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.

OBJECTIVES: To design, implement, and evaluate a complex plan of actions aimed at reducing parasitoses in a rural town in the province of Buenos Aires, Argentina, with the involvement of the community. METHODS: The project took place in General Mansilla, Buenos Aires province, in three stages. First, the initial epidemiological situation of intestinal parasitoses in the community was assessed by analyzing for parasites a series of stool samples and anal swabs taken from a sample of 522 individuals. Second, interventions were implemented: the pharmacological treatment of the infected individuals, and health education for the public involving local promoters. Third, the pharmacological treatment was evaluated with followup stool testing for those treated; the health education effort was evaluated through a survey and stool testing for parasites of those who had participated solely in the education. RESULTS: The frequency of intestinal parasitoses was 58.2%; of the total, 43.9% were protozoa and 35.2%, helminths. The most common pathogens were Enterobius vermicularis, Blastocystis hominis, and Giardia lamblia. The deworming treatment reduced intestinal parasitoses to 15.1% (P < 0.001), and was more effective in helminths than in protozoa. Intestinal parasitoses declined following the health education intervention, in general (from 58.2% to 47.9%; P = 0.019), as well as for helminths (from 35.2% to 20.3%; P < 0.001), and hygiene habits improved significantly. CONCLUSIONS: Treatment of parasitosis and the educational intervention provided by local promoters made it possible to reduce parasitic diseases-particularly those caused by helminths-in the community under study. We recommend extending this experience to other rural communities and broadening the interventions to cutoff additional modes of transmission, such as water and food.

OBJETIVOS: Diseñar, implementar y evaluar un plan complejo de acciones dirigido a reducir las parasitosis en una localidad rural de la provincia de Buenos Aires, Argentina, con la participación de la comunidad. MÉTODOS: El trabajo se realizó en General Mansilla, provincia de Buenos Aires, Argentina, en tres etapas. 1) Se evaluó la situación epidemiológica inicial de las parasitosis intestinales en la comunidad mediante análisis coproparasitológico seriado y de escobillado anal en una muestra de 522 personas. 2) Se implementaron dos intervenciones: el tratamiento farmacológico de las personas parasitadas y la educación sanitaria de la población con la participación activa de divulgadores locales. 3) El tratamiento antiparasitario se evaluó mediante análisis coproparasitológico de seguimiento de todas las personas tratadas; la intervención educativa se evaluó mediante una encuesta y análisis coproparasitológico a personas que solo habían participado en el plan de educación sanitaria. RESULTADOS: La frecuencia de parasitosis intestinal fue de 58,2%; del total, 43,9% por protozoos y 35,2% por helmintos. Los patógenos más frecuentes fueron Enterobius vermicularis, Blastocystis hominis y Giardia lamblia. El tratamiento antiparasitario redujo la parasitosis intestinal a 15,1% (P < 0,001), más eficaz en helmintos que en protozoos. La parasitosis intestinal disminuyó después de la intervención educativa sanitaria, tanto en sentido general (de 58,2% a 47,9%; P = 0,019) como por helmintos (de 35,2% a 20,3%; P < 0,001) y se mejoraron significativamente los hábitos higiénicos. CONCLUSIONES: El tratamiento parasitológico y la intervención educacional mediante divulgadores locales permitieron reducir las parasitosis en la comunidad estudiada, especialmente las provocadas por helmintos. Se recomienda extender esta experiencia a otras comunidades rurales y ampliarla con intervenciones adicionales dirigidas a cortar otras vías de transmisión, como el agua y los alimentos.

The purpose of this study was to investigate the genotypes of Giardia lamblia from human and animal feces and their epidemiological and clinical characteristics in Argentina, South America. Seventy isolates, 60 from humans (adults and children), eight from dogs and two from cows were processed by polymerase chain reaction-restriction fragment length polymorphism. Data corresponding to demographic, socio-cultural and environmental variables and presence/absence of signs/symptoms were collected. The triosephosphate isomerase gene was amplified from 43 (71.66%) of the 60 human fecal samples. Among these, 3/43 (6.98%) were genotype AII and 40/43 (93.02%) were genotype B. Assemblage AII was detected in three children who lived together in a shantytown and they were oligosymptomatic and none had diarrhea. This genotype was not found in animals. Genotype B showed a high prevalence in both adults and children. It was also found in polysymptomatic people, many of whom presented diarrhea. It was also found only in one dog. The present study represents the first contribution to the knowledge of G. lamblia genotypes in Argentina.

