting the 529 bp repetitive DNA fragment of T. gondii. The overall prevalence of infection was 7.3%, with nine species of rodents and two species of shrews being found to carry T. gondii DNA. Five species showed high frequency of infection, with the highest prevalence found in Myodes glareolus (35.5%), followed by Spermophilus citellus (33.3%), Sorex minutus (23.1%), S. araneus (21.7%) and Micromys minutus (11.1%). Adults seemed more often infected than young, however when controlling for season, the difference was not significant, as in spring both adults and young showed higher infection rates, but more adults were sampled. Contrary to our expectations, urban/rural areas (with their implicit high density of domestic feline presence) had no effect on infection prevalence. In addition, neither habitat, nor land-use at sampling sites was important as only geographical location and host species were contributing factors to the infection risk. Conclusions: High prevalence of T. gondii infection showed a highly localised, patchy occurrence, with long living and higher mobility host species being the most common carriers, especially during autumn. [ABSTRACT FROM AUTHOR]

Thelaziosis caused by Thelazia callipaeda is an emerging disease in Europe. Only two reports of naturally infected lagomorphs have been published so far. The aim of this study was to evaluate the status of the Romanian populations of European brown hares, Lepus europaeus as reservoir hosts for T. callipaeda. Between November 2019 and November 2021, the eyes of 326 L. europaeus carcasses were examined for the presence of ocular parasites. Nematodes were stored in plastic vials with physiological saline, followed by morphological and molecular identification. QGis 3.20 and EpiInfoTM 7 were used for mapping and statistical analysis. Four (1.23%) hares harbored T. callipaeda infection, with a total of 84 nematodes collected (mean intensity 21 nematodes/host), with 45 males, 39 females (two sexually immature, seven with only eggs, and 30 with eggs and larvae). One specimen from each host was successfully sequenced resulting in a 100% similarity with several other sequences of T. callipaeda haplotype 1. Statistical analysis revealed no significant results. The current study represents a first report of T. callipaeda in the European brown hare in Romania, and the second in Europe, also reiterating the role of lagomorphs as reservoir hosts for this zoonotic ocular nematode. [ABSTRACT FROM AUTHOR]

Parasitic diseases cause significant economic losses in swine, including free-range swine farms, the number of which in Romania has increased in the last decades. The current study aimed to identify the parasitic profile of swine raised on two free-range (low-input) farms from Transylvania. Nine hundred sixty samples collected from weaners, fatteners, and sows were investigated by flotation, centrifugal sedimentation, modified Ziehl-Neelsen stained fecal smear, modified Blagg technique, and oocyst/egg cultures. The number of oocysts (OPG), cysts (CPG), and eggs (EPG) were counted per gram of fecal matter. The examination revealed parasitic infections with Balantidium coli, Eimeria spp., Ascaris suum, Trichuris suis, Oesophagostomum spp., Strongyloides ransomi and Cryptosporidium spp. Prevalence (P) and the mean intensity (MI) of the infections varied according to age, swine category, farm, and season. The overall prevalence in both free-range farms according to the age category was 63.2%—Eimeria spp., 70.31%—B. coli, 9.38%—Oesophagostomum spp., 3.75% S. ransomi, and 18.12% Cryptosporidium spp. in weaners. In fatteners Eimeria spp. revealed a prevalence of 50.93%, B. coli—72.5 %, A. suum—63.13%, T. suis—39.06%, and in sows Eimeria spp.—39.06%, B. coli—62.19%, A. suum—34.06%, Oesophagostomum spp.—27.19%, S. ransomi—1.56% and Cryptosporidium spp.—9.38%. The study revealed statistically significant (p < 0.05) differences between age groups, seasons, and farms for all diagnosed parasites. Further research is required to better understand the epidemiology of these infections in swine from Transylvania. [ABSTRACT FROM AUTHOR]

