Multilocular infection caused by hypervirulent Klebsiella pneumoniae.

Hypervirulent strains of Klebsiella pneumoniae (hvKP) can cause atypical multilocular infections in otherwise healthy patients. Diagnosis of infection caused by hvKP is based mainly on clinical findings and laboratory results, including detection of virulence genes. It typically manifests as hepatic abscess with metastatic spread. Treatment is based on surgical intervention in combination with targeted antimicrobial therapy. The occurrence of hvKP infection is relatively common in Asia, and while still rare in Europe, incidence is increasing. The article aims to provide a short overview of the issue and increase awareness of the possible occurrence of hvKP infections.

Data from the first wave of Covid-19 from the Central Military Hospital, Prague, Czech Republic.

AIMS: To process data from the first wave of Covid-19 caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) collected in the Infectious Diseases Clinic (IDC) of the First Faculty of Medicine and Central Military Hospital, Prague. To analyse some clinical, diagnostic and therapeutic aspects of Covid-19 in the context of the Czech Republic and to compare them with the data from the most recent literature. PATIENTS AND METHODS: This retrospective study analysed data on patients admitted to the IDC between 12 March 2020 and 5 May 2020. The study cohort included 53 patients with Covid-19, 25 females and 28 males, with an average age of 57 years. The parameters analysed were clinical symptoms, average length of hospital stay, complications, and death. Additional data concerned the age, weight, smoking habits, history of comorbidities, and selected laboratory results.  These data were compared between groups of patients differing in severity of the course of Covid-19. Finally, imaging findings, serology results, and therapy outcomes were studied. Statistical analysis was performed using the SigmaStat software. RESULTS: Eleven (20.8%) patients had a mild course of the disease, 16 (30.2%) patients had a moderate course, 22 (41.5%) patients had a severe course, and four (7.5%) patients had a critical course. The study patients presented with the following clinical symptoms: fever in 88.5% of cases, cough in 84.6% of cases, difficulty breathing in 77.4% of cases, diarrhoea in 23.1% of cases, chest pain in 17.3% of cases, and anosmia in 11.5% of cases. The average length of hospital stay was eight days. The most common complication was a bacterial superinfection, reported in 17 (32.1%) study patients. The overall case fatality rate for Covid-19 in our study was 5.7%. The average age of the study cohort was 57 years, and patients with a severe course of the disease were of older average age than those with a less severe course of the disease (p < 0.05). The predominant comorbidities were hypertension and diabetes mellitus. The analysis of the baseline laboratory data showed significant differences between the groups of patients differing in severity of the course of Covid-19 in CRP, procalcitonin, and d-dimers but not in lymphocyte count. High resolution computed tomography (HRCT) scan of the lungs was performed in 22 patients, and 21 of them had typical findings for Covid-19. The average MuLBSTA score for Covid-19 pneumonia severity in our study cohort was 11.5 points and was not associated with the severity of the course of the disease. Serology tests were performed in 43 study patients, with 29 (67.4%) of them turning out positive in the first test and other five (11.6%) testing positive when retested. Hydroxychloroquine (HCQ) was given experimentally as monotherapy or in combination with azithromycin (AZI) to 24 (45.3%) patients. Two patients on HCQ therapy also received inosinum pranobexum (isoprinosine) for severe lymphopenia, one patient received convalescent plasma, six patients were given AZI alone, and one patient was treated with inosinum pranobexum alone. Altogether 37.7% of study patients were prescribed other antibiotics for confirmed or suspected bacterial superinfection. Standard clinical and pharmaceutical care was provided to patients with particular focus on the safety of off-label drug use. HCQ was with drawn in three patients due to a prolonged corrected QT interval (QTc). CONCLUSIONS: In the first wave of the SARS-CoV-2 epidemic, our study patients showed comorbidities and risk factors which are consistent with the international literature, but the course of the disease was mostly moderate to severe, with a low proportion of critically ill patients and fatal outcomes. As soon as new information became available, new diagnostic and therapeutic options were introduced into routine practice. Based on our experience, we are well prepared for a possible second wave of SARS-CoV-2 in terms of the diagnostics, but the therapeutic options still remain very limited.

Antithrombin as a marker of severe acute hepatitis B.

