commun.). The products of these genes do not have any homologues in the databases. Furthermore, the products of ECA3711, ECA3724 and ECA3730 were detected by Coulthurst et al. (2008) in the secretome of Pa. ECA3724 and ECA3730 are predicted to encode a capsid protein and RG-7204 the major tail tube protein. The presence of these structural components of the

virion in the extracellular medium may suggest that excision of ECA41 from the chromosome is followed by encapsidation. To determine whether these proteins, or any others provided by the prophages, contributed to virulence in Pa, we deleted the entire prophages – both individually and in combination – from the Pa genome, using the limits of the prophage that we had determined experimentally. No differences were detected in the growth rates of TJE101 (ΔECA29), TJE102 (ΔECA41) or TJE103 (ΔECA29, ΔECA41) in PMM or PMB. Culture supernatant samples were taken throughout these growth experiments and the levels of secreted protease, pectate lyase

www.selleckchem.com/products/BAY-73-4506.html and cellulase activities were determined. No changes were observed in the mutants compared with the wild type (data not shown). Swimming motility has previously been shown to be important in Pa potato infections (Mulholland et al., 1993; Evans et al., 2010). Comparison of motility of the prophage deletion strains showed that TJE101 and TJE102 were consistently less motile than the wild type, with a 5–8% reduction in halo size (data Ketotifen not shown). The decrease, even though small, was statistically significant after multiple biological repetitions (P<0.05, paired t-test) and could result in reduced fitness in the environment. Finally, the ability of the prophage-deficient strains to rot potato tubers was assessed in vivo. The prophage deletion mutants showed a statistically significant reduction in virulence compared with the wild type (Fig. 3) (P<0.05). This result demonstrates that the acquisition of

these prophages has contributed towards the pathogenicity of Pa. Similar to each of the single mutants, the double mutant (TJE103) showed a modest, but statistically significant, reduction in motility and a reduction in virulence in tubers (data not shown). However, due to the intrinsically variable nature of such assays, we were unable to determine whether the impacts of the two mutations were additive. Although the impacts on motility and virulence were not drastic under lab conditions, it is possible that such differences could have significant fitness and survival consequences in the environment and during pathogenesis in the field. The two Pa prophages, ECA29 and ECA41, are likely to be maintained at a metabolic cost to the cell: at 68 kb combined, they represent over 1% of the genome, which must be replicated in each cell cycle. This in itself implies that the prophages may confer a selective advantage on cells that carry them. The results herein demonstrate that these two prophages do contribute to in vivo pathogenicity.

The α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate (AMPA) receptor is an ionotropic glutamate receptor

involved in the neuroplasticity that accompanies acute and repeated drug administration. Changing surface expression is one means to regulate AMPA receptor function, and the present study tested the hypothesis that behavioral sensitization to the μ-opioid receptor agonist morphine is accompanied by changes in the subcellular distribution of AMPA receptors in limbic brain regions. To test this hypothesis, we used a protein cross-linking assay to assess cell surface and intracellular levels of GluA1 and GluA2 EGFR inhibitor subunits in the nucleus accumbens, medial prefrontal cortex and ventral pallidum. Repeated morphine treatment decreased surface expression of GluA1 in the medial prefrontal cortex without affecting levels of GluA2. In contrast, surface levels of GluA1 or GluA2 were unchanged in the nucleus accumbens and ventral PS-341 clinical trial pallidum, demonstrating that although AMPA receptors

in accumbal and pallidal regions are critical mediators of behaviors induced by repeated opiate exposure, these effects are not accompanied by changes in surface expression. The findings reveal that the involvement of AMPA receptor trafficking in opiate-induced behavioral sensitization is relegated to selective regions and that AMPA receptors in the medial prefrontal cortex may be particularly sensitive to these actions.

