Atanassova V, Meindl A, Ring C
Department of Food Hygiene and Microbiology, Centre for Food Science, School of Veterinary Medicine Hanover, Hannover, Germany.
Int J Food Microbiol. 2001 Aug 15;68(1-2):105-13. doi: 10.1016/s0168-1605(01)00479-2.
In many countries Staphylococcus aureus is considered to be the second or third most common pathogen causing outbreaks of food poisoning, only outnumbered by Salmonella spp. and in competition with Clostridium perfringens. Often the consumption of ham or meat containing staphylococcal enterotoxins (SE) is identified as cause of the illness. Thus, to gain an insight into the prevalence of S. aureus and its emetic enterotoxins in raw pork and uncooked smoked ham and to investigate how the prevalence of the pathogen is influenced during the fabrication process, a total of 135 samples of raw pork, salted meat and ready-for-sale uncooked smoked ham were examined for the prevalence of S. aureus and staphylococcal enterotoxins A to D (SEA-SED). To this means classical cultural methods were employed as well as molecular biological techniques (PCR) and the results were compared. In 25.9% of all samples S. aureus was detected by culture whereas 51.1% of the samples showed a positive result when PCR was used for the detection of the pathogen. Fresh meat was contaminated most often. By PCR, 62.2% were identified as being S. aureus positive compared to 57.7% positive samples using the cultural technique. The detection rate during the fabrication process declined significantly. The pathogen was cultivated from 8.9% of the salted meat samples. Here, 55.6% of the samples reacted positively in the PCR, and finally, in approximately a third of the ready-for-sale smoked hams, S. aureus genes were found. From 11.1% of these samples, the pathogen could be isolated by culture. From these results, we conclude that the PCR used in this study is more sensitive than the classical cultural method. By PCR, one or more staphylococcal enterotoxin genes were found in 24 of the 135 examined samples. This means that 34.8% of the staphylococcal strains identified using the PCR technique were enterotoxigenic. Using the SET-RPLA, a percentage of 28.6% enterotoxigenic isolates was ascertained. No staphylococcal enterotoxin formation was detected by the SET-RPLA in ready-for-sale ham, although SE-genes were found by PCR. The detection of SE-genes by PCR is faster and easier to perform than the SET-RPLA.
在许多国家，金黄色葡萄球菌被认为是导致食物中毒暴发的第二或第三大常见病原体，仅次于沙门氏菌属，且与产气荚膜梭菌存在竞争关系。通常，食用含有葡萄球菌肠毒素（SE）的火腿或肉类被认定为致病原因。因此，为深入了解生猪肉和未煮熟的烟熏火腿中金黄色葡萄球菌及其催吐性肠毒素的流行情况，并研究在加工过程中该病原体的流行率是如何受到影响的，共对135份生猪肉、腌制肉和待售未煮熟烟熏火腿样本进行了金黄色葡萄球菌和葡萄球菌肠毒素A至D（SEA - SED）流行率的检测。为此采用了经典培养方法以及分子生物学技术（PCR），并对结果进行了比较。通过培养在所有样本的25.9%中检测到了金黄色葡萄球菌，而当使用PCR检测该病原体时，51.1%的样本呈阳性结果。鲜肉受污染最为频繁。通过PCR检测，62.2%的样本被鉴定为金黄色葡萄球菌阳性，而使用培养技术时阳性样本比例为57.7%。在加工过程中检测率显著下降。从8.9%的腌制肉样本中培养出了该病原体。在此，55.6%的样本在PCR检测中呈阳性反应，最后，在大约三分之一的待售烟熏火腿中发现了金黄色葡萄球菌基因。从这些样本的11.1%中，可通过培养分离出该病原体。从这些结果我们得出结论，本研究中使用的PCR比经典培养方法更敏感。通过PCR，在135份检测样本中的24份中发现了一个或多个葡萄球菌肠毒素基因。这意味着使用PCR技术鉴定出的葡萄球菌菌株中有34.8%具有产肠毒素能力。使用SET - RPLA检测，产肠毒素分离株的比例为28.6%。在待售火腿中，尽管通过PCR发现了SE基因，但使用SET - RPLA未检测到葡萄球菌肠毒素的形成。通过PCR检测SE基因比SET - RPLA更快且更易于操作。
