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1.
ChemMedChem ; 16(24): 3739-3749, 2021 12 14.
Artículo en Inglés | MEDLINE | ID: mdl-34550644

RESUMEN

Functionalized nanoparticles reveal new frontiers in therapeutics and diagnostics, simultaneously referred to as theranostics. Functionalization of an inorganic nanoparticle (NP) with an organic ligand determines the interaction of the functionalized NPs with various cellular components, leading to the desired therapeutic effect, while diminishing adverse side effects. Apart from the therapeutic effect of the nanoparticles, other physical properties of the organic-inorganic complex (nanohybrid) including fluorescence, X-ray or MRI contrast offer diagnosis of the anomalous target cell. In this study we functionalized Mn3 O4 NPs with organic citrate (C-Mn3 O4 ) and folic acid (FA-Mn3 O4 ) ligands and investigated their antimicrobial activities using Staphylococcus hominis as a model bacteria, which can be remediated through their membrane rupture. While high-resolution transmission microscopy (HR-TEM), XRD, DLS, absorbance and fluorescence spectroscopy were used for structural characterisation of the functionalised NPs, zeta potential measurements and temperature-dependent reactive oxygen speices (ROS) generation reveal their drug action. We used high-end density functional theory (DFT) calculations to rationalise the specificity of the drug action of the NPs. Picosecond-resolved FRET studies confirm the enhanced affinity of FA-Mn3 O4 to the bacteria relative to C-Mn3 O4 , leading to enhanced antimicrobial activity. We have shown that the functionalised nanoparticles offer significant X-ray contrast in in-vitro studies, indicating the FA-Mn3 O4 NPs to be a potential theranostic agent against bacterial infection.


Asunto(s)
Antibacterianos/farmacología , Teoría Funcional de la Densidad , Staphylococcus hominis/efectos de los fármacos , Antibacterianos/química , Ácido Cítrico/química , Ácido Cítrico/farmacología , Relación Dosis-Respuesta a Droga , Dispersión Dinámica de Luz , Ácido Fólico/química , Ácido Fólico/farmacología , Compuestos de Manganeso/química , Compuestos de Manganeso/farmacología , Pruebas de Sensibilidad Microbiana , Microscopía Electrónica de Transmisión , Estructura Molecular , Nanopartículas/química , Óxidos/química , Óxidos/farmacología , Espectrometría de Fluorescencia , Relación Estructura-Actividad , Nanomedicina Teranóstica , Difracción de Rayos X
2.
Proc Natl Acad Sci U S A ; 118(3)2021 01 19.
Artículo en Inglés | MEDLINE | ID: mdl-33431675

RESUMEN

Antimicrobial activity is being increasingly linked to amyloid fibril formation, suggesting physiological roles for some human amyloids, which have historically been viewed as strictly pathological agents. This work reports on formation of functional cross-α amyloid fibrils of the amphibian antimicrobial peptide uperin 3.5 at atomic resolution, an architecture initially discovered in the bacterial PSMα3 cytotoxin. The fibrils of uperin 3.5 and PSMα3 comprised antiparallel and parallel helical sheets, respectively, recapitulating properties of ß-sheets. Uperin 3.5 demonstrated chameleon properties of a secondary structure switch, forming mostly cross-ß fibrils in the absence of lipids. Uperin 3.5 helical fibril formation was largely induced by, and formed on, bacterial cells or membrane mimetics, and led to membrane damage and cell death. These findings suggest a regulation mechanism, which includes storage of inactive peptides as well as environmentally induced activation of uperin 3.5, via chameleon cross-α/ß amyloid fibrils.


Asunto(s)
Péptidos beta-Amiloides/metabolismo , Péptidos Catiónicos Antimicrobianos/metabolismo , Proteínas Bacterianas/metabolismo , Secuencia de Aminoácidos , Péptidos beta-Amiloides/química , Péptidos beta-Amiloides/farmacología , Animales , Péptidos Catiónicos Antimicrobianos/síntesis química , Péptidos Catiónicos Antimicrobianos/farmacología , Proteínas Bacterianas/química , Sitios de Unión , Cristalografía por Rayos X , Citotoxinas/química , Citotoxinas/metabolismo , Cinética , Lagartos/metabolismo , Pruebas de Sensibilidad Microbiana , Modelos Moleculares , Unión Proteica , Conformación Proteica en Hélice alfa , Conformación Proteica en Lámina beta , Dominios y Motivos de Interacción de Proteínas , Staphylococcus aureus/efectos de los fármacos , Staphylococcus epidermidis/efectos de los fármacos , Staphylococcus hominis/efectos de los fármacos , Homología Estructural de Proteína
3.
Microb Drug Resist ; 27(2): 145-153, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-32456543

RESUMEN

This study aimed at determining the mechanisms of linezolid resistance and the molecular characteristics of clinical Staphylococcus aureus (n = 2) and coagulase-negative staphylococci (n = 15) isolates obtained from four Spanish hospitals. The detection of linezolid resistance mechanisms (mutations and acquisition of resistance genes) was performed by PCR/sequencing. The antimicrobial resistance and virulence profile was determined, and the isolates were typed by different molecular techniques. Moreover, the genetic environment of the cfr gene was determined by whole-genome sequencing. The cfr gene was detected in one methicillin-resistant S. aureus (MRSA) that also displayed the amino acid change Val118Ala in the ribosomal protein L4. The second S. aureus isolate was methicillin susceptible and showed different alterations in the ribosomal protein L4. All remaining linezolid-resistant Staphylococcus epidermidis (n = 14) and Staphylococcus hominis isolates (n = 1) showed the mutation G2576T (n = 14) or C2534T (n = 1) in the 23S rRNA. Moreover, different amino acid changes were detected in the ribosomal proteins L3 and L4 in S. epidermidis isolates. All S. epidermidis isolates belonged to the multilocus sequence type ST2. Linezolid-resistant staphylococci (LRS) showed a multiresistance phenotype, including methicillin resistance that was detected in all isolates but one, and was mediated by the mecA gene. The cfr gene in the MRSA isolate was located together with the fexA gene on a conjugative 38,864 bp plasmid. Linezolid- and methicillin-resistant S. epidermidis ST2 showing mutations in the 23S rRNA and in the ribosomal proteins L3 and L4 are spread among Spanish hospitals, whereas LRS carrying acquired linezolid resistance genes are rarely detected.


