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1.
Cureus ; 16(5): e59830, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38846189

RESUMEN

AIMS: This study was aimed to determine the ideal thresholds for bone mineral densities in our tested Jordanian cohort to initiate bisphosphonate pharmacotherapeutics in order to establish a national protocol for prescribing bisphosphonates that is tailored to the local population, rather than relying on global T and Z scores standards. METHODS: This retrospective study analyzed the entire population of adult patients at Prince Rashid bin Al-Hussein Hospital Rehabilitation and Rheumatology Center between August and October 2023 for the purpose of screening, monitoring, diagnosing, and treating osteoporosis. The study included 328 clients suspected to have osteoporosis, selected based on criteria such as primary osteoporosis or potential secondary osteoporosis. The study used two fracture risk assessment tools (FRAX) dichotomized states: <3% (negative state) and ≥3% (positive state), as well as <20% (negative state) and ≥20% (positive state). Binary logistic regression analysis, receiver-operating characteristic, and sensitivity analysis tests were performed sequentially to analyze the performance of prognosticators and sensitivity indices to evaluate their sensitivity, specificity, and accuracy indexes. RESULTS: The study involved 328 clients at a rehabilitation clinic, with 82.62% (271) females and 17.38% (57) males. The majority were aged between 60 and 69 years, with a slightly higher obesity rate in females. The study found that initiation of bisphosphonates in Jordanian cohorts with optimal bone mineral density thresholds of 0.775 g/cm2 may significantly reduce the risk of hip osteoporosis over 10 years, with sensitivity, specificity, and accuracy indexes of 78.6%, 88.46%, and 50.61%, respectively, with a performance utility of 0.896±0.026 (p-value<0.001), 95% CI (0.846-0.946). CONCLUSION: Due to ethnicity differences, exploring regional or national specific bone mineral density thresholds for bisphosphonates initiation may be a better optional choice than adopting global T-score standards.

2.
Vaccine ; 37(33): 4694-4700, 2019 08 02.
Artículo en Inglés | MEDLINE | ID: mdl-29439871

RESUMEN

Over the last 20 years, natural peptides playing a key role in defense mechanisms and innate immunity have been isolated from unicellular organisms. Amphibian skin secretes dermaseptins, 24-34 amino acids in length that have a wide antimicrobial spectrum incorporating yeast, fungi, protozoa, bacteria and enveloped viruses. The anti-rabies virus (RABV) activity of dermaseptins S3 (30aa) and S4 (28aa) from Phyllomedusa sauvagei has been investigated, and further dissected its molecular basis by comparing punctual mutation or deletion of S4 analogues. The results showed that: (1) S4 is more active than S3 against RABV infection, 89% versus 38% inhibition at 7.5 µM; (2) the 5 NH2-aa of S4 are crucial for its inhibitory potential (S46-28 lost any inhibition) but the COOH terminus stabilizes the inhibitory potential (S41-16 showed only 23% inhibition at 7.5 µM); (3) there is a correlation between viral inhibition and dermaseptin cytotoxicity, which remains however moderated for BSR cells (≤12% at 10 µM). A single mutation in position 4 (S4M4K) slightly reduced cytotoxicity while keeping its antiviral activity, 97% at 7.5 µM. S4 and S4M4K showed an antiviral activity in vitro when provided 1 h after infection. In vivo experiments in mice by intramuscular injection of non-toxic doses of dermaseptin S4M4K 1 h post-infection by a lethal dose of RABV at the same site allowed more than 50% improvement in mice survival. This study highlights the potential interest of dermaseptins as non-expansive alternatives to rabies immunoglobulins for the treatment of rabies that continues to claim about 60,000 human lives per year worldwide, almost exclusively in developing countries.


Asunto(s)
Proteínas Anfibias/uso terapéutico , Péptidos Catiónicos Antimicrobianos/uso terapéutico , Antivirales/uso terapéutico , Rabia/tratamiento farmacológico , Proteínas Anfibias/administración & dosificación , Proteínas Anfibias/efectos adversos , Proteínas Anfibias/genética , Animales , Péptidos Catiónicos Antimicrobianos/administración & dosificación , Péptidos Catiónicos Antimicrobianos/efectos adversos , Péptidos Catiónicos Antimicrobianos/genética , Antivirales/administración & dosificación , Antivirales/efectos adversos , Línea Celular , Supervivencia Celular/efectos de los fármacos , Cricetinae , Relación Dosis-Respuesta a Droga , Femenino , Inyecciones Intramusculares , Ratones , Mutación/genética , Relación Estructura-Actividad
3.
Appl Biochem Biotechnol ; 188(1): 43-53, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-30311172

