Results section “Adaptation to changes in stimulus variance… The rate-level curves associated with higher stimulus variances tended to have shallower Selleck Veliparib slopes or saturated at lower spike rates…. … If the neurons responded to the increase in variance with a pure scaling of their rate response functions then we would expect the slopes

and the firing rates at the 50% points to decrease, and we would not expect the abscissa of the 50% to change…… The firing rates at the 50% points (and therefore the maximum firing rates) were always greatest for the stimuli with the lowest variance (the black diamonds in figure 6D are always below their corresponding green squares and red circles). But the 50% points for higher variance stimuli occurred typically at higher stimulus amplitudes (the black diamonds in figure 6D are usually to the right of their corresponding green squares and red learn more circles). This was due, not to the whole rate level curve shifting as we had seen when the HPRs were shifted, but instead because the rate level curves obtained with the higher variance stimuli often leveled off later than those obtained with lower variance stimuli, as can be seen in the examples shown in Fig.

6B and supplementary figure 2 C and D. Increasing stimulus variance did not appear to produce threshold shifts. We mentioned earlier that the slope of rate-level function can be considered as a measure of ‘neuronal response gain’. Maravall and colleagues (2007) concluded from their results that gain scales with stimulus variance. Expressed mathematically, this means that the gain (or slope) g observed at given stimulus variance v should be proportional to v, i.e. (5) Consequently, if we assume that gain scales inversely with variance (a < 1 and log(a) is negative), then we expect a scatter plot of the log of unit gain against the log of stimulus variance should fall along a line of slope -1, offset by the log of the Alanine-glyoxylate transaminase unit’s gain factor a…… The distribution peaks at minus one,

as one might expect if gain does indeed scale inversely with variance. “
“Early-life stress induces several neuropsychological disorders in adulthood, including depression. Such disorders may be induced by functional alteration of the glutamatergic system. However, their underlying mechanisms have not yet been fully clarified. Furthermore, the involvement of glucocorticoids, which are representative stress hormones, has not yet been fully clarified. In this study, we used maternal deprivation (MD) mice as an early-life-stress model, and studied the changes in the glutamatergic system in adulthood. The glutamate concentration and neuronal activity in the somatosensory cortex (SSC) increased under basal conditions in MD mice. Stressful physical stimulation (SPS) increased the concentration of corticosterone, but not of glutamate, in the control mouse SSC.

Results section “Adaptation to changes in stimulus variance… The rate-level curves associated with higher stimulus variances tended to have shallower ACP-196 research buy slopes or saturated at lower spike rates…. … If the neurons responded to the increase in variance with a pure scaling of their rate response functions then we would expect the slopes

and the firing rates at the 50% points to decrease, and we would not expect the abscissa of the 50% to change…… The firing rates at the 50% points (and therefore the maximum firing rates) were always greatest for the stimuli with the lowest variance (the black diamonds in figure 6D are always below their corresponding green squares and red circles). But the 50% points for higher variance stimuli occurred typically at higher stimulus amplitudes (the black diamonds in figure 6D are usually to the right of their corresponding green squares and red Proteasome inhibitor circles). This was due, not to the whole rate level curve shifting as we had seen when the HPRs were shifted, but instead because the rate level curves obtained with the higher variance stimuli often leveled off later than those obtained with lower variance stimuli, as can be seen in the examples shown in Fig.

6B and supplementary figure 2 C and D. Increasing stimulus variance did not appear to produce threshold shifts. We mentioned earlier that the slope of rate-level function can be considered as a measure of ‘neuronal response gain’. Maravall and colleagues (2007) concluded from their results that gain scales with stimulus variance. Expressed mathematically, this means that the gain (or slope) g observed at given stimulus variance v should be proportional to v, i.e. (5) Consequently, if we assume that gain scales inversely with variance (a < 1 and log(a) is negative), then we expect a scatter plot of the log of unit gain against the log of stimulus variance should fall along a line of slope -1, offset by the log of the Paclitaxel concentration unit’s gain factor a…… The distribution peaks at minus one,

as one might expect if gain does indeed scale inversely with variance. “
“Early-life stress induces several neuropsychological disorders in adulthood, including depression. Such disorders may be induced by functional alteration of the glutamatergic system. However, their underlying mechanisms have not yet been fully clarified. Furthermore, the involvement of glucocorticoids, which are representative stress hormones, has not yet been fully clarified. In this study, we used maternal deprivation (MD) mice as an early-life-stress model, and studied the changes in the glutamatergic system in adulthood. The glutamate concentration and neuronal activity in the somatosensory cortex (SSC) increased under basal conditions in MD mice. Stressful physical stimulation (SPS) increased the concentration of corticosterone, but not of glutamate, in the control mouse SSC.

