Summary An understanding of the mechanisms which facilitate the attachment of Escherichia coli and other bacterial species to abiotic surfaces is desired by numerous industries including the food and medical industries. Numerous studies have attempted to explain bacterial attachment as a function of bacterial properties such as cellular surface charge, hydrophobicity and outer membrane proteins amongst others. Conflicting evidence in the literature both for and against a positive relationship may arise from the nature of the test methods used to measure them. A handful of recent studies utilizing technologies such as atomic force microscopy have begun to look at bacterial attachment at a single cell and molecular level. These studies may provide the information required to fully understand the underlying factors which influence bacterial cell attachment to abiotic surfaces. A number of issues in determining the influential factors of bacterial attachment have been identified from the literature: a lack of standardization and sensitivity of methods, as well as the value of measuring bulk properties of a number of cells rather than the behaviour of single cells which may overlook key interactions at a molecular level. These issues will need to be addressed in future studies in this area.

No abstract

Human noroviruses (NoVs) are the leading cause of foodborne illness in the United States, and they exact a considerable human and economic burden worldwide. In fact, the many challenging aspects of human NoV have caused some to call it the nearly perfect foodborne pathogen. In this review, a brief overview of NoVs and their genetic structure is provided. Additionally, the challenges and recent developments related to human NoVs regarding viral evolution, transmission, epidemiology, outbreak identification, cultivation, animal and human models, and detection are presented.

Escherichia coli O157 are an important group of foodborne pathogens with the ability to attach to materials commonly used in food processing environments such as slightly hydrophilic stainless steel. The aim of this study was to characterise six E. coli isolates, including five E. coli O157, for curli production, autoaggregation, hydrophobicity and attachment to highly hydrophilic glass and hydrophobic Teflon. Curli production and autoaggregation were determined using absorbance assays; hydrophobicity by bacterial adherence to hydrocarbons, hydrophobic interaction chromatography and contact angle measurements; and attachment using epifluorescence microscopy. Curli production varied between strains and for some strains correlated with autoaggregation. Curli production correlated with decreased hydrophobicity for two strains. Four of the six isolates increased attachment to glass, but decreased attachment to Teflon with increased curli production. In contrast, one of the six isolates decreased attachment to glass, but increased attachment to Teflon with increasing curli production. Curli production by the remaining isolate did not correlate with hydrophobicity or attachment. Attachment of some E. coli, including E. coli O157, to abiotic surfaces may be influenced by curli production, autoaggregation and hydrophobicity. However, for other strains, a variety of factors may be of greater influence on these properties and ability to attach to abiotic surfaces. This study highlights the complexity of bacterial surface properties and their relationship with bacterial attachment.