Enteric Bacteriology and Food-borne Zoonosis Research Team

The research team is studying virulence and antimicrobial resistance mechanisms and genetics of foodborne zoonotic agents, primarily of Salmonella and E. coli thereby exploring the ways for more effective preventive and diagnostic interventions against these bacteria.

Scientific advisor, research team leader: 
Primary aim of the research is to perform a complex (phenotypic, genotypic and genomic) characterization of emerging serovars of Salmonella with enhanced public health importance. Characterizations are extended into the in vitro and in vivo pathogenetic and gene expression studies. The group also explores the host/pathogen interactions of virulence and resistance genes, and of pathogenicity and genomic islands of Salmonella and E. coli as well as of environmental bacteria (i.e. Pseudomonas)  with special regards to the early immune response. Explorative studies are directed to the new and so far undetected antimicrobial resistance genes and resistance mechanisms.
 
Another especially important task of the group is studying the origins of Shiga toxin producing E. coli strains responsible for human haemorrhagic colitis, identifying their new clones, exploring the genetic vectors responsible for spreading their virulence and resistance genes, as well as modelling the mechanisms of the dissemination of these genetic elements. They also aim to characterise the bacteriophages associated with these bacteria, and to assess their significance int he evolution of these strains, as well as the potential diagnostic or therapeutic use these phages.
 
Results of the above studies help in the prevention of enteric zoonoses, as well the development of their faster and more specific diagnostic methods, and also new vaccinations and other defense strategies against antibiotic-resistant pathogenic strains.
Principal research activities of the research group Enteric bacteriology and foodborne zoonoses

Principal research activities of the research group Enteric bacteriology and foodborne zoonoses. The source of figure presenting antimicrobial resistance: http://www.tankonyvtar.hu

The S. sonnei 75/02 Stx phage integrated into the ynfG (oxydoreductase) gene in the original S. sonnei strain as well as three lysogenised E. coli K-12 derivative strains. PCR detection performed according to Gray et al (2014). Photo: István Tóth.

The S. sonnei 75/02 Stx phage integrated into the ynfG (oxydoreductase) gene in the original S. sonnei strain as well as three lysogenised E. coli K-12 derivative strains. PCR detection performed according to Gray et al (2014). Photo: István Tóth.

1., 2, Shedding of E. coli (EHEC/STEC) strains by cattle and their isolation; 3. 7, EHEC/STEC infecting humans; 4, Release of Shiga toxin encoding phages and 5, their transfer into Stx-negative bacteria; 6, establishment of a new STEC strain.

1., 2, Shedding of E. coli (EHEC/STEC) strains by cattle and their isolation; 3. 7, EHEC/STEC infecting humans; 4, Release of Shiga toxin encoding phages and 5, their transfer into Stx-negative bacteria; 6, establishment of a new STEC strain. Photo: István Tóth

Services: 

Complex typing of pathogenic and multidrug resistant E. coli strains for diagnostic purposes (DNA microarray analysis, phenotyping and genotyping)

Cooperation in vaccine development (E. coli and Salmonella)

Selected publications: 

Tóth I, Sváb D, Bálint B, Brown-Jaque M, Maróti G (2016) Comparative analysis of the Shiga toxin converting bacteriophage first detected in Shigella sonnei. Infect Genet Evol. 37:150-157. doi: 10.1016/j.meegid.2015.11.022

Sváb D, Bálint B, Maróti G, Tóth I (2015) A novel transducible chimeric phage from Escherichia coli O157:H7 Sakai strain encoding Stx1 production. Infect Genet Evol. 29: 42-47. doi: 10.1016/j.meegid.2014.10.019

Nagy B, Szmolka A, Smole Možina S, Kovač J, Strauss A, Schlager S, Beutlich J, Appel B, Lušicky M, Aprikian P, et al. (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. Int J Food Microbiol. 209:52-59. doi: 10.1016/j.ijfoodmicro.2015.06.026

Szmolka A, Wiener Z, Matulova ME, Varmuzova K, Rychlik I (2015) Gene Expression Profiles of Chicken Embryo Fibroblasts in Response to Salmonella Enteritidis Infection. PLoS One. 10(6):e0127708. doi: 10.1371/journal.pone.0127708.

Sváb D, Horváth B, Maróti G, Dobrindt U, Tóth I (2013) Sequence variability of P2-like prophage genomes carrying the cytolethal distending toxin V operon in Escherichia coli O157. Appl Environ Microbiol. 79: 4958-4964 doi: 10.1128/AEM.01134-13

Szmolka A, Nagy B (2013) Multidrug resistant commensal Escherichia coli in animals and its impact for public health. Front Microbiol. 4:258. doi: 10.3389/fmicb.2013.00258

Szmolka A, Cramer N, Nagy B (2012) Comparative genomic analysis of bovine, environmental, and human strains of Pseudomonas aeruginosa. FEMS Microbiol Lett. 335:113-122. doi: 10.1111/j.1574-6968.2012.02642.x

Szmolka A, Anjum MF, La Ragione RM, Kaszanyitzky EJ, Nagy B (2012) Microarray based comparative genotyping of gentamicin resistant Escherichia coli strains from food animals and humans. Vet Microbiol. 156:110-118. doi: 10.1016/j.vetmic.2011.09.030

Tóth I, Schmidt H, Kardos G, Lancz Zs, Creuzburg K, Damjanova I, Pászti J, Nagy B (2009) Virulence genes and molecular typing of different groups of Escherichia coli O157 strains in cattle. Appl Environ Microbiol. 75: 6282-6291 doi: 10.1128/AEM.00873-09

Tóth I, Hérault F, Beutin L, Oswald E (2003) Production of cytolethal distending toxins by pathogenic Escherichia coli strains isolated from human and animal sources: establishment of the existence of a new cdt variant (type IV). J Clin Mirobiol 41: 4285-4291. doi: 10.1128/JCM.41.9.4285-4291.2003

National and international cooperations: 
University of Debrecen; Hungary
Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
NAIK, Agricultural Biotechnology Institute, Gödöllő, Hungary
National Center for Epidemiology, Budapest, Hungary
SeqOmics Kft., Mórahalom, Hungary
University of Pécs, Pécs, Hungary
Justus-Liebig University, Giessen, Germany,
University of Münster, Institute of Hygiene, Section Microbial Genome Plasticity, Münster, Germany
University of Nottingham, Sutton Bonington, Leicestershire, United Kingdom
Animal and Plant Health Agency, Addleston, United Kingdom
Veterinary Research Institute, Brno, Czech Republic
Professor emeritus: 
Senior research fellow(s): 
Research fellow(s): 
Laboratory technician: