Annals of Clinical Microbiology and Antimicrobials最新文献

{"title":"A longitudinal analysis of Clostridioides difficile virulence profiles across three geographic regions in Israel (2020-2022).","authors":"Orna Schwartz, Avi Peretz, Maya Azrad","doi":"10.1186/s12941-026-00868-1","DOIUrl":"10.1186/s12941-026-00868-1","url":null,"abstract":"<p><strong>Background: </strong>Clostridioides difficile infection (CDI) is one of the leading infectious diarrhea worldwide. C. difficile pathogenicity is mediated by various virulence factors, including toxins and biofilm formation. This study included 313 C. difficile isolates that were previously collected from four medical centers. We aimed to investigate the prevalence, distribution, and associations of virulence factors in C. difficile strains from both healthcare-associated (HA)- and community-acquired (CA)-CDI patients across Israel from 2020 to 2022.</p><p><strong>Methods: </strong>Multi-locus sequence typing (MLST) and whole-genome sequencing (WGS) were performed for strain classification and virulence gene detection. Toxin and biofilm production were also characterized.</p><p><strong>Results: </strong>Sequence type (ST) 42 (12.5%) and ST2 (11.5%) were the most prevalent strains. Toxin production patterns were significantly associated with setting of infection acquisition (p < 0.0001). Isolates producing both toxin A and B were 2.5-fold more common among HA-CDI strains, while toxin-A-producers were more frequent in CA-CDI. Biofilm was produced by 96.9% of isolates, with strong biofilm-producing strains significantly more prevalent in hospitals (p < 0.001). Furthermore, isolates producing both toxins A and B were predominantly moderate or strong biofilm producers (p < 0.0001). agrD presence was significantly associated with ST, toxin production patterns and biofilm-production capacity (p < 0.0001 for ST and biofilm, p = 0.0016 for toxins).</p><p><strong>Conclusions: </strong>This study revealed a high diversity of C. difficile strains in Israel and demonstrated that virulence factor patterns differ significantly across STs and the acquisition setting. The differences between HA-CDI and CA-CDI isolates in some virulence factors underscores the importance of continuous epidemiological surveillance to guide tailored treatment and prevention strategies.</p>","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":" ","pages":""},"PeriodicalIF":5.2,"publicationDate":"2026-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13651375/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148194365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Associations of Mycoplasma pneumoniae load, co-infections, and macrolide resistance with clinical-laboratory profiles in hospitalized pediatric pneumonia: a targeted next-generation sequencing study of bronchoalveolar lavage fluid.","authors":"Xingzhen Liang, Rong Wei, Dongna Liang, Wenxiu Huang, Ruizhen Huang, Siyu Lu, Yining Lu, Huifei Ma, Qi Shi, Dongyun Li, Donglu Chen, Bing Qin, Xiheng Qi, Yupeng Tang, Wugui Mo, Zihan Wei","doi":"10.1186/s12941-026-00870-7","DOIUrl":"10.1186/s12941-026-00870-7","url":null,"abstract":"<p><strong>Purpose: </strong>This study aimed to evaluate the associations of Mycoplasma pneumoniae (MP) DNA load, co-infection, and macrolide resistance with clinical phenotypes in pediatric pneumonia, using targeted next-generation sequencing (tNGS) of bronchoalveolar lavage fluid (BALF).</p><p><strong>Methods: </strong>We conducted a retrospective cohort study of 791 hospitalized children with MP pneumonia. All patients underwent bronchoscopy, and BALF was analyzed using tNGS. This allowed for the simultaneous quantification of MP DNA load, comprehensive co-infection profiling, and detection of macrolide resistance mutations (A2063G/A2064G in 23 S rRNA). Clinical data were analyzed for associations with these multidimensional tNGS parameters using univariate and multivariable statistical methods.</p><p><strong>Results: </strong>Our analysis indicated distinct clinical phenotypes associated with tNGS findings. A high MP DNA load was associated with a \"classic\" phenotype of persistent fever and lung consolidation, typically in monoinfection. Conversely, a low MP DNA load was a key biomarker for a co-infection-driven syndrome in younger children, characterized by more severe respiratory symptoms (wheezing, dyspnea) and systemic inflammation. Furthermore, macrolide-resistant MP (MRMP) was the factor most strongly associated with treatment failure, conferring a three-fold increase in the odds of requiring second-line antibiotics, without influencing initial disease severity.</p><p><strong>Conclusion: </strong>This study demonstrates that the integration of MP DNA load, co-infection status, and resistance profiling from BALF-based tNGS supports the use of a multidimensional framework for stratifying pediatric MP pneumonia. These data may help inform disease course anticipation and therapeutic strategy selection, contributing to the development of more personalized patient management.