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1.
J Appl Microbiol ; 135(5)2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38649930

RESUMEN

AIM: Corallococcus species are diverse in the natural environment with 10 new Corallococcus species having been characterized in just the last 5 years. As well as being an abundant myxobacterial genus, they produce several secondary metabolites, including Corallopyronin, Corramycin, Coralmycin, and Corallorazine. We isolated a novel strain Corallococcus spp RDP092CA from soil in South Wales, UK, using Candida albicans as prey bait and characterized its predatory activities against pathogenic bacteria and yeast. METHODS AND RESULTS: The size of the RDP092CA genome was 8.5 Mb with a G + C content of 71.4%. Phylogenetically, RDP092CA is closely related to Corallococcus interemptor, C. coralloides, and C. exiguus. However, genome average nucleotide identity and digital DNA-DNA hybridization values are lower than 95% and 70% when compared to those type strains, implying that it belongs to a novel species. The RDP092CA genome harbours seven types of biosynthetic gene clusters (BGCs) and 152 predicted antimicrobial peptides. In predation assays, RDP092CA showed good predatory activity against Escherichia coli, Pseudomonas aeruginosa, Citrobacter freundii, and Staphylococcus aureus but not against Enterococcus faecalis. It also showed good antibiofilm activity against all five bacteria in biofilm assays. Antifungal activity against eight Candida spp. was variable, with particularly good activity against Meyerozyma guillermondii DSM 6381. Antimicrobial peptide RDP092CA_120 exhibited potent antibiofilm activity with >50% inhibition and >60% dispersion of biofilms at concentrations down to 1 µg/ml. CONCLUSIONS: We propose that strain RDP092CA represents a novel species with promising antimicrobial activities, Corallococcus senghenyddensis sp. nov. (=NBRC 116490T =CCOS 2109T), based on morphological, biochemical, and genomic features.


Asunto(s)
Myxococcales , Filogenia , Myxococcales/genética , Myxococcales/metabolismo , Myxococcales/aislamiento & purificación , Composición de Base , Genoma Bacteriano , Microbiología del Suelo , Antiinfecciosos/farmacología , Pruebas de Sensibilidad Microbiana , Candida albicans/efectos de los fármacos , Familia de Multigenes , ADN Bacteriano/genética , ARN Ribosómico 16S/genética
2.
Int J Mol Sci ; 25(20)2024 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-39456652

RESUMEN

Galangal (Alpinia galanga (L.) Willd) and bitter ginger (Zingiber zerumbet (L.) Roscoe) are aromatic rhizomatous plants that are typically used for culinary purposes. These rhizomatous plants have many biological properties and the potential to be beneficial for pharmaceutics. In this study, we evaluated the antioxidant and antimicrobial activities, with a specific focus on acne-causing bacteria, as well as the phytochemical constituents, of different parts of galangal and bitter ginger. The rhizomes, stems, and leaves of galangal and bitter ginger were separately dried for absolute ethanol and methanol extractions. The extracts were used to evaluate the antioxidant activity using a DPPH radical scavenging assay (0.005-5000 µg/mL), antimicrobial activity against acne-causing bacteria (0.50-31.68 mg/mL), and in vitro cytotoxicity toward human keratinocytes and fibroblasts (62.5-1000 µg/mL), as well as analyses of bioactive phytochemicals via GC-MS and LC-MS/MS (500 ppm). The ethanol and methanol extracts of bitter ginger and galangal's rhizomes (BRhE, BRhM, GRhE, and GRhM), stems (BStE, BStM, GRhE, and GRhM), and leaves (BLeE, BLeM, GLeE, and GLeM), respectively, showed antioxidant and antimicrobial activities. The extracts of all parts of bitter ginger and galangal were greatly antioxidative with 0.06-1.42 mg/mL for the IC50 values, while most of the extracts were strongly antimicrobial against C. acnes DMST 14916, particularly BRhM, BRhE, GRhM, and GRhE (MICs: 3.96-7.92 mg/mL). These rhizome extracts had also antimicrobial activities against S. aureus TISTR 746 (MICs: 7.92-31.68 mg/mL) and S. epidermidis TISTR 518 (MICs: 7.92-15.84 mg/mL). The extracts of bitter ginger and galangal rhizomes were not toxic to HaCaT and MRC-5 even at the highest concentrations. Through GC-MS and LC-MS/MS analysis, phytochemicals in bitter ginger rhizome extracts, including zerumbone, tectorigenin, piperic acid, demethoxycurcumin, and cirsimaritin, and galangal rhizome extracts, including sweroside and neobavaisoflavone, were expected to provide the antioxidant and anti-microbial activities. Therefore, the results suggest that the bitter ginger and galangal extracts could be natural anti-acne compounds with potential for pharmaceutic, cosmetic, and aesthetic applications.


