Volume 15, Number 5—May 2009
Dispatch
Possible Seasonality of Clostridium difficile in Retail Meat, Canada
, Richard J. Reid-Smith, Henry R. Staempfli, Danielle Daignault, Nicol Janecko, Brent P. Avery, Hayley Martin, Angela D. Thomspon, L. Clifford McDonald, Brandi Limbago, and J. Scott WeeseTable 1
Proportion of retail meat packages yielding Clostridium difficile in 4 culture replicates and estimated method sensitivity, Canada, 2006*†
| Sample | Culture method |
% Samples with C. difficile |
Culture sensitivity, %‡ | ||||
|---|---|---|---|---|---|---|---|
| Enrichment | Agar | Ground beef | Veal from milk-fed calves | Both‡ | |||
| Rinsate | TCDMNB | CDMNA | 2.7 (4/149)§ | 0 (0/65) | 1.9 (4/214) | 31 | |
| Meat¶ | TCDMNB | CDMNA | 2.7 (4/149)§ | 1.5 (1/65) | 2.3 (5/214) | 39 | |
| Meat¶ | TCDMNB | CDMNA | 1.3 (2/149)§ | 1.5 (1/65) | 1.4 (3/214) | 23 | |
| Meat |
TCCFB |
Blood |
1.3% (2/149) |
1.5 (1/65) |
1.4 (3/214) |
23 |
|
| Total of contaminated packages# | 6.7 (10/149) | 4.6 (3/65) | 6.1 (13/214)‡ | 100 | |||
*Rinsate, sediment; TCDMNB, in-house C. difficile broth (CM0601; Oxoid, Basingstoke, UK) supplemented with cysteine hydrochloride, moxalactam, norfloxacin (CDMN, SR0173E; Oxoid), and 0.1% sodium taurocholate (Sigma-Aldrich, Inc., St. Louis, MO, USA) (4); Meat, 2 g; CDMNA, C. difficile agar supplemented with CDMN and 7% laked horse blood (SR0048C; Oxoid); TCCFB, broth supplemented with D-cycloserine and cefoxitin (SR0096E; Oxoid) and 0.1% sodium taurocholate; Blood, 5% defibrinated sheep blood.
†Poor test agreement was found among and between cultures (κ –0.28; p>0.9).
‡Culture sensitivity calculation based on parallel interpretation of all 4 cultures (standard comparator) and 6.1% of overall contamination. Duplicate testing sensitivity ranged from 46.2% (6/13) to 61.5% (8/13).
§Represents 2 packages that simultaneously tested positive in 2 culture replicates.
¶Protocol previously used to test meat; duplicate run (4).
#No statistical differences were found between ground beef and veal in any culture replicate (p>0.1).