</p>","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":" ","pages":""},"PeriodicalIF":5.2,"publicationDate":"2026-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13488122/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148161281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gut microbiome features associated with vancomycin-resistant Enterococcus acquisition in intensive care unit patients.","authors":"Yu-Chung Chuang, Ronald G Collman, Sheng-Yuan Ruan, Ying-Chun Chien, Yu-Shan Huang, Cheng-Chih Hsu, Jann-Tay Wang, Hsin-Bai Zou, Shan-Chwen Chang","doi":"10.1186/s12941-026-00871-6","DOIUrl":"10.1186/s12941-026-00871-6","url":null,"abstract":"<p><strong>Background: </strong>Vancomycin-resistant Enterococcus (VRE) infection poses a significant healthcare burden in intensive care units (ICUs), and is preceded by gut colonization. The gut microbiome may influence susceptibility to VRE, but its role in ICU patients remains incompletely defined.</p><p><strong>Methods: </strong>We conducted a prospective study of patients admitted to a medical ICU from 2019 to 2021. Stool samples were collected for bacterial 16 S rRNA gene sequencing, anal swabs were screened for VRE by culture, and bile acids were measured in initial stool samples.</p><p><strong>Results: </strong>We enrolled 108 patients. Thirty-four patients were VRE + on initial screen and remained so (VRE+/+) while 74 were initially negative, of whom 23 acquired VRE (VRE-/+) and 51 remained negative (VRE-/-). There was no difference in alpha-diversity initially between VRE-/- and VRE-/+ groups, whereas VRE+/+ patients had significantly lower alpha-diversity (P < 0.001). VRE-/+ patients had a significantly more rapid decrease in alpha-diversity than VRE-/- patients (P = 0.04). Beta-diversity of initial stool differed among groups (P = 0.001), driven mainly by VRE+/+ patients. A lower Bacteroides/Enterococcus ratio (P = 0.049) and low Clostridium scindens abundance (P = 0.031) were associated with VRE acquisition. Initial stool from VRE-/- patients had a higher combined concentration of deoxycholic acid and lithocholic acid than that of VRE-/+ patients (P = 0.034).</p><p><strong>Conclusions: </strong>VRE acquisition in the ICU was associated with an initial gut microbiome characterized by lower Bacteroides/Enterococcus ratios, lower C. scindens abundance, and lower deoxycholic and lithocholic acid concentrations. Our findings are consistent with a possible role of these microbiome features in colonization resistance, as suggested by in vitro and animal models. However, given the single-center design, these associations should be considered hypothesis-generating and require validation before clinical application.</p>","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":" ","pages":""},"PeriodicalIF":5.2,"publicationDate":"2026-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13483550/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148148164","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative evaluation of tigecycline susceptibility testing methods for carbapenem-resistant Klebsiella pneumoniae and Acinetobacter baumannii.","authors":"Yu Shi, Shaozeng Li, Lijing He, Haibin Wang, Yupeng Shang, Kang Zhang, Xinwei Han, Yuan Wei, Wanli Chu, Yulin Xiong","doi":"10.1186/s12941-026-00869-0","DOIUrl":"10.1186/s12941-026-00869-0","url":null,"abstract":"&lt;p&gt;&lt;strong&gt;Background: &lt;/strong&gt;In this study, we aimed to evaluate the performance of different tigecycline susceptibility testing methods for CRKP and CRAB using the broth microdilution (BMD) method as the gold standard, under different breakpoint criteria.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Methods: &lt;/strong&gt;A total of 53 CRKP and 47 CRAB clinical isolates, collected from December 2021 to January 2023, were tested for tigecycline susceptibility using six clinically common methods: Vitek2 (using the Vitek2 Compact system), the Kirby-Bauer (KB) disk diffusion susceptibility test, the modified KB (mKB) test with a buffer solution, the Epsilometer test (E-test), minimum inhibitory concentration test strips (MTS) and BMD (as the reference standard). The susceptibility test results were interpreted based on the standards issued by the European Committee on Antimicrobial Susceptibility Testing(EUCAST), the United States Food and Drug Administration (FDA), and the British Society for Antimicrobial Chemotherapy(BSAC). The performance of each method was assessed through essential agreement (EA), categorical agreement (CA), error rates and Kappa (κ) values.