Asunto(s)
Antioxidantes , Queratinocitos , Pruebas de Sensibilidad Microbiana , Fitoquímicos , Extractos Vegetales , Zingiber officinale , Extractos Vegetales/farmacología , Extractos Vegetales/química , Humanos , Fitoquímicos/farmacología , Fitoquímicos/química , Antioxidantes/farmacología , Antioxidantes/química , Zingiber officinale/química , Queratinocitos/efectos de los fármacos , Acné Vulgar/tratamiento farmacológico , Acné Vulgar/microbiología , Antibacterianos/farmacología , Antibacterianos/química , Rizoma/química , Zingiberaceae/química , Fibroblastos/efectos de los fármacos , Antiinfecciosos/farmacología , Antiinfecciosos/química
3.
J Appl Microbiol ; 132(1): 715-724, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34319637

RESUMEN

AIMS: The effectiveness of commercially available wound dressings and a HOCl gel formulation was tested against two- and five-species biofilms in a dynamic in vitro chronic wound infection model. METHOD: Two-species biofilms (Pseudomonas aeruginosa and Staphylococcus aureus) were cultured using a biofilm flow device and treated with wound dressings containing silver, iodine, polyhexamethylene biguanide, crystal violet or HOCl gel at 5 h. Five-species biofilms (P. aeruginosa, S. aureus, Enterococcus faecalis, Streptococcus pyogenes and Escherichia coli) were similarly cultured and treated with HOCl gel at 5 and 24 h. Multidose experiments used two- and five-species biofilms with HOCl applied at 24, 48 and 72 h. RESULTS: None of the treatments completely disrupted the biofilms and, with the exception of silver, bacteria recovered in number post-treatment. HOCl was most effective when applied to 24 h established biofilms with most activity against P. aeruginosa. Recovery post-treatment was negligible with HOCl applied at 24 h and multiple doses indicated that bacteria were not becoming tolerant to treatment. CONCLUSIONS: Realistic models are necessary to test the effectiveness of antimicrobial wound treatments to ensure findings are clinically translatable. HOCl gel shows promise as a new topical antimicrobial for wounds, especially due to its ability to inhibit P. aeruginosa. SIGNIFICANCE AND IMPACT OF THE STUDY: This study highlights a need for robust in vitro data to support development and use of wound treatments that can only be obtained from the refinement of realistic infection models. Furthermore, it indicates the potential use of HOCl gel for chronic wound management.


Asunto(s)
Antiinfecciosos , Infección de Heridas , Antiinfecciosos/farmacología , Biopelículas , Humanos , Pseudomonas aeruginosa , Staphylococcus aureus , Infección de Heridas/tratamiento farmacológico
4.
J Mater Sci Mater Med ; 31(3): 33, 2020 Mar 11.
Artículo en Inglés | MEDLINE | ID: mdl-32162052

RESUMEN

All chronic wounds are colonised by bacteria; for some, colonisation progresses to become infection. Alginate wound dressings are used for highly exuding chronic wounds as they are very absorbent, taking up large quantities of exudate while maintaining a moist wound bed to support healing. Some alginate dressings are doped with antimicrobials, most commonly silver, but evidence regarding the efficacy of these is largely inconclusive. This manuscript describes the development and in vitro assessment of alginate materials doped with chlorhexidine hexametaphosphate (CHX-HMP), a sparingly soluble salt which when exposed to aqueous environments provides sustained release of the common antiseptic chlorhexidine. Comparator materials were a commercial silver alginate dressing material and an alginate doped with chlorhexidine digluconate (CHXdg). CHX-HMP alginates provided a dose-dependent CHX release which was sustained for over 14 days, whereas CHXdg alginates released limited CHX and this ceased within 24 h. CHX-HMP and silver alginates were efficacious against 5 major wound pathogens (MRSA, E. coli, P. aeruginosa, K. pneumoniae, A. baumannii) in a total viable count (TVC) and an agar diffusion zone of inhibition (ZOI) model. At baseline the silver alginate was more effective than the CHX-HMP alginate in the TVC assay but the CHX-HMP alginate was the more effective in the ZOI assay. After 7 days' artificial aging the CHX-HMP alginate was more effective than the silver alginate for four of the five bacteria tested in both assays. These materials may ultimately find application in the development of wound dressings for chronic wounds that provide sustained antimicrobial protection.