Asunto(s)
Farmacorresistencia Bacteriana/efectos de los fármacos , Farmacorresistencia Bacteriana/genética , Linezolid/farmacología , Antibacterianos/farmacología , Coagulasa/genética , Humanos , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Staphylococcus aureus Resistente a Meticilina/genética , Pruebas de Sensibilidad Microbiana , ARN Ribosómico 23S/genética , Proteína Ribosomal L3 , Proteínas Ribosómicas/genética , España , Infecciones Estafilocócicas/tratamiento farmacológico , Infecciones Estafilocócicas/microbiología , Staphylococcus epidermidis/efectos de los fármacos , Staphylococcus epidermidis/genética , Staphylococcus hominis/efectos de los fármacos , Staphylococcus hominis/genética
4.
Nat Commun ; 11(1): 3894, 2020 08 04.
Artículo en Inglés | MEDLINE | ID: mdl-32753597

RESUMEN

Here, we demonstrate the self-assembly of the antimicrobial human LL-37 active core (residues 17-29) into a protein fibril of densely packed helices. The surface of the fibril encompasses alternating hydrophobic and positively charged zigzagged belts, which likely underlie interactions with and subsequent disruption of negatively charged lipid bilayers, such as bacterial membranes. LL-3717-29 correspondingly forms wide, ribbon-like, thermostable fibrils in solution, which co-localize with bacterial cells. Structure-guided mutagenesis analyses supports the role of self-assembly in antibacterial activity. LL-3717-29 resembles, in sequence and in the ability to form amphipathic helical fibrils, the bacterial cytotoxic PSMα3 peptide that assembles into cross-α amyloid fibrils. This argues helical, self-assembling, basic building blocks across kingdoms of life and points to potential structural mimicry mechanisms. The findings expose a protein fibril which performs a biological activity, and offer a scaffold for functional and durable biomaterials for a wide range of medical and technological applications.


Asunto(s)
Antibacterianos/química , Antibacterianos/farmacología , Péptidos Catiónicos Antimicrobianos/química , Péptidos Catiónicos Antimicrobianos/farmacología , Bacterias/efectos de los fármacos , Amiloide/metabolismo , Animales , Péptidos Catiónicos Antimicrobianos/genética , Bacterias/metabolismo , Benzotiazoles , Catelicidinas/farmacología , Cristalografía por Rayos X , Gorilla gorilla , Humanos , Pruebas de Sensibilidad Microbiana , Micrococcus luteus/efectos de los fármacos , Microscopía Confocal , Microscopía Electrónica de Transmisión , Modelos Moleculares , Conformación Proteica , Staphylococcus hominis/efectos de los fármacos , Difracción de Rayos X
5.
J Nat Prod ; 83(6): 1885-1890, 2020 06 26.
Artículo en Inglés | MEDLINE | ID: mdl-32479093

RESUMEN

Four natural lactylates of chlorinated fatty acids, chlorosphaerolactylates A-D (1-4), were isolated from the methanolic extract of the cyanobacterium Sphaerospermopsis sp. LEGE 00249 through a combination of bioassay-guided and MS-guided approaches. Compounds 1-4 are esters of (mono-, di-, or tri)chlorinated lauric acid and lactic acid, whose structures were assigned on the basis of spectrometric and spectroscopic methods inclusive of 1D and 2D NMR experiments. High-resolution mass-spectrometry data sets also demonstrated the existence of other minor components that were identified as chlorosphaero(bis)lactylate analogues. The chlorosphaerolactylates were tested for potential antibacterial, antifungal, and antibiofilm properties using bacterial and fungal clinical isolates. Compounds 1-4 showed a weak inhibitory effect on the growth of Staphylococcus aureus S54F9 and Candida parapsilosis SMI416, as well as on the biofilm formation of coagulase-negative Staphylococcus hominis FI31.


Asunto(s)
Antiinfecciosos/química , Cianobacterias/química , Ácidos Grasos/química , Antibacterianos/farmacología , Antiinfecciosos/aislamiento & purificación , Antiinfecciosos/farmacología , Antifúngicos/farmacología , Biopelículas/efectos de los fármacos , Candida/efectos de los fármacos , Ácidos Grasos/aislamiento & purificación , Ácidos Grasos/farmacología , Espectroscopía de Resonancia Magnética , Espectrometría de Masas , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Staphylococcus aureus/efectos de los fármacos , Staphylococcus hominis/efectos de los fármacos
6.
Microb Drug Resist ; 26(3): 251-260, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31549905

RESUMEN

This study compared changes in antimicrobial susceptibilities and molecular characteristics of coagulase-negative staphylococci (CNS) between the year 2000 and the year 2014-2015 to evaluate the policy of separating drug prescribing and dispensing in Korea. We obtained 68 CNS clinical isolates from two tertiary general hospitals before (the year 2000; n = 25) and after (the year 2014 - 2015; n = 43) implementation of the separation. Isolates were identified as Staphylococcus capitis, Staphylococcus epidermidis, Staphylococcus haemolyticus, Staphylococcus hominis, Staphylococcus saprophyticus, and Staphylococcus warneri. When minimal inhibitory concentrations of 14 antimicrobials were applied to isolates, resistance rates to gentamicin and oxacillin in 2000 were significantly higher than in 2014-2015 (p < 0.05). Fifty-seven isolates were methicillin-resistant CNS (MR-CNS), 42 of which were also multidrug resistant; overall, multidrug resistance decreased from 72% in the year 2000 to 55.8% in 2014-2015. Staphylococcal cassette chromosome mec (SCCmec) type III was the dominant type of MR-CNS in the year 2000, while SCCmec type IV was the dominant type in 2014-2015. Twenty-five sequence types (STs) were identified; ST2 appeared most frequently in both periods. After 15 years of implementation of this policy, multidrug resistance as well as methicillin and gentamicin resistance in CNS decreased, but not resistance to other antibiotics. Long-term surveillance at both genotypic and phenotypic levels of various species is necessary for further evaluation of this policy.


