Journal of Microbiology Immunology and Infection最新文献

Background: Eosinophilic AECOPD is a specific phenotype; however, the clinical outcomes and the short-term changes in sputum microbiome remain unclear.

Methods: We retrospectively included AECOPD patients admitted to National Cheng Kung Universal Hospital from January 2013 to December 2022. The primary outcome was respiratory failure rate. In addition, self-expectorated sputum was prospectively collected on days 1 and 5 of hospitalization between June 2020 and May 2021, and 16S rRNA gene segments (V3-V4) were amplified for sputum microbiome identification. Eosinophilic AECOPD were defined as blood eosinophils (bEOS) exceeding 2 % at admission.

Results: From the analysis of 202 AECOPD hospitalizations, patients with bEOS ≥2 % had shorter hospital stays and respiratory failure days (β-coefficient: 2.98 and -3.86, P < 0.001 and = 0.049, respectively), a lower risk of respiratory failure and intensive care unit admission (odds ratio: 0.29 and 0.35, P = 0.007 and = 0.029, respectively). In a sub-cohort of 30 AECOPD patients undergoing sputum microbiome analysis, 12 had bEOS ≥2 %, a significant decrease in Shannon diversity at the phylum level after 5 days of treatment was observed only in the bEOS <2 % group. Moreover, the relative abundance of Proteobacteria increased after treatment in the patients with bEOS ≥ 2 % while a trend of decrease was observed in those with bEOS<2 %.

Conclusions: Patients with eosinophilic AECOPD demonstrate better short-term clinical outcomes. The sputum microbiota in the eosinophilic and non-eosinophilic patients also respond differently to the treatment for AECOPD.

Background: Cavitary lung disease caused by Mycobacterium tuberculosis (TB) and nontuberculous mycobacteria (NTM) presents overlapping radiologic features but potentially distinct immunopathologic mechanisms. Macrophage polarization and prothymosin-α (PTMA) expression may contribute to disease progression, but their roles in surgically treated patients remain unclear.

Methods: We retrospectively analyzed 33 patients who underwent pulmonary resection for TB (n = 17) or NTM (n = 16) infection. Clinical characteristics, CT-based cavity wall thickening scores, and immunohistochemical staining for PTMA, CD68, iNOS, and Arginase-1 were compared. A monocyte migration assay was also performed to evaluate PTMA function.

Results: NTM patients exhibited lower body mass index and fewer comorbidities than TB patients but had a higher relapse rate. Cavity wall thickness correlated with increased PTMA and CD68 expression, particularly in NTM lesions. No significant difference in iNOS or Arginase-1 expression or M1/M2 ratio was observed. M. kansasii was more often linked to severe cavitary disease. PTMA enhanced monocyte migration in a dose-dependent manner in vitro.

Conclusion: Radiologic cavity wall thickness may reflect underlying immune dynamics, particularly in NTM. PTMA and CD68 are associated with immune activation and cavity progression in chronic mycobacterial infections. PTMA may serve a dual role as both a histologic marker and a functional regulator of monocyte recruitment. Immunohistochemical analysis revealed no clear M1/M2 polarization shift, suggesting a non-classical or depolarized macrophage phenotype. These findings underscore the potential of PTMA as both a tissue marker and a bioactive mediator in chronic pulmonary infection.

Background/purpose(s): Psoriasis is a skin-specific autoimmune disease that causes scaling, erythema and thickening. The disease involves immune cell infiltration and keratinocyte proliferation in skin lesions. Previous studies have demonstrated that Th17 cells and IL-22 play prominent roles in the pathogenesis of psoriasis via IL-17, IL-22 and IL-23 signaling. However, the role of innate cells in this process remains unclear.

Methods: In this study, using the TLR7/8 agonist imiquimod (IMQ) in a well-established murine model, we demonstrated that natural killer (NK) cells play an important role in the pathogenesis of psoriasis. Non-obese diabetic (NOD) mice are prone to Th1 and Th17 responses, and the lack of NK cell activity and macrophages in these animals contribute to their value as a model for type I diabetes.

Results: The NOD mice treated with IMQ (NOD-IMQ) exhibit markedly attenuated skin lesions compared to BALB/c mice treated with IMQ (BALB/c-IMQ). An analysis of immune cell types revealed that the number of macrophages, plasmacytoid dendritic cells (pDCs), neutrophils and Th1, Th2, Th17, Treg, and NK cells increased in the BALB/c-IMQ mice compared to the NOD-IMQ mice. Testing NK cell activity and macrophage function, NK cell cytotoxicity and macrophage phagocytosis, but not macrophage migration, were decreased in the NOD mice compared with the BALB/c mice. After NK cell depletion, normal BALB/c-IMQ mice exhibited milder skin lesions than the NOD-IMQ mice.

Conclusion: These results suggest that NK cells play a critical role in IMQ-induced skin inflammation. Controlling NK cell activity may be a potential therapeutic approach for psoriasis.

Background: Outsourced hospital services may pose underrecognized risks for healthcare-associated infections, particularly in high-risk areas such as neurosurgery. A cluster of Klebsiella aerogenes infections in a neurosurgical ward prompted an investigation to identify the source and transmission route.

Methods: A retrospective outbreak investigation was conducted in the neurosurgical department of a 2600-bed tertiary care hospital in Taiwan between August 2023 and May 2024. The investigation included an epidemiological review, environmental sampling, and molecular typing using pulsed-field gel electrophoresis (PFGE).

