Increased detection of enterovirus 68 (EV68) among patients with acute respiratory infections has been reported from different parts of the world in the late 2000s since its first detection in pediatric patients with lower-respiratory-tract infections in 1962. However, the underlying molecular mechanisms for this trend are still unknown. We therefore aimed to study the antigenicity and receptor binding properties of EV68 detected in recent years in comparison to the prototype strain of EV68, the Fermon strain. We first performed neutralization (NT) and hemagglutination inhibition (HI) tests using antisera generated for EV68 strains detected in recent years. We found that the Fermon strain had lower HI and NT titers than recently detected EV68 strains. The HI and NT titers were also significantly different between strains of different genetic lineages among recently detected EV68 strains. We further studied receptor binding specificities of EV68 strains for sialyloligosaccharides using glycan array analysis. In glycan array analysis, all tested EV68 strains showed affinity for ␣2-6-linked sialic acids (␣2-6 SAs) compared to ␣2-3 SAs. Our study demonstrates that emergence of strains with different antigenicity is the possible reason for the increased detection of EV68 in recent years. Additionally, we found that EV68 preferably binds to ␣2-6 SAs, which suggests that EV68 might have affinity for the upper respiratory tract. IMPORTANCE Numbers of cases of enterovirus 68 (EV68) infection in different parts of the world increased significantly in the late 2000s.We studied the antigenicity and receptor binding properties of recently detected EV68 strains in comparison to the prototype strain of EV68, Fermon. The hemagglutination inhibition (HI) and neutralization (NT) titers were significantly different between strains of different genetic lineages among recently detected EV68 strains. We further studied receptor binding specificities of EV68 strains for sialyloligosaccharides using glycan array analysis, which showed affinity for ␣2-6-linked sialic acids (␣2-6 SAs) compared to ␣2-3 SAs. Our study suggested that the emergence of strains with different antigenicities was the possible reason for the increased detections of EV68 in recent years. Additionally, we revealed that EV68 preferably binds to ␣2-6 SAs. This is the first report describing the properties of EV68 receptor binding to the specific types of sialic acids.
Human enterovirus species A (HEV-A) consists of at least 16 members of different serotypes that are known to be the causative agents of hand, foot, and mouth disease (HFMD), herpangina, and other diseases, such as respiratory disease and polio-like flaccid paralysis. Enterovirus 71 (EV71) and coxsackievirus A16 (CVA16) are the major causative agents of HFMD. CVA5, CVA6, CVA10, and CVA12 mainly cause herpangina or are occasionally involved with sporadic cases of HFMD. We have previously shown that human scavenger receptor class B, member 2 (SCARB2) is a cellular receptor for EV71 and CVA16. Using a large number of clinical isolates of HEV-A, we explored whether all clinical isolates of EV71 and other serotypes of HEV-A infected cells via SCARB2. We tested this possibility by infecting L-SCARB2 cells, which are L929 cells expressing human SCARB2, by infecting human RD cells that had been treated with small interfering RNAs for SCARB2 and by directly binding the viruses to a soluble SCARB2 protein. We showed that all 162 clinical isolates of EV71 propagated in L-SCARB2 cells, suggesting that SCARB2 is the critical receptor common to all EV71 strains. In addition, CVA7, CVA14, and CVA16, which are most closely related to each other, also utilized SCARB2 for infection. EV71, CVA14, and CVA16 are highly associated with HFMD, and EV71 and CVA7 are occasionally associated with neurological diseases, suggesting that SCARB2 plays important roles in the development of these diseases. In contrast, another group of viruses, such as CVA2, CVA3, CVA4, CVA5, CVA6, CVA8, CVA10, and CVA12, which are relatively distant from the EV71 group, is associated mainly with herpangina. None of these clinical isolates infected via the SCARB2-dependent pathway. HEV-A viruses can be divided into at least two groups depending on the use of SCARB2, and the receptor usage plays an important role in developing the specific diseases for each group.
The purpose of this study is to investigate the biological hydrogen production potential of individual organic fraction of municipal solid wastes (OFMSW) by batch experiments. Seven varieties of typical organic solid wastes including rice, cabbage, carrot, egg, lean meat, fat and chicken skin were selected to estimate the hydrogen production potential. Among the OFMSW, carbohydrate produced the most hydrogen through biological hydrogen fermentation compared with proteins or lipids. Subsequently, the biological hydrogen production potentials of some individual carbohydrate were measured: cabbage, 26.3-61.7 mL/g-VS; carrot, 44.9-70.7 mL/g-VS; and rice, 19.3-96.0 mL/g-VS. The hydrogen percentages of the total biogas produced from cabbage, carrot and rice were 33.9-55.1%, 27.7-46.8% and 44.0-45.6%, respectively.
