Autoinducer-2 Activity of Gram-Negative Foodborne Pathogenic Bacteria and Its Influence on Biofilm Formation

2008 ◽  
Vol 73 (3) ◽  
pp. M140-M147 ◽  
Author(s):  
Y. Yoon ◽  
J.N. Sofos
Keyword(s):  
Biofilm Formation ◽  
Pathogenic Bacteria ◽  
Gram Negative ◽  
Autoinducer 2 ◽  
Foodborne Pathogenic Bacteria

scholarly journals Research on the Biofilm Formation of Staphylococcus aureus after Cold Stress

2021 ◽  
Vol 9 (7) ◽  
pp. 1534
Author(s):  
Jiaju Qiao ◽  
Liping Zheng ◽  
Zhaoxin Lu ◽  
Fanqiang Meng ◽  
Xiaomei Bie
Keyword(s):  
Staphylococcus Aureus ◽  
Cold Stress ◽  
Biofilm Formation ◽  
Pathogenic Bacteria ◽  
Proteinase K ◽  
Potential Hazard ◽  
Mrna Levels ◽  
Timely Manner ◽  
Food Pathogen ◽  
Foodborne Pathogenic Bacteria

Staphylococcus aureus is a common food pathogen and has a strong tolerance to environmental stress. Here, the biofilm formation of S. aureus strains after cold stress for 24 weeks were investigated. It was found that the biofilm formation of S. aureus CICC 21600, CICC 22942, W1, W3, and C1 cells was enhanced after cold stress for 20 weeks. What is more, the mRNA levels of the clfA, icaA, icaB, icaC or icaD genes in these strains were increased for >2-fold. The increased gene transcription levels were consistent with the increase in the polysaccharide content in the biofilm matrix of these S. aureus strains after cold stress. Meanwhile, hydrophobicity and the adhesion proteins also played a role in the formation of biofilms. The biofilm of S. aureus cells can be effectively degraded by snailase and proteinase K (125 µg/mL + 20 µg/mL) mixture. In summary, S. aureus frozen at −20 °C for 12 to 20 weeks is still a potential hazard. Food factory equipment should be cleaned in a timely manner to avoid outbreaks of foodborne pathogenic bacteria due to contamination.

scholarly journals Identification and detection of pathogenic bacteria from patients with hospital-acquired pneumonia in southwestern Iran; evaluation of biofilm production and molecular typing of bacterial isolates

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Farzad Mazloomirad ◽  
Sajad Hasanzadeh ◽  
Asghar Sharifi ◽  
Gordafarin Nikbakht ◽  
Narges Roustaei ◽  
...  
Keyword(s):  
Molecular Typing ◽  
Biofilm Formation ◽  
Pathogenic Bacteria ◽  
Typing Method ◽  
Gram Negative ◽  
E Coli ◽  
Type Iii ◽  
Hospital Acquired Pneumonia ◽  
Southwestern Iran ◽  
Hospital Acquired

Abstract Background Hospital-acquired pneumonia (HAP) is the second most common nosocomial infection in intensive care units (ICUs). The present study aims to determine the prevalence of pathogenic bacteria, their biofilm formation, and molecular typing from patients with HAP in southwestern Iran. Methods Fifty-eight patients with HAP participated in this cross-sectional study. Sputum and endotracheal aspirate were collected from each patient for isolation and detection of bacteria. Biofilm formation was evaluated using Congo red agar or Microtiter plate assay. The antimicrobial susceptibility patterns of the isolates were investigated. The multiplex polymerase chain reaction (M-PCR) technique was used to determine the Staphylococcal Cassette Chromosome mec (SCCmec) types of methicillin-resistant Staphylococcus aureus (MRSA) strains. All S. aureus isolates were typed using the agr typing method. A repetitive element sequence-based PCR (rep-PCR) typing method was used for typing of Gram-negative bacteria. Data were analyzed using the Statistical Package for the Social Sciences (SPSS) software version 15 and the chi-square test. Results Bacteria were isolated in 52 (89.7%) of patients. Acinetobacter baumannii (A. baumannii) was the most prevalent organism (37%), followed by S. aureus, Pseudomonas aeruginosa (P. aeruginosa), and Escherichia coli (E. coli). Using the PCR method, 56 bacteria were detected. A. baumannii was the most prevalent (35.7%) organism. A. baumannii and P. aeruginosa were biofilm-producing. All Gram-negative isolates were colistin-sensitive, and most of the A. baumannii isolates were multidrug-resistant (MDR). MRSA was identified in 12 (80%) S. aureus isolates, and 91.6% of MRSA were SCCmec type III. The agr type III was the most predominant. The rep-PCR analysis showed seven different patterns in 20 A. baumannii, six patterns in 13 P. aeruginosa, and four patterns in 6 E. coli. Conclusion A. baumannii was more prevalent than S. aureus in ventilator-associated pneumonia (VAP), while S. aureus is a major pathogen in non-ventilator hospital-acquired pneumonia (NV-HAP), possibly due to the tendency of the former to aquatic environments. Based on the rep-PCR typing method, it was concluded that bacteria were transmitted from patients or healthcare workers among different wards. Colistin can be used as a treatment in Gram-negative MDR isolates.

