Infectious Disease Reports最新文献

Background: Cellulosimicrobium, formerly known as the Oerskovia genus, is a Gram-positive organism known for its characteristic bright yellow colonies. While abundant in nature, it is very rarely linked to pathogenesis in humans. While there is no classical presentation for Cellulosimicrobium-associated infections, cases tend to be foreign body-related or involve immunocompromised patients. Rates of Cellulosimicrobium-associated infections have been hypothesised to rise in the future, due to rising numbers of immunocompromised patients in the community and increasing usage of foreign bodies such as prostheses and long-term catheters. Existing technical difficulties regarding misidentifying cultures as other species (often other coryneforms) may also play a significant role in the low number of documented cases, and this may change in the near future with diagnostic advancements such as whole genomic sequencing. Case Presentation: A 57-year-old immunocompetent Irish male presented with concomitant neck and lung masses. Notably, this was found to be directly following a recent dental procedure. During extensive investigations, Cellulosimicrobium was isolated from biopsied lung tissue using 16S ribosomal ribonucleic acid gene-sequencing analysis. The patient was treated with long-term oral amoxicillin and safely discharged, with both masses showing measurable reductions in size on subsequent imaging. Conclusions: Should Cellulosimicrobium represent the causative pathological organism in this case, then we believe this to represent a potential novel documented presentation of the organism's pathogenesis in humans. We provide detailed discussion surrounding the successful management of this patient and the evaluation of the evolving differential diagnosis throughout this case.

Background: Central venous catheters (CVCs) are essential in intensive care units (ICUs) for monitoring and administering treatments; however, catheter-related bloodstream infections (CRBSIs) are significant complications, leading to severe outcomes and increased healthcare costs. The objective of this study was to evaluate the effectiveness of a simple and inexpensive impregnated dressing (intervention) compared to a non-impregnated dressing in reducing catheter-related infections among critically ill patients using vancomycin and chlorhexidine. Methods: This was a randomized, double-blind, controlled clinical trial in a university hospital in Brazil with 207 beds from June 2022 to October 2023. Patients over 18 years old admitted to the ICU and needing a CVC for a period exceeding 72 h were included. A CVC inserted outside the ICU and the need for two CVCs in the same patient simultaneously were exclusion criteria. One group received an impregnated dressing (intervention) compared to the other group, which received a standard dressing (comparator). The incidence of CRBSIs and the microbiological outcomes were evaluated. The primary endpoint was CRBSI. Results: The clinical trial included 516 patients randomized to receive either the new antimicrobial dressing or a control dressing. The dressing significantly reduced CVC colonization but not CRBSI rates. Conclusions: This new dressing provides enhanced antimicrobial protection but does not decrease CRBSI incidence. Future studies should further explore the cost-effectiveness and long-term benefits of this approach.

Background/objectives: Cryptococcus gattii presents a significant threat to healthy individuals. Titan cell formation, a key virulence factor, is influenced by the nutritional environment and plays a critical role in immune evasion and stress resistance. This study investigates the molecular and biophysical changes in titanized C. gattii cells grown in nutrient-rich Neurobasal™ medium, a potent inducer of titan cells.

Methods: An integrative approach was used, combining scanning electron microscopy, optical tweezers, fluorescence microscopy, and physicochemical methods to analyze C. gattii cells grown in Neurobasal™ medium and minimal media.

Results: Cells grown in Neurobasal™ medium exhibited significant differences compared to those grown in minimal media. These included a thicker and more defined polysaccharide capsule, enhanced capsule elasticity, and the secretion of more elastic polysaccharides. Furthermore, cells grown in the enriched medium showed reduced susceptibility to antifungals and delayed mortality in infection models.

Conclusions: C. gattii adapts to nutritional cues by forming titan cells, thereby enhancing its pathogenicity. Targeting nutritional sensing pathways may offer novel therapeutic strategies against cryptococcal infections.

Background/objectives: Epstein-Barr virus (EBV) detection patterns in lymphoproliferative disorders (LPDs) show significant geographical variation worldwide. Regional epidemiological data are essential for understanding viral distribution patterns and developing appropriate clinical surveillance strategies. This study aimed to determine EBV detection frequency in LPDs using available molecular and immunohistochemical methods in Western Mexico.

Methods: We conducted a cross-sectional study of 200 formalin-fixed paraffin-embedded tissue samples from patients diagnosed with LPDs (2015-2019) at Hospital Civil de Guadalajara. EBV detection combined with real-time PCR targeting the BNTp143 gene and immunohistochemistry for LMP-1 protein. Cases were classified following current WHO criteria. Statistical analysis included multivariate logistic regression, diagnostic concordance assessment, and age-stratified analysis.