Simple Summary: Ticks are important parasites that feed on the blood of various host species, representing the most important arthropods transmitting diseases in Europe. Continuous changes in both tick distribution and abundance are related to multiple factors, including climate change. These changes have strong implications for both animal and human health; therefore, continuous surveillance of tickborne diseases is required for an appropriate evaluation of the potential risks faced by animals and humans in a given area. The spotted fever group Rickettsia comprises a large number of zoonotic agents with an increasing importance recognized in the last 30 years. The aim of this study was to evaluate these bacteria in ticks in Romania. Five Rickettsia species were identified in different tick species, with new pathogen–tick associations reported. Rickettsia hoogstraalii, one member of this group, was detected for the first time in Romania and in Rhipicephalus rossicus ticks. This species was first described in 2006 in Croatia, and its pathogenicity is not well known. In addition, the detection of R. raoultii and R. monacensis in unfed larvae of Haemaphysalis punctata reinforce the hypothesis of transmission of Rickettsia from female ticks to larvae; therefore the bite of larvae could pose a health risk. Tickborne bacterial pathogens have been described worldwide as risk factors for both animal and human health. Spotted fevers caused by Rickettsiae may cause non-specific symptoms, which make clinical diagnosis difficult. The aim of the current study was to evaluate and review the diversity of SFG Rickettsiae in ticks collected in 41 counties in Romania. A total of 2028 questing and engorged ticks collected in Romania belonging to five species were tested by PCR amplification of Rickettsia spp. gltA and 17-D gene fragments: Ixodes ricinus (n = 1128), Dermacentor marginatus (n = 507), D. reticulatus (n = 165), Rhipicephalus rossicus (n = 128) and Haemaphysalis punctata (n = 100). Five Rickettsia species were identified following DNA sequence analysis: R. helvetica, R. monacensis, R. slovaca, R. raoultii, and R. hoogstraalii. The most common species detected was R. monacensis. Moreover, R. hoogstraalii was detected for the first time in Romania and in R. rossicus ticks. The detection of R. raoultii and R. monacensis in questing larvae of Hae. punctata suggests the possible transovarial transmission of these Rickettsia species in ticks. The detection of R. hoogstraalii for the first time in Romania increases the reported SFG Rickettsia diversity in the country. [ABSTRACT FROM AUTHOR]

Background: The population of wild felids is large and stable in Romania with many carnivore habitats being protected. Felids can be infected with a wide variety of cardio-pulmonary nematodes and can act as reservoirs of infection for domestic cats. The aim of this study was to evaluate the distribution and species diversity of cardio-pulmonary nematodes in wild felids from Romania. Methods: A total of 54 wild felids (7 Lynx lynx and 47 Felis silvestris) were legally collected from different locations in Romania and analysed by complete parasitological necropsy. The entire respiratory tract was longitudinally opened and checked for the presence of nematodes. Detected nematodes were collected and morphologically identified to species level. Results: Two Eurasian lynxes and 29 European wildcats were positive for cardio-pulmonary nematodes. Eurasian lynxes were infected with two species of cardio-pulmonary nematodes, Eucoleus aerophilus and Troglostrongylus brevior, while in wildcats the dominant parasite was E. aerophilus (34.0%) followed by Angiostrongylus chabaudi (23.4%) and T. brevior (14.9%). Dirofilaria immitis and Aelurostrongylus abstrusus were each detected in two wildcats (4.3%). Conclusions: The present study expanded the epidemiological knowledge on felid cardiopulmonary nematodes in Romania. We confirmed the presence of A. abstrusus in wildcats and a patent infection with T. brevior in Eurasian lynx. [ABSTRACT FROM AUTHOR]

Dirofilaria immitis is an important mosquito-borne nematode, being of both veterinary and public health concern. The typical final host is represented by the domestic dog, Canis familiaris, but it is able to infect a large variety of mammalian species. During the present study (March 2016–February 2022), a total of 459 wild carnivore carcasses belonging to 17 species, from Romania, were evaluated for the presence of adult D. immitis by necropsy. Overall, 20 animals (4.36%) were positive: twelve golden jackals, C. aureus (19.05%); four red foxes, Vulpes vulpes (6.67%); one raccoon dog, Nyctereutes procyonoides; two wild cats, Felis silvestris (4.65%); and one European badger, Meles meles (0.87%). This study provides further evidence of the occurrence of the canine heartworm, D. immitis, in Romania, expanding the known host spectrum, reports a new host species for this parasite, the European badger, and a new host for Europe, the raccoon dog. [ABSTRACT FROM AUTHOR]

