Angiostrongylus chabaudi Biocca, 1957: a new parasite for domestic cats?
© Varcasia et al.; licensee BioMed Central. 2014
Received: 29 October 2014
Accepted: 2 December 2014
Published: 17 December 2014
Natural infection with a species of Angiostrongylus has been reported only once in wildcats from central Italy by Biocca in 1957. The causative species of this infection was identified as Angiostrongylus chabaudi. Following this report, this parasite had never been found in either wild or domestic cats.
The lungs and the pulmonary arteries of an adult female cat (Felis silvestris catus), road-killed in Sardinia, Italy, were macroscopically examined and dissected under a light microscope for the presence of parasites. A slender nematode was detected and its morphometrical features were consistent with those of A. chabaudi. Morphological data were supplemented by sequencing of the partial cytochrome oxidase c subunit 1 (cox 1) gene, as well as the internal transcribed spacer 2 (ITS2) of the rDNA. Nucleotide sequences displayed 99% homology with the ITS2 sequence [GenBank KM216825.1] of a specimen of Angiostrongylus sp. recovered recently from the pulmonary artery of a wildcat in Germany and 91% with cox 1 sequence [GenBank GU138118.1] of Angiostrongylus vasorum.
The results of the present study indicate, for the first time, that A. chabaudi may also infect domestic cats, and thus should be considered in the diagnosis of metastrongyloid species infecting their cardio-pulmonary system.
Nematodes affecting the cardio-pulmonary system of pets have recently attracted the interest of researchers due to their increasing distribution in several European countries . This is the case of Aelurostrongylus abstrusus and Eucoleus aerophilus (syn. Capillaria aerophila) in cats and of Angiostrongylus vasorum in dogs . Recent reports of infections caused by other members of the superfamily Metastrongyloidea in domestic cats (e.g., Oslerus rostratus, Troglostrongylus brevior and Troglostrongylus subcrenatus) have further stimulated the interest of the scientific community on these little known species -. In addition, cats may act as permissive hosts of A. vasorum, although the first-stage larvae of this nematode are not shed in the faeces of experimentally infected animals ,. A natural infection with a species of Angiostrongylus has been reported only once in wildcats from central Italy by Biocca in 1957, who described and named the causative species as Angiostrongylus chabaudi. Following this report, the species has never been found in either wild or domestic cats. Fifty-seven years after its description, we report the presence of A. chabaudi in a domestic cat from Sardinia together with the first molecular characterization of this little known angiostrongylid infecting cats.
The material originated from an adult female cat, road-killed in the municipality of Villacidro, province of Cagliari, Sardinia, Italy (39°27’33”N, 8°44’02E”). Upon inspection of the pulmonary arteries, a slender nematode was retrieved. This parasite was washed in saline solution and subsequently mounted on a slide with glycerol, for microscopical observation. Light microscopy images and measurements were taken using a digital image processing system (Olympus BX41; Soft Imaging solution GMBH LG20, Munster, Germany). The parasite was identified to the species level using morphological keys ,. A faecal sample was also collected from the rectum of the cat and processed by Baermann method for the detection of first-stage larvae of broncho-pulmonary nematodes . The genetic identity of the cat (i.e., Felis silvestris silvestris, Felis silvestris lybica, Felis silvestris catus or hybrid) was assessed molecularly on a muscle sample as described elsewhere .
Following parasite identification, DNA was extracted from the mid-body of the nematode using a commercial kit (High Pure PCR Template Preparation kit, Roche Diagnostics, Mannheim, Germany). Partial mithocondrial cytochrome c oxidase subunit 1 (cox 1) gene and the internal transcribed spacer 2 (ITS2) of the rRNA gene were amplified, as previously described ,. PCR amplicons were purified using an Exo SAP-IT kit (Amersham Biosciences) and sequenced through an external service (MWG Eurofins), using the same primers as for the PCR. Nucleotide sequences were compared with those available in GenBank® using the basic local alignment search tool (BLAST) analysis (National Centre for Biotechnology Information, ncbi.nlm.nih.gov). In order to investigate the relationships among metastrongyloids affecting wild and domestic carnivores, sequences of cox 1 and ITS2 were analysed with those available in GenBankTM. The evolutionary history was inferred for ITS2, using the maximum parsimony method using the Subtree-Pruning-Regrafting (SPR) algorithm with the software MEGA 6 . The bootstrap consensus trees inferred from over 8,000 replicates were taken to represent the evolutionary history of the taxa analysed. The ITS2 sequence of Nematodirus battus was used as an outgroup.
