3Rd Year Microbiology Ii Sct

Front 1

5 diseases by Staph Aureus ?

Back 1

Impetigo, Furunculus, Pneumonia, Osteomyelitis, Food poisoning

Front 2

2 toxin mediated Staphyloccal diseases

Back 2

Toxic Shock syndrome (TSS), Scalded Skin Syndrome (SSS)

Front 3

3 toxic products of Staph Aureus

Back 3

TSST, Enterotoxin, Leukocidin

Front 4

Most viruent species of Staphylococcus

Back 4

Aureus

Front 5

Enzymatic virulence factor -exclusive- for Staph Aureus

Back 5

Coagulase

Front 6

How can we identify the source of infection in a staphylococcal food poisoning?

Back 6

Phage Typing

Front 7

Which antibacterial drug is the first choice in serious infections caused by methycillin
resistant Staphylococcus aureus (MRSA) strains?

Back 7

Vancomycin

Front 8

In which disease is Staphylococcus saprophyticus considered an obligate pathogen?

Back 8

Cystitis in young women

Front 9

Which cell constituents determine the group-specific, and the type specific antigens of
Streptococcus pyogenes, respectively?

Back 9

Group specific : C-Polysaccharide
Type specfici : M protein

Front 10

Mention 3 enzymes produced by Streptococcus pyogenes that enhance the spread of
the bacterial infection in the body!

Back 10

Streptokinase (fibrinolysin), hyaluronidase, streptodornase (DNAse)

Front 11

List 3 diseases caused by Streptococcus pyogenes in the skin or in subcutaneous
tissues!

Back 11

Impetigo(Pyoderma), Cellulitis, Fasciitis

Front 12

Mention a toxin-mediated streptococcal disease, specify the name of the toxin and its
mechanism of action!

Back 12

Scarlet fever - erythrogenic toxin – superantigen causing capillary destruction

Front 13

2 Post-streptococcal diseases

Back 13

Golmerulonephritis, Rheumatic fever

Front 14

Which product of Streptococcus pyogenes has a major pathogenic role in
poststreptococcal diseases?

Back 14

M Protein : May induce hyper--sensitivity reaction

Front 15

How long does immunity against scarlet fever exist? Which immune effector
mechanism is involved?

Back 15

Life-long immunity. Antitoxic antibodies are involved.

Front 16

What is the drug of first choice in Streptococcus pyogenes infection?

Back 16

Penicillin-G

Front 17

What is the patomechanism of post-streptococcal rheumatic fever?

Back 17

Type II Hyper-sensitivity (Cytotoxic Antibodies)

Front 18

What is the patomechanism of post-streptococcal glomerulonephritis?

Back 18

Type III Hyper-sensitivity (Immune complexes)

Front 19

Which Streptococcus species plays major role in the meningitis of newborn babies?

Back 19

Group B Strep (S.Agalactiae

Front 20

What is the major causative agent for subacute bacterial endocarditis?

Back 20

Streptococcus Viridans

Front 21

What are the characteristics of Enterococci that can be used in their identification?

Back 21

D group polysaccharide antigen; tolerance to bile and hydrolysis of esculin (BEA
medium: bile esculin agar); growth in the presence of 6,5 % NaCl

Front 22

What are the specific morphologic features of Streptococcus pneumoniae

Back 22

Gram positive diplococcus, lancet shape, capsule

Front 23

3 diseases that can be caused by Streptococcus pneumoniae

Back 23

Pneumonia, meningitis, sinusitis

Front 24

What fast diagnostic procedure can be used in acute Neisseria gonorrhoeae infection?

Back 24

Demonstration of bacteria (intracellular in PMNs) from urethral discharge by Gram
or methylene blue stain

Front 25

What kind of immunity develops after Neisseria gonorrhoeae infection?

Back 25

Partial immunity of short duration, no protection from reinfection

Front 26

Most important manifestations of disseminated gonorrhoeal infections

Back 26

Arthritis, Skin erutption, Meningitis, Endocarditis

Front 27

major complication of Neisseria gonorrhoeae infection in newborns? How
can it be prevented?

