European Journal of Clinical Microbiology & Infectious Diseases最新文献

Mobile colistin resistance (mcr) genes, initially described in livestock and humans, remain less frequently reported in companion animals. We conducted a global genomic survey of 14,643 bacterial genomes retrieved from the NCBI National Database of Antibiotic Resistant Organisms and identified 105 (0.7%) mcr-positive Enterobacterales from dogs (79.0%) and cats (21.0%). Escherichia coli (73.3%) and the Enterobacter cloacae complex (20.9%) predominated, with the mcr-1 and mcr-9 variants being the most frequent. Most genomes originated from Asia, Europe, and North America, reflecting the uneven geographic distribution of sequenced mcr-positive strains. Genomic analysis revealed a genetic plurality and co-occurrence of mcr genes with CTX-M-type extended-spectrum β-lactamases (46.6%), carbapenemases (5.7%), and 16S rRNA methyltransferases (8.6%), particularly in international high-risk clones. These findings underscore the diversity and epidemiological relevance of mcr-positive bacteria in pets, reinforcing the need for closer monitoring through One Health-based surveillance.

Respiratory viral infections can influence the human microbiota, promoting disease progression and complications. The gut-lung axis (GLA), as a critical pathway for microecological regulation and immune modulation, remains poorly understood in terms of its microbial characteristics and role in respiratory failure. The aim of this study was to elucidate the microbial characteristics and functions of the upper respiratory tract and gut and their associations in patients with viral pneumonia complicated by respiratory failure. We included three groups of individuals: healthy controls (HT), viral pneumonia patients without respiratory failure (NRF), and those with respiratory failure (RF), and systematically analyzed the characteristics and associations of the upper respiratory tract and gut microbiota. Beta diversity analysis revealed significant separation of upper respiratory tract and gut microbial communities among the three groups, while alpha diversity decreased with increasing disease severity. LEfSe analysis and correlation analyses targeting complete blood count parameters and serum inflammatory factors revealed synchronous enrichment of Rothia in the upper respiratory tract and Enterococcus in the gut of the RF group. Prevotella was enriched in the gut of the HT group but abnormally increased in the upper respiratory tract of the RF group, reflecting ecological niche shifts. Functional prediction indicated significant enrichment of pathways such as beta-lactam resistance in the RF group. Several genera (such as Blautia and Prevotella) were highly correlated with inflammatory cytokines (IL-1β, IL-6, CRP) and platelet counts, suggesting a microbiota-inflammation-immunity interplay. This study reveals significant dysbiosis of the gut-lung axis in patients with viral pneumonia and respiratory failure, with the Rothia-Enterococcus axis serving as a potential early warning and intervention target. The dynamic changes of the gut-lung microbiota and its association with inflammation and immunity provide a theoretical basis for microbiota-based therapies.

Staphylococcus aureus blood cultures were investigated geno- and phenotypically for penicillin susceptibility. A qPCR method detecting the blaZ gene was performed directly on positive blood culture vials and compared with routine disk diffusion results supplemented with the cloverleaf test. Among the collected vials, 100 were blaZ positive and 101 were blaZ negative. Full concordance was observed between genotypical and phenotypical penicillin susceptibility, however one penicillin resistant isolate was only weakly phenotypically positive.

Purpose: We evaluated the performance of CHROMAgar™LIN-R agar plates as part of a multicenter study ("APPLE").

Methods: The study was performed using 1200 rectal swabs and stool samples.

Results: We identified 168 enterococci with 75.6% (127/168) confirmed as linezolid-resistant (LRE) by the disc diffusion method. Among these, 48 LRE were single-patient isolates, of which 75% (36/48) showed resistance to vancomycin and 4.2% (2/48) to vancomycin and tigecycline. Overall LRE prevalence was 4.3% (48/1113) with the highest prevalence at adult hematology wards (11.3%). False-positivity rate was 24.4% (41/168) and significantly lower in neurological intensive care and hematology departments compared to pediatric hematology (adjusted p = 0.0034 and p = 0.0014, respectively). Prevalence was significantly higher in stool samples (8.8% vs. 1.6%) (p < 0.0001).

