Identifying risk factors for blood culture negative infective endocarditis: An international ID-IRI study.

Background: Blood culture-negative endocarditis (BCNE) is a diagnostic challenge, therefore our objective was to pinpoint high-risk cohorts for BCNE. Methods: The study included adult patients with definite endocarditis. Data were collected via the Infectious Diseases International Research Initiative (ID-IRI). The study analysing one of the largest case series ever reported was conducted across 41 centers in 13 countries. We analysed the database to determine the predictors of BCNE using univariate and logistic regression analyses. Results: Blood cultures were negative in 101 (11.65 %) of 867 patients. We disclosed that as patients age, the likelihood of a negative blood culture significantly decreases (OR 0.975, 95 % CI 0.963-0.987, p < 0.001). Additionally, factors such as rheumatic heart disease (OR 2.036, 95 % CI 0.970-4.276, p = 0.049), aortic stenosis (OR 3.066, 95 % CI 1.564-6.010, p = 0.001), mitral regurgitation (OR 1.693, 95 % CI 1.012-2.833, p = 0.045), and prosthetic valves (OR 2.539, 95 % CI 1.599-4.031, p < 0.001) are associated with higher likelihoods of negative blood cultures. Our model can predict whether a patient falls into the culture-negative or culture-positive groups with a threshold of 0.104 (AUC±SE = 0.707 ± 0.027). The final model demonstrates a sensitivity of 70.3 % and a specificity of 57.0 %. Conclusion: Caution should be exercised when diagnosing endocarditis in patients with concurrent cardiac disorders, particularly in younger cases.

Antibody responses post-booster COVID-19 vaccination: Insights from a single-center prospective cohort study.

The study aimed to evaluate the effect of booster dose COVID-19 vaccines on prevention and humoral immune response in individuals with different vaccination schemes during the period BA.4 and BA.5 omicron sub-variants were globally dominant. The study included 146 individuals who preferred different vaccination schemes for booster doses. Anti-spike/RBD-IgG and neutralizing antibody levels were measured 28 days after the booster dose vaccination upon their consent. There is no significant difference between median antibody titers detected according to different vaccination schemes. SARS-CoV-2 neutralizing antibody inhibition percentages were detected significantly higher in serum samples before and after the last booster dose in 2 BNT162b2+1 BNT162b2(99.42 %), 2 BNT162b2 + 2 BNT162b2(99.42 %), and 2 BNT162b2 + 3 BNT162b2(99.42 %) vaccination schemes (p = 0.004, p = 0.044, p = 0.002,respectively). The study indicated that a booster vaccination dose provides a high level of protection against severe COVID-19 and death. We think that the variant-specific pancoronavirus vaccines will be necessary to protect against breakthrough infections.

Predictors of 2-year mortality in geriatric patients hospitalized with COVID-19 in Türkiye: a retrospective cohort study.

Aim: To reveal factors affecting 2-year mortality in geriatric patients hospitalized with COVID-19.Methods: Demographic characteristics, clinical and laboratory data, thorax computed tomography (CT) images, second-year survival status, and causes of death were analyzed.Results: The 2-year post-discharge mortality rate of 605 patients was 21.9%. Mean age of patients in the deceased group was 76.8 ± 8.1 years, which was shorter than the life expectancy at birth in Türkiye. Older age (≥85), delirium, some co-morbidities, and atypical thorax CT involvement were associated with a significant increase in 2-year mortality (p < 0.05).Conclusion: This is the first study to evaluate factors associated with 2-year mortality in older COVID-19 patients. Identifying risk factors for long-term mortality in geriatric COVID-19 patients is important.

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Resistance Genes and Mortality in Carbapenem-resistant Klebsiella pneumoniae Bacteremias: Effects of the COVID-19 Pandemic

