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140 Cards in this Set
- Front
- Back
Mention 5 diseases that can be caused by Staphylococcus aureus!
|
Impetigo, furunculus, pneumonia, osteomyelitis, food poisoning etc.
|
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Mention 2 toxin-mediated staphylococcal diseases!
|
toxic shock syndrome (TSS), scalded skin syndrome, food poisoning
|
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Mention 3 toxic products produced by Staphylococcus aureus!
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TSST (toxic shock syndrome toxin), enterotoxin, exfoliatin, leukocidins, hemolysins
|
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Which is the most virulent species of Staphylococcus?
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S. aureus
|
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Which enzymatic virulence factor is characteristic exclusively for Staphylococcus
aureus? |
coagulase
|
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How can we identify the source of infection in a staphylococcal food poisoning?
|
by phage typing
|
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Which antibacterial drug is the first choice in serious infections caused by methycillin
resistant Staphylococcus aureus (MRSA) strains? |
glycopeptides (vancomycin, teicoplanin)
|
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In which disease is Staphylococcus saprophyticus considered an obligate pathogen!
|
cystitis in young women
|
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Which cell constituents determine the group-specific, and the type specific antigens of
Streptococcus pyogenes, respectively? |
group specific: C- polysaccharide
type specific: M protein |
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Mention 3 enzymes produced by Streptococcus pyogenes that enhance the spread of
the bacterial infection in the body! |
Streptokinase (fibrinolysin), hyaluronidase, streptodornase (DNAse)
|
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List 3 diseases caused by Streptococcus pyogenes in the skin or in subcutaneous
tissues! |
impetigo (pyoderma), cellulitis, erysipelas, fasciitis, myositis
|
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Mention a toxin-mediated streptococcal disease, specify the name of the toxin and its
mechanism of action! |
Scarlet fever - erythrogenic toxin – superantigen causing capillary destruction
|
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Mention 2 poststreptococcal diseases!
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Glomerulonephritis, rheumatic fever, erythema nodosum, chorea minor.
|
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Which product of Streptococcus pyogenes has a major pathogenic role in
poststreptococcal diseases? |
M protein: may induce hypersensitivity reactions
|
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How long does immunity against scarlet fever exist? Which immune effector
mechanism is involved? |
Life-long immunity. Antitoxic antibodies are involved.
|
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What is the drug of first choice in Streptococcus pyogenes infection?
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Penicillin-G
|
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What is the patomechanism of post-streptococcal rheumatic fever?
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type II hypersensitivity (cytotoxic antibodies)
|
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What is the patomechanism of post-streptococcal glomerulonephritis?
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type III hypersensitivity (immune complexes)
|
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Which Streptococcus species plays major role in the meningitis of newborn babies?
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Group B Streptococcus (S. agalactiae)
|
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What is (are) the major causative agent(s) for subacute bacterial endocarditis?
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Viridans streptococci
|
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What are the characteristics of Enterococci that can be used in their identification?
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D group polysaccharide antigen; tolerance to bile and hydrolysis of esculin (BEA
medium: bile esculin agar); growth in the presence of 6,5 % NaCl |
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What are the specific morphologic features of Streptococcus pneumoniae?
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Gram positive diplococcus, lancet shape, capsule.
|
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Mention 3 diseases that can be caused by Streptococcus pneumoniae!
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Pneumonia, meningitis, sinusitis, otitis media, sepsis, (ulcus serpens corneae)
|
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What fast diagnostic procedure can be used in acute Neisseria gonorrhoeae infection?
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Demonstration of bacteria (intracellular in PMNs) from urethral discharge by Gram
or methylene blue stain; PCR amplification of bacterial DNA |
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What kind of immunity develops after Neisseria gonorrhoeae infection?
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Partial immunity of short duration; no protection from reinfection
|
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Specify at least 2 of the most important manifestations of disseminated gonorrhoeal
infections! |
arthritis, skin eruptions, (endocarditis, meningitis)
|
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What is the major complication of Neisseria gonorrhoeae infection in newborns? How
can it be prevented? |
Blenorrhoea (ophtalmia) neonatorum, silver acetate eye drops or erythromycin
ointment |
|
Mention at least 3 major virulence factors of Neisseria gonorrhoeae!
