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Gram stain limitations

Treponema (too thin to be visualized), Mycobacteria (high lipid content in cell wall detected by carbolfuchsin in acid-fast stain), Mycoplasma (no cell wall), Legionella pneumophila (primarily intracellular, silver stain), Rickettsia (ntracellular parasite), Chlamydia (intracellular parasite; lacks muramic acid in cell wall).


Giemsa stain

Chlamydia, Borrelia, Rickettsiae, Trypanosomes, Plasmodium


PAS (periodic acid-Schiff)

Stains glycogen, mucopolysaccharides; used to diagnose Whipple disease (Tropheryma whipplei).


Ziehl-Neelsen (carbol fuchsin)

Acid-fast organisms (Nocardia, Mycobacterium)


India ink

Cryptococcus neoformans (mucicarmine can also be used to stain thick polysacchardie capsule red).


Silver stain

Fungi (e.g., Pneumocystis), Legionella, H. pylori


Special culture requirements

H. influenzae (chocolate agar with factors V (NAD+) and X (hematin); N gonorrhoeae, N. meningitidis (Thayer-Martin (or VPN) media - Vancomycin (inhibits gramp-positive organisms), Polyymyxin (inhibits gram-negative organisms except Neisseria), and Nystatin (inhibits fungi); "to connect to Neisseria, please use your VPN client"; B. pertussis (Bordet-Gengou (potato) agar); C diphtheriae (Tellurite agar, Loffler medium); M tuberculosis (lowenstein-Jensen agar); M. pneumoniae (Eaton agar, requires cholesterol); Lactose-fermenting enterics (Pink colonies on MacConkey agar (fermentation produces acid, turning colony pink) E. coli is also grown on eosin-methylene blue (EMB) agar as colonies with green metallic sheen); Legionella (Charcoal yeast extract agar buffered with cysteine and iron); Fungi (Sabouradud agar)


Obligate aerobes

Nocardia, Pseudomonas aeruginosa, and Mycobacterium tuberculosis


Obligate anaerobes

Clostridium, Bacteroides, and Actinomyces


Obligate intracellular

Rickettsia, Chlamydia


Facultative intracellular

Salmonella, Neisseria, Brucella, Mycobacterium, Listeria, Francisella, Legionella, Yersinia pestis


Encapsulated bacteria

"SHiNE SKiS" Streptococcus pneumoniae, Haemophilus influenzae type B, Neisseria meningitidis, Eschericia coli, Salmonella, Klebsiella pneumoniae, and group B Strep


Catalase-positive organisms

Psuedomonas, Listeria, Aspergillus, Candida, E. coli, S. aureus, Serratia


Encapsulated bacteria vaccines

Pneumococcal vaccine, H. influenzae type B, Meningococcal


Urease-positive bugs

Cryptococcus, H. pylori, Proteus, Ureaplasma, Nocardia, Klebsiella, S. epidermidis, S. saprophyticus


Gram-positive lab algorithm

FA 129


Bugs with exotoxins

Corynebacterium diphtheriae (diptheria toxin), Pseudomonas aeruginosa (exotoxin A), Shigella (shiga toxin), EHEC (Shiga-like toxin), ETEC (Heat labile and heat-stablile toxin), Bacillus anthracis (edema factor), Vibrio cholerae (Cholera toxin), Bordetella pertussis (Pertussis toxin), Clostridium tetani (tetanospasmin), Clostridium botulinum (Botulinum toxin), Clostridium perfringens (Alpha toxin), Streptococcus pyogenes (Streptolysin O), Staph aureus (TSST-1), Strep pyogenes (Exotoxin A)



An LPS found in outer membrane of gram-negative bacteria (both cocci and rods)- Edema, Nitric oxide, DIC/Death, Outer membrane, TNF-a, O-antigen, extremely heat stable, IL-1, Neutrophil chemotaxis


