title: The significance of Lactobacillus crispatus and L. vaginalis for vaginal health and the negative effect of recent sex: a cross-sectional descriptive study across groups of African women.
abstract: BACKGROUND
  Women in sub-Saharan Africa are vulnerable to acquiring HIV infection and reproductive tract infections. Bacterial vaginosis (BV), a disruption of the vaginal microbiota, has been shown to be strongly associated with HIV infection. Risk factors related to potentially protective or harmful microbiota species are not known.
  
  
  METHODS
  We present cross-sectional quantitative polymerase chain reaction data of the Lactobacillus genus, five Lactobacillus species, and three BV-related bacteria (Gardnerella vaginalis, Atopobium vaginae, and Prevotella bivia) together with Escherichia coli and Candida albicans in 426 African women across different groups at risk for HIV. We selected a reference group of adult HIV-negative women at average risk for HIV acquisition and compared species variations in subgroups of adolescents, HIV-negative pregnant women, women engaging in traditional vaginal practices, sex workers and a group of HIV-positive women on combination antiretroviral therapy. We explored the associations between presence and quantity of the bacteria with BV by Nugent score, in relation to several factors of known or theoretical importance.
  
  
  RESULTS
  The presence of species across Kenyan, South African and Rwandan women was remarkably similar and few differences were seen between the two groups of reference women in Kenya and South Africa. The Rwandan sex workers and HIV-positive women had the highest G. vaginalis presence (p = 0.006). Pregnant women had a higher Lactobacillus genus mean log (7.01 genome equivalents (geq)/ml) compared to the reference women (6.08 geq/ml). L. vaginalis (43%) was second to L. iners (81.9%) highly present in women with a normal Nugent score. Recent sexual exposure negatively affected the presence of L. crispatus (<0.001), L. vaginalis (p = 0.001), and Lactobacillus genus (p < 0.001). Having more than one sexual partner in the last three months was associated with an increased prevalence of G. vaginalis (p = 0.044) and L. iners (p = 0.001).
  
  
  CONCLUSIONS
  Although the composition of species across the studied African countries was similar, the presence of protective species i.e. L. crispatus and L. vaginalis in women with a normal Nugent score appeared lower compared to non-African studies. Furthermore, Lactobacillus species were negatively affected by sexual behavioural. Strategies to support protective Lactobacillus species are urgently needed.
  
  
  BACKGROUND
  The study is registered at the Trial Registration at the National Health Research Ethics Council South Africa with the number DOH2709103223.
authors: Department of Public Health, Unit of Epidemiology and Control of HIV/STD, Institute of Tropical Medicine, Nationalestraat 155, B-2000, Antwerp, Belgium. vjespers@itg.be.
authors: Vicky
authors: V
authors: Jespers
authors: Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK. j.vandewijgert@liverpool.ac.uk.
authors: Janneke
authors: J
authors: van de Wijgert
authors: Laboratory Bacteriology Research, University Gent, Ghent, Belgium. piet.cools@ugent.be.
authors: Piet
authors: P
authors: Cools
authors: International Center for Reproductive Health (ICRH), Ghent University, Ghent, Belgium. riet7@icloud.com.
authors: Rita
authors: R
authors: Verhelst
authors: Department of Obstetrics and Gynaecology, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium. hans.verstraelen@ugent.be.
authors: Hans
authors: H
authors: Verstraelen
authors: Wits Reproductive Health & HIV Institute, University of Witwatersrand, Johannesburg, South Africa. sdelany@wrhi.ac.za.
authors: Sinead
authors: S
authors: Delany-Moretlwe
authors: ICRH Kenya, Mombasa, Kenya. mwaura.maryw@gmail.com.
authors: Mary
authors: M
authors: Mwaura
authors: Rinda Ubuzima, Kigali, Rwanda. ndayisaba@gmail.com.
authors: Gilles F
authors: GF
authors: Ndayisaba
authors: ICRH Kenya, Mombasa, Kenya. kishor@icrhk.org.
authors: Kishor
authors: K
authors: Mandaliya
authors: Department of Clinical Sciences, Institute of Tropical Medicine, Antwerp, Belgium. jmenten@itg.be.
authors: Joris
authors: J
authors: Menten
authors: Department of Public Health, Unit of Epidemiology and Control of HIV/STD, Institute of Tropical Medicine, Nationalestraat 155, B-2000, Antwerp, Belgium. lhardy@itg.be.|Department of Clinical Sciences, HIV/STI Reference Laboratory, Institute of Tropical Medicine, Antwerp, Belgium. lhardy@itg.be.
authors: Liselotte
authors: L
authors: Hardy
authors: Department of Clinical Sciences, HIV/STI Reference Laboratory, Institute of Tropical Medicine, Antwerp, Belgium. tcrucitti@itg.be.
authors: Tania
authors: T
authors: Crucitti
mesh_terms: D039903:Actinobacteria / Q000235:genetics / Q000302:isolation & purification; D000293:Adolescent; D000328:Adult; D002176:Candida albicans / Q000235:genetics / Q000302:isolation & purification; D002353:Carrier State / Q000453:epidemiology / Q000382:microbiology*; D016022:Case-Control Studies; D003075:Coitus; D003430:Cross-Sectional Studies; D004926:Escherichia coli / Q000235:genetics / Q000302:isolation & purification; D005260:Female; D006194:Gardnerella vaginalis / Q000235:genetics* / Q000302:isolation & purification; D015658:HIV Infections / Q000150:complications* / Q000453:epidemiology; D006801:Humans; D007630:Kenya; D007778:Lactobacillus / Q000235:genetics* / Q000302:isolation & purification; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000453:epidemiology / Q000382:microbiology*; D018720:Prevotella / Q000235:genetics / Q000302:isolation & purification; D012432:Rwanda; D060386:Sex Workers / Q000706:statistics & numerical data; D013019:South Africa; D014621:Vagina / Q000382:microbiology*; D016585:Vaginosis, Bacterial / Q000150:complications / Q000453:epidemiology / Q000382:microbiology*