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pilus, outer membrane proteins, LOS (lipooligosaccharide), IgA protease
|
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Mention at least 2 major virulence factors of Neisseria meningitidis!
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polysaccharide capsule, LPS, IgA protease
|
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What is the site of entry of Neisseria meningitidis infection? What diseases are caused
by this bacterium? |
The site of entry is the nasopharynx (transmitted by airborne droplets).
Meningococcemia (characterized by skin lesions), and acute (purulent) bacterial meningitis. |
|
What kinds of prophylactic measurements are available against Neisseria meningitidis
infections? |
Chemoprophylaxis: rifampin or ciprofloxacin.
Vaccination: capsular polysaccharide (types A, C, Y and W135). No vaccine against type B! |
|
Which rapid diagnostic methods can be used in the presumptive diagnosis of purulent
bacterial meningitis? |
Gram or methylene blue stain of CSF sediment
Demonstration of bacterial capsular antigens by latex agglutination (from CSF) |
|
Which capsular serotype is included in the vaccine against Haemophilus influenzae?
|
type b
|
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Which are the portals of entry of Bacillus anthracis?
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Skin, lung, gastrointestinal tract
|
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Mention 3 important bacteria involved in nosocomial (hospital-acquired) infections!
|
Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa, Escherichia and klebsiella
coli |
|
Mention four E. coli pathogenetic groups involved in enteric diseases!
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Enteropathogenic E. coli (EPEC)
Enterotoxic E. coli (ETEC) Enteroinvasive E. coli (EIEC) Enterohemorrhagic E. coli (EHEC) Enteroaggregative E. coli (EAggEC) |
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What are the most important extraintestinal infections caused by E. coli?
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urinary tract infections, neonatal meningitis, nosocomial wound infections
|
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The most frequent causative agent of urinary tract infections is:
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Escherichia coli
|
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What disease is caused by E. coli O157:H7?
|
hemorrhagic colitis +/- HUS (hemolytic uraemic syndrome)
|
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What is the reservoir of Salmonella typhi?
|
humans (with disease, or healthy carriers)
|
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Which bacteria cause most frequently typhoid fever and enteric fever, respectively?
|
Salmonella typhi (typhoid)
Salmonella paratyphi A, B, C (enteric fever) |
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When typhoid fever is suspected, what kinds of clinical samples should be used to isolate
the causative agent in the first 2 weeks of the disease? |
Blood, (bone marrow)
|
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What is the route of infection in Salmonella gastroenteritis?
|
Ingestion of contaminated food (such as eggs, cream, mayonnaise, creamed foods, etc.)
containing a sufficient number of Salmonella. |
|
Which antibacterial drugs should be administered in gastroenteritis caused by
Salmonella? |
Antibiotics are not usually necessary unless the infection is generalised. In case of
extraintestinal infection (very young, very old or immunosuppressed patients): ampicillin, gentamicin, trimethoprim/sulfamethoxazole, or ciprofloxacin. |
|
List the 4 Shigella species causing human disease!
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Shigella dysenteriae, S. flexneri, S. boydii, S. sonnei
|
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Mention 2 bacterial species belonging to different genera that cause bacillary dysentery
|
Shigella dysenteriae, Shigella flexneri, Shigella boydii, Shigella sonnei, enteroinvasive
E. coli (EIEC) |
|
Mention 3 bacterial species belonging to different genera that cause enteritis or
enterocolitis! |
Campylobacter jejuni, Escherichia coli, Salmonella enteritidis, Shigella, Yersinia
enterocolitica |
|
Mention two bacteria causing intestinal infections which have animal reservoirs!
|
Salmonella (not Typhi and Paratyphi!), Campylobacter jejuni, Yersinia
enterocolitica, Listeria monocytogenes, E. coli O157 |
|
What are the modes of transmission for the 2 different epidemiologic forms of plague?
|
- Bubonic plague is transmitted by the bite of infected rat fleas from rats to humans.
