Bacterial Vaginosis & Gonococcal infection.pptx

STI

1. Bacterial Vaginosis & Gonococcal Infection . Dr Shan

2. Bacterial Vaginosis Bacterial vaginosis affects women of reproductive age. This condition is associated with an alteration of the normal vaginal flora, which is as follows: ™ Increase in the concentrations of: „ Gardnerella vaginalis : It is normally isolated from the female genital tract in low numbers; but in bacterial vaginosis , it outnumbers other organisms „ Mobiluncus (motile, curved, gram-variable or gramnegative , anaerobic rods) „ Several other anaerobes ( Prevotella and some Peptostreptococcus ) „ Mycoplasma hominis Decrease in the concentrations of lactobacilli (lactobacilli maintain the acidic pH of the vagina

3. Risk Factors Bacterial vaginosis can occur in presence of the following risk factors: ™ Coexisting other infections such as HIV, Chlamydia trachomatis , and Neisseria gonorrhoeae ™ Recent unprotected vaginal intercourse Vaginal douching ™ Premature rupture of membranes and preterm labor.

4. Diagnosis Bacterial vaginosis is so named because there is no associated inflammation. Amsel’s Criteria Bacterial vaginosis is diagnosed if any 3 of the following 4 findings are present: Slight to moderately increased thin (low viscous), white homogeneous vaginal discharge uniformly coated on vaginal wall pH of vaginal discharge more than 4.5 Whiff test +ve : Accentuation of distinct fishy odor immediately after vaginal secretions are mixed with 10% solution of KOH Clue cells: They are vaginal epithelial cells coated with coccobacilli, which have a granular appearance and indistinct borders observed on a wet mount

5. Laboratory Diagnosis ™ Nugent’s score: It is a scoring system followed for the diagnosis of bacterial vaginosis ; done by counting the number of G.vaginalis , Mobiluncus and lactobacilli present in the Gram stained smear of vaginal discharge. A score of more than or equal to 7 is diagnostic Score Lactobacillus Score 0-4 Gardnerella Score 0-4 Mobiluncus Score 0-2 > 30 / OIF 1 5-30 / OIF < 1 / OIF 1-4 /OIF 2 1-4 / OIF 1-4 / OIF > 5 /OIF 3 < 1 / OIF 5-30 / OIF 4 > 30 / OIF

6. Culture : G. vaginalis requires enriched media such as chocolate agar, BHI broth with serum, etc. „ It is gram-negative (appears gram-variable in smears), nonmotile , small pleomorphic rod, which shows metachromatic granules „ It produces minute hemolytic colonies on blood agar, incubated aerobically under 5% CO2 for 24–48 hours Identification from colonies is made either by conventional biochemical tests or by automated identification systems such as MALDI-TOF or VITEK

7. Gonococcal Infection

8. Neisseria gonorrhoeae N oncapsulated , gram-negative kidney-shaped diplococcus . It causes ‘gonorrhea’, a sexually transmitted infection (STI) which commonly manifests as cervicitis , urethritis and conjunctivitis.

9. Virulence Factors 1.™ Pili or fimbriae : H elp in adhesion to host cells and prevent bacteria from phagocytosis ™ 2. Outer membrane proteins: „ Porin (protein I):  T ransmembrane channels (pores) which help in exchange of molecules across gonococcal surface  There are two major serotypes: PorB.1A and PorB.1B serotypes . Opacity-associated protein (Protein II): H elps in adhesion to neutrophils and other gonococci . 3 . Transferrin -binding and lactoferrinbinding proteins, 4. IgA1 protease 5. lipo -oligosaccharide (LOS) with endotoxin

10. Laboratory Diagnosis Specimen Collection: Urethral swab in men and cervical swab in women are the preferred specimens. Dacron or rayon swabs are preferred, as cotton and alginate swabs are inhibitory to gonococci Transport Media: Stuart’s transport medium or Amies medium. Microscopy : Gram staining of urethral exudates reveals gram-negative intracellular kidney-shaped diplococci Culture : Thayer Martin medium Identification: Gonococci are catalase and oxidase positive ™ They ferment only glucose, but not maltose and sucrose ™ Automated systems such as MALDI-TOF can be used . Molecular Method: PCR targeting 16s or 23s rRNA gene.