Showing papers by "Enzo A. Palombo published in 2002"

Genetic analysis of Group A rotaviruses: evidence for interspecies transmission of rotavirus genes

Abstract: Rotaviruses are the major cause of severe gastroenteritis in young children and animals. The rotavirus genome is composed of eleven segments of double-stranded RNA and can undergo genetic reassortment during mixed infections, leading to progeny viruses with novel or atypical phenotypes. There are numerous descriptions of rotavirus strains isolated from human and animals that share genetic and antigenic features of viruses from heterologous species. In many cases, genetic analysis by hybridization has clearly demonstrated the genetic relatedness of gene segments to those from viruses isolated from different species. Together with the observation that some virus strains appear to have been transmitted to a different species as a whole genome constellation, these data suggest that interspecies transmission occurs naturally, albeit at low frequencies. Although interspecies transmission has not been documented directly, there is an increasing number of reports of atypical rotaviruses that are apparently derived from transmission between: humans, cats and dogs; humans and cattle; humans and pigs; pigs and cattle; and pigs and horses. Interspecies evolutionary relationships are supported by phylogenetic analysis of rotavirus genes from different species. The emergence of novel strains derived from interspecies transmission has implications for the design and implementation of successful human rotavirus vaccine strategies.

Antibacterial activity of Australian plant extracts against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE).

Abstract: Ethanolic extracts of five traditional Australian medicinal plants, previously shown to display antibacterial activity against laboratory strains of the Gram positive bacteria Staphylococcus aureus and Enterococcus faecalis, were investigated for their abilities to inhibit clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE). Using plate-hole diffusion assays, the following results were obtained: (a) extract from the leaves of Eremophila alternifolia (Myoporaceae) showed activity against MRSA; (b) extract from the leaves of Acacia kempeana (Mimosaceae) showed incomplete inhibition of VRE; (c) extracts from the leaves of Amyema quandong (Loranthaceae) and Eremophila duttonii (Myoporaceae) were active against both types of bacteria; (d) extract from the stem base of Lepidosperma viscidum (Cyperaceae) was active against MRSA and exhibited incomplete inhibition of VRE. All active extracts were evaluated using time-kill assays. Most of the extracts showed bactericidal effects and reduced the number of viable cells by 4-6 logs within four hours, while the extracts from Acacia kempeana leaves and Lepidosperma viscidum stem base exhibited bacteriostatic activity against VRE. The extract from the leaves of Eremophila duttonii was the most active and reduced the number of viable cells of MRSA and VRE to undetectable levels within 1 hour.

Expanding distribution of human serotype G6 rotaviruses in Australia

Abstract: Serotype G6 rotaviruses are common pathogens of cattle but are rarely found in humans. In Australia, human G6 isolates have previously been detected in two major southern population centres. A new isolate, ASG6.02, was detected in central Australia (Alice Springs) in 1997. Comparison of the deduced amino acid sequence of the major neutralizing antigen, VP7, indicated that ASG6.02 was related to human G6 viruses isolated from children in Italy and Australia. Phylogenetic analysis supported the close relationship between ASG6.02 and other Australian isolates and indicated that G6 VP7 sequences generally clustered according to the species of origin (human, bovine or porcine). The VP4 type of ASG6.02 was determined as P-type [14], in common with other isolates from Australia and Italy. The detection of ASG6.02 indicates that the distribution of this serotype is increasing in this country and may have implications for successful vaccine development.

The effectiveness of different wash basins in reducing the microbial load on the hands of food handlers

Abstract: In Victoria, hands free wash hand basins in food preparation areas were a regulatory requirement introduced under the 1984 Health (Eating House and Food Premises) Regulations. The food safety standards introduced in January 2001 replace existing state, territory and local government food hygiene regulations and the provision of a hands free wash hand basin is no longer prescribed (Australia and New Zealand Food Authority 2001). The aim of the pilot study was to investigate the hypothesis that there is no difference between the effectiveness of hands free wash hand basins and manual tap operated basins in reducing microbial flora on hands. Thirteen premises with manual hand basins and a comparison random sample of 19 premises with hands free basins were selected from the City of Yarra in Melbourne, Australia. Data collection involved an Environmental Health Officer visiting the premises, conducting a survey and swabbing the food handler's hands prior to and post washing. The impact of variables, including the temperature of water supplied to the wash hand basin, number of food handling employees, types of food handled, time the sample was taken and approximate number of meals sold per hour, were also investigated. The results indicated that the mean percentage reduction in the number of colonies compared for the manual and hands free hand basins showed no significant difference (Manual mean = 58%, Hands free mean = 79%, p = 0.163). Overall, there was large variability in pre and post microbial counts for both basins and considerable variability in the temperature of water to wash hand basins. No clear association, however, was found between the number of employees, temperature of wash hand basin, meals served or use of either facility, with the percentage reduction in the microbial load. The pilot study has indicated that there is no difference between the use of either a manual or hands free wash hand basin for a small group of food retailers. Consideration should be given to a range of factors which might have impacted on this study, including frequency of hand washing, types of foods handled, length of mechanical wash, and number of manual wash hand basins available for the study. Education regarding the need to maintain the temperature of the wash hand basin water between 22-40 C should also be investigated among food retailers as well as strategies for the correct washing of hands.

The Effectiveness of Different Wash Basins in Reducing the Microbial Load on the Hands of Food Handlers

Abstract: The City of Yarra in conjunction with the Swinburne University of Technology conducted a pilot study into the effectiveness of hand washing facilities in owner/operated retail food premises within its municipality. The study was undertaken as a result of the Food Safety Small Grants Program, funded by the Victorian State Government, which allocated funding to local government agencies to conduct The Effectiveness of Different Wash Basins in Reducing the Microbial Load on the Hands of Food Handlers