Removal exam Flashcards
The layer just outside the bacterial cytoplasmic membrane
peptidoglycan layer
Composed of repeating disaccharides with 4 amino acids in a side chain extending from each disaccharide
peptidoglycan layer
The enzyme that catalyzes the formation of this linkage
transpeptidase
The antibiotic penicillin binds to and inhibits this enzyme. For this reason the enzyme is
also called _________
penicillin binding protein
Very thick and has extensive cross-linking of the amino-acid side chains
gram-positive cell wall
has S layers, not including the periplasmic space.
gram-negative cell envelope
contains a phospholipid bilayer with embedded proteins
inner cytoplasmic membrane
filled with a gel that contains proteins and enzymes.
periplasmic space
The thin peptidoglycan layer does not contain teichoic acid, although it does have a small helical lipoprotein
murein lipoprotein.
,which is a disaccharide with multiple fatty acid tails reaching into the membrane.
lipid A
toxic to humans and is known as the gram-negative
endotoxin.
lipid A
Embedded in the gram-negative outer membrane, which allow passage of nutrients. These are also unique to gram-negative organism.
porin proteins,
spherical
Cocci
rods.
Bacilli
Short bacilli
coccobacilli.
comma-shaped, S-shaped, or spiral-shaped.
Spiral forms
lacking a distinct shape (like jello)
Pleomorphic
forms strips of cocci
Streptococcus
forms clusters of cocci.
Staphylococcus
Two of the 4 gram-positive rods produce
spores
spheres that protect a dormant bacterium from the
harsh environment
spores
which causes syphilis.
Treponema pallidum
It is actually a diplococcus (looks like 2 coffee beans kissing):
Neisseria
are weakly gram-positive but stain better with a special stain called the acid-fast stain
Mycobacteria
have a gram-negative cell wall but are too small to be seen with the light microscope and so must be visualized with a special darkfield microscope
Spirochetes
Spirochetes have a gram-negative cell wall but are too small to be seen with the light microscope and so must be visualized with a special __________.
darkfield microscope.
do not have a cell wall. They only have a simple cell membrane, so they are neither gram positive nor gram-negative.
Mycoplasma
usually consists of a single circle of double-stranded DNA
Bacterial DNA
are composed of protein and RNA and are involved in the translation process, during the synthesis of proteins.
Ribosomes
have smaller ribosomes (70S) than animals (80S), which are eucaryotes.
Bacterial ribosomes consist of 2 subunits, a large subunit (50S) and a small subunit (30S).
procaryotes,
which surprisingly has endotoxin-surprising because ALL other organisms with endotoxin are gram-negative.
Listeria
breaks down hydrogen peroxide in the following reaction
Catalase
also breaks down hydrogen peroxide
Peroxidase
These critters are just like us
in that they use glycolysis, the Krebs TCA cycle, and the
electron transport chain with oxygen as the final electron acceptor. These guys have all the above enzymes.
Obligate aerobes
Don’t let this name fool you! These bacteria are aerobic. They use oxygen as an
electron acceptor in their electron transfer chain and have catalase and superoxide dismustase.
Facultative anaerobes:
The only difference is that they can grow in the absence of oxygen by using fermentation for energy
Facultative anaerobes:
These bacteria use fermentation and have no electron transport system. They can tolerate low amounts of oxygen because they have superoxide dismustase (but they have no catalase).
Microaerophilic bacteria (also called aerotolerant anaerobes)
These guys hate oxygen and have no enzymes to defend against it. When you are
working on the hospital ward, you will often draw blood for culture.
Obligate anaerobes
Of the organisms that use chemical sources, those that use inorganic sources, such
as ammonium and sulfide, are called a ___________.
autotrophs
use organic carbon sources and are called _________
heterotrophs.
used by many bacteria for oxygen metabolism.
Fermentation (glycolysis)
broken down to pyruvic acid, yielding ATP directly
Glucose
There are different pathways for the breakdown of glucose to pyruvate, but the most common
Embden Meyerhof pathway
This is the pathway of glycolysis that we have all studied in biochemistry
Embden Meyerhof pathway
used with the aerobic and facultative anaerobic organisms.
Respiration
are not capable of the metabolic pathways for ATP synthesis and thus must steal ATP from their host.
Obligate intracellular organisms
These bacteria live in their host cell and cannot survive without the host.
Obligate intracellular organisms
those that can cause disease.
Virulent organisms
the degree of organism pathogenicity.
virulence of an organism
depends on the presence of certain cell structures and on bacterial exotoxins and endotoxins, all of which are virulence factors.
Virulence
are protein filaments that extend like long tails from the cell membranes of certain gram positive and gram-negative bacteria.
Flagella
affixed to the bacteria by a basal body.
Flagellum
does not have flagella.
Shigella
are straight filaments arising from the bacterial cell wall, making the bacterium look like a porcupine.