Results: EBV detection frequency reached 35.5% overall, with marked differences between neoplastic (53.9%) and reactive LPDs (24.2%) (OR: 3.515; 95% CI: 1.859-6.645, p < 0.001). Hodgkin lymphoma showed the highest detection rate (80.6%), significantly exceeding non-Hodgkin lymphoma (39.3%) (OR: 6.43; 95% CI: 2.08-19.41, p = 0.001). Age-stratified analysis revealed predominant adult involvement (49.1% vs. 22.0% in young adults, p = 0.025). We identified three epidemiological categories based on detection probability patterns.

Conclusions: This study represents the first comprehensive molecular and immunohistochemical characterization of Epstein-Barr virus in lymphoproliferative disorders from Western Mexico, establishing distinct epidemiological patterns that align with Latin American regional characteristics. The validated methodology provides a reproducible framework for multi-center studies, while the epidemiological data serve as an essential baseline for future longitudinal research and resource optimization in similar healthcare settings.

Background: The Amazon biome exhibits complex arboviral transmission dynamics influenced by accelerating deforestation, climate change, and socioeconomic inequities.

Objectives/methods: This study integrates official epidemiological records with socioeconomic, environmental, and climate variables by applying advanced geostatistical methods (Moran's I, SaTScan, kernel density estimation) combined with principal component analysis and negative binomial regression to assess the spatiotemporal dynamics of dengue incidence and its association with socio-environmental determinants across municipalities in Pará state (eastern Brazilian Amazon) from 2010 to 2024.

Results: Dengue incidence showed an overall decline but with marked epidemic peaks in 2010-2012, 2016, and 2024. The spatial analysis revealed significant clustering (Moran's I = 0.221, p < 0.01), with persistent high-risk hotspots across most of Pará. Of 144 municipalities, 104 exhibited significant dengue risk, while 58 maintained sustained transmission. Negative binomial regression model identified key determinants: illiteracy, low urbanization, reduced GDP, and climate variables.

Conclusions: Dengue transmission in the Amazon is driven by synergistic socio-environmental disruptions, necessitating intersectoral policies that bridge public health surveillance, sustainable land-use governance, and poverty alleviation. Priority actions include targeted vector control in high-risk clusters, coupled with integrated deforestation and climate monitoring to predict outbreak risks. The findings emphasize the urgency of implementing multisectoral interventions tailored to the territorial and socio-environmental complexities of vulnerable Amazonian regions for effective dengue control.

Background/Objectives: Hemodialysis catheter-related bloodstream infection (HD-CRBSIs) is a main cause of morbidity in hemodialysis. New preventive strategies have emerged, such as using lock solutions with antiseptic or antibiotic capacity. In this study, the antimicrobial effect was analyzed in vitro and with a catheter model of lock solutions of gentamicin (LSG), gentamicin/heparin (LSG/H), and gentamicin/citrate (LSG/C) in clinical and ATCC strains of Pseudomonas aeruginosa and Staphylococcus aureus. Methods: The formation, minimum inhibitory concentration, and minimum inhibitory concentration of the biofilm and minimum biofilm eradication concentration of the lock solutions were determined. Additionally, colony-forming unit assays were performed to evaluate the antimicrobial efficacy of the lock solutions in a hemodialysis catheter inoculation model. Results: The minimum inhibitory concentration (MIC) of planktonic cells of both P. aeruginosa and S. aureus for LSG/H and LSG/C was 4 µg/mL. In the minimum biofilm inhibitory concentration (MBIC) tests, the LSG/H was less effective than LSG/C, requiring higher concentrations for inhibition, contrary to the minimum biofilm eradication concentration (MBEC), where LSG/H was more effective. All lock solutions eradicated P. aeruginosa biofilms in the HD catheter model under standard conditions. Nevertheless, under modified conditions, the lock solutions were not as effective versus ATCC and clinical strains of S. aureus. Conclusions: Our analysis shows that the lock solutions studied managed to eradicate intraluminal mature P. aeruginosa in non-tunneled HD catheters under standard conditions. Biofilm inhibition and eradication were observed at low gentamicin concentrations, which could optimize the gentamicin concentration in lock solutions used in HD catheters.

Scrofuloderma, a cutaneous manifestation of tuberculosis, is a rare but clinically significant form of mycobacterial infection. It typically results from the local spread of Mycobacterium tuberculosis from an infected lymph node or bone area to the overlying skin. This disease is mainly characterized by chronic granulomatous inflammation, leading to skin ulcers and abscesses. Due to its nonspecific clinical presentation, scrofuloderma can mimic various dermatological conditions, making its diagnosis particularly challenging. This case report presents the clinical course of a patient who was positive for the Human Immunodeficiency Virus (HIV) with a diagnosis of scrofuloderma, managed at a tertiary healthcare center, with follow-up before and after treatment. A literature review was also made, highlighting the importance of maintaining a high index of clinical suspicion and utilizing appropriate diagnostic methods to ensure timely diagnosis.

