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15 Cards in this Set
- Front
- Back
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Pneumonia
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condition of lungs
caused by bacteria, viruses, parsite, fungi, particulates (smoke) alveoli damaged/filled with material gas exchange not possible mucous lining/cilia/epiglottal reflex/ cough protects us alveolar macrophages guard against microbes that reach deep lung tissue |
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Streptococcus pneumoniae
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Strep pneumoniae/Diplococcus pneumoniae/pneumococcus
can't type a C carb different lengths of chains of cocci, mostly diplococci, Optochin sensitive (can be eaten) 50% of all bacterial pneumonia - 40% asymptomatic carriers thick polysaccharide capsule, 90 types, immunity is type specific to capsule, = 90 infxns Quellung test, Ab test, (based on anticapsular Abs) distinguishes capsular types nonencapsulated strains are avirulent pus like exudate, fluid in lungs = death d/t drowning DX: Gram+ cocci in sputum, CXR rusty sputum d/t bleeding in lungs fluid, phagocytes allow palpitation of infected area elderly, heart pts, smokers show greatest infxn PCN resistant common - multi Rx TX Penumovax vaccine- 23 most common polysaccharide types. Because of the repeating polysaccharide structure, most of the response is T cell dependent. Booster Q5y Strep. pneumoniae also causes subacute endocarditis, otitis media, and meningitis |
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Walking Pneumonia
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• Bacterial disease of resp tract
• Gram – No PG layer- PCN ineffective • Mycoplasma pneumoniae small gram- round organism, cytoplasmic and outer membranes, unusual - no cell wall, sterols in its membranes • rich media forms fried egg like colonies (sunny side up) • human to human- military/college, very tired still work • CXR- sometimes diffuse infiltrate • best dx tools- cold agglutinins over time. They are antibodies that Mycoplasma induces in the pt that will agglutinate RBCs when stored in the cold, (refridge) |
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Legionnaires’ Disease aka legionellosis
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• Bacterial disease of resp tract
• Gram –Bacilli with many vacuoles • Fastidious, special supplements to culture • Legionella pneumophila – found in water sources (cooling towers - below 50C). • waters are aerosolized, droplet organisms infect via resp tract- Not d/t drinking infected water, resistant to chlorine in H2O (hosp showers high CL smell) • smoking/drinking predispose • 1976 Legionnaires died bicentennial in Phili.-didn’t stain well and special growth conditions weren’t devised for months. • Begins H/A, fever, confusion, shaking chills. Cough/SOB develop, • Surface component- C3b binds to, so alveolar macrophages ingest them. • L. pneumophia grow/multiplying intracellularly in macrophages. numbers increase until alveolar necrosis develops, = pneumonia/death d/t ↓ O2. • Amoebae feed on bacteria, but L. pneumophila turns the tables by killing/eating the host amoebae |
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Chlamydia pneumonia
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• Bacterial disease of resp tract
• Gram – No cell wall (hence roundish), 15% of Pneumonia's- difficult to cure • Developmental cycle- the infectious form different then vegetative form • Chlamydia can’t grow on media, must be grown inside human cells in culture. • obligate intracellular pathogens- must get ATP from host cell • test for Ab in pt serum and DNA hybridization test for chlamydial DNA • C. pneumoniae seen w/ heart attacks/strokes (the # 1 and 2 killers). The > the Ab titer to c. pneumoniae the > the probability of these diseases |
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Streptococcal Diseases
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• Bacterial Disease of the Resp tract
• Gram+ • Spheres (cocci) in chains (strepto) from one to many cells • Fastidious, grow on blood agar plates • hemolysis RXN differeniate DX: Alpha – incomplete hemolysis with a green tinge; Beta – complete hemolysis; Gamma – no hemolysis • Streptococci generally have a C carbohydrate layer in the cell envelope to which humans produce Abs- the Abs aren’t protective, have diagnostic value. • The C carbs called group A, group B, classification system by Rebecca Lancefield • Streptococci don’t secrete Catalase, differentiates from S. aureus. • sites for infxn: throat, oral cavities, vagina, and intestines |
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Acute Pharyngitis
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• Bacterial disease of resp tract
• Beta hemolytic (complete hemolysis) • Group A strep (C-carbohydrate type) • Pyogenic (pus) • Strep pyogenes aka group A strep, known for acute pharyngitis (strep sore throat). • Ab to M protein is opsonic (gets ready to be eaten), = recovery, get Strep. Pyogenes 90 times. • Cell layers from the inside are as follows: Cytoplasmic membrane, The cell wall: (PG), C carbohydrate –prevents lysozyme entry and PG degradation, M protein –attachment factor, antiphagocytic, 90 different antigenic types, Capsule of hyaluronic acid - identical to polysaccharide in connective tissue, (considered self by the immune system). bacterial cloaking devices • Strep pyogenes makes 2 streptolysins (SLO and SLS), damage cell membranes, (heart and WBCs). • secrete erythrotoxin = rash of scarlet fever. • causes acute pharyngitis (strep sore throat), impetigo, necrotizing fasciitis ( flesh eating bacteria) and 2 hypersensitivity reactions -post streptococcal states or sequelae. result from damage by the host’s own immune system. • Rheumatic fever is heart valve and joint damage that occurs several weeks after the acute disease because of immune hypersensitivity, after the bacteria are eliminated. d/t to production of Abs to Strep. Pyogenes that cross- react with heart tissue. • Immune complexes may form = permanent kidney damage d/t glomerulonephritis. (clusters of complex- “lumpy-bumpy glomerulonephritis. Theses 2 sequelae are the real reason for vigorous antibacterial tx in pts. • Strep pyogenes isn’t resistant to PCN tx with amoxicillin. nonompliance w/RX sequelae can still be induced. |
