Serological evidence of Toxoplasma gondii infection as potential risk for the development of lepromatous leprosy in an endemic area for both neglected tropical diseases in Brazil

Background Mycobacterium leprae and Toxoplasma gondii infections are both neglected tropical diseases highly prevalent in Brazil. Infection with certain parasite species can significantly alter susceptibility to other important pathogens, and/or influence the development of pathology. Here we investigated the possible influence of M. leprae/T. gondii co-parasitism on the manifestation of leprosy and its clinical forms. Methods Participants (n=291) were recruited in Campos dos Goytacazes city, Rio de Janeiro state, southeast Brazil, from August 2015 to December 2019 and clinically diagnosed for leprosy. Participants were selected based on the presence (patients) or absence (healthy controls) of the leprosy disease. Contacts of patients were also recruited for this study. Serum samples from patients (n=199) with leprosy, contacts (n=40) and healthy controls (n=52) were investigated for levels of IgM and IgG anti-phenolic glycolipid-1 (PGL-1) by ELISA. Additionally, IgG antibody against soluble Toxoplasma antigen (STAg) was measured in sera samples from leprosy patients, contacts and healthy controls for Toxoplasma gondii serology by ELISA. Anti-PGL-1 IgG and IgM levels were compared using one-way ANOVA Kruskal-Wallis or Mann-Whitney, while Spearman test was used to correlate levels of IgG anti-STAg and IgM/IgG anti-PGL-1 from seropositive and seronegative individuals for T. gondii infection. The risk of T. gondii infection for leprosy disease was assessed using Fisher’s test. Results Levels of IgM anti-PGL-1 antibodies were significantly higher in multibacillary (MB) patients compared to paucibacillary (PB) patients (P=0.0068). Higher IgM and IgG levels anti-PGL-1 were detected in patients with the lepromatous forms. The serologic prevalence for T. gondii infection was 74.9%. We detected increased anti-STAg antibody levels in leprosy patients (79.4%), reaching 88.8% within those with lepromatous form of this disease. The leprosy risk increase in T. gondii seropositive individuals was two-fold (odds ratio [OR]=2.055; 95% confidence intervals [95% CI]: 1.18–3.51) higher than those seronegative, and considering the lepromatous leprosy risk this increase was even dramatic (OR=4.33; 95% CI: 1.76–9.69) in T. gondii seropositive individuals. Moreover the leprosy risk in T. gondii seropositive individuals was weakly correlated to the levels of IgG anti-STAg and IgM/IgG anti-PGL-1. Conclusions Altogether, our results suggest that T. gondii infection may exert immunomodulatory properties that influence to the susceptibility of leprosy, mainly on its more severe clinical form. A better understanding of parasite immunomodulation can ultimately contribute to the development of medical applications.

Serological evidence of Toxoplasma gondii infection as potential risk for the development of lepromatous leprosy in an endemic area for both neglected tropical diseases in Brazil

