Role of Bacteria in Disease Flashcards
1
Q
The clinical management of a Bacterial infection is predicated on the ability to develop an
A
accurate differential diagnosis
2
Q
The development of an infection depends on the complex interaction of:
A
- The host’s susceptibility to infection.
- The organism virulence potential
- The opportunity for interaction between host and organism.
3
Q
Gram positive bacteria
A
Large group of mostly chemoorganotrophs( organisms that depends on organic chemicals for its energy and carbon)
4
Q
proteobacteria
A
is by far the largest and Gram-positive most metabolically diverse of all bacteria
- Constitute the majority of all known, industrial and agricultural significance
- all gram negative
5
Q
firmicutes
A
nonsporulatinng and endospore-forming firmicutes
6
Q
mollicutes
A
mycoplasmas
7
Q
actinobacteria
A
- coryneform & propionic acid bacteria
- mycobacterium
- filamentous
8
Q
filamentous actinobacteria
A
streptomyocytes & relatives
9
Q
key genera nonsporulating firmicutes
A
staphylococcus, micrococcus, lactobacillus, streptococcus, sarcina
10
Q
staphylococus and micrococcus
A
- gram +
- non-motile
- non-sporulated
11
Q
catlase-positive
A
converts H2O2 into H2O and O2
-different from streptococcus
12
Q
staphylococcus and micrococcus are resistant to
A
reduced water potential, tolerate drying and high salt
13
Q
micrococcus is a
A
strictly aerobic pigmented bacteria (yellow, red)
- obligate aerobe
- produce acid from glucose only under aerobic conditions
14
Q
micrococcus can be isolated from
A
skin but is much more common on dust particles and in soil
15
Q
staphylococcus is a
A
facultative anaerobe
-produce acid from glucose both aerobically and anaerobically
16
Q
_____ forms cell clusters whereas _______ does not
A
staphylococcus, micrococcus
17
Q
What are the two major species of staph in humans?
A
Staphylococcus epidermidis and aureus
18
Q
Staphylococcus epidermidis
A
- non pigemented
- non-pathogenic organism found on skin or mucous membranes
- grows well on 7.5% NaCl containing media
19
Q
Staphylococcus aureus
A
Yellow pigmented species associated with pathological conditions
- boils, pimples, pneumonia, osteomyelitis, meningitis and arthritis
20
Q
staphylococcus
A
- grow in grape like cluster
- individual cell about 0.8 micrometer
- gram +
21
Q
Staph lab diagnosis
A
gram + cocci that grow in cluster of grape
-should be innoculated onto nutritional agar with sheep blood
22
Q
Staphylococci grow on
A
non-selective media
- incubated with aerobically or anaerobically
- large, smooth colonies seen within 24 hours
23
Q
S. aureus colonies will
A
gradually turn yellow
-particularly when cultures are incubated at room temperature
24
Q
almost all isolates of S. aureus produce
A
beta-Hemolysis pattern on sheep blood agar due to an alpha-toxin
25
Staph laboratoy diagnosis
coagulase: converts fibrinogen in plasma to fibrin
| mannitol salt agar: selective differential medium (causes phenol red to turn yellow
26
Coagulase Negative
Staphylococcus epidermidis
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Coagulase Positive
Staphylococcus aureus
28
Staphylococcus epidermidis on Mannitol Salt Agar
remains pink/red
29
Staphylococcus aureus on Mannitol Salt Agar
turns yellow
30
lactic acid bacteria
are gram + rods and cocci that produce Lactic acid as a major or sole fermentation product
- dont carry out oxidative phosphorylation
- obtain energy only by substrate-level phosphorylation
31
members of lactic acid group lack
porphyrins and cytochromes
32
all lactic acid bacteria grow
anaerobically
| -not sensitive to oxygen and can grow with it present
33
aerotolerant aneaerobes
anaerobes that aren't sensitive to O2 and can grow in its presence
34
homofermentative
produces a single fermentation product
| -lactic acid
35
heterofermentative
produces other products
| -mainly ethanol, CO2 and lactate
36
streptococcus
homofermentative
- typically arranged in pairs of chains
- some species pathogenic to humans and animals
37
lactococcus
streptococci of dairy significance
38
enterococcus
streptococi primarily of fecal origin