Measurements for the known species of Angiostrongylus reported in carnivores
Dog, Coyote, Fox, Jackal, Wolf
Badger, Pine marten, Beech marten
American badger, Striped skunk
14.6 - 16.3
13.90 ± 4.75 (n = 11)
19.36 ± 7.69 (n = 6)
14.0 - 15.5
13.36 - 21.31
18 - 19.5
185 - 225
221.40 ± 12.13 (n = 11)
243.20 ± 19.63 (n = 6)
170 - 235
254 - 306
300 - 335
300 - 345
255.33 ± 13.60 (n = 8)
333.30 ± 18.24 (n = 6)
220 - 275
336 - 366
300 - 325
Distance from excretory pore to cephalic end
335 - 405
356.50 ± 34.68 (n = 4)
409.5 ± 25.50 (n = 2)
310 - 350
386 - 463
510 - 555
411.06 ± 17.71 (n = 10)
345.57 ± 23.95 (n = 8)
400 - 500
336 - 409
520 - 560
19.1 - 24.1
18.97 ± 10.21 (n = 22)
24.76 ± 13.66 (n = 16)
15 - 20.5
14.39 - 31.12
22 - 24
245 - 298
304.14 ± 14.84 (n = 18)
344.52 ± 17.95 (n = 17)
220 - 306
340 - 511
345 - 380
279.88 ± 20.27 (n = 14)
368.45 ± 17.00 (n = 16)
240 - 280
356 - 556
335 - 350
Distance from excretory pore to cephalic end
395 - 470
391.86 ± 21.44 (n = 7)
447.40 ± 101.72 (n = 5)
350 - 370
379 - 636
Distance from vulva to anus
233.63 ± 32.41 (n = 17)
295.15 ± 46.25 (n = 16)
150 - 220
Distance from anus to caudal end
62 - 75
69.70 ± 2.87 (n = 17)
78.82 ± 3.45 (n = 16)
67 - 100
76 - 115
75 - 95
Distance from vulva to caudal end
170 - 210
275.66 ± 30.75 (n = 18)
366.25 ± 44.17 (n = 16)
220 - 315
269 - 412
The BLASTn of cox 1 sequences herein obtained displayed a nucleotide homology of 91% with A. vasorum [GenBank GU138118.1], 89% with Angiostrongylus cantonensis [GenBank GU138111.1] 88% with A. abstrusus [GenBank KF316481.1] and of 87% with Angiostrongylus costaricensis [GenBank GU138117.1]. Interestingly, the ITS2 sequence displayed 99% nucleotide identity with ITS2 of Angiostrongylus sp. [GenBank KM216825.1], recovered recently from the pulmonary artery of a wildcat in Germany and identity of 87% with A. vasorum [GenBank GU045375.1]. The ITS2 sequence of A. chabaudi displayed lower levels of homology of 79%, 85% and 79%, respectively, with A. dujardini [GenBank GQ181113.1], A. costaricensis [GenBank LK942974.1] and A. cantonensis [GenBank LK949842.1].
