Abnormal Vaginal Flora That Is Distinct From Bacterial Vaginosis.
Aerobic vaginitis (AV) isÂ a state of abnormal vaginal flora thatÂ isÂ distinct fromÂ theÂ more common bacterial vaginosis (BV) (Table 1). AV is caused by a displacement of the healthy vaginal Lactobacillus species with aerobic pathogens such as Escherichia coli, Group B Streptococcus (GBS), Staphylococcus aureus, and Enterococcus faecalis thatÂ triggerÂ a localizedÂ vaginalÂ inflammatoryÂ immune response.Â Clinical signs and symptoms includeÂ vaginal inflammation, an itching or burning sensation, dyspareunia, yellowish discharge, and an increase in vaginal pH > 4.5, and inflammationÂ with leukocyte infiltration.Â (1)Severe, persistent, or chronic forms of AV can also be referred to as desquamative inflammatory vaginitis (DIV). (2, 3)
BV isÂ a common vaginal disorder associated with theovergrowthÂ ofÂ anaerobicÂ bacteria,Â aÂ distinctÂ vaginal malodorous discharge, but is not usually associated with a strong vaginal inflammatory immune response.Â Like AV,BV also includes an elevation of the vaginal pH > 4.5 and a depletion of healthy Lactobacillus species. BV is treated with traditional metronidazole therapy that targets anaerobic bacteria. However, approximately 10% to 20% of women diagnosed with BV and treated with metronidazole will fail
to respond to therapy at one week and will experiencepersistent symptoms. (4, 5) It is believed that a subset of these patients may have been misdiagnosed and actually suffer from AV, which requires an antibiotic therapy withintrinsic activity against specific aerobic bacteria. AV has been implicated inÂ complications of pregnancy such as ascendingÂ chorioamnionitis,Â prematureÂ ruptureÂ ofÂ the membranes, and preterm delivery.
In a study of 631 patients attending routine prenatal care from a vaginitis clinic, 7.9% had moderate to severe AV signs and symptoms and 6% had â€˜full-blownâ€™BV. (1)
In a study of 3,000 women, 4.3% were found to have severe AV, also called DIV. Furthermore, 49.5% of the women with DIV were peri- or postmenopausal. A reported hypothesis is that a drop in estrogen my trigger the development of AV in the aforementioned menopausal women, as well as postpartum nursing women. (3)
Clinical Characteristics Bacterial VaginosisÂ Aerobic Vaginitis (1)Lactobacilli Displaced DisplacedPathogen Gardnerella vaginalis, Atopobium vaginae, Megasphaera species, BVAB2Escherichia coli, Group B Streptococcus, Staphylococcus aureus, Enterococcus faecalisVaginal epithelial inflammation None Present Elevation of pro-inflammatory cytokines (IL-1?, IL-6, IL-8) Moderate elevation High elevation Immune reaction (cytotoxic leukocyte) Non-reactive Reactive pH [Normal = 3.8 â€“ 4.2]T= 4.2-4.5
> 4.5; usually >6
Shed vaginal epithelial cells Clue cells Parabasal cells
Vaginal discharge characteristic White, homogenousÂ Â Yellowish
10% KOH Whiff Test (fishy amine odor) Positive Negative
Kanamycin ovule. (5)
2% clindamycin topical. (3)
Fluoroquinolones are reported to have clinical
GBS is uniformly sensitive to penicillin, ampicillin,
amoxicillin, amoxicillin/ clavulanic acid. (7)
E. faecalisis traditionally treated with ampicillin. (8)
Table 1. AComparison of Bacterial Vaginosis and Aerobic Vaginitis.References are provided for treatment information; Fluoroquinolones, such as ciprofloxacin, ofloxacin, and levofloxacin, are contraindicated in pregnant women. Levofloxacin has improved efficacy against Streptococci compared to ciprofloxacin. T= Transitional.
