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Microbio-2 > Resp Bacterial > Flashcards

Resp Bacterial Flashcards

1
Q

Bacterial Resp infections (strep)

A
  • Gram (+) cocci in chains or pairs
  • Catalase (-) anaerobic
  • Serology: Lancefield grouping (A-G) based on carb Ag in cell wall
  • Also grouped by M-protein KEY Ag to provoke immune response
  • A-Hemolytic: Green-partial hemolysis
  • Pneumoniae (optochin sensitive)
  • Viridans (optochin resistant)
  • B-Hemolytic: Clear-complete hemo
  • Pyogenes A (bacitracin sensitive)
  • Agalactiae B (bacitracin resistant)
  • Y-Hemolytic: No hemolysis
  • Enterococcus (Faecalis/Faecium)
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2
Q

Strep tests

A
  • Catalase Test:
  • Superoxide dismutase splitrs O2+H2O2 into catalase & peroxidase
  • Enzyme that splits Hydrogen peroxide into Water & O2
  • Hydrogen peroxide by-product of resp & is LETHAL in excess
  • Catalase degrades hydrogen peroxide in cell before it can get to excess
  • Result=H2O2 in Free O2 (bubbles/water)
  • PYR (Pyrrogutamyl aminopeptidase):
  • Filter paper= L-pyrrolidonyl-β-naphthylamide (PYR). Bacterial pyrrolidonyl peptidase hydrolizes PYR=Color change
  • ex. Strep Group A(+) & S.pneumoniae (-)
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3
Q

Strep pyogenes (GAS) General

A
  • Gram (+) catalase (-)
  • Beta hemolytic in blood agar
  • Bacitracin sensitive & Group A/PYR(+)
  • Reservoir: Human upper resp & skin
  • Transmission: Resp droplet & P to P HIGH frequency in Winter-Spring
  • Pharyngitis in children 5-15
  • Capsule: Hyaluronic acid (anti-phago)
  • M-protein: Ag variation used for serotype
  • Binds to Fc region on IgG/IgA (anti-phag)
  • Binds to collagen, fibronogen, plasminogen
  • F-protein BINDS to fibronectin=Camo
  • Hemolysins: Strep S & O (toxic)
  • C5A peptidase: inactivates C5a
  • Streptokinase: Lyses blood clots
  • Streptodornases: DNAse
  • Pytogenic exotoxins-Super Ags
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4
Q

GAS M protein Structure

A
  • N terminal: Type specific sequence variation
  • Conserved Region:
  • Ag cross reacting domain w/human tissue
  • Binds to human tissue
  • Carb group Ag=Lancefield grouping common to certain types
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5
Q

Strep GAS Clinical Outline

A
  • Pyogenic infections=Local infections
  • Pharyngitis
  • Otitis media
  • Pneumonia
  • Toxin mediated:
  • Scarlet fever
  • Toxic shock smdrome
  • Fascitis
  • Immune mediated=Untreated pyogenic
  • Rheumatic fever
  • Glomerulonephritis
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6
Q

Strep GAS Pharyngitis

A
  • Pyogenic/Local infection
  • Sudden onset no more than 3-5 days
  • Sore throat, Fever, Headache
  • Inflammation of pharynx/Tonsils
  • Patchy exudates (not always)
  • Palatal petechiae
  • Tender & enlarged Ant cervical nodes
  • Seen in winter or early spring
  • NO COUGH
  • Diagnosis: Beta-hemolytic agar, bacitracin sensitive, Catalase (-), Gram (+) cocci in chains
  • Lancefield-Group A
  • Rapid strep (10-15min) Ag detection-ELISA
  • Throat swab (monoclonal Ab to detect the strep group A cap polysac)
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7
Q

Strep GAS Scarlet Fever

A
  • Associated with Pharyngitis if left untreated=Immune mediated
  • Streptococcal pyrogenic exotoxin=Super Ag causes outbreak
  • Diffuse erythromatous rash ALL over body
  • Fever
  • Strawberry Tongue
  • Skin desquamation=Peeling @ toes/fingers
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8
Q