There was a 96% reduction in HIV transmission risk demonstrated in the HPTN 052 study, which can be considered as ‘extremely low risk’. Within the study partnerships, there was only one genotypically confirmed HIV transmission from an HIV-infected participant on Abiraterone mouse ART. In this case, an individual randomized

to immediate ART had not yet achieved an undetectable viral load at the time of viral transmission. The BHIVA and EAGA statement requires evidence of confirmed HIV viral load < 50 copies/mL for 6 months, which would exclude a comparable risk to that observed in the trial, hence justifying the ‘extremely low’ statement; although this does not mean zero risk. The nature of sexual exposure does influence the actual risk of acquisition/transmission. The actual relative

risk for each individual sex act is not certain, as multiple factors are at play [3-5]. Biologically, the integrity of the exposed mucosal surface is important as well as the presence of concomitant mucosal infections. The latter influence membrane integrity, attract inflammatory Selleckchem STI571 target cells and affect HIV shedding by the genital tract. Estimates of risk of HIV acquisition per coital act are largely influenced by log10 viral load of the HIV-infected partner; whilst the majority of these data are from African heterosexual couples reporting vaginal sex [3, 4, 6], the assumption from these trials is that the majority of sex acts were vaginal sex. The concept that the HIV-positive partner’s viral load is the key determinant of risk of transmission is pertinent for all sex

acts, although the absolute risk is affected by the nature of exposure. NADPH-cytochrome-c2 reductase Because the risk of transmission through anal sex is higher than that through vaginal sex [7], and because of the lack of high-grade evidence that ART prevents viral transmission through this route, it is not possible at this time to confirm the same level of protection by ART as for vaginal sexual exposure. The data overall show that, for each log10 increase in plasma HIV-1 RNA, the per-act risk of transmission increased 2.9-fold [95% confidence interval (CI) 2.2–3.8] [5, 6]. Whilst HIV viral load is the most significant contributor to risk of onward viral transmission, there is an order of magnitude difference in risk of transmission between insertive and receptive anal sex, with transmission by receptive anal sex around 10-fold more likely than transmission by insertive sex [5-7]. Insertive anal sex carries a similar level of risk to insertive or receptive vaginal sex (estimated at 5–6/10 000 exposures), whilst receptive anal sex carries an estimated 10-fold higher risk of viral transmission (estimated at 50/10 000 exposures) [5-8]. UK data from Fisher et al. [8] correlated the risk of onward transmission via anal sex to viral load, recent HIV infection and recent STI (rate ratio 5.32; 95% CI 2.51–11.29).

There was a 96% reduction in HIV transmission risk demonstrated in the HPTN 052 study, which can be considered as ‘extremely low risk’. Within the study partnerships, there was only one genotypically confirmed HIV transmission from an HIV-infected participant on high throughput screening compounds ART. In this case, an individual randomized

to immediate ART had not yet achieved an undetectable viral load at the time of viral transmission. The BHIVA and EAGA statement requires evidence of confirmed HIV viral load < 50 copies/mL for 6 months, which would exclude a comparable risk to that observed in the trial, hence justifying the ‘extremely low’ statement; although this does not mean zero risk. The nature of sexual exposure does influence the actual risk of acquisition/transmission. The actual relative

risk for each individual sex act is not certain, as multiple factors are at play [3-5]. Biologically, the integrity of the exposed mucosal surface is important as well as the presence of concomitant mucosal infections. The latter influence membrane integrity, attract inflammatory PD0325901 cell line target cells and affect HIV shedding by the genital tract. Estimates of risk of HIV acquisition per coital act are largely influenced by log10 viral load of the HIV-infected partner; whilst the majority of these data are from African heterosexual couples reporting vaginal sex [3, 4, 6], the assumption from these trials is that the majority of sex acts were vaginal sex. The concept that the HIV-positive partner’s viral load is the key determinant of risk of transmission is pertinent for all sex

