scholarly journals Identification of cbiO Gene Critical for Biofilm Formation by MRSA CFSa36 Strain Isolated from Pediatric Patient with Cystic Fibrosis

Pathogens ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1363
Author(s):  
Ying Liu ◽  
Junshu Yang ◽  
Michelle Ji ◽  
James Phillips ◽  
Mark Wylam ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Biofilm Formation ◽  
Detrimental Effect ◽  
Pediatric Patients ◽  
Copper Ions ◽  
Defined Medium ◽  
Dependent Manner ◽  
Iron Ions ◽  
Dose Dependent ◽  
Multiple Antibiotics

The colonization of Staphylococcus aureus, especially methicillin-resistant S. aureus (MRSA), has a detrimental effect on the respiratory care of pediatric patients with cystic fibrosis (CF). In addition to being resistant to multiple antibiotics, S. aureus also has the ability to form biofilms, which makes the infection more difficult to treat and eradicate. In this study, we examined the ability of S. aureus strains isolated from pediatric patients with CF to form biofilms. We screened a transposon mutant library of MRSA and identified a putative cobalt transporter ATP binding domain (CbiO) that is required for biofilm formation. We discovered that deleting cbiO creating a CbiO null mutant in CFSa36 (an MRSA strain isolated from a patient with cystic fibrosis) significantly hinders the ability of CFSa36 to form biofilm. The complementation of CbiO restored the ability of the cbiO deletion mutant to generate biofilm. Interestingly, we revealed that incorporating extra copper ions to the chemically defined medium (CDM) complemented the function of CbiO for biofilm formation in a dose-dependent manner, while the addition of extra iron ions in CDM enhanced the effect of CbiO null mutation on biofilm formation. In addition, neither the addition of certain extra amounts of copper ions nor iron ions in CDM had an impact on bacterial growth. Taken together, our findings suggest that CbiO mediates biofilm formation by affecting the transportation of copper ions in the MRSA CFSa36 strain. This study provides new insights into the molecular basis of biofilm formation by S. aureus.

scholarly journals Efficacy of Synthetic Furanones on Listeria monocytogenes Biofilm Formation

Foods ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 647 ◽  
Author(s):  
Pedro Rodríguez-López ◽  
Andrea Emparanza Barrenengoa ◽  
Sergio Pascual-Sáez ◽  
Marta López Cabo
Keyword(s):  
Listeria Monocytogenes ◽  
Biofilm Formation ◽  
Epifluorescence Microscopy ◽  
Dependent Manner ◽  
Antifouling Activity ◽  
Aisi 316 ◽  
Novel Strategy ◽  
And Control ◽  
Acylated Homoserine Lactones ◽  
Dose Dependent

Furanones are analogues of acylated homoserine lactones with proven antifouling activity in both Gram-positive and Gram-negative bacteria though the interference of various quorum sensing pathways. In an attempt to find new strategies to prevent and control Listeria monocytogenes biofilm formation on stainless steel (SS) surfaces, different concentrations of six synthetic furanones were applied on biofilms formed by strains isolated from food, environmental, and clinical sources grown onto AISI 316 SS coupons. Among the furanones tested, (Z-)-4-Bromo-5-(bromomethylene)-2(5H)-furanone and 3,4-Dichloro-2(5H)-furanone significantly (p < 0.05) reduced the adhesion capacity (>1 log CFU cm−2) in 24 h treated biofilms. Moreover, individually conducted experiments demonstrated that (Z-)-4-Bromo-5-(bromomethylene)-2(5H)-furanone was able to not only significantly (p < 0.05) prevent L. monocytogenes adhesion but also to reduce the growth rate of planktonic cells up to 48 h in a dose-dependent manner. LIVE/DEAD staining followed by epifluorescence microscopy visualisation confirmed these results show an alteration of the structure of the biofilm in furanone-treated samples. Additionally, it was demonstrated that 20 µmol L−1 of 3,4-Dichloro-2(5H)-furanone dosed at 0, 24 and 96 h was able to maintain a lower level of adhered cells (>1 log CFU cm−2; p < 0.05). Since furanones do not pose a selective pressure on bacteria, these results represent an appealing novel strategy for the prevention of L. monocytogenes biofilm grown onto SS.

