Prevalencia de Demodex folliculorum e Demodex brevis em uma amostra da população de Botucatu, São Paulo, Brasil

Pela primeira vez no Brasil foi realizado um levantamento para se conhecer a distribuição do D. folliculorum e D. brevis no homem. Uma amostra de 100 pessoas atendida em clínica estética foi examinada, procurando-se estudar a associação entre a presença de ácaros e fatores como idade, raça e sexo do hospedeiro. O material colhido da região facial dos indivíduos foi montado em lâminas com o meio de Berlese. Das 100 pessoas examinadas, 72 % foram positivas. Dos casos positivos, 51 % estavam infestados pelo D. folliculorum, 2% pelo D. brevis e 19% apresentaram-se parasitados por ambas as espécies.

Freqüência de soropositividade para antígenos de Toxocara canis em crianças de classes sociais diferentes

Para estudar a freqüência da infecção pelo Toxocara canis em crianças de classes sociais diferentes de Brasília, Brasil, foram testados soros de 602 crianças de ambos os sexos, de 1 a 12 anos, distribuídas em dois grupos representativos de condições socioeconômicas distintas. As amostras do primeiro grupo foram obtidas em laboratório público que atende bairros pobres. As do segundo grupo foram colhidas em laboratório privado, que serve à classe média. Os anticorpos anti-Toxocara foram detectados pelo método ELISA, com antígenos de Toxocara canis, e absorção com antígenos do Ascaris suum. A prevalência de soropositividade foi de 21,8% (66/302) no primeiro grupo e de 3% (9/300) no segundo (p<0,0001). Não houve diferença quanto ao gênero ou idade das crianças. Os resultados sugerem significativa prevalência de toxocaríase na população infantil de Brasília, com predomínio nas classes sociais menos favorecidas economicamente.

Freqüência de anticorpo anti-Toxocara canis em comunidade do Rio Uatumã, no Estado do Amazonas

Um estudo seccional foi realizado nas Vilas Waimiri e Atroari em Balbina, entre julho e outubro de 2006, com o objetivo de estimar a freqüência de anticorpo antiToxocara canis da classe IgG e avaliar as variáveis epidemiológicas e socioculturais. Foram estudadas 34 famílias e incluídos 100 indivíduos, o que correspondeu a 5% (100/2.000) da população das vilas. A idade variou de zero a 76 anos (M=22,9 Dp=18). Quanto ao gênero, 53% eram femininos e 47% masculino; 52% das amostras foram positivas para Toxocara canis, 44,5% negativas e 3,2% inconclusivas. Observou-se menor número de indivíduos com sorologia negativa na Vila Atroari 29,5% (13/44) em comparação com a Waimiri 46,4% (26/56). Com relação ao contato com cães, dos 55 indivíduos com contato domiciliar 60% (33/55) foram positivos para anticorpo antiToxocara canis Apresentaram sorologia positiva 66,6% (10/15) dos indivíduos que tinham contato domiciliar com filhotes de cão (chi²22,149 p=0,008). A existência de contato domiciliar com cães e filhotes mostrou associação com a presença de anticorpo anti-Toxocara canis na população estudada.

Ocular lesions in gerbils (Meriones unguiculatus) infected with low larval burden of Toxocara canis: observations using indirect binocular ophthalmoscopy

To study the frequency of ocular lesions in 30 gerbils infected with 100 embryonated eggs of Toxocara canis, indirect binocular ophthalmoscopy was performed 3, 10, 17, 24, 31 and 38 days after infection. All the animals presented larvae in the tissues and 80% presented ocular lesions. Hemorrhagic foci in the choroid and retina were present in 92% of the animals with ocular lesions. Retinal exudative lesions, vitreous lesions, vasculitis and retinal detachment were less frequent. Mobile larvae or larval tracks were observed in four (13.3%) animals. Histological examination confirmed the ophthalmoscopic observations, showing that the lesions were focal and sparse. In one animal, there was a larva in the retina, without inflammatory reaction around it. The results demonstrated that gerbils presented frequent ocular lesions after infection with Toxocara canis, even when infected with a small number of embryonated eggs. The lesions observed were focal, consisting mainly of hemorrhages with signs of reabsorption or inflammation in different segments of eye, and differing from the granulomatous lesions described in ocular larva migrans in humans.