acts, although the absolute risk is affected by the nature of exposure. Sucrase Because the risk of transmission through anal sex is higher than that through vaginal sex [7], and because of the lack of high-grade evidence that ART prevents viral transmission through this route, it is not possible at this time to confirm the same level of protection by ART as for vaginal sexual exposure. The data overall show that, for each log10 increase in plasma HIV-1 RNA, the per-act risk of transmission increased 2.9-fold [95% confidence interval (CI) 2.2–3.8] [5, 6]. Whilst HIV viral load is the most significant contributor to risk of onward viral transmission, there is an order of magnitude difference in risk of transmission between insertive and receptive anal sex, with transmission by receptive anal sex around 10-fold more likely than transmission by insertive sex [5-7]. Insertive anal sex carries a similar level of risk to insertive or receptive vaginal sex (estimated at 5–6/10 000 exposures), whilst receptive anal sex carries an estimated 10-fold higher risk of viral transmission (estimated at 50/10 000 exposures) [5-8]. UK data from Fisher et al. [8] correlated the risk of onward transmission via anal sex to viral load, recent HIV infection and recent STI (rate ratio 5.32; 95% CI 2.51–11.29).

The expression from all promoter mutants in the rpoS background was barely detectable

(results not shown), indicating that the expression from the mutant promoters was still dependent on the RpoS sigma factor. Previous observations in our this website laboratory have shown that the addition of phenylacetate or benzoate to the culture medium increased the expression from the cfaB promoter without an augmentation in the relative amount of CFAs in the membranes of P. putida DOT-T1E (Pini et al., 2009). Under these conditions, the levels of trans-UFAs showed a significant increase (with a concomitant reduction in the amount of cis-UFAs). These facts led us to hypothesize that one plausible explanation was competition for the substrate by the two stress-related

enzymes in Pseudomonas: the selleck kinase inhibitor CTI and the CFA synthase (Fig. 1). To explore this possibility, we first analyzed the expression of the cfaB and cti genes in P. putida KT2440 using cti and cfaB promoter fusions to ‘lacZ (Bernal et al., 2007; this work) and measured β-galactosidase activity when phenylacetate was added to cells that had reached the early stationary phase of growth (OD660 nm≈2). Both promoters increased their expression by threefold in the presence of this aromatic acid (from 661 ± 53 Miller units to 1444 ± 134 for the cfaB promoter and from 487 ± 39 to 1664 ± 52 for the cti promoter). However, we found that, under these conditions, in P. putida KT2440 there was a clear increase in the amount of trans-UFAs levels without an increase in the CFA content (Table 1). Because not all the cis-UFAs were converted to the trans-isomers (Table Branched chain aminotransferase 1), we suggest that in P. putida KT2440, the amount of cis-UFAs is not a limiting factor for the CTI or the CFA synthase. We then reasoned that what may limit the activity of the enzymes was not the total amount of cis-UFAs, but the amount of accessible cis-double bonds in the membranes, a hypothesis that is in agreement with the proposal that accessibility of the CTI and CFA synthase to substrate is the key step

in the action of these enzymes (Taylor & Cronan, 1979; Heipieper et al., 2001). To explore the possibility of competition for a substrate between the two enzymes, the wild-type strain, a P. putida KT2440 cti∷Km mutant (Duque et al., 2009) and a P. putida KT2440 cfaB : ΩKm mutant (Muñoz-Rojas et al., 2006) were used to study the membrane lipid composition at the mid-stationary growth phase in the presence or absence of phenylacetate or toluene. The levels of CFAs in the membrane of the cti mutant were not significantly different from those of the wild type, despite the absence of trans-UFAs. Also, the relative amounts of trans-UFAs in response to stress in the cfaB mutant were similar to those in the wild type (Table 2), despite the higher availability of substrate (cis-UFAs). These results indicated that although both the cfaB and the cti genes are expressed in the stationary phase of growth (Fig.

