Microbial pathogenesis最新文献

{"title":"Genetic diversity, virulence genes, antimicrobial resistance genes, and antimicrobial susceptibility of group B Streptococcus (GBS) associated with mass mortalities of cultured Nile tilapia in Brazil","authors":"Inácio Mateus Assane ,&nbsp;Rubens Ricardo de Oliveira Neto ,&nbsp;Daniel de Abreu Reis Ferreira ,&nbsp;André do Vale Oliveira ,&nbsp;Diogo Teruo Hashimoto ,&nbsp;Fabiana Pilarski","doi":"10.1016/j.micpath.2025.107664","DOIUrl":"10.1016/j.micpath.2025.107664","url":null,"abstract":"<div><div><em>Streptococcus agalactiae</em>, group B <em>Streptococcus</em> (GBS), stands as the primary bacterial pathogen affecting cultured Nile tilapia (<em>Oreochromis niloticus</em>) globally, leading to significant mortalities throughout the farming cycle. This study investigated the genetic diversity, virulence and antimicrobial resistance (AMR) genes presence, and antimicrobial susceptibility of 72 GBS strains associated with mass mortalities of Nile tilapia in Brazil. Isolate identity was confirmed by morphological, biochemical and molecular analyses. Capsular serotype, multi-locus sequence typing (MLST) allelic profiles and putative pathogenic factors were determined through polymerase chain reaction (PCR), gel electrophoresis, DNA sequencing and molecular analyses. The presence of AMR genes and antimicrobial susceptibility to florfenicol (FFC), oxytetracycline (OTC), thiamphenicol (TAP) and their combination were evaluated by PCR, followed by gel electrophoresis, and broth microdilution antimicrobial susceptibility testing, respectively. All clinical isolates studied were confirmed to be GBS, one from serotype III (IA2201) and 71 from serotype Ib, suggesting that serotype Ib was the most prevalent strain between 2011 and 2016 in the southern region of Brazil. Eight different allelic profiles were identified for the first time, with <em>adhP-</em>52, <em>pheS-</em>2, <em>atr-</em>31, <em>glnA-</em>4, <em>sdhA-</em>2, <em>tkt-</em>19 being the most predominant. Between one (<em>glcK</em>) and three (<em>adhP</em> and <em>glnA</em>) alleles were present at each locus. All strains, except IA2201, were negative for the <em>glcK</em> gene. Hyaluronate lyase (<em>hlyB</em>) and the GBS immunogenic bacterial adhesin A (<em>bibA</em>) were detected in all strains, except for 18P, which was negative for <em>hlyB</em>. On the other hand, <em>α</em> and <em>β</em> antigens of the C protein were only detected in IA2201. All antimicrobials showed high minimum inhibitory concentration (MIC ≥16 μg/mL) values against several strains with negative results for resistance genes. The combination involving OTC and TAP or FFC is a likely candidate for improving the treatment of streptococcosis caused by GBS using combination therapy, even for strains showing phenotypic and genotypic resistance to OTC. This study provides important data on pathogenic GBS genetic diversity, the presence of virulence and antimicrobial resistance genes and antimicrobial susceptibility, which may be useful in the development of effective vaccines and therapeutic strategies for the prevention and control of streptococcosis in aquaculture farms.</div></div>","PeriodicalId":18599,"journal":{"name":"Microbial pathogenesis","volume":"205 ","pages":"Article 107664"},"PeriodicalIF":3.3,"publicationDate":"2025-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143902292","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}

