Journal of medical microbiology最新文献

{"title":"Establishment of a matrix-assisted laser desorption/ionization time-of-flight mass spectrometry database and evaluation of different methods for cluster analysis of marine bacteria.","authors":"Jia-Qi Guo, Jing Wu, He-Qing Cao, Yue Qiu, Xiao-Fei Liu","doi":"10.1099/jmm.0.002162","DOIUrl":"https://doi.org/10.1099/jmm.0.002162","url":null,"abstract":"<p><p><b>Introduction</b>. Accurate and rapid identification of marine bacteria is essential for the precise diagnosis and treatment of infectious diseases caused by marine pathogens. The accuracy of microbial identification using matrix-assisted laser desorption/ionization time-of-flight MS (MALDI-TOF MS) primarily depends on the diversity and number of strains included in the reference database.<b>Hypothesis/Gap statement</b>. We hypothesized that expanding the MALDI-TOF MS database with a broader collection of protein spectral profiles from marine bacteria would significantly enhance identification accuracy for these strains.<b>Aim</b>. This study aimed to establish a marine bacterial database to improve identification accuracy and to evaluate the applicability of MALDI-TOF MS-based cluster analysis for tracing the origin of clinical strains.<b>Methodology</b>. We collected 203 strains isolated from marine environments and clinical samples, acquired their MALDI-TOF MS spectra and constructed a mass spectral database specific to marine bacteria. To validate the accuracy of the expanded database, 80 external strains were subsequently tested. Furthermore, we assessed the strain classification efficacy of MALDI-TOF MS cluster analysis and phylogenetic trees constructed from gene sequences.<b>Results</b>. The species-level identification rate increased from 88.75 to 97.5%. The proportion of strains achieving a reliable identification score (>2.3) rose markedly from 43.75 to 91.25%. Cluster analysis based on MALDI-TOF MS demonstrated high accuracy in grouping bacteria at the species level. In addition, the maximum likelihood (ML) phylogenetic tree exhibited significantly higher bootstrap support values compared to the neighbour-joining tree.<b>Conclusion</b>. The expanded marine bacterial database markedly enhances the accuracy and reliability of MALDI-TOF MS for identifying marine pathogens. For species identification and traceability, we recommend a combined strategy that includes initial MALDI-TOF MS screening and verification with phylogenetic trees based on the ML method.</p>","PeriodicalId":94093,"journal":{"name":"Journal of medical microbiology","volume":"75 5","pages":""},"PeriodicalIF":2.0,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147857844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Clinician perspectives on patient consent for metagenomic next-generation sequencing of blood samples for the diagnosis of infection in clinical practice.","authors":"Tom G S Williams, Helen Umpleby, Temitope Fisayo, Tommy Rampling, Catherine F Houlihan","doi":"10.1099/jmm.0.002164","DOIUrl":"10.1099/jmm.0.002164","url":null,"abstract":"<p><p><b>Introduction.</b> Pathogen diagnostics based on metagenomic next-generation sequencing (mNGS) are now in clinical use. mNGS can identify unexpected pathogens or organisms of unclear significance and generate human genomic data. Given these features, it has been suggested that patients should provide specific informed consent for mNGS.<b>Gap Statement.</b> There is limited published guidance on the appropriate form of consent for clinical infectious disease mNGS to guide clinical implementation and current practice varies.<b>Aim.</b> To inform a pilot of mNGS for returning travellers delivered at a reference laboratory for use by specialist infection clinicians, we sought clinician perspectives on the form of consent required for mNGS and the information patients require to make an informed decision.<b>Methodology.</b> A national survey of infection specialists provided clinicians' opinions.<b>Results.</b> If consent for an infection screen including blood-borne virus testing had already been provided, only a minority of surveyed clinicians (22 out of 124, 18%) thought that mNGS should be discussed before it was performed on pre-existing blood samples.<b>Conclusion.