Strep GAS Rheumatic Fever

A
  • Immune mediated inflammation in heart, Joints, Blood vessels, & subcutaneous
  • Type 2 hypersensitivity (Ab binds to Ag on cell surface NOT free floating)
  • Immune cross reactive w/Mprotein=Mol mimicry
  • Rheumatogenic Strains=1,3, 6, 18
  • Appear 2-4 weeks after pharyngitis
  • Fever, migratory polyarthritis, Erythema marginatum (Rash), Subcutaneous nodules (elbows,knees, wrists)
  • Carditis (damage to heart tissue)-Assoc w/subcutaneous nodules
  • Chorea (Nerve damage) uncontrollable movement of limbs/face
  • Diagnosis: Ab against Steptolsin O (ASO)-Hemolysins used to ID in Titer
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9
Q

Strep GAS Glomerulonephritis

A
  • Ag/Ab complex deposition (Type 3) on glomerular basement membrane
  • Triggers inflammatory Rxn->tissue damage w/impairment of kidney function
  • Localized skin infection & pharyngitis follows
  • Takes 10-15 days after skin infection
  • Symptoms:
  • Hypertension
  • Edema
  • Hematuria (smoky unrine)
  • Proteinuria
  • Diagnosis: History of skin/throat infections
  • Serology-Anti-ASO & Anti-DNase
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10
Q

Jones Criteria RF

A
  • Diagnostic= 1 required & 2 major OR 1 required & 1 major w/2 minor
  • Required: Strep infection
  • ASO/Strep Ab
  • Strep group A throat culture
  • Recent scarlet fever
  • Anti-DNA-B
  • Anti-Hyaluronidase
  • Major: Cariditis (mitral valve), Polyarthritis (3 days per joint w/3 weeks total), Chorea, Erythema, Subcutaneous Nodules
  • Minor:
  • Fever
  • Arthralgia
  • History of RF or RHD
  • Elevated Acute phase rxns (ESR, CRP, Leukocytosis)
  • Prolonged PR interval
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11
Q

Strep Pyogenes (GAS) Treatment

A
  • All treatment given after (+) Rapid Ag detection test or Strep culture
  • Penicillin G
  • Macrolides for Penicillin Allx-Azithromycin & Erythromycin
  • Prevention: NO vaccine
  • Early treatment of Pharyngitis helps prevent RF
  • Pts recovered from RF given monthly dose of Penicillin to prevent further infection-
    • Strep
    • Recurrence of RF
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12
Q

Strep Pneumoniae-General

A
  • Gram (+) encapsulated, Lancet-shaped (elongated) paired w/cocci (short chains)
  • Alpha hemolytic (stains green)
  • Optochin & Bile sensitive
  • Autolysis-Releases virulence factors
  • NO lancefield type due to lack of carb in cellwall
  • Reservoir: Humans nasopharyngeal more common children
  • Transmission: resp droplets & aspiration of normal flora
  • High risk: Children & elderly
  • Pts w/history of previous viral RT infection
    • Ex. Post-influenza, asthma
  • Alcoholics & smokers
  • Chronic pulm disease pts
  • Congestive heart failure
  • Asplenic/Splenectomy pts
  • <u><strong>Trauma/Meningitis</strong></u>=<em><strong>CSF leakage to nose</strong></em>
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13
Q

Strep Pneumoniae-Pathogenesis

A
  • Polysaccharide capsule=Anti-phagocytic (90 serotypes)-Vaccines
  • IgA proteases: Disrupts IgA activity
  • Pneumolysin-O: Alpha-hemo is Cytotoxin destroys ciliated epi cells (pulm)
  • Teichoic acid & peptidoglycan: Activate alternative complement (inflammation)
  • Phosphrylcholine: Unique to SP=Cell wall component
  • Binds to receptors of platelets activating factor (found on many cells)
  • Bacteria “hide” phagocytes=Spread infection
  • Pneumococcal pneum(typical)-most common cause for Community/Nosocomial
  • Aburtpt onset, fever, chills, rigors, cough w/rusty sputum-Lobular pneumonia
  • Otitis Media most common disease
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14
Q

