CENP-H expression was higher in tongue cancer cell lines and nasopharyngeal carcinoma cell lines [20, 21]Therefore, to study centromere proteins may contributes to exploring

the mechanism of chromosome segregation, revealing the mechanism of malignant cellular proliferation and finding cancer marker proteins, and also may provide new targets for carcinoma therapy and prognosis estimation of cancer patients. Reduced expression of CENP-E in human hepatocellular carcinoma CENP-E is also one of the components directly responsible for capturing and stabilizing spindle microtubules by kinetochores [9, 10]. CENP-E interacts with BubR1 and stimulates its kinase activity, which implicates click here its role in activating and maintaining mitotic checkpoint signalling [6, 19]. Deletion CENP-E by various methods could impair the function of spindle checkpoint [9, 12]. In this study we found TSA HDAC chemical structure that the mRNA and protein expression levels of CENP-E were reduced both in HCC tissues and in human hepatocellular carcinoma-derived cell lines (HepG2), and that the LO2 cells transfected with shRNA vector had a decreased

proliferation rate and an increased proportion of aneuploid and apoptosis cells. Reduced expression of CENP-E may be involved in human hepatocarcinogenesis Our evidence presents that the level of CENP-E protein was reduced in the HCC tissues, which implicates that CENP-E may be involved in human hepatocarcinogenesis. We draw this conclusion from two aspects as follows: (1) Aneuploidy is related with tumorigenesis. A majority of human cancer cells are aneuploid due to an underlying chromosomal instability phenotype [22]. Theodor Boveri proposed an aneuploid hypothesis, in which, aneuploid was presumed as a direct cause of cancerous transformation [23]. With the discovery of oncogenes and tumour suppressors in the late 1970s and 1980s, some researchers suggested that heterozygosity

loss might result in the phenotypic expression of mutated tumour suppressor genes in the aneuploid cell, and aneuploid cells may show chromosome polysomy that harbours oncogenes [24]. Aneuploid is still an important cause of tumorigenesis, and oncogenes hypothesis also supports this SPTLC1 point, although there is no direct evidence to confirm that aneuploidy is a primary contributor to tumorigenesis up to now.   (2) Cancer is associated with weakened spindle checkpoint. A growing body of evidence suggests that defects in the spindle checkpoint might promote aneuploidy and tumorigenesis. Mouse with reduced expression of spindle checkpoint proteins survived but developed aneuploidy at an elevated rate, and in some, but not all cases, these animals are more susceptible to spontaneous tumours [25, 26] Cells over-expressing Mad2 developed a large number of chromosome breaks, fragments, and fusions in addition to whole chromosomal aneuploidy [27].

pleuropneumoniae BGB324 concentration [25] and loss of the ability in colonizing in the gastric mucosa in Helicobacter pylori[26] after frdA genes were inactivated. Furthermore, Joseph et al. described FrdA as an antigen in Brucella abortus [27]. FepA, FrpB and HbpA are important components in several ABC transport pathways for obtaining iron or regulating iron utilization in vivo or vitro. The immunogenic activity of FepA and FrpB was shown in Klebsiella pneumoniae [28] and Neisseria meningitides

[29] respectively, and HbpA was widely conserved and served as an antigen in Leptospira interrogans[30]. Moreover, homologous analysis of these proteins at NCBI revealed a high level identity (>98%) with the sequenced serotype CHIR98014 price 1, 5 and 7 strains respectively. These suggest that they might be new common antigens for A. pleuropneumoniae. High-affinity zinc uptake system protein ZnuA precursor, was essential of B. abortus for intracellular survival and virulence in mice[31] and shown immunogenic in Streptococcus suis[5]. PsaA is needed for the adherence of pneumococcal cells and antibodies to PsaA contributed to reduce the nasopharyngeal colonization

of challenged pneumococcal cells [32, 33]. DegPs, a member of the widely conserved HtrA family of serine proteases, were frequently identified as antigens in other pathogens, such as B. abortus [34] and Chlamydia trachomatis [35]. Besides, trigger factor (TIG) has been demonstrated to be an excellent candidate for vaccination against Brucella melitensis [36] and a virulence-related protein in Listeria monocytogenes [37], and similar findings were described about malate dehydrogenase (MDH) of Candida albicans [38] and spermidine/putrescine-binding

