002% arabinose for 2.5 h under either aerobic or low oxygen conditions before serial dilution and plating on LB plates with antibiotics and 2% glucose. Survival ratio was determined by calculating the ratio of the viable colony counts obtained from the induced cultures versus the viable counts from non-induced culture.

The results represent the average and standard errors from at least three experiments However, chromosomal ΔpurR and Δfnr mutations were found to have little effect on the viable colony counts at 1 and 2 h after treatment with up to 250 ng/ml Saracatinib norfloxacin (data not shown). Greater than 1000-fold lower bactericidal rates were observed for BW27784 with oxygen limitation when compared to incubation with oxygen after treatment with norfloxacin, in agreement with previous BIBF 1120 in vivo report of decreased norfloxacin sensitivity under anaerobic conditions [29]. It is therefore not feasible to investigate any potential protective effect from pInter or the Δfnr mutation under low oxygen conditions. Discussion A segment of E. coli chromosomal DNA spanning the upp-purMN region was selected from a high copy number plasmid library of E. coli genomic DNA fragments based on its ability to confer resistance to cell killing mediated by accumulation of topoisomerase I cleavage complex. The intergenic region of upp-purMN was

found to protect against bacterial cell death initiated by both type I and type II covalent topoisomerase-DNA cleavage complex. Deletion of the binding sites for FNR and PurR decreased the protective effect, suggesting that the protective effect we observed for pInter resulted from titration of the transcription BLZ945 in vivo regulators FNR and PurR. PurR is a repressor of purine biosynthesis in E. coli [19].

The hypothesis that the protective effects observed from the high copy number plasmid pInter is related Interleukin-3 receptor to purine nucleotide pool availability is supported by the increased viability when adenine was added to defined medium. The ΔpurR mutation resulted in up to 475-fold higher survival rate following topoisomerase I covalent cleavage complex accumulation. Although pInter could increase survival rate following norfloxacin treatment, the ΔpurR chromosomal mutation did not affect norfloxacin sensitivity. Deletion mutation of a global transcription regulator is likely to affect the many metabolic genes under its regulation differently than titration of the global transcription regulator by the presence of its binding site on a high copy number plasmid. Chromosomal PurR recognition sites with the strongest binding affinity for PurR might still be repressed by PurR even in the presence of pInter but they would be depressed in the ΔpurR background. The cell death pathways initiated by type IA and type IIA topoisomerases may be affected to different degrees by the change in metabolic gene expression resulting from ΔpurR mutation.

tuberculosis, M. bovis and BCG, but not in M. avium or M. smegmatis [18]. This suggests that the two-component system MtrAB might contribute

to the virulence of the M. SNX-5422 purchase tuberculosis complex through selective regulation of dnaA gene expression. A parallel study [13] has identified a “”GTCACAgcg”" motif for the recognition of MtrA in the fbpB promoter and the origin of replication. Interestingly, there exists a common conserved core sequence between the 9 bp motif and the motif identified within the dnaA promoter in the current study. Using a MalE-EnvZ kinase, but not the cognate partner kinase of MtrB, Rajagopalan et al suggested that the phosphorylation of MtrA had distinct regulation capacities. However, only 5% of the MtrA protein was shown to be phosphorylated [13]. In the present study, efforts to phosphorylate MtrA using the PI3K inhibitor AZD6738 purchase partner kinase of MtrB failed (data not shown). Importantly, using several different methods, we showed that the nonphosphorylated MtrA could bind to the target DNA very well, suggesting that the form of MtrA might be involved in regulating the expression of its target genes. Obviously, the regulation mechanism of MtrAB needs to be further addressed in the future. Attempts to disrupt the mtrA gene in M. tuberculosis have been unsuccessful; thus, mtrA seems to be an essential gene for