{"title":"Cardamom essential oil-loaded zinc oxide nanoparticles: A sustainable antimicrobial strategy against multidrug-resistant foodborne pathogens","authors":"Mabrouk Sobhy ,&nbsp;Tamer Elsamahy ,&nbsp;Esraa A. Abdelkarim ,&nbsp;Ebtihal Khojah ,&nbsp;Haiying Cui ,&nbsp;Lin Lin","doi":"10.1016/j.micpath.2025.107661","DOIUrl":"10.1016/j.micpath.2025.107661","url":null,"abstract":"<div><div>The globalization of the food trade has escalated challenges in ensuring food safety due to foodborne pathogens, including multidrug-resistant (MDR) strains, which pose significant public health risks and economic burdens. Innovative antimicrobial strategies are urgently required. In this study, cardamom essential oil-loaded zinc oxide nanoparticles (CEO-ZnO-NPs) were synthesized and evaluated for their antimicrobial potential and mechanisms of action against MDR <em>Escherichia coli</em> and <em>Staphylococcus aureus</em>. Dynamic light scattering and the transmission electron microscopy (TEM) micrograph confirmed a spherical nanocomposite with an average size of 141.4 nm with good dispersion and stability over 180 days. Antimicrobial activity assessed via the agar well diffusion method showed dose-dependent inhibition, with zones of 25.75 ± 0.90 mm for <em>E. coli</em> and 31.05 ± 0.46 mm for <em>S. aureus</em> at 400 μg/mL. Minimum inhibitory concentrations (MIC) were 25 μg/mL (<em>E. coli</em>) and 12.5 μg/mL (<em>S. aureus</em>), while minimum bactericidal concentrations (MBC) were 50 μg/mL and 25 μg/mL, respectively. Kill-time analysis revealed a marked reduction in bacterial viability after 120 min of exposure. Mechanistic studies using scanning electron microscopy showed structural damage, including disrupted membranes and cell shrinkage. Also, protein levels significantly decreased, with DNA and ATP levels reduced by 74.51 % and 91.15 % in <em>E. coli</em> and 79.40 % and 90.81 % in <em>S. aureus</em>. Enzymatic activities, including ATPase and alkaline phosphatase, were inhibited by up to 84.63 %. In addition, the low cytotoxicity of CEO-ZnO-NPs against Vero cells supporting their potential biosafety for food safety applications. These findings demonstrate that CEO-ZnO-NPs disrupt bacterial processes such as protein synthesis, membrane integrity, and enzymatic activity, offering a promising approach that aligns with the United Nations Sustainable Development Goals (SDGs), particularly SDGs 2, 3, and 12, while promoting circular economy principles by reducing reliance on synthetic preservatives to address antimicrobial resistance in foodborne pathogens.</div></div>","PeriodicalId":18599,"journal":{"name":"Microbial pathogenesis","volume":"205 ","pages":"Article 107661"},"PeriodicalIF":3.3,"publicationDate":"2025-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143902291","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}

{"title":"Assessing multi-drug resistance in Streptococcus agalactiae infecting farmed Nile Tilapia: Findings from Kerala, India","authors":"Keerthana Kalathil Maniyappan,&nbsp;Sneha Kalasseril Girijan,&nbsp;Rahul Krishnan,&nbsp;Asha Gopan,&nbsp;Devika Pillai","doi":"10.1016/j.micpath.2025.107666","DOIUrl":"10.1016/j.micpath.2025.107666","url":null,"abstract":"<div><div><em>Streptococcus agalactiae</em> infections in tilapia are indeed a major concern in the global aquaculture industry, leading to significant economic losses. This study describes the isolation, virulence factors, pathogenicity and antibiotic susceptibility pattern of <em>S. agalactiae</em> in cultured Nile tilapia (<em>Oreochromis niloticus</em>) from aquaculture farms in Kerala, India. The diseased fish showed erratic swimming, lethargy, eye opacity, exophthalmia, darkened body, ascites and haemorrhages. Histopathological findings revealed hepatocytic vacuolization and meningitis. Molecular serotyping of the <em>S. agalactiae</em> isolates identified the serotype Ia. In terms of virulence characteristics, the <em>S. agalactiae</em> isolate obtained from tilapia sample had <em>fbsA, cfB</em> and <em>pbp1A/ponA</em> genes, and they were moderate biofilm producers. It is a matter of concern that the isolates were resistant to the tested macrolides, glycopeptides, chloramphenicol, tetracycline, sulphonamides, lincosamides, oxazolidinones and beta lactam group of antibiotics. Pathogenicity of the isolated strain was tested by experimental challenge through intraperitoneal injection of the isolated strain in Nile tilapia.100 %, 80 %, 40 % and 20 % mortality at doses of 1.0 × 10⁸, 1.0 × 