Methicillin-resistant Staphylococcus aureus and coagulase-negative Staphylococcus produce antimicrobial substances against members of the skin microbiota in children with atopic dermatitis.

Coagulase-negative Staphylococcus (CoNS) species inhibiting Staphylococcus aureus has been described in the skin of atopic dermatitis (AD) patients. This study evaluated whether Staphylococcus spp. from the skin and nares of AD and non-AD children produced antimicrobial substances (AMS). AMS production was screened by an overlay method and tested against NaOH, proteases and 30 indicator strains. Clonality was assessed by pulsed-field gel electrophoresis. Proteinaceous AMS-producers were investigated for autoimmunity by the overlay method and presence of bacteriocin genes by polymerase chain reaction. Two AMS-producers had their genome screened for AMS genes. A methicillin-resistant S. aureus (MRSA) produced proteinaceous AMS that inhibited 51.7% of the staphylococcal indicator strains, and it was active against 60% of the colonies selected from the AD child where it was isolated. On the other hand, 57 (8.8%) CoNS from the nares and skin of AD and non-AD children, most of them S. epidermidis (45.6%), reduced the growth of S. aureus and other CoNS species. Bacteriocin-related genes were detected in the genomes of AMS-producers. AMS production by CoNS inhibited S. aureus and other skin microbiota species from children with AD. Furthermore, an MRSA colonizing a child with AD produced AMS, reinforcing its contribution to dysbiosis and disease severity.

Can habits and behaviors predict colonization by community-associated MRSA in patients admitted to a Brazilian hospital?

This study aimed to identify factors associated with colonization by community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) in adult patients admitted to a Brazilian hospital. This is a cross-sectional study, in which patients underwent a nasal swab and were asked about hygiene behavior, habits, and clinical history. Among the 702 patients, 180 (25.6%) had S. aureus and 21 (2.9%) MRSA. The factors associated with MRSA colonization were attending a gym (OR 4.71; 95% CI; 1.42 - 15.06), smoking habit in the last year (OR 2.37; 95% CI; 0.88 - 6.38), previous hospitalization (OR 2.18; CI 95%; 0.89 - 5.25), and shared personal hygiene items (OR 1.99; 95% CI; 0.71 - 5.55). At the time of admission, colonization by CA-MRSA isolates was higher than that found in the general population. This can be an important public health problem, already endemic in hospitals, whose factors such as those associated with habits (smoking cigarettes) and behaviors (team sports practice and activities in gyms) have been strongly highlighted. These findings may help developing infection control policies, allowing targeting patients on higher-risk populations for MRSA colonization.

Atopic dermatitis pediatric patients show high rates of nasal and intestinal colonization by methicillin-resistant Staphylococcus aureus and coagulase-negative staphylococci.

BACKGROUND: Atopic dermatitis (AD) patients have high rates of colonization by Staphylococcus aureus, which has been associated with worsening of the disease. This study characterized Staphylococcus spp isolates recovered from nares and feces of pediatric patients with AD in relation to antimicrobial susceptibility, staphylococcal cassette chromosome mec (SCCmec) type, presence of pvl genes and clonality. Besides, gut bacterial community profiles were compared with those of children without AD. RESULTS: All 55 AD patients evaluated had colonization by Staphylococcus spp. Fifty-three (96.4%) patients had colonization in both clinical sites, whereas one patient each was not colonize in the nares or gut. Staphylococcus aureus was identified in the nostrils and feces of 45 (81.8%) and 39 (70.9%) patients, respectively. Methicillin-resistant Staphylococcus spp. isolates were found in 70.9% of the patients, and 24 (43.6%) had methicillin-resistant S. aureus (MRSA). S. aureus (55.6%) and S. epidermidis (26.5%) were the major species found. The prevalent lineages of S. aureus were USA800/SCCmecIV (47.6%) and USA1100/SCCmecIV (21.4%), and 61.9% of the evaluated patients had the same genotype in both sites. Additionally, gut bacterial profile of AD patients exhibits greater dissimilarity from the control group than it does among varying severities of AD. CONCLUSIONS: High rates of nasal and intestinal colonization by S. aureus and methicillin-resistant staphylococci isolates were found in AD patients. Besides, gut bacterial profiles of AD patients were distinctly different from those of the control group, emphasizing the importance of monitoring S. aureus colonization and gut microbiome composition in AD patients.

