Jasna Kovac, Ph.D.

  • Lester Earl and Veronica Casida Career Development Professor of Food Safety
  • Assistant Professor of Food Science
Jasna Kovac, Ph.D.
437 Rodney A. Erickson Food Science Building
University Park, PA 16803
Work Phone: 814-865-2883

Areas of Expertise

  • Food Safety
  • Foodborne Pathogens
  • Microbial genomics
  • MicrobiomesFood Microbiology
  • Antimicrobial Resistance
  • Epidemiology


  1. BSc - University of Ljubljana (Microbiology, concentration: Microbial Biotechnology), 2011
  2. PhD - University of Ljubljana (Biosciences, concentration: Biotechnology), 2015
  3. Visiting scholar - University of Graz (Bucar lab), 2011
  4. Visiting scholar - Iowa State University (Zhang lab), 2012
  5. FEMS Fellow - Oxford University (Maiden lab), 2014
  6. Erasmus Fellow - University of Veterinary Medicine Vienna (Wagner lab, Stessl group), 2015
  7. Postdoc - Cornell University (Wiedmann lab), 2015 - 2017


The goal of our research is to advance understanding of genetic and environmental factors driving:

(i) expression of virulence factors;
(ii) evolution of antimicrobial resistance;
(iii) transmission and persistence of foodborne pathogens.

We use a precision food safety approach, including comparative genomics and metagenomics to generate the knowledge needed for the development of effective intervention strategies leading to a safer and sustainable food supply chain.

Lab members

Visit our lab website.

Graduate students

Runan Yan (PhD candidate, mBiome Fellow), Food Science

Taejung Chung (PhD candidate), Food Science

Naomi Niyah (PhD candidate), Molecular, Cellular, and Integrative Biosciences

Laura Rolon (PhD student) - co-advised with R. Roberts, Food Science, dual-title degree program in International Agriculture and Development

Priscilla Sinclair (MS student) - co-advised with L. LaBorde, Food Science


Graduate Programs

Food Science

Molecular, Cellular, and Integrative Biosciences

International Agriculture and Development

Clinical and Translational Sciences



Kovac lab co-authors are indicated in bold type; the corresponding author is indicated with *.


Kovac J.*, Dudley E.G., Nawrocki E., Yan R., Chung T. 2020. Whole genome sequencing: The impact on foodborne outbreak investigations. Reference Module in Food Science, doi:10.1016/B978-0-08-1000596-5.22697-8.

Sullivan G., Guo X., Tokman J.I., Roof S., Trmcic A., Baker R.C., Tang S., Markwell P., Wiedmann M., Kovac J.* 2020. Extended enrichment procedures can be used to define false-negative probabilities for cultural "gold standard" methods for Salmonella detection, facilitating comparisons between gold standard and alternative methods. Journal of Food Protection, doi:10.4315/0362-028X.JFP-19-422.

Šimunović K., Sahin O., Kovac J., Shen Z., Klančnik A., Zhang Q., Smole Možina S. 2020. (-)-α-Pinene reduces quorum sensing and Campylobacter jejuni colonization in broiler chickens. PLoS One, doi:10.1371/journal.pone.0230423. 

Carroll, L. M., Wiedmann, M., Kovac, J.* 2020. Proposal of a taxonomic nomenclature for the Bacillus cereus group which reconciles genomic definitions of bacterial species with clinical and industrial phenotypes. mBio,

Beno, S. M., Cheng, R. A., Orsi, R. H., Duncanm D. R., Guo, X., Kovac, J., Carroll, L. M., Martin, N. H., Wiedmann, M. 2020. Paennibacillus odorifer, the predominant Paennibacillus species isolated from milk in the United States, demonstrates genetic and phenotypic conservation of psychrotolerance but clade-associated differences in nitrogen metabolic pathways. mSphere, 


