Case 138. Panel: Bacteria seen in vaginal smear preparations
    Doederlein bacilli, Gardnerella vaginalis, Mobiluncus sp., Leptothrix sp., Pseudomonas aeruginosa    
Key words : 
Gardnerella vaginalis, bacterial vaginitis, clue cell, Doederlein bacillus, biofilm, Mobiluncus, Leptothrix, Pseudomonas aeruginosa    
sexually transmitted infection
Panel 1
Doederlein bacilli (Lactobacillus) (Papanicolaou). Long rods of this type (Lactobacilli), the normal flora of the vagina in the premenopausal woman, maintain the acidity of the vaginal lumen. Some are phagocytized by neutrophils.
  Panel 2
Gardnerella vaginalis (bacterial vaginitis) (Papanicolaou). Small and short Gram-negative rods are clusterd onto the squamous epithelium to form "clue cells", pathognomonic of G. vaginalis infection. Doederlein bacilli are never seen.
Panel 3
Mobiluncus sp. (bacterial vaginitis) (Gram). Crescent-shaped or curved rods, inconsistently Gram-positive, are seen among the squamous epithelium. Infection of Gardnerella and/or Mobiluncus provokes bacterial vaginitis.
  Panel 4
Leptothrix sp. (Papanicolaou). Mildly curved, hair-like long bacteria are seen. The bacteria are allegedly non-pathogenic. Leptothrix is also occasionally seen in the urine.
Panel 5
Pseudomonas aeruginosa (biofilm infection) (Papanicolaou). Mucoid-type colonies of Pseudomonas aeruginosa are observed on the pap smear. This represents a state of chronic persistent (intractable) infection.
  Reference case 138A
Doederlein bacilli in vaginal squams in a pregnant woman (paraffin section, HE). Doederlein bacilli usually increase in number in a secretory phase and in pregnancy. Deeply basophilic long rods are seen among the exfoliated squams.
Reference case 138A
Doederlein bacilli in vaginal squams in a pregnant woman (paraffin section, Gram). Lactobacillus among the squams is strongly Gram-positive. This represents a normal variation and not a pathogenic state.