Pili (also called fimbriae)
Pili can serve as adherence factors (in which case they are called _______
adhesins
uses its adhesin to bind to ciliated respiratory cells and cause whooping cough.
Bordetella pertussis
has pili that allow it to bind to cervical cells and buccal cells to cause gonorrhea
Neisseria gonorrhea
are protective walls that surround the cell membranes of gram-positive and gram-negative bacteria.
Capsules
They are usually composed of simple sugar residues. Bacteria secrete these sugar moieties, which then coat their outer wall.
Capsules
unique in that its capsule is made up of amino acid residues.
Bacillus anthracis
Because this stain is not taken up by the capsule, the capsule appears as a transparent halo around the cell.
India ink stain
This test is used primarily to identify the fungus Cryptococcus.
India ink stain
The bacteria are mixed with antibodies that bind to the capsule. When these antibodies bind, the capsule swells with water, and this can be visualized microscopically
Quellung reaction
The process of antibodies binding to the capsule
opsonization
are formed by only 2 genera of bacteria, both of which are gram-positive
Endospores
metabolically dormant forms of bacteria that are resistant to heat (boiling),
cold, drying and chemical agents
Endospores
An outer layer called _______.
exosporium
Many bacteria are phagocytosed by the host’s macrophages and neutrophils yet survive within these white blood cells unharmed.
Facultative Intracellular Organisms
proteins that are released by both gram-positive and gram-negative bacteria. They may cause many disease manifestations.
Exotoxins
produces endotoxin
Listeria monocytogenes
exotoxins that act on the gastrointestinal (GI) tract to cause diarrhea. Inhibit NaCl resorption, activate NaCl secretion, or kill intestinal epithelial cells
Enterotoxin
Bacteria colonize and bind to the GI tract, continuously releasing their enterotoxins locally.
Infectious diarrhea
The diarrhea will continue until the bacteria are destroyed by the immune system or antibiotics (or the patient dies secondary to dehydration)
Infectious diarrhea
Bacteria grow in food and release enterotoxin in the food. The enterotoxin is ingested resulting in diarrhea and vomiting for less than 24 hours.
Food poisoning
stimulate the release of cytokines and can cause rash, fever, and toxic shock syndrome
Pyrogenic exotoxins
allow bacteria to destroy and tunnel through tissues. These include enzymes that destroy DNA, collagen, fibrin, NAD, red blood cells, and white blood cells.
Tissue invasive exotoxins
which are the principle virulence factors for many bacteria, can cause disease
unique to the individual bacterium. Often the exact roleof the exotoxin is poorly understood
Miscellaneous exotoxins
is a common and deadly response to both gram-negative and gram positive infection
Septic shock
the number one cause of death in intensive care units and the 13th
most common cause of death in the U.S.
Septic shock
This is simply bacteria in the bloodstream
Bacteremia
Sepsis that results in dangerous drops in blood pressure and organ dysfunction
Septic shock
endotoxin often triggers the immune response that results in sepsis and shock
endotoxic shock
These cells, in response to the stimulus, release a host of proteins that are referred to a _________
endogenous mediators
The most famous endogenous mediator of sepsis.
tumor necrosis factor (TNF).
TNF is called ________.
cachectin
double-stranded DNA molecule that is closed in a giant loop.
bacterial chromosome
Transduction occurs when a virus that infects bacteria, called ________, carries a piece of bacterial DNA from one bacterium to another
bacteriophage
infecting the bacteria, reproducing, and then lysing and killing the bacteria
Virulent phages
have a good temperament and do not immediately lyse the bacteria they infect
temperate phages
The integrated temperate phage genome
prophage
Bacteria that have a prophage integrated into their chromosome, because at some time the repressed prophage can become activated.
lysogenic
the term used to describe the ability of an integrated bacteriophage (prophage) to block a subsequent infection by a similar phage
Lysogenic immunity
these phages can carry bacterial DNA from one bacterium to another. This process is called _______.
transduction
occurs with phage lambda in Escherichia coli. The site of insertion of the lambda prophage lies between the Escherichia coli gene for biotin synthesis and galactose synthesis.
Specialized transduction
the gene for biotin synthesis can now be transferred to another bacteria that does not have that capability. You will frequently hear about this form of gene acquisition; it is called ___________.
lysogenic conversion
For conjugation to occur, one bacterium must have a self-transmissible plasmid
F plasmid
The self-transmissible plasmid (F plasmid) has a gene that encodes enzymes and proteins that form
the sex penis,
sex pilus
the extra-chromosomal F plasmid becomes integrated in the neighboring bacterial chromosome much in the same way as a temperate bacteriophage does. The bacterial cell is then called _________.
Hfr cell
High frequency of chromosomal recombinants. This integration can result in two unique mechanisms
of DNA transfer
Hfr cell
are both gram-positive spheres (cocci) and are responsible for a wide variety of clinical diseases
Streptococci and staphylococci
A second method to differentiate streptococci from staphylococci involves the enzyme
catalase
incubated overnight on a blood agar plate. B
streptococci
Completely lyse the RBCs, leaving a clear zone of
hemolysis around the colony.
