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1.
Med Mycol ; 2024 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-38986508

RESUMEN

Despite severe impact of uncommon yeast fungal infections and the pressing need for more research on the topic, there are still few studies available on the identification, epidemiology, and susceptibility profile of those pathogens. The aims of the current study were to define the profile of uncommon yeast species at Fattouma Bourguiba university hospital using phenotypic, molecular and proteomic methods and to study their antifungal susceptibility profile. Pre-identified uncommon yeast species were collected from 2018 to 2021. These isolates were further identified using phenotypic methods (ID32C® system and Vitek2® YST), matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and sequencing. The antifungal susceptibility profile was studied using the reference CLSI broth microdilution method. In total, 30 strains were collected during the study period. Referring to the sequencing, the most isolated uncommon species were Saprochaete capitata, Candida lusitaniae, Candida kefyr, Candida inconspicua and Candida guilliermondii. Ninety % of isolates were correctly identified by MALDI-TOF MS compared to 76.7% and 63.3% by ID32® C and VITEK® 2 YST respectively. The isolated species showed variable responses to antifungals. Candida guilliermondii showed increased azole minimum inhibitory concentrations. Misidentification of uncommon yeast species was common using commercial phenotypic methods. The high percentage of concordance of MALDI-TOF results with sequencing highlights its high performance and usefulness as a routine diagnosis tool.


There is still little information on the epidemiology of uncommon emergent yeasts although their implication in severe diseases mainly invasive infections. Thus, the importance of an accurate identification and antifungal susceptibility testing for a better monitoring of related infections.

2.
J Water Health ; 21(3): 354-360, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37338315

RESUMEN

Wastewater-based epidemiology (WBE) could be useful as an early warning system for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic spread. Viruses are highly diluted in wastewater. Therefore, a virus concentration step is needed for SARS-CoV-2 wastewater detection. We tested the efficiency of three wastewater viral concentration methods: ultrafiltration (UF), electronegative membrane filtration and aluminum hydroxide adsorption-elution. We spiked wastewater with inactivated SARS-CoV-2 and we collected 20 other wastewater samples from five sites in Tunisia. Samples were concentrated by the three methods and SARS-CoV-2 was quantified by reverse transcription digital PCR (RT-dPCR). The most efficient method was UF with a mean SARS-CoV-2 recovery of 54.03 ± 8.25. Moreover, this method provided significantly greater mean concentration and virus detection ability (95%) than the two other methods. The second-most efficient method used electronegative membrane filtration with a mean SARS-CoV-2 recovery of 25.59 ± 5.04% and the least efficient method was aluminum hydroxide adsorption-elution. This study suggests that the UF method provides rapid and straightforward recovery of SARS-CoV-2 in wastewater.


Asunto(s)
Hidróxido de Aluminio , COVID-19 , Humanos , SARS-CoV-2 , Aguas Residuales , Adsorción
3.
Molecules ; 28(7)2023 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-37050030

RESUMEN

Autism spectrum disorder (ASD) is a neurodevelopmental pathology characterized by the impairment of social interaction, difficulties in communication, and repetitive behaviors. Alterations in the metabolism of amino acids have been reported. We performed a chromatographic analysis of fecal amino acids, ammonium, biogenic amines, and gamma aminobutyric acid (GABA) in Tunisian autistic children from 4 to 10 years, and results were compared with their siblings (SIB) and children from the general population (GP). ASD presented significantly higher levels of fecal amino acids than SIB and GP; differences being more pronounced in younger (4-7 years) than in older (8-10 years) individuals whereas no changes were found for the remaining compounds. Lower levels of histidine were the only difference related with severe symptoms of autism (CARS scale). A linear discriminant analysis (LDA) based on fecal amino acid profiles clearly separated ASD, SIB, and GP at 4 to 7 years but not at more advanced age (8-10 years), evidencing more pronounced alterations in younger children. The relationship of fecal amino acids with autism needs deeper research integrating blood analytical parameters, brain metabolism, and intestinal microbiota. Fecal amino acids could be targeted for designing personalized diets to prevent or minimize cognitive impairments associated with ASD.


