ABSTRACT
Trypanosoma cruzi and Leishmania mexicana are parasites of humans and other mammals, causing American Trypanosomiasis and Cutaneous Leishmaniasis, respectively. Domestic dogs are considered key hosts for these parasites in the domicile and peridomicile cycles of transmission, due to their abundance and contact with human population. In Mexico, there are few studies that involve the study of infection with these parasites in dogs, and have only been carried out mainly in the endemic areas for these diseases. In the state of Querétaro (Mexico), infections with both parasites have been reported for dogs only from rural areas, with no records for the metropolitan zone. We analyzed the seropositivity to T. cruzi and L. mexicana in dogs from localities within of the metropolitan zone of Querétaro City in order to determine if these animals are exposed to these parasites and thus, could be an important part of the transmission cycle of these trypanosomatids in a densely populated urban region within the state of Querétaro, Mexico. Serum samples were collected from 303 dogs housed in the Animal Control centers of the municipalities of Querétaro and El Marques, analyzed by indirect ELISA and Western Blot using as an antigen the Iron Superoxide Dismutase (FeSODe) of the parasites. From the total serum samples, we detected 10.2% of seropositivity for T. cruzi and 2.9% for L. mexicana. Our results represent the first evidence of infection with T. cruzi in domestic dogs from the Metropolitan Zone of Querétaro, and the first record for L. mexicana in Central Mexico. Ongoing investigations seek to confirm the circulation of these parasites in the area to evaluate the risk associated to the human population.
Subject(s)
Chagas Disease/veterinary , Dog Diseases/epidemiology , Leishmania mexicana/isolation & purification , Leishmaniasis, Cutaneous/veterinary , Trypanosoma cruzi/isolation & purification , Animals , Blotting, Western/veterinary , Chagas Disease/epidemiology , Chagas Disease/parasitology , Dog Diseases/parasitology , Dogs , Enzyme-Linked Immunosorbent Assay/veterinary , Leishmaniasis, Cutaneous/epidemiology , Leishmaniasis, Cutaneous/parasitology , Mexico/epidemiology , Prevalence , Seroepidemiologic StudiesABSTRACT
A miniaturized, fast, and efficient ultrasonic probe assisted method for Hg(II) extraction from indoor dust samples, in hydrochloric acid medium, was developed. The combination of the extraction method with the electrochemical determination of mercury by square-wave anodic stripping voltammetry (SWASV) on gold nanoparticles-modified screen-printed carbon electrodes (AuNPs-SPCEs) resulted in a convenient method for rapid, sensitive, and reliable mercury monitoring. Parameters involved in the extraction such as acid concentration, sonication amplitude, and sonication time were optimized using a Face-centered cube Central Composite Design. ICP-MS was also used to contrast the methodology and good agreement with electrochemical results was verified. Optimization and validation of the procedure were carried out by using NIST Standard Reference Material(®) 2583 Trace Elements in Indoor Dust. Finally, the proposed methodology was successfully applied for Hg(II) determination in dust samples collected at different indoor ambients.
ABSTRACT
The applicability of commercial screen-printed gold electrodes (SPGEs) for the determination of Hg(II) in ambient water samples by square wave anodic stripping voltammetry has been demonstrated. Electrode conditioning procedures, chemical and instrumental variables have been optimized to develop a reliable method capable of measuring dissolved mercury in the low ng mL(-1) range (detection limit 1.1 ng mL(-1)), useful for pollution monitoring or screening purposes. The proposed method was tested with the NIST 1641d Mercury in Water Standard Reference Material (recoveries 90.0-110%) and the NCS ZC 76303 Mercury in Water Certified Reference Material (recoveries 82.5-90.6%). Waste water samples from industrial origin and fortified rain water samples were assayed for mercury by the proposed method and by a reference ICP-MS method, with good agreement. Screen printing technology thus opens a useful way for the construction of reliable electrochemical sensors for decentralized or even field Hg(II) testing.
