Molecular diagnosis of Strongyloides stercoralis among transplant candidates.

Strongyloidiasis can occur without any symptoms or as a potentially fatal hyperinfection or disseminated infection, principally in immunosuppressed patients. Our study aimed to evaluate the application of conventional polymerase chain reaction (cPCR) and real-time PCR (qPCR). Polymerase chain reaction (PCR) and real-time PCR (qPCR) targeting the 18S rRNA gene for detection of Strongyloides stercoralis infection among transplant candidates were applied in stool samples obtained from 150 transplant candidates, preliminarily analyzed by parasitological methods. S. stercoralis larvae were visualized in 15/150 (10.0%) transplant candidates by parasitological methods. DNA from S. stercoralis was amplified in 26/150 (17.3%) and 49/150 (32.7%) stool samples of transplant candidates, using cPCR and qPCR, respectively. The results suggest that molecular methods, especially qPCR, should be used as an additional tool for diagnostic of S. stercoralis infection among transplant candidates.

Subtypes of Blastocystis sp. isolated in fecal samples from transplant candidates in São Paulo, Brazil.

Blastocystis sp. is an intestinal protozoan commonly found in fecal samples of many animal species, including humans, but poorly studied in transplant candidates. The aim of this study was to evaluate the occurrence and molecular identification of Blastocystis sp. in fecal samples from transplant candidates. A polymerase chain reaction was performed using specific primers for Blastocystis ribosomal DNA. The DNA sequences obtained were aligned and compared with other sequences from the GenBank and MLST databases. The analyzed samples showed a positivity of 16% (24 of 150) for Blastocystis sp. The highest occurrence was observed in renal transplant candidates (31.4%), followed by hepatic transplant candidates (10.4%) and candidates for bone marrow transplantation (5.9%). Subtype (ST) 3 (45.8%) was the most prevalent among the isolates, followed by ST1 (37.5%), ST2 (12.5%), and ST7 (4.2%). This is the first study of molecular identification Blastocystis sp. in transplant candidates. Our results confirmed that ST3 was the most common subtype in transplant candidates and reinforce the importance of new studies to investigate of Blastocystis sp. in these patients.

Larval recovery of Toxocara cati in experimentally infected Rattus norvegicus and analysis of the rat as potential reservoir for this ascarid.

Toxocara cati is a common feline parasite transmitted by the ingestion of embryonated eggs, by the transmammary route or by predation of paratenic hosts harbouring third-stage larvae in their bodies. In the present study, the larval distribution of T. cati in tissues and organs of Rattus norvegicus experimentally infected with 300 embryonated eggs was analysed. Third-stage larvae were recovered from livers, lungs, kidneys, eyes, brains and carcasses of infected rats, following tissue digestion with HCl 0.5% for 24 h at 37 degrees C. Some differences from the known larval distribution of Toxocara canisin the same rodent species were found.

Relationship between intestinal parasitic infection in children and soil contamination in an urban slum.

PURPOSE: Urban slums are well known for their high infant mortality and morbidity rates, and parasitic infections seem to be a common problem among these children. The aim of the present study was to determine protozoa and nematodes prevalence among children of a selected community located in São Paulo, Brazil, and access the relation between soil and children infection. METHODS: Soil contamination samples from 15 strategic locations in the slum area as well as stool samples (examined for protozoa and nematodes through five different methods) from 120 children aged 2-14 years (49% M: 51% F, mean +/- SD = 7.9 +/- 3.8 years) were assessed in a cross-sectional study. Children's domicile locations were determined, and a comparative analysis was undertaken to correlate children and soil infection. RESULTS: Overall infection rate was 30.8% (n = 37), without difference between genders. The most frequent intestinal protozoa were Endolimax nana (20.8%), Entamoeba coli (15.8%) and Giardia lamblia (16.7%). Frequencies of Ascaris lumbricoides and Enterobius vermicularis in stool samples were 2.5 and 1.7%, respectively. No cases of hookworms, Schistosoma mansoni or Tricuris trichiura were identified. Polyparasitism occurred in 10.8% of the children, while 69.2% were free of parasitic infections. Out of the 15 soil samples analyzed, Ascaris sp. eggs were found in 20% and hookworm eggs in 6.7%. CONCLUSION: Helminth infection is not as prevalent as previously reported in urban slums in São Paulo, neither as clinical disease nor in soil samples. Protozoa intestinal infection, however, is still frequent in some marginalized populations in São Paulo. Improvement in living standards, mostly sanitation might decrease the prevalence of these diseases.

Screening of Strongyloides infection using an ELISA test in transplant candidates.