The expression from all promoter mutants in the rpoS background was barely detectable

(results not shown), indicating that the expression from the mutant promoters was still dependent on the RpoS sigma factor. Previous observations in our Selleck SB203580 laboratory have shown that the addition of phenylacetate or benzoate to the culture medium increased the expression from the cfaB promoter without an augmentation in the relative amount of CFAs in the membranes of P. putida DOT-T1E (Pini et al., 2009). Under these conditions, the levels of trans-UFAs showed a significant increase (with a concomitant reduction in the amount of cis-UFAs). These facts led us to hypothesize that one plausible explanation was competition for the substrate by the two stress-related

enzymes in Pseudomonas: the selleck chemicals llc CTI and the CFA synthase (Fig. 1). To explore this possibility, we first analyzed the expression of the cfaB and cti genes in P. putida KT2440 using cti and cfaB promoter fusions to ‘lacZ (Bernal et al., 2007; this work) and measured β-galactosidase activity when phenylacetate was added to cells that had reached the early stationary phase of growth (OD660 nm≈2). Both promoters increased their expression by threefold in the presence of this aromatic acid (from 661 ± 53 Miller units to 1444 ± 134 for the cfaB promoter and from 487 ± 39 to 1664 ± 52 for the cti promoter). However, we found that, under these conditions, in P. putida KT2440 there was a clear increase in the amount of trans-UFAs levels without an increase in the CFA content (Table 1). Because not all the cis-UFAs were converted to the trans-isomers (Table Methane monooxygenase 1), we suggest that in P. putida KT2440, the amount of cis-UFAs is not a limiting factor for the CTI or the CFA synthase. We then reasoned that what may limit the activity of the enzymes was not the total amount of cis-UFAs, but the amount of accessible cis-double bonds in the membranes, a hypothesis that is in agreement with the proposal that accessibility of the CTI and CFA synthase to substrate is the key step

in the action of these enzymes (Taylor & Cronan, 1979; Heipieper et al., 2001). To explore the possibility of competition for a substrate between the two enzymes, the wild-type strain, a P. putida KT2440 cti∷Km mutant (Duque et al., 2009) and a P. putida KT2440 cfaB : ΩKm mutant (Muñoz-Rojas et al., 2006) were used to study the membrane lipid composition at the mid-stationary growth phase in the presence or absence of phenylacetate or toluene. The levels of CFAs in the membrane of the cti mutant were not significantly different from those of the wild type, despite the absence of trans-UFAs. Also, the relative amounts of trans-UFAs in response to stress in the cfaB mutant were similar to those in the wild type (Table 2), despite the higher availability of substrate (cis-UFAs). These results indicated that although both the cfaB and the cti genes are expressed in the stationary phase of growth (Fig.

1a) and Southern blotting (not shown). Sequence analysis of five of these argR− mutants showed a five amino acid insertion (GVPLL) between the 149th click here and the 150th residue of ArgR (Fig. 4). These mutations all mapped to the terminal α-6 helix of the protein, which we named ArgR5aa. An ArgR derivative

truncated at position 150 was constructed by site-directed mutagenesis. This truncated protein, called ArgR149, was tested for the ability to resolve pCS210 in the argR− strain (DS956/pCS210). ArgR149 displayed the same properties as ArgR5aa, the protein containing the GVPLL insertion between the 149th and the 150th residue, namely a significant reduction in cer site-specific recombination in vivo (Fig. 1b) and the ability to repress an argA∷lacZ fusion in vivo. In order to quantify the levels of repression of the argA∷lacZ fusion in EC146(λAZ-7) with both wild-type and mutant ArgRs, β-galactosidase assays were performed. EC146(λAZ-7) does not produce a functional ArgR, and as a result, expresses β-galactosidase constitutively from the argA∷lacZ promoter fusion (128.15 Miller units). In the presence of a wild-type argR gene (present in a pUC19 plasmid), the levels of this enzyme were

reduced 25-fold (3.5 Miller units). A cloned ArgR mutant containing the C-terminal pentapeptide insertion (ArgR5aa) repressed the fusion sevenfold (19 Miller units), and the clone containing the truncated ArgR (ArgR149) repressed 33-fold (5.4 Miller Units) (Fig. 2). The variant ArgR proteins (ArgR5aa and Selleckchem PCI32765 ArgR149) were then analysed for specific binding to ARG box sites using gel-mobility shift assays. The mutant proteins all retarded the migration of a digoxygenin-labelled E. coli ARG box (Fig. 3). Lanes 2–6 and 9–13 show the effect of the increasing

