Marine Alkaloid 2,2-Bis(6-bromo-3-indolyl) Ethylamine and Its Synthetic Derivatives Inhibit Microbial Biofilms Formation and Disaggregate Developed Biofilms

The antimicrobial activity of the marine bisindole alkaloid 2,2-bis(6-bromo-3-indolyl) ethylamine (1) and related synthetic analogues (compounds 2–8) against target microorganisms was investigated by Minimum Inhibitory Concentration (MIC) determination. Compound 1 showed the greatest antimicrobial activity with the lowest MIC (8 mg/L) against Escherichia coli, Staphylococcus aureus, and Klebsiella pneumoniae, while the derivatives exhibited higher MICs values (from 16 to 128 mg/L). Compounds 1, 3, 4, and 8, the most active ones, were then tested against E. coli, S. aureus, K. pneumoniae, and Candida albicans during biofilms formation as well as on 24 h developed biofilms. The natural alkaloid 1 inhibited the biofilm formation of all the tested microorganisms up to 82.2% and disaggregated biofilms of E. coli, S. aureus, K. pneumoniae, and C. albicans after 30 min of contact, as assessed by viable plate count and crystal violet (CV) staining (optical density at 570 nm). Synthetic derivatives 3, 4, and 8 displayed anti-biofilm activity toward individual bacterial populations. This study highlights the potential of marine bisindole alkaloid 1 as anti-biofilm agent and shows, through a preliminary structure activity relationship (SAR), the importance of halogens and ethylamine side chain for the antimicrobial and antibiofilm activities of this bisindole series

Occurrence and expression of virulence-related properties of Vibrio species isolated from widely consumed seadfood products

none5In this study, widely consumed fresh seafood products were examined for the presence of Vibrio spp. Thirteen percent of the samples examined were found to be contaminated with halophilic vibrios belonging to the species V. alginolyticus (81.48%),V. parahaemolyticus(14.8%) andV. choleraenon 0:1 (3.7%). A greater isolation frequency (18.9%) was found for mussels. Significant adhesiveness and strong cytotoxicity factors were revealed in a significant number of theVibriospp. isolated. These results confirm that the presence of Vibrio spp. in seafood products is common, and suggest that routine examination of such products for these pathogenic agents would be advisable.openW.BAFFONE; A. PIANETTI; F. BRUSCOLINI; E. BARBIERI; B. CITTERIOBaffone, Wally; Pianetti, Anna; Bruscolini, Francesca; Barbieri, Elena; Citterio, Barbar

Synergic combinations of antimicrobial peptides (AMPs) against biofilms of methicillin-resistant Staphylococcus aureus (MRSA) on polystyrene and medical devices.

Abstract Objectives Antimicrobial research is being focused to look for more effective therapeutics against antibiotic-resistant infections caused by methicillin-resistantStaphylococcus aureus (MRSA). In this direction, antimicrobial peptides (AMP) appears a promising solution. The aim of the present study was to investigate the potential activity of Temporin A, Citropin 1.1, CA(1–7)M(2–9)NH2 and Pal-KGK-NH2 in synergic activity against MRSA biofilms developed on polystyrene surface (PSS) and central venous catheter (CVC). Methods The research was subdivided into distinct phases to assess the ability of AMPs to inhibit biofilm formation, to identify a possible synergy between AMPs, and to eradicate preformed biofilms on PSS and CVC using AMPs alone or in combination. Results The activity of the AMPs was particularly evident in the inhibition of biofilm formation on PSS and on CVC, while the eradication of preformed biofilms was more difficult and was reached only after 24 h of contact. The synergic activity of AMPs combinations, selected by their FICI, has led to an improvement in the performance of all the molecules in the removal of different biofilms. Conclusions Overall, AMPs could represent the next generation of antimicrobial agents for a prophylactic or therapeutic tool to control biofilm of antibiotic-resistant and/or biofilm-associated infections on different medical devices

Rapamycin Re-Directs Lysosome Network, Stimulates ER-Remodeling, Involving Membrane CD317 and Affecting Exocytosis, in Campylobacter Jejuni-Lysate-Infected U937 Cells.