Klancnik, A., Simunovic, K., Kovac, J., Sahin, O., Wu, Z., Vuckovic, D., Abram, M., Zhang, Q., Mozina S. The anti-Campylobacter activity and pinocembrin mechanisms of action. Microorganisms, 

Tan, X., Chung, T., Chen, Y., Macarisin, D., LaBorde, L., Kovac., J*. 2019. The occurrence of Listeria monocytogenes is associated with built environment microbiota in three tree fruit processing facilities. Microbiome,
Liao, J., Hohl Orsi, R., Carroll, L. M., Kovac, J., Ou, H., Zhang, H., Wiedmann, M*. 2019. Serotype-specific evolutionary patterns of antimicrobial-resistant Salmonella enterica. BMC Evolutionary Biology,
Kovac, J*. 2019. Precision food safety: a paradigm shift in detection and control of foodborne pathogens. mSystems,
Harrand, A. S., Kovac, J., Carroll, L. M., Guariglia-Oropeza, V., Kent, D. J., Wiedmann, M. 2019. Assembly and characterization of a pathogen strain collection for produce safety applications: Pre-growth conditions have a larger effect on peroxyacetic acid tolerance than strain diversity. Frontiers in Microbiology,
Weller, L. D., Kovac, J., Kent, D. J., Roof, S., Tokman, J. I., Mudrak, E., Wiedmann, M.*. 2019. A conceptual framework for developing recommendations for no-harvest buffers around in-field feces. Journal of Food Protection,
Reichler, S. J., Martin, N. H., Evanowski, R. L., Kovac, J., Wiedmann, M., Orsi, R. H. 2019. A century of gray: a genomic locus found in 2 distinct Pseudomonas spp. is associated with historical and contemporary color defects in dairy products worldwide. Journal of Dairy Science,
Bell, T. H., Hockett, K., Alcala-Briseno, R. I., Barberchek, M., Beattie, G. A., Bruns, M. A., Carlson, J., Chung, T., Collins, A., Emmett, B., Esker, P., Garrett, K., Glenna, L., Gugino, B. K., del Mar Jimenez Gasco, M., Kinkel, L., Kovac, J., Kowalski, K., Kuldau, G., Leveau, J., Mischalska-Smith, M., Myrick, J., Peter, K., Vivanco Salazar, Shade, A., Stopinsek, N., Tan, X., Wickings, K., Tergeau, E. 2019. Manipulating wild and tamed phytobiomes: Challenges and opportunities. Phytobiomes, doi:10.1094/PBIOMES-01-10-0006-W.
Beno, S. B., Orsi, R. H., Cheng, R. A., Kent, D. J., Kovac, J., Duncan, D. R., Martin, N. H., Wiedmann, M. 2019. Genes associated with psychrotolerant Bacillus cereus group isolates. Frontiers in Microbiology, doi:10.3389/fmicb.2019.00662.
Carroll, L.M., Wiedmann, M., Mukherjee, M., Nicholas, D.C., Mingle, L.A., Dumas, N.B., Cole J.A., Kovac, J.* 2019. Characterization of emetic and diarrheal Bacillus cereus strains from 2016 foodborne outbreak using whole-genome sequencing: addressing the microbiological, epidemiological, and bioinformatic challenges. Frontiers in Microbiology, doi:10.3389/fmicb.2019.00144.
Nwanosike, H., Chung, T., Xiaoli, L., Condello, M., Dudley, E. G., Kovac, J.* 2019. Whole-genome sequences of Escherichia coli isolates from cocoa beans imported from Bolivia. Microbiology Resource Announcements, doi:10.1128/MRA.01516-18. 


Miller, R. A., Jian, J., Beno, S. M., Wiedmann, M., Kovac, J.*. 2018. Intraclade variability in toxin production and cytotoxicity of Bacillus cereus group type strains and dairy-associated isolates. Applied and Environmental Microbiology, doi: 10.1128/AEM.02479-17.

