Infection and Drug Resistance最新文献

A patient who had previously undergone varicose vein surgery developed persistent postoperative fever. The results of ultrasonography and computed tomography (CT) indicated the possible presence of a liver abscess. Subsequent blood and drainage fluid cultures yielded Gram-positive bacilli exhibiting characteristic hemolytic rings. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) identified both isolates as Clostridium perfringens (C. perfringens), implicating this pathogen as the etiological agent of the liver abscess. The patient was treated empirically with cefuroxime, ornidazole, and cefoperazone-sulbactam, after which the fever gradually resolved and the patient was discharged in stable condition. To further characterize the microbiological features of the isolates, whole-genome sequencing (WGS) was performed. Comparative genomic analysis demonstrated that the similarity between the two strains was higher than 99.99%, indicating a clonal origin. Further genotypic characterization revealed the presence of the major toxin gene plc, along with several accessory toxin genes, including pfoA, colA, and cloSI. In addition, genes encoding neuraminidases and hyaluronidases were identified, suggesting enhanced tissue invasiveness. The strains also harbored multiple antimicrobial resistance-associated genes, including mprF, tetB(P), and cplR. To contextualize these findings, a literature review was conducted to summarize the clinical and etiological characteristics of liver abscesses caused by C. perfringens. Analysis of reported cases indicated that advanced age, male sex, underlying hepatobiliary disease, and diabetes mellitus were common predisposing factors. Among these cases, only six cases were tested for C. perfringens toxin genes: five cases were associated with the plc gene alone, while one case involved concurrent detection of both plc and pfoA. Overall, this study provided important molecular and clinical evidence to support improved diagnosis, risk assessment, and therapeutic management of liver abscesses caused by C. perfringens.

Tropheryma whipplei (TW), a rare Gram-positive bacterium, is an uncommon cause of pulmonary infection, typically being reported in the context of gastrointestinal or neurological Whipple's disease. We present a case of a patient receiving endocrine therapy and ovarian suppression for breast cancer who developed a concurrent pulmonary infection with both Pneumocystis jirovecii (PJ) and TW. The diagnosis was secured through metagenomic next-generation sequencing (mNGS) of bronchoalveolar lavage fluid, which successfully identified both pathogens. Following the initiation of targeted antimicrobial therapy, the patient exhibited significant clinical and radiological improvement.

Purpose: The rising incidence of Pneumocystis jirovecii pneumonia (PJP) in patients without human immunodeficiency virus (HIV) infection, coupled with high mortality rates, highlights growing challenges in disease management. However, mortality risk factors in non-HIV PJP remain incompletely defined, particularly in large cohorts. Thus, we aimed to explore the clinical characteristics and mortality risk factors in these patients.

Patients and methods: This study included non-HIV patients with PJP who were hospitalized at Peking University Third Hospital between January 2014 and May 2023. We collected relevant clinical data and performed logistic regression analysis to identify mortality risk factors.

Results: This study included 207 participants (127 male and 80 female) with a median age of 57 (interquartile range: 45-68) years. The 90-day all-cause mortality rate was 15%. Renal transplant recipients accounted for the highest proportion of patients with underlying diseases (34.8%), followed by those with immune-mediated inflammatory diseases (23.7%). In multivariate logistic regression analysis, the percentage of neutrophils in bronchoalveolar lavage fluid (BALF) and a ratio of arterial oxygen partial pressure to fraction of inspired oxygen (PaO₂/FiO₂) <300 mmHg were independently associated with 90-day mortality. A neutrophil percentage ≥41.5% in BALF effectively identified patients at high risk of death.

Conclusion: In non-HIV patients with PJP, the percentage of neutrophils in BALF and PaO₂/FiO₂ ratio were strong predictors of adverse outcomes. These markers may help clinicians identify high-risk patients and initiate early intensive care intervention.

Objective: We analyzed the epidemiological trends and spatio-temporal distribution characteristics of varicella incidence in Baise City from 2010 to 2024 to provide a basis for its prevention and control.

Methods: This study describes the epidemiological characteristics of varicella from population, temporal and spatial perspectives by using data from the National Infectious Disease Reporting System. Trend and spatial autocorrelation analyses and spatiotemporal scanning statistics were employed to determine the spatial clustering and spatiotemporal dynamics for the incidence of varicella.