3-mercaptopyruvate sulfurtransferase concentrations of mutant proteins on their binding activity in the presence of a constant quantity of poly-dIdC and digoxygenin-labelled DNA. A retarded complex was observed at low protein concentrations, which became more apparent as the protein concentration increased. The retarded complexes obtained with the mutant proteins displayed a slightly slower migration than that observed with wild-type ArgR–DNA complexes (Fig. 3, lanes 7 and 14). A labelled nonspecific DNA fragment was not retarded in its migration in the presence of wild-type or mutant ArgR proteins (data not shown). The wild-type and mutant forms of ArgR were then subjected to crosslinking analysis (Fig. 5) using glutaraldehyde. All forms of the protein were able to form higher-order multimeric complexes. Both wild-type ArgR and ArgR5aa form hexamers in the presence of 0.08% glutaraldehyde (Fig. 5, lanes 4 and 8).

Interestingly, both FpTK1 and PdTK1, although Gram-negative, grouped together

with the usual Gram-positive TK1-like dNKs, rather than with the previously characterized Gram-negative ones (Fig. 1). Surprisingly for Gram-negative bacteria, in F. psychrophilum JIP02/86, we identified also one non-TK1 dNK (FpdNK), and in Polaribacter sp. MED 152, we found two non-TK1 dNKs, one of them representing a hybrid between non-TK1 and a sequence encoding HPPK (PdHPPK + dNK) (Table S2). The HPPK, 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase, catalyzes the attachment of pyrophosphate to 6-hydroxymethyl-7,8-dihydropterin to form 6-hydroxymethyl-7,8-dihydropteridine selleck inhibitor pyrophosphate. This is the first step in the three-step pathway that leads to 7,8-dihydrofolate. Similar hybrid genes were also found in several other bacteria belonging to Bacteroidetes class (Fig. S1). All the identified

dNKs genes were successfully amplified from genomic DNA (Table S1) and subcloned into the pGEX-2T expression vector. In addition, in order to test the significance of the HPPK domain for the phosphorylating activity of the Polaribacter sp. MED 152 PdHPPK + dNK hybrid, also a recombinant dNK without the HPPK domain Antifection chemical was constructed (PdHPPKΔdNK) (Tables S1 and S2). Initially, the substrate specificity of recombinant dNKs was tested in transformed TK1-negative Escherichia coli KY895 crude extracts (Table S2). dNKs phosphorylating activities were tested with all native dNs substrates: dT, deoxyadenosine (dA), deoxyguanosine (dG), and deoxycytidine

(dC). All assays were performed at 37 °C, except for FpTK1 and PdTK1. For these two enzymes, it was determined that 21 °C was the optimal temperature Progesterone to measure their activity. In short, the subcloned TK1s and non-TK1s indeed represented active dNKs; however, the PdHPPK + dNK hybrid showed poor activity with dG, and the shortened recombinant enzyme PdHPPKΔdNK (without HPPK) also showed very low activity with dA, dC, and dG (Table S2). The hybrid proteins were not characterized further, and the function of the hybrid gene is so far unclear. All recombinant dNKs were expressed in E. coli BL21 and purified using affinity chromatography. The N-terminal GST fusion provided by the pGEX-2T vector was used as the affinity tag. Thrombin was used as a specific protease cleaving the GST tag from the kinase of interest, leaving only two extra amino acids (glycine and serine) at the N terminus. Afterward, pure recombinant protein was eluted from the GSH column. In the case of FpdNK and PddNK, we were not able to remove the GST tag from the dNK of interest; therefore, the whole GST fusion protein was eluted from the column and characterized. Purified dNKs were visualized by denaturing SDS-PAGE and Coomassie staining (Fig. 2). The size of the pure proteins was in reasonable agreement with theoretical molecular weights.

In order to measure the transcript levels of proteins identified in this study, seven genes out of 18 were selected for RT-PCR in the wild-type L. monocytogenes and ΔsigB mutant and the relative mRNA levels were measured. To quantify mRNA levels, the band density of each PCR product was measured after agarose gel electrophoresis. As shown in Fig. 2, the transcript levels are consistent with the proteomic data. Moreover, transcription of the identified genes, including gyrB, lmo1374, ftsA VX-809 purchase and lmo2779, are directly or indirectly under the control of σB. No RT-PCR products were observed in the negative

control (data not shown). Tyrosine Kinase Inhibitor Library manufacturer The role of the L. monocytogenesσB under stress conditions has been studied intensively, especially under osmotic, cold, acid, high hydrostatic pressure or oxidative stress (Cole et al.,