OBJECTIVES: Hyperinfection or disseminated strongyloidiasis has been frequently reported after transplants and is related to high mortality. This study aimed to screen for strongyloidiasis using serological diagnoses in transplant candidates. METHODS: An ELISA test was performed with filariform larvae of Strongyloides venezuelensis as a source of antigen. RESULTS: In the serum from transplant candidates, anti-Strongyloides IgG antibodies were detected in 35/150 (23.3%) samples by soluble fractions in phosphate buffered saline (PBS), 31/150 (20.7%) samples by soluble fractions in Tris-HCl, 27/150 (18.0%) samples by membrane fractions in PBS and 22/150 (14.7%) samples by membrane fractions in Tris-HCl. CONCLUSIONS: The present results suggest the ELISA test, ideally using soluble fractions of filariform larvae S. venezuelensis in PBS, as an additional strategy for the diagnosis of strongyloidiasis in transplant candidates.

[Evaluation of the efficacy of azithromycin and pyrimethamine, for treatment of experimental infection of mice with Toxoplasma gondii cystogenic strain]. / Avaliação da eficácia da azitromicina e pirimetamina em camundongos infectados por cepa cistogênica de Toxoplasma gondii.

The efficacy of prolonged administration of azithromycin and pyrimethamine was evaluated in mice experimentally infected with cystogenic strain of Toxoplasma gondii. The animals were intraperitoneally inoculated with one cyst of T. gondii and after 20 days were allocated into four groups: GI, infected without treatment; GII, infected and treated with the association of pyrimethamine (12.5 mg/kg/day) and azithromycin (100 mg/kg/day); GIII, infected and treated with the same dose of pyrimethamine; and GIV, infected and treated in the same way with azithromycin. The oral treatment lasted 120 days, after this period all the animals were sacrificed and the count of cysts in the brain was done. The association of both drugs provided the best results, by diminishing the cyst count in the brain of the animals treated in this way.

Screening of Strongyloides infection using an ELISA test in transplant candidates

OBJECTIVES: Hyperinfection or disseminated strongyloidiasis has been frequently reported after transplants and is related to high mortality. This study aimed to screen for strongyloidiasis using serological diagnoses in transplant candidates. METHODS: An ELISA test was performed with filariform larvae of Strongyloides venezuelensis as a source of antigen. RESULTS: In the serum from transplant candidates, anti-Strongyloides IgG antibodies were detected in 35/150 (23.3%) samples by soluble fractions in phosphate buffered saline (PBS), 31/150 (20.7%) samples by soluble fractions in Tris-HCl, 27/150 (18.0%) samples by membrane fractions in PBS and 22/150 (14.7%) samples by membrane fractions in Tris-HCl. CONCLUSIONS: The present results suggest the ELISA test, ideally using soluble fractions of filariform larvae S. venezuelensis in PBS, as an additional strategy for the diagnosis of strongyloidiasis in transplant candidates.

Behavioral changes in Rattus norvegicus experimentally infected by Toxocara canis larvae.

Toxocara canis is a common canine nematode parasite and one of its possible transmission mechanisms is the predation of infected rodents by canids. Fifty Rattus norvegicus were used to study behavioral alterations in rodents infected by T. canis larvae. The rats were divided into three groups: G1, 20 rats infected with 300 T. canis eggs; G2, 20 rats infected with 2,000 T. canis eggs; and G3, 10 non-infected rats. Thirty and 60 days post-infection, rats from all the groups were submitted to an open-field apparatus for five min and subsequently, to an elevated plus-maze apparatus, again for five min. The data obtained indicated improvement in mobility (total locomotion time and rearing frequency) and exploratory behavior in infected rats, principally in G2, which provides some support for the hypothesis that behavioral alterations in rodents infected by Toxocara canis larvae enhance the transmission rate of this ascarid to dogs.

Muscular strength decrease in Rattus norvegicus experimentally infected by Toxocara canis.

The muscular strength of experimental infected Rattus norvegicus with 3rd. stage Toxocara canis larvae was investigated. Fifty Wistar rats, divided in three groups (G1-20 rats infected by 300 eggs of T. canis; G2-20 rats infected by 2,000 eggs of T. canis and G3-10 rats without infection) had been used. Ten and 30 days after infection the muscular strength in the fore-feet of the rats was checked; at the same time, the body weight was determined. No significative differences in the body weight were noted among the infected and control rats in both occasions. Otherwise, an impairment on the muscular strength was observed in rats infected with T. canis 30 days after inoculation.

Unusual case of pentastomiasis mimicking liver tumor.

Pentastomiasis is a rare zoonotic disease. Almost all recorded cases of human pentastomiasis had been incidental findings at autopsy. We report an unusual case of human pentastomiasis mimicking liver tumor successfully treated by liver resection. This clinical presentation is uncommon and it was probably caused by a pentastomid that exited its cyst and migrated to the liver causing an infarct that was mistaken as a primary liver tumor. Diagnosis could not be made before the surgery. This is the first reported case of human pentastomiasis in Brazil.

