Microbiota composition may play a role in the development, prognosis, or post-infection of COVID-19. There are studies evaluating the microbiota composition at the time of diagnosis and during the course of COVID-19, especially in adults, while studies in children are limited and no study available in children with multisystem inflammatory syndrome in children (MIS-C). This study was planned to compare intestinal microbiota composition in children diagnosed with MIS-C and acute COVID-19 infection with healthy children. In this prospective multicenter study, 25 children diagnosed with MIS-C, 20 with COVID-19 infection, and 19 healthy children were included. Intestinal microbiota composition was evaluated by 16 s rRNA gene sequencing. We observed changes of diversity, richness, and composition of intestinal microbiota in MIS-C cases compared to COVID-19 cases and in the healthy controls. The Shannon index was higher in the MIS-C group than the healthy controls ( p < 0.01). At phylum level, in the MIS-C group, a significantly higher relative abundance of Bacteroidetes and lower abundance of Firmicutes was found compared to the control group. Intestinal microbiota composition changed in MIS-C cases compared to COVID-19 and healthy controls, and Faecalibacterium prausnitzii decreased; Bacteroides uniformis , Bacteroides plebeius , Clostridium ramosum , Eubacterium dolichum , Eggerthella lenta , Bacillus thermoamylovorans , Prevotella tannerae , and Bacteroides coprophilus were dominant in children with MIS-C. At species level, we observed decreased Faecalibacterium prausnitzii , and increased Eubacterium dolichum , Eggerthella lenta , and Bacillus thermoamylovorans in children with MIS-C and increased Bifidobacterium adolescentis and Dorea formicigenerasus in the COVID-19 group. Our study is the first to evaluate the microbiota composition in MIS-C cases. There is a substantial change in the composition of the gut microbiota: (1) reduction of F. prausnitzii in children with MIS-C and COVID-19; (2) an increase of Eggerthella lenta which is related with autoimmunity; and (3) the predominance of E. dolichum is associated with metabolic dysfunctions and obesity in children with MIS-C. Conclusions : Alterations of the intestinal microbiota might be part of pathogenesis of predisposing factor for MIS-C. It would be beneficial to conduct more extensive studies on the cause-effect relationship of these changes in microbiota composition and their effects on long-term prognosis. What is Known: • Mi...

GirişTrombositopeni için farklı tanımlamalar olmakla beraber tam kan sayımındaki trombosit sayısının 150.000/μL altında olması trombositopeni olarak kabul edilir (1). Ancak bazı yazarlar tarafından trombositopeni sınırı 100.000/μL olarak kabul edilmektedir (2, 3). Trombositopenisi olan hastalarda beklenen en önemli problem kanamadır. Kanama riski trombosit değerleri ile ters orantılıdır (1).Objective: Thrombocytopenia is common in intensive care units (ICUs) and is associated with high mortality. The aim of this study was to determine the incidence of thrombocytopenia and to evaluate the factors affecting the development of thrombocytopenia in patients who stayed at a medical intensive care unit (MICU). Material and Methods:This study was conducted retrospectively in a MICU. The data were obtained from patients' folders and the hospital's electronic records system. Patients who stayed for more than 24 h in the ICU were included in the study. The demographic data, the worst laboratory values in the first 24 h, the lowest platelet counts, and medications that can cause thrombocytopenia were recorded.Results: A total of 237 patients were included in this study; 106 of them (45%) were female and 131 (55%) were male. Their average age was 62±18 years. The most common reasons for hospitalization in the ICU were respiratory failure (33%) and neurological diseases (13%). During follow-up, 45% of the patients developed thrombocytopenia. The mean APACHE-II score was 24±10 and SOFA score was 9±4. The mean MODS score was 6±3, and it was higher in the patients who developed thrombocytopenia than those who did not (p<0.0001). Upon analyzing the factors affecting the development of thrombocytopenia, prophylactic or therapeutic heparin use was determined in 61% of the patients. It was determined that 106 patients (45%) were using one or more drugs that can trigger thrombocytopenia. The patients who developed thrombocytopenia stayed longer in the ICU (p=0.042), and their overall mortality rate was higher than those who did not develop thrombocytopenia (91% vs. 55%; p<0.0001). Bulgular: Çalışmaya 237 hasta dâhil edildi. Hastaların 106'sı kadın (%45), 131'i ise erkekti (%55). Yaş ortalaması 62±18 yıl idi. En sık yoğun bakıma yatış nedenleri; solunum yetmezliği (%33) ve nörolojik hastalıklar (%13) idi. Takiplerinde hastaların %45'inde trombositopeni gelişti. Hastaların ortalama APACHE II skoru 24±10, SOFA skoru 9±4 ve MODS skoru 6±3 idi ve trombositopeni gelişen hastalarda gelişmeyenlere göre daha yüksek bulundu (p<0,0001). Trombositopeni gelişimini etkileyen faktörler incelendiğinde hastaların %61'inin profilaktik veya tedavi dozunda heparin aldığı tespit edildi. Hastaların 106'sında (%45) ise bir veya daha fazla trombositopeni yapan ilaç kullanıldığı görüldü. Trombositopeni gelişen hastalarda yoğun bakımda kalma süresi daha uzun idi (p=0,042). Hastaların genel mortalitesi trombositopeni gelişenlerde gelişmeyenlere göre daha yüksek idi (%91 ve %55; p<0,0001).

