Supatra Peerakome

Genetic Diversity of Norovirus and Sapovirus in Hospitalized Infants with Sporadic Cases of Acute Gastroenteritis in Chiang Mai, Thailand

ABSTRACT Stool specimens from hospitalized infants with sporadic gastroenteritis in Chiang Mai, Thailand, between July 2000 and July 2001 were examined for norovirus and sapovirus by reverse transcription-PCR and sequence analysis. These viruses were identified in 13 of 105 (12%) specimens. One strain was found to be a recombinant norovirus.

Genetic diversity of norovirus, sapovirus, and astrovirus isolated from children hospitalized with acute gastroenteritis in Chiang Mai, Thailand

Norovirus (NV), sapovirus (SV), and human astrovirus (HAstV) are important causes of acute gastroenteritis in infants and young children. This study investigated the prevalence of NV, SV, and HAstV infections in children hospitalized with acute gastroenteritis in Chiang Mai, Thailand from May 2000 to March 2002. Fecal specimens were tested for NV, SV, and HAstV by reverse transcription polymerase chain reaction (RT‐PCR) using degenerate specific primers. These viruses were characterized further by sequence and phylogenetic analyses of the partial capsid gene. From 296 fecal specimens tested, 13.5% (40 of 296) were positive for NV, SV, and HAstV. Of these, NV most predominant, with a prevalence of 60% (24 of 40), of which 17.5% were NVGI and 42.5% were NVGII. Of note, one specimen was positive for both NVGI and SV. SV was detected in 25%, while HAstV was detected in 17.5%. Analysis of nucleotide and amino acid sequences revealed that NVGI strains comprised GI/3, GI/4, GI/6, GI/7, and GI/13 genotypes. Among NVGII strains, approximately half of them belonged to genotype GII/4 (Lordsdale virus cluster), followed by GII/3, GII/10, GII/1, GII/6, GII/8, and GII/15. Analysis of SV sequences revealed that SVGI (Manchester virus) was more common than SVGII (London virus). The SV genotypes detected in this study belonged to SVGI/1, SVGI/4, SVGI/5, SVGII/1, and SVGII/2, whereas the HAstV belonged to genotypes HAstV‐1, HAstV‐2, HAstV‐3, and HAstV‐5. The findings suggest that NV, SV, and HAstV are important enteric viruses cocirculating among hospitalized children in Chiang Mai, Thailand. J. Med. Virol. 80:1749–1755, 2008.

Detection of Rare G3P[19] Porcine Rotavirus Strains in Chiang Mai, Thailand, Provides Evidence for Origin of the VP4 Genes of Mc323 and Mc345 Human Rotaviruses

ABSTRACT Among 175 fecal specimens collected from diarrheic piglets during a surveillance of porcine rotavirus (PoRV) strains in Chiang Mai, Thailand, 39 (22.3%) were positive for group A rotaviruses. Of these, 33.3% (13 of 39) belonged to G3P[19], which was a rare P genotype seldom reported. Interestingly, their VP4 nucleotide sequences were most closely related to human P[19] strains (Mc323 and Mc345) isolated in 1989 from the same geographical area where these PoRV strains were isolated. These P[19] PoRV strains were also closely related to another human P[19] strain (RMC321), isolated from India in 1990. The VP4 sequence identities with human P[19] were 95.4% to 97.4%, while those to a porcine P[19] strain (4F) were only 87.6 to 89.1%. Phylogenetic analysis of the VP4 gene revealed that PoRV P[19] strains clustered with human P[19] strains in a monophyletic branch separated from strain 4F. Analysis of the VP7 gene confirmed that these strains belonged to the G3 genotype and shared 97.7% to 98.3% nucleotide identities with other G3 PoRV strains circulating in the regions. This close genetic relationship was also reflected in the phylogenetic analysis of their VP7 genes. Altogether, the findings provided peculiar evidence that supported the porcine origin of VP4 genes of Mc323 and Mc345 human rotaviruses.