We evaluate the prevalence of intestinal parasites in 504 people and the degree of association between environmental variables and parasites found in population, soil and water in a rural area of Argentina during 2002-2003. A structured survey was used to evaluate the environmental variables and fecal-human, soil and water samples were analyzed. The prevalence of parasites was 45.4%. Most prevalent protozoa were Blastocystis hominis (27.2%) and Giardia lamblia (6.9%), while the most prevalent helminth was Ascaris lumbricoides (3.8%). The analyzed environmental variables showing association (p < 0.05) with presence of parasites in population were: cardboard-tin or wooden house, dirt floor, home or communal water pump, faucet outside the house or public faucet and cesspool or latrine. Parasite forms were found in 82.3% of the soil samples and in 84.2% of the water samples. In both samples we found parasites that were also found in people. In this study we have found deficient sanitary conditions associated with presence of parasites in population and we have evidenced that contaminated soil and water were the source of these parasites.

Hemos evaluado la prevalencia de parásitos intestinales en 504 personas y el grado de asociación entre las variables ambientales y los parásitos intestinales hallados en la población, el suelo y el agua de una zona rural de Argentina durante 2002-2003. Se utilizó una encuesta estructurada para relevar las variables ambientales y se examinaron muestras fecales humanas, de agua y de suelo. La prevalencia parasitaria fue de 45,4%. Los protozoos prevalentes fueron Blastocystis hominis (27,2%) y Giardia lamblia (6,9%), mientras que el helminto mas prevalente fue Ascaris lumbricoides (3,8%). Las variables ambientales analizadas que mostraron asociación (p < 0,05) con la presencia de parásitos en la población fueron: casa de cartón-chapa o de madera con piso de tierra, bomba de agua domiciliaria o comunitaria, canilla fuera de la casa o pública y pozo ciego o letrina. Elementos parasitarios fueron hallados en el 82,3% de las muestras de suelo y en el 84,2% de las muestras de agua. En ambas muestras fueron hallados parásitos que también se encontraron en las personas. En este trabajo hemos hallado deficientes condiciones sanitarias asociadas con la presencia de parásitos en las personas y hemos evidenciado que el suelo y el agua contaminada fueron la fuente de esos parasitos.

The efficiency of lysis procedures and DNA purification treatments of Giardia lamblia trophozoites were evaluated regarding the breaking-up efficiency, quantity and pureness of DNA, processing time and costs. Five lysis methods (distilled water and heating; distilled water, heating and proteinase K; buffer D Lysis; buffer E lysis, and commercial kit), and three DNA purification methods (phenol:chloroform:isoamilic, Chelex 100 and commercial kit) were tested. The obtained data were statistically analyzed. The buffer E lysis and Chelex combination was simple and economic method which produced high DNA performance with low pureness. Commercial kit was simple and expensive method which generated low yields of DNA with appropriate purity level for molecular analysis

Se evaluó la eficiencia de procedimientos de lisis y tratamientos de extracción de ADN de trofozoítos de Giardia lamblia respecto a la eficiencia de ruptura, cantidad y pureza de ADN, además de los tiempos de procesamiento y costos. Se testearon cinco métodos de lisis (agua destilada y calor; agua destilada, calor y proteinasa K; buffer de lisis D; buffer de lisis E y un kit comercial) y tres métodos de purificación de ADN (fenol:cloroformo: isoamílico; Chelex 100 y un kit comercial). Los datos obtenidos se analizaron estadísticamente. La combinación de buffer de lisis E y Chelex fue un método simple y económico, que produjo alto rendimiento de ADN con baja pureza. Ella técnica comercial fue un método simple, más costoso que produjo bajas cantidades de ADN con un nivel de pureza apropiado para estudios moleculares

The objective of this study was to evaluate the relationship between toxocariasis frequency and demographic, environmental, sanitary variables, eosinophylia, and other intestinal parasites in a rural population of Argentina. Serological examination of 100 individuals was carried out by using ELISA technique for the detection of anti-toxocara antibodies. Eosinophiles in peripheral blood, presence of intestinal parasites, and demographic, environmental, and socio-cultural data were evaluated. Eighty-one feces samples of dogs belonging to the studied people were analyzed to detect eggs of Toxocara canis. Thirty of them were from 30 dogs and 51 were pools from dog feces. Samples of dirt from around the homes (n: 47) and from public park (n: 4) were taken. To determine the associations, the c² and Fisher tests were used. The seroprevalence was 23%. Eosinophilia in peripheral blood was detected in 86.95% seropositive individuals and in 37.66% seronegative individuals (p < 0.001, OR = 11.03). Of the 23 people with positive serology, 69.56% had at least one intestinal parasite. All individuals with positive serology had dogs in their homes. Among the dog owners there was a significant association between the presence of anti-toxocara antibodies and home flooding. Eggs of T. canis were detected in the feces of 5/81 dogs and three of these dogs belonged to individuals with positive serology. Eggs of Toxocara spp. were found in 41.17% of the dirt samples, eight of which came from the area surrounding the homes of individuals with positive serology (p = 0.032; OR = 4.36). Taking into account all the variables influencing the frequency of toxocariasis in this population, the implementation of Public Health programs specifically focused on anti-parasitic treatment of dogs is recommended.

