Classification of Infectious Agents: Prokaryotes Part 2 Flashcards
Proteobacteria
From the mythological Greek god Proteus, who could assume many shapes • Gram-negative • Chemoheterotrophic • Largest taxonomic group of bacteria • Five classes mainly defined on the basis of 16S rRNA sequences V2 region 100-200 nucleotides
The Alphaproteobacteria
Most are capable of growing with very low levels
of nutrients
• Many have stalks or buds known as prosthecae
Pelagibacter
Pelagibacter • One of the most abundant microorganisms in oceans • Extremely small • Advantage in low-nutrient environments • Important role in Earth's carbon cycle • Closely related to mitochondrion 16S rRNA -The Alphaproteobacteria Used to be called SAR 11 - 1990 Gene that was retreived from Saargasso 16s rRNA gene Cultured in 2006
Example of bact that was known as uncultured bacteria abd then eventually grown
Closely matched to mitochondrion
Its between riketsia and _ rit is pathogenic
Rickettsia
Obligate intracellular parasites • Cause spotted fevers • R. prowazekii: epidemic typhus • R. typhi: endemic murine typhus • R. rickettsii: Rocky Mountain spotted fever • Transmitted by insect and tick bites -Alphaproteobacteria
Ehrlichia
Transmitted by tick
• Cause ehrlichiosis
-Alphaproteobacteria
Rhizobium and Bradyrhizobium
Fix nitrogen in the roots of leguminous plants
• Known by the common name of rhizobia
Rib does not infect, creats symbiosis
Alphaproteobacteria
Agrobacterium
Plant pathogen; causes crown gall
• Inserts a plasmid into plant cells, inducing a tumor
Agro - useful for vector in gene plamt
Alphaproteobacteria
Bartonella
Human pathogen
• B. henselae: cat-scratch disease
- The Alphaproteobacteria
Brucella
Obligate parasite of mammals; survives phagocytosis • Causes brucellosis Brucella- human disease Notifiable, 7-20/year, Rate = 0.03 - The Alphaproteobacteria
Burkholderia
• B. cepacia: degrades more than 100 organic molecules
• B. pseudomallei: causes meliodosis
- Betaproteobacteria
Bordetella
Non-motile rods
• B. pertussis: causes whooping cough
Pertussis - Notifiable, 700-4000 cases, rate= 2-13/1000
- Controlled with vaccine - Vax called DTap - The Betaproteobacteria
Neisseria
N. gonorrhoeae: cause of gonorrhoea
Gon - notafiable , 11,000-29K, rate: 30-300/100,000
N. meningitidis: cause of meningococcal meningitis
- The Betaproteobacteria
Zoogloea
Important in the activity of the activated sludge system
- The Betaproteobacteria
Gammaproteobacteria
Gamma- largest class of protieobact
Beggiatoa
Grows in aquatic sediments
• Chemoautotrophic; oxidize H2S to S0 for energy
Gammaproteobacteria
F. tularensis
causes tularemia
Notifiable , number of cases, 4-13cases/year rate 0.01-0.03/100kk
- Can be used as a weppon
Gammaproteobacteria
Pseudomonas
Opportunistic pathogens; nosocomial infections
• Metabolically diverse
• Polar flagella; common in soil
• P. aeruginosa: wound and urinary tract infections
Gammaproteobacteria
Moraxella
M. lacunata: causes conjunctivitis
Gammaproteobacteria
Acinetobacter
A. baumanii: respiratory pathogen; resistant to antibiotics
Gammaproteobacteria
Legionella
• Found in streams, warm-water pipes, and cooling towers
• Causes legionellosis
notifiable 200-480 cases year rtae 0.5-2/100K
Gammaproteobacteria
• Coxiella
• C. burnetii: causes Q fever; transmitted via aerosols or
milk
Gammaproteobacteria
Vibrio cholerae
causes cholera
Vib chol- notifiable , 40-11., 0-.11 rate
- dihareaa
Gammaproteobacteria
V. parahaemolyticus
causes gastroenteritis
Gammaproteobacteria
E. coli:
indicator of fecal contamination; causes foodborne
disease and urinary tract infections
• Strain O157:H7 and many othersEcoli verotoxigenic - notifiable 544-819, rate 1.6-3
Gammaproteobacteria
Salmonella
2400 serovars
• Common form of foodborne illness
• Salmonella enterica Var Typhi causes typhoid fever
notifable
- Typoid notifiable , 120-190 cases, 0.2-.6