Multiple Combinations of P[13]-Like Genotype with G3, G4, and G5 in Porcine Rotaviruses

ABSTRACT Epidemiological surveillance of porcine rotavirus (PoRV) strains was carried out in Chiang Mai Province, Thailand, from 2002 to 2003, and eight rotavirus isolates could not be completely typed by PCR. Of these, six were G3 and one was G4 and displayed a P-nontypeable genotype, while another isolate was both G and P nontypeable. Analysis of a partial VP4 gene of all eight P-nontypeable strains revealed a high degree of amino acid sequence identities (94.7% to 100%), suggesting that they belonged to the same P genotype. Comparison of the amino acid sequences of two representative strains (namely, strains CMP178 and CMP213) with those of 27 other known P genotypes revealed a high degree of amino acid sequence identity with those of P[13] porcine rotavirus reference strains HP113 and HP140, which were recently isolated in India. However, amino acid sequence comparison with non-P[13] rotavirus strains revealed relatively low identities, ranging from 58.2% to 84.8% for full-length VP4 sequences and 35.1% to 80.6% for VP8* sequences. Phylogenetic analysis revealed that CMP178 and CMP213 clustered together in a monophyletic branch with P[13]-like genotypes HP113 and HP140 which was clearly separated from the other lineages of P[13] or P[22] strains. Altogether, these findings indicate that PoRV strains CMP178 and CMP213 should be considered the P[13]-like VP4 genotype, a rare genotype that has been identified only in pigs. This study provides additional evidence of increasing genetic diversity among group A rotaviruses in nature.

Molecular Characterization of VP4, VP6, VP7, NSP4, and NSP5/6 Genes Identifies an Unusual G3P(10) Human Rotavirus Strain

An unusual strain of human rotavirus G3P[10] (CMH079/05) was detected in a stool sample of a 2‐year‐old child admitted to the hospital with severe diarrhea in Chiang Mai, Thailand. Analysis of the VP7 gene sequence revealed highest identities with unusual human rotavirus G3 strain CMH222 at 98.7% on the nucleotide and 99.6% on the amino acid levels. Phylogenetic analysis of the VP7 sequence confirmed that the CMH079/05 strain formed a cluster with G3 rotavirus reference strains and showed the closest lineage with the CMH222 strain. Analysis of partial VP4 gene of CMH079/05 revealed highest degree of sequence identities with P[10] rotavirus prototype strain 69M at nucleotide and amino acid levels of 92.9% and 94.6%, respectively. Phylogenetic analysis of the VP4 sequence revealed that CMH079/05 and 69M clustered closely together in a monophyletic branch separated from other rotavirus genotypes. To our knowledge, this is a novel G–P combination of G3 and P[10] genotypes. In addition, analyses of VP6, NSP4, and NSP5/6 genes revealed these uncommon genetic characteristics: (i) the VP6 gene differed from the four other known subgroups; (ii) the NSP4 gene was identified as NSP4 genetic group C, an uncommon group in humans; and (iii) the NSP5/6 gene was most closely related with T152, a G12P[9] rotavirus previously isolated in Thailand. The finding of uncommon G3P[10] rotavirus in this pediatric patient provided additional evidence of the genetic diversity of human group A rotaviruses in Chiang Mai, Thailand. J. Med. Virol. 81:176–182, 2009.

Differential seroprevalences of hepatitis C virus, hepatitis B virus and human immunodeficiency virus among intravenous drug users, commercial sex workers and patients with sexually transmitted diseases in Chiang Mai, Thailand

