39 research outputs found

    Psychosocial factors and T lymphocyte counts in Brazilian peacekeepers

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    OBJECTIVE: To investigate the associations between psychosocial factors and peripheral blood CD4 and CD8 T lymphocyte numbers in Brazilian peacekeepers. METHODS: Venous blood was collected from 759 peacekeepers who had just returned from a peace mission in Haiti. Among the 759 soldiers, 642 individuals completed the psychosocial measures. CD4 and CD8 T lymphocyte counts were measured by flow cytometry using a commercially available kit. Psychosocial factors, including military peace force stressors, clinical stress, anxiety and depression, were recorded. As a reference for T lymphocyte numbers, we measured T lymphocyte counts in 75 blood donors from the Instituto de Biologia do Exército, Rio de Janeiro. RESULTS: The median numbers of CD4 and CD8 T lymphocytes in the blood donors were 819 cells/µl and 496 cells/µl, respectively, with a CD4:CD8 ratio of 1.6. Significantly (

    Virulence profile of tigecycline-resistant Gram-negative bacilli isolated from river waters using the Caenorhabditis elegans infection model / Perfil de virulência de bacilos Gram-negativos resistentes à tigeciclina isolados das águas dos rios usando o modelo de infecção por Caenorhabditis elegans

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    Last-resort antibiotics act as ultimate force to overcome multidrug-resistant strains infections. Cases of tigecycline resistance in gram-negative bacilli in clinical settings are reported worldwide, however, there is no data related to tigecycline resistant strains in river water. This study demonstrates seven tigecycline gram-negative bacilli isolated from river water in Rio de Janeiro metropolitan area, their resistance genes, ability of biofilm formation with/without antibiotics and behavior using the nematode Caenohabidits elegans as infection in vivo model. From 24 gram-negative isolated strains, 16 (66.6%) were classified as multidrug-resistant, however, seven (29.1%) presented resistant to all antimicrobial agents tested, including tigecycline and have been identified by MALDI-TOF as A. baumannii, E. aerogenes and P. agglomerans. All tigecycline-resistant strains presented amplification products for ESBL, AME and PMQR and ability of biofilm formation on hydrophilic and hydro­phobic abiotic surfaces with and without antimicrobial agents. The presence of antimicrobials did not inhibit biofilm formation. Tigecycline-resistant strains differed of OP50 control with P<0,0001 indicating its virulence potential, however, none of them were capable to kill all nematodes during 5 days infection. In conclusion, tigecycline-resistant gram-negative strains have important global public health implications due to the therapeutic problems they pose. Further studies and continuous surveillance of tigecycline-resistant strains in both clinical and aquatic environment remains necessary to track and understand the dissemination of tigecycline resistance

    Antimicrobial and anti-biofilm activities of Alpinia zerumbet (Pers.) B.L. Burtt & R.M. Sm. essential oil against Corynebacterium ulcerans

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    Cepas multirresistentes de Corynebacterium ulcerans destacam a necessidade de pesquisas em novos medicamentos e o uso farmacológico de óleos essenciais (OE) pode ser uma alternativa terapêutica. Assim, este estudo teve como objetivo avaliar a atividade antibacteriana e o efeito da concentração subinibidora de AZEO na morfologia bacteriana e na formação de biofilme na superfície do poliestireno por C. ulcerans utilizados em cães. O AZEO foi usado por destilação a vapor das folhas da planta. Os testes de inibição de fosfomolibdênio e hemólise foram realizados para analisar, respectivamente, uma atividade antioxidante e toxicidade. Foram selecionados como inibidores e bactericidas mínimos (MIC e MBC) do AZEO emC. ulcerans e a partir desses resultados foram testados subinibidos dos testes do AZEO. A inatividade do complexo fosfomolibdênio pelo AZEO foi menor que 1% e a capacidade hemolítica foi baixa. Os resultados do estudo antimicrobiano mostram que o AZEO inibiu o crescimento de fundos como cepas microbianas testadas. Os filamentos bacterianos foram observados na presença do AZEO , bem como uma bactéria de controle automático. Houve diferença significativa na inibição do biofilme. Sugerimos que A. zerumbet pode usar uma terapia alternativa para controlar infecções bacterianas induzidas por C. ulcerans

    Biofilm formation, interaction and survival within A549 pneumocytes of Klebsiella pneumoniae clinical strains: identification of pulsotypes, multidrug-resistance and genes coding for adhesins: Formação de biofilme, interação e sobrevivência dentro dos pneumócitos A549 de cepas clínicas de Klebsiella pneumoniae: identificação de pulsótipos, multirresistência a drogas e codificação de genes para adesinas

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    Klebsiella pneumoniaehas become one of the major causes of hospital-acquired infections over decades due to the spread of virulent clones harboring resistant genes to multiple antimicrobial agents. The aim of this study was to investigate phenotypic and genotypic features of virulence mechanism expressed by K. pneumoniae clinical isolates of different PFGE types, including biofilm formation, interaction with pneumocytes A549 lineage and experimental infection by using C. elegans nematodes.  A total of 17 K. pneumoniae strains were isolated from different clinical specimens including blood, urine and respiratory infections. In this present study, 11 strains presented a varied multidrug-resistance profile harboring resistance genes coding for betalactams, aminoglicosydes, fluorquinolones and carbapenemases. PFGE analysis demonstrated the presence of four distinct pulsotypes among K. pneumoniae strains harboring virulence genes for siderophores and fimbiae type 1 and type 3. High adherence and biofilm formation were positively correlated for both polystyrene and glass surfaces in all K. pneumoniae strains analyzed. K. pneumoniae clinical strains showed the ability of adherence, internalization and persistence within human pulmonary epithelial A549 cell line, at different levels. Respiratory infections demonstrated a higher heterogeneity of PFGE types and levels of adherence, intracellular survival and persistence.K. pneumoniae strains were also submitted to Carnohabidits elegans in vivo infection model and data showed that after 24 hr almost 10% of urine-culture isolates worms were dead evidencing virulence profile. Notably, K. pneumoniae strains, presenting virulence genes, was significantly more virulent than those who did not presented any virulence gene after 5 days (survival >60% and >40%)

    Diphtheria remains a threat to health in the developing world: an overview

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    Changes in the epidemiology of diphtheria are occurring worldwide. A large proportion of adults in many industrialized and developing countries are now susceptible to diphtheria. Vaccine-induced immunity wanes over time unless periodic booster is given or exposure to toxigenic Corynebacterium diphtheriae occurs. Immunity gap in adults coupled with large numbers of susceptible children creates the potential for new extensive epidemics. Epidemic emergencies may not be long in coming in countries experiencing rapid industrialization or undergoing sociopolitical instability where many of the factors thought to be important in producing epidemic such as mass population movements and difficult hygienic and economic conditions are present. The continuous circulation of toxigenic C. diphtheriae emphasizes the need to be aware of epidemiological features, clinical signs, and symptoms of diphtheria in vaccine era so that cases can be promptly diagnosed and treated, and further public health measures can be taken to contain this serious disease. This overview focused on worldwide data obtained from diphtheria with particular emphasis to main factors leading to recent epidemics, new clinical forms of C. diphtheriae infections, expression of virulence factors, other than toxin production, control strategies, and laboratory diagnosis procedures
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