</b> Most of the UK infection clinicians surveyed did not think that mNGS of blood from returning travellers required discussion before being performed when patients had already consented for infection diagnostics to find the cause of their illness. However, clinicians felt that patients should be aware of the potential for additional testing and wanted information on mNGS to be readily available.With the increasing availability of clinical infectious disease mNGS, engagement of non-specialist clinicians and patients is required to confirm the generalizability of these perspectives. The model of consent used for clinical infectious disease mNGS should be ethically adequate in addition to being acceptable to patients and clinicians.</p>","PeriodicalId":94093,"journal":{"name":"Journal of medical microbiology","volume":"75 5","pages":""},"PeriodicalIF":2.0,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13151739/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147848011","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"<i>Candida glabrata</i> and the host: a neglected affair.","authors":"Manisha Ghosh, Mayur Raney, Rupinder Kaur","doi":"10.1099/jmm.0.002161","DOIUrl":"https://doi.org/10.1099/jmm.0.002161","url":null,"abstract":"<p><p><i>Candida glabrata</i> (<i>Nakaseomyces glabratus</i>), a prevalent opportunistic pathogenic yeast of humans, has been classified as a fungal pathogen of high priority by the World Health Organization. <i>C. glabrata</i> is the leading cause of invasive <i>Candida</i> infections in hospitalized and immunocompromised patients and displays co-resistance to azole and echinocandin drugs. <i>C. glabrata</i> is known for its distinct virulence attributes that facilitate infections of the host in the absence of classical virulence factors, viz. filament formation and secreted toxin. The inability of <i>C. glabrata</i> to induce a strong inflammatory response contributes to its persistence in the host. However, the molecular underpinnings that define the <i>C. glabrata</i>-host relationship are not well-understood. In this review, we summarize the findings on the interplay between <i>C. glabrata</i> and different host cell types and outline the molecular strategies that play a pivotal role in the establishment of <i>C. glabrata</i> infections. Our goal is to expand our knowledge of <i>C. glabrata</i>-host crosstalk and underscore the vital questions whose resolution is essential to effectively manage <i>C. glabrata</i> infections.</p>","PeriodicalId":94093,"journal":{"name":"Journal of medical microbiology","volume":"75 5","pages":""},"PeriodicalIF":2.0,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147857810","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Anatomopathological uterine findings of <i>Candida albicans</i> infection in a vulvovaginal model.","authors":"Valéria Mosca, Glaucia Sayuri Arita, Karina Mayumi Sakita, Juliana Aparecida Fernandes, Rita de Cássia Lima Ribeiro, Francieli Gesleine Capote-Bonato, Denis Vinicius Bonato, Marcelo Marcondes Seneda, Erika Seki Kioshima, Patricia de Souza Bonfim-Mendonça, Terezinha Inez Estivalet Svidzinski","doi":"10.1099/jmm.0.002160","DOIUrl":"10.1099/jmm.0.002160","url":null,"abstract":"<p><p><b>Introduction.</b> Vulvovaginal candidiasis (VVC) is a common fungal infection that has a significant impact on global public health. Although studies associate VVC with male infertility, its influence on the female reproductive system, particularly uterine involvement, remains unknown.<b>Gap statement.</b> While recent animal studies propose that <i>Candida albicans</i> migration from the vaginal tract to the uterus in VVC could lead to infertility, the underlying histopathological alterations that support this connection are not well understood.<b>Aim.</b> To investigate possible changes in the uterine tissue of BALB/c mice infected experimentally with <i>C. albicans</i>, by analysing the progression and effects of infection on the uterus.<b>Methodology.</b> Female BALB/c mice were divided into two groups (infected and control). Vaginal infection was induced by <i>C. albicans</i>, and vaginal and uterine tissues were collected at different intervals (1, 3, 5, 7 and 10 days). Analyses included fungal burden (c.f.u. g^-1), histopathology stained with Grocott-Gomori and macroscopic and microscopic evaluation (haematoxylin-eosin staining) of uterine tissue.<b>Results.</b> Vaginal infection was confirmed by a consistent presence of yeast in vaginal tissue. <i>C. albicans</i> migration was observed in the uterus, with a significant increase in fungal burden on day 3, followed by macroscopic alterations such as oedema and hyperaemia. Histologically, inflammatory infiltrates, epithelial necrosis and progressive degeneration were identified until day 7, with signs of resolution by day 10.