Search results for "RICH"
showing 10 items of 3360 documents
Diagnóstico microbiológico de las infecciones gastrointestinales
2009
Resumen Las infecciones agudas del tracto gastrointestinal figuran entre las enfermedades infecciosas más frecuentes. En esta revisión se examinan diversas técnicas para diagnosticar las gastroenteritis que ocasionan bacterias, virus y parásitos. El coprocultivo es el método de elección para el diagnóstico de las infecciones bacterianas intestinales, aunque las infecciones por Clostridium difficile se pueden diagnosticar mediante la detección de las toxinas A y B en las heces y las infecciones por Escherichia coli diarreagénicas se pueden diagnosticar mediante la detección por reacción en cadena de la polimerasa de factores de virulencia específicos de los diversos enteropatotipos. Las técn…
In Situ Characterization of Hfq Bacterial Amyloid: A Fourier-Transform Infrared Spectroscopy Study
2019
Hfq is a bacterial protein that regulates gene expression at the post-transcriptional level in Gram-negative bacteria. We have previously shown that Escherichia coli Hfq protein, and more precisely its C-terminal region (CTR), self-assembles into an amyloid-like structure in vitro. In the present work, we present evidence that Hfq unambiguously forms amyloid structures also in vivo. Taking into account the role of this protein in bacterial adaptation and virulence, our work opens possibilities to target Hfq amyloid self-assembly and cell location, with potential to block bacterial adaptation and treat infections. Fil: Partouche, David. Centre National de la Recherche Scientifique; Francia. …
In vivo effects of intravascularly applied Escherichia coli hemolysin: dissociation between induction of granulocytopenia and lethality in monkeys.
1993
The effects of intravascular application of endotoxin-depleted Escherichia coli hemolysin (HlyA) was studied in rabbits and monkeys. In rabbits, bolus application of HlyA calculated to effect final blood levels of approximately 2-3 HU/ml (200-300 ng/ml) caused an acute fall of polymorphonuclear blood leukocytes to less than 20% of starting levels within 5 min. Additionally, platelet counts dropped to approximately 30% of starting levels, whereas lymphocyte counts varied considerably and seldom fell to less than 50%. Nine out ten animals that received 2-4 HU/ml toxin died within 90 min post application. These animals presented with signs of acute respiratory failure and post mortem inspectio…
Sepsis due to Erysipelothrix rhusiopathiae in a Patient with Chronic Lymphocytic Leukemia Associated with Bronchopneumonia due to PSeudomonas aerugin…
2015
Erysipelothrix rhusiopathiae infections can typically be attributed to exposure to animal products; thus, these infections are more common among farmers, butchers and veterinarians, among others. This article describes a case involving a 54-year-old man who had relative neutropenia subsequent to treatment for chronic lymphocytic leukemia. The patient developed E rhusiopathiae bacteremia with concomitant pneumonia. The author of this article suggests a likely route of infection, which is atypical considering the patient did not report exposure to animal products.
Specific DNA probes to detect Escherichia coli strains producing cytotoxic necrotising factor type 1 or type 2
1994
Cytotoxic necrotising factors type 1 (CNF1) and type 2 (CNF2) are produced by many Escherichia coli strains isolated from man and animals with intestinal or extra-intestinal colibacillosis. In most laboratories, CNF-producing strains are detected by a cell cytotoxicity assay and confirmed with a neutralisation assay or a mouse footpad assay. In this study, we sought to determine whether DNA probes could detect clinical isolates of E. coli producing CNF2 or CNF1, or both, without the need for cell cultures or animal assays. Two internal fragments of the gene encoding CNF2 were used as DNA probes: a 875-bp XhoI-PstI DNA fragment and an adjacent 335-bp PstI-ClaI fragment. A positive response w…
Sensing by the membrane-bound sensor kinase DcuS: exogenous versus endogenous sensing of C(4)-dicarboxylates in bacteria.
2010
Bacteria are able to grow at the expense of both common (succinate, L-malate, fumarate and aspartate) and uncommon (L-tartrate and D-malate) C4-dicarboxylates, which are components of central metabolism. Two types of sensors/regulators responding to the C4-dicarboxylates function in Escherichia coli, Bacillus, Lactobacillus and related bacteria. The first type represents membrane-integral two-component systems, while the second includes cytoplasmic LysR-type transcriptional regulators. The difference in location and substrate specificity allows the exogenous induction of metabolic genes by common C4-dicarboxylates, and endogenous induction by uncommon C4-dicarboxylates. The two-component s…
Antifungal Activity of Bioactive Metabolites Produced by Trichoderma asperellum and Trichoderma atroviride in Liquid Medium
2020
Trichoderma spp. are known as biocontrol agents of fungal plant pathogens and have been recognized as a potential source of bioactive metabolites. The production of antimicrobial substances from strains T. atroviride (TS) and T. asperellum (IMI 393899) was investigated. The bioactivity of 10- and 30-day culture filtrate extracted with ethyl acetate was assessed against a set of pathogenic fungi and oomycetes. The 30-day extracts of both strains had significant cytotoxic effects against the tested pathogens, with values of minimum fungicidal concentration (MFC) ranging between 0.19 and 6.25 mg/mL. Dual culture assay (direct contact and nondirect contact) and the percentage inhibition of radi…
Quantification of denitrifying bacteria in soils by nirK gene targeted real-time PCR.
2004
Abstract Denitrification, the reduction of nitrate to nitrous oxide or dinitrogen, is the major biological mechanism by which fixed nitrogen returns to the atmosphere from soil and water. Microorganisms capable of denitrification are widely distributed in the environment but little is known about their abundance since quantification is performed using fastidious and time-consuming MPN-based approaches. We used real-time PCR to quantify the denitrifying nitrite reductase gene (nirK), a key enzyme of the denitrifying pathway catalyzing the reduction of soluble nitrogen oxide to gaseous form. The real-time PCR assay was linear over 7 orders of magnitude and sensitive down to 102 copies by assa…
Bactericidal activity of human milk: stability during storage
2016
Human milk provides infants with defensive factors against many illnesses. This study aims to analyse global bactericidal activity in fresh human milk and evaluate its stability in relation to milk manipulation and its possible alteration following refrigeration. Nineteen milk samples (mature milk) from 19 healthy women are analysed. Viability testing involving a strain of Escherichia coli NCTC 9111, serovar O111:K58(B4):H- was used to determine the bactericidal effect of human milk. Degree of bacteriolysis is calculated as the difference between E. coli counts in controls and in milk samples, expressed as a percentage of the control sample counts. An evaluation of the effect of refrigerati…
Trichosporon beigelii pneumonia in a neutropenic patient.
1989
A case of pulmonary infection caused by Trichosporon beigelii is reported in an asthmatic patient undergoing steroid treatment who developed fever and lung infiltrates. Arthroconidia and blastoconidia were isolated from repeated sputum, bronchial aspirate and telescopic catheter samples. The infection coincided with neutropenia resulting from pyrazolone treatment. The response to amphotericin B treatment was favourable.