BackgroundThe prevalence of tinnitus is reported to be high in older Western populations, and several risk factors have been suggested. However, community-based evidence on prevalence is limited and, to our knowledge, there is no such information from older non-Western populations. The purpose of this study was to determine the prevalence and factors associated with tinnitus in community-dwelling Japanese elders.MethodsIn this community-based cross-sectional study, 1320 residents of Kurabuchi Town aged 65 years or older (584 men and 736 women; participation proportion = 98.7%) were interviewed at home in 2006, and information on tinnitus and factors associated with tinnitus was collected. We estimated the prevalence of tinnitus by age group and sex and used a logistic regression model to investigate associated factors.ResultsThe prevalence of tinnitus was 18.6% (men: 18.0%; women: 19.0%); there were no statistically significant differences by age group or sex. Hearing difficulty, depressive mood, prescribed medication, past/current history of coronary heart disease, and knee joint pain requiring medical consultation were associated with tinnitus.ConclusionsThese findings suggest that tinnitus is common in Japanese aged over 65 years. Because the factors associated with tinnitus in this cross-sectional study are potentially modifiable, they should be thoroughly investigated in a longitudinal study.
Human respiratory syncytial virus (HRSV) is a major cause of acute lower respiratory tract infections in infants and children worldwide. We performed molecular analysis of HRSV among infants and children with clinical diagnosis of severe pneumonia in four study sites in the Philippines, including Biliran, Leyte, Palawan, and Metro Manila from June 2012 to July 2013. Nasopharyngeal swabs were collected and screened for HRSV using real-time polymerase chain reaction (PCR). Positive samples were tested by conventional PCR and sequenced for the second hypervariable region (2nd HVR) of the G gene. Among a total of 1,505 samples, 423 samples were positive for HRSV (28.1%), of which 305 (72.1%) and 118 (27.9%) were identified as HRSV-A and HRSV-B, respectively. Two genotypes of HRSV-A, NA1 and ON1, were identified during the study period. The novel ON1 genotype with a 72-nucleotide duplication in 2nd HVR of the G gene increased rapidly and finally became the predominant genotype in 2013 with an evolutionary rate higher than the NA1 genotype. Moreover, in the ON1 genotype, we found positive selection at amino acid position 274 (p<0.05) and massive O- and N-glycosylation in the 2nd HVR of the G gene. Among HRSV-B, BA9 was the predominant genotype circulating in the Philippines. However, two sporadic cases of GB2 genotype were found, which might share a common ancestor with other Asian strains. These findings suggest that HRSV is an important cause of severe acute respiratory infection among children in the Philippines and revealed the emergence and subsequent predominance of the ON1 genotype and the sporadic detection of the GB2 genotype. Both genotypes were detected for the first time in the Philippines.
iHuman sapovirus has been shown to be one of the most important etiologies in pediatric patients with acute diarrhea. However, very limited data are available about the causative roles and epidemiology of sapovirus in community settings. A nested matched case-control study within a birth cohort study of acute diarrhea in a peri-urban community in Peru from 2007 to 2010 was conducted to investigate the attributable fraction (AF) and genetic diversity of sapovirus. By quantitative reverse transcription-realtime PCR (qPCR) sapovirus was detected in 12.4% (37/299) of diarrheal and 5.7% (17/300) of nondiarrheal stools (P ؍ 0.004). The sapovirus AF (7.1%) was higher in the second year (13.2%) than in the first year (1.4%) of life of children. Ten known genotypes and one novel cluster (n ؍ 5) within four genogroups (GI, GII, GIV, and GV) were identified by phylogenetic analysis of a partial VP1 gene. Further sequence analysis of the full VP1 gene revealed a possible novel genotype, tentatively named GII.8. Notably, symptomatic reinfections with different genotypes within the same (n ؍ 3) or different (n ؍ 5) genogroups were observed in eight children. Sapovirus exhibited a high attributable burden for acute gastroenteritis, especially in the second year of life, of children in a Peruvian community. Further large-scale studies are needed to understand better the global burden, genetic diversity, and repeated infections of sapovirus. Acute diarrhea is one of the most important causes of morbidity and mortality in pediatric populations, especially in developing countries. Rotavirus, norovirus, and other viruses are common causative etiological agents, and rotavirus accounts for about 440,000 child deaths annually (1), while norovirus is a leading cause of epidemic and sporadic acute diarrhea (2). Currently a rotavirus vaccination program has been implemented in 80 countries as a part of national immunization programs (http://sites.path.org /rotavirusvaccine/rotavirus-vaccines/#global-intro). It successfully reduced the number of hospitalizations and deaths due to acute gastroenteritis (3, 4) and is cost-effective (5). Norovirus has now replaced rotavirus as the leading cause of medically attended acute diarrhea in pediatric populations (6, 7), and sapovirus, belonging to a separate genus of the Caliciviridae family, has been reported as the second most commonly detected virus after norovirus in children with acute diarrhea where rotavirus vaccination was implemented (8, 9). In addition, reports on sapovirus outbreaks across all age groups have increased in South Asia, Europe, and North America recently (10)(11)(12)(13)(14).The genome of sapovirus consists of a positive-sense, singlestranded RNA with two open reading frames (ORFs) (12). ORF1 encodes the nonstructural proteins and a major capsid protein, VP1, and ORF2 encodes a protein whose function is still unknown (12). Like for norovirus, multiple genetic clusters of human sapovirus have been reported, including four genogroups (GI, GII, GIV, and GV) with 17 gen...
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