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;In terms of methodology, the mKB significantly increased the inhibition zone diameter compared with the KB for both CRKP (3.2 ± 0.8 mm) and CRAB (3.6 ± 0.8 mm) (P &lt; 0.05, respectively). Using BMD as the gold standard and following FDA criteria, the mKB demonstrated an accuracy rate significantly higher than the KB in interpreting CRKP susceptibility results (62.3% vs. 1.9%, P &lt; 0.05). The agreement rate between the E-test and the MTS for CRKP was as high as 84.9%, indicating no statistically significant difference (P &gt; 0.05). However, the E-test yielded significantly higher accuracy than the mKB (98.1% vs. 60.4%, P &lt; 0.05). For CRAB, the accuracy of the E-test was lower than that for CRKP (68.1% vs. 98.1%). When compared with BMD, the E-test had a high EA value of 92.5% for CRKP and a lower EA value of 68.1% for CRAB. Under the FDA standard for CRKP, the E-test yielded a CA value of 98.1%, with very major error (VME) and major error (ME) rates of 0%, a minor error (mE) rate of 1.9% and a κ-value of 0.658, indicating substantial agreement. In contrast, when applied to CRAB, the performance of the E-test declined markedly, with a CA value of only 68.1%, VME and ME rates still at 0%, but a much higher mE rate of 31.9% and a κ-value of just 0.082, indicating poor agreement.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusion: &lt;/strong&gt;The mKB improves the detection performance of the KB, suggesting that pH variation is one of the factors affecting the accuracy of KB-test-based TST. Among the five clinical verification methods included in this study, the E-test demonstrates the best overall performance under all interpretive criteria, making it more suitable for confirming the tigecycline susceptibility of CRKP. However, this method appears less reliable for CRAB, indicating the significant impact of interspecies differen","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":" ","pages":""},"PeriodicalIF":5.2,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13491962/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148142197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A cross-sectional study on discordances between Anyplex™ II MTB/MDR and BACTEC MGIT 960 system for assessing susceptibility for Mycobacterium tuberculosis: analysis of clinical specimens from patients with isoniazid-monoresistant, rifampicin-monoresistant, and multidrug-resistant tuberculosis.","authors":"Kanphai Wongjarit, Pattama Torvorapanit, Suthidee Petsong, Ajcharaporn Sawatpanich, Waritta Sawaengdee, Panadda Dhepakson, Suwatchareeporn Rotcheewaphan, Gompol Suwanpimolkul","doi":"10.1186/s12941-026-00864-5","DOIUrl":"10.1186/s12941-026-00864-5","url":null,"abstract":"<p><strong>Background: </strong>Rapid molecular tests have facilitated early diagnosis and guided treatment of tuberculosis (TB) by providing faster results than the gold-standard phenotypic drug susceptibility testing (DST). Anyplex™ II MTB/MDR is an RDT available in Thailand that simultaneously detects Mycobacterium tuberculosis (MTB) complex and mutations associated with isoniazid (INH) and rifampicin (RIF) resistance, enabling genotypic DST in various clinical specimens. However, discordance between the Anyplex™ II MTB/MDR and phenotypic DST creates a decision-making dilemma.</p><p><strong>Methods: </strong>A retrospective review was conducted on clinical and microbiological data from patients with different types of tuberculosis (TB) at King Chulalongkorn Memorial Hospital (KCMH), a referral hospital for TB in Thailand. The study focused on patients with drug-susceptible TB (DS-TB), isoniazid mono-resistant TB (Hr-TB), rifampicin mono-resistant TB (RR-TB), and multidrug-resistant TB (MDR-TB) from January 2018 to June 2023. The correlation between genotypic and phenotypic DST using the Anyplex™ II MTB/MDR and BACTEC MGIT 960 assays, respectively, was investigated using clinical specimens and MTB clinical isolates recovered from specimens collected during the same period.</p><p><strong>Results: </strong>836 MTB clinical isolates from 796 patients had genotypic and phenotypic DST results. 44 MTB (5.2%) clinical isolates had discordant results. There was a significant discordance between the assays in assessing INH (p-value < 0.001) and RIF susceptibility (p-value < 0.022). The Cohen's kappa coefficient for assessing INH and RIF susceptibility was 0.837 and 0.772, respectively. The majority of INH susceptibility discordances (29/32, 90.6%) displayed genotypic susceptibility but phenotypic resistance. RIF susceptibility discordances (11/13, 84.6%) displayed genotypic resistance but phenotypic susceptibility. 52.2% were undertreated, 2.3% were overtreated, and 40.9% experienced no change in treatment in patients with genotypic-phenotypic discordant DST results. Undertreatment was due to false-negative genotypic DST. 6/11 RIF-susceptibility discordant isolates were susceptible by phenotypic DST; mutations in the rpoB gene were identified: Leu430Pro, Asp435Tyr, or Leu452Pro.