Ectoparasitos de roedores da região urbana de Belo Horizonte, MG. I. Interação entre ectoparasitos e hospedeiros

Um levantamento de ectoparasitos de roedores domesticos da região urbana de Belo Horizonte, Minas Gerais, Brasil, foi realizado no período de junho de 1980 a setembro de 1982. As espécies de ectoparasitos capturadas de 950 Rattus norvegicus foram: Xenopsylla cheopis, Ctenocephalides felis felis, Polyplax spinulosa, Laelaps nuttalli, Eschinolaelaps echidninus e Atricholaelaps glasgowi, esta ultima apenas representada por três exemplares intercambiados com roedores silvestres. As espécies P. spinulosa e L. nuttalli, embora cosmopolitas, sao registradas pela primeira vez no Estado de Minas Gerais. A relação entre os sexos dos ectoparasitos bem como a prevalência de pulgas, ácaros e piolho por sexos separados de roedores são apresentadas. 66,9% dos roedores estavam infestados por ácaros, quase duas vezes mais do que as infestações por pulgas e piolho conjuntamente (39%). L. nuttalli foi a espécie mais numerosa e a que apresentou o maior índice de infestação: 55,1%. As infestações simples e associadas se equivaleram numericamente. P. spinulosa, ao contrário de L. nuttalli, raramente ocorreu em infestações simples. Dados sobre a distribuição dos ectoparasitos nos roedores sao também assinalados. A infestação observada em Belo Horizonte e confrontada com aquelas obtidas por outros autores em algumas cidades do mundo.

Species and Strain-specific Typing of Cryptosporidium Parasites in Clinical and Environmental Samples

Cryptosporidiosis has recently attracted attention as an emerging waterborne and foodborne disease as well as an opportunistic infection in HIV infected individuals. The lack of genetic information, however, has resulted in confusion in the taxonomy of Cryptosporidium parasites and in the development of molecular tools for the identification and typing of oocysts in environmental samples. Phylogenetic analysis of the small subunit ribosomal RNA (SSU rRNA) gene has shown that the genus Cryptosporidium is comprised of several distinct species. Our data show the presence of at least four species: C. parvum, C. muris, C. baileyi and C. serpentis (C. meleagridis, C. nasorum and C. felis were not studied). Within each species, there is some sequence variation. Thus, various genotypes (genotype 1, genotype 2, guinea pig genotype, monkey genotype and koala genotype, etc.) of C. parvum differ from each other in six regions of the SSU rRNA gene. Information on polymorphism in Cryptosporidium parasites has been used in the development of species and strain-specific diagnostic tools. Use of these tools in the characterization of oocysts various samples indicates that C. parvum genotype 1 is the strain responsible for most human Cryptosporidium infections. In contrast, genotype 2 is probably the major source for environmental contamination of environment, and has been found in most oysters examined from Chesapeake Bay that serve as biologic monitors of surface water. Parasites of Cryptosporidium species other than C. parvum have not been detected in HIV+ individuals, indicating that the disease in humans is caused only by C. parvum.

Wild Rodents as Experimental Intermediate Hosts of Lagochilascaris minor Leiper, 1909

A total of 25 specimens of Cavia porcellus (guinea pig), 5 Dasyprocta agouti (agouti), and 22 Calomys callosus (vesper mice) were inoculated with infective eggs of Lagochilascaris minor. The inoculum was prepared with embryonated eggs and orally administered to each individual animal through an esophagus probe. In parallel, 100 specimens of Felis catus domesticus were individually fed with 55-70 nodules containing 3rd-stage larvae encysted in tissues of infected rodents. Animals were examined and necropsied at different time intervals. The migration and encystment of L3 larva was observed in viscera, skeletal muscle, adipose and subcutaneous tissues from all rodents. Adult worms localized at abscesses in the cervical region, rhino, and oropharynx were recovered from domestic cats inoculated with infected rodent tissues. Through this study we can conclude that: (1) wild rodents act as intermediate hosts, characterizing this ascarid heteroxenic cycle; (2) in natural conditions rodents could possibly act as either intermediate hosts or paratenic hosts of Lagochilascaris minor; (3) despite the occurrence of an auto-infecting cycle, in prime-infection of felines (definite hosts) the cycle is only completed when intermediate hosts are provided; and (4) in the wild, rodents could serve as a source of infection for humans as they are frequently used as food in regions with the highest incidence of human lagochilascariasis.

