Epidemiologie Mikrobiologie Imunologie最新文献

Corynebaterium (C.) durum is a part of the resident human oral microbiota. Its role in the aetiology of infectious diseases is ambiguous. With the increasing number of immunocompromised patients, it must be considered a potential opportunistic pathogen. It is isolated from the sputum, bronchoalveolar-lavage fluid, as well as blood, especially from immunocompromised patients with pneumonia. In that case, the critical steps involve a correct identification of Corynebacterium to the species level and right interpretation of the findings. The previously widely used commercial test for the identification of Corynebacteria (API Coryne, BioMerieux) is not suitable for all species, including C. durum, as its biotype number is not included in the database. But the obtained result can be compared with the available literature data. Chemotaxonomic and proteomic analysis (matrix-assisted laser desorption/ ionization - time of flight, MALDI-TOF MS) or 16S rRNA sequencing allow for accurate differentiation from the other Corynebacteria species. Nevertheless, these methods are not routinely used in clinical laboratories. A polyphasic approach to the taxonomy based on the data from combined laboratory tests is crucial.

Objective: Pregnancy is not considered a condition that increases the body's susceptibility to SARS-CoV-2 (severe-acute-respiratory-syndrome-related coronavirus-2) infection, but in the case of infection in pregnancy, there is an increased risk of a more severe course of COVID-19 (coronavirus disease-19). However, the course of infection in pregnancy is mild or asymptomatic in most cases. The main objective of the study in pregnant women with COVID-19 was to prove that the delivery method is not changed, and serious complications do not occur more frequently due to this disease.

Methods: In a retrospective, observational, multicentric study, the pregnant women positively tested to COVID-19 were admitted and subsequently gave birth in the period from 15 March 2020 to 15 March 2021. Data from the delivery departments of five centers in the Czech Republic during COVID-19 pandemic were analyzed in relation to the delivery method and time, COVID-19 symptoms and potential complications with respect to demographics and comorbidities of pregnant women. COVID-19 positivity was confirmed with PCR (polymerase-chain reaction). The Excel program was used during statistical analysis.

Results: During the observed study period, 236 pregnant women with COVID-19 were detected at study centers. Most of the patients were asymptomatic (59.7%). In symptomatic patients, most common symptoms were cough (52.6 %), cold (43.2%) and fever (37.9%), and COVID-19 pneumonia was diagnosed in 8 patients. The delivery was performed vaginally in 52.5% patients, the pregnancy was terminated by C-section (cesarean section) in 44.5%, per VEX (vacuum extractor) in 2.1% and per forcipem in 0.8% cases. The average week of pregnancy at the time of delivery was 38 (29-41) and preterm delivery was performed in 19.1% patients. The study results in pregnant women with COVID-19 demonstrated that the method of delivery was not changed and major delivery and neonatological complications did not develop in most cases. However, two presented serious courses of COVID-19 in pregnant women led to premature terminations of pregnancies. The only associated risk factor was the patient's obesity.

Conclusions: Although COVID-19 is a disease that is mostly asymptomatic in pregnant women or with only mild flu-like symptoms, it is associated with increased morbidity and mortality compared to pregnant women without COVID-19. The challenge for the future is the possibility of segregating patients into lowand high-risk groups based on proven risk factors, and consistent vaccination of pregnant women or women planning conception. In critical cases, the correct timing of premature termination of pregnancy and early indication of the beginning of fetal lung maturation is necessary.

Objective: To analyse the impact of the COVID-19 pandemic on the epidemiological situation of invasive meningococcal disease (IMD) and molecular characteristics of Neisseria meningitidis isolates causing IMD in the Czech Republic.

Material and methods: The study was based on IMD surveillance data for 2018-2024 (as of 27 May 2024), and all available N. meningitidis isolates from IMD of these years were subjected to whole genome sequencing (WGS). To analyse the impact of the COVID-19 pandemic, the study period was divided into three parts: the pre-COVID period (2018-2019), the COVID-19 pandemic period (2020-2022), and the post-COVID period (2023-2024).

Results: As a result of the implementation of the COVID-19 control measures, similar to other countries, there has been a decline in the incidence of air-borne infections including IMD in the Czech Republic. However, unlike many other countries, there has not been a resurgence of IMD in the Czech Republic following the release of these epidemiological measures. WGS characterisation of IMD isolates showed a gradual change in the population of meningococci causing IMD in the Czech Republic during the COVID-19 and post-COVID periods. For N. meningitidis isolates of serogroups C, W, and Y, a gradual and significant decline in overall heterogeneity can be observed - from ten different clonal complexes detected in the pre-COVID period to only three in the post-COVID years (cc11, cc23, and cc103). At the same time, a significant reduction was observed in N. meningitidis C isolates; cc11. In contrast, an increase in overall heterogeneity can be observed for N. meningitidis B isolates during the COVID-19 pandemic period, followed by its decline again to overall lowest values in the post-COVID period.

