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La floculación es un método de precipitación que retiene los sólidos suspendidos, liberando aguas grises con una carga orgánica menor. El polvo de moringa tiene un efecto floculante y en este caso se evaluó su efecto entre las poblaciones bacterianas, especialmente las de importancia en salud pública. El estudio se realizó en la Ciudad de Reynosa, Tamaulipas, que tiene dos canales que conducen agua para uso urbano y agrícola. Cuatro sitios fueron muestreados, dos en la ciudad y los otros en la periferia de la ciudad. Las muestras de agua recolectadas en cada punto fueron divididas en dos. Un lote fueron los controles y al otro se les agregó polvo de moringa. Posteriormente, en todos los lotes se realizó una extracción de ADN para análisis metagenómico de la biota presente. Los resultados mostraron que hay un efecto floculante en las muestras de agua y que con el tratamiento se alteran las poblaciones microbianas; finalmente, se observa que las poblaciones de bacterias de importancia en salud pública no son retiradas con el tratamiento.

The fungus Macrophomina phaseolina is a phytopathogen of great importance attacking various crops and causing severe losses especially in sorghum, beans, soybeans and others. Since acetic indole acid (AIA) is a hormone that some authors associate with the pathogenic power of other fungi such as Fusarium oxysporum, it was decided to perform this work to detect whether M phaseolina isolated from beans is layers of producing AIA and which synthesis pathways are involved in its production. The analyses performed using HPLC showed the production of indole acetamide (ACM) that occurs in the first 60 hours of incubation. Another compound produced is Indole (IND) which is released after 60 hours when ACM production has ceased. Similarly, the fungus can metabolize AIA in the culture medium and tryptophan, the main precursor of AIA, apparently has no effect on the amount of AIA synthesized. Conclusion: The phytopathogenic fungus Macrophomina phaseolina can produce indole acetic acid, a hormone that stimulates plant growth through the TRP-D pathway via indole acetamide, which occurs mainly in the first 60 hours of growth of the fungus in the culture medium. In addition, the presence of indole was detected, which allows us to estimate that the fungus uses another little explored route that is TRP-I and that from this compound the AIA can be synthesized directly or transformed into TRP. This means that when a metabolic pathway of IAA is turned off (ACM) it is replaced by another pathway (Indole). The convenient is to correlate the release of indole acetic acid with the pathogenicity of M phaseolina.

Los aceites esenciales se caracterizan por presentar olor, sabor y muchas veces propiedades antifúngicas;son producidos por plantas aromáticas y medicinales. Es importante determinar qué efecto tienen los aceites esenciales de L graveolensen el control de fitopatógenos. Se realizó la evaluación del aceite esencial de Lippia graveolens sobre el hongo Fusarium chlamydosporum, que tiene alta incidencia, reduce la productividad y puede afectar al humano. La extracción de los aceites se realizó en etanol absoluto. De la biomasa se realizó la extracción de DNA y se hizo una PCR utilizando los oligonucleótidos ITS1 e ITS4. El hongose confrontóen cajas de petri con los aceites esencialesde L graveolens. Seobservó menor crecimiento de Fusarium sp, en la muestra Viad 01, con 1.23 cm de crecimiento;mientras que en el testigo se obtuvo una colonia de 4.60 cm, lo cual representa una diferencia de 3.37 cm con respecto a la muestra Viad 01. Lo anterior muestra que los extractos de Lippia graveolenspueden ser una alternativa para el control de enfermedades innovando para la agricultura sostenible y competitiva, además de su uso potencial en salud humana.

In Mexico, corn is the most widely used cereal, however, in arid areas it is not possible to cultivate it, so white sorghum represents an alternative. However, it is important to know the varieties nutritional content. Therefore, this study the proximal profile and fatty acids of six white sorghum varieties grown in Mexico were evaluated. Proximate analysis was carried out based on AACC methods and gas chromatography had been used for fatty acid analysis. Mazatlan and Sureño varieties showed the highest content of proteins (12%), fiber (7%), and ash (1.65%); regarding fat content, the highest values were found in Mazatlan and Costeño (4%). For fatty acid profile, saturated and unsaturated fatty acids were detected, including Omega 6 and 9. Sorghum represents an alternative, specially for arid and semiarid regions. The results indicate that these varieties are a viable source to produce foods for human consumption.

