Helmintos, piolhos, ácaros nasais e microrganismos aeróbicos associados à Sternidae (Aves: Charadriiformes) na região costeira do extremo sul do Brasil

Abstract

The parasites are most often ignored in faunal studies. Due to the great richness of Brazilian fauna, for many species we have not yet been conducted studies on the parasitic fauna, including those belonging to the family Sternidae. Six species of Sternidae are often found on the southern coast of South America. Sterna trudeaui, S. hirundinacea, Thalasseus maximus, T. acuflavidus and Sternula superciliaris South American residents and Sterna hirundo, nearctic migrant. These birds can also be considered carriers or potential reservoirs of several pathogenic bacterial genera and contaminate the environment or the surface of the water used for drinking, recreation or irrigation, playing an important role in the epidemiological chain of diseases with zoonotic potential. Thus, the study of microorganisms associated with wild sea birds is also essential to the knowledge of the natural zoonoses outbreaks. Therefore, this study aimed to carry out a survey of helminths, ectoparasites and microorganisms associated with Sternidae on the coast of southern Brazil. To this we were necropsied 106 individuals belonging to the genera Sterna, Thalasseus and Sternula, the lifting of the microbiota was performed in 52 of these through sterile swab of the trachea, lung and intestinal mucosa. Was observed a similarity of 100% between the parasitic helminth assemblies of the nearctic migrant Sterna hirundo and the South American resident S. trudeaui, and 44% of the S. hirundinacea with the others. There is no significant difference between parasite diversity of three species of Sterna birds and these data demonstrate that even when dealing with a migratory bird, which allows contact with a wider range of different environments during their migrations, Sterna hirundo does not present a greater diversity parasitic front of the resident species. Baruscapillaria rudolphii is the dominant specie in the helminth parasites assembly of Sternidae on the southern coast of Brazil. This nematode was found in all species of birds analyzed with a prevalence of 45.3%. It was observed that all species of Sternidae present in southern Brazil coast have a similarity of at least 40% in its assembly of helminth parasites. Of the total number of birds examined 76.4% were parasitized by lice. Seven species belonging to four genera were found, Saemundssonia laticaudata, S. parvigenitalis, S. sternae, S. meridiana, Austromenopon atrofulvum, Actornithophilus piceus piceus and Quadraceps sp. The similarity of Phthiraptera assemblies between different species of Sternidae was at least 57.1% and the most prevalent specie was Quadraceps sp., which was found in 54.4% of the birds. Of the 106 birds analyzed, 8.5% were parasitized by nasal mites. Were found two species, Sternostoma boydi and Larinyssus orbicularis, both have their first records in South America. In 208 samples analyzed were isolated 19 species of bacteria belonging to 10 genera, Enterobacteriaceae and Staphylococcaceae families were the most frequent. Enterobacteriaceae presented five genera while Staphylococcaceae was represented only by Staphylococcus. There were not isolated fungi in the samples. Escherichia coli was the most common species, isolated from 23.1% of the birds.