10⁶, 1.0 × 10⁴ and 1.0 × 10² CFU/ml, respectively were recorded in the challenged fish. Level of liver enzymes such as Aspartate aminotransferase (AST) and Alanine Aminotransferase (ALT), and glucose were significantly increased compared to that in control. The haematological indices such as RBC and haemoglobin counts were significantly reduced, while WBC count increased in the challenged fish. The haemolysis test on blood agar plate showed beta haemolysis (β). The emergence of multidrug-resistant pathogen <em>S. agalactiae</em> in tilapia farms in the state is an early warning for appropriate preventive measures to be taken to control their spread across farms as tilapia culture is widely popular in the state.</div></div>","PeriodicalId":18599,"journal":{"name":"Microbial pathogenesis","volume":"205 ","pages":"Article 107666"},"PeriodicalIF":3.3,"publicationDate":"2025-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143905843","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}

{"title":"Solar-assisted synthesis of silver nanoparticles from Amphilophium paniculatum (L.) Kunth: Unlocking multi-therapeutic potential for lung cancer, diabetes and drug resistant infections through In vitro studies and In silico antidiabetic evaluations","authors":"Rajalakshmi Ravimoorthy ,&nbsp;Lalitha Pottail ,&nbsp;Muddukrishnaiah Kotakonda","doi":"10.1016/j.micpath.2025.107647","DOIUrl":"10.1016/j.micpath.2025.107647","url":null,"abstract":"<div><div>This study contributes to develop and evaluate the biological applications of eco-friendly synthesized silver nanoparticles using <em>Amphilophium paniculatum</em> leaf ethanol extract via. solar irradiation method. The synthesized silver nanoparticles were characterized using UV, FTIR, FESEM and EDS. UV spectrum of silver nanoparticles showed the surface plasma resonance at 431 nm, which confirms the formation of silver nanoparticles. FTIR revealed the presence of functional groups in the extract which helps in the formation of silver nanoparticles. XRD pattern revealed the crystallite nature of nanoparticles. FESEM images showed spherical morphology with average size of 26–28 nm. Biological evaluations of silver nanoparticles exhibited higher antioxidant (IC₅₀- 57.76 μg/mL) compared to extract (IC₅₀- 100.09 μg/mL). The synthesized silver nanoparticles possess good antibacterial activities against clinical isolates such as <em>Staphylococcus aureus</em> (ZOI- 18 mm) and <em>Klebsiella pneumonia</em> (ZOI- 14 mm). Further, <em>in vitro</em> antidiabetic potential of silver nanoparticles revealed greater alpha amylase inhibition compared with standard drugs. The cytotoxic assessment on A⁵⁴⁹ cell lines revealed lower IC₅₀ value (26.34 μg/mL) for silver nanoparticles, compared to extract (224 μg/mL), suggesting significant cytotoxicity. <em>In silico</em> screening of selected bioactive compounds from <em>Amphilophium paniculatum</em> evaluated for their physicochemical properties, toxicity and docking studies. Molecular docking studies revealed that (+)-lyoniresinol-3-alpha-O-beta-D-glucopyranoside and linarin exhibits better binding interactions with 2RIP-DPPIV receptor, suggesting a potent therapeutic agent for type 2 <em>diabetes mellitus</em>. Therefore, the synthesized silver nanoparticles act as multi therapeutic potential based novel drugs to combat multi-drug resistant pathogens, lung cancer, and <em>diabetes mellitus</em>.</div></div>","PeriodicalId":18599,"journal":{"name":"Microbial pathogenesis","volume":"205 ","pages":"Article 107647"},"PeriodicalIF":3.3,"publicationDate":"2025-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143907674","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}

