Prevalence of Staphylococcus aureus and staphylococcal enterotoxins in raw pork and uncooked smoked ham—a comparison of classical culturing detection and RFLP-PCR

Abstract

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 Ž . 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 Ž . staphylococcal enterotoxins A to D SEA-SED . To this means classical cultural methods were employed as well as Ž . 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. q 2001 Elsevier Science B.V. All rights reserved.

Prevalence and antibiogram study of Salmonella and Staphylococcus aureus in poultry meat

“…Out of all eleven, 45.45% of the Salmonella isolates showed resistance to streptomycin, whereas 27.27% of the isolates were found resistance to ciprofloxacin, ampicillin and sulfamethoxazole/ trimethoprim. Most of the Salmonella isolates (about 73%) were resistant to tetracycline.…”

“…Atanassova et al found 51.1% S. aureus contamination in raw pork meat by PCR detection while he claimed 57.7% S. aureus contamination by using classical microbiological procedures [27] . Heo et al reported 11% S. aureus prevalence in meat, while Lee reported 13% S. aureus presence in poultry meat of Korea [15,28] .…”

Development of Predictive Growth Models for Staphylococcus aureus and Bacillus cereus on Various Food Matrices Consisting of Ready-to-Eat (RTE) Foods

“…If environmental conditions such as time and temperature during food storage and preparation allow the growth of S. aureus, staphylococcal enterotoxins may be produced, offering potential harm to consumers (Sneed et al, 2004). There are several studies reporting the presence of S. aureus in RTE and perishable foods including raw pork or smoked ham (Atanassova et al, 2001), poultry products (Pepe et al, 2006), milk (Fujikawa and Morozumi, 2006), fish (Hiraki et al, 1998), or foods that are pre-pared in advance before consumption and stored after preparation without adequate refrigeration (Roberts, 1986). Furthermore, the presence of S. aureus on the work surfaces and utensils of foodservice outlets has been widely demonstrated by several studies (Gibson et al, 1988;Hiraki and Suzuki, 1999).…”

Enterotoxin production byStaphylococcus aureus(A, B, C, D) during the ripening of sucuk (Turkish dry-fermented sausage)

“…In many countries, S. aureus is considered to be the most common pathogen causing outbreaks of food poisoning (Atanassova, Meindl, & Ring, 2001). It is characterized by symptoms associated with gastroenteritis, including vomiting, caused by the oral ingestion of enterotoxins (Dinges, Orwin, & Schlievert, 2000).…”

“…12, No. 2, 127-133, http://dx.doi.org/10.1080/19476337.2013 even when no viable bacteria can be detected in samples from the suspected food (Atanassova et al, 2001). …”