Staphylococcus aureus

Gram-positive cocci in clusters. Protein A (virulence factor) binds Fc-IgG, inhibiting complement activation and phagocytosis. Commonly colonizes the nose. Causes: Inflammatory disease- skin infections, organ abscesses, pneumonia (often after influenza virus infection), endocarditis, and osteomyelitis; Toxin-mediated disease - toxic shock syndrome (TSST-1), scalded skin syndrome (exfoliative toxin), rapid-onset food poisoning (enterotoxins); MRSA (methicillin-resistant S. aureus) infection - important cause of serious nosocomial and community-acquired infections, resistant to methicillin and nafcillin because of altered penicillin-binding protein


Staphylococcus epidermidis

Infects prosthetic devices and intravenous catheters by producing adherent biofilms. Component of normal skin flora; contaminates blood cultures. Novobiocin sensitive


Staphylococcus saprophyticus

Second most common cause of uncomplicated UTI in young women (first is E. coli). Novobiocin resistant


Streptococcus pneumoniae

Most common cause of (MOPS): Meningitis, Otitis media (children), Pneumonia, Sinusitis. Lancet-shaped, gram-positive diplococci. Encapsulated. IgA protease. Pneumococcus is associated with "rusty" sputum, sepsis in sickle cell anemia and splenectomy. No virulence without capsule.


Viridans group streptococci

Viridans strep are a-hemolytic. They are normal flora of the oropharynx and cause dental caries (strep mutans) and subacute bacterial endocarditis at damaged valves (S. sanguinis). Resistant to optochin, differentiating them from S. pneumoniae.


Streptococcus pyogenes (group A streptococci)

Causes: Pyogenic - pharyngitis, cellulitis, impetigo; Toxigenic - scarelt fever, toxic shock-like syndrome, necrotizing fascitis; Immunologic - rheumatic fever, acute glomerulonephritis. Bacitracin sensitive. Antibodies to M protein enhance host defenses against S. pyogenes but can give rise to rheumatic fever. ASO titer detects recent S. pyogenes infection. JONES criteria for rheumatic fever: Joints (polyarthritis), O (carditis), Nodules (subcutaneous), Erythema marginatum, Sydenham chorea. Pharyngitis can result in rheumatic fever and glomerulonephritis. Impetigo more commonly precedes glomerulonephritis than pharyngits. Scarlet fever: scarlet rash with sandpaper-like texture, strawberry tongue, circumoral pallor.


Streptococcus agalactiae (GBS)

Bacitracin resistant, b-hemolytic, colonizes vagina; causes pneumonia, meningitis, and sepsis, mainly in babies. Produces CAMP (authors of test) factor, which enlarges the area of hemolysis formed by S. aureus. Hippurate test +. Screen pregnant women at 35-37 weeks. Patients with + culture receive intrapartum penicillin prophylaxis.


Enterococci (group D strep)

Enterococci (E. faecalis and E. faecium) are normal colonic flora that are penicillin G resistant and cause UTI, biliary tract infections, and subacute endocarditis (following GI/GU procedures). Lancefield group D includes the enterococci and the nonenterococcal group D streptococci. Lancefield grouping is based on differences in the C carbohydrate on the bacterial cell wall. Variable hemolysis. VRE are an important cause of nosocomial infection.


Streptococcus bovis (group D strept)

Colonizes the gut. Can cause bactermia and subacute endocarditis in colon cancer patients.


Corynebacterium diphtheriae

Causes diphtheria via exotoxin encoded by B-prophage. Potent exotoxin inhibits protein synthesis via ADP-ribosylation of EF-2. Symptoms include pseudomembranous pharyngitis (grayish-white membrane) with lymphadenopathy, myocarditis, and arrythmias. Lab diagnosis based on gram-positive rods with metachromatic (blue and red) granules and Elek test for toxin. Toxoid vaccine prevents diphtheria. Black colonies on cystine-tellurite agar.


