OJVRTM
Online Journal of Veterinary Research ©
Volume 15 (2): 168-176, 2011
First report of swarming in Clostridium
botulinum types C and D
Saeed EMA1,2* (BVSc,MVSc,PhD), Böhnel H1(Prof. Dr.), Gessler
F3 (Dr. med. vet.)
1 Institute for Tropical Animal Health, Georg-August-University, Göttingen, Germany, 2 Department of Microbiology, Faculty of Veterinary Medicine,
University of Khartoum, Khartoum, Sudan, 3 Institute for Applied Biotechnology in the Tropics at the
Georg-August-University, Göttingen, Germany
ABSTRACT
Saeed EMA, Böhnel H, Gessler F, First report
of swarming in Clostridium botulinum types C and D,
Online J Vet Res, 15 (2): 168-176, 2011.
Clostridium botulinum was isolated and identified in samples from botulism-suspected cases of
various animal species and environment, by standard mouse bioassay,
magnetic bead-ELISA and PCR. From 74 samples, only 3 isolates were confirmed C. botulinum. Two were type C and 1 type D. The 2 type
C isolates were taken from intestinal contents of 2 broiler chickens from a
farm with a botulism outbreak and the type D isolate was from a bovine liver.
These isolates revealed swarming when grown on normally dried plates
(refrigerated plates dried for 30 min at 37 °C). The swarming growth was not observed
by the naked eyes in the primary plates but observed by hand lens on the
subsequent sub-culturing plates as very thin film contaminating colonies that
were picked from the primary plates as C. botulinum-like
colonies. The C. botulinum-like colonies were not C. botulinum tested by 3 methods after separation from swarming
growth on plates with increased agar percentage. However, the discrete colonies
of the swarming growth were C. botulinum. Swarming
on anaerobic plates should now be considered when isolating C. botulinum.
Key words: Clostridium botulinum; swarming growth; isolation; mouse bioassay;
magnetic bead-ELISA; PCR