Background: Emerging carbapenem-resistant Klebsiella pneumoniae (K. pneumoniae) (CRKP) bacteremias are presenting significant public health risks due to limited treatment options and increased mortality. K. pneumoniae isolates exhibit carbapenem resistance rates that vary from 25% to 50% throughout the European continent, including our country. Aims: To assess the characteristics of CRKP bacteremia, a condition that has recently demonstrated an increasing prevalence in our center. We sought to ascertain the resistance rates of isolated strains to antibiotics other than carbapenems, identify the responsible carbapenemase genes, evaluate the efficacy of antibiotics, determine mortality rates, explore clonality among strains, and investigate the influence of the COVID-19 pandemic on all these factors. Study Design: Retrospective observational study. Methods: This study included patients aged 18 and older who had experienced meropenem-resistant K. pneumoniae bacteremia. Meropenem resistance was confirmed by employing the Kirby-Bauer disk diffusion method. Meropenem minimum inhibitory concentration (MIC) levels were determined using the gradient test, while colistin MIC levels were ascertained using the disk elution technique. Carbapenemase genes were evaluated via colony polymerase chain reaction (PCR), and clonality analysis was performed using the arbitrarily primed PCR technique. Results: The study comprised 230 patients, with a mean age of 63.1 ± 15.9 years, of whom 58.7% were male. Oxacillinase-48 (OXA-48) was detected in 74.8% of the patients, New Delhi metallo-beta-lactamase (NDM) in 12.6%, OXA-48 + NDM in 7.8%, and KPC in 4.8%. The 14-day and 30-day mortality rates were 57% and 69.6%, respectively. Multivariate analysis of the 30-day mortality revealed several crucial factors, including bacteremia development in the intensive care unit, the occurrence of bacteremia during the COVID-19 pandemic, polymicrobial bacteremia, the use of indwelling intravenous catheters, a platelet count of ≤ 140,000/µl, procalcitonin levels of ≥ 6 µg/l, and a Charlson comorbidity score ≥ 3. Notably, the OXA-48 and KPC genes were upregulated significantly during the COVID-19 pandemic, while the NDM gene groups were downregulated. Additionally, both 14-day and 30-day mortality rates increased significantly. Conclusion: In this study, the most prevalent carbapenemase gene was OXA-48; however, there has been a recent increase in KPC genes. No dominant epidemic strain was identified through clonality analysis. The clustering rate was 68% before the pandemic, increasing to 85.7% during the pandemic. The significance of infection control measures is underscored by the rise in both clustering and mortality rates during the COVID-19 pandemic.

West Nile virus meningitis presenting with migrainous headache.

West Nile Virus (WNV) infection is a clinical picture that is transmitted from wild birds, its natural host, to humans through mosquitoes and generally shows an asymptomatic course. Influenza-like WNV fever is frequently seen in symptomatic individuals, and a neuroinvasive course is more rarely observed. Neuroinvasive WNV has a broad-spectrum profile of neurological signs and symptoms. WNV meningitis is one of the most common neuroinvasive forms of WNV, and it does not differ clinically and radiologically from other viral meningitis. Secondary headaches, which can mimic primary headaches, are an infectious factor that should be kept in mind in the etiology, especially in cases presenting in the summer months. In this study, a case of WNV meningitis presenting with a headache of migrainous character is presented.

Cell free DNA as a new prognostic biomarker for COVID-19, A prospective cohort study.

Predicting the need of hospitalization and intensive care in COVID-19 patients has been challenging with current diagnostic tests since the beginning of the pandemic. We aimed to test cell free DNA (cfDNA) as a novel biomarker for COVID-19 disease severity and mortality. cfDNA concentration was quantified by RT-PCR based test. One hundred and sixty-eight patients(85 outpatients, 61 inpatients,22 ICU) included the study. Mean initial plasma cfDNA levels were significantly different (p < 0.01) in outpatients (1.190,66 ng/ml), inpatients (8.258,10 ng/ml) and ICU patients (84.806,87 ng/ml). ROC analysis showed with 95 % specificity that patients with initial cfDNA concentrations ≥6.389 ng/ml need to be hospitalized and those ≥26.104 ng/ml require ICU referral. cfDNA concentration was correlated with neutrophil/lymphocyte ratio, lymphocyte level, CRP, AST, LDH, CK, fibrinogen, ferritin and D-dimer. Plasma cfDNA levels on admission, well correlating with disease severity and mortality in COVID-19 that found as a useful biomarker.

Urinary tract infections in older adults: associated factors for extended-spectrum beta-lactamase production.