periplasmic protein (PotD) of Streptococcus pneumoniae [39]. Glyceraldehyde 3-phosphate dehydrogenase (GapA) has been proven to be antigenically conserved proteins, suggesting potential for vaccines in several microorganisms [40]. Homologous protein of translation elongation factor EF-Tu (TufB), a very abundant protein, had been detected oxyclozanide in immunological researches of other bacteria, such as C. trachomatis[41] and Shigella flexneri[7]. The periplasm of gram-negative bacteria is well equipped with ATP-independent chaperones and folding catalysts, including peptidyl-prolyl isomerases (FkpA). It is reported recently that FkpA was found to be immunogenic in Bordetella pertussis[42]. Phosphate acetyltransferase (PTA), an enzyme that catalyzes the reversible transfer of the acetyl group from acetyl phosphate to coenzyme A plays a major role in the energy-yielding metabolism[43] and recently has been reported to be immunogenic in S. suis[5].

However,

there are few reports on β-galactosidases obtained via metagenomic strategies up to now. Recently, a novel β-galactosidase gene, zd410, was isolated by screening a soil metagenomic library [18]. Nevertheless, this enzyme was regarded as a cold-adapted β-galactosidase due to its optimal temperature of 38°C and 54% residual activity at 20°C. Thus, identification of novel β-galactosidases https://www.selleckchem.com/products/dorsomorphin-2hcl.html with high thermostability and low inhibition of reaction product via metagenomic strategy is still urgently in demand. In the present study, a metagenomic library from soil samples of Turpan Basin, the hottest and driest area in China, was constructed, and a novel β-galactosidase (Gal308) was identified and expressed in Escherichia coli (E. coli). The enzymatic properties of Gal308 with N-terminal fusion tag were investigated after purification, and this enzyme displayed several novel properties including high thermostability, high tolerance of galactose and glucose, as well as high enzymatic activity for lactose. These properties Trichostatin A mouse make it a good candidate in the production of low-lactose milk and dairy products after further study. Results Screening for β-galactosidase from a metagenomic library

To discover novel thermostable β-galactosidases, a metagenomic library consisting of approximately 8,000 clones was constructed using DNA extracted from soil samples of the Mountain of Flames of the Turpan Basin in China. Restriction analysis of 20 randomly selected clones from

metagenomic library indicated that 95% of clones contained inserts of 2.5 to 7.5 kb in size, with an average size of 4.2 kb. Thus, the metagenomic library covered theoretically about 33.6 MB of soil microbial community DNA. One positive clone with bright blue color was finally identified from the metagenomic library. The activity of the positive clone was reconfirmed after retransformation, and then the plasmid of this clone was extracted and an insert of 5215 bp was sequenced. The ORF-finder and blastX analysis revealed the presence of an open reading frame of 1977 bp, which encoded a glycoside Cyclin-dependent kinase 3 hydrolase family 42 (GH family 42) protein (Gal308) of 658 amino acids. A protein blast (blastp) search in the databases of NCBI indicated that the protein had the highest identity of 49% (291/599) with the β-galactosidase from one thermophilic microbe Geobacillus thermocatenulatus, as well as a low identity of only 38% (224/593) with the β-galactosidase from the other thermophilic microbe Thermoanaerobacterium thermosaccharolyticum DSM 571, suggesting that Gal308 is probably a novel thermostable β-galactosidase from unculturable microorganisms. In addition, multiple sequence alignment of Gal308 and other five homologous β-galactosidases from GH family 42 allowed the identification of the active site residues of Gal308 (Figure 1).

Thanks to this optical behavior, GNRs are able to transform the absorbed energy into localized heat. This optical effect is used to develop cancer therapies as photothermal tumor destruction either by direct enough increase of selleck chemicals llc temperature or indirectly by co-adjuvant drugs, at the same time delivered by the particle, or already present and activated by the heating [5–8]. Our research group has recently developed an optical hyperthermia device based on irradiation of GNRs with a continuous wave (CW) laser in order to induce in vitro death of human brain astrocytoma cells (1321 N1) [9]. Unlike many high-energy pulsed lasers that generally

lead to particle

structure changes and ablation in a very short time, CW lasers allow heat dissipation from particles to surrounding medium (via phonon-phonon relaxation), so they are an appropriate choice in order to use the produced heat for the Fedratinib chemical structure cure of cancer [10]. The effectiveness of the developed method was determined by measuring changes in cell viability after laser irradiation of cells in the presence of GNRs. In accordance to other results in comparable experiments [11–13], ours indicated that continuous laser irradiation in the presence of the particles induced a significant decrease in cell viability, while no decrease in cell viability was observed with laser irradiation or incubation with GNRs alone. Due to the limited capacity of laser penetration in tissues, this method could be used in clinical practice as an additional aid to surgery

