Clin Med 1B Exam 1: ALL Bacterial Infections

Common clinical presentation of a S. aureus skin infection

erythema and purulent drainage

dx of S. aureus skin infection

drain abscess if present and culture

if systemic signs, do a blood culture

outpatient tx of S. aureus skin infection if low MRSA risk (MSSA)

Cephalexin

Inpatient tx of MRSA S. aureus skin infection

vancomycin

when should you consider admitting a pt with S. aureus skin infection

- worsening after 48-72 hrs of appropriate abx and I&D

- infection is on the face, genitalia, joints

- immunocompromised

- inadequate access to care

what bacteria causes osteomyelitis

Staphylococcus aureus

first line dx for osteomyelitis

X-ray!! and ALWAYS CULTURE

(X ray = first line but MRI is more sensitive)

tx for osteomyelitis

broad spectrum abx - IV - vancomycin & 3rd or 4th gen cephalosporin (ex: ceftriaxone)

what bacteria causes toxic shock syndrome

staph aureus

mode of transmission of toxic shock syndrome

vagina - tampon use

nasopharynx - nasal packing

direct inoculation

clinical presentation of toxic shock syndrome

- sudden high fever, hypotension, myalgia, N/V, watery diarrhea

- erythematous rash particularly on palms and soles of feet that desquamates

dx of toxic shock syndrome

clinical picture and history, may culture local site of infection

antibiotic tx of toxic shock syndrome

vancomycin plus clindamycin plus 1 of the following: pip/taz, cefepime, or carbapenem (imipenem or meropenem)

besides staph aureus what other bacteria can cause TSS

strep pyogenes

mode of transmission of scalded skin syndrome

transmitted via birth canal or hands of adult carriers

clinical presentation of scalded skin syndrome

widespread bullae with sloughing - epidermis peels easily

dx of scalded skin syndrome

made clinically, can confirm with culture or biopsy

supportive measures for scalded skin syndrome

fluid management and skin care (treat like burns)

antibiotic tx of scalded skin syndrome for both MSSA and MRSA

MSSA: Nafacillin or Oxacillin

MRSA: vancomycin

scalded skin syndrome is MC in what population

infants and children

what bacteria most commonly causes Impetigo

Staph aureus

most common clinical presentation of Impetigo

non-bullous: focal, vesicular pustular lesions with a thick honey colored crust with a "stuck on" appearance

bullous presentation of Impetigo

localized bullae with sloughing, common on trunk

ecthyma Impetigo

"Punched-out" ulcers covered with yellow crust surrounded by raised violaceous margins typically caused by multiple types of bacteria

dx for Impetigo

clinical

1st line tx of Impetigo

topical Mupirocin

what pt population is Impetigo MC in?

infants and children

most Impetigo are caused by ____________ bacteria, but minority cases are caused by ______________

most caused by S. aureus, minority caused by GABHS (S. pyogenes)

what bacteria causes food poisoning

Staphylococcus aureus

presentation of food poisoning

N/V/D, abdominal cramping as quickly as 2-8 hrs after ingestion

tx of food poisoning

self-limiting, resolved within 12 hrs - no tx needed

mode of transmission of staph epidermis

typically hospital acquired through post op, prosthetic devices, indwelling catheters

presentation of a S. epidermis infection

systemic signs and pain/dysfunction at implantation site

S. epidermis is typically resistant to what abx?

beta lactams

1st line tx for S. epidermis infection

Vancomycin --> can narrow after culture

and remove infected device!

what bacteria causes pharyngitis/strep throat?

strep pyogenes (GABHS)

presentation of pharyngitis/strep throat

- beefy red uvula

- tender anterior cervical lymphadenopathy

- tonsillar hypertrophy with erythema

- sore throat, odynophagia

may have sandpaper rash

dx of pharyngitis/strep throat

clinically, then rapid strep test

how to tx after a rapid strep test for pharyngitis/strep throat

if positive --> treat

if negative --> perform throat culture if high suspicion of bacterial infection --> if positive tx based on bacteria

1st line tx for pharyngitis/strep throat

Benzathine penicillin G (IM)

or PCN VK oral or Amoxicillin

how to tx pharyngitis/strep throat if pt is allergic to PCN?

cephalexin or cefdinir

what bacteria causes scarlet fever

Streptococcus pyogenes (GABHS)

bc it is directly associated with pharyngitis/strep throat

presentation of scarlet fever

- Sandpaper rash

- Strawberry tongue

- Facial flushing with circumoral pallor

- Desquamation can occur

- Forchheimer spots: Small red spots on the soft palate that resolve quickly

tx of scarlet fever

will improve over time once underlying condition has resolved since it is a result of pharyngitis

what bacteria causes Erysipelas?

strep pyogenes (GABHS)

presentation of Erysipelas

painful superficial cellulitis with a dermal lymphatic involvement that frequently involves the face