M. tuberculosis proliferation [11]. The genes encoding the MtrAB two-component system of C. glutamicum were deleted successfully, and

this deletion strongly influenced the cell morphology, antibiotic susceptibility, and expression of genes involved in osmoprotection [15]. In the current study, a large group of target genes for MtrA was characterized from the genomes of both M. tuberculosis and M. smegmatis, including multiple transcriptional factors such as TetR family regulators, stress gene family protein (MSMEG_3308), and the isoniazid inducible protein IniA (MSMEG_0695). Inhibition of the mtrA gene, therefore, resulted in corresponding expression changes in many or all of these Myosin target genes in M. smegmatis (Fig. 5C). In the current study, we found the conserved motifs of the MtrAB two-component system upstream of a large list of genes that have several different functions, including cell cycle progression regulation, secreted antigen, and drug resistance. Interestingly, as shown in Additional file 6, there are 42 genes (10%) that were found in both mycobacterial species. MtrA was reported to be involved in the transcriptional regulation of dnaA in M. tuberculosis; this provides the first direct evidence of its role in cell cycle progression [12]. In M. avium, MtrAB could respond to general stresses and ultimately inhibit cell division [14]. A recent study found that the promoter for immunodominant secreted antigen 85B was also characterized as the targets of MtrA [13]. Therefore, our findings were consistent with these previous studies.

5 h Lsplex, 15 min purification; 1 h post staining, 15 min purification 1. Amplified DNA estimated after the last purification step. The starting material for all protocols was 10 ng genomic S. aureus NCT-501 DNA (ATCC 29213) 2. BDR calculated Blasticidin S manufacturer following the formula: base:dye = (Abase × Єdye)/(Adye × Єbase); Abase = A260 – (Adye × CF260) Єdye is the extinction coefficient for the fluorescent dye (Cy3: 150000 cm-1M-1; Alexa555: 150000 cm-1M-1; Alexa 546: 104000

cm-1M-1) Єbase here is the average extinction coefficient for a base in double strand DNA (6600 cm-1M-1) CF: Correction Factor Cy3: 0.08; Alexa 555: 0.04; Alexa 546: 0.21 3. Ratio recommended by the manufacturer for PCR labelling 4. The manufacturer does not provide a protocol for PCR labelling Figure 2 Microarray detection of LSplex amplification products labelled by different techniques: Hybridization buy GDC-0068 pattern of specific capture probes obtained upon hybridization of 2 μg (A) and 10 ng of S. aureus DNA (B) served as standard for comparison of the profiling fidelity and sensitivity of three labelling protocols for LSplex. LSplex amplification of 10 ng S. aureus DNA with subsequent labelling by random priming (C). Direct incorporation of Chromatide Alexa Fluor 546-47-dUTPs during LSplex amplification (D). Indirect labelling by incorporating

amino-modified nucleotides during LSplex and subsequent coupling with amino reactive dyes (E). Impact of labeling method on the detection efficiency In order to reduce the number of steps in the labeling procedure and to shorten the labeling time we attempted to label DNA by incorporation of modified nucleotides concomitantly to the amplification procedure. Lck Additionally, the impact of different labeling methods on general LSplex specificity and sensitivity upon microarray hybridization were evaluated. The possibility of directly incorporating fluorescent nucleotides during LSplex amplification was examined. Chromatide Alexa Fluor 546-47-dUTPs were used for amplification but resulted in a rather weak incorporation ratio

(one fluorescent nucleotide each 139 bases) (Table 1). The corresponding hybridization profile of S. aureus specific probes was barely more informative than the one obtained with 10 ng of non-amplified genomic DNA (Fig. 2D and 2B). The indirect labeling of LSplex products by incorporating aminoallyl-modified nucleotides during amplification, with subsequent staining by amino reactive fluorescent dyes, was a potential alternative to Klenow labeling with one tagged nucleotide per 64 bases. Some probes displayed reduced fluorescence when compared to the fluorescence levels obtained with LSplex amplification plus Klenow labeling (Fig. 2E). For example the 2nd catalase probe (cata), the 4th coagulase (coa), bsaG, all capsular polysaccharide type 5 related genes (cap5), the gamma hemolysin (hglA), and the enterotoxines G (seg) and T15 (set15) showed weaker signals but were nonetheless identified as positive.