<b>Conclusion.</b> The results demonstrate that vaginal infection by <i>C. albicans</i> was able to cause significant uterine alterations with self-limiting progression. These findings suggest that VVC may have direct implications for female fertility, warranting future investigations into its influence on infertility cases.</p>","PeriodicalId":94093,"journal":{"name":"Journal of medical microbiology","volume":"75 5","pages":""},"PeriodicalIF":2.0,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13152020/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147848028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of <i>Candida</i> spp. from the urinary tract: antifungal susceptibility and virulence traits.","authors":"Filipa O Castro, Francisca Bastos, Ana S Oliveira, José Martinez de Oliveira, Ana Palmeira de Oliveira, Ana R Ferrão, Paula G Pestana, Joana Rolo","doi":"10.1099/jmm.0.002158","DOIUrl":"https://doi.org/10.1099/jmm.0.002158","url":null,"abstract":"<p><p><b>Introduction.</b> <i>Candida</i> spp. are opportunistic pathogens frequently associated with nosocomial infections, and their incidence in urinary tract infections (UTIs) has increased significantly in recent decades, representing a serious public health concern.<b>Hypothesis/Gap Statement.</b> While fungal UTIs are gaining attention, there is a lack of comparative studies linking gender and specific niches to the pathogenic potential and antifungal resistance of <i>Candida</i> isolates in the genitourinary tract.<b>Aim.</b> The aim of this study is to characterize <i>Candida</i> spp. isolated from the urinary tract by investigating their incidence, antifungal resistance patterns and phenotypic virulence factors - including biofilm formation, germ tube production and adhesion to human epithelial cells - while specifically comparing these characteristics between male and female patients.<b>Methodology.</b> A total of 37 urinary isolates were collected from patients at a Portuguese public hospital between December 2022 and June 2023. Antifungal susceptibility to fluconazole (FLC) and clotrimazole (CLT) was determined via European Committee on Antimicrobial Susceptibility Testing (EUCAST) broth microdilution. Virulence was assessed through crystal violet biofilm biomass quantification, germ tube formation assays for <i>Candida albicans</i> and adhesion assays using HeLa cells.<b>Results.</b> <i>C. albicans</i> was the most prevalent species, while <i>Nakaseomyces glabratus</i> was exclusively found in female patients (30%). All isolates were susceptible to FLC (MIC ≤2 µg ml^-1) and CLT (MIC ≤1 µg ml^-1). High biofilm biomass was particularly noted in non-<i>albicans</i> species and isolates from hospitalized patients. While isolates from male patients exhibited higher germ tube formation (<i>P</i><0.05), those from female patients demonstrated a potentially greater capacity for adhesion to HeLa cells (<i>P</i><0.05).<b>Conclusion.</b> <i>Candida</i> isolates from the urinary tract demonstrate a potential virulence trait that varies by patient gender and clinical setting. The findings suggest that hospitalized female patients and elderly patients harbour isolates with greater pathogenic potential, highlighting the need for continuous epidemiological surveillance to improve UTI diagnosis and treatment.</p>","PeriodicalId":94093,"journal":{"name":"Journal of medical microbiology","volume":"75 5","pages":""},"PeriodicalIF":2.0,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147857863","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Strain-specific persistence of <i>Burkholderia cenocepacia</i> in the C3HeB/FeJ mouse model of pulmonary infection.","authors":"Ziting Chen, Mariana Romero-Gonzalez, Andrea Maser, Ruisi Leng, Lindsay J Caverly, Marc Hershenson, Ashlee D Brunaugh","doi":"10.1099/jmm.0.002153","DOIUrl":"10.1099/jmm.0.002153","url":null,"abstract":"<p><p><b>Introduction</b> <i>. Burkholderia cenocepacia</i>, a member of the <i>Burkholderia cepacia</i> complex (Bcc), causes severe, treatment-resistant lung infections in individuals with cystic fibrosis and chronic granulomatous disease.<b>Hypothesis.</b> We hypothesized that the C3HeB/FeJ mouse strain, characterized by impaired macrophage-mediated immunity, would be susceptible to persistent infection by clinical Bcc isolates.<b>Aim.</b> To evaluate C3HeB/FeJ susceptibility to various Bcc isolates and characterize the macrophage-intrinsic responses and antibiotic susceptibility within this model.