RÉSUMÉ
The rhabditid nematode Strongyloides stercoralis is known worldwide as the causative agent of strongyloidiasis in humans. In addition to public health concerns, S. stercoralis also infects dogs, which represent a possible reservoir for potentially zoonotic transmissions. We describe the first confirmed case of fatal disseminated infection in a dog in the Czech Republic. The microscopic and histological results were supported by a complex genotyping approach. Using high-throughput sequencing of the hypervariable region (HVR-IV) of 18S rDNA and Sanger sequencing of the partial cytochrome c oxidase subunit 1 gene (cox1), the potentially zoonotic haplotype/lineage A of S. stercoralis was confirmed, while the solely canine haplotype/lineage B was not found. The development of the disease is mainly associated with immunodeficiency, and in this case, it was triggered by inappropriate treatment, in particular the use of corticosteroids.
RÉSUMÉ
The metastrongyloid nematode Angiostrongylus cantonensis causes eosinophilic meningitis in a variety of homeothermic hosts including humans. Third-stage infectious larvae develop in gastropods as intermediate hosts. Humans are usually infected by intentional or incidental ingestion of an infected mollusk or paratenic host (poikilothermic vertebrates and invertebrates). The infection may also hypothetically occur through ingestion of food or water contaminated by third-stage larvae spontaneously released from gastropods. Larvae are thought to be released in greater numbers from the intermediate host exposed to stress. This study aimed to compare larval release from stressed with unstressed gastropods. Experimentally infected Limax maximus and Lissachatina fulica were exposed to a stress stimulus (shaking on an orbital shaker). The mucus was collected before and after the stress and examined microscopically and by qPCR for the presence of A. cantonensis larvae and their DNA. In the case of L. maximus, no larvae were detected microscopically in the mucus, but qPCR analysis confirmed the presence of A. cantonensis DNA in all experimental replicates, without clear differences between stressed and non-stressed individuals. In contrast, individual larvae of A. cantonensis were found in mucus from Li. fulica after stress exposure, which also reflects an increased number of DNA-positive mucus samples after stress. Stress stimuli of intensity similar to the transport or handling of mollusks can stimulate the release of larvae from highly infected intermediate hosts. However, these larvae are released in small numbers. The exact number of larvae required to trigger neuroangiostrongyliasis is unknown. Therefore, caution is essential when interacting with potential intermediate hosts in regions where A. cantonensis is endemic.
Sujet(s)
Angiostrongylus cantonensis , Larve , Stress physiologique , Animaux , Angiostrongylus cantonensis/physiologie , Larve/physiologie , Gastropoda/parasitologie , Infections à Strongylida/parasitologie , Mucus , Réaction de polymérisation en chaine en temps réelRÉSUMÉ
The brown dog tick, Rhipicephalus sanguineus is a complex of tick species with an unsettled species concept. In Europe, R. sanguineus is considered mainly a Mediterranean tick with sporadic findings in central and northern Europe. R. sanguineus is known as a vector of a range of pathogens of medical and veterinary importance, most of which not yet reported as autochthonous in Hungary. A total of 1839 ticks collected by veterinarians from dogs and cats were obtained in Hungary. The study aims at precise determination of ticks identified as R. sanguineus and detection of pathogens in collected ticks. All ticks were morphologically determined and 169 individuals were identified as R. sanguineus. A subset of 15 ticks was selected for molecular analysis (16S rDNA, 12S rDNA, COI). Phylogenetic analyses invariably placed sequences of all three markers into a single haplotype identified as R. sanguineus sensu stricto. All 169 brown dog ticks were tested for the presence of A. platys, E. canis, R. conorii, B. vogeli and H. canis. None of the investigated ticks was positive for the screened pathogens, though A. phagocytophilum sequence was detected in a single tick.
