DOCSLIB.ORG

Gut Bacteria in Health and Disease Eamonn M

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Gut Bacteria in Health and Disease Eamonn M Gut Bacteria in Health and Disease Eamonn M. M. Quigley, MD, FRCP, FACP, FACG, FRCPI Dr Quigley is chief of the Division of Abstract: A new era in medical science has dawned with the real- Gastroenterology and Hepatology at ization of the critical role of the “forgotten organ,” the gut micro- Houston Methodist Hospital in Houston, biota, in health and disease. Central to this beneficial interaction Texas. between the microbiota and host is the manner in which bacteria Address correspondence to: and most likely other microorganisms contained within the gut Dr Eamonn M. M. Quigley communicate with the host’s immune system and participate in Division of Gastroenterology and a variety of metabolic processes of mutual benefit to the host Hepatology and the microbe. The advent of high-throughput methodologies Houston Methodist Hospital and the elaboration of sophisticated analytic systems have facili- 6550 Fannin Street tated the detailed description of the composition of the microbial Houston, TX 77030; Tel: 713-441-0853; constituents of the human gut, as never before, and are now Fax: 713-790-3089; enabling comparisons to be made between health and various E-mail: [email protected] disease states. Although the latter approach is still in its infancy, some important insights have already been gained about how the microbiota might influence a number of disease processes both within and distant from the gut. These discoveries also lay the groundwork for the development of therapeutic strategies that might modify the microbiota (eg, through the use of probiot- ics). Although this area holds much promise, more high-quality trials of probiotics, prebiotics, and other microbiota-modifying approaches in digestive disorders are needed, as well as labora- tory investigations of their mechanisms of action. ue largely to rapidly evolving advances in analytic tech- niques in microbiology, molecular biology, and bioinfor- matics, the true diversity of microorganisms that inhabit Dthe gastrointestinal tract of humans (collectively referred to as the human gut microbiota) is being revealed and its contributions to homeostasis in health and to the pathogenesis of disease appreciated (Table 1). As a consequence, the study of gut ecology has emerged as one of the most active and exciting fields in biology and medicine. It Keywords is in this context that maneuvers to alter or modify the microbiota, Gut flora, microbiota, probiotic, gut bacteria, either through dietary modifications or by the administration of microbial metabolism, mucosal immunology antibiotics, probiotics, or prebiotics, must now be viewed. 560 Gastroenterology & Hepatology Volume 9, Issue 9 September 2013 GUT BACTERIA IN HEALTH AND DISEASE Table 1. Important Homeostatic Functions of the Gut there is accumulating evidence from a number of sources Microbiota that disruption of the microbiota in early infancy may be a critical determinant of disease expression in later life. 1. Metabolic role • Salvages calories It follows that interventions directed at the microbiota • Produces short-chain fatty acids later in life may, quite literally, be too late and potentially • Produces arginine and glutamine doomed to failure. • Synthesizes vitamin K and folic acid Following infancy, the composition of the intestinal • Participates in drug metabolism (eg, activates microflora remains relatively constant until later life. 5-aminosalicylic acid from sulfasalazine) Although it has been claimed that the composition of each 2. Deconjugation of bile acids individual’s flora is so distinctive that it could be used as 3. Prevention of colonization by pathogens an alternative to fingerprinting, more recently, 3 differ- 4. Immunologic effects ent enterotypes have been described in the adult human • Stimulates immunoglobulin A production microbiome.10 These distinct enterotypes are dominated • Promotes anti-inflammatory cytokines and down- by Prevotella, Ruminococcus, and Bacteroides, respectively, regulates proinflammatory cytokines • Induces regulatory T cells and their appearance seems to be independent of sex, age, nationality, and body mass index. The microbiota is thought to remain stable until old age when changes are seen, possibly related to alterations in digestive physiology The Normal Gut Microbiota: and diet.11-13 Indeed, Claesson and colleagues were able to An Essential Factor in Health identify clear correlations in elderly individuals, not only between the composition of the gut microbiota and diet, Basic Definitions and Development of the Microbiota but also in relation to health status.14 The term microbiota is to be preferred to the older term flora, as the latter fails to account for the many nonbacte- Regulation of the Microbiota rial elements (eg, archea, viruses, and fungi) that are now Because of the normal