El tipo y número de bacterias en leche a nivel de finca está asociado a condiciones de manejo higiénico sanitario de las unidades de producción y sanidad de los animales, afectando su calidad microbiológica. Con el objetivo de estudiar la calidad bacteriológica de leche cruda de cabra, producida en la parroquia Faría, municipio Miranda del estado Zulia, se recolectaron 100 muestras a nivel de pezón, de 50 animales pertenecientes a 10 unidades de producción, y 10 correspondientes al pool de cada unidad. En leche de pezón se identificaron las bacterias presentes por pruebas bioquímicas. En el pool se determinaron contajes de aerobios mesófilos (AM), coliformes totales (CT), psicrófilos (PS), termófilos (TER) y termodúricos (TED) por los métodos de la APHA, también en estas muestras se identificaron con pruebas bioquímicas los coliformes presentes. Los géneros aislados de pezón fueron: Staphylococcus sp (54,84%) (St. coagulasa negativa (32,26%) y St. aureus (22,58%)), Streptococcus (22,58%) (Streptococcus spp (19,35%) y Str. agalactiae (3,23%)), Micrococcus (16,13%) y Pseudomonas (6,45%). Los recuentos promedios en el pool fueron: 1,8x10(7), 8,3x10(5), 2,5x10³, 1,8x10(4) y 1,1x10(4) (ufc.mL-1) para AM, CT, PS, TER y TED, respectivamente. Los coliformes encontrados fueron: E. coli (40%), Enterobacter sakazakii (25%), Citrobacter spp. (20%), Enterobacter spp. (10%) y Klebsiela (5%). Se concluye que en la leche de cabra producida en la parroquia Faría, predominan especies asociadas a infección intramamaria, y elevados recuentos bacterianos, que evidencian una baja calidad bacteriológica de la leche, representando su uso en la elaboración de queso blanco fresco, a partir de la leche cruda, un riesgo para la salud pública.

Type and number of bacteria in milk at farm level is associated with sanitary management conditions of both, farm and animals which affects its microbiological quality. With the objective of studying the bacteriological qualiy of raw goat milk produced in the Faria civil parish, Miranda Municipality of Zulia State, 100 milk samples were collected directly from both nipples of 50 goats belonging to 10 farms and 10 samples from the milk pool of each of such farms. In the nipple samples bacteria were identified by biochemical tests while in the pool samples counts of Mesophilic Aerobic (MA), Total Coliform (TC), Psychrophilic (PS), Thermophilic (TER) and Thermoduric (TED) bacteria were performed according to APHA methods. Coliforms in these pool samples were also identified by biochemical tests. Bacteria genus aisolated from nipples were: Staphylococci sp. 54.84% from which 32.26% were coagulase negative and 22.58% St. aureus, Streptococcus 22.58% from which 19.35% were Streptococcus sp. and 3.23% were Str. agalactiae, Micrococcus 16.13% and Pseudomonas 6.45%. Average pool sample counts were: 1.8x10(7), 8.3x10(5), 2.5x10³, 1.8x10(4) and 1.1x10(4) (ufc.mL-1) for MA, TC, PS, TER and TED respectively. Coliforms found were: E. coli 40%, Enterobacter sakazakii 25%, Citrobacter spp. 20%, Enterobacter spp.10% and Klebsiella 5%.From these results we concluded that in the milk of the farms tested, representatives of the Faria civil parish predominates bacteria species associated with intramammary infections. Elevated bacteria counts evidence a low bacteriological quality of this goat milk therefore making its use for raw milk fresh cheesemaking unsafe and risky for public health.

Se describen cualitativa y cuantitativamente las alteraciones histológicas ocasionadas por Brevipalpus phoenicis a sépalos y pedúnculos de frutos pequeños, medianos y grandes de Psidium guajava L. Estructuras físicamente sanas, con daño moderado y severo causado por el ácaro se recolectaron de plantas establecidas en el Centro Frutícola del Zulia- CORPOZULIA, municipio Mara (19º83'53'' LN y 19º65'09'' LE), Venezuela. Las secciones transversales sanas y dañadas se microfotografiaron y digitalizaron con el programa Image Pro Plus®, a fin de establecer comparaciones mediante la cuantificación realizada con el programa Image Tool®. Las variables evaluadas fueron: espesor de la epidermis o del estrato superficial necrosado, espesor del parénquima, número de células con fenoles (NCF); número de braquiesclereidas (NB) y el espesor de su pared celular. Los procedimientos estadísticos aplicados fueron análisis de varianza, prueba de comparación de medias (Tukey y DMS) y análisis de frecuencias. Los resultados determinaron que los tejidos epidérmicos y parenquimáticos de sépalos y pedúnculos con daño del ácaro se modificaron en un estrato superficial necrosado, cuyo espesor incrementó dependiendo de la combinación de los factores de estudio. El NCF en los frutos pequeños presentó un rango de 0,35 a 24 células células·12.399 µm-2 correspondientes a pedúnculos sin daño y sépalos con daño moderado, respectivamente. El NB se ubicó en el rango 0 a 3 braquiesclereidas células·12.399 µm-2, no siendo abundantes en sépalos ni en pedúnculos, como se ha observado en el mesocarpo. Considerando que tanto la epidermis como el parénquima poseen capacidad meristemática, las alteraciones ocasionadas por el ácaro podrían afectar el crecimiento y la cicatrización de heridas en las estructuras analizadas.