Sujet(s)
Anaplasma , Maladies des chiens , Phylogenèse , ARN ribosomique , Rhipicephalus sanguineus , Infestations par les tiques , Animaux , Chiens , Hongrie , Rhipicephalus sanguineus/microbiologie , Maladies des chiens/parasitologie , Maladies des chiens/diagnostic , Infestations par les tiques/médecine vétérinaire , Infestations par les tiques/parasitologie , Femelle , Mâle , Maladies transmises par les tiques/médecine vétérinaire , Maladies transmises par les tiques/microbiologie , Maladies transmises par les tiques/parasitologie , Rickettsia conorii/isolement et purification , Rickettsia conorii/génétique , ARN ribosomique 16S/analyse , ARN ribosomique 16S/génétique , Chats/parasitologie , Ehrlichia canis/isolement et purification , Ehrlichia canis/génétiqueRÉSUMÉ
BACKGROUND: Ixodes inopinatus was described from Spain on the basis of morphology and partial sequencing of 16S ribosomal DNA. However, several studies suggested that morphological differences between I. inopinatus and Ixodes ricinus are minimal and that 16S rDNA lacks the power to distinguish the two species. Furthermore, nuclear and mitochondrial markers indicated evidence of hybridization between I. inopinatus and I. ricinus. In this study, we tested our hypothesis on tick dispersal from North Africa to Southern Europe and determined the prevalence of selected tick-borne pathogens (TBPs) in I. inopinatus, I. ricinus, and their hybrids. METHODS: Ticks were collected in Italy and Algeria by flagging, identified by sequencing of partial TROSPA and COI genes, and screened for Borrelia burgdorferi s.l., B. miyamotoi, Rickettsia spp., and Anaplasma phagocytophilum by polymerase chain reaction and sequencing of specific markers. RESULTS: Out of the 380 ticks, in Italy, 92 were I. ricinus, 3 were I. inopinatus, and 136 were hybrids of the two species. All 149 ticks from Algeria were I. inopinatus. Overall, 60% of ticks were positive for at least one TBP. Borrelia burgdorferi s.l. was detected in 19.5% of ticks, and it was significantly more prevalent in Ixodes ticks from Algeria than in ticks from Italy. Prevalence of Rickettsia spotted fever group (SFG) was 51.1%, with significantly greater prevalence in ticks from Algeria than in ticks from Italy. Borrelia miyamotoi and A. phagocytophilum were detected in low prevalence (0.9% and 5.2%, respectively) and only in ticks from Italy. CONCLUSIONS: This study indicates that I. inopinatus is a dominant species in Algeria, while I. ricinus and hybrids were common in Italy. The higher prevalence of B. burgdorferi s.l. and Rickettsia SFG in I. inopinatus compared with that in I. ricinus might be due to geographical and ecological differences between these two tick species. The role of I. inopinatus in the epidemiology of TBPs needs further investigation in the Mediterranean Basin.
Sujet(s)
Ixodes , Rickettsia , Animaux , Ixodes/microbiologie , Italie/épidémiologie , Algérie/épidémiologie , Rickettsia/isolement et purification , Rickettsia/génétique , Rickettsia/classification , Maladies transmises par les tiques/épidémiologie , Maladies transmises par les tiques/microbiologie , Prévalence , Borrelia/génétique , Borrelia/isolement et purification , Borrelia/classification , Anaplasma phagocytophilum/génétique , Anaplasma phagocytophilum/isolement et purification , Anaplasma phagocytophilum/classification , Femelle , Hybridation génétique , Mâle , ARN ribosomique 16S/génétique , Borrelia burgdorferi/génétique , Borrelia burgdorferi/isolement et purification , Borrelia burgdorferi/classificationRÉSUMÉ
Parasitic diseases and mitigation of their effects play an important role in the health management of grazing livestock worldwide, with gastrointestinal strongylid nematodes being of prominent importance. These helminths typically occur in complex communities, often composed of species from numerous strongylid genera. Detecting the full diversity of strongylid species in non-invasively collected faecal samples is nearly impossible using conventional methods. In contrast, high-throughput amplicon sequencing (HTS) can effectively identify co-occurring species. During the four-year project, we collected and analysed faecal samples from beef cattle on >120 farms throughout the Czech Republic. Strongylids were the predominant nematodes, detected in 56% of the samples, but at a low level of infection. The apparent limitations in identifying strongylid taxa prompted this pilot study on a representative group of samples testing positive for strongylids using ITS-2 metabarcoding. The most widespread genera parasitizing Czech cattle were Ostertagia (O. ostertagi) and Oesophagostomum spp., followed by Trichostrongylus and Cooperia, while Bunostomum, Nematodirus and Chabertia were present only in a minority. As comparative material, 21 samples of cattle from the Danube Delta in Romania were used, which, in contrast, were dominated by Haemonchus placei. Finally, the effect of ivermectin treatment was tested at two Czech farms. After treatment with the anthelmintic, there was a shift in the strongylid communities, with a dominance of Cooperia and Ostertagia.
