Dier & Kruid 03-06-2015 Prof. Dr. J. Fink-Gremmels DVM, PhD, Dip ECVPT J.Fink@uu.nl
Antibiotics secondary metabolites produced under conditions of stress Fungi imperfecti (Penicillium Fusarium) Streptomyces Actinomyces spp Myxobacteria: Soragium cellulosum
AMR part of the natural homeostasis Co-evolution of bacteria and antimicrobial resistance Fungi: natural antibiotics Bacteria: adaptive AMR
2012
Bacterial communication systems biofilms and more!
Outside a laboratory in the real world Biofilms are prefect niches to survive!.. and to exchange resistance genes
Biofilms: in modern animal facilities Sub-MIC concentrations of antibiotics/disinfectants stimulate biofilm formation (also in slaughter houses) Oral medication via Drinking water: Biofilms and horizontal transmission of resistant organisms within a herd
Biofilms in daily veterinary practice Biofilms In the animal units Drinking water medication as a risk factor? Chronic respiratory tract infections APP Pasteurella Mycoplasma
Almost all pathogens are able to form biofilms
S. aureaus (MSSA, MRSA) S. pseudo-epidermidis (MSSP, MRSP) (dematitis, otitis (dog, cats) E.coli (UTI) Pseudomonas spp Campylobacter spp. Mycoplasma spp. Haemophilus parasuis Actinobacillus pleuropneumonia e.a. Biofilm characteristics - significant shift in antimicrobial sensitivity (MIC versus BMIC)
Staphylococcus aureus Mastitis N305 412 20 256 15 Penicillin 128 10 64 16 5 1 0 MIC BMIC MBEC 1d MBEC 2d MBEC 4d Melchior & Fink-Gremmels, 2008)
Wu et al., 2015
gwe gee allicin
TCM/CHM & Biofilm: Thesis X. Wu, 2015
Clinical relevance Biofilms determine of antimicrobial susceptibility Therapy-resistance; transfer of resistance genes Biofilms are not detected by common culture methods misleading therapeutic outcome monitoring? Biofilms are not detected by the immune system development of chronic recurrent infections
Clinically important biofilm sites in veterinary target species Wu et al., 2015
Biofilms: take-home messages I A biofilm is the most convenient form of life for bacteria Biofilms modulate the susceptibility of bacteria to (all) antimicrobial agents due to the Barrier effect of the extracellular matrix Gene shift in the dormant stage and virtually no proliferation Rapid transfer of genes within a biofilm community
Recent developments: Biofilm genes: an opportunity to modulate virulence? Plant-derived QS inhibitors may prevent biofilm formation and restore/improve the efficiency of antibiotics
Plant metabolites the natural QS inhibitors X. Wu et al, 2014 Yarwood J M et al. J. Bacteriol. 2004;186:1838-1850
Quorum sensing inhibitors: An emerging therapeutic target Planktonic cells Inhibition of major Autoinducers Gram + agr (RNAIII)- auto-inducing peptides (AIP) Proto type: TP-1 Hamamelitannin = inhibitor of MRSA & MRSP QS-inhibitors Gram Acyl-homoserine lactones (AHL) LuxR Proto type: SAM-analoga, Cranberry! ADHESION & Expression of virulence factors inhibited Interspecies communication: LuxS/AI-2 signaling Inter-kingdom signalling: AI-3/epinephrine/norepinephrine i.e. Salmonella, E. coli, Shigella a.o.
Understanding te interactions between host & microorganism microorganisms & microorganisms QS determines the life-style: planctonic or biofilm The expression of virulance factors Pathogenicity Bacterial quorum sensing senses host signals (stress)
Limitations of in vitro testing: Acquisition of resistance genes in a complex environment Hypothesis: Protozoa may promote horizontal gene transfer E. coli J 53 acceptor qnr positive E.coli and Klebsiella as donors Result: The ciliated protozoan promotes the transfer of plasmid-mediated quinolone resistance In bacteria (as well as ESBLCTX-M-27: Oguri et.al., 2011, JAC 2011:66: 527-30) Dietary factors modifying bacterial Gene expression: Plant metabolites (inhibitory) Cd, Zinc = stimulating?, Emerging infectious diseases, Marc, 2015
Collateral effects? 100 000 000 000 bacteriën, > 30 000 species 50 km schimmeldraden, > 500 species Planten groei planten ziekten 100 000 algen > 500 species 10 000 aaltjes > 50 species 5 000 anderen 1000 000 000 000 000 bacteria, > 500 species 10 x more than body cells Reservoir for resistant organisms/ resitance genes
??????? Question: Do we want to establish a biofilm working group: plant/extracts in the prevention of biofilm & as therapeutic support for biofilm infections.