Involvement of the Iron-Regulated Loci hts and fhuC in Biofilm Formation and Survival of Staphylococcus epidermidis within the Host

Staphylococcus epidermidis is one of the most important nosocomial pathogens and a major cause of central line-associated bloodstream infections. Once in the bloodstream, this bacterium must surpass severe iron restriction in order to survive and establish infection.

Multicomponent Polyphenolic Extracts from Vaccinium corymbosum at Lab and Pilot Scale. Characterization and Effectivity against Nosocomial Pathogens

An extraction method was designed and scaled up to produce multicomponent polyphenolic extracts from blueberries (Vaccinium corymbosum) of three different varieties. The process was specifically drawn up to comply with green chemistry principles. Extracts were obtained for the direct assessment of their antimicrobial and antiadhesive activities, and their direct use in the control of infections caused by concerning multidrug-resistant nosocomial pathogens. Analytical characterization was performed by liquid chromatography–tandem mass spectrometry (LC–MS/MS). Similar qualitative profiles were obtained in the three studied varieties with some significant quantitative differences. Up to 22 different polyphenols were identified with a clear predominance of anthocyani(di)ns followed by flavanols, non-flavonoids, and far behind by flavan-3-ols and procyanidins. The individual content of the main polyphenols was also discussed. A pilot scale extract has been also produced as a proof-of-concept, showing that scaling-up triples the content of bioactive phytochemicals. The effect of the polyphenolic extracts was analyzed against seven multidrug-resistance bacterial species by performing biofilm formation and growth and killing curves assays. All the studied varieties showed antibacterial and antiadhesive activities, being the extract containing the highest concentration of bioactive polyphenols, the most active with a high bactericidal effect.

MoWa: A Disinfectant for Hospital Surfaces Contaminated With Methicillin-Resistant Staphylococcus aureus (MRSA) and Other Nosocomial Pathogens

IntroductionStaphylococcus aureus strains, including methicillin-resistant S. aureus (MRSA) and methicillin-sensitive S. aureus (MSSA), are a main cause of nosocomial infection in the world. The majority of nosocomial S. aureus-infection are traced back to a source of contaminated surfaces including surgery tables. We assessed the efficacy of a mixture of levulinic acid (LA) and sodium dodecyl sulfate (SDS), hereafter called MoWa, to eradicate nosocomial pathogens from contaminated surfaces.Methods and ResultsA dose response study demonstrated that MoWa killed 24 h planktonic cultures of S. aureus strains starting at a concentration of (LA) 8.2/(SDS) 0.3 mM while 24 h preformed biofilms were eradicated with 32/1.3 mM. A time course study further showed that attached MRSA bacteria were eradicated within 4 h of incubation with 65/2 mM MoWa. Staphylococci were killed as confirmed by bacterial counts, and fluorescence micrographs that were stained with the live/dead bacterial assay. We then simulated contamination of hospital surfaces by inoculating bacteria on a surface prone to contamination. Once dried, contaminated surfaces were sprayed with MoWa or mock-treated, and treated contaminated surfaces were swabbed and bacteria counted. While bacteria in the mock-treated samples grew at a density of ~104 cfu/cm2, those treated for ~1 min with MoWa (1.0/0.04 M) had been eradicated below limit of detection. A similar eradication efficacy was obtained when surfaces were contaminated with other nosocomial pathogens, such as Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii, or Staphylococcus epidermidis.ConclusionsMoWa kills planktonic and biofilms made by MRSA and MSSA strains and showed great efficacy to disinfect MRSA-, and MSSA-contaminated, surfaces and surfaces contaminated with other important nosocomial pathogens.

Evaluation of a Domestic Steam Disinfector-Dryer Device for Disinfection of Health Care Workers’ Identification Lanyards

Background Fabric lanyards are commonly worn by health care workers (HCWs) and are known to harbor infectious organisms and contribute to the transmission of infection to HCWs and patients. A diverse range of nosocomial pathogens have been found on lanyards, but there are very few studies describing how to successfully disinfect lanyards to break the chain of transmission. Recently, a steam disinfector-dryer device has come on the market, which performs rapid disinfection against nosocomial pathogens and also dries the contents of the device. It was the aim of this study to evaluate steam disinfection-drying as a method to eliminate pathogens from lanyards. Methods Thirty-eight strips of new, unused, and autoclaved polyester neck lanyards (4 × 2 cm) were inoculated with 30 (12 Gram-positive + 18 Gram-negative) bacteria and one yeast organism. The inoculated lanyard fabric (five organisms per lanyard strip) was placed into a steam disinfector-dryer device and disinfected for 5 minutes and dried for 30 minutes, in accordance with the manufacturer’s instructions. Following disinfection and drying, the presence of viable organisms on lanyard fabric was evaluated using enhanced microbiological broth culture methods for 48 hours. Control lanyard strips were treated with organisms and left at room temperature without undergoing disinfection and drying procedures. Findings Steam disinfection-drying eradicated all test organisms from treated lanyards, with no culturable organisms detected following disinfection-drying, even when employing enhanced bacteriological culture conditions. All test organisms remained viable on the control lanyards. Conclusion/Application to Practice Steam disinfection-drying offers a simple method of decontaminating lanyards, producing dry lanyards for immediate reuse. Occupational health practitioners and hospitals should consider assessing the feasibility of adopting this method in their settings to aid in breaking the chain of transmission of nosocomial pathogens via contaminated lanyards.