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In a more recent study of 215 women, 19.1% were found toÂ haveÂ â€˜commonÂ vaginitisâ€™Â causedÂ byÂ BV,Â vulvovaginal candidiasis (VVC), or trichomoniasis (TV), whereas 12.6% were found to have â€˜inflammatory vaginitisâ€™ (IV). Of the IV group,Â 77.8%Â were characterizedÂ asÂ havingÂ DIV.Â (11)Â In fact, 42.9% of the women with DIV were found to be GBS positive, a 5-fold increase over the healthy patients (17.7% positive). (11) This study was similar to an earlier study that found 43% of DIV patients were GBS positive. (2)
PatientsÂ withÂ AVÂ presentÂ withÂ distinctÂ clinicalÂ signsÂ andsymptoms of abnormal vaginal flora that can be confused with common vaginitis etiologies such as BV, VVC, and TV
(Table 1). AVÂ isÂ treatedÂ withÂ anÂ antibioticÂ courseÂ ofÂ therapy characterizedÂ byÂ anÂ intrinsicÂ activityÂ againstÂ theÂ majority ofÂ bacteriaÂ ofÂ fecalÂ origin,Â whichÂ isÂ differentÂ thanÂ the metronidazole (BV, TV) and antifungal (VVC) antimicrobial agents used to treat common vaginitis (Table 1). In addition to the clinical symptoms of vaginal discharge, dyspareunia,Â itchingÂ andÂ burningÂ sensation,Â andÂ a strongÂ inflammatoryÂ response,Â AVÂ wasÂ shownÂ toÂ have anÂ associationÂ withÂ miscarriageÂ andÂ pretermÂ laborÂ and delivery. (12, 13, 14) Inflammation derived from the cervicalvaginal environment (vaginitis) and urinary tract infections are known to be associated with triggering labor. Cellular components of GBS such as peptidoglycan and hemolysin and E. colilipopolysaccharide (LPS), known mediators that trigger the inflammatory response, are proposed to be the
causative agents that can initiate preterm labor. Additionally, GBS and E. coliare also major bacterial species involved in neonatal sepsis.
In 2002, Donders et al. published guidelines to characterize theÂ presenceÂ andÂ severityÂ ofÂ aerobicÂ vaginitis.Â ThisÂ was based on a similar Nugent scoring method used for bacterial vaginosis determination, which is based on a Gram-stained microscopic evaluation that enumerates specific bacterial morphotypes.Â TheÂ presenceÂ andÂ numberÂ ofÂ theÂ different bacterialÂ morphotypes,Â suchÂ asÂ healthyÂ Gram-positive
such as E. coli, and Gram-positive GBS,S. aureus, and E. faecalis. In a study that measured the minimum inhibitory concentrationsÂ (MIC)Â ofÂ prulifloxacin,Â ciprofloxacin, ofloxacin,Â erythromycin,Â doxycycline,Â clindamycin, ampicillin,Â kanamycin,Â andÂ vancomycinÂ antibioticsÂ forÂ 73 vaginal Lactobacillus species,Â theÂ MICsÂ forÂ kanamycin,
ciprofloxacin, and ofloxacin were reported to be the greatest and in a concentration range categorized as intermediate or resistant for the AV pathogens.
In a study by Tempera et al., topical kanamycin ovules (100 mg, corresponding to 83 mg of active compound; one ovule per day for 6 days) was shown to have clinical success for the treatment of AV. (7, 8)
Fluoroquinolones,Â suchÂ asÂ ciprofloxacinÂ andÂ ofloxacin, have also been reported to have clinical success. These fluoroquinolonesÂ wereÂ reportedÂ toÂ haveÂ littleÂ effectÂ on theÂ normalÂ floraÂ allowingÂ forÂ aÂ rapidÂ recovery.Â (8)Â A studyÂ measuringÂ MICsÂ ofÂ theÂ fourÂ mostÂ commonÂ vaginal Lactobacillus speciesÂ foundÂ thatÂ theÂ threeÂ healthy
Lactobacillus species, L.Â crispatus,Â L.Â gasseri,Â andÂ L. jensenii,Â wereÂ resistantÂ toÂ ciprofloxacin,Â while L.Â iners,Â a Lactobacilli not associated with a healthy vaginal flora, was susceptible. (15)
In severe cases of aerobic vaginitis, also referred to as DIV, a successful treatment is 4 to 5 grams of 2% clindamycin creamÂ dailyÂ forÂ 4Â toÂ 6Â weeks,Â whichÂ hasÂ coverageÂ for Gram-positiveÂ GBSÂ andÂ alsoÂ hasÂ beenÂ reportedÂ to
reduce inflammation (5). Although all women experienced improvement using this therapy, it was reported that 32.1% of patients relapsed after 6 weeks and 43.4% of patients
relapsed after 23 weeks. (5) However, GBS vaginitis case reports have demonstrated clindamycin treatment failures due to clindamycin resistant isolates. (16) Approximately
21% (17) to 38% (18) of GBS clinical isolates were reported to be clindamycin resistant; furthermore, clindamycin is not effective against E. coli.
