Search Results (6,936)

The growing problem of antimicrobial resistance in aquaculture, caused by the excessive and unregulated use of antibiotics, highlights the critical necessity for developing new anti-infective solutions. Based on the characteristics of glycine-rich antimicrobial peptides (AMPs) and transcriptomic data, an antimicrobial peptide, namely AfRgly1, was discovered in this study. Subsequently, the peptide was obtained through heterologous expression in E. coli, and its antibacterial spectrum was determined. Molecular dynamics simulation and molecular biology experiments were conducted to explore the antibacterial target of AfRgly1. Results showed that the mRNA expression level of AfRgly1 was significantly upregulated after Vibrio alginolyticus infection. AfRgly1 has broad-spectrum antibacterial activity targeting on bacterial cell membrane, and it may also interact with bacterial DNA. AfRgly1 displayed low selectivity for fish red blood cells. These results indicate that AfRgly1 is an antimicrobial peptide with considerable potential for application in the development of therapeutic agents. Full article

Sepsis is a life-threatening condition caused by an abnormal host response to infection, leading to organ dysfunction and potentially death. Acute kidney injury (AKI) is a critical complication of sepsis. Various pathways, especially signaling through Toll-like receptors (TLRs) and the nucleotide-binding oligomerization domain, leucine-rich repeat and pyrin domain-containing protein 3 (NLRP3) inflammasome, contribute to inflammation and tissue damage. Cilastatin, a renal dehydropeptidase I inhibitor, has shown promise in protecting against AKI induced by nephrotoxic drugs. This study assessed cilastatin’s effectiveness in preventing AKI and inflammation caused by sepsis and its impact on survival. Sepsis was induced in male Sprague-Dawley rats using the cecal ligation puncture (CLP) model, with four groups: sham (control), CLP, sham+cilastatin, and CLP+cilastatin. Cilastatin (150 mg/kg) was administered immediately and 24 h after sepsis induction. Kidney injury was evaluated 48 h later by assessing serum creatinine, blood urea nitrogen, glomerular filtration rate, proteinuria, kidney injury molecule-1 levels, and renal morphology. Inflammatory and fibrotic biomarkers, particularly related to the TLR4 and NLRP3 pathways, were also measured. Cilastatin treatment prevented kidney dysfunction, reduced inflammatory markers, and improved survival by 33%. These results suggest that cilastatin could be a beneficial therapeutic strategy for sepsis-related AKI, improving outcomes and reducing mortality. Full article

Ischemic stroke triggers a dynamic immune response that influences both acute damage and long-term recovery. This review synthesizes a decade of evidence on immunological and inflammatory biomarkers in ischemic stroke, emphasizing their prognostic and therapeutic significance. Following ischemic insult, levels of pro-inflammatory cytokines, such as interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α), and chemokines like interleukin-8 (IL-8) rapidly rise, promoting blood–brain barrier disruption, leukocyte infiltration, and neuronal death. Conversely, anti-inflammatory mediators such as interleukin-10 (IL-10) and transforming growth factor-β (TGF-β) facilitate repair, neurogenesis, and immune regulation in later phases. The balance between these pathways determines outcomes and is reflected in circulating biomarkers. Composite hematological indices including the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and systemic immune-inflammation index (SII) offer accessible and cost-effective prognostic tools. Several biomarkers correlate with infarct size, neurological deterioration, and mortality, and may predict complications like hemorrhagic transformation or infection. Therapeutic strategies targeting cytokines, especially IL-1 and IL-6, have shown promise in modulating inflammation and improving outcomes. Future directions include personalized immune profiling, real-time cytokine monitoring, and combining immunotherapy with neurorestorative approaches. By integrating immune biomarkers into stroke care, clinicians may enhance risk stratification, optimize treatment timing, and identify candidates for novel interventions. This review underscores inflammation’s dual role and evolving therapeutic and prognostic relevance in ischemic stroke. Full article

