Table 1. Summary of phenotypic differences of Bp MSHR5848 (BURK178) variants.
| Phenotype | Difference | Smootha | Roughb | |
|---|---|---|---|---|
| Morphologic | Gram stain | Yes | GNR | typical Bp |
| PI nucleic acid dye | Yes | positive | negative | |
| Colony morphology | Yes | raised, yellowish, shiny | flat, grey, dry | |
| BCSA Sugar utilization | Yes | alkaline | acid | |
| Biochemical | BiOLOG GENIII | Yesc | Bp (36 h) | 4 Burkholderia spp. (36 h) |
| BiOLOG GENIII | Yesc | B. thailandensis (48 h) | Bp (48 h) | |
| VITEK2™ | Noc | Bp | Bp | |
| SherlockMIDI | Noc | Bp | Bp | |
| Antimicrobial sensitivities | Yesd | variable | variable | |
| Phenotype Analyses | GENIII microarraye | Yes | 15/15 positive | 7/15 positive |
| PM metabolic activityf | Yes | more active (59 significant) | less active (47 significant) | |
| Molecular Analyses | DNA sequences | Yes | WGS difference (chrom 2)g | 3-base deletion |
| MLSTh | No | - | - | |
| Riboprinting | No | - | - | |
| Infection | Macrophage cytotoxicityi | Yes | 75% killing | 12.5% killing |
| Macrophage replicationi | Yes | ≥ fivefold greater uptake | reduced | |
| Mouse virulence (IP) | Yes | less virulent | more virulentj | |
| Other | LPS banding pattern | No | type A subtype 3 | Same |
| Persister phenotypek | No | positive | Same | |
aThe Smooth morphotype from the solid medium production stock of strain MSHR5848.
bPhenotypes of the Rough variant of the MSHR5848 solid medium production stock are similar to those of the liquid medium production stock of Rough.
cThe species identifications of the variants reported in the GENIII system differed at the 36 h and 48 h readings. VITEK2™ and SherlockMIDI identification systems reported no differences; all variants were B. pseudomallei.
dInter-experimental variation in sensitivities of the Smooth and Rough strains to selected chemicals and antibiotics in manual microtiter assays.
eBased on GENIII plates (94-phenotypes) incubated and analyzed on the Omnilog.™ Of the 15 carbon source substrates differing most consistently between the variants, 15 were strongly metabolized by Smooth and 7 were strongly metabolized by Rough.
fMetabolic activity of variants for 1,920 substrates or inhibitors (20 PM plates) measured during incubation in Biolog Phenotypic Microarray™.
gSequences from WGS libraries of variant Smooth and Rough colonies were obtained using the PacBio and Illumina MiSeq platforms. A 3-base sequence on chromosome 2 of Smooth was absent in Rough and may impact the downstream gene as described in the text.
hThe multilocus sequence type (MLST) was no. 553 for both variants; their Ribotyping Riboprinter™ rRNA patterns were conserved.
iSmooth variant was more cytotoxic than rough in terms of cell killing and MNGC production; and was phagocytosed to a fivefold greater extent and replicated significantly more as detailed in Fig 5 and Table 5.
jLD50 values (days 21 and 60) of MSHR5848 Rough were almost tenfold lower (and had higher dose-related lethality rates) than MSHR5848/Smooth. Fig 6 confirms the more rapid loss of survival of Rough.
kThis phenotype is based on an in vitro model for development of tolerance to high levels of ciprofloxacin. Both strains exhibited persister tolerance.