aeruginosa, isogenic ampG and ampP insertional inactivation Verubecestat price mutants were constructed in the prototypic P. aeruginosa strain PAO1, referred to as PAOampG {Selleck Anti-infection Compound Library|Selleck Antiinfection Compound Library|Selleck Anti-infection Compound Library|Selleck Antiinfection Compound Library|Selleckchem Anti-infection Compound Library|Selleckchem Antiinfection Compound Library|Selleckchem Anti-infection Compound Library|Selleckchem Antiinfection Compound Library|Anti-infection Compound Library|Antiinfection Compound Library|Anti-infection Compound Library|Antiinfection Compound Library|Anti-infection Compound Library|Antiinfection Compound Library|Anti-infection Compound Library|Antiinfection Compound Library|Anti-infection Compound Library|Antiinfection Compound Library|Anti-infection Compound Library|Antiinfection Compound Library|Anti-infection Compound Library|Antiinfection Compound Library|Anti-infection Compound Library|Antiinfection Compound Library|Anti-infection Compound Library|Antiinfection Compound Library|buy Anti-infection Compound Library|Anti-infection Compound Library ic50|Anti-infection Compound Library price|Anti-infection Compound Library cost|Anti-infection Compound Library solubility dmso|Anti-infection Compound Library purchase|Anti-infection Compound Library manufacturer|Anti-infection Compound Library research buy|Anti-infection Compound Library order|Anti-infection Compound Library mouse|Anti-infection Compound Library chemical structure|Anti-infection Compound Library mw|Anti-infection Compound Library molecular weight|Anti-infection Compound Library datasheet|Anti-infection Compound Library supplier|Anti-infection Compound Library in vitro|Anti-infection Compound Library cell line|Anti-infection Compound Library concentration|Anti-infection Compound Library nmr|Anti-infection Compound Library in vivo|Anti-infection Compound Library clinical trial|Anti-infection Compound Library cell assay|Anti-infection Compound Library screening|Anti-infection Compound Library high throughput|buy Antiinfection Compound Library|Antiinfection Compound Library ic50|Antiinfection Compound Library price|Antiinfection Compound Library cost|Antiinfection Compound Library solubility dmso|Antiinfection Compound Library purchase|Antiinfection Compound Library manufacturer|Antiinfection Compound Library research buy|Antiinfection Compound Library order|Antiinfection Compound Library chemical structure|Antiinfection Compound Library datasheet|Antiinfection Compound Library supplier|Antiinfection Compound Library in vitro|Antiinfection Compound Library cell line|Antiinfection Compound Library concentration|Antiinfection Compound Library clinical trial|Antiinfection Compound Library cell assay|Antiinfection Compound Library screening|Antiinfection Compound Library high throughput|Anti-infection Compound high throughput screening| and PAOampP, respectively. The β-lactamase activity in the two isogenic mutants, PAOampG and PAOampP, was

compared to PAO1. In the absence of β-lactam antibiotics, all strains showed a basal level of β-lactamase activity (Table 1). Upon challenge with 500 μg/ml of benzyl-penicillin, this level was elevated 10-fold (p < 0.05) in PAO1 (Table 1). However, the β-lactamase activities of PAOampP and PAOampG remained low in the presence of β-lactam antibiotic, indicating a loss of β-lactamase induction (Table 1). The loss of inducibility in PAOampG could be partially restored by expressing ampG in trans, whereas the β-lactamase inducibility of PAOampP was completely recovered when ampP was supplied in trans (Table 1). Both PAOampP and PAOampG mutants had the other copy selleck chemical of the permease gene intact. These observations suggest that ampG and ampP are individually important members of the β-lactamase induction system.

To confirm that ampG and ampP play independent roles, cross-complementation of PAOampP with pAmpG, and PAOampG with pAmpP was performed. Similar to the mutants, the cross-complemented strains did not show inducible β-lactamase activity (Table 1). Table 1 β-lactamase activity of P. aeruginosa PAO1, PAOampG and PAOampP in the absence Oxymatrine and presence of β-lactam Strain and plasmid Relevant genotypes (supplement in trans) β-lactamase activitya     Uninduced Induced b PAO1 ampG + ampP + 22.2 ± 9.7 221.4c ± 9.2 PAOampG ampG – ampP + 20.4 ± 6.2 28.8d ± 3.3 PAOampP ampG + ampP – 4.2 ± 6.2 32.2d ± 3.3 PAOampG/pKKF69 ampG – ampP + (ampG + ) 8.4 ± 1.4 87.6 ± 14.4 PAOampP/pKKF73 ampG + ampP – (ampP + ) 8.8 ± 1.8 217.9 ± 35.5 PAOampG/pKKF73 ampG – ampP + (ampP + ) 2.1 ± 2.0 14.4 ± 1.9

PAOampP/pKKF69 ampG + ampP – (ampG + ) 5.3 ± 1.9 10.6 ± 2.7 a Cultures at OD600 of 0.6-0.8 were divided in two. One set was induced with 500 μg/ml benzyl-penicillin for three hours before harvesting. Assays were performed on sonicated lysate using nitrocefin as a chromogenic substrate. One milliunit of β-lactamase is defined as 1 nanomole of nitrocefin hydrolyzed per minute per microgram of protein. Assays were performed in triplicate. b Induction was carried out using 500 μg/ml benzyl-penicillin c p < 0.05 compared to uninduced PAO1 d p < 0.05 compared to induced PAO1 To further understand the role of ampG and ampP in β-lactamase induction, β-lactamase activity was assayed at different concentrations of benzyl-penicillin in PAO1, PAOampG and PAOampP (Figure 5). Upon encounter with the inducer (25 μg/ml), there was approximately 38% induction (Figure 5). For strain PAO1, this increase in β-lactamase activity continued in a dose-dependent manner until the maximum level of β-lactamase activity was reached when 100 μg/ml of benzyl-penicillin was added (Figure 5).