What is the authoritative reference on prokaryote classification called
Bergey's Manual of Systematic Bacteriology
The first edition of the book focused on:
classification of Morphology, Gram reaction, and biochemical characteristics
The current edition of the book focused on:
rRNA differences, while still somewhat using Gram reaction and morphology.
It is important to remember that taxonomy/systematics of bacteria is Not as exact or permanent as that of other living organisms.
The current second edition of Bergey's Manual classifies prokaryotes into 27 phyla: 3 archae and 24 bacteria groups
Archaea
-highly unusual in morphology & in environmental niches
-said to as different from "normal" bacteria as normal is different
from eukaryotes
-no known human pathogens
-thermoacidophiles
-methanogens
-halophiles
thermoacidophiles
-lives at extremely high temps (over 80 degree Celsius)
-record from Geogemma 2 hrs. at 120 degree Celsius
methanogens
-very important in aquatic environments producing methane gas
-also found in intestinal tracts of ruminants such as cows
halophiles
-optimum NaCl concentration for growth of 17-23%
Phototrophic bacteria
no human pathogens
What are the major groupings of bacteria, with concentration on disease causing groups?
-archaea
-phototrophic bacteria
-low G/C (guanine/cytosine), Gram (+) Bacteria
-high G/C (guanine/cytosine), Gram (+) Bacteria
-Gram (-) Proteobacteria
-other gram (-) bacteria
what falls under the low G/C Gram (+) bacteria:
-clostridia
-Veillonella
-mycoplasms
-Bacillus species
-Listeria species
-Lactobacillus species
-Streptococcus & Enteroccus species
-Staphylacoccus species
-Bifidobacterium species
clostridia (rod-shaped, obligate anaerobes)
-Clostridium tetani, causes tetanus
-C. botulinum, causes the food poisoning botulism, botox from
botulism
-C. perfringes, causes food born diarrhea, gangrene/wound
infections
-C. difficile (CDI), causes diarrhea, spreads and infects via spores
C. difficile (CDI) is
-highly resistant to treatment (~40% of patients experience a
recurrence in infection)
-in 2010 CDI surpassed MRSA as leading cause of nosocomial
bacteria infections in US
Veillonella
part of dental biofilms/plaque
mycoplasmas are
obligate anaerobes, lack cell-walls (Pleomorphic-change its shape), filamentous
-associated with pneumonia & UTIs
Bacillus species
-Bacillus anthracis, causes anthrax (inhalational nearly 100% fatal
untreated)
-Bacillus thuringiensis, microbial insect pathogen (Bt toxin)
Listeria species
-Listeria Monocyogenes, causes meningitis, septicemia;
reproduces under refrigeration and can live inside immune cells
in 2011 Listeria outbreak in cantaloupe: deadliest food born outbreak since 1924, 3rd deadliest in US history
-blamed in 5 of the top 12 deadliest food born outbreaks
-dirty equipment, wash water contamination, change in packing
procedure, and reduced anti-microbial wash all contributed to
outbreak at a Colorado packing farm
-could have been just one contaminated
Lactobacillus species
-production of sauerkraut, pickles, buttermilk, & yogurt
-found in human mouth, GI, vagina
Streptococcus & Enterococcus species
-S. pylogens, pharyngitis (strep throat), scarlet fever, necrotizing
fascilitis, septicemia, rheumatic fever
-said to be responsible for more illness and cause a greater variety
of diseases than any group of bacteria
-"flesh-eating" streptococci produce t
Staphylacoccus species
-Staphylococcus aureus, certain strains cuase septicemia,
pneumonia, wound infections, food poisoning, toxic shock
syndrome, misc. infections
-Staphylococcus species, UTIs
Staphylococcus aureus
-common in nasal secretions, sin
-common problem in hospitals
-MRSA: methicillin-resistant Sa
-VRSA: vancomycin-resistant Sa
Bifdobacterium species
GI normal flora, in breast-fed infants- important in protection against pathogens
High G/C Gram (+) Bacteria
-Corynbacterium diphtheria
-Propionibacterium acnes
-Gardnerella vaginalis
-Mycobacterium species
-actinomycetes group
Corynbacterium diphtheria
(pleomorphic rods), causes diphtheria
Propionibacterium acnes
one of the causes of acne
Gardnerella vaginalis
causes vaginitis
Mycobacterium species