Findings reveal that hunger and food intake increased post-exercise in order to compensate for the negative energy balance achieved with training [14]. In contrast, Guelfi et al. demonstrated that 12 weeks of 40–60 minutes of moderate learn more intensity exercise (70–80% HRmax) produced opposite results [15]. Specifically, Guelfi et al. showed no change in perceived hunger,

while levels of perceived fullness increased [15]. It should be noted however, that subjects in the Blundell et al. [14] study were required www.selleckchem.com/products/Bleomycin-sulfate.html to expend approximately 1000 kcal/d with exercise. This level of energy expenditure is far greater than that of our study (estimated to be 150–250 kcal/d). Thus, increases in hunger post-exercise may only occur if energy expenditure with exercise meets Capmatinib concentration or exceeds 1000 kcal/d. Nevertheless, in light of these contradictory findings, the impact of combination diet and exercise therapies on hunger and fullness warrant further investigation. Changes in restrained eating, uncontrolled eating, and emotional eating were also examined. In both the ADF and combination groups, restrained eating increased while uncontrolled eating decreased. These positive changes in eating behaviors are most likely due to the subjects’ involvement in weekly dietary counseling

[16]. As for emotional eating, only the combination group experienced decreases in this parameter. It is possible that emotional eating was not decreased in the ADF group due to the lack of the exercise intervention. Positive changes in mood have been previously reported with short bouts of exercise [12, 17]. Pendleton et al. designed a trial to study the effect of cognitive behavior therapy with or without exercise on binge eating in obese women. After 16 months, only the group that was exercising experienced improvements in mood, which resulted in decreased binge eating [18]. Taken together, it is possible that the combination of ADF plus exercise may have better overall effects on these eating behaviors than each intervention

alone. BCKDHA We also wanted to examine the ability of our dietary counseling program to aid individuals in reducing energy intake. Subjects met with a dietician each week to learn how to ascertain the caloric content of foods, control portion sizes, read food labels, and avoid high fat foods. Dietary intake was measured using a 3-day food record that was completed each week (on feed days). After 12 weeks of treatment, energy intake decreased by approximately 300 kcal in the combination group and by 220 kcal in ADF group, though not significantly. These reported energy deficits are somewhat lower than expected given that the combination and ADF group lost 7 kg and 3 kg, respectively. These incongruences between weight loss and energy deficits are most likely due to reporting errors in the food records.

Each point represents an organ from an individual bird at the indicated day following the infection. The table summarizes the number of animals sampled (n), the geometric mean of the competitive indexes (mean CI), and the P value from a two-tailed SYN-117 T-test. Interestingly, the Δspi2 strain also significantly out-competed by Acalabrutinib clinical trial the Δspi1 strain in the spleen at days three and fourteen post-infection (Figure 5B). This result suggests that SPI1 contributes more than SPI2 to splenic colonization. Since SPI2 has been shown

in several animal models, including the mouse, to be a major factor for the survival of Salmonella in the systemic compartment of the host we decided to verify the accuracy of the results we obtained with the Δspi2 strain in chicken spleen by performing mixed infection experiments in mice. As expected the Δspi2 strain was out-competed by the wild type (Figure 7A) and the Δspi1 strains (Figure 7B) in both the liver and spleen after either intra-peritoneal (Day 3) or oral (Day 5) infections. Collectively, these results show that in contrast to the mouse, SPI2 contributes less than SPI1 to splenic colonization of the chicken. Figure 7 SPI2 is essential to the colonization of mouse spleen by Typhimurium. Competitive indexes are from mixed

