Search results for "Bacterial load"
showing 10 items of 25 documents
Different food sources elicit fast changes to bacterial virulence
2016
Environmentally transmitted, opportunistic bacterial pathogens have a life cycle that alternates between hosts and environmental reservoirs. Resources are often scarce and fluctuating in the outside-host environment, whereas overcoming the host immune system could allow pathogens to establish a new, resource abundant and stable niche within the host. We tested if short-term exposure to different outside-host resource types and concentrations affect Serratia marcescens —(bacterium)'s virulence in Galleria mellonella (moth). As expected, virulence was mostly dictated by the bacterial dose, but we also found a clear increase in virulence when the bacterium had inhabited a low (versus high) re…
Mining metagenomic whole genome sequences revealed subdominant but constant Lactobacillus population in the human gut microbiota
2016
The genus Lactobacillus includes over 215 species that colonize plants, foods, sewage and the gastrointestinal tract (GIT) of humans and animals. In the GIT, Lactobacillus population can be made by true inhabitants or by bacteria occasionally ingested with fermented or spoiled foods, or with probiotics. This study longitudinally surveyed Lactobacillus species and strains in the feces of a healthy subject through whole genome sequencing (WGS) data-mining, in order to identify members of the permanent or transient populations. In three time-points (0, 670 and 700 d), 58 different species were identified, 16 of them being retrieved for the first time in human feces. L. rhamnosus, L. ruminis, L…
Monitoring of wheat lactic acid bacteria from the field until the first step of dough fermentation.
2017
The present work was carried out to retrieve the origin of lactic acid bacteria (LAB) in sourdough. To this purpose, wheat LAB were monitored from ear harvest until the first step of fermentation for sourdough development. The influence of the geographical area and variety on LAB species/strain composition was also determined. The ears of four Triticum durum varieties (Duilio, Iride, Saragolla and Simeto) were collected from several fields located within the Palermo province (Sicily, Italy) and microbiologically investigated. In order to trace the transfer of LAB during the consecutive steps of manipulation, ears were transformed aseptically and, after threshing, milling and fermentation, s…
Microbial Colonization of the Peri-Implant Sulcus and Implant Connection of Implants Restored With Cemented Versus Screw-Retained Superstructures: A …
2016
The aim of this study is to investigate peri-implant and intraconnection microflora of healthy implants restored with cemented and screwed superstructures.Patients with two to three implants restored with cemented or screwed restorations and 5 years of follow-up were recruited. Samples were taken from peri-implant sulci, adjacent teeth, and the inner portion of connections. Prevalence of positive sites and bacterial loads for 10 microorganisms were obtained with quantitative real-time polymerase chain reaction. Implant connection permeability to the studied microorganisms was estimated using a standardized bacterial contamination index. Statistical analysis was performed using a generalized…
Bacterial-viral load and the immune response in stable and exacerbated COPD: significance and therapeutic prospects.
2016
Silvestro Ennio D’Anna,1 Bruno Balbi,2 Francesco Cappello,3,4 Mauro Carone,2 Antonino Di Stefano21Department of Rehabilitation, Cardiorespiratory Unit, Fondazione Istituto G. Giglio di Cefalù, 2Pneumology Unit and Laboratory of Cytoimmunopathology of Heart and Lung, Fondazione Salvatore Maugeri, IRCCS, Veruno (NO) and Cassano delle Murge (BA), 3Human Anatomy Section, Department of Experimental Biomedicine and Clinical Neuroscience, University of Palermo, Palermo, Italy; 4Euro-Mediterranean Institute of Science and Technology, Palermo, ItalyAbstract: Chronic obstructive pulmonary disease (COPD) is characterized by persistent airflow limitation and an abnormal inflammatory respon…
Bronchial inflammation and bacterial load in stable COPD is associated with TLR4 overexpression.
2017
Toll-like receptors (TLRs) and nucleotide-binding oligomerisation domain (NOD)-like receptors (NLRs) are two major forms of innate immune sensors but their role in the immunopathology of stable chronic obstructive pulmonary disease (COPD) is incompletely studied. Our objective here was to investigate TLR and NLR signalling pathways in the bronchial mucosa in stable COPD.Using immunohistochemistry, the expression levels of TLR2, TLR4, TLR9, NOD1, NOD2, CD14, myeloid differentiation primary response gene 88 (MyD88), Toll-interleukin-1 receptor domain-containing adaptor protein (TIRAP), and the interleukin-1 receptor-associated kinases phospho-IRAK1 and IRAK4 were measured in the bronchial muc…
Changes in microflora in dental plaque from cancer patients undergoing chemotherapy and the relationship of these changes with mucositis: a pilot stu…
2015
Background: To assess changes in oral microflora in dental plaque from cancer patients within 7 days of the first course of chemotherapy, and the relationship of the changes with mucositis. Material and Methods: Thirty cancer patients, divided into a test group undergoing chemotherapy and a control group no undergoing chemotherapy, were enrolled in this pilot study. Oral microflora were cultured from three samples of dental plaque at t0 (before chemotherapy), t1 (1 day after chemotherapy) and t2 (7 days after chemotherapy). Single and crossed descriptive analyses were used to establish prevalence, and the χ 2 test was used to establish the statistical significance of the differences observe…
Culture and Real-time Polymerase Chain reaction sensitivity in the diagnosis of invasive meningococcal disease: Does culture miss less severe cases?
2019
BackgroundInvasive meningococcal disease (IMD) is a highly lethal disease. Diagnosis is commonly performed by culture or Realtime-PCR (qPCR).AimsOur aim was to evaluate, retrospectively, whether culture positivity correlates with higher bacterial load and fatal outcome. Our secondary aim was to compare culture and qPCR sensitivity.MethodsThe National Register for Molecular Surveillance was used as data source. Cycle threshold (CT), known to be inversely correlated with bacterial load, was used to compare bacterial load in different samples.ResultsThree-hundred-thirteen patients were found positive for Neisseria meningitidis by qPCR, or culture, or both; 41 died (case fatality rate 13.1%); 1…
Within-host evolution decreases virulence in an opportunistic bacterial pathogen
2015
Abstract Background Pathogens evolve in a close antagonistic relationship with their hosts. The conventional theory proposes that evolution of virulence is highly dependent on the efficiency of direct host-to-host transmission. Many opportunistic pathogens, however, are not strictly dependent on the hosts due to their ability to reproduce in the free-living environment. Therefore it is likely that conflicting selection pressures for growth and survival outside versus within the host, rather than transmission potential, shape the evolution of virulence in opportunists. We tested the role of within-host selection in evolution of virulence by letting a pathogen Serratia marcescens db11 sequent…
Extremely rapid acclimation of Escherichia coli to high temperature over a few generations of a fed-batch culture during slow warming
2014
This study aimed to demonstrate that adequate slow heating rate allows two strains of Escherichia coli rapid acclimation to higher temperature than upper growth and survival limits known to be strain-dependent. A laboratory (K12-TG1) and an environmental (DPD3084) strain of E. coli were subjected to rapid (few seconds) or slow warming (1 degrees C 12 h(-1)) in order to (re) evaluate upper survival and growth limits. The slow warming was applied from the ancestral temperature 37 degrees C to total cell death 46-54 degrees C: about 30 generations were propagated. Upper survival and growth limits for rapid warming (46 degrees C) were lower than for slow warming (46-54 degrees C). The thermal l…