Can habits and behaviors predict colonization by community-associated MRSA in patients admitted to a Brazilian hospital?

ABSTRACT This study aimed to identify factors associated with colonization by community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) in adult patients admitted to a Brazilian hospital. This is a cross-sectional study, in which patients underwent a nasal swab and were asked about hygiene behavior, habits, and clinical history. Among the 702 patients, 180 (25.6%) had S. aureus and 21 (2.9%) MRSA. The factors associated with MRSA colonization were attending a gym (OR 4.71; 95% CI; 1.42 - 15.06), smoking habit in the last year (OR 2.37; 95% CI; 0.88 - 6.38), previous hospitalization (OR 2.18; CI 95%; 0.89 - 5.25), and shared personal hygiene items (OR 1.99; 95% CI; 0.71 - 5.55). At the time of admission, colonization by CA-MRSA isolates was higher than that found in the general population. This can be an important public health problem, already endemic in hospitals, whose factors such as those associated with habits (smoking cigarettes) and behaviors (team sports practice and activities in gyms) have been strongly highlighted. These findings may help developing infection control policies, allowing targeting patients on higher-risk populations for MRSA colonization.

Investigation of possible relationship between atopic dermatitis and salivary biomarkers, stress, and sleep disorders.

Atopic dermatitis (AD) is a chronic, relapsing, multifactorial inflammatory disease with genetic, environmental, and immunological characteristics. The quality of life and sleep of patients and their families are affected by AD, which triggers stress, described as one of the factors that worsens AD. Salivary biomarkers such as cortisol, alpha-amylase, chromogranin A, and melatonin have been associated with stress and sleep disturbances. Therefore, the evaluation of stress and sleep disorders using salivary biomarkers in AD patients is important. This review aims to describe the possible relationship between atopic dermatitis and stress, sleep disorders, and salivary biomarkers, seeking to contribute to better understanding and clinical management of AD. This descriptive study is characterized as a narrative literature review. A literature search was conducted of studies published in English and Portuguese between January 2012 and October 2022 that are available in electronic media from various databases, such as Scientific Electronic Library Online, Latin American and Caribbean Literature on Health Sciences, and PubMed. AD is associated with different degrees of impact on the lives of individuals who present with the disease. Psychological stress may induce changes in saliva composition and worsen AD; at the same time, the severity of the disease may be associated with emotional impact. Further studies are needed to assess and correlate AD severity, stress, and sleep disturbances with salivary biomarkers in order to better understand this association.

Novel biochemical aspects of lugdulysin, a Staphylococcus lugdunensis metalloprotease that inhibits formation and disrupts protein biofilm of methicillin-resistant Staphylococcus aureus.

Staphylococcus lugdunensis produces lugdulysin, a metalloprotease that may contribute to its virulence. This study aimed to evaluate the biochemical aspects of lugdulysin and investigate its effect on Staphylococcus aureus biofilms. The protease was isolated and characterized for its optimal pH and temperature, hydrolysis kinetics, and influence of metal cofactor supplementation. The protein structure was determined via homology modeling. The effect on S. aureus biofilms was assessed by the micromethod technique. The protease optimal pH and temperature were 7.0 and 37 °C, respectively. EDTA inhibited protease activity, confirming it as a metalloprotease. Lugdulysin activity was not recovered by divalent ion supplementation post-inhibition, and supplementation with divalent ions did not change enzymatic activity. The isolated enzyme was stable for up to 3 h. Lugdulysin significantly inhibited the formation and disrupted preestablished protein-matrix MRSA biofilm. This preliminary study indicates that lugdulysin has a potential role as a competition mechanism and/or modulation of staphylococcal biofilm.

Diversity of bacteria carrying antibiotic resistance genes in hospital raw sewage in Southeastern Brazil.