RESUMEN

Lactic acid bacteria produce various antibacterial peptides such as bacteriocins that are active against pathogenic and spoilage microorganisms. Very little attention has been paid to the production of lysozyme as an antimicrobial enzyme. The present work represents one of the few studies reporting lysozyme production by enterococci. Indeed, this study was first conducted to evaluate the antimicrobial activity of Enterococcus lactis Q1, an enterocin P-producing strain previously isolated from fresh shrimp (Penaeus vannamei), against multidrug-resistant clinical isolates. Results showed significant inhibitory activity (P < 0.05) towards diverse pathogens. The purification of the antimicrobial substances produced by Q1 strain leads to the isolation of two active fractions. The SDS-PAGE and mass spectrometry analyses of fraction number 2 (fraction 2) revealed the presence of a protein with molecular mass of 14.3 kDa. Additionally, the experimental results are consistent with mass spectra of industrial lysozyme (Fluka ref. 62970). The lysozyme produced by Enterococcus lactis Q1 strain was confirmed by a plate method against Micrococcus luteus ATCC 4698. Also, sensitivity of the Q1 strain to different concentrations of lysozyme was investigated. For the first time, this study shows that E. lactis Q1 produces lysozyme which could be an excellent candidate in food biopreservation or production of functional foods to promote health benefits.


Asunto(s)
Proteínas Bacterianas/química , Proteínas Bacterianas/aislamiento & purificación , Enterococcus/metabolismo , Espectrometría de Masas/métodos , Muramidasa/química , Muramidasa/aislamiento & purificación , Agua de Mar/microbiología , Microbiología del Agua , Antibacterianos/farmacología , Proteínas Bacterianas/farmacología , Cromatografía Líquida de Alta Presión , Cromatografía de Fase Inversa , Electroforesis en Gel de Poliacrilamida , Enterococcus/enzimología , Conservación de Alimentos , Alimentos Funcionales , Micrococcus luteus/efectos de los fármacos , Muramidasa/farmacología
4.
Biomed Res Int ; 2018: 5827986, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29984239

RESUMEN

In this manuscript, a multiple enterocin-producing Enterococcus lactis strain named 4CP3 was used to control the proliferation of Listeria monocytogenes in refrigerated raw beef meat model. Also, the intraspecific genetic differentiation of 4CP3 strain was assessed by Random Amplified Polymorphic DNA Polymerase Chain Reaction (RAPD-PCR) analysis. E. lactis 4CP3 strain was found to produce the enterocins A, B, and P. It displayed activity against L. monocytogenes EGDe 107776 by agar-well diffusion method. The application of E. lactis 4CP3 culture at 107 CFU/g in raw beef meat was evaluated using both ANOVA and ANCOVA linear models in order to examine its effect on the growth of the pathogen L. monocytogenes during refrigerated storage. Hence, a very interesting result in decreasing (P<0.05) and suppressing the growth of L. monocytogenes in refrigerated raw beef meat was shown during 28 days of storage. In conclusion, E. lactis 4CP3 strain might be useful for prevention of the proliferation and survival of L. monocytogenes in raw meat during refrigerated storage.


Asunto(s)
Microbiología de Alimentos , Listeria monocytogenes/crecimiento & desarrollo , Técnica del ADN Polimorfo Amplificado Aleatorio , Carne Roja , Animales , Hidrocarburos Aromáticos con Puentes/análisis , Bovinos , ADN , Enterococcus
5.
Microb Pathog ; 118: 32-38, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29524547

RESUMEN

This study aims to characterise a potential bacteriocinogenic lactic acid bacterial strain isolated from a raw pink shrimp (Palaemon serratus) and evaluate its safety aspect. The strain designated as 4CP3 was noted to display antibacterial activities (P < 0.05) against Gram-positive and Gram-negative foodborne pathogens (Listeria monocytogenes and Pseudomonas aeruginosa) and some filamentous fungi (e.g. Aspergillus niger A79). Phenotypic and molecular techniques as well as phylogenetic analysis identified the isolate 4CP3 as Enterococcus lactis. Its produced antimicrobial substance was determined as a bacteriocin that was stable over a wide range of pH (2-10) and after heating at 100 °C for 15 min. The maximum bacteriocin production was 1400 AU/ml recorded after 12 h of incubation in de Man, Rogosa and Sharpe (MRS) broth medium at 30 °C. The mode of action of the bacteriocin produced by 4CP3 strain was identified as bactericidal against L. monocytogenes EGDe 107776 and P. aeruginosa ATCC 27853. By specific PCR amplifications, E. lactis 4CP3 was shown to produce the enterocins A, B and P. To our knowledge, this feature is newly described for E. lactis strain isolated from raw shrimps. Regarding safety aspect of E. lactis 4CP3, it has been demonstrated that this strain was not haemolytic, gelatinase negative, sensitive to vancomycin, and free of common antibiotic resistance genes and virulence factors. Therefore, it may be useful as a safe natural agent in preservation of foods or as a new probiotic strain in food and feed.