Strep Pneumoniae-Diagnosis

A
  • Lab Specimen: Aspirate from sinus or Middle ear, CSF, blood
  • Gram stain: (+) diplococci & capsule
  • Quellung test: Capsular swelling applying specific Ab (like gram stain BUT w/Ab)
  • Culture: Alpha-hemolysis on Blood agar w/Optochin sensitive
  • Bile solubility: Addition of Bile to culture=killing of cell (less turbid=clear)
  • PCR/Latex particle agglutination: mainly used for meningitis
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15
Q

Strep Pneumoniae-Treatment

A
  • Penicillin/Erythromycin for most strains w/increasing resistance to penicillin
  • Resistance is NOT due to beta-lactasmase BUT mutation to penicillin binding proteins
  • Ceftriaxone or Vanomycin used as alt
  • Pneumo capsular vaccines used 2 types:
  • Adult PPV: 23 T-cell independent polysac Ags recommended for elderly over 65 (short lived immune response)
  • Pediatric PPV: 13 T-cell dependent conj diphtheria toxin for children under 5 (long lived immune response)
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16
Q

Haemophilus Influenza-General

A
  • Type B most VIRULENT type causes:
  • Localized infections in URT & LRT
  • Bacteremia (bacteria in blood)
  • **Meningitis **
  • Flora=Otitis media, Sinusnitis, pneumonia
  • Gram (-) pleomorphic Rod w/pink stain
  • Grow on chocalate agar or on Blood agar w/Strep aureus that lysis RBCs=Satellite Growth
  • Coccobacilli encapsulated w/diff types
  • Requires growth factors - **Ten(hemin) & five(NAD) **
  • Reservoir: Humans ONLY nasopharynx capsular type B & non-typable strains COMMON (Flora)
  • High Risk: Anyone-Unvaccinated children 2-4 or children w/severe infections
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17
Q

Haemophilus Influenza-Virulence factors

A
  • Polysaccharide capsule: Type B capsule made of polyribose-ribitol phosphatase (PRP)
  • IgA protease-Stops IgA
  • Endotoxin: Lipo-oligosacc (LOS) similar to Neisseria=Adherence, toxic to ciliated cells, Induce inflammation
  • Diseases:
  • Otitis media <strong>(2nd common next to <u>strep pneumo</u>) </strong>seen w/conjunctivitis
  • Sinusitis
  • Lower resp tract infection
  • Invasive disease=<strong>Meningitis & Epiglottitis</strong>
  • Children 2-4 yrs most affected-Milder in adults
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18
Q

Haemophilus Influenza-Epiglottitis

A
  • Acute onset, fever, sore throat
  • Dysphagia
  • Dysphonia=Hoarseness
  • Drooling
  • Distress=Breathing problem
  • Stridor=High pitched sound on inspiration
  • Muffled voice
  • Pharynx inflammed=Beefy cherry red, stiff, Swollen epiglottis
  • Diagnosis: Lateral X-ray of neck=Thumb sign
  • Laryngoscopy before intubation
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19
Q

Haemophilus Influenza-Treatment

A
  • Diagnosis: culture tiny colonies=Gray on chocolate agar or streak around Staph aureus=Satellite growth
  • Ag Detection-Latex agglutination-Rapid PRP capsular Ag for H.Influenza type B ONLY
  • Treatment: Suspected epiglottis is considered hospital emergency
  • Supportive treatment: Cricothyrotomy (between thyroid&ciricoid)
  • Antibiotics: Broad spectrum cephalosporin (Severe) & amoxicillin/Doxycycline (mild)
  • Prevention: Hib vaccine-for type B capsular polysaccharide-conj diphtheria or tetanus used to make it
    • Vaccine reduces carrier rate
  • Chemoprophylaxis(admin of meds to help minimize spread): Rifampin eliminates carriers in HIGH risk groups by type B
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20
Q

Corynebacterium diphtheriae-General

A
  • Pleomorphic, gram (+) rods, w/clubbed ends (Coryneform)
  • Arranged in pairs (V & L shapes)
  • Formation of granules (volutin-stain red w/methyl blue) beaded appearance
  • Reservoir: Human ONLY in nasopharynx, URT, GI, Skin-Normally harmless (flora)
  • Aquires toxin gene from phage=lysogenized carriers
  • Transmission: Resp or P to P spread of lysogenized bacteria
  • High Risk: Unvaccinated, Crowded, CHILDREN
  • Clinical: Diphetheria & skin infections
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21
Q

