European journal of microbiology & immunology最新文献

Dengue is a serious epidemic for Bangladesh affecting thousands of lives. This study aimed to identify and determine the prevalence of the circulating variants of dengue virus (DENV) and their association with demographics and clinical manifestations among the dengue-infected patients. A total of 711 participants with NS1 antigen positivity were enrolled, followed by viral RNA extraction from the collected blood samples and a multiplex real-time reverse transcription-polymerase chain reaction (RT-PCR) assay to determine the dengue virus serotypes. Of 711 dengue-infected patients, 503 (70.7%) were male. Among different age groups, most of the patients were 21-30 years old (n = 255, 35.9%). The DENV2 (n = 483, 67.9%) serotype was more prevalent than the DENV3 (n = 144, 20.3%) and DENV1 (n = 84, 11.8%). The duration of fever was highest in the DENV-1 patients (4.79 ± 1.84 days) in contrast to DENV-3 (4.48 ± 1.68 days) and DENV-2 (4.33 ± 1.45 days) (P = 0.039). Importantly, five highly populated areas were identified as dengue hotspots in Chittagong metropolitan city. Our results provide crucial insights into the patterns of dengue virus transmission and severity among southern Bangladeshi population, thereby aiding in the development of targeted public health interventions and management strategies to combat future outbreaks.

Cell cultures are models in biological and medical research to understand physiological and pathological processes. Cell lines are not always available depending on cell type and required species. In addition, the immortalization process often affects cell biology. Primary cells generally maintain a greater degree of similarity in short-term culture to the cells in tissue. Goal of this study was to verify the suitability of chicken primary epithelial caecal cells (PECCs) for in vitro investigations of host‒pathogen interactions. Epithelial nature of PECCs was confirmed by detection of tight and adherens junctions and cobblestone-like cell morphology. Sialic acids distribution was similar to that in caecal cyrosections. To understand the capacity of PECCs to respond to microbial challenges, the Toll-like receptors (TLRs) repertoire was determined. Exposure of PECCs to polyinosinic-polycytidylic acid (poly(I:C)) or lipopolysaccharide (LPS) led to upregulation of type I and III interferon (IFN) as well as interleukin (IL-) 1β, IL-6 and IL-8 mRNA expression. Overall, the PECCs showed properties of polarized epithelial cells. The presence of TLRs, their differential expression, as well as pattern recognition receptor dependent immune responses enable PECCs to act as suitable in vitro model for host‒pathogen interaction studies, which are difficult to conduct under in vivo conditions.

Serious risks to human health are posed by acute campylobacteriosis, an enteritis syndrome caused by oral infection with the food-borne bacterial enteropathogen Campylobacter jejuni. Since the risk for developing post-infectious autoimmune complications is intertwined with the severity of enteritis, the search of disease-mitigating compounds is highly demanded. Given that benzoic acid is an organic acid with well-studied health-promoting including anti-inflammatory effects we tested in our present study whether the compound might be a therapeutic option to alleviate acute murine campylobacteriosis. Therefore, microbiota-depleted IL-10-/- mice were perorally infected with C. jejuni and received benzoic acid through the drinking water from day 2 until day 6 post-infection. The results revealed that benzoic acid treatment did not affect C. jejuni colonization in the gastrointestinal tract, but alleviated clinical signs of acute campylobacteriosis, particularly diarrheal and wasting symptoms. In addition, benzoic acid mitigated apoptotic cell responses in the colonic epithelia and led to reduced pro-inflammatory immune reactions in intestinal, extra-intestinal, and systemic compartments tested on day 6 post-infection. Hence, our preclinical placebo-controlled intervention trial revealed that benzoic acid constitutes a promising therapeutic option for treating acute campylobacteriosis in an antibiotic-independent fashion and in consequence, also for reducing the risk of post-infectious autoimmune diseases.

Background: Waning immunity and emergence of new variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), highlight the need for further research in vaccine development.

Methods: A recombinant fusion protein containing the receptor-binding domain (RBD) fused to the human IgG1 Fc (RBD-Fc) was produced in CHO-K1 cells. RBD-Fc was emulsified with four adjuvants to evaluate its immunogenicity. The RBD-specific humoral and cellular immune responses were assessed by ELISA. The virus neutralizing potency of the vaccine was investigated using four neutralization methods. Safety was studied in mice and rabbits, and Antibody-Dependent Enhancement (ADE) effects were investigated by flow cytometry.

Results: RBD-Fc emulsified in Alum induced a high titer of anti-RBD antibodies with remarkable efficacy in neutralizing both pseudotyped and live SARS-CoV-2 Delta variant. The neutralization potency dropped significantly in response to the Omicron variant. RBD-Fc induced both TH2 and particularly TH1 immune responses. Histopathologic examinations demonstrated no substantial pathologic changes in different organs. No changes in serum biochemical and hematologic parameters were observed. ADE effect was not observed following immunization with RBD-Fc.

Conclusion: RBD-Fc elicits highly robust neutralizing antibodies and cellular immune responses, with no adverse effects. Therefore, it could be considered a promising and safe subunit vaccine against SARS-CoV-2.