BACKGROUND: Acute hepatitis B (AHB) can run a severe course, which sometimes leads to a fulminant disease with acute liver failure (ALF). Pro-coagulation factors are well-established markers of AHB severity, but less is known about the levels of anti-coagulation parameters in AHB. METHODS: In this study, we demonstrate that antithrombin (AT) plasma levels were associated with AHB severity in 161 patients. RESULTS: Nine (6%) patients had severe AHB (i.e. international normalized ratio [INR] ≥ 1.6 and total bilirubin ≥ 10 mg/dL). Coagulopathy (i.e. INR > 1.2 and/or AT < 80%) was observed in 65 (40%) AHB patients on admission. Low initial plasma AT levels (i.e. < 80%) were observed in 56 (35%) patients. In all, plasma AT levels decreased in 91 (57%) patients during their hospital stay. Both baseline and nadir AT levels were significantly lower in severe than in mild and moderate AHB. Moreover, the concentration of AT negatively correlated with INR, aspartate aminotransferase, and total and conjugated bilirubin levels. Interestingly, nadir AT levels positively correlated with the duration of hospitalization. CONCLUSIONS: These results indicate that plasma AT levels can be used as an additional marker of AHB severity.

Bacteremia due to Staphylococcus aureus - the importance of appropriate management.

Staphylococcus aureus bacteremia (SAB) is the most common cause of severe bloodstream infections with high incidence and lethality. The diagnosis of SAB must be followed by an appropriate diagnostic and therapeutic management. The aim of the study was to identify clinical and epidemiological characteristics of SAB cases treated in the Central Military Hospital Prague and to assess compliance with the guidelines for diagnosis and thera-py. A total of 65 patients with S. aureus blood culture positivity were enrolled in the retrospective study. Sixty SAB cases (92%) were caused by MSSA strains, and MRSA strains were detected in five patients (8%). The source of the infection was confirmed in 83% of patients. The average case fatality rate in the study cohort was 28%. The analysis of the quality of care suggested both diagnostic and therapeutic insufficiencies in 65% of SAB patients. Overall, the result of the study supports the importance of the role of infectious disease specialists played in the bedside management of patients with SAB.

[Toxoplasmosis in immunocompromised patients]. / Toxoplasmóza u imunokompromitovaných pacientu.

In humans, toxoplasmosis mostly occurs as a latent infection, but in immunocompromised individuals, the agent may reactivate and cause severe to life-threatening disease. HIV positive individuals and transplant recipients, in particular hematopoietic stem cell transplant and heart transplant recipients, are at highest risk. The disease most often affects the central nervous system but can involve any organ. Because of the alteration of the immune response in these patients, the serodiagnosis is not reliable and direct detection of the causative agent is needed--namely by microscopy and DNA PCR. If inadequately treated or left untreated, toxoplasmosis generally has a fatal prognosis in immunocompromised patients and therefore, the treatment must be started as early and energetically as possible. The gold standard both in the treatment of reactivation and secondary prophylaxis is the pyrimethamine-sulfadiazine combination while co-trimoxazole can be used in the primary prophylaxis for high-risk patients.

[A case of tuberculous meningitis associated with persistently reduced CD4+ T lymphocyte counts]. / Prípad tuberkulózní meningitidy provázené perzistujícím snízením CD4+ T lymfocytu.

A case history is presented of a 35-year-old man admitted to the hospital with tuberculous meningitis complicated by caseous necrosis of cervical lymph nodes and thrombosis of the left jugular vein. Another complication, malignant brain edema, appeared more than one year after discharge from hospital and was managed at the neurosurgery department. The most probable cause was a post-inflammatory obstruction of the cerebrospinal fluid pathways. A challenging finding, observed repeatedly while in hospital and at follow ups after discharge, was medium significant CD4+ T cell lymphopenia, with the lowest CD4+ T cell count of 308 cells/µl of peripheral blood. For this reason, the patient was screened several times for anti-HIV antibodies, but always with a negative result. Active tuberculous infection was considered as another possible reason behind persistent CD4+ T cell lymphopenia. However, imaging and laboratory analyses were not suggestive of tuberculosis. The patient is currently in good condition and his CD4+ T lymphocyte counts returned to normal at seven years of follow-up. It is underlined that patients after tuberculous meningitis need a long-term follow-up.

[Immune response in the pathogenesis of hepatitis C virus infection]. / Imunitní odpoved v patogenezi infekce virem hepatitidy C.

The pathogenesis of hepatitis C virus (HCV) infection is regulated by the host immunity and several metabolic factors affecting liver metabolism, including oxidative stress, insulin resistance, and hepatic steatosis. Both innate and adaptive immunity play an important role in HCV infection. Cytotoxic lymphocytes have a crucial role in viral eradication or viral persistence. Major cause of viral persistence during HCV infection could be the development of a weak antiviral immune response to the viral antigens, with corresponding inability to eradicate infected cells.