Behavioral changes in Rattus norvegicus experimentally infected by Toxocara canis larvae / Alterações de comportamento em Rattus norvegicus experimentalmente infectados por larvas de Toxocara canis

Toxocara canis is a common canine nematode parasite and one of its possible transmission mechanisms is the predation of infected rodents by canids. Fifty Rattus norvegicus were used to study behavioral alterations in rodents infected by T. canis larvae. The rats were divided into three groups: G1, 20 rats infected with 300 T. canis eggs; G2, 20 rats infected with 2,000 T. canis eggs; and G3, 10 non-infected rats. Thirty and 60 days post-infection, rats from all the groups were submitted to an open-field apparatus for five min and subsequently, to an elevated plus-maze apparatus, again for five min. The data obtained indicated improvement in mobility (total locomotion time and rearing frequency) and exploratory behavior in infected rats, principally in G2, which provides some support for the hypothesis that behavioral alterations in rodents infected by Toxocara canis larvae enhance the transmission rate of this ascarid to dogs.

Toxocara canis é um nematódeo parasita habitual do intestino delgado de cães. Um dos mecanismos conhecidos de transmissão para cães é representado pela predação de pequenos roedores que, como hospedeiros paratênicos albergam larvas de Toxocara canis em seus tecidos. Para avaliar a ocorrência de alterações de comportamento em roedores infectados por Toxocara canis 50 exemplares de Rattus norvegicus foram utilizados no experimento. Os animais foram divididos em três grupos: G1 - 20 ratos infectados com 300 ovos de Toxocara canis; G2 - 20 ratos infectados com 2.000 ovos de Toxocara canis e G3 - 10 ratos sem infecção. Trinta e 60 dias após a infecção avaliou-se a ocorrência de alterações comportamentais nos três grupos submetendo os animais, primeiramente, a uma arena de campo aberto durante cinco minutos e, a seguir, a labirinto em cruz elevado por mais cinco minutos. Os resultados obtidos indicaram aumento significativo da mobilidade (tempo total de movimentação e número de vezes em que os animais se levantaram nas patas traseiras) e comportamento exploratório nos ratos infectados, principalmente nos pertencentes ao G2, sugerindo a ocorrência de alterações comportamentais que favoreceriam a transmissão de Toxocara canis para canídeos por meio de relação presa-predador.

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.

Larval recovery of Toxocara cati in experimentally infected Rattus norvegicus and analysis of the rat as potential reservoir for this ascarid

Toxocara cati is a common feline parasite transmitted by the ingestion of embryonated eggs, by the transmammary route or by predation of paratenic hosts harbouring third-stage larvae in their bodies. In the present study, the larval distribution of T. cati in tissues and organs of Rattus norvegicus experimentally infected with 300 embryonated eggs was analysed. Third-stage larvae were recovered from livers, lungs, kidneys, eyes, brains and carcasses of infected rats, following tissue digestion with HCl 0.5 percent for 24 h at 37°C. Some differences from the known larval distribution of Toxocara canisin the same rodent species were found.

Muscular strength decrease in Rattus norvegicus experimentally infected by Toxocara canis / Diminuição da força muscular em Rattus norvegicus experimentalmente infectados por Toxocara canis

The muscular strength of experimental infected Rattus norvegicus with 3rd. stage Toxocara canis larvae was investigated. Fifty Wistar rats, divided in three groups (G1 - 20 rats infected by 300 eggs of T. canis; G2 - 20 rats infected by 2,000 eggs of T. canis and G3 - 10 rats without infection) had been used. Ten and 30 days after infection the muscular strength in the fore-feet of the rats was checked; at the same time, the body weight was determined. No significative differences in the body weight were noted among the infected and control rats in both occasions. Otherwise, an impairment on the muscular strength was observed in rats infected with T. canis 30 days after inoculation.

Roedores são reconhecidos como hospedeiros paratênicos de Toxocara canis. Um dos mecanismos de transmissão desse ascarídeo para cães, seus hospedeiros habituais, consiste na predação de hospedeiros paratênicos, que albergam larvas de terceiro estágio em seus órgãos e tecidos, entre os quais músculos estriados. No presente trabalho estudou-se se a infecção por larvas de Toxocara canis provoca alterações na força muscular de exemplares de Rattus norvegicus experimentalmente infectados. Cinqüenta Rattus norvegicus foram divididos em três grupos: G1, com 20 ratos infectados com 300 ovos de Toxocara canis; G2, com 20 ratos infectados com 2.000 ovos do ascarídeo e G3, com 10 ratos sem infecção. Dez e 30 dias após a infecção determinou-se a força muscular nas patas dianteiras dos roedores; ao mesmo tempo, avaliou-se seu peso corporal. Não foram observadas diferenças no peso dos animais dos três grupos; contudo, verificou-se decréscimo na força muscular dos ratos infectados com 2.000 ovos após o 30º dia de infecção.

