International Journal of Medical Microbiology最新文献_第2页

Lactobacillus gasseri suppresses the Helicobacter pylori-induced expression of the proliferation-associated factors HBEGF and TGF-α in gastric host cells 胃乳杆菌抑制幽门螺杆菌诱导的胃宿主细胞增殖相关因子HBEGF和TGF-α的表达。

IF 3.6 3区医学 Q1 MICROBIOLOGY

International Journal of Medical Microbiology

Pub Date : 2025-12-11 DOI: 10.1016/j.ijmm.2025.151694

Tanvi Somiah, Priyodip Paul, Sarah Pilheden, James Trumbo, Ann-Beth Jonsson

To date, various probiotic lactobacilli have been tested against Helicobacter pylori. However, a detailed molecular analysis of the various signaling pathways and their associated anti-proliferative activity remains poorly understood. In our previously published research, a disintegrin and metalloprotease 17 (ADAM17) was proposed as a key target for anti-inflammatory activity in H. pylori-infected host macrophages. Therefore, in this study, the anti-H. pylori activity of selected lactobacilli was assessed based on expression of ADAM17 and two of its targets, heparin-binding EGF-like growth factor (HBEGF) and transforming growth factor-alpha (TGF-α), which were measured in gastric epithelial cells. For this purpose, lactobacilli and H. pylori were either added together to the AGS cells (coincubation), or the cells were first exposed to lactobacilli before H. pylori infection (preincubation). In coincubation assays, lactobacilli had no effect on H. pylori-mediated ADAM17, HBEGF, and TGF-α upregulation at the protein level. However, in preincubation assays, L. gasseri downregulated the expression of ADAM17 and its substrates. Furthermore, the proliferation data demonstrated that L. gasseri suppressed H. pylori-induced cellular progression. Using an in vivo mouse model, the anti-inflammatory activity of selected lactobacilli was tested by measuring blood cytokine profiles and tissue staining. L. gasseri significantly decreased the levels of the pro-inflammatory cytokine TNF and reduced immune cell infiltration in stained gastric tissues. Together, these findings suggest that certain lactobacilli can counteract the H. pylori-mediated induction of HBEGF and TGF-α expression, and indicate that ADAM17 could be targeted to inhibit the cancer-related effects of H. pylori.

迄今为止，各种益生菌乳酸菌已被测试对幽门螺杆菌。然而，对各种信号通路及其相关的抗增殖活性的详细分子分析仍然知之甚少。在我们之前发表的研究中，我们提出了一种分解素和金属蛋白酶17 （ADAM17）是幽门螺杆菌感染的宿主巨噬细胞抗炎活性的关键靶点。因此，在本研究中，anti-H。通过测定胃上皮细胞中ADAM17及其两个靶点肝素结合egf样生长因子（HBEGF）和转化生长因子-α (TGF-α)的表达，评估所选乳酸菌的幽门螺杆菌活性。为此，将乳酸杆菌和幽门螺杆菌一起加入AGS细胞（共孵育），或者在幽门螺杆菌感染前先将细胞暴露于乳酸杆菌中（预孵育）。在共孵育实验中，乳酸菌在蛋白水平上对幽门螺杆菌介导的ADAM17、HBEGF和TGF-α上调没有影响。然而，在孵育前实验中，L. gasseri下调ADAM17及其底物的表达。此外，增殖数据表明，L. gasseri抑制幽门螺杆菌诱导的细胞进展。采用小鼠体内模型，通过测定血液细胞因子谱和组织染色检测所选乳酸菌的抗炎活性。L. gasseri显著降低了染色胃组织中促炎细胞因子TNF的水平，减少了免疫细胞的浸润。综上所述，这些发现表明某些乳酸菌可以抵消幽门螺杆菌介导的HBEGF和TGF-α的表达，并表明ADAM17可以靶向抑制幽门螺杆菌的癌症相关作用。

{"title":"Lactobacillus gasseri suppresses the Helicobacter pylori-induced expression of the proliferation-associated factors HBEGF and TGF-α in gastric host cells","authors":"Tanvi Somiah, Priyodip Paul, Sarah Pilheden, James Trumbo, Ann-Beth Jonsson","doi":"10.1016/j.ijmm.2025.151694","DOIUrl":"10.1016/j.ijmm.2025.151694","url":null,"abstract":"<div><div>To date, various probiotic lactobacilli have been tested against <em>Helicobacter pylori</em>. However, a detailed molecular analysis of the various signaling pathways and their associated anti-proliferative activity remains poorly understood. In our previously published research, a disintegrin and metalloprotease 17 (ADAM17) was proposed as a key target for anti-inflammatory activity in <em>H. pylori</em>-infected host macrophages. Therefore, in this study, the anti-<em>H. pylori</em> activity of selected lactobacilli was assessed based on expression of ADAM17 and two of its targets, heparin-binding EGF-like growth factor (HBEGF) and transforming growth factor-alpha (TGF-α), which were measured in gastric epithelial cells. For this purpose, lactobacilli and <em>H. pylori</em> were either added together to the AGS cells (coincubation), or the cells were first exposed to lactobacilli before <em>H. pylori</em> infection (preincubation). In coincubation assays, lactobacilli had no effect on <em>H. pylori</em>-mediated ADAM17, HBEGF, and TGF-α upregulation at the protein level. However, in preincubation assays, <em>L. gasseri</em> downregulated the expression of ADAM17 and its substrates. Furthermore, the proliferation data demonstrated that <em>L. gasseri</em> suppressed <em>H. pylori</em>-induced cellular progression. Using an <em>in vivo</em> mouse model, the anti-inflammatory activity of selected lactobacilli was tested by measuring blood cytokine profiles and tissue staining. <em>L. gasseri</em> significantly decreased the levels of the pro-inflammatory cytokine TNF and reduced immune cell infiltration in stained gastric tissues. Together, these findings suggest that certain lactobacilli can counteract the <em>H. pylori</em>-mediated induction of HBEGF and TGF-α expression, and indicate that ADAM17 could be targeted to inhibit the cancer-related effects of <em>H. pylori</em>.</div></div>","PeriodicalId":50312,"journal":{"name":"International Journal of Medical Microbiology","volume":"322 ","pages":"Article 151694"},"PeriodicalIF":3.6,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145769810","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Dehydroeffusol from Juncus effusus L. exhibits antibacterial activity against methicillin-resistant Staphylococcus aureus in vitro and in vivo 在体外和体内对耐甲氧西林金黄色葡萄球菌具有抑菌活性。

IF 3.6 3区医学 Q1 MICROBIOLOGY

International Journal of Medical Microbiology

Pub Date : 2025-12-11 DOI: 10.1016/j.ijmm.2025.151696

Shengying Lou , Wei Jin , Minyang He , Chunyan Dai , Zhiqiang Zhu , Peng Li , Jichun Han , Xingru Chen , Miaolian Wu , Xiangcheng Fan , Xiaojun Xu

Background

Dehydroeffusol (DHE) is a natural phenanthrene compound derived from Juncus effusus L., traditionally used for its antimicrobial properties. Despite its historical use, its antibacterial efficacy and underlying mechanisms have not been fully explored.

Objectives

To evaluate the antibacterial activity, safety profile, and mechanism of action of DHE against Staphylococcus aureus (S. aureus), including methicillin-resistant S. aureus (MRSA), and to assess its potential as a therapeutic agent.

