Micro Chart

Staphylococcus Types

S. aureus - cause of most infections, coagulase +, golden colonies

Streptococcus

Strep B

Group A: S. pyogenes, S. anginosus

S. Epidermidis - surgery/ skin wounds Group B: S. agalacticae S. Saprophyticus - UTI's S. Capitis Species Classification

Streptococci viridans Streptococci pneumonia Group A, B, C, D according to Lancefield antigens (CHO receptors) CAMP (Cristie Atkins Mundy Peterson)test (only Group B are +)

Epidemiology

Ubiquitous - part of normal skin and nasopharynx flora

transferred by physical contact, fomites, aspiration

Diagnostic Features

Gram +, grapelike clusters

Haemolysis (α: semi lysis,β:group A complete ,γ: no lysis) Might colonize oropharynx of healthy: host develops Ab to Mprotein. Diases occur before Ab or if commensal bacteria insufficient Seasonal variation in disease: Winter: pharyngitis, RF, PSGN. Summer: pyoderma, PSGN transferred by respiratory droplets or break in skin after contact with vector

Gram + pairs/chains

Distinct, raised white colonies (except Variable colony morphology S. aureus is gold) Facultative anaerobes (make O2 with catalase catalase +) can grow in 10 % NaCl no growth in 10% Nacl supplemented media haemolysis S. aureus ONLY: coagulase + (fibrinogen to fibrin)

haemolysis +

Gram + cocci in chains B hemolysis on blood agar cAMP + PYR hippurate, bacitracin and STX resistant (ABCs)

Virulence Factors

Capsule - inhibits chemotaxis, phagocytosis, complement, proliferation of immune cells. Mostly in coagulase staph Peptidoglycan - activates complement, attracts neutrophils, cleaved by lysozymes Protein A - only Staph Aureus. Bings Fc region of Ab and evades immune system Teichoic acids - attachment to mucous membranes

Enzymes Hyaluronidase - facilitates spread in tissue Fibrinolysin - dissolves fibrin clots Lipase - key factor in survival on skin

Nuclease

Capsule - anti-phagocytic later of hyaluronic acid and NAG M-protein - inhibits complement by binding factor H in serum and degrading C3B F-protein - binds fibronectin Streptolysin S - non-immunogenic and destroys phagocytes. Lyses RBCs, leukocytes, platelets. O2 stable Streptolysin O - immunogenic. Lyses RBCs, leukocytes, platelets, cultured cells. ASO test: indirect ELIZA for ASO Abs Streptokinase - lyses blood clots C5a peptidase - anti-phagocytic SPRES (strep pyogenic exotoxins) - heat-labile, superantigens. Mediate shock, organ failure and rash in scarlet fever DNAse - depolymerase DNA to reduce viscosity of pus. Important marker for Group A infections of the skin

Penicillinase - inactivates B-lactam ABCs **resistance Toxins - Cytolytic exotoxins α-toxin - pore forming. Lyses RBCs, WBCs, platelets, blood vessel smooth muscle cells hepatocytes. Mediates tissue destruction β-toxin (sphygomygelinase C) - lyses RBCs, WBCs, macrophages, fibroblasts, membrane phospholipids P-V leukocidin - severe cutanous infections, pore forming, F and S subunits Toxins - Exfoliative exotoxins ETA and ETB - serine proteases, cleave desmosome. Involved in SSSS Enterotoxins 8 types (A-E): A: food poisoning, B: contaminated milk products, C: pseudomembranous colitis (sometims TSS). Heat stable, hydrolysis resitant. Superantigens that cause: hyperperistalsis, damage to brush border layer of jejunum, intense emesis Toxic Shock Syndrome Toxins TSST-1 + strains: most mensturation associated TSS. Superantigen that causes non-specific immune response, endothelial cell leakage or lysis, systemic effects Prevention

Hand washing, fomite cleansing IFF history of RF give prophylactic ABCs before dentistry

S. Viridans

Listeria spp. Major: L. manocytogenes Minor: L. ivanovii

Cornebacterium spp.

Zoonotic: disease of animals Ubiquitous worldwide that is transmissible to humans. distribution on plants and Animal vectors: birds, ticks, animals spiders… Disease is transmitted most rarely affects humans but high commonly by areosolized mortality nasopharyngeal secretion Ubiquitous: direct person to Disease low due to DPT person, ingest contaminated vaccine meat and dairy Vertically transmitted (esp. transplacentally) is the most fatal type of transmission Gram + cocci

small, Gram + cocobacilli

α- or γ- hemolytic

"chinese character clumping"

No Lancefield Antigens

Small, round, weakly βhemolytic

Gardnerella spp.