Beta-hemolytic streptococci
only partially lyse the RBCs, leaving a greenish discoloration of the culture medium surrounding the
colony.
Alpha-hemolytic streptococci
are unable to hemolyze the RBCs, and therefore we should really not use the word “hemolytic” in this situation
Gammahemolytic streptococci
Used as a major way of differentiating the many streptococci.
Lancefield antigens
These organisms are so-named because they possess the Lancefeld group A antigen and are beta-hemolytic on blood agar.
GROUP A BETA-HEMOLYTIC STREPTOCOCCI (also called Streptococcus pyogenes)
which (means pus-producing) and cause the diseases “strep throat,” scarlet fever, rheumatic fever, and post-streptococcal glomerulonephritis
Streptococcus pyogenes
used by Rebecca Lancefield to divide streptococci into groups.
C carbohydrate
C carbohydrates was used by _______
Rebecca Lancefield
This is a major virulence factor for the group A streptococcus.
M protein
It inhibits the activation of complement and protects the organism from phagocytosis. However, it is also the weakest point in the organism’s defense, because plasma (B) cells generate antibodies
against the M protein.
M protein
The stands for oxygen labile as it is inactivated by oxygen.
Streptolysin O
This enzyme destroys red and white blood cells and is the reason for the beta-hemolytic
group A streptococci’s beta-hemolytic ability
Streptolysin O
The stands for oxygen stabile. This is also responsible for beta-hemolysis but is not antigenic.
Streptolysin S
This is found in only a few strains of betahemolytic group A streptococci, but when these strains invade they can cause scarlet fever.
Pyrogenic exotoxin (also called erythrogenic toxin)
activates the proteolytic enzyme plasmin, which breaks up fibrin blood clots
streptokinase
This is the classic strep throat with red swollen tonsils and pharynx, a purulent exudate on the tonsils, high temperature, and swollen lymph nodes. It usually lasts 5 days (penicillin therapy speeds recovery)
Streptococcal pharyngitis
can range from folliculitis (infections of the hair follicles), cellulitis (a deep infection of the skin cells, producing red, swollen skin which is hot to the touch), and impetigo (a vesicular, blistered, eruption, most common in children, that becomes crusty and flaky and is frequently found
around the mouth)
Skin infections
(“Flesh-eating Streptococcus”)
Necrotizing Fasciitis
This type of group A beta-hemolytic streptococcal infection has actually been around for years but may indeed be on the rise (news coverage certainly is).
Necrotizing Fasciitis
gram-negative enterics, or mixed infection with more than one of these bacteria
Clostridium species
Certain beta-hemolytic group A streptococci not only cause a sore throat
Scarlet fever
Certain beta-hemolytic group A streptococci not only cause a sore throat, but also produce an exotoxin called _________.
pyrogenic toxin or erythrogenic toxin
It is now clear that beta-hemolytic group A streptococci can cause toxic shock syndrome like that caused by Staphylococcus aureus
Streptococcal toxic shock syndrome
With the advent of penicillin, is now uncommon. It usually strikes children 5-15 years of age
Rheumatic fever
Rash, because it has a red margin that spreads out from its center.
erythema marginatum
Picture John Travolta in the movie Rheumatic Fever, the upcoming sequel to _______.
Saturday Night Fever
This is an antibody-mediated inflammatory disease of the glomeruli of the kidney
Acute post-streptococcal glomerulonephritis
causes tea colored urine (hematuria).
Acute post-streptococcal glomerulonephritis
About 25% of women carry these bugs vaginally, and a baby can acquire these bacteria during delivery. These organisms cause neonatal (< 3 months of age) meningitis, pneumonia, and sepsis.
GROUP B STREPTOCOCCI
alpha-hemolytic, producing greenish discoloration on blood agar
viridans streptococci
Some of the viridans streptococci, especially S. mutans, can bind to teeth and ferment sugar, which produces acid and dental caries ( cavities!!).
Dental infections
Dental manipulations send showers of these organisms into the bloodstream. Subsequently, they can implant on the endocardial surface of the heart, most commonly on a previously damaged heart valve (such as from old rheumatic fever, a congenital heart defect, or mitral valve prolapse)
Endocarditis
eating heart valves slowly
Viridans Streptococcus
There is a subgroup of the viridans streptococci, which are microaerophilic and are part of the normal G.I. tract flora.