Nematodes of the genus Trichinella are among the most widespread parasites of domestic and wild omnivores and predatory animals. The present study aimed to evaluate the antiparasitic effect of Lactobacillus casei ATCC 393 (original) and L. paracasei CNCM in CD-1 mice experimentally infected with Trichinella britovi. Four groups of 20 mice (10 females and 10 males/group) were used, with two control (C) groups and two experimental (E) groups, in which each animal received a daily oral dose of 100 µL of 105 CFU/mL probiotics in Ringer's solution. On day 7, all mice (except the negative control group) were infected orally with Trichinella (100 larvae/animal) as well as the two probiotics. On day 9 post-infection (p.i.), 10 mice/group were euthanized, and the presence of adult parasites in the intestinal content and wall was tested. On day 32 p.i., 10 mice/group were euthanized, then trichinoscopy and artificial digestion were performed to assess the muscle infection with T. britovi. On day 9 p.i., the experimental group pretreated with L. casei ATCC 393 (6.3 ± 3.03) showed a significantly lower number of adult parasites in the intestinal wall compared with the positive control group (24.6 ± 4.78). Additionally, a significantly lower adult parasite count in the intestinal wall was registered in female mice pretreated with L. paracasei CNCM (7.4 ± 4.71) compared to female mice from the positive control (29.0 ± 5.17). No statistically relevant results were obtained concerning the male mice or the data obtained at 32 days p.i., irrespective of mice gender. [ABSTRACT FROM AUTHOR]

Background: Ticks are hematophagous arthropods which normally attach to the surface of the host's skin. Their aberrant presence in the subcutaneous tissue of a few carnivores, predominantly foxes, has been reported. However, there have been no reports of this phenomenon in other carnivores such as mustelids or golden jackals. Our aim was to investigate the host spectrum for this aberrant localization of ticks. Methods: Between 2015 and 2020, a total of 198 carcasses of 12 species of carnivore were examined by parasitological necropsy. When a subcutaneous tick was found, the nodule was removed, carefully dissected, and stored in ethanol. The morphological identification of the subcutaneous tick was carried out to species level. Results: A single subcutaneous tick was found in one carcass, that of a golden jackal (Canis aureus). The tick was identified as a female Ixodes ricinus. All the other carcasses were negative for the presence of subcutaneous ticks. Conclusion: To our knowledge, this is the first report of a subcutaneous tick in a golden jackal. This finding broadens the host spectrum of subcutaneous ticks, and reinforces the idea that, among carnivores, this phenomenon only occurs in canids. [ABSTRACT FROM AUTHOR]

Background: Ticks are hematophagous arthropods which normally attach to the surface of the host's skin. Their aberrant presence in the subcutaneous tissue of a few carnivores, predominantly foxes, has been reported. However, there have been no reports of this phenomenon in other carnivores such as mustelids or golden jackals. Our aim was to investigate the host spectrum for this aberrant localization of ticks. Methods: Between 2015 and 2020, a total of 198 carcasses of 12 species of carnivore were examined by parasitological necropsy. When a subcutaneous tick was found, the nodule was removed, carefully dissected, and stored in ethanol. The morphological identification of the subcutaneous tick was carried out to species level. Results: A single subcutaneous tick was found in one carcass, that of a golden jackal (Canis aureus). The tick was identified as a female Ixodes ricinus. All the other carcasses were negative for the presence of subcutaneous ticks. Conclusion: To our knowledge, this is the first report of a subcutaneous tick in a golden jackal. This finding broadens the host spectrum of subcutaneous ticks, and reinforces the idea that, among carnivores, this phenomenon only occurs in canids. [ABSTRACT FROM AUTHOR]

Background: Giardia duodenalis is a parasitic protist that infects a large number of species, being localized in the small intestine. Two of the eight recognized assemblages have zoonotic potential, but studies regarding their distribution in less important pet or farm species are scarce. Of these species, the long-tailed chinchilla is a host for Giardia spp., although data on the spread of infection and assemblages involved are confined. The present work aimed to determine the prevalence of Giardia infection and assemblage identification in farmed chinchillas in Romania. A total of 341 fecal samples were collected from 5 farms and microscopically examined using flotation test based on saturated sodium chloride solution. DNA from all positive samples was extracted and identified by PCR targeting the gdh gene. Results: The overall prevalence of Giardia infection was 55.7% (190/341); there was no statistically significant difference (P = 0.25) in prevalence between young animals (58.8%) and adults (52.6%). Assemblages B (151/190), D (33/190) and E (6/190) were identified. Among assemblage B, sub-assemblages BIII (6/151) and BIV (145/151) were determined. Conclusions: This study demonstrates that Giardia spp. infection is highly prevalent in farmed chinchillas from Romania, and the sub-assemblages identified are potentially zoonotic. [ABSTRACT FROM AUTHOR]

