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1.
Artículo en Inglés | MEDLINE | ID: mdl-29914964

RESUMEN

We tested the in vitro susceptibility of ceftazidime-avibactam and ceftolozane-tazobactam and 13 other antibiotics against 91 Burkholderia cepacia complex (BCC) strains isolated from cystic fibrosis patients since 2012. The highest susceptibility (82%) was found for trimethoprim-sulfamethoxazole. Eighty-one and 63% of all BCC strains were susceptible to ceftazidime-avibactam and ceftolozane-tazobactam, respectively. For temocillin, ceftazidime, piperacillin-tazobactam, and meropenem, at least 50% of the strains were susceptible. B. stabilis seems to be more resistant than other BCC species.


Asunto(s)
Compuestos de Azabiciclo/farmacología , Complejo Burkholderia cepacia/efectos de los fármacos , Ceftazidima/farmacología , Cefalosporinas/farmacología , Fibrosis Quística/microbiología , Tazobactam/farmacocinética , Antibacterianos/farmacología , Complejo Burkholderia cepacia/aislamiento & purificación , Combinación de Medicamentos , Humanos , Pruebas de Sensibilidad Microbiana , Sulfametoxazol/farmacología , Tazobactam/farmacología , Trimetoprim/farmacología
2.
Appl Environ Microbiol ; 84(7)2018 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-29352086

RESUMEN

Few data have been published on the occurrence and functional role of acetic acid bacteria (AAB) in lambic beer production processes, mainly due to their difficult recovery and possibly unknown role. Therefore, a novel aseptic sampling method, spanning both the spatial and temporal distributions of the AAB and their substrates and metabolites, was combined with a highly selective medium and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) as a high-throughput dereplication method followed by comparative gene sequencing for their isolation and identification, respectively. The AAB (Acetobacter species more than Gluconobacter species) proliferated during two phases of the lambic beer production process, represented by Acetobacter orientalis during a few days in the beginning of the fermentation and Acetobacter pasteurianus from 7 weeks until 24 months of maturation. Competitive exclusion tests combined with comparative genomic analysis of all genomes of strains of both species available disclosed possible reasons for this successive dominance. The spatial analysis revealed that significantly higher concentrations of acetic acid (from ethanol) and acetoin (from lactic acid) were produced at the tops of the casks, due to higher AAB counts and a higher metabolic activity of the AAB species at the air/liquid interface during the first 6 months of lambic beer production. In contrast, no differences in AAB species diversity occurred throughout the casks.IMPORTANCE Lambic beer is an acidic beer that is the result of a spontaneous fermentation and maturation process. Acidic beers are currently attracting attention worldwide. Part of the acidity of these beers is caused by acetic acid bacteria (AAB). However, due to their difficult recovery, they were never investigated extensively regarding their occurrence, species diversity, and functional role in lambic beer production. In the present study, a framework was developed for their isolation and identification using a novel aseptic sampling method in combination with matrix-assisted laser desorption ionization-time of flight mass spectrometry as a high-throughput dereplication technique followed by accurate molecular identification. The sampling method applied enabled us to take spatial differences into account regarding both enumerations and metabolite production. In this way, it was shown that more AAB were present and more acetic acid was produced at the air/liquid interface during a major part of the lambic beer production process. Also, two different AAB species were encountered, namely, Acetobacter orientalis at the beginning and Acetobacter pasteurianus in a later stage of the production process. This developed framework could also be applied for other fermentation processes.


Asunto(s)
Ácido Acético/metabolismo , Acetobacter/metabolismo , Cerveza/microbiología , Gluconobacter/metabolismo , Fermentación , Microbiota
3.
Eur J Clin Microbiol Infect Dis ; 36(11): 2263-2271, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28840370

RESUMEN

Burkholderia sp. infections are extremely complex in cystic fibrosis (CF) patients, especially considering the lack of knowledge regarding its behavior, its relationship with prognosis, as well as its transmissibility and multidrug resistance features. This study evaluated the frequency of chronic infection by Burkholderia, using microbiological and clinical data. Ninety-eight patients with CF attended from July 2011 to April 2014 in a Brazilian reference hospital were included. Antimicrobial activity, molecular epidemiology, Shwachman score, body mass index, exacerbations, and lung function were analyzed. Nine patients had chronic colonization, and all of them showed preserved pulmonary function levels, body mass index, and Shwachman score. Meropenem was the most effective antibiotic; however, divergent results were shown by other studies. Cross-contamination may have occurred in only two unrelated patients of different ages, who were colonized by B. vietnamiensis, which does not occur frequently. Twelve new sequence types (STs) were identified and three STs have presented intercontinental distribution. None of the patients presented known epidemic strains. In conclusion, a relatively low number of patients with chronic colonization and suspected cross-infection were identified. Different from other studies that have found CF patients chronically colonized with Burkholderia sp. having a greater deterioration of lung function, more frequent antibiotic therapy, and increased mortality, in the current study, the patients showed good clinical outcomes and favorable options for antibiotics therapy. This study also updated the epidemiological database, which facilitates the multicentric collaborative analysis and assists in the control of global infection by these pathogens.


