1,720,976 research outputs found
Intracellular survival and translocation ability of human and avian Campylobacter jejuni and Campylobacter coli strains
No full textEvaluation of the antimicrobial activity of products used for disinfection of work surfaces in the food industry | Valutazione dell{'}attivit{\`a} antimicrobica di prodotti per l{'}igiene e la disinfezione di superfici nel settore alimentare
No full textChitosans as new tools against biofilms formation on the surface of silicone urinary catheters
No full textUrinary catheters contamination by microorganisms is a major cause of hospital acquired infections and represents a limitation for long-term use. In this work, biofilms of Klebsiella pneumoniae and Escherichia coli clinical isolates were developed on urinary catheters for 48 and 72 h in artificial urine medium (AUM) with different molecular weight chitosans (AUM-CS solutions) at pH 5.0. The number of viable bacteria was determined by standard plate count agar while crystal violet (CV) staining was carried out to assess biomass production (optical density at 570 nm) in the mentioned conditions. Re-growth of each strain was also evaluated after 24 h re-incubation of the treated catheters. Significant decreases of log CFU/catheter and biomass production were observed for all the biofilms developed in AUM-CS compared with the controls in AUM. The percentages of biofilm removal were slightly higher for E. coli biofilms (up to 90.4%) than those of K. pneumoniae (89.7%); in most cases, the complete inhibition of bacterial re-growth on treated catheter pieces was observed. Contact time influenced chitosan efficacy rather than its molecular weight or the biofilms age. The results confirmed the potentiality of chitosans as a biomacromolecule tool to contrast biofilm formation and reduce bacterial re-growth on urinary catheters
Synergic combinations of antimicrobial peptides (AMPs) against biofilms of methicillin-resistant Staphylococcus aureus (MRSA) on polystyrene and medical devices
No full textPossible involvement of Pseudomonas fluorescens and Bacillaceae in structural modifications of Tuber borchii fruit bodies
No full textPrevious studies on Tuber borchii fruit bodies in early maturation stages suggested a role of bacteria in sporocarp structural modifications. In order to verify this hypothesis, in the present study we investigated by means of microbial and ultrastructural approaches, the bacterial population of T. borchii sporocarps from intermediate maturation phases to advanced decomposition stages, paying particular attention to chitinolytic and cellulolytic bacteria and to their relationships with ascii and ascospores. We found that Pseudomonas fluorescens and spore-forming Bacillaceae, both able to degrade cellulose and chitin, are present inside the sporocarps in all maturation stages investigated. Moreover, rod-shaped bacteria seem able to erode ascus walls and colonize the interior of ascii containing mature spores. These results suggest a possible role of these bacteria in the process of ascus opening. Moreover, the presence of P. fluorescens and Bacillaceae on isolated mature spores after de..
Bacteria associated to fruit bodies of the ectomycorrhyzal fungus Tuber borchii Vittad
No full textA microbial population was isolated from young sporocarps of Tuber borchii Vittad. to study its possible role in ascus opening. The bacteria in the sporocarps had a mean value of 106 CFU/g and were generally found in quantities higher than that found in the bulk soil (103). In the sporocarps examined the predominant bacteria were Pseudomonas fluorescens (30% of the total population) and spore-forming, gram-positive, bacteria (15% of total). These bacterial species were tested to evaluate their capacity to degrade cellulose and chitin, the most important components of the hyphal walls. Ultrastructural examination of the tested sporocarps revealed the presence of bacteria in the interhyphal space, a portion of which were embedded in the ascus wall. It is suggested that the presence of Pseudomonas strains and Bacillaceae in T. borchii Vittad. sporocarps could be related to their chitinolytic and cellulolytic activities, which could in turn be involved in ascus opening and, perhaps, in spore germination
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