1
Q
Gram negative proteobacteria (3 types)
A
alphaproteobacteria
betaprototeobacteria
gammaproteobacteria
2
Q
Alphaproteobacteria
A
-gram negative
-capable of growth in low levels of nutrients
-capable of nitrogen fixation in symbiosis with plants and several plant and human pathogens
3
Q
Genera of alphaproteobacteria
A
rickettsia and bartonella
4
Q
Rickettsia
A
- gram negative
- rod shapes or coccobacilli
- transmitted to humans by insects and tick bites
- enter host cell by inducing phagocytosis, enter cytoplasm of cell and begin reproducing binary fission
- responsible for spotted fever grop
- damage the permeability of blood capillaries which results in spotted rash
5
Q
Bartonella
A
- B. Henselea
- gram negative that causes cat scratch disease
- parinaud oculaoglandular syndrome
- presents neuroretniti with optic nerve edema, macular star formation, and discrete white retinal or choroid lesions
- alphaproteobacteria
6
Q
Betaproteobacteria
A
- overlaop with alpha
- use nutrient substances that diffuse away from areas of anaerobic decompision or organic matter such as H2 gas, ammonoa, and methane
7
Q
Genera of betaproteobacteria
A
bordetella and neisseria
8
Q
Bordetella
A
- betaproteobacteria
- nonmotile
-aerobic - gram negative rod
- bordetlla pertussis- whooping cough
9
Q
Neisseria
A
- aerobic
- gram negative cocci
- live in membranes of mammals
10
Q
Gammaproteobacteria
A
largest subgroup of proteobacteria
11
Q
Genera of gammaproteobacteria
A
pseudonomas, moraxella, acinetobacter, legionella, enterobacterialis
12
Q
Pseudonomas
A
- aerobic, gram negative rods
- motile by polar flagella
- P. aeruginoda can infect urinary ttacts, burns, and wounds, and can cause blood infections, abscesses, and meningitis
- can be resistant to antibiotics
13
Q
Moraxella
A
- gram negative
- strictly aerobic coccobacilli
- moraxella lacunta causes conjuctivitis
14
Q
Acinetobacter
A
- gram negativ
- aerobic
- typically form in pairs
- A. baumanii
15
Q
A. baumanii
A
- common in healthcare setting
- becoming more resistant to antibiotics
- primatily respitory pathogen
- high mortlality rate due to resistance
- acinetobacter
16
Q
Legionella
A
- gram negative
- common in streams, warm water supply lines, and water in air conditioning systems
- hard to eradicate
17
Q
Enterobacterialis
A
- known as enterics
- faculative anaerobes
- gram -
- if motile: peritrichously flagellated
- inhabit animal intestines
- have fimbriae that help attach to surfaces
- produce bacteriocins that cause lysis of other bacteria
18
Q
Nonproteobacteria gram negative groups
A
cyanobacteria
chlamydia
spirochetes
19
Q
Cyanobacteria
A
Carry out oxygenic photosynthesis
* Capable of fixing nitrogen
* Types:
* unicellular forms that divide by binary fission
* colonial forms that divide by multiple fission
* Filamentous forms that reproduce by fragmentation of the filaments
20
Q
Chlamydia
A
- Gram-negative coccoid
- Most distinguished by their unique developmental cycle
- Their elementary body is the infective agent.
- Transmitted by interpersonal contact
- 3 species significant for pathogens
- C. trachomatis – trachoma - causes blindness, nongonococcal urethritis (STI) and lymphogranuloma venereum (STI)
- Related to Chlamydophila genus that can cause airborne respiratory disease
21
Q
Spirochetes
A
- Develop axial filaments
- gram negative
- Helps in motility. Can move 100 times its body length in a second
- Can be found in human oral cavity
- Genera: Treponema and Borrelia
22
Q
Treponema
A
*gram negative
* Includes many important pathogenic bacteria
* Treponema pallidum
*causes syphilis
23
Q
Borrelia
A
- Borrelia burgdorferi causes Lyme disease
- Most often in Northeast, mid-Atlantic, upper Midwest areas of the U.S.