Asunto(s)
Antibacterianos/farmacología , Prescripciones de Medicamentos/estadística & datos numéricos , Farmacorresistencia Bacteriana Múltiple/genética , Infecciones Estafilocócicas/epidemiología , Staphylococcus epidermidis/genética , Staphylococcus haemolyticus/genética , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Coagulasa/deficiencia , Coagulasa/genética , Expresión Génica , Gentamicinas/farmacología , Humanos , Legislación de Medicamentos , Pruebas de Sensibilidad Microbiana , Oxacilina/farmacología , Filogenia , República de Corea/epidemiología , Infecciones Estafilocócicas/tratamiento farmacológico , Infecciones Estafilocócicas/microbiología , Staphylococcus , Staphylococcus capitis/clasificación , Staphylococcus capitis/efectos de los fármacos , Staphylococcus capitis/genética , Staphylococcus capitis/aislamiento & purificación , Staphylococcus epidermidis/clasificación , Staphylococcus epidermidis/efectos de los fármacos , Staphylococcus epidermidis/aislamiento & purificación , Staphylococcus haemolyticus/clasificación , Staphylococcus haemolyticus/efectos de los fármacos , Staphylococcus haemolyticus/aislamiento & purificación , Staphylococcus hominis/clasificación , Staphylococcus hominis/efectos de los fármacos , Staphylococcus hominis/genética , Staphylococcus hominis/aislamiento & purificación , Staphylococcus saprophyticus , Centros de Atención Terciaria
7.
Eur J Clin Microbiol Infect Dis ; 37(8): 1539-1545, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-29777490

RESUMEN

The study was performed to assess potential differences in the etiological relevance of two coagulase-negative staphylococci (CoNS), Staphylococcus haemolyticus and Staphylococcus hominis, in an observational single-center study. Over a 5-year interval, patients in whom there was detected S. haemolyticus or S. hominis of presumed etiological relevance were assessed for the primary endpoint death during hospital stay and the secondary endpoint transfer to an intensive care unit (ICU) after the detection of S. haemolyticus or S. hominis. Patients with S. haemolyticus or S. hominis died in 11.3% (50 out of 444) and 9.5% (60 out of 631) of cases, respectively, and were transferred to ICU after S. haemolyticus and S. hominis detection in 8.7% (19 out of 219) and 11.7% (44 out of 377) of cases, respectively. There was no significance for species-related influence on the primary outcome parameter (P > 0.1), while ICU transfers were more likely for patients with S. hominis detections (P = 0.016). Delayed diagnosis of both CoNS species was associated with an increased probability of death (P = 0.009). The study revealed comparable morbidity caused by S. haemolyticus and S. hominis identified in a clinically relevant context.


Asunto(s)
Infecciones Estafilocócicas/epidemiología , Infecciones Estafilocócicas/microbiología , Staphylococcus haemolyticus , Staphylococcus hominis , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Técnicas de Tipificación Bacteriana , Biodiversidad , Coagulasa/genética , Alemania/epidemiología , Humanos , Incidencia , Unidades de Cuidados Intensivos , Tiempo de Internación , Evaluación de Resultado en la Atención de Salud , Estudios Retrospectivos , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Infecciones Estafilocócicas/diagnóstico , Infecciones Estafilocócicas/tratamiento farmacológico , Staphylococcus haemolyticus/clasificación , Staphylococcus haemolyticus/efectos de los fármacos , Staphylococcus haemolyticus/genética , Staphylococcus haemolyticus/aislamiento & purificación , Staphylococcus hominis/clasificación , Staphylococcus hominis/efectos de los fármacos , Staphylococcus hominis/genética , Staphylococcus hominis/aislamiento & purificación
8.
Monaldi Arch Chest Dis ; 88(1): 885, 2018 02 26.
Artículo en Inglés | MEDLINE | ID: mdl-29557578

RESUMEN

Raoultella Ornithinolytica (RO) is an encapsulated, Gram- negative, nonmotile aerobic rob which was reclassified from Klepsiella genus belonging in the family of Enterobacteriaceae. It is a rare human infection and few cases have been reported in post thoracotomy patients. Here we present a case of a left lower lobectomy patient that was complicated by pleural effusion and high fever with positive sputum cultures of Raoultella Ornithinolytica and positive pleural fluid cultures of Staphylococcus hominis. It is related with aquatic life poisoning. There are few cases reported and even fewer postoperatively. The infection is rare in human therefore the bacteria is still underreported.


