Introduction Dengue, Zika and Chikungunya are RNA Arboviruses present in some areas of Mexico, mainly in the endemic state of Chiapas that is characterized by presence of the vector that transmit them and an ecology that favors high transmission. According to the national epidemiological surveillance system, Dengue has intensified since 2018 and outbreaks continue in various states while for Zika and Chikungunya a decrease in cases has been reported in recent years. The main objective of this study was to determine the incidence of Dengue, Zika and Chikungunya infections during pregnancy in the state of Chiapas. Principal findings The presence of previous and current infections and coinfections diagnosed by molecular (RT-PCR) and immunological (ELISA for IgG determination) techniques indicates a wide circulation of viruses in asymptomatic people, specifically in pregnant women showing that silent infections in dry season contributes to the preservation of viruses. Conclusions From 136 studied samples, 27.7% tested positive for DENV, 8% for ZIKV and 24.1% for CHIKV by RTPCR and the values of IgG in sera show that 83.9% were positive for IgG antibodies against DENV, 65% against ZIKV and 59.1% against CHIKV. Results demonstrated presence of ZIKV and CHIKV, not detected by the epidemiological surveillance system, so the importance of establishing proactive epidemiological systems more strict, especially because these infections in pregnant women can cause severe health problems for newborn children.

The purpose of the present paper was to analyse the association between sequences of Entamoeba histolytica and their relationship with the development of hepatic abscesses in hamsters, using a complementary DNA library for E. histolytica. From the sequences obtained, we designed oligonucleotides for amplification by PCR. Trophozoites were isolated from faeces of 11 patients in whom cysts from E. histolytica were identified, and these trophozoites were then subjected to monoaxenic culture. Then 1 x 10(5) trophozoites were inoculated into hamster liver, with three hamsters used for every culture. Sequences were obtained for ubiquitin, lectin surface precursor, replication factor MCM3 and surface antigen. The associations between sequences and hepatic abscesses were: 11/11 for ubiquitin, 9/11 for lectin precursor, 4/11 for replication factor and 1/11 for surface antigen. These results suggest that ubiquitin could be an important protein involved in the mechanism of E. histolytica invasion.

No abstract

To identify sequences of Entamoeba histolytica associated with the development of amebic liver abscess (ALA) in hamsters, subtractive hybridization of cDNA from E. histolytica HM-1:IMSS under 2 growth conditions was performed: 1) cultured in axenic medium and 2) isolated from experimental ALA in hamsters. For this procedure, 6 sequences were obtained. Of these sequences, the mak16 gene was selected for amplification in 29 cultures of E. histolytica isolated from the feces of 10 patients with intestinal symptoms and 19 asymptomatic patients. Only 5 of the 10 isolates obtained from symptomatic patients developed ALA and amplified the mak16 gene, whereas the 19 isolates from asymptomatic patients did not amplify the mak16 gene nor did they develop ALA. Based on the results of Fisher's exact test (P<0.001), an association was inferred between the presence of the mak16 gene of E. histolytica and the ability to develop ALA in hamsters and with the patient's symptoms (P=0.02). The amplification of the mak16 gene suggests that it is an important gene in E. histolytica because it was present in the isolates from hamsters that developed liver damage.

ProtozoologíaDeterminación de la expresión de glucosamina-6-fosfato-isomerasa y la glucoproteína de Jacob en el quiste y su diferencia en el trofozoíto de Entamoeba histolyticaMaría del Pilar Crisóstomo-Vázquez, Leticia EligioGarcía Víctor Alberto Maravelez-Acosta, Patricia Antonio-Cruz, Andrés Flores-Luna , René Sánchez-de la Luz , Enedina Jiménez-Cardoso Laboratorio de Investigación en Parasitología, Hospital Infantil de México Federico Gómez, México D.F., MéxicoIntroducción. Entamoeba histolytica es un protozoario que presenta dos formas; el quiste responsable de la transmisión y el trofozoíto que produce la enfermedad. La formación del quiste está asociada con la expresión de los genes glucosamina-6-fosfato isomerasa (gn6pI), y la glicoproteína de Jacob (glyJ) que participan en la formación del polímero de N-acetil glucosamina, componente principal de la pared de quitina. Objetivo. Determinar la expresión de los genes de glucosamina-6-fosfato-isomerasa y la proteína de Jacob en los quistes y trofozoítos de E. histolytica obtenidos de aislamientos de pacientes con amibiasis intestinal. Material y métodos. Se obtuvieron trofozoítos de E. histolytica a partir de quistes procedentes de pacientes. En el ensayo de validación se utilizó la cepa E. histolytica HM-1. Se extrajo ARN total de los quistes y trofozoítos por el método de trizol y se purificó con el kit RNAqueous. Se llevó a cabo RT-PCR en tiempo real con las sondas correspondientes a los genes gn6pI y glyJ de E. histolytica Resultados. Se correlacionó el número de copias de los tres genes amplificados por triplicado. En el ensayo de validación se obtuvieron pendientes negativas con valores de 3,5 y un coeficiente de correlación mayor de 0,99. La expresión de los genes gn6pI y glyJ en la etapa de trofozoíto, presento un valor promedio de 3,5 en cinco de las ocho muestras analizadas y, en la etapa de quiste, fue de 1,2 en todas las muestras. El control positivo presentó un valor de 5 para el gen gn6pI y de 9,8 para el gen glyJ.Conclusiones. En la etapa de quiste no hubo expresión de los genes gn6pI y glyJ y en la etapa de trofozoíto sí. Es necesario sincronizar los cultivos de trofozoítos para conocer si la expresión de los genes gn6pI y glyJ está relacionada con la reciente transformación de la etapa quística a trofozoíto. Papel de los linfocitos T reguladores en la patogénesis y curación de la leishmaniasis cutánea crónica causada por Leishmania (Viannia)Daniel Rodríguez-Pinto, Adriana Navas, Víctor Blanco, Daniel Garcerant, Nancy Saravia Centro Internacional de Entrenamiento e Investigaciones Médicas, Cali, ColombiaIntroducción. La leishmaniasis cutánea crónica causada por Leishmania (Viannia) se caracteriza por una potente respuesta inflamatoria inadecuadamente regulada. Los linfocitos T reguladores pueden contribuir en el desarrollo de la enfermedad y su resolución al mitigar la respuesta inmunitaria específica para el parásito. Materiales y métodos. Se extrajeron muestras de sangre periférica de 12 individuos con infección asintomática y 14 pacientes ...