Group B Streptococci are uniformly susceptible to penicillin, ampicillin,Â amoxicillin,Â amoxicillin-clavulanicÂ acid,Â and cefuroximeÂ axetilÂ andÂ allÂ wereÂ thereforeÂ reportedÂ toÂ be appropriate treatment for GBS vaginitis. (19) For penicillin allergic patients, clindamycin is an acceptable alternative. FluoroquinolonesÂ (levofloxacin)Â appearÂ toÂ haveÂ efficacy againstÂ isolatesÂ ofÂ GroupÂ BÂ Streptococci;Â Â resistanceÂ to fluoroquinolones has only recently been reported. (20)
E.Â faecalis infectionsÂ canÂ beÂ treatedÂ withÂ ampicillin.Â The combinationÂ ofÂ ampicillinÂ andÂ anÂ aminoglycoside,Â such as gentimicin or spectinomycin, has been shown to have
aÂ synergisticÂ effectÂ onÂ thisÂ bacterium,Â whichÂ isÂ effective forÂ severeÂ infectionsÂ (10).Â AlthoughÂ rare,Â strainsÂ with ÃŸ-lactamase activity or increased MIC for gentimicin can be
treated with ampicillin-sulbactam or high-dose gentimicin, respectively.
AVÂ isÂ associatedÂ withÂ anÂ increaseÂ inÂ vaginalÂ pHÂ (>Â 4.5), depletion of vaginal healthy Lactobacilli, and an overgrowth ofÂ aerobicÂ orÂ facultativeÂ anaerobicÂ bacteria,Â usuallyÂ the
Gram-negative bacilli E. colior Gram-positive cocci GBS, andÂ occasionally S.Â aureus and E.Â faecalis.Â TheÂ high concentration of these aerobic bacteria and the absence of
healthy vaginal Lactobacilli results in triggering the immune system as evidenced by vaginal inflammation, high levels ofÂ proinflammatoryÂ cytokineÂ production,Â recruitmentÂ of
leukocytes,Â andÂ theÂ generationÂ ofÂ toxicÂ leukocytesÂ and parabasal cells. The patient may present with all or some of these signs and symptoms of AV: yellowish discharge, itching or burning sensation, dyspareunia, absence of the fishy odor (negative amine test) typically associated with BV,Â inflammationÂ (FigureÂ 1),Â toxicÂ leukocyteÂ infiltration, andÂ theÂ presenceÂ ofÂ parabasalÂ cellsÂ andÂ nakedÂ rounded vaginal epithelial cells (Figure 2).
FigureÂ 1.Â AerobicÂ vaginitisÂ inflammation.
ClinicalÂ pictures adoptedÂ fromÂ Donders etÂ al,Â 2002,Â demonstratesÂ patientsÂ with moderateÂ toÂ severeÂ AV.Â DiscreteÂ (PatientsÂ AÂ &Â B),Â moderate (PatientsÂ CÂ &Â D),Â andÂ severeÂ ulcerationsÂ (PatientsÂ EÂ &Â F)Â are observed along with yellowish discharge and inflammation of the vagina.(1)
FigureÂ 2:Â AerobicÂ VaginitisÂ microscopy.
ImagesÂ ofÂ phasecontrast microscopy (x400) adopted from Donders et al., 2002, of vaginal fluid from patients with AV. The vaginal Lactobacilli are displaced with coccoid bacteria (a) or chains of cocci typical for GBS (b). Leukocytes and â€˜toxicâ€™ leukocytes (full of lysozymic granules) are present in high numbers (c). Parabasal cells or rounded-up vaginal epithelia, are present (d). (1)
Lactobacilli and anaerobic BV associated Gram-negative and Gram-variable rods, contribute to the overall Nugent Score. A Nugent score of 0 to 3 indicates normal flora, 4 to
6 intermediate flora, and 7 to 10 bacterial vaginosis. TheÂ determinationÂ ofÂ AVÂ isÂ alsoÂ establishedÂ byÂ anÂ â€˜AVâ€™ score. The score is calculated with the use of high-power
field microscopy to evaluate the presence or absence of healthy Lactobacilli, number of leukocytes, number of toxic leukocytes, type of vaginal flora, and parabasal epithelial cells (Table 2). Here, the presence of the healthy Grampositive Lactobacilli is compared to the presence of aerobic orÂ facultativeÂ anaerobicÂ Gram-positiveÂ cocciÂ (suchÂ as Streptococci,Â Staphylococci,Â orÂ Enterococci)Â andÂ Gramnegative bacilli (E. coliand Klebsiella species).
