ABSTRACT
【Objective】 To investigate the gene frequency and polymorphism of RBC blood group systems in RhD negtive population in Hunan, so as to lay a foundation for clinical blood transfusion and construction of multiple rare blood group database. 【Methods】 Blood samples were taken from 300 RhD negative blood donors, confirmed by serological method, from June 2019 to June 2020,. RHD genotyping was performed by SSP-PCR. For blood donors with typing results as RhD negative plus RHD gene deletion, antigens genotyping of MNS, Duffy, Kell, Domrock, Diego, Kidd, Sciawnna, Colton, Lutheran and Yt RBC blood group systems were performed by SSP-PCR and analyzed by the chi square test of SPSS 20 statistical software. 【Results】 RHD gene deletions accounted for 58.67% (176 / 300) of serological D negative blood donors. The gene frequencies were as follows: MNS: GYPB*S=0.045 5(8/176), GYPB*s=0.954 5(168/176), GYP*Dane=0.039 8(7/176); Duffy: FY*A =0.965 6(170/176), FY*B=0.034 1(6/176); Dombrock: DO*A=0.082 4(14.5/176), DO*B=0.917 6(161.5/176); Diego: DI*A=0.025 6(4.5/176), DI*B =0.974 4(171.5/176); Kidd: JK*A=0.485 8(85.5/176), JK*B=0.514 2(90.5/176); Kell: KP*A=0.005 7(1/176), KP*B=0.994 3(175/176); Lutheran: LU*A=0.005 7(1/176), LU*B=0.994 3(175/176); Yt: YT*A=0.002 8(0.5/176), YT*B=0.997 2(175.5/176). The genotypes of Kell(K+ /k+ ), Scianna and Colton blood groups were KEL*02 /KEL*02, SC*01 /SC*01 and CO*A /CO*B, respectively. The expected frequencies of the combination of type O, RhD negative and other blood group systems were between 1/100 000 to 1/10 000. 【Conclusion】 Among RhD negative blood donors in Hunan, the gene profiles of MNS, Duffy, Domrock, Diego, Kidd, Kell and Lutheran blood group system were polymorphic, and Kell (K+ /k+ ), Colton and Scianna were homozygous. The data of other RBC blood group systems from RhD negative blood donors is of great significance to establish local database of rare blood groups.
ABSTRACT
Objective To investigate the association of esp, gelE, ebpA and QS-fsr system and biofilm formation in Enterococcus faecalis. Methods Totally 24 isolates of Enterococcus faecalis were collected from urine and catheter of clinical urine tract infection patients in Third Xiangya Hospital from Oct. 2007 to Jun. 2008, and were divided into biofilm group and non-biofilm group. The luminance ratios of esp, gelE, ebpA and fsrrB of Enterococcus faecalis in biofilm group and non-biofilm group were detected by RT-PCR. And the expression of esp, gelE, ebpA, fsrrB genes in different groups were detected by real-time PCR and were relatively quantitated through 2-△△Ct method. Moreover, the relevancies between that fourgenes and biofilm formation in Enterococcus faecalis were analyzed respectively. Results The expression of esp and ebpA in biofilm group were 298 times and 59 times more than the non-biofilm group. The expression level ofgelE and fsrB in biofilm group were 1/244 and 1/249 times less than the non-biofilm group, and the luminance ratios of esp, gelE, ebpA and fsrB were not significant between the two groups (rank sum was 92,79, 42 and 34 respectively,all P ＞ 0. 05 ). Conclusions The results showed that the biofilm formation in Enterococcus faecalis was promoted by esp and ebpA, and was inhabited by gelE and fsrB, which suggested that the expression of esp, ebpA and gelE genes was regulated by fsr system.
ABSTRACT
Objective To clarify the clinical distribution and antimicrobial resistance characteris-tic of bacterial biofilm during catheter-associated urinary tract infection,and to simulate biofilm "real state" in vivo. Methods Totally 120 patients with catheter-associated urinary tract infections (UTIs) were enrolled in the study. The urine specimens were collected for screening biofilm strains and the corresponding planktonic strains. The biofilm was detected with semi-quantitative detecting method. Antibiotics susceptibility test were performed on the biofilm bacteria to clarify the difference of drug resistance in common MH medium the between biofilm strains and the corresponding planktonic strains,as well as the difference of drug resistance of positive strains of the biofilm between Poloxamer medium and common MH medium. Results Totally 48 strains (48/120,40%) of biofilm bacteria were detected. The antibiotic susceptibility test of planktonic and biofilm bacteria in Mueller-Hinton agar showed no significant difference (P>0.05), while the antibiotic resistance of biofilm bacteria in Muel-ler-Hinton agar and Poloxamer hydrogel was statistically different (P<0.05),and the former was stronger. Conclusion The biofilm bacteria during the urinary tract infection were mainly Staphylococci and Enterococci. The antimicrobial resistance of planktonic and biofilm bacteria have no significant difference in vitro, h is speculated that Poloxamer media may simulate the real living environment of biofilm bacteria and display their "true" drug resistance.