Incidence, immunological and clinical characteristics of reactivation of latent Toxoplasma gondii infection in HIV-infected patients.

To determine changes in incidence of reactivation of Toxoplasma gondii infection, manifesting as toxoplasmic encephalitis, and to assess the immunological mechanisms controlling reactivation in HIV-infected patients, a Czech cohort of 502 HIV/T. gondii co-infected patients was followed for 2909·3 person-years. The incidence of toxoplasmic encephalitis between the periods before and after the introduction of combination antiretroviral therapy (cART) was compared. Toxoplasmic encephalitis was diagnosed in 21 patients. In those patients the geometric mean value of CD4+ T lymphocytes was 12·6 times lower than in patients with non-reactivated T. gondii infection but an additionally significant decline in CD8+ T lymphocytes (3·3-fold) and natural killer cells (4·3-fold) was observed. This confirms the significance of these parameters. A twelvefold decrease in Toxoplasma reactivation incidence (40·2 vs. 3·4/1000 person-years) between monitored periods was seen. In the cART era, Toxoplasma reactivation was observed only in patients with unrecognized HIV infection or refusing therapy.

Evaluation of potential biomarkers for the discrimination of bacterial and viral infections.

PURPOSE: Timely knowledge of the bacterial etiology and localization of infection are important for empirical antibiotic therapy. Thus, the goal of this study was to evaluate routinely used biomarkers together with novel laboratory parameters in the diagnosis of infection. METHODS: In this prospective study, 54 adult patients with bacterial infections admitted to the Department of Infectious Diseases were included. For comparison, 27 patients with viral infections were enrolled. In these patients, white blood cell (WBC) counts, differential blood counts, serum levels of procalcitonin (PCT), IL-1ß, IL-6, IL-8, IL-10, IL-12, TNF-α, IFN-γ, soluble CD14 (sCD14), heparin-binding protein (HBP), cortisol (Cort), and monocyte surface expression of TLR2, TLR4, HLA-DR, and CD14 were analyzed. Also, these biomarkers were evaluated in 21 patients with acute community-acquired bacterial pneumonia (CABP), as well as in 21 patients with pyelonephritis and urosepsis. RESULTS: The highest sensitivity and specificity (expressed as the area under the curve [AUC]) for bacterial infection were observed in serum concentration of PCT (0.952), neutrophil and lymphocyte counts (0.852 and 0.841, respectively), and serum levels of HBP (0.837), IL-6 (0.830), and Cort (0.817). In addition, the serum levels of IFN-γ and Cort were significantly higher and IL-8 levels were lower in CABP when compared to pyelonephritis or urosepsis. CONCLUSIONS: From the novel potential biomarkers, only PCT demonstrated superiority over the routine parameters in the differentiation of bacterial from viral infections. However, some of the novel parameters should be further evaluated in larger and better characterized cohorts of patients in order to find their clinical applications.

Differences in Toll-like receptor expression and cytokine production after stimulation with heat-killed Gram-positive and Gram-negative bacteria.

Innate immune surveillance in the blood is executed mostly by circulating monocytes, which recognise conserved bacterial molecules such as peptidoglycan and lipopolysaccharide. Toll-like receptors (TLR) play a central role in microbe-associated molecular pattern detection. Here, we compared the differences in TLR expression and cytokine production after stimulation of peripheral blood cells with heat-killed Gram-negative and Gram-positive human pathogens Neisseria meningitidis, Escherichia coli, Staphylococcus aureus and Streptococcus pneumoniae. We found that TLR2 expression is up-regulated on monocytes after stimulation with S. aureus, S. pneumoniae, E. coli and N. meningitidis. Moreover, TLR2 up-regulation was positively associated with increasing concentrations of Gram-positive bacteria, whereas higher concentrations of Gram-negative bacteria, especially E. coli, caused a milder TLR2 expression increase compared with low doses. Cytokines were produced in similar dose-dependent profiles regardless of the stimulatory pathogen; however, Gram-negative pathogens induced higher cytokine levels than Gram-positive ones at same concentrations. These results indicate that Gram-positive and Gram-negative bacteria differ in their dose-dependent patterns of induction of TLR2 and TLR4, but not in cytokine expression.