All species are opportunistic pathogens C. diphtheriae most notorious

Asymptomatic carrier in 20-40% of healthy women Present in urethra of male partners also isolated from women with postpartum sepsis

Gram + club shaped bacillus Gram variable grows on human blood V shaped or Chinese letters agar in a moist CO2 enriched environment Fastidious growth requirements

aerobic

Catalase +

large dextran capsule

Aerobic or facultative anaerobes

Thick sticky dextran capsule

Surface Components: 1) Endotoxin like factor. Cell wall Exotoxin: Classic A-B type component like LPS, escapes phagosome

lipoteichoic acid

2) Internalins - entry into enterocytes or M cells

A sub unit: catalytic - halts host cell protein synthesis

other acids/enzymes

Soluble components: 1) Listeriolysin O. In all virulent strains

B sub-unit: multifunctional. 1) receptor binding 2) translocation

2) Phospholipase C helps enter cell membrances

3) Intracellular growth Growth at 0-45 Celcius Grow in wide range of pH (5-9)

Microbe

System

Condition

1 2 3

Staphylococcus Aureus Staph. Staph.

Skin Skin Skin

Pustular Imepetigo Folliculitis Furuncle

4

Staph.

Skin

Carbuncle

5

Staph.

Skin

6

Staph.

Skin

Bullous Impetigo

7

Staph.

Skin

TEN (Toxic Epidermal Necrosis)

8

Staph.

Skin

TSS (Toxic Shock Syndrome)

9

Staph.

GI

Staphylococcal Food Poisoning

10

Staph.

GI

Staph. Pseudomembranous Colitis

11

Staphylococcus Aureus

Skin

Bacteremia

12

Staph.

Skin

SSSS (Staph scaled skin syndrome) Secreted Toxin. Perioral erythema & whole body rashes. No scarring

Endocarditis

13

Staphylococcus Aureus

Respiratory

S. aureus pneumonia

14

Staph.

Skeletal

Staph. Mediated Septic Arthritis

15

Staph.

Skeletal

Staph. Associated Osteomyelitis

16

Staphylococcus Epidermidis

17 Staphylococcus Saprophyticus

Coagulase negative staph disease Urinary

Signs and Symptoms

Coagulase negative staph disease

18

Group A Streptococcus

ENT

Strep Throat

19

Group A Streptococcus

ENT

Scarlet Fever

No secreted toxin. Perioral erythema. Rash primarily on fase. Scarring. Painful localized erythema. Large flaccid blisters. Epidermis peels off in sheets. Fever, chills, myalgia, malaise, n/v, H/A. Potentially fatal (fluid imbalance and organ failure)

Group A Streptococcus

Systemic

21

Group A Streptococcus

Skin

Streptococcal Erysipelas

22

Group A Streptococcus

Skin

Streptococcal Cellulitis

Nikolsky sign + (easy to separate stratum corneum) Nikolsky sign Sequelae to certain drugs. DDX from SSSS: age, history, biopsy

Risk factor: hyper absorbency Fever, diffuse mascular erythematous rash that can deqaquamate. Potentially tampons and intravaginal fatal: hypotension, septic shock, multiple organ system failure (MOSF) contraceptive devices Intoxication. Very rapid onset of illness. Severe n.v, ab pain/cramps. No fever From contaminated food: processed & watery, non-bloody diarrhea. Lasts 24 hours or less meats (e.g. ham), turkey, potato salad Watery diarrhea, abdominal cramps. Fever. White, ulcerated plaques on colonic mucosa. Often disseminates to HT (endocarditis) Triad: fever, murmur, anemia. Chest pain, dyspnea, clubbing fingers. Chills, rigor, night sweats. Weight loss. Arthritis. Characteristic skin lesions: 1) Janeway - flat, painless lesions on palms and soles during acute episodes. 2) Osler's Notes - painful red bumps on pads of fingers and toes. 3) Septic embolization - localized infarction in extremeties 4) Splinter hemorrhages linear bleeding under nails

Central cyanosis, dyspnea, chest pain. Sudden fever with prolonged chills. Productive cough with mucupurulent sputum.