Asunto(s)
Antibacterianos/uso terapéutico , Infecciones por Burkholderia/tratamiento farmacológico , Infecciones por Burkholderia/epidemiología , Complejo Burkholderia cepacia/aislamiento & purificación , Fibrosis Quística/microbiología , Adolescente , Adulto , Brasil/epidemiología , Infecciones por Burkholderia/complicaciones , Infecciones por Burkholderia/patología , Complejo Burkholderia cepacia/clasificación , Complejo Burkholderia cepacia/genética , Ceftazidima/uso terapéutico , Niño , Preescolar , Infección Hospitalaria , Fibrosis Quística/complicaciones , Electroforesis en Gel de Campo Pulsado , Femenino , Hospitales , Humanos , Lactante , Pulmón/patología , Masculino , Meropenem , Pruebas de Sensibilidad Microbiana , Tipificación Molecular , Pruebas de Función Respiratoria , Tienamicinas/uso terapéutico , Resultado del Tratamiento , Combinación Trimetoprim y Sulfametoxazol/uso terapéutico , Adulto Joven
4.
Infect Immun ; 84(8): 2307-2316, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-27245408

RESUMEN

A urease-negative, fusiform, novel bacterium named Helicobacter saguini was isolated from the intestines and feces of cotton-top tamarins (CTTs) with chronic colitis. Helicobacter sp. was detected in 69% of feces or intestinal samples from 116 CTTs. The draft genome sequence, obtained by Illumina MiSeq sequencing, for H. saguini isolate MIT 97-6194-5, consisting of ∼2.9 Mb with a G+C content of 35% and 2,704 genes, was annotated using the NCBI Prokaryotic Genomes Automatic Annotation Pipeline. H. saguini contains homologous genes of known virulence factors found in other enterohepatic helicobacter species (EHS) and H. pylori These include flagellin, γ-glutamyl transpeptidase (ggt), collagenase, the secreted serine protease htrA, and components of a type VI secretion system, but the genome does not harbor genes for cytolethal distending toxin (cdt). H. saguini MIT 97-6194-5 induced significant levels of interleukin-8 (IL-8) in HT-29 cell culture supernatants by 4 h, which increased through 24 h. mRNAs for the proinflammatory cytokines IL-1ß, tumor necrosis factor alpha (TNF-α), IL-10, and IL-6 and the chemokine CXCL1 were upregulated in cocultured HT-29 cells at 4 h compared to levels in control cells. At 3 months postinfection, all H. saguini-monoassociated gnotobiotic C57BL/129 IL-10(-/-) mice were colonized and had seroconverted to H. saguini antigen with a significant Th1-associated increase in IgG2c (P < 0.0001). H. saguini induced a significant typhlocolitis, associated epithelial defects, mucosa-associated lymphoid tissue (MALT) hyperplasia, and dysplasia. Inflammatory cytokines IL-22, IL-17a, IL-1ß, gamma interferon (IFN-γ), and TNF-α, as well as inducible nitric oxide synthase (iNOS) were significantly upregulated in the cecal tissues of infected mice. The expression of the DNA damage response molecule γ-H2AX was significantly higher in the ceca of H. saguini-infected gnotobiotic mice than in the controls. This model using a nonhuman primate Helicobacter sp. can be used to study the pathogenic potential of EHS isolated from primates with naturally occurring inflammatory bowel disease (IBD) and colon cancer.