Results: The index case, a 56-year-old woman who underwent craniectomy on August 31, 2023, developed K. aerogenes infection one week postoperatively and died 18 days later. Seventeen additional cases were identified-12 from September 2023 to January 2024, and 5 between April and May 2024. All patients had undergone preoperative hair shaving by an outsourced barber department. PFGE analysis of 10 patient isolates revealed that 8 shared clonal strain A. Environmental samples from two of four shampoo carts used by the outsourced barber service also yielded strain A. Although initial infection control efforts temporarily reduced case numbers, a resurgence in April 2024-with four new cases and repeated recovery of strain A from equipment-confirmed the ongoing transmission source. Staff stool samples were negative, implicating contaminated equipment rather than personnel. After discontinuing the barber service and replacing equipment, no further cases occurred as of November 2024.

Conclusion: This outbreak highlights the importance of incorporating non-clinical outsourced services into infection surveillance and control programs, especially in high-risk clinical settings.

Background: Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) still evolves and spreads worldwide. Mucosal immunity is the first line of defense against SARS-CoV-2 infections. We tested the hypothesis of whether salivary antibodies (sIgA or IgG) induced by common human coronaviruses (HCoVs) have cross-reactivities and neutralizing effects against SARS-CoV-2.

Methods: Paired saliva and serum samples were collected from healthy young adults (n = 98) in 1993 and uninfected healthcare workers during the pandemic (n = 79). sIgA and IgG antibodies against SARS-CoV-2 and HCoV-229E were detected, respectively.

Results: A moderate to strong positive correlation was found between levels of anti-SARS-CoV-2 and anti-HCoV-229E sIgA and IgG in saliva. Specific anti-S of SARS-CoV-2 IgA were found in 14 % of saliva, whereas neither anti-NP nor anti-S IgG were found in serum collected in the pre-pandemic era. Cross-reactivities of these sustained anti-HCoVs sIgA or IgG were enriched and confirmed by immunoblotting and also exhibited neutralizing activities against SARS-CoV-2 and its variants using Luminex-based assay. Furthermore, the incidence rate ratios of subsequent SARS-CoV-2 infection were significantly lower in the healthcare workers group with high salivary anti-HCoV-229E S1 sIgA.

Conclusion: Our findings suggest that salivary anti-HCoV-229E S1 sIgA antibodies with cross-reactivities against SARS-CoV-2 S1 protein may pose protective potential against SARS-CoV-2.

Background: The imbalance of human microbiota has been associated with various inflammatory disease. Compared to intestinal flora, the esophageal microbiome has been understudied,and it remains unclear whether dysbiosis is related to reflux esophagitis (RE) and Barrett's esophagus (BE).This study aimed to synthesize findings on microbial composition changes across different regions of the gastrointestinal tract and their relationship with chronic esophageal reflux diseases.

Methods: We recruited 29 RE patients (10 Grade A; 10 Grade B; 9 Grade C), 9 BE patients, and 10 healthy volunteers to study microbial composition in saliva, gastric juice, and stool using 16S rRNA gene pyrosequencing and analyzed serum inflammatory cytokines using ELISA.

Results: Microbiota alpha diversity exhibited no significant changes between groups. In terms of taxonomy, RE and BE patients had more gram-negative anaerobic bacteria in salivary microbiota. Notably, increased Tannerellaceae abundance correlated with elevated serum IL-6 levels, which have been linked to chronic inflammation. Helicobacter was more abundant in gastric fluid of controls. Stool analysis revealed BE patients had higher abundance of phylum Bacteroidetes, and the genus Prevotella, while Fusobacterium was more prevalent in controls.

Conclusions: The increased abundance of Tannerellaceae in saliva was correlated with elevated serum IL-6 levels and may be a contributing factor in chronic esophageal reflux disease. BE patients had a higher abundance of Prevotella, a gram-negative bacterium, which may be linked to early stage esophageal inflammation in chronic reflux disease. Conversely, the increased abundance of Helicobacter in gastric juice may serve as a protective factor.

Objective: The global rise of carbapenem-resistant Klebsiella pneumoniae bloodstream infection (CRKP-BSI) is alarming due to its link to increased morbidity and mortality from limited treatment options. This study evaluated the impact of virulence plasmid carriage on CRKP-BSI mortality.

Methods: A matched case-control study was conducted among 93 CRKP patients, 23 of whom tested positive for virulence plasmids. The clinical and bacterial characteristics of CRKP-induced BSIs with and without virulence plasmids were analyzed.

Results: Virulence plasmids were present in 24.7 % of CRKP strains, with a 61.1 % mortality rate among patients with virulence plasmid-positive CRKP (pV-CRKP) infections. The ST11-KL64 subtype was predominant in Jiangxi Province. Molecular typing revealed pV-CRKP strains primarily had two identical genotypes, yet virulence plasmids were present across various PFGE genotypes, indicating polymorphic distribution. Logistic regression identified community-acquired infection, neurology department admission, and stroke as independent risk factors. G. mellonella and biofilm assays showed most CRKP strains with virulence plasmids exhibited increased virulence, though some strains did not.

Conclusion: Virulence plasmids generally heighten CRKP strain virulence and directly affect the 7-day survival rate. Certain strains carry virulence plasmids without increased virulence. Community-acquired infection, neurology department admission, and stroke are independent risk factors for pV-CRKP strains. The presence of IncFrepB among pV-CRKP may promote the spread of virulence genes in ST11-type CRKP.