Corynebacterium diphtheriae-Virulence factor

A
  • DT-A/B exotoxin (Secreted or released)
  • Inhibits Protein synthesis VIA ADP ribosylation/inactivation of EF-2
  • Carried by Phage B-Lysogenized corynebacteria
  • Binds to heparin-binding epidermal growth factor found on Heart/nerve cells
  • DT-3 parts 1. receptor binding region, 2.Translocation region (transmembrane), 3.catalytic region(A-unit)
  • Regulation via DTxR (Fe dependent repressor protein) on chromosome=responds to tissue Fe lvls
    • Low lvls = Toxin made
    • High lvls = Toxin Repressed
22
Q

Corynebacterium diphtheriae-Clinical

A
  • Incubation time: 2-6 days (fever, dyspnea)
  • Local inflammation: Characterized by fibrinous exudate (tough, adherent-gray/green/black) pseudomembrane over tonsils
  • Exudate filled w/neutrophils, necrotic epithelial cells, erythrocytes, & bacteria w/fibrin mesh
  • Difficult to detach w/o damaging underlying tissue <strong>(bleeds occur when attempted)</strong>
  • Located @ pharynx = More severe due obstruction to air flow
  • Bull neck appearance-enlarged Ant cervical lymph nodes w/edema of soft tissues
  • Skin diphtheria-Skin ulcer if bacteria enters through skin <strong>(non-healing ulcer)</strong>
23
Q

Corynebacterium diphtheriae-Clinical complications

A
  • Toxin carried to other organs-Heart, liver, kidney = necrosis
  • Myocarditis-Arrhythmias & circulatory collapse
  • Nerve weakness/paralysis: Cranial nerves
  • Paralysis of muscles of soft palate & pharynx=Lead to regurg of fluids through nose
  • Difficulties w/vision, speech, swallowing or movement of legs & arms
  • Swelling/congestion of pharyngeal/tonsilar area w/white exudate
  • Perforation of soft palate-Late effect
  • Skin lesions-More common & present in tropics
24
Q

Corynebacterium diphtheriae-Treatment

A
  • Poor specificity on microscopy NOT all strains produce toxin
  • Culture=isolate organism w/3 medias
  • Cystine-Potassium tellurite (selective NO gram (-) & flora/Grey-Black colonies 24-48hrs)
  • Blood agar (small gray irreg zone & small zone of hemolysis)
  • Loeffer’s serum <u>(granule formation/Stain metachromic-inorganic polyphos)</u>
  • Toxin test for production-Elek test=ouchterlony (<u>bind to Ab to form immune complex</u>) Lines cross same Or PCR
  • Treatment: Early admin of diphtheria antitoxin (passive immunity)
  • Penicillin or erythromycin
  • Resp Support
  • Prevention: DPT (diphtheria, pertussis, tetanus) vaccine followed by boosters
25
Q

Bordetella Pertussis-General

A
  • Gram negative coccobacillus-capsulated
  • Strict aerobic-requires enriched media (Bordet-Gengou)
  • Resistant to penicillin-Added to medias to make it selective
  • Reservoir- Humans only
  • Transmission-Aerosol/Direct contact
  • High Risk-Unvaccinated children-Increasing in adults
  • Pathogenesis-adheres & multiplies rapidly on epi surface of trachea/bronchi
    • Interferes w/ciliary action
26
Q

Bordetella Pertussis-Adhesins (virulence)

A
  • Adhesins:
  • FHA (filamentous hemagglutinin) & pertactin
  • Both bind to:
  • Integrins on ciliated cells
  • CR3 on macrophages=induce phagocytosis w/o initiating oxidative death
  • Result=Intracellular growth in macrophages w/protection from humoral immunity= COUGH
  • It does NOT invade rather it liberates internal toxins that irritate surface cells.
  • Secondary invaders: staph, H.Influenza lead to bacterial pneumonia
27
Q

