• aerobic gram negative rods
• resp. disease with wide range of clinical manifestations

• nonmotile
• aerobic gram negative rod/coccobacilli

bordetella pertussis

• exclussive human pathogen
• spread by aerosolized dropletes (cough)
• 20-30% of adults with prolonged cough may have pertusus
• wannin post vaccine immunity, so adults/adolescents are at risk for disease
• 90% of cases found in developing world

• vaccine has changed epidemiology
  • prevaccine
    • seen in age 1-5 (women surviving infection pass on to kids)
  • post
    • moms dont give passive immunity
    • immunity wanes after 12 yrs

• exposure thorugh inhalation of aerosolized bacteria (infected human reservoir)
• attach to ciliated epithelial cells of bronchial tree
• bacteral prolif.
• VFs produce
  • localized tissue damage
  • systemic toxicity

• filamentaous Hb- block neutrophil phagocytosis, help bind to resp. ciliia
• pertussis toxin (can be local and systemic)
• pili and peractitin- attachment of bacteria to epithelium

MAINLY BINDING/ATTACHMENT

• stage one: incubation period (7-21 days); asymptomatic
  • bacteria attach, prolif on ciliated epithelium
• stage 2: catarrhal stage (1-2 wks); most contagious
  • symptoms- rhinitis, malaise, low grade fever, sjneezing, anorexia, increase WBC
  • peak bacteria prod., disease not recognized
• stage 3: paroxysmal stage (2-4 wks)- 40 to 50 paroxysms/day
  • symptoms- repetitive cough with whooping (expir. cough with inspir. gasp), vomit, exhaustion
  • extrude ciliated epithel. cells impair mucus clearance, lead to mucus plug airway
• stage 4- convulescent stage (improved paroxysmal cough)
  • development of secondary sysmptoms including pneumonia (main cause of mortality), seizures, enxephalopathy

• rare encephalopathy and seizures
• paroxysomal cough can increase intrathoracic and intraabdominal pressure cause:
  • subconj. hemorrhage
  • truncal hemorrhage
  • epistaxis
  • pneumothorax
  • rectal prolapse

• Xray- collapse of lung resulting from mucus plugging of smaller bronchi and bronchioles
• cause- aspiration durin cough, impaired sec.

MAIN CAUSE OF MORTALITY

• difficult
  • organisms decrease as symptoms increase
  • clinical clue- cough 2 wks
• culture Bordet Gengou media (up to 2-7 days)
• direct flurescent Ab (DFA)
• serology- rise between acute and convalescent sera

• supportive therapy (ex: if pneumonia, antibiotics with oxygen therapy)
• current vaccine

• aerobic growth requires two supplements X factor (hemin) and V factor (NAD)

• made against type B capusule producin strains (this strain assoc. with most invasive infections)
  • have six Ag distinct capsular types (A to F)
  • strains without capsule called nontypeable

• humans only natural host
• transmission via contact w/secretions or airborne droplets
• since advent of widespread vaccinations, H influenzea infections most likely to occur:
  • nonencapsulated forms, (A-C, F)
  • type B infection if nonimmune children or elderly with waning immunity
• risk factors
  • HIV/AIDS
  • sickle cell disease
  • splenoectomy
  • chronic lung disease
  • smoking
  • malignancy
  • pregnancy
  • alcoholism

• capsule- inhibit opsonization, intracell. killing
• LPS
  • initiate invasive disease
  • endotoxin like activity, tissue damage
  • facilitate survival on mucosal surface (nasopharynx)
• outer membrane proteins (OMP)
  • contribute to Fe scavengin and bindin required for organism survival
• fimbriae
  • on bacterial surface
  • enhance adherance
  • present in typeable and nontypable

• humoral immunity
  • protective Ab;'s opsonize bacteria
  • increase reisk if functional asplenia or splenomegally
• complement (susceptible if def. in C2, C3)

• meningitis
• epiglotis
• otitis media, sinusitis (URT)
• pneumonia (LRT
• arthritis

• occurs after bacteremic spread of organism from nasopharynx
• assoc. with trauma, neurourgery, CSF leak or paranasal sinusitis

• a life threatening emergency with cellulitis and swelling of supraglottic tissues
• presentation
  • pharyngitis, fever
  • drooling, difficulty swallowing and breathin
  • may progress rapidly to complete airway obstructiona d death

• lateral neck radiograph will show thumbprint sign
• cherry red epiglottis

• most common cause of ottits media in young children
• occur in immunocompromised, chronic lung disease
  • exacerbation of bronchitis
  • pneumonia- lobar consolidation, effusions/empyema

• bacteremic spread to single large joins
• usually on immmunocomp. or with previously damaged joints

• blood cultures for meningitis, epiglottitits, cellulitis, arthritis, pneumonia
• supplement media (X and V factor, chocolate agara)
• Ag detection ELISA (urine, CSF)

• serious infections always should be given IV with epiglottitis and meningtis

• Hib vaccine substantially decreases incidence (98% effective)
• chemoprophylaxis with Rifampin

• STD
• cause of genital ulcers in Asia and Africa, and major contributer to transmission of HIV
• tender papule with erythematous base onthe geintal and perianal area
• lesion ulcerates and is painful with suppurative inguinal lymphadenopathy

• slender, plemorphic, obligately aerobic gram negative bacilli
• seasonal
• 90% of cases of disase caused by this bacteria (serogroup 1 most common)
• use charcoal yeast enriched media
• nutritionally fastidious

• fresh water (lakes, streams)
• most epidemic in summer, fall
• humans are accidental hosts
• optimal for symbiotic microorganisms
• environmental spread through water distrubution
  • showers
  • humidifiers
  • resp. therapy equipment
  • evaporative cooling towers of AC symptoms
  • microaspiration during and after ingestion of contaminated water/ice

1. pulm. alveolar macrophages engulf bacteria
2. no intracellular killing
   • oxidative and nonoxidative intracellular killing mech. are inh.
   • blunted or absent resp. burts with release of microbial oxygen derivatives
   • no acidification of phagosome by lysosome to expose bacteria to toxic lysosomal contents
3. multiplies within specialized endosome and produce cytotoxins
4. macrophage killed and new bacter released and infect other macrophages

Host defense via NK and cytotoxic T cells lyse infected macrophages to end cycle while humoral immunity increases uptake of bacterial into neutrophils where it cannot replicate

• Pontiac fever
• Legionellosis
  • febrile systemic illness with pneumonia (another "atypical" pneumonia)
• pulm. infiltrates- rapid progress of alveolar infiltrates of multilobar consolidation
• resp. deterioration, multisystem failure and DIC
• mortality 15-20%
• pathology
  • intense inflam. changes present in alveoli, alveolar ducts, bronchioles, alveolar septa
• complications- pleuritis, pleural empyema, pericarditis, cavitary lung disease/abscesses
• extrapulm. legionellosis
  • occurs in immunocompromised
  • occurs by bacteremic spread

• high clinical suspicion required
• culture in enriched media- buffer charcoal yeast extract agar
• urine Ag- enzyme immunoassay detects serogroup 1 Ag

• Ab's must have high intracellular concentrations to be effective
• NEED HIGH CLINICAL SUSPICION

• routine envir. culturing of hospital envir. sources only on discovery of cases
• routine envir. culturing of hospitals performing organ and bone marrow transplants
• not contagious- isolation precautions not required