Objective: Urinary tract infections (UTIs) due to extended-spectrum beta-lactamase (ESBL) producing Escherichia coli and Klebsiella pneumoniae are among the leading causes of morbidity and mortality in older adults. Identifying associated factors for ESBL production may contribute to more appropriate empirical treatment. Materials and methods: This was a prospective observational study. Hospitalized patients of age > 65 with community-onset or hospital-acquired upper UTI due to E. coli or Klebsiella pneumoniae were included. A multivariate analysis was performed. Results: A total of 97 patients were included. ESBL prevalence among UTIs with E. coli or Klebsiella pneumoniae was 69.1% (n = 67). CRP values at the time of UTI diagnosis were found to be significantly higher in the ESBL-producing group (p = 0.004). The multivariate analysis revealed that male gender (OR: 2.72, CI: 1.02-7.25), prior recurrent UTI (OR: 3.14, CI: 1.21-8.14), and the development of secondary bacteremia (OR: 4.95, CI: 1.03-23.89) were major associated factors for UTI in older adults due to ESBL-producing E. coli and Klebsiella pneumoniae. Conclusion: Severe UTI in older men with a history of recurrent UTI may be a warning to the clinician for ESBL production in the setting of high ESBL prevalence. Carbapenems may be prioritized in the empirical treatment of patients with known risk factors for ESBL.

Bone Metabolism in Men who Live with HIV Aged 50 years and Over: Impact of Infection Duration.

BACKGROUND: Early diagnosis and effective antiretroviral therapy (ART) lead to similar life expectancy in people living with HIV (PLWH) compared to the general population. This population faces problems such as decreased bone mineral density (BMD) and increased fracture risk. The aim of this study was to determine the prevalence of osteoporosis in men aged 50 years and over who were PLWH and to determine risk factors and changes in bone metabolism with bone turnover markers. METHODS: 79 male PLWH aged 50 years and over were followed up in our outpatient clinic between May 2021 and October 2021. The patients' demographic, clinical, laboratory, and DEXA data were analyzed. Serum levels of bone turnover markers were measured. RESULTS: The prevalence of osteopenia, osteoporosis, and normal BMD was found to be 55.7%, 13.9%, and 30.4%, respectively. A correlation was found between low BMD and low body mass index, elapsed time since diagnosis of HIV infection, high rate of use of ART, and long usage time of tenofovir disoproxil fumarate + protease inhibitor. A one-year increase in HIV infection duration was associated with an increased risk of low BMD by 1.246. CONCLUSION: Compared to studies conducted on the general population, the prevalence of osteoporosis in male PLWH aged 50 years and older was two times higher. The limited effect of the duration of ART use on low BMD may be due to the patients' histories of replacement therapy. Therefore, to eliminate the negative effects of ART on BMD, it may be beneficial to start replacement therapy when necessary.

Discontinuation of Nucleos(t)ide Analog treatment in HBeAg-Negative Non-Cirrhotic Chronic Hepatitis B Patients: Real-Life Data of 20 Years.

BACKGROUND/AIMS: Discontinuation of nucleos(t)ide analog is controversial in HBeAg-negative chronic hepatitis B patients not achieved HBsAg loss. We aimed to evaluate re-treatment rates and risk factors in non-cirrhotic HbeAg-negative chronic hepatitis B patients for whom nucleosi(t)ides analogs were discontinued. MATERIALS AND METHODS: Demographic, clinical, and laboratory data before and at the end after discontinuation of nucleos(t)ide analogs were collected retrospectively. RESULTS: Seventy-two patients followed up between January 2000 and December 2019 were included; 43 were male, with a mean age of 46.3 (±10.8). Baseline median alanine aminotransferase (ALT) and hepatitis B virus DNA levels were 55.5 IU/L and 465 925 IU/mL, respectively. The median histologic activity index was 5.5 and the fibrosis score was 2. The median duration of treatment and consolidation therapy were 59 and 56 months, respectively. The median follow-up time after discontinuation of treatment was 55 months. Among 56 patients eligible for evaluation according to proposed re-treatment criteria, 29 (51.7%) patients were re-treated. The median time for relapse was 11 months. Re-treatment was significantly common in males (P = .034) and patients treated with tenofovir/entecavir (P = .04). Baseline hepatitis B virus DNA and levels of ALT, aspartate aminotransferase (AST) at the third and sixth months of treatment and at the end of treatment were statistically significantly higher in re-treated patients. A cutoff value of ≥405 000 IU/L for hepatitis B virus DNA discriminated patients for re-treatment. HBsAg was lost permanently in 2 non-re-treated patients. CONCLUSION: In resource-limited areas where follow-up of HBsAg or other markers is not possible, nucleos(t)ide analog discontinuation can be considered in patients in the early stage, with low baseline hepatitis B virus DNA and ALT levels, after a long consolidation therapy.

