Emergence of human G9 rotavirus with an exceptionally high frequency in children admitted to hospital with diarrhea in Chiang Mai, Thailand

Abstract

Among 315 fecal specimens collected from children hospitalized with diarrhea in Chiang Mai, Thailand, in 2000-2001, group A rotavirus was detected in 107 (34.0%). Of these, 98 (91.6%) were G9, 6 (5.6%) were G3 and 3 (2.8%) were G2, respectively. Identification of their P-types demonstrated that 103 (96.3%) were P[8], 3 (2.8%) were P[4], and 1 (0.9%) was P[3] genotypes. Determination of G- and P-type combination revealed that all of G9 isolates were associated with P[8]. G9P[8] was the most predominant genotype and accounted for the majority (91.6%) of rotaviruses detected in this study. Molecular characterization of these G9 isolates demonstrated that all had long electropherotype, 96 of 98 (98.0%) belonged to subgroup II, one belonged to subgroup I and the other one was subgroup unidentifiable. All of G9 isolates possessed NSP4 genetic group B except for one isolate that showed dual genetic group specificities, B and C. The full-length VP7 gene nucleotide sequences among 15 representatives of these G9 strains were found to be highly homologous with percent identities of 99.3%-100%. Comparison with other G9 strains recently isolated showed that their nucleotide sequences were closely related to those of the US strain, US1205 (98.7%-99.0%) and Thai strain, 97CM108 (98.1%-99.0%). Interestingly, they were most closely related to the Japanese strain, 00-SG2509VP7, isolated in the same epidemic season, with percent nucleotide sequence identity of 99.4%-99.8%. The data imply that G9 strains isolated in this study and a G9 strain isolated in Japan in the year 2000 might have descended from the same ancestor.

Molecular characterization of VP4, VP6, VP7, NSP4, and NSP5/6 genes identifies an unusual G3P[10] human rotavirus strain

“…Although epidemiological surveillance and genotype identification of rotavirus infections in human and pig populations in Chiang Mai, Thailand, have been carried out extensively over the past two decades, the P[10] genotype had never been reported previously [Maneekarn and Ushijima, 2000;Maneekarn et al, 2006;Khamrin et al, 2006bKhamrin et al, , 2007cChan-It et al, 2008]. The present study conducted in 2005 described the detection of an unusual strain of G3P[10] (CMH079/05) in a 2-year-old boy admitted to hospital with acute gastroenteritis.…”

“…The studies of rotavirus infection carried out in Thailand revealed that rotaviruses are the leading etiologic pathogens that causes diarrhea in children, and are responsible for about 27-58% of diarrheal diseases in hospitalized cases [Maneekarn and Ushijima, 2000;Jiraphongsa et al, 2005;Khamrin et al, 2006b]. Epidemiological surveillance of group A rotavirus infection conducted in Chiang Mai, Thailand, during the period of 2000-2004 [Khamrin et al, 2006b[Khamrin et al, , 2007c During these extensive epidemiological studies, rotavirus strains with unusual G-P combinations were occasionally detected in children hospitalized with acute gastroenteritis; for example, an unusual strain of human rotavirus G3P[3] (CMH222) bearing simian-like VP7 and caprine-like VP4 genes was isolated from a 2-year-old child patient in 2001 [Khamrin et al, 2006a].…”

“…Epidemiological surveillance of group A rotavirus infection conducted in Chiang Mai, Thailand, during the period of 2000-2004 [Khamrin et al, 2006b[Khamrin et al, , 2007c During these extensive epidemiological studies, rotavirus strains with unusual G-P combinations were occasionally detected in children hospitalized with acute gastroenteritis; for example, an unusual strain of human rotavirus G3P[3] (CMH222) bearing simian-like VP7 and caprine-like VP4 genes was isolated from a 2-year-old child patient in 2001 [Khamrin et al, 2006a]. Recently, two other isolates (CMH120/04 and CMH134/04) of unusual human rotavirus G3P [9] genotype were detected during an epidemiological survey of human rotavirus infection in Chiang Mai, Thailand in 2004.…”

Detection and Genotyping of Human Rotavirus VP4 and VP7 Genes by Reverse Transcriptase PCR and Reverse Hybridization

“…Specific genotypes, such as G9 and G12, are emerging in various parts of the world (9,28,33,39,40,45,47). Outbreaks of rotavirus infections have been described, and these also require adequate genotype identification tools (18,46,50).…”

Sequence analysis of the VP7 gene of human rotaviruses G2 and G4 isolated in Japan, China, Thailand, and Vietnam during 2001–2003

“…Rotavirus G9 has emerged as a common global strain [Ramachandran et al, 1998;Santos et al, 2001;Das et al, 2002;Armah et al, 2003;Kirkwood et al, 2003;Reidy et al, 2005;Khamrin et al, 2006] and other genotypes including G5, G8, G10, and G12 are increasingly reported globally [Beards and Graham, 1995;Santos et al, 1998;Das et al, 2003;Fischer et al, 2003;Laird et al, 2003;Castello et al, 2006;Samajdar et al, 2006;Volotao et al, 2006]. Genetic molecular analyses have been conducted previously to investigate whether changes in the genotypes over time could be explained by corresponding genetic changes on the VP7 gene.…”