Pathogens最新文献

Diagnosis of rickettsial infections is challenging due to nonspecific clinical symptoms and limitations of current diagnostic methods. Molecular assays allow early detection but are limited by cost and technical demands, whereas conventional serological tests often exhibit cross-reactivity and low sensitivity during the early stages of infection. This study aimed to develop and evaluate a recombinant-antigen sandwich ELISA for improved antibody detection against Rickettsia spp. Three Rickettsia akari proteins, rGroEL, rDnaK, and rA8GP63 (uncharacterized protein), were produced and validated for immunogenicity. The assay was evaluated using 94 patient serum samples, including those with positive, negative, and unknown clinical course. The optimized ELISA demonstrated high reproducibility, with IgG sensitivity of 89.47-95.39% and specificity of 90%. IgM detection, also assessed, showed lower sensitivity (42.11-82.89%) but maintained strong specificity (83.33%). The diagnostic performance was comparable to that of a commercial indirect immunofluorescence assay, with no cross-reactivity detected in sera from patients with unrelated infections. rDnaK and rA8GP63 represent newly explored diagnostic candidates. These findings highlight the potential of this recombinant protein-based ELISA as an accessible, sensitive and specific diagnostic tool, with a meaningful clinical impact for improving the early and accurate detection of rickettsial infections.

Ceftazidime-avibactam (CA) and CA plus aztreonam (ATM) are the preferred treatment options for KPC and MBL carbapenemase-producing Enterobacterales infections (CPEis). All episodes of monomicrobial CPEis in immunosuppressed patients (IPs) admitted from May 2019 to November 2024, who received definitive antibiotic therapy (AT) with CA or CA + ATM for at least 72 h, were prospectively included. Bacteremic episodes (BEs) and non-bacteremic episodes (NBEs) were compared. Logistic regressions adjusted by propensity score were used to identify variables associated with 30-day overall mortality. In total, 82 CPEis were included (38 NBEs and 44 BEs). BEs more frequently occurred in hematological malignancies (52.3% vs. 15.8%, p = 0.0006), while NBEs were more commonly observed in solid organ transplantation (73.7% vs. 34.1%, p = 0.001). K. pneumoniae was the main isolated microorganism; KPC-CPE was the most common resistance mechanism in both groups, followed by MBL-CPE. The 7-day clinical response, 30-day overall and infection-related mortality between NBEs and BEs were 92.1% vs. 88.6%, p = 0.59, 10.5% vs. 27.3%, p = 0.09, and 2.6% vs. 13.6%, p = 0.11. Septic shock, OR 6.5, 95% CI, 1.58-26.72 (p = 0.01), and refractory malignancy, OR 5.6, 95% CI, 1.03-30.14 (p = 0.046), were associated with 30-day mortality, whereas BEs were not, OR 1.5, 95% CI, 0.36-6.2 (p = 0.56). CPEis in both NBE and BE IPs who received definitive AT with CA or CA + ATM correlated with a high rate of 7-day clinical response and low 30-day infection-related mortality. Underlying malignancy and disease severity were associated with 30-day overall mortality. Regional knowledge of bacterial antibiotic resistance enables the implementation of individualized AT to improve patient survival.

Pulmonary diseases caused by nontuberculous mycobacteria are increasingly becoming common worldwide and are occurring more frequently alongside pulmonary tuberculosis. Given that pulmonary diseases resulting from nontuberculous mycobacteria and pulmonary tuberculosis display similar features-such as clinical manifestations, imaging findings, and laboratory results-the accurate differentiation of each disease type is highly challenging. Mycobacterial culture, as a gold standard method, cannot be considered completely trustworthy because of low bacterioexcretion rates among nontuberculous mycobacterial pulmonary patients. Additional problems result from poor diagnosis. The treatment of lung diseases caused by nontuberculous mycobacteria is also difficult. This could be due to the wide spectrum of bacteria belonging to nontuberculous mycobacteria, as well as low bacterioexcretion. Therefore, bacterial sensitivity to drugs is insufficient. As a result, in this article, our intention is to explain the diagnostic difficulties of pulmonary diseases caused by nontuberculous mycobacteria and the Mycobacterium tuberculosis complex. The review seeks to outline promising directions for the development of novel diagnostic approaches in order to improve clinical decision-making and ultimately treatment outcomes.

