Significant increase in cultivation of Gardnerella vaginalis, Alloscardovia omnicolens, Actinotignum schaalii, and Actinomyces spp. in urine samples with total laboratory automation

Eur J Clin Microbiol Infect Dis. 2018 Jul;37(7):1305-1311. doi: 10.1007/s10096-018-3250-6. Epub 2018 Apr 13.

Abstract

While total laboratory automation (TLA) is well established in laboratory medicine, only a few microbiological laboratories are using TLA systems. Especially in terms of speed and accuracy, working with TLA is expected to be superior to conventional microbiology. We compared in total 35,564 microbiological urine cultures with and without incubation and processing with BD Kiestra TLA for a 6-month period each retrospectively. Sixteen thousand three hundred thirty-eight urine samples were analyzed in the pre-TLA period and 19,226 with TLA. Sixty-two percent (n = 10,101/16338) of the cultures processed without TLA and 68% (n = 13,102/19226) of the cultures processed with TLA showed growth. There were significantly more samples with two or more species per sample and with low numbers of colony forming units (CFU) after incubation with TLA. Regarding the type of bacteria, there were comparable amounts of Enterobacteriaceae in the samples, slightly less non-fermenting Gram-negative bacteria, but significantly more Gram-positive cocci, and Gram-positive rods. Especially Alloscardivia omnicolens, Gardnerella vaginalis, Actinomyces spp., and Actinotignum schaalii were significantly more abundant in the samples incubated and processed with TLA. The time to report was significantly lower in the TLA processed samples by 1.5 h. We provide the first report in Europe of a large number of urine samples processed with TLA. TLA showed enhanced growth of non-classical and rarely cultured bacteria from urine samples. Our findings suggest that previously underestimated bacteria may be relevant pathogens for urinary tract infections. Further studies are needed to confirm our findings.

Keywords: Actinomyces spp.; Actinotignum schaalii; Alloscardovia omnicolens; Gardnerella vaginalis; Laboratory automation; Urine.

MeSH terms

  • Actinomycetaceae / classification
  • Actinomycetaceae / growth & development
  • Actinomycetaceae / isolation & purification*
  • Automation, Laboratory
  • Bacteriuria / diagnosis
  • Bacteriuria / microbiology*
  • Colony Count, Microbial
  • Enterobacteriaceae / classification
  • Enterobacteriaceae / growth & development
  • Enterobacteriaceae / isolation & purification*
  • Gardnerella vaginalis / growth & development
  • Gardnerella vaginalis / isolation & purification*
  • Humans
  • Retrospective Studies
  • Urinary Tract Infections / diagnosis
  • Urinary Tract Infections / microbiology*