{"title":"Mycoplasma hyopneumoniae - an unusual cause of fibrinous pericarditis with pericardial tamponade in pre-weaned piglets","authors":"Monalisa Sahoo ,&nbsp;Shailesh Kumar Patel ,&nbsp;Mamta Pathak ,&nbsp;Jigarji Chaturji Thakor ,&nbsp;M. Dinesh ,&nbsp;Sagar Patel ,&nbsp;Subbaiyan Anbazhagan ,&nbsp;G. Saikumar ,&nbsp;Rajendra Singh ,&nbsp;Karampal Singh ,&nbsp;Prabin Kumar Sahoo ,&nbsp;Mamata Pasayat ,&nbsp;Nihar Ranjan Sahoo","doi":"10.1016/j.micpath.2025.107632","DOIUrl":"10.1016/j.micpath.2025.107632","url":null,"abstract":"<div><div>M. hyo<em>pneumoniae</em> is an atypical bacterium that is frequently associated with porcine enzootic pneumonia, but uncommonly identified as a cause of pericarditis and myocarditis leading to pericardial tamponade. The present report describes the rare case of <em>M. hyopneumoniae</em> causing fibrinous pericarditis and pericardial tamponade in pre-weaned crossbred piglets (n = 7). The piglets showed the predominant lesions of pericardial effusions with tamponade, fibrinous pericarditis, pleural effusions, heavy non-collapsible lungs with multifocal reddish areas on parenchyma, and enlarged lymph nodes. Microscopically, sub-acute fibrinous pericarditis, pleuritis, brocho-interstitial pneumonia with lymphoid depletion in the lymphoid organs were the consistent lesions observed in the piglets. The piglets showed the strong immunoreactivity to <em>M. hyopneumoniae</em> antigens in the infiltrating mononuclear cells, cardiomyocytes, and purkinje fibers of heart, bronchioles, and alveolar lining epithelium of lungs, and lymphocytes of the depleted lymphoid follicles of the lymph nodes. The absence of immunoreactivity to <em>M. hyorhinis</em> in the heart ruled out the cross specificity and confirmed the involvement of <em>M. hyopneumoniae</em> with the cardiac pathologies. Further, <em>M. hyopneumoniae</em> was confirmed in heart, pericardium, and lungs of the piglets by PCR suggesting the role of <em>M. hyopneumoniae</em> with the cardiac lesions. The absence of any other possible etiologies (bacteria/and virus) in the heart tissues further confirms <em>M. hyopneumoniae</em> as a cause of cardiac lesions. Among various viruses screened, lungs, lymph nodes, and liver of the piglets showed the genomic detection of porcine circovirus 2 along with strong cytoplasmic immunolabeling of viral antigens in lungs and lymph nodes. This indicates that co-infection of <em>M. hyopneumoniae</em> and porcine circovirus 2 might be playing a synergistic role by potentiating each other in causing severe pathologies involving lungs and heart. This paper highlights that <em>M. hyopneumoniae</em> should be considered in the differential diagnosis of pneumonia complicated by pericardial effusion leading to complication of pericardial tamponade and should be part of the routine workup for pericarditis of unknown etiology for the effective control and management of piglet mortality. Moreover, the presence of immunosuppressive disease like porcine circovirus 2 has also to be considered as the predisposing factor for the development of fibrinous pericarditis.</div></div>","PeriodicalId":18599,"journal":{"name":"Microbial pathogenesis","volume":"205 ","pages":"Article 107632"},"PeriodicalIF":3.3,"publicationDate":"2025-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143905858","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}

{"title":"The mechanism of outer membrane vesicle-mediated resistance to carbapenem antibiotics","authors":"Dan Zhou ,&nbsp;Xiaoyu Yang ,&nbsp;Yuhong Gao ,&nbsp;Rui Zheng","doi":"10.1016/j.micpath.2025.107654","DOIUrl":"10.1016/j.micpath.2025.107654","url":null,"abstract":"<div><div>The escalating prevalence of carbapenem resistance in Gram-negative bacteria presents a critical therapeutic challenge, demanding urgent elucidation of novel resistance mechanisms. This review systematically examines the emerging role of outer membrane vesicles (OMVs) as multifunctional mediators of carbapenem resistance, synthesizing recent advances in understanding their biological properties and mechanistic contributions. Through comprehensive analysis of β-lactamase dissemination pathways, we demonstrate that OMVs are extracellular vectors facilitating antibiotic degradation through enzymatic cargo delivery