-aerobic rods with filamentous growth similar to fungi
-acid-fast differential stain developed for mycobacteria
-M. tuberculosis, causes tuberculosis (TB)
-M. leprae, causes leprosy
actinomycetes group
-filamentous similar to fungi
-inhabitants of soil (especially Streptomyces)
-pathogenic in immunocompromised patients
-Streptomyces important antibiotic producer
Gram (-) Proteobacteria has the
-largest and most diverse group of bacteria
-five classes of designated with Greek letters
Gram (-) Proteobacteria:
-alphaproteobacteria
-betaproteobacteris
-gammaproteobacteria
-deltaproeobacteria
-epsilonproeobacteria
alphaproeteobacteria:
-a number are nitrogen fixers, important in environment
-Rickettsia species (aerobic rods, obligate intracellular pathogens)
-causes Rocky Mountain spotted fever, misc arthropod-vector'd
diseases
-Brucella species (coccobacills)
-causes brucellosis, impor
betaproteobacteris
-Neisseria gonorrhoeae, causes gonorrhea
-N. menigitidis, causes a form of meningitis infections
-other Nesiseria species, causes various other inflammations
-Bordetella pertussis, causes whooping cough
gammaproteobacteria
-Legionella species
-Shigella species
-Pseudomonas species
-Moracella lacunata
-glycolytic facultative anaerobes (divided into 3 families)
>Enterobacteriaceae (Enterics)
>Vibrionaceae (slightly curved rods0
>Pastuerellaceae
-Deltaproteobacteeria
-Epsilonp
Legionella species
causes Legionaire's disease
Shigella species
causes dysentery
Pseudomonas species (causes in soil, grows at low refridge temps)
-causes UTI, septicemia, meningitis, respiratory infections
-important in burn & wound infections
-grows on unusual sources of carbon (ex. soap residues, cap-liner
adhesives) and in some anticeptics
-resistant to most antibiotics
Moraxella lacunata
causes conjuctivitis
Enterobacteriaceae (Enterics)
-inhabitants of intestinal tracts of animals including humans
-presence in water or food indicates fecal contamination
-Escherichia coli, most common inhabitant of human GI tract;
causes of urinary tract infection and severe food poisoning
(E.coli strain
When E. coli is stressed it
simply turns off most signs of life (no reproduction, no detection on many tests, cannot be cultured but metabolically still alive)
vibrionaceae (slightly curved rods)
-Vibrio cholera, causes cholera
-Vibrio species, causes various gastroenteritis
pasturellaceae
-Haemophilus species, causes meningitis
-H. influenza, named in error as thought it was causative agent of
influenza, meningitis, ear/sinus infections
-Pasteurella multocida, pathogen of domestic animals, also found
as saliva microbiota of Komodo dragons
deltaproteobacteria
no human pathogens
epsilonproteobacterioa (vibrios or spiral bacteria)
-Campylobacter species, causes blood poisoning, GI tract
inflammation
-Helicobacter pylori, causes gastric ulcers, stomach cancer
>found in the stomach of about 1/2 of world's pop
>also helps protect against allergies, asthma, and esophageal
cancer and ac
Other Gram (-) Bacteria-grouped together for convenience rather than genetic relatedness
-chlamydias (obligate intracellular parasites; are smaller than
largest viruses)
-spirochetes (actively motile w/axial filaments)
-Bacteroides species, causes abdominal, blood, other infections;
common human GI tract (~30% of isolated fecal bacteria are o
chlamydias (obligate intracellular parasites; are smaller than larges viruses)
-Chlamydia trachomatis, causes a common form of blindness;
various STDs, conjunctivitis
-C. pneumonia, causes a form of pneumonia
Spirochetes (actively motile w/axial filaments)
-Treponema pallidum, causes STD syphilis
-Borrelia species, causes Lime disease
Bacteroides species,
causes abdominal, blood, other infections; common human GI tract (~30% of isolated fecal bacteria are of this genus)
Aeromonas hydrophila
flesh eating bacteria (necrotizing fasciltis)
-24yr women both hands, 1 foot, 1 leg, part of abdomen
removed in a 2012 zip line accident
Other noteworthy bacteria
-there are only about 5000 or so species of bacteria ID'ed... but
millions??
-one report estimates that 1 gram of soil may contain 10,000 +
species of bacteria!!