Langerhans cells (LCs) constitute a cellular immune network across the epidermis. Because they are located at the skin barrier, they are considered immune sentinels of the skin. These antigen-presenting cells are capable of migrating to skin draining lymph nodes to prime adaptive immune cells, namely T- and B-lymphocytes, which will ultimately lead to a broad range of immune responses. Moreover, LCs have been shown to possess important roles in the anti-cancer immune responses. Indeed, the literature nicely highlights the role of LCs in melanoma. In line with this, LCs have been found in melanoma tissues where they contribute to the local immune response. Moreover, the immunogenic properties of LCs render them attractive targets for designing vaccines to treat melanoma and autoimmune diseases. Overall, future studies will help to enlarge the portfolio of immune properties of LCs, and aid the prognosis and development of novel therapeutic approaches to treating skin pathologies, including cancers.

The 2022–2023 influenza season in Romania was characterized by high pediatric hospitalization rates, predominated due to influenza A subtypes (H1N1) pdm09 and H3N2. The lowered population immunity to influenza after the SARS-CoV-2 pandemic and the subsequent stoppage of influenza circulation, particularly in children who had limited pre-pandemic exposures, influenced hospitalization among immunosuppressed children and patients with concurrent medical conditions who are at an increased risk for developing severe forms of influenza. This study focused on the characteristics of influenza issues among pediatric patients, as well as the relationship between different influenza virus types/subtypes and viral and bacterial co-infections, as well as illness severity in the 2022–2023 season after the SARS-CoV-2 pandemic. We conducted a retrospective clinical analysis on 301 cases of influenza in pediatric inpatients (age ≤ 18 years) who were hospitalized at the National Institute of Infectious Diseases “Prof. Dr. Matei Balș” IX Pediatric Infectious Diseases Clinical Section between October 2022 and February 2023. The study group’s median age was 4.7 years, and the 1–4 year age group had the highest representation (57.8%). Moderate clinical forms were found in 61.7% of cases, whereas severe versions represented 18.2% of cases. Most of the complications were respiratory (acute interstitial pneumonia, 76.1%), hematological (72.1%, represented by intra-infectious and deficiency anemia, leukopenia, and thrombocytopenia), and 33.6% were digestive, such as diarrheal disease, liver cytolysis syndrome, and the acute dehydration syndrome associated with an electrolyte imbalance (71.4%). Severe complications were associated with a risk of unfavorable evolution: acute respiratory failure and neurological complications (convulsions, encephalitis). No deaths were reported. We noticed that the flu season of 2022–2023 was characterized by the association of co-infections (viral, bacterial, fungal, and parasitic), which evolved more severely, with prolonged hospitalization and more complications (p < 0.05), and the time of use of oxygen therapy was statistically significant (p < 0.05); the number of influenza vaccinations in this group was zero. In conclusion, co-infections with respiratory viruses increase the disease severity of the pediatric population to influenza, especially among young children who are more vulnerable to developing a serious illness. We recommend that all people above the age of six months should receive vaccinations against influenza to prevent the illness and its severe complications.

