Cellular fatty acids as chemical markers for differentiation of Acinetobacter baumannii and Acinetobacter calcoaceticus.

Objective: Gas chromatography (GC) was used to investigate the cellular fatty acid (CFA) composition of 141 Acinetobacter baumannii and 32 A. calcoaceticus isolates from different locations in China and to find chemical markers to differentiate these two closely related bacteria.

Methods: Whole cell fatty acid methyl esters (FAMEs) were obtained by saponification, methylation, and extraction for GC analysis, followed by a standardized Microbial Identification System (MIS) analysis.

Use of rich BHI medium instead of synthetic TMH medium for gene regulation study in Yersinia pestis.

Objective: This study is to verify the use of rich BHI medium to substitute synthetic media for gene regulation studies in Yersinia pestis.

Methods: The transcriptional regulation of rovA by PhoP or via temperature upshift, and that of pla by CRP were investigated when Y. pestis was cultured in BHI.

Different strategies for preparation of non-tagged rV270 protein and its efficacy against Yersinia pestis challenge.

Objective: LcrV is an important component for the development of a subunit vaccine against plague. To reduce immunosuppressive activity of LcrV, a recombinant LcrV variant lacking amino acids 271 to 326 (rV270) was prepared by different methods in this study.

Methods: A new strategy that produced non-tagged or authentic rV270 protein was designed by insertion of rV270-thrombin-hexahistidine fusion gene into the vector pET24a, or by insertion of hexahistidine-enterokinase-rV270 or hexahistitine-factor Xa-rV270 fusion gene into the vector pET32a.

[Evaluation of immunization protection efficacy of plague subunit vaccine].

Objective: To evaluate the protective efficacy of plague subunit vaccine, BALB/c mice, guinea pigs and rabbits were used in this study.

Methods: Groups of mice (10 per group), guinea pigs (14 per group) and rabbits (6 per group) were immunized with F1 + rV270 vaccine, EV76 vaccine and alum adjuvant by intramuscular route, respectively. Serum antibody titres of mice, guinea pigs and rabbits were determined by ELISA and the immunized animals were challenged with 10(6) CFU of Y.

[Optimization of the conditions for protein chip preparation].

Objective: To define the optimal conditions for preparing protein chips on aldehyde-coated slides.

Methods: The proteins were diluted in PBS containing 40% glycerol and spotted on aldehyde-coated slides. After the spots were dried for 1 hour at room temperature, the slides were stored at 4 degrees Celsius;.

[In vitro selection and affinity function of the aptamers to Bacillus anthracis spores by SELEX].

To obtain oligonucleotide aptamers, specifically binding to Bacillus anthracis spores, and to find the relationship between the structures and the affinities, and to determine whether the aptamers can be used as a novel molecule for spore detection, a synthetic 35 mer random DNA library was subjected to 18 rounds of selection by using SELEX (systematic evolution of ligands by exponential enrichment) protocol against spores of Bacillus anthracis vaccine strain A. 16R. The selected aptamers were cloned and sequenced.