for removing brain tumors completely. After this proof of concept, our objective was focused in getting a better understanding about the working principles and physical behavior of optical hyperthermia devices. It is not very common to find GPX6 studies including a comprehensive characterization about the global phenomena in optical hyperthermia systems. Moreover, although now there are a huge variety of noble metal nanoparticles that can be used to carry out this kind of therapy, an absolute control about their behavior still does not exist. Therefore, it is necessary to develop a series of characterization and modeling processes to increase the effectiveness of the hyperthermia treatments, thanks to the prediction of the system response. With this aim, a method to calculate the thermal parameters of the system and the photothermal transduction efficiency for different kinds of nanoparticles has been developed. This method, which allows an easy and effective thermal characterization and so predicts the thermal behavior of the system, is not only valid for our device but also for any kind of optical hyperthermia system.

Microbiology 2011,157(4):988–999.PubMedCrossRef 8. Lane WJ, Darst SA: The structural basis for promoter −35 element recognition Transmembrane Transporters inhibitor by the group IV sigma factors. PLoS Biol 2006,4(9):e269.PubMedCrossRef 9. Lambert C, Smith MCM, Sockett RE: A Novel assay to monitor predator–prey interactions for Bdellovibrio bacteriovorus 109 J reveals a role for methyl-accepting chemotaxis proteins in predation. Environ Microbiol 2003,5(2):127–132.PubMedCrossRef

10. Nakahigashi K, Yanagi H, Yura T: Isolation and sequence analysis of rpoH genes encoding sigma 32 homologs from Gram negative bacteria: conserved mRNA and protein segments for heat shock regulation. Nucleic Acids Res 1995,23(21):4383–4390.PubMed 11. Lambert C, Evans KJ, Till R, Hobley L, Capeness

M, Rendulic S, Schuster SC, Aizawa S, Sockett RE: Characterizing the flagellar filament and the role of motility in bacterial prey-penetration by Bdellovibrio BIBF 1120 supplier bacteriovorus. Mol Microbiol 2006,60(2):274–286.PubMedCrossRef 12. Guisbert E, Yura T, Rhodius VA, Gross CA: Convergence of molecular, modeling, and systems approaches for an understanding of the Escherichia coli heat shock response. Microbiol Mol Biol Rev 2008,72(3):545–554.PubMedCrossRef 13. Gupta P, Aggarwal N, Batra P, Mishra S, Chaudhuri TK: Co-expression of chaperonin GroEL/GroES enhances in vivo folding of yeast mitochondrial aconitase and alters the growth characteristics of Escherichia coli. Int J Biochem Cell Biol 2006,38(11):1975–1985.PubMedCrossRef 14. Clare DK, Bakkes PJ, van Heerikhuizen H, van der Vies SM, Saibil HR: Chaperonin complex with a newly folded protein encapsulated in the folding chamber. Nature 2009,457(7225):107–110.PubMedCrossRef 15. Lambert C, Chang CY, Capeness MJ, Sockett RE: The first tetracosactide bite–profiling the predatosome in the bacterial pathogen Bdellovibrio. PLoS One 2010,5(1):e8599.PubMedCrossRef 16. Li J, Wang Y, Zhang CY, Zhang WY, Jiang DM, Wu ZH, Liu H, Li YZ: Myxococcus xanthus viability depends on groEL supplied by either of two genes,

but the paralogs have different functions during heat shock, predation, and development. J Bacteriol 2010,192(7):1875–1881.PubMedCrossRef 17. Iida Y, Hobley L, Lambert C, Fenton AK, Sockett RE, Aizawa S: Roles of multiple flagellins in flagellar formation and flagellar growth post bdelloplast lysis in Bdellovibrio bacteriovorus. J Mol Biol 2009,394(5):1011–1021.PubMedCrossRef 18. Faulds-Pain A, Birchall C, Aldridge C, Smith WD, Grimaldi G, Nakamura S, Miyata T, Gray J, Li G, Tang J, et al.: Flagellin redundancy inCaulobacter crescentusand its implications for flagellar filament assembly. J Bacteriol 2011,193(11):2695–2707.PubMedCrossRef 19. Kass I, Horovitz A: Mapping pathways of allosteric communication in GroEL by analysis of correlated mutations. Proteins 2002,48(4):611–617.PubMedCrossRef 20. Lambert C, Sockett RE: Laboratory maintenance of Bdellovibrio. Curr Protoc Microbiol 2008,:7B 2.1–7B 2.13. Chapter 7 21.