Conclusion: The fact that MenB vaccine and conjugate vaccine A, C, W, Y started to be covered by health insurance for young children (in May 2020) and adolescents (in January 2022) also appears to play a role in the persistent decline of IMD in the Czech Republic. In order to maintain the low incidence of IMD in the Czech Republic, it is desirable to continue vaccination with MenB vaccine and conjugated vaccine A, C, W, Y in accordance with the recommendations of the Czech Society of Vaccinology of the Czech Medical Association of Jan Evangelista Purkyně.

The aim was to compare the general practitioners' attitudes towards pertussis vaccination in pregnancy in the South Moravian Region in 2019 and 2024. Using a questionnaire survey, a significant increase was found in active recommendation of vaccination, in the interest from pregnant women and in vaccinations completed in general practitioners' offices. The main factors behind this shift were increased media coverage of pertussis and growing awareness of the importance of vaccination for the protection of young children. The results point to the need to promote interdisciplinary collaboration between GPs and gynaecologists and to consider the possibility to cover vaccination by health insurance.

Aim: More than one million people are estimated to be infected by Leishmania annually worldwide. Due to the high movement of people and animals in today's globalized world as a result of tourism, migration, war conflicts, and/or climate change, the spread of leishmaniasis to new areas previously regarded as non-endemic has recently been reported. The emergence of phlebotomine sandflies, vectors of Leishmania, in neighbouring countries triggered our interest in leishmaniasis cases reported to the EPIDAT and ISIN databases in the Czech Republic between 1997 and 2024.

Materials and methods: Summary data on the cases reported to the EPIDAT and ISIN databases under the ICD-10 code B55 Leishmaniasis in 1997-2024 were analysed by country of import, travel purpose, nationality, age, sex, reporting date, disease form, agent of infection, and case fatality.

Results: Between 1997 and 2024, a total of 45 cases of leishmaniasis were reported, 40 of which in Czech citizens. Most cases were imported from the European Union (16) and Latin America (13) countries. Men were 3.5 times more often affected than women (ratio 7:2). The patients were mainly Czech citizens returning from travel abroad (24 men, seven women). The most common form of the disease, if indicated, was cutaneous leishmaniasis (17 cases). None of the cases was reported in the age groups under 1 year and 70 years and older. The causative Leishmania species was only indicated in four cases. One death associated with leishmaniasis was reported (case fatality rate 2.2 %).

Conclusions: The number of cases reported annually remained more or less constant between 1997 and 2024. However, more cases might emerge in the future due to increased movement of people and animals and/or climate change. Therefore, it is important to promote the One Health approach and consider the introduction of leishmaniasis surveillance in the Czech Republic.

Aim: We aimed to determine the prevalence of SARS-CoV-2 infection, including both symptomatic and asymptomatic courses, and to identify predictors of asymptomatic or symptomatic SARS-CoV-2 infection in patients within seven months after allo-HSCT (allogenic hematopoietic stem cell transplantation) in the Omicron period.

Methods: Prevalence of the past SARS-CoV-2 infection was determined in patients within seven months after allo-HSCT in the Omicron period using the cellular and humoral immune response against the SARS-CoV-2 nucleoprotein (NCP).

Results: Positive markers of past infection were identified in 45.2% of patients (n = 42). The infection was asymptomatic in 68.4% of anti-NCP positive patients. The search for risk factors for symptomatic SARS-CoV-2 infection in allo-HSCT recipients revealed that a low level of B cell reconstitution was the only significantly associated risk factor.

Conclusion: A high proportion of allo-HSCT recipients who were asymptomatically infected within up to seven months after transplantation from 2022 to 2023 despite being immunosuppressed and unvaccinated indicates an attenuation of the circulating virus and may signal less risk for transplanted patients from SARS-CoV-2 infection in the Omicron period. Vaccination of these patients against SARS-CoV-2 was shown to be associated with a low but significant risk of exacerbation of cured chronic GVHD (graft versus host disease) and the risk of de novo GVHD. The low level of B-cell reconstitution was the only significant risk factor for symptomatic SARS-CoV-2 infection in HSCT recipients.

Objective: Observational study of patients diagnosed with severe community acquired pneumonia (sCAP) carried out to evaluate levels of interleukin 17A (IL-17A) and T helper 17 (Th17) lymphocyte count in peripheral circulation and bronchoalveolar lavage fluid (BALF) in the early course of sCAP of different etiology and to compare them with patient's characteristics and outcome.

Material and methods: Cohort of 74 patients with sCAP was analyzed and respective microbial etiology established. According to pathogens, 3 subgroups of patients were created: bacterial, viral and mixed etiology. Th17 count and IL-17A levels were measured using flow cytometry and ELISA in peripheral blood and BALF. Data were compared with respect to etiology and their correlation with 30and 90-day mortality was statistically analyzed.

Results: There was no statistically significant correlation in Th17 count and IL-17A levels in blood and BALF between etiological subgroups of CAP and no correlation was found with respect to measured parameters and 30and 90-day mortality. Nevertheless, increased Th17 cell count and IL-17A levels in peripheral blood, but not in BALF, in the early course of sCAP are correlated with increased relative risk of death from sCAP. Other factors increasing relative risk of death in patients with sCAP found in our cohort were male sex and advanced age.