- Salmonell notifiable 6100-7800, rate 15-21
Gammaproteobacteria
Shigella
- Most severe is dysenterne
Sonnei -much milder
Causes bacillary dysentery
Gammaproteobacteria
Klebsiella
K. pneumoniae causes pneumonia
Gammaproteobacteria
Serratia
Produces red pigment
• Common cause of nosocomial infections
Gammaproteobacteria
Proteus
Swarming motility; colonies form concentric rings
• Proteus mirabilis causes 90% of proteus infection
linked to utis, and nosocomal diseases
Gammaproteobacteria
Yersinia
• Y. pestis causes plague
• Transmitted via fleas
notifiable, 0 cases,
Gammaproteobacteria
Erwinia
Plant pathogens
Enterobacter
• E. cloacae and E. aerogenes cause urinary tract
infections and nosocomial infections
Gammaproteobacteria
Cronobacter
Cronobacter- used to be an enterobacter but studeis have shown they are diffeent
Discovered in 2007
• C. sakazakii causes meningitis; found in a variety of
environments and foods
Gammaproteobacteria
Pasteurella
Pathogen of domestic animals
• P. multocida is transmitted to humans via animal bites
Gammaproteobacteria
Haemophilus
• Require X factor (heme) and V factor (NAD+, NADP+) in
media
• H. influenzae causes meningitis, earaches, and epiglottitis
• Different serotypes. Vaccine against Serotype b is part of
children vaccination in BC and Canada. Non-b serotypes
are increasing
otifiable, there is a vaccine
- Can caue menengitts
- Dif serotypes
- Vaccine called HIB since serotype B
- Number of casses 17-33/year rate = 0.03-.1/100k
We vaccinate to avoid the diease
Gammaproteobacteria
Fastidious
difficult for bacteria to grow, rewuire a lot of substanece and low media will not cut it
Myxococcales
Myxo = mucus
• Move by gliding and leave a slime trail
• Cells aggregate and form a fruiting body containing
myxospores
Deltaproteobacteria
Deltaproteobacteria
have no known pathogens
Epsilonproteobacteria
Helical or curved; microaerophilic
Campylobacter
• One polar flagellum • C. jejuni causes foodborne intestinal disease notifiable - 9000-10K a year - Rate = 25-30/100K Epsilonproteobacteria
Helicobacter
Multiple flagella
• Cause peptic ulcers and stomach cancer
Epsilonproteobacteria
Chlamydiae
No peptidoglycan in the cell wall; grow
intracellularly
Form an elementary body that is infective
Chlamydia
Clamidya - ntoifiabke , cases: 94K-126K, rate 295-370
- Largest cases per year
Chlamydia trachomatis causes trachoma and urethritis
Chlamydophila
Chlamydophila psittaci causes respiratory psittacosis
Planctomycetes
Gemmata obscuriglobus has a membrane around
DNA resembling a eukaryotic nucleus
No pathogens in this phylum
Has a membrane around nucleoid which is unusak and unique for bacteria and is nto like the classical rep of. A eukar
Bacteroidetes
Anaerobic
• Bacteroides are found in the mouth and large intestine
• Cytophaga degrade cellulose in soil
The Nonproteobacteria Gram-Negative Bacteria
Fusobacteria
• Anaerobic
• Are found in the mouth; cause dental abscesses
• Fusobacterium nucleatum, F. periodonticum
• Normal inhabitant of oral cavity
The Nonproteobacteria Gram-Negative Bacteria
Spirochaetes
• Coiled and move via axial filaments
Treponema
• T. pallidum causes syphilis
Syph- noti diease 2800-5800, rate 8-30
Spirochaetes
Borrelia
• B. burgdorferi causes relapsing fever and Lyme disease
oti- 105-1600 , rate 3-5
Has a liner genome one of few
Spirochaetes
• Leptospira
Animal pathogen excreted in animal urine
• Can be transmitted to humans
• Cause leptospirosis
Spirochaetes
Deinococcus radiodurans
• More resistant to radiation than endospores
Deinococci
• Thermus aquaticus
Found in a hot spring in Yellowstone National Park
• Source of Taq polymerase
Deinococci
Deinococci
Nno path in tgis physkm
Clostridiales
Clostridium (more than 150 species described: most soil
bacteria, many free N fixers)
• Endospore-producing
• Obligate anaerobes
• Includes disease-causing C. tetani, C. botulinum, C.