Streptococcus intermedius group
comprised of Enterococcus faecalis and Enterococcus faecium
enterococci
comprised of many organisms including Streptococcus bovis and Streptococcus equinus)
non-enterococci
Traditionally these alpha-hemolytic bacteria have been divided into two subgroups
GROUP D STREPTOCOCCI
hardy, growing in 40% bile (but not in 6.5% NaCl). It lives in the G.I. tract, and it causes similar diseases
Streptococcus bovis
A very important organism because it is a major cause of bacterial pneumonia and meningitis in adults, and otitis media in children. pneumococcus is to parents what group B streptococcus is to
Babies
Streptococcus pneumoniae
When pneumococci on a slide smear are mixed with a small amount of antiserum (serum with antibodies to the capsular antigens) and methylene blue, the capsule will appear to swell
Quellung reaction
This technique allows for rapid identification of this organism
Quellung reaction
is the most common cause of pneumonia in adults.
Streptococcus pneumoniae
occurs suddenly, with shaking chills (rigors), high fevers, chest pain with respirations, and shortness of breath.
Pneumococcal pneumonia
also the most common cause of otitis media (middle ear infection) in children and the most common cause of bacterial meningitis in adults
Streptococcus pneumoniae
nuchal rigidity (a stiff neck) is usually present in an adult
meningitis
forever underfoot, crawling all over hospitals and living in the nasopharynx and skin of up to 50% of people.
Staphylococci
catalase-positive, thus explaining the cats in the group photo.
Staphylococcus aureus
can be differentiated from the other beta-hemolytic cocci by their elaboration of a golden pigment when cultured on sheep blood agar
Staphylococcus aureus
All staphylococci have the enzyme catalase
Catalase test
Staphylococcus aureus and certain streptococci are beta-hemolytic (completely hemolyze
red blood cells on an agar plate), but Staphylococcus aureus can be differentiated from the other beta-hemolytic cocci by their elaboration of a golden pigment on sheep blood agar.
Culture
This protein has sites that bind the Fc portion of IgG. This may protect the organism from opsonization and phagocytosis
Protein A
This enzyme can lead to fibrin formation around the bacteria, protecting it from phagocytosis
Coagulase
Alpha, beta, gamma, and delta. They destroy red blood cells, neutrophils, macrophages, and platelets.
Hemolysins
They destroy leukocytes (white blood cells).
Leukocidins
This is a secreted form of betalactamase. It disrupts the beta-lactam portion of the penicillin molecule, thereby inactivating the antibiotic
Penicillinase
This protein, also called transpeptidase, is necessary for cell wall peptidoglycan formation and is inhibited by penicillin.
Novel penicillin binding protein
(“Spreading Factor”): This protein breaks down proteoglycans in connective tissue.
Hyaluronidase
This protein lyses formed fibrin clots (like streptokinase).
Staphylokinase
This enzyme degrades fats and oils, which often accumulate on the surface of our body. This degradation facilitates Staphylococcus aureus’ colonization of sebaceous glands
Lipase
destroys tissue proteins
Protease
A diffusible exotoxin that causes the skin to slough off (scalded skin syndrome).
Exfoliatin
Exotoxins which cause food poisoning, resulting in vomiting and diarrhea
Enterotoxins
This exotoxin is analogous to the pyrogenic toxin produced by Lancefield group A beta-hemolytic streptococci, but is far more deadly.
Toxic Shock Syndrome toxin
Staphylococci can grow in food and produce an exotoxin. The victim will then eat the food containing the pre-formed toxin, which then stimulates peristalsis of the intestine with ensuing nausea vomiting, diarrhea, abdominal pain, and occasionally fever. The episode lasts 12 to 24 hours.
Gastroenteritis
This disease is similar in pathogenesis to toxic shock syndrome.
Staphylococcal Scalded Skin Syndrome
Staphylococcus aureus is a rare but severe cause of community-acquired bacterial pneumonia.
Pneumonia
These patients can present with high fever, stiff neck, headache, obtundation, coma, and focal neurologic signs.
Meningitis, Cerebritis, Brain Abscess
This is a bone infection that usually occurs in boys under 12 years of age.
Osteomyelitis
This is a violent destructive infection of the heart valves with the sudden onset of high fever (103-105 F°), chills, and myalgias (like a bad flu)
Acute Endocarditis
Patients complain of an acutely painful red swollen joint with decreased range of motion
Septic Arthritis
caused by staphylococci or streptococci usually follow a major or minor break in the skin, with scratching of the site spreading the infection
Skin infections
This contagious infection usually occurs on the face, especially around the mouth. Small
vesicles lead to pustules, which crust over to become honey-colored, wet, and flaky
Impetigo
This is a deeper infection of the cells. The tissue becomes hot, red, shiny and swollen
Cellulitis
is a collection of pus.
abscess
These may bore through to produce multiple contiguous, painful lesions communicating under the skin
carbuncles
When a sutured post-surgical wound becomes infected, it must be reopened and often
left open to heal by secondary intention (from the bottom of the wound outward).
Wound infections
can migrate from the skin and colonize central venous catheters resulting in bacteremia, sepsis,
and septic shock
Blood and catheter infections: Staphylococcus aureus
a strain of Staphylococcus aureus that has acquired multi-drug resistance, even against methicillin and nafcillin.
