TY  - JOUR
A1  - Trübe, Patricia
A1  - Hertlein, Tobias
A1  - Mrochen, Daniel M.
A1  - Schulz, Daniel
A1  - Jorde, Ilka
A1  - Krause, Bettina
A1  - Zeun, Julia
A1  - Fischer, Stefan
A1  - Wolf, Silver A.
A1  - Walther, Birgit
A1  - Semmler, Torsten
A1  - Bröker, Barbara M.
A1  - Ulrich, Rainer G.
A1  - Ohlsen, Knut
A1  - Holtfreter, Silva
T1  - Bringing together what belongs together: Optimizing murine infection models by using mouse-adapted Staphylococcus aureus strains
JF  - International Journal of Medical Microbiology
N2  - Staphylococcus (S.) aureus is a leading cause of bacterial infection world-wide, and currently no vaccine is available for humans. Vaccine development relies heavily on clinically relevant infection models. However, the suitability of mice for S. aureus infection models has often been questioned, because experimental infection of mice with human-adapted S. aureus requires very high infection doses. Moreover, mice were not considered to be natural hosts of S. aureus. The latter has been disproven by our recent findings, showing that both laboratory mice, as well as wild small mammals including mice, voles, and shrews, are naturally colonized with S. aureus. Here, we investigated whether mouse-and vole-derived S. aureus strains show an enhanced virulence in mice as compared to the human-adapted strain Newman. Using a step-wise approach based on the bacterial genotype and in vitro assays for host adaptation, we selected the most promising candidates for murine infection models out of a total of 254 S. aureus isolates from laboratory mice as well as wild rodents and shrews. Four strains representing the clonal complexes (CC) 8, 49, and 88 (n = 2) were selected and compared to the human-adapted S. aureus strain Newman (CC8) in murine pneumonia and bacteremia models. Notably, a bank vole-derived CC49 strain, named DIP, was highly virulent in BALB/c mice in pneumonia and bacteremia models, whereas the other murine and vole strains showed virulence similar to or lower than that of Newman. At one tenth of the standard infection dose DIP induced disease severity, bacterial load and host cytokine and chemokine responses in the murine bacteremia model similar to that of Newman. In the pneumonia model, DIP was also more virulent than Newman but the effect was less pronounced. Whole genome sequencing data analysis identified a pore-forming toxin gene, lukF-PV(P83)/lukM, in DIP but not in the other tested S. aureus isolates. To conclude, the mouse-adapted S. aureus strain DIP allows a significant reduction of the inoculation dose in mice and is hence a promising tool to develop clinically more relevant infection models.
KW  - Staphylococcus aureus
KW  - host-adapted
KW  - infection model
KW  - mouse
KW  - vole
KW  - CC49
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-229081
VL  - 309
ER  - 
TY  - JOUR
A1  - Soundararajan, Manonmani
A1  - Marincola, Gabriella
A1  - Liong, Olivia
A1  - Marciniak, Tessa
A1  - Wencker, Freya D. R.
A1  - Hofmann, Franka
A1  - Schollenbruch, Hannah
A1  - Kobusch, Iris
A1  - Linnemann, Sabrina
A1  - Wolf, Silver A.
A1  - Helal, Mustafa
A1  - Semmler, Torsten
A1  - Walther, Birgit
A1  - Schoen, Christoph
A1  - Nyasinga, Justin
A1  - Revathi, Gunturu
A1  - Boelhauve, Marc
A1  - Ziebuhr, Wilma
T1  - Farming practice influences antimicrobial resistance burden of non-aureus staphylococci in pig husbandries
JF  - Microorganisms
N2  - Non-aureus staphylococci (NAS) are ubiquitous bacteria in livestock-associated environments where they may act as reservoirs of antimicrobial resistance (AMR) genes for pathogens such as Staphylococcus aureus. Here, we tested whether housing conditions in pig farms could influence the overall AMR-NAS burden. Two hundred and forty porcine commensal and environmental NAS isolates from three different farm types (conventional, alternative, and organic) were tested for phenotypic antimicrobial susceptibility and subjected to whole genome sequencing. Genomic data were analysed regarding species identity and AMR gene carriage. Seventeen different NAS species were identified across all farm types. In contrast to conventional farms, no AMR genes were detectable towards methicillin, aminoglycosides, and phenicols in organic farms. Additionally, AMR genes to macrolides and tetracycline were rare among NAS in organic farms, while such genes were common in conventional husbandries. No differences in AMR detection existed between farm types regarding fosfomycin, lincosamides, fusidic acid, and heavy metal resistance gene presence. The combined data show that husbandry conditions influence the occurrence of resistant and multidrug-resistant bacteria in livestock, suggesting that changing husbandry practices may be an appropriate means of limiting the spread of AMR bacteria on farms.
KW  - non-aureus staphylococci
KW  - NAS
KW  - alternative pig farming
KW  - antimicrobial resistance
KW  - one-health approach
KW  - intervention strategies
KW  - livestock-associated staphylococci
KW  - organic farming
KW  - pig farming methods
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-312750
SN  - 2076-2607
VL  - 11
IS  - 1
ER  -