while concurrently acting as genetic transmission vehicles for resistance determinants. Crucially, OMVs exhibit functional versatility in enhancing bacterial survival via dual mechanisms: structurally, by promoting biofilm matrix formation that establishes antibiotic-protected niches, and immunologically, through modulation of host-pathogen interactions that impair microbial clearance. The review further identifies OMV-mediated antibiotic sequestration and competitive binding as underappreciated resistance amplifiers. These insights refine our understanding of resistance evolution and reveal OMV biogenesis pathways as promising therapeutic targets. This synthesis establishes OMVs as central players in carbapenem resistance architecture, providing a strategic framework for developing countermeasures against multidrug-resistant infections.</div></div>","PeriodicalId":18599,"journal":{"name":"Microbial pathogenesis","volume":"205 ","pages":"Article 107654"},"PeriodicalIF":3.3,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143902287","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}

{"title":"Chlamydia trachomatis infection induces ferroptosis and enhances chlamydial replication","authors":"Yuan Wei ,&nbsp;Qiankun Chen ,&nbsp;Xizhan Xu ,&nbsp;Yan Peng ,&nbsp;Jinding Pang ,&nbsp;Zhenyu Wei ,&nbsp;Qingfeng Liang","doi":"10.1016/j.micpath.2025.107656","DOIUrl":"10.1016/j.micpath.2025.107656","url":null,"abstract":"<div><div><em>Chlamydia trachomatis (C. trachomatis)</em> has been shown to activate multiple programmed cell death pathways, which contribute significantly to host immune responses. Nevertheless, the precise molecular mechanisms by which <em>C. trachomatis</em> induces cell death remain poorly characterized. Ferroptosis, a recently identified form of iron-dependent, lipid peroxidation-driven regulated cell death, may represent a previously unrecognized pathway in chlamydial pathogenesis.</div><div>To investigate the mechanisms underlying <em>C. trachomatis</em>-induced cell death, we first performed transcriptomic analysis to identify differentially expressed genes and enriched pathways in infected HeLa cells. Concurrently, we quantified intracellular iron levels, reactive oxygen species (ROS) accumulation, and lipid peroxidation, all of which are hallmarks of ferroptosis. Transmission electron microscopy (TEM) further revealed distinct mitochondrial alterations in <em>C. trachomatis</em>-infected cells, suggesting potential dysfunction in cellular redox homeostasis. To directly assess the role of ferroptosis in chlamydial infection, we treated cells with the ferroptosis-specific inhibitor Ferrostatin-1 (Fer-1) and evaluated its effects on chlamydial replication and host inflammatory responses.</div><div>Bioinformatic analysis demonstrated significant enrichment of iron homeostasis and ferroptosis-related pathways in <em>C. trachomatis</em>-infected cells, with the ferroptosis signaling pathway exhibiting particularly strong activation. Experimentally, infection disrupted the expression of key iron transporters (e.g., TFR and FPN1), causing dysregulated iron uptake and storage. Concurrently, <em>C. trachomatis</em> downregulated the critical ferroptosis inhibitors SLC7A11 and GPX4, leading to elevated lipid peroxidation. Ultrastructural analysis via TEM revealed pronounced mitochondrial abnormalities in infected HeLa cells, including marked swelling and cristae disintegration—a hallmark of ferroptotic damage. Notably, pharmacological inhibition of ferroptosis using Fer-1 not only attenuated infection-induced cell death but also significantly suppressed bacterial replication, suggesting ferroptosis as a host-pathogen interaction nexus.</div><div>This study provides evidence that <em>C. trachomatis</em> infection induces ferroptosis in host cells, and that targeting the ferroptosis pathway may represent a novel therapeutic strategy for controlling <em>C. trachomatis</em> infections.</div></div>","PeriodicalId":18599,"journal":{"name":"Microbial pathogenesis","volume":"205 ","pages":"Article 107656"},"PeriodicalIF":3.3,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143903792","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}