<b>Methodology.</b> C3HeB/FeJ and C57BL/6 mice were compared for susceptibility to pulmonary infection with <i>B. cenocepacia</i> AU0728 following intratracheal inoculation. Bacterial persistence and extrapulmonary dissemination were monitored for up to 42 days. Host immune responses were assessed through systemic leucocyte profiling and analysis of bone marrow-derived macrophage (BMDM) function, including intracellular bacterial control, cytokine production and time-resolved cell-death responses. Model breadth was evaluated using three additional clinical Bcc isolates. Finally, the <i>in vivo</i> efficacy of high-dose ceftazidime or meropenem was assessed against established pulmonary infection.<b>Results.</b> C3HeB/FeJ mice sustained significantly higher pulmonary burdens of <i>B. cenocepacia</i> AU0728 than C57BL/6 mice, resulting in a stable, non-sterilizing infection with extrapulmonary dissemination lasting at least 42 days. <i>In vitro</i>, C3HeB/FeJ BMDMs supported higher intracellular bacterial loads and failed to mount effective IFN-γ-dependent intracellular control. Mixed-effects modelling of cell-death responses revealed that both strains initiated early apoptotic signalling following infection; however, this response was attenuated in C3HeB/FeJ macrophages and was not restored by IFN-γ pretreatment. In contrast, late-stage membrane permeabilization increased progressively over time and exhibited strain- and IFN-γ-dependent modulation at later stages of infection. Susceptibility was highly strain-specific: three additional clinical Bcc isolates were rapidly cleared from C3HeB/FeJ lungs. Treatment with ceftazidime or meropenem reduced established pulmonary bacterial burdens by ~1.4-1.5 log₁₀ c.f.u. but did not achieve sterilization.<b>Conclusion.</b> These findings identify C3HeB/FeJ mice as a selectively susceptible host for sustained pulmonary infection by <i>B. cenocepacia</i> AU0728 and demonstrate that persistence in this model is strongly strain-dependent. Impaired macrophage-intrinsic IFN-γ-dependent control and stage-specific dysregulation of cell-death responses contribute to bacterial persistence. This immunocompetent mouse model provides a tractable platform for dissecting strain-level virulence mechanisms and for evaluating therapeutic strategies targeting chronic Bcc infection.</p>","PeriodicalId":94093,"journal":{"name":"Journal of medical microbiology","volume":"75 4","pages":""},"PeriodicalIF":2.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13065297/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147647838","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"From colonization to invasion: genomic and phenotypic comparison of faecal and bloodstream isolates from the same patients.","authors":"Aakash Khanijau, Ellie Allman, Ralfh Pulmones, Richard N Goodman, Daire Cantillon, Rachel McGalliard, Christopher M Parry, Enitan D Carrol, Adam P Roberts","doi":"10.1099/jmm.0.002147","DOIUrl":"10.1099/jmm.0.002147","url":null,"abstract":"<p><p><b>Introduction.</b> Gram-negative bloodstream infections (GNBSIs) carry a significant global health burden. <i>Escherichia coli</i> and <i>Klebsiella pneumoniae</i> are the two most common causes of healthcare-associated GNBSI, which may arise from gastrointestinal tract (GIT) colonization.<b>Gap Statement.</b> We do not fully understand how GNBSIs arise from GIT colonization.<b>Aim.</b> To understand <i>E. coli</i> and <i>K. pneumoniae</i> genomic and phenotypic adaptations that underpin transition from GIT colonization to invasive bloodstream infection.<b>Methodology.</b> This study identified 'linked' faecal and blood isolates from children with healthcare-associated GNBSI caused by <i>E. coli</i> and <i>K. pneumoniae</i>. Linked pairs were compared for antimicrobial resistance and biofilm formation and underwent comparative genomic analysis via whole-genome sequencing, comparative average nucleotide identity and core genome single nucleotide polymorphism (SNP) analysis.<b>Results.</b> Five isolate pairs (three <i>E. coli</i>, two <i>K. pneumoniae</i>) showed high relatedness, supporting the GIT origin of bloodstream infection. Isolates within pairs had identical virulence genes, whereas phenotypic assays revealed changes in antimicrobial susceptibility, with one pair undergoing changes in resistance gene profiles and increased biofilm formation in four out of five isolates.<b>Conclusion.