To determine the relationships between miR-96-5p/-182-5p and GPC1 in pancreatic cancer (PC), we conducted the population and in vitro studies. We followed 38 pancreatic cancer patients, measured and compared the expression of miR-96-5p/-182-5p, GPC1, characteristics and patients’ survival time of different miR-96-5p/-182-5p expression levels in PC tissues. In an in vitro study, we investigated the proliferation, cycle and apotosis in cells transfected with mimics/inhibitors of the two miRNAs, and determine their effects on GPC1 by dual-luciferase assay. In the follow-up study, we found that the expressions of miR-96-5p/-182-5p were lower/higher in PC tissues; patients with lower/higher levels of miR-96-5p/-182-5p suffered poorer characteristics and decreased survival time. In the in vitro study, the expressions of miR-96-5p/-182-5p were different in cells. Proliferation of cells transfected with miR-96-5p mimics/inhibitors was lower/higher in Panc-1/BxPC-3; when transfected with miR-182-5p mimics/inhibitors, proliferation of cells were higher/lower in AsPC-1/Panc-1. In a cell cycle study, panc-1 cells transfected with miR-96-5p mimics was arrested at G0/G1; BxPC-3 cells transfected with miR-96-5p inhibitors showed a significantly decrease at G0/G1; AsPC-1 cells transfected with miR-182-5p mimics was arrested at S; Panc-1 cells transfected with miR-182-5p inhibitors showed a decrease at S. MiR-96-5p mimics increased the apoptosis rate in Panc-1 cells, and its inhibitors decreased the apoptosis rate in BxPC-3. Dual luciferase assay revealed that GPC1 was regulated by miR-96-5p, not -182-5p. We found that miR-96-5p/-182-5p as good markers for PC; miR-96-5p, rather than -182-5p, inhibits GPC1 to suppress proliferation of PC cells.

Methicillin-resistant Staphylococcus aureus (MRSA) has become an important nosocomial pathogen, causing considerable morbidity and mortality. During the last 20 years, a variety of genotyping methods have been introduced for screening the prevalence of MRSA. In this study, we developed and evaluated an improved approach capillary gel electrophoresis based multilocus variable-number tandem-repeat fingerprinting (CGE/MLVF) for rapid MRSA typing. A total of 42 well-characterized strains and 116 non-repetitive clinical MRSA isolates collected from six hospitals in northeast China between 2009 and 2010 were tested. The results obtained by CGE/MLVF against clinical isolates were compared with traditional MLVF, spa typing, Multilocus sequence typing/ staphylococcal cassette chromosome mec (MLST/SCCmec) and pulse field gel electrophoresis (PFGE). The discriminatory power estimated by Simpson’s index of diversity was 0.855 (28 types), 0.855 (28 patterns), 0.623 (11 types), 0.517 (8 types) and 0.854 (28 patterns) for CGE/MLVF, traditional MLVF, spa typing, MLST/SCCmec and PFGE, respectively. All methods tested showed a satisfied concordance in clonal complex level calculated by adjusted Rand’s coefficient. CGE/MLVF showed better reproducibility and accuracy than traditional MLVF and PFGE methods. In addition, the CGE/MLVF has potential to produce portable results. In conclusion, CGE/MLVF is a rapid and easy to use MRSA typing method with lower cost, good reproducibility and high discriminatory power for monitoring the outbreak and clonal spread of MRSA isolates.

Carbapenem-resistant hypervirulent Klebsiella pneumoniae (CR-hvKP) is a significant pathogen causing major public health problems worldwide. This study characterized a novel sequence type 6417 (ST6471) CR-hvKP strain recovered from the blood of a male patient with septicemia. Strain CR2021 is not susceptible to carbapenems, cephalosporin, sulfonamides, quinolones, or levofloxacin and is susceptible to amikacin and tigecycline. Molecular typing indicated that ST6417 is derived from the most dominant hypervirulent K. pneumoniae (hvKP) clone in China, ST23, with a single-locus variation in tonB . The genomic characterization of CR2021, which contains three plasmids, was performed through whole-genome sequencing. The plasmid pCR2021_IncFII contains 12 antibiotic resistance genes [ bla _CTX-M-3 , bla _TEM-1B , bla _DHA-1 , aac (3)-Ild , aadA16 , sul1 , sul2 , qnrB4 , ARR-3 , dfrA27 , qacE , merACDE ], all of which are associated with genetic elements. The plasmid pCR2021_IncFIB carries crucial virulence-related genes, while the plasmid pCR2021_IncX3 only harbors the bla _NDM-5 resistance gene and exhibits 99% similarity with two other bla _NDM-5 -carrying IncX3 plasmids (pSHX180-NDM5, pNDM-K725), with coverage of 87% and 100%, respectively. The bla _NDM-5 genetic region contains an additional IS26-Tn3 genetic module. Serum killing and anti-human neutrophil phagocytosis tests indicated that CR2021 exhibits high virulence, which was further confirmed in a Galleria mellonella larvae infection model. CR-hvKP is becoming more prevalent in China; however, the majority have evolved from the multidrug resistance clone ST11 and its variants by acquiring virulence factors. Conversely, CR-hvKP derived from hvKP, such as the clone ST23, remains relatively rare. Therefore, the discovery of ST6417 underscores the need for further research into the genetic characteristics and evolution of bacteria. IMPORTANCE: ST11 and its variants, which often exhibit drug resistance, represent popular clones of carbapenem-resistant hypervirulent Klebsiella pneumoniae (CR-hvKP) in China, often leading to high morbidity and mortality rates owing to their high virulence and robust drug resistance. Conversely, CR-hvKP, originating from the high-virulence sequence type ST23, remains rarely reported. In this study, we identified a novel ST6417 CR-hvKP strain derived from ST23, carrying bla _NDM-5 on an IncX3 plasmid conferring resistance to carbapenems. In addition, we elucidate its virulence, resistance to drugs, and genetic characteristics. The discovery of ST6417 highlights the diverse pathways in the evolution of CR-hvKP, warranting increased attention.