- Primary pneumonic plague spreads directly from human to human via respiratory droplets. |
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What are the possible portals of entry of Francisella tularensis? Specify at least 4!
|
tick bite, mucous membranes, skin abrasions, resp. tract, gastroint. tract
|
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How do humans acquire brucellosis? The Brucellae are located primarily in which organ
system and cells? |
Portals of entry are the mucosal surfaces and abraded skin. Organisms spread to the
mononuclear phagocytes of the reticuloendothelial system (lymph nodes, liver, spleen, bone marrow). |
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What are the reservoirs of the different Brucella species, respectively?
|
B. abortus: cattle
B. melitensis: goat, sheep B. suis: swine |
|
What is the mechanism of action of cholera toxin?
|
Cholera toxin activates the adenylate cyclase enzyme in cells of the intestinal mucosa
leading to increased levels of intracellular cAMP, and the secretion of large amount of water, Na+, K+, Cl-, and CO3- into the lumen of the small intestine. |
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What is the principle of the treatment for cholera?
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Rapid intravenous or oral replacement of the lost fluid and ions. Administration of
isotonic maintenance solution should continue until the diarrhea ceases. In severe cases: administration of tetracycline. |
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Mention 4 diseases caused by Haemophilus influenzae!
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purulent meningitis
epiglottitis (obstructive laryngitis) otitis media and sinusitis pneumonia (cellulitis, arthritis) |
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Which disease is caused by Haemophilus ducreyi?
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Chancroid (soft chancre or ulcus molle)
|
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What can serve as source of infections caused by Pseudomonas aeruginosa?
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Pseudomonas species are normally present in the environment and can be isolated from
the skin, throat, and stool of healthy persons. They often colonize hospital food, sinks, taps, mops, and respiratory equipment. |
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Mention 4 diseases that are frequently caused by Pseudomonas aeruginosa!
|
urinary tract infections
wound infections (burns) pneumonia, sepsis (immunosupression) otitis externa |
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Mention at least 3 drugs which may be effective to treat infections caused by
Pseudomonas aeruginosa! |
certain penicillins: piperacillin, piperacillin/tazobactam combination
a 3rd generation cephalosporin: ceftazidim a 4th generation cephalosporin: cefepime certain aminoglycosides: gentamycin, tobramycin, amikacin carbapenems: imipenem, meropenem |
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Which 2 diseases are caused by Legionella pneumophila?
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- legionellosis, legionnairs’ disease (atypical pneumonia)
- Pontiac fever (mild, flu like illness without pneumonia) |
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. List 3 important virulence factors of Bordetella pertussis!
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filamentous hemagglutinin, pertussis toxin, adenylate-cyclase toxin, tracheal
cytotoxin |
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Mention 3 bacterium species causing food poisoning
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Staphylococcus aureus, Bacillus cereus, Clostridium perfringens, Clostridium
botulinum, Vibrio parahaemolyticus, (Salmonella serotypes causing enterocolitis) |
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Which bacterium has the highest germ number in the colon?
|
Bacteroides fragilis
|
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Mention 4 bacterial genera that are obligate anaerobes!
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Clostridium, Bacteroides, Prevotella, Porphyromonas, Fusobacterium, Actinomyces,
Bifidobacterium, Peptostreptococcus, Propionibacterium |
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Which is the most important gas gangrene Clostridium? What is its main virulence factor?
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Clostridium perfringens
alpha-toxin (lecithinase) |
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Mention 3 Clostridium species causing gas gangrene! How are they acquired?
|
Clostridium perfringens, C. novyi, C. septicum, C. histolyticum, C. tertium, C.
bifermentans, C. sporogenes The site of infection is usually a wound that comes into contact with Clostridium spores that germinate in an anaerobic environment. |
|
How can be tetanus prevented in patients who have wounds possibly contaminated with C.
tetani spores? |
Wound should be cleaned and debrided; tetanus toxoid booster injection given;
tetanus immunoglobulin (TETIG) in previously unvaccinated patients and in case of heavy contamination of wound; penicillin may be added prophylactically |
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What are the main symptoms of tetanus infection? Specify at least 3!
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Spastic paralysis: muscle spasms; lockjaw(trismus), rhisus sardonicus (grimace of the
face), opisthotonus (spasm of the back); respiratory paralysis |
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What is the mechanism of action of the botulinus toxin? What symptoms does it cause?