Asunto(s)
Antibacterianos/metabolismo , Antibacterianos/farmacología , Bacterias/efectos de los fármacos , Enterococcus/metabolismo , Hongos/efectos de los fármacos , Animales , Antibacterianos/química , Bacteriocinas/metabolismo , Bacteriocinas/farmacología , Hidrocarburos Aromáticos con Puentes/química , Hidrocarburos Aromáticos con Puentes/clasificación , Hidrocarburos Aromáticos con Puentes/metabolismo , Hidrocarburos Aromáticos con Puentes/farmacología , Enterococcus/clasificación , Enterococcus/genética , Enterococcus/aislamiento & purificación , Enfermedades Transmitidas por los Alimentos , Calor , Concentración de Iones de Hidrógeno , Palaemonidae/microbiología , Filogenia , Probióticos , Especificidad de la Especie , Factores de Virulencia/genética
6.
Microb Pathog ; 117: 109-117, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-29438718

RESUMEN

The aims of this study are to isolate new bacteriocinogenic lactic acid bacterial strains from white (Penaeus vannamei) and pink (Palaemon serratus) raw shrimps and evaluate their technological and probiotic potentialities. Seven strains were selected, among fifty active isolates, as producing interesting antimicrobial activity. Identified as Enterococcus lactis, these isolates were able to produce enterocins A, B and/or P. The safety aspect, assessed by microbiological and molecular tests, demonstrated that the strains were susceptible to relevant antibiotics such as vancomycin, negative for haemolysin and gelatinase activities, and did not harbour virulence and antibiotic resistance genes. The assessment of potential probiotic and technological properties showed a low or no lipolytic activity, moderate milk-acidifying ability, high reducing power, proteolytic activity and tolerance to bile (P < 0.05) and good autoaggregation and coaggregation capacities. Two strains designated as CQ and C43 exhibiting high enzymatic activities and bile salt hydrolase activity were found to display high survival under simulated in vitro oral cavity and gastrointestinal tract conditions caused by presence of lysozyme, pepsin, pancreatin, bile salts and acidic pH. This study highlights safe Enterococcus lactis strains with great technological and probiotic potentials for future application as new starter, adjunct, protective or probiotic cultures in food industry.


Asunto(s)
Enterococcus/aislamiento & purificación , Enterococcus/fisiología , Palaemonidae/microbiología , Penaeidae/microbiología , Probióticos , Alimentos Marinos/microbiología , Amidohidrolasas , Animales , Antibacterianos/farmacología , Proteínas Bacterianas/genética , Bacteriocinas/genética , Hidrocarburos Aromáticos con Puentes , Medios de Cultivo , ADN Bacteriano , Farmacorresistencia Bacteriana/genética , Enterococcus/clasificación , Enterococcus/genética , Industria de Alimentos , Tracto Gastrointestinal/microbiología , Genes Bacterianos/genética , Concentración de Iones de Hidrógeno , Lactobacillales/aislamiento & purificación , Lactobacillales/fisiología , Pruebas de Sensibilidad Microbiana , Filogenia , ARN Ribosómico 16S/genética , Factores de Virulencia/genética
7.
Antonie Van Leeuwenhoek ; 110(6): 771-786, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28265787

RESUMEN

Screening for lactic acid bacteria (LAB) from fresh shrimp samples (Penaeus vannamei) collected from retail seafood markets in the Tunisian's coast, resulted in the isolation of an Enterococcus strain termed Q1. This strain was selected for its antagonistic activity against pathogenic bacteria such as Listeria monocytogenes, Pseudomonas aeruginosa, Lactococcus garvieae and against fungi (Aspergillus niger and Fusarium equiseti). The Q1 strain was characterised using standard morphological and biochemical tests, growth assays at different temperatures, pH and salinity. 16S rRNA, rpoA and pheS gene sequencing, as well as the 16S-23S rRNA intergenic spacer analyses, were combined to identify strain Q1 as a strain of Enterococcus lactis. The bacteriocin produced by E. lactis Q1 is thermostable, active in the pH range from 4.0 to 9.0 and has a bactericidal mode of action. The enterocin P structural gene was detected by specific PCR in strain E. lactis Q1, which is in good agreement with SDS-PAGE data of the purified bacteriocin. A lack of significant antibiotic resistance genes and virulence determinants was confirmed by specific PCRs. This work provides the first description of an enterocin P producer E. lactis strain isolated from a fresh shrimp. Based on its safety properties (absence of haemolytic activity, virulence factors and antibiotic resistance genes), this strain has the potential to be used as a natural additive or adjunct protective culture in food biopreservation and/or probiotic culture.