Asunto(s)
Colitis Ulcerosa/veterinaria , Colitis/microbiología , Colitis/patología , Helicobacter/fisiología , Enfermedades de los Monos/microbiología , Animales , Anticuerpos Antibacterianos/inmunología , Línea Celular , Colitis/genética , Colitis/inmunología , Citocinas/genética , Modelos Animales de Enfermedad , Heces/microbiología , Expresión Génica , Genoma Bacteriano , Helicobacter/clasificación , Helicobacter/aislamiento & purificación , Histonas/metabolismo , Humanos , Mediadores de Inflamación/metabolismo , Interleucina-10/deficiencia , Ratones , Ratones Noqueados , Filogenia , ARN Ribosómico 16S/genética
5.
Eur J Clin Microbiol Infect Dis ; 34(7): 1403-13, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25820290

RESUMEN

Drug susceptibility testing (DST) of rapidly growing mycobacteria (RGM) are recommended for guiding the antimicrobial therapy. We have evaluated the use of resazurin in Mueller-Hinton medium (MHR) for MIC determination of RGM and compared the results with those obtained with the reference standard broth microdilution in Mueller-Hinton (MH) and with the resazurin microtiter assay (REMA) in 7H9 broth. The MIC of eight drugs: amikacin (AMI), cefoxitin (FOX), ciprofloxacin (CIP), clarithromycin (CLA), doxycycline (DOX), linezolid (LZD), moxifloxacin (MXF) and trimethoprim-sulfamethoxazole (TMP-SMX) were evaluated against 76 RGM (18 species) using three methods (MH, MHR, and REMA) in a 96-well plate format incubated at 37 °C over 3-5 days. Results obtained in the MH plates were interpreted by the appearance of turbidity at the bottom of the well before adding the resazurin. MHR and 7H9-REMA plates were read by visual observation for a change in color from blue to pink. The majority of results were obtained at day 5 for MH and 1 day after for MHR and 7H9-REMA. However, the preliminary experiment on time to positivity results using the reference strain showed that the resazurin can be added to the MH at day 2 to produce the results at day 3, but future studies with large sets of strains are required to confirm this suggestion. A high level of agreement (kappa 1.000-0.884) was obtained between the MH and the MHR. Comparison of results obtained with 7H9-REMA, on the other hand, revealed several discrepancies and a lower level of agreement (kappa 1.000-0.111). The majority of the strains were resistant to DOX and TMP-SMX, and the most active antimicrobials for RGM were AMI and FOX. In the present study, MHR represented an excellent alternative for MIC determination of RGM. The results could be read reliably, more easily, and more quickly than with the classical MH method.


Asunto(s)
Antibacterianos/farmacología , Pruebas de Sensibilidad Microbiana/métodos , Mycobacterium/efectos de los fármacos , Humanos , Mycobacterium/crecimiento & desarrollo , Mycobacterium/aislamiento & purificación , Infecciones por Mycobacterium/microbiología , Micobacterias no Tuberculosas/efectos de los fármacos , Micobacterias no Tuberculosas/crecimiento & desarrollo , Micobacterias no Tuberculosas/aislamiento & purificación , Factores de Tiempo
6.
Int J Syst Evol Microbiol ; 62(Pt 2): 299-306, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21421932

RESUMEN

Three gram-negative, microaerophilic bacteria, strains ASB1(T), ASB2 and ASB3, with a corkscrew-like morphology isolated from the gastric mucosa of cats were studied using a polyphasic taxonomic approach. The isolates grew on biphasic culture plates under microaerobic conditions at 37 °C and exhibited urease, oxidase and catalase activities. They were also able to grow in colonies on dry agar plates. Based on 16S rRNA gene sequence analysis, ASB1(T), ASB2 and ASB3 were identified as members of the genus Helicobacter and showed 98 to 99 % sequence similarity to strains of Helicobacter felis, Helicobacter bizzozeronii, 'Candidatus Helicobacter heilmannii', Helicobacter cynogastricus, Helicobacter baculiformis and Helicobacter salomonis, six related Helicobacter species previously detected in feline or canine gastric mucosa. Sequencing of the partial hsp60 gene demonstrated that ASB1(T), ASB2 and ASB3 constitute a separate taxon among the feline and canine Helicobacter species. The urease gene sequences of ASB1(T), ASB2 and ASB3 showed approximately 91 % similarity to those of 'Candidatus Helicobacter heilmannii'. Protein profiling, the absence of alkaline phosphatase activity and several other biochemical characteristics also allowed strains ASB1(T), ASB2 and ASB3 to be differentiated from other Helicobacter species of feline or canine gastric origin. The results of this polyphasic taxonomic study show that the cultured isolates constitute a new taxon corresponding to 'Candidatus Helicobacter heilmannii', which was previously demonstrated in the stomach of humans, wild felidae, cats and dogs. The name Helicobacter heilmannii sp. nov. is proposed for these isolates; the type strain is ASB1(T) (=DSM 24751 (T) =LMG 26292(T)) [corrected].