Sujet(s)
Anthelminthiques , Haemonchus , Trichostrongyloidea , Bovins , Animaux , République tchèque , Projets pilotes , Anthelminthiques/usage thérapeutique , Résultat thérapeutique , Trichostrongyloidea/génétique , OstertagiaRÉSUMÉ
Cestodes of the family Anoplocephalidae parasitize a wide range of usually herbivorous hosts including e.g. rodents, ungulates, primates, elephants and hyraxes. While in some hosts, the epidemiology of the infection is well studied, information is lacking in others. In this study of mountain gorillas in the Virunga Massif, an extensive sample set comprising adult cestodes collected via necropsies, proglottids shed in feces, and finally, fecal samples from both night nests and identified individuals were analysed. Anoplocephala gorillae was the dominant cestode species detected in night nest samples and individually known gorillas, of which only 1 individual hosted a Bertiella sp. It was shown that the 2 species can be distinguished through microscopy based on egg morphology and polymerase chain reaction (PCR) assays for diagnostics of both species were provided. Sequences of mitochondrial (cox 1) and nuclear (ITS1, 18S rDNA, 28S rDNA) markers were used to evaluate the phylogenetic position of the 2 cestodes detected in mountain gorillas. Both types of fecal samples, from night nests and from identified individuals, provided comparable information about the prevalence of anoplocephalid cestodes, although the analysis of samples collected from identified gorilla individuals showed significant intra-individual fluctuation of A. gorillae egg shedding within a short period. Therefore, multiple samples should be examined to obtain reliable data for wildlife health management programmes, especially when application of anthelmintic treatment is considered. However, while A. gorillae is apparently a common symbiont of mountain gorillas, it does not seem to impair the health of its host.
Sujet(s)
Cestoda , Gorilla gorilla , Animaux , Rwanda/épidémiologie , Parcs de loisirs , Phylogenèse , Cestoda/génétique , ADN ribosomiqueRÉSUMÉ
Bartonelloses are neglected emerging infectious diseases caused by facultatively intracellular bacteria transmitted between vertebrate hosts by various arthropod vectors. The highest diversity of Bartonella species has been identified in rodents. Within this study we focused on the edible dormouse (Glis glis), a rodent with unique life-history traits that often enters households and whose possible role in the epidemiology of Bartonella infections had been previously unknown. We identified and cultivated two distinct Bartonella sub(species) significantly diverging from previously described species, which were characterized using growth characteristics, biochemical tests, and various molecular techniques including also proteomics. Two novel (sub)species were described: Bartonella grahamii subsp. shimonis subsp. nov. and Bartonella gliris sp. nov. We sequenced two individual strains per each described (sub)species. During exploratory genomic analyses comparing two genotypes ultimately belonging to the same species, both factually and most importantly even spatiotemporally, we noticed unexpectedly significant structural variation between them. We found that most of the detected structural variants could be explained either by prophage excision or integration. Based on a detailed study of one such event, we argue that prophage deletion represents the most probable explanation of the observed phenomena. Moreover, in one strain of Bartonella grahamii subsp. shimonis subsp. nov. we identified a deletion related to Bartonella Adhesin A, a major pathogenicity factor that modulates bacteria-host interactions. Altogether, our results suggest that even a limited number of passages induced sufficient selective pressure to promote significant changes at the level of the genome.
RÉSUMÉ
BACKGROUND: Anaplasma phagocytophilum is characterized by a worldwide distribution and distinguished from other Anaplasmataceae by the broadest range of mammalian hosts and high genetic diversity. The role carnivores play in the life cycle of A. phagocytophilum in Europe is uncertain. Currently, only the red fox is considered a suitable reservoir host. In this study, we focused on native and invasive medium-sized carnivore species that live in sympatry and represent the most abundant species of wild carnivores in Poland. METHODS: A total of 275 individual spleen samples from six carnivore species (Vulpes vulpes, Meles meles, Procyon lotor, Nyctereutes procyonoides and Martes spp.) were screened combining nested PCR and sequencing for A. phagocytophilum targeting a partial groEL gene with subsequent phylogenetic analysis inferred by the maximum likelihood method. RESULTS: The DNA of A. phagocytophilum was detected in 16 of 275 individuals (5.8%). Eight unique genetic variants of A. phagocytophilum were obtained. All detected haplotypes clustered in the clade representing European ecotype I. Three variants belonged to the subclade with European human cases together with strains from dogs, foxes, cats, and wild boars. CONCLUSIONS: While carnivores might have a restricted role in the dissemination of A. phagocytophilum due to their relatively low to moderate infection rates, they hold significance as hosts for ticks. Consequently, they could contribute to the transmission of tick-borne infections to humans indirectly, primarily through tick infection. This underscores the potential risk of urbanization for the A. phagocytophilum life cycle, further emphasizing the need for comprehensive understanding of its ecological dynamics.