Prevalence of Toxocara infection in schoolchildren from the Butantã region, São Paulo, Brazil.

Visceral larva migrans syndrome by Toxocara affects mainly children between 2 and 5 years of age, it is generally asymptomatic, and the seroprevalence varies from 3 to 86% in different countries. A total of 399 schoolchildren from 14 public schools of the Butantã region, São Paulo city, Brazil, were evaluated by Toxocara serology (enzyme-linked immunosorbent assay). Epidemiological data to the Toxocara infection obtained from a protocol were submitted to multiple logistic regression analysis for a risk profile definition. Blood was collected on filter paper by finger puncture, with all samples tested in duplicate. Considering titers > or = 1/160 as positive, the seroprevalence obtained was 38.8%. Among infected children, the mean age was 9.4 years, with a similar distribution between genders. A significant association was observed with the presence of onychophagia, residence with a dirty backyard, living in a slum, previous wheezing episodes, school attended, and family income (p < 0.05). All data, except "living in a slum", were considered to be determinant of a risk profile for the acquisition of Toxocara infection. A monthly income > or = 5 minimum salaries represented a protective factor, although of low relevance. Toxocara eggs were found in at least one of the soil samples obtained from five schools, with high prevalence of Toxocara infections, indicating the frequent soil contamination by this agent.

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.

Coinfection by Strongyloides stercoralis in blood donors infected with human T-cell leukemia/lymphoma virus type 1 in Sao Paulo city, Brazil

The frequency of coinfection with Strongyloides stercoralis and human T-cell leukemia/lymphoma virus type 1 (HTML-1) was determined in 91 blood donors examined at the blood bank of a large hospital in Sao Paulo city, Brazil. As control group 61 individuals, not infected by HTLV-1, were submitted to the same techniques for the diagnosis of S. stercoralis infection. In HTLV-1 infected patients the frequency of S. stercoralis infection was 12.1 percent; on the other hand, the control group showed a frequency significantly lower of S. stercoralis infection (1.6 percent), suggesting that HTLV-1 patients shoud be considered as a high risk group for strongyloidiasis in Sao Paulo city.

Avaliação da eficácia da azitromicina e pirimetamina em camundongos infectados por cepa cistogênica de Toxoplasma gondii / Evaluation of the efficacy of azithromycin and pyrimethamine, for treatment of experimental infection of mice with Toxoplasma gondii cystogenic strain

Foi avaliada a eficácia da administração prolongada de azitromicina e pirimetamina em camundongos infectados com cepa cistogênica de Toxoplasma gondii. Os animais foram inoculados intraperitonealmente com um cisto de T. gondii e, após 20 dias, divididos em quatro grupos: GI infectados não tratados, GII infectados e tratados concomitantemente com pirimetamina (12,5mg/kg/dia) e azitromicina (100mg/kg/dia), GIII infectados e tratados com a mesma dose de pirimetamina e GIV infectados e tratados da mesma forma com azitromicina. O tratamento, via oral, estendeu-se por 120 dias; após este período os animais foram sacrificados e foi feita a contagem dos cistos no cérebro. A associação de ambos os medicamentos proporcionou melhores resultados, diminuindo a contagem de cistos no cérebro dos animais tratados de forma concomitante.

Prevalence of Toxocara infection in schoolchildren from the Butantä region, Säo Paulo, Brazil

Visceral larva migrans syndrome by Toxocara affects mainly children between 2 and 5 years of age, it is generally asymptomatic, and the seroprevalence varies from 3 to 86 percent in different countries. A total of 399 schoolchildren from 14 public schools of the Butantä region, Säo Paulo city, Brazil, were evaluated by Toxocara serology (enzyme-linked immunosorbent assay). Epidemiological data to the Toxocara infection obtained from a protocol were submitted to multiple logistic regression analysis for a risk profile definition. Blood was collected on filter paper by finger puncture, with all samples tested in duplicate. Considering titers > 1/160 as positive, the seroprevalence obtained was 38.8 percent. Among infected children, the mean age was 9.4 years, with a similar distribution between genders. A significant association was observed with the presence of onychophagia, residence with a dirty backyard, living in a slum, previous wheezing episodes, school attended, and family income (p < 0.05). All data, except "living in a slum", were considered to be determinant of a risk profile for the acquisition of Toxocara infection. A monthly income > 5 minimum salaries represented a protective factor, although of low relevance. Toxocara eggs were found in at least one of the soil samples obtained from five schools, with high prevalence of Toxocara infections, indicating the frequent soil contamination by this agent