José Guadalupe Rendón-Maldonado

Molecular Diagnosis of Leishmania mexicana in a Cutaneous Leishmaniasis Case in Sinaloa, Mexico

Leishmaniasis has been considered endemic in Sinaloa, Mexico, since 1994. Despite that Leishmania mexicana is the main etiological agent of cutaneous leishmaniasis (CL) in other regions of Mexico, the species causing CL in patients from Sinaloa state has not been previously established, although Leishmania braziliensis has been found in the neighboring southern state, Nayarit. L. braziliensis is also associated with mucocutaneous leishmaniasis, which is a more complicated clinical variant. Due to the implications on individual and public health, the objective of this report was to identify the Leishmania species present in Sinaloa, Mexico. Using the first internal transcribed spacer (ITS-1) polymerase chain reaction-restriction fragment length polymorphism, we identified L. mexicana in a CL patient from Sinaloa and confirmed the extended distribution of this parasite in Mexico.

Non-typhi Salmonella serovars found in Mexican zoo animals.

The aim of the present study was to determine the bacteriological prevalence of subclinical non-typhi Salmonella infections in zoo animals and to determine the most frequently isolated serovars of the bacteria. A total of 267 samples were analyzed, including fecal samples from zoo animals and rodents, insects (Musca domestica and Periplaneta americana) and samples of the zoo animals food. Salmonella was detected in 11.6% of the samples analyzed. Characterization of the isolates was performed with serotyping and pulsed-field gel electrophoresis. The following serovars were isolated: S. San Diego, S. Oranienburg, S. Weltevreden, S. Braenderup, S. Derby, S. 6,7, H:en x:- and S. 3,10, H:r:-. The isolates showed seven pulsed-field gel electrophoresis patterns with a Jaccard coefficient≥0.75 indicating a possible common origin. The prevalence of asymptomatic infections caused by Salmonella spp. in zoo animals was high. These findings demonstrate the diversity of Salmonella serovars in several captive wild animal species.

Intrahepatic growth and maturation of Gnathostoma turgidum in the natural definitive opossum host, Didelphis virginiana

Gnathostoma turgidum is a gastric nematode parasite of opossums found in the Americas. We recently found that G. turgidum juveniles appear in the liver of the opossums where they become mature adults and almost synchronously move to the stomach during certain months of the year, suggesting the importance of the liver for the growth and maturation of this species in the final hosts. In this study we attempted to detect G. turgidum larvae in the liver of opossums, Didelphis virginiana that are the natural final hosts. The results show that tiny (<3mm in length) third stage larvae (L3) appeared in the liver of opossums around November and December. Also in the liver, we found large L3 of up to about 10mm in length together with juveniles and mature adults from February to March. In spite of their length, large L3 have 4 rows of hooklets, and their gonads remained undeveloped. Morphological features of the small and large L3 of G. turgidum are described including scanning electron microscope images. The seasonal switching of the several growth stages of G. turgidum from small L3 to adult worms in the liver and eventual migration to the stomach in opossums suggests the unique feature of G. turgidum utilizing the liver as the maturation site.

First Record of Aedes albopictus in Sinaloa, Mexico

Abstract We report here the discovery of Aedes albopictus for the first time in Sinaloa state, Mexico. The mosquito larvae were collected from small water containers in the urban area of Culiacan city, Sinaloa state. Identification of the species was done primarily by morphology, followed by confirmation with polymerase-chain-reaction–based molecular method.