Asunto(s)
Bacteriocinas/metabolismo , Enterococcus/metabolismo , Penaeidae/microbiología , Animales , Enterococcus/genética , ARN Ribosómico 16S , Virulencia
8.
Dis Aquat Organ ; 118(1): 31-43, 2016 Feb 11.
Artículo en Inglés | MEDLINE | ID: mdl-26865233

RESUMEN

Use of lactic acid bacteria (LAB) as probiotics may provide an alternative to the use of antibiotics in aquaculture. LAB strains isolated from wild fish viscera and skin were evaluated for bacteriocin production and safety aspects (lack of antibiotic resistance, production of virulence factors). 16S rRNA gene sequences revealed the presence of Enterococcus faecium (13 isolates) and Lactococcus lactis (3 isolates) from fish samples. Pulsed-field gel electrophoresis analyses of the 13 enterococci isolates showed that they were all clustered, with greater than 95% similarity. However, RAPD analysis revealed significant molecular diversity between enterococci strains. Six enterococci strains were chosen and evaluated for their antibacterial activities. These strains produced a bacteriocin-like substance and exhibited a broad spectrum of inhibition against pathogenic bacteria isolated from diseased fish, including Streptococcus parauberis, Vagococcus spp., and Carnobacterium maltaromaticum, and in particular against the Gram-negative bacteria Flavobacterium frigidarium, Vibrio pectenicida, V. penaeicida, and Photobacterium damselae. The inhibition activity towards bacterial indicator strains was at a maximum when bacteria were grown at 37°C. However, bacteriocin production was observed at 15°C after 12 h of incubation. Only structural genes of enterocins A and B were detected by PCR in the 6 enterococci strains, suggesting the production of these enterocins. In addition, these strains did not harbor any virulence factors or any significant antibiotic resistance, and they tolerated bile. Our results suggest that enterococci are an important part of the bacterial flora of fish and that some strains have the potential to be used as probiotics.


Asunto(s)
Enterococcus/fisiología , Enfermedades de los Peces/microbiología , Bacterias Gramnegativas/patogenicidad , Animales , Antibacterianos/farmacología , Bacteriocinas/genética , Bacteriocinas/metabolismo , Electroforesis en Gel de Campo Pulsado , Enterococcus/clasificación , Enterococcus/genética , Peces , Calor , Concentración de Iones de Hidrógeno , Filogenia , Reacción en Cadena de la Polimerasa/métodos , ARN Bacteriano/genética , ARN Ribosómico 16S/genética , Técnica del ADN Polimorfo Amplificado Aleatorio , Factores de Virulencia
9.
Adv Exp Med Biol ; 901: 1-15, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26566647

RESUMEN

In our research on natural compounds efficient against human pathogen or opportunist microorganisms contracted by food or water, the antimicrobial activity of 19 essential oils (EOs) was investigated against 11 bacterial species (6 Gram positive, 5 Gram negative) and 7 fungal species (2 dermatophytes, 1 mould, 4 yeasts) using microdilution assays. Five essential oils were obtained from Tunisian plants (EOtun): Artemisia herba-alba Asso, Juniperus phoenicea L., Rosmarinus officinalis L., Ruta graveolens L. and Thymus vulgaris L., whereas others were commercial products (EOcom). Overall, T. vulgaris EOtun was the most efficient EO against both bacteria (Gram negative: MIC ≤ 0.34 mg/mL; Gram positive: MIC ≤ 0.70 mg/mL) and fungi (yeasts: MIC ≤ 0.55 mg/mL; mould: MIC = 0.30 mg/mL; dermatophytes: MIC ≤ 0.07 mg/mL). Two EOcom displayed both acceptable antibacterial and antifungal potency, although weaker than T. vulgaris EOtun activity: Origanum vulgare EOcom (bacteria: MIC ≤ 1.13 mg/mL, fungi: MIC ≤ 1.80 mg/mL), and Cymbopogon martinii var. motia EOcom (bacteria: MIC ≤ 1.00 mg/mL, fungi: MIC ≤ 0.80 mg/mL). Bacillus megaterium, Legionella pneumophila, Listeria monocytogenes and Trichophyton spp. were the most sensitive species to both EOcom and EOtun. This study demonstrated the noteworthy antimicrobial activity of two commercial EOs and points out the remarkable efficiency of T. vulgaris EOtun on all tested bacterial and fungal species, certainly associated with its high content in carvacrol (85 %). These three oils could thus represent promising candidates for applications in water and food protections.


