Case report
Identification of Arcobacter cryaerophilus isolated from a traffic accident victim with bacteremia by 16S ribosomal RNA gene sequencing

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Abstract

Traditional ways of identifying slow growing bacteria is slow and often difficult. In this study, a small, Gram-negative, facultative anaerobic, slow growing bacillus was isolated from the blood culture of a 7-year old traffic accident victim. The bacterium was non-hemolytic, catalase and oxidase positive. An attempt to use the Vitek system (GNI+) and the API system (20NE) to identify the strain was unsuccessful as the growth controls showed negative results. 16S ribosomal RNA gene sequencing showed that there was 1 base difference between the isolate and Arcobacter cryaerophilus (GenBank Accession no. U25805), 1 base difference between the isolate and A. cryaerophilus (GenBank Accession no. U34387), 10 base differences between the isolate and A. cryaerophilus (GenBank Accession no. L14624), 34 base differences between the isolate and A. butzleri (GenBank Accession no. U34386), 34 base differences between the isolate and A. butzleri (GenBank Accession no. U34387), and 38 base differences between the isolate and A. butzleri (GenBank Accession no. L14626), indicating that the isolate most closely resembled a strain of A. cryaerophilus. Identification of the isolate in our case by conventional methods was difficult, as the absence of a curved morphology has made it confused with other Gram-negative non-fermentative bacteria, and the slow growth rate has made it unidentifiable by both the Vitek and API systems. Although the exact source of infection and route of transmission in our case remains elusive, we speculate that the bacteria were transmitted through the respiratory tract while the boy was suffocated in the mud. The present report represents an example of showing the usefulness of 16S rRNA gene sequencing for identification of slow growing bacteria.

Introduction

Identification of bacteria in the clinical microbiology laboratory is traditionally performed by isolation of the organism and studying it phenotypically by elucidation of its Gram-staining, cultural, and biochemical characteristics, which have been the gold standard of bacterial identification. However, these methods of bacterial identification have a few major drawbacks. First, they cannot be used for non-cultivable organisms. Second, we are occasionally faced with organisms with biochemical characteristics that do not fit into patterns of any known genus and species. Third, identification of slow growing organisms would be extremely slow and difficult.

Since the discovery of polymerase chain reaction (PCR) and DNA sequencing, comparison of the gene sequences of bacterial species showed that the 16S ribosomal RNA (rRNA) gene is highly conserved within a species and among species of the same genus, and hence can be used as the new gold standard for speciation of bacteria. Using this new standard, phylogenetic trees, based on base differences between species, are constructed; and bacteria are classified and re-classified into new genera Olsen et al 1992, Olsen and Woese 1993. Furthermore, non-cultivable organisms and organisms with ambiguous biochemical profiles can be classified and identified Relman et al 1990, Relman et al 1992. Recently, we have reported the application of 16S rRNA gene sequencing in the identification of two clinical isolates with ambiguous biochemical profiles Woo et al 2000a, Woo et al 2000b, and a bacterium that was non-cultivable (Cheuk et al., 2000). In this study, we report the application of such a technique in the identification of a strain of Arcobacter cryaerophilus which grew very slowly.

Section snippets

Case report

A 7-year old boy was admitted to hospital because of suffocation after falling into a mud pool while he was driving a mini-motor cycle. The past health was good and he was well before the traffic accident. After initial cardiopulmonary resuscitation, the rectal temperature was 34.8°C. The hemoglobin was 13.2 g/dL, total white cell count 8.9 × 109/L, with neutrophil 1.8 × 109/L and lymphocyte 7.0 × 109/L, and platelet count 357 × 109/L. Blood culture was performed and empiric intravenous

Discussion

Small rRNA gene sequencing, particularly 16S rRNA sequencing in bacteria, have led to advances on multiple fronts in microbiology. First, the construction of a universal phylogenetic tree classifies organisms into 3 domains of life: Bacteria, Archaea, and Eucarya Olsen et al 1992, Olsen and Woese 1993. Second, it revolutionizes the classification of microorganisms, and makes the classification of non-cultivable microorganisms possible Relman et al 1990, Relman et al 1992. Third, it helps to

Acknowledgements

This work was partly supported by the Committee of Research and Conference Grants, The University of Hong Kong.

References (18)

  • S.L. On et al.

    Isolation of Arcobacter butzleri from a neonate with bacteraemia

    J Infect

    (1995)
  • D.L. Suarez et al.

    Detection of Arcobacter species in gastric samples from swine

    Vet Microbiol

    (1997)
  • W. Cheuk et al.

    Intestinal inflammatory pseudotumour with regional lymph node involvementidentification of a new bacterium as the aetiological agent

    J Pathol

    (2000)
  • P.R. Hsueh et al.

    Bacteremia caused by Arcobacter cryaerophilus 1B

    J Clin Microbiol

    (1997)
  • J.A. Kiehlbauch et al.

    Campylobacter butzleri sp. nov. isolated from humans and animals with diarrheal illness

    J Clin Microbiol

    (1991)
  • T.L. Maugeri et al.

    Isolation of Arcobacter spp. from a brackish environment

    New Microbiol

    (2000)
  • G.J. Olsen et al.

    The Ribosomal Database Project

    Nucleic Acids Res

    (1992)
  • G.J. Olsen et al.

    Ribosomal RNAa key to phylogeny

    FASEB J

    (1993)
  • D.A. Relman et al.

    The agent of bacillary angiomatosis. An approach to the identification of uncultured pathogens

    N Engl J Med

    (1990)
There are more references available in the full text version of this article.

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