39
lactobacillus
rod shaped
- vary from long and slender to short, bent rods
- common in dairy products
- resistant to acidic conditions
- grows in pH as low as 4
40
Lactobacillus acidophillus
used in production of acidophilus milk
| -breaks down food in intestine
41
listeria
gram-positive faculative anaerobic cocccobacilli
- form chains 3-5 cells long
- require full oxic or microoxic conditions for growth
42
listeria monocytogenes
causes major food borne illness (listeriosis)
- transmitted in contaminated ready to eat food
- causes mild illness to fatal form of meningitis
43
Oxford Agar media
selective and differential and used for detection of listeria from raw or unpasteurized food
- selective components include lithium chloride, acriflavin, colistin sulphate, cefotetan, cycloheximide and phosphomyocin
- produces black zones under/around Listeria colonies
44
endospore forming firmicutes key genera
bacillus, clostridium, sporosarcina, heliobacterium
45
endospores are advantageous for
soil microorganisms because its highly variable environment (temperature, nutrient levels and water activity)
46
endospore forming bacteria can be selectively isolated from soil and/or food by heating the sample to
80 degrees celsius for 10 min
47
bacillus and paenibacillus produce
extracellular hydrolytic enzymes that break down polymers such as polysaccharides, nucleic acids and lipids
48
many bacilli produce
antibiotics
49
paenibacillus papillae and bacillus thuringinesis produce
insect larvicides
50
What is toxic to certain insects which produce lysis of their intestinal cells
crystalline protein (Bt toxin)
51
clostridium
lack repiratory chain, anaerobic, found in anoxic soils
- posses subterminal spores
- some pathogenic and cause botulism, tetanus and gangrene
52
sporosarcina
unique among endospore formers because cells are cocci
- strictly aerobic, spherical cells
- common in soils
53
mollicutes key genera
mycoplasma, spiroplasma
54
mollicutes
- lack cells walls, peptidoglycan absent
| - dont stain gram +
55
mycoplasma cells are
pleomorphic
56
growth of mycoplasmas
- media typically complex
| - colonies show characteristic fried egg appearance
57
mycoplasma pneumoniae epidemiogolgy
causes up to 40 % of community acquired pneumonia
-incidence greatest among school age children
infection is mild and may be asymptomatic in adults with history of previous infection
-1-3 week incubation period
-bacteria spread by large particles by aerosol to close contact
58
mycoplasma pneumoniae pathogenesis
- inhaled by host and attache to cells in respiratory tract
| - bacteria produce P1 adhesion protein
59
cold agglutinins
autoantibodies believed to be result of antigenic alteration of erythrocytes
60
mycoplasma pneumoniae clinical presentation
infection develop gradually over period of several days and can persist weeks to months
-involve upper respiratory tract, lower respiratory tract or both
61
mycoplasma pneumoniae infections are frequent triggers of
reactive airway disease (asthma)
62
mycoplasma pneumoniae diagnosis mady by
polymerase chain reaction (PCR), nasopharyngeal swab, aspirate or sputum
63
treatment of mycoplasm pneumoniae
macrolide, inhibitors of protein synthesis, tetracycline, inhibitor of protein synthesis
fluoroquinolonies, inhibitor of DNA gyrase
64
actinobacteria key genera
corynebacterium, arthobacter, propionibacterium
65
actinobacteria
form their own phylum
- gram +
- over 30 taxonomic families
- rod shaped to filamentous
- usually aerobic
- valuable for antibiotics and certain fermented dairy
66
corynebacterium
gram-positive
- aerobic
- non-motile
- rod shaped
67
What kind of cell arrangements do Corynebacterium form during normal cell growth?
club-shaped, irregular-shaped or V-shaped
68
corynebacterium are
extremely diverse
| -include animal and plant pathogens
69
arthrobacter
primary soil organisms
- remarkably resistant to desiccation and starvation
- dont form spores or other resting cells
70
propionic acid bacteria
first discovered in swiss cheese
71
What is responsible for the characteristic holes in Swiss cheese?