Results: About 54,969 cases of varicella were reported during the study period, with an annual incidence rate of 102.30 per 100,000, and an annual percentage change of 10.05% (95% CI: 1.10% to 19.79%; P = 0.027). The male-to-female ratio was 1.23:1, with the peak incidence occurring among in the 5-9 age group and the 10-19 age group showed an upward trend in incidence. People under 20 years old had the highest incidence rates of varicella and students accounted for more than half of the cases (55.46%), and 45.19% of townships had an average annual incidence rate exceeding the city's average level. There was a Positive spatial autocorrelation was observed in the varicella incidence across different townships, with a pattern of high-value clustering. Local spatial autocorrelation analysis identified a total of 117 hot spots. Spatiotemporal scanning identified five significant clusters, these included a Most likely cluster of 27 towns in the Youjiang River Valley and secondary clusters in the northwestern mountainous regions of Baise.

Conclusion: The reported incidence rate of varicella in Baise was on the rise, exhibiting distinct spatio-temporal clustering characteristics. Hotspots were aligned with the spatio-temporal clustering zones. Strengthening prevention and control measures in local areas where clusters and hotspots of varicella occur can be an effective strategy to decrease its incidence in a city.

Background: Patients with drug-resistant Pseudomonas aeruginosa (P. aeruginosa)-associated bronchiectasis often exhibit persistent neutrophilic airway inflammation. The immunomodulatory receptor leukocyte immunoglobulin-like receptor B1 (LILRB1) is known to function as an inhibitory checkpoint in immune responses, yet its specific role in regulating neutrophil function in drug-resistant P. aeruginosa-associated bronchiectasis remains incompletely understood. This study aimed to characterize the function of LILRB1 in this clinical context.

Methods: Clinical samples were obtained from bronchiectasis patients with drug-resistant P. aeruginosa infection and control subjects. LILRB1 mRNA expression was quantified by reverse transcription-quantitative polymerase chain reaction (RT-qPCR), and soluble HLA-G (sHLA-G) levels were assessed by enzyme-linked immunosorbent assay (ELISA). Neutrophils isolated from peripheral blood were stimulated with a clinical isolate of drug-resistant P. aeruginosa. NETosis was evaluated using myeloperoxidase (MPO)/citrullinated histone H3 (CitH3) immunofluorescence staining and quantified via PicoGreen dsDNA assay. The modulatory effect of recombinant LILRB1 protein was examined in a Transwell co-culture system composed of neutrophils and P. aeruginosa-infected BEAS-2B bronchial epithelial cells, with neutrophil migration and inflammatory cytokine secretion assessed as outcome measures.

Results: LILRB1 expression was significantly lower in patients with drug-resistant P. aeruginosa infection than in controls (P = 0.0384) and was inversely associated with disease severity, as indicated by the Bronchiectasis Severity Index (P = 0.0089), and with peripheral neutrophil counts (r = -0.35, P = 0.044). Levels of sHLA-G in bronchoalveolar lavage fluid were elevated and showed an inverse correlation with LILRB1 expression. Treatment with recombinant LILRB1 protein significantly attenuated P. aeruginosa-induced neutrophil migration in the co-culture model, reducing the number of migrated cells from 4.43±0.26×10⁴ to 2.75±0.19×10⁴. Furthermore, LILRB1 protein suppressed NETosis and significantly decreased the concentrations of IL1β, IL6, and IL8 in the co-culture supernatants.

Conclusion: Our findings indicate that LILRB1 acts as a significant regulator of neutrophilic inflammation in drug-resistant P. aeruginosa-associated bronchiectasis. By dampening neutrophil migration, NETosis, and pro-inflammatory cytokine release, LILRB1 may represent a potential target for mitigating inflammation in this patient population.

Purpose: Latamoxef has been used to treat various bacterial infections. To provide data supporting the rational clinical use of latamoxef, bacterial resistance over 10 years was analyzed at multiple centers throughout China. The results were used to develop tentative epidemiological cut-off values (TECOFFs) for latamoxef.

Methods: A total of 46,716 strains of common Enterobacteriaceae were collected from patients with bloodstream infections at 72 hospitals in 21 provinces of China between 2014 and 2023. The in vitro antimicrobial activities of latamoxef were compared with those of other commonly used cephalosporin and carbapenem. The distribution of minimum inhibitory concentrations was subjected to cumulative log-normal fitting to obtain the TECOFFs of latamoxef for common Enterobacteriaceae.