</p><p><strong>Conclusions: </strong>The Anyplex™ II MTB/MDR assay demonstrated high agreement with the BACTEC MGIT 960 assay; however, both assays yielded substantial discordance in resistance results. Most of these discordances were false-negative genotypic results for INH resistance, which could lead to undertreatment decisions. Furthermore, some instances of genotypic resistance but phenotypic susceptibility to RIF were associated with borderline rpoB mutations, highlighting the need for careful interpretation of discordant results.</p>","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":" ","pages":""},"PeriodicalIF":5.2,"publicationDate":"2026-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13459834/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148100932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A nomogram for assessing secondary infection risk in hospitalized patients with intestinal CRE colonization: a prospective cohort study.","authors":"Xiaoying Xie, Lijia Ni, Guanping Chen, Jiajian Guo, Xinlu Dai, Mingming Chen, Zhaofan Luo","doi":"10.1186/s12941-026-00867-2","DOIUrl":"10.1186/s12941-026-00867-2","url":null,"abstract":"<p><strong>Objective: </strong>To investigate the epidemiology, risk factors, and molecular characteristics of intestinal carbapenem-resistant Enterobacterales (CRE) colonization and subsequent secondary infections in a hospital setting, and to develop a predictive model for risk stratification.</p><p><strong>Methods: </strong>A large-scale, unbiased active screening for intestinal CRE carriage was conducted among patients (including physical examination, outpatient, and inpatient populations) between August 31, 2021, and February 28, 2022. A prospective cohort design was used to follow colonized inpatients for six months. Clinical data were collected for univariate and multivariate logistic regression analysis to identify independent risk factors for infection. A nomogram prediction model was constructed and validated. Homology between colonizing and infecting isolates was assessed using WGS and MALDI-TOF MS analysis.</p><p><strong>Results: </strong>The overall CRE colonization rate was 4.95% (475/9,615), with significant variation between inpatients (5.55%), outpatients (3.97%), and physical examination subjects (3.54%). Escherichia coli (49.05%) and Klebsiella pneumoniae (46.95%) were the dominant species. The overall secondary infection rate among colonized inpatients was 5.04% (18/357), with the highest rates observed in the Rehabilitation (30.00%), ICU (21.88%), and Neurology (20.00%) departments. Multivariate analysis identified ICU stay ≥ 48 h, carbapenem exposure, fecal incontinence, and tracheostomy as independent risk factors, while admission to Rehabilitation was a protective factor. The prediction model demonstrated high discriminative ability (AUC = 0.960) in this single-center derivation cohort, but external validation is required before clinical application. Molecular analysis revealed that ST11 CRKP was the predominant clone (70%), and most infections (12/18) were genetically homologous to the patient's colonizing strain.</p><p><strong>Conclusion: </strong>CRE intestinal colonization is prevalent across healthcare settings. The progression from colonization to infection is driven by specific clinical risks, which can be used to assess risk by our novel nomogram. These findings underscore the need for targeted screening in high-risk departments, enhanced antimicrobial stewardship, and focused surveillance on dominant clones like ST11 CRKP to effectively prevent CRE transmission and infection.</p>","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":" ","pages":""},"PeriodicalIF":5.2,"publicationDate":"2026-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13491868/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148052068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Breakthrough mucormycosis after hematopoietic stem cell transplantation: a retrospective multiyear cohort study in Eastern China.","authors":"Junjie Luo, Kaidi Song, Baolin Tang, Xiang Wan, Wen Yao, Guangyu Sun, Ke Yuan, Ping Qiang, Xiaoyu Zhu","doi":"10.1186/s12941-026-00862-7","DOIUrl":"10.1186/s12941-026-00862-7","url":null,"abstract":"<p><strong>Background: </strong>This study aimed to update the epidemiology and clinical characteristics of mucormycosis, a rare but life-threatening invasive fungal infection in hematopoietic stem cell transplantation (HSCT) recipients.</p><p><strong>Methods: </strong>We conducted a retrospective, single-center observational study including all consecutive HSCT recipients from November 2020 to October 2024, with follow-up through May 2025.