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Tuberculosis
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• Bacterial respiratory tract
• Neither gram + of gram – • Waxy cell envelope • Dx: Mantoux/tine test, sputum analysis, CXR • Mycobacterium tuberculosis – rod shaped, gram+ like organism • Spread by droplet - Invades lung destroys tissue • Isoniazid – Reserved for TB use only. used with ethambutol, rifampin, Streptomycin |
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Diphtheria
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• Gram+, club shaped bacillus clump together (Chinese writing)
• d/t diphtherotoxin (Corynebacterium diphtheriae), inhibits the 80S ribosomes of the host, affects the heart and nervous system = death. • pseudomembrane in pharynx (on the tonsils) = asphyxiation. (don’t remove = bleed to death) • Vaccine – a toxoid of diphtherotoxin, prevention- modified diphtherotoxin to render it harmless while remaining immunogenic • Historically killed 10% children. • DX: throat culture, ECG • S/S: bluish skin, breathing difficulties, bloody/watery nasal d/c, chills, croup like (barking cough), drooling (airway blockage), fever, hoarseness, painful swallowing, skin lesions (in tropical areas), sore throat (mild to severe), * may be no s/s • Prevention: DTaP given at 2,4,6, 15-18mo, booster @ 4-6yo, unless the fourth dose was after 4th bday) • Prevention: Td booster (adult tetanus and diphtheria) Q10y • TX: Diphtheria anti toxin IM/IV and ABT (PCN/erythromycin) • Complications: Myocarditis, paralysis, kidney damage |
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Pertussis aka whooping cough
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• Bacterial disease of resp tract
• Bordetella pertussis causes the disease, Gram-, coccobacillus • Mainly young children HX killed 50% of infxted, with ABT death rate 0.5% • Paroxysmal sound or whoop generated when coughing finally stops enough that a labored gasp can be inspired.= subconjunctival hemorrhaging • Young adults whose parents refused the vaccines for their children are now having babies infected with pertussis • we use the acellular pertussis vaccine for all people (DaPT) and a modified diphtheria vaccine (daPT) for adults. |
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Group B Strep
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• Bacterial disease of resp tract
• Beta hemolytic (complete hemolysis) • Group B strep (B type C carbohydrate) • Strep agalactiae and group B strep are synonymous • Assoc with mastitis in cow utters and human vaginal tract • Generally harmless (normal flora) to the female, the newborn develops a serious disease. • Strep agalactiae causes 40% of newborn septicemia often = death • Also causes serious meningitis (infection of the meningeal covering of the brain and spinal cavity) of newborn. • A vaccine to protect the newborn in under development • Expectant moms who test + for group B strep are given ABT for a few weeks before delivery |
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Viridans Strep
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• Bacterial resp tract
• Alpha hemolytic (incomplete hemolysis with a green tinge) • Optochin (ethyl hydrocupreine) resistant • Not typeable by C carbohydrate • Viridans refers to this group of streptococci and is not a genus name. • The organisms are not usually speciated. • 100% pts- commensals- mouth/resp tract • in normal pts- no problems; pt heart damage, are at risk • Group A strep can cause initial damage to heart valves via toxins (without growing on the heart tissue), these organisms attach to/grow on damaged valve = subacute endocarditis = further damage. don’t grow on healthy valves. Several bouts of subacute endocarditis is likely lethal. • dental work can = oral flora gaining access to the bloodstream, take accurate histories/ABT prophylaxis. |
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Bacterial Meningitis
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• Bacterial disease of resp tract
• = brain injury/death in infants/young children • vaccine for all types of meningitis except type b • Inflammation of meninges (meningitis), membranes surround /protect the brain & spinal column, d/t a number of organisms. • Spread via respiratory routes, organisms invade from throat to spinal column by passing thru host cells. • Stiff neck/vomiting/fever • Tx: >1 drug and started asap • rifampin prophylactic tx Health care workers/family |
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Hemophilus influenzae
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• Bacterial resp tract
• Gram- pleomorphic rods • Hib conjugate vaccine protects against the B serotype • Fastidious; requires vitamins and CO2 for growth • Most common cause of meningitis is Hemophilus influenzae • Untreated 90% fatal - Even with tx 1/3 of pts = permanent mental damage • b serotype most common - causes 20,000 US cases meningitis/y • A capsular vaccine, Hib, was useful, it was T cell-independent because the antigen is a simple repeating polysaccharide. • A new T cell-dependent vaccine has been developed which contains the same polysaccharide capsule, but the capsular material has been conjugated (chemically linked) to the diphtherotoxoid protein • This conjugate (called Hib conjugate) now induces a memory response because of the protein so that immunity becomes long lived; and the number of diseases has plummeted • Otitis media, as with S. pneumoniae, is another disease caused by H. influenzae. |
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Neisseria meningitidis – (meningococcus)
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• Bacterial resp tract
• Gram- diplococci • Fastidious; growth requires CO2, O2, and vitamins • Also causes serious meningitis • meningococcus in the clinical setting • Highly invasive - Medical emergency – IV ABT stat, Spinal tap – look for gram- diplococci • Neisseria are exceptional in that their outer membrane allows the entry of PCN; aggressive PCN tx is essential • vaccine, menomune, available for 4 types of polysaccharide capsule but not type b- most common type, very poorly immunogenic. |