Spores: bacterial

Some bacteria can form spores at the end of the stationary phase when nutrients are limited. Spores are highly resistant to heat and chemicals. Have dipicoloinic acid in their core. Have no metabolic activity. Must autoclave to kill spores (as is done to surgical equipment) by steaming at 121 C for 15 minutes. Spore-forming gram-positive bacteria found in soil: Bacillus anthracis, Clostridium perfringens, C. tetani. Other spore formers include B. cereus, C. botulinum, Coxiella burnetti


Actinomyces vs Nocardia

Both form long, branching filaments resembling fungi.
Actinomyces (Gram-postive anaerobe, not acid fast, normal oral flora, causes oral/facial abscesses that drain through sinus tracts, form yellow "sulfur granules", treat with penicillin)
Nocardia (Gram-positive aerobe, Acid fast (weak), found in soil, causes pulmonary infections in immunocompromised and cutaneous infections after trauma in immunocompetent, treat with sulfonamides)


Leprosy (Hansen disease)

Caused by Mycobacterium leprae, an acid-fast bacillus that likes cool temperatures (infects skin and superficial nerves- "glove and stocking" loss of sensation) and cannot be grown in vitro. Reservoir in United states: armadillos. Hansen disease has 2 forms: Lepromatous - presents diffusely over the skin, with leonine (lion-like) facies, and is communicable; characterized by low cell-mediated immunit with a humoral Th2 response. Tuberculoid - limited to a few hypoesthetic, hairless skin plaques; characterized by high cell-mediated immunity with a largely Th1-type immune response. Treatment: multidrug therapy consisting of dapsone and rifampin for 6 months for tuberculoid form; and dapsone, rifampin, and clofazimine for 2-5 years for lepromatous form.


Gram-negative algorithm

FA 136


Lactose-fermenting enteric bacteria

Grow pink colonies on MacConkey agar. Citrobacter, Klebsiella, E. coli, Enterobacter, and Serratia. E. coli produces B-galactosidase, which breakes down lactose into glucose and galactose. EMB agar - lactose fermenters grow as purple/black colonies. E. coli grows purple colonies with a green sheen.



Gram-negative diploccoci. Both ferment glucose (but meningococci also ferments maltose) and produce IgA proteases. N. gonorrhoeae is often intracellular


N. gonococci

No polysaccharide capsul, no maltose fermentation, no vaccine (due to rapid antigenic variation of pilus proteins), Sexually transmitted, causes gonorrhea, septic arthritis, neonatal conjunctivitis, pelvic inflammatory disease (PID), and FItz-Hugh-Curtis syndrome. Condoms prevent sexual transmission. Erythromycin oinment prevents neonatal transmission. Treatment: ceftriaxone + (azithromycin or doxycycline) for possible chlamydia coinfection


N. meningococci

Polysaccharid capsule, maltose fermentation, vaccine (none for type B), respiratory and oral secretions, causes meningococcemia and meningitis, Waterhouse-Friderichsen syndomre, Rifampin, cirprofloxacin, or ceftriaxone prophylaxis in close contacts. Treatment: ceftriaxone or penicillin G


Haemophilus influenzae

Small gram-negative (coccobacillary) rod. Aerosol transmission. Most invasive disease caused by capsular type B. Nontypeable strains cause mucosal infections (otitis media, conjunctivitis, bronchitis). Produces IgA protease. Culture on chocolate agar requies factors V (NAD) and X (hematin) for growth; can also be grown with S. aureus, which provides factor V. Haemophilus causes epiglotitis, meningitis, otitis media, and pneumonia. Treat mucosal infections with amoxicillin +/- clavulanate. Treat meningits with ceftriaxone. Rifampin prophylaxis in close contacts. Does not cause the flu. Vaccine contains type B capsular polysaccharide conjugated to diphtheria toxoid or other protein. Given between 2 and 18 months of age.


Legionella pneumophila

Gram-negative rod. Gram stains poorly - use silver stain. Grow on charcoal yeast extract culture with iron and cysteine. Detected clinically by presence of antigen in urine. Aerosol transmission from environmental water source habitat. No person-to-person transmission. Treatment: macrolide or quinolone.
Legionnaires' disease - sever pneumonia, fever, GI and CNS symptoms.
Pontiac fever - mild flu-like syndrome


Pseudomonas aeruginosa

Aerobic gram-negative rod. Non-lactose fermenting, oxidase +. Produces pyocyanin (blue-green pigment); has a grape-like odor. Water source. Produces endotoxin (fever, schock) and exotxoin A (inactivates EF-2). Pseudomonas is assocated with wound and burn infections, Pneumonia (especially cystic fibrosis), Sepsis, External otitis (swimmer's ear), UTI, Drug use and Diabetic Osteomyelitis, and hot tub folliculitis. Malignant otitis externa in diabetics. Echthyma gangrenosum - rapidly progressive, necrotic cutaneous lesions caused by Pseudomonas bacteremia. Typically seen in immunocompromised patients. Treatment: aminoglycoside plus extended-spectrum penicillin (e.g. piperacillin, ticarcillin, cefepime, imipenem, meropenem).



