09.2_taxonomy

• Bacillota

• Pseudomonadota

• Actinomycetota

• Bacteroidota

-> evolutionary relatedness

Phylum Actinomycetota

-> high Gas Chromatography (GC)

-> gram-positve group of pathogens

Actinobacteria

• Actinomycetales

  • Corynebacteriaceae

    • Corynebacterium diphtheriae

  • Mycobacteriaeceae

    • Mycobacterium tuberculosis

• upper respiratory tracks

• grey-green pseudomembrane

• affecting swallowing + breathing

• evading host immune system via diphtheria toxin

• causing further systematic damage

  • kidneys, heart, nerves

  • inhibits host cell protein synthesis

• respiratory tract

• multifacet immune response

  • latent infection w. re-activation possible

  • tubercular (granuloma) disease/lesion in X-ray -> bad

  • complete clearance of pathogen

• reduction of lung capacity

• immune defence: macrophages + CD4+ T cells

  -> numerous strategies to circumvent

• often multi-drug resistant (6 - 9 months w. helpful antibiotics to recover)

• only around 10 % of the 25 % percent infected people w. early progression due to failed immune control (HIV positive individuals)

Phylums Bacteroidota and Chlamydiota

-> 40 - 45 % Gas Chromatography

-> Gram-negative group of pathogens

Bacteroidota

• Bacteroidales

  • Porphyromonadaceae

    • Porphyromonas gingivalis

Chlamydiota

• Chlamydiales

  • Chlamydiaceae

    • Chlamydia trachomatis

• gum disease

• w. fimbria and intracellular survival

• focal infection potential

• can be involved in modified host gene expression leading to activation of oncogenes

• blindness + sexually transmitted

• obligate intracellular pathogen (human only natural host)

• two phases of distinct development

  • infection by elementary bodies (EBs) via binding to receptotrs, remodelling of actin and creation of internal endocytic vacuole

  • EB -> reticulate body (RB) to thrieve via replication and utilisation of host nutrients

  • reaching critical volume -> lysis of host cell/extrusion of cytoplasmic inclusion

  • RB -> EB to attach to adjacent host cells to invade and spread

Phylum Bacillota

-> low Gas chromatography

-> Gram-positive group of pathogens

Bacilli

• Bacillales

  • Bacillaceae

    • Bacillus anthracis

  • Staphylococcaceae

    • Staphylococcus aureus

  • Streptococcaceae

    • Streptococcus pyogenes

Clostridia

• Clostridiales

  • Clostridiaceae

    • Clostridium perfringens

  • Peptostreptococcaceae

    • Clostridioides difficile

• clinical manifestation depending upon route of infection

  • cutaneous (skin, lesions)

  • gastrointestinal (ingestion)

  • pulmonary (inhilation)

• capsule (evading phagocytosis) + two AB type toxins

  • lethal factor (LF)

  • edema factor (EF)

• commonly in livestock, zoonosis possible

• discovered by Robert Koch

• member of microbiota / commensal

  • respiratory/nasal track

  • skin

• range of illnesses

  • skin conditions

  • more serious systemic infections

• 20 - 30 % of human colonised by S. aureus

• high AMR (anti-microbial resistance) + MRSA (multi-drug resistent S. aeureus)

• also known as group A streptococcus (GAS)

• wide array of manifestations

  • mild localised infections

  • life-threatening invasive infections w. rapid spread

    • necrotising fasciitis -> very rare

    • toxic shock syndrome

• multiple virulence factors which fascilitate pathogenesis and host evasion

• human-specific bacterial pathogen

• often multi-drug resistant

• widely associated w. gut diseases in neonatal animals and human

• gas gangrene by primary pathogen

• second common: foodborne pathogen

• dissamination of spores -> readily

• soils, water, GIT of animals and humans

• secrete exotoxins (> 20 different types, not all at once yet)

  • e. g. uncooked meat

  • direct destruction of cell wall/epithelium and their connections

• fast growing

• “superbug”

• colitis symptoms

  • mild-sever diarrhoea

  • abdominal pain

  • fever

  • bowl inflammation

• major cause of hospital acquired infections -> in hospial environment persistent spores

• production of toxins

• often multi-drug resistant

• treatment w. FMT (faecal transplant) besides antibiotics w. reduction of relapse and > 90% of success rate

Phylum Fuscobacteriota

-> low Gas Chromatography

-> Gram-negative group of pathogens

Fuscobacteriia

• Fusobacteriales

  • Fusobacteriaceae

    • Fusobacterium nucleatum

• can cause colorectal cancer

• oral

• w. translocation to gut -> capable of carcinogenesis

• production of toxin

• living in tumor environment

Phylum Pseudomonadota

-> broad Gas Chromatography range

-> Gram-negative group of pathogens

Alphaproteobacteria

• Rickettsiales

  • Rickettsiaceae

    • Rickettsia rickettsii

Betaproteobacteria

• Neisseriales

  • Neisseriaceae

    • Neisseria gonorrhoeae

Epsilonproteobacteria

• Campylobacterales

  • Helicobacteraceae

    • Helicobacter pylori

Gammaproteobacteria

• Enterobacterales

  • Enterobacteriaceae

    • Escherichia coli

    • Klebsiella pneumoniae

    • Salmonella enterica

  • Morganellaceae

    • Proteus mirabilis

  • Yersiniaceae

    • Yersinia pestis

• Legionellales

  • Legionellaceae

    • Legionella pneumophila

• Vibrionales

  • Vibrionaceae

    • Vibrio cholerae

• Rocky Mountain spotted fever

  • acute febrile tick-borne illness

  • late diagnosis: infects vascular endothelial cells through body to the heart

• tick vector

• obligate intracellular pathogen

• difficult diagnosis

• gonorrhea

  • mucosal infections of UGT (epithelia)