Asunto(s)
Alginatos/química , Antibacterianos/farmacología , Clorhexidina/farmacología , Fosfatos/química , Acinetobacter baumannii/efectos de los fármacos , Agar , Antiinfecciosos Locales/farmacología , Vendajes , Difusión , Escherichia coli/efectos de los fármacos , Klebsiella pneumoniae/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Microscopía de Fuerza Atómica , Tamaño de la Partícula , Pseudomonas aeruginosa/efectos de los fármacos , Plata/química , Espectroscopía Infrarroja por Transformada de Fourier , Cicatrización de Heridas
5.
J Antimicrob Chemother ; 70(3): 716-25, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25404649

RESUMEN

OBJECTIVES: Manuka honey is a broad-spectrum antimicrobial agent that seems to affect different bacteria in many different ways. It has been shown to be bactericidal against Pseudomonas aeruginosa by destabilizing the cell wall, but we aimed to investigate whether there were further intracellular target sites. METHODS: In this study inhibitory effects of manuka honey on P. aeruginosa were investigated using hydrophobicity assays, two-dimensional electrophoresis, quantitative RT-PCR, transmission electron microscopy and motility assays. RESULTS: Exposure of P. aeruginosa to manuka honey reduced both swarming and swimming motility. Moreover, this was a consequence of de-flagellation of the bacterial cell, which was correlated with decreased expression of the major structural flagellin protein, FliC, and concurrent suppression of flagellin-associated genes, including fliA, fliC, flhF, fleN, fleQ and fleR. The differential expression of the flagellar regulon in the presence of manuka honey was mapped schematically. Flagella are integral to bacterial adhesion, the initiation of infection and biofilm formation, and swarming has been associated with increased virulence. CONCLUSIONS: By limiting motility in vitro, we infer that manuka honey impacts on the virulence of P. aeruginosa. This deduction must now be tested in vivo.


Asunto(s)
Antiinfecciosos/farmacología , Flagelos/efectos de los fármacos , Regulación Bacteriana de la Expresión Génica/efectos de los fármacos , Miel , Locomoción/efectos de los fármacos , Pseudomonas aeruginosa/efectos de los fármacos , Electroforesis en Gel Bidimensional , Flagelos/fisiología , Perfilación de la Expresión Génica , Genes Bacterianos/efectos de los fármacos , Pseudomonas aeruginosa/fisiología , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
6.
Ann Clin Microbiol Antimicrob ; 13: 19, 2014 May 12.
Artículo en Inglés | MEDLINE | ID: mdl-24884949

RESUMEN

BACKGROUND: Medical grade manuka honeys are well known to be efficacious against Pseudomonas aeruginosa being bactericidal and inhibiting the development of biofilms; moreover manuka honey effectively kills P. aeruginosa embedded within an established biofilm. Sustained honey resistance has not been previously documented for planktonic or biofilm P. aeruginosa. METHODS: Minimum inhibitory concentrations for manuka honey and antibiotics were determined using broth micro-dilution methods. Minimum biofilm eliminating concentrations (MBEC) and biofilm biomass were determined using the crystal violet method. Sub-culture used non-selective media and the grid-plate method. RESULTS: When honey treated biofilm biomass of two strains of P. aeruginosa (reference strain ATCC 9027 and the clinical isolate 867) were sub-cultured onto non-selective media isolates emerged that exhibited reduced susceptibility to manuka honey. Significantly, this characteristic was sustained with repeated sub-culture onto non-selective media resulting in increased minimum inhibitory concentrations (MIC) of between 5-7% (w/v) and increased minimum biofilm eliminating concentrations (MBEC) of up to 15% (w/v). Interestingly the resistant isolates showed reduced susceptibility to antibiotic treatment with rifampicin and imipenem as well as being more prolific biofilm-formers than the progenitor strains. CONCLUSIONS: P. aeruginosa biofilms treated with manuka honey equivalent to the MBEC harbour slow growing, viable persistor organisms that exhibit sustained, increased resistance to manuka honey and antibiotic treatment, suggesting a shared mechanism of resistance. This sheds new light on the propensity for biofilm embedded organisms to resist honey treatment and become persistor organisms that are tolerant to other antimicrobial therapies.