Asunto(s)
Trastorno del Espectro Autista , Microbioma Gastrointestinal , Humanos , Niño , Anciano , Aminoácidos/análisis , Trastorno del Espectro Autista/metabolismo , Túnez , Heces/química
4.
Microb Pathog ; 166: 105530, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35429586

RESUMEN

Turpentine essential oil (TEO) is a commercially available product having application as food additive, due to its ethno-botanical and ethnopharmacological properties. In the present study, we performed chemical composition of TEO by Gas Chromatography-Mass Spectrometry (GC-MS). Further, TEO was nanoemulsified, encapsulated and characterized by droplet size, PDI, Zeta potential and transmittance. The obtained turpentine nanoemulsion (TNE) was investigated for its antibacterial and antibiofilm potentiality against methicillin-resistant Staphylococcus aureus (MRSA), a model biofilm-forming microorganism. Small micellar TEO nanoparticles were succesfully formed with a mean droplet size ranging from 22.52 to 26.54 nm. Thermodynamic stability studies revealed homogeneous dispersion of the droplets size confirming the stability of TNEs. The developed nano-emulsions displayed two fold enhanced antagonistic activity against S. aureus in comparison with TEOs, with minimum inhibitory concentration (MIC) values at 0.039% (v/v) against MRSA. Additionally, TNEs displayed potent antibiofilm activity against MRSA strains with percent biofilm disruption of around 70.83%. Findings from this study validates the phytomedicinal significance of turpentine nanoemulsions and envisage its exploration as a natural and cost-effective strategy against bacterial biofilms in medical and industrial sectors.


Asunto(s)
Staphylococcus aureus Resistente a Meticilina , Aceites Volátiles , Antibacterianos/química , Biopelículas , Pruebas de Sensibilidad Microbiana , Aceites Volátiles/química , Aceites Volátiles/farmacología , Staphylococcus aureus , Trementina/farmacología
5.
Virol J ; 19(1): 45, 2022 03 18.
Artículo en Inglés | MEDLINE | ID: mdl-35303921

RESUMEN

BACKGROUND: Enteroviruses (EVs) are considered the main causative agents responsible for aseptic meningitis worldwide. This study was conducted in the Monastir region of Tunisia in order to know the prevalence of EV infections in children with meningitis symptoms. Detected EV types were compared to those identified in wastewater samples. METHODS: Two hundred CSF samples collected from hospitalized patients suspected of having aseptic meningitis for an EV infection between May 2014 and May 2017 and 80 wastewater samples collected in the same time-period were analyzed. EV detection and genotyping were performed using PCR methods followed by sequencing. Phylogenetic analyses in the 3'-VP1 region were also carried-out. RESULTS: EVs were detected in 12% (24/200) CSF and in 35% (28/80) wastewater samples. EV genotyping was reached in 50% (12/24) CSF-positive samples and in 64% (18/28) sewage. Most frequent types detected in CSF were CVB3, E-30 and E-9 (25% each). In wastewater samples, the same EVs were identified, but also other types non-detected in CSF samples, such as E-17,CVA9 and CVB1 from EV species B, and EV-A71 and CVA8 from EV-A, suggesting their likely lower pathogenicity. Phylogenetic analysis showed that within the same type, different strains circulate in Tunisia. For some of the EV types such as E-9, E-11 or CVB3, the same strains were detected in CSF and wastewater samples. CONCLUSIONS: Epidemiological studies are important for the surveillance of the EV infections and to better understand the emergence of certain types and variants.


Asunto(s)
Infecciones por Enterovirus , Enterovirus , Meningitis Aséptica , Antígenos Virales , Líquido Cefalorraquídeo , Niño , Enterovirus/genética , Infecciones por Enterovirus/epidemiología , Genotipo , Humanos , Lactante , Meningitis Aséptica/líquido cefalorraquídeo , Meningitis Aséptica/epidemiología , Filogenia , Túnez/epidemiología , Aguas Residuales
6.
Can J Infect Dis Med Microbiol ; 2022: 9410024, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35368519

RESUMEN

The interest for green synthesis of metallic nanoparticles (NPs) has acquired particular attention due to its low toxicity and economic feasibility compared with chemical or physical process. Here we carried out an extracellular synthesis approach of silver nanoparticles (AgNPs) using dried orange peel extract. Characterization studies revealed the synthesis of 25-30 nm AgNPs with distinct morphology as observed in transmission electron microscopes. Dynamic light scattering spectroscopy and Fourier transform infrared spectroscopy analyses further characterized nanoparticles confirming their stability and the presence of functional groups. The biological properties of biosynthesized AgNPs were subsequently investigated. Our results revealed anticancer activity of biogenic silver NPs against the B16 melanoma cell line with an IC50 value of 25 µg/ml. Additionally, the developed AgNPs displayed a considerable antagonistic activity against methicillin-resistant Staphylococcus aureus (MRSA) strains colonizing cell phones, with inhibition zones between 12 and 14 mm and minimum inhibitory concentration values between 1.56 and 12.5 µg/ml. Furthermore, the AgNPs exhibited potent antibiofilm activity against MRSA strains with the percent biofilm disruption reaching 80%. Our results highlighted the efficacy of biosynthesized AgNPs against bacterial biofilms and pointed to the exploration of orange peels as a natural and cost-effective strategy.