An intestinal flora that causes lobar pneumonia in alcoholics and diabetics when aspirated. Very mucoid colonies caused by abundant polysaccharide capsules. Red "currant jelly" sputum. Also cause of nosocomial UTIs.


Salmonella vs Shigella

Salmonella (have flagella, can disseminate hematogenously, have many animal reservoirs, produce hydrogen sulfide, antibiotics may prolong fecal excretion of organism, invades intestinal mucosa and causes a monocytic response, can cause bloody diarrhea, does not ferment lactose)
Shigella (no flagella, cell to cell transmission; no hematogenous spread, only reservoirs are humans and primates, does not produce hydrogen sulfide, antibiotics shorten duration of fecal excretion of organism, invades intestinal mucosa and cuases PMN infiltration, often causes bloody diearrhea, does not ferment lactose)


Salmonella typhi

Causes typhoid fever. Found only in humans. Characterized by rose spots on the abdomen, fever, headache, and diarrhea. Can remain in gallbladder and cause a carrier state.


Campylobacter jejuni

Major cause of bloody diarrhea, expecially in children. Fecal-oral transmission through foods such as poultry, meat, unpasteurized milk. Comma or S-shaped, oxidase +, grows at 42 C. Common antecedent to Guillain-Barre syndrome and reactive arthritis.


Vibrio cholerae

Produces rice-water diarrhea via entertoxin that permantly activates Gs, inc cAMP. Comma shaped, oxidase +, grows in alkaline media. Endemic to developing countries. Prompt oral rehydration is necessary.


Yersinia enterocolitica

Usually transmitted from pet feces (e.g. puppies), contaminated milk, or pork. Causes mesenteric adenitis that can mimic Crohn disease or appendicitis.


Helicobacter pylori

Causes gastritis and peptic ulcers (especially duodenal). Risk factor for peptic ulcer, gastric adenocarcinoma and lymphoma. Curved gram-negative rod that is catalase, oxidase, and urease + (can use urea breath test or fecal antigen test for diagnosis). Creates alkaline environment. Most common initial treatment is triple therapy: proton pump inhibitor + clarithromycin + either amoxicillin or metronidazole.



Spiral-shaped bacteria with axial filaments and include Borrelia (big size), Leptospira, and Treponema. Only Borrelia can be visualized using aniline dyes (Wright or Giemsa stain) in light microscopy. Treponema is visualized by dark-field microscopy


Leptospira interrogans

Found in water contaminated with animal urine, causes leptospirosis: flu-like symptoms, jaundice, photophobia with conjunctival suffusion (erythema without exudate). Prevalen amon surfer and in tropics (i.e. Hawaii). Weil disease (icterohemorrhagic leptospirosis) - severe form with jaundice and azotemia from liver and kidney dysfunction; fever, hemorrhage, and anemia.


Lyme disease

Borrelia burgdorferi, which is transmitted by the tick Ixodes (also a vector for babesia). Natural reservoir is the mouse. Common in northeaster US - Initial symptoms - erythema chronicum migrans, flu-like symptoms, +/- facial nerve palsy. Later symptoms - monoarthritis (large joints) and migratory polyarthrits, cardia (AV nodal block), neuologic (encephalopathy, facial nerve palsy, polyneuropathy). Treatment: doxycycline, ceftriaxone.