Acquired benign tracheoesophageal fistulas and bronchoesophageal fistulas (TEF) are typically associated with granulomatous mediastinal infections, 75% of which are iatrogenic. Candida albicans and Actinomyces are commonly occurring organisms, but are uncommon etiologies of TEF. Normal colonization and the slow growth characteristics of some species of these agents rarely result in infection, mycetoma, and broncholithiasis, and thus, delays in diagnosis and treatment are likely. Few reports describe C. albicans or Actinomyces spp. as the etiology of TEF or broncholithiasis. Herein, we report a case of benign acquired TEF secondary to coinfection of Candida and Actinomyces complicated by the formation of an actinomycetoma and broncholithiasis and a comprehensive literature review to highlight the unique nature of this presentation and offer a diagnostic algorithm for diagnosis and treatment of TEFs. Following a presentation of three months of productive cough, choking sensation, night sweats, and weight loss, a bronchoscopy revealed a fistulous connection between the esophagus and the posterior right middle lobe. Pathology identified a calcified fungus ball and a broncholith secondary to the co-infection of Candida and Actinomyces. This unique presentation of Candida and Actinomyces co-infection and the associated diagnostic algorithm are presented as education and a useful tool for clinicians.

Abdominal pain has been rarely reported in individuals infected with Toxoplasma gondii (T. gondii). The aim of this study was to determine the association between T. gondii infection and abdominal pain. Two hundred and ninety-nine patients with abdominal pain (cases) and 299 age- and gender-matched people without abdominal pain (controls) were tested for anti-T. gondii IgG and IgM antibodies. Twenty-four (8.0%) of the 299 cases and 12 (4.0%) of the 299 controls were positive for anti-T. gondii IgG antibodies (OR: 2.08; 95% CI: 1.02-4.25; P = 0.03). The seroprevalence of T. gondii infection was significantly higher in women with frequent abdominal pain than in women without this clinical feature (OR: 2.30; 95% CI: 1.06-4.96; P = 0.02). Twelve (4.0%) of the 299 cases and 7 (2.3%) of the 299 controls had high (>150 IU mL-1) anti-T. gondii IgG antibody levels (OR: 1.74; 95% CI: 0.67-4.49; P = 0.24). Seven (29.2%) of the 24 cases with anti-T. gondii IgG antibodies and 3 (25.0%) of the 12 controls with anti-T. gondii IgG antibodies were positive to anti-T. gondii IgM antibodies (OR: 1.23; 95% CI: 0.25-5.97; P = 1.00). Results suggest an association between T. gondii infection and frequent abdominal pain. Further research to confirm this association should be conducted.

Introduction: Over the past decade, enterococcal bloodstream infection (BSI) shows increasing incidence globally among the elderly and in patients with comorbidities. In this study, we aimed to assess microbiological and clinical characteristics and long-term outcomes of BSIs caused by Enterococcus spp. in adult patients with and without active onco-hematological malignancies hospitalized at a national referral institute.

Methods: A prospective analysis of consecutive enterococcal BSI cases was conducted in the National Institute of Hematology and Infectious Diseases (Budapest, Hungary) between December 2019 and April 2022. We compared characteristics and outcomes at 30-days and 1 year after diagnosis among patients with and without onco-hematological malignancies.

Results: In total, 141 patients were included (median age 68 ± 21 years, female sex 36.9%), 37% (52/141) had active onco-hematological malignancies. The distribution of species was as follows: 50.4% Enterococcus faecalis, 46.1% Enterococcus faecium, 1.4% Enterococcus avium and Enterococcus gallinarum, and 0.7% Enterococcus raffinosus. No statistically significant differences in all-cause mortality rates were observed between patient subgroups at 30 days (32.7 vs. 28.1%; P = 0.57) and 1 year (75.0 vs. 60.7%; P = 0.09).

Conclusion: Enterococcal bloodstream infections yielded a relevant burden of morbidity, but with no statistical difference in long-term outcomes of adult patients with and without active onco-hematological malignancies.

In recent years, the incidence of food-borne bacterial enteric diseases has increased worldwide causing significant health care and socioeconomic burdens. According to the World Health Organization, there are an estimated 600 million cases of foodborne illnesses worldwide each year, resulting in 420,000 deaths. Despite intensive efforts to tackle this problem, foodborne pathogenic microorganisms continue to be spread further. Therefore, there is an urgent need to find novel anti-microbial non-toxic compounds for food preservation. One way to tackle this issue may be the usage of polyphenols, which have received increasing attention in the recent years given their pleotropic health-promoting properties. This prompted us to perform a literature search summarizing studies from the past 10 years regarding the potential anti-microbial and disease-alleviating effects of plant-derived phenolic compounds against foodborne bacterial pathogens. The included 16 studies provide evidence that polyphenols show pronounced anti-bacterial and anti-oxidant effects against both Gram-positive and Gram-negative bacterial species. In addition, synergistic anti-microbial effects in combination with synthetic antibiotics were observed. In conclusion, phenolic compounds may be useful as natural anti-microbial agents in the food, agricultural, and pharmaceutical industries in the combat of foodborne infections.