Asunto(s)
Antibacterianos/metabolismo , Biopelículas/efectos de los fármacos , Farmacorresistencia Bacteriana , Miel , Pseudomonas aeruginosa/efectos de los fármacos , Pseudomonas aeruginosa/fisiología , Biopelículas/crecimiento & desarrollo , Pruebas de Sensibilidad Microbiana , Pseudomonas aeruginosa/crecimiento & desarrollo
7.
ACS Omega ; 9(9): 10201-10206, 2024 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-38463253

RESUMEN

Superabsorbent polymer (SAP) granules, typically used in personal care devices such as diapers, incontinence devices, hygiene pads, and wound dressings, and granular particles of zeolite and bentonite were each subjected to modification by exposure to solutions of 1-chloro-2,2,5,5-tetramethyl-4-imidazolidinone (MC) in ethanol at room temperature. The air-dried granules showed newly acquired properties attributable to the presence of active chlorine (Cl+). The treated particles effectively oxidized the malodorant 3-mercapto-3-methylbutanol (3M3MB). MC-treated granules inactivated urease, a microbial exoenzyme commonly involved in ammonia production. Modified SAP granules and superabsorbent fibers (SAFs) showed powerful antibacterial activity in an in vitro chronic wound model. The results suggest that processing of SAP granules and SAFs by this simple method at an industrial scale could add value to their widespread use in a variety of personal hygiene devices and specifically to the improvement of chronic wound care.

8.
Pathogens ; 12(1)2023 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-36678466

RESUMEN

Understanding chronic wound infection is key for successful treatment and requires accurate laboratory models. We describe a modified biofilm flow device that effectively mimics the chronic wound environment, including simulated wound fluid, a collagen-based 3D biofilm matrix, and a five-species mixture of clinically relevant bacteria (Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, Enterococcus faecalis, and Citrobacter freundii). Mixed biofilms were cultured for between 3 and 14 days with consistent numbers of bacteria that exhibited reduced metabolic activity, which increased with a high dose of glucose. S. aureus was recovered from biofilms as a small colony variant, but as a normal colony variant if P. aeruginosa was excluded from the system. Bacteria within the biofilm did not co-aggregate but formed discrete, species-specific clusters. Biofilms demonstrated differential tolerance to the topical antimicrobials Neosporin and HOCl, consistent with protection due to the biofilm lifestyle. The characteristics exhibited within this model match those of real-world wound biofilms, reflecting the clinical scenario and yielding a powerful in vitro tool that is versatile, inexpensive, and pivotal for understanding chronic wound infection.

9.
Mol Microbiol ; 81(4): 1034-49, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21736640

RESUMEN

The streptococcal antigen I/II (AgI/II)-family polypeptides are cell wall-anchored adhesins expressed by most indigenous oral streptococci. Proteins sharing 30-40% overall amino acid sequence similarities with AgI/II-family proteins are also expressed by Streptococcus pyogenes. The S. pyogenes M28_Spy1325 polypeptide (designated AspA) displays an AgI/II primary structure, with alanine-rich (A) and proline-rich (P) repeats flanking a V region that is projected distal from the cell. In this study it is shown that AspA from serotype M28 S. pyogenes, when expressed on surrogate host Lactococcus lactis, confers binding to immobilized salivary agglutinin gp-340. This binding was blocked by antibodies to the AspA-VP region. In contrast, the N-terminal region of AspA was deficient in binding fluid-phase gp-340, and L. lactis cells expressing AspA were not agglutinated by gp-340. Deletion of the aspA gene from two different M28 strains of S. pyogenes abrogated their abilities to form biofilms on saliva-coated surfaces. In each mutant strain, biofilm formation was restored by trans complementation of the aspA deletion. In addition, expression of AspA protein on the surface of L. lactis conferred biofilm-forming ability. Taken collectively, the results provide evidence that AspA is a biofilm-associated adhesin that may function in host colonization by S. pyogenes.


Asunto(s)
Adhesinas Bacterianas/metabolismo , Proteínas Bacterianas/metabolismo , Biopelículas/crecimiento & desarrollo , Streptococcus pyogenes/fisiología , Eliminación de Gen , Prueba de Complementación Genética , Lactococcus lactis/genética , Unión Proteica , Mapeo de Interacción de Proteínas , Proteínas y Péptidos Salivales/metabolismo , Streptococcus pyogenes/crecimiento & desarrollo , Streptococcus pyogenes/metabolismo
10.
Microbiology (Reading) ; 158(Pt 3): 781-790, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22294681