</b> This study provides insight into within-host evolution from gastrointestinal colonization to bloodstream invasion in Gram-negative pathogens. Convergence on metabolic adaptation and biofilm formation suggests that these traits may be advantageous in healthcare-associated GNBSI. Further studies involving larger cohorts alongside functional validation of mutations are needed to better understand GNBSI pathogenesis.</p>","PeriodicalId":94093,"journal":{"name":"Journal of medical microbiology","volume":"75 4","pages":""},"PeriodicalIF":2.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13061263/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147641046","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pulmonary cryptococcosis in routine care: the clinical-radiologic spectrum and transparent evidence-tier reporting (confirmed versus presumed) among patients with no recorded immunocompromising conditions.","authors":"Xiao-Yao Zhang, Hui Ding, Li-Hong Pei, Qing-Ping Ye, Wei-Bo You, Jian-Min Ren","doi":"10.1099/jmm.0.002159","DOIUrl":"https://doi.org/10.1099/jmm.0.002159","url":null,"abstract":"<p><p><b>Introduction.</b> Pulmonary cryptococcosis is increasingly identified in routine care, including among patients with no recorded immunocompromising conditions.<b>Hypothesis/Gap Statement.</b> Real-world descriptions of pulmonary cryptococcosis are difficult to interpret because diagnostic intensity and case definitions vary across studies, and many cohorts reflect pathway-based rather than population-based case capture.<b>Aim.</b> This study aimed to describe the clinical presentation, including asymptomatic/incidental cases, and chest computed tomography (CT) patterns of pulmonary cryptococcosis by two-level immune status, and to report prespecified diagnostic evidence tiers (confirmed vs presumed).<b>Methodology.</b> We conducted a single-centre, retrospective, observational study at a tertiary hospital in China (January 2016 to December 2020). The analytic cohort comprised adjudicated pulmonary cryptococcosis cases identified along a routine-care diagnostic pathway among patients with pulmonary imaging abnormalities who underwent serum cryptococcal antigen testing as part of clinical evaluation. Cases were classified using a prespecified two-tier evidence scheme (confirmed vs presumed).<b>Results.</b> Among 62 cases, 23/62 (37.1%) were immunocompromised, and 39/62 (62.9%) had no recorded immunocompromising conditions. Evidence tiers comprised 32/62 (51.6%) confirmed and 30/62 (48.4%) presumed cases. Cryptococcal meningitis was documented in 11/62 (17.7%). Asymptomatic/incidental presentation was recorded in 16/62 (25.8%), including 4/23 (17.4%) immunocompromised cases and 12/39 (30.8%) cases with no recorded immunocompromising conditions. On chest CT, nodules/masses were the most frequently recorded pattern in both groups, observed in 17/23 (73.9%) and 31/39 (79.5%) cases, respectively. Opacities/consolidation, cavitation and loculated pleural effusion were recorded less often.<b>Conclusion.</b> In this routine-care diagnostic-pathway cohort, nodules/masses were the most frequently recorded CT pattern, and asymptomatic/incidental presentation was documented in a substantial proportion of cases, including among patients with no recorded immunocompromising conditions. Separate reporting of confirmed and presumed cases may improve interpretation of cohorts assembled under non-uniform diagnostic work-up.</p>","PeriodicalId":94093,"journal":{"name":"Journal of medical microbiology","volume":"75 4","pages":""},"PeriodicalIF":2.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13102314/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147793307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A comparison of routine blood culture methods and multiplex quantitative PCR for detecting pathogens in simulated polymicrobial blood cultures.","authors":"Mariam Doualeh, Christopher Mullally, Martin Thorsen, Edward Raby, Edward Litton, Soraya Leedham, Matthew Payne, Andrew Currie","doi":"10.1099/jmm.0.002155","DOIUrl":"10.1099/jmm.0.002155","url":null,"abstract":"<p><p><b>Introduction.</b> Polymicrobial bacteraemia, the simultaneous presence of multiple bacterial species in the bloodstream, complicates diagnosis and treatment and is linked to poorer patient outcomes. Accurate detection is essential for effective clinical management.<b>Gap Statement.