PART 2- Hussein Exam 1

BASED OF SG I REPEAT BASED OFF SG

Inflammation leads to a low grade fever which leads to…

increase phagocytosis

What’s the definition of epidemic?

a. an endemic that spreads throughout the world

b. present in high but constant level in an area/region

c. more cases than predicted within a certain community, used to describe disease outbreaks

d. total number of cases existing in a community at a given time

c

What’s the definition of endemic?

a. an epidemic that spreads throughout the world

b. present in low but constant level in an area/region

c. more cases than predicted within a certain community, used to describe disease outbreaks

d. total number of cases existing in a population at a given time

b

What’s the definition of pandemic?

a. an epidemic that spreads throughout the world

b. present in high but constant level in an area/region

c. less cases than predicted within a certain population, used to describe disease outbreaks

d. total number of cases existing in a population at a given time

a

What bacteria metabolizes glycogen to glucose to lactic acid. ALL to lower the pH and protect the vagina?

Lactobacillus

Virulence mechanisms basically describe how a bacteria survives inside the host and isn’t destroyed. For each of the following mechanisms, list the pathogen that uses that mechanism to survive phagocytosis:

Virulence Mechanism	Bacteria
Prevention of Phagolysosome fusion
Escape into cytoplasm
Resistance
Inhibition of phagocytes oxidative pathway (no oxidative burst—> no killing)

Virulence Mechanism	Bacteria
Prevention of Phagolysosome fusion	Mycobacterium Tuberculosis
Escape into cytoplasm	Shigella Dysenteriae
Resistance	Leishmania
Inhibition of phagocytes oxidative pathway (no oxidative burst—> no killing)	Legionella Pneumophila

What type of organism is Leishmania?

parasitic, protozoan, unicellular flagellate

What are 2 antiphagocytic mechanisms that allow for intra-host survival of the bacteria? (aka what allows the bacteria to not be noticed by the phagocytes)

• molecular mimicry

  • coat bacteria with sialic acid OR

• O antigen blocks phagocytes access to bactera

How do bacteria evade defensins?

produce peptidase that break down the defensin (a peptide)

Which of the following is a virulence factor?

a. IgA

b. IgA-protease

c. IgG

d. IgG- protease

b.

For each of the following exotoxins, list their AB domain:

• Diphtheria

• Cholera

• Anthrax

• Diphtheria- AB

• Cholera- A+5B

• Anthrax- 2A+B

The 2 main types of GRAM + cocci bacteria are…

staphylococci and streptococci

THE MAJOR DIFFERENCE BETWEEN staphylococci and streptococci is whether it’s catalase + or -. Which is which?

• staphylococci- CATALASE +

• streptococci- CATALASE -

(FYI: catalase enzyme deals with whether it uses O2 or not)

Staphylococci and Streptococci can either be coagulase + or coagulase -

What strains of staphylococci and streptococci are each?

Coagulase +
Coagulase -

Coagulase +	Staphylococcus aureus
Coagulase -	Staph epidermidis Staph saprophyticus Staph haemolyticus Staph lugdunensis ALL STRAINS OF STREP ARE COAGULASE -

Simply just remember—> the ONLY coagulase + is Staphylococcus aureus

Strep hemolysis is used to classify Streptococci bacteria.

There are 3 types—> α/β/𝜸

How do each type present? (green, clear, or nothing?)

α hemolysis	Partial hemolysis—> APPEARS GREEN
β hemolysis	Complete hemolysis—> CLEAR/WHITE
𝜸 hemolysis	No hemolysis

After a strep hemolysis is done, a Bacitracin test can be done to further classify Streptococci bacteria.

Does it further classify α, β, or 𝜸 hemolysis?

For the results—> which is sensitive (S)? which is resistant (R)?

• β hemolysis

• R (resistant)—> S. agalactiae

• S (sensitive)—> S. pyogenes

After a strep hemolysis is done, an Optochin test can be done to further classify Streptococci bacteria.

Does it further classify α, β, or 𝜸 hemolysis?

For the results—> which is sensitive (S)? which is resistant (R)?

• a hemolysis

• R (resistant)—> Viridans Strep

• S (sensitive)—> S. pneumoniae

The bacteria S. pneumoniae(a strep cocci bacteria) is associated with what infection? (hint: look at the name)

pneumonia—> with rusty sputum, and a productive cough

Answer the following about S. pyrogenes (a strep cocci bacteria):

• Can enter through infected _____________

• What infections can be caused by this bacteria?

• What exotoxin is associated? What are the side effects of this exotoxin?