RESUMEN

Streptococcus pyogenes (group A Streptococcus; GAS) is always of clinical significance in wounds where it can initiate infection, destroy skin grafts and persist as a biofilm. Manuka honey has broad spectrum antimicrobial activity and its use in the clinical setting is beginning to gain acceptance with the continuing emergence of antibiotic resistance and the inadequacy of established systemic therapies; novel inhibitors may affect clinical practice. In this study, the effect of manuka honey on S. pyogenes (M28) was investigated in vitro with planktonic and biofilm cultures using MIC, MBC, microscopy and aggregation efficiency. Bactericidal effects were found in both planktonic cultures and biofilms, although higher concentrations of manuka honey were needed to inhibit biofilms. Abrogation of adherence and intercellular aggregation was observed. Manuka honey permeated 24 h established biofilms of S. pyogenes, resulting in significant cell death and dissociation of cells from the biofilm. Sublethal concentrations of manuka honey effectively prevented the binding of S. pyogenes to the human tissue protein fibronectin, but did not inhibit binding to fibrinogen. The observed inhibition of fibronectin binding was confirmed by a reduction in the expression of genes encoding two major fibronectin-binding streptococcal surface proteins, Sof and SfbI. These findings indicate that manuka honey has potential in the topical treatment of wounds containing S. pyogenes.


Asunto(s)
Adhesinas Bacterianas/biosíntesis , Biopelículas/efectos de los fármacos , Biopelículas/crecimiento & desarrollo , Expresión Génica/efectos de los fármacos , Miel , Streptococcus pyogenes/efectos de los fármacos , Streptococcus pyogenes/crecimiento & desarrollo , Antibacterianos/farmacología , Humanos , Leptospermum/química , Pruebas de Sensibilidad Microbiana , Viabilidad Microbiana/efectos de los fármacos
11.
Microbiology (Reading) ; 158(Pt 12): 3005-3013, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23082035

RESUMEN

The presence of Pseudomonas aeruginosa in cutaneous wounds is of clinical significance and can lead to persistent infections. Manuka honey has gained ground in clinical settings due to its effective therapeutic action and broad spectrum of antibacterial activity. In this study, the effect of manuka honey on P. aeruginosa was investigated using MIC, MBC, growth kinetics, confocal microscopy, atomic force microscopy and real-time PCR. A bactericidal mode of action for manuka honey against P. aeruginosa was deduced (12 %, w/v, MIC; 16 %, w/v, MBC) and confirmed by confocal and atomic force microscopy, which showed extensive cell lysis after 60 min exposure to inhibitory concentrations of manuka honey. The inability of honey-treated cells to form microcolonies was demonstrated and investigated using Q-PCR for three key microcolony-forming genes: algD, lasR and oprF. The expression of algD increased 16-fold whereas oprF expression decreased 10-fold following honey treatment; lasR expression remained unaltered. These findings confirm that manuka honey is effective at inducing cell lysis and identify two targets, at the genetic level, that might be involved in this process.


Asunto(s)
Antibacterianos/metabolismo , Proteínas Bacterianas/biosíntesis , Deshidrogenasas de Carbohidratos/biosíntesis , Regulación Bacteriana de la Expresión Génica/efectos de los fármacos , Miel , Pseudomonas aeruginosa/efectos de los fármacos , Bacteriólisis/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Viabilidad Microbiana/efectos de los fármacos , Microscopía de Fuerza Atómica , Microscopía Confocal , Reacción en Cadena en Tiempo Real de la Polimerasa , Transactivadores/biosíntesis
12.
Microorganisms ; 10(11)2022 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-36422349

RESUMEN

The presence of biofilm within a chronic wound may delay the healing process. Thus, control of biofilm formation and providing bactericidal effect are crucial factors for wound healing management. Alginate-based nanocomposite hydrogels have been suggested as dressing materials for wound treatment, which are employed as a biocompatible matrix. Therefore, in this study, we aimed to develop a biocompatible antimicrobial wound dressing containing AgNPs and demonstrate its efficacy against polymicrobial wound biofilms by using a biofilm flow device to simulate a chronic infected, exuding wound and specific wound environment. The results from agar well diffusion, the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) assays showed that TA-AgNPs exhibited antibacterial activity against wound pathogens. Additionally, the Minimum Biofilm Eradication Concentration assay (MBEC) demonstrated it could impair biofilm formation. Importantly, our TA-AgNPs/Alginate hydrogel clearly showed antibacterial activities against Streptococcus pyogenes, Staphylococcus aureus and Pseudomonas aeruginosa. Furthermore, we used the biofilm flow device to test the topical antimicrobial hydrogel against a three-species biofilm. We found that TA-AgNPs/Alginate hydrogel significantly showed a 3-4 log reduction in bacterial numbers when applied with multiple doses at 24 h intervals, and was especially effective against the chronic wound pathogen P. aeruginosa. This work highlighted that the TA-AgNPs/Alginate hydrogel is a promising material for treating complex wound biofilms.