"The bacterium Bradyrhizobium japonicuminduces nodulation in Glycine max (soy) plants and other legumes. It is considered of great importance, since it is in the nodules that the bacteria are established, contributing to the biological fixation of N.. The process is controlled by nitrogenase, an enzyme produced by the nif genes present in the genome of the bacterium. By metabolizing the nitrogenase, the indole acetonitrile transforms it into indole acetic acid (IAA) and releases a nitrogenated molecule. There have been other IAA synthesis routes reported in plants, other genera and species of bacteria, fungi, and algae, named tryptophan-dependent (TRP-D) or tryptophan independent (TRP-I), where this amino acid is the precursor. For TRP-D, there are four pathways to the synthesis of IAA, and only two for TRP-I. The microorganisms may or not have all the routes in their genomes, and the expression of the genes varies with the isolation and the genotype of the host plant. This work reports the results obtained from an B. japonicum soy isolate, cultivated in an enriched LB medium, or alternatively, with tryptophan. With the data obtained, we estimate that B. japonicum uses both TRP-D and TRP-I routes, since in the former type indole acetamide was detected, and in the latter, indole and anthranilic acid were found. Likewise, the presence of TRP in the medium may alter IAA synthesis routes."

Entomologic and serologic surveys were performed in four sentinel communities in the Oaxaca focus in southern Mexico to assess the level of transmission and exposure incidence to Onchocerca volvulus. All communities have been receiving ivermectin mass treatment twice per year since 1997. In one community, parasite DNA was detected by polymerase chain reaction-enzyme-linked immunosorbent assay in 2004 in one pool of 50 vector heads of 170 such pools (8,500 flies) examined, which indicated an estimated transmission potential of 6.7 third-stage larvae/person/year. No evidence for transmission was found in the three other communities in 13,650 flies examined. All persons in a cohort consisting of 117 children in the four communities remained serologically negative for antibodies recognizing a cocktail of recombinant antigens over a four-year period from 2001 to 2004, which indicated an exposure incidence of 0%. Taken together, these data suggest that transmission has been suppressed in the four communities.

Entomologic and serologic surveys were performed in four sentinel communities in the Oaxaca focus in southern Mexico to assess the level of transmission and exposure incidence to Onchocerca volvulus. All communities have been receiving ivermectin mass treatment twice per year since 1997. In one community, parasite DNA was detected by polymerase chain reaction-enzyme-linked immunosorbent assay in 2004 in one pool of 50 vector heads of 170 such pools (8,500 flies) examined, which indicated an estimated transmission potential of 6.7 third-stage larvae/person/year. No evidence for transmission was found in the three other communities in 13,650 flies examined. All persons in a cohort consisting of 117 children in the four communities remained serologically negative for antibodies recognizing a cocktail of recombinant antigens over a four-year period from 2001 to 2004, which indicated an exposure incidence of 0%. Taken together, these data suggest that transmission has been suppressed in the four communities.

BACKGROUND: Since 1991, in Mexico, ivermectin has been administered twice a year to all residents in the onchocerciasis endemic foci which are mainly located in the coffee growing areas. However, the presence of a potentially infected itinerant seasonal labour force which is not treated regularly could jeopardise the attainment of the 85% coverage which is the present target for elimination of the disease. METHODS: The prevalence and intensity of Onchocerca volvulus microfilariae (mf), as well as their transmission from humans to vectors, were assessed during the coffee planting-clearing and harvesting seasons of 1997-1998, and 1998-1999 in two localities (I and II) of Southern Chiapas, Mexico, which regularly receive an influx of untreated migrant coffee labourers. RESULTS: Localities I and II had, respectively, an average of 391 (+/- 32) and 358 (+/- 14) resident inhabitants, and 70 (+/- 52) and 498 (+/- 289) temporary labourers. The ratio of migrants to residents ranged from 0.1:1 in locality I to 2.4:1 in locality II. The proportion of infected Simulium ochraceum s.l. parous flies was significantly lower in locality I than in locality II, and significantly higher during the stay of the migrants than before their arrival or after their departure. Parity and infection were higher in May-July than in November-February (in contrast with the latter being typically considered as the peak onchocerciasis transmission season by S. ochraceum s.l.). CONCLUSION: The presence of significant numbers of untreated and potentially infected migrants may contribute to ongoing transmission, and their incorporation into ivermectin programmes should be beneficial for the attainment of the elimination goals of the regional initiative. However, the possibility that the results also reflect transmission patterns for the area cannot be excluded and these should be analyzed further.

