Step 1 - Micro 6

denniskwinn's version from 2015-04-25 16:10


Question Answer
HIV diagnosis1. Presumptive with ELISA (sensitive) 2. Confirm with western (specific) 3. PCR/viral load tests to monitor effect of drug therapy
AIDS diagnosisHIV + with CD4 count < 200 (normal 500-1500), or HIV+ with AIDs indicator (opportunistic infection)
Opportunistic Brain infections in AIDS1. Cryptococcal meningitis, 2. Toxoplasmosis 3. CMV encephalopathy 4. AIDs dementia 5. PML (JC virus)
Opportunistic Eye infections in AIDSCMV retinitis
Opportunistic Mouth and Throat infections in AIDSThrush (candida albicans), HSV, CMV, Oral hairy leukoplakia (EBV)
Opportunistic Lung infections in AIDSPneumocystic jiroveci pneumonia (PCP), TB, histoplasmosis
Opportunistic GI infections in AIDSCryptosporidiosis, Mycobacterium avium-intracellulare complex, CMV colitis, non-Hodgkins lymphoma(EBV), Isospora belli
Opportunistic Sking infections in AIDSShingles (VZV), Kaposi’s sarcoma (HHV-8)
Opportunistic Genital infections in AIDSGenital herpes, warts and cervical cancer (HPV)
Cd4 < 400 riskOral thrush, tinea pedis, reactivation VZV, reactivation TB, other bacterial infections (H. Flu, S. Pneumo, Salmonella)
Cd4 < 200 riskReactivation HSV, cryptosporidosis, Isospora, disseminated coccidiodomycosis, PCP
Cd4<100 riskCandidal esophagitis, toxoplasmosis, histoplasmosis
Cd4<50 riskCMV retinitis and esophagitis, disseminated m.avium-intracellulare, cryptococcal meningoencephalitis
Neoplasms associated with HIVKaposi’s sarcoma (HHV-8), invasive cervical carcinoma (HPV), primary CNS lymphoma, non-hodgkins lymphoma
HIV encephalitisLate in course of infection, Virus enters CNS in macrophages. -has migroglial nodules with multinucleated giant cells
Prion diseasecaused by conversion of a normal cellular protein to a beta-pleated form which is transmissible and resists degradation and facilitates the conversion of more protein to beta-pleated. Accumulation results in spongiform encephalopathy and dementia, ataxia and death. It can be sporadic (CJD), inherited (Gerstmann-Straussler-Scheinker) or acquired (kuru)
Skin normal floraStaphylcoccus epidermis
Nose normal floraS. Epidermis; colonized by S. Aureus
Oropharynx normal floraviridans group streptococci
Dental plaque normal floraStreptococcus mutans
Colon normal floraBacteroides fragalis > E. Coli
Vagina normal floraLactobacillus colonized by E. Coli and group B strep
Seafood food poisoning Vibrio parahaemolyticus and V. Vulnificus - V. Vulf can calsu infect wounds in contact with contaminated water/shellfish
Reheated rice food poisoningBacillus cereus (starts and ends quickly)
S Aureus food poisoning1. Meats, mayonnaise, custard. 2. Preformed toxin - starts and ends quickly
Reheated meat food poisoningC. Perfringens
Improperly canned foods poisoningC. Botulinum
E Coli O157:H7 food poisoningin undercooked meat
Salmonella food poisoningpoultry, meat and eggs
Blood diarrhea bugs (8)Campylobacter, Salmonella, Shigella, Enterohemorrhagic E. Coli, Enteroinvasive E.coli, Yersinia enterocolitica, C. Difficile, Entamoeba histolytica
Watery diarrhea bugs (5)Enterotoxigenic E.coli, Vibrio cholerae, C. Perfringens, Protozoa, Viruses
Pneumonia in neonates (<4wks)GBS, E. Coli
Pneumonia in Children (4wk-18yr)Viruses (RSV), Mycoplasma, Chlamydia Pneumoniae, Streptococcus pneumonia, (Runts May Cough Sputum)
Pneumonia in Adults (18-40yr)Mycoplasma, C. Pneumoniae, S. Pneumoniae
Pneumonia in older adults (40-65)S.pneumonia, H. Influenza, Anaerobes, Viruse, Mycoplamsa