motility of the intestine (peristalsis known to be normal inhabitants of the gut. Given the and the migrating motor complex) and the antimicrobial relatively greater understanding that currently exists of the effects of gastric acid, bile, and pancreatic and intestinal role of bacteria, in comparison with the other constituents secretions, the stomach and proximal small intestine, of the microbiota in health and disease, gut bacteria will be although certainly not sterile, contain relatively small the primary focus of this review. Within the human gastro- numbers of bacteria in healthy subjects.15 Interestingly, intestinal microbiota exists a complex ecosystem of approx- commensal organisms with probiotic properties have imately 300 to 500 bacterial species, comprising nearly recently been isolated from the human stomach.16 The 2 million genes (the microbiome).1 Indeed, the number of microbiology of the terminal ileum represents a transition bacteria within the gut is approximately 10 times that of all zone between the jejunum, containing predominantly aer- of the cells in the human body, and the collective bacterial obic species, and the dense population of anaerobes found genome is vastly greater than the human genome. in the colon. Bacterial colony counts may be as high as At birth, the entire intestinal tract is sterile; the 109 colony-forming units (CFU)/mL in the terminal infant’s gut is first colonized by maternal and envi- ileum immediately proximal to the ileocecal valve, with a ronmental bacteria during birth and continues to be predominance of gram-negative organisms and anaerobes. populated through feeding and other contacts.2 Factors On crossing into the colon, the bacterial concentration known to influence colonization include gestational age, and variety of the enteric flora change dramatically. Con- mode of delivery (vaginal birth vs assisted delivery), diet centrations of 1012 CFU/mL or greater may be found and (breast milk vs formula), level of sanitation, and exposure are comprised mainly of anaerobes such as Bacteroides, to antibiotics.3,4 The intestinal microbiota of newborns is Porphyromonas, Bifidobacterium, Lactobacillus, and Clos- characterized by low diversity and a relative dominance tridium, with anaerobic bacteria outnumbering aerobic of the phyla Proteobacteria and Actinobacteria; thereafter, bacteria by a factor of 100 to 1000:1. The predominance the microbiota becomes more diverse with the emergence of anaerobes in the colon reflects the fact that oxygen con- of the dominance of Firmicutes and Bacteroidetes, which centrations in the colon are very low; the flora has simply characterizes the adult microbiota.5-7 By the end of the first adapted to survive in this hostile environment. year of life, the microbial profile is distinct for each infant; At any given level of the gut, the composition of the by the age of 2.5 years, the microbiota fully resembles the flora also demonstrates variation along its diameter, with microbiota of an adult in terms of composition.8,9 This certain bacteria tending to be adherent to the mucosal period of maturation of the microbiota may be critical; surface, while others predominate in the lumen. It stands Gastroenterology & Hepatology Volume 9, Issue 9 September 2013 561 QUIGLEY to reason that bacterial species residing at the mucosal only are virtually all components of the gut-associated surface or within the mucus layer are those most likely to and systemic immune systems affected in these animals, participate in interactions with the host immune system, but the development of the epithelium, vasculature, neu- whereas those that populate the lumen may be more rel- romuscular apparatus, and gut endocrine system also is evant to metabolic interactions with food or the products impaired. The subtleties of the interactions between the of digestion. It is now evident that different bacterial pop- microbiota and the host are exemplified by studies that ulations may inhabit these distinct domains. Their relative demonstrate the ability of a polysaccharide elaborated by contributions to health and disease have been explored to the bacterium Bacteroides fragilis to correct T-cell deficien- a limited extent, though, because of the relative inacces- cies and Th1/Th2 imbalances and direct the development sibility of the juxtamucosal populations in the colon and, of lymphoid organs in the germ-free animal.24 Intestinal especially, in the small intestine. However, most studies of dendritic cells appear to play a central role in these critical the human gut microbiota have been based on analyses of immunologic interactions.24,25 fecal samples, therefore representing a major limitation. How does the gut immune system differentiate
Load more

Recommended publications
  • Root Microbiota Assembly and Adaptive Differentiation Among European
