Article Figures & Data
Figures
- FIG 1
β-Lactamase activity in F. philomiragia and H. influenzae. Enzymatic units of β-lactamase activity were measured for clinical isolates 14IUHPL0001 and IUH9 and type strains FSC144 and 8143 cultivated in either ambient air (black bars) or 5% CO2 (gray bars). Enzymatic units were normalized to milligrams of total bacterial protein. (A) Both F. philomiragia strains produced significantly (*, P < 0.05; ****, P < 0.0001) higher levels of β-lactamase in 5% CO2 relative to ambient air, and strain 14IUHPL0001 produced significantly more β-lactamase in 5% CO2 relative to FSC144T. (B) Strain IUH9 produced significantly higher levels of β-lactamase in 5% CO2 relative to growth in ambient air and strain 8143T grown in either 5% CO2 or ambient air. There was no significant difference in activities when strain 8143T was grown in 5% CO2 or ambient air.
- FIG 2
Interrogation of F. philomiragia and H. influenzae for TEM and SHV family β-lactamase genes. blaTEM-specific primers yielded PCR amplicons from both F. philomiragia 14IUHPL0001 and FSC144T, but not from H. influenzae IUH9 or 8143T (top panel). blaSHV-specific primers yielded PCR amplicons from clinical isolates F. philomiragia 14IUHPL0001 and H. influenzae IUH9 but not from either type strain (bottom panel). Negative controls (−) for all reactions were template-free reaction mixtures containing all reagents.
- FIG 3
Phylogenetic analysis of blaTEM. Phylogenetic analysis performed on the translation of the sequenced amplicon indicated that the 14IUHPL0001 and type strain FSC144T allele clusters with the TEM family β-lactamases. The endogenous chromosomal β-lactamase gene from the type strain FSC144T served as the outgroup.
- FIG 4
Cultivation of F. philomiragia in 5% CO2 or ambient air generates an alkaline pH shift. Both 14IUHPL0001 and FSC144T significantly shifted the growth medium pH higher in either ambient air (circles) or 5% CO2 (squares) relative to incubated, uninoculated medium.
Tables
- TABLE 1
Antimicrobial susceptibility of Francisella philomiragia under different atmospheric conditions
Antimicrobial agent(s) MIC (μg/ml) for: 14IUHPL001 FSC144T Ambient air CO2 Ambient air CO2 Amikacin ≤0.5 ≤0.5 ≤0.5 ≤0.5 Amoxicillin-clavulanic acid 1 16 1 4 Ampicillin 32 >32 32 >32 Aztreonam 4 32 2 8 Cefepime 4 32 1 8 Ceftazidime ≤0.5 ≤0.5 ≤0.5 ≤0.5 Ceftriaxone ≤0.5 ≤0.5 ≤0.5 ≤0.5 Cefazolin 2 >32 16 >32 Ciprofloxacin ≤0.25 ≤0.25 ≤0.25 ≤0.25 Colistin >8 >8 >8 >8 Doripenem ≤0.25 1 ≤0.25 0.50 Doxycycline ≤1 ≤1 ≤1 ≤1 Ertapenem ≤0.25 1 ≤0.25 ≤0.25 Gentamicin ≤0.5 ≤0.5 ≤0.5 ≤0.5 Imipenem ≤0.25 0.50 ≤0.25 ≤0.25 Levofloxacin ≤2 ≤2 ≤2 ≤2 Meropenem ≤0.25 0.5 ≤0.25 ≤0.25 Moxifloxacin ≤0.25 ≤0.25 ≤0.25 ≤0.25 Oxacillin ≤0.25 >16 >16 >16 Polymyxin B >4 >4 >4 >4 Ticarcillin-clavulanic acid ≤4 ≤4 ≤4 ≤4 Tigecycline ≤0.25 ≤0.25 ≤0.25 ≤0.25 Tobramycin ≤0.5 ≤0.5 ≤0.5 ≤0.5 Trimethoprim-sulfamethoxazole >4 >4 >4 >4 - TABLE 2
Expression of blaTEM and blaSHV under different atmospheric conditions
Gene and condition Expression of gene under condition showna F. philomiragia H. influenzae 14IUHPL0001 FSC144T IUH9 8143T 5% CO2 bla TEM + + − − bla SHV + − + − Ambient air bla TEM − − − − bla SHV − − − − ↵a The symbols “+” and “−” indicate the presence or absence, respectively, of RNA/cDNA amplification by reverse transcription-PCR.
