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Oral Diseases Jan 2023Periodontitis is a chronic non-communicable disease caused by a dysbiotic microbiota. Pathogens can spread to the bloodstream, colonize other tissues or organs, and... (Review)
Review
Periodontitis is a chronic non-communicable disease caused by a dysbiotic microbiota. Pathogens can spread to the bloodstream, colonize other tissues or organs, and favor the onset of other pathologies, such as Alzheimer's disease (AD). Pathogens could permanently or transiently colonize the brain and induce an immune response. Thus, we analyzed the evidence combining oral bacteria's detection in the brain, both in animals and humans affected with AD. This systematic review was carried out following the PRISMA guideline. Studies that detected oral bacteria at the brain level were selected. The search was carried out in the Medline, Latindex, SciELO, and Cochrane Library databases. SYRCLE tool and Newcastle-Ottawa Scale were used for the risk of bias assessment. 23 studies were selected according to the eligibility criteria. Infection with oral pathogens in animals was related to developing neuropathological characteristics of AD and bacteria detection in the brain. In patients with AD, oral bacteria were detected in brain tissues, and increased levels of pro-inflammatory cytokines were also detected. There is evidence of a microbiological susceptibility to develop AD when the most dysbiosis-associated oral bacteria are present. The presence of bacteria in the brain is related to AD's pathological characteristics, suggesting an etiological oral-brain axis.
Topics: Animals; Humans; Alzheimer Disease; Periodontitis; Bacteria; Microbiota; Brain; Dysbiosis
PubMed: 34698406
DOI: 10.1111/odi.14054 -
FEMS Microbiology Reviews Nov 2014The presence of an abnormal amount of single-stranded DNA in the bacterial cell constitutes a genotoxic alarm signal that induces the SOS response, a broad regulatory... (Review)
Review
The presence of an abnormal amount of single-stranded DNA in the bacterial cell constitutes a genotoxic alarm signal that induces the SOS response, a broad regulatory network found in most bacterial species to address DNA damage. The aim of this review was to point out that beyond being a repair process, SOS induction leads to a very strong but transient response to genotoxic stress, during which bacteria can rearrange and mutate their genome, induce several phenotypic changes through differential regulation of genes, and sometimes acquire characteristics that potentiate bacterial survival and adaptation to changing environments. We review here the causes and consequences of SOS induction, but also how this response can be modulated under various circumstances and how it is connected to the network of other important stress responses. In the first section, we review articles describing the induction of the SOS response at the molecular level. The second section discusses consequences of this induction in terms of DNA repair, changes in the genome and gene expression, and sharing of genomic information, with their effects on the bacteria's life and evolution. The third section is about the fine tuning of this response to fit with the bacteria's 'needs'. Finally, we discuss recent findings linking the SOS response to other stress responses. Under these perspectives, SOS can be perceived as a powerful bacterial strategy against aggressions.
Topics: Bacteria; DNA Repair; Gene Expression Regulation, Bacterial; SOS Response, Genetics; Stress, Physiological
PubMed: 24923554
DOI: 10.1111/1574-6976.12077 -
Enfermedades Infecciosas Y... 2021The discovery, commercialization and administration of antibiotics revolutionized the world of medicine in the middle of the last century, generating a significant... (Review)
Review
The discovery, commercialization and administration of antibiotics revolutionized the world of medicine in the middle of the last century, generating a significant change in the therapeutic paradigm of the infectious diseases. Nevertheless, this great breakthrough was soon threatened due to the enormous adaptive ability that bacteria have, through which they are able to develop or acquire different mechanisms that allow them to survive the exposure to antibiotics. We are faced with a complex, multifactorial and inevitable but potentially manageable threat. To fight against it, a global and multidisciplinary approach is necessary, based on the support, guidance and training of the next generation of professionals. Nevertheless, the information published regarding the resistance mechanisms to antibiotics are abundant, varied and, unfortunately, not always well structured. The objective of this review is to structure the, in our opinion, most relevant and novel information regarding the mechanisms of resistance to antibiotics that has been published from January 2014 to September 2019, analysing their possible clinical and epidemiological impact.