infections in mice with the wild type and the Δspi2 (deletion of SPI2 structural genes), or the Δspi1 (deletion of SPI1) ATM Kinase Inhibitor price and the Δspi2 strains. Data from day 3 and day 5 post-infection correspond to intra-peritoneal and oral infections respectively. Each point represents an organ from an individual mouse. Discussion SPI1 and SPI2 are important virulence determinants of S. enterica serovars that have been extensively studied in several animal models. Few studies have investigated the role of SPI1 and SPI2 in the colonization of the chicken by Typhimurium. These

studies have analyzed the colonization of different organs in chickens infected Galactosylceramidase with a wild type strain or with mutants of SPI1 or SPI2 in which a single T3SS structural gene was inactivated. To gain better insight in the roles played by SPI1 and SPI2 in the chicken we used an approach that combined mixed infections, large deletions in SPI1 and SPI2, and the tracking of infections for fourteen days. We found that SPI1 contributes to colonization of both the cecum and the spleen in chickens. In contrast, SPI2 plays a role in the colonization of the spleen, but not of the cecum. Furthermore, we show for the first time to our knowledge, that SPI1 plays a more important role than SPI2 in colonization of the chicken spleen by Typhimurium.

pseudomallei DD503 BoaB. These animal studies were performed in compliance with institutional, as well as governmental, rules and regulations. Immunofluorescence labeling of E. coli and microscopy Plate-grown SBI-0206965 research buy bacteria were suspended in

5-ml of sterile PBSG to a density of 108 CFU/ml. Portions of these suspensions were spotted onto glass slides and dried using a warming plate. The slides were fixed with PBSG supplemented with 4% paraformaldehyde for 30-min at room temperature, washed with PBS supplemented BTSA1 cost with 0.05% Tween 20 (PBST), and blocked overnight at 4°C using PBST supplemented with 10% goat serum (SIGMA-ALDRICH®). Next, bacteria were probed for 1-hr at room temperature with murine α-BoaA or α-BoaB antibodies diluted (1:200) in PBST supplemented with 10% goat serum. After this incubation, the slides were washed with PBST to remove unbound antibodies and incubated for 30-min at room temperature with a goat α-mouse antibody labeled with Alexa Fluor® 546 (Molecular Probes, Inc) and diluted (1:400) in PBST supplemented with 10% goat serum. Following this incubation, the slides were washed with PBST to remove unbound antibody and bacterial cells were stained using

the nucleic acid dye DAPI (Molecular Probes, Inc). Slides were mounted with SlowFade® reagent (Invitrogen™) and examined by microscopy using a Zeiss LSM 510 Meta confocal system. Acknowledgements This study was supported by a grant from NIH/NIAID (AI062775) and startup funds from the University of Georgia College of Veterinary Medicine to ERL. The authors would Rapamycin like to thank Lauren Snipes and Frank Michel at the University of Georgia for their technical assistance. References 1. Cheng AC, Currie BJ: Melioidosis: epidemiology, pathophysiology, and management. Clin Microbiol Rev 2005,18(2):383–416.PubMedCrossRef 2. Wiersinga WJ, van der Poll T, White NJ, Day NP, Peacock SJ: Melioidosis: insights into the pathogenicity of Burkholderia pseudomallei. Nat Rev Microbiol 2006,4(4):272–282.PubMedCrossRef