Erysipelas dx

clinical - if drainage, culture it

outpatient (no systemic involvement) tx of Erysipelas

Penicillin VK or Amoxicillin

inpatient (systemic involvement) tx of Erysipelas

Vancomycin if severe and S. aureus is also suspected

besides GABHS what other bacteria can cause Erysipelas

strep aureus

what bacteria causes group B strep

Streptococcus agalactiae (GBBHS)

what is GBBHS/presentation of GBBHS?

bacteria that commonly grows in GU/GI tract without causing symptom

dx of Group B strep

pregnancy screening at 35 wks gestation via vaginal and rectal swab bc the bacteria transfers from GI or GU to infants in the birth canal

group B strep can lead to neonatal _______

sepsis

if the swab for Group B strep is positive what is the tx

PCN G or ampicillin

what bacteria if group D strep

strep bovis

strep D s/s

- systemic: fever, malaise, night sweats

- septic emboli: stroke like or PE symptoms

1st line tx for group D strep

Penicillin G

where is GDBHS most commonly seen?

endocarditis, but it is not the most common bacteria for endocarditis

what bacteria can cause otitis media?

Strep pneumo

M. cat

H. flu

presentation of otitis media?

erythematous, bulging TM

dx of otitis media

clinical

1st line tx of otitis media

amoxicillin

tx of otitis media if pt has a PCN allergy

doxycycline

what bacteria cause acute sinusitis?

most commonly starts as viral with a secondary bacterial infection from:

- strep pneumo

- M. cat

- H. flu

presentation of acute sinusitis

- maxillary/frontal sinus pressure

- purulent rhinorrhea

- reduced transillumination

- erythematous, swollen nasal turbinates

- nasal congestion

dx of acute sinusitis

clinical

1st line tx for acute sinusitis

amoxicillin/clavulanate (augmentin)

what bacteria is the most common cause of community acquired pneumonia?

streptococcus pneumonia

what bacteria caused pneumococcal pneumonia, the most common CAP?

streptococcus pneumonia

presentation of pneumococcal pneumonia

rust colored sputum!!

bronchial breath sounds early, then crackles in affected lobe

dx of pneumococcal pneumonia

CXR: lobar consolidation

no sputum culture in otherwise healthy pt but do a culture in pt with comorbidities

first line outpatient tx of pneumococcal pneumonia

healthy pt: amoxicillin

pt with comorbidities: levofloxacin

pneumococcal pneumonia vaccine in adults

PCV20 alone or PCV15 --> PPSV23

routine pneumococcal pneumonia vaccine in children

PCV15 or PCV20 at 2,4,6, 12-15 months

what are the two main bacteria that causes meningitis

S. pneumonia (Pneumococcal) and N. meningitidis (Meningococcal)

presentation of pneumococcal meningitis

- fever, HA, stiff neck

- positive kernig and brudzinski signs

- if pneumococcal may have URI associated symptoms and more focal neuro deficits

dx of meningitis (S. pneumonia and N. meningitidis)

lumbar puncture with CSF analysis

gram stain and culture

tx of S. pneumonia meningitis

vancomycin and 3rd gen cephalosporin

tx of strep viridians

PCN G

where is strep viridians found

affects heart valves (endocarditis by travelling from oral cavity where it colonizes)

what are the two enterococcus species

E. faecalius and E. faecium

tx of endocarditis caused by an enterococcus

ampicillin + gentamicin

tx of skin/wound/UTI infections caused by enterococcus

ampicillin or vancomycin

tx of VRE

linezolid or daptomycin

what bacteria causes anthrax

Bacillus anthracis

How is anthrax transmitted?

via contact with infected animals or their products

- cutaneous (MC)

- ingestion

- inhalation

NOT transmitted person to person

presentation of anthrax

painless black eschar!!

presentation of anthrax if infested?

bloody diarrhea

presentation of anthrax if inhaled?

insidious onset of flu-like symptoms and associated mediastinitis and pleural effusion

dx of anthrax

- culture and gram stain

- CXR with pulm symptoms

- lumbar puncture if systemic to r/o meningitis

antibiotic tx of anthrax all 1st line highlighted!!

Doxycycline

OR

Minocycline

OR

Ciprofloxacin

OR

Levofloxacin

what bacteria causes "fried rice syndrome" from eating leftovers or rice or food left out at room temp

Bacillus cereus

tx of fried rice syndrome

self-limiting can do supportive tx like fluids and rest

which bacteria causes Listeriosis

Listeria monocytogenes

how is Listeriosis transmitted?

ingestion of contaminated food

- dairy/queso fresco cheese

- raw veggies

- meat

presentation of Listeriosis?

- flu-like symptoms

- bacteremia

- meningitis

- dermatitis

- oculoglandular symptoms

dx of Listeriosis

culture blood and CSF

tx of Listeriosis

Ampicillin AND Gentamicin - synergistic for first few days

then..

Amoxicillin outpatient for 2-3 wks

greatest risk of Listeriosis is during ______________

pregnancy

causing spontaneous abortions and neonatal meningitis