7.
BMC Public Health ; 21(1): 1625, 2021 09 06.
Artículo en Inglés | MEDLINE | ID: mdl-34488704

RESUMEN

BACKGROUND: Sexually Transmitted Infections (STIs) are a public health problem, especially for reproductive-age women. The aim of this study was to determine the incidence and trend of STIs during 11 years in Tunisia (2007-17). METHODS: We conducted a descriptive study including all women with curable STIs (chlamydia, gonorrhea, syphilis and trichomoniasis) diagnosed with the syndromic approach in all basic health care centers of the Governorate of Monastir (Tunisia) from 2007 to 2017. Syndromes included, Pelvic Pain (PP), Vaginal Discharge (VD) and Genital Ulceration (GU). RESULTS: We analyzed 40,388 episodes of curable STIs with a crude incidence rate and age standardized incidence rate of 1393 (95% Confidence Interval (CI); 1348-1438) / 100,000 Person Year (PY) and 1328 (95%CI; 1284-1372) /100,000 PY respectively. The incidence rate showed a positive trend over 11 years for all age groups and syndromes. VD was the most common syndrome with a crude incidence rate of 1170/100,000 PY. For all syndromes, women aged 20 to 39 were the most affected age group (p < 0.001). CONCLUSION: In conclusion, the incidence rate of STIs episodes among women diagnosed with the syndromic approach was high, consistent with the global evidence. Focusing on reviewing STIs surveillance system in low and middle-income countries could allow the achievement of the ending of STIs epidemics by 2030.


Asunto(s)
Gonorrea , Enfermedades de Transmisión Sexual , Femenino , Gonorrea/epidemiología , Humanos , Atención Primaria de Salud , Vigilancia de Guardia , Enfermedades de Transmisión Sexual/epidemiología , Túnez/epidemiología
8.
Environ Toxicol ; 36(4): 562-571, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33226166

RESUMEN

Azoxystrobin (AZO) and Iprodione (IPR) fungicides are extensively used worldwide, and therefore, contaminate all environmental compartments. The toxicity and the mechanisms by which they affected immune cells are complex and remain unknown. This study investigated the impact of AZO and IPR on the in vitro function of mice peritoneal macrophages including lysosomal enzyme activity and tumor necrosis factor (TNF)α and nitric oxide (NO) production in response to lipopolysaccharide (LPS) stimulation, the proliferation of mice splenocytes stimulated by concanavalin (Con)A and LPS, and the production of the Th1cytokine interferon-gamma (IFNγ) and the Th2 cytokine interleukin (IL)-4 and IL-10 by ConA-activated splenocytes. This is the first report indicating that AZO and IPR fungicides dose-dependently inhibited mice macrophage lysosomal enzyme activity and LPS-stimulated production of TNFα and NO. Mitogen-induced proliferation of mice splenocytes was also suppressed by AZO and IPR in a dose-dependent manner. More pronounced impact was observed on ConA-induced response. The production of IFNγ by ConA-stimulated splenocytes was dose-dependently inhibited; however, the production of IL-4 and IL-10 increased in the same conditions. These results suggested that AZO and IPR polarized Th1/Th2 cytokine balance towards Th2 response. Overall, marked immunosuppressive effects were observed for AZO. The immunomodulatory effects caused by AZO and IPR were partially reversed by the pharmacological antioxidant N-acetylcysteine (NAC), suggesting that both fungicides exerted their actions through, at least in part, oxidative stress-dependent mechanism. Collectively, our data showed that AZO and IPR fungicides exerted potent immunomodulatory effects in vitro with eventually strong consequences on immune response and immunologically based diseases.


Asunto(s)
Acetilcisteína/farmacología , Aminoimidazol Carboxamida/análogos & derivados , Contaminantes Ambientales/toxicidad , Fungicidas Industriales/toxicidad , Hidantoínas/toxicidad , Macrófagos Peritoneales , Pirimidinas/toxicidad , Estrobilurinas/toxicidad , Aminoimidazol Carboxamida/toxicidad , Animales , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/inmunología , Células Cultivadas , Citocinas/biosíntesis , Relación Dosis-Respuesta a Droga , Macrófagos Peritoneales/efectos de los fármacos , Macrófagos Peritoneales/inmunología , Masculino , Ratones , Bazo/efectos de los fármacos , Bazo/inmunología
9.
COPD ; 18(1): 53-61, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33353408