Asunto(s)
Infecciones por Enterobacteriaceae/microbiología , Enterobacteriaceae/aislamiento & purificación , Infecciones Estafilocócicas/microbiología , Staphylococcus hominis/aislamiento & purificación , Anciano , Antibacterianos/uso terapéutico , Carcinoma de Pulmón de Células no Pequeñas/complicaciones , Carcinoma de Pulmón de Células no Pequeñas/cirugía , Ciprofloxacina/administración & dosificación , Ciprofloxacina/uso terapéutico , Enterobacteriaceae/efectos de los fármacos , Infecciones por Enterobacteriaceae/tratamiento farmacológico , Humanos , Masculino , Meropenem/administración & dosificación , Meropenem/uso terapéutico , Derrame Pleural/tratamiento farmacológico , Derrame Pleural/microbiología , Complicaciones Posoperatorias/microbiología , Esputo/microbiología , Infecciones Estafilocócicas/tratamiento farmacológico , Staphylococcus hominis/efectos de los fármacos , Resultado del Tratamiento
9.
Int J Antimicrob Agents ; 51(6): 875-880, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29407274

RESUMEN

The fusidic acid (FUS) resistance determinants fusB, fusC, fusD and fusF in coagulase-negative staphylococci (CoNS) clinical isolates were examined. Among 208 FUS-resistant isolates, the fusB gene was the most common resistance determinant in each species, except in Staphylococcus hominis subsp. hominis or in species carrying intrinsic fusD or fusF. In S. hominis subsp. hominis, the fusC gene was the major determinant responsible for FUS resistance. To understand the genetic context of fusC in S. hominis subsp. hominis, 31 fusC-positive S. hominis subsp. hominis isolates were examined. Among these isolates, 14 carried SCCfusC, 3 carried an SCC476-like element and 7 carried a new SCC structure (SCC3390). As shown by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) analyses, the S. hominis subsp. hominis clinical isolates showed limited clonality. Taken together, SCCfusC has been found in S. hominis subsp. hominis, Staphylococcus epidermidis, Staphylococcus haemolyticus, Staphylococcus capitis subsp. ureolyticus and Staphylococcus aureus, suggesting its wide distribution and spread among different species of staphylococci.


Asunto(s)
Antibacterianos/farmacología , Farmacorresistencia Bacteriana/genética , Ácido Fusídico/farmacología , Transferencia de Gen Horizontal/genética , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Staphylococcus aureus Resistente a Meticilina/genética , Staphylococcus hominis/genética , Proteínas Bacterianas/genética , Humanos , Staphylococcus aureus Resistente a Meticilina/aislamiento & purificación , Pruebas de Sensibilidad Microbiana , Tipificación de Secuencias Multilocus , Staphylococcus capitis/efectos de los fármacos , Staphylococcus capitis/genética , Staphylococcus capitis/aislamiento & purificación , Staphylococcus epidermidis/efectos de los fármacos , Staphylococcus epidermidis/genética , Staphylococcus epidermidis/aislamiento & purificación , Staphylococcus haemolyticus/efectos de los fármacos , Staphylococcus haemolyticus/genética , Staphylococcus haemolyticus/aislamiento & purificación , Staphylococcus hominis/efectos de los fármacos , Staphylococcus hominis/aislamiento & purificación , Taiwán
10.
Rev Soc Bras Med Trop ; 50(3): 329-333, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28700050

RESUMEN

INTRODUCTION:: Methicillin resistant Staphylococcus hominis (MRSHo) has been recognized as an important human pathogen, particularly in immunocompromised patients. METHODS:: A total of 19 S. hominis isolates were collected from children at the Children's Medical Centre, Tehran, Iran, from March 2012 to February 2013. MRSHo susceptibility against 13 antimicrobial and 3 antiseptic agents was determined using disk diffusion (DAD) and minimum inhibitory concentration (MIC), respectively. All isolates were subjected to polymerase chain reaction (PCR) assay for 15 distinct resistance genes, staphylococcal cassette chromosome mec (SCCmec), and arginine catabolic mobile elements (ACMEs). Biofilm production of the isolates was determined using a colorimetric microtiter plate assay. RESULTS:: Of the 19 isolates, 16 were resistant to oxacillin and harbored mecA. High resistance was also observed against trimethoprim/sulfamethoxazole (81.2%). All MRSHo isolates were susceptible to the three disinfectants tested (Septicidine-PC, Septi turbo, and Sayacept-HP). In total, 15 (78.9%) isolates produced biofilms. Three isolates had SCCmec types (V and VIII), 13 were untypable (UT), and 5 had ACME type II. CONCLUSIONS:: The results indicate that MRSHo with high antibiotic resistance and unknown SCCmec might become a serious problem in the future for the treatment of patients such as children.


Asunto(s)
Antibacterianos/farmacología , Biopelículas/crecimiento & desarrollo , Cromosomas Bacterianos/genética , Resistencia a la Meticilina/genética , Infecciones Estafilocócicas/microbiología , Staphylococcus hominis/efectos de los fármacos , Niño , ADN Bacteriano , Farmacorresistencia Bacteriana , Humanos , Irán , Pruebas de Sensibilidad Microbiana , Staphylococcus hominis/fisiología
11.
Rev. Soc. Bras. Med. Trop ; 50(3): 329-333, May-June 2017. tab
Artículo en Inglés | LILACS | ID: biblio-896967

RESUMEN

Abstract INTRODUCTION: Methicillin resistant Staphylococcus hominis (MRSHo) has been recognized as an important human pathogen, particularly in immunocompromised patients. METHODS: A total of 19 S. hominis isolates were collected from children at the Children's Medical Centre, Tehran, Iran, from March 2012 to February 2013. MRSHo susceptibility against 13 antimicrobial and 3 antiseptic agents was determined using disk diffusion (DAD) and minimum inhibitory concentration (MIC), respectively. All isolates were subjected to polymerase chain reaction (PCR) assay for 15 distinct resistance genes, staphylococcal cassette chromosome mec (SCCmec), and arginine catabolic mobile elements (ACMEs). Biofilm production of the isolates was determined using a colorimetric microtiter plate assay. RESULTS: Of the 19 isolates, 16 were resistant to oxacillin and harbored mecA. High resistance was also observed against trimethoprim/sulfamethoxazole (81.2%). All MRSHo isolates were susceptible to the three disinfectants tested (Septicidine-PC, Septi turbo, and Sayacept-HP). In total, 15 (78.9%) isolates produced biofilms. Three isolates had SCCmec types (V and VIII), 13 were untypable (UT), and 5 had ACME type II. CONCLUSIONS: The results indicate that MRSHo with high antibiotic resistance and unknown SCCmec might become a serious problem in the future for the treatment of patients such as children.


