Genetic variation in the Cytbgene of human cerebral Taenia soliumcysticerci recovered from clinically and radiologically heterogeneous patients with neurocysticercosis

Abstract

Neurocysticercosis (NC) is a clinically and radiologically heterogeneous parasitic disease caused by the establishment of larval Taenia solium in the human central nervous system. Host and/or parasite variations may be related to this observed heterogeneity. Genetic differences between pig and human-derived T. solium cysticerci have been reported previously. In this study, 28 cysticerci were surgically removed from 12 human NC patients, the mitochondrial gene that encodes cytochrome b was amplified from the cysticerci and genetic variations that may be related to NC heterogeneity were characterised. Nine different haplotypes (Ht), which were clustered in four haplogroups (Hg), were identified. Hg 3 and 4 exhibited a tendency to associate with age and gender, respectively. However, no significant associations were found between NC heterogeneity and the different T. solium cysticerci Ht or Hg. Parasite variants obtained from patients with similar NC clinical or radiological features were genetically closer than those found in groups of patients with a different NC profile when using the Mantel test. Overall, this study establishes the presence of genetic differences in the Cytb gene of T. solium isolated from human cysticerci and suggests that parasite variation could contribute to NC heterogeneity.

Suitability of internal transcribed spacers (ITS) as markers for the population genetic structure of Blastocystis spp

“…Considering that we used part of SSUrDNA in our genetic analyses, we can speculate that these biological features may be a secondary effect due to variation in other genes; most likely by a direct genetic hitchhiking phenomenon [32] or by an indirect association, similar to what has been proposed for other parasites [33].…”

Immunopathology in Taenia solium neurocysticercosis

“…Nevertheless, the influence of these genetic differences on the susceptibility to the infection is much less explored. Evidences of the contribution of the cysticercal genetic profile on NC heterogeneity were reported in a recent study, where the Cytb gene in 28 cysticerci recovered from the CNS of 12 human NC patients was analysed .…”

Suitability of internal transcribed spacers (ITS) as markers for the population genetic structure of Blastocystis spp

“…[ 30 ] described high polymorphism between copies of the SSUrDNA gene of Blastocystis ST7 and Stensvold et al [ 7 , 31 ] emphasised a remarkable intra-ST genetic diversity and some cryptic host specificity for Blastocystis . Considering that we used part of SSUrDNA in our genetic analyses, we can speculate that these biological features may be a secondary effect due to variation in other genes; most likely by a direct genetic hitchhiking phenomenon [ 32 ] or by an indirect association, similar to what has been proposed for other parasites [ 33 ].…”