Department of Food Hygiene and Consumer Health Protection

Department of Food Hygiene and Consumer Health Protection

C. K. Norwida 31
50-375 Wrocław

phone fax 71 320 5411
email This email address is being protected from spambots. You need JavaScript enabled to view it.

Head of Department
prof. dr hab. Jacek Bania
phone 71 320 5425
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Higiena team2018

From left: dr Krystyna Morzyk, dr hab. Jarosław Bystroń, prof. nadzw. UPWr, dr inż. Justyna Schubert, prof. dr hab. Jacek Bania, lek. wet. Magdalena Gonet, Karina Głuszek, lek. wet. Sylwia Krakowiak, lek. wet. inż. Aleksandra Orłowska, dr inż. Ewa Wałecka-Zacharska

Division of Raw Animal Materials Hygiene
Division of Food Microbiology and Processing Hygiene


Topic, team involved, details (introduction, main achievements)

Production of staphylococcal enterotoxins in food. Team: Justyna Schubert, Magdalena Gonet, Jarosław Bystroń, Jacek Bania.

Production of enterotoxins by Staphylococcus aureus was identified as a factor of Staphylococcal Food Poisoning (SFP). Dairy products have been associated with SFP. Staphylococcal enterotoxin H (SEH), a gastrointestinal toxin, was first described in 1995. SEH was already implicated in SFP outbreaks associated with reconstituted and raw milk. All data on SEH expression is based on experiments conducted in microbiological broths. Very limited information on its production in food is available.
Milk was reported by many teams as unfavorable environment for enterotoxin production. However, this statement was based on limited number of S. aureus strains producing SEC. We tested a number of S. aureus strains carrying genes encoding SEH as well as SEH together with SEA or SEC. We found that the main feature allowing S. aureus to secrete large amounts of SEH seems to be in part related to the ability to decrease pH of the environment by this microorganism. Microbial broth (brain heart infusion - BHI) tested by us allowed each S. aureus strain to decrease pH during growth which was related to high level of SEH expression and moderate differences in level of secreted SEH between strains. Milk seems not to offer the same opportunity for a significant part of S. aureus strains tested in our laboratory. Some other S. aureus strains growing in milk were not restricted in SEH and SEA expression, unlike SEC which remained down-regulated in milk. Moreover, the level of SEC seems to be down-regulated in milk also in S. aureus producing high levels of SEH in milk. Therefore low food safety risk related to strains producing SEC in milk as suggested previously may not pertain to certain SEA and SEH-producing strains. Occurrence of staphylococci carrying sea and seh genes may pose an increased risk for enterotoxin production in milk-related products (Schubert et al. IJFM, 235, 36-45, 2016).
We demonstrated recently that in a number of S. aureus strains crying sed and ser genes production of SED and SER was significantly decreased in milk when compared to meat juice, supporting previous reports. However, certain strains secreted high amounts of SED and SER irrespective of environment. No clear relation of enterotoxin protein level and expression of known regulators was established. Our results indicate that enterotoxin production in meat is likely to pose higher risk for food safety than enterotoxin production in milk, suggesting area of routine food control should be expanded. Nevertheless, food safety risk related to enterotoxin production in milk should still be considered important (Schubert et al. FPD, 2016 – in press).

Enterotoxins of coagulase-negative staphylococci. Team: Sylwia Krakowiak, Ewa Wałecka-Zacharska, Jacek Bania.

