Pathogens in Genital Tracts

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Pathogens in Genital Tracts
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Genital Tract

• Neisseria gonorrhoeae (GC)
• Diseases
• Uncomplicated infections urethritis in
  heterosexual males urethritis, proctitis, and
  pharyngitis in homosexual males urethritis,
  cervicitis, proctitis and vaginitis in females
• Complicated disease pelvic inflammatory disease
  in females (endometriosis, salpingitis,
  peritonitis)

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Genital Tract

• Neisseria gonorrhoeae
• Diseases
• Complicated diseases disseminated gonococcal
  infections (DGI) in males and females (septic
  arthritis, endocarditis, meningitis)
• Gonococcal ophthalmia neonatorum (neonates become
  infected in the birthing process)

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Genital Tract

• Neisseria gonorrhoeae
• Epidemiology sexually transmitted up to 50 of
  infected females and 10 of infected males are
  asymptomatic (carriers)
• Primary isolation gonococcus is fastidious
  optimum growth on enriched chocolate agar the
  bacterium can be overgrown when normal indigenous
  microbes are present selective media such
  Thayer-Martin or equivalent is required when
  cultured from nonsterile sites

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Genital Tract

• Neisseria gonorrhoeae
• Direct examination Gram stains of urethral
  discharge in males is diagnostic (gram-negative
  intracellular and extracellular kidney-bean cocci
  in pairs) Gram stains of exudates from females
  is not diagnostic because they may carry
  nonpathogenic Neisseria species, as well as
  Acinetobacter species which morphologically
  resembles Neisseria species

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Genital Tract

• Neisseria gonorrhoeae
• Primary isolation many strains of GC fails to
  grow if not provided a carbon dioxide enriched
  environment optimum temperature for growth in
  the laboratory is 35oC, it dies quickly in vitro
  at room temperature refrigeration is lethal to
  it almost instantaneously

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Genital Tract

• Neisseria gonorrhoeae
• Colony and microscopic morphology and identifying
  characteristics were discussed in the respiratory
  Power Point slides in this series a summary of
  these results include
• Tannish-white, smooth, shiny, low convex, 1-2mm
  colonies
• Gram-negative diplococci (kidney beans)

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Genital Tract

• Neisseria gonorrhoeae
• Summary identifying characteristics
• Oxidase positive
• No growth at room temperature (even on chocolate
  agar)
• No growth at 35oC on nutrient agar or TSA without
  blood
• Aerobically acidifies glucose but not maltose,
  sucrose, fructose, or lactose

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Genital Tract

• Neisseria gonorrhoeae
• Summary identifying characteristics
• Positive superoxol test
• Hydroxyprolulaminopeptidase positive
• DNAse negative

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Genital Tract

• Treponema pallidum
• Disease
• Primary syphilis genital lesions (hard chancre)
  in heterosexual males and females rectal and
  ororpharyngeal lesions in homosexual males may
  or may not be self-limiting
• Secondary syphilis widespread lesions on skin
  and mucous membranes very noticeable on palms of
  hands and souls of feet any organ can become
  infected

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Genital Tract

• Treponema pallidum
• Disease
• Latent syphilis primary and secondary lesions
  heal without scarring patient is asymptomatic
  from months to years
• Late syphilis 3-20 years after primary infection
  gummatous lesions of skin, mucous membranes,
  soft tissue, bones, eyes, central nervous system,
  and cardiovascular system

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Genital Tract

• Treponema pallidum
• Disease
• Late syphilis lesions in the central nervous
  system may lead to general paralysis, and
  dementia lesions in the cardiovascular system
  can lead to aortic aneurism

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Genital Tract

• Treponema pallidum
• Epidemiology syphilis is primarily a sexually
  transmitted genital lesions, especially in
  females, may not be noticeable it can be passed
  congenitally from an infected mother to her
  fetus on rare occasions it can be transmitted by
  blood transfusions

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Genital Tract

• Treponema pallidum
• Diagnosis, direct exam
• Detection of T. pallidum on direct exam is
  possible but it is not often performed because
  primary lesions are transitory
• T. pallidum is difficult to visualize using
  bright field microscopy because of its extreme
  thinness it is a spirochete that resists
  staining with the usual microbiological dyes

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Genital Tract

• Treponema pallidum
• Diagnosis, direct exam
• Dark field microscopic examination of fluid from
  the chancre is diagnostic but requires a
  well-trained microscopist
• Direct fluorescent microscopic exam of the
  chancre fluid provides a more specific diagnosis
  but is not widely available

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Genital Tract

• Treponema pallidum
• Diagnosis since T. pallidum has never been
  cultured in vitro definitive diagnosis relies
  mostly on serological procedures
• Nonspecific serology almost all infected
  individuals produce reaginic antibodies
  (directed against a normal phospholipid,
  cardiolipin) within a month of becoming infected

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Genital Tract

• Treponema pallidum
• Nonspecific serology the VDRL and RPR screening
  tests use an antigen made of cardiolipin,
  lecithin, and cholesterol which flocculate when
  bound by reagin the VDRL has been mostly
  replaced by the RPR because the latter uses a
  stable reagent, can be performed on serum or
  plasma, does not require a heat inactivation
  step, and does not have to be read microscopically