scholarly journals TetR-family transcription factors in Gram-negative bacteria: conservation, variation and implications for efflux-mediated antimicrobial resistance

BMC Genomics ◽  
2019 ◽  
Vol 20 (1) ◽  
Author(s):  
A. L. Colclough ◽  
J. Scadden ◽  
J. M. A. Blair
Keyword(s):  
Gene Expression ◽  
Antimicrobial Resistance ◽  
Biofilm Formation ◽  
Pathogenic Bacteria ◽  
Efflux Pump ◽  
Regulate Gene Expression ◽  
Gram Negative ◽  
Single Target ◽  
Dna Binding Factors ◽  
Wide Scale

Abstract Background TetR-family transcriptional regulators (TFTRs) are DNA binding factors that regulate gene expression in bacteria. Well-studied TFTRs, such as AcrR, which regulates efflux pump expression, are usually encoded alongside target operons. Recently, it has emerged that there are many TFTRs which act as global multi-target regulators. Our classical view of TFTRs as simple, single-target regulators therefore needs to be reconsidered. As some TFTRs regulate essential processes (e.g. metabolism) or processes which are important determinants of resistance and virulence (e.g. biofilm formation and efflux gene expression) and as TFTRs are present throughout pathogenic bacteria, they may be good drug discovery targets for tackling antimicrobial resistant infections. However, the prevalence and conservation of individual TFTR genes in Gram-negative species, has to our knowledge, not yet been studied. Results Here, a wide-scale search for TFTRs in available proteomes of clinically relevant pathogens Salmonella and Escherichia species was performed and these regulators further characterised. The majority of identified TFTRs are involved in efflux regulation in both Escherichia and Salmonella. The percentage variance in TFTR genes of these genera was found to be higher in those regulating genes involved in efflux, bleach survival or biofilm formation than those regulating more constrained processes. Some TFTRs were found to be present in all strains and species of these two genera, whereas others (i.e. TetR) are only present in some strains and some (i.e. RamR) are genera-specific. Two further pathogens on the WHO priority pathogen list (K. pneumoniae and P. aeruginosa) were then searched for the presence of the TFTRs conserved in Escherichia and Salmonella. Conclusions Through bioinformatics and literature analyses, we present that TFTRs are a varied and heterogeneous family of proteins required for the regulation of numerous important processes, with consequences to antimicrobial resistance and virulence, and that the roles and responses of these proteins are frequently underestimated.

scholarly journals Maipomycin A, a Novel Natural Compound With Promising Anti-biofilm Activity Against Gram-Negative Pathogenic Bacteria

2021 ◽  
Vol 11 ◽  
Author(s):  
Junliang Zhang ◽  
Xiaoyan Liang ◽  
Shiling Zhang ◽  
Zhiman Song ◽  
Changyun Wang ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Pathogenic Bacteria ◽  
Complex Structure ◽  
Iron Chelator ◽  
Gram Negative Bacteria ◽  
Inhibition Activity ◽  
Biofilm Inhibition ◽  
Gram Negative ◽  
X Ray Crystallography ◽  
Actinomycete Strain

Pathogenic bacterial biofilms play an important role in recurrent nosocomial and medical device-related infections. Once occurred, the complex structure of the biofilm promotes the development of antibiotic resistance and becomes extremely difficult to eradicate. Here we describe a novel and effective anti-biofilm compound maipomycin A (MaiA), which was isolated from the metabolites of a rare actinomycete strain Kibdelosporangium phytohabitans XY-R10. Its structure was deduced from analyses of spectral data and confirmed by single-crystal X-ray crystallography. This natural product demonstrated a broad spectrum of anti-biofilm activities against Gram-negative bacteria. Interestingly, the addition of Fe(II) or Fe(III) ions could block the biofilm inhibition activity of MaiA because it is an iron chelator. However, not all iron chelators showed biofilm inhibition activity, suggesting that MaiA prevents biofilm formation through a specific yet currently undefined pathway. Furthermore, MaiA acts as a synergist to enhance colistin efficacy against Acinetobacter baumannii. Our results indicate that MaiA may potentially serve as an effective antibiofilm agent to prevent Gram-negative biofilm formation in future clinical applications.

