Pathogens最新文献

Coxsackievirus A6 (CVA6) has become increasingly clinically relevant as a cause of Hand, Foot and Mouth Disease (HFMD) globally since 2008. However, most laboratories do not routinely determine the enteroviral type of positive samples. The non-pharmaceutical measures introduced to curb transmission during the COVID-19 pandemic may also have perturbed CVA6 epidemiology. We thus aimed to determine the prevalence, clinical presentation and genetic relationship of CVA6 across three complete epidemic seasons: one pre-SARS-CoV-2 emergence and two post-SARS-CoV-2 emergence in our regional healthcare setting. Surplus diagnostic nucleic acid from diagnosed enteroviral positives diagnosed between September and December of 2018 and between May 2021 and April of 2023 was subject to VP1 gene sequencing to determine the CVA6 cases and interrogate their phylogenetic relationship. The confirmed CVA6 cases were also retrospectively clinically audited. CVA6 infections were identified in 33 and 69 individuals pre- and post-pandemic, respectively, with cases peaking in November of 2018 and 2022, but in October of 2021. HFMD was the primary diagnosis in 85.5% of the post-pandemic cases, but only 69.7% of the pre-pandemic cases, where respiratory and neurological symptoms (45.5% and 12.1%, respectively) were significantly elevated. A complete VP1 sequence was retrieved for 94% of the CVA6 cases, revealing that studied infections were genetically diverse and suggestive of multiple local and international transmission chains. CVA6 presented a significant clinical burden in our regional U.K. hospital setting both pre- and post-pandemic and was subject to dynamic clinical and genetic epidemiology.

West Nile Virus, an arthropod-borne RNA virus, may result in severe neurological disease. West Nile neuroinvasive disease is characterized by meningitis, encephalitis, and possible acute flaccid paralysis. Here, we report a case of neuroinvasive WNV in a 65-year-old woman hospitalized for hyperpyrexia, chills, intense asthenia, and continuous vomiting. Within days, her clinical condition worsened with the onset of severe neurological symptoms, leading to her death within 10 days despite supportive therapies being administered. The diagnosis of West Nile disease was made through nucleic acid amplification testing (NAAT) on blood and cerebrospinal fluid. However, in the final stages of the illness, cerebrospinal fluid collection was not possible due to the patient's critical condition, and a nasopharyngeal swab was used instead. The nasopharyngeal swab facilitated the collection of a sample, which was subsequently analyzed for the presence of the virus and allowed for sequencing, showing that it was a strain that had been circulating in Sardinia for some time and had demonstrated its pathogenicity by causing the death of a hawk in 2021. This case report highlights the rapid progression and severity of WNV infection, particularly in vulnerable individuals, and suggests the potential utility of nasopharyngeal swabs as a less invasive option for sample collection. It also underscores the potential for the zoonotic transmission of the virus from birds to humans through vectors, emphasizing the importance of monitoring and controlling WNV outbreaks, especially in regions where such circulation is observed.

The rapid and accurate detection of SARS-CoV-2 in environmental settings is crucial for effective public health management during the COVID-19 pandemic. This study compares the performance of the Reverse Transcription quantitative polymerase chain reaction (RT-qPCR) and the Reverse Transcription loop-mediated isothermal amplification (RT-LAMP) for SARS-CoV-2 detection from 100 surface samples collected in healthcare environments. The reference method, RT-qPCR, identified a percentage of 25% of positive samples, while RT-LAMP detected a percentage of 27% of positive surfaces. Our findings reveal a sensitivity of 32% and specificity of 75% for RT-LAMP, with a positive predictive value of 30% and a negative predictive value of 77%. The overall accuracy and concordance with RT-qPCR was 64% for both methods. Despite its lower sensitivity compared to RT-qPCR, RT-LAMP had an advantage due to its rapid screening and environmental surveillance, which is particularly useful for confirming negative results. These results underscore the potential of RT-LAMP not only as a valuable method in the environmental monitoring of SARS-CoV-2 but also as a system to control the sanitation process in ordinary and emergency conditions, providing further optimization and validation for its reliability in routine surveillance and outbreak response efforts.