Back 27

Blenorrhoea (ophtalmia) neonatorum, silver acetate eye drops or erythromycin
ointment

Front 28

4 major virulence factors of Neisseria gonorrhoeae?

Back 28

pilus, outer membrane proteins, LOS (lipooligosaccharide), IgA protease

Front 29

3 major virulence factors of Neisseria meningitidis?

Back 29

polysaccharide capsule, LPS, IgA protease

Front 30

What is the site of entry Neisseria meningitidis infection? What diseases are caused by
this bacterium?

Back 30

The site of entry is the nasopharynx. Diseases: Meningococcemia, Acute bacterial meningitis

Front 31

What kinds of prophylactic and therapeutic measurements are available against
Neisseria meningitidis infections?

Back 31

Chemoprophylaxis: rifampin or ciprofloxacin.
Vaccination: capsular polysaccharide (types A, C, Y and W135). No vaccine against
type B!

Front 32

Which rapid diagnostic methods can be used in the presumptive diagnosis of purulent
bacterial meningitis?

Back 32

Gram or methylene blue stain of CSF sediment,
Demonstration of bacterial capsular antigens by latex agglutination (from CSF)

Front 33

3 pathogenic bacteria that account for the majority of purulent meningitis

Back 33

Neisseria meningitidis, Haemophilus influenzae, Streptococcus pneumoniae

Front 34

Which are the portals of entry of Bacillus anthracis?

Back 34

Skin, lung, gastrointestinal tract

Front 35

3 important bacteria involved in nosocomial (hospital-acquired) infections!

Back 35

Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aer

Front 36

4 E. coli pathogenetic groups involved in enteric diseases!

Back 36

Enteropathogenic E. coli (EPEC)
Enterotoxic E. coli (ETEC)
Enteroinvasive E. coli (EIEC)
Enterohemorrhagic E. coli (EHEC)

Front 37

most important extraintestinal infections caused by E. coli?

Back 37

urinary tract infections, neonatal meningitis, nosocomial wound infections

Front 38

most frequent causative agent of urinary tract infections is

Back 38

Escherichia coli

Front 39

What disease is caused by E. coli O157:H7?

Back 39

hemorrhagic colitis +/- HUS (hemolytic uraemic syndrome)

Front 40

What is the reservoir of Salmonella typhi?

Back 40

humans (with disease, or healthy carriers)

Front 41

Which bacteria cause most frequently typhoid fever and enteric fever?

Back 41

Salmonella typhi (typhoid)
Salmonella paratyphi A, B, C (enteric fever)

Front 42

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?

Back 42

Blood, (bone marrow)

Front 43

What is the route of infection in Salmonella gastroenteritis of otherwise healthy adults?

Back 43

Ingestion of contaminated food containing a sufficient number of Salmonella (such as
eggs, cream...)

Front 44

Which antibacterial drugs should be administered in gastroenteritis by Salmonella?

Back 44

Antibiotics are not usually necessary unless the infection spreads from the intestines.
In case of extraintestinal infection (very young, very old or immunosuppressed
patients): ampicillin, gentamicin, trimethoprim/sulfamethoxazole, or ciprofloxacin.

Front 45

List the Shigella species causing human disease!

Back 45

Shigella dysenteriae, S. flexneri, S. boydii, S. sonnei

Front 46

2 bacterial species belonging to different genera that cause bacillary dysentery

Back 46

Shigella dysenteriae,enteroinvasive
E. coli (EIEC)

Front 47

Mention 3 bacterial species belonging to different genera that cause enteritis or
enterocolitis!

Back 47

Campylobacter jejuni, Escherichia coli, Salmonella enteritidis

Front 48

two bacteria causing intestinal infections which have animal reservoirs!

Back 48

Campylobacter jejuni, Yersinia
enterocolitica,

Front 49

Yersinia pestis may infect humans in 2 ways resulting in 2 different courses of disease.
How is plague acquired? How are the 2 different forms of plague termed?