Despite the economic importance of Mizuhopecten yessoensis, little is known about their parasites and immunity. This study, the first to examine the prevalence and intensity of Perkinsus across three age groups of scallops from four locations in the Sea of Japan, revealed that the gills, mantle, and digestive glands of one-year-old specimens from mariculture farms are heavily colonized. The cases of infection were notably higher in older specimens (mostly hemolymph and shell), suggesting that they act as carriers of Perkinsus. An immunological analysis indicated that when the pathogen is found only in the hemolymph and mantle, there is an increase in plasma protein concentrations, which likely plays a crucial role in resisting infection. However, when hypnospores were present in the mantle and gills, a decrease in reactive oxygen species and granulocytes occurred, accompanied by an increase in hemoblasts and agranulocytes. Phagocytic activity increased only when the pathogen appeared in the digestive gland. This evidence highlights the heightened vulnerability of young scallops, emphasizing the necessity for preventive measures against infection. The current troubling epidemiological situation regarding scallop diseases in the region suggests a rise in epizootics, raising doubts about the sustainability of the scallop farming industry unless timely interventions are implemented.

Bacterial contaminants in ambulances could have a major impact on morbidities, mortalities, and healthcare resources, especially if these bacteria are antimicrobial-resistant. As far as we know, this is the first study in Al-Qassim region to evaluate the prevalence of bacterial contaminants in swab samples obtained from ambulances from Alqwarah General Hospital, Al-Qassim region, Saudi Arabia as an indicator for evaluation of the implemented infection control measures, and screen the antibiotics profiles of the isolates against the most regularly used antimicrobials. In total, 204 samples were collected from the ambulances following patient transport. To evaluate the effect of vehicle decontamination, 204 swabs were collected from the same sites of the ambulances immediately after cleaning and disinfection. The isolates were identified using standard bacteriological and biochemical methods, as recommended by the Clinical Laboratory Standard Institute (CLSI). The antibiotic susceptibility patterns were assessed using the Kirby-Bauer disc diffusion method. The prevalence of bacterial contamination in the samples collected following patient transport was 46.08%. In total, 83.33%, 75.00%, and 66.66% of the samples collected from DC shock apparatuses, ceilings, and emergency personnel seats, respectively, were contaminated. Furthermore, ceilings, DC shock apparatuses, emergency personnel seats, cervical collars, and monitors were found to harbor 10.8%, 9.8%, 7.8%, 6.8%, and 6.8% of the 102 bacterial isolates, respectively. Gram-positive organisms represented 96.1% of all bacterial isolates. Bacillus spp. was the most common isolate, accounting for 60.8% of all bacterial isolates. Although Pseudomonas aeruginosa and Proteus spp. isolates were sensitive to all the tested antimicrobials, many Gram-positive bacterial isolates were resistant to some antibiotics in variable frequencies. After 48 h of aerobic incubation (with or without 5-10% CO₂) on nutrient, blood, chocolate, and MacConkey agar plates at 37 °C, no bacterial growth was detected in the samples collected immediately following cleaning and disinfection. This is the second Saudi study to evaluate the prevalence of bacterial contaminants in Saudi Arabian ambulances, and it could help health policy makers in improving the implemented infection prevention and control measures in Saudi Arabian ambulances. The samples taken after patient transport revealed bacterial contaminants with varying rates of antimicrobial resistance. Policies ensuring the optimal cleaning and disinfection of ambulances can minimize the potential of bacterial infection for high-risk patients, their relatives, and healthcare providers.

Visceral leishmaniasis (VL) is a severe zoonotic disease characterized by high mortality and a pronounced systemic inflammatory response. Although Pentraxin 3 (PTX3) has been implicated in infectious and inflammatory disorders, its role in human VL remains poorly defined, and host-derived indicators that simultaneously reflect inflammatory and parasitic activity are limited. This study investigated the association between plasma PTX3 levels, parasite load, and PTX3 gene polymorphisms (rs1840680 and rs2305619) in patients with VL. An observational study was conducted between 2017 and 2021, including 36 patients with confirmed VL and 45 healthy controls matched by age and sex. Plasma PTX3 concentrations were determined by ELISA, parasite load by quantitative PCR (qPCR), and cytokines (IL-2, IL-6, IL-10, IL-17A, IFN-γ and TNF-α) by flow cytometry. PTX3 levels were significantly higher in VL patients than in controls (23.2 ng/mL vs. 0.80 ng/mL; p < 0.0001) and correlated positively with parasite load (r = 0.39; p = 0.02) and cytokines IL-6, IL-10 and IFN-γ. No associations were observed between PTX3 polymorphisms and disease susceptibility. These findings suggest that PTX3 reflects both inflammatory responses and parasitic burden in VL and may serve as a potential indicator of disease activity.

