TY  - CHAP
M1  - Book, Section
TI  - Chlamydia
A1  - Ryan, Kenneth J.
PY  - 2022
T2  - Sherris & Ryan's Medical Microbiology, 8th Edition
AB  - OverviewChlamydiae  are  obligate  intracellular  bacteria  whose  cells  lack  peptidoglycan  and  who  share  a  common  replicative  cycle  that  involves  two  forms:  elementary  and  reticulate  bodies  (Figure  39–1).  Elementary  bodies  (EBs)  are  smaller,  have  rigid  cell  walls,  can  survive  outside  cells,  and  are  infectious.  Once  EBs  attach  to  the  cell  membranes  of  susceptible  cells,  they  enter  the  cell  by  endocytosis  and  transform  into  larger,  but  fragile  reticulate  bodies  (RBs)  that  multiply  by  binary  fission  and  form  more  EBs  that  are  released  by  exocytosis  or  cell  rupture  to  infect  adjacent  cells  and  begin  the  cycle  anew.  Despite  their  biologic  similarities,  the  Chlamydia  are  diverse  in  their  tropisms  and  clinical  features  even  within  a  single  species.  Chlamydia  trachomatis  primarily  produces  infections  of  the  conjunctiva  or  genital  tract  depending  on  which  biovar  is  involved.  Trachoma  is  a  progressive  conjunctivitis  with  inflammation  and  scarring  resulting  in  blindness  and  is  caused  by  C  trachomatis  biovars  A,  B,  and  C.  Sexually  transmitted  biovars  D-K  cause  urethritis,  cervicitis,  salpingitis,  and  neonatal  infections  of  the  eye  and  respiratory  tract  after  vaginal  delivery  by  infected  mothers.  L  biovars  of  C  trachomatis  cause  lymphogranuloma  venereum  (LGV),  a  sexually  transmitted  disease  that  manifests  as  painless  genital  ulcers  followed  by  painful  suppuration  of  regional  inguinal  lymph  nodes.  LGV  biovars  can  also  cause  ulcerative  proctitis,  rectal  fistulae,  and  strictures.Chlamydophila  species  cause  atypical  pneumonia.  Chlamydophila  psittici  causes  psittacosis,  a  zoonotic  pneumonia  contracted  by  inhalation  of  respiratory  secretions  or  aerosols  of  cloacal  droppings  of  infected  birds  of  diverse  species.  Chlamydophilapneumoniae  causes  community-acquired  pneumonia  that  mimics  Mycoplamapneumoniae  in  its  person-to-person  transmission,  clinical  features,  and  treatment.  
SN  - 
PB  - McGraw-Hill Education
CY  - New York, NY
Y2  - 2024/04/16
UR  - accessmedicine.mhmedical.com/content.aspx?aid=1185634157
ER  -