Conclusion: Assessing the performance of CHROMAgar™LIN-R among different patient groups and sample types may enhance its application.

Background: Fungal peritonitis is a rare but serious complication of peritoneal dialysis (PD), associated with high morbidity, mortality, and technique failure. This study aimed to evaluate the clinical course, risk factors, and outcomes of fungal peritonitis in adult PD patients.

Methods: We conducted a nationwide retrospective study including all cases of PD-associated fungal peritonitis identified over the past decade in medical centers across Israel. Clinical, microbiological, and outcome data were analyzed.

Results: Forty patients were identified, with a median age of 72.5 years. The most common symptoms were abdominal pain and cloudy effluent. In 82.5% of cases, cultures grew Candida, most frequently Candida parapsilosis. During the peritonitis episode, 95% of patients required hospitalization, 90% underwent Tenckhoff catheter removal, and 27.5% died. Fluconazole was the most commonly used antifungal (80%). In the preceding three months, 55% of patients had bacterial peritonitis and 62.5% received two or more antibiotic types. Polymicrobial infections and Enterococcus species were common in preceding bacterial episodes. Compared to bacterial peritonitis cases, fungal peritonitis was associated with significantly higher rates of hospitalization (95% vs. 39.1%, p < 0.001), catheter removal (90% vs. 9.4%, p < 0.001), and permanent transfer to hemodialysis (67.5% vs. 3.1%, p < 0.001). Use of multiple antibiotics in the prior 3 months was independently associated with fungal peritonitis (OR 1.940, 95% CI 1.291-2.917; p = 0.001).

Conclusions: Fungal peritonitis in PD patients carries a poor prognosis. Recent bacterial peritonitis-particularly complicated cases such as polymicrobial or enteric-origin infections as well as recent exposure to multiple antibacterial agents, may serve as predisposing risk factors.

Burn wound infections significantly hinder the healing process by disrupting the immune response and limiting treatment options due to increasing antibiotic resistance. In this study, the antimicrobial and tissue regeneration effects of a three-dimensional bacteriophage cocktail bio-gel were evaluated in vivo in burn wounds infected with antibiotic-resistant Pseudomonas aeruginosa, Acinetobacter baumannii, and Klebsiella pneumoniae. Using an experimental burn model in Sprague Dawley rats, the effects of phage bio-gel treatment on inflammatory response, cellular repair mechanisms, and wound closure dynamics were analyzed through molecular, biochemical, and histopathological assessments. Application of the bacteriophage bio-gel significantly accelerated wound healing in infected burn groups, with healing rates ranging from 77.56 to 89.75% on days 15 and 20. Cytokine analysis demonstrated that phage therapy modulated inflammation by reducing IL-1β, IL-6, and TNF-α levels (p < 0.05). Molecular analyses examining extracellular matrix dynamics showed a significant increase in TGF-β1, Smad-2/3, and collagen type 1 gene expression, indicating enhanced fibroblast activation and tissue remodeling. While MMP-2 and hydroxyproline levels increased, MMP-9 levels decreased following phage treatment. Histopathological evaluations revealed that re-epithelialization and tissue remodeling were accelerated, while inflammation was reduced in the A. baumannii and K. pneumoniae infected groups. These findings suggest that bacteriophage-based bio-gels provide a promising alternative for treating polymicrobial burn wound infections. The results indicate that bacteriophage biomaterials exhibit superior wound healing potential compared to conventional treatments, particularly in infections caused by antibiotic-resistant pathogens.

Infections due to Mycobacterium shigaense, a slow-growing mycobacterium of the Mycobacterium simiae complex, are rarely reported. We describe a case of M. shigaense infection in a 68-year-old woman with diabetes and found that its infections are often associated with immunocompromised conditions or underlying pulmonary diseases in East Asia.

Purpose: Klebsiella pneumoniae (Kp) is a major cause of bloodstream infections (BSI) globally. Yet, detailed characterization of invasive isolates, particularly from datasets not biased toward resistance, remains limited. This baseline study, conducted prior to the expansion of carbapenemase producers in Portugal, characterizes multidrug-resistant (MDR) and non-MDR Kp causing BSIs in a northern district hospital to elucidate resistance emergence and dissemination.