1990; Sleator et al., 2001; Wemekamp-Kamphuis et al., 2004). Recently, the relationship between alternative sigma factor and antimicrobial resistance has been reported in various bacteria. In B. subtilis, sigma factors σM, σW and σX contribute to resistance to various cell envelope-targeting antibiotics (Mascher et al., 2007). In addition, σB contributes to the upregulation of its own regulon upon exposure to bacitracin or vancomycin (Mascher et al., 2003). In L. monocytogenes, σB is important for growth and survival upon treatment with bacteriocin (lacticin 3147 and nisin) or antibiotics (penicillin G and ampicillin) (Begley et al., 2006). According to a recent report, both σB and σL contribute to tolerance selleck to the antimicrobial peptide SdpC and the bacteriocin nisin in L. monocytogenes (Palmer et al., 2009). Antibiotic-induced cell wall stress is known to induce the expression of many genes. In our two independent proteomic analyses, 18 vancomycin-inducible proteins were identified with minimum twofold upregulation in

the wild-type L. monocytogenes compared with the ΔsigB mutant. Among these proteins, Lmo0539, Lmo0524, Lmo2085, Lmo2114, Pgm, InlD, Lmo1027 and Lmo0079 were already confirmed to be σB-dependent proteins induced under salt or stationary-phase stress (Kazmierczak et al., 2003; Raengpradub et al., 2008; Oliver et al., 2009). Among the three transporter proteins identified under vancomycin stress, Lmo0524 and Lmo1431 were induced only in wild-type L. monocytogenes, whereas Lmo2114 showed a 3.5-fold increase in the wild-type strain (Table 2). Indeed, bacitracin treatment highly stimulated the bceAB gene, which encodes a putative ABC transporter in B.

In order to measure the transcript levels of proteins identified in this study, seven genes out of 18 were selected for RT-PCR in the wild-type L. monocytogenes and ΔsigB mutant and the relative mRNA levels were measured. To quantify mRNA levels, the band density of each PCR product was measured after agarose gel electrophoresis. As shown in Fig. 2, the transcript levels are consistent with the proteomic data. Moreover, transcription of the identified genes, including gyrB, lmo1374, ftsA Tanespimycin and lmo2779, are directly or indirectly under the control of σB. No RT-PCR products were observed in the negative

control (data not shown). SB203580 The role of the L. monocytogenesσB under stress conditions has been studied intensively, especially under osmotic, cold, acid, high hydrostatic pressure or oxidative stress (Cole et al.,

1990; Sleator et al., 2001; Wemekamp-Kamphuis et al., 2004). Recently, the relationship between alternative sigma factor and antimicrobial resistance has been reported in various bacteria. In B. subtilis, sigma factors σM, σW and σX contribute to resistance to various cell envelope-targeting antibiotics (Mascher et al., 2007). In addition, σB contributes to the upregulation of its own regulon upon exposure to bacitracin or vancomycin (Mascher et al., 2003). In L. monocytogenes, σB is important for growth and survival upon treatment with bacteriocin (lacticin 3147 and nisin) or antibiotics (penicillin G and ampicillin) (Begley et al., 2006). According to a recent report, both σB and σL contribute to tolerance Carbohydrate to the antimicrobial peptide SdpC and the bacteriocin nisin in L. monocytogenes (Palmer et al., 2009). Antibiotic-induced cell wall stress is known to induce the expression of many genes. In our two independent proteomic analyses, 18 vancomycin-inducible proteins were identified with minimum twofold upregulation in

the wild-type L. monocytogenes compared with the ΔsigB mutant. Among these proteins, Lmo0539, Lmo0524, Lmo2085, Lmo2114, Pgm, InlD, Lmo1027 and Lmo0079 were already confirmed to be σB-dependent proteins induced under salt or stationary-phase stress (Kazmierczak et al., 2003; Raengpradub et al., 2008; Oliver et al., 2009). Among the three transporter proteins identified under vancomycin stress, Lmo0524 and Lmo1431 were induced only in wild-type L. monocytogenes, whereas Lmo2114 showed a 3.5-fold increase in the wild-type strain (Table 2). Indeed, bacitracin treatment highly stimulated the bceAB gene, which encodes a putative ABC transporter in B.