Life is a gardenWith Gardnerella vaginalis

By: Edison Sexton

Case

Q.C. Is a 28 year old woman. Went to doctor complaining about fishy smelling

vaginal discharge. Denied soreness or itching Stated several sexual partners including other

women Gram stain revealed clue cells, PMNs and a

score of 8 on the nugent scale. Vaginal pH of 6

Case continued

“Whiff” test was positive Affirm VPIII was positive for Gardnerella

vaginalis. Culture revealed gamma hemolysis on SBA

agar and Beta on HBT agar

Organisms associated with BV

Lactobacillus sp. are normal flora Mobiluncus spp. Gardnerella vaginalis Mycoplasma hominis Prevotella spp. Peptostreptococcus spp. Porphyromonas spp. Atopobium vaginae Usually polymicrobial

BV tests Vaginal discharge >4.5 pH Affirm VPII

– Detect Gardnerella vaginalis, Candida albicans and Trichomonas vaginalis.

“Whiff” test

– Add two drops of 10% KOH

– Wait for fishy odor Microscopic

Clue cells PMNs

More BV tests

Nugent Scoring System

– Preliminary identification microscopically

– Gives insight to vaginal microbiota prior to culture

– Quantitate Lactobacillus morphology

– Compare to Gardnerella morphology

– More accurate than cultures

Gardnerella vaginalis

Gram-positive coccobacillus (gram variable) Normal flora in 40% of women (in small

amounts) Also possible in urine Rarely in blood or

wounds

Growing in lab

5-7% CO2 37°Celsius SBA

pinpoint, gamma hemolysis Human blood bilayer tween agar (HBT)

Beta hemolytic, small, gray, opaque Similar to V agar

Culture rarely done, normally presumptive diagnosis

Biochemical results

Catalase, Oxidase negative Motility negative Esculin hydrolysis negative Acid produced from glucose and maltose

Biochemical continued

-Gamma hemolysis (Beta on HBT)

-Positive urease

-Rapid antigen testing

-Affirm VPIII (DNA hybridization)

-16S rRNA gene sequencing

Treatment

Oral or topical Metronidazole or tinidazole Twice daily for seven days Pregnant women at high risk Probiotics

Sources

Amatnieks, Yuri. Fun with microbiology. N.p., 14 Nov. 2010. Web. 27 Apr. 2014.

Connie, Mahon, Lehman Donald, and Manuselis George. Textbook of Diagnostic Microbiology. 4th ed. Maryland Heights: Saunders Elsevier, 2011. Print.

Questions?