Pathology - Lung Flashcards
Forms of acute bacterial pneumonias
Bronchopneumonia and lobar pneumonia
Brochoopneumonia
Patchy and involves more than one lobe
Lobar pneumonia
Part or all of a lobe filled with exudate that can be seen as lobar or segmental
What organism is responsible for 90% of lobar pneumonia
Streptococcus pneumoniae
Origin of most community acquired pnemoniae
Bacterial
Most common cause of community acquired pneumoniae
S. pneumoniae (lobar )
Four stages of lobar pneumonial evolvement in lobes
Congestion, Red hepatization, Gray hepatization, Resolution
Congestion Stage
Lobe is red, heavy,boggy,proteinous fluid, neutrophils and bacteria lasting for few days
Red hepatization
lung has liver-like consistency, alveolar spaces packed with neutrophils, red cells, fibrin
Gray hepatization
lung is dry, gray, firm due to RBCs lysing out
Resolution
enzymes digest exudate,debris eating by macrophages, fibroblasts growing around it
Empyema
is suppurative accumulate in the pleural cavity
Complication of pneumoniae occurs through
Type 3 serology
Gram positive lancet shaped diplococci is good evidence for
S. pneumoniae but be careful of false positive
Community acquired acute pneumoniae
S. pneumoniae, H. influenza, Moraxella catarrhalis, S. aureus, Legionella, Klebsiella and Pseudomonas
Community acquired atypical pneumoniae
Mycoplasma, Chlamydia, Coxiella, RSV, Parainfluenza, Influenza A and B, adenovirus
Nosocomial pneumoniae
G- rods - Klebsiella, Serratia, E. coli and Pseudomonas,S aureus
Aspiration pneumoniae
anaerobic oral flora - bacteroides, prevotella, fusobacterium, peptostreptococcus admixed with S. pneumoniae, S aureus, H. influenza, Pseudomonas. Caused mainly by aerobes
Chronic pneumoniae
Nocardia, Actinomyces, Granulomatous-Mycobacterium, Atypical Mycobacteria, Histoplasma, Coccidiodes, Blastomyces
Necrotizing pneumoniae and lung abscess
anaerobic bacteria, S aureus, Klebsiella, S. Pyogenes, Type 3 pneumococcus
Pneumonia in the immunocompromised
CMV, pneumocystis, Mycobacterium avian, invasive aspergillosis, invasive candidiasis,
Most common bacteria causing acute exacerbation in COPD
H. influenza, secondly M. catarrhali
3 most common causes of otitis media
S. pneumoniae, H. influenza, M. catarrhalis
IV drug use causing right sided endocarditis by which organism
S. aureus
Most common cause of G- bacteria pneumoniae, affecting alcoholics
Klebsiella
Rapid diagnosis of legionella
Antigen in urine or PCR
Atypical pneumonia means
means moderate amount of sputum produced, no consolidation, moderate WBC count, no exudates, inflammation in alveolar septa only
Most common atypical pneumoniae organisms
Mycoplasma pneumoniae occurring in closed communities
What type of Influenza causes most pandemic and epidemic
Type A by mutations of the hemagglutinin and neuraminidase
Epidemics of Influenza A due to
antigenic drift
Pandemics of Influenza A due to
antigenic shift. Recombination with other RNA viruses
what organism seen in Cystic Fibrosis, burn and neutropenic patients
Pseudomonas
What organism is secondary to viral respiratory infections
S. aureus
What organism is seen in organ transplants
Legionella
All lung abscess possess what kind of organism
Anaerobes - Fusobacterium, Bacteroides, Peptostreptococcus and microaerophilic streptococcus
What side of lung is aspirations more common on
Right side, at posterior segment of upper lobe and in the apical segments of the lower lobe
Most important organism in chronic pneumonias
TB - center undergoing caseous necrosis
Most important risk factor for developing TB
HIV infection
Infection
seeding of a tissue with an organism without any damage
Disease
Damage caused to a tissue by an organism
Positive tuberculin test signifies
cell mediated hypersensitivity
Features of Tuberculosis
Caseating granulomas with cavitation due to destruction of tissue by host immune
how long is primary pulmonary tuberculosis
0-3 weeks ( proliferation of TB in pulmonary macrophages) with mild flu and asymptomatic
NRAMP I ( natural resistance assoc. macrophage protein I)
transmembrane ion transport found in lysosome and endosome to help with TB killing
How long for cell mediated immunity to develop in TB
3 weeks after exposure
What cytokines needed for macrophage/dendritic cells to get help
IL-12, CD4+ of the Th1 type( secretes IF-gamma)
Role of CD4+ -Th1 subtype in TB control
Secretes IF-gamma needed to activate macrophage
Role of Activated macrophage in TB control
secrete TNF ( recruit monocytes),express inducible NO synthase and ROS
What are the total cytokines needed to effectively deal with TB
IL-12, IFN-gamma, TNF, NO production
What primarily mediates immunity response to TB infection
TH1 cells to stimulate macrophages
Ghon focus
gray white inflammatory consolidation after unsensitized person encounter first TB
Ghon Complex
parenchymal lesion and nodal involvement of TB. TB traveling i the lymph to regional nodes
Ranke complex
Progressive fibrosis and calcification of Ghon complex
Progressive primary TB
seen in HIV+ people with CD count of <200
Primary TB
TB that develops in a person previously unexposed and therefore unsensitized
Secondary TB ( Reactivation TB)
pattern of disease seen in a previously sensitized person
Location of secondary pulmonary TB
one or both upper lobes
Does cavitation occur in primary or secondary TB infection and why?