    bioRxiv preprint doi: https://doi.org/10.1101/640623; this version posted May 17, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. 1 Root microbiota assembly and adaptive differentiation among European 2 Arabidopsis populations 3 4 Thorsten Thiergart1,7, Paloma Durán1,7, Thomas Ellis2, Ruben Garrido-Oter1,3, Eric Kemen4, Fabrice 5 Roux5, Carlos Alonso-Blanco6, Jon Ågren2,*, Paul Schulze-Lefert1,3,*, Stéphane Hacquard1,*. 6 7 1Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany 8 2Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, SE‐752 36 9 Uppsala, Sweden 10 3Cluster of Excellence on Plant Sciences (CEPLAS), Max Planck Institute for Plant Breeding Research, 11 50829 Cologne, Germany 12 4Department of Microbial Interactions, IMIT/ZMBP, University of Tübingen, 72076 Tübingen, 13 Germany 14 5LIPM, INRA, CNRS, Université de Toulouse, 31326 Castanet-Tolosan, France 15 6Departamento de Genética Molecular de Plantas, Centro Nacional de Biotecnología (CNB), Consejo 16 Superior de Investigaciones Científicas (CSIC), 28049 Madrid, Spain 17 7These authors contributed equally: Thorsten Thiergart, Paloma Durán 18 *e-mail: [email protected], [email protected], [email protected] 19 20 Summary 21 Factors that drive continental-scale variation in root microbiota and plant adaptation are poorly 22 understood. We monitored root-associated microbial communities in Arabidopsis thaliana and co- 23 occurring grasses at 17 European sites across three years.
    [Show full text]
  • How Your Body Decides If Bacteria Are Friends Or Foes § Would You
    §How your body decides if bacteria are friends or foes § Would you: • Let you child eat food that dropped on the ground? • Let your child suck their thumbs? • Take antibiotics without knowing the true reason you are feeling sick? Humans and Microbes • Leeuwenhoek’s discovery of microorganisms in 17th century led people to suspect they might cause diseases • Robert Koch (1876) offered proof of what is now considered germ theory of disease; showed Bacillus anthracis causes anthrax • Today, we now know that most of the bacteria we associate with are not pathogens, and many are critical for our health. Bacteria Are Ubiquitous § We contact numerous microorganisms daily • Every surface on earth is covered! • Even clouds have microbes – Could play a role in seeding rain.. • Some have tremendous commercial value • Yogurts, wine, cheese, vinegar, pickles, etc. • Our bodies: • Breathe in, ingest, pick up on skin • Vast majority do not make us sick, or cause infections • Some colonize body surfaces; or slough off with dead epithelial cells • Most that are swallowed die in stomach or are eliminated in feces • Relatively few are pathogens that cause damage Microbes, Health, and Disease § Most microbes are harmless • Many are beneficial • Normal microbiota (normal flora) are organisms that routinely reside on body’s surfaces • Relationship is a balance, and some can cause disease under certain conditions-- opportunistic infections • Weaknesses in innate or adaptive defenses can leave individuals vulnerable to invasion – malnutrition, cancer, AIDS or
    [Show full text]
  • The Neuroprotective Effect of Tea Polyphenols on the Regulation of Intestinal Flora
    molecules Review The Neuroprotective Effect of Tea Polyphenols on the Regulation of Intestinal Flora Zhicheng Zhang 1,2,3, Yuting Zhang 4, Junmin Li 2,3,*, Chengxin Fu 1,* and Xin Zhang 4,* 1 Key Laboratory of Conservation Biology for Endangered Wildlife of the Ministry of Education, College of Life Sciences, Zhejiang University, Hangzhou 310058, China; [email protected] 2 Taizhou Biomedical Industry Research Institute Co., Ltd., Taizhou 317000, China 3 College of Life Sciences, Taizhou University, Taizhou 317000, China 4 Department of Food Science and Engineering, Ningbo University, Ningbo 315211, China; [email protected] * Correspondence: [email protected] (J.L.); [email protected] (C.F.); [email protected] (X.Z.) Abstract: Tea polyphenols (TPs) are the general compounds of natural polyhydroxyphenols extracted in tea. Although a large number of studies have shown that TPs have obvious neuroprotective and neuro repair effects, they are limited due to the low bioavailability in vivo. However, TPs can act indirectly on the central nervous system by affecting the “microflora–gut–brain axis”, in which the microbiota and its composition represent a factor that determines brain health. Bidirectional communication between the intestinal microflora and the brain (microbe–gut–brain axis) occurs through a variety of pathways, including the vagus nerve, immune system, neuroendocrine pathways, and bacteria-derived metabolites. This axis has been shown to influence neurotransmission and behavior, which is usually associated with neuropsychiatric disorders. In this review, we discuss that TPs and their metabolites may provide benefits by restoring the imbalance of intestinal microbiota and Citation: Zhang, Z.; Zhang, Y.; Li, J.; that TPs are metabolized by intestinal flora, to provide a new idea for TPs to play a neuroprotective Fu, C.; Zhang, X.