• This bacteria has lipoteichoic acid that binds to…

• can enter through infected mosquito bites

• Infections—> Impetigo (skin infection), necrotizing fasciitis (flesh-eating infection), scarlet fever

• Spe or Streptococcal pyrogenic exotoxin causes:

  • donut-like petechiae (red spots on roof of mouth)

  • sore throat

  • erythrogenic toxin (cause of red rash in scarlet fever) (FYI: this toxin causes another toxin if that makes sense)

  • pyrogenic (fever)

• has lipoteichoic acid that binds to ECM protein fibronectin

Answer the following about Streptococcus agalactiae:

• Gram + or -

• hemolytic α/β/𝜸?

• ________- resistant

• Lancefield group ___

• what infection does this cause?

(disclaimer: a lot of this info was in the sg, but not his pp)

• gram +

• beta-hemolytic

• bacitracin-resistant

• Lancefield group B

• cause of neonatal/newborn MENINGITIS

Answer the following about Enterococcus faecalis:

• Gram + or -

• ____________ resistant

• What test do we use to test for this bacteria? what indicates a + result?

• causes what infection?

(disclaimer: this bacteria was in the study guide, but not his pp)

• gram +

• vancomycin resistant

• Esculin test—> we react the bacteria with Fe, if it forms a black complex= positive result

• causes UTI

The bacteria S. Saprophyticus (a staph cocci bacteria) is most associated with what infection? It is the second leading cause of this infection to what bacteria?

• Honeymoon cystitis aka UTIs in sexually active young females

• 2nd leading cause of these UTIs, 1st leading cause is G- E.coli

Answer the following about S. aureus (a staph cocci bacteria):

• coagulase + or -

• What syndromes/conditions can be caused by this?

• coagulase +

• S. aureus can cause:

  • scaled skin syndrome (caused by EF)

  • bullous impetigo (caused by EF)

  • food poisoning (fast acting, associated with turkey stuffing)

MRSA stands for Methicillin resistant S. aureus and would cause resistance to what abx? What are some symptoms of MRSA?

• resistance to BETA LACTAM ABX

• symptoms: 101 degree fever, spider-bite-like sores with pus

Answer the following about S. epidermidis (a staph cocci bacteria):

• Gram + or -

• Catalase + or -

• Coagulase + or -

• is normally harmless on the skin flora, but can become _________.

• G+

• Catalase +

• Coagulase -

• is normally harmless on the skin flora, but can become opportunistic (aka lead to infection, especially if immunocompromised)

Answer the following about Alloiococcus otitidis (a cocci bacteria):

• Gram + or -

• Catalase + or -

• Causes WHAT type of infection in children?

• G+

• Catalase+

• causes OTITIS MEDIA (ear infection) in children

STAPH-COCCI BACTERIA REVIEW:

(grouped in Allo bc it’s similar)

STREP-COCCI REVIEW:

(grouped in entero bc its similar)

A capsule is a common virulence factor in what bacterial strains?

• meningitis strains of e.coli

• Streptococcus pneumoniae

• Haemophilus influenzae Type B

• Neisseria meningitidis

What are the 4 most important G+ bacilli species? Which are spore forming?

• Clostridium tetani- spore forming

• C. perfingens- spore forming

• C. botulinum- spore forming

• C. difficile

Answer the following about Clostridium tetani (G+ bacilli):

• What can this bacteria cause? (adults?, kids?)

• What vaccine is available to protect from this toxin?

• Can cause:

  • spasmic paralysis- caused by tetanospasmin toxin

  • generalized tetanus

  • opisthotonos (severe back arching due to muscle spasms)

  • risus sardonicus in kids—> “sardonic smile” (face muscles contract and in kids you can’t breastfeed)

  • lockjaw

• vaccine that contains tetanus toxoid—> DPT

Answer the following about Clostridium perfringens (G+ bacilli):

• can cause what?

• how is C. perfringens muscle destruction different from S. pyogenes flesh eating?

• can cause GAS GANGRENE (muscle destruction, gas release)

• differences:

  • C.perfringens—> targets muscle, a-toxin, G+ rod bacteria

  • S. pyogenes—> targets soft tissue, Spe toxin, G+ cocci bacteria

Answer the following about Clostridium botulinum (G+ bacilli):

• can cause what symptoms/conditions?

