Insectos asociados a productos alimenticios almacenados en el área urbana de Culiacán, Sinaloa, México / Insects associated with food products stored in the urban area of Culiacán Sinaloa, Mexico

Resumen Los insectos asociados a productos almacenados dañan a una amplia variedad de alimentos en hogares y expendios, provocando baja calidad nutricional e incluso riesgo a la salud de los consumidores. El objetivo de este estudio fue determinar las especies y abundancia de insectos asociados a alimentos secos almacenados en casas y tiendas de abarrotes de la ciudad de Culiacán, Sinaloa. Se obtuvieron productos alimenticios, en casas o tiendas de abarrotes, con indicios de daños por insectos o presencia de los mismos, los cuales fueron trasladados al laboratorio, donde se aislaron los imagos. Los organismos inmaduros y las muestras de alimento seco se depositaron en cámaras de emergencia de adultos debido a que la identificación se llevó a cabo por morfología en la fase de imago. Se recolectaron 181 ejemplares de insectos pertenecientes a 8 especies; de ellas, Oryzaephilus mercator (Fauvel), Necrobia rufipes (De Greer), Plodia interpunctella (Hubner) y Cadra cautella (Walker) son nuevos registros para Sinaloa. En las casas se encontró la mayor cantidad de insectos, principalmente del orden coleoptera (U = 96.000, n = 154, P = 0.004). Las especies N. rufipes, T. castaneum (Herbst) y P. interpunctella fueron las más comunes en los sitios de estudio y en las muestras recolectadas. Por primera vez se caracterizó y se determinó la abundancia de insectos plaga de productos alimenticios almacenados en una zona urbana de Sinaloa, entidad federativa con importancia agraria en México. Ubicar taxonómicamente las especies que infestan productos almacenados ayuda a determinar el riesgo económico y de salud que representan para las zonas donde fueron encontrados. También es útil para desarrollar y aplicar medidas adecuadas de control entomológico, en caso de presentarse una plaga en la zona, lo que mantendrá la calidad e integridad de los productos que se comercializan.

Abstract Insects associated with stored produce damage a wide variety of foods in homes and grocery stores, causing poor nutritional quality and even health risk in consumers. The objective of this study was to determine the species and abundance of insects associated with dry food products stored in homes and grocery stores of the city of Culiacán, Sinaloa. Food products were obtained, in houses or grocery stores, with signs of damage by insectes or their presence, which were transferred to the laboratory, where the imagos were isolated immature and dry food samples were deposited in adult emergency chambers because the identification was carried out by morphology in the imago stage. 181 insects belonging to 8 species were collected, of which Oryzaephilus mercator (Fauvel), Necrobia rufipes (De Greer), Plodia interpunctella (Hubner) and Cadra cautella (Walker) represent new records for the state of Sinaloa. The highest number of insects that belong mainly to the order coleoptera were collected in homes (U = 96.000, n = 154, P = 0.004). N. rufipes, T. castaneum (Herbst) and P. interpunctella were the most common species at the study sites and of the food samples collected, dog food and flour were the most affected. For the first time, the abundance of insect pests of stored food products was characterized and determined in an urban area of Sinaloa, an agriculturally important state in Mexico. Identifying taxonomically the species that infest stored products will allow to determine the economic and health risk that they represent for the areas where they were found. It is also useful in developing and applying the appropriate entomological control that will maintain the quality and integrity of the products.

First Evidence of Horizontal Transmission by Fecal Shedding of Dengue Virus 4 Among Aedes aegypti Larvae (Diptera: Culicidae) Under Laboratory Conditions.

The transmission pathways of dengue virus (DENV) among mosquitoes are a topic that has gained relevance in recent years because they could explain the maintenance of the virus in the wild independently of the human-mosquito horizontal transmission cycle. In this regard, Aedes aegypti larvae exposed to supernatants of C6/36 cells infected with DENV-4 were evaluated for virus excretion in feces and viability of infection in immature stages (larvae). The results demonstrate that larvae excrete DENV-4 in their feces with the potential to at least infect immature individuals of the same species. A horizontal transmission pathway of larvae-larvae DENV-4 under laboratory conditions is suggested.

Molecular Detection of Leishmania (L.) mexicana (Kinetoplastida: Trypanostomatidae) DNA in Culicoides furens (Diptera: Ceratopogonidae) from an Area with Autochthonous Canine Leishmaniasis in Northwestern Mexico.

PURPOSE: Mexico is considered endemic for Leishmania; recent reports indicate autochthonous human and canine leishmaniasis caused by Leishmania mexicana in Sinaloa state. Lutzomyia sand fly are the primary vector of the parasite, although no records of phlebotomine vectors of Leishmania exist from Sinaloa. Other hematophagous dipterans, like Culicoides, could represent possible vectors of Leishmania in absence of phlebotomines. The known distribution of Culicoides includes the southern portion of Sinaloa state, in northwestern Mexico, with records of Culicoides furens. However, no studies have demonstrated the presence of Leishmania in C. furens or its possible participation in the parasite's life cycle in Mexico. This study, therefore, sought to detect DNA of Leishmania in C. furens captured in an endemic area of autochthonous canine leishmaniasis in northwestern Mexico. METHODS: Culicoides were captured with CDC light traps, identified morphologically, and organized in pools. DNA was extracted, and used to amplify the ribosomal ITS1 region of Leishmania. PCR products were digested with HaeIII endonuclease; the banding patterns obtained were compared to reference strains. RESULTS: Leishmania mexicana DNA was detected in five out of nine pools (55%) of female C. furens. CONCLUSION: This study offers the first evidence of L. mexicana DNA in C. furens, in an endemic area of canine leishmaniasis in northwestern Mexico, where no evidence exists of the presence of phlebotomine sand fly.

First report of autochthonous canine leishmaniasis caused by Leishmania (L.) mexicana in Sinaloa, Mexico.

Leishmaniasis is a neglected tropical disease caused by different species of protozoan parasites of the genus Leishmania. Dogs have been proven as primary hosts of the parasite. Cases of cutaneous leishmaniasis in humans caused by Leishmania mexicana have been reported in Sinaloa; however, the vectors and hosts involved in the epidemiology of the parasite in northwestern Mexico are still unknown. Given the public health implications of this parasite's domestic hosts regarding the permanence and transmission of the disease to humans, the objective of the present study was to detect and determine the species of Leishmania that caused the first three cases of autochthonous canine leishmaniasis in the state of Sinaloa, Mexico. Three domestic dogs showing symptoms similar to canine leishmaniasis were identified, including chronic eye inflammation, corneal opacity, ocular exudate, emaciation and hyporexia. DNA was extracted from venous blood of the infected animals using a commercial kit. The internal transcribed spacer (ITS-1) of ribosomal DNA (rDNA) was amplified by specific primers for Leishmania from the extracted DNA, and the PCR products were digested with the restriction enzyme HaeIII. In addition, PCR products were subjected to automated sequencing. Molecular analysis showed that the infecting species was L. mexicana. This is the first report of autochthonous canine leishmaniasis caused by L. mexicana in Sinaloa, Mexico. Further studies are required to identify the species that serve as vectors and other wild and domestic hosts of the parasite, as well as to determine if there are more species of Leishmania circulating in Sinaloa.