bacterial infections I - G+ & G- Flashcards
what is the most pathogenic staphylococcus
s. aureus
what staphylococcus is most common on skin and hospital acquired infections
s. epidermidis
what stapholococcus is common in UTIs
s. saprophyticus
what staphylococcus is common in foreign body/prosthetic device infections
s. lugdunensis
what is the difference between coagulase positive and negative species?
positive - able to clot
negative - cannot
what type of staphylococcus species is most virulent
coagulase positive species
resistance is increasing = MRSA
what staphlyococcus are coagulase positive and coagulase negative?
positive - S. aureus
negative - S. epidermidis, S. saprophyticus, S. lugdunensis
what is the most common mode of transmission of staphylococcus
direct tissue invasion
- skin/soft tissue infectios
- osteomyelitis
- septic arthritis
- pneumonia
- endocarditis
severe local staphylococcus infection can lead to ?
bacteremia
how do staphylococcal skin infections most commonly present?
erythema
purulent drainage
steps in treating staphylococcal skin infections?
- drain abscess
- empiric abx
- alter tx after cx results
what abx do you use for a staph skin infection with a low risk of MRSA
- cephalexin (keflex)
- dicloxacillin
what abx do you use for a staph skin infection with a high risk of MRSA
- clinda
- sulfamethoxazole/trimethoprim (bactrim)
- doxy/minocycline
what is the first line inpatient tx for a staph skin infection
vancomycin
most of osteomyelitis is caused by ?
s. aureus
how do you confirm osteomyelitis?
x-ray
bone scan most sensitive
tx for staph osteomyelitis
- culture!
- x-ray
- empiric coverage (no first line tx) - vancomycin + 3/4 gen cephalo
- prolonged therapy for 4-6 weeks
- surgery (sometimes)
if a pt presents with a MSSA osteomyelitis, what is the abx?
nafcillin (IV) / oxacillin / cefazolin
if a pt presents with a MRSA osteomyelitis, what is the abx?
vancomycin IV
what is the disease that is caused by a toxin produced by S. aureus, commonly seen from tampon use and nasopharynx packing?
Toxic shock snydrome (TSS)
common presentation for TSS
- erythematous rash on palms and soles that desquamates*
- sudden onset fever*
- hypotension
- N/V/D
- myalgia
can cause hepatic damage, thrombocytopenia, confusion*
tx for TSS
- supportive
- antipyretics
- IV fluids
- monitor hepatic and renal functions - debride/decontaminate*
- empiric - vancomycin + clinda + (pip/taz)/cefepime/carbapenem *
scalded skin syndrome is most common in?
infants, younger children
scalded skin syndrome is transmitted via ?
birth canal
hands of adult carriers
symptoms of scalded skin syndrome
- bullae with sloughing
- fever, malaise
can lead to sepsis and electrolyte abnormalities
what causes scalded skin syndrome?
s. aureus toxins
tx for scalded skin syndrome
- biopsy
- fluid management
- skin care - tx as burns*
- abx
- MSSA - nafcillin / oxacillin
- MRSA - vancomycin
staph food poisoning is caused by ?
ingestion of exotoxin
symptoms of staph food poisoning
quick onset - 2-8hrs after ingestion
self limiting within 12hrs
characteristics of coagulase negative staph infections? Main tx?
- humans are natural carriers
- typically hospital acquired
- resistant to most beta-lactams
- tx: vancomycin*
what streptococcus is the most common cause of pharyngitis and skin infections
S. pyogenes (group A) (GABHS)
what streptococcus can cause septic abortion and illness in neonates
S. agalactiae (group B)
what steptococcus can cause endocarditis esp. prosthetic valve
S. bovis (group D)
pharyngitis is most common in ?
ages between 5 - 15
common presentations of pharyngitis
- beefy red uvula*
- palatal petechiae*
- tender ant. cervical lympadenopathy
- tonsillar exudate possible
how do you diagnose pharyngitis
diagnosis made by presentation THEN rapid strep test
3 tx for pharyngitis - strep pyogenes (GABHS)
- benzathine PCN G
- PCN VK
- amoxicillin (better for kids)
what is the tx for pharyngitis if there is a PCN allergy?
cephalo
what is the tx for pharyngitis if there is a PCN and cephalo allergy?
