Many bacteria swim in liquid or swarm over solid surfaces by synthesizing rotary flagella The same bacteria that are motile also commonly form nonmotile multicellular aggregates called biofilms Biofilms are an important part of the lifestyle of pathogenic bacteria, and it is assumed that there is a motility-to-biofilm transition wherein the inhibition of motility promotes biofilm formation The transition is largely inferred from regulatory mutants that reveal the opposite regulation of the two phenotypes Here, we review the regulation of motility during biofilm formation in Bacillus, Pseudomonas, Vibrio, and Escherichia, and we conclude that the motility-to-biofilm transition, if necessary, likely involves two steps In the short term, flagella are functionally regulated to either inhibit rotation or modulate the basal flagellar reversal frequency Over the long term, flagellar gene transcription is inhibited and in the absence of de novo synthesis, flagella are diluted to extinction through growth Both short-term and long-term motility inhibition is likely important to stabilize cell aggregates and optimize resource investment We emphasize the newly discovered flagellar functional regulators and speculate that others await discovery in the context of biofilm formation

Regulation of flagellar motility during biofilm formation

Biofilm-associated persistence of food-borne pathogens.

Attachment and biofilm formation by foodborne bacteria in meat processing environments: causes, implications, role of bacterial interactions and control by alternative novel methods.

Antibiotic-resistant bacteria were first described in the 1940s, but whereas new antibiotics were being discovered at a steady rate, the consequences of this phenomenon were slow to be appreciated. At present, the paucity of new antimicrobials coming into the market has led to the problem of antibiotic resistance fast escalating into a global health crisis. Although the selective pressure exerted by the use of antibiotics (particularly overuse or misuse) has been deemed the major factor in the emergence of bacterial resistance to these antimicrobials, concerns about the role of the food industry have been growing in recent years and have been raised at both national and international levels. The selective pressure exerted by the use of antibiotics (primary production) and biocides (e.g., disinfectants, food and feed preservatives, or decontaminants) is the main driving force behind the selection and spread of antimicrobial resistance throughout the food chain. Genetically modified (GM) crops with antibiotic resistance marker genes, microorganisms added intentionally to the food chain (probiotic or technological) with potentially transferable antimicrobial resistance genes, and food processing technologies used at sub-lethal doses (e.g., alternative non-thermal treatments) are also issues for concern. This paper presents the main trends in antibiotic resistance and antibiotic development in recent decades, as well as their economic and health consequences, current knowledge concerning the generation, dissemination, and mechanisms of antibacterial resistance, progress to date on the possible routes for emergence of resistance throughout the food chain and the role of foods as a vehicle for antibiotic-resistant bacteria. The main approaches to prevention and control of the development, selection, and spread of antibacterial resistance in the food industry are also addressed.

Antibiotic-Resistant Bacteria: A Challenge for the Food Industry

Decreased antimicrobial efficiency has become a global public health issue. The paucity of new antibacterial drugs is evident, and the arsenal against infectious diseases needs to be improved urgently. The selection of plants as a source of prototype compounds is appropriate, since plant species naturally produce a wide range of secondary metabolites that act as a chemical line of defense against microorganisms in the environment. Although traditional approaches to combat microbial infections remain effective, targeting microbial virulence rather than survival seems to be an exciting strategy, since the modulation of virulence factors might lead to a milder evolutionary pressure for the development of resistance. Additionally, anti-infective chemotherapies may be successfully achieved by combining antivirulence and conventional antimicrobials, extending the lifespan of these drugs. This review presents an updated discussion of natural compounds isolated from plants with chemically characterized structures...

Plant Natural Products Targeting Bacterial Virulence Factors

Biofilms are a self-protection growth pattern of bacteria, which are different from planktonic cells. They have been of considerable interest in food hygiene since biofilms may contain spoilage and pathogenic bacteria which increases post-processing contamination and risk to public health. In addition, biofilm cells are more resistant to cleaning and disinfection processes in the food industry. Biofilm formation is a complex process in which genetic mechanisms and numerous factors such as the properties of substratum and bacterial cell surfaces are involved. In order to further understand the intricate mechanisms behind biofilm formation, various techniques including physical, chemical and molecular methods have been used to establish the possible model of biofilm formation in food industry. Therefore, the importance of bacterial biofilms in food safety control and biofilm formation mechanisms will be discussed in this paper. The objective of all efforts is to provide new insights for developing biofilm-free food-processing systems.

Xianming Shi

Papers

Biofilm formation and food safety in food industries