Expression and production of staphylococcal enterotoxin C is substantially reduced in milk

Valihrach, Lukás; Alibayov, Babek; Zdeňková, Kamila; Demnerova, Kateřina

doi:10.1016/j.fm.2014.05.020

Cited by 31 publications

(31 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…SEC was detectable but not quantifiable in milk matrix, except for the Sa1612 strain which produced quantification level of toxin at 18-24 h (>261 pg/mL). Without LAB inoculation, temporal level of S. aureus enterotoxin C production was detected at 12-18 h in milk and TSB culture corresponding with kinetics of growth 8.11-9.6 log CFU mL −1 [34]. SEA and SEC production was significantly reduced in milk compared to TSB in pure culture [34].…”

Section: Resultsmentioning

confidence: 96%

“…Without LAB inoculation, temporal level of S. aureus enterotoxin C production was detected at 12-18 h in milk and TSB culture corresponding with kinetics of growth 8.11-9.6 log CFU mL −1 [34]. SEA and SEC production was significantly reduced in milk compared to TSB in pure culture [34]. After 24 h cultivation, S. aureus MW2 and Sa1612 SEC production was 179 and 332 times lower in milk compared to TSB, respectively (0.07 and 0.39 ng/mL in milk, versus 13.1 and 129.2 ng/ mL in TSB, respectively).…”

Section: Resultsmentioning

confidence: 99%

“…Difference in the level of SEC production among these strains is probably associated with diversity of SEC subtypes [17,34]. The reduction of S. aureus enterotoxin production in pasteurized milk is closely linked with different protein and enzymes constituents, and these components are able to decrease detectable level of toxin as measured by ELISA [34].…”

Section: Resultsmentioning

confidence: 99%

“…Five dilutions of the cDNA were performed to determine the PCR efficiency (ranging from 94 to 109 %) and cDNA was serially fivefold diluted. The reference genes were selected based on results of our previous work [34]. In addition, the primer specificity was checked using NCBI database.…”

Section: Relative Quantification and Data Analysismentioning

confidence: 99%

See 3 more Smart Citations

Transcriptomic and metabolic responses of Staphylococcus aureus in mixed culture with Lactobacillus plantarum, Streptococcus thermophilus and Enterococcus durans in milk

Zdeňková

Alibayov

Karamonová

et al. 2016

Journal of Industrial Microbiology and Biotechnology

Self Cite

View full text Add to dashboard Cite

Staphylococcus aureus is a major food-borne pathogen due to the production of enterotoxin and is particularly prevalent in contaminated milk and dairy products. The lactic acid bacteria (LAB) are widely used as biocontrol agents in fermented foods which can inhibit pathogenic flora. In our work, we investigated the influence of three strains of LAB (Lactobacillus plantarum, Streptococcus thermophilus and Enterococcus durans) on the relative expression of three enterotoxin genes (sea, sec, sell) and eight virulence and/or regulatory genes (sarA, saeS, codY, srrA, rot, hld/RNAIII, agrA/RNAII, sigB) in two S. aureus strains (MW2 and Sa1612) in TSB and reduced-fat milk (1.5 %) at 30 °C over a 24-h period. The tested LAB and S. aureus strains proved to be mutually non-competitive or only slightly competitive during co-cultivation. In addition, under the above-mentioned conditions, differential gene expression between the S. aureus MW2 and Sa1612 strains was well documented. S. aureus growth was changed in mixed culture with LAB; however, its effect on the repression of sea and sec expression correlated with production of these virulence factors. In comparison, the presence of LAB strains generally inhibited the expression of sec, sell, sarA, seaS, agrA/RNAII and hld/RNAIII genes. The effect of LAB strains presence on the expression of sea, codY, srrA, rot and sigB genes was medium, time, LAB and S. aureus strain specific. SEA and SEC production was significantly reduced in milk compared to TSB in pure culture. After the 24-h cultivation, S. aureus MW2 and Sa1612 SEC production was 187 and 331 times lower in milk compared to TSB, respectively (0.07 and 0.39 ng/mL in milk, versus 13.1 and 129.2 ng/mL in TSB, respectively). At the same time S. aureus MW2 and Sa1612 SEA production was 77 and 68 times lower in milk compared to TSB, respectively (0.99 and 0.17 ng/mL in milk, versus 76.4 and 11.5 ng/mL in TSB, respectively). This study has revealed new insights into the interaction between S. aureus and LAB (L. plantarum, S. thermophilus, E. durans) on the level of the expression and/or production of S. aureus enterotoxins, regulatory and virulence genes in different media, including milk. This study provides data which may improve the quality of food production.

