Mycoplasma

Ureaplasma

• lack cell wall (pleomorphic shapes, flashlike)
• smallest self replicating life form
• fastidious growth requirements
• large number of species
• can be commensals and/or pathogens

• Chlamydia species
• early divergence in bacterial evolution
• unique, biphasic life cycle
• responsible for diverse clinical infections in human hosts
• obligate intracellular bacteria

• ubiquitous
• commensals and pathogens
• two categores of clinical disease
  • respiratory infections
  • genital infections
• common cell culture contaminant due to ability to pass through biologic filters

• M pneumoniae
  • tracheobronchitis
  • pneumonia (atypical or walking)

• M hominis- PID, pyelonephritis
• Ureaplasma urealyticum- urethritis
• M genitalium- urethritis, PID

• particular affinity for epithelium
  • respiratory
  • urogenital
• after inoculation, ciliary action decrease
• desquamation and loss of cilia contributes to manifestations of disease
  • cough
  • infertility

• lack cell wall (NOT visible by gram stain)
• slow growers (3-4 wks)
• fastidious, require steorles for growth
• unusual appearance on agar
  • fried egg appearance of colonies
  • exception: M pneumoniae has spherical mulberry colonies
• differentiate species with glucose met.

• highest attack rate: age 5-20 yrs
• spread by aerosolized droplets
• single cases or as "mini" epidemics (family, military recruits)
• particular risk
  • sickle cell disease
  • hemaglobinopathies
• incubation period of 2-3 wks

• adhere to epithelial lining
  • polar, flask like shape- slips btw cilia
  • P1- adherence protein
  • P1 localize to bacterial tips and binds to glycoproteins on host cell
• anticiliary action (suppress normal clearance mechanisms)
• immunopathogenesis via cytokines and host immune cell activation
• toxic products produced- damaged host cells, hydrogen peroxide
• inh. ciliary action
• exfoliate and inflame
  • cough
  • exudates
  • bronchial plugging

• tracheobronchitis
• pneumonia
  • one of several "atypical" pneumonias
    • culture negative
    • gram stain negative
    • do not respond to beta lactam antibiotics
  • mild symptoms (walking pneumoniae
    • rarely fatal
    • self limited in most cases
• pneumonia
  • insidious onset
  • prolong symtpoms
  • prolonged dry, hacking cough
  • bilateral infiltrates on chest X ray
  • slow resolution
• help differentiate from other atypical/viral pneumonia
  • bullous myringitis (rare)
  • clinical symptoms worse than pulmonary exam
  • GI complaints, myalgias uncommon

• extrapulm. involvement
  • dermatologic
    • Stevens-Johnson syndrome (erythema multiforme)
  • cardiac
  • Rynaud's phenomenon
  • neurologic

• clinical suspicion, eval. includes:
  • sputum
    • gram stain
    • culture (2-3 wks special media, unique colonies)
  • serologic
    • M. pneumoniae specific complement fixing Ab's
    • cold agglutinins

• M pneumoniae- an do early at time of presentation (blood clumps under cold conditions)
• complement Ab's- 6 weeks look for 4x rise

• penumoniae is usually mild, therapy often emperic (antibiotcs reduce symptoms)
• choose antibacterial therapies not active at the cell wall

• opportunists
• normal floura of UG tract of men and women
• transmission
  • direct genital-genital contact: sexual transmission
  • vertical (mother to child)

• urethreitis (non gonoccoccal)
  • symptoms persists post GC (due to inappropriate antibiotic therapy
  • 20% asssociated with M genitalium or ureaplasma (30% are chylamidia

• culture- special media, days-wks, fried eggs, use in combo with clinical suspicioun
• therapy- emperic

• unique biphasic dev. cycle
• bind to columnar epithelium
• gram negative, obligate intracellular bacteria

• elementary bodies- infectious form that binds to receptors and initate infection and extracelluar (so resistant)
• reticulate bodies- noninfectous form intracellar (fragile), metabolically active replicating form

• EB binds to receptors on susceptible cells
• internalized
• exists in inclusion vesicle (protected, membrane bound) in host
• inh. fusion with lysosomes
• Rb;s replicate, reorganize into EB;s
• inclusions contains many new organisms
  • Lyse with psittaci
  • extrude without lysis in pneumoniae, trachomitis species

• ocular infection
  • worlwide
  • transmission
    • droplet
    • person to person
    • contaminated clothings
    • flies
    • vertical
• genital infection
  • urethritis/cervicitis (STD's)
  • lymphogranuloma venerum
    • Africa, Asia, South America
    • MSM

• infect nonciliated columnar epithelial cells, leading to cell destruction with scarrin and fibrosis via inflammation response
• you cant get long lasting immmunity
  • allow reinfectionto be common
• can be assoc. with post-infectious complications

• trachoma
  • first infections usually less than 2 years old in endemic areas
  • repeated infection- inflammation and scaring
  • corneal opacification leads to blindness

• neonatal conjunctivitis
  • usually 5-12 days post partum
• infant pneumonitis
  • usually 4-11 wks post partum

• men- urethritis, epididymitis, prostatitis, proctitis
  • 75% asymp.
• women- cervicitus, urethritis, salpingitis, proctitis
  • 80% asymp
  • may progress to PID
  • complications
    • ectopic pregnancies
    • premature delivery
    • chronic pelvic pain
    • post partum fevers
• non GC urethritis
• post GC urethritis (conifection w/gonorrhoea)
  • dual infection with GC is common
  • symptoms can occur after therapy for GC
• reactive arthritis (post infectious, Reiter's syndrome)
• lymphogranuloma venereum (LGV)
  • primary lesion small painless, vescicular pustular lesion at inoc. site (genitals)
  • systemic symptoms positive for LAN (lymphatenopathy)
  • progress to local lymph nodes (enlarged, unilateral, painful) "buboes"
    • groove sign
    • eventual rupture and drain

• diagnosis difficult
  • culture
  • serology
  • cytology
  • special stains
• nucleic acid amplification (swabs)

• if not GC or post GC supsected, MUST TREAT EMPIRICALLY
• SCREEN high risk population- sexually active, pregnant
• SCREEN HIV
• SCREENHPV
  treat the partners of infected individuals

• conjunctivitis/pneumonitis in children
  • systemic antibiotics, prenatal screening
• LGV
  • prolonged couses of antibiotics
  • surgery to drain bubles
• ocularly trachoma
  • antibiotics effective, mass therapy with Axithromyocin
  • surgery (lid deformities)
  • face washing (access to clean water)
  • envir. controls (hygeine, fly control)

• birds are natural reservoir
  • exposure to feathers, feces from birds
• bird owners, veterinarians, zoo/pet shop, poultry industry
• clincial presentation
  • 7-14 days

• one cause of atypical pneumonia
• epi- young adults (crowding conditions, person to person)
• clinical presentation- similar to M pneumoniae