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Host genetic factors affect susceptibility to norovirus infections in Burkina Faso.

Nordgren J, Nitiema LW, Ouermi D, Simpore J, Svensson L - PLoS ONE (2013)

Bottom Line: Lewis-negative (Le(a-b-)) children, representing 32% of the study population, were susceptible to GII, but were not infected with any NoV GI.GII.4 strains preferentially infected children with blood group B whereas secretor-positive children with blood group O were infected with the largest variety of genotypes.This is the first study identifying host genetic factors associated with susceptibility to NoV in an African population, and suggests that while the non-secretor phenotype provides protection; the Lewis b antigen is not necessary for GII infection.

View Article: PubMed Central - PubMed

Affiliation: Division of Molecular Virology, Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden. johan.nordgren@liu.se

ABSTRACT
Norovirus (NoV) constitutes the second most common viral pathogen causing pediatric diarrhea after rotavirus. In Africa, diarrhea is a major health problem in children, and yet few studies have been performed regarding NoV. The association of histo-blood group antigens (HBGA) and susceptibility to NoV infection is well established in Caucasian populations with non-secretors being resistant to many common NoV strains. No study regarding HBGA and NoV susceptibility has yet been performed in Africa. We collected 309 stool and 208 saliva samples from diarrheal children in Ouagadougou, Burkina Faso; May 2009 to March 2010. NoV was detected using real-time PCR, and genotyped by sequencing. Saliva samples were ABO, Lewis and secretor phenotyped using in house ELISA assays. NoV was detected in 12% (n = 37) of the samples. The genotype diversity was unusually large; overall the 37 positive samples belonged to 14 genotypes. Only children <2 years of age were NoV positive and the GII.4 NoVs were more frequent in the late dry season (Jan-May). NoV infections were observed less in children with the secretor-negative phenotype or blood group A (OR 0.18; p = 0.012 and OR 0.31; p = 0.054; respectively), with two non-secretors infected with genotypes GII.7 and GII.4 respectively. Lewis-negative (Le(a-b-)) children, representing 32% of the study population, were susceptible to GII, but were not infected with any NoV GI. GII.4 strains preferentially infected children with blood group B whereas secretor-positive children with blood group O were infected with the largest variety of genotypes. This is the first study identifying host genetic factors associated with susceptibility to NoV in an African population, and suggests that while the non-secretor phenotype provides protection; the Lewis b antigen is not necessary for GII infection.

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Phylogenetic analysis of the NS region (nt 1–301, ORF2) of NoV GI strains from Burkina Faso, May 2009–March 2010 with references strains from all known GI genotypes and most similar NoV strains detected in sub-Saharan Africa (panel A).Phylogenetic analysis of the NS region (nt 1–274) of NoV GII strains from Burkina Faso, May 2009–March 2010 with references strains from all known GII genotypes and most similar identities detected in sub-Saharan Africa (panel B). The Burkina Faso strains are marked with filled circles. Scale bar represents the number of substitutions per site and bootstrap values are shown at branch nodes (values of <50% are not shown).
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pone-0069557-g002: Phylogenetic analysis of the NS region (nt 1–301, ORF2) of NoV GI strains from Burkina Faso, May 2009–March 2010 with references strains from all known GI genotypes and most similar NoV strains detected in sub-Saharan Africa (panel A).Phylogenetic analysis of the NS region (nt 1–274) of NoV GII strains from Burkina Faso, May 2009–March 2010 with references strains from all known GII genotypes and most similar identities detected in sub-Saharan Africa (panel B). The Burkina Faso strains are marked with filled circles. Scale bar represents the number of substitutions per site and bootstrap values are shown at branch nodes (values of <50% are not shown).

Mentions: A markedly large genetic diversity of circulating NoV strains was observed. Overall, the 37 NoV positive samples belonged to 14 genotypes: GI.1 (n = 1), GI.3 (n = 1), GI.6 (n = 1), GI.7 (n = 2), GII.1 (n = 1), GII.4 (n = 10), GII.6 (n = 3), GII.7 (n = 3), GII.8 (n = 1), GII.10 (n = 5), GII.14 (n = 1), GII.16 (n = 3) and GII.17 (n = 1) (Figures 1–2). Two GI samples, 116 and 225, belong to one as of yet undefined genotype (Figure 2A), whereas two GII samples could not be genotyped. The GII.4 genotypes (n = 10) could further be divided into three different variants; namely 2006a (n = 5; nt identity 98.5–99.6% to Terneuzen 2006a strain, Figure 2B), and two undefined variants (n = 1, isolate 289, nt identity 98.1% to New Orleans strain), and a variant (n = 4), most closely similar to GII.4 NoV strains detected in Cameroon (nt identity 97.4–98.1%) (Figure 2B). The two GI strains 116 and 225 that could not be assigned a genotype (86.1% nt identity to most similar reference sequence DSV [4]) were most similar to the Incheon 152 strain (98.5–98.9% nt identity) detected in South Korea in 2005.