{"title":"Amplicon sequencing reveals growth-associated microbial communities in black tiger shrimp (Penaeus monodon)","authors":"Preety Sweta Hembrom ,&nbsp;Mottakunja Deepthi ,&nbsp;Shalini Kannoth ,&nbsp;Narchikundil Reeja ,&nbsp;Ginny Antony ,&nbsp;Tony Grace","doi":"10.1016/j.micpath.2025.107636","DOIUrl":"10.1016/j.micpath.2025.107636","url":null,"abstract":"<div><div>Recent evidence has underscored the significance of intestinal microbes in host growth performance, shedding light on the complex relationship between gut microbiota and host physiology. Even though <em>Penaeus monodon</em> exhibits notable size variations attributed to rapid growth and larger body mass, the specific association of the microbial community with body size remains unexplored. In this study, we employed a 16S rRNA amplicon sequencing approach to investigate the composition, diversity, and functional potential of gut microbiota in two populations of adult <em>P. monodon</em> (fast-growing and slow-growing). Significant variations in microbial architecture were found between the study groups based on alpha and beta diversity analyses. Differential abundance analysis identified the enrichment of specific genera, including <em>Desulfovibrio</em>, <em>Ferrimonas</em>, and <em>Fusibacter</em>, in the fast-growing <em>P. monodon</em>. These genera have been previously implicated in female shrimp growth. Functional prediction of the observed microbiota composition highlighted the predominance of growth-associated pathways, such as iron and sulfur metabolism, in the fast-growing population. Overall, our comprehensive analysis revealed discernible differences in gut microbiota between fast-growing and slow-growing populations of <em>P. monodon</em>, possibly indicating dynamic changes associated with host growth and development. The variations observed in the abundance of growth-related microbial taxa between these populations may provide insights into the underlying mechanisms influencing shrimp growth and development.</div></div>","PeriodicalId":18599,"journal":{"name":"Microbial pathogenesis","volume":"205 ","pages":"Article 107636"},"PeriodicalIF":3.3,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143900268","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}

{"title":"Molecular mechanisms of resistance in Morganella morganii with exclusive resistance to imipenem: Whole genome sequencing analysis of 12 clinical isolates","authors":"Cong Zhang ,&nbsp;Qinqin Shi ,&nbsp;Ying Gao ,&nbsp;Xiaolin Ge","doi":"10.1016/j.micpath.2025.107653","DOIUrl":"10.1016/j.micpath.2025.107653","url":null,"abstract":"<div><h3>Background</h3><div><em>Morganella morganii</em> (<em>M. morganii</em>) is a significant opportunistic pathogen, increasingly linked to infections with high mortality rates.</div></div><div><h3>Objective</h3><div>This study aimed to explore the resistance mechanisms and molecular profiles of 12 clinical <em>M. morganii</em> isolates exclusively resistant to imipenem, employing whole genome sequencing (WGS) to guide infection prevention and control strategies.</div></div><div><h3>Methods</h3><div>A retrospective analysis of 12 isolates from a tertiary hospital, collected between May 2014 and March 2023, was conducted, incorporating strain identification and antimicrobial susceptibility testing. Genomic data were acquired via WGS, followed by gene analysis and replicon typing using Abricate. A broader epidemiological assessment of 227 <em>Morganella</em> isolates was performed using Snippy, Gubbins, and FastTree, leading to the construction of a phylogenetic tree to delineate evolutionary relationships.