In recent decades, antibiotic-resistant bacteria (ARB) emerged and spread among humans and animals worldwide. In this study, we evaluated the presence of ARB and antibiotic resistance genes (ARGs) in the raw sewage of two hospitals in Brazil. Sewage aliquots were inoculated in a selective medium with antibiotics. Bacterial identification was performed by MALDI-TOF and ARGs were assessed by polymerase chain reaction (PCR). A total of 208 strains from both hospitals were isolated (H1 = 117; H2 = 91). A wide variety of Enterobacterales and non-Enterobacterales species were isolated and most of them were Enterobacter spp. (13.0%), Proteus mirabilis (10.1%), and Klebsiella pneumoniae (9.6%). blaTEM and blaKPC were the most frequent ß-lactamase-encoding genes and the predominant macrolide resistance genes were mph(A) and mel. Many species had the three tetracycline resistance genes (tetD, tetM, tetA) and strB was the prevalent aminoglycoside resistance gene. Two Staphylococcus haemolyticus strains had the mecA gene. Quinolone, colistin, and vancomycin resistance genes were not found. This study showed that hospital raw sewage is a great ARB and ARG disseminator. Strict monitoring of hospital sewage treatment is needed to avoid the spread of these genes among bacteria in the environment.

Methicillin-resistant and methicillin-sensitive Staphylococcus aureus isolates from skin and nares of Brazilian children with atopic dermatitis demonstrate high level of clonal diversity.

BACKGROUND: Atopic dermatitis (AD) primarily affects the pediatric population, which is highly colonized by S. aureus. However, little is known about the genetic features of this microorganism and other staphylococcal species that colonize AD patients. OBJECTIVE: This study aimed to characterize Staphylococcus spp. isolated from the nares and skin (with and without lesion) of 30 AD and 12 non-AD Brazilian children. METHODS: Skin and nasal swabs were cultured onto mannitol salt agar, and bacterial colonies were counted and identified by matrix assisted laser desorption ionization time of flight mass spectrometry and polymerase chain reaction (PCR). Antimicrobial susceptibility was evaluated by phenotypic and genotypic tests. In S. aureus isolates, Panton-Valentine leukocidin genes were detected by PCR, and their clonality was assessed by pulsed-field gel electrophoresis and multilocus sequence typing. RESULTS: S. aureus was more prevalent in the nares (P = 0.005) and lesional skin (P = 0.0002) of children with AD, while S. hominis was more frequent in the skin of non-AD children (P < 0.0001). All children in the study, except one from each group, were colonized by methicillin-resistant coagulase-negative Staphylococcus and 24% by methicillin-resistant S. aureus. Despite the great clonal diversity of S. aureus (18 sequence types identified), most AD children (74.1%) were colonized by the same genotype in both niches. CONCLUSION: High colonization by polyclonal S. aureus isolates was found among children with AD, while S. hominis was more frequent among non-AD children. The high prevalence of methicillin-resistant staphylococcal isolates highlights the importance of continued surveillance, especially when considering empiric antibiotic therapy for the treatment of skin infections in these patients.

Pandemic clone USA300 in a Brazilian hospital: detection of an emergent lineage among methicillin-resistant Staphylococcus aureus isolates from bloodstream infections.

BACKGROUND: Staphylococcus aureus is one of the leading causes of bloodstream infections (BSI) worldwide. In Brazil, the hospital-acquired methicillin-resistant S. aureus USA100/SCCmecII lineage replaced the previously well-established clones. However, the emergence of community-associated (CA) MRSA lineages among hospitalized patients is an increasing issue. METHODS: Consecutive S. aureus isolates recovered from BSI episodes of patients admitted between January 2016 and December 2018 in a Brazilian teaching hospital were tested for antimicrobial resistance, their genotypic features were characterized, and the clinical characteristics of the patients were evaluated. RESULTS: A total of 123 S. aureus isolates were recovered from 113 patients. All isolates were susceptible to linezolid, teicoplanin and vancomycin and 13.8% were not susceptible to daptomycin. Vancomycin MIC50 and MIC90 of 2 mg/L were found for both MRSA and MSSA isolates. The MRSA isolation rate was 30.1% (37/123), and 51.4% of them carried the SCCmec type II, followed by SCCmecIV (40.5%). Among the 37 MRSA isolates, the main lineages found were USA100/SCCmecII/ST5 and ST105 (53.7%) and USA800/ST5/SCCmecIV (18.9%). Surprisingly, six (16%) CA-MRSA isolates, belonging to USA300/ST8/SCCmecIVa that carried PVL genes and the ACME cassette type I, were detected. These six patients with USA300 BSI had severe comorbidities, including cancer, and most had a Charlson score ≥ 5; furthermore, they were in wards attended by the same health professionals. MRSA isolates were associated with hospital acquired infections (p = 0.02) in more elderly patients (p = 0.03) and those diagnosed with hematologic cancer (p = 0.04). Among patients diagnosed with MRSA BSI, 19 (54.3%) died. CONCLUSIONS: The pandemic MRSA USA300 was detected for the first time in the Brazilian teaching hospital under study, and its cross-transmission most probably occurred between patients with BSI. This lineage may already be circulating among other Brazilian hospitals, which highlights the importance of carrying out surveillance programs to fight multidrug resistant and hypervirulent isolates.