Homologous or heterologous COVID-19 vaccine schemes: comparison of immune responses and side effects.

Real-life data are needed regarding the appropriate time and selection of vaccination strategies, homologous or heterologous. We aimed to compare neutralizing antibody levels and side effects in different vaccination schemes. The study included 310 Health Care Workers (HCWs) vaccinated with 5 different schemes. Antispike/RBD IgG levels were measured between 28 and 60 days after the last dose. Side effects in participants were recorded, and pharmacovigilance records were reviewed from the outpatient vaccine clinic. Mean age of the participants was 38 ± 11 years of whom 226 (72.9%) were female, and 84 (27.1%) were male. After booster doses, increasing antibody levels were detected in all groups. Mean antibody levels were detected to be statistically lower in 3 doses of inactivated vaccines group. The side effects were no significant difference between groups. Booster dose administration with mRNA vaccines stands out as the most accurate strategy for those at risk of contracting severe COVID-19 and HCWs caring for this population.

Higher rates of cefiderocol resistance among NDM producing Klebsiella bloodstream isolates applying EUCAST over CLSI breakpoints.

BACKGROUND: Cefiderocol is generally active against carbapenem-resistant Klebsiella spp. (CRK) with higher MICs against metallo-beta-lactamase producers. There is a variation in cefiderocol interpretive criteria determined by EUCAST and CLSI. Our objective was to test CRK isolates against cefiderocol and compare cefiderocol susceptibilities using EUCAST and CLSI interpretive criteria. METHODS: A unique collection (n = 254) of mainly OXA-48-like- or NDM-producing CRK bloodstream isolates were tested against cefiderocol with disc diffusion (Mast Diagnostics, UK). Beta-lactam resistance genes and multilocus sequence types were identified using bioinformatics analyses on complete bacterial genomes. RESULTS: Median cefiderocol inhibition zone diameter was 24 mm (interquartile range [IQR] 24-26 mm) for all isolates and 18 mm (IQR 15-21 mm) for NDM producers. We observed significant variability between cefiderocol susceptibilities using EUCAST and CLSI breakpoints, such that 26% and 2% of all isolates, and 81% and 12% of the NDM producers were resistant to cefiderocol using EUCAST and CLSI interpretive criteria, respectively. CONCLUSIONS: Cefiderocol resistance rates among NDM producers are high using EUCAST criteria. Breakpoint variability may have significant implications on patient outcomes. Until more clinical outcome data are available, we suggest using EUCAST interpretive criteria for cefiderocol susceptibility testing.

Effect of the povidone iodine, hypertonic alkaline solution and saline nasal lavage on nasopharyngeal viral load in COVID-19.

OBJECTIVE: The present study aimed to investigate the in vivo activity of nasal irrigation (NI) with saline, NI with povidone-iodine (PVP-I) 1%, NI with a mix of hypertonic alkaline and PVP-I 1% against Severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). DESIGN: This study was a prospective randomised clinical trial. SETTING: A multicenter study involving tertiary care centres. PARTICIPANTS: The study included adult outpatients whose qualitative SARS-CoV-2 RT-PCR tests in nasopharyngeal swabs were positive. One hundred twenty patients were divided into four equal groups. Standard COVID-19 treatment was given to Group 1, NI containing saline was added to patients' treatment in Group 2, NI containing 1% PVP-I solution was added to patients' treatment in Group 3, and NI containing 1% PVP-I solution and the hypertonic alkaline solution was added to patients' treatment in Group 4. MAIN OUTCOME MEASURES: On the first day of diagnosis (Day 0), nasopharyngeal swab samples were taken, on the third and fifth days the nasopharyngeal viral load (NVL) reduction in quantitative RT-PCR test was calculated. RESULTS: Between the zeroth to third days and zeroth to fifth days, the NVL reduction was significant in all groups (p < .05). In paired comparisons of groups, the NVL decrease in Group 4 in the first 3 days was significantly lower than all groups (p < .05). The NVL decrease in Groups 3 and 4 in the first 5 days were significantly lower than Group 1 (p < .05). CONCLUSION: This study revealed that the use of NI of 1% PVP-I and the hypertonic alkaline solution mixture was more effective in reducing NVL.