</div></div><div><h3>Results</h3><div>Three <em>M. morganii</em> isolates were identified as exclusively imipenem-resistant, while remaining susceptible to meropenem and ertapenem, each harboring carbapenemase resistance genes, <em>bla</em>_KPC-2, <em>bla</em>_NDM-1, and <em>bla</em>_OXA-48, respectively. Replicon type analysis revealed that isolate GK07 carried two replicons: IncL/M(pOXA-48)_1_pOXA-48 and IncX8_1.</div></div><div><h3>Conclusion</h3><div>These findings suggest that selective imipenem resistance in <em>M. morganii</em> may be associated with carbapenemase genes and the potential for plasmid-mediated horizontal transmission of resistant clones. The results highlight the need for continuous monitoring of resistance gene dissemination across hosts, targeted interventions to curb resistant clone spread, and sustained vigilance regarding global epidemiological trends.</div></div>","PeriodicalId":18599,"journal":{"name":"Microbial pathogenesis","volume":"205 ","pages":"Article 107653"},"PeriodicalIF":3.3,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143900337","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}

{"title":"Inhibitory effect of naringin, naringenin, and crocin on biofilm formation and lecA gene expression in Pseudomonas aeruginosa clinical isolates","authors":"Sara Sherafati ,&nbsp;Mehrdad Gholami ,&nbsp;Mohammad Ali Ebrahimzadeh ,&nbsp;Hamid Reza Goli","doi":"10.1016/j.micpath.2025.107652","DOIUrl":"10.1016/j.micpath.2025.107652","url":null,"abstract":"<div><div>Biofilm formation by <em>Pseudomonas aeruginosa</em> is a considerable challenge in treating infections. We aimed to investigate the inhibitory effect of crocin, naringin, and naringenin on biofilm formation capacity and the expression of the <em>lecA</em> gene by this organism. One hundred unrepeated <em>P. aeruginosa</em> isolates were collected from hospitalized patients and were identified. The antibiotic resistance pattern of the isolates was determined using the disk agar diffusion method. The minimum inhibitory concentration (MIC) of naringin, naringenin, and crocin was determined by a micro broth dilution test. Then, the biofilm production ability of the isolates was evaluated before and after treatment with the investigated flavonoids using the microtiter plate test. Finally, the <em>lecA</em> gene expression of the isolates was checked before and after treatment with investigated flavonoids using the Real-time PCR method. Among 89 biofilm-producer isolates, 48 (53.93 %), 17 (19.1 %), and 24 (26.96 %) showed a strong, moderate, and weak biofilm formation ability. Biofilm-positive isolates were more resistant to all tested antibiotics. Also, among 41 multidrug-resistant (MDR) isolates, 33 (80.48 %) were strong biofilm producers (P-<em>value</em> = 0.01). A strong correlation was observed between the <em>lecA</em> gene expression and the biofilm production ability of the isolates (P-<em>value</em> = 0.000). The investigated flavonoids were significantly effective on biofilm production by <em>P. aeruginosa</em>. Among 10 strong-biofilm producers, all (100 %) showed a moderate ability to form biofilm after treatment with crocin (P-<em>value</em> = 0.02), and 6 (60 %) isolates had lost their ability to produce biofilm after treatment with the simultaneous use of crocin with ciprofloxacin or tobramycin (P-<em>value</em> = 0.000). Also, one isolate was grouped as biofilm-negative after treatment with naringin (P-<em>value</em> = 0.012). The crocin, naringin, and naringenin and their concurrent use of antibiotics decreased 2-8-fold of the <em>lecA</em> gene expression in strong biofilm-producer isolates (P-<em>value</em>˂0.05). Crocin, naringin, and naringenin can be used separately or simultaneously with antibiotics to inhibit biofilm and reduce the expression of virulence factors effective in biofilm production in <em>P. aeruginosa</em>.</div></div>","PeriodicalId":18599,"journal":{"name":"Microbial pathogenesis","volume":"205 ","pages":"Article 107652"},"PeriodicalIF":3.3,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143902290","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}