The effect of probiotics on the clinical status of adult patients with atopic dermatitis: a systematic review.

OBJECTIVES: To describe, through a literature review, the results and benefits of oral and topical probiotics for adult patients with atopic dermatitis. DESIGN: A systematic review of articles published over a 13-year period was conducted to answer the following questions: (1) what information is given in the scientific literature concerning the use of probiotics in adult patients with atopic dermatitis? (2) Was there an improvement in the clinical status of the patients? (3) Was there a change in the microbial profile in patients after using such approaches? (4) Among the probiotics used, which was the most used in adult AD patients? (5) What was the average time of these interventions? (6) What were the outcomes? RESULTS: Seven studies with different sample sizes, ranging from 16 to 109 patients, were included in this review. These studies were all clinical trials (7/7), and probiotics (7/7) was the model of intervention chosen. Probiotics showed a potential to relieve the symptoms of the study groups with a reduction of pruritus and SCORAD when compared to the placebo groups. However, their effectiveness varied according to the strain, period, and form of administration. CONCLUSIONS: Many studies have demonstrated that probiotics improve the symptoms of atopic dermatitis and even its prevention. However, there is still much controversy and divergence concerning the real benefits. Despite this, probiotics have demonstrated a fair ability in improving AD adult patients' symptoms in terms of decreasing pruritus and severity related to SCORAD.

Depressão, ansiedade e estresse em profissionais da linha de frente da COVID-19 / Depression, anxiety and stress in COVID-19 front line professionals / Depresión, ansiedad y estrés en profesionales de primera línea COVID-19

Resumo Introdução: A pandemia de coronavírus 2019 (COVID-19) representa um desafio à saúde mental dos profissionais de saúde que atuam na assistência direta ao paciente. Dados de pesquisas são necessários para auxiliar a implementação de intervenções e medidas de proteção. Objetivo: Avaliar a prevalência e os fatores relacionados à ansiedade, depressão e estresse na equipe de saúde de um hospital de referência no atendimento a pacientes com COVID-19 quatro meses após o primeiro caso confirmado no Brasil. Métodos: Trata-se de um estudo transversal, correlacional e quantitativo com enfermeiros, técnicos de enfermagem, fisioterapeutas e médicos. Foi utilizado um questionário sociodemográfico e sobre os aspectos profissionais relacionados a COVID-19. Para a avaliação da ansiedade, depressão e estresse foi utilizada a escala DASS-21. Resultados: Participaram do estudo 112 pessoas, das quais 52,68% apresentaram sintomas de depressão, 57,14% de ansiedade e 78,57% de estresse. Houve associação da depressão com o cargo de enfermeiro, com o fato de estar em acompanhamento psicológico anterior a pandemia, com a ausência de participação em treinamento para assistência. A ansiedade apresentou associação com o sexo feminino e com o medo de adoecer. O estresse foi associado a idade mais jovem, 30 a 39 anos e ao estado civil casado ou em união estável. Conclusão: Durante a fase inicial do surto de COVID-19 houve uma alta prevalência de transtornos mentais nos profissionais de assistência direta ao paciente e os sintomas de depressão, ansiedade e estresse se manifestaram na maioria dos participantes de forma moderada e grave.