Smole Mozina, S., Klancnik, A., Kovac, J., Jersek, B., Bucar, F. 2018. Antimicrobial natural products against Campylobacter. In Merillon, J. M., Riviere, C. (Eds). Natural Antimicrobial Agents. Sustainable Development and Biodiversity, vol. 19., Springer, Cham, doi:10.1007/978-3-319-67045-4_1.


Goodman, L. B., Lawton, M. R., Franklin-Guild, R. J., Anderson, R. R., Schaan, L., Thachil, A. J., Wiedmann, M., Miller, C. B., Alcaine, S. D.*, Kovac, J.*. 2017. Lactococcus petauri sp. nov. is a new species isolated from an abscess of a sugar glider. International Journal of Systematic and Evolutionary Microbiology, doi:10.1099/ijsem.0.002303.

Carroll, L. M., Kovac, J.*, Miller, R. A., Wiedmann, M. 2017. Rapid, high-throughput identification of anthrax-causing and emetic Bacillus cereus group genome assemblies using BTyper, a computational tool for virulence-based classification of Bacillus cereus group isolates using nucleotide sequencing data. Applied and Environmental Microbiology, doi:10.1128/AEM.01096-17

Weller, D., Kovac, J., Roof, S., Kent, D, Tokman, J., Kowalcyk, B., Oryang, D., Ivanek, R., Aceituno, A., Sroka, C., Wiedmann, M. 2017. Survival of Escherichia colion lettuce under field conditions encountered in the Northeastern United States. Journal of Food Protection, 80(7), 1214-1221.

Weller, D. L., Kovac, J., Kent, D. J., Roof, S., Tokman, J. I., Mudrak, E., Kowalcyk, B., Oryang, D., Aceituno, A., Wiedmann, M. 2017. Escherichia coli transfer from simulated wildlife feces to lettuce during foliar irrigation: A field study in the Northeastern United States. Food Microbiology, 68: 24-33.

Kovac, J., den Bakker, H., Carroll, L. M., Wiedmann, M. 2017. Precision food safety: a systems approach to food safety facilitated by genomics tools. TrAC Trends in Analytical Chemistry.

Kovac, J.*, Stessl., B., Cadez, N., Gruntar, I., Cimerman, M., Stingl, K., Lusicky, M., Ocepek, M., Wagner, M., Smole Mozina, S. 2017. Population structure and attribution of human clinical Campylobacter jejuni isolates from central Europe to livestock and environmental sources. Zoonoses and Public Health. doi: 10.1111/zph.12366.

Liao, J., Wiedmann, M., Kovac, J*. 2017. Genetic stability and evolution of sigBallele used for Listeria sensu stricto subtyping and phylogenetic inference. Applied and Environmental Microbiology, doi:10.1128/AEM.00306-17.

Kovac, J., Cummings, K. J., Rodriguez-Rivera, L. D., Carroll, L. M., Thachil, A., Wiedmann, M. 2017. Temporal genomic phylogeny reconstruction indicates a geospatial transmission path of Salmonella Cerro in the United States and a clade-specific loss of hydrogen sulfide production. Frontiers in Microbiology, doi: 10.3389/fmicb.2017.00737.


Miller, A. R., Beno, S. M., Kent, D. J., Carroll, L. M., Martin, N. H., Boor, K. J., Kovac, J*. 2016. Bacillus wiedmannii sp. nov. is a new psychrotolerant and cytotoxic Bacillus cereus group species isolated from dairy foods and environments in the USA. International Journal of Systematic and Evolutionary Microbiology, Accepted for publication on Aug 12, doi: 10.1099/ijsem.0.001421.

Kovac, J., Miller, R. A., Carroll, L. M., Kent, D. J., Jian, J., Beno, S. M., Wiedmann, M. 2016. Production of hemolysin BL by Bacillus cereus group isolates of dairy origin is associated with whole-genome phylogenetic clade. BMC Genomics, 17:581, doi: 10.1186/s12864-016-2883-z.