“
“Fragile X syndrome (FXS) is characterized Sitaxentan by intellectual disability and autistic traits, and results from the silencing of the FMR1 gene coding for a protein implicated in the regulation of protein synthesis at synapses. The lack of functional Fragile X mental retardation protein has been proposed to result in an excessive signaling of synaptic metabotropic glutamate receptors, leading to alterations of synapse maturation and plasticity. It remains, however, unclear how mechanisms of activity-dependent spine dynamics are affected in Fmr knockout (Fmr1-KO) mice and whether they can be reversed. Here we used a repetitive imaging approach in hippocampal slice cultures to investigate properties of structural plasticity and their modulation by signaling pathways. We found that basal spine turnover was significantly reduced in Fmr1-KO mice, but markedly enhanced by activity. Additionally, activity-mediated spine stabilization was lost in Fmr1-KO mice. Application of the metabotropic glutamate receptor antagonist α-Methyl-4-carboxyphenylglycine (MCPG) enhanced basal turnover, improved spine stability, but failed to reinstate activity-mediated spine stabilization. In contrast, enhancing phosphoinositide-3 kinase (PI3K) signaling, a pathway implicated in various aspects of synaptic plasticity, reversed both basal turnover and activity-mediated spine stabilization.

5 Hz). Total power was computed relative to a baseline interval (−1.6 to −1.2 s before electrical stimulus onset). Average power in the baseline interval was first subtracted from the interval after clip onset and before electrical stimulus onset (prestimulus interval; −1 to 0 s) and the resulting difference was divided by the baseline interval activity as follows: Pow(t, f )normalised = 100 * ((Pow(t, f )prestimulus − Pow( f )baseline)/Pow( f )baseline) (e.g. Pfurtscheller & Aranibar, 1977). For the statistical analysis, a cluster-based permutation test was applied on electrode–time–frequency

data (Maris & Oostenveld, 2007; Schneider et al., 2011). The dependent samples t-tests were thresholded at P = 0.005 and the permutation P-value of the cluster was set to P = 0.05. For the source reconstruction, a linear beamforming approach was applied (dynamic imaging of coherent sources; Van Veen et al., 1997; Gross

et al., 2001). In this approach, GSK126 manufacturer source-level power is calculated using an adaptive spatial filter that passes activity from one specific location of interest with unit gain and maximally suppresses activity from surrounding locations. In the present study, one common filter was used, comprising all conditions (i.e. needle and Q-tip) as well as all time intervals (i.e. baseline and prestimulus). As linear beamforming is based on the calculation of the cross-spectral density matrix over trials, this approach is particularly suitable for the analysis of total power in the human electroencephalogram (Schneider

et al., 2008, 2011). The leadfield Proteases inhibitor matrix was calculated on a boundary element model for each grid point in the brain with a regular 7 mm grid using a forward model based on closed compartments representing brain tissue (gray and white matter), bone, and skin (Oostenveld et al., 2001). A spatial filter was constructed for each grid point and subsequently applied to estimate the power at that source location. In accordance with previous studies on pain anticipation (Babiloni et al., 2005a, 2006) and with the activity patterns observed in the present study, the main focus of the statistical analysis of oscillatory responses was on the examination of ABA (8–12 Hz). The time interval for the source analysis was selected based Fluorouracil mw on the results of the cluster-based permutation test on electrode–time–frequency data (Fig. 3) and was centered at −0.5 s (interval −0.7 to −0.3 s) before electrical stimulus onset; the respective baseline was centered at −1.4 s (interval −1.6 to −1.2 s). Source data were analysed voxel-wise by means of a cluster-based permutation test. The dependent samples t-tests for this analysis were thresholded at P = 0.0001 and the permutation P-value of the cluster was set to P = 0.05. Based on the results obtained in the cluster-based analysis of source data (Fig. 5), a region in the posterior cingulate cortex (PCC) and in the right fusiform gyrus (FG) was selected for further analysis.

After the preparatory period, we measured the monkeys’ ability to recognize the objects across changes in viewing angle, by introducing the object set to the Object task. Results indicated significant view-invariant recognition after the second but not first preparatory task. These results suggest

that discrimination of objects from distractors at each of several viewing angles is required Pirfenidone research buy for the development of view-invariant recognition of the objects when the distractors are similar to the objects. “
“Members of the miR-183 family are unique in that they are highly abundant in sensory organs. In a recent study, significant downregulation was observed for miR-96 and miR-183 in the L5 dorsal root ganglion (DRG) 2 weeks after spinal nerve ligation (SNL). In this study, we focused on miR-183, which is the most regulated member of the miR-183 family, to look at the specific role on neuropathic pain. Persistent mechanical allodynia was induced with the L5 SNL model in 8-week-old male selleck chemicals Sprague-Dawley rats. Paw withdrawal thresholds in response to mechanical stimuli were assessed with Von Frey filaments. Expression of miR-183 in the L5 DRG was assessed with quantitative real-time polymerase chain reaction (qPCR)

analysis. Lentivirions expressing miR-183 were injected intrathecally into SNL rats. Changes in mechanical allodynia were assessed with Von Frey filaments. In addition, changes in the predicted target genes of miR-183 were assessed with qPCR. L5 SNL produced marked mechanical allodynia in the ipsilateral hindpaws of adult rats, beginning at postoperative day 1 and continuing to day 14. L5 SNL caused significant downregulation of miR-183 in adult DRG cells. Intrathecal administration of lentivirions expressing miR-183 downregulated DNA Synthesis inhibitor SNL-induced increases

in the expression of Nav1.3 and brain-derived neurotrophic factor (BDNF), which correlated with the significant attenuation of SNL-induced mechanical allodynia. Our results show that SNL-induced mechanical allodynia is significantly correlated with the decreased expression of miR-183 in DRG cells. Replacement of miR-183 downregulates SNL-induced increases in Nav1.3 and BDNF expression, and attenuates SNL-induced mechanical allodynia. “
“The microtubule-associated protein Tau is responsible for a large group of neurodegenerative disorders, known as tauopathies, including Alzheimer’s disease. Tauopathy result from augmented and/or aberrant phosphorylation of Tau. Besides aging and various genetic and epigenetic defects that remain largely unknown, an important non-genetic agent that contributes is hypothermia, eventually caused by anesthesia. Remarkably, tauopathy in brains of hibernating mammals is not pathogenic, and, because it is fully reversible, is even considered to be neuroprotective. Here, we assessed the terminal phase of Tau.

5% SDS, 20 mM EDTA, and 50 μg mL−1 proteinase К at 56 °C for 3 h. The DNA was extracted with phenol/chloroform (1 : 1) and then precipitated with ethanol supplemented with sodium acetate. Restriction fragment length see more polymorphism (RFLP) analysis of the phage DNA was performed using endonucleases AluI, ApaI, BamHI, BglII, CfrI, ClaI, DraI, DraII, Eco52I, EcoR91I, EcoRI, EcoRV, HindIII, HinfI, MspI, NcoI, NheI, NotI, PstI, PvuII, RsaI, SalI, SmaI, SmiI, SspI, TaqI, VspI, and XmiI (Fermentas, Lithuania).

The procedure was carried out according to instructions provided by the manufacturer. DNA fragments were separated by 0.8% and 1.5% agarose gel electrophoresis in TBE electrophoresis buffer. The approximate molecular sizes of separated DNA fragments were calculated using Quantity One software (Bio-Rad). One-kb DNA Ladder (Fermentas) and phage lambda DNA digested with HindIII were used as molecular markers.

Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis was performed according to the Laemmli’s standard protocol (Laemmli, 1970) using the CsCl-purified phage preparation. The phage was examined by negative contrast electron microscopy (EM; Brenner & Horne, 1959). The purified and concentrated virus preparation was fixed with 1% glutaraldehyde in 0.1 M phosphate buffer (pH 7.0) and then placed on transmission EPZ015666 EM support grids followed by rinsing with distilled water several times. The phage samples were stained with 1% uranyl acetate aqua solution for further examination with a Hitachi H-300TM electron microscope (Japan). Electron microscope magnification was calibrated using T4 phage as size standard. At least 20 electronic phage images were used for phage morphology determination.

To obtain electron microphotographs of the phage–host cell interaction, the mixture of A. baumannii 1053 cells (107 CFU mL−1) with the phage AP22 (108 PFU mL−1) was incubated in 0.05 M phosphate buffer (pH 7.0) for 10 min at room temperature. The phage–cell mixture was fixed with 1% glutaraldehyde L-NAME HCl in 0.1 M phosphate buffer (pH 7.0) and analyzed as described earlier. The problem of the search for potentially therapeutic A. baumannii phages and their characterization has recently attracted considerable attention because of the increasing interest of the microorganism itself as a threatening causative agent of nosocomial infections worldwide. Phage AP22 was isolated from clinical materials provided by the burn center of N.V. Sklifosovsky Scientific Research Institute of First Aid (Moscow). A phage was isolated from the burn center in a month and found to be identical in host range and RFLP assays with AP22. It can be assumed that the bacterial virus is stable in the hospital environments. The phage AP22 formed clear, round plaques of 2–3 mm in diameter with haloes (zone of clearance around each plaque) on A. baumannii-sensitive strains.