RESUMEN

Patients with chronic obstructive pulmonary disease (COPD) exhibit frequent acute exacerbations (AE). The objectives of this study were first to evaluate the prevalence of pathogens associated to these episodes by combining conventional bacteriology and multiplex viral and bacterial PCR assays in sputum specimens, and second to determine whether C-reactive protein (CRP) value and clinical outcome could be influenced by the type of microbial agent(s) recovered from these samples. A cohort of 84 Tunisian patients hospitalized at the emergency room for AECOPD was investigated prospectively for the semi-quantitative detection of bacteria by conventional culture (the threshold of positivity was of 107 CFU/ml) and for the detection of viral genome and DNA of atypical bacteria by quantitative PCR using two commercial multiplex respiratory kits (Seegene and Fast-track). The two kits exhibited very similar performances although the Seegene assay was a bit more sensitive. A large number and variety of pathogens were recovered from the sputum samples of these 84 patients, including 15 conventional bacteria, one Chlamydia pneumoniae and 63 respiratory viruses, the most prevalent being rhinoviruses (n = 33) and influenza viruses (n = 13). From complete results available for 74 patients, the presence of bacteria was significantly associated with risk of recurrence at 6 and 12 months post-infection. The combination of these different markers appears useful for delineating correctly the antimicrobial treatment and for initiating a long-term surveillance in those patients with high risk of recurrent exacerbation episodes. A prospective study is required for confirming the benefits of this strategy aimed at improving the stewardship of antibiotics.


Asunto(s)
Enfermedad Pulmonar Obstructiva Crónica , Virosis , Antibacterianos/uso terapéutico , Antiinfecciosos , Bacterias , Humanos , Enfermedad Pulmonar Obstructiva Crónica/complicaciones , Enfermedad Pulmonar Obstructiva Crónica/tratamiento farmacológico , Esputo , Virosis/complicaciones , Virosis/tratamiento farmacológico , Virosis/epidemiología
10.
J Infect Dis ; 222(5): 836-839, 2020 08 04.
Artículo en Inglés | MEDLINE | ID: mdl-32188998

RESUMEN

In Tunisia, we observed that rotavirus P[8]-3 and P[4] strains in young children with gastroenteritis associate with secretor histo-blood group phenotype. In contrast, the emerging P[8]-4 strain, representing 10% of cases, was exclusively found in nonsecretor patients. Unlike VP8* from P[8]-3 and P[4] strains, the P[8]-4 VP8* protein attached to glycans from saliva samples regardless of the donor's secretor status. Interestingly, a high frequency of FUT2 enzyme deficiency (nonsecretor phenotype) was observed in the population. This may allow cocirculation of P[8]-3 and P[8]-4 strains in secretor and nonsecretor children, respectively.


Asunto(s)
Fucosiltransferasas/genética , Especificidad del Huésped , Proteínas de Unión al ARN/metabolismo , Infecciones por Rotavirus/genética , Rotavirus/genética , Proteínas no Estructurales Virales/metabolismo , Preescolar , Genotipo , Humanos , Lactante , Recién Nacido , Fenotipo , Polisacáridos/metabolismo , Proteínas de Unión al ARN/genética , Rotavirus/fisiología , Saliva , Proteínas no Estructurales Virales/genética , Acoplamiento Viral , Galactósido 2-alfa-L-Fucosiltransferasa
11.
Microb Pathog ; 118: 74-80, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29522803

RESUMEN

Antibacterial resistance is an increasingly serious threat to global public health. The search for new anti-infection agents from natural resources, with different mode of actions and competitive effects became a necessity. In this study, twenty height methicillin-resistant Staphylococcus aureus (MRSA) strains were investigated for their biofilm formation ability. Subsequently, the antibiofilm effects of Eucalyptus globulus essential oil and its main component 1,8-cineole, against MRSA, as well as their antiquorum sensing potential, were evaluated. Our results displayed the potent efficacy of both E. globulus essential oil and 1,8-cineole against the development of biofilms formed by the methicillin-resistant strains. Additionally, E. globulus essential oil showed more potent of anti-QS activity, even at a low concentration, when compared to 1,8-cineole. All these property of tested agents may pave the way to prevent the development of biofilm formation by MRSA and subsequently the spreading of nosocomial infection.


