Appropriate handling and storage reduce the risk of bacterial growth in enteral feeding systems reused within 24 hours.

BACKGROUND: Enteral tube feeding can require considerable amounts of plastic equipment including delivery sets and containers, often disposed of after a single feeding session because of bacterial contamination concerns. The aim of this research was to assess whether reuse of delivery sets and containers for up to 24 h is safe from a microbiological perspective. METHODS: Four enteral tube feeding systems (FS) were tested under hygienic controlled or repeated inoculation challenge conditions using key foodborne pathogens, to assess bacterial growth over time (FS1: ready-to-hang, closed 1-L system with delivery set reused, stored at room temperature [RT]; FS2: a prepared, powdered, open 1-L system with delivery set and container reused, stored at RT; FS3 and FS4: prepared, powdered, open 200-ml bolus systems with delivery set and container reused, stored at RT [FS3] and refrigeration [FS4]). Feed samples were cultured at 0.5, 6.5, 12.5, 18.5, and 24.5 h with >2 Δlog considered significant bacterial growth. RESULTS: Under hygienic control, FS1, FS3, and FS4 were below the level of enumeration (<5 CFU/g) for all bacteria tested, at all time points. In FS2, significant bacterial growth was observed from 18.5 h. Under repeated bacterial inoculation challenge, no significant growth was observed in FS1 and FS4 over 24.5 h; however, significant growth was observed in FS2 after 6.5 h and in FS3 after 10-12 h. CONCLUSION: With hygienic handling technique, there is limited bacterial growth with reuse of delivery sets and containers over 24 h. Refrigeration between feeding sessions and using boluses of reconstituted powdered feed reduce bacterial growth risk.

pilF polymorphism-based real-time PCR to distinguish Vibrio vulnificus strains of human health relevance.

The Gram-negative bacterium Vibrio vulnificus is a common inhabitant of estuarine environments. Globally, V. vulnificus is a significant foodborne pathogen capable of causing necrotizing wound infections and primary septicemia, and is a leading cause of seafood-related mortality. Unfortunately, molecular methods for the detection and enumeration of pathogenic V. vulnificus are hampered by the genetically diverse nature of this pathogen, the range of different biotypes capable of infecting humans and aquatic animals, and the fact that V. vulnificus contains pathogenic as well as non-pathogenic variants. Here we report an alternative approach utilizing the development of a real-time PCR assay for the detection of pathogenic V. vulnificus strains based on a polymorphism in pilF, a gene previously indicated to be associated with human pathogenicity. Compared to human serum reactivity, the real-time PCR assay successfully detected pathogenic strains in 46 out of 47 analysed V. vulnificus isolates (97.9%). The method is also rapid, sensitive, and more importantly can be reliably utilised on biotype 2 and 3 strains, unlike other current methods for V. vulnificus virulence differentiation.