As the costs of medical air transportation are likely to increase in the future, the form of transportation and planning should be optimized by further epidemiological assessment in larger studies. By comparing the costs per flight time (min) and per distance (km), we showed that a stretcher in

a scheduled aircraft is significantly cheaper than an air ambulance IBET762 (p < 0.0001). Although there is no doubt that proper medical response should be the main goal while choosing the appropriate form of air transportation, awareness of the different costs, and logistical characteristics of different forms of AE should be considered. Furthermore, we believe that besides an emergency physician who accompanies and monitors the patient, auxiliary personnel, such as an intensive care nurse or paramedic, are essential for providing adequate care. We have observed that medical assistance enables the physician to concentrate exclusively on the medical care of the patient and this should be considered in the planning of AE cases. Planning of AE cases often represents a logistical challenge. Difficulties involving gathering adequate patient medical information, decisions on transport, route planning, different time zones, languages, and the variety of different health organizations in the country of transport origin should

not be underestimated. Defining the factors for evaluating the necessity of immediate AE has been the subject of recent research. Duchateau and colleagues High Content Screening identified patient age <15 years, lack of a high standard of structure in the country and location in sub-Saharan Africa as independent factors indicating the need for AE.5 They also reported on the Marco Polo evaluation program, which evaluates 1,143 hospitals in 120 countries worldwide. Each year it rates medical

facilities on a five-point scale and thereby assists decision making for immediate AE. Despite all of the identified assisting factors, it is the role of the physician who is in charge of transport planning to communicate with the patient, with the physician on-site, and with the patients’ relatives to determine and evaluate the need for AE. Limitations of the present study are the small Clomifene study size, the fact that patients were all transported by the same organization, and that they resided in a single European country. As the demand for AE is likely to increase in the future, the cost-effectiveness and selection of the appropriate form of air transportation, while assuring the right medical response, will be of increasing importance. M. S., M. B., D. S., H. L., C. T., C. C., P. A., and F. G. B. critically revised the manuscript for intellectual content. All authors read and approved the final manuscript and had full access to the study data. The authors M. S., D. S., C. T., P. A., and F. G. B. declare that they have no competing interests. The authors M. B., C. C., and H. L. work for the Workers’ Samaritan Federation Germany.

As the costs of medical air transportation are likely to increase in the future, the form of transportation and planning should be optimized by further epidemiological assessment in larger studies. By comparing the costs per flight time (min) and per distance (km), we showed that a stretcher in

a scheduled aircraft is significantly cheaper than an air ambulance Alectinib in vitro (p < 0.0001). Although there is no doubt that proper medical response should be the main goal while choosing the appropriate form of air transportation, awareness of the different costs, and logistical characteristics of different forms of AE should be considered. Furthermore, we believe that besides an emergency physician who accompanies and monitors the patient, auxiliary personnel, such as an intensive care nurse or paramedic, are essential for providing adequate care. We have observed that medical assistance enables the physician to concentrate exclusively on the medical care of the patient and this should be considered in the planning of AE cases. Planning of AE cases often represents a logistical challenge. Difficulties involving gathering adequate patient medical information, decisions on transport, route planning, different time zones, languages, and the variety of different health organizations in the country of transport origin should

not be underestimated. Defining the factors for evaluating the necessity of immediate AE has been the subject of recent research. Duchateau and colleagues U0126 chemical structure identified patient age <15 years, lack of a high standard of structure in the country and location in sub-Saharan Africa as independent factors indicating the need for AE.5 They also reported on the Marco Polo evaluation program, which evaluates 1,143 hospitals in 120 countries worldwide. Each year it rates medical

facilities on a five-point scale and thereby assists decision making for immediate AE. Despite all of the identified assisting factors, it is the role of the physician who is in charge of transport planning to communicate with the patient, with the physician on-site, and with the patients’ relatives to determine and evaluate the need for AE. Limitations of the present study are the small Dapagliflozin study size, the fact that patients were all transported by the same organization, and that they resided in a single European country. As the demand for AE is likely to increase in the future, the cost-effectiveness and selection of the appropriate form of air transportation, while assuring the right medical response, will be of increasing importance. M. S., M. B., D. S., H. L., C. T., C. C., P. A., and F. G. B. critically revised the manuscript for intellectual content. All authors read and approved the final manuscript and had full access to the study data. The authors M. S., D. S., C. T., P. A., and F. G. B. declare that they have no competing interests. The authors M. B., C. C., and H. L. work for the Workers’ Samaritan Federation Germany.