Secondary because individual already sensitized and they quickly mount immune response to fibrocase the TB in that upper lobe
Miliary pulmonary disease
TB drains through lymphaticsand gets into ride side of heart and into pulmonary arteries
Most frequent form of extrapulmonary tuberculosis
lymphadenitis usually in the cervical region
Hallmark of host reaction to TB in immunocompromised persons is
Granulomas presence
Cavity lesion in lung apices means
secondary or reactivation
Features of Mycobacterium avium
Disseminated non-tuberculous disease
Epidemiology of Histoplasma
Ohio and Central Mississippi Rivers enriched by bats and birds small yeast
Epidemiology of Coccidioides
Western US….San Joaquin Valley, thin walled, non budding spherules with endospores
Epidemiology of Blastomyces
Overlaaping areas with histoplasmosis - broad-based budding, larger than Histo
“Owl eye” -giant cell, within the nucleus an enlarged inclusion with a celar halo
Cytomegalovirus
Cause of infectious mononucleosis type infection
CMV
Most common opportunistic viral pathogen in AIDS
CMV, yet it spares the CNS system
NAme of most opportunistic CMV
CMV retinitis
Diagnosis of CMV
viral inclusions in tissue cultures
What is Pneumocystis pneumoniae
fungus
When AIDS person get Pneumocystis pneumoniae
CD4+ <200cells/uL
Most sensitive test for diagnosing Pneumocystis pneumoniae
Identify organism in induced sputum
Most common disease causing fungus
Candida albicans with pseudohyphae
What players defend against Candida
TH17, CD4+
Mutation on TH17
Job syndrome
Most common fungal endocarditis
Candida
Diagnosis of Crytococcus
Gelatinous capsule in a clear halo with India Ink
Non-septate hyphae, at right angle causing Mucormycosis
Zygomycetes
Septate branched at acute angles causing Mucormycosis
Aspergillus
Wha molds invade blood vessels causing vascular necrosis
Aspergillus and Rhizopus and Mucor
What mold invades diabetic patient
Mucor and Rhizopus
CD4+ >200cell/uL in AIDS patient
Bacterial and TB infections
CD4+<200cells/uL in AIDS patient
Pneumocystis pneumoniae
CD4+<50cells/uL in AIDS patient
CMV and M. avium
Animal reservoirs of cholera
Shellfish and plankton
What causes disease by cholera
preformed enterotoxin interacting with ADP ribosylation factors and activate Gs opening the CFTR which releases Cl ion to the lumen
Source of Campylobacter
improper cooked chicken, unpasturized milk,
Organisms in self limited colitis
Campylobacter, Shigella, Salmonella, Yersenia, E. coli
Low infective doses
Shigella, Salmonella and Campylobacter
Site of Shigella in body
Left colon
Triad of arthritis, urethritis and conjunctivitis( reactive artritis) - what organism
Shigella
HUS organisms
Shigella and EHEC
Sources of Salmonella
Raw meat, poultry, eggs and milk
Rose spots
Salmonella
What organisms go by M cells
Shigella, Salmonella
Pseudomonas membrane
Clostridium difficle
Most common cause of severe childhood diarrhea
Rotavirus
Most common pathogenic parasitic in humans
Giardia
Most common bacterial enteric pathogen in developed countries
Campylobacter