Histopathological Changes in Third-Instar and Adult Anastrepha ludens (Diptera: Tephritidae) After in vitro Heat Treatment

ABSTRACT. The Mexican fruit fly, Anastrepha ludens Loew (Diptera: Tephritidae), is one of the most harmful pests of mango causing direct damage by oviposition on the fruit pulp. Mango for export is subjected to hydrothermal treatment as a quarantine method for the control of this pest, but exposure to heat for long periods of time reduces considerably the quality and shelf-life of treated fruit. The aim of this work was to study morphological changes of third-instar larvae and adults of A. ludens after in vitro exposure to high temperature at sublethal times. A heating block system was used to expose larvae at 46.1°C for 19.6 and 12.9 min, producing 94.6 and 70% mortality, respectively. Treated larvae were processed for optical microscopy. A fraction of surviving treated larvae was separated into containers with artificial diet to allow development into adults. Adult sexual organs were dissected and processed for transmission electron microscopy analysis. Results showed that 94.6% of the treated larvae died at 46.1°C for 19.6 min and none of the surviving larvae eclosed to adulthood, as they developed as malformed puparia. For the in vitro treatment at 46.1°C during 12.9 min, 70% of the treated larvae died and only 3.75% reached the adult stage, but ultrastructural damage in the male testes and in the female ovaries was observed. Additionally, 11.1% of the adult flies from the in vitro treatment also showed wing malformation and were incapable of flying. The analysis showed that surviving flies were unable to reproduce.

Spontaneous Cure after Natural Infection with Gnathostoma turgidum (Nematoda) in Virginia Opossums (Didelphis virginiana)

Abstract Seasonality of the nematode Gnathostoma turgidum in Virginia opossums (Didelphis virginiana) in the wild has been reported; however, the mechanisms involved in deworming are unknown. We monitored the parasitologic and biologic changes in four Virginia opossums naturally infected with G. turgidum by coproparasitologic examination and abdominal ultrasonography. Eggs became detectable in the feces of opossums in May, peaked in July and August, and suddenly decreased in October. Adults of G. turgidum were expelled in the feces mainly in September. Ultrasonography of the liver showed slight damage during May. Lesions in the stomach appeared in April and persisted until September. The abnormalities of the liver and stomach were resolved in November. These data suggest that G. turgidum is likely expelled as a result of host immunologic mechanisms, although termination of a natural life span cannot be definitively excluded.

Prevalence of Salmonella enterica serovar Albany in captive zoo wild animals in the Culiacán Zoo in Mexico.

Abstract:  Salmonellosis is an important zoonotic disease but little is known about the role that free-living animals play as carriers of this pathogen. Moreover, the primary route of infection in the wild needs to be elucidated. The aim of this study was to determine the source and the route of transmission of Salmonella enterica serovar Albany (S. Albany) infection in captive zoo wild animals in the Culiacán Zoo. A total of 267 samples were analyzed including 220 fecal samples from zoo animals, 15 fecal samples from rodents, 5 pooled samples each of two insects (Musca domestica and Periplaneta americana), and 22 samples of animal feed. We detected S. Albany in 28 (10.5%) of the samples analyzed, including in samples from raw chicken meat. Characterization of isolates was performed by serotyping and pulsed-field gel electrophoresis. All isolates shared a single pulsed-field gel electrophoresis profile, indicating a possible common origin. These data suggest that the infected meat consumed by the wild felines was the primary source of infection in this zoo. It is likely that the pathogen was shed in the feces and disseminated by insects and rats to other locations in the zoo.

Evaluación de Mesocyclops edax 1 como Agente de Control Biológico de Larvas 2 de Aedes aegypti en Condiciones de Laboratorio

Resumen. Se evaluó en condiciones de laboratorio al copépodo Mesocyclops edax como agente de control biológico de larvas de Aedes aegypti. Larvas L1 de Ae. aegypti, en diferentes densidades, se expusieron por 24 h a una hembra de M. edax con ayuno de 24 h, observando que la depredación de M. edax fue mayor a medida que la densidad de lavas de Ae. aegypti aumentaba, alcanzando hasta 49 larvas consumidas en 1 día. Mediante el modelo estadístico de Spearman se determinó que la depredación de M. edax dependió fuertemente de la densidad de las larvas. Mesocyclops edax tiene potencial para sus uso dentro de las estrategias del control integrado del mosquito vector del virus del dengue, Chikungunya, y Zika.