Abstract Introduction: The 2019 coronavirus pandemic (COVID-19) represented a challenge to the mental health of health professionals working in direct paciente care. Research data is important to assist with the implementation of interventions and protective measures. Objective: To assess the prevalence and factors related to anxiety, depression and stress in the health team of a referral hospital in the care of patients with COVID-19 four months after the first confirmed case in Brazil. Method: This is a cross-sectional, descriptive and quantitative study with nurses, nursing technicians, physiotherapist and physicians. A sociodemographic and profesional aspects related to COVID-19 questionnaire were used. To assess anxiety, depression and stress the DASS-21 scale was used. Results: 112 people participated in the study, of which 52,68% had depression symptoms, 57,14% of anxiety and 78,57% of stress. There was an association of depression with the position of nurse, with being under psychological monitoring prior the pandemic, with absence of participation in care training. Anxiety was associated with female gender and the fear of falling ill. Stress was associated with the younger age, 30 to 39 years, and with marital status, married or in stable union. Conclusion: during the initial phase of COVID-19 outbreak there was a high prevalence of mental disorders among professionals directly assisting patients and symptoms of depression, anxiety and stress were manifested in most participants in a moderated or severe manner.

Resumen Introdución: La pandemia del coronavirus 2019 (COVID-19) representa un desafío a la salud mental de los profesionales de la salud que trabajan en la atención directa al paciente. Se necesitan datos de investigación para apoyar la implementación de las intervenciones e las medidas de protección. Objetivo: Evaluar la prevalencia y factores relacionados con la ansiedad, depresión y estrés en el equipo de salud de un hospital de referencia en la atención de pacientes con COVID-19 cuatro meses después del primer caso confirmado en Brasil. Método: Se trata de un estudio transversal, descriptivo y cuantitativo con enfermeros, técnicos de enfermería, fisioterapeutas y médicos. Se utilizó un cuestionario sociodemográfico y los aspectos profesionales relacionados a la COVID-19. Se utilizó la escala DASS-21 para evaluar la ansiedad, depresión y el estrés. Resultados: Participaron de la investigación 112 personas, de las cuales el 52,68% presentaron síntomas de depresión, el 57,14% de ansiedad y el 78,57% de stress. Hubo asociación de depresión con el puesto de enfermero, con el hecho de estar bajo acompañamiento psicológico previo a la pandemia, con la ausencia de participación en capacitaciones para la asistencia. La ansiedade presentó asociacion con el sexo feminino y con el miedo a enfermarse. El estrés se asoció a una edad más joven, de 30 a 39 años y al estado civil casado o en unión estable. Conclusión: Durante la fase inicial del brote de COVID-19 hubo una alta prevalencia de trastornos mentales entre los profesionales de la asistencia directa al paciente y los síntomas de depresión, ansiedad y estrés se manifestaron en la mayoría de los participantes de manera moderada y severa.

Report of a Mental Health Intervention in the Covid-19 Pandemic through the Internet / Relato de uma intervenção em Saúde Mental na Pandemia de Covid-19: intervenção em Saúde Mental baseada na internet / Informe sobre una Intervención de Salud Mental en la Pandemia de Covid-19 Basada en la Internet

This article aims to report the experience of conducting a mental health intervention against Covid-19 using the Internet to discuss issues about psychosocial factors arising from the pandemic. The intervention was directed to health professionals working in the Intensive Care Unit of a University Hospital. The proposal involved 113 employees, including coordinators, physicians, physiotherapists, nurses, nursing technicians, multiprofessional residents, technical level professionals and outsourced employees who perform administrative functions and in cleaning. Videos, posters, and texts were used to work on themes that go through the impacts of the new coronavirus pandemic. The intervention made it possible to access a different and empowering way to face the Covid-19 outbreak period.

Este artigo tem como objetivo relatar a experiência da condução de uma intervenção em saúde mental frente a Covid-19 utilizando a internet para discutir temáticas sobre os fatores psicossociais decorrentes da pandemia. A intervenção foi direcionada aos profissionais de saúde lotados na Unidade de Terapia Intensiva de um Hospital Universitário. Participaram da proposta 113 colaboradores, entre eles, coordenadores, médicos, fisioterapeutas, enfermeiros, técnicos de enfermagem, residentes multiprofissionais, profissionais de nível técnico e colaboradores terceirizados que exercem funções administrativas e na higienização. Foram utilizados vídeos, cartazes e textos para trabalhar temas que atravessam os impactos da pandemia do novo coronavírus. A realização da intervenção possibilitou o acesso a uma forma diferente e potencializadora de enfrentar o período de surto da Covid-19.

