Cervix
Inflammatory / infectious
Lactobacillus
Authors: John K.S.S. Philip, M.D., Ziyan T. Salih, M.D.
Topic Completed: 1 January 2015
Minor changes: 18 February 2021
Copyright: 2003-2021, PathologyOutlines.com, Inc.
PubMed Search: Lactobacillus [title] cervix
Table of Contents
Definition / general | Terminology | Epidemiology | Etiology | Clinical features | Cytology description | Cytology images | Differential diagnosisCite this page: Philip J. Lactobacillus. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/cervixcytologylactobacillus.html. Accessed June 23rd, 2021.
Definition / general
- Presence of gram positive rods (lactobacilli) with cytolysis of intermediate cells
Terminology
- Also known as bacillus vaginalis, bacillus Doderlein
Epidemiology
- Lactobacilli are the most abundant bacteria found in normal vaginal flora which varies from person to person
- Found in 50% of women with "good" vaginal hygiene versus 20% with "poor" vaginal hygiene and high levels of sexual exposure (Koss' Diagnostic Cytology, 5th Edition, pg 262)
Etiology
- Aerobic gram - positive bacilli which produce enzymes that dissolve cell membranes of intermediate cells to utilize their cytoplasmic glycogen
- Fully mature superficial squamous cells and parabasal cells are less likely to be cytolyses because they have a firm cytoplasmic skeleton
- Cytolysis is mainly observed when intermediate cells predominate, including premenstrual phase of cycle, pregnancy and early menopause
- Lactobacillus survives best at vaginal pH of 5, which is maintained by glycolysis
- Lactobacilli prevent bacterial vaginosis, gonorrhea, Candida or other sexually transmitted diseases by multiple mechanisms, such as lowering pH and producing hydrogen peroxide (FEMS Immunol Med Microbiol 2006;48:424, Microbios 1994:80:125)
Clinical features
- Normal flora of GI tract, mouth and vagina; more commmonly found in vagina in second half of menstrual cycle, pregnancy and diabetes mellitus
- Decreased with bacterial vaginosis, antibiotic use and postmenopausal
- Occasionally, excessive colonization causes marked cytolysis and production of clear vaginal discharge (cytolytic vaginosis / lactobacillus vaginitis) (Indian J Sex Transm Dis 2009;30:48)
Cytology description
- Slender rod shaped pale blue bacilli (on Papanicolaou stain), arranged singly or in short chains of variable length
- In conventional smears, found on surface of squamous cells and in background
- In liquid based preparations, found overlying squamous epithelium or trapped in mucus
- The background is usually clean
- Lysis of intermediate cell cytoplasm creates moth eaten appearance and presence of isolated nuclei (bare nuclei)
- Abundant cytolysis ( > 50%), may be reported as a quality indicator but most of these specimens do not qualify as unsatisfactory
- Nuclear preservation and visualization are of key importance in determining specimen adequacy
- Unless nearly all of the nuclei are devoid of cytoplasm, the specimen is considered as satisfactory for evaluation
Cytology images
Images hosted on other servers:
Bacilli on surface of squamous cells
Cytolysis of intermediate cells with bare nuclei
Differential diagnosis
- Bacterial vaginosis: coccoid overgrowth over superficial cells, causing a bacterial haze
- Corynebacterium: arranged as groups as opposed to short chains but difficult to differentiate by morphology in a cervical smear (Gray: Diagnostic Cytopathology, 3rd Edition, pages 578-9)
- Leptothrix: very long thread-like bacteria that may form loops