3. Currie BJ, Fisher DA, Anstey NM, Jacups SP: Melioidosis: acute and chronic disease, relapse and re-activation. 3-mercaptopyruvate sulfurtransferase Trans R Soc Trop Med Hyg 2000,94(3):301–304.PubMedCrossRef 4. Currie BJ, Fisher DA, Howard DM, Burrow JN, Lo D, Selva-Nayagam S, Anstey NM, Huffam SE, Snelling PL, Marks PJ, Stephens DP, Lum GD, Jacups SP, Krause VL: Endemic melioidosis in tropical northern Australia: a 10-year prospective study and review of the literature. Clin Infect Dis 2000,31(4):981–986.PubMedCrossRef 5. Adler NR, Govan B, Cullinane M, Harper M, Adler B, Boyce JD: The molecular and cellular basis of pathogenesis in melioidosis: how does Burkholderia pseudomallei cause disease? FEMS Microbiol Rev 2009,33(6):1079–1099.PubMedCrossRef 6. Wiersinga WJ, van der Poll T: Immunity to Burkholderia pseudomallei. Curr Opin Infect Dis 2009,22(2):102–108.PubMedCrossRef 7. Vietri NJ, Deshazer D: Melioidosis. In Medical Aspects of Biological Warfare. U.

Interestingly, the ori locus tends to localise close to the cell poles in cells with disrupted nucleoids, whereas the right and ter loci localise towards midcell. This suggests that Ndd action changes the intracellular orientation of the chromosome. We

conclude that Ndd affects functions that maintain the central compaction and the orientation of the chromosome without provoking a complete GSK1120212 in vitro disorganisation of the chromosomal DNA. Conclusions We have developed an approach that allows to reliably observing the mean positioning of fluorescent objects along the width of rod-shaped bacterial cells from two-dimension images. We have successfully used this approach to study the positioning of E. coli chromosome loci and shown that loci of different chromosome region position differently along cell width. Most interestingly, loci of the terminal region of the chromosome are preferentially located at the periphery of the nucleoid consistent Alpelisib datasheet with the specific roles of this region in chromosome organisation and dynamics. Methods Strains and plasmids Most strains used were derived from DLT812 (CB0129 Δ(ara-leu) zac3051 ::Tn 10 [30]), rendered lysogen for λDE3 using the λDE3 lysogenisation kit (Novagen),

and pcp18 :: araE, FRT-Kn-FRT by transduction to obtain DLT1886. The Kn resistance cassette was removed by transitory expression of Flp recombinase from pCP20 [31], yielding strain DLT1915. Glycogen branching enzyme The parS -Kn cassette at positions 3909 kb (ori) and 1568 kb (ter), and the parS-FRT-Cm-FRT cassette at positions 316 kb (NS-right) and 738 kb (right) (see map Figure 1A) were transferred into DLT1915 from strains CC4711, CC4713 [19] and from strains carrying the NSR-3 and Right-3 [9] to yield strains FC542, FC543, FC541 and FC540, respectively. Insertion of the parS-FRT-Cm-FRT at the trg (1490 kb) locus of strain LN2666 (CB0129 rpsL (StR)) was obtained using standard transgenesis procedure with the λred system [19]. Transformation by pCP20 was used to remove the Cm resistance

gene. To obtain the Ndd-producing plasmid pRM7, a fragment carrying lacI and a pT7- ndd2ts fusion [25] was ligated as a Nru I- Hind III fragment into pACYC184. Plasmid pBAD24-YFPΔ30ParB was used to produce the check details YFP-ParB fusion (gift from O. Espeli). Cell growth and microscopy Strains carrying plasmids pBAD24-YFPΔ30ParB, and either pACYC184 (Ndd untreated cells), pRM7 (Ndd-treated cells) or no second plasmid (LN2666 derivative), were grown overnight at 42°C (derivatives of DLT1915) or 30°C (derivative of LN2666) in M9 medium supplemented with 0.2% casamino acids, 0.4% glucose; 2 μg/ml thiamine; 20 μg/ml leucine, 20 μg/ml thymine, 100 μg/ml ampicillin and, when required, 10 μg/ml chloramphenicol. These cultures were diluted 1/100 in the same medium and grown at the same temperature to an OD600 of 0.5-0.6.

