Showing papers by "Enzo A. Palombo published in 2001"

Rotavirus encephalopathy: pathogenesis reviewed.

Abstract: Two cases of rotavirus gastroenteritis associated with neurological involvement, one with encephalitis (defined by abnormal neurological signs, cerebrospinal fluid (CSF) pleocytosis and detection of rotavirus genomic nucleic acid in the CSF) and one with a non-inflammatory encephalopathy (defined by abnormal neurological signs, an entirely normal CSF and detection of rotavirus genomic nucleic acid in the CSF), are presented and used as a basis to review and explore potential pathogenetic mechanisms, including direct viral replication within neurons and indirect effects of the newly described rotavirus 'enterotoxin'.

Characterisation and phylogenetic analysis of the VP7 proteins of serotype G6 and G8 human rotaviruses.

Abstract: Serotype G6 and G8 rotaviruses are rarely found in man and may have originated in animals. Human serotype G6 and G8 rotaviruses, isolated from hospitalised children at various locations in Australia, were characterised. Deduced amino acid sequences of the major neutralising antigen, V7, showed significant identity to the cognate proteins of prototype human and bovine G6 and G8 viruses, respectively, and the strains reacted with G6 and G8 serotype-specific neutralising monoclonal antibodies, respectively, in an enzyme immunoassay. The VP4 type was determined as P[14] for all strains tested. Phylogenetic analysis of these and other human and bovine VP7 sequences suggested that a single inter-species transmission event, possibly from cattle, may have led to the emergence of G6 viruses in man. In contrast, the exchange of genes between human and bovine G8 viruses may have occurred on more than one occasion, or these genes may have originated in a different host.

Isolation of Pathogenic Bacteria and Opportunistic Pathogens from Public Telephones

Abstract: A survey of 20 randomly selected public telephones in the central business district of Melbourne, Australia, revealed the presence of contaminating pathogenic bacteria and opportunistic pathogens. Bacteria were recovered from all telephones sampled: 40% were contaminated with coagulase-positive Staphylococcus aureus and 80% with lactose-fermenting and non-fermenting bacteria, indicating possible faecal contamination. Further identification revealed the presence of the following enteric and non-enteric bacteria: Acinetobacter anitratus, Enterobacter cloacae, Escherichia coli and Pantoea agglomerans (formerly Enterobacter agglomerans). A viridans Streptococcus, most probably from the "S. mitis" group, was recovered from one of the telephones. All these bacteria are pathogens or opportunistic pathogens. Inoculation of one of the S. aureus isolates onto an inert plastic surface and incubation at room temperature indicated that, although a significant reduction in the recovery of viable bacteria was observed after one day, over 10% of bacteria survived for up to seven days. This was reduced to less than 5% survival after 14 days. Our results suggest that telephone surfaces may serve as potential reservoirs for the transmission of disease-causing bacteria.

Genetic relatedness of VP1 genes of Australian and Taiwanese rotavirus isolates.

Abstract: Gene 1 (which encodes the viral RNA-dependent RNA polymerase, VP1) of an atypical human reassortant rotavirus strain, E210 (serotype G2P1B), is unrelated to genes 1 of standard human rotaviruses. To ascertain the origin of this gene, we determined a partial sequence and found that it exhibited greatest identity to gene 1 of a Taiwanese isolate, TE83, which is representative of G2 strains that caused an epidemic of gastroenteritis in 1993. Limited sequence identity to genes 1 of standard human and animal viruses was observed. This was confirmed by phylogenetic analysis. However, hybridization analysis using an E210 gene 1-specific probe indicated that a related gene was found among other Australian G2 isolates and in a Japanese strain isolated in the 1970s.

The biology and epidemiology of human autoviruses

Abstract: Human astroviruses (HAstV) are now recognised as important causes of acute gastroenteritis in young children world-wide. The development of improved and more reliable diagnostic methods such as enzyme immunoassays and molecular methods has led to an increase in our understanding of the characteristics of astroviruses and astrovirus infections. Astroviruses can be classified into genogroups, genotypes and serotypes depending on whether genetic or antigenic criteria are used. Epidemiological studies have shown that astrovirus infections are associated with sporadic infections of children in the community as well as focal outbreaks in settings such as hospital wards and day-care centres. Astrovirus outbreaks have also been noted among adults. Recent reports have shown that, in some settings, astrovirus is the second most common cause of diarrhoea in children, thus establishing the medical importance of HAstV. World-wide, HAstV-1 seems to be the predominant type with varied distribution of the other types. Continued studies of the epidemiology of astrovirus infection and the extent of genetic variability of clinical isolates, coupled with an increased understanding of immune responses to astrovirus infection, are needed to develop strategies for the control of disease caused by this enteric pathogen.