Methods

DHE was isolated and its antibacterial effects were assessed using broth microdilution, time-kill assays, and biofilm inhibition assays. The cytotoxicity and hemolytic activity of DHE were evaluated in vitro using several cell lines and red blood cells. Mechanistic studies included scanning electron microscopy, membrane potential and permeability assays, network pharmacology analysis, molecular docking, and untargeted metabolomic profiling.

Results

DHE exhibited appreciable bactericidal activity against S. aureus and MRSA with minimal cytotoxicity. It inhibited biofilm formation, disrupted bacterial membranes, and maintained bactericidal activity without rapid resistance, while synergizing with ciprofloxacin, streptomycin, and azithromycin. Network pharmacology and docking identified 56 infection-related targets (hub proteins EGFR, BCL2, HSP90AA1/B1, ESR1, SRC) enriched in PI3K–Akt/ErbB/EGFR pathways, supporting additional modulation of host infection-related signaling. In MRSA, untargeted metabolomics showed broad disturbances in amino acid, energy, and nucleotide metabolism, indicating disruption of essential biosynthetic and energy pathways. In vivo, DHE significantly reduced bacterial load and alleviated tissue damage in a murine MRSA infection model, demonstrating measurable protective effects.

Conclusions

DHE is a promising natural antimicrobial agent with notable activity against S. aureus and MRSA. Its mechanism of action involves membrane disruption and biofilm inhibition, along with preliminary safety in vitro, supporting its potential for further development as an effective antimicrobial agent.

背景：脱氢effusol （DHE）是一种天然菲化合物，从积液菌中提取，传统上用于抗菌性能。尽管其历史悠久，但其抗菌功效和潜在机制尚未得到充分探索。目的：评估DHE对金黄色葡萄球菌（S. aureus）的抗菌活性、安全性和作用机制，包括耐甲氧西林金黄色葡萄球菌（MRSA），并评估其作为治疗药物的潜力。方法：分离DHE，采用微量肉汤稀释法、时间杀伤法、生物膜抑制法评价其抑菌效果。在体外用多种细胞系和红细胞对DHE的细胞毒性和溶血活性进行了评价。机制研究包括扫描电子显微镜、膜电位和渗透性分析、网络药理学分析、分子对接和非靶向代谢组学分析。结果：DHE对金黄色葡萄球菌和MRSA具有明显的杀菌活性，且细胞毒性最小。它能抑制生物膜的形成，破坏细菌膜，保持杀菌活性而不产生快速耐药性，同时与环丙沙星、链霉素和阿奇霉素协同作用。网络药理学和对接发现56个感染相关靶点（枢纽蛋白EGFR， BCL2, HSP90AA1/B1, ESR1， SRC）富集于PI3K-Akt/ErbB/EGFR通路，支持宿主感染相关信号的额外调节。在MRSA中，非靶向代谢组学显示氨基酸、能量和核苷酸代谢广泛紊乱，表明必需的生物合成和能量途径被破坏。在小鼠MRSA感染模型中，DHE显著降低细菌负荷并减轻组织损伤，显示出可测量的保护作用。结论：DHE对金黄色葡萄球菌和MRSA具有明显的抗氧化活性，是一种很有前景的天然抗菌药物。其作用机制涉及膜破坏和生物膜抑制，以及初步的体外安全性，支持其作为有效抗菌剂进一步发展的潜力。

{"title":"Dehydroeffusol from Juncus effusus L. exhibits antibacterial activity against methicillin-resistant Staphylococcus aureus in vitro and in vivo","authors":"Shengying Lou , Wei Jin , Minyang He , Chunyan Dai , Zhiqiang Zhu , Peng Li , Jichun Han , Xingru Chen , Miaolian Wu , Xiangcheng Fan , Xiaojun Xu","doi":"10.1016/j.ijmm.2025.151696","DOIUrl":"10.1016/j.ijmm.2025.151696","url":null,"abstract":"<div><h3>Background</h3><div>Dehydroeffusol (DHE) is a natural phenanthrene compound derived from <em>Juncus effusus L.</em>, traditionally used for its antimicrobial properties. Despite its historical use, its antibacterial efficacy and underlying mechanisms have not been fully explored.</div></div><div><h3>Objectives</h3><div>To evaluate the antibacterial activity, safety profile, and mechanism of action of DHE against <em>Staphylococcus aureus</em> (<em>S. aureus</em>), including methicillin-resistant <em>S. aureus</em> (MRSA), and to assess its potential as a therapeutic agent.</div></div><div><h3>Methods</h3><div>DHE was isolated and its antibacterial effects were assessed using broth microdilution, time-kill assays, and biofilm inhibition assays. The cytotoxicity and hemolytic activity of DHE were evaluated <em>in vitro</em> using several cell lines and red blood cells. Mechanistic studies included scanning electron microscopy, membrane potential and permeability assays, network pharmacology analysis, molecular docking, and untargeted metabolomic profiling.</div></div><div><h3>Results</h3><div>DHE exhibited appreciable bactericidal activity against <em>S. aureus</em> and MRSA with minimal cytotoxicity. It inhibited biofilm formation, disrupted bacterial membranes, and maintained bactericidal activity without rapid resistance, while synergizing with ciprofloxacin, streptomycin, and azithromycin. Network pharmacology and docking identified 56 infection-related targets (hub proteins EGFR, BCL2, HSP90AA1/B1, ESR1, SRC) enriched in PI3K–Akt/ErbB/EGFR pathways, supporting additional modulation of host infection-related signaling. In MRSA, untargeted metabolomics showed broad disturbances in amino acid, energy, and nucleotide metabolism, indicating disruption of essential biosynthetic and energy pathways. <em>In vivo</em>, DHE significantly reduced bacterial load and alleviated tissue damage in a murine MRSA infection model, demonstrating measurable protective effects.</div></div><div><h3>Conclusions</h3><div>DHE is a promising natural antimicrobial agent with notable activity against <em>S. aureus</em> and MRSA. Its mechanism of action involves membrane disruption and biofilm inhibition, along with preliminary safety <em>in vitro</em>, supporting its potential for further development as an effective antimicrobial agent.</div></div>","PeriodicalId":50312,"journal":{"name":"International Journal of Medical Microbiology","volume":"322 ","pages":"Article 151696"},"PeriodicalIF":3.6,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145776199","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Metabolite-responsive regulator RpiRB modulates Staphylococcus aureus pathogenicity via regulation of agr expression 代谢物反应调节因子RpiRB通过调节agr表达调节金黄色葡萄球菌的致病性

IF 3.6 3区医学 Q1 MICROBIOLOGY

International Journal of Medical Microbiology

Pub Date : 2025-12-11 DOI: 10.1016/j.ijmm.2025.151695

Shihui Yuan , Ping Yan , Huimin Su , Ayesha Serwat , Yujie Li , Baolin Sun

Staphylococcus aureus is a well-known pathogenic bacterium that can produce a variety of virulence factors that cause disease in humans. RpiRB is a regulator of metabolic response, whose regulatory role in the virulence of S. aureus is largely unknown. In this study, we demonstrated that the disruption of rpiRB led to down-regulation of the transcription levels of agr-related virulence factors, and reduced the hemolytic activity of methicillin-resistance S. aureus (MRSA). In addition, we also found that RpiRB was involved in regulating the inflammatory response of the host. A mouse subcutaneous abscess model showed that the pathogenicity of the strain was significantly reduced after the destruction of rpiRB. Interestingly, RpiRB enhanced the pathogenic capacity of S. aureus in an agr-dependent manner, while it was directly inhibited by SarA. This study aims to highlight the role of RpiRB in the regulation of the pathogenicity of S. aureus, so as to provide theoretical references for illustrating the infection mechanism and coping strategies of S. aureus.