Asunto(s)
Enfermedades de los Gatos/microbiología , Mucosa Gástrica/microbiología , Infecciones por Helicobacter/veterinaria , Helicobacter heilmannii/clasificación , Helicobacter heilmannii/aislamiento & purificación , Animales , Proteínas Bacterianas/química , Técnicas de Tipificación Bacteriana , Gatos , Chaperonina 60/genética , Chaperonina 60/metabolismo , ADN Bacteriano/análisis , ADN Ribosómico/análisis , Perros , Electroforesis/métodos , Genes de ARNr , Infecciones por Helicobacter/microbiología , Helicobacter heilmannii/genética , Helicobacter heilmannii/metabolismo , Humanos , Datos de Secuencia Molecular , Filogenia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Especificidad de la Especie , Ureasa/genética
7.
Lett Appl Microbiol ; 55(4): 265-73, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22774847

RESUMEN

AIMS: To evaluate the potential use of MALDI-TOF MS for fast and reliable classification and identification of lactic acid bacteria (LAB) from traditional fermented foods. METHODS AND RESULTS: A total of 119 strains of LAB from fermented meat (nem chua) were analysed with both (GTG)(5)-PCR fingerprinting and MALDI-TOF MS. Cluster analysis of the profiles revealed five species represented by a single isolate both in (GTG)(5)-PCR and in MALDI-TOF MS; five species grouped alike for (GTG)(5)-PCR and for MALDI-TOF MS; however, differences in minimal similarity between the delineated (GTG)(5)-PCR and MALDI-TOF MS clusters could be observed; three species showed more heterogeneity in their MALDI-TOF MS profiles compared to their (GTG)(5)-PCR profiles; two species, each represented by a single MALDI-TOF cluster, were subdivided in the corresponding (GTG)(5)-PCR dendrogram. As proof of the identification potential of MALDI-TOF MS, LAB diversity from one fermented mustard sample was analysed using MALDI-TOF MS. PheS gene sequencing was used for validation. CONCLUSIONS: MALDI-TOF MS is a powerful, fast, reliable and cost-effective technique for the identification of LAB associated with the production of fermented foods. SIGNIFICANCE AND IMPACT OF THE STUDY: Food LAB can be identified using MALDI-TOF MS, and its application could possibly be extended to other food matrices and/or other food-derived micro-organisms.


Asunto(s)
Fermentación , Microbiología de Alimentos/métodos , Lactobacillaceae/clasificación , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , Análisis por Conglomerados , Ácido Láctico , Lactobacillaceae/aislamiento & purificación , Reacción en Cadena de la Polimerasa , Vietnam
8.
New Microbes New Infect ; 39: 100829, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33473321

RESUMEN

An immunocompetent patient without a history of recent travel or animal exposure developed persistent abdominal bloating and cramps without diarrhoea or fever. Negative additional investigations excluded gastritis, infectious colitis, inflammatory bowel disease and neoplasia, but routine stool culture detected a Campylobacter-like organism. The isolate was obtained with use of a polycarbonate filter technique, emphasizing the importance of culture to support and validate the occurrence of emerging and new bacterial enteric pathogens. The ensuing extensive laboratory examinations proved challenging in identifying this potential pathogen. Phylogenetic marker analysis based on the 16S ribosomal RNA and rpoB gene sequences revealed that the isolate was most closely related to Arcobacter lanthieri and Arcobacter faecis. Subsequent analysis of a draft whole genome sequence assigned the isolate to A. lanthieri. We report the presence of five virulence genes, cadF, ciaB, mviN, hecA and iroE, indicating a possible pathogenic nature of this organism. This case demonstrated the importance of the use of agnostic methods for the detection of emerging pathogens in cases of enteric disease with a wide array of gastrointestinal symptoms.