We used a virus co-expressing Cre recombinase and the red fluorescent protein tdTomato using Thosea asigna virus 2A self-cleavage sequences (AAV8/iCre-2A-tdTomato) to test the accuracy with which a virally-expressed fluorescent protein labeled cells that underwent Cre-mediated recombination. The AAV8-iCre-2A-tdTomato virus was co-injected at varying titers with AAV8-YFP into P0 pups from the R26R lacZ reporter line

(Soriano, 1999). Importantly, we found that tdTomato (Figs 9A–C) and β-gal (Figs 9G–I) were reliably co-localised (Figs 9P–R), indicating that the viral fluorescent protein served as an selleckchem accurate indicator of Cre-induced genetic modification within most brain regions, including the hippocampus and striatum (96 ± 0.4% of cells in the CA1 hippocampus and 94 ± 0.6% of cells in the striatum co-expressed tdTomato and β-gal; n = 22–25 sections, four to five sections/brain from five animals). Co-localisation was less dependable within the neocortex where, in layers 2/3 and 4, β-gal was often detected in cells with very low red fluorescence (89.4 ± 0.1.0% of cells in the cortex

co-expressed tdTomato and β-gal, n = 29 sections, six sections/brain from five animals). Although the majority of controllable genetic models are based on the Cre-loxP system, transgenic mice that utilise the tTA-rtTA system for inducible, reversible expression of transgenes are becoming increasingly available. To test viral delivery of tTA, we designed a virus encoding tdTomato-2A-tTA (AAV8-tdTomato-2A-tTA) and injected it into green fluorescent protein (GFP) tet reporter BYL719 supplier mice (tetO-nls-GFP-LacZ) (Mayford et al., 1996). We observed reliable co-expression of viral tdTomato and transgenic GFP in most brain areas in these mice (Fig. 10). Neonatal injection of 5.0 × 109 particles Edoxaban of AAV8-tdTomato-2A-tTA

into GFP tet reporter mice resulted in highly reliable co-expression of tdTomato and GFP in individual neurons, with very low mismatch in the hippocampus and cerebellum and slightly higher mismatch in the cortex (98 ± 0.5% of pyramidal neurons in CA1, 95 ± 1.0% of Purkinje cells in the cerebellum, and 83 ± 2.1% of neurons in the cerebral cortex co-expressed tdTomato and GFP; n = 12–19 sections, three to four sections/brain from four to five animals). These data provide proof-of-principle that the neonatal injection of viruses co-expressing a transgene and fluorescent marker can be employed to genetically manipulate a subset of cells in brain tissue and accurately identify these cells for further study. We recognised that the distributed transduction pattern of our low-titer injections resembled the sparse labeling seen in the Thy1-GFP transgenic M and S mouse lines that have been widely used for imaging dendritic processes in vivo (Holtmaat & Svoboda, 2009; Holtmaat et al., 2009). We wondered if viral transgenesis might allow live imaging of neurons in the intact brain as had these two Thy1 transgenic lines.

Prevention in VFR travelers to South Asia is critical and efforts should be targeted at better education and pre-travel immunization. Typhoid fever is endemic in

many areas of the world and also a leading cause of fever in the returning traveler.[1] Approximately 21 million people are affected with typhoid each year, which results in 200,000 to 600,000 deaths annually.[2-4] The highest prevalence is among infants, children, and adolescents in South Asia, where poor sanitation and food handling practices continue to make typhoid a persistent public health issue.[1-6] There is growing concern over the emergence of multidrug-resistant strains of Salmonella Typhi in many parts of Asia and Africa.[7] Since the rapid spread

of Roxadustat concentration multidrug-resistant (as defined by resistance to chloramphenicol, amoxicillin, and co-trimoxazole) S Typhi in the 1990s[7] and early 2000s,[8] quinolones have been the mainstay of treatment in adults.[9-11] However, during the last 2 decades, nalidixic acid-resistant strains (NARST) are being isolated with increasing frequency. Despite in vitro sensitivity to ciprofloxacin [minimum inhibitory concentration (MIC) < 1, though usually >0.1], the disease caused by these strains can have a prolonged and sometimes unfavorable course when treated with quinolones.[12] In the United States, approximately 400 cases of typhoid are reported each year, 70% to 90% of which are associated CP-868596 supplier with recent travel.[7, 13-15] Immigrants and travelers visiting friends and relatives (VFR travelers) are at a higher risk of acquiring typhoid.[8, 9, 16-19] Another 10% to 30% are domestic cases.[14] The vast majority of imported cases come from seven countries: India, Bangladesh, Pakistan, Mexico, the Philippines, El Salvador, and Haiti.[3, 8, 9] The overall risk of acquiring typhoid from travel to the Indian subcontinent is at least 10 to 20[20] and up to 100 times[21]