金黄色葡萄球菌是一种众所周知的致病菌，可以产生多种致病因子，导致人类疾病。RpiRB是代谢反应的调节因子，其在金黄色葡萄球菌毒力中的调节作用在很大程度上是未知的。在这项研究中，我们证明了rpiRB的破坏导致农业相关毒力因子的转录水平下调，并降低了耐甲氧西林金黄色葡萄球菌（MRSA）的溶血活性。此外，我们还发现RpiRB参与调节宿主的炎症反应。小鼠皮下脓肿模型显示，破坏rpiRB后，菌株的致病性明显降低。有趣的是，RpiRB以agr依赖的方式增强了金黄色葡萄球菌的致病能力，而SarA则直接抑制了RpiRB。本研究旨在突出RpiRB在金黄色葡萄球菌致病性调控中的作用，为阐明金黄色葡萄球菌的感染机制和应对策略提供理论参考。

{"title":"Metabolite-responsive regulator RpiRB modulates Staphylococcus aureus pathogenicity via regulation of agr expression","authors":"Shihui Yuan , Ping Yan , Huimin Su , Ayesha Serwat , Yujie Li , Baolin Sun","doi":"10.1016/j.ijmm.2025.151695","DOIUrl":"10.1016/j.ijmm.2025.151695","url":null,"abstract":"<div><div><em>Staphylococcus aureus</em> is a well-known pathogenic bacterium that can produce a variety of virulence factors that cause disease in humans. RpiRB is a regulator of metabolic response, whose regulatory role in the virulence of <em>S. aureus</em> is largely unknown. In this study, we demonstrated that the disruption of <em>rpiRB</em> led to down-regulation of the transcription levels of <em>agr</em>-related virulence factors, and reduced the hemolytic activity of methicillin-resistance <em>S. aureus</em> (MRSA). In addition, we also found that RpiRB was involved in regulating the inflammatory response of the host. A mouse subcutaneous abscess model showed that the pathogenicity of the strain was significantly reduced after the destruction of <em>rpiRB</em>. Interestingly, RpiRB enhanced the pathogenic capacity of <em>S. aureus</em> in an <em>agr</em>-dependent manner, while it was directly inhibited by SarA. This study aims to highlight the role of RpiRB in the regulation of the pathogenicity of <em>S. aureus</em>, so as to provide theoretical references for illustrating the infection mechanism and coping strategies of <em>S. aureus</em>.</div></div>","PeriodicalId":50312,"journal":{"name":"International Journal of Medical Microbiology","volume":"322 ","pages":"Article 151695"},"PeriodicalIF":3.6,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145719061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Epidemiology of gonococcal arthritis in Brittany - France (EpGAr study) 布列塔尼-法国淋球菌性关节炎流行病学（EpGAr研究）

IF 3.6 3区医学 Q1 MICROBIOLOGY

International Journal of Medical Microbiology

Pub Date : 2025-12-10 DOI: 10.1016/j.ijmm.2025.151692

Valentin Lemoine , Simon Rolland , Sophie Reissier , David Luque Paz , Marion Souffez , Mathilde Favalelli , Victor Scavazzin , Julie Brousseau , Claudie Lamoureux , Caroline Piau , Vincent Cattoir , François Caméléna , Béatrice Berçot , Geneviève Héry-Arnaud

Background

Gonococcal infections are sexually-transmitted infections (STIs), which in 0.5–3 % of cases, can progress to disseminated infections (DGI). This study aimed to characterize the epidemiology of septic arthritis and tenosynovitis caused by Neisseria gonorrhoeae, the two most common clinical manifestations of DGI (30–90 %).

Methods

A retrospective observational study was conducted in two French referral hospitals from June 2014 to June 2024. Adult patients treated for septic arthritis due to N. gonorrhoeae with a positive culture of joint fluid were included.

Results

We identified ten cases (eight males and two females) with a mean age of 44 years. The infected joints were the wrist, knee, thumb, elbow, ankle, and hip. On average, it took 13 days from the onset of symptoms to the administration of appropriate antibiotic treatment. Among the ten cases, seven strains were available. Of these, five were resistant to fluoroquinolones and six to tetracyclines. All strains were susceptible to third-generation cephalosporins. All patients received ceftriaxone as first-line therapy and achieved complete recovery in 70 % (7/10) of cases at the one-year follow-up. Whole genome sequencing identified virulence-associated alleles, such as porB1a, but no clustering of hypervirulent clones was observed.

Conclusions

Our findings highlight the variety of joints affected by septic arthritis caused by N. gonorrhoeae, as well as high level of resistance to both fluoroquinolones and tetracyclines. These results emphasize the importance of vigilance when diagnosing and managing gonococcal infections, particularly in high-risk populations, and highlight the need for further research into alternative treatments to address emerging resistance.

淋球菌感染是性传播感染（STIs），在0.5 - 3. %的病例中，可发展为播散性感染（DGI）。本研究旨在探讨淋病奈瑟菌引起的感染性关节炎和腱鞘炎的流行病学特征，这是DGI最常见的两种临床表现（30-90 %）。方法2014年6月至2024年6月在法国两家转诊医院进行回顾性观察研究。成人患者治疗感染性关节炎淋病奈瑟菌与关节液培养阳性。结果10例，男8例，女2例，平均年龄44岁。受感染的关节包括手腕、膝盖、拇指、肘部、脚踝和臀部。从出现症状到给予适当的抗生素治疗平均需要13天。在10例病例中，有7株菌株可用。其中5例对氟喹诺酮类药物耐药，6例对四环素类药物耐药。所有菌株均对第三代头孢菌素敏感。所有患者均接受头孢曲松作为一线治疗，在1年随访中，70% %（7/10）的病例完全康复。全基因组测序鉴定出毒力相关等位基因，如porB1a，但未观察到高毒力克隆的聚集性。结论淋病奈瑟菌所致脓毒性关节炎患者关节形态多样，对氟喹诺酮类药物和四环素类药物均有较高耐药性。这些结果强调了在诊断和管理淋球菌感染时保持警惕的重要性，特别是在高危人群中，并强调需要进一步研究解决新出现的耐药性的替代治疗方法。