Azithromycin (Zpack)
presentation of scarlet fever
- erythematous rash resembling a sunburn with superimposed fine red papules (sandpaper rash)
-fine desquamatino - strawberry tongue
a focal, vasicular, pustular lesions with a thick, honey-colored crust with a “stuck-on” appearance
impetigo
what is the main bacteria that causes impetigo
Strep
S. aureus can cause too
3 tx for impetigo MSSA
- topical mupirocin*
- cephalexin* (1st) (keflex)
- dicloxacillin
tx for impetigo MRSA
- sufanethoxazole/trimethoprim (bactrim)*
- clinda*
- doxycycline
what is the main cause of erysipelas
strep
s. aureus can cause too
a painful superficial cellulitis with derma lymphatic involvement that frequently involves the face
erysipelas
outpatient tx for erysipelas
- PCN VK*
- amoxicillin*
- dicloxacillin
- cephalexin* (PCN allergy)
- clinda/erthyromycin
inpatient abx for erysipelas
- vanco
- cefazolin (1st)
- ceftriaxone (3rd)
- clinda
cellulitis is most caused by either ___ or ___
GABHS
S. aureus
how is strep agalactiae (group B strep) important in pregnancy
- must have routine screening during pregnancy at 35th week
- can lead to neonatal sepsis if no prenatal care done
if a pregnant pt is positive for group B strep, what do you give? (3)
treatment prophylaxis - intrapartum
1. PCN G or ampicillin
2. cefazolin (1st)
3. clinda or vanco
what strep is most common cause of CAP
s. pneumoniae
what streptococcus commonly causes upper & lower rsp tract and meninges
s. pneumoniae
what streptococcus is seen in endocarditis in the native valve
s. viridans
3 organisms that cause acute OM
- s. pneumoniae
- m. catarrhalis
- h. influenzae
otitis media is most common in?
children between 2-14
signs of otitis media (3)
- bulging TM
- absence/displacement of light reflex, poor mobility
- otorrhea with TM rupture
acute sinusitis most commonly starts as ?
viral
first line tx for acute sinusitis? 2nd?
- amoxicillin / clavulanic acid (augmentin)
- doxy
- clinda
s/s of pneumococcal pneumonia
- early onset rigors*
- productive cough - rust colored*
- SOB
- pleuritic chest pain
- crackles and riles heard in affected lobe*
What is the difference between diagnosing outpatient vs inpatient/comorbidities of pneumococcal pneumonia
outpatient - NO sputum culture
inpatient/with comorbidities - DO sputum culture
first line tx for pneumococcal pneumonia? 2nd?
-
amoxicillin
then - doxy
- azithromycin (zpack) - only in areas w/ <25% resistance
what 2 abx is given with an OUTPATIENT pt with COPD/comorbidities or with recent abx tx for pneumonia with the LAST 3 MONTHS
- levofloxacin (levaquin)
- combo:
- amoxicillin/clavulanate (augmentin)/cephalosporin + macrolide/doxy
2 tx for inpatient pneumococcal pneumonia
- levofloxacin (levaquin)
OR - macrolide + beta-lactam (amoxicillin or can use ceftriaxone)
how do you determine the severity of pneumococcal pneumonia?
pneumonia severity index (PSI)
prevention for pneumococcal pneumonia
- pneumococcal vaccine
recommended for:
1. ALL adults +65 y/o
2. chronic health problems
3. immunocompromised
4. 19-64 y/o:
- who smokes or have asthma
- residents of nursing homes/long-term care facilities
causative organisms for meningitis in children and young adults
- group B strep - 1 - 3 m/o
- s. pneumoniae - 3m - 10 y/o
- Neisseria meningitidis - 10 - 19 y/o
causative organism for meningitis in adults and elderly
s. pneumoniae
what is the tx for endocarditis (enterococcus)
ampicillin + gentamicin
tx for both mild and complicated skin/wound/UTI infection (enterococcus)
ampicillin or vancomycin
tx for VRE enterococcus
linezolid
daptomycin
a encapsulated, toxin producing bacteria that is a bioterrorism agent
bacillus anthracis
modes of transmission of bacillus anthracis
- direct contact
- ingestion - inadequately cooked meat of infected animals
- inhalation - most fatal
if a pt presents with a painless black eschar, it is most likely from?
bacillus anthracis
ingesting spores from bacillus anthracis can cause ?
lesions and bleeding in GI tract
inhalation of b. anthracis can present with?
- insidious onset of flu-like symptoms
- chest pain and severe rsp distress - hypoxia, shock
if a b. anthracis exposure is suspected, what do you start with?
cipro prophylaxis
7-10 days (cutaneous)
60 days (inhalation)
what is the alternative of cipro for B. anthracis
doxy
what organism is present in foods, esp rice and left overs, that can cause quick onset of N/V/D within 1-10 hrs of exposure
bacillus cereus
self-limiting
supportive tx
what infection presents a greater risk during pregnancy by ingesting contaminated foods such as dairy, raw veggies, and meat
listeriosis
how do you diagnose and tx listeriosis
diagnose:
1. culture
- blood
- CSF
tx:
- ampicillin + gentamicin
- amoxicillin (outpatient)
what causes an adherent dense, grey cover on the tonsils and pharynx
(pharyngeal diphtheria)
corynebacterium diphtheriae
followed by toxemia and prostration
tx for corynebacterium dipheriae (3)
- diphtheria equine antitoxin - must get from CDC
- PCN
- erythromycin
ppl in contact with corynebacterium diphtheriae, what abx do they get
erythromycin
what is the prevention for corynebacterium diphtheriae?