Histological alterations caused to sepals and peduncles of small, medium and large size fruits of Psidium guajava L. by Brevipalpus phoenicis are described and quantified. From 30/10/2003 to 22/01/2004 samples of healthy, moderately and severely damaged fruits were collected from plants located at Centro Frutícola del Zulia, Mara County (19º83'53''N and 19º65'09''E), Venezuela. Transversal sections of tissues were micro photographed and digitalized by using Pro Plus® software Image program, with the purpose of establishing comparisons through quantification made by using Tool® software Image program. The variables evaluated were: epidermal thickness or necrosed superficial layer (NSL), parenchyma thickness, and number of phenolic cells (NPC), number of sclereids (NS) and thickness of cell wall. The statistical procedures analysis of variance, test of means comparison (Tukey and DMS) and frequency analysis. The results showed that the epidermal and parenchyma tissues of sepals and peduncles with flat mite damage were modified into a necrosed superficial layer, whose thickness increased according to the combination of the studied factors. The NPC in small fruits with healthy peduncles and moderately damaged sepals ranged from 0.35 to 24 cells.12399 µm-2. The NS ranged from 0 to 3 sclereids.12399 µm-2, not being as abundant in sepals or peduncles, as observed in mesocarp. Considering that the epidermal and parenchymatic layers have meristematic capacity, the alterations caused by the mite could affect the cellular regeneration which is important and necessary to the fruit growing, as well as to the wounds healing in the analyzed structures.

Se caracterizó el fruto de variantes de guayabo del municipio Mara, Venezuela. Las plantas de las variantes Blanca, Criolla Roja, Cubana y Montalbán formaron los tratamientos, con 10 plantas por variante. Se determinó la forma, ápice, base, cavidad, masa, diámetro, longitud, punto de inserción del pedúnculo, presencia y forma del seno del fruto; color y textura del epicarpo; color y masa del mesocarpo y endocarpo; número y masa de las semillas. Se construyeron tablas de frecuencias y análisis de varianza para las variables cualitativas y cuantitativas, respectivamente y un análisis de componentes principales. Los caracteres que permitieron separar a las variantes fueron la forma de los frutos, en Blanca, Criolla Roja y Cubana predominó la forma esférica, en Montalbán la forma piriforme. La forma de la base del fruto en Blanca y Cubana fue cóncava, en Criolla Roja convexa con cuello y en Montalbán con cuello. En Criolla Roja, Cubana y Montalbán, el color del epicarpo fue amarillo y en la Blanca verde-amarillo. Hubo diferencias estadísticas (P<0,05) para la masa del fruto, mesocarpo y endocarpo. La variante Blanca presentó la mayor masa del fruto, mesocarpo y endocarpo. Se presentaron diferencias estadísticas (P<0,05) al comparar la masa de las semillas de Blanca, Criolla Roja, Cubana y Montalbán y el número de semillas de Blanca y Criolla Roja con las otras variantes. Blanca y Criolla Roja presentaron el mayor número de semillas por fruto. La morfología de los frutos fue diferente entre las variantes evaluadas. Las variables cualitativas influyeron en la caracterización morfológica del fruto.

In order to characterize morphologically the fruit of guava of several variants an essay was conducted in Mara municipality, Venezuela. Plants of "Blanca", "Criolla" "Roja", "Cubana" and "Montalbán" variants formed the treatments, with ten plants of each variant. Shape, apex, base, cavity, mass, diameter, and longitude of the fruit, the insertion point of the peduncle, presence and shape of the sinus, color and texture of the epicarp, color and mass of the mesocarp and endocarp, number and mass of seeds were evaluated. Frequency tables were done for the qualitative and quantitative variables were evaluated through analysis of variance, and principal component analysis. In "Blanca", "Criolla Roja" and "Cubana" the spherical fruit was the shape predominating, in "Montalban" was the piriform shape. Shape of fruit base in "Blanca" and "Cubana" was concave, in "Criolla Roja" was convex with neck and in "Montalban" with neck. In variants "Criolla Roja", "Cubana" and "Montalban" the epicarp color was yellow, while in Blanca dominated the green-yellow epicarp. There were statistical differences (P<0.05) for the mass of the fruit, mesocarp, endocarp, and epicarp. "Blanca" variant showed a higher mass of the fruit, mesocarp, endocarp, and epicarp. The seeds mass of "Blanca", "Criolla Roja", "Cubana" and "Montalban", and the seeds number of Blanca and "Criolla Roja" were statistically different (P<0.05) when they were compared to the other variants. "Blanca" and "Criolla Roja" had the higher number of seeds by fruits. Results confirmed that fruit morphology was different among the evaluated variants. The information generated by the CP highlight the qualitative variables as the ones which mainly affected the morphological characterization.