scholarly journals Comparison of the Effects of Deferiprone versus Deferoxamine on Growth and Virulence of Yersinia enterocolitica

2002 ◽  
Vol 46 (6) ◽  
pp. 1741-1745 ◽  
Author(s):  
Biliana Lesic ◽  
Jeannine Foulon ◽  
Elisabeth Carniel
Keyword(s):  
Chelation Therapy ◽  
Lethal Dose ◽  
Iron Chelation ◽  
Defined Medium ◽  
Dependent Manner ◽  
Chemically Defined Medium ◽  
Mouse Model Of Infection ◽  
Orally Active ◽  
Dose Dependent

ABSTRACT Deferoxamine, a drug used to treat patients with iron overload, has the capacity to promote systemic Y. enterocolitica infections in humans. The aim of this study was to determine whether deferiprone, the only orally active alternative treatment, has the same potential. When Y. enterocolitica IP864 was grown in an iron-poor chemically defined medium, addition of deferoxamine promoted its growth, while various concentrations of deferiprone did not display this activity. Similarly, on iron-poor agar plates, various Y. enterocolitica strains were able to grow around paper disks impregnated with deferoxamine in a dose-dependent manner, while no growth was observed around the deferiprone disks. In a mouse experimental model of infection, the 50% lethal dose (LD50) of strain IP864 was decreased by more than 5 log units in mice pretreated with deferoxamine, while a deferiprone pretreatment did not affect it. Therefore, in contrast to deferoxamine, deferiprone does not enhance growth of pathogenic Y. enterocolitica in vitro and does not have the potential to promote Y. enterocolitica septicemia in a mouse model of infection. Deferiprone may thus represent a useful alternative iron-chelation therapy during invasive Y. enterocolitica infections.

Insulin and transferrin restore important cellular functions of human fetal kidney in serum-free organ culture

1991 ◽  
Vol 69 (4) ◽  
pp. 256-262 ◽  
Author(s):  
Normand Brière ◽  
Joseph Ferrari ◽  
Pierre Chailler
Keyword(s):  
Renal Cortex ◽  
Defined Medium ◽  
Dependent Manner ◽  
Direct Influence ◽  
Fetal Kidney ◽  
Cellular Functions ◽  
Insulin Effect ◽  
Serum Free ◽  
Dose Dependent ◽  
Human Fetal Kidney

A model previously developed in our laboratory to culture human fetal kidneys in serum-free chemically defined medium was used to evaluate the direct influence of potential regulators on nephrogenesis. The aim of the present work was to verify the effects of insulin and transferrin, two hormones considered as essential in other serum-free culture systems. Explants of renal cortex from human fetuses (15–21 weeks) were cultured for 2 and 5 days in serum-free Leibovitz's L-15 medium (37 °C, 95% air – 5% CO2). The addition of transferrin (5 μg/mL) had no effect, but insulin (30, 60, and 125 mU/mL) increased DNA and protein syntheses in a dose-dependent manner. The influence of insulin (125 mU/mL) was potentiated by the addition of transferrin and the combination of the two stimulated DNA synthesis by threefold on day 2 when compared with controls and by sixfold on day 5 of culture. After 5 days, synthesis was restored to values observed at day 0. Transferrin did not modify the insulin effect on protein synthesis, since the latter was already maximally stimulated as early as day 2 of culture and at levels well above that of uncultured explants (day 0). The activities of four hydrolases considered as markers of brush border differentiation were not importantly changed by any of the hormones, supplemented alone or in combination. The results indicate that proliferation rather than differentiation is the parameter mostly influenced by these two hormones. The combination of insulin plus transferrin restores cellular functions of human fetal kidney explants cultured in serum-free medium. The potentiation of insulin influence possibly results from an increase in the number of transferrin receptors. The above additions optimize the present culture system and establish its usefulness as a valuable tool to study the direct influence of different effectors involved in human metanephrogenesis.Key words: insulin, transferrin, culture, nephrogenesis.