{"title":"Epidemiology of gonococcal arthritis in Brittany - France (EpGAr study)","authors":"Valentin Lemoine , Simon Rolland , Sophie Reissier , David Luque Paz , Marion Souffez , Mathilde Favalelli , Victor Scavazzin , Julie Brousseau , Claudie Lamoureux , Caroline Piau , Vincent Cattoir , François Caméléna , Béatrice Berçot , Geneviève Héry-Arnaud","doi":"10.1016/j.ijmm.2025.151692","DOIUrl":"10.1016/j.ijmm.2025.151692","url":null,"abstract":"<div><h3>Background</h3><div>Gonococcal infections are sexually-transmitted infections (STIs), which in 0.5–3 % of cases, can progress to disseminated infections (DGI). This study aimed to characterize the epidemiology of septic arthritis and tenosynovitis caused by <em>Neisseria gonorrhoeae</em>, the two most common clinical manifestations of DGI (30–90 %).</div></div><div><h3>Methods</h3><div>A retrospective observational study was conducted in two French referral hospitals from June 2014 to June 2024. Adult patients treated for septic arthritis due to <em>N. gonorrhoeae</em> with a positive culture of joint fluid were included.</div></div><div><h3>Results</h3><div>We identified ten cases (eight males and two females) with a mean age of 44 years. The infected joints were the wrist, knee, thumb, elbow, ankle, and hip. On average, it took 13 days from the onset of symptoms to the administration of appropriate antibiotic treatment. Among the ten cases, seven strains were available. Of these, five were resistant to fluoroquinolones and six to tetracyclines. All strains were susceptible to third-generation cephalosporins. All patients received ceftriaxone as first-line therapy and achieved complete recovery in 70 % (7/10) of cases at the one-year follow-up. Whole genome sequencing identified virulence-associated alleles, such as <em>porB1a</em>, but no clustering of hypervirulent clones was observed.</div></div><div><h3>Conclusions</h3><div>Our findings highlight the variety of joints affected by septic arthritis caused by <em>N. gonorrhoeae</em>, as well as high level of resistance to both fluoroquinolones and tetracyclines. These results emphasize the importance of vigilance when diagnosing and managing gonococcal infections, particularly in high-risk populations, and highlight the need for further research into alternative treatments to address emerging resistance.</div></div>","PeriodicalId":50312,"journal":{"name":"International Journal of Medical Microbiology","volume":"322 ","pages":"Article 151692"},"PeriodicalIF":3.6,"publicationDate":"2025-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145739291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A pan-azole and pan-echinocandin resistant Wickerhamomyces anomalus isolate causing bloodstream infection: ERG11Y140F, K151R with copy number variation and FKS1 F665S mutation 一株引起血流感染的抗泛唑和泛棘白菌素的异常Wickerhamomyces: ERG11Y140F， K151R，拷贝数变异，FKS1F665S突变。

IF 3.6 3区医学 Q1 MICROBIOLOGY

International Journal of Medical Microbiology

Pub Date : 2025-12-01 DOI: 10.1016/j.ijmm.2025.151689

Zhengyu Luo , Yating Ning , Rongchen Dai , Ailifeire Ainiwaer , Yanhong Li , Ruike Zhang , Meng Xiao , Xiaoxi Wang , Yang Yang , Yuyan Huang , Dingding Li , Lingli Liu , Roujie Huang , Tingying Xu , Yingchun Xu , Zhiyong Liu , Li Zhang , Tianshu Sun

Fungal infections pose a growing global threat, particularly due to the emergence of multidrug-resistant pathogens. This study reports the first globally documented case of a Wickerhamomyces anomalus isolate (XN272) displaying dual high-level resistance to all tested azoles and echinocandins. Genomic analysis of the strain, which was isolated from a bloodstream infection in a 64-year-old male post-pancreatic surgery, identified two key resistance mechanisms: the azole target gene ERG11 harbored missense mutations (Y140H, K151R) and tandem copy number variations, while the echinocandin target gene FKS1 carried an F665S mutation. Transcriptomic profiling under antifungal exposure suggested an additional resistance mechanism, the upregulation of membrane-associated genes and efflux transporters (e.g., FLU1). Strain XN272 exhibited robust biofilm-forming capacity, a trait linked to reduced drug susceptibility. Despite its resistant phenotype, virulence assessments in immunosuppressed mice showed comparable tissue colonization and clearance rates to strain ATCC 8168. The discovery of pan-azole and pan-echinocandin resistance in W. anomalus highlights the expanding landscape of antifungal resistance and its clinical management challenges.

真菌感染构成日益严重的全球威胁，特别是由于耐多药病原体的出现。本研究报告了全球首例记录在案的异常Wickerhamomyces anomalus分离物（XN272）对所有测试的唑类和棘白菌素均表现出高水平的双重耐药性。对从一名64岁男性胰腺手术后血液感染中分离出来的菌株进行基因组分析，确定了两种关键的耐药机制：唑靶基因ERG11携带错义突变（Y140H, K151R）和串接拷贝数变异，而棘白菌素靶基因FKS1携带F665S突变。抗真菌暴露下的转录组分析表明了另一种抗性机制，即膜相关基因和外排转运蛋白（如FLU1）的上调。菌株XN272表现出强大的生物膜形成能力，这一特性与降低药物敏感性有关。尽管其具有抗性表型，但免疫抑制小鼠的毒力评估显示，与ATCC 8168菌株的组织定植和清除率相当。异常W. anomalus中pan-azole和pan-echinocandin耐药的发现凸显了抗真菌药物耐药性的扩大及其临床管理的挑战。

{"title":"A pan-azole and pan-echinocandin resistant Wickerhamomyces anomalus isolate causing bloodstream infection: ERG11Y140F, K151R with copy number variation and FKS1 F665S mutation","authors":"Zhengyu Luo , Yating Ning , Rongchen Dai , Ailifeire Ainiwaer , Yanhong Li , Ruike Zhang , Meng Xiao , Xiaoxi Wang , Yang Yang , Yuyan Huang , Dingding Li , Lingli Liu , Roujie Huang , Tingying Xu , Yingchun Xu , Zhiyong Liu , Li Zhang , Tianshu Sun","doi":"10.1016/j.ijmm.2025.151689","DOIUrl":"10.1016/j.ijmm.2025.151689","url":null,"abstract":"<div><div>Fungal infections pose a growing global threat, particularly due to the emergence of multidrug-resistant pathogens. This study reports the first globally documented case of a <em>Wickerhamomyces anomalus</em> isolate (XN272) displaying dual high-level resistance to all tested azoles and echinocandins. Genomic analysis of the strain, which was isolated from a bloodstream infection in a 64-year-old male post-pancreatic surgery, identified two key resistance mechanisms: the azole target gene <em>ERG11</em> harbored missense mutations (Y140H, K151R) and tandem copy number variations, while the echinocandin target gene <em>FKS1</em> carried an F665S mutation. Transcriptomic profiling under antifungal exposure suggested an additional resistance mechanism, the upregulation of membrane-associated genes and efflux transporters (e.g., <em>FLU1</em>). Strain XN272 exhibited robust biofilm-forming capacity, a trait linked to reduced drug susceptibility. Despite its resistant phenotype, virulence assessments in immunosuppressed mice showed comparable tissue colonization and clearance rates to strain ATCC 8168. The discovery of pan-azole and pan-echinocandin resistance in <em>W. anomalus</em> highlights the expanding landscape of antifungal resistance and its clinical management challenges.</div></div>","PeriodicalId":50312,"journal":{"name":"International Journal of Medical Microbiology","volume":"321 ","pages":"Article 151689"},"PeriodicalIF":3.6,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145715589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Clinical characteristics and whole-genome analysis of methicillin-resistant Staphylococcus aureus in ICU patients from a tertiary hospital in southern China 中国南方某三级医院ICU患者耐甲氧西林金黄色葡萄球菌临床特征及全基因组分析

IF 3.6 3区医学 Q1 MICROBIOLOGY

International Journal of Medical Microbiology

Pub Date : 2025-12-01 DOI: 10.1016/j.ijmm.2025.151686

Ying Wang , Zhihan Xiao , Huimin Xi , Qing Zhu , Peng Liu , Rui Zhao

Objectives

This study aimed to characterize the molecular epidemiology, antimicrobial resistance, virulence profiles, and clinical outcomes of Methicillin-resistant Staphylococcus aureus (MRSA) infections among intensive care unit (ICU) patients in southern China.