Cortisol kinetics in cerebrospinal fluid during bacterial meningitis.

Bacterial meningitis (BM) remains an infectious disease with a significant morbidity and mortality. The aim of this study was to describe the kinetics of cerebrospinal fluid (CSF) cortisol levels during BM and to assess its relationship to disease severity and etiology. A total of 55 patients with BM were enrolled in the study. Elevated CSF cortisol upon admission and its rapid decrease after starting therapy were associated with increased BM severity as assessed by the Acute Physiology and Chronic Health Evaluation II score, the Sequential Organ Failure Assessment score, Glasgow Coma Scale score and the Glasgow Outcome Scale score. The comparison of CSF cortisol according to BM etiology revealed a trend toward higher concentrations in meningitis caused by Streptococcus pneumoniae compared to Neisseria meningitidis. Our results demonstrate that the initially elevated CSF cortisol concentrations decrease rapidly after administration of BM therapy (i.e. antibiotics and dexamethasone). Moreover, this rapid reduction of CSF cortisol was found in patients with high severity scores.

Sequential analysis of biomarkers in cerebrospinal fluid and serum during invasive meningococcal disease.

The aim of the present study was to determine the profile of different inflammatory molecules in serum and cerebrospinal fluid (CSF) during invasive meningococcal disease (IMD). Their relationship with IMD severity was also assessed. A cohort of 12 patients with IMD was investigated. Paired serum and CSF samples were obtained at the time of diagnostic and follow-up lumbar puncture and were examined using Luminex analysis. IMD severity correlated with serum interleukin-6 (IL-6) and interleukin-1 receptor antagonist (IL-1 ra) on admission. Furthermore, the CSF levels of IL-1 beta, IL-1 ra, IL-6, IL-8, macrophage inflammatory protein-1 beta (MIP-1 beta), and monocyte chemoattractant protein-1 (MCP-1) were significantly higher than their respective serum levels. The strongest correlations were found between serum concentrations of IL-1 beta and IL-1 ra, IL-6, IL-8, and MIP-1 beta, whereas the strongest correlations in CSF were found between endotoxin and IL-8, IL-17, MIP-1 beta, and MCP-1. As was expected, the concentrations of inflammatory molecules in both serum and CSF significantly decreased after antibiotic treatment. With regard to kinetics, a severe course of IMD correlated positively with rapid declines of CSF IL-6 and cortisol levels. Sequential multiple analyses revealed patterns of inflammatory responses that were associated with the severity of IMD, as well as with the compartmentalization and kinetics of the immune reaction.

Neisseria meningitidis strains from patients with invasive meningococcal disease differ in stimulation of cytokine production.

Cytokine production was determined in vitro after stimulation with three different Neisseria meningitidis (NM) strains. Virulent NM B strain isolated from a patient with mild course of invasive meningococcal disease (IMD) elicited higher cytokine production than NM B and NM C hypervirulent strains isolated from patients with moderate and fatal course of IMD, respectively. Endotoxin concentration after in vitro stimulation correlated with cytokine production: the highest endotoxin levels were observed with virulent NM B strain. Serum cytokines and endotoxin levels showed an opposite trend. These results suggest that inflammatory response during IMD is predominantly influenced by host factors.

Interferon-gamma and cortisol levels in cerebrospinal fluid and its relationship to the etiology of aseptic meningoencephalitis.

The aim of the study was to analyze the concentrations of Th1/Th2 cytokines and cortisol in the cerebrospinal fluid (CSF) from patients with aseptic meningoencephalitis (AM). The study enrolled 37 patients with AM and 11 control subjects. CSF concentrations of IL-2, IL-4, IL-5, IL-10, IFN-gamma, and TNF-alpha were analyzed using cytokine bead array and flow cytometry; CSF cortisol concentrations were measured by a RIA method. Cortisol was detected in 37 CSF samples (100%) from patients with AM, and it was significantly elevated in comparison to control subjects. IFN-gamma was detected in 32 CSF samples (86.5%) and IL-10 was detectable in 9 CSF samples (24.3%). The CSF cortisol levels correlated negatively with the duration of AM. The intrathecal concentration of IFN-gamma correlated positively with CSF numbers of leukocytes and lymphocytes, and negatively with the duration of AM. The etiology of AM influenced the CSF cortisol concentration, which was significantly higher in patients with tick-borne encephalitis when compared to persons with AM of unknown origin and control subjects. The results indicate that the prevailing intrathecal immune reaction during AM is shifted to a Th1-like response, whereas anti-inflammatory response in the brain is executed by the effect of cortisol.

