The wztYS-11 was introduced into strain 455, and the changes in the phenotype were observed by SEM. The fragment including the wztYS-11 ORF was amplified by PCR using the primers wzt-EcoF and wzt-PstR (Table 1). An EcoRI site or a PstI site (Table 1, underlined) was introduced into the 5′ end of the PCR product. The reaction

mixture contained 10 ng μL−1 genome DNA of strain YS-11, 1 × PCR buffer, 0.2 mM dNTPs, 0.5 μM each primer, and 25 mU μL−1 KOD dash DNA polymerase (Toyobo, Osaka, Japan), and sterile-distilled water was added to the mixture to a final volume of 50 μL. The reaction conditions were as follows: 94 °C for 6 min, 35 cycles of 94 °C for 1 min, 60 °C for 1 min, and 72 °C for 1 min, and 72 °C for 2 min with a PCR thermal cycler (Takara Bio). The PCR product purified with the QIAquick gel extraction kit (Qiagen) was digested with EcoRI and PstI (Takara Bio), and ligated Pexidartinib supplier to the plasmid vector pSTV28 (Takara Bio), which was predigested with the same combination of restriction enzymes. Ligation was performed using a DNA ligation kit ver. 2.1 (Takara Bio)

according to the manufacturer’s directions. Escherichia coli DH5α (Invitrogen) was transformed with this ligation solution. Aurora Kinase inhibitor The constructed plasmid, named pWZT, was purified from a colony grown on TSAY containing 20 μg mL−1 of chloramphenicol. Ten nanograms of constructed plasmid was added to 50 μL of the competent cell of strain 455, and transformation was carried CHIR-99021 concentration out as described above. Measurement of the viscosity of spent culture media and SEM observation for the presence of meshwork-like surface structures were carried out on the recombinants grown on the TSAY containing 50 μg mL−1 of kanamycin and 20 μg mL−1 of chloramphenicol. The wztYS-11 on the pWZT was fused with the α-peptidase gene on pSTV28 so that the viscosity and the cell surface-associated phenotype were examined under culture conditions with or without 1 mM isopropyl-β-d(−)-thiogalactopyranoside (IPTG; Wako Pure Chemical Industries, Osaka, Japan). Strain 455 with pSTV28 and E. coli DH5α with pWZT were used as controls. The bacterial strains and plasmids used in this study are listed

in Table 2. Escherichia hermannii strains YS-11 and 455-LM with meshwork-like structures were compared with those of strains 455 and ATCC33650 that lacked this phenotype for the ability to induce abscess formation in mice. Bacterial strains were cultured in TSBY for 12 h (early stationary phase). Five hundred microliters of bacterial suspensions (107–109 CFU mL−1) were injected subcutaneously into the inguen of each BALB/c mouse (male, 4 weeks; three mice per strain). Changes in abscess lesions were recorded photographically using a camera (Nikon FIII, Nikon, Japan) set at a fixed magnification for five consecutive days. Stock cultures of YS-11 were inoculated into TSBY and grown for 48 h. The viscosities of the spent culture media were measured using a rotary viscometer.