Methods: A total of 174 Kp strains isolated from blood cultures of hospitalized patients (2016-2018) were identified by VITEK2 or MALDI-TOF MS. Antibiotic resistance phenotypes were determined by reference methods, β-lactamases screened by PCR/sequencing, and clonal sublineages identified by FT-IR spectroscopy, MLST and/or WGS, including for putative hypervirulent strains (hvKp).

Results: Isolates were categorized as MDR (49%) or non-MDR (51%), with MDR rates nearly double national reports. Most MDR-Kp (67%) produced CTX-M-15, 25% produced carbapenemases (mainly KPC-3 and/or OXA-48/CTX-M-15), and 8% lacked acquired β-lactamases. Half (53%) belonged to three high-risk sublineages (ST147-KL64, ST307-KL102, ST15-KL19), while non-MDR showed greater diversity, with ST14-KL2 most frequent (13%) and consistently resistant to amoxicillin-clavulanate. Several sublineages circulated across both cohorts (e.g., ST307-KL102, ST348-KL62), some with variable β-lactamase content (e.g., ST147-KL64, ST45-KL24). Two hvKp (1.1%) were identified (ST380-KL2, ST268-KL20).

Conclusion: This baseline study reveals a high local burden of MDR-Kp driven by CTX-M-15 and KPC-3-producing high-risk sublineages, underscoring the importance of local surveillance beyond national reporting. High clonal diversity and variable β-lactamase content suggest heterogeneous acquisition and dissemination routes, with resistance often preceding clonal expansion. Though rare, hvKp detection underscores the need for continued surveillance and multicenter monitoring.

Purpose: To evaluate the efficacy of the EUCAST Rapid Antimicrobial Susceptibility Testing (RAST) on Klebsiella pneumoniae carrying various carbapenemases, with a focus on KPC variants.

Methods: A total of 130 carbapenemase-producing K. pneumoniae (CPKP), encompassing those harboring class A (KPC-2: n = 38; KPC variants: n = 30), class B (n = 42), class D (n = 4) and strains co-producing class A and class B carbapenemases (n = 16), were evaluated for susceptibility to seven antibiotics, including ceftazidime/avibactam (CAZ/AVI), using the EUCAST RAST. Results obtained after 6 h and 8 h of incubation were compared with those obtained by reference broth microdilution. Additionally, the capacity of the RAST method to screen for different types of carbapenemases was assessed.

Results: All 130 CPKP isolates generated 100% readable zones at both 6 h and 8 h, with overall categorical agreement (CA) rates of > 90% for all tested antibiotics. For isolates producing class A carbapenemases, particularly the KPC variants, the EUCAST RAST showed excellent performance in determining CAZ/AVI susceptibility, achieving 100% CA and no errors at each reading time. However, significant challenges arose for meropenem (MEM), characterized by low CA (73.9%) and high major errors (MEs, 20.1%) at 6 h reading. Extending incubation to 8 h dramatically improved the performance, while the proportion of strains within the ATU remained high (23.3% at 6 h; 30.0% at 8 h).

Conclusions: The EUCAST RAST can be effectively implemented in routine clinical laboratories, particularly in regions like China where K. pneumoniae carrying KPC-2 is widely prevalent. However, caution should be exercised when interpreting the results of MEM for KPC variants.

Schaalia infections are uncommon, with Schaalia cardiffensis infections being exceptionally rare. A 66-year-old, penicillin-allergic female presented with fever, cough and purulent sputum. Chest computed tomography revealed bilateral pneumonia, right loculated empyema and right lower lobe atelectasis. Initial drainage cultures identified only Streptococcus oralis, but subsequent anaerobic enrichment and 16 S rRNA gene sequencing confirmed S. cardiffensis, an obligate anaerobe. Due to absent susceptibility data, we established initial antimicrobial susceptibility profile for S. cardiffensis. Successful management was achieved using alternative antibiotics combined with percutaneous drainagein. This first Chinese case of an empyema co-infected with S. cardiffensis and S. oralis highlights diagnostic challenges and provides crucial susceptibility guidance.