Kovac, J., Cadez, N., Stessl, B., Stingl, K., Gruntar, I., Ocepek, M., Trkov, M., Wagner, M. and Mozina, S.S., 2015. High genetic similarity of ciprofloxacin-resistant Campylobacter jejuni in central Europe. Frontiers in Microbiology, 6:1169, doi: 10.3389/fmicb.2015.01169.

Kovac, J., Simunovic, K., Wu, Z., Klancnik, A., Bucar, F., Zhang, Q. and Mozina, S.S., 2015. Antibiotic resistance modulation and modes of action of (-)-α-pinene in Campylobacter jejuni. PLoS One, 10(4):e0122871, doi: 10.1371/journal.pone.0122871.

Nagy, B., Szmolka, A., Mozina, S.S., Kovac, J., Strauss, A., Schlager, S., Beutlich, J., Appel, B., Lusicky, M., Aprikian, P. and Pászti, J., 2015. Virulence and antimicrobial resistance determinants of verotoxigenic Escherichia coli (VTEC) and of multidrug-resistant E. coli from foods of animal origin illegally imported to the EU by flight passengers. International Journal of Food Microbiology, 209:52-9, doi: 10.1016/j.ijfoodmicro.2015.06.026.

Before 2015

Videnska, P., Rahman, M.M., Faldynova, M., Babak, V., Matulova, M.E., Prukner-Radovcic, E., Krizek, I., Smole-Mozina, S., Kovac, J., Szmolka, A. and Nagy, B., 2014. Characterization of egg laying hen and broiler fecal microbiota in poultry farms in Croatia, Czech Republic, Hungary and Slovenia. PLoS One, 9(10):e110076, doi: 10.1371/journal.pone.0110076.

Kovac, J., Gavaric, N., Bucar, F. and Smole Mozina, S., 2014. Antimicrobial and Resistance Modulatory Activity of Alpinia katsumadai Seed Phenolic Extract, Essential Oil and Post-Distillation Extract. Food Technology and Biotechnology, 52(2), 248-254.

Janez, N., Kokosin, A., Zaletel, E., Vranac, T., Kovac, J., Vuckovic, D., Mocina, S.S., Serbec, V., Zhang, Q., Accetto, T. and Podgornik, A., 2014. Identification and characterisation of new Campylobacter group III phages of animal origin. FEMS Microbiology Letters, 359(1), 64-71.

Kovac, J., Cadez, N., Lusicky, M., Nielsen, E.M., Ocepek, M., Raspor, P. and Mozina, S.S., 2014. The evidence for clonal spreading of quinolone resistance with a particular clonal complex of Campylobacter jejuni. Epidemiology and Infection, 142(12), 2595-2603.

Klancnik, A., Gröblacher, B., Kovac, J., Bucar, F. and Mozina, S.S., 2012. Anti-Campylobacter and resistance-modifying activity of Alpinia katsumadai seed extracts. Journal of Applied Microbiology, 113(5),1249-1262.


FD SC 409 - Laboratory in Food Microbiology (Fall semester; 2 cr)

FDSC 497 - Foodborne Pathogen Genomic Epidemiology (Spring semester; 3 cr)

FDSC/INTAG 460 - Food Production in Italy (Spring break; study abroad; 1 cr)

FDSC 496 - Independent Studies (all semesters; variable cr)

FDSC 600/MCIBS 600 - Thesis Research (all semesters, variable cr)

FDSC 494H - Honors Thesis - (all semesters, variable cr)



Research Interests

Food Safety Researchers

Precision food safety supported by (meta)genomics. Transmission and evolution of pathogens and antimicrobial resistance in the food supply chain. Characterization of virulence factors and antimicrobial resistance determinants in foodborne pathogens. Focus on Campylobacter, Salmonella, Bacillus cereus group.

Food Microbiology