Do patients infected with human coronavirus before the COVID-19 pandemic have less risk of being infected with COVID-19?

Background/aim: Although seasonal human coronaviruses (HCoVs) have long been recognized as respiratory tract viruses, the newly identified SARS-CoV-2 caused a pandemic associated with severe respiratory failure. We aimed to evaluate the incidence of COVID-19 infection in patients diagnosed in three tertiary teaching hospitals, both with and without prior confirmed HCoV infection, and to compare these cohorts in terms of COVID-19 contraction. Materials and methods: In our study, we examined HCoV PCR-positive cases obtained retrospectively between January 2014 and March 2020 from three University Hospital Microbiology Laboratories (Cohort 1), as well as PCR-negative patients detected in the same PCR cycle as the positive cases (Cohort 2). We also evaluated subgroups of HCoV-positive cases. Results: There was no difference in COVID-19 contraction rates between Cohort 1 and Cohort 2 (p = 0.724). When previous HCoV subgroups of COVID-19-positive patients were examined, no significant difference was found between the betacoronavirus and alphacoronavirus subgroups (p = 0.822), among the four groups (NL63, 229E, OC43, HKU-1) (p = 0.207), or between the OC43 subgroup and the other groups (p = 0.295). Conclusion: Being previously infected with HCoV did not provide protection against COVID-19 in our study group. We suggest evaluating the possible effect of previous OC43 infection on COVID-19 contraction in larger cohorts.

Prognostic value of interleukin-18 and its association with other inflammatory markers and disease severity in COVID-19.

BACKGROUND: The effectual immune response is crucial to defeat viral infections. However, exuberant immune response with features of macrophage activation syndrome (MAS) lead detrimental consequences in COVID-19 patients. Interleukin (IL)-18 is one of the leading cytokines in MAS which has not been studied in COVID-19. OBJECTIVE: To investigate the association of IL-18 with the other inflammatory markers and disease severity in COVID-19 for predicting disease prognosis. METHODS: Patients with COVID-19 who had confirmed diagnosis with SARS-CoV-2 nucleic acid RT-PCR were enrolled into the study. Data on demographic and clinical characteristics, and laboratory values of CRP, ferritin, d-dimer and procalcitonin were measured on admission. Patients were followed up prospectively with a standardized approach until hospital discharge or death. Individuals were classified as asymptomatic, mild and severe pneumonia according to their clinical, laboratory and radiological characteristics. Worse outcome was defined as requirement of intensive care unit (ICU) admission or death. Blood samples were collected at enrollment and serum levels of IL-6 and IL-18 were determined by ELISA. Association between IL-18 and other inflammatory markers and prognosis were analyzed. RESULTS: There were 58 COVID-19 patients (50% male) with a median age of 43 (min 22-max 81) years. Twenty age and sex matched healthy subjects were served as control group. The study population was divided into three groups according to disease severity: asymptomatic (n = 20), mild pneumonia group (n = 27) and a severe group (n = 11). During follow up nine (15.5%) patients required ICU admission and three of them were died eventually. Serum IL-18 were correlated with other inflammatory markers and biochemical markers of organ injury; creatinine, liver enzymes and troponin. Serum IL-18 levels were remarkably higher in COVID-19 patients compared to healthy subjects with being highest in severe pneumonia group (p < 0.001). IL-18 serum concentrations were almost four-fold higher in patients with worse outcome compared to good outcome (p < 0.001). Serum IL-18 above the cut off value of 576 pg/mL on admission was associated with 11.7 fold increased risk of ICU admission. CONCLUSIONS: The serum concentrations of IL-18 correlate with other inflammatory markers and reflect disease severity. Results of the present study shed light on role of IL-18 on COVID-19 pathogenesis and might provide an evidence for the clinical trials on IL-18 antagonists for the treatment of severe COVID-19 patients.

The assessment of serum ACE activity in COVID-19 and its association with clinical features and severity of the disease.