Methods

A total of 104 non-duplicate MRSA isolates were collected from ICU patients at a tertiary hospital between 2021 and 2024. Whole-genome sequencing was used to determine molecular characteristics. Antimicrobial susceptibility, biofilm formation, and hemolytic activity were conducted. Clinical data were analyzed to evaluate associations between MRSA lineages and patient outcomes.

Results

Eight clonal complexes and 16 sequence types were identified, with Clonal Complex (CC)5 (31.7 %), CC59 (20.2 %), and CC398 (18.3 %) being the most predominant. The dominant clones, namely CC5-ST5-SCCmec II-agr II, CC398-ST398-SCCmec V-agr I, and CC59-ST59-SCCmec IV-agr I, each exhibited distinct phylogenetic clustering patterns and resistance patterns. Notably, ST764, a variant of ST5, showed extensive multidrug resistance and robust biofilm-forming capacity, while ST59 isolates displayed the highest hemolytic activity. ST5 and ST764 exhibited the broadest resistance profiles. Virulence genes hla, psmα1–4 and psmβ1 present in all isolates, while tst was more frequent in CC5 and associated with higher 30-day death rate (P = 0.038). CC5 infections were linked to worse outcomes, with a death rate of 45.5 %. Renal insufficiency (P < 0.001) and malignancy (P = 0.011) were independent predictors of 30-day death rate.

Conclusion

ICU-derived MRSA isolates in southern China display considerable molecular diversity and varying resistance and virulence profiles. CC5, especially ST764, is associated with multidrug resistance and poor clinical outcomes, highlighting the need for enhanced infection control in ICUs.

目的：本研究旨在了解中国南方重症监护病房（ICU）患者耐甲氧西林金黄色葡萄球菌（MRSA）感染的分子流行病学、耐药性、毒力特征和临床结果。方法：收集某三级医院2021 - 2024年ICU患者非重复MRSA分离株104株。采用全基因组测序确定分子特征。进行了抗菌敏感性、生物膜形成和溶血活性的检测。分析临床数据以评估MRSA谱系与患者预后之间的关系。结果：共鉴定出8种克隆复合物和16种序列类型，其中克隆复合物（CC）5（31.7 %）、CC59（20.2 %）和CC398（18.3 %）最为突出。优势克隆CC5-ST5-SCCmec II-agr II、CC398-ST398-SCCmec V-agr I和CC59-ST59-SCCmec IV-agr I表现出不同的系统发育聚类模式和抗性模式。值得注意的是，ST5的变体ST764表现出广泛的多药耐药和强大的生物膜形成能力，而ST59菌株表现出最高的溶血活性。ST5和ST764表现出最宽的抗性谱。毒力基因hla、psmα1-4和psmβ1在所有分离株中均存在，而tst在CC5中更常见，且与较高的30天死亡率相关（P = 0.038）。CC5感染与较差的结果相关，死亡率为45.5% %。结论：中国南方icu来源的MRSA分离株具有相当大的分子多样性和不同的耐药和毒力谱。CC5，特别是ST764，与多药耐药和不良临床结果相关，突出了加强icu感染控制的必要性。

{"title":"Clinical characteristics and whole-genome analysis of methicillin-resistant Staphylococcus aureus in ICU patients from a tertiary hospital in southern China","authors":"Ying Wang , Zhihan Xiao , Huimin Xi , Qing Zhu , Peng Liu , Rui Zhao","doi":"10.1016/j.ijmm.2025.151686","DOIUrl":"10.1016/j.ijmm.2025.151686","url":null,"abstract":"<div><h3>Objectives</h3><div>This study aimed to characterize the molecular epidemiology, antimicrobial resistance, virulence profiles, and clinical outcomes of Methicillin-resistant <em>Staphylococcus aureus</em> (MRSA) infections among intensive care unit (ICU) patients in southern China.</div></div><div><h3>Methods</h3><div>A total of 104 non-duplicate MRSA isolates were collected from ICU patients at a tertiary hospital between 2021 and 2024. Whole-genome sequencing was used to determine molecular characteristics. Antimicrobial susceptibility, biofilm formation, and hemolytic activity were conducted. Clinical data were analyzed to evaluate associations between MRSA lineages and patient outcomes.</div></div><div><h3>Results</h3><div>Eight clonal complexes and 16 sequence types were identified, with Clonal Complex (CC)5 (31.7 %), CC59 (20.2 %), and CC398 (18.3 %) being the most predominant. The dominant clones, namely CC5-ST5-SCC<em>mec</em> II-<em>agr</em> II, CC398-ST398-SCC<em>mec</em> V-<em>agr</em> I, and CC59-ST59-SCC<em>mec</em> IV-<em>agr</em> I, each exhibited distinct phylogenetic clustering patterns and resistance patterns. Notably, ST764, a variant of ST5, showed extensive multidrug resistance and robust biofilm-forming capacity, while ST59 isolates displayed the highest hemolytic activity. ST5 and ST764 exhibited the broadest resistance profiles. Virulence genes <em>hla, psmα1–4</em> and <em>psmβ1</em> present in all isolates, while <em>tst</em> was more frequent in CC5 and associated with higher 30-day death rate (<em>P</em> = 0.038). CC5 infections were linked to worse outcomes, with a death rate of 45.5 %. Renal insufficiency (<em>P</em> < 0.001) and malignancy (<em>P</em> = 0.011) were independent predictors of 30-day death rate.</div></div><div><h3>Conclusion</h3><div>ICU-derived MRSA isolates in southern China display considerable molecular diversity and varying resistance and virulence profiles. CC5, especially ST764, is associated with multidrug resistance and poor clinical outcomes, highlighting the need for enhanced infection control in ICUs.</div></div>","PeriodicalId":50312,"journal":{"name":"International Journal of Medical Microbiology","volume":"321 ","pages":"Article 151686"},"PeriodicalIF":3.6,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145607025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Emergence and genetic heterogeneity of STEC O113:H4: insights from whole-genome sequences of isolates across human and non-human sources 产志贺毒素大肠杆菌O113:H4的出现和遗传异质性：来自人类和非人类源分离株全基因组序列的见解

IF 3.6 3区医学 Q1 MICROBIOLOGY

International Journal of Medical Microbiology

Pub Date : 2025-12-01 DOI: 10.1016/j.ijmm.2025.151688

Florence Crombé , Frederic Auvray , Angela H.A.M. van Hoek , Bavo Verhaegen , Sigrid C.J. De Keersmaecker , Carolina Silva Nodari , Aurélie Cointe , Jacques Mainil , Caroline Willis , Gro S. Johannessen , Ralph Litjens , Joost Stassen , Denis Piérard

The increased detection of Shiga toxin-producing Escherichia coli (STEC) O113:H4 among human cases in Belgium questions the importance of this serotype as an emerging pathogen. However, detailed information focusing on serotype O113:H4 from human and non-human sources remains limited. We analysed a collection of 140 STEC O113:H4 isolates and their whole genomes, originating from animal hosts (cattle, deer, goats, and sheep), food, and humans, to determine their genetic relationship and assess key virulence genes. All STEC O113:H4 genomes lacked the locus of enterocyte effacement (LEE) and belonged to Pasteur Sequence Type (pST) 367 complex, dominated by pST367 (ehxA^-, stx_2d⁺) and pST1729 (ehxA⁺, stx_2b⁺). Compared to stx_2d⁺ isolates, stx_2b⁺ isolates carried on median more virulence factors, which might thus contribute to enhanced pathogenicity. Besides, humans appear to be infected with distinct subgroups of STEC O113:H4 carrying distinct stx subtypes and originating from potentially different sources: deer, goats, and sheep for STEC carrying stx_2b (alone or in combination with stx_1c) and mainly cattle for STEC carrying stx_2d. Our results call for improved understanding and continuous surveillance of emerging STEC O113:H4.