The Gram-negative Campylobacter jejuni is a major cause of foodborne gastroenteritis in humans worldwide. The cytotoxic effects of Campylobacter have been mainly ascribed to the actions of the cytolethal distending toxin (CDT): it is mandatory to put in evidence risk factors for sequela development, such as reactive arthritis (ReA) and Guillain-Barré syndrome (GBS). Several researches are directed to managing symptom severity and the possible onset of sequelae. We found for the first time that rapamycin (RM) is able to largely inhibit the action of C. jejuni lysate CDT in U937 cells, and to partially avoid the activation of specific sub-lethal effects. In fact, we observed that the ability of this drug to redirect lysosomal compartment, stimulate ER-remodeling (highlighted by ER-lysosome and ER-mitochondria contacts), protect mitochondria network, and downregulate CD317/tetherin, is an important component of membrane microdomains. In particular, lysosomes are involved in the process of the reduction of intoxication, until the final step of lysosome exocytosis. Our results indicate that rapamycin confers protection against C. jejuni bacterial lysate insults to myeloid cells

Unsaturated fatty acids lactose esters: cytotoxicity, permeability enhancement and antimicrobial activity

Sugar based surfactants conjugated with fatty acid chains are an emerging broad group of highly biocompatible and biodegradable compounds with established and potential future applications in the pharmaceutical, cosmetic and food industries. In this work, we investigated absorption enhancing and antimicrobial properties of disaccharide lactose, mono-esterified with unsaturated fatty acids through an enzymatic synthetic approach. After chemical and cytotoxicity characterizations, their permeability enhancing activity was demonstrated using intestinal Caco-2 monolayers through transepithelial electrical resistance (TEER) and permeability studies. The synthesised compounds, namely lactose palmitoleate (URB1076) and lactose nervonate (URB1077), were shown to exhibit antimicrobial activity versus eight pathogenic species belonging to Gram-positive, Gram-negative microorganisms and fungi

Assessment of Antimicrobial Activity in Different Sanitizer Products Commonly Used in Food Processing Environment and Home Setting

The presence of microorganisms to work surfaces represents a potential risk to transmit pathogens to food or humans by cross-contaminations. In food processing and in home setting, disinfectants or sanitizer products are used on inanimate objects and surfaces to inactivate all recognized pathogenic microorganisms. Uncorrected disinfection procedures, in term of declared concentration or time of contact, can lead to the survival of different types of microorganisms. In this study, six sanitizers (herein named A, B, C, D, E, F) belonging to different class of chemical disinfectants were considered: acids (products A, E), halogens (B), quaternary ammonium compounds (C), oxidizing agents (F), mixed classes (D). The antimicrobial activity of each sanitizer was evaluated against Escherichia coli O157:H7 ATCC 35150, Staphylococcus aureus ATCC 43387, Pseudomonas aeruginosa ATCC 9027, Enterococcus faecalis ATCC 29212 and Candida albicans ATCC 14053 was examined by the quantitative suspension test indicated by EN 1276. Our investigation confirmed that different factors affect the activity of chemical sanitizers such as formulation, temperature, time of contact, target microorganism, organic load. The last factor is taken in consideration in the suspension test indicated by EN 1276, that required performing experiments in both dirty and clear simulated conditions. Our data showed that, in general, the examined sanitizers are effective in reducing bacterial growth (logarithmic reduction >5) at the manufacturer recommended concentrations or lower, but in some cases the presence of organic matter interfered with their activity. In this case, it was necessary to use a more high concentration of the chemical product, as reported for the products A, B and F. In conclusion, this work highlighted the need that, in each sanitizer product label, the exact information regarding concentration and time of contact are better specified to obtain the indicated bactericidal effect and avoid the onset of bacterial resistance. Moreover, it’s important that disinfectants are applied on work surfaces after cleaning and removing organic matter that could create a physical barrier protecting microorganisms from the activity of the sanitizers

Live and heat-killed Lactobacillus spp. interfere with Streptococcus mutans and Streptococcus oralis during biofilm development on titanium surface

This research investigates the ability of live and heat-killed (HK) Lactic Acid Bacteria (LAB) to interfere with Streptococcus mutans ATCC 25175 and Streptococcus oralis ATCC 9811 during biofilm formation