Bordetella Pertussis-Virulence factors

A
  • Pertussis Toxin (Ptx)-Ab type toxin
  • ADP ribosylation of G protein=Increase cAMP lvls
  • Increased resp secretion/mucus made
  • Inhibits signal transduction by cytokine receptors
  • Interfere signals from cell surface receptors to intracellular mediator sustems
  • Interfere w/chemotaxis of lymph/neutophils & phagocytosis <strong>(increase WBC)</strong>
  • Tracheal cytotoxin (peptidoclygan)
    • Interferes w/DNA synth, kills clilated resp cells
  • Adenylate cyclase toxin/hemolysin: Secreted by bacteria, absorbed by host cells, & activated to convert ATP to cAMP
  • Impairs chemotaxis=Inhibit phagocytosis
28
Q

Bordetella Pertussis-Clinical

A
  • Incubation 7-10 days NO symptoms
  • Catarrhal: 1-2 weeks=Inflammation mucous membranes nose and throat
    • Highly contagious
    • Best time to culture
  • Paroxysmal: 2-4 weeks=destruction of ciliated epithelium, impairment of mucous clearing, whooping w/series of coughs vomiting, leukocytosis “sudden attacks”
  • Convalescent: 3-4 weeks (+)=secondary complications lack of oxygen supply: Pneumonia, seizures, encephalopathy & diminished cough (recovering)
    • Possible stage for super infection
29
Q

Bordetella Pertussis-Diagnosis

A
  • Microscopy: Fluorescent Ab on aspirated specimens (false + high)
  • Specimen: Calcium alginate swabs
  • Culture: Not very sensitive
  • Bordet Gengou (Potato/Blood/glycerol agar w/High amount of blood 20-30%)
    • Nicotinic acid + to support growth
    • charcoal & Starch + to remove FA
  • Molecular method: PCR
  • Serology: ELISA-titers against pertussis to Hemagglutinin using acute/Convalescent serum (blood from recovering pt)
30
Q

Bordetella Pertussis-Treatment

A
  • Macrolides: Erythromycin or Azithromycin for early stage
  • Treatment of dehydration & Low O2 for late stage-Steroids for babies/elderly
  • Prevention & control:
  • DPT vaccine (diphteria, pertussis, tetanus)
  • Whole cell inactivated=80-85% effective w/SE
  • DaPT vaccine-Multivalent acellular vaccine effective w/less SE
  • Made up of several purified proteins, pertussis, hemagglutinin, peractin, fimbriae (contains @ least 2)-Booster needed
  • Main immunogen is pertussis-engineered by intro 2 AA to inactivate enzyme activity
  • Erythromycin prophylaxis-in young children prevent relaspse-In catarrhal stage shorten length/severity
31
Q

Moraxella Catarrhalis-General

A
  • Large # of gram(-) rod/bean shaped cocci attached or residing w/in PMNs in sputum
  • Neisseriaceae family=Oxidase +(cyto C-electron transfer chain)
  • Does NOT ferment glucose, maltose, sucrose
  • Reservoir: Pharyngeal flora in children/adults
  • High Risk: Children/elderly & may be combo infection w/other pathogen=Lower resp tract infection
  • Clinical: Otitis media, sinusitis=Children & Bronchitis, pneumonia=Elderly
  • Diagnosis-Gram stain
  • Treatment-Beta lactamase(+)=Penicillin resistant
  • Ampicillin/Clavulanate(Augmentin-beta inhibitor) 2nd or 3rd gen cephalosporins
32
Q

Klebsiella Pneumoniae (General)

A
  • Gram (-) rods, Faculative anaerobe
  • **Lactose fermenter on MacConkey **
  • Enteronacteriaciae=Non-motile, Oxidase <em><strong>(cyto-c</strong></em>) & Indole (reduction of trytophane) negative
  • High Mucoid colonies due to LARGE cap
  • Reservior: Part of normal flora GI & URT
  • Transmission: endogenous, aspiration/inhalation of resp droplets.
  • High risk: Chonic lung disease, alcoholism, diabetes, resp equipment (MEN)
  • Virulence: Capsule-Antiphago
    • Endotoxin(LPS)= Inflammation leads to Septic shock
33
Q

Klebsiella Pneumoniae (Clinical)

A
  • Presents: Typical pneumonia (productive)=hospital/community
  • Upper lobes w/50% mortality
  • Necrotic destruction of alveolar spaces=Cavity formation
  • Sputum THICK & Blood tinged jelly
  • Complications: Septicemia (bacteria in blood) or UTI
  • Diagnosis: Sputum w/gram stain <strong>(BIG CAPSULES)</strong>
  • Pink colonies on **MacConkey-Lactose **
  • Treatment: Antibiotic resistance, even vancomycin resistance
34
Q

