Total alkaloids from Sophora alopecuroides L. increase susceptibility of extended-spectrum β-lactamases producing Escherichia coli isolates to cefotaxime and ceftazidime / 中国结合医学杂志

<p><b>OBJECTIVE</b>To evaluate the antimicrobial activity of total alkaloids extracted from Sophorea alopecuroides L. (TASA) against clinical isolated extended-spectrum beta-lactamases (ESBLs) producing Escherichia coli (E. coli) strains.</p><p><b>METHODS</b>The antibacterial activity of TASA either itself or in combination with cefotaxime (CTX) or ceftazidime (CAZ) was investigated by using the microbroth dilution method and phenotypic confirmatory disk diffusion test against three clinical isolated ESBLs-producing E. coli strains; the interactions of TASA and CTX or CAZ were ascertained by evaluating the fractional inhibitory concentration index (FICI).</p><p><b>RESULTS</b>The antibacterial activity of either TASA itself or in combination with CTX or CAZ was found. The minimum inhibitory concentration (MICs) of TASA against the ESBLs producing isolates was 12.5 mg/mL. In the combinations with a sub-inhibitory concentration of TASA, a synergistic effect on CTX and CAZ against the ESBLs producing isolates was observed. Similarly, the isolates exposed to lower dose of TASA yielded an increased susceptibility to CTX and CAZ by 8-16 folds determined by microdilution assay. Moreover, enzymatic detection of ESBLs demonstrated that TASA induced reversal resistance to CTX and CAZ partially by a mechanism of inhibition of ESBLs activity in these isolates. Additionally, in the tested isolates following the exposure of TASA, molecular analysis verified the SHV-type beta-lactamase encoding ESBL gene in these isolates, and no mutation was introduced into the ESBL gene.</p><p><b>CONCLUSIONS</b>These results suggest that TASA could be used as a source of natural compound with pharmacological activity of reversal resistance to antimicrobial agent. These findings also indicated that the application of the TASA in combination with antibiotics might prove useful in the control and treatment of infectious diseases caused by the ESBLs producing enterobacteriaceae.</p>

Genetic polymorphism of twelve Y chromosomal short tandem repeat loci in Chinese Hui ethnic group / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To obtain the genetic polymorphism of Y chromosomal short tandem repeat (Y-STR) loci in Ningxia Hui population.</p><p><b>METHODS</b>Blood samples were collected from 150 unrelated healthy male individuals of Ningxia Hui ethnic group. Twelve Y-STR loci were amplified in one tube by using the PowerPlex System STR Amplification Kit, and the genotypes were determined using Genescan and Genotype software of ABI377 DNA sequencer and the frequency of alleles and haplotypes of Ningxia Hui ethnic was obtained.</p><p><b>RESULTS</b>Seventy-five alleles were observed at 12 Y-STR loci. The frequency ranged from 0.0067-0.7067 and the gene diversity ranged from 0.4446-0.8877. Totally 148 different haplotypes were found, which were unique in 150 males. Two haplotypes were shared by 2 males respectively. The haplotype diversity was 0.9864.</p><p><b>CONCLUSION</b>The 12 Y-STR loci are highly polymorphic in Ningxia Hui population and are suitable for genetics and forensic research.</p>

System of Intein-mediated PHB Purified Human Antimicrobial Peptide LL-37 / 中国生物工程杂志

The new intein-mediated PHB purify protein system is a high expression, automatic cutting, for purification, low-cost protein purification system,it is conducive to large-scale protein purification.Choose human antibacterial peptide LL-37 as the purification objects,which is poison to prokaryotic cell.We construct intein-mediated PHB purified human antimicrobial peptide LL-37 system through genetic engineering technology and use this system to purify LL-37. The results show that this system can highly express LL-37 fusion protein and purifiy the product as same size with expectations.

Using Uniform Design to Optimize Expressive Conditions of rPA(K) in E.coli / 中国生物工程杂志

Using uniform design to optimize some relative factors influencing the expressing of t-PA variant-rPA(K) in E.coli system, and found the best expressive conditions. They were(by using 300ml culture fask): the volume of media was 25ml, inducing time was 5.3 hours, pH was 6.0, the concentration of IPTG was 0.1mmol/L, inducing time was 25℃, and best culture media was HD. After being optimized, the yield of expression had been improved from 0.16 to 0.48, and it was as 3 times as before. The results above will offer the basement for purification and renaturation of rPA(K).

Genetic polymorphism of 5 short tandem repeat loci in Hui population in Ningxia area / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To analyze the genetic polymorphism of 5 short tandem repeat(STR) loci in Hui population in Ningxia area.</p><p><b>METHODS</b>The genetic polymorphisms of five selected STR loci(D11S1984, D14S306, D14S617, D17S1290 and D19S433) in chromosomes 11, 14, 17 and 19 in 144 unrelated individuals in Hui population in Ningxia area were analyzed by PCR amplification, denaturing polyacrylamide gel electrophoresis(PAGE) and silver staining.</p><p><b>RESULTS</b>10, 8, 11, 13 and 8 alleles, 30, 25, 33, 40 and 23 genotypes of the 5 STR loci in Hui population in Ningxia were detected. The measured values of the heterozygosity of the 5 STR loci were 0.8413, 0.8033, 0.8331, 0.8369 and 0.7703; of the polymorphism information content were 0.8217, 0.7746, 0.8121, 0.8174 and 0.7332; of the discrimination power (DP) were 0.9516, 0.9257, 0.9611, 0.9660 and 0.9135. The calculated discrimination power was 0.9999995. The measured values of paternity exclusion were 0.7046, 0.6367, 0.6911, 0.7012 and 0.5801; the calculated paternity exclusion was 0.9958. The genotype distributions were in accordance with Hardy-Weinberg equilibrium.</p><p><b>CONCLUSION</b>The 5 STR loci have better polymorphism in Hui population in the Ningxia area, and thus could serve as useful markers for population genetics research and for individual identification and paternity test in forensic medicine.</p>

Cloning of CTB-PROIN fusion gene and its expression in Escherichia coli / 生物工程学报

A fusion gene CTB-PROIN, in which Proinsulin gene was fused to the 3' end of CTB gene by a hinge peptide 'GPGP', was constructed and cloned into pET-30a(+) to obtain a prokaryotic expression vector pETCPI. Subsequently the recombinant plasmid pETCPI was transformed into E. coli stain BL21 (DE3). After induced by IPTG, the expression product was analyzed by sodium dodecyl sulphate-polyacrylamide gel (15%) electrophoresis (SDS-PAGE), and its result indicated that the recombinant protein CTB-PROIN was expressed and accumulated as inclusion bodies. The recombinant CTB-PROIN protein accumulated to the level of 25% of total bacterial proteins. After inclusion bodies was denaturalized and refolded in vitro, significant assembly of monomers had occurred, and the recombinant protein represented assembled pentamers. The results of western blotting analysis also demonstrated that the fusion protein could be recognized by the anti-CT and anti-insulin antibody, respectively. In addition, the result of the CTB-PROIN-GM1 binding assay, that the protein could bind to monosialoganglioside specifically, showed it possesed biological activity in vitro. These results provided the possibility of developing a cheaper and more efficient oral vaccine for type I diabetes using such constructs.