Use of polymerase chain reaction and enzymatic cleavage in the identification of Helicobacter spp. in gastric mucosa of human beings from North Paraná, Brazil

Helicobacter pylori is the most common gastric bacteria of human beings. Animal-borne helicobacter have been associated with gastritis, ulceration, and gastric mucosa-associated lymphoid-tissue lymphoma in people. We attempted to identify the species of Helicobacter spp. that infect human beings in north Paraná, Brazil. Samples of gastric mucosa from 38 dyspeptic patients were analyzed by optic microscopy on silver stained slides, polimerase chain reaction (PCR), and enzymatic cleavage. Genus and species-specific primers to H. pylori, H. heilmannii, H. felis, and consensual primers to H. bizzozeronii or H. salomonis were used. The PCR products were submitted to enzymatic cleavage by VspI (Helicobacter spp. product) and HinfI (species products) enzymes. Thirty-two out of 38 patients evaluated had 3.2 to 5 µm long bacteria that resembled H. pylori in Warthin-Starry stained slides and were positive to the genus Helicobacter by PCR. In 30 of these patients the bacteria were identified as H. pylori. Two samples positive by silver stain were negative to all species tested by PCR. None of the 38 samples was positive to animal-origin helicobacter species. These results show that PCR and enzymatic restriction are practical methods to identify the species of helicobacters present in gastric mucosa of human beings. People in north Paraná appear to be infected mostly with H. pylori.

Rickettsia infection in five areas of the state of São Paulo, Brazil

This study investigated rickettsial infection in animals, humans, ticks, and fleas collected in five areas of the state of São Paulo. Eight flea species (Adoratopsylla antiquorum antiquorum, Ctenocephalides felis felis, Polygenis atopus, Polygenis rimatus, Polygenis roberti roberti, Polygenis tripus, Rhopalopsyllus lugubris, and Rhopalopsyllus lutzi lutzi), and five tick species (Amblyomma aureolatum, Amblyomma cajennense, Amblyomma dubitatum, Ixodes loricatus, and Rhipicephalus sanguineus) were collected from dogs, cats, and opossums. Rickettsia felis was the only rickettsia found infecting fleas, whereas Rickettsia bellii was the only agent infecting ticks, but no animal or human blood was shown to contain rickettsial DNA. Testing animal and human sera by indirect immunofluorescence assay against four rickettsia antigens (R. rickettsii, R. parkeri, R. felis, and R. bellii), some opossum, dog, horse, and human sera reacted to R. rickettsii with titers at least four-fold higher than to the other three rickettsial antigens. These sera were considered to have a predominant antibody response to R. rickettsii. Using the same criteria, opossum, dog, and horse sera showed predominant antibody response to R. parkeri or a very closely related genotype. Our serological results suggest that both R. rickettsii and R. parkeri infected animals and/or humans in the studied areas.

Cortisol influence on testicular testosterone secretion in domestic cat: An in vitro study

The aim of the present experiment was to investigate the effect of corticosteroids (exogen) on in vitro testosterone secretion after stress by transportation (40 minutes). Feline testes (Felis silvestris catus) were incubated in the following media: TCM 199; TCM 199 + hCG 10_7M; TCM 199 + hydrocortisone 10_7M, or TCM 199 + hCG + hydrocortisone. The animals (n=21) were allocated into three groups: (S) that arrived at 3 h prior to surgery, (A) that remained in the laboratory for 36 h before being submitted to surgical procedure, and (C) that were also allowed to remain for 36 hours in the laboratory before the surgical procedure, but whose testes had been incubated with hydrocortisone prior to incubation in the referred media. The results showed that group S secreted higher levels of testosterone, regardless of the culture media. It is noteworthy that the suppressing action of hydrocortisone sodium succinate led to a reduction in the testosterone concentration, despite the presence of hCG.

Ectoparasitos de animais silvestres no Maranhão

Objetivou-se identificar os ectoparasitos de animais silvestres recepcionados pelo Centro de Triagem de Animais Silvestres, São Luís, Maranhão. Os ectopararasitos identificados foram: piolhos Acidoproctus sp., Trinoton sp., Ciconiphilus sp, Austromenopon sp., Quadraceps sp., Saemundssonia sp. e Trichodectes canis; carrapato Amblyomma rotundatum e Rhipicephalus sanguineus; pulgas Ctenocephalides felis e larvas de Cochliomyia hominivorax. Os resultados apresentados documentam a infestação de mamíferos, répteis e aves silvestres por ectoparasitos.

