Detection of biofilm formation, virulence factors genes, antibiotic-resistance, adherence properties and some beneficial properties of cheese-related S. infantarius, S. gallolyticus, and S. lutetiensis strains belonging to the S. bovis/S. equinus complex

LWT ◽  
2021 ◽  
pp. 112077
Author(s):  
Edibe Rabia Özkan ◽  
Hale İnci Öztürk ◽  
Talha Demirci ◽  
Nihat Akın
Keyword(s):  
Antibiotic Resistance ◽  
Virulence Factors ◽  
Biofilm Formation

scholarly journals Virulence Factors in Coagulase-Negative Staphylococci

Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 170
Author(s):  
Angela França ◽  
Vânia Gaio ◽  
Nathalie Lopes ◽  
Luís D. R. Melo
Keyword(s):  
Antibiotic Resistance ◽  
Virulence Factors ◽  
Resistance Genes ◽  
Biofilm Formation ◽  
Antibiotic Resistance Genes ◽  
Coagulase Negative Staphylococci ◽  
Healthcare Associated ◽  
Major Pathogens

Coagulase-negative staphylococci (CoNS) have emerged as major pathogens in healthcare-associated facilities, being S. epidermidis, S. haemolyticus and, more recently, S. lugdunensis, the most clinically relevant species. Despite being less virulent than the well-studied pathogen S. aureus, the number of CoNS strains sequenced is constantly increasing and, with that, the number of virulence factors identified in those strains. In this regard, biofilm formation is considered the most important. Besides virulence factors, the presence of several antibiotic-resistance genes identified in CoNS is worrisome and makes treatment very challenging. In this review, we analyzed the different aspects involved in CoNS virulence and their impact on health and food.

Virulence Factors of Pseudomonas aeruginosa Isolated from ICU

2021 ◽  
Vol 30 (2) ◽  
pp. 9-14
Author(s):  
Yasser M. Ismail ◽  
Sahar M. Fayed ◽  
Aliaa H. Wehedy
Keyword(s):  
Antibiotic Resistance ◽  
Virulence Factors ◽  
Alkaline Protease ◽  
Biofilm Formation ◽  
Treatment Strategies ◽  
University Hospital ◽  
Disk Diffusion Assay ◽  
Esculin Hydrolysis ◽  
Objective Detection ◽  
Prolonged Hospital

Background: P.aeruginosa has many virulence factors which are the main reason for infection and the emergence of antibiotic resistance leading to an increase of morbidity and mortality. Currently, multidrug resistance is the hardest problem, which made it imperative to search for alternative treatment strategies. Objective: detection of some phenotypic virulence factors of P.aeruginosa isolated from ICU patients and the possibility of any antibiotic resistance related to certain virulence factors released by P. aeruginosa. Methodology: Our study was carried out on patients admitted to ICU Department in Benha University Hospital and infected with P.aeruginosa, the isolates subjected to phenotypic detection of the virulence factors: phospholipase, alkaline protease, lipase, gelatinase, esculin hydrolysis, biofilm formation, hemolysin and DNase production using specific media for each and evaluation of the antibiotic susceptability pattern using Kirby Bauer disk diffusion assay. Results: P.aeruginosa virulence factors were recorded as follow: hemolysin (70%) followed by alkaline protease (68%), phospholipase (62%), gelatinase & biofilm formation (60%) for each, lipase & bile esculin hydrolysis (54%) for each and DNase (2%).High antibiotic resistance was detected to mostly all of the used antibiotic discs. Also, presence of invasive device, prolonged hospital stay, ICU stay and higher number of virulence factors were associated with poor outcome. Conclusions: Production of different phenotypic virulence factors in high amount reflects their important role in spread of infection and pathogenicity with increased antibiotic resistance. Therefore finding anti-virulence factors as adjuvant therapy has an important role in treatment of P. aeruginosa especially MDR isolates.

scholarly journals A Role of Epithelial Cells and Virulence Factors in Biofilm Formation by Streptococcus pyogenes In Vitro

2020 ◽  
Vol 88 (10) ◽  
Author(s):  
Feiruz Alamiri ◽  
Yashuan Chao ◽  
Maria Baumgarten ◽  
Kristian Riesbeck ◽  
Anders P. Hakansson
Keyword(s):  
Antibiotic Resistance ◽  
Epithelial Cells ◽  
Virulence Factors ◽  
Streptococcus Pyogenes ◽  
Biofilm Formation ◽  
Model Systems ◽  
Respiratory Epithelial Cells ◽  
Abiotic Surfaces ◽  
Respiratory Epithelial

ABSTRACT Biofilm formation by Streptococcus pyogenes (group A streptococcus [GAS]) in model systems mimicking the respiratory tract is poorly documented. Most studies have been conducted on abiotic surfaces, which poorly represent human tissues. We have previously shown that GAS forms mature and antibiotic-resistant biofilms on physiologically relevant epithelial cells. However, the roles of the substratum, extracellular matrix (ECM) components, and GAS virulence factors in biofilm formation and structure are unclear. In this study, biofilm formation was measured on respiratory epithelial cells and keratinocytes by determining biomass and antibiotic resistance, and biofilm morphology was visualized using scanning electron microscopy. All GAS isolates tested formed biofilms that had similar, albeit not identical, biomass and antibiotic resistance for both cell types. Interestingly, functionally mature biofilms formed more rapidly on keratinocytes but were structurally denser and coated with more ECM on respiratory epithelial cells. The ECM was crucial for biofilm integrity, as protein- and DNA-degrading enzymes induced bacterial release from biofilms. Abiotic surfaces supported biofilm formation, but these biofilms were structurally less dense and organized. No major role for M protein, capsule, or streptolysin O was observed in biofilm formation on epithelial cells, although some morphological differences were detected. NAD-glycohydrolase was required for optimal biofilm formation, whereas streptolysin S and cysteine protease SpeB impaired this process. Finally, no correlation was found between cell adherence or autoaggregation and GAS biofilm formation. Combined, these results provide a better understanding of the role of biofilm formation in GAS pathogenesis and can potentially provide novel targets for future treatments against GAS infections.