Destruição de ovos de Toxocara canis pelo fungo nematófago Pochonia chlamydosporia

INTRODUÇÃO: Toxocara canis é um ascarídeo parasita do intestino delgado de cães, causador da larva migrans visceral em seres humanos. MÉTODOS: Com o objetivo de demonstrar a eficácia do fungo Pochonia chlamydosporia sobre ovos de Toxocara canis em condições laboratoriais, foi montado ensaio experimental em placas de Petri com ágar-água 2%. RESULTADOS: Houve atividade ovicida de 43,8% (p<0,01) do grupo tratado em relação ao grupo controle durante os intervalos estudados. CONCLUSÕES: Os resultados demonstrados no presente trabalho sugerem a empregabilidade de Pochonia chlamydosporia como uma alternativa de controle biológico dos ovos embrionados de Toxocara canis.

Prevalência e fatores de risco da infecção humana por Toxocara canis em Salvador, Estado da Bahia

INTRODUÇÃO: Larva migrans visceral é causada por Toxocara sp e nunca foi estudada na Bahia. Neste trabalho, investigou-se a prevalência e fatores de risco de infecção por Toxocara canis, em indivíduos de Salvador. MÉTODOS: Trezentos e trinta e oito indivíduos foram investigados para presença de anticorpos IgG séricos anti-T. canis. RESULTADOS: IgG anti-T. canis foi mais alta em indivíduos de classe social baixa com maior contato com cães e gatos, indicando que estas variáveis são fatores de risco para esta infecção. CONCLUSÕES: A prevalência de infecção por T. canis foi alta. Os fatores de risco desta infecção encontrados estão de acordo com a literatura.

Serological cross-reactivity of Trypanosoma cruzi, Ehrlichia canis, Toxoplasma gondii, Neospora caninum and Babesia canis to Leishmania infantum chagasi tests in dogs

Introduction: The aim of this study was to evaluate the serological cross-reactivity between Leishmania sp. and other canine pathogens. Methods: Positive serum samples for Ehrlichia canis, Babesia canis, Toxoplasma gondii, Neospora caninum and Trypanosoma cruzi were tested using three serological methods enzyme linked immunosorbent assay (ELISA), indirect immunofluorescent antibody test (IFAT) and Kalazar Detect™, for canine visceral leishmaniasis. Results: Of the 57 dog samples tested, 24 (42.1%) tested positive using one of the three serological methods: 10/57 (17.5%) for ELISA, 11/57 (19.3%) for IFAT and 3/57 (5.3%) for Kalazar Detect™. Conclusions: Our results demonstrated that the presence of other infectious agents may lead to cross-reactivity on leishmaniasis serological tests.

Human and dogs Toxocara canis infection in a poor neighborhood in Bogota

Prevalence of Toxocara canis antibodies was studied in a poor community of Bogotá, Colombia. Two-hundred-sevem patients, from both sexes and all age groups, were studied. Positive Elisa titers were found in 47.5% of the population, a high prevalence compared with reports from developed countries. T. canis ova were positive in 43.6% of fecal samples from dog puppies. An endemic pattern of the disease is described: socioeconomic status, weathers, pollution, poor hygiene and a significant population of infected dogs. Neither the physical examination nor Elisa titers could detect any case of T. canis disease.

The ue of polysiloxane/polyvinyl alcohol beads as solid phase in IgG anti-Toxocara canis detection using a recombinant antigen

Immunodetection of human IgG anti-Toxocara canis was developed based on ELISA and on the use of polysiloxane/polyvinyl alcohol (POS/PVA) beads. A recombinant antigen was covalently immobilized, via glutaraldehyde, onto this hybrid inorganic-organic composite, which was prepared by the sol-gel technique. Using only 31.2 ng antigen per bead, a peroxidase conjugate dilution of 1:10,000 and a serum dilution of 1:200 were adequate for the establishment of the procedure. This procedure is comparable to that which utilizes the adsorption of the antigen to conventional PVC plates. However, the difference between positive and negative sera mean absorbances was larger for this new glass based assay. In addition to the performance of the POS/PVA bead as a matrix for immunodetection, its easy synthesis and low cost are additional advantages for commercial application.