Asunto(s)
Antibacterianos/farmacología , Biopelículas/efectos de los fármacos , Ciclohexanoles/farmacología , Eucalyptus/química , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Monoterpenos/farmacología , Aceites Volátiles/farmacología , Extractos Vegetales/farmacología , Percepción de Quorum/efectos de los fármacos , Antibacterianos/química , Antibacterianos/aislamiento & purificación , Biopelículas/crecimiento & desarrollo , Ciclohexanoles/química , Eucaliptol , Pruebas de Sensibilidad Microbiana , Monoterpenos/química , Aceites Volátiles/química , Aceites Volátiles/aislamiento & purificación , Extractos Vegetales/aislamiento & purificación , Aceites de Plantas/aislamiento & purificación , Aceites de Plantas/farmacología
12.
BMC Infect Dis ; 18(1): 560, 2018 Nov 13.
Artículo en Inglés | MEDLINE | ID: mdl-30424731

RESUMEN

BACKGROUND: Methicillin resistant Staphylococcus aureus (MRSA) is recognized worldwide as a leading cause of hospital and community infections. Biofilm formation by MRSA is an extremely important virulence factor to be understood. Our aim was to establish phenotypic and genotypic characterization of virulence factors among 43 MRSA clinical isolates in a Tunisian hospital. METHODS: We investigated enzymatic profiles, biofilm production and prevalences of genes encoding intracellular adhesion molecules (icaA and icaD), Microbial Surface Components Recognizing Adhesive Matrix Molecules genes (fnbA, fnbB and cna) and exoenzymes genes (geh, sspA and sspB). RESULTS: Our findings revealed that caseinase, gelatinase, lipase and lecithinase activities were detected in 100%, 100%, 76.6% and 93.3% of cases respectively. This study showed that 23 strains (76.7%) were slime producers on Congo red medium. Furthermore, 46.5% and 53.5% of isolates were respectively highly and moderately biofilm-forming on polystyrene. Significant association was found between both biofilm tests. PCR detection showed that 74.4%, 18.6%, 69.8%, 65.1% and 74.4% of isolates harbored fnbA, fnbB, icaA, icaD and cna genes respectively. In addition, 34.9%, 18.6% and 30.2% of MRSA strains were found positive for sspA, sspB and geh genes respectively. Further, statistical data showed that the presence of the fnbA and fnbB genes was significantly associated with a high biofilm production on polystyrene. However, no statistical association was observed for the icaA, icaD and cna genes. CONCLUSIONS: This study indicates that the detection of fnbA and fnbB contributing to the first step of biofilm formation has been predictable of high biofilm production. As studied factors contribute to MRSA virulence, this research could be of value in orienting towards the development of new preventive and therapeutic measures.


Asunto(s)
Staphylococcus aureus Resistente a Meticilina/fisiología , Infecciones Estafilocócicas/microbiología , Factores de Virulencia/genética , Biopelículas/crecimiento & desarrollo , Regulación Bacteriana de la Expresión Génica , Regulación del Desarrollo de la Expresión Génica , Genes Bacterianos , Genotipo , Humanos , Staphylococcus aureus Resistente a Meticilina/genética , Staphylococcus aureus Resistente a Meticilina/aislamiento & purificación , Reacción en Cadena de la Polimerasa , Infecciones Estafilocócicas/genética , Virulencia/genética
13.
Molecules ; 23(10)2018 Oct 17.
Artículo en Inglés | MEDLINE | ID: mdl-30336602

RESUMEN

The problem of antibiotic resistance among pathogens encourages searching for novel active molecules. The aim of the research was to assay the anti-quorum sensing (anti-QS) and antibiofilm potential of Melaleuca alternifolia essential oil and its main constituent, terpinen-4-ol, to prevent the infections due to methicillin-resistant Staphylococcus aureus strains as an alternate to antibiotics. The tea tree oil (TTO) was evaluated for its potential in inhibiting QS-dependent phenomena such as violacein production in Chromobacterium violaceum, swarming motility of Pseudomonas aeruginosa PAO1, and biofilm formation in MRSA strains on glass. The results showed that terpinen-4-ol was able to inhibit MRSA strain biofilm formation on the glass strips by 73.70%. TTO inhibited the violacein production at a mean inhibitory concentration (MIC) value of 0.048 mg/mL by 69.3%. At 100 µg/mL TTO and terpinen-4-ol exhibited inhibition in swarming motility of PAO1 by 33.33% and 25%, respectively. TTO revealed anti-QS and anti-biofilm activities at very low concentrations, but it could be further investigated for new molecules useful for the treatment of MRSA infections.


