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mycoplasma

mycoplasma

introduction

  • a genus of bacteria that lack a cell wall around their cell membrane and thus are not affected by penicillins or cephalosporins
  • usual antibiotic Rx are with macrolide antibiotics but resistance is increasing
  • if a patient does not respond appropriately to a macrolide, a fluoroquinolone should be added to the treatment regimen
  • patients with significant Mycoplasma hepatitis may be considered for a renally excreted fluoroquinolone rather than a hepatic metabolised macrolide, although either class can cause hepatotoxicity, although antibiotic induced fulminant hepatic failure is very rare
  • they are amongst the smallest of bacterial species and are typically 0.1 micron in diameter
  • can survive without oxygen

mycoplasma pneumoniae

  • a common cause of "atypical pneumonia" acquired in the community accounting for ~40% of cases, particularly in children and the elderly
    • also causes tracheobronchitis (esp. children), wheeze, headache, myalgias and URTI
    • ~25% also develop extrapulmonary symptoms such as autoimmune responses, central nervous system complications, and dermatological disorders
    • 20% develop abnormal LFTs, and 2-5% of cases present as hepatitis in which case average C reactive protein (CRP) is 140 instead of 70 for M.pneum without hepatitis 1)
  • exclusively parasitizes the respiratory tract epithelium of humans
  • has never been isolated as a free-living organism due to its dependence upon the host for survival thus spread is via droplets to those in close and prolonged contact such as households, schools, nursing homes.

mycoplasma genitalium

  • lives on the ciliated epithelial cells of the urinary and genital tracts in humans as well as throat and anus
  • it is a co-factor in HIV transmission
  • has been regarded as “normal flora” in many women but is now regarded as a cause of sexually transmitted infections (STDs/STIs) with an incubation period of perhaps 1-3wks
  • can become symptomatic causing:
  • suspected to play a role in development of some cancers such as prostate cancer, ovarian tumours, and lymphoma
  • treatment is usually single dose of azithromycin as well as partners being treated and then re-tested after 1 month to ensure clearance
  • resistance to azithromycin is developing rapidly since ~2007 when the 1st cases in Australia were found to be resistant, in 2017, 50-80% had become resistant!
mycoplasma.txt · Last modified: 2018/03/18 10:28 (external edit)