Toxocara canis (Werner, 1782) eggs in the Pleistocene site of Menez-Dregan, France (300,000-500,000 years before present)

On the archaeological site of Menez-Dregan in Brittany, France, dated 300,000-500,000 years-old, paleoparasitological analysis of cave deposits led to the detection of well-preserved helminth eggs, which morphology and morphometry pointed to the diagnosis of Toxocara canis eggs, a parasite of carnivore mammals. Paleolithic remains suggested a parasitism of the hyena Crocuta spelaea or other canids that inhabited the region.

Larval recovery of Toxocara canis in organs and tissues of experimentally infected Rattus norvegicus

The aim of this note was to record for the first time the recovery of Toxocara canis larvae from tissues and organs of Rattus norvegicus (Berkenhout, 1769), Wistar strain, until the 60th day after experimental infection. Rats were orally infected with embryonated T. canis eggs, killed on days 3, 5, 8, 10, 15, 30, and 60 after inoculation and larvae were recovered from liver, lungs, kidneys, brain, and carcass after acid digestion, showing a pattern of migration similar of that previously observed in mice.

In vitro and in vivo effects of Enterococcus faecalis CECT7121 on Toxocara canis

The aim of the present paper was to evaluate the larvicidal effect of Enterococcus faecalis CECT7121 (Ef7121) on the Toxocara canis cycle both in vitro and in vivo. For the in vitro experiments, T. canis larvae were incubated with the supernatants of Ef7121 (EI) and mutant Ef7121 (EIm), in a pre-culture of Ef7121 (EII) and in a fresh culture with Ef7121 (EIII) and the Ef7121 mutant strain (EIIIm). The viability of the larvae was calculated after a 48 h incubation. A significant reduction of the viability of T. canis larvae was observed in EI, EII and EIII. A decrease of this inhibitory effect was observed in EIm and EIIIm (p = 0.008). In the in vivo experiments, mice were orally inoculated with three doses of Ef7121. To study the probiotic persistence in the intestine, the animals were sacrificed every four days and their intestines were dissected. The initial average bacterial levels were 9.7 x 10(4) for Ef7121 (colony forming units/g). At the end of the assay the levels were 1.46 x 10(4). No bacterial translocation was detected in mesenteric lymphatic nodules and spleen. Ef7121 interference with the biological cycle was evaluated in mice challenged with T. canis. The interference was significant when the mice were challenged with probiotic and T. canis simultaneously (p = 0.001), but it was not significant when the challenge was performed 15 days after administration of the bacterial inoculum (p = 0.06). In conclusion, Ef7121 possessed in vitro and in vivo larvicidal activity.

Detection of Leishmania infantum in naturally infected Lutzomyia longipalpis (Diptera: Psychodidae: Phlebotominae) and Canis familiaris in Misiones, Argentina: the first report of a PCR-RFLP and sequencing-based confirmation assay

In this study, a genotypification of Leishmaniawas performed using polimerase chain reaction-restriction fragment length polymorfism (PCR-RFLP) and sequencing techniques to identify species of Leishmaniaparasites in phlebotomine sand flies and dogs naturally infected. Between January-February of 2009, CDC light traps were used to collect insect samples from 13 capture sites in the municipality of Posadas, which is located in the province of Misiones of Argentina. Sand flies identified as Lutzomyia longipalpiswere grouped into 28 separate pools for molecular biological analysis. Canine samples were taken from lymph node aspirates of two symptomatic stray animals that had been positively diagnosed with canine visceral leishmaniasis. One vector pool of 10 sand flies (1 out of the 28 pools tested) and both of the canine samples tested positively for Leishmania infantumby PCR and RFLP analysis. PCR products were confirmed by sequencing and showed a maximum identity with L. infantum. Given that infection was detected in one out of the 28 pools and that at least one infected insect was infected, it was possible to infer an infection rate at least of 0.47% for Lu. longipalpisamong the analyzed samples. These results contribute to incriminate Lu. longipalpis as the vector of L. infantumin the municipality of Posadas, where cases of the disease in humans and dogs have been reported since 2005.