    [Show full text]
  • Presence of Archaea in the Indoor Environment and Their Relationships with Housing Characteristics
    Microb Ecol (2016) 72:305–312 DOI 10.1007/s00248-016-0767-z ENVIRONMENTAL MICROBIOLOGY Presence of Archaea in the Indoor Environment and Their Relationships with Housing Characteristics Sepideh Pakpour1,2 & James A. Scott3 & Stuart E. Turvey 4,5 & Jeffrey R. Brook3 & Timothy K. Takaro6 & Malcolm R. Sears7 & John Klironomos1 Received: 3 April 2016 /Accepted: 5 April 2016 /Published online: 20 April 2016 # Springer Science+Business Media New York 2016 Abstract Archaea are widespread and abundant in soils, Based on the results, Archaea are not equally distributed with- oceans, or human and animal gastrointestinal (GI) tracts. in houses, and the areas with greater input of outdoor However, very little is known about the presence of Archaea microbiome and higher traffic and material heterogeneity tend in indoor environments and factors that can regulate their to have a higher abundance of Archaea. Nevertheless, more re- abundances. Using a quantitative PCR approach, and search is needed to better understand causes and consequences of targeting the archaeal and bacterial 16S rRNA genes in floor this microbial group in indoor environments. dust samples, we found that Archaea are a common part of the indoor microbiota, 5.01 ± 0.14 (log 16S rRNA gene copies/g Keywords Archaea . Bacteria . Indoor environment . qPCR . dust, mean ± SE) in bedrooms and 5.58 ± 0.13 in common Building characteristics . Human activities rooms, such as living rooms. Their abundance, however, was lower than bacteria: 9.20 ± 0.32 and 9.17 ± 0.32 in bed- rooms and common rooms, respectively. In addition, by mea- Introduction suring a broad array of environmental factors, we obtained preliminary insights into how the abundance of total archaeal The biology and ecology of the third domain of life, Archaea, 16S rRNA gene copies in indoor environment would be asso- have been studied far less when compared to the other do- ciated with building characteristics and occupants’ activities.
    [Show full text]
  • 11 Microbial Communities in the Phyllosphere Johan H.J
    Biology of the Plant Cuticle Edited by Markus Riederer, Caroline Müller Copyright © 2006 by Blackwell Publishing Ltd Biology of the Plant Cuticle Edited by Markus Riederer, Caroline Müller Copyright © 2006 by Blackwell Publishing Ltd 11 Microbial communities in the phyllosphere Johan H.J. Leveau 11.1 Introduction The term phyllosphere was coined by Last (1955) and Ruinen (1956) to describe the plant leaf surface as an environment that is physically, chemically and biologically distinct from the plant leaf itself or the air surrounding it. The term phylloplane has been used also, either instead of or in addition to the term phyllosphere. Its two- dimensional connotation, however, does not do justice to the three dimensions that characterise the phyllosphere from the perspective of many of its microscopic inhab- itants. On a global scale, the phyllosphere is arguably one of the largest biological surfaces colonised by microorganisms. Satellite images have allowed a conservative approximation of 4 × 108 km2 for the earth’s terrestrial surface area covered with foliage (Morris and Kinkel, 2002). It has been estimated that this leaf surface area is home to an astonishing 1026 bacteria (Morris and Kinkel, 2002), which are the most abundant colonisers of cuticular surfaces. Thus, the phyllosphere represents a significant refuge and resource of microorganisms on this planet. Often-used terms in phyllosphere microbiology are epiphyte and epiphytic (Leben, 1965; Hirano and Upper, 1983): here, microbial epiphytes or epiphytic microorganisms, which include bacteria, fungi and yeasts, are defined as being cap- able of surviving and thriving on plant leaf and fruit surfaces. Several excellent reviews on phyllosphere microbiology have appeared so far (Beattie and Lindow, 1995, 1999; Andrews and Harris, 2000; Hirano and Upper, 2000; Lindow and Leveau, 2002; Lindow and Brandl, 2003).