Long-term follow-up of treatment-naïve HBeAg-negative patients with chronic hepatitis B.

BACKGROUND/AIMS: We aimed to explore long-term results of oral antiviral agents in treatment-naïve "HBeAg negative chronic hepatitis B (CHB)" and determine the factors affecting the complete virological response. METHOD: Patients with HBeAg-negative CHB who used oral antiviral agents for at least 3 years were evaluated retrospectively. RESULTS: A total of 173 patients were recorded. The mean duration of treatment was 62.2 ± 28.9 months. Complete virological responses (CVR) were 82.8% (n = 53/64) in tenofovir disoproxil fumarate (TDF), 84.4% (n = 49/58) in lamivudine (LAM), 83.9% (n = 26/31) in entecavir (ETV), 95% in telbivudine (LdT) (n = 19/20) (p = 0.290). Multivariate analysis revealed age ≤ 40 (p = 0.012, 95%CI = 1.38-13.76, OR = 4.36) and baseline HBV DNA value (p = 0.003, 95%CI = 1.23-2.63, OR = 1.78) as independent factors for CVR. Virological breakthrough was detected in 29 (50%) patients on LAM therapy, two (6.4%) patients on ETV therapy, and two (10%) patients on LdT therapy. Treatment was switched to another antiviral agent due to osteoporosis in four patients in the TDF group, muscle pain in nine patients in the LDT group, and headache in one patient in the ETV group. Hepatocelluler cancer was detected in five patients. HBsAg seroclearance developed in two patients. Anti-HBs seroconversion was not detected. CONCLUSION: CVR was achieved at similar rates with all four antiviral agents, while younger age (≤ 40) and low baseline viral load were the main factors for virological response. However, drug resistance and virological breakthrough in the LAM group and side effects in the LdT group were detected during the long-term follow-up. Moreover, HBsAg seroclearance was achieved at very low rates with oral antiviral agents.

Waning immunity to inactive SARS-CoV-2 vaccine in healthcare workers: booster required.

AIMS: Despite high vaccination rates, increasing case numbers continue to be reported with the identification of new variants of concern, and the issue of durability of the vaccine-induced immune response remains hot topic. Real-life data regarding time-dependent immunogenicity of inactivated COVID-19 vaccines are scarce. We aimed to investigate the changes in the antibody at the different times after the second dose of the CoronaVac vaccine. METHODS: The study included 175 HCWs vaccinated with inactive CoronaVac (Sinovac Life Sciences, China) SARS-CoV-2 vaccine in two doses. Anti-spike/RBD IgG levels were measured first, third, and sixth months after the second dose. Chemiluminescent microparticle immunoassay (IgG II Quant test, Abbott, USA), which is 100% compatible with plaque reduction neutralization test, was used. RESULTS: Mean age of the participants was 38 ± 11.23 years (range between 22 and 66) of whom 119 (63.9%) were female, and 56 (32%) were male. Dramatic reductions were demonstrated in median antibody levels particularly in the infection-naïve group, comprising 138 HCWs compared to those with prior history of COVID-19 infection (n = 37) (p < 0.001). There was no difference between the two groups in terms of age, gender, blood groups, BMI, and comorbid diseases. CONCLUSIONS: While antibody positivity remained above 90% in the 6th month after two doses of inactivated vaccine in HCWs, the median titers of neutralizing antibodies decreased rapidly. The decrease was more rapid and significant in those with no history of prior COVID-19 infection. In this critical phase of the pandemic, where we are facing the dominance of the Omicron variant after Delta, booster doses have become vital.

Performance of noninvasive fibrosis indices in chronic hepatitis B during pretreatment and post-treatment periods.

Background: Pretreatment and post-treatment performances of noninvasive fibrosis indices were determined in patients with chronic hepatitis B. Method: This was a retrospective, single-center study. Results: The best area under the receiver operating characteristic curve values were detected for aspartate aminotransferase-to-alanine aminotransferase ratio (0.685) for ≥F2, Fibrosis Index (FI; 0.703) for ≥F3; FI (0.872) for ≥F4 and FI (0.864) for cirrhosis. After antiviral treatment, the best area under the receiver operating characteristic curve values were detected in aspartate aminotransferase-to-alanine aminotransferase ratio (0.615) for ≥F2; in FI based on four factors (FIB-4; 0.634) for ≥F3; in FIB-4 (0.678) for ≥F4 and in FIB-4 (0.814) for cirrhosis. Conclusion: FIB-4 and FI showed better performance in defining advanced fibrosis (≥F4) and cirrhosis.