• sexually transmitted infection (STI)

• type IV pili to attack to epithelial cells

• obligate human host-adapted pathogen

• super gonorrhea: high levels of AMR (antimicrobial resistance)

• chronic gastric infections

• can cause H. pylori-related gastric cancer

  -> CagA as oncogenic virulence factor

• in gastric lumen w. adaption to acidic environment

• normal member of gut microbiota

• multiple pathotypes

  • Enterotoxogenic E. coli - ETEC

  • Enteropathogenic E. coli - EPEC

  • Enteroaggregative E. coli - EAEC

  • Shiga Toxin-Producing E. coli - STEC/VTEC/EHEC

  • Enteroinvasive E. coli - EIEC

  • Diffusely-adherent E. coli DAEC

Enterotoxogenic E. coli - ETEC

• acute watery diarrheoa in infants + adults

• bacterial diarrheoal disease

• consumption of faecally contaminated food / water

• attachment w. CFA (colonisation factor antigen) to intestinal mucosa

• elaboration of enterotoxins -> diarrhoea

  • STa/b - heat-stable toxins

  • LT-I/-II - heat-labile toxins

Enteropathogenic E. coli - EPEC

• increased secretion and watery diarrheoa

• outbreaks of infant-associated diarrheoa

• faecal-oral exposure via contaminated surfaces / food products

• non-toxigenic and non-invasive

• adhesion w. pili to intestinal mucosa w. pedestal formation afterwards

• production of A/E (attaching and effacing lesions) on intestinal epithelium

• rapid disease onset (after 2-3 days resolved)

Enteroaggregative E. coli - EAEC

• persistent and acute diarrheoa (self-limiting) + other symptoms

• stacked-brick arrangement over intestinal epithelium

• probably underappreciated w. different diagnosis -> some symptoms like those of others

• aggregative adhesion fimbriae I w. EAST I toxin production

  -> Shiga-like toxin possible

Shiga Toxin-Producing E. coli - STEC/VTEC/EHEC

• wide range of diseases

  • mild form of diarrheoa

  • hemorrhagic colitis -> severe abdominal pain, bloody diarrheoa

  • hemolytic uremic syndrom (HUS)

• production of Shiga-toxin/verocytotoxin/enterohemorrhagic

  -> Stx1/Stx2

• undercooked beef/meet, water, unpasteurised milk/fruit juice, uncooked vegetables

• < 100 bacteria to infect (ID50!)

Enteroinvasive E. coli - EIEC

• watery diarrheoa

• dysenteric form of disease

  • fever

  • abdominal cramps

  • blood and leukocytes in stool

• colonic ulceration due to process of epithelial cell destruction with inflammatory infilitration

• closely related to Shigella

• active invasion and destruction of colonic epithelium

• plasmid encoded genes mediating invasion into colonic epithelium

• movement through formation of actin tails

Diffusely-adherent E. coli DAEC

• diarrheoa in children (2-6 y. o. primarily)

• asymptomatic intestinal microbiota strains in children + adults

• adhesion in diffuse pattern (fimbriae) w. bacteria uniformly covering the entire cell surface

  -> contribution to pathogenesis

• respiratory, oropharynx and GIT

• can cause pneumonia

• different capsules to evade host-mediated killing

• multi-drug resistance

• opportunistic

• atypical pneumonia

  • survival inside macrophages

• intracellular pathogen in amoebae in fresh water

  • hot water tanks

  • hot tubs

  • cooling towers of large air conditioners

• UTIs

• can lead to kidney stones

• member of gut microbiota

• urease activity

  • hydrolyses urea to ammonia

• swarming motility with whip-like structures (flagella)

• depending on type of S. enterica

  • S. Typhimurium

  • S. Typhi

• odd nomenclature -> only full name counts

• numerous virulence factors

  • flagella

  • capsule

  • plasmids

  • adhesion system

  • T3SS

  • SPI encoding

• localised gastroenteritis (>= 5 days ill)

• bloodstream infection possible after invasion w. non-typhoidal Salmonella

• food poisoning

• active invasion of epithelial cells w. T3SS encoded within SP1 -> inflammation + breaching of epithelial barrier

• survival and replication within invaded phagocytes by utilisation of SP-2 encoded T3SS

• typhoid fever

• restriced to humans

• relatively new disease

• polysaccharide capsule - Vi antigen -> inhibiting phagocytosis

• expression of typhoid toxin encoded on SPI-11

• emerging thread of AMR (antimicrobial resistance)

• watery diarrheoa + vomiting

• undercooked/raw shellfish or contaminated water

• production of cholera toxin

• pump memorializing John Snow

• disease pleague

  • pneumonic

  • septicemic

  • buboni

• infects rodents

• transmitted by ectoparasites like fleas

• w. o. antibiotic treatment 50 - 100 % lethal

Phylums Spirochaetota & Tenericutes

-> low Gas chromatography range

-> (considered) Gram-negative pathogens

Spirochaetia

• Spirochaetales

  • Spirochaetaceae

    • Borrelia burgdorferi

Mollicutes

• Mycoplasmatales

  • Mycoplasmataceae

    • Mycoplasma pneumoniae

• Lyme disease (zoonotic, vector-borne)

  • bull’s eye rash

• long term untreated: e.g. heart disease

• slow-growing microaerophilic spirochete

• ticks and vertebrate host

  
  

• mild infections of the respiratory system = “walking pneumonia”

• obligate pathogen

• lacks peptidoglycan cell wall

• tiny genome, small bacteirum

• very rarely diagnosed