    [Show full text]
  • Lesson 7.Normal Flora of Human Body(290
    MODULE Normal Flora of Human Body Microbiology 7 Notes NORMAL FLORA OF HUMAN BODY 7.1 INTRODUCTION In a healthy human, the internal tissues, e.g. blood, brain, muscle, etc., are normally free of microorganisms. However, the surface tissues, i.e., skin and mucous membranes, are constantly in contact with environmental organisms and become readily colonized by various microbial species. The mixture of organisms regularly found at any anatomical site is referred to as the normal flora. The normal flora of humans consists of a few eucaryotic fungi and protists, but bacteria are the most numerous and obvious microbial components of the normal flora. A healthy foetus in utero is free from microorganisms. During birth the infant in exposed to vaginal flora. Within a few hours of birth oral and nasopharyngeal flora develops and in a day or two resident flora of the lower intestine appears OBJECTIVES After reading this lesson, you will be able to: z describe normal flora z enlist the Advantages and Disadvantages of flora z describe the normal flora of various parts of the body 7.2 NORMAL MICROBIAL FLORA The term “normal microbial flora” denotes the population of microorganisms that inhabit the skin and mucous membranes of healthy normal persons. The skin and mucous membranes always harbor a variety of microorganisms that can be arranged into two groups: 78 MICROBIOLOGY Normal Flora of Human Body MODULE 1. The resident flora consists of relatively fixed types of microorganisms Microbiology regularly found in a given area at a given age; if disturbed, it promptly reestablishes itself. 2.
    [Show full text]
  • Archaea: Essential Inhabitants of the Human Digestive Microbiota Vanessa Demonfort Nkamga, Bernard Henrissat, Michel Drancourt
    Archaea: Essential inhabitants of the human digestive microbiota Vanessa Demonfort Nkamga, Bernard Henrissat, Michel Drancourt To cite this version: Vanessa Demonfort Nkamga, Bernard Henrissat, Michel Drancourt. Archaea: Essential inhabi- tants of the human digestive microbiota. Human Microbiome Journal, Elsevier, 2017, 3, pp.1-8. 10.1016/j.humic.2016.11.005. hal-01803296 HAL Id: hal-01803296 https://hal.archives-ouvertes.fr/hal-01803296 Submitted on 8 Jun 2018 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Human Microbiome Journal 3 (2017) 1–8 Contents lists available at ScienceDirect Human Microbiome Journal journal homepage: www.elsevier.com/locate/humic Archaea: Essential inhabitants of the human digestive microbiota ⇑ Vanessa Demonfort Nkamga a, Bernard Henrissat b, Michel Drancourt a, a Aix Marseille Univ, INSERM, CNRS, IRD, URMITE, Marseille, France b Aix-Marseille-Université, AFMB UMR 7257, Laboratoire «architecture et fonction des macromolécules biologiques», Marseille, France article info abstract Article history: Prokaryotes forming the
    [Show full text]
  • Gut Flora-Mediated Metabolic Health, the Risk Produced by Dietary Exposure to Acetamiprid and Tebuconazole
    foods Article Gut Flora-Mediated Metabolic Health, the Risk Produced by Dietary Exposure to Acetamiprid and Tebuconazole Jingkun Liu 1, Fangfang Zhao 2, Yanyang Xu 1 , Jing Qiu 1,* and Yongzhong Qian 1 1 Institute of Quality Standards & Testing Technology for Agro-Products, Key Laboratory of Agro-Product Quality and Safety, Chinese Academy of Agricultural Sciences, Key Laboratory of Agri-Food Quality and Safety, Ministry of Agriculture and Rural Affairs, Beijing 100081, China; [email protected] (J.L.); [email protected] (Y.X.); [email protected] (Y.Q.) 2 Analysis & Testing Center, Chinese Academy of Tropical Agricultural Sciences, Haikou 571101, China; [email protected] * Correspondence: [email protected] Abstract: The low-level and long-term exposure of pesticides was found to induce metabolic syn- drome to mice. Metabolic pathways and mechanisms were investigated by detecting gut flora with metabolites, host circulation, and their interrelations. Results showed that the abundances of flora species and their metabolism were