Jallat et al. [11] used HEp-2 adherence to identify DAEC in a French study and found these organisms to be significantly associated with disease in patients of all ages (p < 0.0001). In that study, only 33 of the 100 DAEC isolates identified hybridized with the daaC probe and interestingly, five of these strains also hybridized with the CVD432 probe for enteroaggregative E. coli and showed an aggregative-diffuse

pattern of adherence. Ten daaC positive strains were non-adherent. A second study, by Gunzburg et al. [39], found that DAEC were not associated with diarrhoea overall, and were more common in healthy patients under 18 months CP673451 of age. However, Gunzburg et al. did find that in children aged 18 months to five years, DAEC were recovered from 11 cases and 4 controls (p ≤ 0.05). Similarly, Scaletsky et al. [9] found that DAEC was not associated with disease overall in a study performed in North-East Brazil but was significantly associated with diarrhoea among children in the 13-24 month old age group. These studies provide evidence to advocate that future investigations aim to determine whether there is a role for DAEC in diarrhoea in some populations, particularly in children over one year of age, and that

they do so using techniques other than the daaC probe. There are important implications for the

role of pathogens other than DAEC SBE-��-CD clinical trial in disease that may come to light if the daaC probe is replaced with more specific testing methods. Recent studies have demonstrated that AAF/II-positive EAEC are more significantly associated with diarrhoea than the EAEC category as a whole 40-43. Thus any test for DAEC that detects potentially AAF/II EAEC will skew the results towards a stronger association of the DAEC category with disease, particularly if the EAEC strains in question are negative for the commonly used but inadequately sensitive EAEC CVD432 probe. Additionally, evidence supporting a role in diarrhoea for less-studied E. coli categories such as cell-detaching E. coli or cytolethal distending Vitamin B12 toxin-producing E. coli, appears to be equivalent to supporting data for DAEC, if daaC-derived data is discounted. Future investigators may want to consider these under-studied categories as worthy of further study. There is some suggestion that DAEC could be an important pathogen in weaned children but in order to correctly gauge the relative contributions of DAEC and other pathogens such as AAF/II-producing EAEC to diarrhoea epidemiology, it is imperative that the SLM862 daaC probe, which detects AAF/II-positive EAEC as well as DAEC, be discarded in favour of more specific methodology.

208; von Benda-Beckmann and von Benda-Beckmann 2007) or the effects

of large scale, government sponsored transmigration programs as that of Indonesia (Murray Li 2007, p. 259; Sodhi et al. 2009; Rist et al. 2010). Concepts of “indigenous” space then often clash with the concept of citizenship in a young nation state where anyone can settle wherever they like (Murray Li 2007, pp. 114–116). What’s more, displaced communities argue that their identities and associated rights should not be dependent on fixed associations with a certain territory, but should be portable (Murray Li 2007, p. 173). A further problem with essentialised understandings of “indigenous and local communities” is that as legal classifications and categories they AZ 628 purchase force communities to live up to the expectations of outsiders, especially of lawyers and administrators, with regards to the “authenticity” of

their “traditional lifestyles”. Such categories favour “tribal” over urban based knowledge check details and “indigenous” knowledge over tradition based forms of knowledge related to court cultures and elites, to a country’s majority population or to migrant communities (Antons 2008, p. 295). All too often, villagers and forest dwellers who attempt to improve their situation are subsequently seen as no longer matching the expectations with regards to the authenticity of their “traditional lifestyles”. Forsyth and Walker (2008, pp. 213–214) explain how in Thailand, “traditional” village life may become associated with lack of education, electricity or public health in the case of one Karen village, whereas another Karen village with road access and market integration is seen as already too “modernised”. Different from settler societies such as Australia, New Zealand, the United

States and Canada, much of traditional knowledge in Asia may also reside in fairly large majority population groups or even at the national level. Examples from traditional medicine are Indian Ayurveda, Chinese or Thai traditional medicine and Indonesian jamu, which is originally associated Calpain with the main island of Java, but has meanwhile become a term of the national language Bahasa Indonesia referring to Indonesian traditional medicine more generally (Antons 2005; Antons and Antons-Sutanto 2009). As a consequence, many Asian governments for many years have expressed reservations about the applicability of the term “indigenous people” in Asia, a concept which in their views was more appropriately used in connection with the situation in Anglo-American settler colonies (Kingsbury 1999; Persoon 2009; Benjamin 2002, pp. 14–15; Murray Li 2000). The difference came to expression during the deliberations in the WIPO IGC about a voluntary fund established to support the participation of accredited local and indigenous communities in the IGC debates (Antons 2007, pp. 5–6).

