Gram - Bugs Flashcards

1
Q

what is one thing all gram - bugs have in common??

A

-all have a lipopolysaccharid outer membrane of cell wall-endotoxin

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2
Q

What are the medically relevant gram - cocci?

A

neisseria

  • -neisseria meningitidis»meningitis
  • -neisseria gonorrheae

moraxella catarrhalis (resides in respiratory tract, causes tracheobronchitis and pneumonia)

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3
Q

What is the most prevalent human bacterial STI?

A

-gonorrhea

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4
Q

Where is a gonorrheal infection found in women and men?

A
  • women: cervix

- men: urethra, may extend to prostate and epididymis causing sterility

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5
Q

Gonorrhea, does this spread beyond the urethra and cervix? if so, where?

A
  • yes, may become systemic disease.
  • -arthritis, endocarditis, meningitis

-gonorrhea neonatorum, eye infection during passage through birth canal, may lead to blindness

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6
Q

Neisseria meningitidis

  • causes what?
  • natural reservoir
  • transmission?
A
  • meningitis, septicemia
  • natural reservoir is the human nasopharyngeal mucosa
  • transferred via direct contact or droplets
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7
Q

Neisseria meningitidis
-subclinical/minimal disease sx

  • fulminant meningeal sepsis sx
  • meningitis sx
A

-subclinical: short febrile flu-like sx, cleared spontaneously

OVERT DISEASE
-fulminant meningeal sepsis: fever, severe HA, vomiting, neck/back pain, stiffness, petechial rash, altered mental status, shock, organ failure.

  • meningitis
  • fever, HA, vomiting, neck/back pain, skin rash, AMS
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8
Q

Fulminant meningeal sepsis and meningitis may progress to what?

A
  • shock; endotoxin causes capillary leakage, poor vascular tone, intravascular microthrombi, myocardial dysfunction
  • DIC; endothelial damage»> hemorrahges, microthrombi
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9
Q

Meningitis rash, where is it often found on the body?

A

-pin point rash often on the trunk but sometimes on the hands.

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10
Q

Diagnosis of Fulminant meningeal sepsis and meningitis?

A
  • FMS lesions appear 6-12 hours
  • meningitis lesions appear 12-18hrs after onset, no lesions in 20% or pts

Bacteriologic dx:
FMS: gram stain of skin lesion biopsy specimen
Meningitis: only CSF positive

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11
Q

How do you treat FMS and meningitis?

A

-always start ABX IMMEDIATELY!! even before other diagnostic procedures.

  • use cefotaxime or ceftriaxone plus vanco
  • patients in contac… prophylactic abc Rocephin (ceftriaxone)
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12
Q

Moraxella Catarrhalis

  • gram +/-?
  • cause infections of?
  • resistant to which meds?
  • treat w/?
A
  • gram -
  • cause infection of upper and lower respiratory, middle ear, eye, CNS, joints
  • resistant to PCN, SMX/TMP, tetracyclines
  • treat w/ FQ, most 2nd, 3rd cephalosporins, macrolides, augmentin
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13
Q

Pseudomonas aeruginosa

  • morphology?
  • common inhabitant of?
  • frequent contaminant of?
  • most common cause of?
  • complications
A
  • gram - rod w/ single polar flagellum
  • common inhabitant of soil and water
  • contaminant of ventilators, IV solutions, anesthesia equipment
  • most common cause of nosocomial infections
  • complications include pneumonia, UTI, abcesses, otitis, corneal disease, endocarditis, meningitis, bronchopneumonia
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14
Q

Pseudomonas aeruginosa

  • odor?
  • color?
  • treatment
A
  • grape-like odor
  • greenish-blue pigment
  • treat w/ cephalosporins, aminoglycosides, carbenicillin, polymixin, quinolones, and monobactams.
  • Harleys go to is quinolones
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15
Q

Brucella and Brucellosis

  • morphology
  • what are the 2 species
  • sx
  • treatmen?
A

-gram - coccobacilli

-Brucella abortus (cattle)
Brucella suis (pigs)
  • sx: malta fever, undulant fever*, bang disease(zoonosis transmitted to humans from infected animals
  • *fluctuating patter of fever, weeks to a year.

-tx: tetracycline and rifampin or streptomycin

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16
Q

How do you get Brucella species?

A

-consumption of unpasteurized milk and soft cheeses made from milk of infected animals.