Asunto(s)
Chromobacterium/efectos de los fármacos , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Infecciones Estafilocócicas/tratamiento farmacológico , Terpenos/farmacología , Biopelículas/efectos de los fármacos , Chromobacterium/patogenicidad , Humanos , Melaleuca/química , Staphylococcus aureus Resistente a Meticilina/patogenicidad , Aceites Volátiles/química , Aceites Volátiles/farmacología , Extractos Vegetales/química , Extractos Vegetales/farmacología , Pseudomonas aeruginosa/efectos de los fármacos , Pseudomonas aeruginosa/patogenicidad , Percepción de Quorum/efectos de los fármacos , Infecciones Estafilocócicas/microbiología , Aceite de Árbol de Té/farmacología , Terpenos/química
14.
Microb Pathog ; 109: 169-176, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28552808

RESUMEN

Emergence of antibiotic resistance among pathogenic bacteria encourages us to search for new molecules as an alternative treatment. The aim of this study was to evaluate the antiquorum sensing (anti-QS) and antibiofilm potential of Salvadora persica L. methanolic extracts to prevent the infections due to Staphylococcus as an alternate to antibiotics. The methanolic extracts of S. persica L. fruit, leaves and stems was assessed for their activity in inhibiting QS-depedent phenomenon such as violacein pigment production in Chromobacterium violaceum, swarming motility of Pseudomonas aeruginosa PAO1 and biofilm formation in oral Staphylococcus strains on polymethylmetacrylate (PMMA). Methanolic fruit extract of S. persica L. showed a high degree of anti-biofilm formation on PMMA and on violacein inhibition with a percentage of reduction equal to 90% when MIC value (20 mg/ml) was used. 100 µg/ml of S. persica L. leaves exhibited inhibition in swarming motility of PAO1 at 29.17%. Because the methanolic extracts of S. persica L. demonstrated anti-QS and antibiofilm activity at very low concentrations, it could be further exploited for novel molecules to treat oral Staphylococcus infections.


Asunto(s)
Biopelículas/efectos de los fármacos , Frutas/química , Fitoquímicos/farmacología , Extractos Vegetales/farmacología , Tallos de la Planta/química , Percepción de Quorum/efectos de los fármacos , Salvadoraceae/química , Antibacterianos/farmacología , Chromobacterium/efectos de los fármacos , Indoles/metabolismo , Metanol , Pruebas de Sensibilidad Microbiana , Hojas de la Planta/química , Polimetil Metacrilato , Polifenoles/química , Polifenoles/aislamiento & purificación , Polifenoles/farmacología , Poliestirenos , Pseudomonas aeruginosa/efectos de los fármacos , Infecciones Estafilocócicas/prevención & control , Staphylococcus/efectos de los fármacos , Staphylococcus/crecimiento & desarrollo , Staphylococcus/patogenicidad , Yemen
15.
Microb Pathog ; 104: 84-89, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-28087493

RESUMEN

Biosurfactants also called bioemulsifiers are amphipathic compounds produced by many microorganisms that allow them to exhibit a wide range of biological activities. The aim of this study was to determine the antioxidant and antiproliferative potential of biosurfactants isolated from Lactobacillus casei and to assess their anti-adhesive and anti-biofilm abilities against oral opportunistic Staphylococcus aureus strains. The antioxidant activity of biosurfactant was evaluated using the in vitro scavenging ability on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. The antiproliferative activity was determined on epithelial cell line (HEp-2) by the Methylthiazole tetrazolium (MTT) reduction assay. The anti-adhesive and antibiofilm activity against S. aureus strains were achieved using crystal violet staining. Our results revealed that the DPPH scavenging activity of biosurfactants at 5.0 mg/mL concentration is between 74.6 and 77.3%. Furthermore, biosurfactants showed antiproliferative potency against studied epithelial cells as judged by IC50 and its value ranged from 109.1 ± 0.84 mg/mL to 129.7 ± 0.52 mg/mL. The results of the growth inhibition indicate that biosurfactant BS-LBl was more effective against oral S. aureus strains 9P and 29P with an IC50 of 1.92 ± 0.26 mg/mL and 2.16 ± 0.12 mg/mL respectively. Moreover, both biosurfactants displayed important antibiofilm activity with eradication percentages ranging from 80.22 ± 1.33% to 86.21 ± 2.94% for the BS-LBl, and from 53.38 ± 1.77% to 64.42 ± 2.09% for the BS-LZ9. Our findings demonstrate that biosurfactants from L. casei strains exhibited considerable antioxidant and antiproliferative potencies and were able to inhibit oral S. aureus strains with important antibiofilm efficacy. They could have a promising role in the prevention of oral diseases.