Background: HIV-associated neurocognitive disorders (HANDs) continue to be a significant concern, despite the advancements in prognosis achieved through Combination Antiretroviral Therapy (cART). Neuropsychological assessment, recommended by international guidelines for HANDs diagnosis, can be resource-intensive. Brief screening tools, like the International HIV Dementia Scale (IHDS) and the Montreal Cognitive Assessment (MoCA), are crucial in facilitating initial evaluations. This study aims to assess the Italian IHDS (IHDS-IT) and evaluate its sensitivity and specificity in detecting cognitive impairment in HIV patients. Methods: This cross-sectional study involved 294 patients aged ≥30 years, evaluated at the Immunology Unit of the University of Cagliari. Cognitive function was assessed using the MoCA and IHDS. Laboratory parameters, such as CD4 nadir, current CD4 count, and HIV-RNA levels, were also collected. Statistical analyses included Spearman's correlation, Receiver Operating Characteristic analysis, and the Youden J statistic to identify the optimal IHDS-IT cut-off for cognitive impairment detection. Results: The IHDS and MoCA scores showed a moderate positive correlation (Spearman's rho = 0.411, p < 0.0001). ROC analysis identified an IHDS-IT cut-off of ≤9, yielding an Area Under the Curve (AUC) of 0.76, sensitivity of 71.7%, and specificity of 67.2%. At this threshold, 73.1% of patients with MoCA scores below 23 also presented abnormal IHDS scores, highlighting the complementary utility of both cognitive assessment instruments. Conclusions: The IHDS-IT exhibited fair diagnostic accuracy for intercepting cognitive impairment, with a lower optimal cut-off than previously reported. The observed differences may reflect this study cohort's demographic and clinical characteristics, including advanced age and long-lasting HIV infection. Further, longitudinal studies are necessary to validate these findings and to confirm the proposed IHDS cut-off over extended periods.

Background: Trichosporon spp. are opportunistic fungi, capable of causing infection, especially in critically ill individuals who often use broad-spectrum antibiotics, invasive devices, and have comorbidities. Objectives The aim of this study was to analyze individuals' clinical characteristics, evaluate tolerance to biocides, as well as biofilm formation and efflux pump activity in isolates of Trichosporon asahii.

Methods: Clinical isolates of T. asahii collected between 2020 and 2023 from both hospitalized and non-hospitalized individuals, of both sexes, regardless of age, were tested for tolerance to sodium hypochlorite, hydrogen peroxide, benzalkonium chloride, and ethyl alcohol. Efflux pump activity was also assessed using ethidium bromide, and biofilm formation was measured with the Safranin test. Clinical parameters such as outcomes, source, and length of hospitalization were analyzed through electronic medical records.

Results: A total of 37 clinical isolates of T. asahii were identified. Thirty-three (83.8%) isolates were from hospitalized individuals, with 81.82% collected in ICUs, an average hospital stay of 35 days, and a mortality rate of 51.6%. The tested strains displayed the largest mean inhibition zone for 2% sodium hypochlorite, indicating lower tolerance. A high level of efflux pump expression was detected among clinical isolates. Biofilm formation was detected in 25/67.5% of the isolates.

Conclusions: These findings highlight the clinical relevance of T. asahii, particularly in critically ill individuals, and underscore the pathogen's ability to tolerate biocides, express efflux pumps, and form biofilms, all of which may contribute to its persistence and pathogenicity in hospital environments. Enhanced surveillance and effective microbial control measures are essential to mitigate the risks associated with T. asahii infections.

Background/Objectives: Due to the significant overlap in symptoms between COVID-19 and other respiratory infections, a multiplex PCR-based platform was developed to simultaneously detect 22 respiratory pathogens. Target sequences were retrieved from the GenBank database and aligned using Clustal Omega 2.1 to identify conserved regions prioritized for primer design. Primers were designed using Primer Express^® 3.0.1 and evaluated in Primer Explorer to ensure specificity and minimize secondary structures. A multiplex strategy organized primers into three groups, each labeled with distinct fluorophores (FAM, VIC, or NED), allowing for detection by conventional PCR or capillary electrophoresis (CE). Methods: After reverse transcription for RNA targets, amplification was performed in a single-tube reaction. A total of 340 clinical samples-nasopharyngeal and saliva swabs-were collected from patients, during the COVID-19 pandemic period. The automated analysis of electropherograms enabled precise pathogen identification. Results: Of the samples analyzed, 57.1% tested negative for all pathogens. SARS-CoV-2 was the most frequently detected pathogen (29%), followed by enterovirus (6.5%). Positive results were detected in both nasopharyngeal and saliva swabs, with SARS-CoV-2 predominating in saliva samples. Conclusions: This single-tube multiplex PCR-CE assay represents a cost-effective and robust approach for comprehensive respiratory pathogen detection. It enables rapid and simultaneous diagnosis, facilitating targeted treatment strategies and improved patient outcomes.