Onchocerciasis is a serious disease vectored by black flies in the genus Simulium that are infected with the filarial parasite Onchocerca volvulus. In the Americas, black flies of the Simulium ochraceum s.l. species complex are important vectors of this parasite. Cytological studies have suggested that this species complex consists of at least three cytotypes that inhabit distinct habitats. In this study, the NADH dehydrogenase subunit four (ND4) and internal transcribed spacer (ITS) of the ribosomal RNA gene cluster were used to explore the degree of genetic diversity among S. ochraceum s.l. populations found in the three O. volvulus foci in Mexico. Both sequence regions were found to exhibit intra- and interpopulation variation. Four different ND4 alleles were found among the populations examined. Similarly, variation was noted in the ITS domain sequences within and among populations. Variation within the ITS sequence was primarily confined to a complex microsatellite locus. Four ITS length variants were observed, two of which were only seen in flies collected from the onchocerciasis focus in northern Chiapas. These data suggest that the ND4 and ITS sequences may prove to be useful markers for exploring interactions within and among the S. ochraceum s.l. populations in Mexico.

The impact of quarterly Mectizan (ivermectin) treatments on transmission, microfiladermia, and ocular lesions was evaluated in two formerly hyperendemic communities (Las Golondrinas and Las Nubes II) located in the main endemic focus for onchocerciasis in Southern Chiapas, Mexico. The data suggest that Onchocerca volvulus transmission has been suppressed after elimination of microfiladermia in these two communities. Increasing the frequency of Mectizan treatment to four times per year appears to have resulted in the rapid suppression of transmission in communities with residual transmission.

Resumen en español: "Desde hace más de un siglo, la oncocercosis es un problema de salud pública en África y América Latina. En México, el principal vector de la oncocercosis es Simulium ochraceum y, S. metallicum es considerado vector secundario. En comunidades del foco sur de Chiapas, la presencia de nódulos en niños menores de cinco años indica evidencia de infección con el parásito, y transmisión residual dado que todavía existen S. ochraceum infectados con Onchocerca volvulus. El objetivo de este trabajo fue determinar si S. metallicum también es transmisor del parásito en esas comunidades y pudiera estar contribuyendo al mantenimiento de la transmisión de O. volvulus. Los simúlidos fueron recolectados, utilizando la técnica de cebo humano, durante la época de mayor transmisión del parásito. Los simúlidos fueron agrupados y se extrajo ADN para la amplificación del gen O-150. Los productos de la PCR fueron detectados por ELISA. Se recolectaron un total de 13,750 ejemplares de S. metallicum en cinco comunidades: Estrella Roja, Primero de Mayo, Las Golondrinas, Nueva Reforma y José María Morelos. De los lotes de cuerpos examinados de S. metallicum resultaron ocho positivos, procedentes de las comunidades Primero de Mayo y Nueva Reforma Agraria. De las comunidades donde se obtuvo lotes de cuerpos positivos, se analizaron 201 lotes de cabezas obteniéndose una tasa de infectividad de 0.29 (I.C 95% 0.0003-0.78). Los datos sugieren que S. metallicum es también vector del parásito en ambas comunidades. Sería interesante analizar un mayor número de S. metallicum para confirmar que este también es el responsable del mantenimiento de la transmisión residual en comunidades del foco Sur de Chiapas "