Bacteria Flashcards
G+ coccus?
Streptococcus & Staphylococcus
G+ Spore forming rods
Bacillus and clostridium
G+ non-spore forming rods
Corynebacterium, listeria
which G- pathogen is spiral shaped?
Spirochetes, including Treponema pallidum (syphilis)
Layers of G+ cells? lipid content of G+? what can kill it?
- inner cytoplasmic membrane
- outer thick peptidoglycan layer
low lipid content
vulnerable to lysozyme and penicillin attack
Layers of G- cell?
lipid content?
endotoxin?
what can attack it?
(1) inner cytoplasmic, (2) thin peptidoglycan layer, (3) outer LPS layer
high lipid content, endotoxin is LPS - Lipid A, periplastic space, porin channel, RESISTANT to lysozyme and penicillin attack.
G+ , but seen best with Acid Fast stain?
Mycobacteria - TB and Leprosy
G- bacteria with addition phospholipid membrane to protect from immune recognition, with periplastic flagella
Spirochetes
G- Coccus?
Neisseria and Moraxella
G+ Rod (bacillus)
Corynebacterium listeria bacillus clostridium mycobacterium (acid fast)
G- Rod (bacillus)
ENTERICS = escherichia coli, shigella, salmonella, yersina, klebsiella, proteus, enterobacter, serratia, Vibro, campylobacter, helicobacter, pseudomonas, bacteroies (anaerobic) other = Haemophilus, bordetella, legionella, yersinia, francisella, brucella, pasteurella, gardnerella
G- spiral?
Spirochetes = Treponema, Borrelia, Leptospira
G- pleomorphic?
Chlamydia and Rickettsiae
G+ Obligate Aerobes?
Nocardia, bacillus cereus
G- Obligate Aerobes
Neisseria, pseudomonas, bordetella, legionella, brucella
No cell wall?
Mycoplasma
G+ Facultative Anaerobes
Staphulococcus bacillus anthracis Corynebacterium listeria actinomyces
G- Faculatative anaerobes
Most other G- Rods
G+ Microaerophilic
enterococcus
streptococcus (some are anaerobes)
G+ obligate anaerobes
clostridium
G- Obligate Anaerobes
Bacteroides
Proc vs Euk ribosomes
Proc are 70s and Euk and 80s
G+ and Catalase+
Staphlococcus
G+ and Catalase -
Steptococcus
G+, Catalase +, Coagulase +
Staphylococcus Aureus
What do you use and india ink stain for?
Fungi like cryptococcus that has a capsule.
What are the two endospore formers and what are the layers?
Bracillus and clostridium (G+) (5 layers) cell membrane thick peptidoglycan mesh another cell membrane a wall of keratin-like mesh and outer layer call the exosporium
Exotoxin vs Endotoxin
Exotoxin is released from G+ bacteria, wherase endotoxins are portions of the cell walls
bacteremia
bacteria in the blood
define sepsis
bacteremia that causes a systemic immune response to infection
define septic shock
sepsis (bacteria in blood causing immune response) that results in dangerous drops in blood pressure and organ dysfunction (endotoxic shock when with bacteria)
TNF, IL-1, NO
help cause Septic shock
TNF = cachexia, hypotension, death
IL-1 = released from MQ and endothelial cells that trigger inflammatory responses.
NO = vasodilation
exchange of genetic material allows bacteria to?
become pathogenic, resist antibiotic therapy, and survive.
example of genetic transformation
streptococcus pneumoniae can change their capsle from rough to smooth
define bacteriophages
bacteria that carry a piece of bacterial DNA from one bacterium to another
Lysogenic immunity
the term used to describe the ability of an integrated bacteriophage to block subsequent infection by a similar phage.
define conjugation
BACTERIAL SEX ;)
what is needed for conjugation to occur?
must have the F+ plasmid for the sex pilus
define transposons
the DNA does not need marker to inject itself into the cell. no DNA homology required. rapid spread and resistance.
What is the hemolytic reaction in blood agar?
killing the local RBCs
four disease associated with streptococci Group A?
streptococcal pharyngitis
streptococcal skin infections
scarlet fever
streptococcal toxic shock syndrome.