Cd38 expression on Cd8+ T cells in Human immunodeficiency virus 1-positive adults treated with HAART.

The aim of this study was to assess whether the density of CD38 antigen expression on CD8+ T cells can be used as a marker of activation of the immune system in Human immunodeficiency virus 1 (HIV-1)-positive patients treated with highly active antiretroviral therapy (HAART). T cell subsets, expression of CD38 antigen on CD8+T cells, HIV-1 viral load and stage of the disease were analyzed at baseline and after 12 months of HAART in 24 HIV-1-infected patients. Our data showed that the use of HAART is effective in reducing plasma viral load and in achieving a stable CD4+ count and percentage of CD8+/CD38+ cells. The percentages of CD8/CD38+ cells in HIV-1-infected patients at baseline and after 12 months of HAART were significantly higher than those of controls. Analysis of the density of CD38 expression revealed that it was due to CD8+/CD38+ subsets with low and medium density of antigen expression. Absolute number of CD4+ T cells correlated negatively with the percentage of CD8+/CD38+ cells at baseline of the study. Persistent up-regulation of the CD38 expression on CD8+ T cells and its correlation with the decreased CD4+ count despite the reduction of plasma viral load may reflect residual replication of HIV-1 in reservoirs. Thus, this immunological parameter can serve as a biological marker of HIV-1 infection and might have utility in clinical management of HIV-1-infected persons.

Lymphocyte subset numbers depend on the bacterial origin of sepsis.

OBJECTIVE: To determine the quantitative variances in peripheral blood lymphocyte subsets during sepsis, and their clinical significance. METHODS: Peripheral blood lymphocyte subsets were enumerated in 32 non-surgical septic patients during the first 14 days of hospitalization; results from septic patients were compared with those from 34 healthy controls. Influences of the severity and the bacterial etiology of sepsis on changes in lymphocyte subsets were also assessed. RESULTS: Significant decreases (P < 0.05) from normal values of CD4+, CD8+ and total T-lymphocytes were observed in septic patients, but the decline persisted only for CD4+ T-lymphocytes and natural killer (NK) cells for 3 and 7 days, respectively. In addition, the numbers of CD3+/DR+ lymphocytes were significantly elevated on day 14. There were no correlations between these alterations and the severity of sepsis. Gram-positive sepsis (n = 10), which was mainly due to Streptococcus pneumoniae and Staphylococcus aureus, caused prolonged decreases in CD4+, CD8+ and total T-lymphocytes, and a reduction in NK cells, that lasted for >or=14 days. Conversely, patients with sepsis due to Gram-negative pathogens (Neisseria meningitidis, n = 8; enterobacteria, n = 2) achieved full recovery of the subsets within 3 days. Moreover, the patients with Gram-negative sepsis demonstrated a significant increase in B-lymphocytes, and a rise in the numbers of CD3+/DR+ and CD4+ T-lymphocytes, which were more rapid than in patients with Gram-positive sepsis. CONCLUSION: Our results indicate that Gram-positive sepsis causes stronger suppression of peripheral blood lymphocyte subsets in comparison to sepsis due to Gram-negative pathogens.

Lymphocyte subset numbers in cerebrospinal fluid: comparison of tick-borne encephalitis and neuroborreliosis.

OBJECTIVE: The aim of this study was to analyze lymphocyte subset numbers in cerebrospinal fluid (CSF) from patients with tick-borne encephalitis (TBE) and acute neuroborreliosis. METHODS: CSF lymphocyte subsets were enumerated in 42 TBE and nine neuroborreliosis patients using flow cytometry. RESULTS: The CSF numbers of CD4+, CD8+, HLA-DR+ and total-T lymphocytes, B lymphocytes, and NK cells were all greater in neuroborreliosis patients than in TBE patients. Neuroborreliosis patients showed positive correlation of CSF protein levels with the numbers of CD4+, HLA-DR+ and total-T lymphocytes. Also, the numbers of CSF B lymphocytes correlated positively with intrathecal Borrelia burgdorferi-specific IgG antibodies. Conversely, TBE patients demonstrated intrathecal protein levels that correlated positively with all investigated CSF lymphocyte subsets. CONCLUSION: These results suggest an intensive recruitment of lymphocyte subsets into the central nervous system (CNS) during acute neuroborreliosis, whereas TBE is characterized by a lower accumulation of lymphocyte subsets in the CSF.