- Carried by ticks
- Causes: fever, rash, facial paralysis, an irregular heartbeat,
and arthritis (CDC)
gram negative
24
Q
Gram Positive types
A
Firmicutes and actinobacteria
25
Firmicutes
- Low G + C gram positive bacteria
- Endospore forming
- Genera:
* Clostridium
* Bacillus
* Staphylococcus * Enterococcus
* Streptococcus
* Listeria
* Mycoplasmas
26
Clostridium
* Obligate anaerobes
* Rod shaped
* Usually contain endospores * C. tetani, botulinum, difficile
27
Bacillus
* gram positive
* Rods
* Produce endospores
* Common in soil
* Few are pathogenic to humans
* Serval are used to produce antibiotics * B. anthracis
* Nonmotile facultative anaerobe
* cause of anthrax in cattle, sheep, humans
28
Staphylococcus
* gram positive
*Grapelike clusters
* S. aureus names for its yellow pigmented colonies
* Facultative anaerobes
* Grow well under high osmotic pressure and low moisture
* Carried in our noses and on skin
* Can infect surgical wounds
* Can be resistant against penicillin
* Produce toxins responsible for toxic shock syndrome
* Produced enterotoxins – one of the most common causes of food
poisoning
29
Enterococcus
* gram positive
* Well-adapted to areas of the body that are rich in nutrients, but low in oxygen like the GI and oral cavity.
* Can be found in human stool.
* High resistance to antibiotics
* Known for many surgical wounds and urinary tract infections
* Enter bloodstream through invasive procedures such as
indwelling catheters
30
Streptococcus
* Spherical chains
* Gram-positive
* Causative of a greater variety of diseases more than other groups of bacteria
* Produce extracellular substances that destroy phagocytic cells and produce enzymes that digest host’s connective tissue.
* Bacterial enzymes digest the fibrin of blood clots, so infections spread
31
Listeria
* gram positive
* L. monocytogenes contaminate food especially dairy products
* Survives within phagocytic cells and is capable of growth at refrigeration temperatures.
* Can cause stillbirth or serious damage to the fetus of pregnant women
32
Mycoplasma
* Polymorphic
* Lack a cell wall
* Can produce filaments thar resemble fungi (mykes=fungus, plasma=formed)
* Very small 0.1 to 0.25 microns; cell volume 5% of the typical bacillus
* Smallest self-replicating organism capable of free-living existence.
* Related to gram-positive bacteria like Bacillus and Streptococcus but have lost genetic material over time in a process called degenerative evolution.
* Special in that their cell membranes contains sterols unlike other prokaryotes
* M. pneumoniae – cause of mild pneumonia
33
Actinobacteria
* gram positive
*High G+C gram-positive bacteria
* Actino means ray
* Referring to a radiate or starlike form of growth by often branching filaments
* Morphology resembles that of filamentous fungi
* Allows for a higher surface-to-volume ratio and enhances absorbing nutrients
* Their filaments have a diameter much smaller than that of eukaryotic molds
* Some carry asexual spores that are used for reproduction
* Genera:
* Mycobacterium
* Corynebacterium * Actinomyces
34
Mycobacterium
* gram positive
*Aerobic, non-endospore forming rods
* Myco (fungus-like) because of the occasional exhibition of filamentous growth
* Acid-fast stain, drug resistance, pathogenicity all related to their distinctive cell wall containing mycolic acid forming a waxy, water-resistant layer
* Cell wall causes resistance to stresses like drying and antimicrobials to enter the cell, but also slows down the entrance of nutrients thus the slow growth rate of the bacteria
* M. tuberculosis causes TB
* M. leprae causes leprosy
* Two distinct groups:
* Slow growing – more pathogenic
* Rapid growers – mostly infectious to wounds but tend to be more nonpathogenic soil and
water microbes
35
Cornyebacterium
* Coryne = Club-shaped
* Pleomorphic
* C. diphtheriae causes diphtheria
* gram positive
36
Actinomyces
* Facultative anaerobes
* Live in the mouth and throat of humans
and animals
* Occasionally form filaments that can fragment
* Actinomyces israelii – causes actinomycosis
* Tissue -destroying disease affecting the head, neck, or lungs
* Can csue multiple eye conditions including canaliculitis
* gram positive
BVS 511 Micro
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