To elucidate the differences in the mode of transmission of three blood-borne viruses, hepatitis C virus (HCV), hepatitis B virus (HBV) and human immunodeficiency virus (HIV), under comparable conditions of study, we analyzed the prevalences of anti-HCV antibodies (anti-HCV), anti-HBV core antibodies (anti-HBc), HBV surface antigen (HBsAg) and anti-HIV antibodies (anti-HIV) in different risk populations in Chiang Mai, Thailand, where the prevalence of HIV infection is high. The subjects consisted of 98 intravenous drug users (IVDU), 100 commercial sex workers (CSW) and 50 male patients with sexually transmitted diseases (STD). In IVDU the prevalence of anti-HCV was the highest (85%), followed by anti-HBc (77%) and anti-HIV (46%), whereas in CSW and STD the prevalence of anti-HCV was 2 and 0%, respectively, that of anti-HBc 69 and 64%, respectively, and that of anti-HIV 11 and 14%, respectively. The prevalence of anti-HBc minus that of HBsAg, representing horizontal transmission of HBV, was similar for IVDU (63%), CSW (58%) and STD (64%). Thus, HCV is mainly transmitted by blood contact, HIV primarily by blood contact rather than by sexual contact, and HBV equally readily by blood or sexual contact. These findings were supported by the results of logistic regression analysis.

Genetic characterization of group C rotavirus isolated from a child hospitalized with acute gastroenteritis in Chiang Mai, Thailand

During an epidemiological survey of human rotavirus infection in Chiang Mai, Thailand, from 2002 to 2004, in which 263 stool specimens tested, one isolate of group C rotavirus was detected from a two-year-old child admitted to hospital with acute gastroenteritis. The human group C rotavirus, named CMH004/03, was characterized further by molecular analyses of its VP4, VP6, and VP7 gene segments as well as determination of RNA pattern by polyacrylamide gel electrophoresis (PAGE). Molecular characterization of VP4, VP6, and VP7 genes by sequence analyses showed high levels of sequence identities with those of human group C rotavirus reference strains isolated worldwide at 95.2% to 99.4% on nucleotide and 97.5% to 100% on amino acid levels. In contrast, the CMH004/03 strain exhibited far lesser nucleotide and amino acid sequence identities at 67.7% to 84.1% and 68.7% to 91.3%, respectively, when compared with those of porcine and bovine group C rotaviruses. Phylogenetic analyses of VP4, VP6, and VP7 genes clearly confirmed that the CMH004/03 strain clustered in a monophyletic branch with other human group C rotavirus reference strains and distantly related to the clusters of animal group C rotavirus strains. In addition, the RNA electrophoretic migration pattern of CMH004/03 showed a typical pattern (4-3-2-2) of group C rotavirus. To our knowledge, this study is the second report of group C rotavirus infection in pediatric patients in Thailand after it was reported for the first time about two decades ago.

Analysis of the VP6 gene of human and porcine group A rotavirus strains with unusual subgroup specificities

Full‐length VP6 amino acid sequences of human and porcine rotaviruses with subgroup (SG) (I + II) and SG non‐(I + II) were analyzed in comparison with those of SG I and SG II. In human rotaviruses, the strains in the same SG shared a very high degree of amino acid identity, ranging from 97.4% to 99.4% for SG I, 95.9% to 100% for SG II, and 99.4% to100% for SG non‐(I + II), while viruses in different SGs shared somewhat lower sequence identity at 90.4–93.1%. Conserved amino acids that distinguished the strains of SG I from SG II were observed at 21 positions. The viruses with SG non‐(I + II) shared sequence identity with SG II as high as 97.2–99.7%, suggesting that they belonged to genogroup II. Similarly, porcine rotaviruses in the same SG shared 96.4–99.7% for SG I, 98.2–100% for SG II, 97.4–100% for SG (I + II), and 96.2–99.7% for SG non‐(I + II), while strains in different SGs shared sequence identity ranging from 91.9% to 94.4%. Interestingly, the strains with SG (I + II) and SG non‐(I + II) shared a high degree of sequence identity with SG I, at 96.4–100% and 94.7–99.7% respectively, suggesting that they are related to porcine SG I strains. The conserved amino acids which distinguished SG I from SG II were observed at 13 positions. The strains with SG I, SG (I + II), and SG non‐(I + II) showed identical amino acid residues at these positions. Phylogenetic analysis strongly supported the findings of the sequence analysis. J. Med. Virol. 81:183–191, 2009.

Molecular Characterization of VP4 and VP7 Genes of Nontypeable Strains Identifies a Novel P[28] Genotype in Porcine Rotaviruses

This article has been retracted.