13.
Mol Microbiol ; 77(2): 276-86, 2010 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-20497507

RESUMEN

Streptococcus mutans antigen I/II (AgI/II) protein was one of the first cell wall-anchored adhesins identified in Gram-positive bacteria. It mediates attachment of S. mutans to tooth surfaces and has been a focus for immunization studies against dental caries. The AgI/II family polypeptides recognize salivary glycoproteins, and are also involved in biofilm formation, platelet aggregation, tissue invasion and immune modulation. The genes encoding AgI/II family polypeptides are found among Streptococcus species indigenous to the human mouth, as well as in Streptococcus pyogenes, S. agalactiae and S. suis. Evidence of functionalities for different regions of the AgI/II proteins has emerged. A sequence motif within the C-terminal portion of Streptococcus gordonii SspB (AgI/II) is bound by Porphyromonas gingivalis, thus promoting oral colonization by this anaerobic pathogen. The significance of other epitopes is now clearer following resolution of regional crystal structures. A new picture emerges of the central V (variable) region, predicted to contain a carbohydrate-binding trench, being projected from the cell surface by a stalk formed by an unusual association between an N-terminal alpha-helix and a C-terminal polyproline helix. This presentation mode might be important in determining functional conformations of other Gram-positive surface proteins that have adhesin domains flanked by alpha-helical and proline-rich regions.


Asunto(s)
Adhesinas Bacterianas/química , Proteínas Bacterianas/química , Streptococcus/química , Epítopos/química , Modelos Moleculares , Estructura Terciaria de Proteína , Análisis de Secuencia de Proteína
14.
Clin Microbiol Infect ; 27(11): 1697.e1-1697.e5, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34186210

RESUMEN

OBJECTIVES: To determine the presence and genotypic macrolide susceptibility of Mycoplasma amphoriforme, and the presence of Ureaplasma spp. and Mycoplasma fermentans among clinical samples from England previously investigated for Mycoplasma pneumoniae. METHODS: Quantitative and conventional PCR methods were used to retrospectively screen a collection of 160 clinical samples previously submitted to Public Health England (PHE) for the detection of M. pneumoniae between October 2016 and December 2017. Samples which were positive for M. amphoriforme DNA were further investigated for mutations associated with genotypic macrolide resistance by sequencing domain V of the 23s rRNA. RESULTS: M. amphoriforme was detected in 10/160 samples (6.3%), Ureaplasma parvum was detected in 4/160 samples (2.5%), and M. fermentans was not detected in any samples (0/160). Of the nine individuals (two samples were from the same patient) in which M. amphoriforme was detected, eight were male (age range 10-60 years) and one was female (age range 30-40 years). One individual with cystic fibrosis was positive for both M. amphoriforme and U. parvum. All M. amphoriforme DNA was genotypically susceptible to macrolides. CONCLUSIONS: Mycoplasma amphoriforme was found in clinical samples, including lower respiratory tract samples of patients with pneumonia. In the absence of other respiratory pathogens, these data suggest a potential role for this organism in human disease, with no evidence of acquired macrolide resistance. Ureaplasma parvum was detected in cerebrospinal fluid and respiratory tract samples. These data suggest that there is a need to consider these atypical respiratory pathogens in future diagnostic investigations.


Asunto(s)
Infecciones por Mycoplasma , Mycoplasma fermentans , Mycoplasma/aislamiento & purificación , Ureaplasma/aislamiento & purificación , Adolescente , Adulto , Antibacterianos/farmacología , Niño , Farmacorresistencia Bacteriana/genética , Femenino , Humanos , Macrólidos/farmacología , Masculino , Persona de Mediana Edad , Mycoplasma/efectos de los fármacos , Mycoplasma/genética , Infecciones por Mycoplasma/epidemiología , Mycoplasma fermentans/efectos de los fármacos , Mycoplasma fermentans/genética , Mycoplasma fermentans/aislamiento & purificación , Estudios Retrospectivos , Ureaplasma/efectos de los fármacos , Ureaplasma/genética , Adulto Joven
15.
Microbiol Res ; 215: 141-147, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-30172300