Asunto(s)
Antibacterianos/farmacología , Antibiosis , Antioxidantes/farmacología , Biopelículas/efectos de los fármacos , Lacticaseibacillus casei/metabolismo , Boca/microbiología , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/fisiología , Tensoactivos/farmacología , Antibacterianos/biosíntesis , Antioxidantes/aislamiento & purificación , Antioxidantes/metabolismo , Adhesión Bacteriana/efectos de los fármacos , Línea Celular , Proliferación Celular/efectos de los fármacos , Humanos , Tensoactivos/aislamiento & purificación , Tensoactivos/metabolismo
16.
Microb Pathog ; 103: 129-134, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27993700

RESUMEN

Staphylococcus aureus (S. aureus) is one of several opportunistic microbial pathogens associated with many healthcare problems. In the present study, S. aureus was assessed for its biofilm-forming ability on materials routinely used in dental offices, including stainless steel (SS), polyethylene (PE), and polyvinyl chloride (PVC). Materials that were tested were characterized for roughness (Ra) and surface free energy (SFE). The adhesion forces exerted by S. aureus to each substratum were investigated using atomic force microscopy (AFM), and biofilm formation was quantitatively assessed by crystal violet staining assay. AFM measurements demonstrated that the strongest adhesion forces (20 nN) were exerted on the PE surfaces (P < 0.05) and depended more on Ra. In addition, the results of biofilm formation capability indicated that S. aureus exhibited more affinity to SS materials when compared to the other materials (P < 0.05). This ability of biofilm formation seems to be more correlated to SFE (R = 0.65). Hence, control of the surface properties of materials used in dental practices is of crucial importance for preventing biofilm formation on dental materials to be used for patients' dental care.


Asunto(s)
Adhesión Bacteriana , Infección Hospitalaria , Consultorios Odontológicos , Infecciones Oportunistas , Infecciones Estafilocócicas/microbiología , Staphylococcus aureus/fisiología , Biopelículas , Humanos , Microscopía de Fuerza Atómica , Staphylococcus aureus/ultraestructura , Propiedades de Superficie
17.
Folia Med (Plovdiv) ; 59(4): 387-395, 2017 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-29341945

RESUMEN

Ebola virus disease (EVD) is one of the deadliest viral diseases. It is characterized by a high mortality rate due to the lack of effective and safe treatments or vaccines and its ability to spread at an unstoppable pace. The West Africa outbreak ended but the disease may strike again at any time. The latest epidemic was, by far, the deadliest to date. The most concern was why this outbreak was so different from the previous ones. We proposed in this review firstly to summarize the principal causes of its unprecedented spread and secondly to identify the steps for an effective management approach of a future Ebola outbreak. Attributes of the affected populations and insufficient control efforts were the main reasons of its amplification. This was complicated by a delayed international response. The health crisis was ignored for months until it got out of control. The management of Ebola presents a multitude of challenges in terms of preparedness and capacity to face an outbreak. In addition to the need for adequate health care facilities, ongoing surveillance tools, appropriate training of health workers and raising population awareness, readiness requires a large scale and coordinated international intervention to support affected and at-risk nations, to intensify their response activities and to strengthen their capacities. Constant interventions after the outbreak are still needed to ensure that vital health and related service institutions in these countries are fully prepared to respond to an eminent epidemic.


Asunto(s)
Brotes de Enfermedades , Fiebre Hemorrágica Ebola/epidemiología , África Occidental/epidemiología , Atención a la Salud , Adhesión a Directriz , Fiebre Hemorrágica Ebola/etiología , Fiebre Hemorrágica Ebola/prevención & control , Fiebre Hemorrágica Ebola/terapia , Humanos , Aislamiento de Pacientes , Transferencia de Pacientes
18.
Microb Pathog ; 91: 61-7, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26620082

RESUMEN

Orthodontic and other oral appliances act as reservoir of opportunistic pathogens that can easily become resistant to antibiotics and cause systemic infections. The aim of this study was to investigate the ability of Staphylococcus aureus strains isolated from healthy patients with orthodontic appliances, to adhere to biotic (HeLa cells) and abiotic surfaces (polystyrene and dental alloy). Adhesive ability to polystyrene was tested by crystal violet staining and quantitative biofilm production on dental alloy surfaces was evaluated by MTT reduction assay. In addition, the presence of icaA and icaD genes was achieved by polymerase chain reaction (PCR). Qualitative biofilm production revealed that 70.6% of strains were slime producers. The metabolic activity of S. aureus biofilms on dental alloy surfaces was high and did not differ between tested strains. Moreover, all the isolates were adhesive to HeLa cells and 94% of them harbor icaA and icaD genes. Considerable adhesion and internalization capacity to the epithelial HeLa cells and strong biofilm production abilities together, with a high genotypic expression of icaA/icaD genes are an important equipment of S. aureus to colonize orthodontic appliances and eventually to disseminate towards other body areas.