Introduction: Hepatitis B is the most prevalent virus that causes severe liver infection worldwide. According to the current guidelines, the HBV viral load and other factors can help in treatment decisions. Therefore, the present study explores the relationship between the HBV viral load and blood-based laboratory parameters. Methods: The HBV viral load was evaluated in blood samples from 159 HBsAg-positive patients (ICT-positive). The viral load was categorized as high (above 200,000 IU/mL), moderate (between 2000 and 200,000 IU/mL), or low (below 2000 IU/mL). The viral load was then compared with laboratory parameters. Results: A significant association was observed between the Hepatitis B viral load and the patient’s age (p < 0.01). The males showed a substantially higher viral load, with 29.2% of the male patients exhibiting elevated levels, compared to 11% of the females. A statistically significant correlation was found between the viral load and liver enzymes, specifically AST (p < 0.005) and ALT (p < 0.04), as well as calcium (p < 0.01). Notably, the elevated ALT and AST levels were more pronounced in the patients with moderate and high viral loads, suggesting a potential link to liver dysfunction. A remarkable insight uncovered in our study revolves around the notable increase in the serum calcium levels (p < 0.01). Conclusions: The AST, ALT, and serum calcium levels were the most altered parameters with high HBV viral load. Though limited reports are available on altered serum calcium levels, they could serve as potential laboratory markers for assessing disease progression in HBV infection. Moreover, focusing on potential therapies to normalize the AST, ALT, and serum calcium levels could offer promising avenues for combating HBV infection. Full article

The immune response to SARS-CoV-2 infection involves significant alterations in the phenotype and function of natural killer (NK) cells. This study aimed to investigate the dynamic changes in NK cell subsets during COVID-19 by analyzing their activation and inhibitory markers [CD3, CD14, CD16, CD19, CD25, CD45, CD56, CD57, CD69, CD159a (NKG2A), CD159c (NKG2C), CD314 (NKG2D), CD335 (NKp46)], cytotoxic potential (perforin, interferon-gamma, granzyme B), and direct cytotoxicity against a newly genetically modified K562 cell line. Peripheral blood samples were collected from COVID-19 patients on days 3–5 and day 30 post-symptom onset and were compared to healthy controls. 16-color flow cytometry analysis revealed distinct shifts in NK cell subpopulations, characterized by increased expression of the inhibitory receptor NKG2A and the activating receptors NKG2D and NKG2C, particularly in the CD56⁺CD16⁻ subset. Elevated IFN-γ production on day 30 suggested a recovery-phase immune response, while the persistent upregulation of NKG2A indicated an ongoing regulatory mechanism. The CD16⁺CD56⁻ subpopulation exhibited increased expression of the markers CD69 and CD25 over time; however, its cytotoxic potential, assessed through granzyme B levels and direct cytotoxicity assays, remained lower than that of healthy controls. Significant correlations were observed between CD57 and CD69 expression, as well as NKp46 and IFN-γ production, highlighting a coordinated balance between activation and regulatory mechanisms. These findings suggest that NK cells undergo functional adaptation during COVID-19, displaying signs of partial exhaustion while retaining antiviral potential. Understanding the interplay between NK cell activation and suppression may provide valuable insights into immune dysregulation in COVID-19 and inform potential therapeutic interventions. Full article

A new human pathogen triggering a pandemic can impact health directly through disease resulting from infection and indirectly through health system disruption. The COVID-19 pandemic is hypothesised to have impacted pathology testing by impacting healthcare and pathology operations and reducing healthcare attendance for fear of infection. The impacts of COVID-19 incidence and pandemic control measures on non-COVID pathology testing were assessed in four Australian states/territories using pathology data (histology, prostate-specific antigen, gynaecological cytology, complete blood count, haemoglobin A1c, and human immunodeficiency virus) from a large national private pathology provider (January 2019–December 2024). Weekly testing volumes from lockdown periods were compared to the equivalent weeks in 2019. All pathology tests demonstrated a substantial decline during the initial national lockdown in March 2020. Subsequent lockdowns were also associated with disruption. For example, complete blood count testing in Victoria was −22% in March 2020 and −5% in the second wave that year. Total annual testing volumes were lower for all tests in 2020 compared to 2019, excluding haemoglobin A1c, and reduced testing persisted through to 2024. The findings indicate substantial and sustained negative pandemic impacts on pathology testing. Reductions in pathology testing signal heightened risk of delayed disease diagnosis, disrupted chronic disease management, and poorer health outcomes. Full article