Pseudomonas Aeruginosa (General)

A
  • Gram (-) rod in pairs, Oxidase (+) non-fermenter (aerobic)
  • Makes pigments:
    • Pyocyanin (blue
    • Pyoverdin (yellow/green)
  • Some strains have Cap, slime layer, mucoid colonies
  • Fruity grape-like oder
  • Beta Hemolytic
  • Reservoir: Uniquitous (everywhere)-moist/wet sources, AC towers, Respirators, soil, disinfectant sol=Requires minimal nutrition
    • Normal flora in some people
  • High risk: Oppurtunistic: immunocomprimised (COPD, CF) hospitalized pts, Mech ventilation, or Pts on Broad spec antibio
35
Q

Pseudomonas Aeruginosa (Pathogenesis)

A
  • Several virulence factors, adhesions, toxin, exoenzymes
  • Adhesins=Pili, LPS, capsule
  • Exotoxin A=A-B exo in single protein-ADP ribosyltransferase reacts w/EF-2=Inhibit protein synthesis (diphtheria toxin)
  • Pigments: Pyocyanin (blue) activates O2 radicals (ROI) attracts WBCs-Destruction of tissues
  • Phopholipase=Digests lecithin leads to cell lysis
  • Capsule/slime layer=Creates Biofilm (some strains)
  • Most common cause of nosocomial pneumonia can be fatal <strong>(necrotizing bronchopneumonia)</strong>
36
Q

Pseudomonas Aeruginosa (Clinical)

A
  • Virulence facts must work TOGETHER to cause disease
  • Typical pneumonia: Tracheobronchitis w/pneumonia=Necrotizing
  • Biofilm formation found in CF pts
    • Comprimised neutrophils fail to clear bacteria=Population grows
    • Exo toxin A produced once pop reaches quarum sensing (biofilm)=slimey mucous
  • Bacteremia/Endocarditis: Leads to shock
  • Otitis media & externa (swimmer’s ear)
  • Skin: Burn wounds or Folliculitis (hot tub)
  • Eye infection: Trauma (contact lens)
  • UTI: Hospital w/catheters
37
Q

Pseudomonas Aeruginosa (Diagnosis)

A
  • Culture on blood agar or enteric MacConkey=Grey colonies (non-lactose)
  • Oxidase (+)=Presence of Cyto C (remove electrons)
  • On colorles media makes Blue, green-yellow
  • Mucoid colonies=Frutiy order
  • Treat: Multidrug resistant due inherent resistance
  • Combo of antibiotics-Anti-pseudomonal beta lactams + aminoglycosides or fluorquinolones
  • Prevention: Hospital control * CL- of Hot tubs
38
Q

Burkholderia Cepacia

A
  • *Nine species *
  • Gram (-) bacilli, aerobic non-fermenter, Oxidase (+)
  • Does NOT product diffusible pigments
  • Reservoir: Moist envrioments like Pseudomonas
  • Transmission: Inhalation
  • High Risk: Oppurtunistic pathogen (CPD, CF, Chronic granulomatous disease)
  • Weak & NOT pathogenic in healthy people
  • Typical pneumonia & UTI in catherized pts
  • Diagnosis: isolated from sputum/catheters put in Blood agar or w/**polymyxin for which it is resistant **
  • Treat: less resistant to Antibiotics - Trimethoprium sulfa
  • Prevent by cleaning resp equipment BUT it is ubiquitous=hard to control
39
Q

Acinetobater Baumannii

A
  • Gram(-) coccobacilli (small rods), Non-motile
  • Aerobic (oxidase negative) & Highly resistant to antibio (some are completely Immune)
  • Reservoir: Ubiquitous (pseudomonas)-VERY resitant to enviroment dryness
  • Normal flora oropharyngeal
  • Transmission: Inhalation, trauma to skin, Hospital setting
  • High Risk: Opportunistic-Pts
  • w/resp vent
  • Catherized pts (urine dialysis)
  • Surgery or trauma
  • Broad spectrum antibiotics
  • Presents as typical pneumonia, UTI, septecemia, Infections in aged & ICU pts
  • Soft tissue infections=Gun shot wound (Iraq Bacillus)
40
Q