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Genital Tract

• Treponema pallidum
• Nonspecific serology patients with many other
  conditions may be reactive with the VDRL and RPR
  all reactive samples must be tested with a
  specific serologic test
• Specific serology almost all patients with
  syphilis have antibodies directed against T.
  pallidum as well as antibodies directed against
  other treponemes that make up the normal
  indigenous microbiota

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Genital Tract

• Treponema pallidum
• Specific serology serum or plasma to be tested
  for T. pallidum specific antibodies must first be
  absorbed using a cultural suspension of
  nonpathogenic treponemes (Reiters strain) once
  absorbed the plasma or serum can be tested
  against a pathogenic T. pallidum (Nichols strain
  taken from infected rabbit testes lesions)

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Genital Tract

• Treponema pallidum
• Specific serology the Fluorescent Treponemal
  Antibody-Absorbed (FTA-ABS) is an indirect
  procedure that uses antihuman globulin conjugated
  with FITC the test is extremely specific and
  sensitive but somewhat tedious and requires a
  well trained microscopist the MHA-TP is a
  passive hemagglutination procedure

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Genital Tract

• Treponema pallidum
• Specific serology the MHA-TP is easier to
  perform and much less tedious since reading the
  results does not a microscope it is as specific
  and sensitive as the FTA-ABS
• The only reliable serologic test for diagnosing
  neurological syphilis is the VDRL

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Genital Tract

• Chlamydia trachomatis
• Disease
• Trachoma chronic eye infections in young
  children
• Lymphogranuloma venereum transient genital
  ulcers in adults
• Nongonococcal urethritis, cervicitis,
  salpingitis, and proctitis in adults
• Newborn inclusion conjunctivitis

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Genital Tract

• Chlamydia trachomatis
• Epidemiology
• Trachoma person to person
• Lymphogranuloma venereum and nongonococcal
  urethritis direct sexual contact
• Newborn inclusion conjunctivitis acquired from
  infected mothers while giving birth

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Genital Tract

• Chlamydia trachomatis
• Isolation this is an obligate intracellular
  bacterium (must have living cells for growth)
  may be cultured on cell cultures, embryonated
  eggs, or live laboratory animals special
  equipment and supplies, and specially trained
  personnel are required and are unavailable in
  most hospital labs

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Genital Tract

• Diagnosis can be made using DNA probes directly
  on the genital specimen (a bimodal DNA probe
  for C. trachomatis and N. gonorrhoeae are
  routinely performed at LGH)
• Cell cultures (McCoy cell line), serology, or
  other serological tests (e.g. complement
  fixation) are performed in reference labs

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Genital Tract

• Haemophilus ducreyi
• Disease Chanchroid (soft chancre) penile and
  vaginal lesions satellite regional
  lymphadenitis with suppuration
• Epidemiology sexually transmitted, most often in
  men of low socioeconomic groups more men become
  infected than women

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Genital Tract

• Haemophilus ducreyi
• Direct examination Gram stain of aspirated
  material reveals gram-negative coccobacilli in
  tangled arrays (said to resemble a school of
  fish)
• Isolation slow but definite growth on chocolate
  agar selective chocolate with fetal bovine serum
  plus vancomycin is optimal mature colonies may
  require 4-5 days (high humidity,CO2, 35oC)

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Haemophilus ducreyiGram Stain of Soft Chancre
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• Haemophilus ducreyi

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• (chanchroid) tiny pleomorphic gram negative rod
• When observed in gram stain of genital lesion it
  is said to resemble a school of fish
• Requires X factor for growth grows on non-
  selective chocolate agar or chocolate agar
  supplemented with antibiotics in 3-5 days

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• Incubation requires high humidity and CO2
• Identified biochemically like other Haemophilus
  species

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Genital Tract

• Bacterial vaginosis (common non-inflammatory
  malodorous genital discharge)
• Etiology unknown, associated with the a
  preponderance of Gardnerella vaginalis
  (pleomorphic gram variable coccobacilli),
  Mobiluncus species (motile anaerobe) and various
  gram negative anaerobes

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• Diagnosis is usually not by culture but
  microscopic exam (clue cells and lack of
  lactobacillus morphotypes) or direct bedside
  procedures (fishy odor, pH greater than 6)

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Genital Tract

• Herpes virus (HSV-2) (genital herpes)
• Like all viruses, this obligate intracellular
  parasite requires cell cultures or other special
  methods beyond the means of most hospitals
• Lesions are painful and highly infectious

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• Sexually transmitted herpes infections include
  genital lesions in sexual partners and the eyes
  of neonates acquired from infected mothers
• Diagnosis is usually by culture or serology for
  antibodies at reference labs

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Genital Tract

• Streptococcus agalactiae (Group B Strep) gram
  positive coccus in chains
• Can be associated with urogenital infections but
  is also part of vaginal normal microbiota
• Neonates can be acquired GBS during the birthing
  process and develop meningitis or septicemia
• Enrichment broth (Lim) inoculated with
  vaginal/rectal swab and incubated 8 or more hours
  before subculture onto SBA

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Genital Tract

• Group B strep
• Subcultured-SBA is examined for weak beta
  hemolytic colonies
• Identification is most efficiently by passive
  agglutination (GBS antigen is first extracted
  from suspicious colonies and then tested with
  antibody coated latex particles)
• GBS is also CAMP test positive