Methicillin-Resistant Staphylococcus aureus (MRSA)
is one of the few antibiotics useful in treating infections caused by MRSA, although organisms resistant even to vancomycin have been reported in the U.S. and Japan
Vancomycin
This organism is part of our normal bacterial flora and is widely found on the body.
Staphylococcus epidermidis
is a frequent skin contaminant of blood cultures.
Staphylococcus epidermidis
This organism is a leading cause (second only to E. coli) of urinary tract infections in sexually active young women.
Staphylococcus saprophyticus
It is most commonly acquired by females (95%) in the community (NOT in the hospital). This organism
is coagulase-negative.
Staphylococcus saprophyticus
causes gastroenteritis (food poisoning).
Bacillus cereus
causes the disease anthrax
Bacillus anthracis
This capsule prevents phagocytosis. causes anthrax, a disease that primarily affects herbivores (cows and sheep)
Bacillus anthracis
This is the active A subunit of this exotoxin and is a calmodulin-dependent adenylate cyclase.
Edema factor (EF)
promotes entry of EF into phagocytic cells (similar to a B subunit of the other A-B toxins,
Protective antigen (PA)
a zinc metalloprotease that inactivates protein kinase
Lethal factor
This toxin stimulates the macrophage to release tumor necrosis factor a and interleukin-1
Lethal factor
encodes three genes necessary for the synthesis of a poly-glutamyl capsule.
A second plasmid, pXO2
causes food poisoning (nausea, vomiting, and diarrhea).
Bacillus cereus
similar to the enterotoxin of cholera and the LT from Escherichia coli (causes nausea, abdominal pain and diarrhea, lasting 12-24 hours.
A heat-labile toxin
produces a clinical syndrome similar to that of Staphylococcus aureus food poisoning,
with a short incubation period followed by severe nausea and vomiting, with limited diarrhea.
heat-stable toxin
also gram-positive spore-forming rods. However, they are anaerobic, and can therefore
be separated from the aerobic spore-forming rods
Clostridium
produces an extremely lethal neurotoxin that causes a rapidly fatal food poisoning.
Clostridium botulinum
Eating smoked fish or home-canned vegetables is associated with the transmission of botulism.
Adult Botulism
spores float in the air and can land on food.
Clostridium botulinum
occurs when infants ingest food contaminated with Clostridium botulinum spores (cases have followed ingestion of fresh honey contaminated with spore)
Infant Botulism
causes tetanus, a disease that classically follows a puncture wound by a rusty nail but
can follow skin trauma by any object contaminated with spores
Clostridium tetani
Clostridium tetani releases its exotoxin,
tetanospasmin
The tetanus toxin ultimately causes a sustained contraction of skeletal muscles
tetany
Clinically, the patient with tetanus presents with severe muscle spasms, especially in the muscles of the jaw (lockjaw)
trismus
The affected patient exhibits a grotesque grinning expression,
sardonicus
Necrotic skin which grows and damages local tissue.
Clostridium perfringens
Palpation reveals a moist, spongy, crackling consistency to the skin due to pockets of gas;
crepitus
These anaerobic bacteria release other enzymes that ferment carbohydrates, resulting in gas formation.
Clostridial myonecrosis
is the pathogen responsible for antibiotic-associated pseudomembranous colitis (diarrhea), which can follow the use of broad spectrum antibiotics (such as ampicillin, clindamycin, and the cephalosporins)
Clostridium difficile
Examination by colonoscopy can reveal red inflamed mucosa and areas of white exudate on the surface of the large intestine
pseudomembranes
The diphtheria antitoxin only inactivates circulating toxin, which has not yet reached its target tissue, so this must be administered quickly to prevent damage to the heart and nervous system
Antitoxin
Either antibiotic will kill the bacteria, preventing further exotoxin release and rendering the patient non-contagious
Penicillin or erythromycin
as infection by Corynebacterium diphtheriae does not always result in immunity to future infection by this organism
DPT vaccine
a gram positive motile rod, actually has endotoxin!
LISTERIA MONOCYTOGENES
shaped like a kidney bean, and a pair of cocci sticks together with their
concave sides facing each other, almost making the diplococcus look like a small doughnut
coccus
It’s time to examine the only pathogenic gram-negative
cocci,
Neisseria
These guys hang out in pairs and are thus
diplococci
drinks a pot of coffee and becomes very nervous and irritable (central nervous system irritation-meningitis
Neisseria meningitidis
who is a pervert (notice how he is displaying the latest center-fold pin-up). He
enjoys hanging out on sexual organs and swimming in “sexual fluids.”
Neisseria gonorrhoeae
causes life threatening sepsis
meningococcus
A polysaccharide capsule surrounds the bacterium and is antiphagocytic, as long as there are no
specific antibodies to coat (opsonize) the bacterium.
Capsule
The meningococci can release blebs of endotoxin, which causes blood vessel destruction (hemorrhage) and sepsis.
