Identification of fusobactrium spp and bacteroides spp from the vagina of a premenopausal woman 1-3

Description

ABSTRACT

THE GRAM-NEGATIVE anaerobic bacilli that form part of the normal commensal flora of the vagina and cervix have been carried out and it was discovered that the number of viable Bacteroides spp and fusobaterium spp. per ml of vaginal secretions was 7-8 but they isolatedfusobaterium spp and Bacteroides spp. from only 4% of normal women, 1% of pregnant women and 28% of women with cervicitis. The differences may reflect different methods of investigation. The vagina is not a single environment; the flora of the lower vagina is related to that of the perineum and introitus and differs from that of the cervix and fornices. Moreover, the physiological state of the vaginal mucosa and secretions changes with age, with the menstrual cycle and with pregnancy (Hurley et al., 1974). The Bacteroides spp and fusobaterium spp. isolated in most studies have not been identified and the relationship of these isolates to those from other sites is not clear. The present study was undertaken to determine the carriage of Bacteroides, fusobactarium and identify the strains isolated from 20 normal healthy women attending a family-planning clinic.

CHAPTER ONE

1.0                                          INTRODUCTION

1.1                            BACKGROUND OF THE STUDY

With recent advancements in sequencing technologies, we have begun to appreciate the role of human microbiota and particularly bacteria, which are not passive commensals, but have a profound influence on host homeostasis. Indeed, bacteria play a significant role at multiple levels, including protection against pathogens, maturation of the immune system, metabolic pathways, vitamin synthesis, and others [Rosenberg, 2018]. It is, thus, not surprising that an imbalance or dysbiosis of the microbiota has been associated with several adverse outcomes and diseases [Belizário, 2015]. The genital system is certainly not an exception to bacterial colonization [Younes, 2015]. Aside from pathogenic bacteria that may be associated with adverse pregnancy outcomes or infertility by attacking female genital tract, the role of physiological microbiota has been underestimated.

Our understanding of the bacterial species inhabiting the female genital tract has been limited primarily by our ability to detect them. Early investigations using microscopy and culture-based techniques identified lactobacilli as the predominant members of the vaginal microbiota and suggested that these organisms might serve a protective function at the mucosal surface. Improvements in cultivation techniques and the development of molecular-based detection strategies validated these early findings and enabled us to recognize that the microbiota of the female genital tract is much more complex than previously suspected. Disruption of the vaginal microbial community due to invasion of exogenous organisms or by overgrowth of one or more endogenous species has important health implications for both the mother and newborn.

Bacteroides is a genus of Gram-negative, obligate anaerobicbacteria. Bacteroides species are non endospore-forming bacilli, and may be either motile or nonmotile, depending on the species (Madigan, 2015). The DNA base composition is 40–48% GC. Unusual in bacterial organisms, Bacteroides membranes contain sphingolipids. They also contain meso-diaminopimelic acid in their peptidoglycan layer.

Bacteroides species are normally mutualistic, making up the most substantial portion of the mammalian gastrointestinal microbiota (Dorland, 2013) where they play a fundamental role in processing of complex molecules to simpler ones in the host intestine (Wexler, 2017).As many as 10¹⁰–10¹¹ cells per gram of human feces have been reported. They can use simple sugars when available; however, the main sources of energy for Bacteroides species in the gut are complex host-derived and plant glycans. Studies indicate that long-term diet is strongly associated with the gut microbiome composition—those who eat plenty of protein and animal fats have predominantly Bacteroides bacteria, while for those who consume more carbohydrates the Prevotella species dominate (Wexler, 2017).

Fusobacterium is a genus of anaerobic, Gram-negative, non-sporeforming bacteria, similar to Bacteroides. Individual cells are slender, rod-shaped bacilli with pointed ends (Madigan, 2015). Strains of Fusobacterium cause several human diseases, including periodontal diseases, Lemierre’s syndrome, and topical skin ulcers.

Although older sources state that Fusobacterium is part of the normal flora of the human oropharynx, the current consensus is that Fusobacterium should always be treated as a pathogen (Aliyu , 2014). F. prausnitzii, a gut commensal associated with healthy patients, was completely reclassified as Faecalibacterium (Clostridiales:Ruminococcaceae) in 2002.

This study was aimed at assessing the prevalence of bacterial vaginal infections among the premenopausal women.

1.2                                   PROBLEM STATEMENT

The microbial inhabitants of the female genital tract and the contribution of these organisms to health and disease have been investigated for well over a century, yet they remain incompletely understood. The earliest studies focused on the microbiology of the lower genital tract and relied upon growth of bacteria in rich medium and identification based on observable characteristics (including shape, Gram stain, and arrangement of cells).

1.3                     AIM AND OBJECTIVES OF THE STUDY

The aim of the study was to assess the prevalence of bacterial vaginal infections among the premenopausal women. The objectives of this study are:

1. To have an understanding of the breadth and diversity of bacterial species inhabiting the female genital tract.
2. To have a full understanding of fusobactrium spp and bacteroides spp
3. To take a specimen from premenopausal women vigina in other to isolate and identify the presence of fusobactrium spp and bacteroides spp.
4. To collect a vaginal swab samples from a premenopausal women for a microorganisms identification.

1.4                             SIGNIFICANCE OF THE STUDY

These investigations led to important insights including the identification of fusobactrium spp and bacteroides spp as the predominant members of the vaginal ecosystem in most women, to the hypothesis that these organisms might serve protective functions at the vaginal mucosal surface, and to the presumption that the upper genital tract is sterile under normal conditions. With advances in bacteriological culture strategies, scientific understanding of the vaginal microbiota became significantly more nuanced. However, only a fraction of microbes can be cultured in the laboratory even with the most modern techniques, limiting studies of the host-associated microbiota.

1.5                                    SCOPE OF THE STUDY

As culture-independent measures of microbial diversity have been developed and used, the microbiota of the vagina and upper genital tract have been revealed as considerably more dynamic and complex than previously suspected, with important implications for the health of women and infants.