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Biofilm is a group of heterogeneously structured and densely packed bacteria with limited access to nutrients and oxygen. These intrinsic features can allow a mono-species biofilm to diversify into polymorphic subpopulations, determining the overall community's adaptive capability to changing ecological niches. However, the specific biological functions underlying biofilm diversification and fitness adaptation are poorly demonstrated. Here, we launched and monitored the experimental evolution of Pseudomonas aeruginosa biofilms, finding that two divergent molecular trajectories were adopted for adaptation to higher competitive fitness in biofilm formation: one involved hijacking bacteriophage superinfection to aggressively inhibit kin competitors, whereas the other induced a subtle change in cyclic dimeric guanosine monophosphate signaling to gain a positional advantage via enhanced early biofilm adhesion. Bioinformatics analyses implicated that similar evolutionary strategies were prevalent among clinical P. aeruginosa strains, indicative of parallelism between natural and experimental evolution. Divergence in the molecular bases illustrated the adaptive values of genomic plasticity for gaining competitive fitness in biofilm formation. Finally, we demonstrated that these fitness-adaptive mutations reduced bacterial virulence. Our findings revealed how the mutations intrinsically generated from the biofilm environment influence the evolution of P. aeruginosa.

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Breast phyllodes tumor (PT) is a rare fibroepithelial neoplasm with potential malignant behavior. Long non-coding RNAs (lncRNAs) play multifaceted roles in various cancers, but their involvement in breast PT remains largely unexplored. In this study, microarray was leveraged for the first time to investigate the role of lncRNA in PT. We identified lncRNA ZFPM2-AS1 was significantly upregulated in malignant PT, and its overexpression endowed PT with high tumor grade and adverse prognosis. Furthermore, we elucidated that ZFPM2-AS1 promotes the proliferation, migration, and invasion of malignant PT in vitro. Targeting ZFPM2-AS1 through nanomaterial-mediated siRNA delivery in patient-derived xenograft (PDX) model could effectively inhibit tumor progression in vivo. Mechanistically, our findings showed that ZFPM2-AS1 is competitively bound to CDC42, inhibiting ACK1 and STAT1 activation, thereby launching the transcription of TNFRSF19. In conclusion, our study provides evidence that ZFPM2-AS1 plays a pivotal role in the pathogenesis of breast PT, and suggests that ZFPM2-AS1 could serve as a prognostic indicator for patients with PT as well as a promising novel therapeutic target.

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BACKGROUND: Malignant phyllodes tumors (MPTs) are rare breast tumors with high risks of local recurrence and distant metastasis. Surgical intervention is the primary treatment, but the effectiveness of adjuvant therapies is uncertain. This study was designed to analyze the prognostic risk factors associated with MPTs and evaluate the efficacy of postoperative adjuvant chemotherapy. PATIENTS AND METHODS: Patients who were first diagnosed with MPT without distant metastasis and received R0 resection surgery between 1999 and 2023 were included in the present study and stratified into 2 groups: chemotherapy and nonchemotherapy groups. Propensity score matching (PSM) was used to balance baseline characteristics between groups. Kaplan-Meier curves were used to estimate local recurrence-free survival (LRFS) and overall survival (OS). Cox proportional hazards analyses (univariate and multivariate) were conducted to identify prognostic risk factors. RESULTS: We conducted a study involving 145 patients, 31 of whom underwent a total of 12 different chemotherapy regimens following initial surgical resection. Most patients received chemotherapy regimens primarily consisting of anthracyclines, including anthracycline + ifosfamide (AI) or anthracycline + cyclophosphamide/docetaxel (AC-T) regimens. After a median follow-up of 54.5 months, 37 (25.5%) patients experienced local recurrence and 24 (16.6%) experienced distant metastasis. No significant difference was detected in the rates of local recurrence or distant metastasis between the 2 groups. Axillary lymph node positivity was the only risk factor for LRFS, whereas older age, larger tumors, axillary lymph node positivity, local recurrence, and distant metastasis were significantly associated with worse OS. Chemotherapy did not emerge as a protective factor for LRFS (P=.501) or OS (P=.854). After PSM, patients in the chemotherapy group did not exhibit better 5-year LRFS (P=.934) or 5-year OS (P=.328). CONCLUSIONS: According to our retrospective evaluation, postoperative adjuvant chemotherapy was not associated with improved survival in patients with MPTs without distant metastasis.

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During a 2020 routine epidemiological investigation of carbapenem-resistant Enterobacterales at a local food market in Guangzhou, China, two Escherichia coli ST410 isolates coproducing NDM-5 and OXA-181 were obtained from environmental samples. Antimicrobial susceptibility testing, whole-genome sequencing, and conjugation assays were applied to identify their resistance phenotypes, phylogenetic relatedness, and genetic characteristics. Phylogenetic analysis showed that the two isolates were clonally related with only one core-genome single-nucleotide polymorphism (SNP) difference and clustered into a branch with 87 E. coli ST410 isolates deposited in GenBank. These 89 ST410 isolates were closely related (≤51 SNPs), and most were from humans in Southeast Asian countries (n = 47). A Vietnamese clinical isolate collected in 2017 showed the strongest epidemiological link (seven SNPs) to the two ST410 isolates detected in this study. Complete-genome analysis revealed that the carbapenem resistance determinants blaNDM-5 and blaOXA-181 were located on an IncF1:A1:B49-IncQ1 plasmid and IncX3 plasmid, respectively. Conjugation experiments confirmed that the IncX3 plasmid was self-transmissible while the IncF1:A1:B49-IncQ1 plasmid was nonconjugative. BLASTn analysis indicated that the two plasmids showed high similarity to other blaNDM-5-bearing IncF1:A1:B49-IncQ1 and blaOXA-181-bearing IncX3 plasmids from other countries. Altogether, the high similarity of the core genomes and plasmids between the ST410 isolates found in this study and those human source isolates from foreign countries suggested the clonal spread of E. coli ST410 strains and horizontal transmission of blaOXA-181-bearing IncX3 plasmids across Southeast Asian countries. Stringent sanitary management of food markets is important to prevent the dissemination of high-risk clones to the public. IMPORTANCE This is the first report of an Escherichia coli ST410 clone that coproduces NDM-5 and OXA-181 in China. The high similarity of the core genomes and plasmids between the ST410 isolates characterized in this study and human source isolates from foreign countries strongly suggests that this ST410 lineage is an international high-risk clone, highlighting the need for continuous global surveillance of ST410 clones.

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The presence and molecular characteristics of carbapenemase-producing Enterobacteriaceae (CPE) among meat products in China were investigated. A total of 110 carbapenem-resistant Enterobacteriaceae (CRE) isolates, including 94 Escherichia coli and 10 Klebsiella pneumoniae isolates, were identified from 105 of 794 (13.2%) samples. The positive rates markedly increased from 2016 (9.4%) to 2018 (22.2%). Only blaNDM genes were detected; 79.1% of blaNDM genes were carried by IncX3 plasmids. Routine monitoring of carbapenemase-producing Enterobacteriaceae in the animal food supply is highly recommended.

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