Bacterial related inflammation of joints. In children, adults with prosthetic or diseased joints, and intra-articular injection therapy. Painful, erythematous joints with purulent aspiration of fluid. Infection of osseous tissue. Children: sudden pain in metaphyseal area. Adults: intense back pain with fever. Infections associated with: catheters, surgery, CVS shunts and artificial joints. Primary cause of endocarditis in artificial HT valves Cause UTI's in sexually active women. Dysuria, pyuria, culture + urine Erythematous posterior pharynx. Culture + creamy yellow exudate. Localized lymphadenopathy. Halitosis (bad breath) Spreads via person to person contact. Resolution or abcess or Rhematic Fever (sequele) Complication of Strep Throat. Fever, H/A, malaise, anorexia, pharyngitis. Diffuse erythematous rash that blances with pressure. Strawberry tongue. 1st appeard on upper chest and then spreads to extremities. Circumoral pallor. Spares palms and soles.

Cause by different strain of S. pyogenes than one causing pharyngitis. Localized pain and inflammation. Systemic signs (feverl/chills/n/v/diarrhea). Streptococcal Toxic Shock Syndrome Can progress to shock and organ failure. Sudden fever. Hypotension, Rash (diffuse, blanching). Involvement of 3 or more organ systems.

20

DDX and Lab Dx

Macule --> Papule --> Honey Crusted Lesion Superficial, raised, red, pus-filled bump Unresolved folliculitis. Painful raised nodule with underlying necrotic tissue. Unresolved furuncle. Deep into cutaneous tissue. Also have chills and fevers (could lead to sepsis)

Acute superficial skin infection after URI. Localized erythema, bullae and pain. Clear distinction between infected and non-infected skin. Localized lymphadenopahy and possible systemic signs. Deeper infection of the skin and subcutaneous tissue. Most commonly face and trunk. Erythema, warmth, tenderness. No clear distinction between infected and non-infected tissue. Systemic signs and symptoms are more common than with erysipelas

Very similar to disease caused by Clostridium Difficile. DDX by lab dx: Stool culture + and Stool leukocyte + Most common source is iatrogenic 50% mortality. Initially looks like fly but can progress rapidly if not treated ASAP. Suspect if: congenital HT dx, IV drug use, chronic localized abcess or infection 2 types: 1) Apiration - in young/elderly. People with COPD , post-influenza. 2) Hematogenous. LAB: CXR - patchy infiltrates with consolidation and abscesses. Culture + sputum with neutrophils Number one cause of this: Neiserrio Gonorrhea Lab dx: blood culture +, Brodies abcess on Xray (necrosis)

Rapid Strep Test (+) (Direct Elisa) High Anti-ASO Ab titer

DDX Staph TSS: Strep is most commonly after deep tissue infection vs tampon usage. No single virulence factor (vs. TSST-1) No exfoliative rash.

23

Group A Streptococcus

Skin

Necrotizing Fasciitis

Caused by mutant form of S. pyogenes in susceptible people. Possibly fatal. Unexplained localized redness, swelling and pain. May have flu symptoms. Rapid spread, descruction of tissue. TSS develops if not aggresively treated.

24

Group A Streptococcus

Respiratory

Rheumatic Fever

Complication of Srep A associated URI. Damage to HT valve predisposes patient to bacterial endocarditis. CHANCE: Chorea, migratory polyArthritis, subcutaneous Nodules, Carditis, Erythema marginatum

25

Group A Streptococcus

Urinary

Acute Glomerulonephritis

Complication of Strep A disease. Cause of renal failure. Generalized edem, oligouria, dark urine, fatigue, ab pain

Systemic

Early Onset Neonatal Disease

Endogenous infection acquired in utero or in 1st 7 days of lige. Pneumonia, meningitis, bacteremia with neurological squelae.

Systemic

Late Onset Neonatal disease

Exogenous disease within 1 week - 3 months after birth. Meningitis.

Systemic

Postpartum (peurpural) feverl

26

Group B Streptococcus Agalactaciae)

(S.

27

Group B Streptococcus Agalactaciae)

(S.

28

Group B Streptococcus Agalactaciae)

(S.