According to the EU legislation foodstuffs are being examined for staphylococcal enterotoxins only if the presence of coagulase-positive staphylococci, like S. aureus is confirmed. The fact that also coagulase-negative staphylococci might possess enterotoxin genes was revealed not long ago, but current status of knowledge remains to scarce to provide insights into their significance for public health.
In the genome sequence of Staphylococcus epidermidis strain, designated 4S, isolated from ready-to-eat food we identified 21,426-bp region flanked by direct-repeats, encompassing sec and sel genes, corresponding to the previously described composite staphylococcal pathogenicity island (SePI) in S. epidermidis. We provided the first evidence that S. epidermidis occurring in food bears an element encoding an orthologue to Staphylococcus aureus SEC, and that SECepi can be produced in microbial broth, milk and meat juices. Regarding that only enterotoxins produced by S. aureus are officially tracked in food in EU, the ability to produce enterotoxin by S. epidermidis pose real risk for food safety (Podkowik et al. IJFM, 229, 52-59, 2016).
Our data indicate that among enterotoxigenic coagulase-negative staphylococci appear strains with stable enterotoxin genes (like in S. epidermidis 4S), similarly as in all known S. aureus strains, and strains that are heterogeneous in term of enterotoxin genes content. This latter seem to constitute mixed assemblage of bacterial cells where some are positive and some are negative for enterotoxin genes. We think that instability of enterotoxin genes perceived in some coagulase-negative staphylococci might contribute to overall enterotoxicity evolution of the genus Staphylococcus. According to our hypothesis enterotoxins of coagulase-negative staphylococci may impact staphylococcal pathogenicity in a twofold manner. Firstly, acting directly as virulence factors of coagulase-negative staphylococci; secondly, they may constitute the gene pool to supply pathogenic staphylococcal species with virulence factors.
In order to explain the significance of enterotoxins of coagulase negative staphylococci, a number of questions remain to be answered. They include:
- Evaluation of heterogeneity of coagulase-negative strains, and assessment of laboratory conditions to stabilize heterogenic cultures,
- Evaluation of possible intra- and interspecies transfer of mobile genetic elements harbouring enterotoxin genes.
- Characterization of mobile genetic elements harboring enterotoxin genes, their insertion sites in the genomes of coagulase-negative staphylococci, and identification of motives associated with enterotoxin gene transfer. Resolving of abovementioned issues allow to assess real safety hazards for public health posed by enterotoxins of coagulase negative staphylococci (ongoing NCN project 2015/19/B/NZ7/00447).

Research projects:
Title, financing body, project number, period, project leader

• Studies on expression of enterotoxins in Staphylococcus aureus strains from food and humans. Project MNiSW NN312215136. Period: 2009-2012. Leader Jacek Bania.
• Species identification in meat and meat products of game and farm animals using DNA analysis. Project MNiSW NN312427237. Period: 2009-2012. Leader Lech Rak.
• Genotypes and oxacillin-resistance of Staphylococcus aureus isolates from farm animals and food. Project MNiSW N N312 258140. Period: 2011-2014. Leader Jarosław Bystroń.
• Assessment of enterotoxin production by Staphylococcus aureus in food. Project NCN OPUS, nr 2012/05/B/NZ9/03343. Period: 2013-2016. Leader Jacek Bania.
• Antibiotic resistance and enterotoxigenicity of coagulase-negative staphylococci from food. Projevt NCN PRELUDIUM, nr 2012/05/N/NZ7/01945. Period: 2013-2016. Leader Magdalena Podkowik.
• Structure of genetic elements encoding enterotoxins in coagulase-negative staphylococci, assessment of their stability and transfer potential. Project NCN OPUS, nr 2015/19/B/NZ7/00447. Period: 2016-2019. Leader Jacek Bania.

Authors, journal name, year, volume no, pages, title (bez limitu liczby pozycji)

1. Bystroń J., Podkowik M., Piasecki T., Wieliczko A., Molenda J., Bania J. Vet. Microbiol. 2010, 144, 498-501. Genotypes and enterotoxin gene content of S. aureus isolates from poultry (IF: 3.256)
2. Bystroń J., Podkowik M., Korzekwa K., Lis E., Molenda J., Bania J. J. Food Protect. 2010, 73, 1325-1327. Characterization of borderline oxacillin-resistant Staphylococcus aureus isolated from food of animal origin (IF: 1.720)
3. Dąbrowska A. Wałecka E., Bania J., Żelazko M., Szołtysik M., Chrzanowska J. Small Rumin. Res. 2010, 94, 32-37. Quality of UHT goat's milk in Poland evaluated by real-time PCR (IF: 1.395)
4. Kowalska-Krochmal B., Dworniczek E., Dolna I., Seniuk A., Bania J., Wałecka E., Wrzyszcz E. Adv. Clin. Exp. Med. 2010, 19, 155-162. Antibiotic susceptibility levels of clinical Enterococcus spp. strains, including those resistant to glycopeptides and high concentrations of aminoglycosides (IF: 0.103)

