PubMed Health⌕ Search

Biomedical subjects

Weiping Cao

Publications and source records attributed to Weiping Cao.

2 recordsLinked to original sources
PubMed2026

Antibacterial activity and mechanistic insights of Lucilia illustris antimicrobial peptide Cecropin A2 against Pseudomonas aeruginosa.

Pseudomonas aeruginosa (P. aeruginosa) poses a serious public health threat due to multidrug resistance and biofilm formation. This study investigated the antibacterial mechanisms of the antimicrobial peptide, Cecropin A2 (CA2), against P. aeruginosa. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of CA2 against P. aeruginosa ATCC 9027 (PA ATCC 9027) were determined by broth microdilution. Antibacterial activity was evaluated using growth curves and time-kill assays. The mechanism was explored by assessing membrane integrity (outer/inner membrane permeability, SEM, and fluorescence microscopy), and intracellular responses (ATP, SDH activity, and ROS). Biofilm effects were assessed by crystal violet staining (biomass) and viable cell counting (biofilm-embedded bacteria). The MIC and MBC of CA2 against PA ATCC 9027 were 37.34 μM and 74.68 μM, respectively. CA2 exhibited moderate antibacterial activity against PA ATCC 9027. Scanning electron microscopy (SEM) revealed marked morphological damage after treatment. CA2 affected intracellular metabolism, potentially interacted with genomic DNA, and reduced biofilm biomass. Cecropin A2 exhibits concentration-dependent in vitro antibacterial activity against P. aeruginosa ATCC 9027, providing mechanistic insights and a theoretical basis for the development of alternative antimicrobial strategies.

Antimicrobial activity↗
PubMed2026

A new highly discriminatory typing scheme for Treponema pallidum reveals similar levels of genetic variability across lineages.

UNLABELLED: The global resurgence of treponematoses, particularly syphilis, poses a growing public health challenge. Despite advances in sequencing technologies, obtaining complete Treponema pallidum genome sequences for epidemiological studies remains challenging due to clinical sampling and methodological constraints. There is, therefore, a need for rapid, cost-effective, and accessible typing methods. Based on the analysis of 121 T. pallidum genomes spanning all three subspecies (TPA, TPE, and TEN) from diverse regions, we selected seven highly variable genes (tp0136, tp0326, tp0548, tp0705, tp0858, tp0865, and tp1031) to form a new typing system, combined with analysis of macrolide resistance mutations in the 23S rRNA gene. The scheme was validated on 542 global T. pallidum samples, using either Sanger reads or whole genome sequence data, obtaining 82 sequence types (STs) among the 415 fully typed samples. Macrolide resistance mutations were frequently detected, highlighting the need for ongoing epidemiological surveillance. Phylogenetic analyses based on concatenated multilocus typing (MLST) loci recovered the expected subspecies and lineage structure. Consistently, almost all sequence types formed monophyletic groups, indicating strong concordance between MLST-based classification and whole-genome phylogenies. In addition, population genetic analyses revealed comparable levels of within-lineage diversity across subspecies and lineages, despite pronounced differences in geographic distribution, and identified distinct regional genetic clusters consistent with localized transmission dynamics. Importantly, the scheme employs a single-step PCR for all seven targets, facilitating implementation in standard laboratories and is publicly accessible through PubMLST. Overall, our novel MLST scheme offers a rapid, cost-effective tool to advance molecular epidemiology of T. pallidum, facilitate transmission and resistance tracking, and support global surveillance to strengthen public health interventions for syphilis and endemic treponematoses control. IMPORTANCE: We have developed a new multilocus typing (MLST) scheme useful for all Treponema pallidum lineages after the analysis of 121 complete genome sequences of this species. The new scheme can be used directly with uncultured clinical samples, thus providing an excellent contribution to the molecular surveillance of syphilis and other treponematoses. The application of this MLST scheme to over 500 samples from all lineages and main geographical regions has revealed similar levels of genetic variation within them. Furthermore, the analyses show a complex pattern of spread, with global and local contributions to the observed distribution of genetic variation in the syphilis-producing sublineages. The new scheme represents a significant improvement over previous proposals and also reveals unsuspected levels of variability in T. pallidum lineages.

Treponema pallidum↗