Results: The sensitivities of Escherichia coli (E. coli), Salmonella species, Serratia marcescens (S. marcescens) and Proteus mirabilis (P. mirabilis) to latamoxef ranged from 94.37% to 98.08%. Klebsiella oxytoca (K. oxytoca) and Enterobacter aerogenes (E. aerogenes) had sensitivities of 89.91% and 87.21%, respectively, whereas Klebsiella pneumoniae (K. pneumoniae) and Enterobacter cloacae (E. cloacae) had lower sensitivities. The in vitro activity of latamoxef against these bacteria, especially extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae, was similar to the activities of ertapenem and meropenem and significantly higher than the activities of ceftriaxone, ceftazidime, and cefepime. The sensitivities of ESBL (+) E. coli and ESBL (+) P. mirabilis to latamoxef were similar to their sensitivities to ertapenem and meropenem. ESBL (+) K. pneumoniae and ESBL (+) K. oxytoca exhibited comparable but lower rates of sensitization to latamoxef, ertapenem, and meropenem. Latamoxef had TECOFFs of 2 µg/mL for E. coli, K. pneumoniae, K. oxytoca, P. mirabilis, E. aerogenes, Salmonella, and S. marcescens, and 4 µg/mL for E. cloacae.

Conclusion: Latamoxef has good and stable in vitro antimicrobial activity against Enterobacteriaceae, including ESBL-producing Enterobacteriaceae. The calculated TECOFFs of latamoxef provide an important reference for subsequent use of this antibiotic against Enterobacteriaceae.

Background: Nontuberculous mycobacteria pulmonary disease (NTM-PD) frequently coexists with bronchiectasis. This study aimed to compare clinical profiles and identify risk factors between NTM-PD patients with/without bronchiectasis and explore differences between rapid- vs slow-growing non-tuberculous mycobacteria (NTM) species.

Methods: A retrospective analysis was conducted on patients diagnosed with NTM-PD and admitted to Beijing Tsinghua Changgung Hospital between April 2021 and April 2025. Among 496 inpatients with pulmonary diseases who underwent metagenomic next-generation sequencing (mNGS) analysis of bronchoalveolar lavage fluid, NTM were identified in 57 patients. Ultimately, 43 of these cases were confirmed and diagnosed as having NTM-PD. Relevant clinical data were collected, and the association between each variable and adverse outcomes was assessed using univariate and multivariate logistic regression analyses.

Results: Among the 43 confirmed NTM-PD patients, 24 had concurrent bronchiectasis (NTM-PD with bronchiectasis group) and 19 did not (NTM-PD group). In terms of baseline characteristics, the NTM-PD with bronchiectasis had a significantly higher proportion of females (79.17% vs 31.57%, P=0.002) and lower BMI (19.46 vs 22.46, P=0.023). Slow-growing NTM (SGM, mainly Mycobacterium avium complex [MAC]) was more common in the NTM-PD with bronchiectasis group (70.83% vs 31.58%, P=0.010); rapid-growing NTM (RGM, mainly M. abscessus) was more prevalent in the NTM-PD group (57.89% vs 20.83%, P=0.013). The positive rate of T-SPOT.TB in the NTM-PD group was higher than that in the NTM-PD with bronchiectasis group (47.37% vs 8.33%, P=0.010). Multivariate logistic regression identified female sex as an independent risk factor for NTM-PD complicated with bronchiectasis (OR=17.784, 95% CI: 1.103-286.857, P=0.042), while T-SPOT.TB was not (OR=0.047, 95% CI: 0.002-1.341, P=0.074).

Conclusion: Female sex is an independent risk factor for NTM-PD complicated with bronchiectasis. NTM-PD patients with bronchiectasis are more likely to be infected with SGM (especially MAC), while those without bronchiectasis tend to have RGM (especially M. abscessus) infection.

Purpose: Ventilator-associated pneumonia (VAP) caused by multidrug-resistant (MDR) Acinetobacter baumannii is associated with high morbidity and mortality, and optimal antimicrobial dosing strategies remain uncertain. Although ampicillin-sulbactam is increasingly used for MDR Acinetobacter baumannii infections, limited clinical data exist regarding the efficacy and safety of different dosing regimens when used as part of combination therapy. This study aimed to compare the clinical outcomes of low- versus high-dose ampicillin-sulbactam in combination of meropenem and colistin in patients with MDR Acinetobacter baumannii associated VAP.

Patients and methods: In this randomized clinical trial, patients with MDR Acinetobacter baumannii associated VAP admitted to the intensive care unit were allocated to receive either low-dose ampicillin-sulbactam (6 g IV every 6 h; total 24 g/day) or high-dose ampicillin-sulbactam (9 g IV every 6 h; total 36 g/day). Meropenem and colistin were administered concomitantly in both groups, as they remain commonly used standard therapies for severe MDR infections despite increasing resistance and toxicity concerns. Clinical outcomes, including fever duration, pulmonary secretions, Clinical Pulmonary Infection Score (CPIS), duration of mechanical ventilation, length of ICU and hospital stay, mortality, and adverse drug reactions, were assessed over a 10-day follow-up period.