Sujet(s)
Anaplasma phagocytophilum , Carnivora , Mustelidae , Tiques , Suidae , Animaux , Humains , Chiens , Anaplasma phagocytophilum/génétique , Pologne/épidémiologie , Phylogenèse , Sympatrie , Sus scrofaRÉSUMÉ
BACKGROUND: Ixodes ricinus is an important vector of several pathogens, primarily in Europe. Recently, Ixodes inopinatus was described from Spain, Portugal, and North Africa and then reported from several European countries. In this study, a multiplex polymerase chain reaction (PCR) was developed to distinguish I. ricinus from I. inopinatus and used in the surveillance of I. inopinatus in Algeria (ALG) and three regions in the Czech Republic (CZ). METHODS: A multiplex PCR on TROSPA and sequencing of several mitochondrial (16S rDNA, COI) and nuclear markers (TROSPA, ITS2, calreticulin) were used to differentiate these two species and for a subsequent phylogenetic analysis. RESULTS: Sequencing of TROSPA, COI, and ITS2 separated these two species into two subclades, while 16S rDNA and calreticulin could not distinguish I. ricinus from I. inopinatus. Interestingly, 23 nucleotide positions in the TROSPA gene had consistently double peaks in a subset of ticks from CZ. Cloning of these PCR products led to a clear separation of I. ricinus and I. inopinatus indicating hybridization and introgression between these two tick taxa. Based on a multiplex PCR of TROSPA and analysis of sequences of TROSPA, COI, and ITS2, the majority of ticks in CZ were I. ricinus, no I. inopinatus ticks were found, and 10 specimens showed signs of hybridization. In contrast, most ticks in ALG were I. inopinatus, four ticks were I. ricinus, and no signs of hybridization and introgression were detected. CONCLUSIONS: We developed a multiplex PCR method based on the TROSPA gene to differentiate I. ricinus and I. inopinatus. We demonstrate the lack of evidence for the presence of I. inopinatus in Central Europe and propose that previous studies be re-examined. Mitochondrial markers are not suitable for distinguishing I. inopinatus from I. ricinus. Furthermore, our data indicate that I. inopinatus and I. ricinus can hybridize, and the hybrids can survive in Europe.
Sujet(s)
Ixodes , Animaux , Réaction de polymérisation en chaine multiplex , Phylogenèse , Europe , ADN ribosomique/génétiqueRÉSUMÉ
The rat lungworm Angiostrongylus cantonensis is a metastrongyloid nematode that causes neurological disorders in its accidental hosts, including humans. This invasive pathogen is native to Southeast Asia and adjacent regions and is gradually expanding its distribution to tropical and subtropical areas with new foci discovered near temperate regions. The parasite has a complex life cycle with a range of gastropods serving as intermediate hosts. A broad spectrum of poikilotherm vertebrates and invertebrates can serve as paratenic hosts. Since it has already been demonstrated that other, non-zoonotic metastrongyloids can survive in their intermediate hosts during the winter, the aim of our study was to evaluate the survival of A. cantonensis third-stage larvae in experimentally infected slugs (Limax maximus) kept at 4.57°C for 60 days. Third-stage larvae of A. cantonensis survived the period of low temperature and remained capable of infecting definitive hosts (laboratory rats) afterwards, even though their numbers dropped significantly. These results suggest that further spread to higher latitudes or altitudes is possible in areas with sufficient abundance of definitive hosts, since low winter temperatures are not necessarily an obstacle to the spread of the parasite.
Sujet(s)
Angiostrongylus cantonensis , Angiostrongylus , Infections à Strongylida , Humains , Rats , Animaux , Escargots/parasitologie , Larve , Étapes du cycle de vie , Saisons , Infections à Strongylida/médecine vétérinaire , Infections à Strongylida/parasitologieRÉSUMÉ
Rapid increases in human populations and environmental changes of past decades have led to changes in rates of contact and spatial overlap with wildlife. Together with other historical, social and environmental processes, this has significantly contributed to pathogen transmission in both directions, especially between humans and non-human primates, whose close phylogenetic relationship facilitates cross-infections. Using high-throughput amplicon sequencing, we studied strongylid communities in sympatric western lowland gorillas, central chimpanzees and humans co-occurring in an unprotected area in the northern periphery of the Dja Faunal Reserve, Cameroon. At the genus level, we classified 65 strongylid ITS-2 amplicon sequencing variants (ASVs) in humans and great apes. Great apes exhibited higher strongylid diversity than humans. Necator and Oesophagostomum were the most prevalent genera, and we commonly observed mixed infections of more than one strongylid species. Human strongylid communities were dominated by the human hookworm N. americanus, while great apes were mainly infected with N. gorillae, O. stephanostomum and trichostrongylids. We were also able to detect rare strongylid taxa (such as Ancylostoma and Ternidens). We detected eight ASVs shared between humans and great apes (four N. americanus variants, two N. gorillae variants, one O. stephanostomum type I and one Trichostrongylus sp. type II variant). Our results show that knowledge of strongylid communities in primates, including humans, is still limited. Sharing the same habitat, especially outside protected areas (where access to the forest is not restricted), can enable mutual parasite exchange and can even override host phylogeny or conserved patterns. Such studies are critical for assessing the threats posed to all hosts by increasing human-wildlife spatial overlap. In this study, the term "contact" refers to physical contact, while "spatial overlap" refers to environmental contact.