Association between presence of Bacillus Calmette-Guerin vaccine scar and coronavirus disease 2019.

Bacillus Calmette-Guerin vaccine is administered for protection against tuberculosis and may also have beneficial effects against some viral respiratory tract infections. In this study, it was aimed to investigate the relationship between Bacillus Calmette-Guerin vaccination which is confirmed by BCG scar, and the frequency and course of Coronavirus disease 2019 (COVID-19). Among 490 patients, 400 patients who accepted to participate in the study were included. After the consent of patients, age, gender, body mass index, comorbidities, smoking, history, and the progress of COVID-19 of these patients were investigated; the presence and number of Bacillus Calmette-Guerin scars were recorded by a physician. Data from groups with and without COVID-19 history were compared. There was no relation between presence and number of the BCG scar and COVID-19 related hospitalization and intensive care unit admission. When groups with and without COVID-19 history compared, no statistically significant difference was found with the presence and number of Bacillus Calmette-Guerin scars (P > 0,05). No association was found between the presence or number of BCG scars and the frequency and course of COVID-19 in individuals with Bacillus Calmette-Guerin vaccination history confirmed by the presence of Bacillus Calmette-Guerin vaccine scars. Currently, the most important protection against COVID-19 is the COVID-19 vaccine.

Assessment of the role of neutrophil extracellular traps in SARS-CoV-2 pneumonia.

BACKGROUND: Abnormal neutrophil extracellular traps are associated with lung diseases, thrombosis, increased mucosal secretion in the airways. The aim of this study is to evaluate the possible place of the most specific NETosis marker Cit-H3 protein in diagnostic algorithms by revealing its relationship with the severity, mortality and prognosis of SARS-CoV-2 pneumonia. PATIENTS AND METHODS: Patients (n = 78) who applied to the Emergency Department between March 11, 2020 and June 10, 2020, with positive SARS-CoV-2 polymerase chain reaction (PCR) test and lung involvement were included in the prospective study. Serum Cit-H3 levels and critical laboratory parameters were measured at baseline on the day of clinical deterioration and before recovery/discharge/death. Cit-C3 levels were determined by enzyme immunassay method. RESULTS: Cit-H3 levels in patients with SARS-CoV-2 pneumonia during their first admission to the hospital were significantly higher compared to the healthy control group (p < 0.05). Repeated measurements of Cit-H3 levels of the patients significantly correlated with D-dimer, procalcitonin, Neutrophil/ Lymphocyte ratio, lymphocyte, CRP, and oxygen saturation. Cit-H3 levels of the patients who died were significantly higher than that of those who survived (p < 0.05). Cit-H3 levels were found to be statistically significantly higher in patients who developed acute respiratory distress syndrome, were admitted to the intensive care unit, and had mortality (p < 0.05). CONCLUSIONS: Cit-H3 plays a role in inflammatory processes in SARS-CoV-2 pneumonia, and changes in serum Cit-H3 levels of these patients can be used to determine prognosis and mortality (Tab. 5, Fig. 1, Ref. 21).

Comparison of SARS-CoV-2 Antibody Levels after a Third Heterologous and Homologous BNT162b2 Booster Dose.