Asunto(s)
Antiinfecciosos/farmacología , Aceites Volátiles/farmacología , Aceites de Plantas/farmacología , Antiinfecciosos/química , Bacterias/efectos de los fármacos , Bacterias/crecimiento & desarrollo , Infecciones Bacterianas/microbiología , Evaluación Preclínica de Medicamentos , Hongos/efectos de los fármacos , Hongos/crecimiento & desarrollo , Humanos , Pruebas de Sensibilidad Microbiana , Micosis/microbiología , Aceites Volátiles/química , Aceites de Plantas/química , Plantas/química
10.
Chem Biodivers ; 12(10): 1565-74, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26460561

RESUMEN

The aim of this study was to investigate the composition of six essential oils extracted from Tunisian plants, i.e., Artemisia herba-alba Asso, Citrus sinensis (L.) Osbeck, Juniperus phoenicea L., Rosmarinus officinalis L., Ruta graveolens L., and Thymus vulgaris L., and to evaluate their activity against Legionella pneumophila (microdilution assays). Eight Legionella pneumophila strains were studied, including the two well-known serogroup 1 Lens and Paris strains as controls and six environmental strains isolated from Tunisian spas belonging to serogroups 1, 4, 5, 6, and 8. The essential oils were generally active against L. pneumophila. The activities of the A. herba-alba, C. sinensis, and R. officinalis essential oils were strain-dependent, whereas those of the J. phoenicea and T. vulgaris oils, showing the highest anti-Legionella activities, with minimum inhibitory concentrations (MICs) lower than 0.03 and lower than or equal to 0.07 mg/ml, respectively, were independent of the strains' serogroup. Moreover, the microorganisms treated with T. vulgaris essential oil were shorter, swollen, and less electron-dense compared to the untreated controls. Isoborneol (20.91%), (1S)-α-pinene (18.30%) ß-phellandrene (8.08%), α-campholenal (7.91%), and α-phellandrene (7.58%) were the major components isolated from the J. phoenicea oil, while carvacrol (88.50%) was the main compound of the T. vulgaris oil, followed by p-cymene (7.86%). This study highlighted the potential interest of some essential oils extracted from Tunisian plants as biocides to prevent the Legionella risk.


Asunto(s)
Antibacterianos/aislamiento & purificación , Antibacterianos/farmacología , Legionella pneumophila/efectos de los fármacos , Aceites Volátiles/aislamiento & purificación , Aceites Volátiles/farmacología , Aceites de Plantas/aislamiento & purificación , Aceites de Plantas/farmacología , Antibacterianos/química , Artemisia/química , Citrus sinensis/química , Relación Dosis-Respuesta a Droga , Juniperus/química , Pruebas de Sensibilidad Microbiana , Aceites Volátiles/química , Aceites de Plantas/química , Rosmarinus/química , Ruta/química , Relación Estructura-Actividad , Thymus (Planta)/química , Túnez
11.
J Food Sci Technol ; 52(4): 2148-56, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25829595

RESUMEN

The combined effects of enterocin A with Thymus vulgaris essential oils (EOs) against Listeria monocytogenes and Escherichia coli O157:H7 were investigated in vitro by enumeration of surviving populations of testing pathogens and minimal inhibitory concentration (MIC) determination. Enterocin A was purified to homogeneity by RP-HPLC from the culture fluid of Enterococcus strain and thyme EOs were extracted from local Thymus vulgaris plants. The major constituent of thyme EOs oils determined by GC-MS was thymol (78.4 %). Combination of enterocin A with thyme EOs showed an enhanced bactericidal effect against Listeria monocytogenes. Checkerboard assay and isobologram construction displayed a synergistic interaction between these compounds against Listeria (FIC index <0.5). Moreover, the MIC value of enterocin A has fallen fivefold (from 4.57 to 0.9 µg/ml), while the MIC of thyme EOs decreased threefold (from 3.6 to 1.2 µg/ml). Treatments with enterocin A alone did not affect the growth of the enteric pathogen E. coli O157:H7. However, the addition of thyme EOs and enterocin A yielded a synergistic antimicrobial effect against E. coli (MIC thyme EOs decrease from 2.2 to 0.71 µg/ml). This is the first report on the combined effect of enterocin A and thyme EOs against food pathogen bacteria. This combination could be useful in food bio-preservation.

12.
APMIS ; 123(3): 260-8, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25556393

RESUMEN

Pseudomonas strains isolated from hot spring water were tested for bacteriocin-like substance (BLS) production using a target panel of closely related microorganisms and other Gram-positive and Gram-negative bacteria. Molecular identification was carried out through specific PCR and 16S RNA sequence analysis. Isolates were identified as Brevundimonas diminuta and Pseudomonas putida, the latter exhibited antimicrobial activity. Pseudomonas putida strains produce an inhibitory substance against other Pseudomonas strains and other species including food-borne pathogens. The BLS was sensitive to the proteolytic action of proteinase K, pronase E and trypsin but resistant to α-amylase, RNase and lipase C, reflecting its proteinaceous nature. The BLS was stable at 100 °C and also after thermal treatment at 121 °C for 15 min. Additionally, it was stable within a wide range of pH (2-10). The substance from P. putida T01 strain was bactericidal to Escherichia coli. SDS-PAGE analysis of the partial purified supernatant of strain T01 revealed a BLS with an approximate molecular mass of 8 kDa. Therefore, the results of this study show that P. putida strain T01 produces a BLS with a higher activity spectrum, which may find application in human medicine and in minimally processed food preservation.


