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Infectious Disease Clinics of North... Dec 2020Multidrug-resistant bacteria are among the most important current threats to public health. Typically, they are associated with nosocomial infections. However, some have... (Review)
Review
Multidrug-resistant bacteria are among the most important current threats to public health. Typically, they are associated with nosocomial infections. However, some have become prevalent causes of community-acquired infections, such as Neisseria gonorrhoeae, Shigella, Salmonella, and Streptococcus pneumoniae. The community spread of multidrug-resistant bacteria is also a crucial development. An important global threat on the horizon is represented by production of carbapenemases by community-acquired hypervirulent Klebsiella pneumoniae. Such strains have already been found in Asia, Europe, and North America. Prevention of further community spread of multidrug-resistant bacteria is of the utmost importance, and will require a multidisciplinary approach involving all stakeholders.
Topics: Agriculture; Bacteria; Community-Acquired Infections; Cross Infection; Drug Resistance, Multiple, Bacterial; Escherichia coli; Global Health; Humans; Klebsiella pneumoniae; Methicillin-Resistant Staphylococcus aureus; Prevalence
PubMed: 33011046
DOI: 10.1016/j.idc.2020.08.002 -
Journal of Clinical Laboratory Analysis Jan 2022A variety of bacteriocins originate from lactic acid bacteria, which have recently been modified by scientists. Many strains of lactic acid bacteria related to food... (Review)
Review
A variety of bacteriocins originate from lactic acid bacteria, which have recently been modified by scientists. Many strains of lactic acid bacteria related to food groups could produce bacteriocins or antibacterial proteins highly effective against foodborne pathogens such as Staphylococcus aureus, Pseudomonas fluorescens, P. aeruginosa, Salmonella typhi, Shigella flexneri, Listeria monocytogenes, Escherichia coli O157:H7, and Clostridium botulinum. A wide range of bacteria belonging primarily to the genera Bifidobacterium and Lactobacillus have been characterized with different health-promoting attributes. Extensive studies and in-depth understanding of these antimicrobials mechanisms of action could enable scientists to determine their production in specific probiotic lactic acid bacteria, as they are potentially crucial for the final preservation of functional foods or for medicinal applications. In this review study, the structure, classification, mode of operation, safety, and antibacterial properties of bacteriocins as well as their effect on foodborne pathogens and antibiotic-resistant bacteria were extensively studied.
Topics: Animals; Anti-Bacterial Agents; Bacteria; Bacteriocins; Foodborne Diseases; Gastrointestinal Microbiome; Humans; Lactobacillales; Mice
PubMed: 34851542
DOI: 10.1002/jcla.24093 -
The Journal of Clinical Investigation Feb 2022The importance of the microbiota in the development of colorectal cancer (CRC) is increasingly evident, but identifying specific microbial features that influence CRC... (Review)
Review
The importance of the microbiota in the development of colorectal cancer (CRC) is increasingly evident, but identifying specific microbial features that influence CRC initiation and progression remains a central task for investigators. Studies determining the microbial mechanisms that directly contribute to CRC development or progression are revealing bacterial factors such as toxins that contribute to colorectal carcinogenesis. However, even when investigators have identified bacteria that express toxins, questions remain about the host determinants of a toxin's cancer-potentiating effects. For other cancer-correlating bacteria that lack toxins, the challenge is to define cancer-relevant virulence factors. Herein, we evaluate three CRC-correlating bacteria, colibactin-producing Escherichia coli, enterotoxigenic Bacteroides fragilis, and Fusobacterium nucleatum, for their virulence features relevant to CRC. We also consider the beneficial bioactivity of gut microbes by highlighting a microbial metabolite that may enhance CRC antitumor immunity. In doing so, we aim to elucidate unique and shared mechanisms underlying the microbiota's contributions to CRC and to accelerate investigation from target validation to CRC therapeutic discovery.
Topics: Animals; Bacteria; Carcinogenesis; Colorectal Neoplasms; Gastrointestinal Microbiome; Humans
PubMed: 35166235
DOI: 10.1172/JCI155101 -
PloS One 2021Microorganisms in oral cavity are called oral microbiota, while microbiome consists of total genome content of microorganisms in a host. Interaction between host and... (Clinical Trial)
Clinical Trial
BACKGROUND
Microorganisms in oral cavity are called oral microbiota, while microbiome consists of total genome content of microorganisms in a host. Interaction between host and microorganisms is important in nervous system development and nervous diseases such as Autism, Alzheimer, Parkinson and Multiple Sclerosis (MS). Bacterial infections, as an environmental factor in MS pathogenesis play role in T helper 17(Th17) increase and it enhancing the production of pro-inflammatory cytokines such as Interlukin-21(IL-21), IL-17 and IL -22. Oral microbiota consists diverse populations of cultivable and uncultivable bacterial species. Denaturing gradient gel electrophoresis (DGGE) is an acceptable method for identification of uncultivable bacteria. In this study, we compared the bacterial population diversity in the oral cavity between MS and healthy people.
METHODS
From October to March 2019, samples were taken at Kermanshah University of Medical Sciences' MS patients center. A total of 30 samples were taken from MS patients and another 30 samples were taken from healthy people. Phenotypic tests were used to identify bacteria after pure cultures were obtained. DNA was extracted from 1 mL of saliva, and PCR products produced with primers were electrophoresed on polyacrylamide gels.
RESULTS
The genera Staphylococcus, Actinomyces, Fusobacterium, Bacteroides, Porphyromonas, Prevotella, Veillonella, Propionibacterium and uncultivable bacteria with accession number MW880919-25, JQ477416.1, KF074888.1 and several other un-culturable strains were significantly more abundant in the MS group while Lactobacillus and Peptostreptococcus were more prevalent in the normal healthy group according to logistic regression method.