RESUMEN

Several models exist for the study of chronic wound infection, but few combine all of the necessary elements to allow high throughput, reproducible biofilm culture with the possibility of applying topical antimicrobial treatments. Furthermore, few take into account the appropriate means of providing nutrients combined with biofilm growth at the air-liquid interface. In this manuscript, a new biofilm flow device for study of wound biofilms is reported. The device is 3D printed, straightforward to operate, and can be used to investigate single and mixed species biofilms, as well as the efficacy of antimicrobial dressings. Single species biofilms of Staphylococcus aureus or Pseudomonas aeruginosa were reproducibly cultured over 72 h giving consistent log counts of 8-10 colony forming units (CFU). There was a 3-4 log reduction in recoverable bacteria when antimicrobial dressings were applied to biofilms cultured for 48 h, and left in situ for a further 24 h. Two-species biofilms of S. aureus and P. aeruginosa inoculated at a 1:1 ratio, were also reproducibly cultured at both 20 °C and 37 °C; of particular note was a definitive Gram-negative shift within the population that occurred only at 37 °C.


Asunto(s)
Antiinfecciosos/farmacología , Vendajes , Biopelículas/efectos de los fármacos , Biopelículas/crecimiento & desarrollo , Infección de Heridas , Alginatos , Técnicas de Cultivo de Célula/instrumentación , Técnicas de Cultivo de Célula/métodos , Clorhexidina , Recuento de Colonia Microbiana , Diseño Asistido por Computadora , Diseño de Equipo , Ácido Glucurónico , Ácidos Hexurónicos , Infecciones por Pseudomonas/microbiología , Pseudomonas aeruginosa/efectos de los fármacos , Pseudomonas aeruginosa/crecimiento & desarrollo , Infecciones Estafilocócicas/microbiología , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/crecimiento & desarrollo
16.
FEMS Microbiol Lett ; 365(10)2018 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-29659799

RESUMEN

Hepcidin belongs to the antimicrobial peptide family but has weak activity with regards to bacterial killing. The regulatory function of hepcidin in humans serves to maintain an iron-restricted environment that limits the growth of pathogens; this study explored whether hepcidin affected bacterial iron homeostasis and oxidative stress using the model organism Escherichia coli. Using the Miller assay it was determined that under low iron availability exposure to sub-inhibitory doses of hepcidin (4-12µM) led to 2-fold and 4-fold increases in the expression of ftnA and bfd, respectively (P < 0.05), in both a wild type (WT) and Δfur (ferric uptake regulator) background. Quantitative real-time PCR analysis of oxyR and sodA, treated with 4 or 8 µM of hepcidin showed that expression of these genes was significantly (P < 0.05) increased, whereas expression of lexA was unchanged, indicating that hepcidin likely mediated oxidative stress but did not induce DNA damage.


Asunto(s)
Infecciones por Escherichia coli/microbiología , Escherichia coli/metabolismo , Regulación Bacteriana de la Expresión Génica/efectos de los fármacos , Hepcidinas/farmacología , Hierro/metabolismo , Estrés Oxidativo/efectos de los fármacos , Escherichia coli/efectos de los fármacos , Escherichia coli/genética , Infecciones por Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Ferritinas/genética , Ferritinas/metabolismo , Hepcidinas/metabolismo , Homeostasis/efectos de los fármacos , Humanos , Proteínas Represoras/genética , Proteínas Represoras/metabolismo
17.
Pathog Dis ; 76(1)2018 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-29342260

RESUMEN

Debate regarding the co-existence of Staphylococcus aureus and Pseudomonas aeruginosa in wounds remains contentious, with the dominant hypothesis describing a situation akin to niche partitioning, whereby both microorganisms are present but occupy distinct regions of the wound without interacting. In contrast, we hypothesised that these microorganisms do interact during early co-colonisation in a manner beneficial to both bacteria. We assessed competitive interaction between S. aureus and P. aeruginosa in biofilm cultured for 24-72 h and bacterial aggregates analogous to those observed in early (<24 h) biofilm formation, and interaction with human keratinocytes. We observed that S. aureus predominated in biofilm and non-attached bacterial aggregates, acting as a pioneer for the attachment of P. aeruginosa. We report for the first time that S. aureus mediates a significant (P < 0.05) increase in the attachment of P. aeruginosa to human keratinocytes, and that P. aeruginosa promotes an invasive phenotype in S. aureus. We show that co-infected keratinocytes exhibit an intermediate inflammatory response concurrent with impaired wound closure that is in keeping with a sustained proinflammatory response which allows for persistent microbial colonisation. These studies demonstrate that, contrary to the dominant hypothesis, interactions between S. aureus and P. aeruginosa may be an important factor for both colonisation and pathogenicity in the chronic infected wound.