Asunto(s)
Bacteriocinas/biosíntesis , Manantiales de Aguas Termales/microbiología , Pseudomonas putida/aislamiento & purificación , Antiinfecciosos/farmacología , Bacteriocinas/farmacología , ADN Bacteriano/genética , Electroforesis en Gel de Poliacrilamida , Escherichia coli/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Datos de Secuencia Molecular , Pseudomonas putida/clasificación , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN
13.
Antimicrob Agents Chemother ; 58(4): 2221-8, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24492362

RESUMEN

The rising number of infections caused by biofilm formation and the difficulties associated with their treatment by conventional antimicrobial therapies have led to an intensive search for novel antibiofilm agents. Dermaseptins are antimicrobial peptides with a number of attractive properties that might offer alternative therapies against resistant microorganisms. In this study, we synthesized a set of dermaseptin-derived peptides and evaluated their activities against Gram-positive and Gram-negative bacterial biofilm formation. All dermaseptin-derived peptides demonstrated concentration-dependent antibiofilm activities at microgram concentrations, and their activities were dependent on the nature of the peptides, with the highest levels of activity being exhibited by highly charged molecules. Fluorescent binding and confocal microscopy demonstrated that dermaseptin K4S4, a substituted derivative of the native molecule S4, significantly decreased the viability of planktonic and surface-attached bacteria and stopped biofilm formation under dynamic flow conditions. Cytotoxicity assays with HeLa cells showed that some of the tested peptides were less cytotoxic than current antibiotics. Overall, these findings indicate that dermaseptin derivatives might constitute new lead structures for the development of potent antibiofilm agents.


Asunto(s)
Proteínas Anfibias/farmacología , Antibacterianos/farmacología , Péptidos Catiónicos Antimicrobianos/farmacología , Biopelículas/efectos de los fármacos , Escherichia coli/efectos de los fármacos , Pseudomonas aeruginosa/efectos de los fármacos , Staphylococcus aureus/efectos de los fármacos , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Grampositivas/efectos de los fármacos , Células HeLa , Humanos , Pruebas de Sensibilidad Microbiana
14.
World J Microbiol Biotechnol ; 30(4): 1207-17, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24189971

RESUMEN

Nine lactic acid bacteria strains showing bacteriocin-like activity were isolated from various fresh fish viscera. The following species were identified based on 16S rDNA sequences: Enterococcus durans (7 isolates), Lactococcus lactis (1) and Enterococcus faecium (1). These strains were active against Listeria innocua and other LAB. Random amplified polymorphic DNA analyses showed four major patterns for the E. durans species. PCR analyses revealed a nisin gene in the genome of the Lc. lactis strain. Genes coding enterocins A, B and P were found in the genome of the E. faecium isolate. Enterocins A and B genes were also present in the genome of E. durans GM19. Hence, this is the first report describing E. durans strains producing enterocins A and B. Electrospray ionization mass spectrometry revealed that the purified bacteriocin produced by the E. durans GMT18 strain had an exact molecular mass of 6,316.89 Da. This bacteriocin was designated as durancin GMT18. Edman sequencing failed to proceed; suggesting that durancin GTM18 may contain terminal lanthionine residues. Overall, the results obtained revealed the presence of a variety of enterococci in Mediterranean fish viscera, as evidenced by their genetic profiles and abilities to produce different bacteriocins. These strains could be useful for food biopreservation or as probiotics.


Asunto(s)
Bacteriocinas/metabolismo , Peces/microbiología , Lactobacillales/clasificación , Lactobacillales/metabolismo , Animales , Análisis por Conglomerados , ADN Bacteriano/química , ADN Bacteriano/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Ácido Láctico/metabolismo , Lactobacillales/genética , Lactobacillales/aislamiento & purificación , Mar Mediterráneo , Datos de Secuencia Molecular , Filogenia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Vísceras/microbiología
15.
Eur J Contracept Reprod Health Care ; 18(2): 79-87, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23472604

RESUMEN

BACKGROUND AND OBJECTIVES: Sexually transmitted infections (STIs) and unplanned pregnancies have serious effects on the reproductive health of women. The present study was undertaken with a view to develop an effective means of prevention. The microbicidal and contraceptive potential of cationic peptides from frog's skin, namely, dermaseptin S4 and its derivatives were investigated in vitro.: STUDY DESIGN Different bacterial and fungal strains were resorted to for determining the antimicrobial activity of the new compounds. The spermicidal activities of the latter were assessed using normal human semen samples, and their toxic effects were identified in a HeLa culture. RESULTS: All S4 derivatives elicited concentration-dependent spermicidal and antimicrobial activities at microgram concentrations. The highest levels recorded for both types of activity were displayed by K4K20S4, and the lowest levels were exhibited by D4D20S4 and S4(5-28). Cytotoxicity assays revealed that some of these compounds were significantly safer than nonoxynol-9 (N-9). CONCLUSIONS: The ability of these peptides to instantaneously kill human sperm and STI pathogens at low concentrations indicates that their application as active ingredients in vaginal contraceptive preparations could induce considerably better effects than N-9.


