Bacteria to Remember

Question 1

Mycoplasma Pneumoniae

Answer 1

Picture: Pond Hockey
No cell wall (absent gram stain)
Cholesterol in cell membrane
Atypical pneumonia (can’t culture microbe)
Walking pneumonia (x-ray appears worse than patient presents), (patchy infiltrate)
Young adults in close contact (military recruits)
Cold erythrocyte agglutination
Eaton’s agar for growth
Macrolide treatment (azithromycin)

Question 2

Chlamydia General

Answer 2

Picture: Pirates
Obligate intracelluar
Poor gram staining
Needs NAD+ and CoA from cell
No muramic acid
Elementary bodies: Infection
Reticular body: Multiply (inclusion bodies in cell)
Giemsa’s stain
Nucleic Acid Amplification Test (PCR)
Macrolides (ezythrimycin oral only) and doxycycline
Co-infection with gonorrhea treat with ceftriaxeone

Question 3

Chlamydia Trachomatis

Answer 3

D-K: STI
Most common STI in US
Watery discharge (gonorrhea has thick discharge)
Can complicate to pelvic inflammatory disease
Passed onto baby, shows as conjunctivitis and pneumonia (present later 1-2 weeks; staccato cough)

L1-L3: Lymphogranuloma venereum
Inguinal lymphadenopathy

A-C: Blindness (leading cause)
Transmitted hand to eye or fomites

Knee and Sacroiliac reactive arthritis, uveitis, urethritis, arthritis

Question 4

Chlamydia Psittaci

Answer 4

Pneumonia transmitted by birds (parrots)

Question 5

Mycobacterium TB General and Virulence and Treatment

Answer 5

Picture: Shootout
Stains acid fast from mycolic acid in cell wall from carbol fustian stain
Grows on Lowenstein-Jensen agar
Obligate aerobe
Transmitted through respiratory droplets, proliferates in macrophages
Glycolipids to make serpentine shape (cord factor): increases TNF alpha and cytokines, walls off bacteria in granuloma
Sulfatides: prevent phagolysosome fusion
Positive TB test for primary, latent, and BCG vaccine
Treatment: RIPE: Rifampin, Isoniazid, Pyrazinamide, and Ethambutol
Latent TB prophylaxis: RI, Rifampin and Isoniazid

Question 6

Mycobacterium TB Progression

Answer 6

Primary infection: affects middle or lower lobes, Hilar lymphadenopathy, these form Ghon complex
Tuubercles formed from necrotic macrophages with central caseating necrosis
Primary infection symptoms: prolonged fever in children
Resolution:
1. Most resolve into latent infection through fibrosis
2. Miliary TB: can seed anywhere in body, presentation depends on organs infected (think systemic disease in immigrant)
3. Reactivation: 5-10% caused by immuno-suppression through down regulation of TNF (screen PPD if you want to use TNF inhibitor)
Reactivated TB affects upper lobes
Reactivation symptoms: cough, night sweats, hymoptisis, may also be wasting
Pot’s disease when in vertebrae (damages and causes deminerilization and soft tissue swelling)
CNS: Meningitis and cavitary lesion

Question 7

Mycobacterium Leprae

Answer 7

Picture: Jail Break
Leprae thrives in cool temperatures (periphery)
Acid fast bacteria (mycolic acids)
2 presentations: Tuberculoid (Th1 cells) and Lepromatous (Th2 cells)
Tuberculoid: in macrophages
Main symptom: well demarcated hairless lesions (TB like test)
Lepromatous: Humoral response, can’t contain from weakened Th1 response
High human to human transmition
Symmetric neuropathy in glove and stocking pattern, raised lesions on extensor surfaces (large amounts of bacteria in lesion), lion face
Treatment:
1: Rifampin and Dapsone
2: Rifampin, Dapsone, and Clofazimine

Question 8

Mycobacterium Leprae

Answer 8

Picture: Jail Break
Leprae thrives in cool temperatures (periphery)
Acid fast bacteria (mycolic acids)
2 presentations: Tuberculoid (Th1 cells) and Lepromatous (Th2 cells)
Tuberculoid: in macrophages
Main symptom: well demarcated hairless lesions (TB like test)
Lepromatous: Humoral response, can’t contain from weakened Th1 response
High human to human transmition

Question 9

Bordetella Pertussis

Answer 9

Picture: Vet in Care
Gram neg bacilli
Whooping Cough
Spread via respiratory droplets
Attaches via pili (filamentous hemagglutinin) to respiratory epithelium where it release toxins
Pertussis toxin: ribosylation of Gi (disables) this leads to rise in cAMP, and lymphocytosis do to inability of white cells to leave blood
Adenolate cyclase toxin: acts like edema factor increases cAMP
Tracheal toxin: Damages ciliated cells in epithelium
Clinical findings:
Catarrhal stage: Palatially non-specific (1-2 weeks)
Paroxysmal stage: Extreme cough and whooping noise
Convalescence stage: up to 3 months, slow symptom reduction
Treatment: Macrolides
Prevention: Acellular pertussis vaccine, purified antigens (DTaP)