The genus Orthoflavivirus includes several mosquito-borne pathogenic viruses, notably West Nile virus (WNV), which is endemic to the Mediterranean region. In Portugal, WNV circulation has been documented in equines, birds and mosquitoes, however human cases remain rare and no recent human seroprevalence studies have been conducted. This study aimed to estimate the national and regional seroprevalence of WNV among blood donors in mainland Portugal and explore associations with sociodemographic factors. A cross-sectional study conducted in 2022 included 3593 blood donors from across mainland Portugal. Serum samples were tested for WNV immunoglobulin G (IgG) by enzyme-linked immunosorbent assay (ELISA) and positive and borderline samples were confirmed using a virus neutralization test. Sociodemographic data were collected through a structured paper questionnaire. Statistical analyses, including multivariate logistic regression, identified factors associated with seropositivity. A total of 55 samples (1.5%) tested positive, and 21 samples (0.6%) were classified as borderline for WNV antibodies by ELISA. Of these, 47 were confirmed by viral neutralization, giving an estimated national seroprevalence of 1.4%. Significant regional variation was noted, with higher seroprevalence observed in the Beira Baixa, Grande Lisboa and Médio Tejo regions. Some seropositive individuals were identified in northern coastal regions such as Ave, Cávado and Área Metropolitana do Porto. In multivariate analysis, geographical area of residence was the only factor associated with seropositivity. This study highlights regions at potential higher risk for human WNV exposure, primarily in the southern half of Portugal. Continued and integrated surveillance is crucial to inform public health strategies to mitigate WNV transmission risks in these regions, as well as in other regions where WNV may be emerging as a relevant One Health concern. Implementing preventive measures for both animals and humans is critical to minimizing exposure and infection, and further confirmatory studies using virus neutralization tests will be important for refining these estimates. Full article

Background: Systematic studies providing differentiated insight into the contribution of immunity directed against conserved and non-conserved epitopes of SARS-CoV-2 Spike on long-term protection are rare and insufficiently guide future pan-variant vaccine research. The present observational cohort study aimed to evaluate the correlation of neutralizing antibody levels and cellular immunity against the Spike protein with symptomatic Omicron breakthrough infection. Methods: Neutralizing antibody levels against multiple (sub)variants were analyzed 6 months following the second wild-type mRNA vaccination and 6 months after booster in 107 subjects using a multiplex surrogate virus neutralization assay. To assess cellular immunity, cytokine mRNA expression levels were determined after peptide pool stimulation in whole blood samples of a study subgroup. Results: Neutralizing antibody titers were found to serve as a reasonably reliable correlate of protection prior to booster immunization. However, the predictive power of neutralizing antibody titers was diminished after boosting. This loss appears to be due to a critical remodeling of the antibody repertoire—a process that was dose-dependent on pre-boost humoral immunity. Vaccination against Omicron infection was most effective when a balanced immune response to both conserved and non-conserved epitopes of the viral Spike protein was induced. While neutralizing antibodies against receptor-binding domain epitopes affected by mutations were specifically associated with protection from symptomatic variant infection, cellular immunity was most effective when targeting conserved Spike epitopes. Conclusions: Optimal long-term protection against Omicron infection requires balanced immunity to both conserved and non-conserved epitopes of the viral Spike protein. The limited availability of cross-neutralizing antibodies targeting non-conserved epitopes and their inherently lower efficacy renders them a limiting factor as humoral immunity wanes over time. Future pan-SARS-CoV-2 variant vaccines that primarily target conserved epitopes may therefore provide less effective long-term protection against symptomatic variant infection than vaccines targeting a broader epitope spectrum including both conserved and non-conserved epitopes. Full article

