Lymphocyte B Subtypes in Peripheral Blood: A Prognostic Biomarker for COVID-19 Patients.

BACKGROUND: In view of the scientific gap in knowledge of the involvement of the B-cell compartment and clinical prognostic in SARS-CoV-2 infection, this work aims to evaluate the B-cell subsets and the presence of specific IgM and IgG, as well as neutralizing antibodies against SARS-CoV-2, in unvaccinated patients diagnosed with COVID-19. METHODS: This study included 133 patients with COVID-19. Cellular components were assessed by flow cytometry, and immunoglobulin levels and reactivity were measured by indirect enzyme-linked immunosorbent assay. RESULTS: Our results showed no changes in less differentiated B cells. However, non-switched memory B cells (NS-MBCs) and class-switched memory B cells (CS-MBCs) were reduced in the patients with moderate disease. Also, plasmablasts and double-negative (DN) or "atypical" memory B cells were increased in groups of patients with moderate to critical conditions. In addition, the production of IgM, IgG, and neutralizing antibodies against SARS-CoV-2 demonstrated a positive correlation between the positivity of antibodies against SARS-CoV-2 and disease severity. Besides being related to the development of a more severe course of the disease, the increase in DN B-cell count also contributed to a poorer disease outcome in patients with a higher percentage of these cells. On the other hand, we observed an increase in the absolute number of CS-MBCs in patients with greater chances of survival. CONCLUSIONS: This study demonstrates that the B-cell compartment may contribute to the development of clinical symptoms of COVID-19, with changes in B-cell subset counts linked to disease course and patient prognosis.

T cell maturation is significantly affected by SARS-CoV-2 infection.

Coronavirus disease 2019 (COVID-19) is a respiratory tract infection caused by the new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). An adequate T cell response is essential not only for fighting disease but also for the creation of immune memory. Thus, the present study aims to evaluate the T cells of patients with moderate, severe and critical COVID-19 not only at the time of illness but also 2 months after diagnosis to observe whether changes in this compartment persist. In this study, 166 COVID-19 patients were stratified into moderate/severe and critical disease categories. The maturation and activation of T cells were evaluated through flow cytometry. In addition, Treg cells were analysed. Until 15 days after diagnosis, patients presented a reduction in absolute and relative T lymphocyte counts. After 2 months, in moderate/severe patients, the counts returned to a similar level as that of the control group. In convalescent patients who had a critical illness, absolute T lymphocyte values increased considerably. Patients with active disease did not show differentiation of T cells. Nonetheless, after 2 months, patients with critical COVID-19 showed a significant increase in CD4+ EMRA (CD45RA+ effector memory) T lymphocytes. Furthermore, COVID-19 patients showed delayed T cell activation and reduced CD8+ suppressor T cells even 2 months after diagnosis. A reduction in CD4+ Treg cells was also observed, and their numbers returned to a similar level as that of healthy controls in convalescent patients. The results demonstrate that COVID-19 patients have a delayed activation and differentiation of T cells. In addition, these patients have a great reduction of T cells with a suppressor phenotype.

The relationship between peripheral immune response and disease severity in SARS-CoV-2-infected subjects: A cross-sectional study.

Coronavirus disease 2019 (COVID-19) is a respiratory infection caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and marked by an intense inflammatory response and immune dysregulation in the most severe cases. In order to better clarify the relationship between peripheral immune system changes and the severity of COVID-19, this study aimed to evaluate the frequencies and absolute numbers of peripheral subsets of neutrophils, monocytes, and dendritic cells (DCs), in addition to quantifying the levels of inflammatory mediators. One hundred fifty-seven COVID-19 patients were stratified into mild, moderate, severe, and critical disease categories. The cellular components and circulating cytokines were assessed by flow cytometry. Nitric oxide (NOx) and myeloperoxidase (MPO) levels were measured by colourimetric tests. COVID-19 patients presented neutrophilia, with signs of emergency myelopoiesis. Alterations in the monocytic component were observed in patients with moderate to critical illness, with an increase in classical monocytes and a reduction in nonclassical monocytes, in addition to a reduction in the expression of HLA-DR in all subtypes of monocytes, indicating immunosuppression. DCs, especially plasmacytoid DCs, also showed a large reduction in moderate to critical patients. COVID-19 patients showed an increase in MPO, interleukin (IL)-12, IL-6, IL-10, and IL-8, accompanied by a reduction in IL-17A and NOx. IL-10 levels ≥14 pg/ml were strongly related to the worst outcome, with a sensitivity of 78·3% and a specificity of 79·1%. The results of this study indicate the presence of systemic effects induced by COVID-19, which appear to be related to the pathophysiology of the disease, highlighting the potential of IL-10 as a possible prognostic biomarker for COVID-19.

Healthcare-Associated Infections-Related Bacteriome and Antimicrobial Resistance Profiling: Assessing Contamination Hotspots in a Developing Country Public Hospital.

