Objective: To investigate the molecular typing and drug resistance of Salmonella in market-sold raw livestock meats in Shaoxing City, Zhejiang Province, so as to provide the basis for the prevention and control of drug-resistant Salmonella. Methods: Salmonella isolates were detected and serotyped from raw livestock meat samples collected from supermarkets, agricultural markets and restaurants in Shaoxing City between March and November 2023. Molecular typing was performed using pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Antibiotic resistance phenotypes and resistance gene analyses were conducted using broth microdilution method and whole genome sequencing. Results: A total of 34 Salmonella isolates were detected from 329 samples and the positive rate was 10.33%. There were 14 serotypes, with S. Rissen (9 isolates, 26.47%) and S. London (8 isolates, 23.53%) being dominant. PFGE typing revealed 31 band patterns and 23 banding pattern clusters of Salmonella, and the similarity ranged from 30.80% to 100.00%, without dominant band patterns. MLST identified 15 sequence typing (ST) types, and S. Rissen were all ST469 and S. London were all ST155. Salmonella strains exhibited high levels of resistance to tetracycline (44.12%) and ampicillin (35.29%). Thirteen resistance patterns were identified, with 8 multidrug resistant patterns (29.41%). There were 8 classes of 14 resistance genes, with aminoglycoside resistance gene aac(6' )-Iaa found in 100.00% of the strains. The highest concordance rate between the resistance phenotype and gene was observed for phenicol antibiotics (97.06%), while there was no concordance between the quinolone resistance phenotype and genes. Conclusions S. Rissen and S. London are the predominant serotypes in market-sold raw livestock meats in Shaoxing City. The PFGE band types of the Salmonella isolates show polymorphism distribution, and MLST are mainly ST469 and ST155. The isolates have high levels of resistance to tetracycline and ampicillin, manifesting multidrug resistance.

Objective To analyze the enzymatic activity of Leptospira interrogans ( L. interrogans) LA_2144 gene product to hydrolyze platelet activating factor acetylhydrolase ( PAF-AH) and phosphatidase A2(PLA2). Methods Bioinformatic softwares were used to predict transmembrane regions, signal peptides and domains of the LA_2144 gene of L. interrogans strain Lai. A prokaryotic expression system for signal peptide-free LA_2144 gene was established. The expressed target recombinant protein rLep2144 was extrac-ted by Ni-NTA affinity chromatography and then renatured. Spectrometry was used to detect the activity of rLep2144 to hydrolyze PAF-AH substrate 2-thio PAF and the Km and Kcat values as well as the activity to hy-drolyze PLA2 substrate arachidonoyl 2-thio PC. Real-time fluorescence quantitative RT-PCR and Western blot were performed to detect the transcription, protein expression and secretion of LA_2144 gene during infection of human and mouse vascular endothelial cells ( HUVEC and EOMA) with L. interrogans. Results L. interrogans LA_2144 gene contained a signal peptide and a domain belonging to SGNH hydrolase super-family, but no transmembrane regions. The established prokaryotic expression system for signal peptide-free LA_2144 gene could efficiently express rLep2144. The extracted rLep2144 was shown as a single protein fragment in separation gel and then successfully renatured. rLep2144 had a stronger PAF-AH activity with the Km and Kcat values of 688. 235 μmol/L and 0. 976/s, but its PLA2 activity was relatively weak. Expres-sion of the LA_2144 gene at mRNA and protein levels in HUVEC and EOMA was rapidly increased after the cells were infected with L. interrogans (P<0. 05) and the secretion of LA_2144 gene product could be detec-ted. Conclusions L. interrogans LA_2144 gene product had a stronger PAF-AH and a certain PLA2 activi-ty, which might involve in the hemorrhage and inflammatory response in leptospirosis.

Objcetive: To explore the treatment of long segment defect of tibia by using tensor fascia lata combined with iliac flap or deep circumflex iliac pedicle iliac flap. Methods: From February 2012 to August 2017, The People′s Hospital of Zun Yi City Bo Zhou District treated 16 patients who had long segment defect of tibia.There were 11 males and 5 females, age from 22 to 58 years old, the average age was 42 years old. Iliac flap grafting with tensor fascia lata combined with iliac flap or deep circumflex iliac pedicle was used to treat the defect of long segment of tibia. There were 4 cases with simple tibial defect and 12 cases with skin defect. The longest tibial defect was 5-8 cm. Results: In this study, four patients used iliac flaps with deep circumflex iliac pedicle, the area of flaps ranged from 2.5 cm×5.0 cm to 5.0 cm×10.0 cm, while the area of iliac flaps ranged from 5.0 cm×2.5 cm to 8.0 cm×4.0 cm. Twelve patients used grafting with tensor fascia lata combined with iliac flap, the area of flaps ranged from 5.0 cm×12.0 cm to 12.0 cm×23.0 cm, while the area of iliac flaps ranged from 7.0 cm×2.0 cm to 8.0 cm×4.0 cm. All 16 cases of bone flap were survived, fracture healing, without surgical complications. The average follow-up period was 1.5 years, the flaps had good appearance in 10 cases and was slightly bloated in 6 cases; the ankle had normal motion in 14 cases and had poor dorsal extension in 2 cases. X-ray films showed that the bone flap repaired the bone defects and reached bone healing. Conclusions Vascularized tensor fascia lata combined with iliac flap or deep circumflex iliac pedicle iliac flap grafts increase local blood supply and accelerate the process of fracture healing.