TableÂ 2.Â CriteriaÂ forÂ theÂ microscopicÂ diagnosisÂ of AerobicÂ VaginitisÂ (AV)Â (400XÂ magnification,Â phase contrast microscopy). (1, 14)
The Aerobic Vaginitis (AV) Panel by PCR developed and validatedÂ byÂ MedicalÂ DiagnosticÂ Laboratories,Â L.L.C. (MDL) utilizes four qPCR reactions to detect the four most common AV-associated bacteria (E. coli, GBS, S. aureus, and E. faecalis). Along with the clinical signs and symptoms (TableÂ 1),Â thisÂ assay,Â whichÂ correlatesÂ withÂ the AVÂ flora discussed in the clinical AV scoring characterization (Table 2), can identify for healthcare providers the AV pathogens involved in the inflammatory vaginitis. (1, 14)
Treatment for Aerobic Vaginitis
The therapy for aerobic vaginitis should include an antibiotic with an intrinsic activity against the majority of bacteria of fecal origin. To increase the safety and compliance, it is best to use a topical formulation which has slow or little absorbency, but is able to maintain the correct pharmaceutical concentration in situ. (8) The optimal treatment includes antibiotics that have little effect on the normal flora, commonly Lactobacillusspecies, whileÂ effectivelyÂ eradicatingÂ theÂ Gram-negativeÂ enterics
3.Â Sobel JD, Reichman O, Misra D, Yoo W. 2011. Prognosis andÂ TreatmentÂ ofÂ DesquamativeÂ InflammatoryÂ Vaginitis. Obstet Gynecol 117: 850-855.
4.Â Wilson J. 2004. Managing recurrent bacterial vaginosis. Sex Transm Infect 80: 8-11.
5.Â LarssonÂ PG. 1992. TreatmentÂ ofÂ bacterialÂ vaginosis. IntÂ J
STD AIDS 3: 239-247.
6.Â CentersÂ forÂ DiseaseÂ ControlÂ andÂ PreventionÂ (CDC). 2010. Sexually Transmitted Diseases Treatment Guidelines.
7.Â Tempera, G, Bonfiglio G, Comparata E, Corsello S, Cianci
A. 2004. Microbiological/clinical characteristics and validation
of topical therapy with kanamycin in aerobic vaginitis: a pilot
study. Int J Antimicrob Agents24: 85-88.
8.Â TemperaÂ G,Â FurneriÂ PM. 010.Â Man2 agementÂ ofÂ Aerobic
Vaginitis. Gynecol Obstet Invest70: 244-249.
9.Â ClinicalÂ andÂ LaboratoryÂ StandardsÂ Institute . 2010. PerformanceÂ standardsÂ forÂ antimicrobialÂ susceptibility testing:Â 21stÂ informationalÂ supplement.Â M100-S21,Â Vol.Â 31
(1), Clinical and Laboratory Standards Institute, Wayne, PA.
10.Â Arias CA, Contreras GA, Murray BE. 2010. Management
of multidrug-resistant enterococcal infections. Clin Microbiol
Infect 16: 555-562.
11.Â Leclair CM, Hart AE, Goetsch MF, Carpentier H, Jensen
JT. 2010.Â GroupÂ BÂ Streptococcus:Â PrevalenceÂ inÂ aÂ nonobstetric population. J Low Genit Tract Dis14: 162-166.
12.Â Donders G, Van Calsteren K, Bellen G, Reybrouck R, Van
den Bosch T, Riphagen I, Van Lierde S .2009. Predictive valueÂ forÂ pretermÂ birthÂ ofÂ abnormalÂ vaginalÂ flora,Â bacterial
vaginosisÂ andÂ aerobicÂ vaginitisÂ duringÂ theÂ firstÂ trimesterÂ of
pregnancy. Br J Obstet Gynecol 116:1315â€“1324.
13.Â Donati L, Di Vico A, Nucci M, Quagliozzi L, Spagnuolo T,
Labianca A, Bracaglia M, Ianniello F, Caruso A, Paradisi
G. 2010. Vaginal microbial flora and outcome of pregnancy.
Arch Gynecol Obstet 281: 589-600.
14.Â Donders G, Bellen G, Rezeberga D. 2011. Aerobic vaginitis
in pregnancy. Br J Obstet Gynecol 118: 1163-1170.
15.Â DeÂ BackerÂ E,Â VerhelstÂ R,Â VerstraelenÂ H,Â ClaeysÂ G,
Verschraegen G, Temmerman M, Vaneechoutte M. 2006.