Hospital-built environment colonization by healthcare-associated infections-related bacteria (HAIrB) and the interaction with their occupants have been studied to support more effective tools for HAI control. To investigate HAIrB dynamics and antimicrobial resistance (AMR) profile we carried out a 6-month surveillance program in a developing country public hospital, targeting patients, hospital environment, and healthcare workers, using culture-dependent and culture-independent 16S rRNA gene sequencing methods. The bacterial abundance in both approaches shows that the HAIrB group has important representativeness, with the taxa Enterobacteriaceae, Pseudomonas, Staphylococcus, E. coli, and A. baumannii widely dispersed and abundant over the time at the five different hospital units included in the survey. We observed a high abundance of HAIrB in the patient rectum, hands, and nasal sites. In the healthcare workers, the HAIrB distribution was similar for the hands, protective clothing, and mobile phones. In the hospital environment, the healthcare workers resting areas, bathrooms, and bed equipment presented a wide distribution of HAIrB and AMR, being classified as contamination hotspots. AMR is highest in patients, followed by the environment and healthcare workers. The most frequently detected beta-lactamases genes were, bla SHV-like, bla OXA- 23 -like, bla OXA- 51 -like, bla KPC-like, bla CTX-M- 1, bla CTX-M- 8, and bla CTX-M- 9 groups. Our results demonstrate that there is a wide spread of antimicrobial resistance due to HAIrB in the hospital environment, circulating among patients and healthcare workers. The contamination hotspots identified proved to be constant over time. In the fight for patient safety, these findings can reorient practices and help to set up new guidelines for HAI control.

Suscetibilidade a antimicrobianos de bactérias isoladas de culturas de urina provenientes do Hospital Universitário da Universidade Federal de Santa Catarina / Antimicrobial susceptibilty of urine culture bacterial isolates from a teaching hospital in Brazil

Este artigo descreve a frequência e o perfil de suscetibilidade a antimicrobianos dos microrganismos isolados em amostras de urina analisadas pelo laboratório de análises clínicas do Hospital Universitário Prof. Polydoro Ernani de São Thiago, localizado em Florianópolis ­ SC, Brasil. Os dados foram obtidos de exames de culturas de urina de origem comunitária, submetidas a testes de suscetibilidade antimicrobiana automatizada, realizadas no período de janeiro de 2013 a dezembro de 2016. Foram analisadas 7964 uroculturas. O microrganismo mais frequente foi Escherichia coli (65,7%), seguido por Klebsiella pneumoniae (8,5%), Proteus mirabilis (6,8%), e Enterococcus faecalis (4,9%). Destaca-se que na faixa etária <15 anos a prevalência do P. mirabilis foi de 13,5%, para o sexo feminino, e 37,7%, para o sexo masculino. Nos idosos (≥60 anos) a prevalência de E. faecalis foi de 6,0% para o sexo feminino e 13,8% para o sexo masculino. A suscetibilidade de E. coli ao ciprofloxacino na população foi de 83,9%, variando de 72,5% em homens a 85,4% em mulheres e de 97,7% em meninos entre 0-14 anos a 58,9% em homens com 60 anos ou mais. O modelo de regressão logística demonstrou que, para os isolados de E coli, o sexo masculino e o aumento da idade estão significantemente ligados a maior resistência a vários antimicrobianos, entre os quais o ciprofloxaxino (P<0,001). Concluiu-se que a frequência dos microorganismos identificados e seu perfil de sensibilidade variam conforme o sexo e a idade dos pacientes. Recomenda-se considerar tais fatores durante a escolha de antibioticoterapia empírica para infecções do trato urinário.

This article describes the frequency and susceptibility profile of microbial isolates from urine cultures samples analyzed by the Hospital Universitário Prof. Polydoro Ernani de São Thiago's clinical analysis laboratory, located in Florianópolis ­ SC, Brasil. Community-acquired isolates were analyzed between January, 2013 and December, 2016. A total of 7964 urine culture isolates were analyzed. Escherichia coli (65,7%), Klebsiella pneumoniae (8,5%), Proteus mirabilis (6,8%) and Enterococcus faecalis (4,9%) were the most frequent isolates. Among the age <15 years, P. mirabilis accounted for 13,5% and 37,7% of female and male respectively isolates. Within the elderly group (aged 60 years and over), E. faecalis was found in 6,0% and 13,8% of female and male respectively isolates. Ciprofloxacin resistance rates in E. coli was 83,9%, ranging from 72,5% in men to 85,4% in women, and from 97,7% in boys between 0-14 years old to 58,9% in men aged 60 year and over. A logistic regression model demonstrated significant relationship of higher antimicrobials resistance rates with increasing age and the male gender for several antimicrobials including ciprofloxacin (P<0,001). In conclusion, microbial profile and susceptibility rates may vary significantly according to gender and age. These factors should be considered when choosing an antimicrobial agent for empiric treatment of urinary tract infections.

Infeccao bacteriana em pacientes com sindrome da imunodeficiencia adquirida (AIDS): revisao da literatura / Bacterial infections in patients with acquired immunodeficiency syndrome (AIDS): review of literature

A incidencia de pacientes infectados pelo HIV tem aumentado em quase todos os paises do mundo, e atualmente alem das infeccoes denominadas oportunistas, o numero de infeccao bacteriana tem aumentado de forma significativa nestes pacientes. A apresentacao clinica destas infeccoes e semelhante aos pacientes imunocompetentes, mas quadros mais prolongados e recorrencia sao mais frequentes em pacientes com infeccao pelo HIV, assim como infeccoes por bacterias pouco usuais. A terapeutica adequada proporciona boa resposta na maioria das pacientes, mas, recorrencias podem ocorrer