Asunto(s)
Adhesión Bacteriana , Contaminación de Equipos/estadística & datos numéricos , Aparatos Ortodóncicos/microbiología , Staphylococcus aureus/fisiología , Adolescente , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Biopelículas , Femenino , Humanos , Masculino , Infecciones Estafilocócicas/microbiología , Staphylococcus aureus/clasificación , Staphylococcus aureus/genética , Staphylococcus aureus/aislamiento & purificación , Adulto Joven
19.
Am J Respir Crit Care Med ; 191(6): 637-45, 2015 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-25584431

RESUMEN

RATIONALE: The occurrence of ventilator-associated pneumonia (VAP) is linked to the aspiration of contaminated pharyngeal secretions around the endotracheal tube. Tubes with cuffs made of polyurethane rather than polyvinyl chloride or with a conical rather than a cylindrical shape increase tracheal sealing. OBJECTIVES: To test whether using polyurethane and/or conical cuffs reduces tracheal colonization and VAP in patients with acute respiratory failure. METHODS: We conducted a multicenter, prospective, open-label, randomized study in four parallel groups in four intensive care units between 2010 and 2012. A cohort of 621 patients with expected ventilation longer than 2 days was included at intubation with a cuff composed of cylindrical polyvinyl chloride (n = 148), cylindrical polyurethane (n = 143), conical polyvinyl chloride (n = 150), or conical polyurethane (n = 162). We used Kaplan-Meier estimates and log-rank tests to compare times to events. MEASUREMENTS AND MAIN RESULTS: After excluding 17 patients who secondarily refused participation or had met an exclusion criterion, 604 were included in the intention-to-treat analysis. Cumulative tracheal colonization greater than 10(3) cfu/ml at Day 2 was as follows (median [interquartile range]): cylindrical polyvinyl chloride, 0.66 (0.58-0.74); cylindrical polyurethane, 0.61 (0.53-0.70); conical polyvinyl chloride, 0.67 (0.60-0.76); and conical polyurethane, 0.62 (0.55-0.70) (P = 0.55). VAP developed in 77 patients (14.4%), and postextubational stridor developed in 28 patients (6.4%) (P = 0.20 and 0.28 between groups, respectively). CONCLUSIONS: Among patients requiring mechanical ventilation, polyurethane and/or conically shaped cuffs were not superior to conventional cuffs in preventing tracheal colonization and VAP. Clinical trial registered with clinicaltrials.gov (NCT01114022).


Asunto(s)
Intubación Intratraqueal/instrumentación , Neumonía Bacteriana/prevención & control , Anciano , Diseño de Equipo , Femenino , Humanos , Unidades de Cuidados Intensivos , Intubación Intratraqueal/efectos adversos , Masculino , Persona de Mediana Edad , Poliuretanos , Cloruro de Polivinilo , Estudios Prospectivos , Tráquea/microbiología
20.
Curr Microbiol ; 73(3): 324-334, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-27189386

RESUMEN

Hepatitis C virus (HCV) is a causative agent of chronic liver disease, cirrhosis, and hepatocellular carcinoma. It constitutes a major public health around the world. There is no vaccine available against HCV, and current therapies are effective in only small percentage of patients. HCV has wide population-specific genotype variability. Genotype knowledge and viral load assessment are equally important for designing therapeutic strategies. Taking into account that the molecular epidemiology of HCV variants circulating in Tunisia is not yet well elucidated, and that, at present, little is known about the distribution pattern of HCV in Monastir region (Tunisia), we aimed, herein, to evaluate the prevalence of HCV genotypes in Monastir and to identify risk-related factors. For this purpose, 50 anti-HCV antibody-positive cases were diagnosed and subjected to viral RNA extraction, amplification, genotyping, and viral load quantification. Molecular epidemiology was studied by 5' untranslated region (5' UTR) sequencing as compared with the non-structural 5B (NS5B) and core region sequences. Overall concordance between 5' UTR, core, and NS5B sequencing was 100 %. The highest prevalent genotype was 1b (50 %) followed by genotypes 1a (16 %), 4a (12 %), 2a (10 %), 2c (8 %), and 3a (4 %). Interestingly, the subtype 1b had a statistically significant higher viral load than the other genotypes followed by subtype 1a. Based on these data, this study revealed a high prevalence of HCV genotype 1 (subtypes 1b and 1a) compared to other genotypes. A continued monitoring of HCV and knowledge of circulating genotypes could impact on future vaccine formulations.


Asunto(s)
Regiones no Traducidas 5' , Hepacivirus/genética , Hepacivirus/aislamiento & purificación , Hepatitis C/virología , Proteínas del Núcleo Viral/genética , Proteínas no Estructurales Virales/genética , Adulto , Anciano , Femenino , Genotipo , Hepacivirus/clasificación , Hepatitis C/epidemiología , Humanos , Masculino , Persona de Mediana Edad , Prevalencia , Túnez/epidemiología , Proteínas del Núcleo Viral/metabolismo , Proteínas no Estructurales Virales/metabolismo
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