نظري Flashcards
grow in very salty water. Aerobic, can be autotrophic
Halophiles
growth in very hot temperature, e.g. hot springs,
anaerobes
Thermophiles
Gram Staining, Shapes, arrangements, motility
Microscopic morphology
colony appearance, motility
Macroscopic morphology
aerobic, anaerobic, photosynthetic, growth on selective media
Physiological / biochemical characteristics
e.g.peptides and lipids in cell membranes
Chemical analysis
which phage infects the bacterium
Phage Typing
what antibodies are produced
against the bacterium
Serological analysis
what diseases does the bacterium cause.
Pathogenicity
G + C base composition
DNA analysis using genetic probes Nucleic acid sequencing & rRNA analysis
Genetic & molecular analysis
anaerobes, produce methane as waste product, sewage, landfills, swamps
Methanogens
Are prokaryotes
Can be autotrophs and heterotrophs
Eubacteria
require oxygen to grow (mycobacteria)
obligate aerobes
only grow in absence of oxygen (clostridium tetanus)
obligate anaerobes:
can grow in oxygen and without oxygen (Enterobacteriaceae)
facultative anaerobes:
require low concentrations of oxygen E.g. Neisseria gonorrhoeae
microaerophilic aerobes (microaerophiles):
grows better in absence of oxygen
aerotolerant anaerobes:
– contains bile
– selects for the Enterobacteriaceae
MacConkey agar:
– contains colistin and nalidixic acid
– selects for Staphylococci and Streptococci.
CAN blood agar:
Selective media:
Sodium azide
selects for gram-positive bacteria over gram-negative bacteria
-Bile salts (eg, sodium deoxycholate)—
Acute illness due to the presence of pathogens or their toxins in the blood
Septicemia
Systemic inflammatory response syndrome (SIRS
Sepsis
Inflamed lymph vessels
Lymphangitis
Decreased blood pressure and dysfunction of at least one organ
Severe sepsis
Sepsis and uncontrollable decreased blood pressure
Septic Shock
Klebsiella spp., E.coli, and Pseudomonas aeruginosa are most frequently
involved
Gram-Negative Sepsis
Enterococcus faecium and Enterococcus faecalis
Gram-Positive Sepsis
-Autoimmune complication of S. pyogenes infections -Inflammation of the heart valves
-Immune reaction against Streptococcal M protein
-Subcutaneous nodules at the joints
Rheumatic Fever
Caused by Bacillus anthracis
Anthrax
• Gram-positive endospores-forming aerobic rod
Bacillus anthracis
binds the toxins to target cells, permitting their entry
Protective antigen:
causes local swelling and interferes with phagocytosis
Edema toxin:
targets and kills macrophages
Lethal toxin:
Endospores enter through a minor cut
20% mortaility rate without treatment
Cutaneous anthrax
• Ingestion of undercooked, contaminated food
• >50% mortality rate
Gastrointestinal anthrax
• Inhalation of endospores
• Bacteria enter the bloodstream; progresses into septic shock
• Near 100% mortality rate
Inhalational (pulmonary) anthrax
Vaccination of livestock
Anthrax
loss of blood supply
Ischemia
death of tissue
Necrosis
death of soft tissue
Gangrene
Caused by Clostridium perfringens,
a gram-positive, endospores-forming anaerobic rod
Ø Gas gangrene
Caused by Yersinia pestis
Plague
Transmitted by the rat flea (Xenopsylla cheopis)
Plague
Endemic to rats, ground squirrels, and prairie dogs
Plague
Flea bites the host and ingested blood is regurgitated into the host.
Cause intense swellings called buboes
Plague
Bacterial growth in the blood and lymph
• Most common from 50-75% mortality rate
Bubonic plague
• Septic shock due to bacteria in the blood
Septicemic plague
• Bacteria in the lungs.
• Easily spread by airborne droplets
• Near 100% mortality rate
Ø Antibiotic prophylaxis for exposure.
Pneumonic plague
Most prevalent STD in the world
Gonorrhea
Gram (-) diplococci, Neisseria gonorrhea
Gonorrhea
Virulent strains have pili (fimbrae) for attachment, and outer membrane proteins and lipids help the bacteria escape phagocytosis
Gonorrhea
Purulent (pus forming) urethritis in males – painful urination often called the “clap” old std films in the services
Gonorrhea
causative agent – Treponema pallidum,
Syphilis
causes ؟
Urinary Tract Infection
E. coli usually normal flora,
UTI infections
Production is key factor is this infection
Biofilm