Fermentative production of CO2 from propionic acid bacteria
72
What is partly responsible for unique flavor of swiss cheese?
propionic acid
73
gram positive anaerobes that ferment
lactic acid, carbohydrates and polyhydroxy alcohols
| -primarily produce propionic acid, acetic acid and CO2
74
mycobacterium
nonmotile, non-spore forming aerobic Gram+ rods
| -stain acid fast
75
What unique lipids are only found in the presence of mycobacterium
mycolic acids
76
acid fastness
resistance to decolorization by acids during Gram staining procedures
-not readily stained by gram stain because of high waxy-surface due to lipid content
77
What mixture of dyes is used in acid-fast stain?
Ziehl-Neelsen stain
| -red dye basic fuchsin and phenol
78
Cells are somewhat______
pleomorphic
79
pleomorphic
ability of some bacteria to alter their shape or size in response to environmental conditions
80
What kind of colonies does Mycobacteria form?
On solid media, it forms tight, compact, wrinkled colonies due probably to the high lipid content and hydrophobic nature of the cell surface
81
What is needed to stiumulate the growth of M. tuberculosis in the laboratory?
Lipids and fatty acids
82
What is often used in primary isolation of M tuberculosis?
Glycerol-Egg medium
83
What are the three groups mycobacteria can be classified into?
1. Nonpigmented
2. Photochromogenesis
3. Scrotochromogenesis
84
M. Tuberculosis is carried in
airborne particles, Infectious droplet nuclei
85
How is TB spread?
From person to person through the air
86
Filamentous actinobacteria key genera
Streptomyces, Actinomyces
87
Actinomycetes
large group of phylogenetically related filamentous
| -gram + bacteria
88
most actinomycetes form
spores
89
Most important genus of actinomycetes
Streptomyces
90
Streptomyces
over 500 species
- spores are called conidia
- primarily soil microorganisms, responsible for earthy odor of soil
- strict aerobes that produce many extracellular enzymes
91
Most striking physiological property of streptomyces
they produce ATM (antibiotics)
92
About ___ of all isolated_____ produce_____
50%, streptomycetes, antibiotics
93
Streptomyces species are
important to soil environments because they're capable of metabolizing other organisms's remains
94
What do Streptomyces release when they die?
Geosmin
| -responsible for the earthy aroma often after rain
95
Chlamydia key genera
chlamydia, chlamydophila
96
chlamydia
obligate intracellular parasites with poor metabolic capacities
-gram - type cell walls
97
chlamydophilia psittaci
causative agent of the disease psittacosis
98
chlamydophiila pneumoniae
cause respiratory syndromes
99
chlaymydia trachomatis
causative agent of disease trachoma
100
psittacosis
epidemic disease of birds thats occasionally transmitted to humans and causes pneumoia-like symptoms
101
trachoma
debilitating disease of the eye characterized by vascularization and scarring of the cornea
-leading cause of blindness in humans
102
elementary body
small, dense cell
- relatively resistant to drying
- infectious
- non-multiplying
103
reticulate body
larger, less dense cell
- divides by binary fission
- non-infectious
104
chlamydias are primarily____ invaders of the________ system
airborne, respiratory
105
_______ is the most prevalent STI
chlamydia
106
What causes chlamydia?
Bacterium chlamydia trachomatis
| -obligate intracellular bacterium
107
Where can women get chlamydia?
In the cervix, rectum or throat
108
Where can men get chlamydia?
