Objective To analyze the correlation between antibiotic susceptibility andbiofilm formation of Staphylococcus aureus. Methods According to Standardized Operational Guidance for Clinical Microbiological Testing, fifty-eight non-repetitive pathogenic Staphylococcus aureus isolates were collected from blood, urine, sputum and purulent secretions of inpatients in the Laboratory Department of the First Affiliated Hospital of Guangxi Medical University in January 2018. The antibiotics susceptibility of strains was characterized by disk diffusion method and VITEK-2.96-hole culture. The biofilm formation ability was detected bythe crystal violet assay and Congo redplate methods.The in vitro dynamic forming process of S.aureus′sbiofilm was analyzed by crystal violet staining combined with bacterial culture in 96 wells.Besides, the rate differences of drug resistance between biofilm producers and non-producers was performed by Chi-square test. The diameter of bacteriostasis zone of biofilm producers and non-producers was compared by t test. The drug resistance among strains with different biofilm formation ability was analyzed withnonparametric rank sum test. Results The positive ratio of biofilm producing S. aureus was higher in MRSA (68.42％) than in MSSA(20.00％)(χ2=12.304,P=0.001. Antibiotic resistance rates of biofilm producers were higher than non-producers.The resistance rates of biofilm positive strains to oxacillin and clindamycin were 73.33％ and 53.33％, respectively. The antibiotic resistance of the strain was higher along with the biofilm forming ability was increasing. (χ2=9.099, P=0.008). Depths of the S. aureus′s biofilm on the 96-well plates increased significantly over time and reached biofilm maturation after 72 hours′ incubation. Light microscopic observation revealed that the mature biofilm was compact and growing with many layers. Conclusions For the clinical isolates of S. aureus, the antibiotic resistance of biofilm producers is significantly higher than non-producers. Strains with stronger biofilm forming ability had higher antibiotics resistance. Depths of the S. aureus′s biofilm on the 96-well plates increased significantly over time and reached biofilm maturation after 72 hours′incubation.

Objective To investigate the effect of transmembrane protein CD147 expression on AIM2 inflammasome-mediated pyroptosis and proliferation of cervical cancer cells.Methods Western Blot was used to detect the expression of CD147 in cervical cancer cell lines SiHa(HPV+)and C33a(HPV-)and normal cervical epithelial cells H8(HPV+)and HCer Epic(HPV-).SiHa cells were transfected with lentivirus to down-regulate the expression of CD147.According to the different treatments,SiHa cells were divided into SiHa group,negative control group(shCD147-NON),knockdown group 1(shCD147-1)and knockdown group 2(shCD147-2).The transfection effect was verified by Western Blot,RT-qPCR and green fluorescence expression.The protein and mRNA expressions of AIM2,Caspase-1,IL-18 and GSDMD were detected by Western Blot and RT-qPCR.The lactate dehydrogenase(LDH)release was measured in the cell culture supernatant,and the cell morphology was observed under the fluorescence inverted microscope;the proliferation ability of cells was measured by CCK-8 and the colony formation ability was measured by cell cloning experiments.Results Western Blot results showed that CD147 protein expression in SiHa cells was the highest compared with that in HCerEpic cells.CD147 low expression lentivirus effectively down-regulated the expression of CD147 in SiHa cells.The results of Western Blot and RT-qPCR experiments showed that the expression of AIM 2,Caspase-1,IL-18,GSDMD protein and mRNA increased in shCD147-1 and shCD147-2 group(P<0.05).Lactate dehydrogenase(LDH)release assay showed that compared with the SiHa group,the shCD147 group had a significant increase in LDH release(P<0.05).Fluorescence inverted microscope showed that the shCD147 group had swelling and vacuolization,showing typical pyroptosis.Compared with the SiHa group,the shCD147-1 and shCD147-2 groups had significantly reduced the cell proliferation and colony formation ability(P<0.05).Conclusion Low expression of CD147 effectively up-regulates the expression of AIM2 inflammation-related factors in cervical cancer SiHa cells,induces the pyroptosis,and inhibits the cell proliferation and cloning.