Figure 8 Infection with the galU mutant of FT LVS elicits protective immunity WT FT LVS. C57Bl/6J mice (n = 5) that had survived intranasal challenge with the galU mutant FT strain and naïve control mice (n = 5) were challenged intranasally with 5 × 104 CFU (50 × LD50) of WT FT LVS eight weeks following the initial infection. The body weight (Panel A) and survival (Panel B) of mice were monitored for survival for 30 days. Statistical analyses of changes in body weight were performed via two-way ANOVA

using a Bonferroni multiple comparisons post-test and p-values are indicated as follows: * P < 0.05 and *** P < 0.001. Statistical analysis of the survival data was PS-341 research buy performed using a Gehan-Breslow-Wilcoxon test (** indicates a p-value of 0.0043). Discussion A major focus of FT research continues to be the identification of virulence-mechanisms used by this extremely virulent pathogen. A number of virulence determinants have been identified, but there remains much to discover regarding the virulence mechanisms used by FT to survive and cause disease within its mammalian hosts. In this report we show that mutation of galU results in a dramatic

attenuation of FTLVS virulence that appears to be unrelated to any in vivo infectivity or growth defects. Although it is known that mutation of the galU gene leaves some other bacterial pathogens attenuated for virulence [27, 32, 43, 44], this is the first report examining the role of galU in the pathogenesis of FT. Neutrophils are a critical component of the innate immune responses to bacterial infection, and the recruitment of these cells into the lungs following pneumonic infection typically peaks by 48-hours post-infection KU-60019 mouse [45–47]. However, it has been reported elsewhere [22, 25] and confirmed here that neutrophil recruitment following wild type FT infection in the lungs is not detected until approximately Aldol condensation 72 h post-infection. Because it is known that neutrophils are required for control of FT infection [48], it is reasonable to speculate that the ability of FT to delay the kinetics

of neutrophil recruitment into the lungs following pulmonary infection may be an important virulence Angiogenesis inhibitor determinant. Interestingly, a comparative analysis following pulmonary infection of mice with the galU mutant and WT strains of FT revealed that the kinetics of neutrophil recruitment (and production of chemokines/cytokines involved in neutrophil recruitment) occurs much more rapidly following infection with the galU mutant (peaks at 48 h post-infection). Kinetic analyses of bacterial burdens in the lungs, spleens, and livers of mice following infection with the galU mutant and WT strains of FT revealed that the two strains disseminated and replicated at comparable rates, but the bacterial burdens in galU-infected animals became significantly lower than in WT-infected animals by 72 h post-infection. The significant difference in bacterial burdens observed in galU mutant- vs.

The fluorescence selleck products decays were analyzed by software provided by Becker & Hickl (EX 527 research buy SPCImage). All measurements were performed at 22°C. The plants were dark-adapted at 20°C for 30 min before the measurements. Time-correlated single photon counting Time-correlated single photon counting (TCSPC) was used to perform time-resolved fluorescence measurements using a setup

described earlier (Borst et al. 2005). For the fitting procedure, the dynamic instrumental response of the experimental setup was recorded using the fast and single-exponential fluorescence decay (6 ps) of the reference compound pinacyanol in methanol (van Oort et al. 2008). Data analysis was performed using the computer program described earlier (Digris et al. 1999; Novikov et al. 1999). The fit quality was evaluated from χ2, and from the plots of the weighted residuals and the autocorrelation thereof (Visser et al. QNZ cell line 2008). Typical values of χ2 were 1.0–1.1. For Chl a fluorescence measurements, the samples were excited at 470 nm, and the emission was collected using an interference filter at 688 nm with a bandwidth of 10 nm. The samples were sequentially thermostated at increasing

discrete temperatures, between 7 and 70°C, for 10 min at each temperature. The decay curves were analyzed by a four-exponential model; for each decay trace, the average lifetime (τave) was calculated by the formula: $$ \tau_\textave = \sum\limits_i = 1^n \alpha_i \tau_i $$ τ being the fluorescence lifetime and α the pre-exponential factor proportional to the fractional population, with \( \sum\nolimits_i = 1^n \alpha_i = 1. \) For the calculation of τave, the minor contribution (typically about 1–2%) of a component