Este artículo tiene como objetivo informar de las experiencias en la realización de una capacitación en salud mental ante el COVID-19 utilizando la internet para discutir temas sobre los factores psicosociales resultantes de la pandemia. La intervención fue dirigido a profesionales de la salud asignados a la Unidad de Cuidados Intensivos de un Hospital Universitario. Participaron en la propuesta 113 profesionales, incluidos coordinadores, médicos, fisioterapeutas, enfermeras, técnicos de enfermería, residentes multiprofesionales, profesionales de nivel técnico y empleados externos que ejercen la función administrativas y de higienización. Se utilizaron videos, carteles y textos para trabajar en temas que atraviesan los impactos de la pandemia de COVID-19. La realización de la propuesta permitió el acceso a una forma distinta y poderosa de enfrentar el período de brote del nuevo coronavirus.

Methicillin-resistant Staphylococcus aureus from infected skin lesions present several virulence genes and are associated with the CC30 in Brazilian children with atopic dermatitis.

Atopic dermatitis (AD) is a chronic inflammatory skin disease and colonization by Staphylococcus aureus may affect up to 100% of these patients. Virulent and resistant isolates can worsen AD patient clinical condition and jeopardize the treatment. We aimed to detect virulence genes and to evaluate the biofilm production of S. aureus isolates from infected skin lesions of children with AD. Methicillin resistance was detected by phenotypic and molecular tests and the virulence genes were detected by PCR. Biofilm formation was assessed by bacterial growing on microtiter plates and later stained with safranin. Genotyping was performed by Pulsed-Field Gel Electrophoresis and Multilocus Sequence Typing. Among 106 AD patients, 55 (51.8%) had developed S. aureus cutaneous infections and 23 (41.6%) were methicillin-resistant (MRSA). All 55 isolates carried the fnbA, hla, icaA, sasG, and seu genes, and more than 70% presented cna, eap, ebpS, hlg, and pvl genes. Clonal complex (CC) 30 was the main lineage found (34.5%), especially among MRSA isolates (52.2%). The egc cluster and the bbp gene were significantly the most frequent in MRSA isolates and in USA1100/ST30/CC30 lineage. Most of the isolates (74.5%) were non-biofilm producers and many of them only started to produce it in the presence of fibrinogen. There was no significant association between S. aureus isolates features and the AD severity. This study demonstrated a high frequency of CC30 MRSA isolates presenting several virulence genes in infected skin lesions of AD children in Brazil, that may influence the severity of the disease and the treatments required.

Clinical oral profile of pediatric patients with atopic dermatitis: A cross-sectional study.

OBJECTIVES: This work aims to describe oral health conditions, eating habits, and oral hygiene in pediatric and adolescent patients with atopic dermatitis and correlate them with the severity of the Scoring Atopic Dermatitis (SCORAD). Also, we aim to estimate the effect of several variables on the diagnosis of dental caries in these patients. MATERIAL AND METHODS: A total of 92 children and adolescents with atopic dermatitis had their oral cavities examined. The effect of independent variables on the diagnosis of dental caries (outcome) was assessed using multiple binary logistic regression model. RESULTS: Mild patients presented higher score of decayed, missing, and filled teeth in permanent dentition than moderate patients (p = 0.040). In the multivariable regression final model, the covariates using inhaled corticoid (OR = 6.4; p = 0.003), type of teething [deciduous dentition (OR = 7.9; p = 0.027) and mixed dentition (OR = 10.5; p = 0.007)], and brushing quality [poor mechanical control (OR = 10.6; p < 0.0001)] demonstrated significant direct effect on the diagnosis of dental caries. CONCLUSIONS: Our findings suggest that the presence of dental biofilm, use of inhaled corticoid, and type of teething are related to the presence of caries in atopic dermatitis patients.

Early high avidity specific IgG production in experimental hamster visceral leishmaniasis.

Visceral leishmaniasis (VL) by Leishmania (Leishmania) infantum is epidemic in Brazil. Hypergammaglobulinemia appears early in patients with VL and is ineffective. Usually, high-affinity IgG B cells are selected during most infections, a critical step for an effective humoral response. The avidity of IgG antibodies in VL is unexplored due to the absence of temporal parameters in most patients, associated to low clinical significance. Experimental infection models overcome this fact, allowing the monitoring of the disease temporal evolution. In this study, the avidity of IgG antibodies was evaluated in experimental models, in infection in hamsters, and in immunization in rabbits. Specific IgG antibodies were detected by ELISA, using chaotropic solution to determine avidity, as reported for viral infections. The levels of IgG antibodies correlated with the progression of experimental infection in hamsters or antigenic stimulation in immunized rabbits. However, IgG avidity was high early in infected animals, even in early periods (> 80%), while in immunized rabbits, they had early antibodies of low avidity with progressive maturation, similar as other infections. These data suggest that the affinity maturation of the avidity of anti-Leishmania IgG antibodies promoted at an early stage, influencing the appropriate interaction between antigens and affecting the disease progression. This fact could be associated to monovalent immune complexes, as reported in human and experimental VL. This scenario may be related to an independent process of immune cell activation by the parasite but absent in antigen preparation used as immunogens.

