DNA preparation Bacteria were cultured at 37°C for 24 h, suspended in 3 ml sterile distilled water, harvested (2000 × g, 10 minutes) and resuspended in 567 μl of 50 mM Tris, 50 mM EDTA,

100 mM NaCl (pH 8.0). Then, 30 μl of 10% (w/v) SDS and 3 μl of 2% (w/v) proteinase K were added, the mixture was held at 37°C for 1 h and extracted twice with phenol-chloroform. Nucleic acids in the aqueous phase were precipitated with two volumes of cold ethanol, dissolved in CP673451 manufacturer 100 μl of 10 mM Tris, 1 mM EDTA (pH 8.0) and the amount of DNA estimated by electrophoresis on 0.8% agarose gels using appropriate DNA solutions as the standards. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) The 20-mer primers were selected to amplify manB O – Ag , manA O – Ag , manC O – Ag , wbkF, wkdD, wbkE, wboA and wboB, wa* and manB core according to the B. melitensis 16 M genome sequence (Genbank accession numbers

AE008917 and AE008918) (Table2). Amplification mixtures were prepared in 100 μl volumes containing 10 mM Tris-HCl (pH 9.0), 50 mM KCl, 1.5 mM MgCl2, 0.1% Triton X-100, 0.2 mg ml-1gelatin (1 × PCR buffer; Appligene), 200 μM each deoxynucleoside triphosphate, 1 μM each primer, 100 ng of genomic DNA, and 2.5 U of Taq DNA polymerase (Appligene). Amplification was performed in a GeneAmp PCR System 9600 thermocycler (Perkin Elmer) as follows: cycle 1, 94°C for 5 GSK2126458 price minutes (denaturation); the next 30 cycles, 58°C for 30 s (annealing), 70°C for 30 s (extension) and 94°C for 30 s (denaturation); the last cycle, 58°C for 30 s (annealing) and 70°C for 10 minutes (extension). For PCR-RFLP, Alu I, Ava I, Ava II, Bam HI, Bgl I, Bgl II, Cla I, Eco RI, Eco RV, Hind III, Hae II, Hinf I, Pst I, Pvu II, Sau 3A, SaI I, Sty I were used. The restriction enzymes were chosen according to the B. melitensis 16 M genomic

sequences of the above-listed genes. 2.4. Nuceotide sequence and data analysis PCR products of the expected sizes were purified selleck screening library from 1% agarose gels (Invitrogen) with a QIAquick gel extraction kit (Qiagen GmbH, Hilden, Germany), cloned into pGEM-T Easy vector (Promega, Madison, Wis.), and transformed into competent JM109 Escherichia coli cells (Promega). The transformants were selected with ampicillin, and recombinants were selected by blue-white differentiation. Plasmids were isolated from several clones with a Qiagen Plasmid Mini kit. To check for the presence of the correct insert, plasmids were digested with EcoRI and the restriction products were separated on 1% agarose gels. Nucleotide sequencing of clone was performed by automated cycle sequencing with Big Dye terminators (ABI 377XL; PE Applied Biosystems, Foster City, Calif.) and primers RP (reverse primer) and UP (universal selleck inhibitor primer M13-20). Multiple DNA and amino acid sequence alignments were performed with CLUSTAL Whttp://​www2.​ebi.​ac.​uk/​clustalw/​.