Epidemiological surveillance of chikungunya fever in Mexico since its introduction in 2014-2016 and identification of circulating genotypes.

In 2014, the chikungunya virus (CHIKV) was detected for the first time in Mexico, the identified strain was the one corresponding to the Asian genotype which was phylogenetically grouped with the strains that circulated in the British Virgin Islands outbreak and was later classified with lineages of Caribbean strains. In three years, 13,569 cases of chikungunya were registered in Mexico. Although the transmission and spread of the virus are now considered a moderate risk, the danger that the virus reemerges is not ruled out due to the infestation of Aedes mosquitoes. In this study, we reviewed the chikungunya fever (CHIKF) cases reported between 2014 and 2016 to reanalyze the data. Seventeen cases were selected from different states where the circulation of the virus had been reported. Statistical data were analyzed and a retrospective analysis was carried out. Nucleic acid sequences were determined of these 17 samples. 2015 was the year with the highest number of cases (92.8%) and they were detected in 28 states of the country. There is a predominance of females, and the most affected age group was between 25 and 44 years. In 2016, CHIKV genotypes were not known, in this study the presence of the Asian genotype of Caribbean lineage was confirmed. The presence of the West African and ECSA genotypes was phylogenetically ruled out. The sequences obtained were deposited in GeneBank.

Comparative leucocyte populations between two sympatric carnivores (Nasua narica and Procyon lotor).

Coatis (Nasua narica) and raccoons (Procyon lotor) potentially play an important role in zoonotic diseases because they may carry pathogens and can transmit them to humans. To date, our understanding of the immune function of these two carnivores is deficient. The aim of this study was to compare the number of leucocyte subtypes and the phagocytic capacity between the coati and the raccoon. Blood samples were collected, and leucocyte subtypes were characterized and counted by flow cytometry and microscopy, respectively. Phagocytosis was analysed by kinetic assay. Differences in leucocytes between these two species were found; the total count of neutrophils was higher in raccoons than in coatis, but lymphocytes and eosinophils were higher in coatis than in raccoons. Antigen reduction was more rapid for the coatis. However, raccoons had a higher efficient endocytic process than coatis. This study provides the basis for understanding the procyonid immune system, which informs conservation, particularly since some procyonids are imperilled.

Susceptibility of mouse macrophage J774 to dengue virus infection.

The aim of this study was to investigate whether the J774 mouse macrophage cell line could be used as an in vitro model for dengue virus infection (DENV). After 3 days, infection in J774 cells was assessed by detecting dengue virus non-structural protein 1 (NSP-1) production either by dot blot or indirect immunofluorescence assay (IFA) of saponine-permeabilized J774 cells and then confirmed by RT-PCR (171 bp product, corresponding to the DENV-2 core). Based on the presence of NSP-1 in infected but not in non-infected cells by both IFA and dot blot, as well as the amplification of a 171-bp DENV-2-specific RT-PCR product exclusively in the infected cells, the J774 cell line was found to be permissive for dengue virus infection. As far as we know, this is the first report that the J774 mouse macrophage cell line is infected with dengue virus and, thus, that it can be used as an alternative in vitro model for dengue virus infection studies. This finding could help to further elucidate the mechanisms involved in dengue virus infection and pathogenesis.