9.
J Appl Microbiol ; 106(4): 1081-92, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19187144

RESUMEN

AIMS: To investigate the circulation of predominant sourdough lactic acid bacteria (LAB) species in the production environment of two Belgian artisan sourdough bakeries. METHODS AND RESULTS: Isolates were collected from sourdoughs, flour, hands of the baker and air in the bakery setting and taxonomically characterized using repetitive element sequence-based PCR fingerprinting, pheS and/or 16S rRNA gene sequencing and amplified fragment length polymorphism (AFLP) analysis. In parallel, PCR-DGGE (denaturing gradient gel electrophoresis) analysis of V3-16S rDNA amplicons was applied to visualize the predominant bacterial population in the sourdoughs and the corresponding bakery environment (flour, hands of the baker, air and bakery equipment). Both approaches revealed that sourdoughs produced at D01 and D10 were mainly dominated by Lactobacillus spicheri and L. plantarum and by L. sanfranciscensis, respectively, and that these LAB species also circulated in the corresponding bakery environment. Furthermore, AFLP fingerprinting demonstrated that sourdough and bakery environment isolates of these species were genetically indistinguishable. For more sensitive source-tracking, SYBR Green-based real-time PCR assays were developed using species-specific primers targeting the pheS gene of L. plantarum and L. sanfranciscensis, detected in air samples from D01 and D10, respectively. CONCLUSIONS: The results obtained in this study indicate that specific strains of LAB persist in artisan doughs over years and circulate in the bakery environment. Furthermore, the importance of air as a potential carrier of LAB in artisan bakery environments was demonstrated. SIGNIFICANCE AND IMPACT OF THE STUDY: PheS-based real-time PCR can be used to detect, quantify and/or monitor specific LAB species (e.g. starter cultures) in sourdough and bakery environment samples.


Asunto(s)
Pan/microbiología , Fermentación , Industria de Alimentos , Lactobacillus/clasificación , Aire/análisis , Análisis del Polimorfismo de Longitud de Fragmentos Amplificados , Bélgica , Dermatoglifia del ADN/métodos , ADN Bacteriano/genética , Electroforesis en Gel de Poliacrilamida/métodos , Harina/microbiología , Variación Genética , Mano/microbiología , Humanos , Lactobacillus/genética , Lactobacillus/aislamiento & purificación , Reacción en Cadena de la Polimerasa/métodos , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN
10.
J Appl Microbiol ; 106(2): 486-95, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19054226

RESUMEN

AIMS: To identify lactic acid bacteria (LAB) present in Moroccan dairy products to establish and preserve their microbial species diversity. METHODS AND RESULTS: Thirty-seven samples were collected from different farms. A total of 146 LAB were isolated and subjected to (GTG)(5)-PCR analysis. Comparison of the profiles with data available at the Moroccan Coordinated Collections of Micro-organisms allowed identification of 85 isolates. The remaining 61 were subjected to SDS-PAGE analysis of whole cell proteins. Comparison of the profiles with data available at the Belgian Coordinated Collections of Micro-organisms allowed identification of 43 isolates. Several of the remaining 18 isolates exhibited identical protein electrophoretic fingerprints. Therefore, eight representatives of them were subjected to partial pheS gene sequencing which allowed identification of all remaining isolates. In raw milk, six genera were found while in 'lben', three were found. This is the first report of Leuconostoc kimchii in dairy products. CONCLUSIONS: LAB diversity was established using a stepwise polyphasic identification approach. It used the expertise of both research bodies involved in this study and proved to be cost-effective for the identification of all isolates. SIGNIFICANCE AND IMPACT OF THE STUDY: To establish LAB diversity in Moroccan dairy products which could be a source of strains with specific properties.


Asunto(s)
Microbiología de Alimentos , Lactobacillaceae/aislamiento & purificación , Leche/microbiología , Animales , Técnicas de Tipificación Bacteriana , Productos Lácteos Cultivados/microbiología , Dermatoglifia del ADN , ADN Bacteriano/genética , Electroforesis en Gel de Poliacrilamida , Lactobacillaceae/clasificación , Lactobacillaceae/genética , Leuconostoc/clasificación , Leuconostoc/genética , Leuconostoc/aislamiento & purificación , Marruecos
11.
Clin Microbiol Infect ; 13(7): 734-6, 2007 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-17403131

RESUMEN

Intra-species discrimination in the highly clonal pathogen Mycobacterium ulcerans was studied in a diverse collection of isolates by PCR amplification of a short sequence repeat locus containing heterogeneous arrays of tri-nucleotide repeats with an ACC consensus pattern. Post-amplification analysis indicated excellent typeability and identified five M. ulcerans alleles, including a unique Angolan type differentiated for the first time among a genetically conserved cluster of African isolates. These results are consistent with previously investigated independent markers, and provide an additional locus for variable number tandem repeat-based typing of M. ulcerans.