</p><p><strong>Results: </strong>Among 1224 HSCT recipients receiving antifungal prophylaxis, mucormycosis was diagnosed in 49 patients (4.0%), with an incidence density of 3.4 per 100 person-years. The median time to onset was 73.0 days post-transplant (interquartile range, 30.0-223.0 days). Pulmonary involvement was present in 75.5% of cases. Rhizopus spp. accounted for the highest proportion (37.3%) among the isolated fungal genera. Multivariate analysis identified myelodysplastic syndrome (adjusted hazard ratio [aHR] = 2.65), prior fungal infection (aHR = 2.33), and severe acute graft-versus-host disease (aGvHD) (aHR = 2.96) as independent risk factors. Among 43 patients treated with antifungals, the 84-day survival rate was 46.5%. Severe aGvHD was an independent predictor of mortality. Combination therapy with amphotericin B plus posaconazole or isavuconazole was associated with a lower rate of treatment failure compared to amphotericin B alone, although this difference was not statistically significant (42.3% vs. 80.0%; P = 0.172).</p><p><strong>Conclusions: </strong>Mucormycosis poses a serious risk post-HSCT; early identification and optimized treatment are critical to improving outcomes.</p>","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":" ","pages":""},"PeriodicalIF":5.2,"publicationDate":"2026-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13440071/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148004291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Infection timing and immuno-inflammatory profiles determine prognosis of Pneumocystis jirovecii pneumonia in kidney transplant recipients.","authors":"Shuo Wang, Chuanyou Xia, Yuchong Zhu, Guanbao Tang, Yunchao Wang, Lingquan Meng, Xiaoming Zhang, Jianning Wang, Jiwei Yang","doi":"10.1186/s12941-026-00865-4","DOIUrl":"https://doi.org/10.1186/s12941-026-00865-4","url":null,"abstract":"<p><strong>Background: </strong>Pneumocystis jirovecii pneumonia (PJP) is a severe opportunistic infection in kidney transplant recipients (KTRs). Clinical presentation varies widely among patients. We aimed to identify key prognostic factors for PJP in KTRs, build a visual nomogram to predict outcomes, and examine the effect of infection timing on survival.</p><p><strong>Methods: </strong>We analyzed data from 169 KTRs diagnosed with PJP at a single center between July 2019 and October 2025. Using multivariate Cox regression with restricted cubic spline (RCS) analysis, we identified independent prognostic factors. Using these factors, we developed a predictive nomogram and an online calculator. Model performance was assessed using the concordance index (C-index), ROC curves, calibration plots, and decision curve analysis (DCA). We also compared survival in patients with PJP within six months of transplantation versus after six months.</p><p><strong>Results: </strong>Thirty-three patients (19.5%) died or required ICU admission. Multivariate Cox regression analysis showed that low CD4 + T-lymphocyte counts, high C-reactive protein (CRP) levels, and high serum 1,3-β-D-glucan (G-test) levels were key risk factors for adverse outcomes. The nomogram based on these indicators demonstrated high accuracy and clinical usefulness, with AUC values of 0.884 (4 months), 0.793 (9 months), and 0.877 (12 months) for predicting adverse outcomes. Patients with late-onset PJP (after 6 months) had a lower risk of adverse outcomes than those with early-onset PJP (within 6 months) (OR 0.36, P = 0.013).</p><p><strong>Conclusion: </strong>PJP outcomes in KTRs depend heavily on immune status and inflammatory response. Infection timing matters: early-onset PJP often leads to a higher risk of death. Our dynamic nomogram helps clinicians identify high-risk patients early, supporting a shift from standard treatment to stepwise precision care.</p>","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":" ","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147961834","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temporal dynamics of serum Mycoplasma pneumoniae antibodies in patients with acute respiratory infections: a large retrospective study.","authors":"Xia Kang, Shan-Shan Zhang, Lei-Li Wang, Ji-Hong Yu, Wen-Feng Ni, Xiao-Qin Qi, Qing-Bin Lu, Yan Wang","doi":"10.1186/s12941-026-00861-8","DOIUrl":"10.1186/s12941-026-00861-8","url":null,"abstract":"<p><strong>Objective: </strong>Mycoplasma pneumoniae (MP) has re-emerged with a surging incidence in China following the lifting of COVID-19 non-pharmaceutical interventions, posing a critical challenge for clinical diagnosis and management of acute respiratory infections (ARI). We aimed to investigate the epidemiological characteristics of MP infection among all-age patients with ARI in China, as well as the temporal dynamics of serum MP-specific antibodies.