Virulence factors for Streptococci? (5)
C carb = separates groups A and C M protein = major virulence factor for group A streptococcus, inhibits complement and protects the organism from phagocytosis Streptolysin O = inactivated oxygen that is antigenic for Beta hemolytic group A strep Streptolysin S = oxygen stable, not antigenic Pyrogenic Exotoxin (erythrogenic toxin) = cause scarlet fever
two diseases caused by beta-hemolytic group A strepyococci
these are delayed antibody mediated disease
rheumatic fever
glomerulonephritis
classic strep throat with red swollen tonsils and pharynx with a purulent exudate on the tonsils, high temp, swollen lymph nodes. lasts 5 days and then recovery.
test to know the diagnosis?
streptococcal pharyngitis
rapid antigen detection test (RADT) will be pos for this bacteria
Skin infections with streptococci and Staphlococcus aureus
folliculitis (infection of the hair follicles), pyoderma, erysipelas, cellulitis (deep infection of the skin producing a red, swollen skin that is hot to the touch) and impetigo
near a cut there is swelling, heat, and redness that moves rapidly from the initial skin infection site. skin color changes from red to purple to blue and large blisters form. skin died and muscle has become infected.
caused by? follows what path?
necrotizing fasciitis (flesh eating streptococcus)
group A hemolytic streptococcal, staphylococcus, clostridium sps
caused by M proteins that block phagocytosis
necrotizing fasciitis involving the male genital area and perineum.
disease name?
caused by?
Fournier’s gangrene
Streptococcus pyrogenes
rash begins on the trunk and neck, and then spreads to the extremities, sparing the face, the skin may peel off in fine scales during healing.
scarlet fever
beta-hemolytic group A streptococci
caused by exotoxin pyrogenic toxin, erythrogenic toxin
severe skin infections, necrotizing facititis
Streptococcal toxic shock syndrome
beta-hemolytic group A streptococcal similar (strep pyrogenes) to staph aureus
mediated by the release of pyrogenic toxin
5-10 years of age, pharyngitis (without a skin infection), fever, myocarditis, arrythmia, joint swelling (arthritis), Chorea that begins 2-3 weeks pose pharyngitis, subcutaneous rubbery nodules under the skin, rash (erythema marginatum - red margin that spreads out from its center).
name the disease?
how is it caused?
fatal outcome?
Rheumatic Fever
antibody mediated
beta-hemolytic group A steptococci
heart disease develops with chronic disease
face is puffy, urine is darker than normal tea, hematuria, hypervolemia, high BP, sore throat or skin infection a week ago
Acute Post-streptococcal glomerulonephritis
post and infection of either the PHARYNX OR SKIN by nephritogenic
caused by beta-hemolytic group A streptococci
genus and species name of Group B streptococci?
Streptococcus agalactiae
Name for Group A Beta hemolytic Streptococci?
Streptococci pyogenes
Age group related to Group B strep? and clinical manifestations
most common in neonates
Three most common pathogens associated with meningitis in neonates and infants less than three months of age?
Group B strep (Strep agalactiae), Listeria, E. coli (G-)
test when you suspect meningitis in a neonate? and clinical symptoms
Lumbar puncture
two bacteria associated with meningitis later in life after maternal Abs wane and new Abs haven’t been produced?
Neissaria meningitis and Haemophilus influenzae
secondary complications that can increase the risk of Group B strep?
diabetes, malignancy, renal or liver failure, neurological disease, and elderly >65y/o.
bacteria that cause a greenish discoloration in the blood agar?
and four members of this group?
Viridans group streptococci
mitis, salivarius, Mutans, Anginosus
(alpha hemolytic)
Where do the Viridans group strep normally live?
GI tract, Nasopharynx, gingivia
Three main infections with Viridans strep?
dental, endocarditis (subacute bacterial endocarditis), and Abcess
low grade fever, fatigue, anemia, heart murmurs secondary to valve destruction.
subacute bacterial endocarditis (SBE)
viridans strep - will eat the heart slower.
also caused by group D streptococci
drug abuse, abrupt onset of shaking chills, high spiking fevers, and rapid valve destruction.
acute infective endocarditis
staphylococcal aureus will eat the heart quickly
order of bacteria causing SBE
streptococci pyrogenes causes the rheumatic fever, damaging the heart valves and then viridans and group D strep can then invade the valves causing SBE
subgroups of strep viridans that cause brain and abdominal abscesses?
where are these normally found?
clinical diagnosis?