Asunto(s)
Técnicas de Tipificación Bacteriana , Repeticiones de Minisatélite/genética , Infecciones por Mycobacterium no Tuberculosas/diagnóstico , Mycobacterium ulcerans/clasificación , Mycobacterium ulcerans/aislamiento & purificación , Reacción en Cadena de la Polimerasa/métodos , África , ADN Bacteriano/análisis , ADN Bacteriano/aislamiento & purificación , Humanos , Infecciones por Mycobacterium no Tuberculosas/microbiología , Mycobacterium ulcerans/genética , Alineación de Secuencia , Análisis de Secuencia de ADN , Especificidad de la Especie
12.
Int J Food Microbiol ; 116(1): 82-7, 2007 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-17300847

RESUMEN

One hundred and seventy-six Enterococcus faecium isolates from Slovak dairy product Bryndza were tested for the presence of plasmid DNA. Eighty-two isolates were positive and their plasmid DNA was isolated and digested by EcoRI and HindIII restriction endonucleases. The patterns obtained were compared with those obtained after pulsed-field gel electrophoresis of macrorestriction fragments (PFGE), (GTG)(5)-PCR and ERIC-PCR. All these molecular approaches were applied for the study of genetic variability and determination of strain relatednesses among plasmid-positive isolates of E. faecium. In general, all methods revealed a considerable genetic diversity of E. faecium isolates. Plasmid profiling and ERIC-PCR have offered a higher resolution than PFGE and (GTG)(5)-PCR.


Asunto(s)
Queso/microbiología , ADN Bacteriano/análisis , Enterococcus faecium/genética , Microbiología de Alimentos , Variación Genética , Electroforesis en Gel de Campo Pulsado , Enterococcus faecium/clasificación , Enterococcus faecium/aislamiento & purificación , Plásmidos , Reacción en Cadena de la Polimerasa , Mapeo Restrictivo
13.
Syst Appl Microbiol ; 40(1): 42-50, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-27816261

RESUMEN

Nine strains of a novel Fusobacterium sp. were isolated from the stomach of 6-8 months old and adult pigs. The isolates were obligately anaerobic, although they endured 2h exposure to air. Phylogenetic analysis based on 16S rRNA and gyrase B genes demonstrated that the isolates showed high sequence similarity with Fusobacterium mortiferum, Fusobacterium ulcerans, Fusobacterium varium, Fusobacterium russii and Fusobacterium necrogenes, but formed a distinct lineage in the genus Fusobacterium. Comparative analysis of the genome of the type strain of this novel Fusobacterium sp. confirmed that it is different from other recognized Fusobacterium spp. DNA-DNA hybridization, fingerprinting and genomic %GC determination further supported the conclusion that the isolates belong to a new, distinct species. The isolates were also distinguishable from these and other Fusobacterium spp. by phenotypical characterization. The strains produced indole and exhibited proline arylamidase and glutamic acid decarboxylase activity. They did not hydrolyse esculin, did not exhibit pyroglutamic acid arylamidase, valine arylamidase, α-galactosidase, ß-galactosidase, ß-galactosidase-6-phosphate or α-glucosidase activity nor produced acid from cellobiose, glucose, lactose, mannitol, mannose, maltose, raffinose, saccharose, salicin or trehalose. The major fatty acids were C16:0 and C18:1ω9c. The name Fusobacterium gastrosuis sp. nov. is proposed for the novel isolates with the type strain CDW1(T) (=DSM 101753(T)=LMG 29236(T)). We also demonstrated that Clostridium rectum and mortiferum Fusobacterium represent the same species, with nomenclatural priority for the latter.


Asunto(s)
Infecciones por Fusobacterium/veterinaria , Fusobacterium/clasificación , Fusobacterium/aislamiento & purificación , Estómago/microbiología , Anaerobiosis , Animales , Técnicas de Tipificación Bacteriana , Composición de Base , Análisis por Conglomerados , Citosol/química , ADN Bacteriano/química , ADN Bacteriano/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Ácidos Grasos/análisis , Fusobacterium/genética , Infecciones por Fusobacterium/microbiología , Hibridación de Ácido Nucleico , Filogenia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Porcinos
14.
Benef Microbes ; 7(4): 585-95, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-27291404