scholarly journals Genistein Inhibits the Pathogenesis of Aeromonas hydrophila by Disrupting Quorum Sensing Mediated Biofilm Formation and Aerolysin Production

2021 ◽  
Vol 12 ◽  
Author(s):  
Jing Dong ◽  
Defu Zhang ◽  
Jianrong Li ◽  
Yongtao Liu ◽  
Shun Zhou ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Aeromonas Hydrophila ◽  
Biofilm Formation ◽  
Cell Injury ◽  
Foodborne Pathogen ◽  
Opportunistic Pathogen ◽  
Dependent Manner ◽  
Novel Drugs ◽  
Encoding Gene ◽  
Dose Dependent

Aeromonas hydrophila is an opportunistic pathogen that is responsible for a variety of infectious diseases both in human and animals, particularly aquatic animals. Moreover, the pathogen has become a foodborne pathogen by transmitting from seafood to human. The abuse of antibiotics in aquaculture results in the emergence of antibiotic resistance and treatment failure. Therefore, novel approaches are urgently needed for managing resistant A. hydrophila associated infections. Aerolysin, an essential virulence factor of pathogenic A. hydrophila strain, has been identified as target developing novel drugs against pathogenesis of A. hydrophila. In the present study, genistein, without anti-A. hydrophila activity, was identified that could decrease the production of aerolysin and biofilm formation at a dose-dependent manner. Transcription of aerolysin encoding gene aerA and quorum sensing related genes ahyI and ahyR was significantly down-regulated when co-cultured with genistein. Cell viability studies demonstrated that genistein could significantly improve aerolysin mediated A549 cell injury. Furthermore, genistein could provide a remarkable protection to channel catfish infected with A. hydrophila. These findings indicate that targeting quorum sensing and virulence can be a useful approach developing drugs against A. hydrophila infections in aquaculture. Moreover, genistein can be chosen as a promising candidate in developing drugs against A. hydrophila.

scholarly journals Enhancement of Biofilm Formation by Subinhibitory Concentrations of Macrolides in icaADBC-Positive and -Negative Clinical Isolates of Staphylococcus epidermidis

2010 ◽  
Vol 54 (6) ◽  
pp. 2707-2711 ◽  
Author(s):  
Qian Wang ◽  
Feng-Jun Sun ◽  
Yao Liu ◽  
Li-Rong Xiong ◽  
Lin-Li Xie ◽  
...  
Keyword(s):  
Staphylococcus Epidermidis ◽  
Clinical Relevance ◽  
Biofilm Formation ◽  
Clinical Isolates ◽  
Dependent Manner ◽  
Biofilm Growth ◽  
Subinhibitory Concentrations ◽  
Dose Dependent

ABSTRACT Biofilm formation in Staphylococcus epidermidis is mediated by icaADBC-dependent and -independent pathways. Subinhibitory concentrations of erythromycin, azithromycin, and clarithromycin enhanced, in a dose-dependent manner, the level of biofilm formation by 20% (21/105 isolates) by macrolide-resistant ica-positive and -negative isolates tested in vitro. The presence of ica, however, apparently produced an enhanced effect on biofilm formation. The levels of expression of the biofilm-related genes icaA, atlE, fruA, pyrR, sarA, and sigB were increased in response to erythromycin. The results likely underscore the potential clinical relevance of macrolide-induced biofilm growth.

scholarly journals New Thiazole Nortopsentin Analogues Inhibit Bacterial Biofilm Formation

Marine Drugs ◽  
2018 ◽  
Vol 16 (8) ◽  
pp. 274 ◽  
Author(s):  
Anna Carbone ◽  
Barbara Parrino ◽  
Maria Cusimano ◽  
Virginia Spanò ◽  
Alessandra Montalbano ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Microbial Growth ◽  
Bacterial Biofilm ◽  
Dependent Manner ◽  
Gram Negative ◽  
Ic50 Values ◽  
Planktonic Form ◽  
New Compounds ◽  
Dose Dependent