Caused by spirochet Treponema pallidum. Treatment penicillin G
Primary - Localized disease presenting with painless chancre. If available, use dark-field microscopy to visualize treponemes in fluid from chancre. Serologic testing: VDRL/RPR (non-specific), confirm diagnosis with specific test (e.g., FTA-ABS).
Secondary - Disseminated disease with constituational symptoms, maculopapular rash (palms and soles), conylomata lata (also confirmable with dark-field microscopy). Serologic testing: VDRL/RPR (non-specific), confirm diagnosis with specific test (e.g., FTA-ABS).
Tertiary - Gummas (chronic granulomas), aortitis (vasa vasorum destruction), neurosyphilis (tabes dorsalis, "general paresis"), Argyll Roberston pupil. Signs: broad-based ataxia, + Romberg, Charcot joint, stroke without hypertension. For neurosyphilis: test spinal fluid with VDRL or RPR.
Congenital - Saber shins, saddle nose, CN VIII deafness, Hutchinson teeth, mulberry molars. To prevent, treat mother early in pregnancy, as placental transmission typically occurs after first trimester.


VDRL false positives

VDRL detects nonspecific antibody that reacts with beef cardiolipin. Inexpensive, widely available test for syphilis, quantitative, sensitive but not specific. Many false positives, including viral infection (e.g., mononucleosis [EBV], hepatitis), some drugs, and SLE


Jarisch-Herxheimer reaction

Flu-like syndrome after antibiotics are started - due to killed bacteria releasing pyrogens.


Zoonotic bacteria

Anaplasma spp. - Anaplasmosis (Ixodes ticks)
Bartonella spp - Cat scratch disease, bacillary angiomatosis (cat scratch)
Borrelia burgdorferi - Lyme disease (Ixodes ticks)
Borrelia recurrentis - relapsing fever (Louse, recurrent due to various surface antigens)
Brucella spp. - Brucellosis/ undulant fever (unpasteurized dairy)
Campylobacter - Bloody diarrhea (Puppies, livestock (fecal-oral, ingestion of undercooked meat)
Chlamydophila psittaci - Psittacosis (parrots, other birds)
Coxiella burnetii - Q fever (Aerosols of cattle/sheep amniotic fluid)
Ehrlichia chaffeensis - Ehrlichiosis (Lone Star ticks)
Francisella tularensis - Tularemia (Ticks, rabbits, deer fly)
Leptospira spp. - Leptospirosis (animal urine)
Mycobacterium leprae - Leprosy (Humans w/leprosy; armadillo)
Pasteurella multocida - Cellulitis, osteomyelitis (animal bite, cats, dogs)
Rickettsia prowazekii - Epidemic typhus (louse)
Rickettsia rickettsii - Rocky mountain spotted fever (Dermacentor ticks)
Rickettsia typhi - Endemic typhus (Fleas)
Yersinia pestis - Plague (Fleas (rats and prarie dogs are vectors))


Garnderella vaginalis

A pleomorphic, gram-variable rod that is involved in vaginosis. Presents as a gray vaginal discharge with a fishy smell; nonpainful (vs. vaginitis). Associated with sexual activity, but not sexually transmitted. Bacterial vaginosis is also characterized by overgrowth of certain anaerobic bacteria in vagina. Clue cells, or vaginal epithelial cells covered with Gardnerlla bacteria are visible under microscope. Treatment: metronidazole or (to treat anaerobic bacteria) clindamycin


Rocky Mountain spotted fever

Rickettsia rickettsii, vector is tick. Despite its name, disease occurs primarily in the South Atlantic states, especially North Carolina. Rash typically starts at wrists and ankles and then spreads to trunk, palms, and soles. Rickettsia are obligate intracellular organisms that need CoA and NAD+ becuase they cannot synthesize ATP.



Endemic (fleas) - R. typhi. Epidemic (human body oouse) - R. prowazekii. Rash starts centraly and spreads out, sparing palms and soles.



Ehrlicia; vector is tick. Monocytes with morulae in cytoplasm.



Anaplasma, vector is tick. Granulocytes with morulae in cytoplasm.


Q fever

Coxiella burnetii; no arthropod vector. Tick feces and cattle placenta release spores that are inhaled as aerosols. Presents as pneumonia.