Klebsiella oxytoca originating from shellfish Scapharca subcrenata contains a number of virulence-related genes. In this study, we investigated its pathogenicity using a murine intestinal infection model and predicted its antibacterial compounds and targets via molecular docking analysis. The results revealed that the intake of K. oxytoca 8-2-11 strain (10⁹ CFU/day) via oral gavage for 7 days reduced the average body weight of the mice. The bacterium was present in fecal samples but absent from blood, lung, and liver samples from the mice. The intake of K. oxytoca 8-2-11 significantly altered colon bacteriota, with reduced abundance of Firmicutes, Lachnospiraceae, Lactobacillaceae, Lactobacillus, and Lactobacillus murinus, and increased in Bacteroidota, Muribaculaceae, and Alistipes (p < 0.05). Forty-four bioactive compounds in Scutellaria baicalensis and Forsythia suspensa were screened for docking with 117 potential virulence factors (VFs) in K. oxytoca 8-2-11. The compound baicalin displayed higher binding affinity toward these VFs, with the lowest mean binding energy (−8.4 kcal/mol). Baicalin was able to bind to key VFs in biofilm formation and adherence/motility (e.g., Mrks and EcpA) via forming stable hydrogen bonds, π-stacking, and π-cation interaction. In vitro, baicalin inhibited the bacterial growth and biofilm formation. This study establishes the first murine infection model using aquatic animal-derived K. oxytoca, and it provides candidate antibacterial compounds and targets for control of K. oxytoca infections. Full article

Background/Objectives. Women living with human immunodeficiency virus (WLWH) have a six-fold higher risk of developing cervical cancer associated with high-risk human Papillomavirus (HR-HPV) than HIV-negative women. We herein assessed HR-HPV genotype distribution and plasma levels of the cancer antigen 125 (CA-125) in WLWH in a rural town in Gabon, in Central Africa. Methods. Adult WLWH attending the local HIV outpatient center were prospectively enrolled and underwent cervical visual inspection and cervicovaginal and blood sampling. HIV RNA load and CA-125 levels were measured from plasma using the Cepheid^® Xpert^® HIV-1 Viral Load kit and BioMérieux VIDAS^® CA-125 II assay, respectively. HPV detection and genotyping were performed via a nested polymerase chain reaction (MY09/11 and GP5+/6+), followed by sequencing. Results. Fifty-eight WLWH (median age: 52 years) were enrolled. Median CD4 count was 547 cells/µL (IQR: 412.5–737.5) and HIV RNA load 4.88 Log₁₀ copies/mL (IQR: 3.79–5.49). HPV prevalence was 68.96%, with HR-HPV detected in 41.37% of women. Among HR-HPV-positive samples, 87.5% (21/24) were genotypes targeted by the Gardasil vaccine, while 12.5% (3/24) were non-vaccine types. Predominant HR-HPV types included HPV-16 (13.8%), HPV-33 (10.34%), HPV-35 (5.17%), HPV-31, and HPV-58 (3.45%). Most participants had normal cervical cytology (62.07%), and a minority (14.29%) had elevated CA-125 levels, with no correlation to cytological abnormalities. Conclusions. In the hinterland of Gabon, WLWH are facing an unsuspected yet substantial burden of cervical HR-HPV infection and a neglected risk for cervical cancer. Strengthening cervical cancer prevention through targeted HPV vaccination, sexual education, and accessible screening strategies will help in mitigating associated risk. Full article