RESUMEN

The isolation of potentially probiotic strains and the subsequent study of their properties are very important steps to gain insight in the health benefits ascribed to sugary and milk kefir. The aim of the present study was to characterise fifteen Lactobacillus strains isolated from these beverages by determining some surface properties and their ability to antagonise enterocyte cell damage after Salmonella infection in vitro. Lactobacillus surface properties were determined by hydrophobicity, autoaggregation, and coaggregation assays with Salmonella. In addition, lactobacilli adhesion to Caco-2/TC-7 cells and the effect on Salmonella invasion were evaluated. Finally, the disassembly of F-actin cytoskeleton on intestinal epithelial cells was assayed in vitro when Salmonella infection was performed in the presence of selected Lactobacillus strains. Ten out of the 15 strains showed a high adhesion capacity to Caco-2/TC-7 cells. Most of the strains were hydrophilic and non-autoaggregating. Strains isolated from sugary kefir were non-coaggregating with Salmonella, while strains Lactobacillus paracasei CIDCA 83120, 83121, 83123, 83124, 8339, 83102 isolated from milk kefir were able to coaggregate after 1 h. L. paracasei CIDCA 8339 and Lactobacillus kefiri CIDCA 83102 were able to diminish Salmonella invasion to the enterocytes. An antagonistic effect on cytoskeleton disruption elicited by the pathogen was also demonstrated. Our results suggest that both strains isolated from milk kefir could be considered as appropriate probiotic candidates.


Asunto(s)
Enterocitos/microbiología , Kéfir/microbiología , Lactobacillus , Leche/microbiología , Probióticos/uso terapéutico , Infecciones por Salmonella/terapia , Animales , Adhesión Bacteriana , Células CACO-2 , Línea Celular , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Lactobacillus/aislamiento & purificación , Lactobacillus/fisiología
15.
Int J Tuberc Lung Dis ; 20(9): 1257-62, 2016 09.
Artículo en Inglés | MEDLINE | ID: mdl-27510255

RESUMEN

SETTING: Over 150 potentially pathogenic non-tuberculous mycobacteria (NTM) species have been described, posing an onerous challenge for clinical laboratory diagnosis. OBJECTIVE: To evaluate different approaches for the identification of 40 clinically relevant NTM isolates whose species were not reliably identified using our routine diagnostic workflow comprising phenotypic tests and hsp65 polymerase chain reaction restriction analysis. DESIGN: We used 1) sequencing analysis of four conserved gene targets: 16S rRNA, rpoB, hsp65 and sodA; 2) two commercial reverse hybridisation assays; and 3) protein analysis using matrix-assisted laser desorption/ionisation time of flight mass spectrometry (MALDI-TOF MS). RESULTS: Combined, but not individual, sequence analysis allowed reliable species identification for 30/40 (75%) isolates, including species previously unknown to be circulating in Argentina. Commercial kits outperformed our routine identification in only 5/35 isolates, and misclassified many more. MALDI-TOF MS accurately identified species in 22/36 (61%) isolates and did not misidentify any. CONCLUSIONS: Commercial kits did not resolve the problem of species of NTM isolates that elude identification. Combined DNA sequence analysis was the approach of choice. MALDI-TOF MS shows promise as a powerful, rapid and accessible tool for the rapid identification of clinically relevant NTM in the diagnostic laboratory, and its accuracy can be maximised by building up a customised NTM spectrum database.


Asunto(s)
Infecciones por Mycobacterium no Tuberculosas/diagnóstico , Micobacterias no Tuberculosas/genética , Micobacterias no Tuberculosas/aislamiento & purificación , Argentina , Proteínas Bacterianas/genética , Técnicas Bacteriológicas , Chaperonina 60/genética , ADN Bacteriano/genética , Genes Bacterianos , Humanos , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Superóxido Dismutasa/genética
17.
Res Microbiol ; 144(1): 35-46, 1993 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-8327781

RESUMEN

In 1987, an outbreak of pneumonia and meningitis caused by an unknown bacterium occurred in a spa therapy centre. Nine isolates of this pathogen constituted a tight DNA hybridization group. rRNA-DNA hybridization and 16S rRNA sequencing showed that the studied bacteria represented a new branch in superfamily II (= gamma subclass) of the Proteobacteria, close to the genus Oceanospirillum. The new bacterium was highly polymorphic and, in young cultures, had curved Gram-negative cells, motile by polar single flagella. The new bacterium differed from the genus Oceanospirillum by its lacking the NaCl requirement and by reducing nitrate into nitrite, producing indole from tryptophan and producing acid from carbohydrates. The name Balneatrix alpica gen. nov., sp. nov. is proposed for the studied organism. The type strain is strain 4-87 (= CIP 103589).