Sujet(s)
Ancylostoma , Pan troglodytes , Animaux , Humains , Cameroun/épidémiologie , Phylogenèse , Animaux sauvagesRÉSUMÉ
Invasive wild mammals are present in all continents, with Europe, North America, and the Asian-Pacific region having the largest number of established species. In particular, Europe has been the continent with the highest number of zoonotic parasites associated with invasive wild mammals. These invasive species may represent a major threat for the conservation of native ecosystems and may enter in the transmission cycle of native parasites, or act as spreaders of exotic parasites. Here, we review the role of invasive wild mammals as spreaders of zoonotic parasites, presenting important examples from Europe, America, and the Asia-Pacific region. Finally, we emphasize the need for more research on these mammals and their parasites, especially in areas where their monitoring is scantily performed.
Sujet(s)
Animaux sauvages , Parasites , Animaux , Écosystème , Mammifères , Asie/épidémiologieRÉSUMÉ
BACKGROUND: Vector-borne pathogens (VBPs) are a major threat to humans, livestock and companion animals worldwide. The combined effect of climatic, socioeconomic and host composition changes favours the spread of the vectors, together with the expansion of invasive carnivores contributing to the spread of the pathogens. In Europe, the most widespread invasive species of carnivores are raccoons (Procyon lotor) and raccoon dogs (Nyctereutes procyonoides). This study focused on the detection of four major groups of VBPs namely Babesia, Hepatozoon, Anaplasma phagocytophilum and Bartonella in invasive and native carnivores in the Czech Republic, with the emphasis on the role of invasive carnivores in the eco-epidemiology of said VBPs. METHODS: Spleen samples of 84 carnivores of eight species (Canis aureus, Canis lupus, Lynx lynx, P. lotor, Martes foina, Lutra lutra, Mustela erminea and N. procyonoides) were screened by combined nested PCR and sequencing for the above-mentioned VBPs targeting 18S rRNA and cytB in hemoprotozoa, groEL in A. phagocytophilum, and using multilocus genotyping in Bartonella spp. The species determination is supported by phylogenetic analysis inferred by the maximum likelihood method. RESULTS: Out of 84 samples, 44% tested positive for at least one pathogen. Five different species of VBPs were detected in P. lotor, namely Bartonella canis, Hepatozoon canis, Hepatozoon martis, A. phagocytophilum and Bartonella sp. related to Bartonella washoensis. All C. lupus tested positive for H. canis and one for B. canis. Three VBPs (Hepatozoon silvestris, A. phagocytophilum and Bartonella taylorii) were detected in L. lynx for the first time. Babesia vulpes and yet undescribed species of Babesia, not previously detected in Europe, were found in N. procyonoides. CONCLUSIONS: Wild carnivores in the Czech Republic are hosts of several VBPs with potential veterinary and public health risks. Among the studied carnivore species, the invasive raccoon is the most competent host. Raccoons are the only species in our study where all the major groups of studied pathogens were detected. None of the detected pathogen species were previously detected in these carnivores in North America, suggesting that raccoons adapted to local VBPs rather than introduced new ones. Babesia vulpes and one new, probably imported species of Babesia, were found in raccoon dogs.