Question 10

Haemophilus Influenzae

Answer 10

Picture: Cherry Shop
Gram Negative, Coccobacilliary
Grown on Chocolate Agar: factor 5 (NAD) and 10 (Hemotin)
Aerosol transmission
Causes:
Pneumonia
Epiglottitis: Inflamed epiglottis (cherry red), inhalation stridor, and drooling (in children)
Otitis Media: Middle ear infection
Meningitis: only by type B capsulated form
More at risk when asplenic (sickle cell)
Vaccine covers only type B capsule (conjugated to diptheria toxin given between 2-18 months)
Treatment: Ceftriaxone and Rifampin for close contacts

Question 11

Legionella

Answer 11

Picture: Battleship
Gram negative bacilli, must be silver stained to visualize, oxidase positive
Grows on charcoal yeast extract with cysteine and iron
Causes Legionaires disease and pontiac fever
Pontiac Fever: Fever and malaise, self-limited
Legionaires disease: More common in smokers, atypical pneumonia (unilobar infiltrate), hyponatremia (<130), Neuro symptoms, diarrhea, high fever
Rapid urine antigen test
Treatment: Macrolides and Flouroquinolones

Question 12

Actinomyces Israelii

Answer 12

Picture: Israeli Soldier
Gram positive branching filamentous rod
Obligate anaerobe
Normal oral flora (recent dental procedure)
Non-tender lump that forms abscess and sinus track drainage, SULFUR GRANULE
Treatment: Penicillin G and surgical drainage

Question 13

Nocardia Astoroydies

Answer 13

Picture Card Game
Gram positive branching filamentous rod, weakly acid fast (mycolic acid)
Obligate aerobe, catalase positive, urease positive
Found in soil (not spore forming)
Symptoms: Immunocompromised patients and men
Pulmonary: Pneumonia and cavitating lesions in lung
CNS: Brain abscesses
Cutaneous: indurated lesions and inflammation
Treatment: Sulfonamide

Question 14

Staph Aureus

Answer 14

Picture: Moses
Gram Positive Cocci, Grape like golden bundles
Catalase positive, Coagulase positive, Beta Hemolytic, Manatol fermentor
Virulence factor: Protein A binds Fc portion of antibody, preventing compliment
Colonizes nose
Diseases:
Pneumonia (patchy infiltrate) secondary post-viral infection, septic arthritis (number 1), large erythemitis abscesses, acute endocarditis (IV drug user, tricuspid valve), osteomylitis (most common cause)
Toxin diseases:
Scaulded skin syndrome (exfoliateve toxin), Toxic shock syndrome (TSST, super antigen activation of T-cells), rapid onset staph food poisoning (vomiting, meats and mayo’s)
MRSA: Transpeptidase altering (treated with Vancomycin)
nafcillin (naf for staph) if not MRSA

Question 15

Staph epidermidis

Answer 15

Picture: Plumber
Gram positive cocci,
Catalase Pos, urease pos, coagulase neg
Novobiocin sensitive
Infects hardware, catheters, and artificial heart valves
Biofilm coating (prevents response and helps stick)
Treatment: Vancomycin

Question 16

Streptococcus pyogenes

Answer 16

Picture: Bakers
Group A Strep
Gram positive cocci,
Encapsulated (Hyaluronic acid: made in humans), Beta hemolysis, Bacitracin sensitive
Impetigo, Strep throat, cellulitis, and erysipelas
Streptococcal Pyrogenic Exotoxin (SPE): Scarlet fever: Strawberry tongue, pharyngitis, rash everywhere (except face); toxic shock like syndrome; necrotizing fasciitis (caused by SPE B)
Rheumatic fever (only after pharyngitis): caused by M-protein: Anti-phagocytic; molecular mimicry of myosin in heart (mitral valve); JONES criteria (Joints polyarthritis, O heart problems, Nodules in subcutaneous, Erythema marginatum, Sydenham’s chorea sudden movements in hands)
Post strep glamular nephritis (after either pharyngitis or impetigo can happen even after penicillin treatment): Facial swelling and cola urine, 2 weeks post strep
Streptolysin O: lyses red blood cells, (B hemolysis)
Streptokinase: phosphates plasminogen, lyses clots
DNase: depolimerize DNA
ASO titer to diagnose GAS