New thiazole nortopsentin analogues were conveniently synthesized and evaluated for their activity as inhibitors of biofilm formation of relevant Gram-positive and Gram-negative pathogens. All compounds were able to interfere with the first step of biofilm formation in a dose-dependent manner, showing a selectivity against the staphylococcal strains. The most active derivatives elicited IC50 values against Staphylococcus aureus ATCC 25923, ranging from 0.40–2.03 µM. The new compounds showed a typical anti-virulence profile, being able to inhibit the biofilm formation without affecting the microbial growth in the planktonic form.

scholarly journals Evaluation of Origanum vulgare Essential Oil and Its Active Ingredients as Potential Drugs for the Treatment of Toxoplasmosis

2021 ◽  
Vol 11 ◽  
Author(s):  
Na Yao ◽  
Qiong Xu ◽  
Jia-Kang He ◽  
Ming Pan ◽  
Zhao-Feng Hou ◽  
...  
Keyword(s):  
Essential Oil ◽  
Mtt Assay ◽  
Detrimental Effect ◽  
Animal Husbandry ◽  
Dependent Manner ◽  
Origanum Vulgare ◽  
Parasitic Activity ◽  
Dose Dependent ◽  
Better Than

Toxoplasma gondii is a serious hazard to public health and animal husbandry. Due to the current dilemma of treatment of toxoplasmosis, it is urgent to find new anti-T. gondii drugs to treat toxoplasmosis. In this study, the anti-T. gondii activity of Origanum vulgare essential oil (Ov EO) was firstly studied, and then, carvanol (Ca), the main ingredient of Ov EO was evaluated using the MTT assay on human foreskin fibroblast (HFF) cells in vitro. The cytotoxicity was evaluated using the MTT assay on HFF cells. The CC50 of Ov EO and Ca was 134.9 and 43.93 μg/ml, respectively. Both of them exhibited anti-parasitic activity, and inhibited the growth of T. gondii in a dose-dependent manner. For the inhibition effect, Ca was better than Ov EO at the same concentration, the IC50 of Ov EO and Ca was 16.08 and 7.688 μg/ml, respectively. In addition, treatment with Ca, was found to change the morphology of T. gondii tachyzoites and made their shapes curl up. These results showed that Ca was able to inhibit the proliferation of T. gondii by reducing invasion, which may be due to its detrimental effect on the mobility of tachyzoites. Our results indicated that Ca could be a potential new and effective drug for treating toxoplasmosis.

scholarly journals Antibacterial Effects of Bicarbonate in Media Modified to Mimic Cystic Fibrosis Sputum

2020 ◽  
Vol 21 (22) ◽  
pp. 8614
Author(s):  
Pongsiri Jaikumpun ◽  
Kasidid Ruksakiet ◽  
Balázs Stercz ◽  
Éva Pállinger ◽  
Martin Steward ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Biofilm Formation ◽  
Pathogenic Bacteria ◽  
Culture Media ◽  
Anion Channel ◽  
Ambient Air ◽  
Hereditary Disease ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Cell Counts

Cystic fibrosis (CF) is a hereditary disease caused by mutations in the gene encoding an epithelial anion channel. In CF, Cl− and HCO3− hyposecretion, together with mucin hypersecretion, leads to airway dehydration and production of viscous mucus. This habitat is ideal for colonization by pathogenic bacteria. We have recently demonstrated that HCO3− inhibits the growth and biofilm formation of Pseudomonas aeruginosa and Staphylococcus aureus when tested in laboratory culture media. Using the same bacteria our aim was to investigate the effects of HCO3− in artificial sputum medium (ASM), whose composition resembles CF mucus. Control ASM containing no NaHCO3 was incubated in ambient air (pH 7.4 or 8.0). ASM containing NaHCO3 (25 and 100 mM) was incubated in 5% CO2 (pH 7.4 and 8.0, respectively). Viable P. aeruginosa and S. aureus cells were counted by colony-forming unit assay and flow cytometry after 6 h and 17 h of incubation. Biofilm formation was assessed after 48 h. The data show that HCO3− significantly decreased viable cell counts and biofilm formation in a concentration-dependent manner. These effects were due neither to extracellular alkalinization nor to altered osmolarity. These results show that HCO3− exerts direct antibacterial and antibiofilm effects on prevalent CF bacteria.