Chlamydiae cannot make their own ATP. They are obligate intracellular organisms that cause mucosal infections. 2 forms: elementary body (small, dense) is "Enfectious" and Enters cell via Endocytosis; transforms into reticulate body. Reticulate body Replicates in cell by fission; reorganizes into elementary bodies. Chlamydia trachomatis causes reactive arthrits (Reiter syndrome), follicular conjunctivitis, nongonococcal urethritis, and PID. C. pneumoniae and C. psittaci cause atypical pneumonia; transmitted by aerosol. Treatment: azithromycin (one-time RX) or doxycyline.


Chlamydia trachomatis serotypes

Types A, B, and C (Chronic infection, cause blindness due to follicular conjunctivits in Africa)
D-K (Urethritis/PID, ectopic pregnancy, neonatal pneumonia (staccato cough), neonatal conjunctivits)
L1-L3 (Lymphogranuloma venerum - smal, painless ulcers on genitals -> swollen, painful inguinal lymph nodes that ulcerate ("buboes"). Treat with doxycycline


Mycoplasma pneumoniae

Classic cause of atypical "walking" pneumonia (insidious onset, headache, nonproductive cough, patchy or diffuse interstitial infiltrate). X-ray looks worse than patient. High titer of cold agglutinins (IgM), which can agglutinate or lyse RBCs. Grown on Eaton agar. Treatment: macrolide, doxycyline, or fluoroquinolone (penicillin ineffective no cell wall)


Systemic mycoses



Giardia lamblia

Giardiasis: bloating, flatulence, foul-smelling, fatty diarrhea (often seen in campers/hikers). Transmission - cysts in water. Dx - Trophozoites or cysts in stool. Tx - Metronidazole


Entamoeba histolytica

Amebiasis: bloody diarrhea (dysentery), liver abscess ("anchovy paste" exudate), RUQ pain (histology shows flask-shaped ulcer if submucosal abscess of colon ruptures) Transmission cysts in water. Diagnosis - Serology and/or trophozoites (with RBCs in the cytoplasm) or cysts (with up to 4 nuclei) in stool. Tx- Metronidazole; iodoquinol for asymptomatic cyst passers



Severe diarrhea in AIDS. Mild disease (water diarrhea) in nonimmunocompromised. Transmission - Oocysts in water. Diagnosis - Oocysts on acid-fast stain. Treatment - Prevention (by filtering water supplies); nitazoxanide in immunocompetant hosts.


Toxoplasma gondii

Brain abscess in HIV (seen as ring-enhancing brain lesions on CT/MRI); congential toxoplasmosis = "classic triad" of chorioretinitis, hydrocephalus, and intracranial calcifications. Transmission - cysts in meat or oocysts in cat feces; crosses placenta (pregnant women should avoid cats). Diagnosis - Serology, biopsy (tachyzoite). Treatment - Sulfadiazine + pyrimethamine.


Naegleria fowleri

Rapidly fatal meningoencephalitis. Transmission - swimming in freshwater lakes; enters via cribriform plate. Diagnosis - Amoebas in spinal fluid. Treatment - Amphotericin B


Trypanosoma brucei

African sleeping sickness: enlarged lymph nodes, recurring fever (due to antigenic variation), somnolence, coma. Two subspecies: Trypanosmoa brucei rhodiensiense, Trypanosoma brucei gambiense. Transmission 0 Tsetse flay, a painful bite. Diagnosis - Blood smear. Treatment - Suramin for blood-borne disease or melarsoprol for CNS penetration.


Plasmodium vivax/ovale/falciparum/malariae

Malaria: fever, headache, anemia, splenomegaly. P. vivax/ovale - 48 hr cycle (tertian; includes fever on first day and third day, thus fevers are 48 hr apart; dormant form (hypnozoite) in liver.
P. falciparum - severe; irregular fever patterns; parasitized RBCs occlude capillaries in brain (cerebral malaria), kidneys, lungs
P. malariae - 72 hr cycle
Transmission - Mosquito (Anopheles). Diagnosis - blood smear, throphozoite ring from within RBC, schizont containing merozoites. Treatment - Begin with chloroquine, chich blocks Plasmodium heme polymerase; if resistant, use mefloquine or atovaquone/proguanil. If life-threatening, use intravenous quinidine (test for G6PD deficiency). Vivax/ovale add primaquine for hypnozoite (test for G6PD deficiency)