Pneumonia in elderlyS.pneumonia, Viruse, Anaerobes, H. Influenza, Gram - rods
Nosocomial pneumoniaStaphylococcus, enteric gram - rods
Immunocompromised pneumoniaStaphylococcus, enteric gram - rods, fungi, viruses, Pneumocystis jiroveci (with HIV)
Aspiration pneumoniaAnaerobes
Alcoholic/IV drug user pneumoniaS. Pneumoniae, Klebsiella, Staphylococcus
Cystic fibrosis pneumoniaPseudomonas
Postviral pneumoniaStaphylococcus, H. Influenza
Atypical pneumoniaMycoplasma, Legionella, Chlamydia
Newborn meningitis (0-6mo)GBS, E. Coli, Listeria
Childhood meningitis (<6yr)Streptococcus pneumoniae, Neisseria meningitidis, Haemophilus influenzae type B, Enteroviruses
Adult meningitis bugs N. Meningitidis, Enterovirus, S. Pneumoniae, HSV
Elderly meningitis bugsS. Pneumoniae, Gram - rods, listeria
Viral causes of meningitisEnteroviruses (esp coxsackie), HSV, HIV, West Nile virus, VZV
Meningitis in HIV bugsCryptococcus, CMV, toxoplasmosis, JC (PML)
CSF findings in bacterial meningitis↑ pressure, ↑PMNs, ↑ Protein, ↓ sugar
CSF findings in Fungal/TB meningitis↑ pressure, ↑ lymphocytes, ↑ protein, ↓ sugar
CSF findings in Viral meningitisNormal/↑ pressure, ↑ lymphocytes, Normal/↑ protein, Normal sugar
Most common cause of osteomyelitisS. Aureus - most osteomyelitis occurs in children - elevated CRP and ESR
Osteomyelitis in Sexually activeN. Gonorrhoeae (rare), septic arthritis more common
Osteomyelitis in diabetics and drug addicts Pseudomonas aeruginosa
Osteomyelitis in Sickle cellSalmonella
Osteomyelitis in Prosthetic replacementS. Aureus and S. Epidermis
Osteomyelitis in VertebraeMycobacterium tuberculosis (Pott’s disease)
Osteomyelitis from Cat or dog bite/scratchPasteurella multocida
UTI presentation1. Dysuria, frequency, urgency, suprpubic pain and WBCs in urine.
UTI1. Primarily caused by ascension of microbes from urethra to bladder. 2. Males - infants w/ congenital defects, vesicouteral reflus. 3. Elderly - enlarged prostate 4. Ascension to kidney results in pyelonephritis (fever, chills, flank pain, CVA tenderness, hematuria, WBC casts) 5. 10x more common in women
UTI diagnostic markers 1. Positive leukocyte esterase test = bacterial UTI 2. Positive nitrite test = Gram - bacterial UTI
UTI bugsSSEEK PP - Serratia marcescens, Staphylococcus sarprophyticus, E. Coli, Enterobacter cloacae, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa
Serratia marcescens UTI features1. Sometimes red pigment 2. Often nosocomial and drug resistant
Staphylococcus saprophyticus UTI features1. Second leading cause of community acquired UTI in sexually active women
E Coli UTI features 1. Leading cause of UTI 2. Colonies show metallic sheen on EMB agar
UTI diagnostic markers 1. Leokocyte esterase (positive = bacteria) 2. Nitrite test (positive = gram negative)
Enterobacter cloacae UTI featuresOften nosocomial and drug resisant
Klebsiella pneumonia UTI featuresLarge mucoid capsule and viscous colonies
Proteus mirabilis UTI featuresMotility causes swarming on agar - produces urease, associated with struvite stones
Pseudoomonas aeurginosa UTI featuresBlue-green pigment and fruity odor, usually nosocomial and drug resistant
ToRCHeS infections1. May pass from mother to fetus 2. Nonspecific signs common to many = hepatosplenomegaly, jaundice, thrombocytopenia, growth retardation 3. Other important Strep agalactiae, E. Coli, Listeria
ToRCHeS infectionsToxo, Rubella, CMV, HIV, HSV, Syphilis