5. Wałecka E., Molenda J., Karpiskova R., Bania J. Int. J. Food Microbiol. 2011, 144, 440-445. Effect of osmotic stress and culture density on invasiveness of Listeria monocytogenes strains (IF: 3.327)
6. Król J., Bania J., Florek J., Pliszczak-Król J., Staroniewicz Z. J. Vet. Diagn. Invest. 2011, 23, 532–537. PCR-based identification of clinically relevant Pasteurellaceae isolated from cats and dogs in Poland (IF: 1.214).
7. Wałecka E., Molenda J., Karpiskova R., Bania J. Foodborne Pathog. Dis. 2011, 8, 839-841. Effect of heat exposure on invasiveness of Listeria monocytogenes strains (IF: 2.260).
8. Król J., Bania J., Podkowik M., Florek M., Pliszczak-Król M., Staroniewicz Z. Curr. Microbiol. 2011, 63, 87-93. Genetic diversity of Pasteurella dagmatis as assessed by analysis of the 16S rRNA and rpoB gene sequences. (IF: 1.815)
9. Kowalska-Krochmal B, Dworniczek E, Dolna I, Bania J, Wałecka E, Seniuk A, Gościniak G. Adv Med. Sci. 2011, 56, 304-314. Resistance patterns and occurrence of virulence determinants among GRE strains in southwestern Poland. (IF: 0.952)
10. Płoneczka-Janeczko K., Kiełbowicz Z., Bania J., Bednarek K. Pol. J. Vet. Sci. 2011, 14, 679-681. Real-time PCR detection of Mycoplasma felis in domestic cats suffering from chronic conjunctivitis (Poland) (IF: 0.565)

11. Lis E., Podkowik M., Bystroń J., Stefaniak T., Bania J. J. Food Protect. 2012, 75, 238-244. Temporal expression of staphylococcal enterotoxin SEH in comparison with Agr-dependent and independent enterotoxins (IF: 1.832)
12. Podkowik M., Bystroń J., Bania J. Foodborne Pathog. Dis. 2012, 9, 91-93. Genotypes, antibiotic resistance and virulence factors of staphylococci from ready-to-eat food (IF: 2.283)
13. Podkowik M., Bystroń J., Bania J. Pol. J. Vet. Sci. 2012, 15, 233-237. Prevalence of antibiotic resistance genes in staphylococci isolated from ready-to-eat meat products. (IF: 0.570)
14. Lis E., Podkowik M., Schubert J., Bystroń J., Stefaniak T., Bania J. Foodborne Pathog. Dis. 2012, 9, 762-766. Production of staphylococcal enterotoxin R by Staphylococcus aureus strains. (IF: 2.283)
15. Dworniczek E., Piwowarczyk J., Bania J., Kowalska-Krochmal B., Wałecka E., Seniuk A., Dolna I., Gościniak G. Acta Microbiol. Immunol. Hung. 2012, 59, 263-269. Enterococcus in wound infections: Virulence and antimicrobial resistance (IF: 0.646)

16. Wałecka-Zacharska E., Kosek-Paszkowska K., Bania J., Karpiskova R., Stefaniak T., Lett. Appl. Microbiol. 2013, 56, 216-221. Salt stress-induced invasiveness of major L. monocytogenes serotypes. (IF: 1,749)
17. Podkowik M., Park J. Y., Seo K. S., Bystroń J., Bania J. Int. J. Food Microbiol. 2013, 163, 34-40. Enterotoxigenic potential of coagulase-negative staphylococci (IF: 3.155)
18. Rypuła K., Płoneczka-Janeczko K., Bania J., Wałecka E., Bierowiec K., Rozpędek W. Pol. J. Vet. Sci. 2013, 16, 381-383. Reduction of prevalence of persistent BVDV infection in cattle herds by long-term vaccination program (preliminary clinical study) (IF: 0.712)