Asunto(s)
Bacterias Gramnegativas/aislamiento & purificación , Meningitis Bacterianas/microbiología , Neumonía/microbiología , Microbiología del Agua , Balneología , Bacterias Gramnegativas/genética , Bacterias Gramnegativas/ultraestructura , Humanos , Hibridación Genética/genética , Técnicas In Vitro , Microscopía Electrónica , Fenotipo , ARN Ribosómico 16S/genética
18.
Chest ; 117(6): 1661-5, 2000 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10858399

RESUMEN

BACKGROUND: Burkholderia cepacia remains a significant pathogen in persons with cystic fibrosis (CF). The medical and psychosocial consequences of pulmonary colonization with this bacterium are enormous. However, B cepacia may be frequently misidentified from CF sputum culture. STUDY OBJECTIVES: To determine the rate of misidentification of B cepacia recently recovered from CF sputum culture of persons receiving care in US treatment centers. DESIGN: Bacterial isolates cultured from CF sputum and putatively identified as B cepacia or other related nonlactose-fermenting Gram-negative species were referred from participating treatment centers. Isolates underwent polyphasic analyses employing phenotypic (selective media and biochemical testing) and genotypic (polymerase chain reaction) assays to determine species identification. Taxonomic evaluations were performed by using sodium dodecyl sulfate-polyacrylamide gel electrophoresis of whole-cell proteins and amplified-fragment length polymorphism analysis. MEASUREMENTS AND RESULTS: A total of 1,051 isolates recovered from 608 patients were received from 115 treatment centers in 91 US cities. Among the isolates identified as B cepacia by referring laboratories, 11% could not be confirmed as B cepacia by polyphasic analyses. In addition, 36% of isolates not specifically identified by the referring laboratory or identified as a species other than B cepacia were, in fact, found to be members of the B cepacia complex. CONCLUSIONS: Rates of misidentification of B cepacia remain unacceptably high among US treatment centers. These data suggest the need for increased awareness of this problem among CF centers and their affiliated laboratories, better adherence to recommended protocols for evaluation of CF sputum, and greater use of reference laboratories equipped to provide advanced analyses.


Asunto(s)
Infecciones por Burkholderia/microbiología , Burkholderia cepacia , Fibrosis Quística/microbiología , Esputo/microbiología , Técnicas Bacteriológicas , Infecciones por Burkholderia/diagnóstico , Fibrosis Quística/diagnóstico , Errores Diagnósticos , Humanos , Reacción en Cadena de la Polimerasa , Estados Unidos
19.
Infect Control Hosp Epidemiol ; 19(2): 112-3, 1998 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-9510111

RESUMEN

During a 3-day period, eight patients developed septicemia with Burkholderia cepacia. Heparin injection was found to be a risk factor. Heparin was diluted with dextrose solution, which was aspirated from a 1-L bag. B cepacia, genotypically identical to the blood isolates, was isolated from this bag.


Asunto(s)
Bacteriemia/microbiología , Infecciones por Burkholderia/microbiología , Burkholderia cepacia , Infección Hospitalaria/microbiología , Brotes de Enfermedades , Cateterismo Cardíaco , Servicio de Cardiología en Hospital , Contaminación de Medicamentos , Glucosa , Hospitales Universitarios , Humanos , Control de Infecciones , Factores de Riesgo , Soluciones
20.
FEMS Microbiol Lett ; 193(1): 89-94, 2000 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-11094284

RESUMEN

A multiplex PCR assay with five primers targeting the 16S and 23S rRNA genes was developed for the simultaneous detection and identification of Arcobacter butzleri, Arcobacter cryaerophilus and Arcobacter skirrowii. The selected primers amplify a 257-bp fragment from A. cryaerophilus, a 401-bp fragment from A. butzleri and a 641-bp fragment from A. skirrowii. No PCR product was generated for closely related bacteria including Campylobacter and Helicobacter species. The assay was useful to identify cultures after in vitro cultivation and to detect and identify A. butlzeri and A. cryaerophilus from poultry samples present in 24-h old enrichment in Arcobacter broth with cefoperazone, amphotericin and teicoplanin (CAT)-supplement.


Asunto(s)
Arcobacter/clasificación , Arcobacter/aislamiento & purificación , Pollos/microbiología , Carne/microbiología , Reacción en Cadena de la Polimerasa/métodos , Animales , Arcobacter/genética , Medios de Cultivo , Cartilla de ADN , ADN Bacteriano/análisis , ADN Bacteriano/genética , ADN Ribosómico/análisis , ADN Ribosómico/genética , Genes de ARNr , ARN Ribosómico 16S/genética , ARN Ribosómico 23S/genética , Sensibilidad y Especificidad , Piel/microbiología
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