Mom to fetus Toxoplasma gondii1. Transmitted to mom from cat feces or undercooked meat 2. Mother is usually asx, rarely with lymphadenopathy 3. Classic triad in neonate: chorioretinitis, hydrocephalus and intracranial calcifications
Mom to fetus Rubella1. Transmitted to mom w/ resp droplets 2. Mother has rash, lymphadenopathy, arthritis 3. Classic triad in neonates: PDA (or pulm artery hypoplasia), cataracts, deafness +/- “bluebarry muffin” rash
Mom to fetus CMV 1. Mom gets from sexual contact, organ transplants 2. Mother usually asymptomatic or mono-like illness 3. Neonate with hearing loss, seizures
Mom to fetus HIV1. Mom gets from sexual contact 2. Mom presents depending on CD4+ 3. Recurrent infections and chronic diarrhea in neonate
Mom to fetus HSV1. Mom gets from skin or mucous membrane contact 2. Mom usually asx, herpetic lesions 3. Neonate has encephalitis, herpetic lesions
Mom to fetus syphilis1. Mom gets from sex 2. Mom present with Chancre (1), disseminated rash (2) or cadriac/neuro disease(3) 3. Neonate could be: stillborn, hydrops fetalis, facial abnormalities (notched teeth, saddle nose, short maxilla, saber shins)
Rubella rashbegins at head and moves down - postauricular lymphadenopathy
Measles virus rashbeginning at head and moving down - preceded by cough, coryza, conjunctivitis, and blue-white buccal mucosa spots
Mumps virus rashno rash - can present with parotitis, meningitis (orchitis or oophoritis in young adults)
VZV rashbegins on trunk; spreads to face and extremities with lesions of different age
HHV-6 rash (Roseola)Macular rash over body appears after several days of high fever; usually affects infants
Parvovirus B19 rash“slapped cheek” rash on face later appears over body in reticular “lace-like” pattern (can cause hydrops fetalis in pregnant women)
Streptococcus pyogenes rashErythematous, sandpaper-like rash with fever and sore throat
Coxsackievirus type A RashVesicular rash on palms and soles, ulcers in oral mucosa
Gonorrhea clinUrethritis, cervicitis, PID, prostatitis, epididymitis, arthritis, creamy purulent discharge
Primary syphilis clin Painless chancre
Secondary syphilis clinFever, lymphadenopathy, skin rashes, condylomata lata
Tertiary syphilis clinGummas, tabes dorsalis, general paresis, aortitis, Argyll robertson pupil
Chancroid clinpainful genital ulcer, inguinal adenopathy - Haemophilus ducreyi
Genital herpes clinPainful penile, vulvar or cervical ulcers - can cause systemic sx such as fever, headache, myalgia -HSV-2
Chlamydia clinUrethritis, cervicitis, conjunctivitis, Reiter’s syndrome, PID - C. Trachomatis (D-K)
Lymphogranuloma venereum clinUlcers, lymphadenopathy, rectal strictures - C. Trachomatis (L1-L3)
Trichomoniasis clinVaginitis, strawberry-colored mucosa - Trichomonas vaginalis
AIDS clinOpportunistic infections, Kaposi’s sarcoma
Condylomata acuminata clingenital warts, koilocytes - HPV 6 and 11
Bacterial Vaginosis clinNoninflammatory malodorous discharge (fishy smell), positive whiff test, clue cells - Gardnerella vaginalis
Top PID bugschlamydia trachomatis, N. Gonorrhea
PID clin1. Cervical motion tenderness 2. Purulent cervical discharge 3. Maybe salpingitis, endometritis, hydrosalpinx, tubo-ovarian abscess
Fitz-Hugh-Curtis syndromeinfection of liver capsule and “violin string” adhesions of parietal peritoneum to liver - can occur from PID
Most common nosocomialE.coli (UTI) and S. Aureus (wound infection)
Newborn nursery nosocomialCMV, RSV
Urinary catheter nosocomialE. Coli, Proteus mirabilis
