Search results for "Bacteriology"
showing 10 items of 114 documents
mcr-1- like detection in commensal Escherichia coli and Salmonella spp. from food-producing animals at slaughter in Europe
2017
International audience; We evaluate here the presence of the mcr-1-like and mcr-2 genes in Escherichia coli and Salmonella spp. isolated from healthy food-producing animals at slaughter between 2002 and 2014 in Europe. Isolates were retrieved from cattle, pig and chicken from 11 European countries of production. The susceptibility to colistin and antibiotics used in human medicine was determined by agar dilution. Colistin-resistant isolates were PCR-screened for mcr genes. mcr-positive isolates were typed by Pulsed-Field Gel Electrophoresis (PFGE) and Multi-Locus Sequence Typing. Among the 10,206 E. coli and 1774 Salmonella spp. isolated from cattle, pigs and chickens, 148 E. coli and 92 Sa…
panISa: ab initio detection of insertion sequences in bacterial genomes from short read sequence data.
2018
Abstract Motivation The advent of next-generation sequencing has boosted the analysis of bacterial genome evolution. Insertion sequence (IS) elements play a key role in prokaryotic genome organization and evolution, but their repetitions in genomes complicate their detection from short-read data. Results PanISa is a software pipeline that identifies IS insertions ab initio in bacterial genomes from short-read data. It is a highly sensitive and precise tool based on the detection of read-mapping patterns at the insertion site. PanISa performs better than existing IS detection systems as it is based on a database-free approach. We applied it to a high-risk clone lineage of the pathogenic spec…
The Antisense RNA Approach: a New Application for In Vivo Investigation of the Stress Response of Oenococcus oeni, a Wine-Associated Lactic Acid Bact…
2015
ABSTRACT Oenococcus oeni is a wine-associated lactic acid bacterium mostly responsible for malolactic fermentation in wine. In wine, O. oeni grows in an environment hostile to bacterial growth (low pH, low temperature, and ethanol) that induces stress response mechanisms. To survive, O. oeni is known to set up transitional stress response mechanisms through the synthesis of heat stress proteins (HSPs) encoded by the hsp genes, notably a unique small HSP named Lo18. Despite the availability of the genome sequence, characterization of O. oeni genes is limited, and little is known about the in vivo role of Lo18. Due to the lack of genetic tools for O. oeni , an efficient expression vector in O…
Prevalence of Listeria spp. and characterization of Listeria monocytogenes isolated from food products in Tetouan, Morocco
2018
A total of 1096 food samples were purchased in Tetouan, North-Western of Morocco, to examine the presence of Listeria spp. Eighty (7.3%) of the tested samples were found positive for the presence of Listeria spp., while L. monocytogenes was detected in 16 (1.5%) samples. L. monocytogenes isolates belonged to clonal complexes CC2 (PCR serogroup IVb) and CC199 (PCR serogroup Ila) and to 8 different combined AscI/Apal pulsed-field gel electrophoresis profiles. Core genome multilocus sequence typing (cgMLST) allowed to distinguish 12 different cgMLST types and revealed the presence of 3 clusters of closely-related isolates from different samples, suggesting the existence of common sources of co…
Efficient and reproducible experimental infections of rats with Blastocystis spp.
2018
Although Blastocystis spp. infect probably more than 1 billion people worldwide, their clinical significance is still controversial and their pathophysiology remains poorly understood. In this study, we describe a protocol for an efficient and reproducible model of chronic infection in rats, laying the groundwork for future work to evaluate the pathogenic potential of this parasite. In our experimental conditions, we were unable to infect rats using vacuolar forms of an axenically cultivated ST4 isolate, but we successfully established chronic infections of 4 week-old rats after oral administration of both ST3 and ST4 purified cysts isolated from human stool samples. The infection protocol …
Expert Opinion on Three Phage Therapy Related Topics: Bacterial Phage Resistance, Phage Training and Prophages in Bacterial Production Strains
2018
Phage therapy is increasingly put forward as a "new" potential tool in the fight against antibiotic resistant infections. During the "Centennial Celebration of Bacteriophage Research" conference in Tbilisi, Georgia on 26-29 June 2017, an international group of phage researchers committed to elaborate an expert opinion on three contentious phage therapy related issues that are hampering clinical progress in the field of phage therapy. This paper explores and discusses bacterial phage resistance, phage training and the presence of prophages in bacterial production strains while reviewing relevant research findings and experiences. Our purpose is to inform phage therapy stakeholders such as po…
In Silico Conformational Features of Botulinum Toxins A1 and E1 According to Intraluminal Acidification
2022
International audience; Although botulinum neurotoxins (BoNTs) are among the most toxic compounds found in nature, their molecular mechanism of action is far from being elucidated. A key event is the conformational transition due to acidification of the interior of synaptic vesicles, leading to translocation of the BoNT catalytic domain into the neuronal cytosol. To investigate these conformational variations, homology modeling and atomistic simulations are combined to explore the internal dynamics of the sub-types BoNT/A1 (the most-used sub-type in medical applications) and BoNT/E1 (the most kinetically efficient sub-type). This first simulation study of di-chain BoNTs in closed and open s…
Performance of a Highly Sensitive Mycobacterium tuberculosis Complex Real-Time PCR Assay for Diagnosis of Pulmonary Tuberculosis in a Low-Prevalence …
2018
ABSTRACT The potential impact of routine real-time PCR testing of respiratory specimens from patients with presumptive tuberculosis in terms of diagnostic accuracy and time to tuberculosis treatment inception in low-prevalence settings remains largely unexplored. We conducted a prospective intervention cohort study. Respiratory specimens from 1,020 patients were examined by acid-fast bacillus smear microscopy, tested by a real-time Mycobacterium tuberculosis complex PCR assay (Abbott RealTi me MTB PCR), and cultured in mycobacterial media. Seventeen patients tested positive by PCR (5 were acid-fast bacillus smear positive and 12 acid-fast bacillus smear negative), and Mycobacterium tubercul…
Identification of a Unique Helicobacter Species by 16S rRNA Gene Analysis in an Abdominal Abscess from a Patient with X-Linked Hypogammaglobulinemia
2000
ABSTRACT A unique Helicobacter species, MZ640285, was isolated from a patient with X-linked hypogammaglobulinemia suffering from recurrent abdominal abscesses and was identified by 16S rRNA gene sequence analysis. In the phylogenetic tree, the isolate fell into a cluster which included Flexispira rappini , Helicobacter bilis , and Helicobacter sp. strain Mainz. Helicobacters are being increasingly recognized as pathogens in immunocompromised hosts. These fastidious bacteria are not easily cultured in the routine diagnostic laboratory, and this is the first report of their identification by 16S rRNA gene sequencing performed directly from a clinical specimen.
Bacteremia following dental implant surgery : preliminary results
2010
Objectives: The aims of this study were to investigate the incidence of bacteremia, bacteriology and antibiotic susceptibility against to causative bacteria associated with dental implant installation. Study Design: 30 generally healthy patients were enrolled in this study. Blood samples were collected at baseline and at 30 minutes after dental implant installation and 24 hours after dental implant surgery. Blood samples were cultured in a BACTEC system. The isolated bacteria were identified using conventional methods. Antimicrobial sensitivity tests were performed by disc diffusion. Results: No bacteria were isolated at the baseline and 24 hours after surgery, whereas the prevalence of bac…