Babesiosis: fever and hemolytic anemia; predominantly in northeastern United States; asplenia inc risk of severe disease. Transmission - ixodes tick. Diagnosis - blood smear, ring form, "Maltese cross"; PCR. Treatment - Atovaguone + azithromycin


Trypanosoma cruzi

Chagas disease: dilated cardiomyopathy, megacolon, megaesophagus; predominantly in South America. Transmission - Reduviid bug (kissing bug) feces, deposited in a painless bite. Diagnosis - Blood smear. Treatment - Benzndiazole or nifurtimox


Leishmania donovani

Visceral leishmaniasis: spiking fevers, hepatosplenomegaly, pancytopenia. Transmission - Sandfly. Diagnosis - Macrophages containing amastigotes. Treatment - Amphotericin B, sodium stiboguconate.


Trichomonas vaginalis

Vaginitis: foul-smelling, greenish discharge; itching and burning; do not confuse with Gardnerella vaginalis, a gram-variable bacterium associated with bacterial vaginosis. Transmission - Sexual. Diagnosis - Trophozoites on wet mount; "strawberry cervix". Treatment - Metronidazole for patient and partner (prophylaxis)



FA 154 -155


Congenital rubella

Congenital rubella syndrome is predominantly characterized by neonatal defects of the head (microcephaly, mental retardation), eyes (cataracts(, ears (deafness), and heart/cardiovascular system (patent ductus arteriosus, peripheral pulmonic stenosis). The most classic clinical triad of congenital rubella includes congenital cataracts (white pupils), sensory-neural deafness, and patent ductus arteriosus. Live attenuated rubella virus vaccine is currently recommended not only for children at 12-15 months and again at 4-6 years of age, but also in non-pregnant women of childbearing age who lack serum antibody against rubella. At the time of vaccination, women are strongly advise to avoid pregnancy for the next four weeks.


Nematode routes of infection

EAT SAND, Lay LOW to avoid bites. Ingested - Enterobius, Ascaris, Toxocara. Cutaneous - Strongyloides, Ancylostoma, Necator. Bites - Loa loa, Onchocerca volvulus, Wuchereria bancrofti


DNA viral genomes

All DNA viruses except the Parvoviridae are dsDNA. All are linear except papilloma, polyoma, and hepadnaviruses (circular)


RNA viral genomes

All RNA virus except Reoviridae are ssRNA. Postive-stranded RNA viruses: I went to a retro (retrovirus) toga (togavirus) party, where I drank flavored (flavivirus) Corona (cornoavirus) and ate hippy (hepevirus) california (calicivirus) pickles (picornavirus)



Toxoplasmoses, other (syphilis, varicella-zoster, parvovirus B19), Rubella, Cytomegalovirus, and Herpes infections



Diploid genemoe (2 molecules of RNA). The 3 structural genes (protein coded for):
enf (gp120 and gp41): Fromed from cleavage of gp160 to form glycoproteins. gp120 - attachment to host CD4 T cell. gp 41 - fusion and entry.
gag (p24) - capsid protein
pol - reverse transcriptase, aspartate protease, integrase. Reverse transcriptase synthesis dsDNA from RNA; dsDNA integrates into host genome. Virus binds CCR5 (early) or CXCR4 (late) co-receptors and CD4 on T cells; binds CCR5 and CD4 on macrophages. Homozygouse ccr5 = immunity. Heterozygous ccr5= slower course. Dx - ELISA (inc sens) then western (inc spec)


B-lactamase inhibitors

Include Clavulanic Acid Sulbactam, Tazobactam. (CAST). Often added to penicillin antibiotics to protect the antibiotic from destruction by B-lactamase (penicillinase)


Buy AT 30, CCEL at 50

30 S inhibitors - Aminoglycosides, Tetracyclines
50 S inhibitors - Chloramphenicol, Clindamycin, Erythromycin, Linezolid


GET GAP on the Metro

Giardia, Entamoeba, Trichomonas, Garnderella vaginalis, Anaerobes (Bacteroides, C. difficile). Used with a ppi and claithromycin for "triple therapy" against H. pylori


