Phylogenetic analysis of the precore/core gene of hepatitis B virus genotypes E and A in West Africa: new subtypes, mixed infections and recombinations.
One hundred and twenty-two new hepatitis B virus (HBV) preC/C sequences and three complete genomes from three major countries in West Africa were analysed. The majority of sequences were of genotype E and the only other genotype found was genotype A. Although for genotype E sequences, the genetic diversity of the preC/C gene was about two to three times higher than that of the preS/S gene, it was still considerably lower than that for genotype A sequences. The HBV/E preC/C gene was related most closely to subgenotype D1 and D2 sequences. Evidence of recombination was found in two strains that were of genotype A in the preS/S gene and of genotype E in the preC/C gene. The genotype A strains from Cameroon, Mali and Nigeria could be divided phylogenetically into three subtypes, A3 and two new subtypes, tentatively designated A4 and A5. Each subtype presented a genetic diversity of 2.19-3.85 % and intersubtype distances of 4.47-5.97 %. Interestingly, one sample from Nigeria showed evidence of a triple recombination of genotypes E/D and A, separated by a genotype G-specific insert of 36 bp. Of 110 patients, 19 (17.3 %) showed a coinfection of genotypes A and E, mostly in human immunodeficiency virus-positive children from Cameroon. Thus, in Cameroon, where both genotypes coexist, 37 % of all individuals tested had mixed infections. The low genetic variability in the preC/C gene of genotype E supports our previous speculation about a relatively short evolutionary history of this genotype, in contrast to the subtype-rich African genotype A strains.
Olinger
Christophe M
CM
Institute of Immunology, National Public Health Laboratory, 20A rue Auguste-Lumière, L-1950 Luxembourg, Luxembourg.
Venard
Véronique
V
Unité Mixte de Recherche 7565 UHP-CNRS, Laboratoire de Bactériologie-Virologie, Faculté de Médecine, Vandœuvre-lès-Nancy, France.
Njayou
Mounjohou
M
Laboratoire de Microbiologie Microbienne, Centre de Biotechnologie - Nkolbisson, Yaoundé, Cameroon.
Oyefolu
Akeeb O Bola
AOB
Department of Medical Microbiology and Parasitology and Department of Medicine, College of Medicine of the University of Lagos, Nigeria.
Maïga
Ibrahim
I
Laboratoire de Biologie Médicale, Hôpital du Point G, Bamako, Mali.
Kemp
Alain J
AJ
Institute of Immunology, National Public Health Laboratory, 20A rue Auguste-Lumière, L-1950 Luxembourg, Luxembourg.
Omilabu
Sunday A
SA
Department of Medical Microbiology and Parasitology and Department of Medicine, College of Medicine of the University of Lagos, Nigeria.
le Faou
Alain
A
Unité Mixte de Recherche 7565 UHP-CNRS, Laboratoire de Bactériologie-Virologie, Faculté de Médecine, Vandœuvre-lès-Nancy, France.
Muller
Claude P
CP
Institute of Immunology, National Public Health Laboratory, 20A rue Auguste-Lumière, L-1950 Luxembourg, Luxembourg.
D000328:Adult; D000354:Africa, Western; D002648:Child; D016679:Genome, Viral; D006509:Hepatitis B / Q000821:virology*; D006515:Hepatitis B virus / Q000145:classification* / Q000235:genetics; D006801:Humans; D008969:Molecular Sequence Data; D011995:Recombination, Genetic; D013045:Species Specificity; D014758:Viral Core Proteins / Q000235:genetics
D014758:Viral Core Proteins