Legionella Pneumophilia (Legionnaire’s disease)

A
  • Gram (-) bacilli (pleomorphic) HARD to stain-Silver impregnation
  • Fastidious growth (Needs nutrition) Cysteince/Iron
  • Special medium-BCYE (buffered charcoal yeast extract agar)-Charcoal neutralize FAs
  • Reservoir: Aquatic, Survives in amoebae(Natural water), cooling towers, Showers, water misters, hot tubs, decorative fountains.
  • Resistant to Cl- Can grow @ 45 C
  • Transmission: inhalation of aerosol & water NO person to person
  • High risk: Middle age or older=immunocomprimised <strong>(alcoholics, smokers, COPD, diabetes, transplant pts)</strong>
41
Q

Legionella Pneumophilia (Pathogenesis)

A
  • Faculative intracellular of alveolar macrophage, monocytes, & epithelial
  • C3B deposition facilitate phagocytosis
  • NO fusion of phagosome/lysosome=Avoid intracellular killing (survive inside macrophage)
  • Infected macrophage-Make inflammatory cytokines=Robust inflammatory response
  • Diagnosis: Direct fluorescent Ab or silver staining
  • Culture on BCYE w/cysteine&iron
  • Urine Ag Test: BEST method specific for LPS Ag
  • Ab Rxn: ELISA or indirect fluorescent Ab test = Lvl of 1:128 or more (+)
42
Q

Legionella Pneumophilia (Clinical)

A
  • Pontiac Fever: Flu-like symptoms
  • Incubation time=1/2 dats & lasts 2/5 days
  • Fever, chills, myalgia, malaise, headache
  • No pneumonia
  • Possible Hypersensitivity rxn
  • No Antibiotic treatment
  • Legion Disease: Atypical pneumonia
  • Incubation time=2/10 days
  • Male middle age (smoking, drinking, underlying pulm disease)
  • Sever Toxic pneumonia-Rapid onset w/flu-like symptoms, high fever, chest pain DRY cough
  • Patchy interstitial infiltration w/tendency to develop into conslidation w/micro-abcess
  • Progress to multi-organ failure
  • Mortality 75% in immunocomprimised
43
Q

Legionella Pneumophilia (treatment)

A
  • Antibiotic must be able to penetrate HUMAN cells
  • Macrolides-Azithromycin or Clarithromycin
  • Fluoroquinolones-Cipro or Levo
  • Control-
  • ID Source & eliminate
  • Hyperchlorination & elevated water temp
  • Replace shower heads
  • Stop water mists on vegetables
  • Copper-silver ionization of water supply
44
Q

Mycoplasma Pneumoniae (general)

A
  • Cell-wall less=Pleomorphic
  • Sterol in cell membrane
  • Smallest free living organism (extracellular)
  • Requires cholesterol in culture
  • Lives in Human Resp Tract
  • Infected by aerosol spread w/in Close people - Incucation 1-4 weeks
  • High Risk: Teenagers/Young adults
  • Outbreaks occur in military & colleges
  • Adhesion: Surface P1 binds to sialic acid on ciliated resp epi cells
  • Tissue damage: Produce hydrogen peroxide-Superoxide radicals & cytolytic enzymes=Killing cells/Destroying ciliary action
45
Q

Mycoplasma Pneumoniae (Clinical)

A
  • Incubation time 2-3 weeks
  • Pharyngitis
  • Tracheobronchitis-Low grade fever w/Dry cough
  • Pneumonia-Atypical-walking w/low grade fever, patchy broncho-Dry cough
  • Complications: Hemolytic anemia & Neurologic Due to MP binds to sialic acid glycoproteins on RBCs
  • Treatment: Beta-lactam antibios
  • Tetracycline, erythromycin & quinolones
  • Mulberry colonies or Fried egg colonies
46
Q

Mycoplasma Pneumoniae (diagnosis)

