ABSTRACT
Urban parks are not only important for the wellbeing of the human population, but are also widely considered to be potentially important sites for the conservation of biodiversity. However, they may offer risk parasitic infections, such as schistosomiasis and fascioliasis, which are both transmitted by freshwater snails. The present study investigated the occurrence of freshwater gastropods in urban parks of the Brazilian city of Rio de Janeiro, and their possible infection by helminths of medical-veterinary importance. Gastropods were collected from six parks (2021 - 2022) and examined for the presence of larval helminths. In all, 12 gastropod species from different families were collected: Ampullariidae, Assimineidae, Burnupidae, Lymnaeidae, Physidae, Planorbidae, Succineidae, and Thiaridae. The parasitological examination revealed cercaria of three types in five snail species, with the Pleurolophocerca cercariae type in Melanoides tuberculata (the most abundant species), Echinostoma cercariae in Physella acuta and Pomacea maculata, and Virgulate cercariae, in Pomacea sp. and Pomacea maculata. None of the Biomphalaria tenagophila and Pseudosuccinea columella (the most frequent species) specimens were parasitized by Schistosoma mansoni or Fasciola hepatica, respectively. Even so, some parks may represent a considerable potential risk for transmission of both Schistosoma mansoni and Fasciola hepatica, given the presence of these gastropod vectors and the frequent contact of visitors with the waterbodies.
Subject(s)
Fresh Water , Gastropoda , Parks, Recreational , Animals , Brazil/epidemiology , Fresh Water/parasitology , Gastropoda/parasitology , Gastropoda/classification , Humans , Snails/parasitologyABSTRACT
Acinetobacter baumannii is a Gram-negative, immobile, aerobic nosocomial opportunistic coccobacillus that causes pneumonia, septicemia, and urinary tract infections in immunosuppressed patients. There are no commercially available alternative antimicrobials, and multi-drug resistance is an urgent concern that requires emergency measures and new therapeutic strategies. This study evaluated a multi-drug-resistant A. baumannii whole-cell vaccine, inactivated and adsorbed on an aluminum hydroxide-chitosan (mAhC) matrix, in an A. baumannii sepsis model in immunosuppressed mice by cyclophosphamide (CY). CY-treated mice were divided into immunized, non-immunized, and adjuvant-inoculated groups. Three vaccine doses were given at 0D, 14D, and 28D, followed by a lethal dose of 4.0 × 108 CFU/mL of A. baumannii. Immunized CY-treated mice underwent a significant humoral response, with the highest IgG levels and a higher survival rate (85%); this differed from the non-immunized CY-treated mice, none of whom survived (p < 0.001), and from the adjuvant group, with 45% survival (p < 0.05). Histological data revealed the evident expansion of white spleen pulp from immunized CY-treated mice, whereas, in non-immunized and adjuvanted CY-treated mice, there was more significant organ tissue damage. Our results confirmed the proof-of-concept of the immune response and vaccine protection in a sepsis model in CY-treated mice, contributing to the advancement of new alternatives for protection against A. baumannii infections.
ABSTRACT
An ample variety of parasitic associations are found between mollusks and nematodes, in which the mollusks may act as intermediate, paratenic or definitive hosts. Some free-living nematodes, in particular those of the order Rhabditida, are also found frequently in terrestrial mollusks. The present study reviews the results of the parasitological testing on samples of terrestrial mollusks conducted at the Brazilian National Reference Laboratory for Schistosomiasis and Malacology between 2008 and 2021. The samples were supplied primarily by the public health authorities from the different regions of Brazil, but also by research institutions and general population. The mollusks were processed individually and the obtained larvae were identified from their morphology and, whenever necessary, by molecular analysis. A total of 1,919 service orders were registered during the period, including 19,758 mollusk specimens collected from 23 of the 26 Brazilian states, as well as the Federal District, totalizing 145 municipalities. There was a marked predominance of the synanthropic species that are widely distributed in Brazil-Achatina fulica (87.08%), Bulimulus tenuissimus (4.18%), Bradybaena similaris (2.06%), and Sarasinula linguaeformis (1.50%). Of the 16,750 terrestrial mollusks examined, nematodes were recorded in 1,308 service orders, with the predominance of the superfamily Metastrongyloidea, in 616 service orders. They included Angiostrongylus cantonensis, rat lungworm, which was found in 252 samples, and Aelurostrongylus abstrusus in 145 samples. Free-living nematodes were found in 952 samples, Ancylostoma caninum and Cruzia tentaculata (previously identified as Strongyluris sp.) in one and 275 samples, respectively, and other parasites in 210 samples (not identified). The results highlight the diversity of the associations between nematodes and terrestrial mollusks in Brazil, in particular invasive and synanthropic species, with emphasis on the giant African land snail, Achatina fulica. They demonstrate the prominent role of this species of mollusk in the transmission of medically-important nematodes, which affect the health of both humans and animals, in particular eosinophilic meningitis, which is caused by Angiostrongylus cantonensis. This reinforces the need for more studies, and justify the growing demand for information as well as parasitological diagnosis of this mollusk, given its wide distribution in Brazil and its impact as an urban pest.
ABSTRACT
A prevalência de enteroparasitoses foi observada em crianças usuárias de creches públicas de bairros periféricos do município de Coari, estado do Amazonas, Brasil. Foram realizados exames coproparasitológicos em 211 crianças, com 66,4por cento de amostras positivas. Os agentes etiológicos mais frequentes foram: Ascaris lumbricoides (37por cento), Trichuris trichiura (21,6por cento), ancilostomatídeos (5por cento), Entamoeba histolytica/E. dispar (14por cento), E. coli (11por cento), Giardia duodenalis (4,4por cento), Strongyloides stercoralis (0,8por cento), Endolimax nana (1por cento), Enterobius vermicularis (2,4por cento), Hymenolepis nana (2por cento) e Hymenolepis diminuta (0,4por cento). Para que o problema das parasitoses intestinais seja solucionado nas localidades estudadas, são necessárias ações de orientação sobre prevenção e tratamento para educar o público-alvo, de modo que sejam evitados danos à saúde infantil decorrentes da falta de conhecimento sobre essas enfermidades por parte da família e da escola.
Subject(s)
Humans , Child , Child Day Care Centers , Parasitic Diseases/epidemiology , Poverty AreasABSTRACT
A prevalência de enteroparasitoses foi observada em crianças residentes em comunidades rurais do município de Coari, estado do Amazonas, Brasil. Foram realizados exames coproparasitológicos em 123 crianças, obtendo-se o índice de 74por cento de amostras positivas. Os agentes etiológicos mais frequentes foram: Ascaris lumbricoides (68,1por cento), Trichuris trichiura (41,8por cento), ancilostomatídeos (17,6por cento), Entamoeba histolytica/E. dispar (17,6por cento)por cento), E. coli (11por cento), Giardia duodenalis (9,9por cento), Strongyloides sterocalis (8,8por cento), Endolimax nana (3,3por cento) e Iodamoeba butschilii (1,1por cento). A elevada prevalência de enteroparasitos nas comunidades estudadas demonstra a dificuldade de controlar estas infecções na região amazônica e indica a necessidade de medidas preventivas e educativas adequadas à realidade da região.
