2020.02 婦產科

1. Journal Reading
Presenter: FM R2盧敬文
Supervisor: VS 何宗錦
2020.02.14

2. • vaginal microbiota (VMB)
• vaginal dysbiosis
• bacterial vaginosis (BV)
characterized by a reduction of lactobacilli and an increase of other anaerobes
• bacterial pathobionts
(Proteobacteria, streptococci, staphylococci, and enterococci)
• Candida albicans
• Trichomonas vaginalis

3. • Vaginal dysbiosis  pelvic inflammatory disease, HIV acquisition, and
adverse pregnancy outcomes.
• BV is diagnosed by:
Nugent scoring of vaginal Gram stains
or by the Amsel criteria.
• BV is treated with antibiotics
• recurrence rates are high
https://en.wikipedia.org/wiki/Nugent_score

4. • Metronidazole is a nitroimidazole class drug.
• Culture studies have shown that lactobacilli are not sensitive to
metronidazole.
High recurrence rate?
• Hypothesized:
due to vaginal mucosal biofilm formation
by G. vaginalis and other BV-associated anaerobes

5. Materials and Methods
• Rinda Ubuzima research clinic in Kigali, Rwanda, in 2015
• women at high risk of BV/T. vaginalis
• in the last 12 months
• more than 1 sex partner
• having been treated for BV and/or a sexually transmitted infection
• BV-positive and/or T. vaginalis -positive
• treated with 7 days of 500 mg generic oral metronidazole, BID
• Posttreatment visit within 3 days after treatment completion

6. Diagnostic procedures
• BV was diagnosed by
• Gram stain Nugent scoring
a score of 0-3 was considered optimal,
4-6 intermediate microbiota,
and 7-10 BV
• modified Amsel criteria
defined as the presence of 2/3 criteria:
• vaginal pH >4.5
• positive whiff test
• and/or > 20% clue cells
黃珮茹、林益卿。常見陰道炎診斷與治療。家庭醫學與基層醫療。第三十一卷，第五期。

7. Molecular VMB testing
• DNA was extracted from 1 swab per woman per visit
• The V3-V4 region of 16S rRNA genes were amplified and sequenced
• The panbacterial 16S rRNA gene copy concentration per sample was
determined
http://www.yourgene.com.tw/content/messagess/contents/655643254701452640/
16S 核糖體 RNA (16S rRNA) 在演化過程中，改變的程度相當
的低，大多數 16S rRNA 其中有 V1~V9 共 9 個高度變異區域
(High Variable Regions，HVRs)
透過選擇其中高變區的序列，進行 PCR 專一性增幅放大，
經過定序，將序列作為分類與鑑定環境或生物體內微生物
之種類與群落

8. Statistical analyses
• VMB characteristics pre- and posttreatment were compared
• all women (N=68),
• women stratified by treatment success/failure(n=55)
• Pretreatment C. trachomatis/N. gonorrhoeae status(N=67)
• Received another antibiotic in addition to metronidazole at the pretreatment
visit or not (N=68)
• having reported unusual vaginal discharge pretreatment or not(N=68)

9. Ethical statement
• Written informed consent provided
• approved by the National Ethics Committee of Rwanda
• and the University of Liverpool Research Ethics Subcommittee for
Physical Interventions.

10. Results

12. Results

13. 82.4%: BV alone
2.9%: T. vaginalis alone
14.7%: both BV and T. vaginalis
38.2%: Ongoing C. trachomatis
and/or N. Gonorrhoeae infection

14. mean bacterial group relative abundances

15. Pre- and posttreatment
16S microbiota data
shift toward
increased relative
abundance of
lactobacilli
 decreased relative
abundances of several
BV anaerobes

16. Total bacterial concentration Total lactobacilli
Total BV-anaerobes Total pathobionts
But interindividual variability was high
Most
variability

17. • Participants with treatment failure as defined by Nugent scoring
• posttreatment
Lower mean lactobacilli relative abundance,
smaller decreases in mean total bacteria and BV-anaerobes concentrations,
less often a lactobacilli-dominated VMB type,
• pretreatment
Greater mean pathobionts concentration

18. • Successfully treated participants:
significant decreases in the mean concentrations of all 8 common BV
anaerobes
• unsuccessfully treated participants:
not decreases in G. vaginalis and BVAB1
• not identify any statistically significant sociodemographic or biological
correlates of treatment failure
• except for pathobionts concentration pretreatment

19. Discussion
• cure rate of 7-day oral metronidazole treatment by Nugent scoring
only 54.5%.
• Treatment failure associated with:
• greater levels of pretreatment Gardnerella vaginalis or pathobionts
• not with sociodemographic factors.

20. • unknown which concentrations of which pathobionts in the vagina
should be treated to prevent complications
• metronidazole treatment
 not change the pathobionts concentration
 increase the relative abundance
• Greater pretreatment pathobionts concentration
 increased likelihood of treatment failure

21. Results of the study in context of what is known
• The extent of BV-anaerobes reduction was more modest than
expected
• lactobacilli are not sensitive to Metronidazole
• Women with a pretreatment VMB type containing a relative
abundance of >50% G. vaginalis, compared with <50%
more likely to continue to have a dysbiotic VMB type posttreatment
• CRISPR-genes may protect the bacteria against metronidazole.

22. Research and clinical implications
• vaginal biofilm disrupting treatment?
• adjuvant therapy with lactobacilli-based live biotherapeutics?
• treatment with drugs that specifically target all G. vaginalis clades?
• diagnostic tests to determine
the presence of a biofilm
or concentrations of G. vaginalis
 are not yet available

23. Strengths and limitations of the study
• limited generalizability of the results
to lower risk and non-African populations
• lack of vaginal biofilm detection
• Strength: used multiple laboratory and analytic methods

24. 黃珮茹、林益卿。常見陰道炎診斷與治療。家庭醫學與基層醫療。第三十一卷，第五期。

25. Thank you
for
your attention.
https://www.flickr.com/photos/lksriv/9413310222/