The prevalence and distribution of intestinal parasites (IP) were investigated in children from two populations of different socioeconomic level, located in the same area of the city of Neuquén, in order to evaluate their relationship with habitat conditions and socioeconomic factors. Serial samples of faeces and anal scraping of 126 children between 2 and 14 years from two sectors of the suburban area of Neuquen (Sector I and Sector II) were analyzed. Data concerning habitat conditions and socioeconomic parameters were obtained by home visits and an observational structured survey. Presence of IP was detected in 50.7% of children from Sector I (suburban neighborhood with adequate sanitary conditions and middle or middle low socioeconomic level) and in 92.9% from children of Sector II (marginal settlement with poor sanitary conditions and low socioeconomic status). Seven intestinal protozoan and 4 helminth species were identified. Blastocystis hominis was the most frequent species found in both populations. No helminths different from Enterobius vermicularis were found in Sector I and the prevalence of such species was very low in Sector II. Deficient habitat conditions and low socioeconomic parameters showed relation with a higher prevalence of IP of direct transmission as protozoan and E.vermicularis in the studied populations. Nevertheless, even in this context favourable to transmission, the parasitic species which require intermediate stages of development in soil, don't find an adequate habitat for dissemination in this region

Se investigó la prevalencia y distribución de parásitos intestinales (PI) en niños de 2 poblaciones de diferente nivel socioeconómico del área periurbana de la ciudad de Neuquén (Sectores I y II) a fin de evaluar su relación con las condiciones de hábitat y factores socio-económicos. Se procesaron muestras seriadas de materia fecal y de escobillado anal de 126 niños entre 2 y 14 años de edad. Se registraron datos acerca de condiciones de hábitat y factores socioeconómicos mediante visitas domiciliarias y encuestas observaciones estructuradas. Se detectó presencia de PI en el 50,7% de los niños del Sector I (barrio suburbano con adecuadas condiciones sanitarias y nivel socioeconómico medio o medio-bajo) y en el 92,9% de los niños del Sector II (asentamiento marginal con deficientes condiciones sanitarias y bajo nivel socioeconómico). Se identificaron 7 especies de protozoos intestinales y 4 especies de helmintos. Blastocystis hominis fue la especie más frecuente encontrada en ambas poblaciones. No se encontraron helmintos diferentes de Enterobius vermicularis en el Sector I y la prevalencia de tales especies fue muy baja en el Sector II. Las condiciones de hábitat deficientes y los bajos parámetros socioeconómicos se relacionaron con una mayor prevalencia de PI de transmisión directa como protozoos y E. vermicularis en las poblaciones estudiadas. Sin embargo, aún en ese contexto favorable a la transmisión, las especies parasitarias que requieren estadíos intermedios de maduración en el suelo no encuentran un hábitat adecuado para su diseminación en esta región patagónica

The aim of this study was to analyze the Doubling Time (DT) and the Lag phase of a cell line with two concentrations of fetal bovine serum (FBS) and two initial inocula. Four growth curves of RK13 cells in Minimal Essential Medium (MEM) supplemented with glutamine, penicillin, streptomycin and 5% and 7% non-inactivated FBS were performed. The initial inocula were 3 x 10(4) and 6.8 x 10(4) viable cells/mL. DT was 24 h for the culture with 7% FBS with the two inocula and 16.36 h for the culture with 5% FBS with the greatest inoculum. The culture with 5% FBS and 3 x 10(4) viable cells/mL had limited growth. There was significant difference in DT (p = 0.0055) when the inoculum was 6.8 x 10(4) viable cells/mL with the two concentrations of FBS. There was no significant difference with the 7% FBS and the two inocula (3 x 10(4) and 6.8 x 10(4) viable cells/mL).