AntibioticÂ susceptibilityÂ of AtopobiumÂ vaginae.Â Â BMCÂ Infect
Dis 6: 51.
16.Â HonigÂ E,Â MoutonÂ JW,Â vanÂ derÂ MeijdenÂ WI.Â 1999. Can GroupÂ BÂ StreptococciÂ causeÂ symptomaticÂ vaginitis? Infect
Dis Obstet Gynecol 7: 206-209.
17.Â Gygax SE, Schuyler JA, Kimmel LE, Trama JP, Mordechai
E,Â AdelsonÂ ME. 2006.Â ErythromycinÂ andÂ clindamycin
resistanceÂ inÂ GroupÂ BÂ StreptococcalÂ clinicalÂ isolates.
Antimicrob Agents Chemother 50: 1875â€“1877.
18.Â Back EE, Oâ€™Grady EJ, Back JD. 2012. High rates of perinatal GroupÂ BÂ StreptococcusÂ clindamycinÂ andÂ erythromycin
resistanceÂ inÂ anÂ upstateÂ NewÂ YorkÂ hospital.Â Antimicrob
Agents Chemother 56: 739-742.
19.Â Clark LR, Atendido M. 2005. Group B Streptococcal vaginitis
inÂ postpubertalÂ Â adolescentÂ girls. JÂ AdolescentÂ Health 36:
20.Â WuÂ HM,Â JanapatlaÂ RP,Â HoÂ YR,Â HungÂ KH,Â WuÂ CW,Â Yan JJ, et al. 2008. Emergence of fluoroquinolone resistance in group B streptococcal isolates in Taiwan. Antimicrob Agents Chemother 52:1888-1890.
Summary of Treatment
â€¢Â Kanamycin ovules (100 mg, corresponding to 83 mg of active compound) one ovule per day for 6 days. (7, 8)
â€¢Â 2% topical clindamycin. 4 to 5 grams of 2% clindamycin creamÂ dailyÂ forÂ 4Â toÂ 6Â weeks.Â (desquamative inflammatory vaginitis). (5)
â€¢Â Ciprofloxacin or ofloxacin (8, 15).
â€¢Â FluoroquinolonesÂ (ciprofloxacin,Â ofloxacin,Â and levofloxacin) are contrain dicated in pregnant women.
â€¢Â GroupÂ BÂ StreptococcusÂ isÂ uniformlyÂ susceptible toÂ penicillin,Â ampicillin,Â amoxicillin,Â amoxicillinclavulanic acid, and cefuroxime axetil. Alternatives are clindamycin and levofloxacin.
â€¢Â E.Â faecalis isÂ traditionallyÂ treatedÂ withÂ ampicillin.Â A combinationÂ ofÂ ampicillinÂ plusÂ anÂ aminoglycoside (gentimicinÂ orÂ spectinomycin)Â isÂ usedÂ forÂ severe infections. (10)
Clinical Benefits of Testing
MDL offers highly sensitive and specific quantitative RealTime PCR (qPCR)-based assays for the detection of AVassociatedÂ pathogensÂ utilizingÂ the OneSwabÂ®platform
TestÂ 182:Â AerobicÂ VaginitisÂ (AV)Â byÂ Real-TimeÂ PCR.
Benefits of this system include:
â€¢Â Â Â Simple and convenient sample collection.
â€¢Â Â Â NoÂ refrigerationÂ isÂ requiredÂ beforeÂ orÂ after collection.
â€¢Â Â Â Specimen stable for up to five days.
â€¢Â Â Â TestÂ additionsÂ areÂ availableÂ upÂ toÂ 30Â daysÂ after receipt of the specimen.
â€¢Â Â Â 24 – 48 hour turnaround time.
â€¢Â Â Â High diagnostic specificity and sensitivity.
â€¢Â Â Â One vial, multiple pathogens.
1.Â Donders GGG, Vereecken A, Bosmans E, Dekeersmaecker
A,Â SalembierÂ G,Â SpitzÂ B.2002.Â DefinitionÂ ofÂ aÂ typeÂ of
abnormal vaginal flora that is distinct from bacterial vaginosis:
aerobic vaginitis. Br J Obstet Gynecol 109: 34-43.
2.Â SobelÂ JD. 1994.Â DesquamativeÂ inflammatoryÂ vaginitis:Â a
new subgroup of purulent vaginitis responsive to topical 2%
clindamycin therapy. Am J Obstet Gynecol 171: 1215-1220.