GC-MS/FID analysis, antibacterial activity and modes of action of essential oils from three Aframomum species found in Cameroon against foodborne pathogenic bacteria

2021 ◽  
Vol 14 (2) ◽  
pp. 24-34
Author(s):  
Gueaba Helene Mbuntcha ◽  
Dongmo Hervet Paulin Fogang ◽  
Armel Jackson Seukep ◽  
Christine Schippa ◽  
Elisabet Dunach ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Cell Membrane ◽  
Essential Oils ◽  
Biofilm Formation ◽  
Pathogenic Bacteria ◽  
Membrane Integrity ◽  
Cell Membrane Integrity ◽  
Modes Of Action ◽  
Alpha Pinene ◽  
Foodborne Pathogenic Bacteria

Background: The current study examined the chemical profile and in vitro antibacterial activity of essential oils (EOs) extracted from Aframomum danielli (leaves and seeds), Aframomum chlamydentum (leaves), and Aframomum melegueta (leaves) against foodborne pathogenic bacteria. Methods: The hydro-distillation technique using a Clevenger-type apparatus was used to extract EOs, whereas the Gas  Chromatography-Mass Spectrometry (GC-MS) and GC coupled to Flame Ionization Detector (GC-FID) allowed the chemical  characterization of oil constituents. The broth micro-dilution method was applied for the determination of the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Besides, some modes of action were studied on the cell membrane integrity and biofilm formation of Salmonella typhi. Results: The major compounds identified from EOs of A. danielli seeds were eucalyptol (48.707%), limonene (11.368%), beta pinene (10.342-10.335%), and alpha terpineol (8.785-9.049%), whereas EOs from A. danielli leaves were dominated by sabinene (42.87%), beta pinene, (11.22%), caryophyllene (7.84%), terpinen-4-ol (5.68%), linalool (3.48%) and gamma terpinene (2.02%). Major volatile markers from EOs of A. chlamydentum leaves comprised beta pinene (49.72%), caryophyllene (10.62%), alpha pinene (6.21%) and linalool (2.96%), while those of EOs from A. melegueta included beta pinene (37.15%), caryophyllene (17.64%), caryophyllene oxide (8.72%) and alpha pinene (8.26%). This study is the first to report on the chemical constituents of EOs from A. chlamydentum. Test oils displayed significant antibacterial activity with the MIC ranging from 0.0625 to 0.5% (v/v). EOs from A. melegueta (leaves) appeared to be the most active, acting against all tested bacteria. All EOs identified displayed bactericidal effects against Citrobacter freundii, a bacterium known to cause a broad range of infections associated with a higher rate of in-hospital mortality. The EOs from A. melegueta may act through perturbation of cell membrane integrity and permeability as well as the inhibition of bacterial biofilm formation. Conclusion: Our findings suggest the possible application of essential oils in agricultural food products for the control of bacterial diseases.

Antibiotics Application Strategies to Control Biofilm Formation in Pathogenic Bacteria

2020 ◽  
Vol 21 (4) ◽  
pp. 270-286 ◽  
Author(s):  
Fazlurrahman Khan ◽  
Dung T.N. Pham ◽  
Sandra F. Oloketuyi ◽  
Young-Mog Kim
Keyword(s):  
Biofilm Formation ◽  
Pathogenic Bacteria ◽  
Extracellular Polymeric Substances ◽  
Quorum Quenching ◽  
Resistance Mechanisms ◽  
Bacterial Biofilm ◽  
Bacterial Cells ◽  
High Concentration ◽  
Biofilm Inhibition ◽  
Abiotic Surfaces

Background: The establishment of a biofilm by most pathogenic bacteria has been known as one of the resistance mechanisms against antibiotics. A biofilm is a structural component where the bacterial community adheres to the biotic or abiotic surfaces by the help of Extracellular Polymeric Substances (EPS) produced by bacterial cells. The biofilm matrix possesses the ability to resist several adverse environmental factors, including the effect of antibiotics. Therefore, the resistance of bacterial biofilm-forming cells could be increased up to 1000 times than the planktonic cells, hence requiring a significantly high concentration of antibiotics for treatment. Methods: Up to the present, several methodologies employing antibiotics as an anti-biofilm, antivirulence or quorum quenching agent have been developed for biofilm inhibition and eradication of a pre-formed mature biofilm. Results: Among the anti-biofilm strategies being tested, the sub-minimal inhibitory concentration of several antibiotics either alone or in combination has been shown to inhibit biofilm formation and down-regulate the production of virulence factors. The combinatorial strategies include (1) combination of multiple antibiotics, (2) combination of antibiotics with non-antibiotic agents and (3) loading of antibiotics onto a carrier. Conclusion: The present review paper describes the role of several antibiotics as biofilm inhibitors and also the alternative strategies adopted for applications in eradicating and inhibiting the formation of biofilm by pathogenic bacteria.

Sign in / Sign up

Export Citation Format

Share Document