Endotoxin (LPS)
The blood vessel hemorrhage is seen on the skin as tiny, round, red dots of hemorrhage
petechiae
This is only found in pathogenic species of Neisseria. This enzyme cleaves IgA (a type of
antibody) in half.
IgA1 protease
can extract iron from human transferrin via a non-energy requiring mechanism
Neisseria meningitidis
spreads via respiratory secretions and usually lives asymptomatically in the
nasopharynx
Neisseria meningitidis
This is septic shock. Bilateral hemorrhage into the adrenal glands occurs, which causes adrenal insufficiency.
Fulminant meningococcemia (WaterhouseFriderichsen syndrome)
This is the most common form of meningococcal disease, usually striking infants < 1
year of age.
Meningitis
The classic medium for culturing Neisseria
Thayer-Martin VCN media
This is chocolate agar with antibiotics, which are included to kill competing bacteria.
Thayer-Martin VCN media
eliminates fungi
nystatin
which kills all gram-negative organisms (except Neisseria).
colistin (polymyxin)
which kills gram-positive organisms.
vancomycin
required at the first indication of disseminated meningococcemia
penicillin G or ceftriaxone
Close contacts of an infected patient are treated with
rifampin
causes the second most commonly transmitted sexual disease
NEISSERIA GONORRHOEAE
A gonococcal infection of the cervix can progress to
pelvic inflammatory disease
infection of the uterus
endometritis
infection of fallopian tubes
salpingitis
infection of ovaries
oophoritis
most commonly caused by scarring of the fallopian tubes, which occludes the lumen and prevents sperm from reaching the ovulated egg
Sterility
the most common site for an ectopic pregnancy
fallopian tubes
The risk of a fetus developing at a site other than the uterus is significantly increased with previous fallopian tube inflammation (salpingitis).
Ectopic pregnancy
may develop in the fallopian tubes, ovaries, or peritoneum
Abscesses
Bacteria may spread from ovaries and fallopian tubes to infect the peritoneal fluid .
Peritonitis
This is an infection by Neisseria gonorrhoeae of the capsule that surrounds the liver
Peri-hepatitis (Fitz-Hugh-Curtis syndrome)
A patient will complain of right upper quadrant pain and tenderness
Peri-hepatitis (Fitz-Hugh-Curtis syndrome)
can invade the bloodstream. Manifestations include fever, joint pains, and skin lesions (which usually erupt on the extremities).
Gonococcal bacteremia:
Acute onset of fever occurs along with pain and swelling of 1 or 2 joints. W
Septic arthritis
Neisseria gonorrhoeae can be transmitted from a pregnant woman to her child during delivery, resulting in __________.
ophthalmia neonatorum
eye drops, which are effective against both Nisseria gonorrhoeae and Chlamydia, are given to all
newborns
erythromycin
This organism is part of the normal respiratory flora but can cause otitis media, sinusitis, bronchitis, and
pneumonia (all respiratory tract illnesses)
BRANHAMELLA CATARRHALIS
are gram-negative bacteria that are part of the normal intestinal flora or cause gastrointestinal disease.
enterics
Methylene blue inhibits gram-positive bacteria, and colonies of lactose fermenters become deep purple to black in this medium
EMB agar
Bile salts in the medium inhibit gram-positive bacteria, and lactose fermenters develop a pink-purple coloration.
MacConkey agar
A classic method for determining whether water has been contaminated with feces demonstrates some of the practical uses of biochemical reactions and some important properties of Escherichia coli
Fecal Contamination of Water
You add the river water samples to test tubes containing nutrient broth (like agar)
that contains lactose
Presumptive Test
Streak EMB agar plates with the water samples, and the Escherichia coli should form colonies with a metallic green sheen
Confirmed Test
Colonies that were metallic green are placed in the broth again
Completed Test
This is the most external component of the lipopolysaccharide (LPS) of gram-negative bacteria.
0 antigen
This is a capsule that covers the 0 antigen
K antigen
This antigenic determinant makes up the subunits of the bacterial flagella, so only bacteria
that are motile will possess this antigen. Shigella does not have an H antigen. Salmonella has H antigens that change periodically, protecting it from our antibodies.
H antigen
Diarrhea is caused by the release of exotoxins
enterotoxins in the GI tract
The bacteria bind to the intestinal epithelial cells but do not enter the cell
No cell invasion
The bacteria have virulence factors that allow binding and invasion into cells
Invasion of the intestinal epithelial cells
Along with abdominal pain and diarrhea containing white and red cells, this deeper invasion results
in systemic symptoms of fever, headache, and white blood cell count elevation
Invasion of the lymph nodes and bloodstream
normally resides in the colon without causing disease
Escherichia coli
travelers’ diarrhea
Montezuma’s revenge
This Escherichia coli causes traveler’s diarrhea
Enterotoxig enic Escherichia coli
These Escherichia coli also have a pili colonization factor like the ETEC but differ in that they secrete
the powerful Shiga-like toxin ( also called verotoxin) that has the same mechanism of action as the Shigella toxin
Enterohemorrhagic Escherichia coli (EHEC):
with anemia, thrombocytopenia (decrease in platelets), and renal failure (thus uremia), is associated with infection by a strain of EHEC
Hemolytic uremic syndrome (HUS)
This disease is the same as that caused by Shigella
Enteroinvasive Escherichia coli
The acquisition of a pili virulence factor allows Escherichia coli to travel up the urethra and infect the
bladder (cystitis) and sometimes move further up to infect the kidney itself (pyelonephritis).
