RESUMO
An 840-bp fragment of the 18S rRNA gene was used to identify Cryptosporidium spp. recovered from human immunodeficiency virus (HIV)-infected and -uninfected patients from Kenya, Malawi, Brazil, the United Kingdom, and Vietnam. Initial identification was by Ziehl-Neelsen acid-fast staining. Confirmation was by nested PCR, targeting the most polymorphic region of the 18S rRNA gene. Genotyping was by restriction endonuclease digestion of the PCR product followed by nucleotide sequencing. Among 63 isolates analyzed, four genotypes of Cryptosporidium were identified; 75% of the isolates were of the C. parvum human genotype, while the potentially zoonotic species were of the C. parvum bovine genotype (21.7%), the C. meleagridis genotype (1.6% [one isolate]), and the C. muris genotype (1.6% [one case]). HIV-infected individuals were more likely to have zoonotic genotypes than the HIV-uninfected individuals. Among the C. parvum group, strains clustered distinctly into either human or bovine genotypes regardless of the geographical origin, age, or HIV status of the patients. The intragenotypic variation observed in the C. parvum human genotype was extensive compared to that within the C. parvum bovine genotype group. The variation within genotypes was conserved in all geographical regions regardless of the patients' HIV status. The extensive diversity within genotypes at the 18S rRNA gene locus may limit its application to phylogenetic analyses.
Assuntos
Infecções Oportunistas Relacionadas com a AIDS/parasitologia , Criptosporidiose/parasitologia , Cryptosporidium/classificação , DNA Ribossômico/análise , RNA Ribossômico 18S/genética , Adulto , Animais , Sequência de Bases , Brasil , Bovinos , Criança , Cryptosporidium/genética , Cryptosporidium/isolamento & purificação , Cryptosporidium parvum/classificação , Cryptosporidium parvum/genética , Cryptosporidium parvum/isolamento & purificação , DNA de Protozoário/análise , Genes de RNAr/genética , Infecções por HIV/complicações , Humanos , Quênia , Malaui , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Análise de Sequência de DNA , Reino Unido , VietnãRESUMO
Visceral leishmaniasis (VL) is a vector-borne disease highly influenced by environmental factors. A model was developed for mapping the distribution and incidence of VL in Gedaref State, eastern Sudan, in relation to different environmental factors. Geographical information systems (GIS) were used to extract and map regression results for environmental variables of 190 villages in Gedaref State, including rainfall, vegetation status, soil type, altitude, distance from river, topography, wetness indexes, and average rainfall estimates. VL incidence in each village was calculated from hospital records. By use of logistic and linear multivariate regression analyses, models were developed to determine which environmental factors explain variability in VL presence and incidence. We found that average rainfall and the altitude were the best predictors of VL incidence. The resulting models were mapped by GIS software predicting both VL presence or absence and incidence at any locality in Gedaref State. The results are discussed in relation to VL control.
Assuntos
Altitude , Leishmaniose Visceral/epidemiologia , Chuva , Animais , Humanos , Incidência , Modelos Lineares , Modelos Logísticos , Modelos Biológicos , Análise Multivariada , Probabilidade , Fatores de Risco , Sudão/epidemiologiaRESUMO
We describe a case of Cryptosporidium muris infection in an HIV-infected adult with diarrhea in Kenya. Sequence analysis of an 840-bp region of the 18S rRNA gene locus demonstrated the isolate had 100% nucleotide identity with C. muris recovered from a rock hyrax, 98.8% with a C. muris "calf" isolate, 95.5% with C. serpentis, but only 87.8% with C. parvum "human" type.
