scholarly journals Probiotic-mediated competition, exclusion and displacement in biofilm formation by food-borne pathogens

2013 ◽  
Vol 56 (4) ◽  
pp. 307-313 ◽  
Author(s):  
J. Woo ◽  
J. Ahn
Author(s):  
Amina Ojochide Hassan ◽  
Innocent Okonkwo Ogbonna ◽  
Victor Ugochukwu Obisike

Microbial resistance to antibiotics and biofilm formation ability of food-borne pathogens are major global health challenges. Most milk and milk products (Madara and Nono) could be vehicles for the transmission of multidrug resistant genes among any community. This study was aimed at determining the antibiotic susceptibility patterns and biofilm forming ability of some food-borne pathogens isolated from common dairy products: Madara and Nono in Makurdi metropolis. Two hundred and forty (240) samples comprising of one hundred and twenty (120) each of Madara (fresh raw milk from cow “FRM”)) and Nono (chance fermented cow milk “CFM”) were examined for the presence of pathogens. Antibiogram of bacterial isolates (Staphylococcus aureus, Escherichia coli, Shigella spp., Salmonella spp. and Klebsiella spp.) using the disc diffusion method revealed that susceptibility for Ampicillin (86.9%), Streptomycin (83.9%) and Ciprofloxacin (75.0%). Resistance was shown (26.7%) to Nalidixic acid, a commonly used antibiotic reflecting a public health concern. Most resistant isolates had a multiple antibiotics index of 0.3 (27.54%) with a least multiple antibiotics resistance index of 0.6 (0.85%). Detection of biofilm formation of isolates was done by Tube method. The study also revealed that out the total of 236 isolates tested for biofilm formation, 67 (28.4%) isolates were non or weak biofilm producers, 77 (32.6%) isolates were moderate biofilm producers and 92 (39%) isolates were strong biofilm producers. Findings of this research show high presence of a wide range of microorganisms, particularly enteric pathogens and enterotoxigenic strains of S. aureus which portrayed multidrug resistance and biofilm formation suggesting that FRM (Madara) and CRM (Nono) products might be important sources of food-borne infections and intoxication.


2019 ◽  
Vol 12 (4) ◽  
pp. 186 ◽  
Author(s):  
Raffaella Campana ◽  
Alessio Merli ◽  
Michele Verboni ◽  
Francesca Biondo ◽  
Gianfranco Favi ◽  
...  

A small library of sugar-based (i.e., glucose, mannose and lactose) monoesters containing hydrophobic aliphatic or aromatic tails were synthesized and tested. The antimicrobial activity of the compounds against a target panel of Gram-positive, Gram-negative and fungi was assessed. Based on this preliminary screening, the antibiofilm activity of the most promising molecules was evaluated at different development times of selected food-borne pathogens (E. coli, L. monocytogenes, S. aureus, S. enteritidis). The antibiofilm activity during biofilm formation resulted in the following: mannose C10 > lactose biphenylacetate > glucose C10 > lactose C10. Among them, mannose C10 and lactose biphenylacetate showed an inhibition for E. coli 97% and 92%, respectively. At MICs values, no toxicity was observed on Caco-2 cell line for all the examined compounds. Overall, based on these results, all the sugar-based monoesters showed an interesting profile as safe antimicrobial agents. In particular, mannose C10 and lactose biphenylacetate are the most promising as possible biocompatible and safe preservatives for pharmaceutical and food applications.


2020 ◽  
Vol 8 (7) ◽  
pp. 964
Author(s):  
Akosiererem S. Sokaribo ◽  
Elizabeth G. Hansen ◽  
Madeline McCarthy ◽  
Taseen S. Desin ◽  
Landon L. Waldner ◽  
...  

Among human food-borne pathogens, gastroenteritis-causing Salmonella strains have the most real-world impact. Like all pathogens, their success relies on efficient transmission. Biofilm formation, a specialized physiology characterized by multicellular aggregation and persistence, is proposed to play an important role in the Salmonella transmission cycle. In this manuscript, we used luciferase reporters to examine the expression of csgD, which encodes the master biofilm regulator. We observed that the CsgD-regulated biofilm system responds differently to regulatory inputs once it is activated. Notably, the CsgD system became unresponsive to repression by Cpx and H-NS in high osmolarity conditions and less responsive to the addition of amino acids. Temperature-mediated regulation of csgD on agar was altered by intracellular levels of RpoS and cyclic-di-GMP. In contrast, the addition of glucose repressed CsgD biofilms seemingly independent of other signals. Understanding the fine-tuned regulation of csgD can help us to piece together how regulation occurs in natural environments, knowing that all Salmonella strains face strong selection pressures both within and outside their hosts. Ultimately, we can use this information to better control Salmonella and develop strategies to break the transmission cycle.


2021 ◽  
Vol 22 (21) ◽  
pp. 11307
Author(s):  
Ondrej Chlumsky ◽  
Heidi J. Smith ◽  
Albert E. Parker ◽  
Kristen Brileya ◽  
James N. Wilking ◽  
...  

In the food industry, the increasing antimicrobial resistance of food-borne pathogens to conventional sanitizers poses the risk of food contamination and a decrease in product quality and safety. Therefore, we explored alternative antimicrobials N-acetyl-L-cysteine (NAC), rhamnolipids (RLs), and usnic acid (UA) as a novel approach to prevent biofilm formation and reduce existing biofilms formed by important food-borne pathogens (three strains of Salmonella enterica and two strains of Escherichia coli, Listeria monocytogenes, Staphylococcus aureus). Their effectiveness was evaluated by determining minimum inhibitory concentrations needed for inhibition of bacterial growth, biofilm formation, metabolic activity, and biofilm reduction. Transmission electron microscopy and confocal scanning laser microscopy followed by image analysis were used to visualize and quantify the impact of tested substances on both planktonic and biofilm-associated cells. The in vitro cytotoxicity of the substances was determined as a half-maximal inhibitory concentration in five different cell lines. The results indicate relatively low cytotoxic effects of NAC in comparison to RLs and UA. In addition, NAC inhibited bacterial growth for all strains, while RLs showed overall lower inhibition and UA inhibited only the growth of Gram-positive bacteria. Even though tested substances did not remove the biofilms, NAC represents a promising tool in biofilm prevention.


Sign in / Sign up

Export Citation Format

Share Document