1.Analysis on correlation between biofilm formation and bacterial resistance in Staphylococcus epidermidis
Yangqin YE ; Yujie BAO ; Ke MA ; Wenyan ZHANG ; Ting XI ; Fangying CHEN ; Ming ZONG ; Lieying FAN
International Journal of Laboratory Medicine 2016;37(5):618-620
Objective To investigate the formation of biofilm in clinical isolates of Staphylococcus epidermidis ,and to analyse the correlation between biofilm formation and antibacterial resistance of Staphylococcus epidermidis .Methods A total of 62 strains of Staphylococcus epidermidis isolated from blood specimens of inpatients with bloodstream infection ,from January 2014 to February 2015 ,were collected .The biofilm formation of Staphylococcus epidermidis was detected by using the semi‐quantitative adherence as‐say and polymerase chain reaction(PCR) amplification experiment .The antibacterial susceptibility test was carried out according to K‐B method .Results The positive rate of biofilm formation detected by using the semi‐quantitative adherence assay and PCR for icaA gene were 37 .1% (23 strains) and 43 .5% (27 strains) respectively ,and there was no statistically significant difference(P>0 .05) .There were 14 positive strains detected by both methods .The resistance rates of strains producing biofilm to antibacterial a‐gents were generally higher than those of non‐producing biofilm strains ,and there were statistically significant differences in resist‐ance rates of strains to gentamicin ,penicillin ,oxacillin ,levofloxacin and cefoxitin(P<0 .05) .All bacteria were sensitive to vancomy‐cin ,linezolid and quinupristin/dalfopristin .Conclusion There is no significant difference between the two methods in detecing bio‐film formation .The resistance rates of strains producing biofilm to antibacterial agents were generally higher than those of non‐pro‐ducing biofilm strains .
2.Spatial distribution pattern of local tumor progression analysis after microwave ablation of hepatocellular carcinoma based on three-dimensional magnetic resonance imaging
Fangying FAN ; Wenzhen DING ; Fangyi LIU ; Zhigang CHENG ; Zhiyu HAN ; Xiaoling YU ; Ping LIANG ; Jie YU
Chinese Journal of Hepatology 2024;32(3):208-213
Objective:To investigate the spatial distribution pattern of local tumor progression (LTP) for hepatocellular carcinoma (HCC) ≤5 cm after microwave ablation.Methods:A retrospective analysis was performed on 169 HCCs with matched MRI before and after ablation from December 2009 to December 2019. A tumor MRI was reconstructed using three-dimensional visualization technology. LTP was classified as contact or non-contact, early or late stage, according to whether LTP was in contact with the edge of the ablation zone and the occurrence time (24 months). The tumor-surrounded area was divided into eight quadrants by using the eight-quadrant map method. An analysis was conducted on the spatial correlation between the quadrant where the ablative margin (AM) safety boundary was located and the quadrant where different types of LTP occurred. The t-test, or rank-sum test, was used for the measurement data. 2-test for count data was used to compare the difference between the two groups.Results:The AM quadrant had a distribution of 54.4% LTP, 64.2% early LTP stage, and 69.1% contact LTP, suggesting this quadrant was much more concentrated than the other quadrants ( P ?0.001). Additionally, the AM quadrant had only 15.2% of non-contact type LTP and 17.1% of late LTP, which was not significantly different from the average distribution probability of 12.5% (100/8%) among the eight quadrants ( P = 0.667, 0.743). 46.6% of early contact type LTP was located at the ablation needle tip, 25.2% at the body, and 28.1% at the caudal, while the location distribution probabilities of non-early contact LTP were 34.8%, 31.8%, and 33.3%, respectively. Conclusion:LTP mostly occurs in areas where the ablation safety boundary is the shortest. However, non-contact LTP and late LTP stages exhibit the feature of uniform distribution. Thus, this type of LPT may result from an inadequate non-ablation safety boundary.
3.Primary assessment of the diversity of Omicron sublineages and the epidemiologic features of autumn/winter 2022 COVID-19 wave in Chinese mainland.
Gang LU ; Yun LING ; Minghao JIANG ; Yun TAN ; Dong WEI ; Lu JIANG ; Shuting YU ; Fangying JIANG ; Shuai WANG ; Yao DAI ; Jinzeng WANG ; Geng WU ; Xinxin ZHANG ; Guoyu MENG ; Shengyue WANG ; Feng LIU ; Xiaohong FAN ; Saijuan CHEN
Frontiers of Medicine 2023;17(4):758-767
With the recent ongoing autumn/winter 2022 COVID-19 wave and the adjustment of public health control measures, there have been widespread SARS-CoV-2 infections in Chinese mainland. Here we have analyzed 369 viral genomes from recently diagnosed COVID-19 patients in Shanghai, identifying a large number of sublineages of the SARS-CoV-2 Omicron family. Phylogenetic analysis, coupled with contact history tracing, revealed simultaneous community transmission of two Omicron sublineages dominating the infections in some areas of China (BA.5.2 mainly in Guangzhou and Shanghai, and BF.7 mainly in Beijing) and two highly infectious sublineages recently imported from abroad (XBB and BQ.1). Publicly available data from August 31 to November 29, 2022 indicated an overall severe/critical case rate of 0.035% nationwide, while analysis of 5706 symptomatic patients treated at the Shanghai Public Health Center between September 1 and December 26, 2022 showed that 20 cases (0.35%) without comorbidities progressed into severe/critical conditions and 153 cases (2.68%) with COVID-19-exacerbated comorbidities progressed into severe/critical conditions. These observations shall alert healthcare providers to place more resources for the treatment of severe/critical cases. Furthermore, mathematical modeling predicts this autumn/winter wave might pass through major cities in China by the end of the year, whereas some middle and western provinces and rural areas would be hit by the upcoming infection wave in mid-to-late January 2023, and the duration and magnitude of upcoming outbreak could be dramatically enhanced by the extensive travels during the Spring Festival (January 21, 2023). Altogether, these preliminary data highlight the needs to allocate resources to early diagnosis and effective treatment of severe cases and the protection of vulnerable population, especially in the rural areas, to ensure the country's smooth exit from the ongoing pandemic and accelerate socio-economic recovery.