Microbiology: Systems

Staph epidermidis

Staph epidermidis

Colonized by Staph aureus

Viridans Group Streptococci

Strep mutans

Bacteroides fragilis > E. coli

Lactobacillus

Colonized by E coli and Group B Strep

• Vibrio parahaemolyticus/vulnificus
• -Contaminated seafood

• Bacillus cereus
• -reheated rice
• -"Food poisoning from reheated rice? Be serious!"

• S. aureus (preformed toxin)
• -meats
• -mayo
• -custard

• Clostridium perfringens
• -reheated meat dishes

• C. botulinum
• -improperly canned foods
• -honey

• E. coli O157:H7
• -undercooked meat

• Salmonella:
• -poultry
• -meat
• -eggs

• -S aureus
• -B cereus

"mesenteric adenitis"

Yersinia enterocolitica

Nontyphoidal Salmonella

Campylobacter jejuni

• Campylobacter
• -Comma or S shaped
• -growth at 42C

• Salmonella
• -lactose negative
• -flagellar motility
• -animal reservoir
• -poultry and eggs

• Shigella
• -lactose negative
• -low ID50
• -Shiga toxin
• -only human reservoir

• EHEC:
• -O157:H7
• -can cause HUS
• -Shiga-like toxin

• EIEC:
• -invades colonic mucosa

• Yersinia enterocolitica:
• -day-care outbreaks
• -pseudoappendicitis

• Entamoeba histolytica:
• -protozoan

• ETEC:
• -Traveler's diarrhea
• -ST and LT toxins

• Vibrio cholerae:
• -comma shaped
• -rice water diarrhea

• C. difficile:
• -can also cause bloody diarrhea
• -pseudomembranous colitis

• C. perfringens:
• -also causes gas gangrene

• Protozoa:
• -Giardia
• -Cryptosporidium (in immunocompromised)

• Viruses:
• -rotavirus
• -norovirus

• -Group B streptococci
• -E coli

• -Viruses (RSV)
• -Mycoplasma
• -Chlamydia trachomatis (infants - 3 years)
• -C. pneumoniae (school age)
• -Streptococcus pneumo

"Runts May Cough Chunky Sputum"

• -Mycoplasma
• -C. pneumo
• -S. pneumo

• -S. pneumo
• -H. flu
• -Anaerobes
• -Viruses
• -Mycoplasma

• -S. pneumo
• -Influenza virus
• -Anaerobes
• -H. flu
• -GNRs

• -Staphylococcus
• -enteric GNRs

• -Staphylococcus
• -enteric GNRs
• -fungi
• -viruses
• -PCP (HIV)

-anaerobes

• -S. pneumo
• -Klebsiella
• -Staphylococcus

• -Pseudomonas
• -S. aureus
• -S. pneumo

• -Staphylococcus
• -H. flu
• -Strep pneumo

• -Mycoplasma
• -Legionella
• -Chlamydia

• -Group B strep
• -E. coli
• -Listeria

• -S. pneumo
• -N. meningitidis
• -H flu B
• -Enterovirus

• -S pneumo
• -N. meningitidis (#1 in teens)
• -Enterovirus
• -HSV

• -S. pneumo
• -GNRs
• -Listeria

• -Enterovirus (esp Coxsackie)
• -HSV2 (HSV causes encephalitis)
• -HIV
• -West Nile Virus
• -VZV

• -Cryptococcus
• -CMV
• -Toxoplasmosis
• -JC virus (PML)

• -Ceftriaxone and vancomycin empirically
• -Add ampicilin if Listeria is suspected

• ↑ Opening Pressure
• ↑ PMNs
• ↑ Protein
• ↓ Glucose

• ↑ Opening Pressure
• ↑ Lymphocytes
• ↑ Protein
• ↓ Glucose

• Normal/↑ Opening Pressure
• ↑ Lymphocytes
• Normal/↑ Protein
• Normal Glucose

• If no other info available, assume:
• -S. aureus

• Sexually Active:
• -septic arthritis (more common)
• -Neisseria gonorrhea (rare)