- immunization
- susceptible persons = booster + PCN or erythromycin
characteristics of acinetobacter infections
- opportunistic infections
- can affect any organ system
- survive on dry surfaces for up to a month
moraxella catarrhalis is the common cause of ___ infections
- rsp tract
1. acute OM
2. acute and chronic sinusitis
3. COPD exacerabtions
neisseria can cause …
meningococcal
meningitis
gonorrhea
characteristics of meningococcal meningitis
- human reservoir
- outbreaks occur in close communities
clinical presentation of meningococcal meningitis
- stiff neck*
- maculopapular rash, petechiae*
- kernig and brudzinski signs*
- Fever, HA
- N/V, photophobia, lethargy
how do you diagnose meningococcal meningitis
gram stain and culture
- lumbar puncture with CSF analysis
- blood
tx for meningococcal meningitis
- ceftriaxone (start)
- PCN G - if known meningococcal susceptible to PCN
close contacts of meningococcal meningitis receive?
prophylactic abx
meningococcal vaccine covers what strain?
B
starting at age 11-12 with booster at 16
diagnosis with yellow-green purulent discharge and erythematous cervix
gonorrhea
disease states of neisseria gonorrhoeae
- cervicitis, urethritis
- prostatitis
- PID
- conjunctivitis
conjunctivitis from n. gonorrhoeae is especially seen in?
newborns
tx for gonorrhea
ceftriaxone - single dose
must report to local health department
pseudomonas is the #1 pathogen of: (3)
- otitis externa
- corneal ulcers
- osteochondritis after puncture through tennis shoe
pseudomonas is the #2 pathogen of:
nosocomial pneumonia
pseudomonas is the #3 pathogen of:
hospital-aquired UTI
folliculitis also known as “hot-tub folliculitis” is caused by what organism
pseudomonas
what is the most common first symptom from pseudomonas
fever
outpatient/oral tx options for pseudomonas
- ciprofloxacin
- levofloxacin
why avoid ciprofloxacin and levofloxacin in children when treating pseudomonas
can have cartilage effects
what is the inpatient beta-lactam tx for pseudonomas (5)
- pip/taz
- ceftazidime (3rd)
- cefepime (4th)
- meropenem
- aztreonam
what organism causes whooping cough
b. pertussis
4 rsp tract infections caused by H. flu
- pneumonia
- bronchitis
- OM
- sinusitis
what rsp infection is transmitted via aerosolized droplets that affects mostly children and presents with coughing fit w/ gasps for breath that could continue for months
whooping cough
what abx can be given for whooping cough? alternative?
- azithromycin
- bactrim
epiglottitis is commonly caused by what organism
h. flu
what organism colonize the upper rsp tract in COPD pts and frequently cause purulent bronchitis
h. flu
legionnaires disease is more common in ? (3)
immunocompromised
smokers
chronic lung disease
outbreaks of legionnaires disease have been associated with ?
contaminated water sources
presentation of legionnaires disease
scant sputum*
pleuritic chest pain
fever
toxic appearance
focal patchy infiltrates or consolidation in CXR
how do you confirm legionnaires disease?
antigen detection
tx for legionnaires disease
- macrolides
- fluoroquinolone
10-14 days/21 day course for immunocompromised
typically, klebsiella pneumoniae only causes disease in: (4)
- immunocompromised
- alcoholics
- DM
- HIV
normal intestinal flora
red, currant-jelly sputum is commonly seen in ?
klebsiella pneumoniae
tx for klebsiella pneumoniae
empiric - rsp fluoroquinolone, carbapenem
gastrointestinal illnesses causing organisms (g- rods)
- E. coli
- campylobacter
- salmonella
- shigella
- vibrio
pt presenting with who recently went on a trip
1. increased freq, volume, and weight of stool
2. freq loose stools
3. tenesmus
4. N/V
E coli - traveler’s diarrhea
if traveler’s diarrhea is not resolving, what do you give?