Background Mycobacterium leprae and Toxoplasma gondii infections are both neglected tropical diseases highly prevalent in Brazil. Infection with certain parasite species can significantly alter susceptibility to other important pathogens, and/or influence the development of pathology. Here we investigated the possible influence of M. leprae/T. gondii co-parasitism on the manifestation of leprosy and its clinical forms. Methods Participants (n=291) were recruited in Campos dos Goytacazes city, Rio de Janeiro state, southeast Brazil, from August 2015 to December 2019 and clinically diagnosed for leprosy. Participants were selected based on the presence (patients) or absence (healthy controls) of the leprosy disease. Contacts of patients were also recruited for this study. Serum samples from patients (n=199) with leprosy, contacts (n=40) and healthy controls (n=52) were investigated for levels of IgM and IgG anti-phenolic glycolipid-1 (PGL-1) by ELISA. Additionally, IgG antibody against soluble Toxoplasma antigen (STAg) was measured in sera samples from leprosy patients, contacts and healthy controls for Toxoplasma gondii serology by ELISA. Anti-PGL-1 IgG and IgM levels were compared using one-way ANOVA Kruskal-Wallis or Mann-Whitney, while Spearman test was used to correlate levels of IgG anti-STAg and IgM/IgG anti-PGL-1 from seropositive and seronegative individuals for T. gondii infection. The risk of T. gondii infection for leprosy disease was assessed using Fisher’s test. Results Levels of IgM anti-PGL-1 antibodies were significantly higher in multibacillary (MB) patients compared to paucibacillary (PB) patients (P=0.0068). Higher IgM and IgG levels anti-PGL-1 were detected in patients with the lepromatous forms. The serologic prevalence for T. gondii infection was 74.9%. We detected increased anti-STAg antibody levels in leprosy patients (79.4%), reaching 88.8% within those with lepromatous form of this disease. The leprosy risk increase in T. gondii seropositive individuals was two-fold (odds ratio [OR]=2.055; 95% confidence intervals [95% CI]: 1.18–3.51) higher than those seronegative, and considering the lepromatous leprosy risk this increase was even dramatic (OR=4.33; 95% CI: 1.76–9.69) in T. gondii seropositive individuals. Moreover the leprosy risk in T. gondii seropositive individuals was weakly correlated to the levels of IgG anti-STAg and IgM/IgG anti-PGL-1. Conclusions Altogether, our results suggest that T. gondii infection may exert immunomodulatory properties that influence to the susceptibility of leprosy, mainly on its more severe clinical form. A better understanding of parasite immunomodulation can ultimately contribute to the development of medical applications.

Hypervirulent Mycobacterium tuberculosis strain triggers necrotic lung pathology associated with enhanced recruitment of neutrophils in resistant C57BL/6 mice.

Tuberculosis (TB) is a chronic infectious disease caused by Mycobacterium tuberculosis (Mtb) that in most cases induces irreversible necrosis of lung tissue as a result of excessive inflammatory reactions. The murine model of TB in resistant C57BL/6 mice infected with reference Mtb strains is widely used in TB studies; however, these mice do not show a necrotic pathology, which restricts their use in studies of irreversible tissue damage. Recently, we demonstrated that necrotic lung lesions could be induced in the C57BL/6 mice by highly virulent Mtb strains belonging to the modern Beijing sublineage. However, the pathogenic mechanisms leading to necrosis in this model were not elucidated. In this study, we investigated the dynamics of lung lesions in mice infected with highly virulent Beijing Mtb strain M299, compared with those infected with laboratory Mtb strain H37Rv. The data demonstrate that necrotic lung lesions in mice infected by the strain M299 were associated with enhanced recruitment of myeloid cells, especially neutrophils, and increased levels of proinflammatory cytokines, consistent with exacerbated inflammation. High levels of IFN-γ production contributed to the control of bacterial growth. Further progression to chronic disease was associated with a reduction in the levels of inflammatory mediators in the lungs, the accumulation of foamy macrophages and partial healing of the necrotic tissue by fibrosis. At a late stage of disease, degradation of foamy cells resulted in the liberation of accumulated lipids and persisting bacilli and further activation of inflammation, which promoted lung consolidation. Overall, our studies show that C57BL/6 mice infected with highly virulent Mtb strain may serve as a TB model reproducing an exacerbated inflammatory response in a resistant host to hypervirulent mycobacteria, leading to irreversible necrotic lung lesions.

Investigação de acidentes biológicos entre profissionais de saúde / Investigation of biological accidents among health care workers / Investigación de accidentes biológicos entre los trabajadores de la salud

Os objetivos deste trabalho foram identificar a principal categoria profissional exposta a risco biológico e os principais tipos de acidentes ocorridos entre trabalhadores da área de saúde, em Campos dos Goytacazes, RJ. A partir da análise das fichas denotificação de acidentes biológicos dos 183 profissionais acidentados entre janeiro de 2005 e setembro de 2005, observamos que a categoria profissional mais exposta foi a dos auxiliares/técnicos de enfermagem (54,1%), seguida pela dos acadêmicos de medicina e odontologia (10,4%). A ocorrência de acidentes com materiais perfurocortantes foi relacionada à manipulação frequente desses objetos e ao comportamento dos profissionais que utilizam práticas que oferecem riscos de acidentes com agulhas, tais como o descarte inadequado de objetos perfurocortantes.