Background: Given the potential for additional development to clarify a better knowledge of generally influence of COVID-19 upon the pediatric population, the clinical symptoms of SARS-CoV-2 infection in children and adolescents are still being explored. Morbidity in children is characterized by a variable clinical course. Our study’s goal was to compare clinical aspects of 230 pediatric patients who analyzed positive for SARS-CoV-2 and were hospitalized between April 2020 and March 2022. Methods: This retrospective study aimed to compare the clinical characteristics of coronavirus disease 2019, (COVID-19) in two groups of pediatric patients hospitalized in the infectious disease clinical ward IX at the National Institute for Infectious Diseases “Prof. Dr. Matei Bals,” Bucharest, Romania. Clinical characteristics of 88 patients (first group), admitted between April–December 2020 were compared with the second group of 142 children admitted between July 2021 and March 2022. Results: Of 230 children, the median age was 4.5 years, and 53.9% were male. Fever (82.17%) and sore throat (66%) were the most common initial symptoms. Rhinorrhea (42%), cough (34%) and diarrhea (41.74%), with abdominal pain (26%) were also reported in a considerable number of cases. 88 (36.21%) patients (first group) were admitted during the second wave in Romania, mostly aged <5 years old, and experienced digestive manifestations like fever (p = 0.001), and diarrhea (p = 0.004). The second group experienced different clinical signs when compared with the first group, with higher temperature and increased respiratory symptoms analogous to persons who suffer acute respiratory viral infections. The proportion in the second group increased by 23.48% from the first group, and the 0–4 age group for both groups had symptoms for a median interval of 5 days; age (0–4-years old) and length of stay were both proportionally inversely and required longer hospitalization (5 days), for the first group. During study time, the fully vaccinated children for 5–12 years old were 10%, and for 13–18 years old, 14.35% respective. We report two Pediatric Inflammatory Multisystem Syndrome (PIMS) in the second group, with favorable evolution under treatment. Comorbidities (obesity and oncological diseases) were reported in both groups and are risk factors for complications appearing (p < 0.001). All pediatric cases admitted to our clinic evolved favorably and no death was recorded. Conclusions: Clinical characteristics of pediatric patients with COVID-19 are age-related. In the first group, 85.29% of 0–4 years old children experienced digestive symptoms, whereas in the second group 83.78% underwent mild and moderate respiratory symptoms for the 5–12 age range. The potential effects of COVID-19 infection in children older than 5 years should encourage caregivers to vaccinate and improve the prognosis among pediatric patients at risk.

Dendritic cells (DCs) are antigen-presenting cells with an important role in the innate and adaptive immune system. In skin lesions, cutaneous DCs (Langerhans cells, dermal DCs and plasmacytoid DCs) are involved in immune activation in inflammatory benign lesions, as well as in malignant lymphoid proliferations. Density and distribution of DCs in the dermal infiltrate can be helpful to differentiate benign, reactive infiltrate from malignant nature of the lymphoid population. We performed a retrospective study including 149 patients: 35 with mycosis fungoides, 35 with spongiotic dermatitis, 35 with psoriasis, 35 with lupus and 9 with cutaneous T-cell lymphomas (other than mycosis fungoides), diagnosed using histopathological and immunohistochemical stains. Density and distribution of DCs were evaluated using specific markers (CD1a, CD11c and langerin). In all cases, numerous DCs were identified in the dermal infiltrate. Their number was significantly increased in mycosis fungoides and T-cell lymphomas and moderately increased in inflammatory lesions. Variable patterns of distribution were identified such as clusters of DCs with arachnoid extension in mycosis fungoides, nodular pattern in inflammatory lesions and dispersed distribution with peripheric accumulation in T-skin lymphomas. Therefore, immunohistochemical characterization of DC distribution can be an adjuvant tool in differential diagnosis in inflammatory dermatosis and skin lymphomas.