Asunto(s)
Biopelículas/crecimiento & desarrollo , Interacciones Microbianas , Pseudomonas aeruginosa/crecimiento & desarrollo , Staphylococcus aureus/crecimiento & desarrollo , Adhesión Bacteriana , Línea Celular , Coinfección/microbiología , Coinfección/patología , Citocinas/metabolismo , Ensayo de Inmunoadsorción Enzimática , Humanos , Queratinocitos/inmunología , Queratinocitos/microbiología , Modelos Biológicos , Infecciones por Pseudomonas/microbiología , Infecciones por Pseudomonas/patología , Pseudomonas aeruginosa/fisiología , Infecciones Estafilocócicas/microbiología , Infecciones Estafilocócicas/patología , Staphylococcus aureus/fisiología
18.
Genome Announc ; 5(48)2017 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-29192089

RESUMEN

Pseudomonas aeruginosa ATCC 9027 was isolated in 1943 from a case of otitis externa and is commonly employed as a quality control strain for sterility, assessment of antibiofilm agents, and in vitro study of wound infection. Here, we present the 6.34-Mb draft genome sequence and highlight some pertinent genes that are associated with virulence.

19.
Microbiol Spectr ; 4(2)2016 04.
Artículo en Inglés | MEDLINE | ID: mdl-27227296

RESUMEN

Antibiotics are undoubtedly a pillar of modern medicine; their discovery in 1929 revolutionized the fight against infectious disease, instigating a worldwide decline in infection-associated mortality. Throughout the 1930s, 1940s, and 1950s the golden age of antibiotic discovery was underway with numerous new classes of antibiotics identified and brought to market. By 1962 all of our currently known families of antibiotics had been discovered, and it was a widely held belief, that humanity had conquered infectious disease. Despite varying bacterial cellular targets, most antibiotics targeted exponentially multiplying bacteria by interfering with integral processes such as peptidoglycan synthesis or ribosomal activity. The very nature of this targeted approach has driven the emergence of antibiotic-resistant bacteria.Methods of antibiotic identification relied solely on scientific observation, and while chemical analogues such as amoxicillin, derived from penicillin, continued to be developed, they retained the same mechanisms of action and hence the same bacterial targets. This article describes and discusses some of the emerging novel targets for antimicrobial treatments, highlighting pivotal research on which our ability to continue to successfully treat bacterial infection relies.


Asunto(s)
Antiinfecciosos/farmacología , Antiinfecciosos/uso terapéutico , Animales , Bacterias/efectos de los fármacos , Infecciones Bacterianas/tratamiento farmacológico , Infecciones Bacterianas/microbiología , Farmacorresistencia Bacteriana , Farmacorresistencia Bacteriana Múltiple , Humanos , Terapia Molecular Dirigida
20.
J Ethnopharmacol ; 194: 457-468, 2016 Dec 24.
Artículo en Inglés | MEDLINE | ID: mdl-27729284

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: Date fruit, Phoenix dactylifera L. has traditionally been used as a medicine in many cultures for the treatment of a range of ailments such as stomach and intestinal disorders, fever, oedema, bronchitis and wound healing. AIM OF THE REVIEW: The present review aims to summarise the traditional use and application of P. dactylifera date fruit in different ethnomedical systems, additionally the botany and phytochemistry are identified. Critical evaluation of in vitro and in vitro studies examining date fruit in relation to anti-inflammatory, anti-angiogenic and antimicrobial activities are outlined. KEY FINDINGS: The ethnomedical use of P. dactylifera in the treatment of inflammatory disease has been previously identified and reported. Furthermore, date fruit and date fruit co-products such as date syrup are rich sources of polyphenols, anthocyanins, sterols and carotenoids. In vitro studies have demonstrated that date fruit exhibits antibacterial, anti-inflammatory and anti-angiogenic activity. The recent interest in the identification of the numerous health benefits of dates using in vitro and in vivo studies have confirmed that date fruit and date syrup have beneficial health effects that can be attributed to the presence of natural bioactive compounds. CONCLUSIONS: Date fruit and date syrup have therapeutic properties, which have the potential to be beneficial to health. However, more investigations are needed to quantify and validate these effects.


Asunto(s)
Inhibidores de la Angiogénesis/uso terapéutico , Antibacterianos/uso terapéutico , Antiinflamatorios/uso terapéutico , Medicina Tradicional , Phoeniceae , Humanos , Phoeniceae/química
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