Results: A total of 77 patients were enrolled (39 in the low-dose group and 38 in the high-dose group). The high-dose group demonstrated significantly shorter hospital stay (15.34 ± 4.99 vs 19.46 ± 6.91 days; P = 0.007), ICU length of stay (11.66 ± 6.11 vs 17.08 ± 7.40 days; P < 0.001), and duration of mechanical ventilation (6.39 ± 2.14 vs 7.74 ± 2.60 days; P = 0.003).

Conclusion: Among patients receiving combination therapy for MDR Acinetobacter baumannii associated VAP, higher-dose ampicillin-sulbactam was associated with improved clinical outcomes without increased toxicity. However, the small sample size, short follow-up period, and use of concomitant antibiotics limit attribution of outcomes solely to ampicillin-sulbactam dosing. Larger, well-controlled studies are needed to define the optimal dosing strategy.

Background: Urinary tract infections (UTIs) are a public health concern worldwide, with Escherichia coli (E. coli) being the primary cause. Biofilm-forming E. coli increases bacterial resistance to antibiotics, leading to significant morbidity and mortality among patients with UTIs. This study was conducted to determine biofilm formation potential and assess antimicrobial susceptibility patterns of E. coli isolated from adults with suspected UTIs attending Ruhengeri Level Two Teaching Hospital (RLTTH), Rwanda.

Methods: A cross-sectional laboratory-based study was conducted between April and June 2025 on 151 adults with suspected UTIs. A questionnaire was used to record sociodemographic characteristics and risk factors contributing to UTIs among the participants. Midstream urine samples were collected, cultured, and biochemically analyzed to identify E. coli in urine samples. Antimicrobial susceptibility profiles were determined using the disc diffusion method. Biofilm production in E. coli isolates was detected using Congo Red Agar (CRA) method.

Results: Of 151 adults, 64.2% were female and 35.8% male, and the majority of participants were in the age group of 29-39 years (34.4%). E. coli accounted for 37/151 (24.5%) isolates, of which 16 (43.2%) were confirmed biofilm producers. High resistance was observed for amoxicillin (100%), trimethoprim-sulfamethoxazole (93.8%), nitrofurantoin (87.5%), ampicillin (87.5%), cefixime (56.2%), gentamycin (50%), and ceftazidime (37.5%). Ciprofloxacin and meropenem were effective. Age was the only risk factor associated with biofilm production by E. coli in the study population (p ₌ 0.000).

Conclusion: This study highlights the critical role of E. coli in biofilm production in adults with UTI at RLTTH. A high prevalence of drug resistance was observed among biofilm-producing strains. Intervention strategies, such as frequent biofilm screening, continuous surveillance, and enhanced antimicrobial stewardship programs, are needed.

Introduction: Invasive fungal infections (IFIs) are a major cause of morbidity and mortality in critically ill patients. While early empirical antifungal therapy (EAFT) is a common strategy to combat diagnostic delays, the choice of agent and its overall benefit remain debated. This study evaluates the clinical outcomes and safety profiles associated with different empirical antifungal strategies in non-neutropenic ICU patients with suspected IFIs.

Methods: A retrospective observational study was conducted on 324 non-neutropenic patients who received EAFT in eight ICUs from 2015 to 2023. Data on demographics, comorbidities, treatments, and outcomes were collected from medical records. The primary endpoints were survival, clinical improvement, and incidence of confirmed fungal infection. Mortality predictors were identified using multivariate logistic regression.

Results: Among the 324 patients, the overall in-hospital mortality rate was 78.70%. Mortality was significantly lower in the group receiving fluconazole (63.16%) compared to those receiving caspofungin (76.80%), liposomal amphotericin B (75%), and anidulafungin (84.83%) (p = 0.028). Regarding safety, fluconazole demonstrated the lowest incidence of hepatotoxicity (13.16%) and nephrotoxicity (7.89%). In contrast, anidulafungin was associated with the highest rate of hepatotoxicity (33.79%, p=0.035), and caspofungin was associated with the highest rate of nephrotoxicity (39.52%, p=0.003). Only 17.28% of patients achieved clinical improvement. After the initiation of EAFT, a fungal infection was confirmed in only 7.41% of patients.

Conclusion: Fluconazole-based EAFT was associated with lower mortality rates compared to other antifungal agents. However, with a confirmed fungal infection rate of only 7.41%, these findings suggest that current patient selection for EAFT is suboptimal. The high overall mortality, coupled with the low infection confirmation rate, underscores the need for improved risk stratification tools to ensure the judicious use of antifungals in this critically ill population.