Asunto(s)
Humanos , Niño , Infecciones Estafilocócicas/microbiología , Resistencia a la Meticilina/genética , Cromosomas Bacterianos/genética , Biopelículas/crecimiento & desarrollo , Staphylococcus hominis/efectos de los fármacos , Antibacterianos/farmacología , ADN Bacteriano , Pruebas de Sensibilidad Microbiana , Farmacorresistencia Bacteriana , Staphylococcus hominis/fisiología , Irán
12.
Indian J Med Res ; 146(3): 420-425, 2017 09.
Artículo en Inglés | MEDLINE | ID: mdl-29355151

RESUMEN

Staphylococcus hominis subsp. novobiosepticus is a new sub-species of S. hominis, thus dividing S. hominis into subsp. hominis and novobiosepticus. This study was designed to identify subsp. novobiosepticus isolates amongst the S. hominis isolated from blood samples of patients with malignancy and septicaemia and to study their resistance profile. The identification was performed by using three simple tests which differentiated between the two sub-species. It was found that 22.8 per cent of S. hominis isolates belonged to subsp. novobiosepticus.


Asunto(s)
Resistencia a Múltiples Medicamentos/genética , Neoplasias/tratamiento farmacológico , Sepsis/tratamiento farmacológico , Staphylococcus hominis/aislamiento & purificación , Acetilglucosamina/metabolismo , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neoplasias/complicaciones , Neoplasias/microbiología , Neoplasias/patología , Novobiocina/farmacología , Sepsis/complicaciones , Sepsis/microbiología , Staphylococcus hominis/efectos de los fármacos , Staphylococcus hominis/patogenicidad , Trehalosa/metabolismo
13.
PLoS One ; 11(12): e0167995, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27930711

RESUMEN

BACKGROUND: Coagulase negative staphylococci (CoNS) and Listeria monocytogenes have important roles in pathogenesis of various genital tract infections and fatal foetomaternal infections, respectively. The aim of our study was to investigate the inhibitory effects of two novel bacteriocins on biofilms of CoNS and L. monocytogenes genital isolates. METHODS: The effects of licheniocin 50.2 from Bacillus licheniformis VPS50.2 and crude extract of bacteriocins produced by Lactococcus lactis subsp. lactis biovar. diacetylactis BGBU1-4 (BGBU1-4 crude extract) were evaluated on biofilm formation and formed biofilms of eight CoNS (four S. epidermidis, two S. hominis, one S. lugdunensis and one S. haemolyticus) and 12 L. monocytogenes genital isolates. RESULTS: Licheniocin 50.2 and BGBU1-4 crude extract inhibited the growth of both CoNS and L. monocytogenes isolates, with MIC values in the range between 200-400 AU/ml for licheniocin 50.2 and 400-3200 AU/ml for BGBU1-4 crude extract. Subinhibitory concentrations (1/2 × and 1/4 × MIC) of licheniocin 50.2 inhibited biofilm formation by all CoNS isolates (p < 0.05, respectively), while BGBU1-4 crude extract inhibited biofilm formation by all L. monocytogenes isolates (p < 0.01 and p < 0.05, respectively). Both bacteriocins in concentrations of 100 AU/mL and 200 AU/mL reduced the amount of 24 h old CoNS and L. monocytogenes biofilms (p < 0.05, p < 0.01, p < 0.001). CONCLUSIONS: This study suggests that novel bacteriocins have potential to be used for genital application, to prevent biofilm formation and/or to eradicate formed biofilms, and consequently reduce genital and neonatal infections by CoNS and L. monocytogenes.


Asunto(s)
Antibacterianos/farmacología , Bacillus licheniformis/fisiología , Bacteriocinas/farmacología , Biopelículas/efectos de los fármacos , Lactococcus lactis/fisiología , Listeria monocytogenes/efectos de los fármacos , Staphylococcus/efectos de los fármacos , Bacillus licheniformis/metabolismo , Biopelículas/crecimiento & desarrollo , Humanos , Lactococcus lactis/metabolismo , Listeria monocytogenes/crecimiento & desarrollo , Pruebas de Sensibilidad Microbiana , Staphylococcus/crecimiento & desarrollo , Staphylococcus epidermidis/efectos de los fármacos , Staphylococcus epidermidis/crecimiento & desarrollo , Staphylococcus haemolyticus/efectos de los fármacos , Staphylococcus haemolyticus/crecimiento & desarrollo , Staphylococcus hominis/efectos de los fármacos , Staphylococcus hominis/crecimiento & desarrollo , Staphylococcus lugdunensis/efectos de los fármacos , Staphylococcus lugdunensis/crecimiento & desarrollo
14.
Bull Tokyo Dent Coll ; 57(3): 133-42, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27665691

RESUMEN

Periapical periodontitis usually results from microbial infection, with these microorganisms occasionally migrating to the root canal, which can lead to further, potentially life-threatening, complications. Here, the susceptibility of 27 bacterial strains to various antimicrobial agents was evaluated. These strains comprised 13 species; 16 of the strains were clinical isolates from periapical lesions. Each strain was inoculated onto blood agar plates containing one of the antimicrobial agents. The plates were incubated anaerobically at 37°C for 96 hr and the minimal inhibitory concentrations (MICs) determined. Ten strains required an MIC of 32 µg/ml or greater for amoxicillin, 6 for cefmetazole, and 5 for cefcapene among ß-lactam antibiotics; 8 strains required an MIC of 32 µg/ml or greater for clindamycin, 4 for azithromycin, and 11 for clarithromycin among macrolide antibiotics; 3 strains required an MIC of 32 µg/ml or greater for ciprofloxacin and 2 for ofloxacin among fluoroquinolones. The effect of cefcapene on 5 strains was evaluated after biofilm formation to investigate the relationship between biofilm formation and susceptibility. All strains showed a decrease in susceptibility after biofilm formation. The results revealed that several antimicrobial agents commonly used in a clinical setting, including amoxicillin, cefmetazole, and clindamycin, are potentially effective in the treatment of orofacial odontogenic infections. The development of resistant strains, however, means that this can no longer be guaranteed. In addition, azithromycin, ciprofloxacin, and ofloxacin were more effective than the 3 ß-lactam antibiotics tested. These results suggest that sensitivity testing is needed if odontogenic infections are to be treated safely and effectively.