Escherichia coli Urinary Tract Infections (UTIs)
the second most common cause of neonatal meningitis
Escherichia coli meningitis
the most common cause of gram-negative sepsis.
Escherichia coli sepsis
a common cause of hospital-acquired pneumonia
Escherichia coli Pneumonia
This organism is very motile. In fact, when you smear the bacteria on a plate it will grow not as distinct round colonies, but rather as a confluence of colonies as the bacteria rapidly move and cover the plate
Proteus mirabilis
another common cause of urinary tract infections and hospital-acquired (nosocomial) infections.
Proteus
This highly motile gram-negative rod is part of the normal flora of the intestinal tract.
Enterobacter
notable for its production of a bright red pigment.
Serratia
This is the same toxin as in EHEC and EIEC, and its mechanism is the same
Shiga Toxin
a non-lactose fermenter, is motile (like a salmon), and produces H2S
Salmonella
This is a polysaccharide capsule that surrounds the O antigen, thus protecting the bacteria from antibody attack on the O antigen
Salmonella’s Vi antigen
This illness caused by Salmonella typhi
enteric fever
caused by Salmonella typhi, depicted by a Salmon with fever (thermometer) and rose spots on its belly
Typhoid fever
considered appropriate therapy of typhoid fever
Ciprofloxacin or ceftriaxone
the most common type of Salmonella infection and can be caused by any of hundreds of serotypes of Salmonella enteritidis
Salmonella diarrhea
This motile gram-negative rod is another cause of acute gastroenteritis
Yersinia enterocolitica
This organism can secrete an enterotoxin, very similar to the heat-stable enterotoxin of Escherichia coli, that causes diarrhea.
Enterotoxin
Like Salmonella typhi, this organism possesses virulence factors that allow binding to the intestinal wall and systemic invasion into regional lymph nodes and the bloodstream
Invasion
can survive and grow in the cold.
Yersinia enterocolitica
the diarrheal disease caused by Vibrio cholera
Cholera
curved gram-negative rod with a single polar flagellum.
Vibrio cholera
The bacteria attach to the epithelial cells and release the cholera toxin, which is called
choleragen
Physical findings such as diminished pulses, sunken eyes, and poor skin turgor will develop with severe dehydration.
Cholera causes death by dehydration
This organism is a marine bacterium that causes gastroenteritis after ingestion of uncooked seafood (sushi). This organism is the leading cause of diarrhea in Japan.
Vibrio parahaemolyticus
(Camping bacteria in the jejunum with nothing better to do than cause diarrhea.
Campylobacter jejuni
This organism is the most common cause of duodenal ulcers and chronic gastritis (inflamed stomach)
Helicobacter pylori
You are going to hear so much about this bug while working in the hospital that you will wish the Lord had never conjured it up.
Pseudomonas aeruginosa
It also produces a sweet grape-like scent, so wound dressings and agar plates are often sniffed for organism identification.
Pseudomonas aeruginosa
carries an extremely high mortality rate
Pseudomonas sepsis
rapidly becoming an important pathogen, infecting hospitalized patients (burn and cystic fibrosis patients) in a similar manner
Pseudomonas cepacia
This bacterium is notable for being one of the few gram-negative bacteria that does not contain lipid
Bacteroides fragilis
This organism produces a black pigment when grown on blood agar.
Bacteroides melaninogenicus
It lives in the mouth, vagina, and intestine, and is usually involved in necrotizing anaerobic pneumonias caused by aspiration of lots of sputum from the mouth
melaninogenicus
This bacterium is just like Bacteroides melaninogenicus in that it also causes periodontal disease and aspiration pneumonias.
Fusobacterium
are gram-positive anaerobes that are part of the normal flora of the mouth, vagina, and intestine
Peptostreptococcus (strip or chain of cocci) and Peptococcus (cluster of cocci)
means “blood loving.” This organism requires a blood-containing medium for growth
Haemophilus
This bacterium often attacks the lungs of persons debilitated by a viral influenza infection
influenzae
an obligate human parasite that is transmitted via the respiratory route
Haemophilus influenzae
This is the most serious infectioncaused by encapsulated Haemophilus influenzae type b. Prior to the introduction of vaccination of U.S. children in 1991
Meningitis
Haemophilus influenzae type b can also cause rapid swelling of the epiglottis, obstructing the respiratory tract and esophagus
Acute epiglottitis
can be used for less serious infections, such as otitis media.