Sujet(s)
Babesia , Carnivora , Lynx , Loutres , Animaux , Humains , Chiens viverrins , Ratons laveurs , République tchèque/épidémiologie , Phylogenèse , Babesia/génétiqueRÉSUMÉ
Domestic camels (Camelus bactrianus, the Bactrian camel; and Camelus dromedarius, the dromedary) are pseudo-ruminant herbivores kept as livestock in rural, inhospitable regions (cold deserts and dry steppes of Asia, arid to semi-arid regions of Africa, western and central Asia). Their close contact with humans makes them a potential reservoir for zoonotic parasite infections, as has been suggested for human balantidiasis. However, there is confusion about the ciliate species that infects camels: Infundibulorium cameli was originally described in dromedaries, but this name has almost never been used and most authors identified their findings as Balantioides coli and, to a lesser extent, Buxtonella sulcata, a cattle ciliate. To clarify the taxonomic status of the parasite and the corresponding zoonotic significance for camels, we performed morphological characterization of cysts and genetic analysis (SSU-rDNA and ITS markers) of B. coli-like isolates from Bactrian camels from Bulgaria and from dromedaries from Spain and the United Arab Emirates. Our results indicate that the camel ciliate is not B. coli, nor is it B. sulcata, but is a different species that should be placed in the same genus as the latter. Thus, camels are not a reservoir for human balantidiasis. Although the correct genus name would be Infundibulorium according to the principle of priority, this would lead to confusion since this name has almost fallen into disuse since its initial description, but Buxtonella is almost universally used by researchers and veterinarians for the cattle ciliate. We therefore propose to apply the reversal of precedence and use Buxtonella as the valid genus name. Consequently, we propose Buxtonella cameli n.comb. as the name for the camel ciliate.
Sujet(s)
Balantidiase , Maladies des bovins , Bovins , Animaux , Humains , Chameaux/parasitologie , Balantidiase/médecine vétérinaire , Zoonoses/épidémiologie , Asie , AfriqueRÉSUMÉ
Among vector-borne helminths, filarioids of the genus Dipetalonema (Spirurida: Onchocercidae) localize in several tissues and body cavities of several animal species, causing mild to moderate lesions. The pathological findings associated with Dipetalonema spp. infection in Neotropical monkeys from southern Brazil are herein described, along with a fatal case due to filarial polyserositis and entrapment of an intestinal segment. At necropsy, nematodes were observed in abdominal and thoracic cavities, or in the pericardium of 37 (31.3%) out of the 118 individuals examined (i.e., 35 Alouatta guariba clamitans and two Sapajus nigritus). In addition, at histology, 27.0% of positive animals presented microfilarie (inside blood vessels of lung, spleen, liver, and brain) and 8.1% presented adult nematodes in the heart, lung, and liver. In two cases, cross-sections of filarioids were associated with areas of epicardial thickening with intense fibrosis and pyogranulomatous inflammation in the brain, heart, liver, lungs, or spleen. The DNA fragment was amplify using the cox1 gene, sequenced and analyzed to identify the nematode species collected; presence of Wolbachia was assessed in the filarioids using the 16S rRNA gene. At BLAST analysis of the cox1 gene, 10 sequences showed 91.7% nucleotide identity with Dipetalonema gracile, and two with D. gracile (98.5%) and Dipetalonema graciliformis (98.3%). Phylogenetic analyses clustered sequences of the cox1 obtained in this study in two clades corresponding with the host species. Wolbachia sp. endosymbiont was detected in four samples. Data herein reported provide a description of pathological lesions associated with the infection by Dipetalonema spp., suggesting that they may cause disease in Neotropical monkeys. In addition, a better understanding of diversity and biology of Dipetalonema spp. in South America is needed to assess the impact they may cause in native non-human primates from Brazil.
