Infectivity, Pathogenicity, and Virulence of Trypanosoma cruzi Isolates from Sylvatic Animals and Vectors, and Domestic Dogs from the United States in ICR Strain Mice and SD Strain Rats

Roellig, Dawn M.; Yabsley, Michael J.

doi:10.4269/ajtmh.2010.09-0663

Cited by 22 publications

(20 citation statements)

References 24 publications

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“…cruzi DTUs caused differential infection dynamics in mice and rats as determined by PCR detection of T . cruzi DNA in the blood and tissues [57]. These authors found that sylvatic TcI isolates from the United States had greater infectivity to laboratory rodents than TcIV isolates, contradicting our results with isolates from Brazilian Amazon.…”

Section: Discussioncontrasting

confidence: 99%

Trypanosoma cruzi I and IV Stocks from Brazilian Amazon Are Divergent in Terms of Biological and Medical Properties in Mice

et al. 2013

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BackgroundIn the Brazilian Amazon, clinical and epidemiological frameworks of Chagas disease are very dissimilar in relation to the endemic classical areas of transmission, possibly due to genetic and biological characteristics of the circulating Trypanosoma cruzi stocks. Twenty six T. cruzi stocks from Western Amazon Region attributed to the TcI and TcIV DTUs were comparatively studied in Swiss mice to test the hypothesis that T. cruzi clonal structure has a major impact on its biological and medical properties.Methodology/Principal FindingsSeventeen parameters were assayed in mice infected with 14 T. cruzi strains belonging to DTU TcI and 11 strains typed as TcIV. In comparison with TcI, TcIV stocks promoted a significantly shorter pre-patent period (p<0.001), a longer patent period (p<0.001), higher values of mean daily parasitemia (p = 0.009) and maximum of parasitemia (p = 0.015), earlier days of maximum parasitemia (p<0.001) and mortality (p = 0.018), higher mortality rates in the acute phase (p = 0.047), higher infectivity rates (p = 0.002), higher positivity in the fresh blood examination (p<0.001), higher positivity in the ELISA at the early chronic phase (p = 0.022), and a higher positivity in the ELISA at the late chronic phase (p = 0.003). On the other hand TcI showed higher values of mortality rates in the early chronic phase (p = 0.014), higher frequency of mice with inflammatory process in any organ (p = 0.005), higher frequency of mice with tissue parasitism in any organ (p = 0.027) and a higher susceptibility to benznidazole (p = 0.002) than TcIV. Survival analysis showing the time elapsed from the day of inoculation to the beginning of the patent period was significantly shorter for TcIV strains and the death episodes triggered following the infection with TcI occurred significantly later in relation to TcIV. The notable exceptions come from positivity in the hemocultures and PCR, for which the results were similar.Conclusion/Significance T. cruzi stocks belonging to TcI and TcIV DTUs from Brazilian Amazon are divergent in terms of biological and medical properties in mice.

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Section: Discussioncontrasting

confidence: 99%

Trypanosoma cruzi I and IV Stocks from Brazilian Amazon Are Divergent in Terms of Biological and Medical Properties in Mice

et al. 2013

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“…If this features is reproduced in human hosts, an important implication is the lack or delay in diagnosis of acute Chagas disease, since direct methods are being used and recommended in the Amazon region because this is the same approach used for the detection of malaria cases, which would make a parallel program control. These data support the findings of previous studies, which reported that sylvatic stocks from the United States, where the TcI and zymodeme 3 genotypes circulate, as in the Brazilian Amazon, were largely avirulent and did not cause morbidity or mortality in rodent models 25 . In contrast, T. cruzi stocks from the classic endemic areas of South America readily infect a wide variety of laboratory mouse strains and many cause significant morbidity and mortality 12,16,26 .…”

Section: Ethical Considerationssupporting

confidence: 82%

Biological behavior of Trypanosoma cruzi stocks obtained from the state of Amazonas, Western Brazilian Amazon, in mice

Monteiro

Magalhães

Oliveira

et al. 2012

Rev. Soc. Bras. Med. Trop.