Background: The genus Troglostrongylus includes nematodes infecting domestic and wild felids. Troglostrongylus brevior was described six decades ago in Palestine and subsequently reported in some European countries (Italy, Spain, Greece, Bulgaria, and Bosnia and Herzegovina). As the diagnosis by the first-stage larvae (L1) may be challenging, there is a possibility of confusion with Aelurostrongylus abstrusus. Hence, the knowledge on the distribution of this neglected feline parasite is still scarce. The present paper reports the first case of T. brevior infection in Romania. In July 2017, a road-killed juvenile male Felis silvestris, was found in in Covasna County, Romania. A full necropsy was performed and the nematodes were collected from the trachea and bronchioles. Parasites were sexed and identified to species level, based on morphometrical features. A classical Baermann method was performed on the lungs and the faeces to collect the metastrongyloid larvae. Genomic DNA was extracted from an adult female nematode. Molecular identification was accomplished with a PCR assay targeting the ITS2 of the rRNA gene. Results: Two males and one female nematodes were found in the trachea and bronchioles. They were morphologically and molecularly identified as T. brevior. The first-stage larvae (L1) recovered from the lung tissue and faeces were morphologically consistent with those of T. brevior. No other pulmonary nematodes were identified and no gross pulmonary lesions were observed. Conclusions: This paper represents the first report of Troglostrongylus brevior infection in Romania, so far representing the second northernmost location for this genus in Europe. The diversity of species infecting wild and domestic felids and the differences regarding the clinical significance of these nematodes highlight the need for a more intense surveillance and proper diagnosis of feline lungworm infections, especially in countries where more species were demonstrated to be present. Furthermore, an increased awareness between clinicians is needed for a correct diagnostic approach to feline lungworm diagnosis. [ABSTRACT FROM AUTHOR]

The golden jackal (Canis aureus) is a species under significant and fast geographic expansion. Various parasites are known from golden jackals across their geographic range, and certain groups can be spread during their expansion, increasing the risk of cross-infection with other carnivores or even humans. The current list of the golden jackal parasites includes 194 species and was compiled on the basis of an extensive literature search published from historical times until April 2017, and is shown herein in synoptic tables followed by critical comments of the various findings. This large variety of parasites is related to the extensive geographic range, territorial mobility and a very unselective diet. The vast majority of these parasites are shared with domestic dogs or cats. The zoonotic potential is the most important aspect of species reported in the golden jackal, some of them, such as Echinococcus spp., hookworms, Toxocara spp., or Trichinella spp., having a great public health impact. Our review brings overwhelming evidence on the importance of Canis aureus as a wild reservoir of human and animal parasites. [ABSTRACT FROM AUTHOR]

Ticks are medically important vectors of infectious diseases that are able to transmit pathogens to humans and animals. Tick-borne diseases represent a major health concern, posing an increasing risk to the public health during the last century and affecting millions of people. The aim of the current study was to provide epidemiological data regarding the presence of certain tick-borne pathogens in ticks feeding on humans in Romania. Overall, 522 Ixodes ricinus ticks collected from humans were screened for six pathogens: Borrelia spp., Neoehrlichia mikurensis, Babesia spp., Coxiella spp., Bartonella spp., and Francisella tularensis. Ticks attached to humans were collected between 2013–2015 in Cluj County, Romania. Conventional, nested and quantitative PCR were used to detect specific genetic sequences of each pathogen. For identifying the infectious agents, positive samples were sequenced. The infection prevalence was 21.07% from which 8.18% were mixed infections. The detected agents were Borrelia spp., N. mikurensis and Babesia spp. The present data reveal the endemic occurrence of potentially zoonotic pathogens in Romania. Revealing the current distribution of tick-borne pathogens in ticks collected from humans may provide new insights in understanding the complex ecology of tick-borne diseases and enlightens current knowledge about the infection prevalence at local, regional and national levels. [ABSTRACT FROM AUTHOR]

