Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
111 Cards in this Set
- Front
- Back
|
List 3 important virulence factors of Bordetella pertussis!
|
filamentous hemagglutinin, pertussis toxin, adenylate-cyclase toxin, tracheal
cytotoxin |
|
|
. Mention 3 bacterium species causing food poisoning!
|
<b> Staphylococcus aureus, Bacillus cereus, Clostridium perfringens, Clostridium
botulinum, Vibrio parahaemolyticus, </b> (Salmonella serotypes causing enterocolitis |
|
|
Which bacterium has the highest germ number in the colon?
|
Bacteroides fragilis
|
|
|
Mention 4 bacterial genera that are obligate anaerobes!
|
Clostridium,
Bacteroides, Prevotella, Porphyromonas, Fusobacterium, Actinomyces, Bifidobacterium, Peptostreptococcus, Propionibacterium |
|
|
Which is the most important gas gangrene Clostridium? What is its main virulence factor?
|
Clostridium perfringens
alpha-toxin (lecithinase) |
|
|
Mention 3 Clostridium species causing gas gangrene! How are they acquired?
|
<b> Clostridium perfringens, C. novyi, C. septicum, C. histolyticum, </b>
, 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 <b> anaerobic environment. </b> |
|
|
How can be tetanus prevented in patients who have wounds possibly contaminated with C.
tetani spores? |
Wound should be <b> cleaned and debrided; tetanus toxoid booster injection given;
tetanus immunoglobulin </b> (TETIG) in previously unvaccinated patients and in case of heavy contamination of wound; penicillin may be added prophylactically |
|
|
What are the main symptoms of tetanus infection? Specify at least 3!
|
Spastic paralysis: muscle spasms; <b> lockjaw(trismus), rhisus sardonicus (grimace of the
face), opisthotonus (spasm of the back); respiratory paralysis </b> |
|
|
What is the mechanism of action of the botulinus toxin?
|
Blocks release of acetylcholine in peripheral nerve synapses
|
|
|
What are the main symptoms of botulism? Specify at least 3!
|
flaccid paralysis: diplopia (double vision), dysphagia (difficulty to swallow), dysphonia (hoarseness), respiratory paralysis
|
|
|
What kind of therapy is used to treat botulism?
|
Treatment: respiratory support + <b> trivalent antitoxin </b>
|
|
|
Explain whether or not antibiotic treatment is useful in botulism!
|
Not, because antibiotics are not effective against preformed toxins
|
|
|
What diseases may be associated with Helicobacter pylori? Specify at least 3!
|
Gastritis, peptic and duodenal ulcers, gastric carcinoma, MALT lymphoma
|
|
|
What is the most important virulence factor of Corynebacterium diphtheriae?
|
Diphtheria toxin
|
|
|
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
|
|
|
Which assays should be done in the lab in order to prove diphtheria?
|
Smears of the <b> throat swab should be stained with methylene blue or Neisser stain </b> ;
bacteria are <b> cultured on Löffler’s or tellurite (Clauberg) medium ; toxin production </b> must be demonstrated by <b> agar precipitation </b> ( 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. |
|
|
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
|
|
|
Mention 3 antituberculotic drugs that are of first choice against Mycobacterium
tuberculosis! |
isoniazid (INH)
pyrazinamid rifampin (ethambutol, streptomycin*) *discontinued |
|
|
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)
|
|
|
What is the reservoir of Mycobacterium tuberculosis?
|
human
|
|
|
What is the reservoir of atypical Mycobacteria?
|
environment (soil, water)
|
|
|
What are the 2 distinct forms of leprosy?
|
Tuberculoid
lepromatous forms |
|
|
Mention 3 Gram-negative bacteria belonging to different genera causing zoonosis!
|
Brucella
Francisella tularensis Yersinia pestis Pasteurella |
|
|
Mention 2 Gram-positive bacteria belonging to different genera causing zoonosis!
|
Listeria monocytogenes
Bacillus anthracis Erysipelothrix rhusiopathiae |
|
|
Mention 3 bacterial species belonging to different genera that are frequent causes of
urinary tract infections! |
E. coli
Klebsiella Proteus Pseudomonas aeruginosa Enterococcus faecalis |
|
|
Mention one aerobic and one anaerobic bacterium of the normal flora of the skin!
|
aerobic: Staphylococcus epidermidis
anaerobic: Propionobacterium acnes |
|
|
Give two genuses for each category of bacteria!
|
Gram positive aerobic: Staphylococcus, Streptococcus, Bacillus, Corynebacterium
Gram positive anaerobic: Clostridium, Actinomyces, Propionibacterium, Lactobacillus |
|
|
Give two genuses for each category of bacteria!