scholarly journals Antibiotic Resistance, Biofilm Formation, and Presence of Genes Encoding Virulence Factors in Strains Isolated from the Pharmaceutical Production Environment

Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 130
Author(s):  
Magdalena Ratajczak ◽  
Dorota Kaminska ◽  
Jolanta Dlugaszewska ◽  
Marzena Gajecka
Keyword(s):  
Antibiotic Resistance ◽  
Virulence Factors ◽  
Antimicrobial Susceptibility ◽  
Biofilm Formation ◽  
Bacterial Resistance ◽  
Susceptibility Testing ◽  
Antimicrobial Susceptibility Testing ◽  
Production Environment ◽  
Genes Encoding ◽  
Pharmaceutical Production

The spread of bacterial resistance to antibiotics affects various areas of life. The aim of this study was to assess the occurrence of Pseudomonas aeruginosa, and other bacteria mainly from orders Enterobacterales and Staphylococcus in the pharmaceutical production sites, and to characterize isolated strains in the aspects of antibiotic resistance, biofilm formation, and presence of genes encoding virulence factors. Genes encoding selected virulence factors were detected using PCR techniques. Antimicrobial susceptibility testing was applied in accordance with the EUCAST recommendations. A total of 46 P. aeruginosa strains were isolated and 85% strains showed a strong biofilm-forming ability. The qualitative identification of genes taking part in Quorum Sensing system demonstrated that over 89% of strains contained lasR and rhlI genes. An antimicrobial susceptibility testing revealed nine strains resistant to at least one antibiotic, and two isolates were the metallo-β-lactamase producers. Moreover, the majority of P. aeruginosa strains contained genes encoding various virulence factors. Presence of even low level of pathogenic microorganisms or higher level of opportunistic pathogens and their toxic metabolites might result in the production inefficiency. Therefore, the prevention of microbial contamination, effectiveness of sanitary and hygienic applied protocols, and constant microbiological monitoring of the environment are of great importance.

scholarly journals Inhibition of Pseudomonas aeruginosa Biofilm Formation with Surface Modified Polymeric Nanoparticles

Pathogens ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 55 ◽  
Author(s):  
Tyler Flockton ◽  
Logan Schnorbus ◽  
Agustin Araujo ◽  
Jill Adams ◽  
Maryjane Hammel ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibiotic Resistance ◽  
Virulence Factors ◽  
Biofilm Formation ◽  
Polymeric Nanoparticles ◽  
Bacterial Pathogen ◽  
Gram Negative ◽  
Treatment Technologies ◽  
New Treatment ◽  
Surface Modified

The gram-negative bacterial pathogen Pseudomonas aeruginosa represents a prominent clinical concern. Due to the observed high levels of antibiotic resistance, copious biofilm formation, and wide array of virulence factors produced by these bacteria, new treatment technologies are required. Here, we present the development of a series of P. aeruginosa LecA-targeted polymeric nanoparticles and demonstrate the anti-adhesion and biofilm inhibitory properties of these constructs.

scholarly journals No Correlation between Biofilm Formation, Virulence Factors, and Antibiotic Resistance in Pseudomonas aeruginosa: Results from a Laboratory-Based In Vitro Study

Antibiotics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1134
Author(s):  
Márió Gajdács ◽  
Zoltán Baráth ◽  
Krisztina Kárpáti ◽  
Dóra Szabó ◽  
Donatella Usai ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibiotic Resistance ◽  
Virulence Factors ◽  
Biofilm Formation ◽  
Bacterial Infections ◽  
Pearson Correlation ◽  
Pigment Production ◽  
Virulence Determinants ◽  
Secretion Systems

Pseudomonas aeruginosa (P. aeruginosa) possesses a plethora of virulence determinants, including the production of biofilm, pigments, exotoxins, proteases, flagella, and secretion systems. The aim of our present study was to establish the relationship between biofilm-forming capacity, the expression of some important virulence factors, and the multidrug-resistant (MDR) phenotype in P. aeruginosa. A total of three hundred and two (n = 302) isolates were included in this study. Antimicrobial susceptibility testing and phenotypic detection of resistance determinants were carried out; based on these results, isolates were grouped into distinct resistotypes and multiple antibiotic resistance (MAR) indices were calculated. The capacity of isolates to produce biofilm was assessed using a crystal violet microtiter-plate based method. Motility (swimming, swarming, and twitching) and pigment-production (pyoverdine and pyocyanin) were also measured. Pearson correlation coefficients (r) were calculated to determine for antimicrobial resistance, biofilm-formation, and expression of other virulence factors. Resistance rates were the highest for ceftazidime (56.95%; n = 172), levofloxacin (54.97%; n = 166), and ciprofloxacin (54.64%; n = 159), while lowest for colistin (1.66%; n = 5); 44.04% (n = 133) of isolates were classified as MDR. 19.87% (n = 60), 20.86% (n = 63) and 59.27% (n = 179) were classified as weak, moderate, and strong biofilm producers, respectively. With the exception of pyocyanin production (0.371 ± 0.193 vs. non-MDR: 0.319 ± 0.191; p = 0.018), MDR and non-MDR isolates did not show significant differences in expression of virulence factors. Additionally, no relevant correlations were seen between the rate of biofilm formation, pigment production, or motility. Data on interplay between the presence and mechanisms of drug resistance with those of biofilm formation and virulence is crucial to address chronic bacterial infections and to provide strategies for their management.

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