After 57 years of successful control of schistosomiasis in Venezuela, the prevalence and intensity of infection have declined. Approximately 80% of the individuals eliminate less than 100 eggs/g of stools, therefore morbidity is mild and the majority are asymptomatic. The sensitivity of Kato-Katz decreases to approximately 60%. Available serological methods for the detection of circulating antigens only reach a 70% of sensitivity. Tests based on the detection of antibodies by immunoenzymatic assays have been improved. The circumoval precipitine test has shown a high sensitivity (97%), specificity (100%), and correlation with oviposition, being considered the best confirmatory diagnostic test. Additionally to the classical immunoenzymatic assays, the development of the alkaline phosphatase immunoassay, allowed to reach a 100% specificity with an 89% sensitivity. Recently, we have developed a modified ELISA in which the soluble egg antigen is treated with sodium metaperiodate (SMP-ELISA) in order to eliminate the glycosilated epitopes responsible for the false positive reactions. The specificity and sensitivity reaches 97% and 99%, respectively. Synthetic peptides from the excretory-secretory enzymes, cathepsin B (Sm31) legumain (Sm32) and cathepsin D (Sm45), have been synthesized. The combination of two peptides derived from the Sm31 have been evaluated, reaching a sensitivity of 96% when analyzed independently and with a 100% specificity. Antibodies raised in rabbits against peptides derived from the Sm31 and Sm32 are currently evaluated in two different antigen-capture-based assays. The development of a simple, cheap and reliable test that correlates with parasite activity is a major goal.

Severe schistosomiasis is a rare event in Venezuela nowadays, after a successful national campaign by the Schistosomiasis Control Program. Unfortunately, this program has practically disappeared, and snail surveillance in field is not a priority, anymore. Thus, schistosomiasis has become a neglected disease in this country. However, surveys in different populations from the endemic area have shown particular epidemiological features described herein. In five communities we evaluated 2,175 persons and searched for the presence of Biomphalaria glabrata snails. Some markers were used for classifying schistosomiasis foci: mean age of the persons with Schistosoma mansoni eggs in the stools, serological tests, presence of B. glabrata snails, and intensity of infection. Places without B. glabrata snails and with few schistosomiasis cases were defined as "past transmission sites"; a site with abundant snails but few cases was defined as "potential risk"; "new transmission" foci were characterized by the presence of infected snails and young people passing eggs in the stools. A "re-emergent" focus has shared these last features, showing in addition a place where schistosomiasis had been reported before. Recent evidences of active transmission with the increasing dispersion of B. glabrata snails, point out the necessity for the re-establishment of the Schistosomiasis Control Program in Venezuela.

Las condiciones geográficas, ambientales, culturales y económicas facilitan en algunas áreas las infecciones simultaneas por varios agentes. Parásitos de un mismo género o de diferentes familias o phyla, entre parásitos y sus hospederos, comparten moléculas capaces de despertar respuestas inmunes comunes. Este fenómeno permitiría la reactividad cruzada entre parásitos, que tendría como ventaja la eficacia de un producto de amplio espectro (vacuna o medicamento) al poder atacar varios agentes parasitarios en una población poliparasitada. Por el contrario, como desventaja se destaca la inespecificidad del inmunodiagnóstico reflejada como falsos positivos por reactividad cruzada, detectándose anticuerpos o antígenos compartidos que no pertenecen propiamente al agente sospechado. Adicionalmente, la respuesta inmune a un agente patógeno puede dirigirse contra tejidos del propio huésped, desencadenando fenómenos de autoinmunidad. En esquistosomiasis se han desarrollado técnicas de inmunoensayo de mejor especificidad que las tradicionales. Sin embargo, siendo Venezuela un país en el cual coexisten áreas endémicas donde se solapan infecciones parasitarias tales como esquistosomiasis, nematodes intestinales y cisticercosis, se presentan inconvenientes de sobreestimación de prevalencias ocasionando limitaciones en el tratamiento masivo con praziquantel y confusión en la definición de verdaderos casos de esquistosomiasis o cisticercosis. Investigaciones tendientes a mejorar el inmunodiagnóstico disminuyendo los falsos positivos, mediante ensayos de captura de anticuerpos y antígenos para ambas parasitosis, se desarrollan en la actualidad.

Geographical, environmental, cultural and economical conditions favor polyparasitism of several agents in tropical areas. Different species of parasites or from different genera, families or phyla, or between parasites and their vectors, usually share molecules that are able to elicit common immune responses, that are defined as antigenic community, responsible for cross reactivity. This phenomenon may have the advantage of the possible application of an effective product (vaccine or drug) simultaneous against different species of parasites. One of the most deleterious consequences is the inespecific reactions in immunodiagnostic test. Additionally, immune response against some pathogens could be inespecifically directed against host tissues, being responsible for autoimmune reactions. In certain parasitic diseases like schistosomiasis, there are still some problems of inespecifity with other helminths. In Venezuela where intestinal parasites, schistosomiasis and cysticercosis can overlap, classic immunoenzymatic assays overestimate prevalences, limiting the capacity of the control programme for the application of massive treatment with praziquantel. Research directed to improve immunodiagnosis, reducing false positives with tests based on the demonstration of specific circulating antibodies or antigens, are currently being investigated.