1. No category

Teixobactin Kills Pathogens
Without Detectable Resistance
Kim Lewis
Teixobactin Kills Pathogens
Without Detectable Resistance
Prof. Kim Lewis
Director, Antimicrobial Discovery Center
Department of Biology
College of Science
Northeastern University
Boston, USA
1
Quinolones
Year of Introduction
Glycopeptides
Ansamycins
Tetracyclines
Fidaxomycin
Macrolides
Lipopetides
Chloramphenicols
Oxazolidinones
Aminoglycosides
Streptogramins
β-lactams
Sulfadrugs
1920
1930
1940
1950
1960
1970
1980
1990
2000
2010
Ansamycins
β-lactams
Quinolones
Sulfadrugs
Streptogramins
Aminoglycosides
Lipopeptides
Tetracyclines
Chloramphenicols
Year of Discovery
Macrolides
Glycopeptides
Oxazolidinones
S. Waksman systematically screened soil bacteria
for their ability to inhibit growth of bacteria
2
K. Lewis. Nature Rev Drug Disc 12: 371-387 (2013)
The high-tech platform
Genomics
Proteomics
Target
hit
Closing of anti infectives
divisions in the big Pharma
HTP screening
Payne et al., Nature Rev.
Drug Disc., 6: 29-40 (2007)
Combinatorial
Chemistry
Rational design
Synthetic Compounds:
Running into a barrier
Molecules recognition based on polarity
Lomovskaya, O., and Lewis, K. (1992) Proc. Natl. Acad. Sci. USA 89: 8938-8942
Zgurskaya and Nikaido (1999) Proc. Natl. Acad. Sci. USA 96: 7190-7195
3
The screen versions of these slides have full details of copyright and acknowledgements
1
Teixobactin Kills Pathogens
Without Detectable Resistance
Kim Lewis
Reviving the Waksman platform
4
K. Lewis. Nature 485: 439-440 (2012)
Uncultured bacteria
Environmental
sample
Dilute
Petri dish
Microscope
“The great plate count anomaly”
5
Winterberg H. (1898) Zur Methodik der Bakterienzahlung. Zeitschr f Hyg 29: 75–93
How to grow unculturables
Diffusion chambers
in soil
Dilute soil sample,
mix with agar
6
Kaeberlein et al., Science 296: 1127-1129
The screen versions of these slides have full details of copyright and acknowledgements
2
Teixobactin Kills Pathogens
Without Detectable Resistance
Kim Lewis
7
Efficiency of recovery in diffusion chamber
vs. Petri dish
60
Diffusion chambers 25-40%
Petri dishes 0.05%
Growth recovery, %
50
40
30
20
10
0
June
July
August
Months
8
Trap for capturing actinomycetes
Diffusion chamber
A.
9
B.
Trap
C.
D.
Gavrish et al., 2008. J. Microbiol. Methods. 72: 257-262
The screen versions of these slides have full details of copyright and acknowledgements
3
Teixobactin Kills Pathogens
Without Detectable Resistance
Kim Lewis
iChip
10
Nichols et al., Appl. Environ. Microbiol. 76: 2445-2450 (2010)
11
Efficiency of recovery in iChip vs. Petri dish
Seawater
Soil
12
The screen versions of these slides have full details of copyright and acknowledgements
4
Teixobactin Kills Pathogens
Without Detectable Resistance
Kim Lewis
iChip
13
Epstein et al., AEM 2010
From sand to mechanism
14
The sand biofilm
15
The screen versions of these slides have full details of copyright and acknowledgements
5
Teixobactin Kills Pathogens
Without Detectable Resistance
Kim Lewis
16
The basic mechanism of uncultivability
Maribacter polysiphoniae sp.