Topics: Anti-Bacterial Agents; Bacteria; Drug Resistance, Microbial
PubMed: 34088451
DOI: 10.1016/j.eimce.2020.02.017 -
Current Pharmaceutical Biotechnology 2023Bacterial engineering modifies bacteria's genomic sequence using genetic engineering tools. These engineered bacteria can produce modified proteins, peptides, nucleic... (Review)
Review
Bacterial engineering modifies bacteria's genomic sequence using genetic engineering tools. These engineered bacteria can produce modified proteins, peptides, nucleic acids, and other biomolecules that can be used to treat various medical conditions. Engineered bacteria can target diseased tissues or organs, detect specific biomarkers in the diseased environment, and even induce specific conditions. Furthermore, a meticulously designed intracellular metabolic pathway can activate or inhibit the expression of related genes, synthesise biologically active therapeutic molecules, and precisely deliver drug payloads to diseased tissues or organs. Lactococcus (L. lactis), Salmonella (S. typhi), and E. coli (E. coli Nissle) are the most studied engineered microorganisms used as drug carriers. These have been used in vaccines to treat multifactorial diseases such as cancer, autoimmune diseases, metabolic diseases, and inflammatory conditions. Other promising strains include Bifidobacterium animalis, Listeria monocytogenes, Staphylococcus epidermidis, Staphylococcus lugdunensis, and Clostridium sporogenes. Despite the low reported risk, toxic effects associated with bacterial cells, limiting their efficacy and rapid clearance due to immune responses stimulated by high bacterial concentrations, remain major drawbacks. As a result, a better and more effective method of drug delivery must be developed by combining bacterial-based therapies with other available treatments, and more research in this area is also needed.
Topics: Drug Delivery Systems; Escherichia coli; Lactococcus lactis; Listeria monocytogenes
PubMed: 36545730
DOI: 10.2174/1389201024666221220113517 -
Critical Reviews in Eukaryotic Gene... 2015Intracellular bacterial pathogens drive the formation of host membrane-derived pseudo-organelles that facilitate their replication, survival, or dormancy. The formation... (Review)
Review
Intracellular bacterial pathogens drive the formation of host membrane-derived pseudo-organelles that facilitate their replication, survival, or dormancy. The formation and maintenance of these bacteria-containing vacuoles (BCVs) are dependent on the bacteria's ability to usurp the host's intracellular membrane system, in particular dynamic compartments involved in exo-/endocytic membrane traffic and autophagy. Bacteria are typically internalized by phagocytosis, and the compartment matures through endosomal fusion. The bacteria-containing phagosome/endosome often becomes the base for BCV formation. Diverse strategies used by different bacterial pathogens prevent the BCV from being destroyed via the endolysosomal pathway. Furthermore, bacterial survival or proliferation in BCVs could be augmented by host membrane transport processes subverted by secreted bacterial factors, which facilitate the acquisition of membrane sources and nutrients. BCVs may be targeted for destruction by autophagy, and various facultative and obligate intracellular bacteria have evolved ways to evade or even exploit autophagy. Here we review examples of bacterial subversion of host cellular membrane transport and autophagy machinery for a productive invasion.
Topics: Autophagy; Bacteria; Cell Membrane; Host-Pathogen Interactions; Lysosomes; Phagosomes; Vacuoles
PubMed: 26080610
DOI: 10.1615/critreveukaryotgeneexpr.2015013572 -
Medicina Clinica May 2020One of the current priorities of the World Health Organization is multidrug-resistant bacteria, because they are a global problem due to their rapid spread and the... (Review)
Review
One of the current priorities of the World Health Organization is multidrug-resistant bacteria, because they are a global problem due to their rapid spread and the difficulty of their treatment. In addition, they are associated with high morbidity, mortality and high economic costs. There are multidrug-resistant bacteria, both Gram-positive and Gram-negative, including Pseudomonas aeruginosa and Acinetobacter baumannii resistant to carbapenems, enterobacteria producing carbapenemases, Staphylococcus aureus resistant to methicillin and/or with intermediate sensitivity to vancomycin, and Enterococcus faecium (and less frequently Enterococcus faecalis) resistant to vancomycin. This review will comment on the new antibiotics that have been incorporated into the therapeutic arsenal in recent years, as well as other promising antibiotics that are in their final stages of development.