Respiratory therapy equipment nosocomialPseudomonas aeruginosa
Work in renal dialysis unit nosocomialHBV
Hyperalimentation nosocomialCandida albicans
Water aerosol nosocomialLegionella
HIV + with low grade fevers, cough, hepatosplenomegaly1. Histoplasma capsulatum (pulm sx only in immunocompetent hosts) 2. Shows oval yeast cells within macrophages
HIV+ with fluffy white cottage-cheese lesionsOften on buccal mucosa (C. Albicans)
HIV+ superficial vascular proliferations1. Bartonella henselae (biopsy reveals nphilic inflammation)
HIV+ with superficial neoplastic proliferation of vasculature1. HHV-8 (biopsy reveals lymphocytic inflammation)
HIV+ with chronic watery diarrhea1. Cryptosporidium spp. - 2. Acid-fast cysts seen in stool
HIV+ meningitis1. Cryptococcus neoformans (may also cause encephalitis) 2. Narrow based budding
HIV+ encephalopathy1. JC virus 2. Due to reactivation of latent viruse; results in demyelination
HIV+ Neuro abscesses1. Toxoplasma gondii 2. Ring-enhancing lesions on imaging
HIV+ Retinitis1. CMV 2. Cotton-wool spots on funduscopic exam
HIV+ hairy leukoplakia1. EBV 2. Often on lateral tongue
HIV + Non-hodgkins lymphoma (large cell)1. EBV 2. Often on oropharynx (waldeyer’s ring)
HIV+ Squamous cell carcinoma1. HPV 2. Often in anus (MSM) or cervix
HIV+ Interstitial pneumonia1. CMV 2. Biopsy reveals cells with intranuclear and cytoplasmic inclusion bodies
HIV+ pleuritic pain, hemoptysis, infiltrates on imaging1. Invasive aspergillosis (aspergillus fumigatus)
HIV+ Pneumonia1. Pneumocystis jiroveci 2. Especially w/CD4<200 cells/mm
HIV+ TB like disease1. Mycobacterium avium intracellulare 2. Cd4<50 cells/mm
Rash in unimmunized children1. Rubella virus ( begins on head, moves down, postauricular lymphadenopathy) 2. Measles virus (begins on head and down preceded by cough, coryza, conjunctivitis)
Meningitis in unimmunized children 1. H. Influenzae type B, Poliovirus 2. Microbe colonizes nasopharynx - can lead to myalgia and paralysis
Pharyngitis in unimmunized children1. Corynebacterium diptheria 2. Grayish oropharyngeal exudate (maybe with pseudomembranous obstruction), painful throat 3. Elaborates toxin that causes necrosis in cardiac and CNS)
Epiglottitis in unimmunized children1. H. Influenzae type B (also can cause epiglottitis in fully immunized children 2. Fever w/ dysphagia, drooling and difficulty breathing due to edematous “cherry red” epiglottis
Bug assoc w/ Pus, epyema, abscessS. Aureus
Bug assoc w/ Pediatric infectionHaemophilus influenzae (including epiglottitis)
Bug assoc w/ Pneumonia in cystic fibrosis, burn infectionPseudomonas aeruginosa
Bug assoc w/ Branching rods in oral infection, sulfur granulesactinomyces israeli
Bug assoc w/ Traumatic open woundClostridium perfringens
Bug assoc w/ surgical woundS. Aureus
Bug assoc w/ dog or cat bitePasteurella multocida
Bug assoc w/ currant jelly sputumKlebsiella
Bug assoc w/ Positive PAS stainTropheryma whippelii (Whipple disease)
Bug assoc w/ sepsis/meningitis in newbornGroup B strep
Bug assoc w/ Healt care provider (needle stick)HBV
Fungal infection in diabeticMucor or Rhizopus spp.
Bug assoc w/ asplenic patientEncapsulated microbes, esp SHiN (strep pneumoniae, H. Influenzae type B, N. Meningitidis)
Bug assoc w/ chronic granulomatous diseasecatalase positive microbes (S. Aureus, Nocardia, serratia marcescens, Pseudomonas cepacia, aspergillus
Bug assoc w/ neutropenic patientssystemic candida albicans
Bug assoc w/ bilateral bell’s palsyBorrellia burgdorferi (Lyme disease)