|
Gram negativ aerobic: Vibrio, Neisseria, Haemophilus
Gram negativ anaerobic: Bacteroides, Prevotella, Porphyromonas, Veillonella |
|
|
Give 2 genuses for each category of bacteria!
|
Gram positive coccus: Staphylococcus, Streptococcus
Gram negative coccus: Neisseria, Veillonella Gram positive rod: Clostridium, Bacillus |
|
|
Give 2 genuses for each category of bacteria!
|
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!
|
Metronidazol
amoxicillin + clavulanic acid imipenem |
|
|
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
|
|
|
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) |
|
|
Mention 5 diseases that can be caused by Staphylococcus aureus!
|
<b> Impetigo
Furunculus Pneumonia Osteomyelits Food poisoning </b> |
|
|
Mention 2 toxin-mediated staphylococcal diseases!
|
TSS*
Scalded Skin Syndrome Food Poisoning (Toxic Shock Syndrome) |
|
|
Mention 3 toxic products produced by Staphylococcus aureus!
|
<b> TSST*
Hemolysins Enteroxin Exfolatin Leukocidins</b> *(Toxic Shock Syndrome Toxin) |
|
|
Which is the most virulent species of Staphylococcus?
|
<b> S. aureus </b>
|
|
|
Which enzymatic virulence factor is characteristic exclusively for Staphylococcus aureus?
|
<b> Coagulase </b>
|
|
|
How can we identify the source of infection in a staphylococcal food poisoning?
|
By phage typing
|
|
|
Which antibacterial drug is the first choice in serious infections caused by methycillin
resistant Staphylococcus aureus (MRSA) strains? |
<b> Glycopeptides (Vancomycin, Teicoplanin) </b>
|
|
|
In which disease is Staphylococcus saprophyticus considered an obligate pathogen!
|
cystitis in young women
|
|
|
Which cell constituents determine the group-specific, and the type specific antigens of
Streptococcus pyogenes, respectively? |
group specific: C-polysaccharide
type specific: M protein |
|
|
Mention 3 enzymes produced by Streptococcus pyogenes that enhance the spread of
the bacterial infection in the body! |
Streptokinase (fibrinolysin)
Hyaluronidase Streptodornase (DNase) |
|
|
List 3 diseases caused by Streptococcus pyogenes in the skin or in subcutaneous
tissues! |
Myositis
Impetigo (pyoderma) Cellulitis Erysipelas Fascitis |
|
|
Mention a toxin-mediated streptococcal disease, specify the name of the toxin and its
mechanism of action! |
Scarlet fever
Erythrogenic toxin Superantigen causing papillary destruction |
|
|
Mention 2 poststreptococcal diseases!
|
<b> Glomerulonephritis
Rheumatic fever </b> Erythema nodosum Chorea minor |
|
|
Which product of Streptococcus pyogenes has a major pathogenic role in poststreptococcal diseases?
|
<b> M protein </b> may induce hypersensitivity reactions
|
|
|
How long does immunity against scarlet fever exist? Which immune effector mechanism is involved?
|
Life-long immunity. Antitoxic antibodies are involved.
|
|
|
What is the drug of first choice in Streptococcus pyogenes infection?
|
Penicillin-G
|
|
|
What is the patomechanism of post-streptococcal rheumatic fever?
|
Type II Hypersensitivity (cytotoxic antibodies)
|
|
|
What is the patomechanism of post-streptococcal glomerulonephritis?
|
Type III Hypersensitivity (immune complexes)
|
|
|
Which Streptococcus species plays major role in the meningitis of newborn babies?
|
Group B Streptococcus (S. agalactiae)
|
|
|
What is (are) the major causative agent(s) for subacute bacterial endocarditis?
|
Viridens streptococci
|
|
|
What are the characteristics of Enterococci that can be used in their identification?
|
> D group polysaccharide antigen
> Tolerence to bile and hydrolysis of esculin (BEA medium: bile eusculin agar) > Growth in presence of 6.5% NaCl |
|
|
What are the specific morphologic features of Streptococcus pneumoniae?
|
Gram positive diplococcus
Lancet shape Capsule |
|
|
Mention 3 diseases that can be caused by Streptococcus pneumoniae!
|
<b> Pneumonia
Meningitis Sinusitis Otitis media Sepsis </b> Ulcus serpens corneae |
|
|
What fast diagnostic procedure can be used in acute Neisseria gonorrhoeae infection?
|
<b> Demonstration of bacteria (intracellular PMNs) from urethral discharge by Gram or methylene blue stain </b>
PCR amplification of bacterial DNA |
|
|
What kind of immunity develops after Neisseria gonorrhoeae infection?
|
Partial immunity of short duration
No protection from reinfection |
|
|
Specify at least 2 of the most important manifestations of disseminated gonorrhoeal
infections! |
<b> Arthritis
Skin eruptions </b> endocarditis meningitis |
|
|
What is the major manifestation of Neisseria gonorrhoeae infection in newborns?