show abstract

Section: Resultsmentioning

confidence: 96%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Relative Quantification and Data Analysismentioning

confidence: 99%

See 2 more Smart Citations

Transcriptomic and metabolic responses of Staphylococcus aureus in mixed culture with Lactobacillus plantarum, Streptococcus thermophilus and Enterococcus durans in milk

Zdeňková

Alibayov

Karamonová

et al. 2016

Journal of Industrial Microbiology and Biotechnology

Self Cite

View full text Add to dashboard Cite

show abstract

“…(32). Enterotoksynę C wymienia się jako najczęstszą przyczynę gronkowcowych zatruć pokarmowych spowodowanych spożyciem zanieczyszczonego mleka i produktów mlecznych (43), jednak wyniki najnowszych badań wskazują mleko jako niekorzystne środowisko dla produkcji enterotoksyn przez szczepy S. aureus, chociaż dane dotyczą jedynie enterotoksyn C, D, H oraz R (17,(46)(47)(48). W pracach Hunt i wsp.…”

Section: Wytwarzanie Enterotoksyn Gronkowcowychunclassified

Production of staphylococcal enterotoxins in food

Schubert¹,

Krakowiak²,

Bania³

2018

Medycyna Weterynaryjna

View full text Add to dashboard Cite

Gronkowcowe zatrucia pokarmowe Jednym z wielu zagrożeń bezpieczeństwa żywności są gronkowcowe zatrucia pokarmowe. Są one wywoływane przez spożycie produktów zawierających enterotoksyny wytwarzane przez niektóre szczepy gronkowca złocistego (Staphylococcus aureus). Typowe symptomy takich zatruć występują zazwyczaj po 0,5-8 godzinach od spożycia i obejmują wymioty, któ-rym może towarzyszyć biegunka oraz bolesne skurcze mięśni gładkich przewodu pokarmowego. Początek występowania objawów i ich charakter zależą od ilości spożytej toksyny i indywidualnej wrażliwości osoby. Ze względu na szybki okres rekonwalescencji i niezgłaszanie przypadków gronkowcowych zatruć pokarmowych dane dotyczące liczby przypadków tych zatruć mogą być zaniżone (21). Europejski Urząd ds. Bezpieczeństwa Żywności (EFSA) corocznie publikuje raporty dotyczące m.in. przypadków zatruć pokarmowych odnotowanych w 32 państwach Europy. W 2015 r. S. aureus był odpowiedzialny za 434 (10,1%) spośród 4362 zewidencjonowanych przypadków zatruć pokarmowych, z czego zdecydowana większość miała miejsce we Francji (91,7%). Fakt ten może wiązać się z wysokim poziomem spożycia serów przez mieszkań-ców tego kraju. Zaobserwowano niewielką tendencję wzrostową w porównaniu z rokiem poprzednim, gdzie liczba zgłoszonych przypadków w Europie wynosiła 393 (http://www.efsa.europa.eu/en/publications). Schubert J., Krakowiak S., Bania J. Production of staphylococcal enterotoxins in foodSummary Staphylococcal food poisoning results from ingestion of food contaminated with toxins produced by enterotoxigenic Staphylococcus aureus strains. Common symptoms of this intoxication include vomiting, diarrhea, and abdominal cramps. Staphylococcal enterotoxins are resistant to heat and a number of environmental factors. Certain cheeses, milk powder, and whey powder are the only foodstuffs that are being routinely examined for the presence of staphylococcal enterotoxins SEA-SEE. The newly identified enterotoxins are not included in the current examination scheme. Enterotoxin-producing staphylococci were already isolated from meat, meat products, milk, dairy products, fermented food products, vegetables, pastries and fish products. It has been demonstrated that many environmental factors associated with food processing and storage can significantly influence the level of secreted enterotoxins by S. aureus strains. Nevertheless, only a few studies on the production of staphylococcal enterotoxins were conducted in foodstuffs. Most data on their expression is based on experiments performed with a low number of S. aureus strains, and usually only SEA-SEE enterotoxins are investigated. These results inclined many authors to the conclusion that milk and dairy products are unfavorable environments for expression of staphylococcal enterotoxins. However, recent research has indicated a significant heterogeneity in the ability of enterotoxin production in milk among S. aureus strains derived from diverse sources. S. aureus strains able to secrete high levels of enterotoxins in milk and meat juice w...

show abstract