29

Streptococcus Viridans

Teeth

S. mutans and dental carries

30

Streptococcus Pneumonia

Respiratory

Lobar Pneumonia

31

Streptococcus Pneumonia

ENT

Sinusitis

32

Streptococcus Pneumonia

ENT

Otitis Media

33

Streptococcus Pneumonia

Systemic

Meningitis

34

Listeria

Systemic

Listeriosis

35

Cornyebacterium diphtheriae

Respiratory

Cornyebacterium diphtheriae respiratory diseases

36

Cornyebacterium diphtheriae

Skin

Cornyebacterium diphtheriae cutaneous diseases

Jones Criteria 1) Supporting evidence for preceding Group A strep infection (+ throat swab, rising ASO titers) 2) at least 1 major and 2 minor manifestations (see notes) Document group A strep infection. Blood: Anti DNAse B+, Urine: frank hematuria, proteinuria, RBC casts Risk factors: heavily colonized birth canal. Maternal disseminated group B Strep infection Risk factor: contact with heavily colonized persons. Breastfeeding is important!!

A condition of the mother. Rise in temperature to greater than 38 on any 2 Risk factors: Unsterile obstetric consecutive days after the 1st 24 hours post-partum. Fever, chills, malaise… techniques!! Hand washing! foul smelling, yellow green/blood tinged lochia (discharge) Risk: inadequate salivary flow (And all Poor flossing/brushing --> S. mutans sticks to enamel --> acidic environment the usual stuff like hygiene and high --> plaque. Carie develops if demineralization is greater than minteralization sucrose) Physical exam: increased fremitus (vibration), dullness on percussion, Adventitious sounds (crackles) on Very rapid onset. Single severe shaking chill with persistently high fever. auscultation. CXR: dense uni-lobar Productive cough: hemoptysis, copious purulent "rust" colored sputum. May consolidation with typical air have URI before and immunocompromized have minimal symptoms. Occurs bronchograms. Rapid onset of visible most commonly due to failure of natural defence mechanisms like" epiglottal signs. Lab: Gram +, lancet shaped, cough reflex, mucous secretions, cilia encapsulated bacteria. Quelleng reaction +. Detect free capsular Ag in CSF or urine. Facial pain, tightness, H/A. Decreased valsalva (defection) and dependency Many causes: Strep pneumonia, H. (gravity). Tenderness. Low fever and mucopurulent discharge influenza, Moraxella catarrhalis. Otaglia (pain in ear), otorrhea, tinnitus, vertigo, nystagmus. Reduced acuity. Increased risk with dietary sensitivites, Bulging, erythematous TM with reduced visible landmarks, gluid line and ABC,s… displaced COL Common causes: N. meingitides, H. Sudden onset of fever, nuchal rigidity (stiff neck), blinding H/A, n/v. Irritability, influenza, S. pneumonia. CSF culture malaise, restlessness, delerium. Petechial rash. Seizures. S. pneumonia is 4- +, decreased CSF glucose, 20x more likesly to cause neruological complications than other bacterial predominate cells are PMNs. Viral meningitis. Sequelae: defness, blindness, mental retardation, memory loss, mengitis is less severe/quick and is SIADH (syndrome of inappropriate ADH secretion) culture -, increased CSF protein and lymphocytes in CSF Dark red rash over trunk and legs. Endocarditis, feverl malaise, septic shock, circulatory collapse and hepatosplenomegaly. Occur in 4 populations: 1) Pregnant female: causes abortion and most common in 3rd trimester with mild brief disease of chills, fever, malaise. 2) Fetus: aborted or early onset CSF culture -, motility test +, cold disease (granulomatosis infantiseptica) - multi organ disseminated abscesses enrichment of granulomas and high mortailty; 3) Neonate: signs of meningitis; 4) Adults: low grade fever with personality changes. Also may get meningitis/gastroenteritis Form grey pseudomembrane that bleeds if forcibly removed. Malaise, sore throat, low grade fever, chills, pharyngitis. Can cause sequelae of myocarditis, CHF, focal neurological signs Clinical signs and symptoms are most important. Culture +, PCR for tox papule that can progress to chronic persistent ulcer with greyish membrane. gene, Elek test for toxin produced. Can progress to systemic signs and symptoms if not treated Treat with diphtheriae anti-toxin or ABC's. Screening test: Pchick (like TB test)

37

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Gardnerella vagninalis

Reproductive

Gardnerella vaginalis disease

Most common cause of vaginal infxn in sexually active women in the US. Asymptomatic in more than 50%. Excessive thin, white adherent, malodorous Must 1st disrupt normal flora. Positive discharge. Vaginal pruritis, pain with urination, dyspaerunia (painful WHIFF TEST with 10% KOH (fishy, intercourse). Sequelae: increased risk of complications in pregnancy. musty, amine odor), Clue cells in urine, vaginal pH > 4.5

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