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Introduction:The biological diversity of circulating Trypanosoma cruzi stocks in the Amazon region most likely plays an important role in the peculiar clinic-epidemiological features of Chagas disease in this area. Methods: Seven stocks of T. cruzi were recently isolated in the State of Amazonas, Brazil, from humans, wild mammals, and triatomines. They belonged to the TcI and Z3 genotypes and were biologically characterized in Swiss mice. Parasitological and histopathological parameters were determined. Results: Four stocks did not promote patent parasitemia in mice. Three stocks produced low parasitemia, long pre-patent periods, and a patent period of 1 day or oscillating parasitemia. Maximum parasitemia ranged from 1,400 to 2,800 trypomastigotes/0.1mL blood. Mice inoculated with the T. cruzi stocks studied showed low positivity during fresh blood examinations, ranging from 0% to 28.6%. In hemoculture, positivity ranged from 0% to 100%. Heart tissue parasitism was observed in mice inoculated with stocks AM49 and AM61. Stock AM49 triggered a moderate inflammatory process in heart tissue. A mild inflammatory process was observed in heart tissue for stocks AM28, AM38, AM61, and AM69. An inflammatory process was frequently observed in skeletal muscle. Examinations of brain tissue revealed inflammatory foci and gliosis in mice inoculated with stock AM49. Conclusions: Biological and histopathological characterization allowed us to demonstrate the low infectivity and virulence of T. cruzi stocks isolated from the State of Amazonas. Keywords: Chagas disease. Trypanosoma cruzi. Virulence. Pathogenicity. Swiss mice. Amazon. RESUMO Introdução:A diversidade biológica dos estoques Trypanosoma cruzi circulantes na Região Amazônica pode desempenhar importante papel nas características clínico-epidemiológicas peculiares da doença de Chagas nesta área. Métodos: Sete isolados de T. cruzi do Estado do Amazonas provenientes de humanos, mamíferos silvestres e triatomíneos, pertencentes aos genótipos TcI e Z3, foram biologicamente caracterizados em camundongos Swiss. Foram avaliados parâmetros parasitológicos e histopatológicos. Resultados: Quatro isolados não produziram parasitemia patente em camundongos. Três isolados promoveram baixa parasitemia com longos períodos pré-patentes, período patente de um dia ou parasitemia oscilante. A parasitemia máxima variou de 1.400 a 2.800 tripomastigotas/0,1mL de sangue. Os camundongos inoculados com os isolados estudados mostraram baixa positividade no exame a fresco, variando de 0 a 28,6%. Para a hemocultura, a positividade variou de 0 a 100%. Parasitismo cardíaco foi observado em camundongos inoculados com os isolados AM49 e AM61. O isolado AM49 produziu inflamação moderada no tecido cardíaco. Processo inflamatório discreto foi observado no tecido cardíaco de camundongos inoculados com os isolados AM28, AM38, AM61 e AM69. Processo inflamatório em músculo esquelético foi muito frequente. O exame do tecido cerebral revelou focos inflamatórios e gliose em camundongos inoculados com o i...

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“…In our study, the majority of genetic variability was noted in the TcIV isolates. Interestingly, TcIV isolates from the US tend to be less virulent to laboratory mice and to date, no human infections with this genotype have been reported in North America [49]; TcIV strains have been isolated from primates, prosimians, and domestic dogs [34], [50], [51]. Previously, different T. cruzi MSH2 phenotypes have exhibited different levels of susceptibility to cisplatin and oxidative damage [48], [52].…”

Section: Discussionmentioning

confidence: 99%

Genetic Variation and Exchange in Trypanosoma cruzi Isolates from the United States

et al. 2013

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Trypanosoma cruzi, the causative agent of Chagas disease, is a multiclonal parasite with high levels of genetic diversity and broad host and geographic ranges. Molecular characterization of South American isolates of T. cruzi has demonstrated homologous recombination and nuclear hybridization, as well as the presence of 6 main genetic clusters or “discrete typing units” (DTUs). Few studies have extensively investigated such exchange events and genetic diversity in North American isolates. In the current study, we genetically characterized over 50 US isolates from wildlife reservoirs (e.g., raccoons, opossums, armadillos, skunks), domestic dogs, humans, nonhuman primates, and reduviid vectors from nine states (TX, CA, OK, SC, FL, GA, MD, LA, TN) using a multilocus sequencing method. Single nucleotide polymorphisms were identified in sequences of the mismatch-repair class 2 (MSH2) and Tc52 genes. Typing based on the two genes often paralleled genotyping by classic methodologies using mini-exon and 18S and 24Sα rRNA genes. Evidence for genetic exchange was obtained by comparing sequence phylogenies of nuclear and mitochondrial gene targets, dihydrofolate reductase-thymidylate synthase (DHFR-TS) and the cytochrome oxidase subunit II- NADH dehydrogenase subunit I region (COII-ND1), respectively. We observed genetic exchange in several US isolates as demonstrated by incongruent mitochondrial and nuclear genes phylogenies, which confirms a previous finding of a single genetic exchange event in a Florida isolate. The presence of SNPs and evidence of genetic exchange illustrates that strains from the US are genetically diverse, even though only two phylogenetic lineages have been identified in this region.

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Infectivity, Pathogenicity, and Virulence of Trypanosoma cruzi Isolates from Sylvatic Animals and Vectors, and Domestic Dogs from the United States in ICR Strain Mice and SD Strain Rats

Cited by 22 publications

References 24 publications

Trypanosoma cruzi I and IV Stocks from Brazilian Amazon Are Divergent in Terms of Biological and Medical Properties in Mice

Trypanosoma cruzi I and IV Stocks from Brazilian Amazon Are Divergent in Terms of Biological and Medical Properties in Mice

Biological behavior of Trypanosoma cruzi stocks obtained from the state of Amazonas, Western Brazilian Amazon, in mice

Genetic Variation and Exchange in Trypanosoma cruzi Isolates from the United States

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