Molecular epidemiology of cryptosporidiosis in children in Malawi.
Few studies have examined the molecular epidemiology of cryptosporidiosis in developing countries. In this study, DNA of 69 microscopy-positive human fecal samples collected from Malawi were examined by multilocus genetic analyses. From 43, 27 and 28 of the samples, the SSU rRNA, 70 kDa heat shock protein (HSP70) and 60 kDa glycoprotein (GP60) genes, respectively, were successfully PCR-amplified. Restriction analysis of the SSU PCR products showed that 41 of the 43 PCR-positive samples had C. hominis and 2 had C. parvum. Sequence analysis of the HSP70 and GP60 gene confirmed the species identification by SSU rRNA PCR-RFLP analysis, but also revealed high intraspecific variations. Altogether, six HSP70 subtypes and six GP60 subtypes (belonging to four subtype alleles) of C. hominis were found. Linkage disequilibrum analysis of the two genetic loci showed possible intraspecific recombination. Thus, cryptosporidiosis in the study area was largely caused by anthroponotic transmission. The high intraspecific variation and existence of genetic recombination were probably results of high transmission of cryptosporidiosis in this area.
Peng
Michael M
MM
Centers for Disease Control and Prevention, Atlanta, GA, USA.
Meshnick
Steve R
SR
Cunliffe
Nigel A
NA
Thindwa
Benson D M
BD
Hart
C Anthony
CA
Broadhead
Robin L
RL
Xiao
Lihua
L
D017677:Age Distribution; D000818:Animals; D002675:Child, Preschool; D003457:Cryptosporidiosis / Q000453:epidemiology*; D003458:Cryptosporidium / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D016054:DNA, Protozoan / Q000235:genetics / Q000302:isolation & purification; D005243:Feces / Q000469:parasitology; D006801:Humans; D015994:Incidence; D007223:Infant; D008295:Malawi / Q000453:epidemiology; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D012621:Seasons
D016054:DNA, Protozoan