Anti-Rickettsia spp. antibodies in free-ranging and captive capybaras from southern Brazil

Capybaras (Hydrochaeris hydrochaeris) are among the main hosts of Amblyomma spp. ticks, which is able to transmit Rickettsia species to human beings and animals. Since they are often infested with potential vector ticks, capybaras may be used as sentinels for rickettsiosis, such as the Brazilian Spotted Fever. The aim of the present study was to determine the prevalence of antibodies against Rickettsia spp. using the indirect immunofluorescence assay (IFA) in 21 free-ranging and 10 captive animals from the Zoological Park of the 'Bela Vista Biological Sanctuary' (BVBS), Itaipu Binational, Foz do Iguaçu, Southern Brazil. Antigens of six rickettsial species already identified in Brazil (Rickettsia rickettsii, R. parkeri, R. bellii, R. rhipicephali, R. amblyommii and R. felis) were used for IFA. Ticks from each capybara were collected for posterior taxonomic identification. A total of 19 (61.3%) samples reacted to at least one of tested species. Seropositivity was found in 14 (45.2%), 12 (38.7%), 5 (16.1%), 4 (12.9%), 3 (9.7%) and 3 (9.7%) animals for R. rickettsii, R. bellii, R. parkeri, R. amblyommii, R. felis and R. rhipicephali, respectively. Two captive capybaras presented suggestive titers of R. rickettsii infection and one sample showed homologous reaction to R. parkeri. Only one free-ranging capybara presented evidence R. bellii infection. Ticks collected on capybaras were identified as Amblyomma dubitatum e Amblyomma sp. Results evidenced the rickettsial circulation in the area, suggesting a potential role of capybaras on bacterial life cycle.

Parasitos de aves e mamíferos silvestres em cativeiro no estado de Pernambuco

Resumo: Os animais silvestres são hospedeiros de uma grande variedade de parasitos que podem interferir em sua conservação ex situ. O objetivo deste estudo foi identificar os parasitos gastrointestinais (PGI) e ectoparasitos dos animais do Centro de Triagem de Animais Silvestres (CETAS) do Instituto Brasileiro de Meio Ambiente e Recursos Naturais Renováveis (IBAMA) de Recife, Pernambuco, além de determinar os aspectos do manejo em cativeiro que possam estar relacionados com os parasitos identificados. Foram coletados ectoparasitos e amostras fecais de 223 aves e mamíferos, as quais foram processadas pelos métodos: microscopia direta, flutuação e sedimentação. Helmintos e/ou protozoários foram detectados em 91 (40,8%) amostras fecais, sendo 64 (70,3%) de aves e 27 (29,7%) de mamíferos. Ovos de Capillaria sp., Ascaridida, Spirurida e oocistos de Eimeria sp. foram detectados nas amostras fecais das aves, enquanto ovos de Trichuris trichiura, Strongyloides sp., Toxocara canis, Ancylostoma sp., Strongylida e oocistos de Coccídios foram encontrados nas amostras fecais de mamíferos. Os ectoparasitos identificados em aves foram Colpocephalum turbinatum, Kurodaia (Kurodaia) fulvofasciata, Halipeurus sp., Naubates sp., Saemundssonia sp., Austromenopon sp., Paragoniocotes sp., Brueelia sp., Myrsidea sp. and Pseudolynchia sp., enquanto em mamíferos os ectoparasitos identificados foram Rhipicephalus sanguineus, Amblyomma varium, A. calcaratum, A. nodosum, Ornithodoros talaje e Ctenocephalides felis felis. A. calcaratum e O. talaje são registrados pela primeira vez em Pernambuco e T. tetradactyla é apresentado como novo hospedeiro de O. talaje. Nenhum dos animais estudados apresentou sinais clínicos em decorrência da infecção/infestação parasitária. Parasitos com potencial zoonótico como T. trichiura, Strongyloides sp., T. canis e Ancylostoma sp. foram identificados em primatas não humanos e carnívoros. Precárias condições estruturais e sanitárias do CETAS-PE estão relacionadas com os parasitos identificados neste estudo e devem ser levadas em consideração para a adoção de medidas adequadas de controle. Os resultados deste estudo contribuirão de maneira significativa para a conservação de animais selvagens no CETAS-PE e para a saúde dos profissionais responsáveis pela manutenção destes animais.

Plasma cortisol levels in captive wild felines after chemical restraint

Eight Panthera onca (Po), 13 Felis concolor (Fc), 7 Felis yagouaroundi (Fy), 7 Felis tigrina (Ft) and 5 Felis pardalis (Fp) specimens from São Paulo State zoos were used. All animals were restrained with darts containing 10 mg/kg ketamine and 1 mg/kg xylazine. Venous blood samples were collected as soon as possible (within 15-20 min) and serum was frozen until the time for cortisol quantification. Cortisol was determined using a solid phase radioimmunoassay with an intra-assay coefficient of 8.51%. Data were analyzed statistically by the Kruskal-Wallis test, followed by Dunn's multiple comparisons test, and the one-sample t-test, with the level of significance set at P<0.05. Data are reported as means ± SEM. Cortisol levels differed among the captive felines: Po = 166 ± 33a, Fc = 670 ± 118b, Fy = 480 ± 83b, Ft = 237 ± 42ab, Fp = 97 ± 12a nmol/l (values followed by different superscript letters were significantly different (P<0.001)). Since most of the veterinary procedures on these species involve chemical restraint, these results show the necessity of preventive measures in order to minimize the effect of restraint stress on more susceptible species