An 89-year-old male developed a persistent high fever (around 39 °C) approximately two weeks following endoscopic reduction of sigmoid volvulus. He had no history of hypercalcemia but was using diuretics and proton pump inhibitors. Renal and thyroid status were normal. He was largely bedridden and asymptomatic except for fever. Laboratory tests demonstrated elevated C-reactive protein (4.75 mg/dL), but some tumor markers (including CEA, CA19-9, and CA125), anti-nuclear antibodies, MPO-ANCA, PR3-ANCA, β-D-glucan, and interferon-gamma release assay were all negative. Urinalysis was unremarkable. Blood cultures obtained from two sets were negative. Chest–abdomen–pelvis contrast-enhanced computed tomography (CT), and echocardiography did not reveal any evident neoplastic lesions or focal sites of infection. Despite various antibiotic therapies, the patient’s spike fever persisted for nearly one month, leading to a diagnosis of fever of unknown origin (FUO). The patient experienced partial symptomatic relief with corticosteroid therapy, though mild fever continued. Two months after the volvulus onset, diffusion-weighted whole-body imaging with background body signal suppression (DWIBS) was performed, revealing hyperintensities at the right sternoclavicular joint, leading to a diagnosis of sternoclavicular arthritis. Neck CT revealed calcification in this joint. Despite difficulty in joint fluid analysis, low infection risk and the patient’s prolonged bedridden state and advanced age led to suspicion of pseudogout. Nonsteroidal anti-inflammatory drugs relieved fever and normalized inflammatory markers. DWIBS may be a valuable tool for detecting potential focus sites in FUO. Full article

Background/Objectives: Digital morphology analysers have been developed to overcome the limitations of manual microscopy. This study aimed to evaluate the performance of the DC-1 on leukaemia samples, determining if it is a suitable for the identification of leukaemia in low-throughput or remote laboratories. To the best of our knowledge, there is no current published literature evaluating the performance of the DC-1 with leukaemia samples. Methods: This study utilised 88 leukaemia peripheral blood smears donated from various anonymous hospitals and medical laboratories in collaboration with RMIT university. DC-1 pre-classification was compared with post-classification using Cohen’s kappa, sensitivity, and specificity calculations. Pre- and post-classification was compared with manual microscopy using Passing–Bablok regression, Pearson’s r correlation, and Bland–Altman analysis. Results: DC-1 pre-classification results showed a moderate agreement with post-classification (k = 0.52), a very high specificity for most leukocytes (>94%) and variable sensitivity (21–86%). Pre- and post-classification displayed a higher accuracy and correlation with manual results for segmented neutrophils and lymphocytes, compared to other leukocyte classes. Additionally, there was an improvement in the post-classification of immature granulocytes, band neutrophils, and blast cells compared to pre-classification. Conclusions: The results indicate that the DC-1 displayed a better performance for the classification of segmented neutrophils and lymphocytes compared to other cell classes, indicating that the DC-1 is more acceptable for use in infection or normal samples, as opposed to leukaemia. The gold standard therefore remains with the morphologist who can distinguish leukaemia samples. Full article

African swine fever virus (ASFV) and classical swine fever virus (CSFV) are important transboundary animal diseases (TADs) affecting swine. ASFV is a large DNA virus with a genome size of 170–190+ kilobases (kB) belonging to the family Asfarviridae, genus Asfivirus. CSFV is a single-stranded RNA virus with a genome size of approximately 12 kB, belonging to the family Flaviviridae, genus Pestivirus. Outbreaks involving either one of these viruses result in similar disease syndromes and significant economic impacts from: (i) high morbidity and mortality events; (ii) control measures which include culling and quarantine; and (iii) export restrictions of swine and pork products. Current detection methods during an outbreak provide minimal genetic information on the circulating virus strains/genotypes that are important for tracing and vaccine considerations. The increasing availability and reduced cost of next-generation sequencing (NGS) allow for the establishment of NGS protocols for the rapid identification and complete genetic characterization of outbreak strains during an investigation. NGS data provides a better understanding of viral spread and evolution, facilitating the development of novel and effective control measures. In this study, panels of primers spanning the genomes of ASFV and CSFV were independently developed to generate approximately 10 kB and 6 kB amplicons, respectively. The primer panels consisted of 19 primer pairs for ASFV and 2 primer pairs for CSFV, providing whole genome amplification of each pathogen. These primer pools were further optimized for batch pooling and thermocycling conditions, resulting in a total of 5 primer pools/reactions used for ASFV and 2 primer pairs/reactions for CSFV. The ASFV primer panel was tested on viral DNA extracted from blood collected from pigs experimentally infected with ASFV genotype I and genotype II viruses. The CSFV primer panel was tested on 11 different strains of CSFV representing the three known CSFV genotypes, and 21 clinical samples collected from pigs experimentally infected with two different genotype 1 CSF viruses. ASFV and CSFV amplicons from optimized PCR were subsequently sequenced on the Oxford Nanopore MinION platform. The targeted protocols for these viruses resulted in an average coverage greater than 1000X for ASFV, with 99% of the genome covered, and 10,000X–20,000X for CSFV, with 97% to 99% of the genomes covered. The ASFV targeted whole genome sequencing protocol has been optimized for genotype II ASF viruses that have been responsible for the more recent outbreaks outside of Africa. The CSFV targeted whole genome sequencing protocol has universal applications for the detection of all CSFV genotypes. Protocols developed and evaluated here will be essential complementary tools for early pathogen detection and differentiation, as well as genetic characterization of these high-consequence swine viruses, globally and within the United States, should an outbreak occur. Full article