Angiotensin-converting enzyme (ACE)/Angiotensin (Ang) II pathway has crucial regulatory effects on circulatory hemostasis and immune responses. This pathway has a major role in the development of acute lung injury and acute respiratory distress syndrome (ARDS), which is a devastating complication of SARS-CoV-2 infection. The aim of this study is to investigate the serum ACE activity and its correlation with clinical features and the disease severity in patients with COVID-19. Patients with confirmed COVID-19 by detecting SARS-CoV-2 nucleic acid RT-PCR were included in the study. Demographic data, clinical features, laboratory and radiologic investigations were recorded. Patients were classified by disease severity; asymptomatic, mild, and severe pneumonia. The serum ACE activity was evaluated with an autoanalyzer based on a spectrophotometric method. Fifty-five patients (50.9% female) and 18 healthy subjects (33.3 % female) were enrolled in the study. The median age of patients was 40 years, ranging from 22 to 81 years. Eighteen healthy subjects were served as the control group. The baseline characteristics were comparable between groups. The median serum ACE activity of patients and controls (38.00 [IQR 21] U/L and 32.00 [IQR 24] U/L, respectively) and of between patients grouped by disease severity (38.5 [IQR 19], 36 [IQR 25], and 38 [IQR 22] U/L, asymptomatic, mild and severe pneumonia group, respectively) were similar. There was no correlation between the serum ACE activity and conventional inflammatory markers. In this study, we did not find an association between serum ACE activity and COVID-19 and serum ACE activity on admission did not reflect disease severity.

Monoclonal outbreak of Ralstonia solanacearum catheter-related bloodstream infection associated with contaminated package of normal saline solution in a tertiary care hospital

Background/aim: Ralstonia solanacearum is a very rare cause of infection in humans. There is no described nosocomial outbreak due to R. solanacearum so far. We determined R. solanacearum as the source of catheter-related bloodstream infection (CRBSI) outbreak. Materials and methods: This outbreak analysis was carried out in a 1000-bed tertiary care university hospital in Turkey. The outbreak analysis included hematology, oncology, nephrology, gastroenterology wards, emergency department, and intensive care units. The first case with R. solanacearum CRBSI was detected on May 20, 2019 and R. solanacearum was isolated in catheter blood cultures in 34 patients until October 3, 2019 Results: Standard outbreak analysis procedures were applied. Culture samples were taken from the fluids administered via catheters. The cultures did not yield any bacteria. As a result of the investigation in storage area, it was found that there were leaks, air bubbles, and water drops inside the packaging of saline solutions. R. solanacearum was yielded in the cultures obtained from the surface of saline bags and the inner sides of plastic packings. To validate our hypothesis, a clonal analysis was performed using arbitrarily primed-PCR method and Sanger sequencing of the 16S rRNA gene for identification among isolates. All R. solanacearum isolates were monoclonal and identical. Conclusion: This is the first outbreak of R. solanacearum CRBSI described in a hospital setting. The source of the outbreak was a contamination in the surface of saline bags and the inner sides of plastic packings. Efficacy of an active surveillance system, accurate and rapid conduction of microbiological identification are essential for outbreak management.

Evaluation of extensively drug-resistant gram-negative bacteremia among solid-organ transplant recipients: a multicenter study

Background/aim: The aim of this study is to evaluate the distribution, sources, clinical features, and mortality rates of bacteremia due to evaluation of extensively drug-resistant (XDR) gram negative among solid-organ transplant (SOT) recipients. Materials and methods: A retrospective study of SOT recipients with bacteremia due to XDR gram-negative pathogens in 11 centers between 2016 and 2018 was conducted. Patients' records were evaluated. Results: Of 171 bacteremia that occurred in 164 SOT recipients, 93 (56.7%) were liver, 46 (28%) kidney, 14 (8.5%) heart, and 11 (6.7%) lung recipients. Bacteremia episodes were recorded in the first year in 63.7% of the patients (n = 109), early-onset bacteremia was recorded in 45% (n = 77) of the episodes. In multivariate analysis, catheter-associated bacteremia was an independent risk factor for 7-day mortality (p = 0.037), and early-onset bacteremia was found as an independent risk factor for 30-day mortality (p = 0.017). Conclusion: Difficult-to-treat infections due to XDR bacteria in SOT recipients shadow the success of transplantation. Central venous catheters seem to be the main risk factor. Judicious use of medical devices is of pivotal importance.

Retrospective analysis of the association of the expression and single nucleotide polymorphisms (SNPs) of the TLR4, PTX3 and Dectin-1 (CLEC/A) genes with development of invasive aspergillosis among haematopoietic stem cell transplant recipients with oncohaematological disorders.

OBJECTIVES: Several studies described single nucleotide polymorphisms (SNPs) on pattern recognition receptor (PRR) such as toll-like receptors (TLRs), dendritic cell-associated C-type lectin-1 (Dectin-1/CLEC7A) genes of patients with invasive fungal infections (IFIs) caused by Candida and Aspergillus. We screened TLR4, Dectin-1 and PTX3 polymorphisms in a Turkish population with invasive aspergillosis (IA) underlying haematological malignancies. METHODS: In this case-control study, a cohort of 59 patients with haematological malignancies were included. There were 26 IA patients assigned by the EORTC-MSG criteria and 33 patients with no evidence of fungal disease. DNA and RNA were isolated from frozen bone marrow and serum samples. RNA levels and polymorphisms of TLR4 (rs4986790, rs4986791), Dectin-1 (rs16910526, rs7309123) and PTX3 (rs2305619, rs3816527) were determined. The odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were calculated by unconditional logistic regression analysis. RESULTS AND CONCLUSIONS: TLR4, PTX3 and Dectin-1 genes were downregulated in aspergillosis cohort under similar haematological conditions. TLR4 expression was 0.0626 ± 0.032 in controls when compared to IA patients as 0.0077 ± 0.014, and the difference was significant (P = .026). There was a difference in also the PTX3 gene among IA (0.0043 ± 0.004) and control (0.5265 ± 0.0043) groups (P = .035). The Dectin-1 (CLEC/A) expression was downregulated in IA group (0.1887 ± 0.072 & 0.0655 ± 0.010) but not statistically significant (P > .05). Conditional logistic regression analyses indicated that the GT genotype of rs16910526 polymorphism in Dectin-1 gene was associated with lower risk of IA (odds ratio = 3.635, 95% confidence interval = 0.690-3.138, P = .04).

The factors predicting pneumonia in COVID-19 patients: preliminary results from a university hospital in Turkey

Background/aim: Pneumonia is the most serious clinical presentation of COVID-19. This study aimed to determine the demographic, clinical, and laboratory findings that can properly predict COVID-19 pneumonia. Materials and methods: This study was conducted in the Gazi University hospital. All hospitalized patients with confirmed and suspected SARS-CoV-2 infection between 16 March 2020 and 30 April 2020 were analyzed retrospectively. COVID-19 patients were separated into two groups, pneumonia and nonpneumonia, and then compared to determine predicting factors for COVID-19 pneumonia. Variables that had a P-value of less than 0.20 and were not correlated with each other were included in the logistic regression model. Results: Of the 247 patients included in the study 58% were female, and the median age was 40. COVID-19 was confirmed in 70.9% of these patients. Among the confirmed COVID-19 cases, 21.4% had pneumonia. In the multivariate analysis male sex (P = 0.028), hypertension (P = 0.022), and shortness of breath on hospital admission (P = 0.025) were significant factors predicting COVID-19 pneumonia. Conclusion: Shortness of breath, male sex, and hypertension were significant for predicting COVID-19 pneumonia on admission. Patients with these factors should be evaluated more carefully for diagnostic procedures, such as thorax CT.

Peripheral arterial disease increases the risk of multidrug-resistant bacteria and amputation in diabetic foot infections

Background/aim: The aim of this study was to investigate the microbiological profile and resistance rates of diabetic foot infections (DFIs) and to determine the effect of peripheral arterial disease (PAD) on the microbiology, clinical condition, and treatment outcomes. Materials and methods: Characteristics, laboratory and imaging data, and the treatment modalities of patients admitted to our hospital with a diagnosis of DFI (PEDIS classification 3­4) during 2005­2016 were analyzed according to the presence of PAD. Results: Of 112 patients who were included in this study, 86 (76.8%) had PAD. Patients with PAD were older and had higher amputation rates (P < 0.05). A microbiological profile of patients revealed a predominance of gram-positive bacteria (57.1%). Staphylococcus aureus and Streptococcus spp. were the most frequently encountered bacteria. Incidence of Pseudomonas spp. infection was higher in the PAD group (P < 0.05). Of all patients, 24.1% had multidrug-resistant (MDR) microorganisms in their wound cultures. Presence of MDR bacteria in patients with PAD was 4.9-fold higher than that in patients without PAD (P < 0.05). Conclusion: This retrospective study indicates that PAD has a significant role, especially in elderly patients with DFIs. Patients should be promptly evaluated and treated for PAD to prevent infections with resistant microorganisms and limb loss.

