Assessment of diagnostics and antimicrobial susceptibility testing of Brachyspira species using a ring test

• Published in: Veterinary microbiology Vol. 109; no. 3; pp. 229 - 243
• Main Authors: Råsbäck, T., Fellström, C., Bergsjø, B., Cizek, A., Collin, K., Gunnarsson, A., Jensen, S.M., Mars, A., Thomson, J., Vyt, P., Pringle, M.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 30-08-2005; Elsevier Science
• Subjects: Animals; Anti-Bacterial Agents - pharmacology; Bacterial diseases; Bacterial diseases of the digestive system and abdomen; Bacterial Typing Techniques; Biological and medical sciences; Brachyspira hyodysenteriae; Brachyspira pilosicoli; Brachyspira spp; Diagnostics; Europe; Feces - microbiology; Fundamental and applied biological sciences. Psychology; Human bacterial diseases; Infectious diseases; Medical sciences; Microbial Sensitivity Tests; Microbiology; Ring test; Spirochaetaceae - drug effects; Spirochaetaceae - isolation & purification; Spirochaetales Infections - diagnosis; Spirochaetales Infections - microbiology; Spirochaetales Infections - veterinary; Spirochaetes; Susceptibility test; Swine; Swine Diseases - diagnosis; Swine Diseases - microbiology; Swine dysentery; Europe; Swine dysentery; Spirochaetes; Ring test; Diagnostics; Susceptibility test; Brachyspira spp; Microbiology; Drug susceptibility test; Vertebrata; Mammalia; Sensitivity resistance; Swine; Digestive diseases; Intestinal disease; Dysentery; Artiodactyla; Veterinary; Ungulata
• ISSN: 0378-1135; 1873-2542
• DOI: 10.1016/j.vetmic.2005.05.009

There is no ring test for quality assessment available in Europe for diagnostics and antimicrobial susceptibility testing of the fastidious, anaerobic bacteria of the genus
Brachyspira. Therefore, an international ring test for
Brachyspira spp. was performed once a year during 2002–2004. Two sets of coded samples were prepared and distributed on each occasion. One set comprised six swabs dipped in pig faeces spiked with
Brachyspira spp. intended for diagnostics. The other set comprised two pure strains intended only for susceptibility testing. All methods used were in-house methods. The species used were
Brachyspira hyodysenteriae,
Brachyspira pilosicoli,
Brachyspira innocens,
Brachyspira murdochii and
Brachyspira intermedia. In most cases, the correct
Brachyspira spp. were detected. However, the results showed that
Brachyspira spp. could be difficult to identify, especially if two
Brachyspira spp. were mixed or if the concentration of
Brachyspira in faeces was low. Additionally, some laboratories reported
Brachyspira growth in control samples that were not seeded with any spirochaetes.
The lowest detection level was 10
2 bacteria/ml faeces for both
B. hyodysenteriae and
B. pilosicoli. The susceptibility tests performed showed that disc diffusion was not recommendable for
Brachyspira spp. Extended antimicrobial dilution series gave most congruent results. The diversity of the results highlights the importance of ring tests for a high quality of diagnostics and antimicrobial susceptibility tests for
Brachyspira spp. This is the first ring test described for
Brachyspira spp.