Chemical synthesis of flower-like ZnO-Ag2O composites Flower-like ZnO-Ag2O composites with different mole

ratios were prepared by the chemical precipitation method. A typical experimental process for the composite with a mole ratio of 1:1 is given as follows: 0.4 g of flower-like ZnO was dispersed in 100 mL of deionized water, and 2 g of PEG-8000 was added into the mixture in order to immerse the ZnO thoroughly. Subsequently, 1.8 g of AgNO3 was added to the suspension, and the mixture was stirred magnetically for 30 min. Then Duvelisib order 0.2 M of NaOH was dropped into the above mixture with the final pH value of 14. Finally, flower-like ZnO decorated by Ag2O nanoparticles was washed repeatedly with deionized water followed by a filtration and drying in air at 90°C for 2 h. In order to assess the relationship between the component and the photocatalytic activity of the composites, variable mole ratios of ZnO to Ag2O composites were prepared through a similar process. Characterizations and photocatalytic testing X-ray diffraction (XRD) measurement was carried out using a Rigaku-D/max 2500 diffractometer (Rigaku, Shibuya-ku, Japan) with Cu-Kα radiation (λ = 0.15418 nm) Selleckchem CH5183284 for crystallization identification. The morphology, particle size, and chemical composition

of the product were examined by scanning electron microscopy (SEM; Hitachi S-4800, Chiyoda-ku, Japan). X-ray photoelectron spectroscopy (XPS) experiments were performed with a Thermo Fisher K-Alpha X-ray photoelectron spectrometer (Thermo Fisher Scientific, Waltham, MA, USA) using Al Kα radiation (12 kV, 6 mA). The binding energies of elements were calibrated using C 1s (284.6 eV) as reference. Room-temperature ultraviolet–visible (UV–vis) absorption spectrum was recorded on a spectrophotometer (PerkinElmer Lambda-35, Waltham, MA, USA) in the wavelength range of 300 to 800 nm. The UV–vis diffuse reflectance spectra (DRS) were measured using Teicoplanin a Shimadzu UV-2550 spectrophotometer (Shimadzu, Kyoto, Japan). Room-temperature photoluminescence (PL) spectra were collected with a laser micro-Raman (JY HR800, HORIBA, Kyoto, Japan). MO

was employed as a representative dye pollutant to evaluate the photocatalytic activity of ZnO-Ag2O composites. Next, 0.02 g of ZnO-Ag2O composites was suspended into 60-mL 2 × 10−5 M of MO aqueous solution and stirred for 30 min in a 200-mL beaker in the dark to reach an adsorption/desorption equilibrium for MO on the surface of ZnO-Ag2O composites. Then the mixture was irradiated by 16-W ultraviolet irradiation (Philips, Amsterdam, The Netherlands) at room temperature. After the reaction mixture was irradiated for a given time, the samples of 4 mL were withdrawn at each time and centrifuged for 20 min. The quantitative determination of MO was performed by measuring its absorption with a UV–vis spectrophotometer (PerkinElmer Lambda-35).

What is interesting to note, however, is that when both the ΔnagA mutants were grown on Aga, the induced levels of nagB fell drastically to about 10% of that in glycerol grown ΔnagA mutants (Table 1). A very likely reason why this happens is that upon induction of agaA in ΔnagA mutants by Aga, the induced AgaA deacetylates the accumulated GlcNAc-6-P to GlcN-6-P thereby lowering the intracellular concentration of GlcNAc-6-P which results in turning down the expression of the nag regulon. This strongly suggests that AgaA can deacetylate GlcNAc-6-P

in addition to Aga-6-P just like NagA can substitute for the absence of AgaA. Finally, in Aga grown EDL933 ΔnagA the induced levels of agaA and agaS were about 220% and 180%, respectively, of that in Aga grown EDL933 and likewise, in E. coli C ΔnagA grown on Aga, the induced levels of agaA and agaS were about 550% and 150%, respectively, of Batimastat ic50 that in E. coli C grown on Aga. Why this happens remains to be investigated. Constitutive expression of the aga/gam regulon enables a ΔnagA mutant to grow on GlcNAc The induction of nagB in ΔnagA mutants grown on glycerol and its repression when grown on Aga (Table 1) indicated that AgaA deacetylated GlcNAc-6-P. Unlike ΔagaA mutants which grew on Aga (Figure 2) because nagA was expressed in these mutants by Aga (Table 1), check details ΔnagA mutants did not grow on GlcNAc most likely

