This study verifies the identity of adult specimens of the parasite Profilicollis chasmagnathi (Acanthocephala, Polymorphidae) recovered from kelp gulls Larus dominicanus (Aves, Laridae), and cystacanths found in crabs Cyrtograpsus altimanus (Crustacea, Decapoda) from the southwestern Atlantic coast. The life cycle of this parasite is elucidated in the intertidal zone of Patagonia, Argentina, based on morphological and molecular data. Preferences by size and sex of the intermediate host and seasonal variation of this parasite are provided, contributing to the knowledge of this host-parasite association.

Gigantobilharzia Odhner, 1910 (Schistosomatidae) includes species that parasitize several orders of birds and families of gastropods from both freshwater and marine environments worldwide. Due to their delicate bodies, most of the species descriptions are incomplete, and lumped in the genus Gigantobilharzia, in some cases despite major morphological variability. Only three of those species have molecular sequence data but then lack a robust morphological description, making species differentiation very difficult. For this reason, several authors consider that many of the species of Gigantobilharzia should be reassigned to new genera. The aim of this paper is to describe two new genera and two new species of schistosomes using morphological and molecular characterization. We described Marinabilharzia patagonense n. g., n. sp. parasitizing Larus dominicanus from north Patagonian coast, and Riverabilharzia ensenadense n. g., n. sp. parasitizing L. dominicanus, Chroicocephalus maculipennis and Chroicocephalus cirrocephalus from freshwater Río de La Plata, in South America, Argentina. We then analysed and discussed the combinations of characters defining species of Gigantobilharzia and, based on that and on the available molecular data, we propose at least four possible new genera.

The aim of this work is to contribute to the knowledge of gastrointestinal parasites of the European starling Sturnus vulgaris, an invasive bird from Argentina. Seventy-six birds were collected during the spring of 2007 and were examined for helminths. Six parasite species were found: one trematoda of the Echinostoma revolutum "group," four nematodes (Synhimantus nasuta, Microtetrameres sp., Pterothominx exilis, and Ornithocapillaria ovopunctata), and one acanthocephalan (Plagiorhynchus cylindraceus). All species found have been recorded in Eurasia and/or North America previously, although present reports enlarge their geographical distribution. As expected in an invasive host, the parasite community shows much lower species richness (n = 6) than those observed in their native area (79 and 35 in the Eurasia and North America, respectively).

SummaryThe aim of this study is to describe the nematode cysts and larvae found in Achatina fulica, the giant African snail, in the northeast of Argentina. A total of 373 snails were collected from the cities of Puerto Iguazú and Corrientes. Cysts (N= 2958) containing nematodes identifi ed as L3 Strongyluris sp. were found in the mantle cavity of 87 snails from Puerto Iguazú City (Prevalence 23 %; Mean Intensity= 34; Mean Abundance= 8). The shell size correlated with prevalence, mean intensity and mean abundance (p<0.05) indicating that there is an exposure-infection constant rather than an accidental one. In other hand, the absence of infection in the smallest shell size suggests a threshold of size to be infected. Taking into account that there exist records of A. fulica infected by nematodes of medical and veterinary importance such as Angiostrongylus and Aelurostrongylus in some Brazilian states near Puerto Iguazú, we emphasize the need for snail surveillance.

Although knowledge about parasitic diseases in Antarctic birds is scarce, an increasing number of studies are currently being carried out in this area. The importance of the host-parasite relationship in Antarctic seabirds is key to understanding trophic ecology and epidemiology of infection diseases, especially in those birds with extensive migratory routes that can act as reservoirs and distributors of diseases. This study aims to provide information on helminths of two Storm Petrel species, the Wilson’s storm-petrel Oceanites oceanicus and the Black-bellied storm-petrel Fregetta tropica. Twenty individuals were analysed: 18 O. oceanicus (8 adults, 10 chicks) and 2 F. tropica (adults); 89% of the O. oceanicus were parasitized with the nematode Stegophorus macronectes, whereas 100% of F. tropica was parasitized by at least one of three parasite species identified: S. macronectes, Seuratiasp., and Tetrabothrius sp. The low richness of parasites observed is associated with a stenophagic diet. However, a clear difference is observed between both species related to a higher fish ingestion by F. tropica, unlike O. oceanicus with a higher ingestion of krill.

The aim of this communication was to establish if Enterobacterales associated with gulls in Argentina harbored antimicrobial resistance (AMR) genes. We analyzed cloacal swabs in two contrasting areas: Ensenada, Buenos Aires province (26 Larus dominicanus and 22 Chroicocephalus maculipennis) and Puerto Madryn, Chubut province (20 L. dominicanus). In Ensenada, bla CTX-M and mcr-1 genes, were isolated from both gull species, whereas in the Puerto Madryn, only bla CTX-M gene was found. We report for the fi rst time C. maculipennis as carrier of AMR. The fi nding of AMR in wildlife constitutes a useful tool in evaluating the anthropogenic impact on environmental health.

No abstract

Haemosporidia (Apicomplexa, Haemosporida) are protozoa that infect vertebrate blood cells and are transmitted by vectors. Among vertebrates, birds possess the greatest diversity of haemosporidia, historically placed in 3 genera: Haemoproteus, Leucocytozoon and Plasmodium, the causative agent of avian malaria. In South America, existing data on haemosporidia are spatially and temporally dispersed, so increased surveillance is needed to improve the determination and diagnosis of these parasites. During the non-breeding season in 2020 and 2021, 60 common terns (Sterna hirundo) were captured and bled as part of ongoing research on the population health of migratory birds on the Argentinian Atlantic coast. Blood samples and blood smears were obtained. Fifty-eight samples were screened for Plasmodium, Haemoproteus and Leucocytozoon, as well as for Babesia parasites by nested polymerase chain reaction and by microscopic examination of smears. Two positive samples for Plasmodium were found. The cytochrome b lineages detected in the present study are found for the first time, and are close to Plasmodium lineages found in other bird orders. The low prevalence (3.6%) of haemoparasites found in this research was similar to those reported for previous studies on seabirds, including Charadriiformes. Our findings provide new information about the distribution and prevalence of haemosporidian parasites from charadriiforms in the southernmost part of South America, which remains understudied.