Streptococcus research
Hello and welcome to the website of the Streptococcus Working Group of the Institute of Medical Microbiology and Hygiene.
Research topics
Our research group focusses on the molecular basis of the pathogenesis of streptococcal infections. Our work focusses on S. agalactiae. This pathogen is mainly known under the name Group B Streptococcus (GBS) as the cause of severe neonatal meningitis and septicaemia. In recent years, however, an increasing number of invasive diseases in adulthood have become apparent.
Horizontal gene transfer
One focus of our work is the characterisation of a mobile genetic element that has the structure of a "composite transposon". In addition to the known virulence factor C5a peptidase, this element contains a gene (lmb) that mediates the binding of pathogens to laminin. As the region is missing in many veterinary GBS strains, but is conserved in human isolates, it appears to be of particular importance for human infections. This region was probably acquired by horizontal gene transfer between different haemolytic streptococci.
Haemolysin
Another focus of our research group is the analysis of the haemolytic activity of S. agalactiae. A few years ago, we were able to identify the chromosomal locus (cyl gene cluster) that is responsible for the haemolytic activity and pigment formation of S. agalactiae. This locus contains several genes whose exact role in the production of haemolysin and pigment is still unclear. Our latest work on this topic shows that the ABC transporter of the gene cluster, which is responsible for the export of the haemolysin molecule, transports substrates of classical MDR (multidrug resistance) transporters. These results could provide important clues to the structure of the haemolysin molecule, which has not yet been clearly identified biochemically.
Regulation of adhesion and invasion
Work on the characterisation of adhesion factors required for the interaction of S. agalactiae with extracellular matrix proteins led to the discovery of new surface proteins of S. agalactiae that mediate binding to extracellular matrix proteins such as laminin and fibrinogen and a two-component regulatory system involved in the regulation of fibrinogen binding and the expression of known virulence factors. In some cases, the expression of bacterial pathogenicity factors only occurs in vivo when the bacteria come into contact with the host tissue and is in many cases much more specifically regulated than has long been assumed. We are currently analysing S. agalactiae genes that are specifically activated when the pathogens come into contact with the human host.
Publications
further publications ( PubMed)
selected publications
1: Spellerberg B, Rabsch W, Pietsch M, Denzer C, Posovszky C, Essig A, Pfeifer Y.
ESBL acquisition in Salmonella spp. and Shigella spp. in the context of systemic
cephalosporin treatment. Clin Infect Dis. 2019 Jun 4. pii: ciz468. doi:
10.1093/cid/ciz468. [Epub ahead of print] PubMed PMID: 31165140.
2: Bauer R, Mauerer S, Spellerberg B. Regulation of the β-hemolysin gene cluster
of Streptococcus anginosus by CcpA. Sci Rep. 2018 Jun 13;8(1):9028. doi:
10.1038/s41598-018-27334-z. PubMed PMID: 29899560; PubMed Central PMCID:
PMC5998137.
3: Shabayek S, Spellerberg B. Group B Streptococcal Colonisation, Molecular Characteristics, and Epidemiology.
Characteristics, and Epidemiology. Front Microbiol. 2018 Mar 14;9:437. doi:
10.3389/fmicb.2018.00437. eCollection 2018. review. PubMed PMID: 29593684; PubMed
Central PMCID: PMC5861770.
4: Bauer R, Mauerer S, Grempels A, Spellerberg B. The competence system of
Streptococcus anginosus and its use for genetic engineering. Mol Oral Microbiol.
2018 Apr;33(2):194-202. doi: 10.1111/omi.12213. Epub 2018 Feb 12. PubMed PMID:
29290101.
5: Shabayek S, Spellerberg B. Acid Stress Response Mechanisms of Group B
Streptococci. Front Cell Infect Microbiol. 2017 Sep 7;7:395. doi:
10.3389/fcimb.2017.00395. eCollection 2017. review. PubMed PMID: 28936424; PubMed
Central PMCID: PMC5594096.
6: Rosa-Fraile M, Spellerberg B. Reliable Detection of Group B Streptococcus in
the Clinical Laboratory. J Clin Microbiol. 2017 Sep;55(9):2590-2598. doi:
10.1128/JCM.00582-17. epub 2017 Jun 28. review. PubMed PMID: 28659318; PubMed
Central PMCID: PMC5648696.
7: Sendi P, El Hay MA, Brandt CM, Spellerberg B. Group B Streptococcal Toxic
Shock Syndrome and covR/S Mutations Revisited. Emerg Infect Dis. 2017
Jan;23(1):150-152. doi: 10.3201/eid2301.161063. PubMed PMID: 27983484; PubMed
Central PMCID: PMC5176209.
8: Shabayek S, Bauer R, Mauerer S, Mizaikoff B, Spellerberg B. A streptococcal
NRAMP homologue is crucial for the survival of Streptococcus agalactiae under low
pH conditions. Mol Microbiol. 2016 May;100(4):589-606. doi: 10.1111/mmi.13335.
Epub 2016 Feb 29. PubMed PMID: 27150893.
9: Sendi P, Furitsch M, Mauerer S, Florindo C, Kahl BC, Shabayek S, Berner R,
Spellerberg B. Chromosomally and Extrachromosomally Mediated High-Level
Gentamicin Resistance in Streptococcus agalactiae. Antimicrob Agents Chemother.
2016 Jan 4;60(3):1702-7. doi: 10.1128/AAC.01933-15. PubMed PMID: 26729498; PubMed
Central PMCID: PMC4775929.
10: Rosa-Fraile M, Dramsi S, Spellerberg B. Group B streptococcal haemolysin and
pigment, a tale of twins. FEMS Microbiol Rev. 2014 Sep;38(5):932-46. doi:
10.1111/1574-6976.12071. Epub 2014 Apr 4 Review. PubMed PMID: 24617549; PubMed
Central PMCID: PMC4315905.
11: Asam D, Mauerer S, Walheim E, Spellerberg B. Identification of
β-haemolysin-encoding genes in Streptococcus anginosus. Mol Oral Microbiol. 2013
Aug;28(4):302-15. doi: 10.1111/omi.12026. Epub 2013 Apr 18. PubMed PMID:
Team
Prof. Dr med Barbara Spellerberg
Deputy Head of Institute
Schwerpunkte
- Streptococcus research