Asunto(s)
Farmacorresistencia Bacteriana , Periodontitis Periapical/microbiología , Actinomyces/efectos de los fármacos , Amoxicilina/farmacología , Antibacterianos/farmacología , Azitromicina/farmacología , Biopelículas/efectos de los fármacos , Campylobacter/efectos de los fármacos , Cefmetazol/farmacología , Cefalosporinas/farmacología , Ciprofloxacina/farmacología , Claritromicina/farmacología , Clindamicina/farmacología , Fusobacterias/efectos de los fármacos , Haemophilus/efectos de los fármacos , Humanos , Klebsiella/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Ofloxacino/farmacología , Porphyromonas/efectos de los fármacos , Propionibacterium/efectos de los fármacos , Staphylococcus hominis/efectos de los fármacos , Veillonella/efectos de los fármacos
15.
Mater Sci Eng C Mater Biol Appl ; 61: 728-35, 2016 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-26838903

RESUMEN

Green synthesis of zinc oxide nanoparticles (ZnO-NPs) is gaining importance as an eco-friendly alternative to conventional methods due to its enormous applications. The present work reports the synthesis of ZnO-NPs using the endosperm of Cocos nucifera (coconut water) and the bio-molecules responsible for nanoparticle formation have been identified. The synthesized nanoparticles were characterized using UV-Visible spectroscopy (UV-Vis), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Transmission Electron Microscopy (TEM) and Zeta potential measurement. The results obtained reveal that the synthesized nanoparticles are moderately stable with the size ranging from 20 to 80 nm. The bactericidal effect of the nanoparticles was proved by well diffusion assay and determination of minimum inhibitory concentration (MIC) against marine biofilm forming bacteria. Further the green synthesized ZnO-NPs were doped with TEOS sol-gels (TESGs) in order to assess their antimicrofouling capability. Different volumes of liquid sol-gels were coated on to 96-well microtitre plate and cured under various conditions. The optimum curing conditions were found to be temperature 60 °C, time 72 h and volume 200 µl. Antiadhesion test of the undoped (SG) and ZnO-NP doped TEOS sol-gel (ZNSG) coatings were evaluated using marine biofilm forming bacteria. ZNSG coatings exhibited highest biofilm inhibition (89.2%) represented by lowest OD value against Pseudomonasotitidis strain NV1.


Asunto(s)
Geles/química , Nanopartículas del Metal/química , Silanos/química , Óxido de Zinc/química , Biopelículas/efectos de los fármacos , Enterobacter cloacae/efectos de los fármacos , Enterobacter cloacae/fisiología , Tecnología Química Verde , Nanopartículas del Metal/toxicidad , Pruebas de Sensibilidad Microbiana , Microscopía Electrónica de Rastreo , Tamaño de la Partícula , Pseudomonas/efectos de los fármacos , Pseudomonas/fisiología , Espectroscopía Infrarroja por Transformada de Fourier , Staphylococcus hominis/efectos de los fármacos , Staphylococcus hominis/fisiología , Temperatura
16.
Microb Drug Resist ; 22(2): 147-54, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26248114

RESUMEN

We investigated the prevalence of methicillin-resistant coagulase-negative staphylococci (MRCoNS) isolated from hospitalized patients and outpatients (OP). Out of 350 staphylococcal isolates collected from three hospitals, 190 were coagulase-negative staphylococci (CoNS). These isolates were subjected to antimicrobial susceptibility tests, detection of mecA, and pulsed-field gel electrophoresis (PFGE) typing. Among the 190 isolated CoNS, Staphylococcus epidermidis (47.3%) and Staphylococcus haemolyticus (44.2%) were the most prevalent species. Other CoNS species that were isolated were Staphylococcus saprophyticus (2.1%), Staphylococcus warneri (2.1%), Staphylococcus simulans (1.6%), Staphylococcus capitis (1.1%), Staphylococcus schleiferi (1.1%), and Staphylococcus hominis (0.5%). The rate of resistance to methicillin was 60% with 58 (50%) S. epidermidis and 55 (49%) S. haemolyticus. The rate of resistance to 13 antibiotics tested with the lowest and highest to chloramphenicol and penicillin, respectively. High clonal diversity with different PFGE patterns was obtained for methicillin-resistant S. epidermidis and S. haemolyticus by 32 and 31 types, respectively. Our results indicated that the dissemination of MRCoNS is widespread in Tehran. The majority of these isolates showed distinct genotyping patterns. At the same time, the common patterns were found among the MRCoNS obtained from outpatient and inpatient isolates, suggestive of an epidemiological link.


Asunto(s)
Antibacterianos/farmacología , Proteínas Bacterianas/genética , Variación Genética , Resistencia a la Meticilina , Staphylococcus/genética , Proteínas Bacterianas/metabolismo , Cloranfenicol/farmacología , Células Clonales , Coagulasa/deficiencia , Coagulasa/genética , Electroforesis en Gel de Campo Pulsado , Genotipo , Humanos , Pacientes Internos , Irán , Meticilina/farmacología , Pruebas de Sensibilidad Microbiana , Pacientes Ambulatorios , Penicilinas/farmacología , Filogenia , Infecciones Estafilocócicas/tratamiento farmacológico , Infecciones Estafilocócicas/microbiología , Staphylococcus/clasificación , Staphylococcus/efectos de los fármacos , Staphylococcus/aislamiento & purificación , Staphylococcus epidermidis/efectos de los fármacos , Staphylococcus epidermidis/genética , Staphylococcus epidermidis/aislamiento & purificación , Staphylococcus haemolyticus/efectos de los fármacos , Staphylococcus haemolyticus/genética , Staphylococcus haemolyticus/aislamiento & purificación , Staphylococcus hominis/efectos de los fármacos , Staphylococcus hominis/genética , Staphylococcus hominis/aislamiento & purificación
17.
Folia Microbiol (Praha) ; 61(2): 143-7, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26253583

RESUMEN

Coagulase-negative staphylococci (CoNS) are the most frequently isolated bacteria from the blood and the predominant cause of nosocomial infections. Macrolides, lincosamides and streptogramin B (MLSB) antibiotics, especially erythromycin and clindamycin, are important therapeutic agents in the treatment of methicillin-resistant staphylococci infections. Among CoNS, Staphylococcus hominis represents the third most common organism. In spite of its clinical significance, very little is known about its mechanisms of resistance to antibiotics, especially MLSB. Fifty-five S. hominis isolates from the blood and the surgical wounds of hospitalized patients were studied. The erm(C) gene was predominant in erythromycin-resistant S. hominis isolates. The methylase genes, erm(A) and erm(B), were present in 15 and 25% of clinical isolates, respectively. A combination of various erythromycin resistance methylase (erm) genes was detected in 15% S. hominis isolates. The efflux gene msr(A) was detected in 18% of isolates, alone in four isolates, and in different combinations in a further six. The lnu(A) gene, responsible for enzymatic inactivation of lincosamides was carried by 31% of the isolates. No erythromycin resistance that could not be attributed to the genes erm(A), erm(B), erm(C) and msr(A) was detected. In S. hominis, 75 and 84%, respectively, were erythromycin resistant and clindamycin susceptible. Among erythromycin-resistant S. hominis isolates, 68% of these strains showed the inducible MLSB phenotype. Four isolates harbouring the msr(A) genes alone displayed the MSB phenotype. These studies indicated that resistance to MLSB in S. hominis is mostly based on the ribosomal target modification mechanism mediated by erm genes, mainly the erm(C), and enzymatic drug inactivation mediated by lnu(A).


Asunto(s)
Antibacterianos/farmacología , Lincosamidas/farmacología , Macrólidos/farmacología , Infecciones Estafilocócicas/microbiología , Staphylococcus hominis/efectos de los fármacos , Estreptograminas/farmacología , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Farmacorresistencia Bacteriana Múltiple , Humanos , Metiltransferasas/genética , Metiltransferasas/metabolismo , Pruebas de Sensibilidad Microbiana , Staphylococcus hominis/clasificación , Staphylococcus hominis/enzimología , Staphylococcus hominis/genética
18.
PLoS One ; 10(12): e0144684, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26659110

RESUMEN

OBJECTIVES: We aimed to characterise the staphylococcal cassette chromosome mec (SCCmec) type, genetic relatedness, biofilm formation and composition, icaADBC genes detection, icaD expression, and antibiotic susceptibility of planktonic and biofilm cells of Staphylococcus hominis isolates from blood. METHODS: The study included 67 S. hominis blood isolates. Methicillin resistance was evaluated with the cefoxitin disk test. mecA gene and SCCmec were detected by multiplex PCR. Genetic relatedness was determined by pulsed-field gel electrophoresis. Biofilm formation and composition were evaluated by staining with crystal violet and by detachment assay, respectively; and the biofilm index (BI) was determined. Detection and expression of icaADBC genes were performed by multiplex PCR and real-time PCR, respectively. Antibiotic susceptibilities of planktonic cells (minimum inhibitory concentration, MIC) and biofilm cells (minimum biofilm eradication concentration, MBEC) were determined by the broth dilution method. RESULTS: Eighty-five percent (57/67) of isolates were methicillin resistant and mecA positive. Of the mecA-positive isolates, 66.7% (38/57) carried a new putative SCCmec type. Four clones were detected, with two to five isolates each. Among all isolates, 91% (61/67) were categorised as strong biofilm producers. Biofilm biomass composition was heterogeneous (polysaccharides, proteins and DNA). All isolates presented the icaD gene, and 6.66% (1/15) isolates expressed icaD. This isolate presented the five genes of ica operon. Higher BI and MBEC values than the MIC values were observed for amikacin, vancomycin, linezolid, oxacillin, ciprofloxacin, and chloramphenicol. CONCLUSIONS: S. hominis isolates were highly resistant to methicillin and other antimicrobials. Most of the detected SCCmec types were different than those described for S. aureus. Isolates indicated low clonality. The results indicate that S. hominis is a strong biofilm producer with an extracellular matrix with similar composition of proteins, DNA and N-acetylglucosamine; and presents high frequency and low expression of icaD gene. Biofilm production is associated with increased antibiotic resistance.


