Gram Positives - BI1S209 Lecture 4 PDF

PUBLIC / Gram Positives CYHOEDDUS Classifying Prokaryotes PUBLIC / CYHOEDDUS...

PUBLIC / Gram Positives CYHOEDDUS Classifying Prokaryotes PUBLIC / CYHOEDDUS Domain Bacteria Domain Archaea Gram Negative Gram Positive PseudomonadotaNon-Pseudomonadota Enteric Bacteria Cyanobacteriota Salmonella Spirochetota Yersinia pestis Treponema palladium Non-enteric Bacteria Bacteroidota Vibrio fischeri Alistipes Bdellovibrio Caulobacter Chlamydiota Chlamydia trachomatis  PUBLIC / Classifying Prokaryotes CYHOEDDUS Domain Bacteria Domain Archaea Gram Negative Gram Positive PseudomonadotaNon-Pseudomonadota Bacillota Actinomyceto ta  PUBLIC / Learning Objectives CYHOEDDUS Describe some major lineages of Bacteria Describe some major features of the Gram positives and give some detailed examples Gram Positive vs. Gram Negatives PUBLIC / CYHOEDDUS Thick layer of peptidoglycan Small or no periplasmic space Teichoic acid Thin layer of peptidoglycan Large periplasmic space Outer membrane Lipopolysaccharides  PUBLIC / Phylum: Bacillota (Firmicutes) CYHOEDDUS Low GC content Obligate aerobes or facultative anaerobes Majorcomponent of the human intestinal microbiome Decrease with age Maybe related to obesity  PUBLIC / Order: Lactobacillales CYHOEDDUS Low GC content Bacilli or cocci Acid tolerant Lactic acid Bacteria- Streptococcus, Lactobacillus Probiotics Food industry- yoghurt, cheese, wine Disease  PUBLIC / Streptococcus CYHOEDDUS Commensal or pathogenic Can cause a variety of diseases- strep throat, pink eye, meningitis, endocarditis and, necrotising fasciitis- Streptococcus pyrogens Emmenthal cheese- Streptococcus thermophilus  PUBLIC / Lactobacillus CYHOEDDUS Commensal- mouth, stomach, gut, vagina Probiotic- outcompete pathogens Cavities- Lactic acid corrodes enamel, but prevent Streptococcus build up Food and drink industry- sourdough, kimchi, beer  PUBLIC / Order: Bacillales CYHOEDDUS Common in soil Anaerobic, facultative or aerobic Spore formers  PUBLIC / Staphylococcus aureus CYHOEDDUS 25% of people carriers Opportunistic pathogen Hospital acquired infections Wide range of diseases- toxic shock syndrome, endocarditis, pneumonia, abscesses, furunculosis and scalded skin syndrome Food poisoning common at picnics and buffets Causes secondary infections in those with influenza Scalded skin Cellulitis syndrome  PUBLIC / S. aureus Virulence Factors CYHOEDDUS Coatedwith protein A- disables antibodies Capsule- inhibit endocytosis abscess Toxins- enterotoxin, endotoxin Haemolysins- lyse RBCs Coagulase- coagulates fibrinogen Staphylokinase- dissolves fibrin Antibiotic resistance- MRSA S. aureus “chased” by neutrophil  PUBLIC / Bacillus thuringiensis CYHOEDDUS Insecticidal- natural pesticide Protoxin- crystalline protein Pesticide- safe for plants and the environment Controlof blackfly larvae- vectors for Onchocera volvulus GM crops  PUBLIC / Bacillus anthracis CYHOEDDUS Anthrax Contact with livestock Cutaneous- eschars, low mortality Pulmonary- shortness of breath, very high mortality Gastrointestinal- sickness and diarrhoea, moderate mortality Weaponised  PUBLIC / Order: Clostridiales CYHOEDDUS Anaerobic Most species non-pathogenic Pathogenic species: Clostridium botulinum, Clostridium perfringens, Clostridium difficile, Clostridium tetani Digestion of cellulose in ruminants  PUBLIC / Clostridium botulinum CYHOEDDUS Botulism Canned food Botulinum toxin Antitoxin Medicaluses: muscle spasm, cross eyes, excessive sweating Botox Phylum: Actinomycetota PUBLIC / CYHOEDDUS (Actinobacteria) High GC content Terrestrial or aquatic Important in soil Nitrogen fixing Pathogens  PUBLIC / Streptomyces CYHOEDDUS Largest genus of Actinobacteria Aerobic Spore forming Soil dwelling Geosmin- earthy smell Antibiotics- streptomycin, chloramphenicol, tetracycline, neomycin  PUBLIC / Mycobacterium CYHOEDDUS Cannot be Gram stained Aerobic Slow growing Pathogens:Mycobacterium tuberculosis, Mycobacterium leprae Tuberculosis (TB): commonly occurs in lungs, latent and active infection Leprosy:skin and peripheral nerves, very slow growing, social stigma  PUBLIC / CYHOEDDUS Domain Domain Archaea Bacteria Gram Gram Negative Positive Pseudomonad Non- Bacillota Actinomyceto ota Pseudomonadota ta Cyanobacteriota Lactobacillales Streptomyces Enteric Bacteria Streptococcus Mycobacterium Spirochetota Lactobacillus Salmonella tuberculosis Treponema Yersinia pestis Mycobacterium leprae palladium Bacillales Staphylococcus aureus Non-enteric Bacteria Bacteroidota Bacillus thuringiensis Bacillus anthracis Vibrio fischeri Alistipes Bdellovibrio Caulobacter Chlamydiota Clostridiales Chlamydia Clostridium botulinum trachomatis  PUBLIC / Learning Outcomes CYHOEDDUS Give an overview of Gram positive Bacteria Describe some of the diseases caused by S. aureus Describe some of the main features of some of the low GC content species Briefly describe some uses of and diseases caused by the high GC content species  PUBLIC / Extra Reading CYHOEDDUS Tortora Chapter 11- The Prokaryotes: Domains Bacteria and Archaea (the section on Gram positive Bacteria) Bauman Chapter 19- Pathogenic Gram- Positive Bacteria Open access book chapter