with a lifetime above 1 ns, originating from closed reaction centers, was not taken into account. almost The mean value of τave and its standard error presented in this article were determined from five different decay curves measured on different samples. Time-resolved fluorescence measurements of Merocyanine 540 For studying the lipid packing the lipophilic fluorescence probe, Merocyanine 540 (MC540, purchased from Sigma–Aldrich) was added, from a 1 mM ethanol stock solution (to a final concentration of 0.2 μM), to a suspension of thylakoid membranes (containing 20 μg Chl ml−1) and incubated for 30 min before the experiments. During this time, the sample was gently stirred and kept on ice in the dark. Longer incubation with MC540 did not result in increased incorporation of the probe (see Krumova et al. 2008a and references therein). For fluorescence lifetime measurements, the TCSPC set-up described in the previous section was used. The excitation wavelength was set to 570 nm, and the emission was collected between 610 and 630 nm using a Schott OG 610 nm (3 mm) cut-off filter and a Balzers K60 interference filter.

One such study, of particular interest to our laboratory, reported that the H. pylori ortholog of CsrA would not functionally complement the E. coli mutant as it failed to repress glycogen biosynthesis [23]. It is likely that the H. pylori CsrA complementation failure was due to differences in the functional mechanism

of ε-proteobacterial CsrA, however, this may have been specific to the two CsrA-binding sites of the glgCAP mRNA but not to other CsrA targets. IWR-1 supplier To test this for C. jejuni CsrA, we examined the ability of CsrACJ to complement multiple E. coli csrA mutant phenotypes. We first expressed the C. jejuni ortholog in the E. coli csrA mutant and assessed its ability to repress glycogen biosynthesis under gluconeogenic conditions. Similar to H. pylori CsrA, the C. jejuni CsrA ortholog was incapable of repressing glycogen accumulation in the E. coli csrA mutant. We next examined the ability of the C. jejuni protein to complement the GSK621 purchase motility, biofilm accumulation, and cellular morphology phenotypes of the E. coli mutant as well. As with glycogen biosynthesis, CsrA-mediated regulation of biofilm formation in E. coli is based on repression of a synthetic pathway, in this case the pgaABCD operon [15]. However, CsrA mediated expression of PgaABCD appears to be more complicated than that of glycogen biosynthesis, as it was reported that the mRNA leader

sequence Temsirolimus mw of the operon contains as many as six CsrA binding sites compared to the two binding sites observed on the glg leader sequence. Regardless of the complexity of the molecular mechanism of CsrA regulation of PGA we found that, when expressed in the E. coli csrA mutant, C. jejuni CsrA successfully complemented the

biofilm formation phenotype (p<0.001). Considering that the regulation of the glg and pga operons are both examples of CsrA-mediated repression of a biosynthetic pathway, we wanted to determine the ability of C. jejuni CsrA to Cytidine deaminase substitute for its E. coli ortholog when the activation of gene expression is required. Wei and colleagues demonstrated that CsrA is a potent activator of flhDC expression and is therefore required for synthesis of the E. coli flagellum [38]. When we expressed C. jejuni CsrA within the non-motile E. coli csrA mutant the phenotype was completely rescued (p<0.001) suggesting that the C. jejuni ortholog is capable of promoting FlhDC expression. Finally, we assessed the ability of C. jejuni CsrA to rescue an uncharacterized phenotype such as the altered cellular morphology of the E. coli csrA mutant. When CsrA was discovered, Romeo and colleagues reported that the csrA mutant displayed a greater cellular size as compared to the wild type, which was most obvious in early stationary phase [40]. This phenotype was explained as a possible indirect effect of endogenous glycogen accumulation. When we grew the wild type, csrA mutant, and complemented E.