Research article

Association of Atopobium vaginae, a recently described metronidazole resistant anaerobe, with bacterial vaginosis

Michael J Ferris^1,2,6 , Alicia Masztal² , Kenneth E Aldridge³ , J Dennis Fortenberry⁵ , Paul L Fidel Jr⁶ and David H Martin⁴

¹Dept. of Pediatrics, Louisiana State University Health Sciences Center, New Orleans, LA, 70112, USA

²Research and Education Bldg., The Research Institute for Children, 200 Henry Clay Ave, New Orleans, LA 70118, USA

³Dept. of Infectious Disease, Louisiana State University Health Sciences Center, 1542 Tulane Ave, New Orleans, LA 70112, USA

⁴Dept. of Internal Medicine, Louisiana State University Health Sciences Center, New Orleans, LA, 70112, USA

⁵Department of Pediatrics, Indiana University School of Medicine, Section of Adolescent Medicine, 575 N West St., Room 070, Indianapolis, IN 46202, USA

⁶Dept. of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center, 1901 Perdido St., New Orleans, LA 70112, USA

author email corresponding author email

BMC Infectious Diseases 2004, 4:5doi:10.1186/1471-2334-4-5

Published:	13 February 2004

Abstract

Background

Bacterial vaginosis (BV) is a polymicrobial syndrome characterized by a change in vaginal flora away from predominantly Lactobacillus species. The cause of BV is unknown, but the condition has been implicated in diverse medical outcomes. The bacterium Atopobium vaginae has been recognized only recently. It is not readily identified by commercial diagnostic kits. Its clinical significance is unknown but it has recently been isolated from a tuboovarian abcess.

Methods

Nucleotide sequencing of PCR amplified 16S rRNA gene segments, that were separated into bands within lanes on polyacrylamide gels by denaturing gradient gel electrophoresis (DGGE), was used to examine bacterial vaginal flora in 46 patients clinically described as having normal (Lactobacillus spp. predominant; Nugent score ≤ 3) and abnormal flora (Nugent score ≥ 4). These women ranged in age from 14 to 48 and 82% were African American.

Results

The DGGE banding patterns of normal and BV-positive patients were recognizably distinct. Those of normal patients contained 1 to 4 bands that were focused in the centre region of the gel lane, while those of BV positive patients contained bands that were not all focused in the center region of the gel lane. More detailed analysis of patterns revealed that bands identified as Atopobium vaginae were present in a majority (12/22) of BV positive patients, while corresponding bands were rare (2/24) in normal patients. (P < 0.001) Two A. vaginae isolates were cultivated from two patients whose DGGE analyses indicated the presence of this organism. Two A. vaginae 16S rRNA gene sequences were identified among the clinical isolates. The same two sequences were obtained from DGGE bands of the corresponding vaginal flora. The sequences differed by one nucleotide over the short (~300 bp) segment used for DGGE analysis and migrated to slightly different points in denaturing gradient gels. Both isolates were strict anaerobes and highly metronidazole resistant.

Conclusion

The results suggest that A. vaginae may be an important component of the complex bacterial ecology that constitutes abnormal vaginal flora. This organism could play a role in treatment failure if further studies confirm it is consistently metronidozole resistant.