How can it be prevented? |
Manifestation: Blenorrhea (opthalmia) neonatorum
Prevention: Silver acetate eye drops or erythromycin ointment |
|
|
Mention at least 3 major virulence factors of Neisseria gonorrhoeae!
|
Pilus
Outer Membrane Proteins LOS (lipooligosaccharride) IgA protease |
|
|
Mention at least 2 major virulence factors of Neisseria meningitidis!
|
Polysaccharride capsule
LPS IgA protease |
|
|
What is the site of entry of Neisseria meningitidis infection?
Which diseases are caused by this bacterium? |
Site of entry: <b> Nasopharynx </b> (transmitted by airborne droplets
<b> Meningococcemia </b> (characterised by skin lesions) and by acute (purulent) bacterial <b> meningitis </b> |
|
|
What kinds of prophylactic measurements are available against Neisseria meningitidis
infections? |
Chemoprophylaxis: Rifampin or Ciprofloxacin
Vaccination: Capsular polysaccharide (types A, C, Y & W135). No vaccine against type B |
|
|
Which rapid diagnostic methods can be used in the presumptive diagnosis of purulent bacterial meningitis?
|
Gram or methylene stain of CSF sediment
Demonstration of bacterial capsular antigens by latex aggregation (from CSF) |
|
|
Which capsular serotype is included in the vaccine against Haemophilus influenzae?
|
type B
|
|
|
Which are the portals of entry of Bacillus anthracis?
|
Skin
Lungs Gastrointestinal tract |
|
|
Mention 3 important bacteria involved in nosocomial (hospital-acquired) infections!
|
Staphlococcus aureus
Enterococcus faecalis Pseudomonas aeruginosa Escherichia coli |
|
|
Mention four E. coli pathogenetic groups involved in enteric diseases!
|
<b> Enteropathogenic E. coli </b> (EPEC)
<b> Enterotoxic E. coli </b> (ETEC) <b> Enterovasive E. coli </b> (EIEC) <b> Enterohemorrhagic E. coli </b> (EHEC) Enteroaggregatvie E. coli (EAggEC) |
|
|
What are the most important extraintestinal infections caused by E. coli?
Mention at least 3 of them! |
Urinary tract infections
Neonatal meningitis Nosocomial wound infections |
|
|
The most frequent causative agent of urinary tract infections is:
|
Escherichia coli
|
|
|
Which 2 diseases are caused by E. coli O157:H7?
|
haemorrhagic colitis +/- HUS (hemolytic uraemic syndrome)
|
|
|
What is the reservoir of Salmonella typhi?
|
humans (with disease or healthy carriers)
|
|
|
Which bacteria cause most frequently typhoid fever and enteric fever, respectively?
|
Salmonella typhi (typhoid)
Salmonella paratyphi A, B, C (enteric fever) |
|
|
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? |
<b> Blood </b>
Bone marrow |
|
|
What is the route of infection in Salmonella gastroenteritis?
|
<b> Ingestion of contaminated food </b> such as eggs, cream, mayonaisse, creamed foods etc) <b> containing a sufficient number of Salmonella </b>
|
|
|
Which antibacterial drugs should be administered in gastroenteritis caused by Salmonella?
|
Antibiotics are not usually necessary unless the infection is generalised.
In cases of extraintestinal infection (very young, very old or immunosuppressed patients) Ampicillin, Gentamicin, Trimethoprim/ Sulfamethoxozale or Ciproflaxin |
|
|
List the 4 Shigella species causing human disease!
|
S. dysenteriae
S. flexneri S. boydii S. sonnei |
|
|
Mention 2 bacterial species belonging to different genera that cause bacillary dysentery
|
Shigella dysenteriae </b> (S. flenxeri, boydii & sonnei)
<b> enteroinvasive E. coli (EIEC) |
|
|
Mention 3 bacterial species belonging to different genera that cause enteritis or enterocolitis!
|
Campylobacter jejuni
Escherichia coli Salmonella enteritis Shigella Yersinia enterocolitica |
|
|
Mention 2 bacteria causing intestinal infections which have animal reservoirs!
|
Salmonella (not Typhi or Paratyphi)
Campylobacter jejuni Yersinia enterocolitica |
|
|
What are the modes of transmission for the 2 different epidemiologic forms of plague?
|
<u> Bubonic Plague </u> : transmitted by the bite of infected rat fleas from rats to humans
<u> Primary Pneumonic Plague </u> : spreads directly from human to human via respiratory droplets |
|
|
What are the possible portals of entry of Francisella tularensis? Specify at least 4!