Fifty-seven years after its original description , A. chabaudi is reported here for the first time in a domestic cat from Sardinia. In addition, the present study represents the first report, ever, of an angiostrongylid of the genus Angiostrongylus naturally infecting domestic cat. The recovery of this nematode is of importance as it suggests that cats may also be infected by metastrongyloids localizing in the cardio-vascular system. Morphological features and size of the parasite found in the present survey are similar to those reported in the original description of A. chabaudi (Table 1). Although eggs were observed in the uterus of the specimen herein studied, the absence of specific first-stage larvae at the Baermann test indicates that the parasite was an immature or unfertilized female, thereby explaining its smaller size compared to that previously recorded . The morphometry of the parasite here described differs from that of A. vasorum in dogs and wildlife hosts (Table 1) , in that four sensorial papillae are present in the anterior region posteriorly to perityls, and the distance between the vulvar aperture and the caudal extremity (i.e., 160.6 μm) is significantly shorter than in other species of Angiostrongylus but similar to that of A. chabaudi (170-210 μm) (Table 1). These morphological differences were also clearly supported by the nucleotide homology with sequences from other species (i.e., up to 91% for cox 1 sequences with that of A. vasorum). The phylogenetic analyses, based on ITS2, supported their morphological identification, in that sequences derived from this nematode were clustered within those belonging to the genus Angiostrongylus.
In the original description, A. chabaudi was considered typical for wildcats, having been found in 85% of a sample from central Italy, but not in stray cats and dogs or in other wildlife species (i.e., Meles meles and Vulpes vulpes) from the same area .
Here A. chabaudi is reported for the first time in a domestic cat. No data are available on the presence of this nematode in wildcats from Sardinia, which belong to another subspecies (F. silvestris lybica) than that found in continental Italy . Therefore, at least for Sardinia, it is not yet possible to infer that wildcats may be regarded as wild reservoirs of A. chabaudi. On the other hand, according to Biocca’s study , wildcats may be highly infected by A. chabaudi. In addition, the ITS2 sequence of A. chabaudi herein characterized displayed a very high nucleotide homology (99%) with that of Angiostrongylus sp. collected from a wildcat in Germany. Also, both nematodes above were collected from the pulmonary artery, which is the same site of collection of A. chabaudi as described by Biocca .
The data presented here suggest that a careful inspection of the vascular system of lungs should be undertaken during necropsies of domestic and wild cats. Also, first-stage larvae of A. chabaudi have not been described so far  and thus their morphological delineation from those of other metastrongyloids affecting felids warrants investigation. Additional studies should elucidate the life history of A. chabaudi, determine its distribution and impact of this little known parasite on the health of wild and domestic cats.
The research was funded by the Regional Government of Sardinia, prot. CRP2 134 (L.R. 7, 2007). The authors thank Miss Claudia Serra (University of Sassari, Italy) for the parasite drawings, Dr. Stefania Latrofa and Dr. Bronwyn Campbell (University of Bari, Italy) for revising the English and the phylogenetical analysis. Authors thanks Dr. Ettore Randi and Dr. Federica Mattucci, Istituto Superiore per la Protezione e la Ricerca Ambientale (ISPRA), Bologna, Italy for the genetic analyses performed to assess cat genotype.