El objetivo de este trabajo fue analizar el Tiempo de Duplicación (TD) y la Fase de Latencia (Lag) de una línea celular con 2 concentraciones de Suero Fetal Bovino (SFB) y 2 inóculos celulares iniciales. Se realizaron 4 curvas de crecimiento de células adherentes RK13 (rabbit kidney) en Minimal Essential Medium (MEM) suplementado con glutamina, penicilina, estreptomicina y SFB no inactivado al 5% y 7%. Los inóculos iniciales fueron de 3 x 10(4) y 6,8 x 10(4) células viables/mL. El TD fue de 24 h para el cultivo con 7% de SFB con ambos inóculos y de 16,36 h para el cultivo con 5% de SFB con el mayor inóculo. El cultivo con 5% de SFB y 3 x 10(4) viables/mL presentó escaso desarrollo. Se observaron diferencias significativas en el TD (p = 0,0055) cuando se utilizó el inóculo de 6,8 x 10(4) viables/mL y se varió el SFB (5% y 7%). La diferencia no fue significativa al utilizar los inóculos de 3 x 10(4) y 6,8 x 10(4) viables/mL manteniendo constante la concentración de suero fetal (7%).

A longitudinal study to determine the presence of intestinal parasites in canine faeces and their relationship with seasonal weather conditions during a year was carried out. 481 fecal canine deposits were collected from 13 public parks in two cities of Chubut Province, Patagonia Argentina. Stools were analyzed by means of Telemann and Willis methods. Weather conditions were daily registered from local stations. The frequency of positive canine faeces to intestinal parasites was found between 34,9% and 51,2% over the studied period and was season independent (p > 0.05). A predominance of helminths over protozoa was detected in all seasons. Frequency of Entamoeba spp. and Nematoda was seasonal dependent (p < 0.05). The finding of Toxocara canis eggs varied from 12,7% in winter to 20,9% in spring. Pathogens to humans such as T. canis, Taenia spp., Uncinaria spp. and Entamoeba spp. were found. Spirocerca spp. and Capillaria spp. have been reported for the first time for this region.

Se realizó un estudio longitudinal durante un año, para determinar la presencia de parásitos intestinales en heces caninas y su relación con las condiciones climáticas. 481 muestras de heces fueron recolectadas en 13 plazas de dos ciudades de la Provincia del Chubut, Patagonia Argentina. Las muestras fueron analizadas por medio de los métodos de Telemann y Willis. Los datos meteorológicos se registraron diariamente. La frecuencia de aparición de muestras positivas para parásitos intestinales estuvo comprendida entre el 34,9% y 51,2% durante el periodo estudiado, resultando la misma independiente de la estación climática (p > 0,05). Se registró un predominio de helmintos sobre protozoos durante las cuatro estaciones. La frecuencia de aparición de Entamoeba spp. y Nematoda resultó dependiente de la estación estudiada (p < 0,05). El hallazgo de huevos de T. canis varió de un 12,7% en invierno a un 20,9% en primavera. Se detectaron patógenos para el humanos como T. canis, Taenia spp., Uncinaria spp. y Entamoeba spp. Se reportan por primera vez para ésta región Spirocerca spp. y Capillaria spp.

The aim of the present estudy was to determine the epidemiological factors of toxocarosis in Gualeguaychú, Argentina. It was evaluated the seroprevalence of this parasitoses in 272 healthy blood donors (ELISA test), and the relationship of this parameter with the socioeconomic conditions of persons, presence or absence of parasitized dogs in their dwellings and sorroundings; and the contamination of publics places of this city with Toxocara spp ova. The seroprevalence was 12,13% with most of the individuals being asymptomatic. Neither socioeconomic status nor dog ownership correlated significantly with positive serology. Toxocara canis eggs were found 25% of the dogs studied and in 100% of relevated public places. It can be therefore concluded that there is a high frequency of contamination in the soils of public places with T. canis eggs, as well as a high percentage of dog infected with this nematode. This situation establishes an important risk to acquire toxocarosis for the inhabitans of this city

El objetivo del estudio fue determinar factores epidemiológicos de toxocarosis en la ciudad de Gualeguaychú, Entre Ríos, Argentina. Se evaluó en 272 donantes de sangre la seroprevalencia de esta parasitosis, su relación con las condiciones socioeconómicas de las personas estudiadas, presencia o ausencia de perros parasitados en sus hogares y en los alrededores; y la contaminación de plazas y paseos públicos con huevos de Toxocara spp. La seroprevalencia fue del 12,13% sin correlacionarse significativamente con condiciones socioeconómicas ni tenencia de perros, siendo la mayoría de los individuos asintomáticos. El 25% de los perros y el 100% de los paseos públicos estudiados, resultaron parasitados. Esta situación establece un riesgo importante de adquirir toxocarosis en los habitantes de esta ciudad.

With the aim of recovering and identifying parasitic elements we studied soil samples from all public place of La Plata, Argentina (urban area). We surveyed 23 places during March and April, 2000 and at the time of study we measured both the pH and moisture content of each sample taken. We detected 552 parasitic elements, with 98 corresponding to protozoon cysts, 106 to helminth eggs and 348 to nematode larvae. We conclude that the soils in surveyed public places are contaminated with parasites of animal as well as human origin.