Asunto(s)
Proteínas Anfibias/farmacología , Antiinfecciosos Locales/farmacología , Péptidos Catiónicos Antimicrobianos/farmacología , Proteínas Anfibias/genética , Antiinfecciosos Locales/síntesis química , Péptidos Catiónicos Antimicrobianos/genética , Femenino , Humanos , Masculino , Valores de Referencia , Análisis de Semen , Enfermedades de Transmisión Sexual/prevención & control , Piel/química , Piel/metabolismo
16.
Res Microbiol ; 164(4): 342-50, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23385143

RESUMEN

The aim of this study was to evaluate the frequency of Legionella pneumophila in three hot spring water recreation areas by conventional culture on GVPC and by Real Time-PCR. No legionellae were isolated from the spring water upstream the distribution system suggesting strongly that the thermal area was the probable source of these pathogens. L. pneumophila was present at high level in some samples, reaching values of 8.2 × 10(3) CFU/l at the site C. We observed a low diversity among the 18 isolated Legionella strains according to 16S DNA analysis, since only L. pneumophila and Legionella londiniensis were identified. All of the L. pneumophila strains belong to five serogroups (1, 4, 5, 6 and 8). Pulsed-field gel electrophoresis analysis identified various genotypes among these serogroups and showed that these strains had pulsotypes distinct from L. pneumophila present in the CNRL Legionella-database. These environmental strains showed higher tolerance to heat shock stress at 48 °C than L. pneumophila clinical strain, which may explain their presence in warm waters. Our data suggested that potential pathogen legionellae are present in Tunisian medicalized thermal spas and emphasized the importance of adopting control measures to prevent infection.


Asunto(s)
Biodiversidad , Manantiales de Aguas Termales/microbiología , Legionella/clasificación , Legionella/aislamiento & purificación , Técnicas de Tipificación Bacteriana , Análisis por Conglomerados , ADN Bacteriano/química , ADN Bacteriano/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Electroforesis en Gel de Campo Pulsado , Calor , Legionella/genética , Legionella/crecimiento & desarrollo , Datos de Secuencia Molecular , Tipificación Molecular , Filogenia , ARN Ribosómico 16S/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Análisis de Secuencia de ADN , Serotipificación , Túnez
17.
J Med Virol ; 85(2): 272-81, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23161023

RESUMEN

Herpes simplex virus (HSV) infections have become a public health problem worldwide. The emergence of acyclovir-resistant viral strains and the failure of vaccination to prevent herpetic infections have prompted the search for new antiviral drugs. Accordingly, the present study was undertaken to synthesize chemically and evaluate Dermaseptin S(4) (S(4)), an anti-microbial peptide derived from amphibian skin, and its derivatives in terms of anti-herpetic activity. The effects of biochemical modifications on their antimicrobial potential were also investigated. The peptides were incubated together with HSV-2 on target cells under various conditions, and the antiviral effects were examined via a cell metabolic labeling method. The findings revealed that DS(4) derivatives elicited concentration-dependent antiviral activity at micromole concentrations. The biochemical modifications of S(4) allowed for the reduction of peptide cytotoxicity without altering antiviral activity. Dermaseptins were added at different times during the viral cycle to investigate the mode of antiviral action. At the highest non-cytotoxic concentrations, most of the tested derivatives were noted to exhibit high antiviral activity particularly when pre-incubated with free herpes viruses prior to infection. Among these peptides, K(4)K(20)S(4) exhibited the highest antiviral activity against HSV-2 sensitive and resistant strains. Interestingly, the antiviral activity of K(4)K(20)S(4) was effective on both acyclovir-resistant and -sensitive viruses. The findings indicate that K(4)K(20)S(4) can be considered a promising candidate for future application as a therapeutic virucidal agent for the treatment of herpes viruses.


