Table 1.
Minimum inhibitory concentration (MIC) of hygromycin A and clinically relevant antibiotics against spirochaetes, human pathogens and commensals. MIC was determined by microdilution assay as described in material and methods. MIC of doxycycline and ceftriaxone against T. pallidum from (Edmondson et al., 2020; Norris et al., 2001).
| Concentration (μg/ml) | ||||
|---|---|---|---|---|
| Organism and genotype | Hygromycin A | Doxycycline | Amoxicillin | Ceftriaxone |
| Spirochaetes | ||||
| Treponema pallidum | 0.03 | 0.1d | N/A | 0.0007e |
| Borreliella burgdorferi P1286a | 0.12 | 0.25 | 0.12 | 0.01 |
| Borreliella afzelii a | 0.25 | 0.12 | 0.01 | <0.01 |
| Borreliella bavariensis a | 0.25 | 0.12 | 0.06 | 0.01 |
| Borreliella burgdorferi 297a | 0.25 | 0.25 | 0.25 | 0.01 |
| Borreliella burgdorferi B31a | 0.25 | 0.25 | 0.25 | 0.01 |
| Borreliella burgdorferi N40a | 0.25 | 0.25 | 0.12 | 0.01 |
| Borreliella garinii a | 0.25 | 0.12 | 0.12 | 0.01 |
| Borreliella miyamotoi a | 0.25 | 0.12 | 0.12 | 0.01 |
| Borrelia turcica DSM 16138a | 0.5 | 0.25 | 0.25 | 0.06 |
| Alkalispirochaeta americana DSM 14872b | 0.5 | N/A | N/A | N/A |
| Brevinema andersonii ATCC 43811a | 2 | 0.12 | 0.12 | 0.01 |
| Leptospira biflexa ATCC 23582 | 4 | 2 | 8 | 2 |
| Leptospira interrogans ATCC BAA-1198 | 4 | N/A | N/A | N/A |
| Opportunistic pathogens | ||||
| Fusobacterium nucleatum KLE 2428b,c | 1 | 0.12 | 2 | 0.5 |
| Clostridium tertium KLE 2303b,c | 8 | 0.03 | 32 | 1 |
| Clostridium perfringens KLE 2326b,c | 8 | 0.25 | 0.12 | <0.01 |
| Staphylococcus aureus HG003 | 8 | 0.12 | 1 | 8 |
| Escherichia coli W0153 | 16 | 0.12 | 4 | 0.01 |
| Staphylococcus epidermidis KLE 2378b,c | 32 | 0.5 | >128 | 1 |
| Shigella sonnei ATCC 25931b | 64 | 4 | 2 | 0.25 |
| Escherichia coli MG1655 | 128 | 2 | 16 | 0.06 |
| Pseudomonas aeruginosa PAO1 | >128 | 32 | >128 | 64 |
| Salmonella typhimurium LT2 ATCC 19585b | >128 | 8 | 16 | 0.25 |
| Gut commensal bacteria | ||||
| Streptococcus salivarius KLE 2370b,c | 2 | 0.12 | 0.06 | 0.03 |
| Streptococcus parasanguinis KLE 2375b,c | 4 | 4 | 64 | 0.06 |
| Bifidobacterium longum ATCC BAA-999b | 8 | 0.25 | 1 | 4 |
| Bacteroides nordii KLE 2369b,c | 8 | 0.25 | 32 | 1 |
| Bacteroides cellulosilyticus KLE 2342b,c | 8 | 2 | 128 | 128 |
| Streptococcus sanguinis KLE 2374b,c | 16 | 0.25 | 2 | 0.12 |
| Parabacteroides merdae KLE 2238b,c | 16 | 0.06 | 1 | 0.25 |
| Lactobacillus reuteri ATCC 23272b | 32 | 8 | 4 | 32 |
| Bacteroides fragilis ATCC 25285b | 32 | 0.5 | 16 | 2 |
| Blautia producta ATCC 27340b | 64 | 2 | 1 | 0.5 |
| Bacteroides ovatus KLE 2306b,c | 64 | 0.01 | 0.5 | 0.02 |
| Bacteroides vulgatus KLE 2381b,c | 64 | 1 | 128 | 128 |
| Bacteroides eggerthii KLE 2382b,c | 64 | 0.01 | 0.5 | N/A |
| Enterococcus faecalis KLE 2341b,c | >128 | 0.5 | 0.5 | >128 |
| Enterobacter cloacae ATCC 13047b | >128 | 8 | >128 | 64 |
| Bacteroides xylanisolvens KLE 2305b,c | >128 | 0.5 | 32 | 64 |
N/A, not available.
a
Cultivated under microaerophilic conditions
b
Cultivated under anaerobic conditions
c
Human stool isolate, KLE laboratory collection