What kind of therapy is available? |
Blocks release of acetylcholine in peripheral nerve synapses; flaccid paralysis: diplopia
(double vision), dysphagia (difficulty to swallow), dysphonia (hoarseness), respiratory paralysis; treatment: respiratory support + trivalent antitoxin |
|
Explain whether or not antibiotic treatment is useful in botulism!
|
Not, because antibiotics are not effective against preformed toxins.
|
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What diseases may be associated with Helicobacter pylori? Specify at least 3!
|
Gastritis, peptic and duodenal ulcers, gastric carcinoma, MALT lymphoma
|
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What is the most important virulence factor of Corynebacterium diphtheriae
|
Diphtheria toxin
|
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What is the mechanism of action of the diphtheria toxin?
|
Inhibits protein synthesis. Inhibits peptide elongation in eukaryotic ribosomes by
ADP ribosylation of EF-2 (elongation factor-2) |
|
How long does immunity against diphtheria exist? Which immune effector mechanism is
involved? |
Antitoxic antibodies, long lasting immunity
|
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Which assays should be done in the lab in order to prove diphtheria?
|
Smears of the throat swab should be stained with methylene blue or Neisser stain;
bacteria are cultured on Löffler’s or tellurite (Clauberg) medium; toxin production must be demonstrated by agar precipitation ( ELEK-test) |
|
What feature of Mycobacteria make them acid fast?
|
The cell envelope contains a high amount (60 – 70 %) of complex lipids: mycolic acid,
cord factor. Once the cells are stained (by carbol-fuchsin) they resist decolorisation by acid-ethanol. |
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Mention 2 atypical Mycobacterium species!
|
M. kansasii, M. marinum, M. avium-intracellulare complex, M. fortuitum-chelonei
complex |
|
How can one demonstrate the presence of Mycobacterium tuberculosis in clinical
samples? |
Acid-fast staining (Ziehl-Neelsen)
Culture on selective media(Löwenstein-Jensen agar, liquid BACTEC medium) PCR amplification of bacterial DNA |
|
Why is multi-drug therapy used for tuberculosis?
|
To prevent the overgrowth of drug-resistant mutants during the long treatment
period (if bacteria resistant to one drug emerge, they are most probably inhibited by the other drugs). |
|
What is the main immune defense mechanism against Mycobacterium tuberculosis?
|
activated macrophages
|
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. Mention 3 antituberculotic drugs that are of first choice against Mycobacterium
tuberculosis! |
isoniazid (INH), pyrazinamid, rifampin, (ethambutol, streptomycin)
|
|
What disease is caused by Mycobacterium avium-intracellulare? What patients are
characteristically susceptible to infection? |
It causes TB, especially in immunosuppressed patients (such as AIDS patients).
|
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What is the reservoir of Mycobacterium tuberculosis?
|
human
|
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What is the reservoir of atypical Mycobacteria?
|
environment (soil, water)
|
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. What are the 2 distinct forms of leprosy?
|
Tuberculoid, lepromatous forms
|
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Mention 3 Gram-negative bacteria belonging to different genera causing zoonosis!
|
Brucella, Francisella tularensis, Yersinia pestis, Pasteurella
|
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Mention 2 Gram-positive bacteria belonging to different genera causing zoonosis
|
Listeria monocytogenes, Bacillus anthracis, Erysipelothrix rhusiopathiae
|
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Mention 3 bacterial species belonging to different genera that are frequent causes of
urinary tract infections! |
E. coli, Klebsiella, Proteus, Pseudomonas, Enterococcus faecalis
|
|
Mention one aerobic and one anaerobic bacterium of the normal flora of the skin!
|
aerobic: Staphylococcus epidermidis
anaerobic: Propionobacterium acnes |
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Give two genuses for each category!
|
Gram positive aerobic: Staph., Strepto., Bacillus, Corynebacterium, Listeria…
Gram positive anaerobic: Clostridium, Actinomyces, Propionibacterium, Lactobacillus Gram negativ aerobic: Vibrio, Neisseria, Haemophilus… Gram negativ anaerobic: Bacteroides, Prevotella, Porphyromonas, Veillonella… |
|
Give 1 example for each category!