Conclusions: Systemic Th17 count and IL-17A levels in the early course (up to 7 days from admission) of sCAP may be correlated with severity and outcome of sCAP.

Objective: The aim of our study was to describe and analyze HAI incidence, etiology and risk factors in pediatric intensive care unit (ICU).

Background: Intensive care patients are at high risk of hospital-acquired infections (HAI) due to their underlying diseases and exposure to invasive devices.

Methods: The study group consisted of patients admitted to children's hospital ICU for more than 2 days during a six-month period (267 patients, 1570 patient-days). We used the European Centre for Disease Prevention and Control standard protocol HAI-Net ICU v2.2 for data collection.

Results: HAI occurred in 17 (6.4%) included patients (10.8 infections per 1000 patient-days). The most frequent were catheter-related bloodstream infections (33%, 7.6 per 1000 catheter-days) and intubation-associated pneumonia (25%, 10.9 per 1000 intubation-days). Gram-negative bacteria (Pseudomonas aeruginosa, Klebsiella spp.) were identified as the most common etiological agents. Significantly higher risk of HAI had patients with central venous catheter (OR: 14.5, 95% CI 3.2-65.1), intubated (OR: 14.4, 95% CI 4.4-46.2), with Pediatric Index of Mortality score higher than 10 (OR: 17, 95% CI 2.7-111.5) and with previous bacterial or/ and fungal colonization (OR: 30.6, 95% CI 9.2-101.3).

Conclusions: Active surveillance identified unreported HAI cases and proved to be an effective tool of infection control.

Aim: To determine the occurrence of species of Babesia potentially pathogenic for humans in ticks and in the blood of dogs and deer in selected regions of the Czech Republic. To compare the prevalence of Babesia spp. in ticks with that of other tick-borne pathogens, such as Borrelia spp., Anaplasma spp., and Rickettsia spp.

Material and methods: Tick samples were individually homogenized. DNA was isolated from tick samples and animal blood. The detection of Babesia spp. was based on PCR of the 18S rRNA gene, and the identification to the species level was done by sequencing analysis of the PCR products.

Results: In 2014-2016, ticks and blood of dogs and deer collected in various areas of the Czech Republic were analyzed. In a set of 675 Ixodes ricinus ticks, the positivity rate for Babesia spp. varied from 0.0 to 3.3 %. The species Babesia venatorum, Babesia microti (both pathogenic for humans), and Babesia capreoli were identified in ticks by sequencing analysis. The prevalence of Babesia spp. in ticks compared to that of other pathogens such as Borrelia burgdorferi s. l. (29.3 %) or Anaplasma phagocytophilum (4.9 %) was lower and comparable to that of Rickettsia spp. (1.6 %). Co-infection with Borrelia burgdorferi s.l (B. venatorum - Borrelia garinii, Borrelia afzelii, and B. microti - B. afzelii) was found in a third of Babesia spp. positive ticks. Out of 109 dog blood samples, 3.7 % were positive for Babesia spp., specifically Babesia gibsoni and Babesia vulpes. Of 50 blood samples of wild deer from the natural ecosystem, the positivity rate reached 4.0 %. The species Babesia divergens, a major human pathogen, was identified. Out of 80 blood samples from farmed deer, 5.0 % were positive for the species Babesia odocoilei. Nucleotide sequences of the agents causing human babesiosis were deposited in the gene bank under accession numbers ON892053 (B. venatorum), ON892061 (B. microti), and ON892067 (B. divergens).

Conclusions: Using PCR of the 18S rRNA gene and amplicon sequencing, three species of Babesia causing human babesiosis were detected in the Czech Republic: B. divergens, B. venatorum, and B. microti. Babesia spp. pathogenic for humans pose a potential risk especially in asplenic and immunocompromised patients. The detected co-infections with Borrelia spp. can be the cause of a complicated course of the disease.

Tularemia is a zoonosis caused by Francisella tularensis, a gram-negative aerobic bacterium belonging to the class of Gammaproteobacteria and the family Francisellaceae. Despite its undeniable importance for human health, there is little data on the current distribution of F. tularensis in various hematophagous arthropods. The aim of this study was to perform a mass molecular screening of different possible hematophagous vectors: ticks (4348 ticks of the species Ixodes ricinus, Dermacentor reticulatus, and Haemaphysalis concinna), mosquitoes (4100 specimens of Aedes vexans), and blackflies (6900 specimens of the Simulium spp.) for the presence of F. tularensis in the Břeclav district in 2022. Only two specimens were positive for the specific DNA of Francisella tularensis subsp. holarctica. Both samples originated from D. reticulatus, one collected from infested roe deer and the other included in a pooled sample (n = 10). Both positive samples were sequenced, and the presence of F. tularensis subsp. holarctica was confirmed. In addition, the absence of F. tularensis in mosquitoes and black flies was documented.