This study evaluated dietary inclusion of tannin-based feed additives on heifer performance and physiological measures associated with fescue toxicosis and vaccine response. Forty-five yearling beef heifers (292.6 ± 29.0 kg) grazing toxic, endophyte-infected (E+) tall fescue pastures were assigned to 1 of 3 treatment groups: (1) soybean hulls (SH; n = 3 pastures), (2) SH and BX tannin-saponin additive (BX; 10.0 g heifer⁻¹ d⁻¹; n = 3 pastures), and (3) SH and ATX tannin-polyphenol additive (ATX; 5.0 g heifer⁻¹ d⁻¹; n = 3 pastures). Treatments were administered over an 84 d period. Data were analyzed using R and SAS 9.4 with treatment as a fixed effect, block as a random effect, and pasture as the experimental unit. Treatment effects were assessed at the pasture level. Average daily gain (ADG) of heifers receiving ATX (0.53 kg/d) and BX (0.49 kg/d) were increased relative to heifers receiving SH only (0.23 kg/d) between D56 and D84 (p = 0.07). There was no impact of treatment on other performance measures (p > 0.15) or on serum metabolite responses including bovine herpesvirus type 1 (BHV-1) titers (p > 0.15), prolactin (p = 0.97), haptoglobin (p = 0.26), and blood urea nitrogen (BUN; p = 0.38). Preliminary results show the potential for improved weight gain, suggesting further investigation with more experimental units is warranted. Full article

Background: Klebsiella pneumoniae represents a major cause of healthcare-associated infections in intensive care units, with resistance profiles ranging from multidrug-resistant to extensively drug-resistant and pandrug-resistant. Critically ill patients, who often require invasive devices and prolonged antibiotic therapy, are especially vulnerable to colonization and infection by these strains. Surveillance data on resistance trends and specimen-specific patterns in Romanian intensive care units (ICUs) remain limited. Methods: We conducted a four-year surveillance study (2021–2024) in a tertiary Romanian ICU, analyzing K. pneumoniae isolates collected from diverse clinical specimens. Resistance phenotypes were classified as MDR, XDR, PDR, or susceptible based on standard definitions. Trends over time were assessed using Cramér’s V and correspondence analysis, while stratification by specimen type evaluated associations between anatomical site and resistance profiles. Results: A total of 254 K. pneumoniae isolates were analyzed. MDR strains predominated in 2021 and 2022 but sharply declined by 2024 (from 80% to 8.3%). In parallel, XDR and PDR phenotypes increased substantially, indicating a shift toward more complex resistance profiles. A significant temporal association was found (Cramér’s V = 0.43), with 2024 marked by a sharp decline in MDR isolates and a predominance of XDR and PDR phenotypes, reflecting an advanced resistance profile. Specimen-type analysis showed tracheal aspirates as the main reservoir for resistant strains, followed by urine and blood cultures, with a weaker but meaningful association (Cramér’s V = 0.24). Conclusions: These findings reveal a change in resistance patterns in ICU-acquired K. pneumoniae infections, with MDR strains being displaced by XDR and PDR phenotypes. These findings highlight the urgent need for time- and specimen-informed resistance monitoring and adaptive antimicrobial stewardship. Without targeted interventions, gains made in controlling MDR strains risk being rapidly eclipsed by the spread of highly resistant organisms. Full article