Sujet(s)
Infections à Dipetalonema , Dipetalonema , Filarioidea , Nematoda , Spirurida , Animaux , Dipetalonema/génétique , Spirurida/génétique , Brésil/épidémiologie , Haplorhini/génétique , Phylogenèse , ARN ribosomique 16S/génétique , Filarioidea/génétique , Infections à Dipetalonema/parasitologie , Nematoda/génétiqueRÉSUMÉ
Human angiostrongylosis is an emerging zoonosis caused by the larvae of three species of metastrongyloid nematodes of the genus Angiostrongylus, with Angiostrongylus cantonensis (Chen, 1935) being dominant across the world. Its obligatory heteroxenous life cycle includes rats as definitive hosts, mollusks as intermediate hosts, and amphibians and reptiles as paratenic hosts. In humans, the infection manifests as Angiostrongylus eosinophilic meningitis (AEM) or ocular form. Since there is no comprehensive study on the disease in the Indian subcontinent, our study aims at the growing incidence of angiostrongylosis in humans, alongside its clinical course and possible causes. A systematic literature search revealed 28 reports of 45 human cases from 1966 to 2022; eosinophilic meningitis accounted for 33 cases (75.5%), 12 cases were reported as ocular, 1 case was combined, and 1 case was unspecified. The presumed source of infection was reported in 5 cases only. Importantly, 22 AEM patients reported a history of eating raw monitor lizard (Varanus spp.) tissues in the past. As apex predators, monitor lizards accumulate high numbers of L3 responsible for acute illness in humans. For ocular cases, the source was not identified. Most cases were diagnosed based on nematode findings and clinical pathology (primarily eosinophilia in the cerebrospinal fluid). Only two cases were confirmed to be A. cantonensis, one by immunoblot and the other by q-PCR. Cases of angiostrongylosis have been reported in Delhi, Karnataka, Kerala, Maharashtra, Madhya Pradesh, Puducherry, Telangana, and West Bengal. With a population of more than 1.4 billion, India is one of the least studied areas for A. cantonensis. It is likely that many cases remain undetected/unreported. Since most cases have been reported from the state of Kerala, further research may focus on this region. Gastropods, amphibians, and reptiles are commonly consumed in India; however, typical preparation methods involve cooking, which kills the nematode larvae. In addition to studying rodent and mollusk hosts, monitor lizards can be used as effective sentinels. Sequence data are urgently needed to answer the question of the identity of Angiostrongylus-like metastrongylid nematodes isolated from all types of hosts. DNA-based diagnostic methods such as q-PCR and LAMP should be included in clinical diagnosis of suspected cases and in studies of genetic diversity and species identity of nematodes tentatively identified as A. cantonensis.
RÉSUMÉ
Tick-transmitted apicomplexans of the genera Cytauxzoon and Hepatozoon affect a wide range of felids worldwide, but little is known about them. Recently, several studies addressed the species circulating in Europe, their distribution, and their hosts. Molecular assays are the method of choice for their detection. Unfortunately, conventional PCRs already described are time- and cost-consuming and specific for either Hepatozoon or Cytauxzoon detection. This study was developed to evaluate (i) the occurrence of Cytauxzoon and Hepatozoon in felids using a fast and cost-saving real-time PCR capable of detecting both protozoa simultaneously, (ii) the distribution of Cytauxzoon and Hepatozoon species in north-eastern Italy, and (iii) the involvement of other susceptible felid hosts in the same area. An SYBR® Green-based real-time PCR with primers targeting the 18S-rRNA was validated and applied to 237 felid samples, i.e., whole blood from 206 domestic cats and 12 captive exotic felids, and tissues from 19 wildcats. Positive results were obtained by melting temperature curve analysis due to the specific melting peak (i.e., 81°C Cytauxzoon spp.; 78-78.5°C Hepatozoon spp.). Positive samples were subjected to conventional PCR, followed by sequencing for species identification. Phylogenetic analyses were performed to assess relatedness among European isolates. Data on domestic cats (age class, sex, origin, management, and lifestyle) were recorded, and statistical analyses were performed to identify potential risk factors. A total of 31 (15%) domestic cats were positive for Hepatozoon spp. (i.e., 12 for H. felis, 19 for H. silvestris), while six (2.9%) for C. europaeus. The prevalence of Hepatozoon felis was significantly (p < 0.05) higher in domestic cats, while H. silvestris was higher in strays and animals from the Eastern region (i.e., Friuli-Venezia Giulia). Cytauxzoon europaeus was detected only in stray cats from Friuli-Venezia Giulia (province of Trieste). Among captive felids, one tiger was infected with H. felis and another with H. silvestris; eight out of 19 (42%) wildcats were positive for Hepatozoon spp. (i.e., six with H. felis, two with H. silvestris) and four out of 19 (21%) for Cytauxzoon europaeus. Outdoor lifestyle and origin (i.e., Friuli-Venezia Giulia region) were the most relevant risk factors for H. silvestris and C. europeus infections. Conversely, H. felis was most frequently isolated from domestic cats, suggesting different modes of transmission.