Fluoride stimulates cystic fibrosis transmembrane conductance regulator Cl− channel activity

1998 ◽  
Vol 274 (3) ◽  
pp. L305-L312 ◽  
Author(s):  
Herbert A. Berger ◽  
Sue M. Travis ◽  
Michael J. Welsh
Keyword(s):  
Cystic Fibrosis ◽  
Single Channel ◽  
Single Channels ◽  
Dependent Manner ◽  
Transmembrane Conductance Regulator ◽  
Transmembrane Conductance ◽  
Binding Domains ◽  
Cytosolic Domains ◽  
Cystic Fibrosis Transmembrane ◽  
Dose Dependent

While studying the regulation of the cystic fibrosis transmembrane conductance regulator (CFTR), we found that addition of F− to the cytosolic surface of excised, inside-out membrane patches reversibly increased Cl− current in a dose-dependent manner. Stimulation required prior phosphorylation and the presence of ATP. F− increased current even in the presence of deferoxamine, which chelates Al3+, suggesting that stimulation was not due to A[Formula: see text]. F− also stimulated current in a CFTR variant that lacked a large part of the R domain, suggesting that the effect was not mediated via this domain. Studies of single channels showed that F−increased the open-state probability by slowing channel closure from bursts of activity; the mean closed time between bursts and single-channel conductance was not altered. These results suggested that F− influenced regulation by the cytosolic domains, most likely the nucleotide-binding domains (NBDs). Consistent with this, we found that mutation of a conserved Walker lysine in NBD2 changed the relative stimulatory effect of F− compared with wild-type CFTR, whereas mutation of the Walker lysine in NBD1 had no effect. Based on these and previous data, we speculate that F− interacts with CFTR, possibly via NBD2, and slows the rate of channel closure.

scholarly journals Vitamin D represses rhinovirus replication in cystic fibrosis cells by inducing LL-37

2015 ◽  
Vol 47 (2) ◽  
pp. 520-530 ◽  
Author(s):  
Aline Schögler ◽  
Ricardo J. Muster ◽  
Elisabeth Kieninger ◽  
Carmen Casaulta ◽  
Caroline Tapparel ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Vitamin D ◽  
Viral Load ◽  
Inverse Correlation ◽  
Dependent Manner ◽  
Bronchial Epithelial ◽  
Immunomodulatory Properties ◽  
Anti Inflammatory ◽  
Dose Dependent ◽  
Primary Bronchial Epithelial Cells

Vitamin D has immunomodulatory properties in the defence against pathogens. Its insufficiency is a widespread feature of cystic fibrosis (CF) patients, which are repeatedly suffering from rhinovirus (RV)-induced pulmonary exacerbations.To investigate whether vitamin D has antiviral activity, primary bronchial epithelial cells from CF children were pre-treated with vitamin D and infected with RV16. Antiviral and anti-inflammatory activity of vitamin D was assessed. RV and LL-37 levels were measured in bronchoalveolar lavage (BAL) of CF children infected with RV.Vitamin D reduced RV16 load in a dose-dependent manner in CF cells (10−7 M, p<0.01). The antiviral response mediated by interferons remained unchanged by vitamin D in CF cells. Vitamin D did not exert anti-inflammatory properties in RV-infected CF cells. Vitamin D increased the expression of the antimicrobial peptide LL-37 up to 17.4-fold (p<0.05). Addition of exogenous LL-37 decreased viral replication by 4.4-fold in CF cells (p<0.05). An inverse correlation between viral load and LL-37 levels in CF BAL (r=−0.48, p<0.05) was observed.RV replication in primary CF bronchial cells was reduced by vitamin D through the induction of LL-37. Clinical studies are needed to determine the importance of an adequate control of vitamin D for prevention of virus-induced pulmonary CF exacerbations.

Sign in / Sign up

Export Citation Format

Share Document