CONCLUSION
Oral micro-organisms may alleviate or exacerbate inflammatory condition which impact MS disease pathogenesis. It may be assumed that controlling oral infections may result in reduction of MS disease progression.
Topics: Adult; Bacteria; Female; Humans; Mouth; Multiple Sclerosis
PubMed: 34847159
DOI: 10.1371/journal.pone.0260384 -
Nutrients Mar 2020Autism spectrum disorder (ASD) is a public health problem and has a prevalence of 0.6%-1.7% in children. As well as psychiatric symptoms, dysbiosis and gastrointestinal... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Autism spectrum disorder (ASD) is a public health problem and has a prevalence of 0.6%-1.7% in children. As well as psychiatric symptoms, dysbiosis and gastrointestinal comorbidities are also frequently reported. The gut-brain microbiota axis suggests that there is a form of communication between microbiota and the brain underlying some neurological disabilities. The aim of this study is to describe and compare the composition of gut microbiota in children with and without ASD.
METHODS
Electronic databases were searched as far as February 2020. Meta-analyses were performed using RevMan5.3 to estimate the overall relative abundance of gut bacteria belonging to 8 phyla and 17 genera in children with ASD and controls.
RESULTS
We included 18 studies assessing a total of 493 ASD children and 404 controls. The microbiota was mainly composed of the phyla Bacteroidetes, Firmicutes, and Actinobacteria, all of which were more abundant in the ASD children than in the controls. Children with ASD showed a significantly higher abundance of the genera , , , and and a lower percentage of and .
DISCUSSION
This meta-analysis suggests that there is a dysbiosis in ASD children which may influence the development and severity of ASD symptomatology. Further studies are required in order to obtain stronger evidence of the effectiveness of pre- or probiotics in reducing autistic behaviors.
Topics: Autism Spectrum Disorder; Bacteria; Child; Dysbiosis; Female; Gastrointestinal Microbiome; Humans; Male
PubMed: 32192218
DOI: 10.3390/nu12030792 -
Cell Host & Microbe May 2021The gut is inhabited by a densely populated ecosystem, the gut microbiota, that is established at birth. However, the succession by which different bacteria are...
The gut is inhabited by a densely populated ecosystem, the gut microbiota, that is established at birth. However, the succession by which different bacteria are incorporated into the gut microbiota is still relatively unknown. Here, we analyze the microbiota from 471 Swedish children followed from birth to 5 years of age, collecting samples after 4 and 12 months and at 3 and 5 years of age as well as from their mothers at birth using 16S rRNA gene profiling. We also compare their microbiota to an adult Swedish population. Genera follow 4 different colonization patterns during establishment where Methanobrevibacter and Christensenellaceae colonize late and do not reached adult levels at 5 years. These late colonizers correlate with increased alpha diversity in both children and adults. By following the children through age-specific community types, we observe that children have individual dynamics in the gut microbiota development trajectory.
Topics: Adult; Bacteria; Child Development; Child, Preschool; Cohort Studies; Feces; Female; Gastrointestinal Microbiome; Humans; Infant; Male; Sweden; Young Adult
PubMed: 33794185
DOI: 10.1016/j.chom.2021.02.021 -
Aging Aug 2021
Topics: Animals; Bacteria; Bone and Bones; DNA Damage; Gastrointestinal Microbiome; Humans; Intestines; Radiation, Ionizing; Radiotherapy
PubMed: 34406126
DOI: 10.18632/aging.203446 -
Cellular Microbiology May 2021
Topics: Animals; Bacteria; Bacterial Infections; Host-Pathogen Interactions; Humans; Immune Evasion; Virulence
PubMed: 33369087
DOI: 10.1111/cmi.13300 -
International Journal of Molecular... Nov 2019Breast cancer is the second most common cause of cancer-related mortality among women around the world. Conventional treatments in the fight against breast cancer, such... (Review)
Review
Breast cancer is the second most common cause of cancer-related mortality among women around the world. Conventional treatments in the fight against breast cancer, such as chemotherapy, are being challenged regarding their effectiveness. Thus, strategies for the treatment of breast cancer need to be continuously refined to achieve a better patient outcome. We know that a number of bacteria are pathogenic and some are even associated with tumor development, however, recent studies have demonstrated interesting results suggesting some bacteria may have potential for cancer therapy. Therefore, the therapeutic role of bacteria has aroused attention in medical and pharmaceutical studies. Furthermore, genetic engineering has been used in bacterial therapy and may led to greater efficacy with few side effects. Some genetically modified non-pathogenic bacterial species are more successful due to their selectivity for cancer cells but with low toxicity for normal cells. Some live, attenuated, or genetically modified bacterias are capable to multiply in tumors and inhibit their growth. This article aims to review the role of bacteria and their products including bacterial peptides, bacteriocins, and toxins for the treatment of breast cancer.
Topics: Animals; Bacteria; Bacteriocins; Breast Neoplasms; Colicins; Humans; Nisin; Peptides, Cyclic
PubMed: 31771178
DOI: 10.3390/ijms20235880 -
Current Biology : CB Oct 2020Florian Maderspacher introduces the microbiology special issue and asks how the study of microbes has shaped our understanding of evolution.
Florian Maderspacher introduces the microbiology special issue and asks how the study of microbes has shaped our understanding of evolution.
Topics: Bacteria; Biodiversity; Biological Evolution; Ecology; Environmental Microbiology; Microbial Interactions; Phylogeny
PubMed: 33022245
DOI: 10.1016/j.cub.2020.09.010