A 460 bp internal fragment of the AcrA gene from Vibrio alginolyticus strain HY9901 was amplified by PCR with designed primers and the unknown flanking sequence of 5 '- and 3 '- ends of the AcrA gene was finally characterized by inverse PCR and nested PCR. Sequence analysis showed the AcrA gene contained 1101 bp ORF encoding 366 amino acids and the deduced amino acid sequence of the precursor from Vibrio alginolyticus strain HY9901 showed significant homology with the putative protein of other Vibrio species. The AcrA shows 76%, 73%, 71% and 70% homology with V.vulnificus strain YJ016, V. parahaemolyticus strain RIMD 2210633, V. splendidus strain 12B01 and V. cholerae O1 biovar eltor str. N16961 respectively.

A mutant strain ΔVcrV was constructed by using homologous recombination method for investigating the function of the VcrV gene in Vibrio alginolyticus type Ⅲ secretion system. The genetic stability of ΔVcrV was detected by PCR, and the biological characteristics between the mutant and the wild type strains were compared. ΔVcrV muntat had no significant changes in growth rate and autoagglutination compared with the wild type strain, but the ability to form biofilms was reduced, and the LD₅₀ was increased by 16.5 times. The swimming and swarming motility of the mutant strain ΔVcrV were significantly enhanced, while cell adhesion was significantly reduced than the wild strain (P < 0.01). The tolerance of ΔVcrV mutant to H₂O₂ and NaCl was decreased. Compared with that of the wild type strain, the sensitivity of ΔVcrV mutant to cefuroxime, medimycin and clindamycin was increased, but to amikacin and polymxin B was decreased. The reactive oxygen species (ROS) content of ΔVcrV mutant was significantly decreased (P < 0.01), and the indexes of proline, peptidoglycan, β-lactamase, catalase, superoxide dismutase and glutathione peroxidase of ΔVcrV mutant were significantly increased than that of the wild type strain (P < 0.01). The biological characteristics of ΔVcrV mutant indicated that VcrV gene was involved in pathogenicity and various biological functions of V. alginolyticus type Ⅲ secretion system.
Animals ; Bacterial Proteins/metabolism* ; Fish Diseases ; Hydrogen Peroxide/metabolism* ; Type III Secretion Systems ; Vibrio Infections ; Vibrio alginolyticus/genetics*

Objective: To determine the levels of vitamin D in patients with pulmonary tuberculosis in Shenzhen and identify the influencing factors of vitamin D levels and key groups of vitamin D deficiency, so as to provide a scientific basis for tuberculosis- and nutrition-related health education and promotion in Shenzhen. Methods: Patients with smear-positive pulmonary tuberculosis who were diagnosed in 2016 were selected as the research subjects. Their relevant information and blood samples were collected, and the sample pool was established according to the inclusion criteria. One hundred and twenty patients were selected based on simple random sampling, including 84 men (70.0%) and 36 women (30.0%). Blood 25-hydroxyvitamin D [25(OH)D] concentrations were measured using chemiluminescence technology. Vitamin D statuses in patients were statistically described, and vitamin D levels in patients with different characteristics were compared. Multivariate linear regression analysis was performed to identify important factors influencing vitamin D levels in patients. Results: Mean serum concentration of 25(OH)D in 120 patients was (40.2±16.0) nmol/L. There were 2 cases of vitamin D sufficiency (1.7%), 28 cases of vitamin D insufficiency (23.3%), and 90 cases of vitamin D deficiency (75.0%), of which 23 cases (19.2%) were of severe deficiency. 25(OH)D concentrations in patients with different lifestyles (indoors; indistinguishable indoors or outdoors; outdoors) were significantly different (35.3 nmol/L vs. 40.6 nmol/L vs. 49.5 nmol/L, F=8.274, P<0.001). Mean concentration of 25(OH)D in patients with sun exposure time of >30 min/d was higher compared to that in those with sun exposure time <30 min/d in the last month (46.4 nmol/L vs. 36.7 nmol/L, t=3.342, P=0.001). Multivariate linear regression analysis showed that the risk factors for 25(OH)D with statistical significance were Han ethnicity or not (β=-11.576, t=-1.991, P=0.049), housekeeping (including unemployment and retirement) or not (β=-6.136, t=-1.998, P=0.048), sun exposure time<30 min/d or none (β=-9.644, t=-2.829, P=0.006), body mass index (β=-2.056, t=-3.439, P=0.001) , and indoor degree of lifestyles (β=-4.419, t=-2.155, P=0.033). Conclusion Level of vitamin D is generally insufficient in patients with pulmonary tuberculosis in Shenzhen. It is necessary to strengthen health education related to vitamin D in patients with tuberculosis, especially in the high-risk population of vitamin D deficiency, such as in those with a lack of exposure to sunlight or high BMI.