</b> Despite being the diagnostic gold standard, conventional blood culture may fail to detect all pathogens in polymicrobial infections, particularly when species differ in growth rate or abundance. The relative performance of culture versus molecular methods under these conditions remains poorly characterized.<b>Aim.</b> To compare the performance of conventional blood culture and quantitative PCR (qPCR) for detecting pathogens in simulated polymicrobial blood cultures containing fast- and slow-growing bacteria at varying ratios and concentrations.<b>Methodology.</b> Four clinically relevant polymicrobial mixtures were prepared using seven bacterial species. Human blood was spiked with bacterial suspensions at varying ratios and inoculated into BACTEC blood culture bottles. After incubation, samples were analysed using standard culture techniques and an in-house multiplex qPCR assay.<b>Results.</b> Routine culture detected both organisms in only 42% of samples, while qPCR identified both pathogens in 83%. Differences in bacterial growth rates significantly influenced culture outcomes, with slower-growing or less abundant species frequently missed. Notably, <i>Staphylococcus aureus</i> was not detected when co-cultured with <i>Escherichia coli</i> at ratios of 1:1 to 25:1, and only visible on Gram stain when <i>S. aureus</i> was initially 50 times more abundant.<b>Conclusion.</b> These findings highlight a key limitation of conventional methods in detecting polymicrobial infections and underscore the need for more sensitive diagnostics. qPCR offers improved detection, particularly when organism abundance and growth rates vary. Incorporating molecular tools alongside routine culture may enhance diagnostic accuracy and provide a more complete understanding of polymicrobial bacteraemia.</p>","PeriodicalId":94093,"journal":{"name":"Journal of medical microbiology","volume":"75 4","pages":""},"PeriodicalIF":2.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13068292/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147647843","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pre-analytical barriers to blood culture completion in a large laboratory network.","authors":"Timothy J J Inglis, Teagan F Paton, Benjamin R McFadden, Elizabeth Thomas, Michael J Leung","doi":"10.1099/jmm.0.002151","DOIUrl":"10.1099/jmm.0.002151","url":null,"abstract":"<p><p><b>Introduction.</b> Sepsis is a major contributor to the global burden of disease. Its effective treatment is time-critical and relies on timely access to significant blood culture (BC) results.<b>Hypothesis/gap statement.</b> The value of BC results to the requesting service is reduced by delays in report completion. Centralized clinical laboratory networks have little insight into pre-analytical causes of delayed BC results.<b>Aim.</b> We aimed to assess variations in laboratory investigation of bloodstream infection and sepsis throughout a state-wide laboratory network, with the goal to design suitable remedial action.<b>Methodology.</b> We analysed BCs from collection to final reporting in a public pathology service by univariate analysis and supervised machine learning.<b>Results.</b> Of the 5,436 first-positive BCs from all Western Australian (WA) public laboratories in 2023, 1,343 (24.7%) came from regional sources. A total of 1,052 (78.3%) regional BCs were from emergency departments, and 831 (64.5%) of these were collected out of hours, rising during the 24 h cycle. Regional BCs took 33 h more than urban area cultures to reach a final report (103 compared with 70 h). Regional BC Gram stains were delayed by 31 h (69 compared with 38 h) and took over 97 h from collection to report in 25% regional Gram-stain results. Regional BCs added a 15 h delay to first results when significant species were mixed with potential contaminants, and 23 h when mixed with other significant species.<b>Conclusion.</b> In WA, substantial delays to actionable BC results were common. The time taken to transport specimens to a laboratory was a small fraction of these delays. Monitoring of the steps in BC workflow completion can be used to improve the quality and safety of BC service provision within the limits of current technology, though solutions to this critical capability gap vary with location.</p>","PeriodicalId":94093,"journal":{"name":"Journal of medical microbiology","volume":"75 4","pages":""},"PeriodicalIF":2.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13056214/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147635112","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}