Measles, also known as rubeola, is a highly contagious and potentially life-threatening disease caused by the measles virus. It classically presents with fever, cough, coryza, conjunctivitis, and a maculopapular rash. Despite the availability of an effective vaccine for decades, measles outbreaks continue to occur globally, largely driven by declining vaccination coverage and increased international travel. With no specific antiviral therapy available, rapid and accurate diagnosis remains essential for timely clinical management and effective outbreak control. Diagnostic methods have evolved from traditional virus isolation in cell culture to serologic assays and, more recently, to molecular techniques such as real-time reverse transcriptase polymerase chain reaction (rRT-PCR). Each diagnostic method has unique advantages and limitations influenced by specimen type, timing of collection, and laboratory capacity. This minireview summarizes the progress of measles virus diagnostics, outlines current laboratory detection strategies, and discusses emerging technologies and ongoing challenges amid global measles resurgence and increasing public health demands.

People who use crack cocaine (PWUCC) constitute a key population due to vulnerability and marginalization, especially in a socio-ecologically diverse, relatively isolated region with limited public health infrastructure. This study aimed to perform a genetic characterization of circulating HCV among PWUCC in the municipality of Bragança, situated on the Brazilian Amazon coast, identifying viral genotypes, subtypes, resistance-associated substitutions (RAS)-naturally occurring mutations in the viral genome that can reduce the efficacy of direct-acting antiviral (DAA) agents-and predictions of phenotypic resistance.

Methods: Between 2016 and 2018, biological samples and epidemiological data were obtained from 165 PWUCC. Viral detection was performed using RT-PCR, while genotyping, subtyping, and RAS profiling were conducted through nucleotide sequencing and fragment analysis.

Results: In 165 PWUCC, 22 (13.3%) tested positive for HCV RNA. Most of them had not had access to public health services (91.5%), and more than half (57.0%) reported living in unstable housing conditions. HCV subtypes 1a (27.3%), 1b (40.9%), and 3a (31.8%) were detected. Evidence of resistance associated with DAAs, such as daclatasvir and dasabuvir, was detected in five PWUCC with HCV (22.7%).

Conclusions: The high prevalence of HCV infection, predominantly subtype 1b, and significant levels of resistance are very concerning. This demonstrates the urgent need for targeted public health interventions to expand access to testing, treatment, and effective antiviral therapy in this vulnerable population of the Brazilian Amazon.

Urinary tract infections are among the most common bacterial infections worldwide, with increasing antimicrobial resistance posing a significant public health challenge. This study aimed to determine the demographic distribution, antimicrobial susceptibility patterns of uropathogens, and the clinical implications of UTIs in patients with renal comorbidities in the Al-Baha region of Saudi Arabia. A retrospective, cross-sectional study was conducted at King Fahad Hospital, Al-Baha, from January 2021 to September 2022. A total of 1126 culture-positive UTI cases were included. Patient demographics, uropathogen distribution, antimicrobial resistance profiles, and clinical characteristics were extracted from hospital records. Subgroup analysis was performed for 32 patients with renal comorbidities, including end-stage renal disease (ESRD), glomerulonephritis (GN), and kidney transplant recipients (KTs). Statistical analysis was performed using SPSS version 25. Most cases occurred in patients aged >70 years (43.2%) and females (68.29%). Escherichia coli (38.09%) and Klebsiella pneumoniae (14.02%) were the leading pathogens. High resistance to ampicillin (47-67%), cotrimoxazole (35-37%), and third-generation cephalosporins (34-47%) was observed, whereas carbapenems and aminoglycosides remained largely effective. Among the 32 patients with renal comorbidities, E. coli (43.8%), Staphylococcus aureus (25%), and Enterococcus spp. (18.8%) were the most common isolates. Dysuria (46.87%) and fever (31.25%) were the most frequent clinical presentations. Treatment regimens in this subgroup often required multidrug combinations, reflecting higher resistance burdens. Uropathogens in the Al-Baha region shows rising resistance to first-line antibiotics, with vulnerable populations such as patients with renal comorbidities experiencing distinct pathogen distributions and treatment challenges. Continuous surveillance, prudent antibiotic use, and targeted strategies for high-risk patients are essential to mitigate the impact of multidrug-resistant UTIs in Saudi Arabia.

Glioblastoma (GB) is a highly aggressive brain tumor with a very poor prognosis. Treatment usually consists of surgery, followed by radiotherapy and chemotherapy, but the prognosis remains poor due to its resistance to therapies and a high recurrence rate. Multiple studies have reported the presence of human cytomegalovirus (HCMV) proteins and/or nucleic acids in GB tissues, suggesting its possible implication. These findings have led to the hypothesis that HCMV may contribute to tumor progression, immune evasion, angiogenesis, and resistance to therapy. Clinical trials using anti-HCMV therapies have shown promising preliminary results, indicating a potential therapeutic benefit. This review aims to provide a comprehensive overview of the current evidence linking HCMV to GB and the therapeutic implications. A deeper understanding of this complex interaction could unveil novel strategies for GB treatment.