Back 49

- Bubonic plague is transmitted by the bite of infected rat fleas.
- The pneumonic form spreads directly from human to human via respiratory droplets.

Front 50

What are the possible portals of entry of Francisella tularensis?

Back 50

tick bite, mucous membranes, skin abrasions, resp. tract, gastroint. tract

Front 51

How do humans acquire brucellosis? The Brucellae are located primarily in which organ
system and cells?

Back 51

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).

Front 52

What are the reservoirs of the Brucella species, respectively?

Back 52

B. abortus: cattle
B. melitensis: goat, sheep
B. suis: swine

Front 53

What is the mechanism of action of the cholera toxin?

Back 53

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 HCO3
- into the lumen of the small intestine.

Front 54

How to treat a patient suffering from cholera?

Back 54

How to treat a patient suffering from cholera?
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.

Front 55

4 diseases caused by Haemophilus influenzae!

Back 55

purulent meningitis
epiglottitis (obstructive laryngitis)
otitis media and sinusitis
pneumonia

Front 56

Which disease is caused by Haemophilus ducreyi?

Back 56

Chancroid (soft chancre or ulcus molle). Sexually transmitted disease (STD).

Front 57

What can serve as source of infections by Pseudomonas aeruginisa?

Back 57

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.

Front 58

4 diseases that are frequently caused by Pseudomonas aeruginosa!

Back 58

urinary tract infections
wound infections (burns)
pneumonia, sepsis (immunosupression)
otitis externa

Front 59

Mention at least 3 drugs which may be effective to treat infections caused by
Pseudomonas aeruginosa!

Back 59

penicillins: piperacillin
3. generation cephalosporins: ceftazidim,
aminoglycosides:tobramycin, carbapenems: imipenem

Front 60

Which diseases are caused by Legionella pneumophila?

Back 60

- atypical pneumonia (legionellosis, legionnaires disease)
- Pontiac fever (mild, flu like illness without pneumonia)

Front 61

4 important virulence factors of Bordetella pertussis!

Back 61

filamentous hemagglutinin, pertussis toxin, adenylate-cyclase toxin, tracheal
cytotoxin

Front 62

3 bacterium species causing food poisoning!

Back 62

Staphylococcus aureus, Clostridium perfringens, Clostridium
botulinum

Front 63

Which bacterium has the highest germ number in the colon?

Back 63

Bacteroides fragilis

Front 64

4 bacterial genera that are obligate anaerobes!

Back 64

Clostridium, Bacteroides, Prevotella, Porphyromonas,

Front 65

Which is the most important gas gangrene Clostridium? What is its main virulence factor?

Back 65

Clostridium perfringens
alpha-toxin (lecitinase)

Front 66

Mention 3 gas gangrene Clostridium species! How are they acquired?

Back 66

Clostridium perfringens, C. novyi, C. septicum.
The site of infection is usually a wound that comes into contact with C. perfringens spores
that germinate in an anaerobic environment.

Front 67

How can be tetanus prevented in patients who have wounds possibly contaminated with C.
tetani spores?

Back 67

Wound should be cleaned and debrided; tetanus toxoid; tetanus immunoglobulin
(TETIG) in previously unvaccinated patients and in case of heavy contamination of
wound; penicillin may be added prophylactically

Front 68

What are the main symptoms of tetanus infection?

Back 68

Spastic paralysis: muscle spasms; lockjaw(trismus), rhisus sardonicus (grimace of the
face), opisthotonus (spasm of the back); respiratory paralysis

Front 69

What is the mechanism of action of the botulinus toxin? What symptoms does it cause?
What kind of therapy is available?

Back 69

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

Front 70

Explain whether or not antibiotic treatment is useful in botulism!

Back 70

Not, because antibiotics are not effective against preformed toxins.

Front 71

What diseases are caused by Helicobacter pylori?

Back 71

Gastritis, peptic and duodenal ulcers, gastric carcinoma, MALT lymphoma

Front 72

What is the most important virulence factor of Corynebacterium diphtheriae?

Back 72

Diphtheria toxin

Front 73

What is the mechanism of action of the diphtheria toxin?

