First report of mixed Trypanosoma cruzi discrete typing units infection in Triatoma phyllosoma in the peri-urban environment of Oaxaca, Mexico

ABSTRACT Background: Chagas disease, a zoonosis transmitted mainly by hematophagous insects of the subfamily Triatominae, is caused by Trypanosoma cruzi, classified into six discrete typing units (DTUs: TcI-TcVI and Tcbat). Methods: Insect vectors were collected from 84 human dwellings in the municipality of Santo Domingo Tehuantepec, Oaxaca, Mexico; 4.76% were infested. DTUs were determined using conventional and nested PCR. Results: The infection rate was 43.6%. All insects were infected with TcI while one specimen showed mixed infection with TcII. Conclusions: This is the first report of T. cruzi mixed infection in Triatoma phyllosoma, its main vector in the study region.

Infection with Trypanosoma cruzi TcII and TcI in free-ranging population of lion tamarins (Leontopithecus spp): an 11-year follow-up

Here, we present a review of the dataset resulting from the 11-years follow-up of Trypanosoma cruzi infection in free-ranging populations of Leontopithecus rosalia (golden lion tamarin) and Leontopithecus chrysomelas (golden-headed lion tamarin) from distinct forest fragments in Atlantic Coastal Rainforest. Additionally, we present new data regarding T. cruzi infection of small mammals (rodents and marsupials) that live in the same areas as golden lion tamarins and characterisation at discrete typing unit (DTU) level of 77 of these isolates. DTU TcII was found to exclusively infect primates, while TcI infected Didelphis aurita and lion tamarins. The majority of T. cruzi isolates derived from L. rosalia were shown to be TcII (33 out 42) Nine T. cruzi isolates displayed a TcI profile. Golden-headed lion tamarins demonstrated to be excellent reservoirs of TcII, as 24 of 26 T. cruzi isolates exhibited the TcII profile. We concluded the following: (i) the transmission cycle of T. cruzi in a same host species and forest fragment is modified over time, (ii) the infectivity competence of the golden lion tamarin population fluctuates in waves that peak every other year and (iii) both golden and golden-headed lion tamarins are able to maintain long-lasting infections by TcII and TcI.

Trans Sialidase Genes Allow Clustering of TcI Trypanosoma cruzi Mexican Isolates.

Aims: Polymorphism of the trans sialidase (TS) family of genes is common in Trypanosoma cruzi. Our goal was to cluster Mexican TcI DTU (Discrete Typing Unit) using a set of primers specific for TS genes. Methodology: The DNA of 12 Mexican T. cruzi stocks (TcI) and reference strain were amplified using the CRP-1 primer, which anneals to the conserved 5' ends of CRP (Complement Regulatory Protein), TS, and FL-160 genes, and the CRP-2 primer, which anneals to conserved region within the GPI (Glycosil Phosphatidil Inositol) anchor sequence. Amplicons were analysed using PCR-SSCP (Single Strand Conformation Polymorphims) followed by construction of a nominal matrix data (presence/absence bands) to calculated the Jaccard and Dice similarity coefficient, and clustering with UPGMA. Results: Mexican TcI stocks produced a common pattern of amplification products and cluster in a separate group to CL-Brener strain (TcVI). The PCR-SSCP revealed that within the TcI Mexican stocks there were a complex pattern, but T. cruzi from the Yucatan peninsula clustered in special and separate group. Conclusion: The CRP-1 and CRP-2 primers were helpful for the analysis of genetic traits in T. cruzi DTU I and revealed the existence of special group in Yucatan Mexico.

Specific primers design based on the superoxide dismutase b gene for Trypanosoma cruzi as a screening tool: Validation method using strains from Colombia classified according to their discrete typing unit

Objective: To classify 21 new isolates of Trypanosoma cruzi (. T. cruzi) according to the Discrete Typing Unit (DTU) which they belong to, as well as tune up a new pair of primers designed to detect the parasite in biological samples. Methods: Strains were isolated, DNA extracted, and classified by using three Polymerase Chain Reactions (PCR). Subsequently this DNA was used along with other isolates of various biological samples, for a new PCR using primers designed. Finally, the amplified fragments were sequenced. Results: It was observed the predominance of DTU I in Colombia, as well as the specificity of our primers for detection of T. cruzi, while no band was obtained when other species were used. Conclusions: This work reveals the genetic variability of 21 new isolates of T. cruzi in Colombia.Our primers confirmed their specificity for detecting the presence of T. cruzi.

Specific primers design based on the superoxide dismutase b gene for Trypanosoma cruzi as a screening tool: Validation method using strains from Colombia classified according to their discrete typing unit

OBJECTIVE@#To classify 21 new isolates of Trypanosoma cruzi (T. cruzi) according to the Discrete Typing Unit (DTU) which they belong to, as well as tune up a new pair of primers designed to detect the parasite in biological samples.@*METHODS@#Strains were isolated, DNA extracted, and classified by using three Polymerase Chain Reactions (PCR). Subsequently this DNA was used along with other isolates of various biological samples, for a new PCR using primers designed. Finally, the amplified fragments were sequenced.@*RESULTS@#It was observed the predominance of DTU I in Colombia, as well as the specificity of our primers for detection of T. cruzi, while no band was obtained when other species were used.@*CONCLUSIONS@#This work reveals the genetic variability of 21 new isolates of T. cruzi in Colombia.Our primers confirmed their specificity for detecting the presence of T. cruzi.