|
Gram positive coccus: Staphylococcus, Streptococcus
Gram negative coccus: Neisseria, Veillonella Gram positive rod: Clostridium, Bacillus Gram negative rod: E. coli, Salmonella, Shigella Spirochetes: Treponema, Borrelia, Leptospira |
|
Describe the color and the shape of Clostridia in a Gram stained smear of gas
gangrene exudate! |
Gram positive (dark blue) rod
(it usually does not form spores in vivo) |
|
Mention 2 antibiotics which can be used in the empirical treatment against Gram
negative obligate anaerobic bacteria! |
Imipenem, Augmentin (amoxicillin + clavulanic acid), Metronidazol
|
|
Which 3 bacterial species are the most important causative agents of neonatal (< 1
month of age) meningitis? |
Streptococcus agalactiae, E. coli, Listeria monocytogenes
|
|
Which 3 bacterial species are the most important causative agents of meningitis
among babies (> 1 month of age) and children? |
Neisseria meningitidis, Haemophilus influenzae, Streptococcus pneumoniae
|
|
What is the causative agent of febris undulans (undulant fever)?
|
Brucellae
|
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What is the precise definition of bacterial food poisoning?
|
Acute disease, usually with vomiting and diarrhea, caused by preformed toxins
produced by bacteria contaminating the food. The period between consumption of food and the appearance of symptoms is short (< 4-6 hours). |
|
. Which are the two different kinds of antibodies which may indicate syphilis? Give
examples for tests demonstrating them!: |
Reagin (nonspecific antibody) – RPR, VDRL (flocculation tests)
Immobilisin (specific antibody) – TPHA (T. pallidum hemagglutination), FTA-ABS (fluorescent treponemal assay – with antibody absorption), TPI (T. pallidum immobilisation test), |
|
101. What is the advantage and disadvantage of the FTA-ABS syphilis serologic test
compared to the VDRL test? |
pecific (treponemal) tests such as FTA-ABS are more specific, but they can not be used
to follow the efficacy of treatment (because the specific antibodies persist even after effective eradication of bacteria |
|
What is the drug of first choice in the treatment of syphilis?
|
penicillin
|
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What is the reservoir and what is the vector for Borrelia recurrentis?
|
Reservoir: human; vector: louse
|
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What is used for the laboratory diagnosis of relapsing fever?
|
Direct demonstration of bacteria from peripheral blood smear by microscopy (Giemsa
stain or dark field illumination) |
|
What is the first characteristic symptom of Lyme disease? What is the causative
agent? |
Erythema (chronicum) migrans. Borrelia burgdorferi.
|
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Which antibacterial drugs are of first choice in early stage Lyme disease?
|
Tetracyclines, amoxicillin
|
|
Which symptoms are characteristic for the early and the late phases of disease by
Borrelia burgdorferi? |
Early: erythema chronicum migrans
Late: arthritis, cardiac (myocarditis, pericarditis) and neurological involvement (meningitis, peripheral neuropathies) |
|
What is the reservoir of Leptospira interrogans?
|
rodents, household animals (dog, swine etc.)
|
|
Mention 2 obligate intracellular bacterial genuses!
|
Rickettsia, Chlamydia, (Coxiella, Ehrlichia)
|
|
. Mention 4 bacteria causing atypical pneumonia!
|
Chlamydia pneumoniae
Chlamydia psittaci Coxiella burnetii Mycoplasma pneumoniae Legionella pneumophila |
|
. What diseases are caused by Rickettsia prowazekii?
|
Louse-borne epidemic typhus
Recurrent form: Brill-Zinsser disease |
|
Mention an antibacterial drug active against rickettsial infections!
|
Tetracycline, chloramphenicol
|
|
What are the reservoir and vector of Rickettsia prowazekii infections?
|
reservoir: human; vector: louse
|
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What are the reservoir and vector of Rickettsia typhi infections?
|
reservoir: rodents; vector: flea
|
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What is the causative agent of epidemic typhus?
|
Rickettsia prowazekii
|
|
How can be Chlamydiae and Rickettsiae cultivated?
|
These are obligate intracellular bacteria, can be culture in experimental animals,
embryonated eggs, and cell culture |
|
Mention an antibacterial drug active against chlamydial infections!