perfringens, and C. difficile
Firmicutes (Low G + C Gram-Positive Bacteria)
disease-causing Clostridiales
C. tetani, C. botulinum, C.
perfringens, and C. difficile
C. tetani
etini- Notifiabil, 4-6 cases , rate 0.003-0.01/ year
- toxoid vaxxine - soil
C. botulinum
otu- botulism, notifiable, 4-12 cases a tyear, rate 0.01-.02
food
C. difficile
Cdif- nosocomial , notifiable, 700-8K, rate 62-104
• Epulopiscium
Can be seen with the unaided eye
• Daughter cells form within the parent cell; no binary
fission
Epu- largest backeria discovererd
Firmicutes (Low G + C Gram-Positive Bacteria)
Bacillales
Firmicutes (Low G + C Gram-Positive Bacteria)
• Bacillus
Endospore-producing rods
• B. anthracis causes anthrax
- Notifiable , 0 cases
• B. cereus causes food poisoning
• Staphylococcus
Grapelike clusters
• S. aureus causes wound infections, is often antibiotic
resistant, and produces an enterotoxin
• Bacillales
Listeria
• L. monocytogenes contaminates food. Can cause
meningitis
Listeria- Notifiable , 120-190 cases yaer, rate0.3-0.5/100k
• Bacillales
• Lactobacillales
Aerotolerant anaerobes; produce lactic acid from simple
carbohydrates
• Lactobacillus colonize the body and are used
commercially in food production
Streptococcus
Spherical in chains
• Produce enzymes that destroy tissue
• Beta-hemolytic streptococci hemolyze blood agar;
includes S. pyogenes
• Non-beta-hemolytic streptococci include S. pneumoniae
and S. mutans, which causes dental caries
Lactobacillales
Enterococcus
Found in intestinal tract; hospital contaminants
• E. faecalis and E. faecium infect surgical wounds and the
urinary trac
Lactobacillales
Mycoplasmatales
Lack a cell wall; pleomorphic
• Mycoplasma pneumoniae causes mild pneumonia
Mycobacterium
Outermost layer of mycolic acids that is waxy and waterresistant • Often slow-growing • M. tuberculosis causes tuberculosis • M. leprae causes leprosy Both notifiabe; Tb - 1500-2000, rate 5 Lepre- 1-12, rate .003-.1
Corynebacterium
• C. diphtheriae causes diphtheria
Dipth- notifiable, 1-2 cases, rate 0.001
Propionibacterium
Forms propionic acid
• P. acnes causes acne
Gardnerella
• G. vaginalis causes vaginitis
Streptomyces
• Isolated from soil; produce most antibiotics
Actinomyces
• Form filaments in the mouth and throat; destroy tissue
Nocardia
Form fragmenting filaments; acid-fast
• N. asteroides causes pulmonary infections
