Clinical characteristics and genotypes of rotaviruses in a neonatal intensive care unit.

BACKGROUND: There are few reports on the symptoms of rotavirus infections in neonates. This study aims to describe clinical signs of rotavirus infections among neonates, with a particular focus on preterm infants, and to show the distribution of genotypes in a neonatal intensive care unit (NICU). METHODS: A prospective observational study was conducted at a regional NICU for 1 year. Stool specimens from every infant in the NICU were collected on admission, at weekly intervals, and from infants showing symptoms. Rotavirus antigens were detected by enzyme-linked immunosorbent assay (ELISA), and genotypes were confirmed by Reverse transcription-Polymerase chain reaction (RT-PCR). The infants were divided into three groups: symptomatic preterm infants with and without rotavirus-positive stools [Preterm(rota+) and Preterm(rota-), respectively] and symptomatic full- or near-term infants with rotavirus-positive stools [FT/NT(rota+)]. Demographic and outcome data were compared among these groups. RESULTS: A total of 702 infants were evaluated for rotaviruses and 131 infants were included in this study. The prevalence of rotavirus infections was 25.2%. Preterm(rota+) differed from Preterm(rota-) and FT/NT(rota+) with respect to frequent feeding difficulty (p = 0.047 and 0.034, respectively) and higher percentage of neutropenia (p = 0.008 and 0.011, respectively). G4P[6] was the exclusive strain in both the Preterm(rota+) (97.7%) and FT/NT(rota+) (90.2%), and it was the same for nosocomial, institutional infections, and infections acquired at home. CONCLUSION: Systemic illness signs such as feeding difficulty and neutropenia are specific for preterm infants with rotavirus infections. G4P[6] was exclusive, regardless of preterm birth or locations of infections. This study might be helpful in developing policies for management and prevention of rotavirus infections in NICUs.

Genetic characterization of norovirus GII.4 2006b variants from Jeju island, South Korea.

Ninety-seven fecal specimens collected from children with acute gastroenteritis between 2007 and 2008 that were found to be negative for group A rotavirus in prescreening by ELISA with VP6-specific antibody were re-screened for viruses by reverse transcription (RT)-PCR. Forty (41.2%) samples were found to be positive for virus by RT-PCR; of these, norovirus (32.5%, n = 13) and rotavirus (32.5%, n = 13) were the most common, followed by astrovirus (5.0%, n = 2) and enterovirus (2.5%, n = 1). Co-infection was found in 11 (27.5%) samples. Phylogenetic analyses of the ORF2 nucleotide sequences of 21 norovirus strains showed that 19 (90.5%) belonged to the genogroup GII genotype 4 and two (9.5%) belonged to genogroup GI genotype 4. The GII.4 strains demonstrated high sequence homology and were closely related to new 2006b variants observed in Europe, China, Hong Kong, and Japan in 2006. This study provides new information concerning the recent global epidemic of 2006b strains.

Genetic variation of G4P[6] rotaviruses: evidence for novel strains circulating between the hospital and community.

One hundred forty-six fecal specimens collected between 2007 and 2008 from infants with acute gastroenteritis were screened for rotavirus by ELISA with VP6-specific antibody. One hundred twenty-three of the samples (84.2%) were confirmed to be positive for group A rotavirus (community-acquired, n = 90 [73.2%] and nosocomial, n = 33 [26.8%]), and were typed subsequently using RT-PCR and sequence analysis methods. Determination of G- and P-type combinations showed that G4P[6] (78.9%) was the most common strain, followed by G3P[8] (7.3%), G1P[8] (6.5%), G2P[4] (0.8%), G2P[6] (0.8%), G1P[6] (0.8%), and G9P[8] (0.8%) strains. Of the 97 G4P[6] strains, 62 (63.8%) were responsible for community-acquired cases and 35 (36.1%) were hospital-acquired cases. Phylogenetic analysis of the VP7 gene from the G4P[6] strains revealed that both the community-acquired and nosocomial strains were segregated to the human rotaviruses circulating world-wide, including the prototype vaccinal strain, ST3, which constituted a novel sublineage in lineage 1. Owing to the recent emergence of G4P[6] rotaviruses within the hospital, as well as in the community, the findings from this study are important since they provide new information concerning the community and nosocomial spread of rotaviruses.

Corynebacterium doosanense sp. nov., isolated from activated sludge.

The taxonomic position of a Gram-positive, non-motile, non-spore-forming coryneform, isolated from activated sludge and designated strain CAU 212(T), was investigated using a polyphasic approach. Cellular morphology, biochemical tests and chemotaxonomic investigations revealed that strain CAU 212(T) had the characteristics of the genus Corynebacterium. Comparative 16S rRNA gene sequence analysis showed that the organism formed a hitherto-unknown subline within the genus Corynebacterium. Sequence divergence values of more than 4.3 % from recognized Corynebacterium species, together with phenotypic differences, showed that the bacterium represents a previously unrecognized member of the genus Corynebacterium, for which the name Corynebacterium doosanense sp. nov. is proposed. The type strain is CAU 212(T) (=KCTC 19568(T)=CCUG 57284(T)).