M. luteus sp.
99.8% identity by 16S rRNA gene
17
D’Onofrio et al., 2010. Chem. & Biol. 17: 254–264
The basic mechanism of uncultivability:
growth factors from neighboring species
18
The screen versions of these slides have full details of copyright and acknowledgements
6
Teixobactin Kills Pathogens
Without Detectable Resistance
Kim Lewis
19
Siderophore specificity in growth induction
Growth induction
No growth induction
Strains in Bold are Bacteroidetes
20
Fe(III)
Fe(III)
Fe(II)
ē
ē
Culturable helper
Fe(II)
Uncultured
21
The screen versions of these slides have full details of copyright and acknowledgements
7
Teixobactin Kills Pathogens
Without Detectable Resistance
Kim Lewis
Domestication of uncultured producers
Novo 25
Kaeberlein et al., 2002, Science 296: 1127-1129
Bollmann et al., 2007, Appl. Environ. Microbiol. 73: 6386-6390
22
Domestication of unculturables
23
Bollmann et al., 2007, Appl. Environ. Microbiol. 73: 6386-6390
A low-resistance antibiotic
A Genes
txo1
Domains
txo2
A MT T C A T C A T C A T C A T C A T C A T C A T C A T C A T C A T C TE TE
Amino acids
NmPhe Ile
B
NmPhe
Ser
Ile
Ser
Gln
Gln
Ile
Ile
Ile
Ile
Ser
Ser
Thr
Thr
Ala
Ala
End
End
Ile
Ile
C
Teixobactin
Eleftheria terrae
24
Ling et al., Nature 2015
The screen versions of these slides have full details of copyright and acknowledgements
8
Teixobactin Kills Pathogens
Without Detectable Resistance
Kim Lewis
25
26
Teixobactin spectrum
(MIC, µg ml-1)
Organism
Low frequency
of resistance –
compound hits
a particular target
27
Teixobactin
S. aureus (MSSA)
S. aureus +10% serum
S. aureus (MRSA)
Enterococcus faecalis (VRE)
Enterococcus faecium (VRE)
Streptococcus pneumonia
0.25
0.25
0.25
0.5
0.5
<0.03
Streptococcus pyogenes
Streptococcus agalactiae
Viridans Group Streptococci
B. anthracis
Clostridium difficile
Propionibacterium acnes
M. tuberculosis H37Rv
Haemophilus influenzae
Moraxella catarrhalis
Escherichia coli
Escherichia coli (asmB1)
Pseudomonas aeruginosa
Kebsiella pneumoniae
0.06
0.12
0.12
≤0.06
0.005
0.08
0.125
4
2
25
2.5
>32
>32
IC50 >100 µg/ml
The screen versions of these slides have full details of copyright and acknowledgements
9
Teixobactin Kills Pathogens
Without Detectable Resistance
Kim Lewis
Teixobactin resistance development
256
Teixobactin
Ofloxacin
128
Fold-change in MIC
64
32
16
8
4
2
1
0.5
0
5
10
15
20
25
30
Time [days]
28
Specificity of action
120
Erythromycin
80
20
DNA
RNA
Vancomycin
40
Rifampicin
60
Ciprofloxacin
% Incorporation
100
Teixobactin
Control antibiotic
0
Peptidogl.
Protein
29
Finding the targets
Growth inhibition antagonism by Lipid II
Teixobactin
Vancomycin
(-)
(-)
Teixobactin
Vancomycin
+ Lipid II
+ Lipid II
(+)
(+)
Lipid II
Lipid II
(D-Lac)
Lipid-III
Molar ratio
TEIX:lipid
0:1
1:1
2:1
30
The screen versions of these slides have full details of copyright and acknowledgements
10
Teixobactin Kills Pathogens
Without Detectable Resistance
Kim Lewis
Teixobactin: mechanism of action
T
CM
CW
OM
vancomycin
T
WTA
PG
CW
CM
• Binds targets outside the cytoplasmic membrane
• There are two targets, neither is a protein and the moiety is highly conserved
• The producing organism doesn’t have any specific mechanism of resistance to teixobactin
31
Killing of S. aureus by teixobactin
6
8
Teixobactin
4
Log(cfu/ml)
Vancomycin
5
Log(cfu/ml)
9
Oxacillin
7
6
5
4
3
3
2
2
0
4
8
12
16
Time [h]
Control
20
24
0
4
8
12
16
Time [h]
20
24
Oxacillin Vancomycin Teixobactin
32
33
The screen versions of these slides have full details of copyright and acknowledgements
11
Teixobactin Kills Pathogens
Without Detectable Resistance
Kim Lewis
34
The screen versions of these slides have full details of copyright and acknowledgements
12