Urethra (inside the penis) rectum or throat
109
Symptoms of chlamydia in women include
- abnormal vaginal discharge (may have strong smell)
- burning sensation when urinating
- pain during intercourse
110
Symptoms of chlamydia in men include
- discharge from the penis
- burning sensation when urinating
- burning or itching around the opening of the penis
- pain and swelling in one or both testicles
111
treatment of chlamydia
antibiotics
| -doxycycline, erythromycin
112
Bacteroides
- Obligately anaerobic, non-sporulating Gram-Negative bacteria
- saccharolytic, fermenting sugars or proteins to acetate and succinate as major fermentation products.
- Numerically dominant bacterium in human intestinal tract
- Some species of bacteroides can occasionally be pathogens
- Synthesize sphingolipids
113
Flavobacterium
- Found primarily in aquatic environments
- Aerobic, nutritionally restricted using glucose as a C & E
- frequently yellow-pigmented
- Rarely pathogenic
114
Spirochetes key genera
Spirochaeta, Treponema, Cristispira, Leptospira, Borrelia
115
Spirochetes
- gram-Negative, motile, and tightly coiled Bacteria, slender and flexuous in shape.
- Widespread in aquatic environments and in animals
- Some cause diseases
116
Spirochetes classified into 8 genera based on
habitat, pathogenicity, phylogeny, morphology, and physiology
117
Spirochaeta
- Free-living
- anaerobic and facultative anaerobic spirochetes
- common in aquatic environments
118
Cristispira
- Found in nature
- primarily in the crystalline style of molluscs such as clams and oysters
- crystalline style is a flexible, semi-solid rod in the digestive tract of the molluscs
119
Treponema
- Anaerobic or microaerophilic host-associated spirochetes
| - commensal or parasites of humans
120
treponoma palidium
- causal agent of syphilis
- the cell is flat and wavy
- only 0.2μm in diameter
121
Borrelia
Majority are human or animal pathogens
122
Borrelia recurrentis
causative agent of relapsing fever in humans and is transmitted via an insect vector, lice
123
relapsing fever
- characterize by a high fever and generalized muscular pain that last for 3-7 days
- followed by a recovery period of 7-9 days.
- Left untreated, the fever returns in two to three more cycles and can cause death from hemorrhaging and organ failure
124
Borrelia burgdorferi
-causes Lyme disease
~transmitted to humans by the bite of infected ticks
-Early symptoms may include fever, headache, fatigue
and characteristic circular skin rash called erythema migrans
(bulls’-eye pattern)
-Left untreated later symptoms may involve the joints, heart and CNS
125
Leptospira and Leptonema
Strictly aerobic spirochetes that use long-chain fatty acids (for
example, oleic acid) as e- donor and carbon sources.
126
Leptospiras
thin, finely coiled, and usually bent at each end into a semicircular hook
127
All genera within the pseudomonad group are
- Straight or curved Gram-Negative rods with polar flagella
- Chemoorganotrophs
- aerobes
128
Psuedonomads
- Nutritionally versatile (very simple)
- Ecologically important organisms in water and soil
- Some species are pathogenic
129
Zymomonas
Genus of large, Gram-Negative rods that carry out
vigorous fermentation of sugars to ethanol
-Used in production of fermented beverages
130
In the genus _________ the cells are always ________
Neisseria, cocci
131
Neisseria gonorrhoeae
causative agent of the disease gonorrhea
132
Neisseria meningitidis
is a serious pathogen that can cause a potential fatal inflammation of the membranes lining the brain
133
Acinetobacter
common soil and water organisms
| occasionally found as parasites of animals and have been implicated in some nosocomial infections
134
Chromobacterium
rod-shaped
- best known is C. violaceum (a purple pigmented organism)
- found in soil and water and occasionally in pus-forming infections of humans and animals
135
Enteric Bacteria
a major group of highly related, Gram-Negative, facultative bacteria
136
Mixed-acid fermenters
three acids are formed in significant amounts: Acetic, Lactic, and Succinic