比利时人类病例中产生志贺毒素的大肠杆菌（STEC） O113:H4检出率的增加对这种血清型作为一种新发病原体的重要性提出了质疑。然而，关于人类和非人类来源的O113:H4血清型的详细信息仍然有限。我们分析了来自动物宿主（牛、鹿、山羊和绵羊）、食物和人类的140株产大肠杆菌O113:H4分离株及其全基因组，以确定它们的遗传关系并评估关键毒力基因。所有STEC O113:H4基因组都缺乏肠细胞湮没（LEE）位点，属于巴斯德序列型（pST） 367复合体，以pST367 （ehxA-, stx2d+）和pST1729 （ehxA+, stx2b+）为主。与stx2d+分离株相比，stx2b+分离株携带的毒力因子中值更多，这可能有助于增强致病性。此外，人类似乎感染了携带不同stx亚型的STEC O113:H4的不同亚群，并且可能来自不同的来源：鹿、山羊和绵羊感染了携带stx2b的STEC（单独或与stx1c结合），而主要是牛感染了携带stx2d的STEC。我们的研究结果呼吁加强对新发产志贺毒素大肠杆菌O113:H4的了解和持续监测。

{"title":"Emergence and genetic heterogeneity of STEC O113:H4: insights from whole-genome sequences of isolates across human and non-human sources","authors":"Florence Crombé , Frederic Auvray , Angela H.A.M. van Hoek , Bavo Verhaegen , Sigrid C.J. De Keersmaecker , Carolina Silva Nodari , Aurélie Cointe , Jacques Mainil , Caroline Willis , Gro S. Johannessen , Ralph Litjens , Joost Stassen , Denis Piérard","doi":"10.1016/j.ijmm.2025.151688","DOIUrl":"10.1016/j.ijmm.2025.151688","url":null,"abstract":"<div><div>The increased detection of Shiga toxin-producing <em>Escherichia coli</em> (STEC) O113:H4 among human cases in Belgium questions the importance of this serotype as an emerging pathogen. However, detailed information focusing on serotype O113:H4 from human and non-human sources remains limited. We analysed a collection of 140 STEC O113:H4 isolates and their whole genomes, originating from animal hosts (cattle, deer, goats, and sheep), food, and humans, to determine their genetic relationship and assess key virulence genes. All STEC O113:H4 genomes lacked the locus of enterocyte effacement (LEE) and belonged to Pasteur Sequence Type (pST) 367 complex, dominated by pST367 (<em>ehxA</em><sup>-</sup>, <em>stx</em><sub>2d</sub><sup>+</sup>) and pST1729 (<em>ehxA</em><sup>+</sup>, <em>stx</em><sub>2b</sub><sup>+</sup>). Compared to <em>stx</em><sub>2d</sub><sup>+</sup> isolates, <em>stx</em><sub>2b</sub><sup>+</sup> isolates carried on median more virulence factors, which might thus contribute to enhanced pathogenicity. Besides, humans appear to be infected with distinct subgroups of STEC O113:H4 carrying distinct <em>stx</em> subtypes and originating from potentially different sources: deer, goats, and sheep for STEC carrying <em>stx</em><sub>2b</sub> (alone or in combination with <em>stx</em><sub>1c</sub>) and mainly cattle for STEC carrying <em>stx</em><sub>2d</sub>. Our results call for improved understanding and continuous surveillance of emerging STEC O113:H4.</div></div>","PeriodicalId":50312,"journal":{"name":"International Journal of Medical Microbiology","volume":"321 ","pages":"Article 151688"},"PeriodicalIF":3.6,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145623587","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Distribution and antimicrobial resistance of Acinetobacter spp. isolated from different types of clinical specimens from hospitalized patients and outpatients in Poland 波兰住院和门诊患者不同类型临床标本分离不动杆菌的分布及耐药性分析

IF 3.6 3区医学 Q1 MICROBIOLOGY

International Journal of Medical Microbiology

Pub Date : 2025-12-01 DOI: 10.1016/j.ijmm.2025.151685

Tomasz Kasperski , Monika Pobiega , Monika Pomorska-Wesołowska , Wiktoria Papuga , Agnieszka Chmielarczyk

Background

Acinetobacter baumannii (AB) is the most frequently isolated nosocomial pathogen, but severe infections by A. pittii, A. ursingii, and A. bereziniae are increasing. This study investigated the distribution and antibiotic resistance of Acinetobacter spp. strains from various clinical specimens.

Methods

Data were collected between 2021–2023 from clinical samples of hospitalized and outpatient individuals in southern Poland. Strains were identified using MALDI-TOF Biotyper, and antibiotic susceptibility was tested with the MIDITECH-Analyzer system. Statistical analyses were conducted using IBM SPSS Statistics.

Results

Among 1507 isolated Acinetobacter strains, 951 (63.1 %) were AB, while 556 (36.9 %) represented 27 non-AB species. Most isolates (73.6 %) came from outpatients, while 26.4 % were from hospitalized patients. A. ursingii (30.2 %), A. pittii (20.6 %), and A. junii (13 %) were the most common non-AB species. A. bereziniae, A. calcoaceticus, and A. proteolyticus were more frequently found in hospitalized patients. Non-AB species dominated in clinical specimens from genitourinary tract (87 %), whereas AB was more common in clinical specimens from invasive sites. Nearly all strains were non-susceptible to ciprofloxacin (98.4 %), with lower resistance rates to ampicillin/sulbactam (11.1 %), trimethoprim/sulfamethoxazole (5.8 %), gentamicin (2.9 %), amikacin (2.5 %), meropenem (1.6 %), and colistin (1.6 %). A. bereziniae showed frequently resistance to carbapenems, aminoglycosides, and trimethoprim/sulfamethoxazole. Colistin resistance was observed in A. ursingii and A. pittii.

Conclusions

While AB accounted for 63.1 % of isolates, non-AB species were common, particularly in clinical specimens from genitourinary tract and from skin and wound. Emerging hospital-acquired infections by species like A. pittii underline the need for vigilant monitoring. The high resistance to ciprofloxacin and low but noticeable resistance to carbapenems and colistin highlights the importance of early detection and resistance surveillance to prevent the spread of resistant strains.