A1 The outcome of patients with recurrent versus non-recurrent pneumococcal meningitis in a tertiary health-care hospital in Bucharest Cristian-Mihail Niculae, Eliza Manea, Raluca Jipa, Simona Merisor, Ruxandra Moroti, Serban Benea, Adriana Hristea A2 Influence of bacteriophages on sessile Gram-positive and Gram-negative bacteria Alina Cristina Neguț, Oana Săndulescu, Anca Streinu-Cercel, Dana Mărculescu, Magdalena Lorena Andrei, Veronica Ilie, Marcela Popa, Coralia Bleotu, Carmen Chifiriuc, Mircea Ioan Popa, Adrian Streinu-Cercel A3 The utility of inflammatory biomarkers in the prognostic evaluation of septic patients – past, present and future Alina Orfanu, Cristina Popescu, Anca Leuștean, Remulus Catană, Anca Negru, Alexandra Badea, Radu Orfanu, Cătălin Tilișcan, Victoria Aramă, Ştefan Sorin Aramă A4 Etiologic and clinical features of bacterial meningitis in infants Constanța-Angelica Vișan, Anca-Cristina Drăgănescu, Anuța Bilașco, Camelia Kouris, Mădălina Merișescu, Magdalena Vasile, Diana-Maria Slavu, Sabina Vintilă, Endis Osman, Alina Oprea, Sabina Sandu, Monica Luminos A5 The diagnostic and prognostic role of neutrophil to lymphocyte count ratio in sepsis Alina Orfanu, Victoria Aramă, Ştefan Sorin Aramă, Anca Leuştean, Remulus Catană, Anca Negru, Gabriel Adrian Popescu, Cristina Popescu A6 Whooping cough in a HIV positive patient Ramona Georgiana Stanculete, Ana Vaduva Enoiu, Adelina Raluca Marinescu, Voichita Lazureanu A7 Cronobacter sakazakii sepsis in varicella patient Adelina-Raluca Marinescu, Alexandru Crișan, Voichița Lăzureanu, Virgil Musta, Narcisa Nicolescu, Ruxandra Laza A8 Anaerobes an underdiagnosed cause of prosthesis joint infection Anca-Ruxandra Negru, Daniela-Ioana Munteanu, Raluca Mihăilescu, Remulus Catană, Olga Dorobăț, Alexandru Rafila, Emilia Căpraru, Marius Niculescu, Rodica Marinescu, Olivera Lupescu, Vlad Predescu, Adrian Streinu-Cercel, Victoria Aramă, Daniela Tălăpan A9 Streptococcus pneumoniae meningitis presenting with normal CSF – case presentation Ramona Ștefania Popescu, Luminița Bradu, Dragoș Florea, Adrian Streinu-Cercel A10 Extrapulmonary manifestations of infection with Mycoplasma pneumoniae – study on 24 cases Daniela Anicuta Leca, Elena Bunea, Andra Teodor, Egidia Miftode A11 The molecular diagnosis of severe bacterial sepsis in pediatric population Mădălina Merișescu, Gheorghiță Jugulete, Adrian Streinu-Cercel, Dragoș Florea, Monica Luminos A12 Acute Staphylococcus aureus endocarditis with multiple septic complications in a patient with diabetes mellitus – case presentation Ramona Ștefania Popescu, Anamaria Dobrotă, Adina Ilie, Liliana Lucia Preoțescu A13 Is Streptococcus suis meningitis an under-diagnosed zoonosis? Adriana Hristea, Raluca Jipa, Nicoleta Irimescu, Irina Panait, Eliza Manea, Simona Merisor, Cristian Niculae, Daniela Tălăpan A14 Klebsiella pneumoniae isolated from blood. Antimicrobial resistance – past and present Liana Cătălina Gavriliu, Otilia Elisabeta Benea, Șerban Benea, Alexandru Rafila, Olga Dorobăț, Mona Popoiu A15 Antibiotics resistance in Staphylococcus aureus isolated from blood cultures Livia Dragonu, Augustin Cupşa, Iulian Diaconescu, Irina Niculescu, Lucian Giubelan, Florentina Dumitrescu, Andreea Cristina Stoian, Camelia Guţă, Simona Puiu A16 Predominance of CTX-M enzymes in extended-spectrum β-lactamase-producing Enterobacteriaceae in two hospitals of Quebec City Bunescu Irina, Marilyse Vallée, Ann Huletsky, Dominique K. Boudreau, Ève Bérubé, Richard Giroux, Jean Longtin, Yves Longtin, Michel G. Bergeron A17 Postoperative meningoencephalitis with Acinetobacter baumannii XDR – a therapeutic challenge - Case report Cleo Nicoleta Roșculeț, Dalila-Ana Toma, Catrinel Ciuca, Daniela Tălăpan, Cătălin Apostolescu, Andrei Rogoz, Andrei Stangaciu, Viorica Mitescu, Tudor Vladoiu, Doina Iovănescu A18 Septic arthritis with Burkholderia cepacia Michaela Oana, Simona Costin A19 A novel approach for managing hard-to-treat infections Alina