Anginosus sp. = intermedius, constellatus, and anginosus.
normal GI flora
intermedius grows in blood culture, suspect an abscess
Six clinical G+
Streptococcus, Staphlococcus, Bacillus, Clostridium, Corynebacterium, Listeria
subgroups of Group D strep
Enterococci - enterococcus faecalis and enterococcus faecium
non-enterococci = streptococcus bovis, and streptococcus equinus
where doe group D strep normally live?
they are normal bowel flora and cause similar diseases
what are the conditions for the Group D strep?
where are they common infectious agents, and diseases?
enterococci = 40% bile and 6.5% NaCl (UTI, biliary tract, wound infections, mative and prosthetic valve, bacteremia, sub acute endocarditis and sepsis after infecting intravenous catheters. pray and weak hospitalized pts. non-enterococci = only 40% bile
bacteria with a common association with colon cancer?
Sreptococcus bovis - from polyps causing adenocarcinomas
the most common community acquired and lobar pneumonia of the middle of the right lobe and lower lobe on the left?
Streptococcus pneumoniae (group D strep)
major cause of meningitis in adults and otitis media in children?
streptococcus pneumonia (group D strep)
G+ cocci arranged in pairs (diplococci)?
streptococcus pneumonae (group D)
Major cause of meningitis in adults and children?
adults = Steptococcus pneumoniae children = group B streptococcus
three organisims that are associated with otitis media?
streptococcus pneumoniae, Haemophilius infuenzae, Moraxella catarrhalis
Quellung reaction?
pneumococci on a slide smear mixed with small amounts of antiserum (abs for the capsular antigens) and methylene blue, the capsule will appear to swell. used for rapid identification of streptococcus pneumoniae.
who gets a streptococcus pneumoniae vaccination??
given to people whom are pneumococcal pneumoniae would be exceptionally deadly like the immunocompromised or elderly, people without spleens, HIV disease.
wont work well in children
Genus and species of Staphylococci?
Staph aureus (MOST IMPORTANT)
Staph epidermis
Staph saprophyticus
testing for the three strains of staph?
aureus = G+, Cat +, Coagulase + (activates prothrombin to clot blood) epidermis = G+, Cat +, Coagulase - saprophyticus = G+, Cat+, Coagulase -
proteins that disable immune defenses for staph aureus?
Protein A (bind to Fc on IgG and protects from oponization)
Coagulase (leads to fibrin formation)
hemolysins (destroy, RBC, Neutrophils, MQ, and platlets)
leukocidins (causes CA-MRSA, Panton-Valentine Leukocidin (PVL))
Penicillinase (disrupts penicillin molecules)
Novel penicillin binding protein (transpeptidase used for inhibition of penicillin.
Staph Aureus exotoxins and diseases
Exfaliation (causes skin to slough off - scalded skin syndrome)
Enterotoxins (heat stable) - cause food poisening, resulting in vomiting and diarrhea
Toxic Shock Syndrome Toxin (TSST-1) - causes a t cell response to out pour cytokines.
three diseases caused by staph aureus exotoxin release?
Gastroenteritis (food poisoning)
Toxic shock syndrome
scalded skin syndrome
pneumonia, meningitis, osteomyelitis, quick acute bacterial endocarditis with vegetation on valves, septic arthritis, skin infections, bacteremia, UTI, necrotizing sickness. associated with IV drugs.
Staph Aureus
causes of ankylosis of a joint?
Staph aureua, hemophalis influenzae, untreated gonorrhea.
bacteria that causes indwelling catheters, prosthetic devises with biofilms leading to sepsis?
S. epidermis
a leading cause (but second to E. coli) of community-aquired UTI’s in sexually-active young women?