-Ethanol, CO2 and H2
137
2,3-butanediol fermenters
smaller amounts of acid are form, and Butanediol
| -Ethanol, CO2 and H2 are the main products
138
Escherichia
- Universal inhabitants of intestinal tract of humans and warm-blooded animals
- Synthesize vitamins, particularly Vitamin K2
- Some strains are pathogenic, implicated in diarrheal diseases, also urinary tract infections (mostly in women)
139
Salmonella and Shigella
- Closely related to Escherichia
- Usually pathogenic, typhoid fever and gastroenteritis
- Salmonella characterized immunologically by 3 surface antigens
- found primarily in strains of Salmonella causing typhoid fever
- Shigella typically pathogenic to humans, causing a severe gastroenteritis, release endotoxins
140
Proteus
- Genus containing highly motile cells
- produce the enzyme urease
- Frequent cause of urinary tract and wound infections in humans
- an opportunistic pathogen of humans. E.g. Proteus vulgaris
141
Butanediol fermenters
closely related group of organisms
| -Enterobacter, Klebsiella, and Serratia
142
Enterobacter aerogenes
common cause of urinary tract infections
143
Klebsiella pneumoniae
causes pneumonia in humans but are commonly found in soil and water
144
Serratia marcescens
causes a broad range of hospital-acquired infections
-including respiratory tract infections, UTI, septicemia, meningitis, pneumonia, conjunctivitis wound and eye infections, osteomyelitis, keratoconjunctivitis, keratitis, endophthalmitis and endocarditis.
145
Vibrio
- GramNegative,
- Cells are Motile
- straight or curved rods
- Facultative aerobes
- Fermentative metabolism
146
One key difference between the Vibrio group and Enteric bacteria is that
members of the Vibrio group are Oxidase-positive
147
_________ is one of the most common human infectious diseases in
developing countries and is transmitted almost exclusively via _______.
Cholera, water
148
Cholera
- is an infection in the small intestine caused by the bacterium vibrio cholerae
- main symptoms are profuse watery diarrhea and vomiting
149
Vibrio treatment
- Oral or IV hydration is the mainstay of cholera treatment.
- Doxycycline is recommended as first-line treatment for adults
- Azithromycin is recommended as first-line treatment for children and pregnant women
- During an epidemic or outbreak, antibiotic susceptibility should be monitored through regular testing of sample isolates from various geographic areas
150
Rickettsias
- Small Gram Negative, coccoid or rod-shaped cells
- Alpha or Gammaproteobacteria
- Most obligate intracellular parasites
- Causative agent of several human diseases, including Typhus (Rickettsia typhi) and Q fever (Coxiella burnetii).
- cell wall contains peptidoglycans
- cells divide by binary fission.
- Rickettsias do not survive long outside their hosts
151
Gliding Bacteria
- typically either long rods or filaments
- Lack flagella, can move when in contact with surfaces
- Myxobacteria is a group of gliding bacteria that form multicellular structures
- Deltaproteobacteria
- Aerobic Chemoorganotrophic soil bacteria
- Lifestyle includes consumption of dead organic matter or other bacterial cells
152
Epsilonproteobacteria
- Abundant in oxic–anoxic interfaces in sulfur-rich environments.
- Many are autotrophs
- Use H2, formate, sulfide, or thiosulfate as electron donor.
153
Campylobacter
-motile, comma-shape or spiral, strictly microaerophilic Gram Negative rods.
154
The primary diseases caused by campylobacters are
gastroenteritis and septicemia
| -Causes colicky abdominal pain and diarrhea.
155
Helicobacter pylori
Spiral-shaped, nonspore-forming Gram Negative rods, Oxidase and Catalase-positive, Highly motile bacterium with 4-6 flagella
- Produce an abundance of Urease
- associated with gastritis that can evolve into Chronic Gastritis
156
QuickVue H. pylori Test
detects IgG antibodies specific to Helicobacter pylori in human serum, plasma or whole blood
157
Urea Breath Test
checks if the patient has H. pylori in the stomach. It can show if there is a H. pylori infection