The in vitro effect of antimicrobial photodynamic therapy on Candida and Staphylococcus biofilms

Background/aim: This study was designed to evaluate the effect of antimicrobial photodynamic treatment (APDT) in a biofilm model using combinations of various dyes (rose bengal, riboflavin, and methylene blue) as photosensitizers and light sources (LED and UVA) against staphylococcal and candidal biofilms. Materials and methods: Sterile microtiter plates were used for the development and quantification of the biofilms. APDT was carried out using combinations of the light sources and dyes. The percentage of the growth inhibition was then calculated using a spectrophotometer. The broth media in the wells were aspirated, wells were stained with crystal violet, and optical density values were measured spectrophotometrically. SEM analysis of the impact of APDT on bacterial and fungal biofilms was also performed. Results: The experiments showed that the most efficacious combination was red LED + methylene blue against both staphylococcal and candidal biofilms. A marked inhibition (45.4%) was detected on both C. albicans and C. parapsilosis biofilms. Red LED + methylene blue was also effective on S. aureus and S. epidermidis biofilms. SEM images suggested that the number of adherent cells and biofilm mass were markedly reduced after APDT treatment. Conclusion: Although the results of this study indicated the in vitro efficacy of APDT, it might also be a promising technique for the control of biofilm growth within intravenous catheters.

[A rare and mortal infection agent in patients with hematological malignancies: Saprochaete capitata]. / Hematolojik maligniteli hastalarda nadir ve mortal bir enfeksiyon etkeni: Saprochaete capitata.

Saprochaete capitata (formerly known as Geotrichum capitatum and Blastoschizomyces capitatus) is a rare invasive fungal agent that may lead to mortal clinical course in patients with hematological malignancies. This agent can be colonized in skin, lungs and intestines, and it can cause major opportunistic infections. Invasive systemic infections due to S.capitata have been reported in immunosuppressed patients. In this report, two patients with invasive S.capitata infections detected during the course of persistent neutropenic fever in acute leukemia, were presented. In both cases empirical caspofungin was added to the treatment, as no response was obtained by board-spectrum antibacterial therapy in neutropenic fever. In the first patient, there were no significant findings except the chronic inflammation observed in the biopsies which was performed for the symptoms of lymphadenitis, myositis, and hepatosplenic candidiasis. While persistent fever was on going, S.capitata was isolated from the blood and catheter cultures. There was no response after catheter removing and the introduction of amphotericin B and voriconazole therapy, therefore allogeneic stem cell transplantation plan for the second time for bone marrow aplasia was taken an earlier time. However, the patient died due to progressive pericardial and pleural effusion and multiorgan failure, although an afebrile process after stem cell transplantation could be obtained. Similarly the second patient had persistent fever despite empirical caspofungin treatment. The additional symptoms of diarrhea, abdominal pain and subileus have indicated an intraabdominal infection. During the follow up, S.capitata was isolated from the blood and catheter cultures. Catheter was removed and amphotericin B was initiated. No response was obtained, and voriconazole was added to treatment. Despite of an afebrile and culture-negative period, the patient died as a result of Acinetobacter sepsis and multiorgan failure. Minimal inhibitory concentration values for both of the Saprochete strains were found as 0.25 µg/ml for amfoterisin B, 1 µg/ml for flukonazol, 0.125 µg/ml for vorikonazol and 0.25 µg/ml for itrakonazol. Virulence model was created by injecting the isolates to the Galleria mellonella larvae, and the life cycle of the larvae were determined. The observation revealed that the infected larvae began to die on the second day and there was no live larvae remained on the eleventh day. In conclusion, S.capitata should be considered as an infection agent with high mortality risk in the neutropenic patients with hematologic malignancies, especially in the presence of persistent fever during the use of caspofungin.