S. saprophyticus
name the aerobic, G+, spore forming rod bacteria with a capsule made of protein (poly-d-glutamic acid) that prevents phagocytosis. It is acquired by contact with an infected animal or soil, or infected animal products. pt has widening of the mediastinum and hemorrhagic mediastinhtis. phagocytosed and released by MQ.
Bacillus Antharacis
means of infection of Bacillus Antharacis?
skin, pulmonary, GI
skin lesion with local tissue necrosis, evidenced by a painless found black lesion with a rim of edema. called a malignant pustule. can resolve spontaneously.
Bacillus anthracis
Bacillus Antharacis exotoxins of pOX1
Edema factor (inc cAMP disrupting the homeostasis) Protective Ag (promotes EF into phagocytosed cells) Lethal factor (zinc Metalloprotease that inactivates protein kinase) stimulates release of Il-1 and TNFalpha
Bacillus Antharacis plasmids leading to virulence?
pXO1 (collection of EF, PA, and LF) and pXO2 (poly-glutamyl capsule fo synthesis of the genes.
motile, non-encapsulated, and resistant to penicillin that causes food poisoning (nausea, vomiting,diarrhea)
Bacillus cereus
Anaerobic, G+, spore-forming, rod need a rapid diagnosis or pt will die
Clostridium
rapidly fatal food poisoning, due to neurotoxin that blocks the release of Ach from presynaptic nerve terminals on the automatic nervous system and motor endplates, causing flaccid muscle paralysis.
Clostridium botulinum
botulism
home-canned food, smoked fish, secreting a neurotoxin that will be potent when ingested. bilateral cranial nerve palsy, double vision (diplopia) and difficulty swallowing (dysphagia). followed by general weakness, rapidly leading to sudden respiratory paralysis and death.
Adult Botulism
TREAT WITH ANTITOXIN IMMEDIATELY to neutralize the free toxins.
ingest infected honey, constipated for 2-3 days, difficulty swallowing, followed by flaccid paralysis. pos BIG-IV.
infant botulinum
give human derived antitoxin.
rusty nails, anaerobic, found in soil and animal feces, releases tetanospasmin exotoxin leading to lock jaw and skeletal ms tetany. blocks the interneurons (Renshaw cells preventing GABA and glycine)
Clostridium tetani
Tetanus
inhibition of the inhibitory neurons.
wounded in battle. necrotic skin, moist, spongy, crackling, pockets of gas (crepitus). myonecrosis, diarrheal illness due to hemorrhagic jejunum.
clostridium perfringens
Gas Gangrene
antibiotic associated pseudomembranous (on the surface of the large intestine) colitis (diarrhea), follow by the use of longterm antibiotics. Toxin A causes diarrhea and toxin B is cytotoxic to colonic cells. characterized by severe diarrhea, abdominal cramping, fever.
pseudomembranous enterocolitis
clostridium difficile
can become difficult if you give Abs.
non-spore forming G+ rods?
Corynebacterium, Listeria
These are primarily pathogens of the pediatric age groups?
Corynebacterium dipttheriae and Listeria monocytogenes
child with a sore throat and fever has a grey exudate that seems darker and thicker than strep in the back of the throat that looks necrotic. what is it made from and what bacteria is colonizing? what should you do?
Corynebacterium Diptheriae and
composed of fibrin, leukocytes, necrotic epithelial cells
do not scrap off the membrane because the exotoxin will be released into the blood stream damaging heart and neural cells by interfering with protein synthesis. get cultures on potassium tellurite agar and Loeffler’s coagulated blood serum and give antitoxin, penicillin, and DPT vaccine.
explain how corynebacterium diptheriae looks on culture.
on potassium-tellurite plates the colonies turn grey to black within 24 hrs. on Loffler’s after incubation for 12 hrs by staining with methylene blue will reveal rod-shaped pleomorphic bacteria.
How are group A hemolytic strep an corynebacterium toxins related, in terms of interactive process resulting in pathogenicity, with external agent?
for nonimmunized children, not all C. diph secrete exotoxin, just like group A strep must first be lysogenized by a temperate bacteriophage to produce erythrogenic toxin that causes scarlet fever, C. diph must be lysogenized by a temperate bacteriophage which codes for the diphtheria exotoxin.