Ampicillin or amoxicillin
The key to controlling this organism is to stimulate the early generation of protective antibodies in young children
Hib capsule vaccine
This species is responsible for the sexually transmitted disease chancroid
Haemophilus ducreyi
Treat chancroid
erythromycin or trimethoprim/sulfamethoxazole
This organism causes bacterial vaginitis in conjunction with anaerobic vaginal bacteria
Gardnerella vaginalis
Women with vaginitis develop burning or pruritis (itching) of the labia, burning on urination (dysuria), and a copious, foul-smelling vaginal discharge that has a fishy odor.
Gardnerella vaginalis
Treat this infection (Gardnerella vaginalis)
metronidazole
it was discovered in the early 1900’s by two scientists named Bordet and Gengou. It
seems that Bordet got the better end of the deal.
Bordetella
means “violent cough.”
Pertussis
a violently militant critte with a (gram) negative attitude
Bordetella pertussis
This toxin destroys the ciliated epithelial cells, resulting in impaired clearance of
bacteria, mucus, and inflammatory exudate. This toxin is probably responsible for the violent cough.
Tracheal cytotoxin
It attaches to ciliated epithelial cells of the bronchi and then releases its damaging exotoxins
Filamentous hemagglutinin
They are swallowed by host neutrophils, lymphocytes, and monocytes. The internalized adenylate cyclase then synthesizes the messenger cAMP, resulting in impaired chemotaxis and impaired generation of H2O2 and superoxide
Extra cytoplasmic adenylate cyclase
Like many bacterial exotoxins this toxin has a B subunit that Binds to target cell receptors, “unlocks” the cell, allowing entry of the A subunit
Pertussis toxin
This stage lasts from 1-2 weeks and is similar to an upper respiratory tract infection, with low-grade fevers, runny nose, sneezing, and mild cough
Catarrhal stage
The fever subsides and the infected individual develops characteristic bursts of
nonproductive cough.
Paroxysmal stage
The attacks become less frequent over a month, and the patient is no longer contagious
Convalescent stage
The swab is then wiped on a special culture medium with potato, blood, and glycerol agar.
Bordet-Gengou medium
This organism is ubiquitous in natural and manmade water environments
Legionella pneumophila
an aerobic gram-negative rod that is famous for causing an outbreak of pneumonia at an American Legion convention in Philadelphia in 1976 (thus its name)
Legionella pneumophila
this organism is a facultative intracellular parasite that settles in the lower respiratory tract and is gobbled up by macrophages
Mycobacterium tuberculosis
responsible for diseases ranging from asymptomatic infection and a flulike illness
Legionella
severe pneumonia
Legionnaires’ disease
a flulike illness
Pontiac fever
Like influenza, this disease involves headache, muscle aches, and fatigue, followed
by fever and chills
Pontiac fever
Patients develop very high fevers and a severe pneumonia.
Legionnaires’ disease
one of the most common causes of community acquired pneumonia and is estimated to be diagnosed correctly in only 3% of cases.
Legionella pneumophila
Treat for Legionella pneumophila
erythromycin
The organism now resides in squirrels and prairie dogs of the southwestern U. S.
Yersinia pestis
heard of bubonic plague and that rats were somehow involved
Yersinia pestis
This capsular antigen has antiphagocytic properties.
Fraction 1
These antigens, which are a protein and lipoprotein respectively, are unique to the
Yersinia genus. Their actions are unknown
V and W antigens
a gram-negative bacterium with a bipolar staining pattern
Yersinia pestis
a disease that resembles bubonic plague so closely that it is always included in the differential diagnosis when considering bubonic plague
Francisella tularensi
This disease is most commonly acquired from handling infected rabbits and from the bites of ticks and deerflies.
Francisella tularensi
Following the bite of a tick or deerfly, or contact with a wild rabbit, a welldemarcated hole in the skin with a black base develops
Ulceroglandular tularemia
Aerosolization of bacteria during skinning and evisceration of an infected
rabbit or hematogenous spread from the skin
Pneumonic tularemia
Humans acquire from direct contact with infected animal meat or aborted placentas, or ingestion of infected milk products
Brucella
(goats)
Brucella melitensis
(causes abortions in cows)
Brucella abortus
(pigs)
Brucella suis
(dogs)
• Brucella canis
The slow rise in temperature during the day, declining at night. These symptoms can last from months to years, but fortunately the disease is rarely fatal
undulant fever
This organism is a gram-negative zoonotic organism
Pasteurella multocida
This bacterium colonizes the mouths of cats much in the same way that Streptococcus viridans colonizes the human nasopharynx.
Pasteurella multocida
This bacterium causes the most frequent wound infection following a cat or dog bite
Pasteurella multocida
extremely tiny. It is classified as gramnegative because it stains red with Gram stain technique and has an inner and outer membrane.
Chlamydia