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17
Q

Francisella tularensis

  • morphology
  • causes what?
  • transmitted how?
  • sx
  • tx
A
  • facultative intracellular coccobacillus
  • causese tularemia (zoonotic disease of mammals endemic to norther hemisphere, particularily rabbits)
  • transmitted by contact with infected animals, water and dust or bites by vectors.
  • Sx: HA, backkache, fever, chills, malaise, weakness
  • tx: gentamycin or tetracycline
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18
Q

Bordetella pertussis

  • morphology
  • causes what disease?
  • reservoir
  • transmission
A
  • encapsulated coccobacillus
  • causes pertussis or whooping cough “100 day cough”
  • reservoir is healthy carreiers
  • transmitted by direct contact or inhalation of aerosols
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19
Q

Bordetella Pertussis

  • virulence factors
  • vaccine for this?
  • treatment?
A

Virulence: bind to ciliated respiratory epithelial cells, toxins destroy and dislodge ciliated cells. Loss of ciliary mechanism leads to buildup of mucus and blockage of the airways.

  • Tdap vaccine
  • treat with macrolides….AZITHROMYCIN!
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20
Q

Legionella pneumophilia and Legionellosis

  • transmission?
  • how did this bug get its name?
  • sx
  • tx
A
  • distributed in water, organisms inhaled in aerosolized mist
  • pneumonia afflicted 200 American Legion members
  • sx: fever, cough, diarrhea, abdomin pain
  • tx: azithromycin
21
Q

What are the pathogenic strains of e.coli? What

A
  • enterotoxigenic E.Coli -causes severe diarrhea d/t heat-labile toxin and heat-stable toxin- stimulate secretion and fluid loss
  • enteroinvasive e.coli: causes inflammatory disease of large intestine
  • enteropathogenic e. coli: linked to wasting from infantile diarrhea
  • enterohemorrhagic e.coli: O157:H7 strain, causes hemorrhagic syndrome and kidney damage
22
Q

What is a coliform count used for?

A

-indicator of fecal contamination in water

23
Q

e.coli is a major causes of what?

A
  • travelers diarrhea

- UTI

24
Q

e.coli tx

A

-SMX/TMP, nitrofurantoin, FQs

25
Q

Other than e.coli what are some other coliforms? Where are they found in the body? What type of infections do they cause?

A
  • klebsiella pneumoniae-normal inhabitant of respiratory tract, has large capsule, cause of nosocomial pneumonia, meningitis, bacteremia, wound infections and UTIs
  • enterobacter: UTI, surgical wounds
  • serratia marcescens: produces red pigment, causes pneumonia, burn and wound infections, septicemia, and meningitis
  • citrobacter: opportistic UTI and bacteremia
26
Q

Yersenia Pestis?

  • aka
  • morphology
  • how do you get this?
A
  • Plague
  • gram - rod, unusual bipolar staining and capsules
  • contact with wild animals or infected humans *found in rodents, flea vectors
27
Q

Pathology of Bubonic plague?

-may progress into what?

A

bacillus multiplies in flea bite, enters lymph, causes necrosis and swelling called a bubo in groin or axilla.

  • septicemic: progression to massive bacterial growth; intravascular coagulation, subcutaneous hemorrhage and purpura-black plague.
  • pneumonic: infection localized to lungs, highly contagious; fatal without treatment.
28
Q

Tx of plague

A

streptomycin, tetracycline, or chloramphenicol

29
Q

Pasteruella multocida

  • what is this?
  • how does it present?
  • treatment?
A
  • zoonotic genus; normal flora in animals.
  • animal bites/scratches cause local abscess that can spread to joints, bones, and lymph nodes

-PCN and tetracycline

30
Q

Haemophilus

  • morphology
  • what type of agar do you need to groww?
  • colonize where in the body?
A
  • gram - pleomorphic rods
  • chocolate agar
  • colonize of the upper respiratory tract or vagina
31
Q

What are the strains of Haemophilus and what illness do they cause?

Treatment of Haemopholus sp?

A

H. flu= bacterial meningitis, epiglottitis, otitis media, sinusitis, pneumonia, bronchitis

H.aegyptius= conjunctivitis

H. ducreyi = chancroid STD

H.parainfluenzae= normal oral and nasopharyngeal flora, infective endocarditis

Tx: amoxicillin, azothrymycin, cephalosporins, FQ, and clarithromycin

32
Q

Characteristics of anaerobic infections?

A
  • most pathogenic anaerobes are usually commnesal
  • have predisposing conditions such as..breech in mucocutaneous barrier, compromised vascular supply
  • complex flora; multiple species,
  • synergisic mixture of aerobes and anaerobes
    (e. coli –> consume O2, allow growth for anaerobes
33
Q

Clues to anaerobic infections?