Meningococcal carriage studies and transmission modeling can predict IMD epidemiology and used to define invasive meningococcal disease (IMD) control strategies. In this multicenter study, we aimed to evaluate the prevalence of nasopharyngeal Neisseria meningitidis (Nm) carriage, serogroup distribution, and related risk factors in Turkey. Nasopharyngeal samples were collected from a total of 1267 children and adolescents and were tested with rt-PCR. Nm carriage was detected in 96 participants (7.5%, 95% CI 6.1–9.0), with the peak age at 13 years (12.5%). Regarding age groups, Nm carriage rate was 7% in the 0–5 age group, was 6.9%in the 6–10 age group, was 7.9% in the 11–14 age group, and was 9.3% in the 15–18 age group. There was no statistically significant difference between the groups (p > 0.05). The serogroup distribution was as follows: 25% MenX, 9.4% MenA, 9.4% MenB, 2.1% MenC, 3.1% MenW, 2.1% for MenY, and 48.9% for non-groupable. The Nm carriage rate was higher in children with previous upper respiratory tract infections and with a high number of household members, whereas it was lower in children with antibiotic use in the last month (p < 0.05 for all). In this study, MenX is the predominant carriage strain. The geographical distribution of Nm strains varies, but serogroup distribution in the same country might change in a matter of years. Adequate surveillance and/or a proper carriage study is paramount for accurate/dynamic serogroup distribution and the impact of the proposed vaccination.

In the original published version of the above article, the coauthor's name "Saliha Kanik Yuksek" should have been presented as "Saliha Kanik-Yuksek" and cited as Kanik-Yuksek S. The name is presented correctly above.The original article has been corrected.Publisher's Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Introduction: While there is a significant amount of information about invasive meningococcal disease (IMD), meningococcal carriage, and meningococcal vaccines in children and adolescents, data in older adults are limited. Studies of meningococcal carriage and transmission modeling can be utilized to predict the spread of IMD and guide prevention and treatment strategies. Our study’s main objective was to assess the prevalece of Neisseria meningitidis (Nm) carriage, serogroup distribution, and associated risk factors among older adults in Türkiye. Methods: Nasopharyngeal samples were collected between December 2022 and January 2023 from a total of 329 older adults (65 years of age and above). The samples were tested via PCR for Nm, and a serogroup (A, B, C, Y, W, X, E, Z, H) analysis of the positive samples was performed. Results: In total, 329 adults over 65 years of age (150 females and 179 males; 69% were 65–75 years old and 31% were 75 years of age and older) were included in the study. Nm carriage was detected in 46 participants (13.9%), and the serogroup distribution was as follows: 2.4% MenY (n = 8), 1.8% MenB (n = 6), 0.2% MenW (n = 2), and 9.4% non-groupable (n = 31). Other serogroups were not detected. Between the meningococcal carriers and the non-carriers, there were no differences between previous vaccination histories (meningococcal, pneumococcal, influenza, and COVID-19), travel history for Hajj and/or Umrah, and the presence of chronic disease. Of the 16 cases positive for the serogroups Y, B, and W, 13 patients were between the ages of 65 and 74 and three patients were over 75 years old, and these three cases represented MenY. Conclusion: In our study, the percentage of meningococcal carriage was found to be 13.9%, the carriage rate for encapsulated strains was 4.8%, and the most common serogroup was MenY. Men Y was also the only serogroup detected in patients over 75 years of age. The MenY serogroup, which is one of the most important causes of IMD (especially in pneumonia cases) in people older than 65 years, was the most frequently carried serogroup in people over 65 years of age in our study. Adequate surveillance and/or a proper carriage study would help to define potential vaccination strategies for older adults.