RÉSUMÉ
BACKGROUND: Angiostrongylus cantonensis (rat lungworm) is recognised as the leading cause of human eosinophilic meningitis, a serious condition observed when nematode larvae migrate through the CNS. Canine Neural Angiostrongyliasis (CNA) is the analogous disease in dogs. Both humans and dogs are accidental hosts, and a rapid diagnosis is warranted. A highly sensitive PCR based assay is available but often not readily accessible in many jurisdictions. An alternative DNA amplification assay that would further improve accessibility is needed. This study aimed to assess the diagnostic utility of a newly designed LAMP assay to detect DNA of globally distributed and invasive A. cantonensis and Angiostrongylus mackerrasae, the other neurotropic Angiostrongylus species, which is native to Australia. METHODOLOGY/PRINCIPAL FINDINGS: Cerebrospinal fluid (CSF) from dogs with a presumptive diagnosis of A. cantonensis infection (2020-2022) were received for confirmatory laboratory testing and processed for DNA isolation and ultrasensitive Angiostrongylus qPCR targeting AcanR3390. A newly designed LAMP assay targeting the same gene target was directly compared to the reference ultrasensitive qPCR in a diagnostic laboratory setting to determine the presence of A. cantonensis DNA to diagnose CNA. The LAMP assay (Angie-LAMP) allowed the sensitive detection of A. cantonensis DNA from archived DNA specimens (Kappa = 0.81, 95%CI 0.69-0.92; n = 93) and rapid single-step lysis of archived CSF samples (Kappa = 0.77, 95%CI 0.59-0.94; n = 52). Only A. cantonensis DNA was detected in canine CSF samples, and co-infection with A. mackerrasae using amplicon deep sequencing (ITS-2 rDNA) was not demonstrated. Both SYD.1 and AC13 haplotypes were detected using sequencing of partial cox1. CONCLUSIONS/SIGNIFICANCE: The Angie-LAMP assay is a useful molecular tool for detecting Angiostrongylus DNA in canine CSF and performs comparably to a laboratory Angiostrongylus qPCR. Adaptation of single-step sample lysis improved potential applicability for diagnosis of angiostrongyliasis in a clinical setting for dogs and by extension, to humans.
Sujet(s)
Angiostrongylus cantonensis , Angiostrongylus , Méningite , Infections à Strongylida , Humains , Chiens , Rats , Animaux , Angiostrongylus cantonensis/génétique , Escargots/génétique , Infections à Strongylida/diagnostic , Infections à Strongylida/médecine vétérinaire , Angiostrongylus/génétique , ADN ribosomique , Méningite/diagnostic , Méningite/médecine vétérinaireRÉSUMÉ
The brown dog tick Rhipicephalus sanguineus (sensu lato) in the southeastern Mediterranean region and the Middle East is difficult to identify due to the presence of multiple mitochondrial DNA haplogroup lineages. The purpose of this study was to clarify the identity of the "southeastern Europe" lineage of this tick species complex. Our research shows that female ticks of the "southeastern Europe" lineage correspond to the morphology of R. rutilus Koch, 1844 as found in type-material at the Museum für Naturkunde Berlin in Germany. We characterised the complete mitogenomes of R. rutilus, R. turanicus Pomerantsev, 1940 and Rhipicephalus sanguineus (Latreille, 1806) in order to improve our understanding of the phylogenetic relationships among species within the R. sanguineus (sensu lato) complex. The material associated with the morphology of R. rutilus was previously labelled as the "southeastern Europe" lineage and found in Israel and Egypt, including Lower Egypt and the Nile Delta, where the original type-material was collected. Based on the morphology, genetic identity, and geographical distribution of the species, we conclude that the name R. rutilus is correctly linked to the "southeastern Europe" lineage of R. sanguineus (sensu lato).
RÉSUMÉ
BACKGROUND: Endemic lizards of the genus Gallotia are of high ecological value to the terrestrial ecosystem of the archipelago of the Canary Islands, being potent seed spreaders as well as an important component of the diet of other vertebrates. The endemic lizard Gallotia galloti in Tenerife has recently been reported to be a paratenic host of Angiostrongylus cantonensis, an invasive metastrongylid with zoonotic potential that is associated with rats as definitive hosts. However, microscopic examination of G. galloti tissue samples also revealed the presence of other metastrongylid larvae inside granulomas on the liver of this reptile. The aim of this study was to investigate the presence of helminths other than A. cantonensis in tissues of G. galloti from Tenerife. METHODS: A multiplex-nested PCR targeting the internal transcribed spacer 1 was designed that enabled the species-specific detection of A. cantonensis, Angiostrongylus vasorum, Aelurostrongylus abstrusus, Crenosoma striatum and Crenosoma vulpis. Liver samples from 39 G. galloti were analysed. RESULTS: Five metastrongylids were detected: A. cantonensis (15.4% of samples analysed), A. vasorum (5.1%), Ae. abstrusus (30.8%), C. striatum (30.8%) and undetermined metastrongylid sequences (12.8%). Co-infection was highly prevalent among the lizards which tested positive. CONCLUSIONS: The study provides a new specific tool for the simultaneous detection of a range of metastrongylids of veterinary importance as well as new data on the circulation of metastrongylids in an ecosystem dominated by lizards.