鲍曼不动杆菌（AB）是最常见的医院病原菌，但皮氏不动杆菌、熊氏不动杆菌和贝氏不动杆菌的严重感染正在增加。本研究调查了不同临床标本中不动杆菌的分布及耐药情况。方法收集波兰南部地区2021-2023年住院和门诊患者的临床样本。采用MALDI-TOF生物分型法对菌株进行鉴定，采用MIDITECH-Analyzer系统进行药敏试验。采用IBM SPSS Statistics进行统计分析。结果1507株分离不动杆菌中，AB型951株（63.1 %），非AB型27株556株（36.9 %）。大多数分离株（73.6% %）来自门诊患者，26.4% %来自住院患者。最常见的非ab种分别为ursingii（30.2% %）、pittii（20.6 %）和junii（13 %）。在住院患者中更常发现贝氏假单胞菌、钙溶假单胞菌和溶蛋白假单胞菌。非AB种在泌尿生殖道临床标本中占主导地位（87% %），而AB更常见于侵袭部位的临床标本。几乎所有菌株对环丙沙星（98.4% %）均不敏感，对氨苄西林/舒巴坦（11.1 %）、甲氧苄啶/磺胺甲新唑（5.8 %）、庆大霉素（2.9 %）、阿米卡星（2.5 %）、美罗培南（1.6 %）、粘菌素（1.6 %）的耐药率较低。A. bereziniae经常对碳青霉烯类、氨基糖苷类和甲氧苄啶/磺胺甲恶唑耐药。耐粘菌素菌株分别为熊氏和皮氏单胞杆菌。结论AB菌占分离株的63.1 %，但非AB菌在泌尿生殖道、皮肤和创面的临床标本中较为常见。新出现的医院获得性感染，如皮氏单胞杆菌，强调了警惕监测的必要性。对环丙沙星的高耐药性和对碳青霉烯类和粘菌素的低但明显的耐药性突出了早期发现和耐药性监测对防止耐药菌株传播的重要性。

{"title":"Distribution and antimicrobial resistance of Acinetobacter spp. isolated from different types of clinical specimens from hospitalized patients and outpatients in Poland","authors":"Tomasz Kasperski , Monika Pobiega , Monika Pomorska-Wesołowska , Wiktoria Papuga , Agnieszka Chmielarczyk","doi":"10.1016/j.ijmm.2025.151685","DOIUrl":"10.1016/j.ijmm.2025.151685","url":null,"abstract":"<div><h3>Background</h3><div><em>Acinetobacter baumannii</em> (AB) is the most frequently isolated nosocomial pathogen, but severe infections by <em>A. pittii</em>, <em>A. ursingii</em>, and <em>A. bereziniae</em> are increasing. This study investigated the distribution and antibiotic resistance of Acinetobacter spp. strains from various clinical specimens.</div></div><div><h3>Methods</h3><div>Data were collected between 2021–2023 from clinical samples of hospitalized and outpatient individuals in southern Poland. Strains were identified using MALDI-TOF Biotyper, and antibiotic susceptibility was tested with the MIDITECH-Analyzer system. Statistical analyses were conducted using IBM SPSS Statistics.</div></div><div><h3>Results</h3><div>Among 1507 isolated Acinetobacter strains, 951 (63.1 %) were AB, while 556 (36.9 %) represented 27 non-AB species. Most isolates (73.6 %) came from outpatients, while 26.4 % were from hospitalized patients. <em>A. ursingii</em> (30.2 %), <em>A. pittii</em> (20.6 %), and <em>A. junii</em> (13 %) were the most common non-AB species. <em>A. bereziniae</em>, <em>A. calcoaceticus</em>, and <em>A. proteolyticus</em> were more frequently found in hospitalized patients. Non-AB species dominated in clinical specimens from genitourinary tract (87 %), whereas AB was more common in clinical specimens from invasive sites. Nearly all strains were non-susceptible to ciprofloxacin (98.4 %), with lower resistance rates to ampicillin/sulbactam (11.1 %), trimethoprim/sulfamethoxazole (5.8 %), gentamicin (2.9 %), amikacin (2.5 %), meropenem (1.6 %), and colistin (1.6 %). <em>A. bereziniae</em> showed frequently resistance to carbapenems, aminoglycosides, and trimethoprim/sulfamethoxazole. Colistin resistance was observed in <em>A. ursingii</em> and <em>A. pittii</em>.</div></div><div><h3>Conclusions</h3><div>While AB accounted for 63.1 % of isolates, non-AB species were common, particularly in clinical specimens from genitourinary tract and from skin and wound. Emerging hospital-acquired infections by species like <em>A. pittii</em> underline the need for vigilant monitoring. The high resistance to ciprofloxacin and low but noticeable resistance to carbapenems and colistin highlights the importance of early detection and resistance surveillance to prevent the spread of resistant strains.</div></div>","PeriodicalId":50312,"journal":{"name":"International Journal of Medical Microbiology","volume":"321 ","pages":"Article 151685"},"PeriodicalIF":3.6,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145623585","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Stability of Clostridioides difficile toxins in stool samples 粪便样品中艰难梭菌毒素的稳定性。

IF 3.6 3区医学 Q1 MICROBIOLOGY

International Journal of Medical Microbiology

Pub Date : 2025-12-01 DOI: 10.1016/j.ijmm.2025.151691

Nicolas Heyer , Tobias Grebe , Andreas Schlattmann , Ahmed Mostafa Abdrabou , Jonel Trebicka , Frieder Schaumburg

Clostridioides difficile infection (CDI) is mediated by the cytotoxins TcdA and/or TcdB. The reliable detection of these toxins using enzyme immunoassays (EIA) could be affected by toxin stability. We assessed the toxin stability in stool samples spiked with TcdA or TcdB and in stool samples from CDI patients under transport conditions. In the spiked samples, the concentration of TcdB decreased faster than TcdA within 72 h. In contrast, toxin levels in stool samples from CDI patients remained stable within 24 h, while viable C. difficile slightly increased. In conclusion, toxin instability did not affect C. difficile toxin detection in our study.

艰难梭菌感染（CDI）由细胞毒素TcdA和/或TcdB介导。利用酶免疫分析法（EIA）对这些毒素的可靠检测可能受到毒素稳定性的影响。我们评估了加入TcdA或TcdB的粪便样本以及运输条件下CDI患者的粪便样本中毒素的稳定性。在加标后的样品中，TcdB的浓度在72 h内比TcdA下降得更快。相比之下，CDI患者粪便样本中的毒素水平在24 h内保持稳定，而活的艰难梭菌略有增加。总之，毒素不稳定性不影响本研究中艰难梭菌毒素的检测。

引用次数: 0

Emergence of KL57 hypervirulent Klebsiella pneumoniae in Wuxi, China: Genomic insights into virulence plasmid evolution and blaKPC-2-bearing IncFIIK34 plasmid transmission 中国无锡出现KL57高毒肺炎克雷伯菌：毒力质粒进化和携带blakpc -2的IncFIIK34质粒传播的基因组见解