Erastin in vivo because agaA is not expressed with GlcNAc (Figure 1). If this is true, then deleting the agaR gene, that codes for the repressor of the aga/gam regulon, in a ΔnagA mutant would result in the constitutive expression of the aga/gam regulon and thereby of agaA that would allow its growth on GlcNAc. Therefore, agaR deletion mutants in E. coli C and in E. coli C ΔnagA were constructed and examined for growth on GlcNAc. As shown in Figure 3, E. coli C and E. coli C ΔagaR grew on GlcNAc and the ΔnagA mutant

did not grow but the double knockout strain, E. coli C ΔnagA ΔagaR, did indeed grow on GlcNAc. Phenotypic microarray [13] done with E. coli C ΔnagA ΔagaR also revealed that it regained the ability to utilize ManNAc and N-acetylneuraminic acid in addition to that of GlcNAc (data not shown) as their utilization is nagA dependent [5]. Analysis by qRT-PCR was done to confirm that agaA and agaS were constitutively expressed in E. coli C ΔagaR and in E. coli C ΔnagA ΔagaR. As shown in Table 2, agaA and agaS were expressed in E. coli C ΔagaR and E. coli C ΔnagA ΔagaR irrespective of the carbon source used for growth but nagA and nagB were induced only by GlcNAc and, as expected, nagA expression was not detected in E. coli C ΔnagA ΔagaR. In fact, agaA and agaS were induced higher in these ΔagaR mutants than that in Aga grown E. coli C, the only exception being that of agaA whose induction was slightly lower in GlcNAc grown E. coli ΔagaR.

All authors read and approved the final manuscript.”
“Background Cholera is a severe disease characterized by watery diarrhea that is caused by the gram-negative bacterium V. cholerae. The massive diarrhea experienced by patients is mainly due to the colonization of toxigenic V. cholerae strains in the small intestine and their production of cholera toxin (CT) [1]. Cholera continues to be a major public health concern in many developing countries [2, 3]. Outbreaks of cholera have been increasing globally in the past decade, most recently in Haiti [4]. V. cholerae

is CDK inhibitor naturally present in the environment and autochthonous to coastal and estuarine ecosystems. Based on the heat-stable somatic O antigen, the species V. cholerae is divided into more than 200 serogroups [5, 6]. Only two serogroups, O1 and O139, have thus far been demonstrated to cause epidemic and pandemic cholera. Seven pandemics caused by V. cholerae O1 have been reported since 1871. V. cholerae O139 emerged in late 1992 on the India subcontinent [7, 8]. V. cholerae O1 exists as two biotypes, classical and El Tor, which are distinguished by a variety of phenotypic markers, and differ in this website the severity of their infections and ability to

survive outside the human intestine as well [3, 9–11]. Two of the first six cholera pandemics are known to have been caused by the classical biotype, while the ongoing seventh pandemic, which began in 1961, is caused by the El Tor biotype. The vast majority of strains within the O1 serogroup display one of two serotypes, Ogawa or Inaba. A third serotype called Hikojima also exists, but is rare and unstable

and not recognized by some authorities [3]. The Ogawa and Inaba serotypes differ by the presence of a 2-O-methyl group in the nonreducing terminal carbohydrate in the Ogawa O antigen [12, 13]. The O antigen is not a primary gene product, but rather, an assemblage of sugar moieties. The genes responsible for the synthesis of the O1-specific antigens are present in a cluster designated the rfb region [14]. Sorafenib purchase Genetic changes in this region are correlated with specific somatic antigens which are serologically different. The serogroup O139 resulted from a 22 kb deletion of the rfb region of an O1 El Tor strain, with replacement by a 35 kb wbf region encoding the O139 specific O antigen [15]. Serotype conversion within the O1 serogroup has been demonstrated to occur during subculture in vitro, passage in vivo, epidemics and during phage treatment [16–21]. Genetic alterations in the rfbT gene account for the serotype shift which encodes a transferase responsible for the expression of the Ogawa-specific antigen [19, 22, 23]. Site-specific sequence mutations causing a frameshift in the rfbT gene, thus producing truncated RfbT proteins, were previously detected in Inaba strains [19, 22, 24]. Generally, the serotype shift occurs more frequently in the direction of Ogawa to Inaba [3].