1 / 54

03-22-12 Medically important bacteria - PowerPoint PPT Presentation

  • Uploaded on

03-22-12 Medically important bacteria. Chemoorganotrophs (fermentation). Variety of end products (acids and gases) Ex. Clostridium species - form endospores Ex. Lactic acid bacteria ( Lactobacillus, Streptococcus, Enterococcus). Clostridium tetani (23.8).

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

PowerPoint Slideshow about ' 03-22-12 Medically important bacteria' - taima

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript


Medically important bacteria

Chemoorganotrophs fermentation
Chemoorganotrophs (fermentation)

  • Variety of end products (acids and gases)

  • Ex. Clostridium species - form endospores

  • Ex. Lactic acid bacteria (Lactobacillus, Streptococcus, Enterococcus)

Streptococcus pyogenes stained

with fluorescent antibody (24.2)

Streptococcus pyogenes

growing on blood agar (22.6)

Lactobacillus species 11 3
Lactobacillus species (11.3)

Produce lactic acid; aerotolerant anaerobe, obligate fermenter.

Metabolizes glycogen in the vagina, low pH protects against infection

Aerobic chemoorganotrophs
Aerobic Chemoorganotrophs

  • Obligate aerobes

  • Facultative anaerobes

Obligate aerobes
Obligate Aerobes

  • Large variety of bacteria

  • Ex. Mycrococcus species

  • Ex. Mycobacterium species

  • Ex. Pseudomonas species

Micrococcus luteus 11 11
Micrococcus luteus (11.11)

Airborne, common contaminant in petri dishes,

recognized by yellow pigments

Pseudomonas species 11 12
Pseudomonas species (11.12)

Pigmented Gram-negative rods, diverse biochemical capabilities, important in bioremediation, P. aeruginosa is a common opportunistic pathogen in hospitals

Mycobacterium tuberculosis

in sputum from a tuberculosis patient (24.17)

Stained lung

tissue showing a tubercule

(a granuloma containing

inflammatory cells) and

lung X-ray from a


patient (24.18)

Facultative anaerobes
Facultative Anaerobes

  • Ex. Corynebacterium species

  • Ex. Enterobacteriaceae family

Corynebacterium 11 13
Corynebacterium (11.13)

Gram-positive pleomorphic rods (coryneforms)

C. diptheriae causes diphtheria

Enterobacteriaceae 11 14
Enterobacteriaceae (11.14)

E. coli O157:H7 in

uncooked burgers

caused gastroenteritis

epidemic in Washington

State in 1993

Enterobacteria, Gram-negative rods, reside in intestinal tract

Enterobacter, Klebsiella, Proteus are part ofnormal flora,

Shigella, Salmonella, some E. coli stains, Yersina pestis

cause disease

Endospore formers 11 15
Endospore – formers (11.15)

Gram-positive rods

Bacillus anthracis

Clostridium tetani

Aquatic bacteria
Aquatic Bacteria

Vibrio cholerae - cholera

Vibrio parahaemolyticus - gastrointestinal disease

Legionella pneumophila - Legionaire’s disease

Gram-negative aerobes that use aa’s

Leptospira interrogans - leptospirosis

Treponema pallidum – syphilis

Borrelia burgdorferi - Lyme disease

Legionella pneumophila,

stained with a fluorescent antibody (24.20)

Scanning EM of Vibrio cholerae

attached to intestinal mucosa using pili (25.12)

Spirochetes 11 26

Syphilitic chancre, the entry point for

Treponema pallidum (22.12)

Scanning EM of Borrelia burgdorferi(22.13)

Life cycle of the

Deer Tick (22.16)

Animals as habitats
Animals as Habitats

  • Skin

  • Mucous membranes

  • Obligate intracellular parasites


  • Ex. Staphylococcus aureus. Gram-positive cocci,

    catalase positive, causes wound infections,

    food poisoning

  • Ex. Staphylococcus epidermidis (normal flora)

    Can cause disease in individuals with

    other medical problems

Mucous membrane
Mucous Membrane

  • Ex. Bacteroides.Anaerobic, Gram-negative rods and coccobacilli, 30% of bacteria in feces

  • Ex. Bifidobacterium. Anaerobic, Gram-positive rods, common intestinal flora in breast fed infants, may provide protective function

  • Ex. Campylobacter and Helicobacter. Gram-negative rods, microaerophiles, C. jejuni causes diarrhea in humans Helicobacter pylori causes stomach ulcers

  • Ex. Haemophilus. Small, Gram-negative coccobacilli,

    love blood, H. influenzae causes ear infections,

    respiratory infections and meningitis in children

Otis media


Meningitis is also

caused by:





Streptococcus pneumoniae in spinal fluid

from a meningococcal meningitis patient (27.4)

Mucous membrane1
Mucous Membrane

  • Ex. Neisseria. Gram-negative diplococci, grow on mucous membranes, N. gonorrhoeae causes gonorrhea, N. meningitidis causes menengitis

  • Ex. Mycoplasma. No cell wall, small pleiomorphic cells,

    M. pneumoniae causes “walking pneumonia”

  • Ex. Treponema and Borrelia. Spirochetes, T. pallidium

    causes syphillis, Borrelia species cause Lyme Disease, relapsing fever

M ycoplasma pneumoniae growing on agar 11 27
Mycoplasma pneumoniae growing on agar (11.27)

Obligate intracellular parasites
Obligate Intracellular Parasites

  • Cannot reproduce outside a host cell

  • Transferred by blood-sucking arthropods

    eg Rickettsia rickettsii causes Rock Mountain

    Spotted Fever

  • Can form a sporelike structure (Ex. Coxiella) Q fever

  • Person to person transmission (Ex. Chlamydia)

    C. trachomatis causes eye infection,

    gonorrhea-like STD

Coxiella 11 29

Chlamydia 11 30
Chlamydia (11.30)

1 = reticulate bodies, noninfectious

2-4 = dense bodies, infectious upon cell lysis