• Diabetes and IV drug users:
• -Pseudomonas
• -Serratia

• Sickle Cell:
• -Salmonella

• Prosthetic Replacement:
• -S. aureus
• -S. epidermidis

• Vertebral Disease:
• -TB (Pott's)

• Cat and Dog bites/scratches:
• -Pasteurella multocida

• ⊕ Leukocyte esterase = bacterial
• ⊕ Nitrate test = GN
• ⊕ Urease test = Proteus, Klebsiella
• ⊖ Urease test = E coli, Enterococcus

• E coli
• -leading cause
• -green sheen on EMB

• Staph. saprophyticus
• -second leading cause of community-acquired UTI in sexually active women

• Klebsiella pneumo:
• -third leading cause
• -large mucoid capsule

• Serratia marcescens
• -red pigment
• -often nosocomial and drug resistance

• Enterobacter cloacae
• -often nosocomial and drug resistant

• Proteus mirabilis:
• -swarming motility
• -produces  urease
• -struvite stones

• Pseudomonas:
• -blue-green
• -fruity odor
• -nosocomial, drug resistance

Microbes that pass from mother to fetus (usually transplacental)

• Common sx:
• -HSM
• -jaundice
• -thrombocytopenia
• -growth retardation

• Toxoplasma gondii
• Rubella
• CMV
• HIV
• Herpes simplex virus 2
• Syphilis

• Additional Infections (all cause meningitis)
• -Group B strep
• -E coli
• -Listeria

Parvo B19 causes hydrops fetalis

• Mode of Transmission:
• -cat feces
• -ingestion of undercooked meat

• Maternal Manifestations:
• -usually asymptomatic
• -rare lymphadenopathy

• Neonatal Manifestations (triad):
• -chorioretinitis
• -hydrocephalus
• -intracranial calcifications

• Mode of Transmission:
• -respiratory droplets

• Maternal Manifestations:
• -rash
• -lymphadenopathy
• -arthritis

• Neonatal Manifestations (triad):
• -PDA (pulmonary artery hyperplasia
• -cataracts
• -deafness
• -+/- "blueberry muffin" rash

• Mode of Transmission:
• -sexual contact
• -organ transplants

• Maternal Manifestations:
• -usually asx
• -mononucleois-like sx

• Neonatal Manifestations:
• -hearing loss
• -seizures
• -petechial rash
• -"blueberry muffin" rash

• Mode of Transmission:
• -sexual contact
• -needle stick

• Maternal Manifestations:
• -variable depending on CD4 count

• Neonatal Manifestations:
• -recurrent infections
• -chronic diarrhea

• Mode of Transmission:
• -skin or mucous membrane contact

• Maternal Manifestations:
• -usually asx
• -vesicular lesions

• Neonatal Manifestations:
• -encephalitis
• -herpetic vesicular lesions

• Mode of Transmission:
• -sexual contact

• Maternal Manifestations:
• -chancre (primary)
• -disseminated rash (secondary)

• Neonatal Manifestations:
• -still birth
• -hydrops fetalis
• -facial abnormalities (dry, wrinkled skin, addle nose, short maxilla)
• -Hutchinson's teeth (notched, widely spaced central incisors)
• -saber shins
• -CN VIII deafness

• Rubella
• Measles
• VZV
• HHV 6
• Parvo B19
• S. pyogenes
• Coxsackie virus A

• -begins at head and moves down
• -fine truncal rash (spares hands and feet?)
• -postauricular lymphadenopathy

• -begins at head and moves down
• -preceded by cough, coryza, conjunctivitis, blue-white (Koplik) spots
• -includes hands and feet (vs. Rubella)

• Chicken pox
• -vesicular rash
• -begins on trunk
• -spreads to face and extremities
• -lesions of different age

