Van Driessche Ellen, Houf Kurt
Department of Veterinary Public Health and Food Safety, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium.
Int J Food Microbiol. 2007 Aug 15;118(1):20-6. doi: 10.1016/j.ijfoodmicro.2007.05.006. Epub 2007 May 31.
In the present study, the occurrence of Arcobacter was assessed at four sites on 169 porcine carcasses (foreleg, chest, pelvis and ham) at different stages of slaughter and 47 pork products at retail. Carcass swab samples were enriched in Arcobacter broth containing 5-fluorouracil, amphotericine B, cefoperazone, novobiocine and trimethoprim as selective supplement. After microaerobic incubation, arcobacters were isolated using Arcobacter selective agar plates, containing the selective supplement described above. Some carcass samples and all pork samples were also examined quantitatively. All 862 isolates were identified by a species-specific m-PCR-assay and 182 isolates were further characterized by ERIC-PCR. Arcobacters were isolated from one or more sampling places on 96.4% of the carcasses, with the foreleg and the chest area as the two most contaminated sites. Furthermore, A. cryaerophilus was the most common species. Chilling decreased the number of positive carcasses, but did not eliminate all arcobacters. Direct isolation revealed that only a few carcasses were contaminated with arcobacters on foreleg and/or chest at levels higher than 10(2 )cfu/100 cm(2). Characterization demonstrated a large heterogeneity among the isolates, with ten genotypes present on more then one site per carcass. Fourteen genotypes were simultaneously present on carcasses from different herds slaughtered on the same day, which may indicate cross-contamination. Arcobacters were present in 21% of the pork samples taken at retail, but contamination levels did not exceed 100 cfu per gram. Characterization of the A. butzleri and A. cryaerophilus isolates indicated an additional contamination during processing at retail.
在本研究中，对169头猪胴体不同屠宰阶段的四个部位（前腿、胸部、骨盆和后腿）以及47种零售猪肉产品中的嗜冷弧菌发生情况进行了评估。胴体拭子样本在含有5-氟尿嘧啶、两性霉素B、头孢哌酮、新生霉素和甲氧苄啶作为选择性补充剂的嗜冷弧菌肉汤中进行增菌培养。微需氧培养后，使用含有上述选择性补充剂的嗜冷弧菌选择性琼脂平板分离嗜冷弧菌。还对一些胴体样本和所有猪肉样本进行了定量检测。所有862株分离株通过种特异性多重PCR分析进行鉴定，182株分离株通过ERIC-PCR进一步鉴定。在96.4%的胴体的一个或多个采样部位分离到了嗜冷弧菌，前腿和胸部区域是污染最严重的两个部位。此外，嗜冷嗜冷弧菌是最常见的菌种。冷却减少了阳性胴体的数量，但并未消除所有嗜冷弧菌。直接分离显示，只有少数胴体的前腿和/或胸部被嗜冷弧菌污染，污染水平高于10² cfu/100 cm²。鉴定表明分离株之间存在很大的异质性，每个胴体的多个部位存在十种基因型。在同一天屠宰的不同猪群的胴体上同时存在十四种基因型，这可能表明存在交叉污染。在零售的猪肉样本中，21%检测到嗜冷弧菌，但污染水平不超过每克100 cfu。对布氏嗜冷弧菌和嗜冷嗜冷弧菌分离株的鉴定表明，在零售加工过程中存在额外污染。