Question 17

Streptococcus Agalactiae

Answer 17

Picture: Galactic Baby
Group B Strep
Gram positive cocci, Hippurate positive test, CAMP test positive (staph aureus increases hemolysis), B hemolysis, encapsulated, bacitracin resistant
Causes meningitis (number one), sepsis, pneumonia
Passed on via vaginal canal, 35 week colonization test
Prophylaxis: Mother gets intrapartum penicillin

Question 18

Strep Pneumoniae and Viridans

Answer 18

Picture: Knight jousting
Alpha hemolytic, Gram positive cocci
Strep Pneumo:
Encapsulated (polysaccharide virulence factor), optochin sensitive, diplococci lancet shaped, bile soluble (can’t grow in bile)
Number one cause (MOPS): pneumonia (lobar and rust-colored sputum); Meningitis; Otitis media; Sinusitis
IgA protease: reduces hosts defenses
Asplenic increases risk (sickle cell)
Treatment: Macrolide and ceftriaxone
Vaccine: 23 valant IgM (adult), 7 valant conjugate IgG (children)
Viridans: non-encapsulated, optochin resistant, bile resistant (insoluble)
Dental caries
Most likely to affect mitral valve: subacute endocarditis in damaged valves
Adheres to platelets and dextrans

Question 19

Bacillus Anthracis and Cereus

Answer 19

Picture: Vikings
Gram Positive Bacilli (in chains)
Black eschars
Encapsulated (protein capsule, Poly-D glutamate), obligate aerobe, spore forming
Toxins: LF and EF (both need to be present to cause symptoms)
EF: functions as adenylate cyclase, increases cAMP
LF: exo toxin, functions as protease, cleaves MAP kinase (causes eschar)
Pulmonary anthrax (wool sorter’s disease): non-specific symptoms to begin, causes pulmonary hemorrhage (widened mediastinum)
Treatment: Flouroquinalones and doxycycline
B Cereus: Food poisoning (reheated fried rice)

Question 20

Clostridium Tetani

Answer 20

Picture: Monkeys
Gram Positive Bacilli
Obligate anaerobe, spore forming, found in soil
Symptoms: Spastic paralysis, Risus sardonicus (Evil Grin), exaggerated arching back
Pathenogenesis: Spores imbed, reproduce, and produce tetanus toxin; travel retrograde and cleave snare proteins, inhibiting G and G release (inhibitory) from Renshaw cells
Vaccine: Toxoid (toxin conjugated to protein)

Question 21

Clostridium botulinum

Answer 21

Picture: Robots
Gram Positive Bacilli
Spore forming, obligate anaerobe
Improper canning transmission (family with neuro similar symptoms), preformed toxin in adults
Symptoms: Descending flacid paralysis (diplopia or ptosis)
Pathenogenesis: Cleave snare proteins responsible for ACh release (can’t excite)
Infant Botulism: Floppy baby syndrome; spores grow in intestine from lack of competing flora, then toxin gets made and released, come from honey

Question 22

Clostridium Difficile

Answer 22

Picture: Chocolate factory
Gram positive bacilli
Spore forming, Clindamycin causes C. Diff, obligate anaerobe
Exotoxins A and B
A: Targets brush border causes watery diarrhea
B: Depolarizes cytoskelton actin causes pseudomembranous formation
Diagnosis: Toxin in stool and pseudomembrane visualization
Treatment: Oral Vancomycin and Metronidazole

Question 23

Clostridium Perfringens

Answer 23

Picture: Motorcyle Wreck
Gram Positive bacilli
Spore forming, obligate anaerobe, found in soil
Diseases:
Gas gangrene: crepitus and gas under wound, alpha toxin (lecithinase: cleaves phospholipids) causes double zone of hemolysis
Treatment: IV penicillin G
Food poisoning: Late onset watery diarrhea (ingestion of spores), transient and no treatment

Question 24

Corynebacterium diptheriae

Answer 24

Picture: Bull fighting
Gram positive bacilli, club shaped, metachromatic granules in V or Y formation
Causes diptheria, transmitted via droplets
Exotoxin: A/B (active/binding); ribosylation of elongation factor 2 inhibits protein synthesis and cell death; leads to pseudomembranes
Symptoms: bull neck due to lymphadenopathy, cardio toxic effects (myocarditis, arrhythmia, heart block), local paralysis in posterior oralpharynx
Diagnosis: culture on tellurite and loeffler’s agar; Elek’s test for toxin
Vaccine: Toxoid (bound to protein) DTaP

Question 25

Listeria monocytogenes

Answer 25

Picture: Santa
Gram positive bacilli, motile, facultative intracellular
Beta hemolytic, catalase positive, grows in cold (soft cheeses, milk, meats)
Outside cells (tumbles), inside cells (actin rockets)
more common in pregnant women
newborn (and elder) meningitis
Treatment: Ampicillin