In addition, results of RT-PCR showed an increase of peb3 and a decrease of kpsM gene expression over time, suggesting that a shielding effect of capsule may be selleck screening library essential at the initial stages of infection, hiding bacterial cell surface structures. Subsequent down regulation of CPS production during colonisation may lead to exposure of other bacterial cell surface structures required for the attachment and/or evasion of host immune response. Conclusions The results of this study demonstrated a complex interplay of Campylobacter capsule and glycoprotein adhesins in pathogen-host interaction. The developed assay

will assist in more detailed investigation of such interaction and in the development of inhibitors of attachment as novel antibacterials. Methods Bacterial strains and growth conditions C. jejuni strain 11168H and its isogenic mutant 11168H/kpsM::kan

r were described previously [19, 36]. C. jejuni was grown CHIR98014 under microaerophilic conditions (5% O2, 10% CO2, 85% N2) at 37°C on Columbia Blood Agar (Oxoid) containing 6% defibrinated horse blood (Fisher) and Skirrow supplement (Sigma). Antibiotics (chloramphenicol 10 μg/ml and/or kanamycin 50 μg/ml) were added to the media as required. E. coli strains XL1 and XL2 (Stratagene) were used in cloning experiments. E. coli strains were maintained on Luria–Bertani agar (Oxoid) plates or in Luria–Bertani broth (Oxoid) supplemented with appropriate antibiotics (ampicillin 100 μg/ml, kanamycin 50 μg/ml or chloramphenicol 34 μg/ml) at 37°C. General cloning techniques Molecular cloning was performed using standard protocols. The plasmids used in this study are listed in Table 1. Restriction enzymes and antarctic phosphatase were purchased from New England Biolabs. T4 DNA ligase and T4 DNA polymerase were purchased from Promega. Oligonucleotides were ordered from Sigma-Genosys. Genomic and plasmid DNAs were SCH727965 ic50 extracted using Qiagen kits. Restriction, DNA ligation, PLEKHB2 dephosphorylation and blunt-ending were performed according to manufacturers’ protocols. Table 1 Plasmids

used in this study Plasmids Description Source (reference) pGEM-T Easy Cloning vector Promega pJMK30 Source of kan r cassette [37] pAV35 Source of cam r cassette [37] pBAD33 Contains pBAD promoter [38] pPGL1 C. jejuni 16 kb fragment, containing pgl gene cluster, cloned into pBR322 [24] pRRC Cassette cloned into pRR (fragment of rRNA gene cluster cloned into pGEM-T easy) [39] Construction of C. jejuni mutants Fragments of the genes peb3 and jlpA were PCR amplified using the primers listed in Table 2 and cloned into pGEM-T Easy (Promega) vector to produce plasmids pGEM_peb3 and pGEM_jlpA respectively. In order to disrupt the peb3 gene, the pGEM_peb3 plasmid was digested with PflMI, blunt ended and ligated with the SmaI-digested kan r cassette producing pGEMpeb3_kan construct.