Host genetic factors affect susceptibility to norovirus infections in Burkina Faso.

Nordgren J, Nitiema LW, Ouermi D, Simpore J, Svensson L - PLoS ONE (2013)

Phylogenetic analysis of the NS region (nt 1–301, ORF2) of NoV GI strains from Burkina Faso, May 2009–March 2010 with references strains from all known GI genotypes and most similar NoV strains detected in sub-Saharan Africa (panel A).Phylogenetic analysis of the NS region (nt 1–274) of NoV GII strains from Burkina Faso, May 2009–March 2010 with references strains from all known GII genotypes and most similar identities detected in sub-Saharan Africa (panel B). The Burkina Faso strains are marked with filled circles. Scale bar represents the number of substitutions per site and bootstrap values are shown at branch nodes (values of <50% are not shown).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3716642&req=5

pone-0069557-g002: Phylogenetic analysis of the NS region (nt 1–301, ORF2) of NoV GI strains from Burkina Faso, May 2009–March 2010 with references strains from all known GI genotypes and most similar NoV strains detected in sub-Saharan Africa (panel A).Phylogenetic analysis of the NS region (nt 1–274) of NoV GII strains from Burkina Faso, May 2009–March 2010 with references strains from all known GII genotypes and most similar identities detected in sub-Saharan Africa (panel B). The Burkina Faso strains are marked with filled circles. Scale bar represents the number of substitutions per site and bootstrap values are shown at branch nodes (values of <50% are not shown).
Mentions: A markedly large genetic diversity of circulating NoV strains was observed. Overall, the 37 NoV positive samples belonged to 14 genotypes: GI.1 (n = 1), GI.3 (n = 1), GI.6 (n = 1), GI.7 (n = 2), GII.1 (n = 1), GII.4 (n = 10), GII.6 (n = 3), GII.7 (n = 3), GII.8 (n = 1), GII.10 (n = 5), GII.14 (n = 1), GII.16 (n = 3) and GII.17 (n = 1) (Figures 1–2). Two GI samples, 116 and 225, belong to one as of yet undefined genotype (Figure 2A), whereas two GII samples could not be genotyped. The GII.4 genotypes (n = 10) could further be divided into three different variants; namely 2006a (n = 5; nt identity 98.5–99.6% to Terneuzen 2006a strain, Figure 2B), and two undefined variants (n = 1, isolate 289, nt identity 98.1% to New Orleans strain), and a variant (n = 4), most closely similar to GII.4 NoV strains detected in Cameroon (nt identity 97.4–98.1%) (Figure 2B). The two GI strains 116 and 225 that could not be assigned a genotype (86.1% nt identity to most similar reference sequence DSV [4]) were most similar to the Incheon 152 strain (98.5–98.9% nt identity) detected in South Korea in 2005.

Bottom Line: Lewis-negative (Le(a-b-)) children, representing 32% of the study population, were susceptible to GII, but were not infected with any NoV GI.GII.4 strains preferentially infected children with blood group B whereas secretor-positive children with blood group O were infected with the largest variety of genotypes.This is the first study identifying host genetic factors associated with susceptibility to NoV in an African population, and suggests that while the non-secretor phenotype provides protection; the Lewis b antigen is not necessary for GII infection.

View Article: PubMed Central - PubMed

Affiliation: Division of Molecular Virology, Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden. johan.nordgren@liu.se

ABSTRACT
Norovirus (NoV) constitutes the second most common viral pathogen causing pediatric diarrhea after rotavirus. In Africa, diarrhea is a major health problem in children, and yet few studies have been performed regarding NoV. The association of histo-blood group antigens (HBGA) and susceptibility to NoV infection is well established in Caucasian populations with non-secretors being resistant to many common NoV strains. No study regarding HBGA and NoV susceptibility has yet been performed in Africa. We collected 309 stool and 208 saliva samples from diarrheal children in Ouagadougou, Burkina Faso; May 2009 to March 2010. NoV was detected using real-time PCR, and genotyped by sequencing. Saliva samples were ABO, Lewis and secretor phenotyped using in house ELISA assays. NoV was detected in 12% (n = 37) of the samples. The genotype diversity was unusually large; overall the 37 positive samples belonged to 14 genotypes. Only children <2 years of age were NoV positive and the GII.4 NoVs were more frequent in the late dry season (Jan-May). NoV infections were observed less in children with the secretor-negative phenotype or blood group A (OR 0.18; p = 0.012 and OR 0.31; p = 0.054; respectively), with two non-secretors infected with genotypes GII.7 and GII.4 respectively. Lewis-negative (Le(a-b-)) children, representing 32% of the study population, were susceptible to GII, but were not infected with any NoV GI. GII.4 strains preferentially infected children with blood group B whereas secretor-positive children with blood group O were infected with the largest variety of genotypes. This is the first study identifying host genetic factors associated with susceptibility to NoV in an African population, and suggests that while the non-secretor phenotype provides protection; the Lewis b antigen is not necessary for GII infection.

Show MeSH
Related in: MedlinePlus