</p><p><strong>Methods: </strong>This retrospective study was based on the data of patients detected by total MP antibodies (predominantly IgM) in Chinese PLA General Hospital, Beijing, China between December 2022 and January 2024. Blood samples were collected from patients who visited or were hospitalized due to ARI for the detection of MP antibody. Adjusted odds ratio (aOR) and its 95% confidence interval (CI) were calculated to evaluate the association between MP antibody and outcome using logistic regression models adjusted by age groups, sex and diagnosis.</p><p><strong>Results: </strong>Totally 18,054 patients were included in this study with the MP antibody detection rate of 36.2% (95% CI 35.5%-36.9%). The detection rate of MP antibody was higher in female than that in male (40.5% vs. 32.4%, aOR = 1.493, 95% CI 1.402-1.590, P < 0.001) and it was lower in adults compared to children (26.8% vs. 46.7%, aOR = 0.403, 95% CI 0.378-0.429, P < 0.001). The detection rate of MP antibody was the highest in the group of 10 ~ 20 years (53.7%, 95% CI 52.0%-55.4%). In all patients, the detection rate of MP antibody peaked at the 3rd week with 94.4% (95% CI 91.9%-95.0%), and then went down gradually, falling to 89.5% (95% CI 83.8%-95.1%) at the 8th week. The MP antibody peaked at the 1st week after symptom onset, followed by a gradual decline, and was predicted to turn to negative at about the 29th week. In children aged < 18 years, the interval between symptom onset and the MP antibody turning negative was about 24 weeks while it was 59 weeks in adults aged 18 ~ 59 years and 18 weeks in those aged ≥ 60 years.</p><p><strong>Conclusions: </strong>The detection rate of MP antibody differed in the patients with different characteristics. MP antibody could persist for 29 weeks and age was a significant factor affecting the duration of MP antibody. The lack of population representativeness and other relevant variables may have some impact on the results, but these findings still provided new evidence for the understanding of the epidemiology and immunology MP.</p>","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":" ","pages":""},"PeriodicalIF":5.2,"publicationDate":"2026-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13289474/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147760278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Within-host mechanisms of resistance evolution in polymyxin B-resistant Klebsiella pneumoniae without prior exposure.","authors":"Jun Li, Yuyao Wang, Haolan Wang, Zhaojun Liu, Yubing Xia, Yongmei Hu, Haichen Wang, Fengjun Xia, Mingxiang Zou","doi":"10.1186/s12941-026-00860-9","DOIUrl":"10.1186/s12941-026-00860-9","url":null,"abstract":"<p><p>BACKGROUND: Polymyxin B-resistant Klebsiella pneumoniae (PBR-KP) has been emerging as a significant concern. This study investigated the within-host mechanisms of resistance evolution in PBR-KP without prior PB exposure. METHODS: Six groups were enrolled [PB-sensitive K. pneumoniae (PBS-KP) evolved into PBR-KP from the same patient], and antimicrobial susceptibility testing was conducted using the microdilution broth method. Whole-genome sequencing was performed to analyze molecular characteristics, and to investigate the resistance mechanisms, gene expression analysis of pmrAB, phoPQ, crrAB, and eptA was performed using RT-qPCR. Fitness costs were assessed through biofilm formation, in vitro growth rate, and virulence analysis. RESULTS: All 12 strains belonged to ST11-KL64, except for PB9 and PB10, which were classified as ST11-KL47. Each resistant strain was highly related to its corresponding sensitive strain. The relative expression levels of phoPQ, eptA, and pmrAB were significantly upregulated in most PBR-KP strains. PBR-KP strains exhibited no fitness cost regarding in vitro growth rate and biofilm formation. Notably, the eptA gene was highly expressed in the four PBR-KP strains with enhanced virulence, indicating its association with virulence. Furthermore, PBR-KP strains with enhanced virulence were highly associated with KL64, whereas those without enhanced virulence were linked to KL47, except for PB12, indicating a potential relationship between virulence and serotype. CONCLUSIONS: PB resistance can develop in KP strains without prior exposure to the drug, possibly driven by upregulation of phoPQ, pmrAB, and eptA, as supported by validated transcriptomics data. These resistant strains did not exhibit fitness costs related to biofilm formation or growth rate. Enhanced virulence, found in most PBR-KP strains, may be closely associated with eptA overexpression and specific serotypes. </p>","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":" ","pages":""},"PeriodicalIF":5.2,"publicationDate":"2026-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13262486/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147670109","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}