- antimotility agents/antididiarrheals
- bismuth subsalicylate (pepto)
- cipro
antimotility agents/antididiarrheals are not recommended for ?
infants or ppl with fever or bloody stool
bismuth subsalicylate is not recommended for ?
children
pregnant women
what is one of the main causes of bacterial foodbourne illness that produces inflammatory, sometimes blood, diarrhea
campylobacter jejuni
abx for campylobacter jejuni
ciprofloxacin
azithromycin
what infection causes diarrhea, often with blood and mucus, with WBC in stools
shigellosis
tx for shigellosis
ciprofloxacin (cipro)
TMP-SMX DS (bactrim)
a pt complains of liquid, gray, non-odor stool what do they most likely have?
cholera - vibro cholerae
4 tx for cholera - vibrio cholerae (DNA/protein synthesis ABX)
- tetracycline/doxy
- TMP-SMZ- DS
- azithromycin
- quinolones - cipro
vibrio parahaemolyticus infections are from ?
ingestion of shellfish or contaminated seawater, usually occurs in Japan and coastal US
tx for non-cholerae vibrio infections
doxy or ciprofloxacin
two main clinical patterns of salmonella infection:
- enteric fever (typhoid fever)
- acute enterocolitis
prodomal stage of typhoid fever presents with:
typhoid/enteric fever
1. blood “pea” soup
2. rose spots
3. malaise
4. N/V
5. abd pain
3 tx for typhoid fever
- ciprofloxacin/levofloxacin
- ceftriaxone
- azithromycin
presentation of enterocolitis (salmonella)? how do you get it?
- diarrhea - inflammatory
- Nausea, abd pain
- fever
from ingesting infected food or direct contact with infected animals (turtles and reptiles)
tx for enterocolitis (salmonella)
- Supportive
- SEVERE!! do not treat in uncomplicated cases
- cipro
- ceftriaxone
- azithromycin
- TMP-SMX
most UTI/pyelonephritis is caused by ?
E. coli
also klebsiella, proteus mirabilis , enterobacter
most UTIs involve what part of the bladder?
lower urinary tract - bladder, urethra
an infection in any part of the urinary system
UTI
untreated UTI spread to kidneys and can cause permanent kidney damage
pyelonephritis
5 tx for UTI (uncomplicated)
- TMP-SMZ DS
- nitrofurantoin
- fosfoycin
- cephalos - cephalexin/cefdinir
- ciprofloxacin
what would you use in children for uncomplicated UTIs
cephalosporins - cephalexin/cefdinir WITH Bactrim
tx for pyelonephritis
- ciprofloxacin
- levofloxacin
- ceftriaxone PLUS bactrim/augmentin/omnicef (cefdinir)
what is transmitted among rodents and to humans by bites of fleas or from contact with infected animals
bubonic plague by yersinia pestis
presentation of bubonic plague
- bubo (enlarged, painful LNs)
- purpuric spots
- blood-tinged sputum
- cyanosis with pneumonia
- sudden onset of fever, malaise
tx for bubonic plague? what is the prophylactic tx
- streptomycin
- gentamyicin
- doxy
- fluoroquinolones
prophylactic therpay for any contacts with doxy AND ciprofloxacin
a pt who has been in recent contact with rabbits/rodents/ticks that presents with an ulcer at site of being bitten is dx with ?
tularemia
tx for tularemia
- streptomycin
- gentamicin
- doxy
- fluoroquinolone
What temp is considered a fever
+38C or +100.4F
shaking chills seen with a fever is more likely what type of etiology?
infectious
usually s. pneumoniae
tx for FUO
- no empiric
- treatment directed toward etiology once determined
- referral if cannot be determined
SIRS is defined as 2+ of the following:
- fever (+38C/100.4F) or <36C (96.8F)
- +90bpm
- rsp +20 bpm, <32 mmHg (PaCO2)
- Abnormal WBC
- >12k
- <4k
- >10% bands
when bacteria is in the bloodstream and can multiply and produce systemic s/s
bacteremia
what is the most common cause of bacteremia
respiratory infection
highest among +65 y/o
G+ most prevalent
8 risk factors of sepsis
- ICU admission
- bacteremia
- +65 y/o
- immunosuppressed
- DM and cancer
- CAP
- previous hospitalization
- genetic factors
common s/s of sepsis
- hypotension
- elevated temp or hypothermia
- +90 bpm
- tachynpea
- signs of organ perfusion
- warm flushed skin
- altered mental status
- absent bowel sounds
what is the scoring system in identifying sepsis
- qSOFA score of +2 findings
- rsp rate +22 bpm
- altered mental status
- <100 mmHg BP - do full SOFA score
tx for sepsis
- abx within 1 hr of suspected dx
- empiric abx used to depend on source of infection
- IV fluids
- vasopressors
- central lines
prognosis of sepsis
- nosocomial pathogens > community-acquired
- UTI (lowest mortality)
- ischemic bowel (highest mortality)