altered, consequently leading to metabolic disorders. A correlation analysis between gut flora and their metabolic profiling further explained these changes and associations. The metabolic profiling of host circulation was also performed to characterize metabolic disorders. The associations of host circulation with gut flora were established via their significantly different metabolites. Alterations to the liver metabolism clarified potential pathways and mechanisms for the disorders. Metabolic disorders were evidently released by dietary and micro-ecological intervention, directly proving that gut flora comprise a vital medium in metabolic health risk caused by pesticide exposure. This work supplied theoretical bases and intervention Citation: Liu, J.; Zhao, F.; Xu, Y.; Qiu, J.; Qian, Y.
    [Show full text]
  • Methods in Microbiome Research Namrata Iyer
    TECHNOLOGY FEATURE Methods in microbiome research Namrata Iyer From the freezing lakes of Antarctica to satisfied most of these requirements. The metametabolomics are more technically the thermal vents deep within the oceans, most widely used method in microbiome challenging, given the sheer diversity of microbes have managed to survive and analysis is 16s rRNA sequencing2. The proteins and metabolites that each microbe thrive in the most inhospitable of con- 16s rRNA gene is highly conserved in all can produce. While these techniques are ditions. Unsurprisingly, the relatively bacteria and sequencing of its regions of still in their infancy, they promise to reveal luxurious abode of the human body is hyper- variability allows the identification unique insights into the communication chockablock with microbial life. We have of different bacterial species. But this tech- and cooperation between the different coevolved over centuries with these micro- nique suffers from inaccuracies at species members of the microbiota, and also host- organisms, collectively referred to as our level classification2. Furthermore, it limits microbiota interactions. microbiota, resulting in a relationship the analysis to only bacterial species while that is mutually beneficial. However, it has ignoring other members in the community. Microbiota structure only been in the past few decades that the Platforms are now being developed that can Community structure is a function of who importance of the microbiota to human couple this technique with other genetic is present in the microbiota community health has been uncovered. It is now well- markers, allowing detection of eukaryotic and how these members interact with each known that imbalance in the microbiota— members of the microbiota as well3.
    [Show full text]
  • The Nasal Microbiota: Diversity, Dynamicity, and Vaccine-Mediated Effects
    THE NASAL MICROBIOTA: DIVERSITY, DYNAMICITY, AND VACCINE-MEDIATED EFFECTS Jane C. Deng, M.D., M.S. Associate Professor of Medicine David Geffen School of Medicine University of California, Los Angeles Section Chief, Pulmonary and Critical Care Veteran Affairs Medical Center, Ann Arbor, Michigan Why do we care about the nasopharyngeal microbiota? • Pneumonia – bacterial and influenza – is a leading cause of death in the United States and worldwide • 1.3 million child deaths annually (O’Brien, et al, Lancet 2009) • We believe the upper respiratory tract flora informs, to a large extent, the microbiota of the lower respiratory tract (LRT) and is a precursor to LRT infections (e.g., pneumonia) • Involved in maintenance and dissemination of pathogens across the population • May also govern the acquisition of antibiotic resistance genes among bacteria from different genera “The Big Four” in the nasopharynx Streptococcus Staphylococcu pneumoniae s aureus Moraxella Haemophilus catarrhalis influenzae Sources: http://imgtagram.com/rewtos2d-streptococcus-pneumoniae-bacteria/ List of members of the “normal” bacterial flora in the nose and oropharynx (partial) • Staph epi • Propionobacteria Our bodies are • Staph aureus • Streptococcus pneumoniae“colonized” with • Strept pyogenes potentially pathogenic • Neisseria spp (including meningitidis)bacteria • Haemophilus influenzae • Mycoplasma • Corynebacterium diphtheriae (less common member of the normal flora after vaccination) Unanswered questions • How does bacterial colonization happen in the first