|
Tick bite
Mucous membranes Skin abrasions Resp. tract GI tract |
|
|
How do humans acquire brucellosis? Where do the bacteria replicate in the human body?
|
Via contaminated milk products or through skin abrasions (contact with animals). Organisms spread to mononuclear phagocytes of the reticuloendothelial system (lymph nodes, spleen, liver, bone marrow)
|
|
|
What are the reservoirs of the different Brucella species, respectively?
|
B. arbotus: 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 the cells of the intestinal mucosa leading to <b> increased levels of intracellular cAMP </b> and the <b> secretion of large amount of water, K+, Na+, Cl- and HCO3- in the lumen <b/> of the small intestine
|
|
|
What is the principle of the treatment for cholera?
|
Rapid intravenous or oral <b> replacement of the lost fluid and ions </b>.
(Administration of isotonic maintenance solution should continue until the diarrhoea ceases). In severe cases administration of tetracycline (in addnt to rehydration). |
|
|
Mention 4 diseases caused by Haemophilus influenzae!
|
<b> Purulent meningitis
Epiglottitis (obstructive laryngitis) otitis media and sinustitis pneumonia </b> cellulitis arthritis |
|
|
Which disease is caused by Haemophilus ducreyi?
|
Chancroid (soft chancre or ulcus molle)
|
|
|
What can serve as source of infections caused by Pseudomonas aeruginosa?
|
Pseudonomas species are normally present in the <b> environment </b> and can be isolated from <b> skin, throat and stool </b> of some healthy persons.
They often colonise hospital food, sinks, mops, and respiratory equipment. |
|
|
Mention 4 diseases that are frequently caused by Pseudomonas aeruginosa!
|
Urinary Tract Infections
Wound infections (burns) pneumonia, sepsis (immunosuppression) otitis externa |
|
|
Mention at least 3 drugs which may be effective to treat infections caused by Pseudomonas aeruginosa!
|
certain penicillins: <b> piperacillin/tazobactam combo
3rd gen cephalosporin: <b> ceftazidim </b> 4th gen cephalosporin: <b> cefepime </b> certain aminoglycosides: gentamycin, <b> tobramycin, amikacin </b> carbapenams: <b> imipenam </b> meropenam |
|
|
Which 2 diseases are caused by Legionella pneumophila?
|
<b> legionellosis, legionaires's disease </b> (atypical pneumonia)
<b> Pontiac fever </b> (mild, flu-like illness without pneumonia) |
|
|
List 3 important virulence factors of Bordetella pertussis!
|
filamentous hemagglutinin
pertussis toxin adenylate-cyclase toxin tracheal cytotoxin |
|
|
Mention 3 bacterium species causing food poisoning!
|
Staphlococcus aureus
Bacillus cereus Clostridium perfingens Clostridium botulinum Vibrio parahaemolyticus (Salmonella serotypes causing enterocolitis) |
|
|
Which bacterium has the highest germ number in the colon?
|
Bacteroides fragilis
|
|
|
Mention 4 bacterial genera that are obligate anaerobes!
|
Actinomyces
Bacteroides Bifidobacterium Clostridium Fusobacterium Peptostreptococcus Porphyrommas Propionibacterium Prevotella |
|
|
Which is the most important gas gangrene Clostridium?
What is its main virulence factor? |
Clostridium perfingens
alpha toxin (lecithinase) |
|
|
Mention 3 Clostridium species causing gas gangrene!
How are they acquired? |
<b> Clostridium perfingens,
C. novyi, C. septicum, C histolyticum </b> C. tertium, C. bifermentans, C. sporogenes Site of infection is usually a wound that comes in contact with Clostridium spores that germinate <b> in an anaerobic environment </b> |
|
|
How can be tetanus prevented in patients who have wounds possibly contaminated with C. tetani spores?
|
Wound should be <b> cleaned and debrided; tetanus toxoid booster injection given
tetanus immunoglobulin </b> (TETIG) given in previously unvaccinated patients and in case of heavy contamination of wound penicillin may be added prophylactically |
|
|
What are the main symptoms of tetanus infection? Specify at least 3!
|
<b> lockjaw (trismus)
rhisus sardonicus (grimace of the face) opisthotonus (spasm of back) respiratory paralysis </b> Spastic paralysis Muscle spasms |
|
|
What is the mechanism of action of the botulinus toxin?
|
<b> Blocks release of acetylcholine </b> in peripheral nerve synapses
|
|
|
What are the main symptoms of botulism? Specify at least 3!
|
Flaccid paralysis
Diplopia (double vision) Dysphagia (difficulty swallowing) Dysphonia (hoarseness) Respiratory paralysis |