Cristina Neguț, Oana Săndulescu, Anca Streinu-Cercel, Maria Magdalena Moțoi, Mircea Ioan Popa, Adrian Streinu-Cercel A20 Nineteen months surveillance for multidrug resistant organisms (MDRO) by detecting asymptomatic colonization Daniela Tălăpan, Olga Mihaela Dorobăț, Mona Popoiu, Alexandru Mihai, Doina Iovănescu, Cleo Roşculeț, Cătălin Apostolescu, Gabriel-Adrian Popescu, Adrian Abagiu, Ruxandra Moroti-Constantinescu, Adriana Hristea, Victoria Aramă, Otilia Benea, Mădălina Simoiu, Rodica Bacruban, Adrian Streinu-Cercel, Alexandru Rafila A21 Antimicrobial resistance of Gram-positive cocci isolated from clinical specimens in the National Institute of Infectious Diseases “Prof Dr. Matei Balș” between 2009–2015 Olga Mihaela Dorobăț, Daniela Tălăpan, Alexandru Mihai, Ioana Bădicuț, Mona Popoiu, Alina Borcan, Alexandru Rafila A22 The high percentage of carbapenem-resistant Gram-negative bacilli in Romania: an analysis and some proposals Gabriel Adrian Popescu A23 Etiological, clinical and therapeutic considerations on 78 cases of healthcare associated meningitis or ventriculitis admitted in the “Sf. Parascheva” infectious diseases clinical hospital, Iași, from 2011 to 2015 Mihnea Hurmuzache, Georgiana Enache, Alexandra Ciocan, Mircea Bararu, Madalina Popazu A24 Nosocomial infection dynamics in an Intensive Care Department – an overview (epidemiological and clinical monitoring, advanced therapeutic intervention). Doina Viorica Iovănescu, Cleo Nicoleta...

Background: Given the potential for additional development to clarify a better knowledge of the overall impact of COVID-19 on the pediatric population, the clinical symptoms of SARS-CoV-2 infection in children and adolescents are still being explored. Morbidity in children is characterized by a variable clinical course. Our study's goal was to compare clinical aspects of 230 pediatric patients who tested positive for SARS-CoV-2 and were hospitalized between April 2020 and March 2022. Methods: In a retrospective analysis, we compared two groups hospitalized in the infectious diseases clinical ward IX at the National Institute for Infectious Diseases "Prof. Dr. Matei Bals," Bucharest, Romania. The first group of 88 patients was admitted between (April–December 2020) and their clinical manifestations were compared with the second group of 142 children followed between July 2021 and March 2022. Results: Of 230 children, the median age was 4.5 (interquartile range 0.6-17) years, 53.9% were male. 88 (36.21%) patients (first group) were admitted during the second wave in Romania, mostly aged < 5 years old, and experienced digestive manifestations like fever (p=0.001), and diarrhoea (p=0.004). The second group experienced different clinical signs when compared with the first group, with higher temperature and increased respiratory symptoms analogous to those of acute respiratory viral infections. The proportion in the second group increased, and 64.5% had symptoms for a median interval of 5 days; age (0-4 -years old) and length of stay were both proportionally inversely (p<0.01) and with correlation with hospital admission (p = 0.04). We report two Paediatric Inflammatory Multisystem Syndrome (PIMS) in the second group, with favourable evolution under treatment. Comorbidities were risk factors for complications appear (p < 0.001) in both groups. All paediatric cases admitted to our clinic evolved favourably and no death was recorded. Conclusions: In the first group children experienced digestive symptoms, whereas the second group experienced mild and moderate respiratory symptoms. We confirmed risk factors for severe cases as manifestations across the age spectrum, 0-4 (digestive symptoms) and 5-12 years old (for respiratory symptoms), associated comorbidities, fever, and male gender. The potential effects of COVID-19 infection in children older than 5 years should encourage caregivers to vaccinate and improve the prognosis among pediatric patients at risk.