A
  • infection in continuity to mucosal surfaces
  • infection w/ tissue necrosis and abscess formation
  • putrid odor
  • gas in tissues
  • polymicrobial flora
  • failure to grow in lab
34
Q

Bacteroides fragilis
-when does this infection most commonly occur?
-what benefits come from having a capsule in this bug?
-

A
  • major disease causing strict anaerobic after abdominal surgery*
  • capsule: anti-phagocytic and abscess formation
35
Q

Campylobacter jejuni

  • leading cause of what kind of illness?
  • transmission?
  • treatment?
A
  • leading cause of bacterial diarrheal illness
  • transmission is oral/fecal route, ingestion of contaminated food and water, uncooked meat.
  • treat w/ azithromycin, increasing resistance to FQ.
36
Q

Lymes Disease
-what bug causes this?
-sx?
-

A

-borrellia burgdorgeri

  • early sx: fever, HA, fatigue
  • Late sx: rash (may or may not be bulls eye), joints, heart, and CNS involvement.
37
Q

Dx and Tx of Lymes

A
  • bulls eye rash
  • Elisa: measures the levels of abys against the lyme bacteria
  • western blot: identifies abys directed against a panel of proteins found in the lyme bactera

Tx:
-doxycycline or amoxicillin for 2-4weeks

38
Q

Chlamydia trachomatis

  • signs and symptoms in male and female
  • treatment
A
  • femaile patients may not have sx, males will have urethral drip and painful urination.
  • treat w/ azithromycin, doxycycline or ofloxocin
39
Q

Lymphogranuloma venereum (LGV)

  • what is this?
  • sx
  • tx
A

-uncommon STI caused by three serovars of chlamydia trachomatis

  • sx: swollen inguinal nodes, drainage through skin from buboes or abscesses in inguinal nodes
  • -painful bowel movements
  • -small painless sore on genitals
  • -swelling of the labia
  • -blood or pus from the rectum
  • -left untreated may develop fistulas
  • Tx: doxycyline, erythromycin, azithromycin)
  • -I&D of buboes
40
Q

Psittacosis

  • what is this?
  • symptoms
  • diagnosis
  • tx
A

“parrot fever”…zoonotic disease caused by chlamydia pssitaci contracted from parrots, pigeons, ducks, chickens, and gulls.

  • sx: high fever, arthralgias, diarrhea, conjunctivitis, epistaxis, splenomegaly, HA, may mimic meningitis, cough
  • dx: exposure hx!, microbiological cultures from respiratory secretions or serology from blood cultures
  • tx: doxycycline and chloramphenicol
41
Q

What are the two types of relapsing fever? What bacteria are they caused from?

A
  • Tick borne (TBRF) & Louse borne (LBRF)

- caused from Borellia spirochetes

42
Q

Where does TBRF and LBRF occur?

sx?
dx?

A
  • TBRF=wester US, linked to sleeping in rustic, rodent infested cabins in mountainous areas.
  • LBRF: transmitted by the human body louse and is generallly restricted to refugee settings in the third world.
    sx: flu-like, sudden fever, chills, HA, arthralgias, nausea, may develop rash.
  • dx: on blood smear, spirochetes
43
Q

Treatment of Relapsing fever?

A

doxycycline, may cause Jarish-Herxheimer rxn.
^^^massive die of of spirochetes, rash chills, not feeling well. not an allergy, just killing off the bug you intended to leading to mass release of endotoxin

44
Q

Salmonella sp.

  • flagellinated?
  • sx
  • most common cause of what illness?
A

-motile, flagellated gram neg.

  • gastroenteritis (diarrhea, abd cramp, fever) to enteric fevers (typhoid fever)
  • may be asymptomatic and be a carrier (typhoid marys)

-most common from is food poisoning

45
Q

Selmonella typhi

  • sx
  • dx
  • tx
A
  • N/V/D, septicemia, fever, anorexia, HA, myalgias
  • dx: stool &/or blood cultures, serology for abys
  • Tx: replace fluids by oral or IV, pain control, treat nausea, abx=cipro.
46
Q

Shigella

  • sx
  • who does this usually occur in?
  • dx
  • tx
A

sx: bloody diarrhea, abdominal pain/cramps, fever
- seen in kids 2-4
- dx: stool studies
- tx: replace lost fluids, usually self limiting within a weeks, cipro or cefixime should be used if abx indicated.

47
Q

Vibro sp.

  • what are the two distinct groups?
  • how do you get ill from this?
  • tx of non-cholera
A
  • 2 types: cholera infections, non-cholera infections
  • non-cholera: contaminated food or eating raw shellfish
  • tx non-cholera: gasteroenteritis is usually self-limited with fluid replacement, no abx needed.
  • *non-cholera wound infection or septicemia will need doxycyline or quinolone, debridement of infected wound.
48
Q

Vibrio cholerae

  • sx
  • tx
A

-watery diarrhea, occasional vomiting, cramps, dehydration

death d/t dehydration can occur within a few hours to days if untreated.