Back 73

Inhibits protein synthesis. Inhibits peptide elongation in ribosomes by ADP
ribosylation of EF-2 (elongation factor-2)

Front 74

How long does immunity against diphtheria exist? Which immune effector mechanism is
involved?

Back 74

Antitoxic antibodies, long lasting immunity

Front 75

Which assays should be done in the lab in order to prove diphtheria?

Back 75

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)

Front 76

What feature of Mycobacteria make them acid fast?

Back 76

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.

Front 77

2 atypical Mycobacterium species!

Back 77

M. kansasii, M. marinum

Front 78

How can one demonstrate the presence of Mycobacterium tuberculosis in clinical
samples?

Back 78

Acid-fast staining (Ziehl-Neelsen)
Culture on selective media(Löwenstein-Jensen agar, liquid BACTEC medium)
PCR amplification of bacterial DNA

Front 79

Why is multi-drug therapy used for tuberculosis?

Back 79

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).

Front 80

What is the main immune defense mechanism against Mycobacterium tuberculosis?

Back 80

activated macrophages

Front 81

Mention 3 antituberculotic drugs that are of first choice against Mycobacterium
tuberculosis!

Back 81

isoniazid (INH), pyrazinamid, rifampin

Front 82

What disease is caused by Mycobacterium avium-intracellulare? What patients are
characteristically susceptible to infection?

Back 82

It causes TB, especially in immunosuppressed patients (such as AIDS patients).

Front 83

What is the reservoir of Mycobacterium tuberculosis?

Back 83

human

Front 84

What is the reservoir of atypical Mycobacteria?

Back 84

environment (soil, water)

Front 85

What are the 2 distinct forms of leprosy?

Back 85

Tuberculoid, lepromatous forms

Front 86

3 Gram-negative bacteria belonging to different genera causing zoonosis

Back 86

Brucella, Francisella tularensis, Yersinia pestis

Front 87

2 Gram-positive bacteria belonging to different genera causing zoonosis!

Back 87

Listeria monocytogenes, Bacillus anthracis

Front 88

3 bacterial species belonging to different genera that are frequent causes of
urinary tract infections!

Back 88

E. coli, Klebsiella, Proteus

Front 89

one aerobic and one anaerobic bacterium of the normal flora of the skin!

Back 89

aerobic: Staphylococcus epidermidis
anaerobic: Propionobacterium acnes

Front 90

2 Genuses for each category :
Gram + aerobic Gram + anaerobic, Gram - Aeorbic, Gram - Anaerobic

Back 90

Gram + Aerobic : Staph, Strep
Gram + Anaerobic : Clostridium, Lactobacillus
Gram - Aerobic : Vibrio, Nisseria
Gram - Anerobic : Bacteroids, Prevotella

Front 91

1 example for each category!
Gram + Coccus, Gram - Coccus, Gram + rod, Gram - rod, Spirochetes

Back 91

Gram positive coccus: Streptococcus
Gram negative coccus: Neisseria
Gram positive rod: Bacillus
Gram negative rod: E. coli
Spirochetes: Treponema

Front 92

Describe the color and the shape of Clostridia in a Gram stained smear of gas
gangrene exudate!

Back 92

Gram positive (dark blue) rod

Front 93

2 antibiotics which can be used in the empirical treatment against Gram
negative obligate anaerobic bacteria!

Back 93

Imipenem, Augmentin (amoxicillin + clavulanic acid)

Front 94

Which 3 bacterial species are the most important causative agents of neonatal (< 1
months of age) meningitis?

Back 94

Streptococcus agalactiae, E. coli, Listeria monocytogenes

Front 95

Which 3 bacterial species are the most important causative agents of meningitis
among babies (> 1 months of age) and children?

Back 95

Neisseria meningitidis, Haemophilus influenzae, Streptococcus pneumoniae

Front 96

What is the causative agent of febris undulans (undulant fever)?

Back 96

Brucellae

Front 97

What is the precise definition of bacterial food poisoning?

Back 97

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)