Objective: This study investigated the mechanisms underlying the reduced tigecycline sensitivity of Acinetobacter baumannii strains isolated from infected patients during antimicrobial therapy. The goal is to provide clinical insights into the development of tigecycline resistance in A. baumannii, with a focus on multidrug-resistant strains commonly associated with hospital-acquired infections. Methods: We conducted dynamic tracking of multidrug-resistant Acinetobacter baumannii (MDR-AB) infections in three patients to monitor changes in tigecycline sensitivity during antimicrobial therapy. From each patient, tigecycline-sensitive and -resistant A. baumannii strains were collected and paired into groups. A total of six strains were subjected to molecular typing and phylogenetic analysis to assess the genetic homology between the tigecycline-sensitive and -resistant strains within each group. Whole-genome sequencing and comparative genomic analysis were performed to identify single nucleotide polymorphisms and small insertions/deletions between paired strains, aiming to pinpoint mutated genes. Gene knockout experiments were conducted to validate the role of the identified genes in modulating tigecycline sensitivity and contributing to the development of tigecycline resistance in A. baumannii. Results: Molecular typing and phylogenetic analysis confirmed that the tigecycline-resistant Acinetobacter baumannii strains isolated from each patient evolved from the initially infecting tigecycline-sensitive strains. All three patients had received tigecycline therapy before the emergence of tigecycline resistance. Notably, in one patient, resistance developed 21 days after discontinuing tigecycline treatment. Comparative genomic analysis of the paired strains revealed point mutations in the conserved domain of the trimeric autotransporter adhesin in all three groups. Additionally, a frameshift mutation in the acrR gene was identified in two of the three groups. To investigate the role of acrR in the development of tigecycline resistance, an acrR knockout strain was constructed. The results indicated that the acrR gene did not significantly impact tigecycline resistance or biofilm formation. Conclusion: The use of tigecycline promotes the development of tigecycline resistance in Acinetobacter baumannii, and resistance may continue to evolve even after discontinuing tigecycline treatment. Mutations in the ata, adeS, and acrR genes may contribute to the development of tigecycline resistance in A. baumannii. Although gene knockout experiments in this study showed that acrR did not directly impact tigecycline resistance or biofilm formation, clinical isolates are influenced by a complex, multifactorial environment. Therefore, the role of acrR warrants further investigation.

目的: 探讨MMP-3和VEGF蛋白在胰腺癌组织中的表达及其与胰腺癌临床病理特征、预后及胰腺癌组织中血管新生的关系. 方法: 用免疫组织化学检测了56例手术切除的胰腺癌组织和正常胰腺组织中MMP-3、VEGF的蛋白表达和微血管密度, 并请相关专业人员进行微血管密度计数分析. 结果: 在56例胰腺癌标本中有42例MMP-3 (75.00%)和38例VEGF(67.85%)蛋白的表达阳性, 明显高于正常胰腺组织. MMP-3和VEGF的阳性表达呈正相关(χ2 = 30.42, P<0.01). MMP-3在临床分期较晚和有淋巴结转移的胰腺癌中呈高表达. 56例胰腺癌组织中的微血管密度与MMP-3、VEGF蛋白的阳性表达有关(tVEGF =3.67, P<0.01; tMMP-3 = 3.05, P<0.01). 结论: MMP-3和VEGF可能通过相互促进的表达, 促进胰腺癌组织中新生血管的形成, 可能在胰腺癌的发生发展中起到重要作用. MMP-3对预测肿瘤的早期转移有一定的临床意义. 而VEGF的相对低表达与临床所见胰腺癌在增强CT的低密度低动脉供血可能有关联.