• Roseola
• -macular rash over body
• -appears after several days of high fever
• -can present with febrile seizures
• -usually infants

• Erythema infectiosum
• -"slapped cheek" rash on face
• -can cause hydrops fetalis in pregnant women

• Scarlet Fever
• -erythematous, sandpaper-like rash
• -spares face
• -fever and sore throat

• Hand-foot-mouth disease
• -vesicular rash and palms and soles
• -ulcers in oral mucosa

• -Gonorrhea
• -Syphilis
• -Chanroid
• -Genital herpes
• -Chlamydia
• -Lymphogranuloma venereum
• -Trichomoniasis
• -AIDS
• -Condylomata acuminata
• -Hepatitis B
• -Bacterial vaginosis

• Neisseria gonorrhea
• -urethritis
• -cervicitis
• -PID
• -prostatitis
• -epididymitis
• -arthritis
• -creamy purulent discharge

Treponema pallidum

• Primary syphilis
• -painless chancre

• Secondary syphilis
• -fever
• -lymphadenopathy
• -skin rashes
• -condylomata lata

• Tertiary Syphilis
• -gummas
• -tabes dorsalis
• -general paresis
• -aortitis
• -Argyll Robertson pupil

• Haemophilus ducreyi
• "it's so painful, you do cry"

• -painful genital ulcer
• -inguinal adenopathy

• HSV2, HSV1 (less common)
• -painful penile, vulvar or cervical vesicles and ulcers
• -systemic sx: fever, HA, myalgia

Chlamydia trachomatis (D-K)

• -most common STD
• -urethritis
• -cervicitis
• -conjunctivitis
• -Reiter's syndrome
• -PID

Chlamydia trachomatis (L1-L3)

• -infection of lymphatics
• -genital ulcers
• -lymphadenopathy
• -rectal strictures

Trichomonas vaginalis

• -vaginitis
• -strawberry colored mucosa
• -motile in wet prep

HIV

• -opportunistic infections
• -Kaposi's sarcoma
• -lymphoma

HPV 6, 11

• -genital warts
• -koilocytes

HBV

-jaundice

Gardnerella vaginalis

• -Noninflammatory, malodorous discharge (fishy)
• -positive whiff test
• -clue cells
• -not exclusively an STD

• Top bugs:
• -Chlamydia trachomatis (subacute, often undiagnosed)
• -Neisseria gonorrhea (acute)

• -CMV,RSV
• -E coli, Proteus mirabilis
• -Pseudomonas
• -HBV
• -Candida albicans
• -Legionella

-new born nursery

• -urinary catheterization
• -E coli is second most common causes of nosocomial infections

-respiratory therapy equipment

"Presume pseudomonas "airguinosa" when air or burns are involved"

-work in renal dialysis unit

-hyperalimentation

-water aerosols

Rash

• Rubella
• -begins at head and moves down
• -post auricular adenopathy
• Measles
• -begins at head and moves down
• -preceded by cough, coryza and conjunctivitis, Koplik spots

Meningitis

HIB: microbe colonizes nasopharynx

Poliovirus: can also lead to myalgias and paralysis

• Pharyngitis
• -Corynebacterium diphtheriae: grayish oropharyngeal exudate, painful throat

• Epiglottitis:
• -HIB: fever with dysphagia, drooling and difficult breathing, Cherry red epiglottis

S. aureus

H. flu

-Pseudomonas

Actinomyces israelii

C. perfringens

-S. aureus

Pasteurella multocida

Klebsiella

Tropheryma whipplei (Whipple's disease)

Group B strep

HBV (needle stick)

Mucor or Rhizopus

-encapsulated microbes

• SHiN
• -S. pneumo
• -H. influenza type B
• -N. meningitidis

• Catalase positive microbes
• -especially S. aureus

• Candida albicans (systemic)
• Aspergillus

-Borrelia burgdorferi (lyme disease)