Integrative analysis of microRNA and mRNA expression profiles of monocyte-derived dendritic cells differentiation during experimental cerebral malaria.

Heterogeneity and high plasticity are common features of cells from the mononuclear phagocyte system: monocytes (MOs), macrophages, and dendritic cells (DCs). Upon activation by microbial agents, MO can differentiate into MO-derived DCs (MODCs). In previous work, we have shown that during acute infection with Plasmodium berghei ANKA (PbA), MODCs become, transiently, the main CD11b+ myeloid population in the spleen (SP) and once recruited to the brain play an important role in the development of experimental cerebral malaria (ECM). Here, we isolated 4 cell populations: bone marrow (BM) MOs (BM-MOs) and SP-MOs from uninfected mice; BM inflammatory MOs (BM-iMOs) and SP-MODCs from PbA-infected mice and used a system biology approach to a holistic transcriptomic comparison and provide an interactome analysis by integrating differentially expressed miRNAs (DEMs) and their differentially expressed gene targets (DEGs) data. The Jaccard index (JI) was used for gauging the similarity and diversity among these cell populations. Whereas BM-MOs, BM-iMOs, and SP-MOs presented high similarity of DEGs, SP-MODCs distinguished by showing a greater number of DEGs. Moreover, functional analysis identified an enrichment in canonical pathways, such as DC maturation, neuroinflammation, and IFN signaling. Upstream regulator analysis identified IFNγ as the potential upstream molecule that can explain the observed DEMs-Target DEGs intersections in SP-MODCs. Finally, directed target analysis and in vivo/ex vivo assays indicate that SP-MODCs differentiate in the SP and IFNγ is a main driver of this process.

Staphylococcus aureus nasal isolates may have the same genetic profile in atopic dermatitis paediatric patients and their close contacts.

Atopic dermatitis (AD) is a chronic skin disease that affects up to 20 % of the paediatric population worldwide. Staphylococcus aureus colonizes anterior nares and can be transmitted in the home environment, aggravating AD. This study aimed to detect S. aureus from nares of AD patients and their family contacts, as well as to evaluate the antimicrobial resistance, virulence and clonality of these isolates. Among the 48 family groups investigated, 30 groups were selected, as both the child and his/her respective contact had methicillin-sensitive S. aureus (MSSA) (24 cases; 54 MSSA isolates) or methicillin-resistant S. aureus (MRSA) isolates (6 cases; 13 MRSA isolates). All MRSA isolates carried SCCmec IV. S. aureus carrying PVL genes were detected in 60 % of patients. Pulsed-field gel electrophoresis (PFGE) analysis was performed for 31 isolates from 15 family groups: all 6 with MRSA and 9 with MSSA isolates. Similar genotypic profiles between isolates from patients and their family contacts were noted in 10 (66.6 %) family groups, 5 (83.3 %) of the MRSA family groups and 5 (55.5 %) of the MSSA family groups, indicating that the pathogen was transmitted through family contacts.

High incidence of acquiring methicillin-resistant Staphylococcus aureus in Brazilian children with Atopic Dermatitis and associated risk factors.