A
  • Specimen from bronchial washings (NO sputum produced)
  • Mulberry colony on A8 agar enriched media w/animal serum (cholesterol) & antibios to inhibit bacteria=Grow SLOW up to 6 weeks
  • Cold aggutinin-IgM Ab bind to Ag on erythrocytes of O blood @ 4 C
    • Can be preformed @ bed side takes mins
    • For children under 12 not a good test
  • Serology-ELISA 4 fold increase (1:128) detect Ab against P1 Ag
47
Q

Chlamydiaceae (general)

A
  • Under another family Clamydiopilia (Psittaci & Pneumoniae)-Non-STD
  • “Energy Parasites”-Use ATP produced by host cell
  • Obligate intracellular parasites w/o host cell ATP they cannot make their own
  • Cannot grow w/o culture-Has cell wall BUT lacks muramic acid (sugar acid)
  • NO Gram stain
  • Biphasic growth cycle:
  • Elementary body=Infectous stage (metab inactive comes from outside-In)
  • Reticulate Body=Metab active-replicate inside cell & convery EB to RB-Lyse cell
48
Q

Chlamydophilia Pneumoniae (general)

A
  • Reservoir: Human RT
  • High risk: most cases are asymptomatic or *present w/Pharyngitis *
  • Elderly
  • Pathogenesis: Intracellular growth infects-
  • Macrophages
  • Endothelial cells
  • Coronary artery
  • Smooth muscle
  • Presents:
  • Pharyngitis
  • Sinusitis
  • Bronchitis
  • Atypical pneumonia (mycoplasma)
  • Linked to atherosclerosis, Alzheimer’s, asthma, & reactive arthritis
49
Q

Chlamydophilia Pneumoniae (Diagnosis)

A
  • Difficult to diagnose
  • Culture: Grow on HE-p2 cell line (not common)
  • DFA staining to detect inclusion bodies (stain green)
  • Serology: Best method-Microimmunofluorescence or comp fix test
  • Detect IgM or 2x increase of IgG
  • Treat: Reaccurance of symptoms tends to happen so 2-3 weeks treatment recommended
  • Doxycycline, fluoroquinolones, erythromycin
50
Q

Chlamydophilia psittaci

A
  • Reservoir: Birds (farmhand working on turkey farm) present in tissue, feces, urine of bird (sick/healthy)
  • Transmission: Aero via dust w/resp secretions/handling of avian feces
  • NO person to person
  • Pathogenesis: Parrot fever/Ornithosis
  • Atypical pneumonia
  • Bronchitis/Pharyngitis/Sinusitis
  • Severe cases spread to Multi system
  • Diagnosis: Serology 4x increase comp fixation or micro immuno
  • Treatment: Doxycycline, macrolides, fluoroquinolones
  • Treat imported birds w/chlortetracycline
51
Q

Bacillus Anthracis (general)

A
  • Large gram (+) spore forming bacilli
  • Chain formation
  • Aerobic spore former-Poly glutamic acid capsule (not a protein=NO gram stain)
  • Reservoir: Ubiquitous around the world (soils/animals)
  • Transmission: Disease of **herbivores aquire pathogen by grazing **
  • Humans infected by contact w/animals
  • Entry-injured skin, inhalation, ingestion
  • High risk: Farm hands, vets, tanners, taxidermists
  • Diagnosis: Resp secretions, Pus on skin, or Blood
  • Culture: Blood agar-non/hemo w/white-grey rough colonies (rounded glass appearance)
  • PCR best diagnosis
52
Q

Bacillus Anthracis (Clinical)

A
  • Virulence:
  • Poly-glutamate cap (non-phago)
  • Anthrax: A-B toxin coded by genes on plasmids
  • PA (protective Ag), EF (edema Ag), LF (lethal factor)
  • PA=Binding unit-entry <strong>(bind multi-system)</strong>
  • EF=Adenylate cyclase increase cAMP=edema
  • LF=Zn dependent protease inhibits kinases-Cell death
  • Skin: entry through wound, black necrotic center w/raised edematous edges
  • GI: RARE in humans, High mortality
  • Inhalation(wool sorter’s): incubation 2+ months, alveolar macrophage engulf spores-carry to mediastinal lymph
  • Massive chest edema, hemorrhagic (widened mediastinum), bacteremia/toxemia=Cyanosis-shock-death w/in 3 days (meningeal symtptoms)

Microbio-2 (20 decks)

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