higher than from other geographic areas. History Glycogen branching enzyme of travel to the above regions,[15-17] in conjunction with clinical and laboratory features unique to typhoid, may be helpful in the initial diagnosis, prior to blood culture results being available.[22] Clinically, typhoid is typically characterized by a syndrome of prolonged high fever, relative bradycardia, splenomegaly, and abdominal symptoms.[1-3] Laboratory abnormalities often consist of pancytopenia with zero or near-zero eosinophils[10, 23-25] and mild transaminitis.[1-3, 9, 10, 15] This study is a retrospective analysis of the epidemiologic, clinical, and basic hematologic features of patients diagnosed with typhoid, as well as an analysis of the sensitivity profiles of S Typhi isolates collected over a 5-year period at Jacobi Medical Center, a municipal tertiary center that serves a large immigrant population. We queried all positive S Typhi isolates over a 5-year period, from January 2006 to December 2010.

After incubation, the number of viable cells was counted by plating the sample on Luria–Bertani agar plates. Escherichia

coli strains were cultured in Luria–Bertani medium to OD600 = 0.3. Bacterial cells were collected by centrifugation and suspended in PBS. Ten microliters of the bacterial suspension was mixed with fresh swine serum (NihonBiotest Co, Tokyo, Japan) and incubated at 37 °C for 90 min without shaking. After incubation, the selleck compound number of viable cells was counted by plating the sample on Luria–Bertani agar plates. First, we compared the virulence of the EHEC O157:H7 Sakai strain and laboratory E. coli strain W3110 in silkworms. Injection of the Sakai strain into silkworm hemolymph and incubation at 37 °C for 20 h killed the silkworms (Fig. 1a). The LD50 of the Sakai strain was 4.3 × 106 CFU per larva (Table 1). The LD50 of W3110 was 90 times

higher than that of Sakai (Table 1). Next, to identify the genes of EHEC O157:H7 required to kill silkworms, we investigated whether the supposed virulence factors of EHEC O157:H7 Sakai contribute to killing silkworms. The killing ability of double-deletion mutants of the stx1 and stx2 genes that encode Shiga toxin 1 and 2, respectively, in silkworms was indistinguishable from that of the parent strain, SKI5142 (Table 2). Moreover the deletion of ehxA, which encodes enterohemolysin, killed silkworms with an LD50 similar ZVADFMK to that of the parent strain (Table 2). Similarly, the killing ability of the mutant with a deletion of eae, which encodes intimin and plays an essential role in bacterial adhesion to host cells, was indistinguishable from that of the parent strain (Table 2). Deletion of flhDC, which encodes a master regulator of flagellar genes, and deletion of the lrhA gene, which encodes a transcription factor of enterohemolysin,

flagellar genes, and LEE genes, did not attenuate PD184352 (CI-1040) the silkworm-killing ability of EHEC O157:H7 (Table 2). These results suggest that Shiga toxins, enterohemolysin, functions of LEE, and flagellar genes are not required by EHEC O157:H7 to kill silkworms, but some other factors are necessary. We focused our attention on the LPS O-antigen of the outer membrane as a factor involved in the high virulence of EHEC O157:H7 against silkworms. We constructed a deletion mutant of the rfbE gene in the Sakai background, which encodes perosamine synthase, a monosaccharide component of the O-antigen that is specific for O157:H7. We also constructed a deletion mutant of the waaL gene that encodes a ligase of the O-antigen to core-lipid A (Fig. S1a and b). To confirm the absence of the LPS O-antigen in these mutants, we immunostained LPS fractions of these mutants using anti-O157 immunoglobulin. The findings indicated that both deletion mutants, rfbE and waaL, lacked the LPS O-antigen (Fig. S1c). We further confirmed that introducing rfbE or waaL into the respective mutant restored the LPS O-antigen (Fig. S1c).