|
Tetracycline, erythromycin, azithromycin
|
|
List the serotypes of Chlamydia trachomatis and the diseases caused by them!
|
Types A,B and C: trachoma (chronic conjunctivitis)
Types D-K: genital tract infections (NGU, PID), inclusion conjunctivitis Types L1-L3: lymphogranuloma venereum (STD) |
|
Mention an antibacterial drug effective against Mycoplasma pneumoniae infections!
|
Erythromycin, azythromycin, tetracycline
|
|
. Why are penicillins not effective against Mycoplasma pneumoniae infections?
|
Because of the absence of a cell wall, penicillins are ineffective (penicillins inhibit cell
wall synthesis) |
|
What is the Weil-Felix reaction?
|
It is based on the cross-reaction of an antigen present in many rickettsiae with the O
antigen polysaccharide found in certain Proteus vulgaris strains (OX19 OX2, OXK). The test is a tube agglutination test in which these proteus strains are used as antigens to demonstrate antibodies from the patient’s serum sample. |
|
Mention 4 bacteria frequently causing sexually transmitted diseases (STD)!
|
Treponema pallidum, Neisseria gonorrhoeae, Haemophilus ducreyi, Chlamydia
trachomatis, Calymmatobacterium granulomatis |
|
Which bacterial species can cause hepatitis (jaundice)?
|
Leptospira interrogans
|
|
Mention 2 bacteria causing aseptic (serous) meningitis!
|
Treponema pallidum, Leptospira interrogans, Borrelia burgdorferi
|
|
Mention a bacterial pathogen which eludes the host immune response by frequent
antigenic changes! |
Borrelia recurrentis, Neisseria gonorrhoeae
|
|
. What is the causative agent of febris recurrens (recurrent fever)?
|
Borrelia recurrentis
|
|
What does fungal dimorphism mean?
|
The same species is capable of existing in two morphological forms (yeast or mold),
depending upon enviromental conditions (temperature, nutrients). |
|
Which are the fungi causing systemic infections?
|
Coccidioides immitis, Histoplasma capsulatum, Blastomyces dermatitidis, Paracoccidioides
brasiliensis |
|
Mention 3 species causing opportunistic fungal infections!
|
Candida albicans, Cryptococcus neoformans, Aspergillus fumigatus, Mucor spp., Rhizopus
spp. |
|
Mention 3 diseases caused by dermatophytons!
|
Tinea corporis, tinea capitis, onychomycosis, tinea barbae
|
|
Which fungal genera have species belonging to the dermatophytons?
|
Trichophyton, Microsporum, Epidermophyton
|
|
What is the route of transmission of Sporothrix schenkii?
|
Traumatically introduced into the skin.
|
|
Mention a Candida infection associated with mucosal surfaces!
|
Soor, vulvovaginitis
|
|
Which fungal species is the most important causative agent of meningitis?
|
Cryptococcus neoformans
|
|
What are the characteristics manifestations of Candida albicans infections in AIDS?
|
generalised oral candidiasis (GOC), oesophagitis, endocarditis, sepsis
|
|
What are the different forms of pulmonary aspergillosis?
|
1. Aspergillus ball (in preformed cavities)
2. invasive aspergillosis (in immunosuppression) 3. allergic bronchopulmonary aspergillosis |
|
What is the usual source of infection in systemic mycoses?
|
soil
|
|
What is the usual site of entry of fungi causing systemic mycoses?
|
respiratory tract (inhalation)
|
|
Which morphological form of Coccidioides immitis can be found in the human body?
|
spherule
|
|
Which human pathogenic fungus has a capsule?
|
Cryptococcus neoformans
|
|
What are the main symptoms in the different stages of syphilis?
|
Primary syphilis: nontender ulcer (hard chancre)
Secondary lesions: maculopapular rash on skin, and condylomata lata on mucous membranes Tertiary stage: granulomas (gummas), central nervous system involvement (tabes dorsalis, paralysis progressiva), cardiovascular lesions (aortitis, aorta aneurysm) |
|
When syphilis is diagnosed in the lab, which antigens are used in the non-treponemal and
in the specific treponemal antibody tests, respectively? |
Non-treponemal antibody tests: cardiolipin
Specific treponemal antibody tests: Treponema pallidum |