• treatment in general

• additional tx for neonatal botulism and umbilical cord infections

• can cause:

  • flaccid paralysis

  • blurred vision

  • food poisoning—> from home-canned vegetables (not an infection)

• treatment: anti-botulinum, antitoxin

• neonatal botulism AND umbilical cord infections MUST ALSO be treated with antibiotics

Answer the following about C.difficile:

• This bacteria can cause severe inflammation of the colon with pseudomembranes called _________________.

• Use of abx can lead to C.difficile associated _____________.

• Treatment?

• can cause pseudomembranous colitis

• abx associated colitis/diarrhea (When using abx you kill good/bad bacteria, this allows C.difficile to overgrow and release toxins= colitis & diarrhea)

• treatment with VANCOMYCIN after d/c amoxicillin

G+ BACILLI REVIEW:

Answer the following about Bacillus anthracis:

• aerobe or anaerobe?

• has ____________ that survive very long

• has _________ plasmid that encodes what?

• can cause what disease?

• strict aerobe (needs O2 for growth)

• has endospores that survive very long

• has PXO1 plasmid that codes for EF (edema toxin/edema factor) which is an adenylate cyclase = leads to edema

• can cause ANTHRAX MENINGITIS—> nickname “cardinal’s cap”

What would a positive Neisseria Oxidase test look like?

a. produces cytochrome c oxidase, turns TMPD blue

b. produces cytochrome c oxidase, turns colorless

c. does not produce cytochrome c oxidase, turns TMPD blue

d. does not produce cytochrome c oxidase, turns colorless

a

Answer the following about Neisseria meningitidis:

• G + or - diplococci in CSF

• Symptoms of meningitis

• 3 virulence mechanisms this bacteria uses

• vaccines for meningitis

• does it ferment sugars? if so which?

• G- diplococci in CSF

• symptoms:

  • nuchal rigidity (neck stiffness)

  • low bp (105/65)

  • fever

  • rash, petechiae, ecchymoses (bruising), and DIC (small blood clots in blood)

• 3 virulence mechanisms

  • Por A (resistance to serum killing)

  • Meningobactin (siderophore that allows bacteria to get IRON)

  • IgA protease

• vaccines

  • Tetravalent for serogroup A, C, Y, W135

  • Bexsero for serogroup B

• yes, ferments sugars—> Glc and maltose

Answer the following about Neisseria Gonorrhoeae:

• what can this bacteria cause? if left untreated what occurs?

  • what can happen during pregnancy?

  • men?

• 2nd most common STI to what bacteria and STI?

• 2 virulence factors this bacteria uses?

• does it ferment sugars? if so which?

• causes:

  • gonorrhea

  • females: untreated= female sterility—> scarring of the fallopian tube, ectopic pregnancy

  • in pregnancy—> if mother is effected can cause Opthalmia neonatorum

  • male: male sterility—> infection spreads to prostate and epididymis

• gonorrhea the 2nd most common STI in the world, 1st is Chlamydia

• 2 virulence factors

  • Por B (helps survive intracellular)

  • Gonobactin (siderophore that allows bacteria to get IRON)

• yes, ferments sugars—> glucose

Answer the following about Moraxella catarrhalis:

• G + or - diplococci

• symptoms

• risk factors

• does it ferment sugars? if so which?

• G - diplococci

• symptoms- bronchitis

• RFs- smoker, immunocompromised

• NO sugar fermentation

Polymicrobic infection in an abscess is when multiple bacteria are in the same spot. What order do these bacteria grow in?

(hint: based on O2 needs)

1. strict aerobes

2. facultative anaerobes

3. strict anaerobe

Answer the following about Prevotella melaninogenica:

• where is this bacteria most commonly seen/found?

• G + or -

• bile-sensitive?

• aerobic or anaerobic?

• unique characteristic of this bacteria is…

(disclaimer: this bacteria was in sg, not pp)

• most common—> in abdominal abscess after appendectomy

• G-

• bile-sensitive

• anaerobic

• unique characteristic—> releases BLACK PIGMENT in agar (due to production of porphyrin)

Answer the following about Bacteroides fragilis:

• where is this bacteria most commonly seen/found?

• G + or -

• bile-sensitive?

• aerobic or anaerobic?

• has a plasmid that encodes what kind of gene? results?

• sensitive to what abx?

• Results of Esculetin test?

(disclaimer: this bacteria was in sg, not pp)

• most common—> infection after surgery like appendectomy

• G-

• NOT bile-sensitive, bile-resistant

• anaerobic

• plasmid that codes for beta-lactamase—> results in beta-lactam abx resistance

• sensitive to metronidazole

• Esculetin test—> reacts with iron to form black complex

GRAM - REVIEW!!!!!!