    [Show full text]
  • A Study on Microbial Flora on Skin of Health Care Providers in a Tertiary
    Review Article Clinician’s corner Images in Medicine Experimental Research Case Report Miscellaneous Letter to Editor DOI: 10.7860/JCDR/2018/37717.12266 Original Article Postgraduate Education A Study on Microbial Flora on Skin of Case Series Health Care Providers in a Tertiary Microbiology Section Microbiology Care Hospital in Southern India Short Communication MATHAVI SURESHKUMAR1, R SURIYAPRABA2, R INDRA PRIYADHARSINI3 ABSTRACT and subjected to bacterial and fungal culture. Blood agar and Introduction: Human skin is constantly covered with MacConkey agar was used for bacterial culture and Sabouraud’s microorganisms both commensals and pathogens depending dextrose agar for fungal culture. The bacterial isolates were then on topography, environmental factors and host factors. subjected to antibiotic sensitivity testing. Though these organisms are regarded as commensals in Results: Bacterial growth was observed in all the HCWs immunocompetent individuals, they can become pathogenic (100%) and fungus was isolated from eight HCWs (6.2%). in immunocompromised persons especially in hospitalised Among the bacterial isolates, Diphtheroids (47) were the individuals. In recent years, Staphylococcus epidermidis is predominant isolate accounting for 29% followed by coagulase regarded as an agent of hospital and community acquired negative Staphylococcus (39) which was 24% of isolates. The infections. When the health care workers do not wash their predominant pathogen isolated was Staphylococcus aureus hands between patients or do not practice standard infection (15%, 25 isolates). 17% (11 isolates) of Staphylococci were control measures, they are responsible for transmission of resistant to Cefoxitin which indicates both MRSA and MR-CONS. nosocomial infections. Among gram-negative isolates, most of them were resistant to Aim: This study was done to know the microbial flora on skin ampicillin, cotrimoxazole and cephalosporins.
    [Show full text]
  • Response of Fecal Bacterial Flora to the Exposure of Fumonisin B1 in BALB/C Mice
    toxins Article Response of Fecal Bacterial Flora to the Exposure of Fumonisin B1 in BALB/c Mice Fan Zhang, Zhiwei Chen, Lin Jiang, Zihan Chen and Hua Sun * State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, 1# Xiannongtan Street, Xicheng District, Beijing 100050, China; [email protected] (F.Z.); [email protected] (Z.C.); [email protected] (L.J.); [email protected] (Z.C.) * Correspondence: [email protected] Abstract: Fumonisins are a kind of mycotoxin that has harmful influence on the health of humans and animals. Although some research studies associated with fumonisins have been reported, the regulatory limits of fumonisins are imperfect, and the effects of fumonisins on fecal bacterial flora of mice have not been suggested. In this study, in order to investigate the effects of fumonisin B1 (FB1) on fecal bacterial flora, BALB/c mice were randomly divided into seven groups, which were fed intragastrically with 0 mg/kg, 0.018 mg/kg, 0.054 mg/kg, 0.162 mg/kg, 0.486 mg/kg, 1.458 mg/kg and 4.374 mg/kg of FB1 solutions, once a day for 8 weeks. Subsequently, feces were collected for analysis of microflora. The V3-V4 16S rRNA of fecal bacterial flora was sequenced using the Illumina MiSeq platform. The results revealed that fecal bacterial flora of mice treated with FB1 presented high diversity. Additionally, the composition of fecal bacterial flora of FB1 exposure groups showed marked differences from that of the control group, especially for the genus types including Alloprevotella, Prevotellaceae_NK3B31_group, Rikenellaceae_RC9_gut_group, Parabacteroides and phylum types including Cyanobacteria.
    [Show full text]