Pharmaceutical preclinical tests using cell cultures are nowadays commonly automated. Incubator microbial contaminations impact such tests. Chlorine dioxide (ClO₂) is widely used in aqueous solutions. However, a gaseous form, such as chlorine dioxide gas (gClO₂), can effectively access unreachable spaces, such as closed cell culture incubators. Steam sterilization requires a temperature rise to at least 121 °C, thus limiting the possibility of automation elements for sensors and actuators. gClO₂ sterilization is an ambient-temperature sterilization method. This article aims to demonstrate that gClO₂ generated from solid powder tablets is efficient for sterilizing incubators and can be automated. We selected (i) Bacillus subtilis strain, (ii) Saccharomyces cerevisiae, and (iii) T7 phages as representatives for (i) bacteria, (ii) fungi, and (iii) viruses for each domain to evaluate the sterilization efficiency. This study demonstrated that gClO₂ can be generated inside the incubator from a solid powder tablet without specific equipment and can effectively fight biological proxies in 15 min. After 30 sterilization cycles, the actuators and sensors mounted inside the incubator were still operating. Our proposed sterilization method seems to be generally applicable for automated in situ sterilization of incubators and medical robots.

Congenital cytomegalovirus infection (cCMV) is a frequent cause of non-hereditary sensorineural hearing loss (SNHL) and developmental disabilities. The contribution of cCMV to childhood hearing loss has been estimated to be about 25% of all hearing loss in children at 4 years of age. Although the vestibular insufficiency (VI) in cCMV has not been well-characterized and therefore, underestimated, recent studies suggest that VI is also frequent in children with cCMV and can lead to adverse neurodevelopmental outcomes. The pathogenesis of SNHL and VI in children with cCMV has been thought to be from direct viral cytopathic effects as well as local inflammatory responses playing a role. Hearing loss in cCMV can be of varying degrees of severity, unilateral or bilateral, present at birth or develop later (late-onset), and can progress or fluctuate in early childhood. Therefore, newborn hearing screening fails to identify a significant number of children with CMV-related SNHL. Although the natural history of cCMV-associated VI has not been well characterized, recent data suggests that it is likely that VI also varies considerably with respect to the laterality, timing of onset, degree of the deficit, and continued deterioration during early childhood. This article summarizes the current understanding of the natural history and pathogenesis of auditory and vestibular disorders in children with cCMV.

Alzheimer's disease (AD) is a multifactorial brain disorder and infectious diseases are considered as one of the predisposing factors for AD. Toxoplasma gondii, an obligate intracellular parasitic protozoan, is suspected of being associated with AD. Serum samples were collected from 109 AD patients and 114 age-matched healthy controls. ELISA was performed using recombinant T. gondii cyst wall protein 1 (CST1) to detect T. gondii antibodies. A parallel experiment was performed with Toxoplasma gondii tachyzoites lysate protein. To analyze whether factors associated with the onset of AD included chronic T. gondii infection, a multivariate logistic regression model was applied, further validating the correlation between chronic T. gondii infection and AD. AD patients exhibited significantly higher levels of Toxoplasma-specific antibodies in their serum compared to the control group, with statistically significant differences (p < 0.05). Multivariate logistic regression analysis revealed that Toxoplasma infection is a risk factor for AD (p < 0.01), and the CST1 antigen can significantly improve the model's performance in predicting the occurrence of AD. The results indicate that chronic infection with Toxoplasma gondii could be one of the risk factors for the development of AD, potentially predisposing individuals with underlying health conditions to the disease. This further validates the correlation between Toxoplasma gondii and AD.

Cutaneous leishmaniasis (CL), caused by Leishmania braziliensis, is closely associated with a severe form of the disease, indicated by a positive Leishmania skin test (LST) that assesses and reflects the presence of immune T cells specific to Leishmania antigens. In this study, we compare the clinical, immunologic, and histopathologic features between Leishmania skin test-positive (LST+) and Leishmania skin test-negative (LST-) in CL. Compared to LST+ patients, LST- patients had larger lesions and had been sicker for longer, presented with more instances of therapeutic failure with meglumine antimonate, (MA) and the healing times were higher than LST+. While granulomas were less frequent and the parasite load was higher in LST-, there were more CD8+ T cells and an enhanced production of Granzyme B in the supernatants of biopsies from LST- subjects. This study shows that in LST-, an impairment in Th1 immune response is associated with a high parasite burden, and the pathology is mediated by CD8+ T cells and the enhanced production of Granzyme B. The abnormalities in the immunologic response in LST- patients lead to a more severe disease with a high rate of failure to therapy.