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) colonization in Atopic Dermatitis (AD) patients can contribute to worsening their clinical condition. OBJECTIVE: A cohort study was carried out to determine the incidence of MRSA acquisition and its risk factors in AD children. METHODS: Patients with AD (2 months-14 years old) were followed up for about 1 year at a reference center for AD treatment in Rio de Janeiro, Brazil, from September 2011 to February 2014. Nasal swabs from patients and contacts were collected every 2 months. The SCORAD system assessed the severity of the AD. S. aureus isolates were evaluated to determine the methicillin resistance and the clonal lineages. RESULTS: Among 117 AD patients, 97 (82.9%) were already colonized with S. aureus and 26 (22.2%) had MRSA at the first evaluation. The incidence of MRSA acquisition in the cohort study was 27.47% (n = 25). The SCORAD assessments were: mild (46.15%), moderate (37.36%) or severe (16.48%). Risk factors were: colonized MRSA contacts (HR = 2.27; 95% CI: 1.16-7.54), use of cyclosporine (HR = 5.84; 95% CI: 1.70-19.98), moderate or severe AD (HR = 3.26; 95% CI: 1.13-9.37). Protective factors were: availability of running water (HR = 0.21; 95% CI: 0.049-0.96) and use of antihistamines (HR = 0.21; 95% IC: 0.64-0.75). MRSA isolates carried the SCCmec type IV and most of them were typed as USA800/ST5. CONCLUSIONS: The high incidence of MRSA acquisition found among AD patients and the risk factors associated show that an effective surveillance of MRSA colonization in these patients is needed.

Genetic mutations in the quinolone resistance-determining region are related to changes in the epidemiological profile of methicillin-resistant Staphylococcus aureus isolates.

OBJECTIVES: Methicillin-resistant Staphylococcus aureus (MRSA) is an important causative agent of nosocomial infections. Mutations in the quinolone resistance-determining regions (QRDRs) of the gyr and par genes have been described. This study aimed to characterise phenotypic and genotypic fluoroquinolone resistance in 69 MRSA isolates of different clonal lineages from hospitals in Rio de Janeiro, Brazil. METHODS: QRDR mutations in the gyrA, gyrB, parC and parE genes were detected by DNA sequencing. Minimum inhibitory concentrations (MICs) for ciprofloxacin and moxifloxacin were determined by broth microdilution. The occurrence of associations between mutations and MICs among the different clonal lineages of MRSA isolates was then verified. RESULTS: Most isolates from the USA400/ST1/SCCmec IV lineage, but mainly USA100/ST5/SCCmec II isolates, which have been more recently found in Rio de Janeiro hospitals, showed different patterns of mutations, including double mutation in the QRDR of parC (Ser-80â¿¿â¿¿â¿¿Tyr and Glu-84â¿¿â¿¿â¿¿Lys/Gly) and/or gyrA (Ser-84â¿¿â¿¿â¿¿Leu and/or Glu-88â¿¿â¿¿â¿¿Lys) associated with higher moxifloxacin and ciprofloxacin MICs (MIC90, â¿¥8â¿¿mg/L and 256â¿¿mg/L, respectively). On the other hand, all USA800/ST5/SCCmec IV and the BEC/ST239/SCCmec III isolates, which have disappeared from hospitals, showed single mutations in parC (Ser-80â¿¿â¿¿â¿¿Phe) and gyrA (Ser-84â¿¿â¿¿â¿¿Leu or Glu-88â¿¿â¿¿â¿¿Gly) and lower fluoroquinolones MICs (MIC90, â¿¥2â¿¿mg/L and â¿¥16â¿¿mg/L). CONCLUSION: This study highlights an increase in the number and types of mutations in the QRDRs ofgyrA and parC associated with high fluoroquinolones MICs that may be related to changes in the epidemiological profile of MRSA isolates from hospitals in Rio de Janeiro.

Congenital Hypothyroidism is Associated With Impairment of the Leptin Signaling Pathway in the Hypothalamus in Male Wistar Animals in Adult Life.

The goal of this study is to investigate whether congenital hypothyroidism induced by MMI during gestation (G) or gestation plus lactation (GL) would affect the leptin action upon body weight control on hypothalamus. Six to eight pups per group were killed at 90 days of age. For statistical analysis one-way ANOVA followed by the Holm-Sìdak post hoc test was used. Hypothyroidism resulted in a significant increase in leptin serum levels in G 20% and GL 25% (p<0.04). There was a significant expression decrease of OBR in G 45% and GL 63%; pSTAT3 in G 56% and GL 51%; pERK in G 50% and GL 48%; POMC in G 41% and GL 46% (p<0.04), while a significant increase was assigned to SOCS3 in G 52% and GL 170% (p<0.04) protein expression. We can conclude that hypothyroxinemia condition in rats on adulthood results in impairment of the leptin signaling pathway via ObRb-STAT3 in the hypothalamus, which is likely to be involved in the leptin resistance.