Asunto(s)
Proteínas Anfibias/farmacología , Péptidos Catiónicos Antimicrobianos/farmacología , Antivirales/farmacología , Productos Biológicos/farmacología , Herpesvirus Humano 2/efectos de los fármacos , Piel/química , Proteínas Anfibias/aislamiento & purificación , Proteínas Anfibias/toxicidad , Anfibios , Animales , Péptidos Catiónicos Antimicrobianos/aislamiento & purificación , Péptidos Catiónicos Antimicrobianos/toxicidad , Antivirales/aislamiento & purificación , Antivirales/toxicidad , Productos Biológicos/aislamiento & purificación , Productos Biológicos/toxicidad , Chlorocebus aethiops , Pruebas de Sensibilidad Microbiana , Células Vero
18.
J Med Case Rep ; 6: 153, 2012 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-22691187

RESUMEN

INTRODUCTION: Renal infarct is rare and often misdiagnosed because the symptoms are misleading. The mechanisms are various, mainly thrombotic and embolic. CASE PRESENTATION: In this review, we report the case of a 61-year-old Tunisian woman presented to the emergency unit with a 4-hour history of abdominal pain diffused at both flanks, ultrasounds was performed to remove a surgical emergency, showed a peri-renal fluid collection with heterogeneous parenchyma.We followed by a CT scan, which confirmed the diagnosis of renal infarct. The patient was treated by heparin at a curative dose, and the outcome was favorable. CONCLUSION: Diagnosis is difficult and should be considered in patients with inexplicable flank or abdominal pain and with risk factors to this disease. Our purpose is to raise clinician's awareness for this condition so that they will be more likely to diagnose it. This will facilitate prompt diagnosis and treatment.A review of the literature was performed and the case is discussed in the context of the current knowledge of this condition.

19.
Nat Prod Res ; 26(23): 2215-8, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22132736

RESUMEN

Rhus tripartitum (African sumac) is a plant commonly used in Tunisian traditional medicine to treat diarrhoea and dysentery. In this study, we have demonstrated that R. tripartitum extracts exhibited a significant broad spectrum activity against one or more of the test microorganisms with a zone size ranging from 8 to 28 mm in diameter. These diameters are much higher than those obtained with standard antibiotics. The chloroformic extracts were found to be effective against bacterial and fungal strains tested, with MIC values ranging between 0.07 and 0.62 mg mL(-1) against Staphylococcus aureus and Candida albicans. However, ethyl-acetate/methanol fractions showed a selective activity only against bacterial microorganisms with low MIC values between 0.07 and 0.15 mg mL(-1). The overall results suggested that the traditional use of R. tripartitum for the treatment of diarrhoea tract infections was attributed to the presence of antibacterial agents.


Asunto(s)
Antibacterianos/farmacología , Antifúngicos/farmacología , Extractos Vegetales/farmacología , Rhus/química , Antidiarreicos/uso terapéutico , Candida albicans/efectos de los fármacos , Escherichia coli/efectos de los fármacos , Medicinas Tradicionales Africanas , Pruebas de Sensibilidad Microbiana , Componentes Aéreos de las Plantas/química , Plantas Medicinales/química , Staphylococcus aureus/efectos de los fármacos , Túnez
20.
J Biomed Biotechnol ; 2009: 452567, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19893636

RESUMEN

Sexually transmitted infections (STIs) and human immunodeficiency virus (HIV), the causative agents of acquired immunodeficiency syndrome (AIDS), are two great concerns in the reproductive health of women. Thus, the challenge is to find products with a double activity, on the one hand having antimicrobial/antiviral properties with a role in the reduction of STI, and on the other hand having spermicidal action to be used as a contraceptive. In the absence of an effective microbicide along with the disadvantages of the most commonly used spermicidal contraceptive worldwide, nonoxynol-9, new emphasis has been focused on the development of more potential intravaginal microbicidal agents. Topical microbicides spermicides would ideally provide a female-controlled method of self-protection against HIV as well as preventing pregnancies. Nonoxynol-9, the only recommended microbicide spermicide, damages cervicovaginal epithelium because of its membrane-disruptive properties. Clearly, there is an urgent need to identify new compounds with dual potential microbicidal properties; antimicrobial peptides should be candidates for such investigations. Dermaseptins and magainins are two classes of cationic, amphipathic alpha-helical peptides that have been identified in the skin extracts of frogs Phyllomedusa sauvagei and Xenopus laevis. Regarding their contraceptive activities and their effect against various STI-causing pathogens, we believe that these two peptides are appropriate candidates in the evaluation of newer and safer microbicides spermicides in the future.


Asunto(s)
Proteínas Anfibias/metabolismo , Péptidos Catiónicos Antimicrobianos/metabolismo , Magaininas/metabolismo , Magaininas/uso terapéutico , Ranidae/metabolismo , Enfermedades de Transmisión Sexual/prevención & control , Piel/metabolismo , Proteínas Anfibias/uso terapéutico , Animales , Antiinfecciosos/química , Antiinfecciosos/metabolismo , Antiinfecciosos/uso terapéutico , Péptidos Catiónicos Antimicrobianos/uso terapéutico , Femenino , Humanos , Magaininas/química , Masculino , Espermicidas/química , Espermicidas/uso terapéutico
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