This study aimed to determine the anti-S (receptor binding protein) RBD IgG antibody titers formed against Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV2) and the neutralizing antibody inhibition percentages (nAb IH%) in blood samples taken after two doses of inactive or mRNA-based vaccine and a booster dose. Volunteers with two doses of inactivated CoronaVac (heterologous group; n = 75) and BioNTech (BNT)162b2 mRNA vaccine (homologous group; n = 75) were included in this study. All participants preferred the BNT162b2 vaccine as a booster dose. First, peripheral blood samples were taken 3 months after the second vaccine dose. Second, peripheral blood samples were taken 1 month after the booster dose. Anti-S-RBD IgG titers were determined by CMIA (SARS-CoV-2 IgG II Quant). Neutralizing antibodies were detected by a surrogate neutralization assay (SARS-CoV-2 NeutraLISA, Euroimmun, Lübeck, Germany). The median age of the volunteers was 40 (IQR 29-47) years old. After the heterologous booster dose, anti-S-RBD IgG levels and neutralizing antibodies increased approximately 50-fold and 9-fold, respectively. Anti-S-RBD IgG titers increased by 9 and 57 times, respectively, while nAb IH% increased by 1.5 and 16 times, respectively, among those with heterologous reminder doses and those with and without a prior history of coronavirus disease (COVID-19). This study showed that after the administration of a heterologous booster dose with BNT162b2 to those whose primary vaccination was with inactivated CoronaVac, the binding and neutralizing antibody levels were similar to those who received a homologous BNT162b2 booster dose. It was observed that the administration of heterologous and homologous booster doses resulted in the development of similar levels of neutralizing antibodies, independently from a prior history of COVID-19.

Changing Bacterial Etiology and Antimicrobial Resistance Profiles as Prognostic Determinants of Diabetic Foot Infections: A Ten-Year Retrospective Cohort Study.

Background: In this single-center study, we analyzed a retrospective cohort of patients with diabetic foot infections (DFIs) between 2011 and 2020. Patients and Methods: The first and second five-year periods were compared. A poor prognosis was defined as a primary composite end point including re-infection, major amputation, or mortality at six months. Results: A total of 484 patients were enrolled. Overall, 269 patients had the primary composite end point. A substantial decrease was detected in the second five-year period in terms of re-infection (n = 132, 66.0% vs. n = 68, 23.9%; p < 0.001) and mortality (n = 22, 11.0% vs. n = 7, 2.5%; p < 0.001). A total of 798 micro-organisms were isolated from 484 patients. A substantial increase was detected in polymicrobial infections (48.5% vs. 65.1%; p = 0.001) as well as Streptococcus spp. (2.5% vs. 9.2%; p = 0.003), Corynebacterium spp. (9.5% vs. 22.9%; p < 0.001), and extended-spectrum ß-lactamase (ESBL) producing Escherichia coli (3.0% vs. 12.7%; p < 0.001) in the second five-year period, whereas the prevalence of multi-drug-resistanct (MDR) Pseudomonas aeruginosa (17.0% vs. 10.2%; p = 0.029) and carbapenem-resistant Acinetobacter baumannii (7.5% vs. 2.8%; p = 0.017) decreased. Multivariable regression analysis revealed that MDR Pseudomonas aeruginosa (odds ratio [OR], 1.917; 95% confidence interval [CI], 1.074-3.420; p = 0.028) and carbapenem-resistant Acinetobacter baumannii (OR, 3.069; 95% CI, 1.114-8.453; p = 0.030) were independent predictors for poor prognosis. Conclusions: This 10-year cohort study provides reassuring information about the changing epidemiology of DFIs and the prognostic determinants in patients with DFIs.

Association of SARS-CoV-2 IgG Antibody Levels with Clinical/Laboratory Characteristics in COVID-19 Patients: Data from a Turkish Study.

BACKGROUND: COVID-19 causes clinical manifestations ranging from asymptomatic infection to multi-organ failure. It is reported that those with severe disease have higher anti-SARS-CoV-2 antibody titers compared to asymptomatic or mild cases. We evaluated the correlation of antibody responses with laboratory and clinical indicators in COVID-19 patients. METHODS: Seventy-nine male and 66 female patients (mean age: 39) with at least one positive SARS-CoV-2 RT-PCR test and SARS-CoV-2 IgG antibody result after acute infection were included. RESULTS: Seventy-six (52%), 45 (31%), and 24 (17%) patients had mild, moderate, and severe clinical findings, respectively. Patients with high body mass index and advanced age had significantly more severe disease (p < 0.001). A significant correlation was found between the increase in lymphopenia, C-reactive protein, ferritin, D-dimer, and lactate dehydrogenase and the severity of clinical findings (p = 0.0001). SARS-CoV-2 IgG antibody test was positive in 128 (88.3%) patients. A significant correlation was found between disease severity and antibody levels in the comparison of all groups (p < 0.001). CONCLUSIONS: Long-term monitoring of immune responses will be required to determine the appropriate time for the administration of new vaccines.