- Conboy G: Helminth parasites of the canine and feline respiratory tract. Vet Clin North Am Small Anim Pract. 2009, 39: 1109-1126.View ArticlePubMedGoogle Scholar
- Traversa D, Di Cesare A, Conboy G: Canine and feline cardiopulmonary parasitic nematodes in Europe: emerging and underestimated. Parasit Vectors. 2010, 3: 62-PubMed CentralView ArticlePubMedGoogle Scholar
- Millán J, Casanova JC: High prevalence of helminth parasites in feral cats in Majorca Island (Spain). Parasitol Res. 2009, 106: 183-188.View ArticlePubMedGoogle Scholar
- Brianti E, Gaglio G, Giannetto S, Annoscia G, Latrofa MS, Dantas-Torres F, Traversa D, Otranto D:Troglostrongylus brevior and Troglostrongylus subcrenatus (Strongylida: Crenosomatidae) as agents of broncho-pulmonary infestation in domestic cats. Parasit Vectors. 2012, 5: 178-PubMed CentralView ArticlePubMedGoogle Scholar
- Brianti E, Gaglio G, Napoli E, Falsone L, Giannelli A, Annoscia G, Varcasia A, Giannetto S, Mazzullo G, Otranto D: Feline lungworm Oslerus rostratus (Strongylida: Filaridae) in Italy: first case report and histopathological findings. Parasitol Res. 2014, 113: 3853-3857.View ArticlePubMedGoogle Scholar
- Otranto D, Brianti E, Dantas-Torres F:Troglostrongylus brevior and a nonexistent ‘dilemma’. Trends Parasitol. 2013, 29: 517-518.View ArticlePubMedGoogle Scholar
- Tamponi C, Varcasia A, Brianti E, Pipia AP, Frau V, Pinna Parpaglia ML, Sanna G, Garippa G, Otranto D, Scala A: New insights on metastrongyloid lungworms infecting cats of Sardinia, Italy. Vet Parasitol. 2014, 203: 222-226.View ArticlePubMedGoogle Scholar
- Guilhon J, Cens B: Essais de transmission d’Angiostrongylus vasorum (Baillet, 1866) du chat. Comp Rend Acad Sci. 1970, 271: 936-939.Google Scholar
- Dias SRC, Oliveira EL, Viana MH, Lima WS: Permissivity of the domestic cat (Felis catus) to infection by Angiostrongylus vasorum (Nematoda: Protostrongylidae). Revue Méd Vet. 2008, 159: 87-90.Google Scholar
- Biocca E:Angiostrongylus chabaudi n. sp. parassita del cuore e dei vasi polmonari del gatto selvatico (Felis silvestris). R Accad Naz Lincei. 1957, 22: 526-532.Google Scholar
- Costa JO, De Araújo Costa HM, Guimarães MP: Redescription of Angiostrongylus vasorum (Baillet, 1866) and systematic revision of species assigned to the genera Angiostrongylus Kamensky, 1905 and Angiocaulus Schulz, 1951. Revue Méd Vét. 2003, 154: 9-16.Google Scholar
- Mattucci F, Oliveira R, Bizzarri L, Vercillo F, Anile S, Ragni B, Lapini L, Sforzi A, Alves PC, Lyons LA, Randi E: Genetic structure of wildcat (Felis silvestris) populations in Italy. Ecol Evol. 2013, 3: 2443-2458.View ArticleGoogle Scholar
- Gasser RB, Chilton NB, Hoste H, Beveridge I: Rapid sequencing of rDNA from single worms and eggs of parasitic helminths. Nucleic Acids Res. 1993, 21: 2525-2526.PubMed CentralView ArticlePubMedGoogle Scholar
- Caldeira RL, Carvalho OS, Mendonça CL, Graeff-Teixeira C, Silva MC, Ben R, Maurer R, Lima WS, Lenzi HL: Molecular differentiation of Angiostrongylus costaricensis, A. cantonensi s, and A. vasorum by polymerase chain reaction-restriction fragment length polymorphism. Mem Inst Oswaldo Cruz. 2003, 98: 1039-1043.View ArticlePubMedGoogle Scholar
- Tamura K, Stecher G, Peterson D, Filipski A, Kumar S: MEGA6: molecular evolutionary genetics analysis version 6.0. Mol Biol Evol. 2013, 30: 2725-2729.PubMed CentralView ArticlePubMedGoogle Scholar
- Gerrikagoitia X, Barral M, Juste RA:Angiostrongylus species in wild carnivores in the Iberian Peninsula. Vet Parasitol. 2010, 174: 175-180.View ArticlePubMedGoogle Scholar
- Randi E, Pierpaoli M, Beaumont M, Ragni B, Sforzi A: Genetic identification of wild and domestic cats (Felis silvestris) and their hybrids using Bayesian clustering methods. Mol Biol Evol. 2001, 18: 1679-1693.View ArticlePubMedGoogle Scholar
- Janchev J, Genov T:Angiostrongylus daskalovi sp. n. Nematoda: Filaroididae from Mustelidae in Bulgaria. Helminthologia. 1988, 252: 81-88.Google Scholar
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