19. Bystroń J., Krupa P., Podkowik M., Bania J. Med Weter. 2014, 70, 20-24. Arcobacter spp. – a potential risk for food safety (IF: 0,196)
20. Płoneczka-Janeczko K., Bierowiec K., Bania J., Kiełbowicz M., Kiełbowicz Z. Berl. Munch. Tierarztl. (Berliner und Münchener Tierärztliche Wochenschrift) 2014, 127, 243-246. Feline herpesvirus 1 (FHV-1) carriers among urban breeding facilities in Wroclaw (IF: 0.887)
21. Rak L., Knapik K., Bania J., Sujkowski J., Gadzinowski A. Eur. Food Res. Technol. 2014, 239, 189-194. Detection of roe deer, red deer, and hare meat in raw materials and processed products available in Poland (IF: 1.387)
22. Krupa P., Bystroń J., Bania J., Podkowik M., Empel J., Mroczkowska A. Poultry Sci. 2014, 93, 3179-3186. Genotypes and oxacillin resistance of Staphylococcus aureus from chicken and chicken meat in Poland (IF: 1.544)

23. Krupa P., Bystroń J., Podkowik M., Empel J., Mroczkowska A., Bania J. BioMed Res. Int. (formerly Journal of Biomedicine and Biotechnology) 2015, Article ID 141475, doi:10.1155/2015/141475. Population structure and oxacillin resistance of Staphylococcus aureus from pigs and pork meat in south-west Poland (IF: 2.706)
24. Płoneczka-Janeczko K., Kiełbowicz Z., Bierowiec K., Bania J., Kiełbowicz M. J. Small Anim. Pract. 2015, 56, 203-206. Characteristics of the bacterial flora in the conjunctival sac of cats from Poland (IF: 0,907)
25. Zacharow I., Bystroń J., Wałecka-Zacharska E., Podkowik M., Bania J. Pol. J. Vet. Sci. 2015, 18, 63–69. Prevalence and antimicrobial resistance of Arcobacter butzleri and Arcobacter cryaerophilus isolates from retail meat in Lower Silesia region, Poland (IF: 0.712)
26. Bystroń J., Podkowik M., Bania J., Krupa P., Schubert J. Med. Weter. 2015, 71, 341-345. Distribution of enterotoxins genes in Staphylococcus aureus isolates from pork and pigs (IF: 0.196)
27. Król J., Twardoń J., Mrowiec J., Podkowik M., Dejneka G., Dębski B., Nowicki T. Zalewski W. J. Dairy Sci. 2015. Streptococcus canis is able to establish a persistent udder infection in a dairy herd. (MNiSW: 45, IF: 2.550)
28. Zacharow I., Bystroń J., Wałecka-Zacharska E., Podkowik M, Bania J. BioMed Res. Int. 2015, Article ID 956507 (formerly Journal of Biomedicine and Biotechnology) Genetic diversity and incidence of virulence-associated genes of Arcobacter butzleri and Arcobacter cryaerophilus isolates from pork, beef and chicken meat in Poland (IF: 1.579)
29. Wałecka-Zacharska E., Kosek-Paszkowska K., Bania J., Staroniewicz Z., Bednarski M., Wieliczko A. Pol. J. Vet. Sci. 2015, 18, 697-702. Invasiveness of L. monocytogenes strains isolated from animals in Poland (IF: 0.604)
30. Płoneczka-Janeczko K., Bania J., Bierowiec K., Kiełbowicz M., Kiełbowicz Z. Veterinární Medicína 2015, 60, 654-661. Reduction of Chlamydophila-felis-associated signs by roxithromycin treatment regimen in cats showing doxycycline intolerance (IF: 0.639)