Topics: Acinetobacter baumannii; Anti-Bacterial Agents; Drug Resistance, Multiple, Bacterial; Gram-Negative Bacteria; Microbial Sensitivity Tests; Staphylococcus aureus
PubMed: 31926653
DOI: 10.1016/j.medcli.2019.11.002 -
Enfermedades Infecciosas Y... Dec 2017The presence of colonised patients is one of the main routes for the spread of multiresistant bacteria, and its containment is a clinical and public health priority.... (Review)
Review
The presence of colonised patients is one of the main routes for the spread of multiresistant bacteria, and its containment is a clinical and public health priority. Surveillance studies are essential for early detection of colonisation by these bacteria. This article discusses the different microbiological methods, both based on culturing and molecular methods, for detection of carriers of multiresistant bacteria. Those species with a high clinical/epidemiological impact or generating therapeutic difficulties are included: Methicillin-resistant Staphylococcus aureus, Enterococcus spp. resistant to glycopeptides, enterobacteriaceae producing extended spectrum β-lactamases and plasmid-mediated AmpC, carbapenemases producing enterobacteriaceae, Acinetobacter baumannii and multiresistant Pseudomonas aeruginosa. The information in this document should be considered as a structure matrix to be tailored to the specific needs of each centre.
Topics: Bacteria; Bacterial Infections; Bacterial Proteins; Bacteriological Techniques; Carrier State; Drug Resistance, Multiple, Bacterial; Humans; Molecular Diagnostic Techniques; Population Surveillance; Specimen Handling
PubMed: 26869070
DOI: 10.1016/j.eimc.2015.12.013 -
Revista Do Instituto de Medicina... 1979
Topics: Gram-Negative Anaerobic Bacteria
PubMed: 538396
DOI: No ID Found -
Critical Reviews in Oral Biology and... 1998The global distribution of individual species of oral bacteria demonstrates their ability to survive among their human hosts. Such an ubiquitous existence is the result... (Review)
Review
The global distribution of individual species of oral bacteria demonstrates their ability to survive among their human hosts. Such an ubiquitous existence is the result of efficient transmission of strains and their persistence in the oral environment. Genetic analysis has identified specific clones of pathogenic bacteria causing infection. Presumably, these express virulence-associated characteristics enhancing colonization and survival in their hosts. A similar situation may occur with the oral resident flora, where genetic variants may express specific phenotypic characteristics related to survival. Survival in the mouth is enhanced by dental plaque formation, where persistence is associated with the bacteria's capacity not only to adhere and grow, but also to withstand oxygen, wide fluctuations in pH and carbohydrate concentration, and a diverse array of microbial interactions. Streptococcus mutans has been discussed as a 'model' organism possessing the biochemical flexibility that permits it to persist and dominate the indigenous microflora under conditions of stress.
Topics: Adaptation, Biological; Bacteria; Bacterial Adhesion; Bacterial Physiological Phenomena; Biofilms; Dental Plaque; Ecosystem; Genetic Variation; Humans; Hydrogen-Ion Concentration; Oxidative Stress
PubMed: 9488248
DOI: 10.1177/10454411980090010401 -
Mikrochimica Acta Nov 2019Forensic saliva identification represents an increasingly useful auxiliary means of crime investigations, particularly in sex crimes. Salivary bacteria detection...
Forensic saliva identification represents an increasingly useful auxiliary means of crime investigations, particularly in sex crimes. Salivary bacteria detection techniques have been shown to be viable methods for identifying the presence of saliva. A one-pot method is described for the fabrication of bovine serum albumin-stabilized SiC nanoparticles (SiC@BSA NPs). The SiC@BSA NPs were conjugated to antibacterial peptide GH12 to allow for fluorometric detection and imaging of bacteria in saliva. More specifically, the nanoprobe, with fluorescence excitation/emission maxima at 320/410 nm, was used to detect the oral bacteria S. salivarius levels. The detection limit is 25 cfu·mL, and the assay can be performed within 40 min. The nanoprobe was also used to detect bacteria in forensic body fluids including blood, urine, and semen. In all cases, positive results were obtained with (mixed) samples containing saliva, while other saliva samples without saliva showed negative results. Fluorescent images of S. salivarius cells were obtained by implementing a high-content image analysis system. These results suggest that this new nanoprobe can be applied to screen for forensic saliva stains. Graphical abstractSchematic representation of the preparation of SiC@BSA-GH12 nanoprobe for fluorometric detection and imaging of S. salivarius in saliva.
Topics: Animals; Bacterial Typing Techniques; Carbon Compounds, Inorganic; Cattle; Fluorescent Dyes; Humans; Limit of Detection; Nanoparticles; Oligopeptides; Saliva; Serum Albumin, Bovine; Silicon Compounds; Spectrometry, Fluorescence; Streptococcus salivarius
PubMed: 31707552
DOI: 10.1007/s00604-019-3890-y