Viral replication

DNA viruses (All replicate in the nucleus (except poxvirus))
RNA virus ( All replicate in the cytoplasm (except influenza virus and retroviruses))


Viral envelopes

Naked (nonenveloped) viruses include - Papillomavirus, Adenomavirus, Parvovirus, Polyomavirus, Calicivirus, Picornavirus, Reovirus, and Hepevirus. DNA (PAPP); RNA (CPR)



Envelope, DS and linear.
HSV-1 - oral (and some genital) lesions, spontaneous temporal lobe encephalitis, keratoconjunctivits
HSV-2 - genital (and some oral) lesions
VZV (HHV-3) - chickenpox, zoster (shingles); vaccine available
EBV (HHV-4) - mononucleosis, Burkitt lymphoma, Hodgkin lymphoma
CMV (HHV-5) - infection in immunosuppressed patients (AIDS retinitis), expecially transplant recipients; congenital defects
HHV-6 - roseola (exanthem subitum)
HHV-7 - less common cause of roseola
HHV-8 - causes Kaposi sarcoma



enveloped, partially DS and circular. HBV: acute or chronic hepatitis, vaccine available - contains HBV surface antigen, not a retrovirus but has reverse transcriptase.



No envelope, DS and linear. Febrile pharyngitis - sore throat; Acute hemorrhagic cystitis, pneumonia, conjunctivitis "pink eye"



no envelope, SS and linear (-). B19 virus - aplastic crisis in sickle cell disease, "slapped cheeks" rash in children - erythema infectiosum (fifth disease), RBC destruction in fetus leads to hydrops fetalis and death, pure RBC aplasia and rheumatoid arthritis - like symptoms in adults



no envelope DS and circular.
JC virus - progressive multifocal leukoenceophalopaty (PML) in HIV
BK virus - transplant patients, commonly targets kidney



envelope ds and linear.
Smallpox, although eradicated, could be used in germ warfare.
Cowpox ("milkmaid blisters")
Molluscum contagiosum - flesh-colored dome lesions with central umbilicated dimple



no envelope, DS linear, icosahedral capsid. Coltivirus - colorado tick fever. Rotavirus - #1 cause of fatal diarrhea in children



no envelope, SS linear, icosahedral capsid.
Poliovirus - Salk/Sabin vaccines
Echovirus - aseptic meningitis
Rhinovirus - common cold
Coxsackievirus - aseptic meningitis; herpangiona; hadn, foot, mouth diease; myocarditis; pericarditis
HAV - acute viral hepatitis



No envelope, SS linear, Icosahedral capsid. HEV



no envelope ss + linear, icosahedral capsid. Norovirus - viral gastroenteritis



envelope, ss + linear, icosahedral capsid. HCV, Yellow fever, Dengue, St. Louis encephalits, West Nile virus



envelope, ss + linear, icosahedral. Rubela, Eastern equine encephalits, Western equine encephalitis



envelope, SS + linear, icosahedral (HTLV) conical (HIV). Have reverse trancriptase. HTLV - T-cell lukemia; HIV - AIDS



envelope, SS + linear, Helical. Cornoavirus "common cold" and SARS



envelope, SS - linear helical. Influenza virus



envelope, ss - linear helical. Parainfluenza - croup, RSV - bronchiolitis in babeis; Rx - ribavirn. Measles, mumps.



envelope, ss - linear, helical. Rabies



envelope. SS - linear. Helical . Ebola/Marburg hemorrhagic fever - often fatal.



envelope, ss - circular, helical. LCMV - lymphocytic choriomeningitis virus. Lassa fever encephalitis - spread by mice.



envelope, ss - circular, helical. California encephalitis, Sadnfly/Rift Valley fevers, Crimean-Congo hemorrhagic fever. Hantavirus - hemorrhagic fever, pneumonia


Delta virus

Envelope, SS - circular. HDV is a "defective" virus that requires HBV co-infection.


Hepatitis viruses



HIV associated diseases

FA 169


Torch infection symptoms

FA 174


Fitz-Hugh Curtis syndrome

infection fo the liver capsule (PID) and "violin sting" adhesions of peritoneum to liver


Bug hints

FA 178