IF 3.6 3区医学 Q1 MICROBIOLOGY

International Journal of Medical Microbiology

Pub Date : 2025-12-01 DOI: 10.1016/j.ijmm.2025.151687

Yutong Liu , Lin Wan , Xiong Li , Yingshun Zhou , Renjing Hu

<div><h3>Objective</h3><div>KL57 <em>Klebsiella pneumoniae</em> (<em>K. pneumoniae</em>) is an emerging serotype with epidemiological characteristics and pathogenic mechanisms that remain incompletely understood. This study comprehensively analyzed the genomic features of KL57 <em>K. pneumoniae</em> strains isolated in Wuxi from 2016 to 2023, and investigated the global molecular epidemiology and population dynamics of KL57 <em>K. pneumoniae</em>.</div></div><div><h3>Methods</h3><div>From January 2016 to December 2023, 17 KL57 <em>K. pneumoniae</em> isolates were collected from various clinical specimens at the Wuxi No.2 People's Hospital, Jiangsu Province, China. Antimicrobial susceptibility testing (AST), whole-genome sequencing (WGS), and bioinformatics analysis including evaluation of virulence genes, resistance genes, and plasmid replicon types were performed on these strains. To elucidate the genetic relationships and global distribution of the KL57 <em>K. pneumoniae</em>, phylogenetic trees were constructed through comparative analyses of our KL57 strains alongside those obtained from public databases. Additionally, the distribution patterns of serotypes and carbapenemase genes among these strains were examined.</div></div><div><h3>Results</h3><div>Seventeen KL57 <em>K. pneumoniae</em> strains were categorized into four distinct sequence types (STs), with ST412 being the most prevalent in Wuxi, and ST2846, which was identified for the first time. Analysis of virulence genes indicated KL57 <em>K. pneumoniae</em> isolates often express multiple virulence factors. Antimicrobial resistance profiling revealed that only one ST218 isolate contained the <em>bla</em><sub>KPC-2</sub> gene, which was located on an IncFII<sub>K34</sub> plasmid. Geographically, ST412, ST218, and ST592 were the main predominant epidemic sequence types of the KL57 <em>K. pneumoniae</em>. A global analysis indicated that KL57 carbapenem-resistant <em>K. pneumoniae</em> (CRKp) strains predominantly harbored the <em>bla</em><sub>NDM-1</sub>, <em>bla</em><sub>OXA-48</sub>, <em>bla</em><sub>KPC-2</sub>, and <em>bla</em><sub>OXA-181</sub> genes. Furthermore, phylogenetic analysis demonstrated significant diversity in the sequence types of KL57 <em>K. pneumoniae</em> strains across continents, with notable variations even between countries.</div></div><div><h3>Conclusion</h3><div>Our study corroborates the widespread occurrence of the ST412 KL57 <em>K. pneumoniae</em> in China and identifies a specific strain harboring the IncFII<sub>K34</sub> resistance plasmid. Additionally, the KL57 CRKp strain carries a variety of carbapenemase genes, and some of these strains simultaneously harbor multiple such genes. Our findings suggest that this subtype demonstrates enhanced resistance adaptability and may facilitate the dissemination of drug resistance through horizontal gene transfer. Consequently, it is necessary to develop more targeted surveillance strategies that focus on resistan

目的kl57肺炎克雷伯菌（克雷伯菌）是一种新兴的血清型，其流行病学特征和致病机制尚不完全清楚。本研究综合分析2016 - 2023年无锡地区分离的KL57肺炎克雷伯菌基因组特征，研究KL57肺炎克雷伯菌全球分子流行病学和种群动态。方法2016年1月至2023年12月，从江苏省无锡市第二人民医院的临床标本中分离出KL57肺炎克雷伯菌17株。对这些菌株进行了药敏试验（AST）、全基因组测序（WGS）和生物信息学分析，包括毒力基因、抗性基因和质粒复制子类型的评估。为了阐明KL57肺炎克雷伯菌的遗传关系和全球分布，通过与公共数据库中获得的KL57菌株进行比较分析，构建了系统发育树。此外，还检测了这些菌株的血清型和碳青霉烯酶基因的分布规律。结果17株KL57肺炎克雷伯菌可分为4种不同的序列型（STs），其中ST412在无锡市最常见，ST2846为首次检出。毒力基因分析表明，KL57肺炎克雷伯菌分离株可表达多种毒力因子。抗微生物药物耐药性分析显示，只有一个ST218分离株含有blaKPC-2基因，该基因位于IncFIIK34质粒上。从地理上看，ST412、ST218和ST592是KL57肺炎克雷伯菌的主要优势流行序列类型。一项全球分析表明，KL57耐碳青霉烯类肺炎克雷伯菌（CRKp）菌株主要携带blaNDM-1、blaOXA-48、blaKPC-2和blaOXA-181基因。此外，系统发育分析显示，各大洲KL57肺炎克雷伯菌菌株的序列类型存在显著差异，甚至在国家之间也存在显著差异。结论本研究证实了ST412 KL57肺炎克雷伯菌在中国广泛存在，并鉴定出一株携带IncFIIK34耐药质粒的特异性菌株。此外，KL57 CRKp菌株携带多种碳青霉烯酶基因，其中一些菌株同时携带多个此类基因。我们的研究结果表明，该亚型表现出增强的耐药适应性，并可能通过水平基因转移促进耐药性的传播。因此，有必要制定更有针对性的监测策略，重点关注耐药基因特征和流行亚型。

{"title":"Emergence of KL57 hypervirulent Klebsiella pneumoniae in Wuxi, China: Genomic insights into virulence plasmid evolution and blaKPC-2-bearing IncFIIK34 plasmid transmission","authors":"Yutong Liu , Lin Wan , Xiong Li , Yingshun Zhou , Renjing Hu","doi":"10.1016/j.ijmm.2025.151687","DOIUrl":"10.1016/j.ijmm.2025.151687","url":null,"abstract":"<div><h3>Objective</h3><div>KL57 <em>Klebsiella pneumoniae</em> (<em>K. pneumoniae</em>) is an emerging serotype with epidemiological characteristics and pathogenic mechanisms that remain incompletely understood. This study comprehensively analyzed the genomic features of KL57 <em>K. pneumoniae</em> strains isolated in Wuxi from 2016 to 2023, and investigated the global molecular epidemiology and population dynamics of KL57 <em>K. pneumoniae</em>.</div></div><div><h3>Methods</h3><div>From January 2016 to December 2023, 17 KL57 <em>K. pneumoniae</em> isolates were collected from various clinical specimens at the Wuxi No.2 People's Hospital, Jiangsu Province, China. Antimicrobial susceptibility testing (AST), whole-genome sequencing (WGS), and bioinformatics analysis including evaluation of virulence genes, resistance genes, and plasmid replicon types were performed on these strains. To elucidate the genetic relationships and global distribution of the KL57 <em>K. pneumoniae</em>, phylogenetic trees were constructed through comparative analyses of our KL57 strains alongside those obtained from public databases. Additionally, the distribution patterns of serotypes and carbapenemase genes among these strains were examined.</div></div><div><h3>Results</h3><div>Seventeen KL57 <em>K. pneumoniae</em> strains were categorized into four distinct sequence types (STs), with ST412 being the most prevalent in Wuxi, and ST2846, which was identified for the first time. Analysis of virulence genes indicated KL57 <em>K. pneumoniae</em> isolates often express multiple virulence factors. Antimicrobial resistance profiling revealed that only one ST218 isolate contained the <em>bla</em><sub>KPC-2</sub> gene, which was located on an IncFII<sub>K34</sub> plasmid. Geographically, ST412, ST218, and ST592 were the main predominant epidemic sequence types of the KL57 <em>K. pneumoniae</em>. A global analysis indicated that KL57 carbapenem-resistant <em>K. pneumoniae</em> (CRKp) strains predominantly harbored the <em>bla</em><sub>NDM-1</sub>, <em>bla</em><sub>OXA-48</sub>, <em>bla</em><sub>KPC-2</sub>, and <em>bla</em><sub>OXA-181</sub> genes. Furthermore, phylogenetic analysis demonstrated significant diversity in the sequence types of KL57 <em>K. pneumoniae</em> strains across continents, with notable variations even between countries.</div></div><div><h3>Conclusion</h3><div>Our study corroborates the widespread occurrence of the ST412 KL57 <em>K. pneumoniae</em> in China and identifies a specific strain harboring the IncFII<sub>K34</sub> resistance plasmid. Additionally, the KL57 CRKp strain carries a variety of carbapenemase genes, and some of these strains simultaneously harbor multiple such genes. Our findings suggest that this subtype demonstrates enhanced resistance adaptability and may facilitate the dissemination of drug resistance through horizontal gene transfer. Consequently, it is necessary to develop more targeted surveillance strategies that focus on resistan","PeriodicalId":50312,"journal":{"name":"International Journal of Medical Microbiology","volume":"321 ","pages":"Article 151687"},"PeriodicalIF":3.6,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145623586","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0