Background: Small mammals play an important role in the life-cycle of ticks and are reservoirs for several zoonotic pathogens. The aim of this study was to provide epidemiological data regarding the presence of Borrelia spp. in tissues of small mammals from Romania. Methods: We examined 401 individuals belonging to 11 small mammal species collected in Romania. Collections cover the largest effort to survey these reservoirs in the country. Tissue samples were analyzed by multiplex qPCR targeting the ospA gene of Borrelia burgdorferi (s.l.) and a part of the flaB gene of B. miyamotoi. Positive samples were further analysed by conventional PCR and sequenced. Results: The overall prevalence of infection with Borrelia spp. in small mammal tissues was 4.9%. The most commonly detected species were B. afzelii, followed by B. garinii/B. bavariensis, B. miyamotoi and B. burgdorferi (s.s.). To our knowledge, we report for the first time the detection of Borrelia spp. in Crocidura leucodon and C. suaveolens, and B. miyamotoi in the liver of Myodes glareolus. Conclusions: To our knowledge, our study evaluates for the first time the occurrence of Borrelia spp. in small mammals in Romania, contributing to a better knowledge of the distribution of these bacteria. This survey upgrades previous data on the spatial distribution of the pathogens and reveals the importance of animal surveillance regarding Lyme borreliosis and relapsing fever caused by B. miyamotoi. [ABSTRACT FROM AUTHOR]

Background: Thelazia callipaeda (Spirurida, Thelaziidae) is a vector-borne zoonotic eye worm with a broad host spectrum. In Europe, it is an emerging threat, having greatly expanded its geographical distribution during the past two decades. In Romania, T. callipaeda has been previously reported in domestic and wild canids and felids. The aim of the present study was to assess the occurrence of T. callipaeda in mustelids in the country. Methods: Between March 2015 and April 2019, 77 road-killed mustelids (3 pine martens, Martes martes; 6 European polecats, Mustela putorius; 13 beech martens, Martes foina; and 55 European badgers, Meles meles) were examined by necropsy. If present, all ocular nematodes were collected and stored in absolute ethanol, for subsequent morphological and molecular identification. Results: Two animals were found to be infected with T. callipaeda: one European badger and one beech marten. The molecular analysis revealed a 100% nucleotide similarity to T. callipaeda haplotype h1 for all the sequenced specimens. Conclusions: To our knowledge, the present study demonstrates for the first time the occurrence of T. callipaeda in mustelids from Romania, records the easternmost locality of the parasite in Europe, and represents the first report of T. callipaeda in the European badger, Meles meles, extending the known host range for this parasite in Europe. [ABSTRACT FROM AUTHOR]

Background: A century of debates on the taxonomy of members of the Metastrongyloidea Molin, 1861 led to many reclassifications. Considering the inconstant genus assignation and lack of genetic data, the main aim of this study was to support the validity of the genus Perostrongylus Schlegel, 1934, previously considered a synonym of Aelurostrongylus Cameron, 1927, based on new molecular phylogenetic data and to understand its evolutionary relationships with other metastrongyloid nematodes. Results: Specimens of lungworm collected from European badgers in Germany, Romania and Bosnia and Herzegovina were morphologically and molecularly (rDNA, cox1) characterized. From a phylogenetic standpoint, Perostrongylus is grouped with high support together with the genera Filaroides van Beneden, 1858 and Parafilaroides Dougherty, 1946 and includes probably two species: Perostrongylus falciformis (Schlegel, 1933), a parasite of Meles meles in Europe and P. pridhami (Anderson, 1962), a parasite of Neovison vison in North America. Perostrongylus and Aelurostrongylus are assigned to different clades. Aelurostrongylus becomes a monotypic genus, with the only species Aelurostrongylus abstrusus (Railliet, 1898). In addition, we provide morphological and morphometric data for the first-stage (L1), second-stage (L2), and third-stage (L3) larvae of P. falciformis and describe their development in experimentally infected Cornu aspersum snails. The pathological and histopathological lesions in lungs of infected European badgers are also described. This is the first record of P. falciformis in Romania. Conclusions: Molecular phylogenetic and morphological data support the validity of the genus Perostrongylus, most probably with two species, P. falciformis in European badgers and P. pridhami in minks in North America. The two genera clearly belong to two different clades: Perostrongylus is grouped together with the genera Filaroides and Parafilaroides (both in the family Filaroididae Schulz, 1951), whereas Aelurostrongylus belongs to a clade with no sister groups. [ABSTRACT FROM AUTHOR]