Asunto(s)
Antibacterianos/farmacología , Proteínas Bacterianas/genética , Biopelículas/efectos de los fármacos , Farmacorresistencia Bacteriana/genética , Regulación Bacteriana de la Expresión Génica , Staphylococcus hominis/genética , Amidohidrolasas/genética , Amidohidrolasas/metabolismo , Bacteriemia/tratamiento farmacológico , Bacteriemia/microbiología , Proteínas Bacterianas/metabolismo , Biopelículas/crecimiento & desarrollo , Cefoxitina/farmacología , Cromosomas Bacterianos/química , Cromosomas Bacterianos/metabolismo , Ciprofloxacina/farmacología , Humanos , Meticilina/farmacología , Pruebas de Sensibilidad Microbiana , Operón , Oxacilina/farmacología , Proteínas de Unión a las Penicilinas/genética , Proteínas de Unión a las Penicilinas/metabolismo , Filogenia , Plancton/efectos de los fármacos , Plancton/crecimiento & desarrollo , Infecciones Estafilocócicas/tratamiento farmacológico , Infecciones Estafilocócicas/microbiología , Staphylococcus hominis/clasificación , Staphylococcus hominis/efectos de los fármacos , Staphylococcus hominis/aislamiento & purificación , Vancomicina/farmacología
19.
APMIS ; 123(10): 867-71, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26227107

RESUMEN

The aim of this article were to determinate the mechanism of linezolid resistance in coagulase-negative methicillin-resistant staphylococci from hospitals in the northeast of Brazil. We identified the isolates using VITEK(®) 2 and MALDI-TOF. Susceptibility to antibiotics was measured by the disk-diffusion method and by Etest(®) . Extraction of the whole genome DNA was performed, followed by screening of all the strains for the presence of mecA and cfr genes. The domain V region of 23S rRNA gene was sequenced and then aligned with a linezolid-susceptible reference strain. Pulsed-field gel electrophoresis (PFGE) macro-restriction analysis was performed. Three linezolid-resistant Staphylococcus hominis and two linezolid-resistant Staphylococcus epidermidis strains were analyzed. The isolates showed two point mutations in the V region of the 23S rRNA gene (C2190T and G2603T). We did not detect the cfr gene in any isolate by PCR. The S. hominis showed the same pulsotype, while the S. epidermidis did not present any genetic relation to each other. In conclusion, this study revealed three S. hominis and two S. epidermidis strains with resistance to linezolid due to a double mutation (C2190T and G2603T) in the domain V of the 23S rRNA gene. For the first time, the mutation of C2190T in S. epidermidis is described. This study also revealed the clonal spread of a S. hominis pulsotype between three public hospitals in the city of Natal, Brazil. These findings highlight the importance of continued vigilance of linezolid resistance in staphylococci.


Asunto(s)
Linezolid/farmacología , Meticilina/farmacología , ARN Ribosómico 23S/genética , Staphylococcus epidermidis/efectos de los fármacos , Staphylococcus hominis/efectos de los fármacos , Antibacterianos , Secuencia de Bases , Coagulasa/biosíntesis , Humanos , Resistencia a la Meticilina/genética , Pruebas de Sensibilidad Microbiana , Mutación/genética , Análisis de Secuencia de ARN , Staphylococcus epidermidis/genética , Staphylococcus epidermidis/aislamiento & purificación , Staphylococcus hominis/genética , Staphylococcus hominis/aislamiento & purificación
20.
Vet Microbiol ; 177(3-4): 353-8, 2015 Jun 12.
Artículo en Inglés | MEDLINE | ID: mdl-25891423

RESUMEN

The aim of this study was to investigate the genetic basis of combined pleuromutilin-lincosamide-streptogramin A resistance in 26 unrelated methicillin-resistant Staphylococcus aureus (MRSA) and coagulase-negative staphylococci (CoNS) from dairy cows suffering from mastitis. The 26 pleuromutilin-resistant staphylococcal isolates were screened for the presence of the genes vga(A), vga(B), vga(C), vga(E), vga(E) variant, sal(A), vmlR, cfr, lsa(A), lsa(B), lsa(C), and lsa(E) by PCR. None of the 26 isolates carried the genes vga(B), vga(C), vga(E), vga(E) variant, vmlR, cfr, lsa(A), lsa(B), or lsa(C). Two Staphylococcus haemolyticus and single Staphylococcus xylosus, Staphylococcus lentus, and Staphylococcus hominis were vga(A)-positive. Twelve S. aureus, two Staphylococcus warneri, as well as single S. lentus and S. xylosus carried the lsa(E) gene. Moreover, single S. aureus, S. haemolyticus, S. xylosus, and Staphylococcus epidermidis were positive for both genes, vga(A) and lsa(E). The sal(A) gene was found in a single Staphylococcus sciuri. All ABC transporter genes were located in the chromosomal DNA, except for a plasmid-borne vga(A) gene in the S. epidermidis isolate. The genetic environment of the lsa(E)-positive isolates was analyzed using previously described PCR assays. Except for the S. warneri and S. xylosus, all lsa(E)-positive isolates harbored a part of the previously described enterococcal multiresistance gene cluster. This is the first report of the novel lsa(E) gene in the aforementioned bovine CoNS species. This is also the first identification of the sal(A) gene in a S. sciuri from a case of bovine mastitis. Moreover, the sal(A) gene was shown to also confer pleuromutilin resistance.


Asunto(s)
Transportadoras de Casetes de Unión a ATP/genética , Antibacterianos/farmacología , Mastitis Bovina/microbiología , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Staphylococcus/efectos de los fármacos , Animales , Bovinos , Coagulasa/genética , Diterpenos/farmacología , Farmacorresistencia Bacteriana Múltiple/genética , Femenino , Lincosamidas/farmacología , Mastitis Bovina/tratamiento farmacológico , Meticilina/farmacología , Staphylococcus aureus Resistente a Meticilina/genética , Pruebas de Sensibilidad Microbiana , Compuestos Policíclicos , Infecciones Estafilocócicas/microbiología , Infecciones Estafilocócicas/veterinaria , Staphylococcus/enzimología , Staphylococcus epidermidis/efectos de los fármacos , Staphylococcus epidermidis/genética , Staphylococcus haemolyticus/efectos de los fármacos , Staphylococcus haemolyticus/genética , Staphylococcus hominis/efectos de los fármacos , Staphylococcus hominis/genética , Estreptogramina A/farmacología , Estreptograminas/farmacología , Pleuromutilinas
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