In the Global Poliovirus Laboratory Network (GPLN), participation and successful completion in annual proficiency test (PT) panels has been a part of the WHO accreditation process for decades. The PT panel is a molecular external quality assessment (mEQA) that evaluates laboratory preparedness, technical proficiency, the accuracy of data interpretation, and result reporting. Using the Intratypic Differentiation (ITD) real-time RT-PCR kits from CDC, laboratories run screening assays and report results in accordance with the ITD algorithm to identify and type polioviruses. The mEQA panels consisted of 10 blinded, non-infectious lyophilized RNA transcripts, including programmatically relevant viruses and targets contained in the real-time PCR assays. Sample identities included wildtype, vaccine-derived (VDPV), Sabin-like polioviruses, enterovirus, and negatives, as well as categories of invalid and indeterminate. The performance of individual laboratories was assessed based on the laboratory's ability to correctly detect and characterize the serotype/genotype identities of each sample. The scoring scheme assessed the laboratory readiness following GPLN guidelines. Laboratories receiving mEQA scores of 90 or higher passed the assessment, scores of less than 90 failed and required remedial actions and re-evaluation. In 2021 and 2022, 123 and 129 GPLN laboratories were invited to request the annual PT panel, and 118 and 127 laboratories submitted results, respectively. The overall results were good, with 86% and 91.5% of laboratories passing the PT panel on their first attempt in 2021 and 2022, respectively. Most labs scored the highest score of 100, and less than one quarter scored between 90 and 95. Less than 10% of submitting laboratories failed the PT, resulting in in-depth troubleshooting to identify root causes and remediations. Most of these laboratories were issued a second PT panel for repeat testing, and almost all laboratories passed the repeat PT panel. The results of the 2021 and 2022 annual mEQA PTs showed that, despite the COVID-19 pandemic, the performance remained high in the GPLN, with most labs achieving the highest score. For these labs, the real-time PCR assay updates that were implemented during 2021-2022 were carried out with full adherence to procedures and algorithms. Even initially failing labs achieved passing scores after remediation.

Fusobacterium nucleatum (F. nucleatum), a key pathogen implicated in periodontal disease, contributes to oral biofilm maturation and is linked to development of systemic diseases like colorectal cancer and liver cirrhosis. Photodynamic therapy (PDT) combined with 5-aminolevulinic acid (5-ALA) treatment (ALA-PDT) selectively targets F. nucleatum by inducing porphyrin accumulation. The bactericidal effect of red light-based PDT on F. nucleatum has not been evaluated previously. This study investigates the effect of ALA-PDT using red light-emitting diode (LED) light on F. nucleatum subspecies and their porphyrin accumulation. F. nucleatum subspecies were cultured with varying concentrations of 5-ALA under anaerobic conditions. Porphyrin accumulation was measured via fluorescence spectroscopy, and colony-forming units were measured to determine bacterial viability post-treatment. Additionally, other subspecies responded well to 0.01% 5-ALA, and uroporphyrin I accumulation correlated with bacterial death, revealing optimal bactericidal conditions. These results suggest that optimizing light intensity and 5-ALA concentration can significantly enhance the therapeutic potential of ALA-PDT in oral healthcare.

Human T-cell leukemia virus type 1 (HTLV-1) infects CD4⁺ T-cells through close cell-cell contacts. The viral Tax-1 (Tax) protein regulates transcription by transactivating the HTLV-1 U3R promoter in the 5' long terminal repeat of the integrated provirus. Here, we generated a clonal Tax-responsive T-cell line to track HTLV-1 infection at the single-cell level using flow cytometry, bypassing intracellular viral protein staining. Jurkat T-cells stably transduced with the SMPU vector carrying green fluorescent protein (GFP) under control of 18 × 21 bp Tax-responsive element repeats of the U3R were evaluated. Among 40 clones analyzed for Tax responsiveness, the top two were characterized. Upon overexpression of Tax, over 40% of the cells showed GFP positivity, and approximately 90% of the Tax-positive cells were GFP-positive, indicating efficient reporter activity. However, with CREB-deficient Tax mutant M47, both total GFP-positive cell counts and those within the Tax-positive group significantly decreased. Co-culture with chronically HTLV-1-infected MT-2 or C91-PL cells led to an average of 0.9% or 2.4% GFP-positive cells, respectively, confirming the suitability to monitor HTLV-1 transmission and that HTLV-1 infection is very low. Thus, the novel Tax-responsive reporter T-cell line is a suitable tool to monitor infection of HTLV-1 on the single-cell level.