31. Allen K.J., Wałecka-Zacharska E., Chen J.C., Kosek-Paszkowska K., Devlieghere F., Van Meervenne E., Osek J., Wieczorek K., Bania J. Food Microbiol. 2016, 54, 178–189. Listeria monocytogenes – An examination of food chain factors potentially contributing to antimicrobial resistance (MNiSW: 35, IF: 3.374)
32. Król J., Wanecka A., Twardoń J., Mrowiec J., Dropińska A., Bania J., Podkowik M., Korzeniowska-Kowal A. Vet. Microbiol. 2016, 182 163–169. Isolation of Staphylococcus microti from milk of dairy cows with mastitis (MNiSW: 40, IF: 2.511)
33. Magdalena Podkowik, Keun Seok Seo, Justyna Schubert, Isaiah Tolo, D. Ashley Robinson, Jacek Bania, Jarosław Bystroń Int. J. Food Microbiol. 2016, 229, 52-59. Genotype and enterotoxigenicity of Staphylococcus epidermidis isolate from ready to eat meat products (MNiSW: 40, IF: 3.082)
34. Kovacevic J, Ziegler J, Wałecka-Zacharska E, Reimer A, Kitts DD, Gilmour MW. Appl. Environ. Microbiol. 2016, 82, 939-953. Tolerance of Listeria monocytogenes to Quaternary Ammonium Sanitizers Is Mediated by a Novel Efflux Pump Encoded by emrE (IF: 3.952)
35. Justyna Schubert, Magdalena Podkowik, Jarosław Bystroń, Jacek Bania Int. J. Food Microbiol. 2016, 235, 36–45. Production of staphylococcal enterotoxins in microbial broth and milk by Staphylococcus aureus strains harboring seh gene (IF: 3.445)
36. Marek Houszka, Jolanta Piekarska, Magdalena Podkowik, Michał Gorczykowski, Jacek Bania J. Vet. Res. 2016, 60, 435-439. Morphology and molecular study of Fascioloides magna – a growing threat to cervids (Cervidae) in Poland (IF: 0.468)

37. Justyna Schubert, Magdalena Podkowik, Jarosław Bystroń, Jacek Bania Foodborne Pathog. Dis. 2016, 14, 1-8. Production of staphylococcal enterotoxins D and R in milk and meat juice by Staphylococcus aureus strains (IF: 2.270).

PhD theses
Title, year, author, director of the thesis

• Ewa Wałecka, PhD, 2012. Title: Assessment of impact of environmental stress on Listeria monocytogenes virulence. Director of the thesis Jacek Bania
• Elżbieta Lis, PhD, 2012. Title: Assessment of expression of staphylococcal enterotoxins H and R in Staphylococcus aureus strains. Director of the thesis Jacek Bania
• Magdalena Podkowik, PhD, 2013. Title: Genotypes, antibiotic resistance and virulence factors in coagulase-negative staphylococci from ready-to-eat food. Director of the thesis Jacek Bania

Research equipment

• UV-Vis spectrophotometer Cary 100 (Varian).
• Microvolume DS-11 FX Spectrophotometer/Fluorometer (DeNovix).
• Real-Time PCR systems IQ-5 (5-channel) and CFX (2-channel) (BioRad).
• Thermal cyclers MJ-Mini (BioRad), SimpliAmp (ThermoScientific).
• Gel documentation system GelDoc XR (BioRad).
• -86°C upright freezers MDF-U486S and MDF-U73V (Sanyo).
• Microbiological incubator MIR-162 (Sanyo).
• CO2 incubator MCO-18AIC(UV) (Sanyo).
• Laminar flow hood TopSafe 1.2 (Euroclone).
• Benchtop incubator shaker Excella E24 (New Brunswick).
• Horizontal and vertical electrophoresis systems Sub-Cell 192 (BioRad).
• Bath Circulator NESLAB RTE7 (ThermoScientific).
• Automated strip washer for microplates ELx50 (Biotec).
• Homogenizer - ball mill TissueLyser LT (Qiagen).
• Refrigerated centrifuges 5415R and 5804R (Eppendorf).

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