Host immune response to Toxoplasma gondii and Ascaris lumbricoides in a highly endemic area: evidence of parasite co-immunomodulation properties influencing the outcome of both infections.

Toxoplasmosis and ascaridiasis evoke polar Th-1 and Th-2 host immune responses, respectively. A study to investigate the specific cytokine profile production by in vitro cultures of peripheral blood mononuclear cells from individuals living under precarious sanitary conditions in a highly endemic area for the parasites Toxoplasma gondii and Ascaris lumbricoides was conducted. High levels of both IFN-gamma (Th-1) and IL-13 (Th-2) were observed in groups of co-infected individuals presenting toxoplasmic ocular lesions. Significantly lower IL-10 and TGF-beta levels were produced by co-infected individuals in comparison with groups of individuals not infected with A. lumbricoides and either positive or negative for T. gondii living under good sanitary conditions (control groups). The possible influence of co-parasitism on the clinical presentation of ocular toxoplasmosis is discussed.

Host immune response to Toxoplasma gondii and Ascaris lumbricoides in a highly endemic area: evidence of parasite co-immunomodulation properties influencing the outcome of both infections

Toxoplasmosis and ascaridiasis evoke polar Th-1 and Th-2 host immune responses, respectively. A study to investigate the specific cytokine profile production by in vitro cultures of peripheral blood mononuclear cells from individuals living under precarious sanitary conditions in a highly endemic area for the parasites Toxoplasma gondii and Ascaris lumbricoides was conducted. High levels of both IFN-³ (Th-1) and IL-13 (Th-2) were observed in groups of co-infected individuals presenting toxoplasmic ocular lesions. Significantly lower IL-10 and TGF-² levels were produced by co-infected individuals in comparison with groups of individuals not infected with A. lumbricoides and either positive or negative for T. gondii living under good sanitary conditions (control groups). The possible influence of co-parasitism on the clinical presentation of ocular toxoplasmosis is discussed.

Um olhar psicológico acerca do desemprego e da precariedade das relações de trabalho / A psychological view about the unemployment and the work relationship's worsening

O mundo do trabalho tem passado por intensas metamorfoses nas últimas décadas. A globalização, levada ao extremo na contemporaneidade, e seus subprodutos – elevação das taxas de desemprego e precarização das relações e condições de trabalho – vêm contribuindo para a marginalização dos sujeitos desprovidos de uma ocupação. O presente estudo possui um objetivo duplo, a saber: a) delinear o perfil dos desempregados e das vagas de trabalho disponibilizadas pelo mercado na cidade de Assis (SP) e região; e b) apresentar considerações psicológicas acerca do desemprego e das relações de trabalho no mundo contemporâneo. Os dados necessários para tanto foram coletados junto ao Balcão de Empregos da cidade e, inicialmente, analisados estatística e quantitativamente. Posteriormente, tais dados foram interpretados a partir do referencial teórico de autores que propõem uma leitura crítica das transformações da conjuntura econômica moderna(AU)

Um olhar psicológico acerca do desemprego e da precariedade das relações de trabalho / A psychological view about the unemployment and the work relationship's worsening

O mundo do trabalho tem passado por intensas metamorfoses nas últimas décadas. A globalização, levada ao extremo na contemporaneidade, e seus subprodutos – elevação das taxas de desemprego e precarização das relações e condições de trabalho – vêm contribuindo para a marginalização dos sujeitos desprovidos de uma ocupação. O presente estudo possui um objetivo duplo, a saber: a) delinear o perfil dos desempregados e das vagas de trabalho disponibilizadas pelo mercado na cidade de Assis (SP) e região; e b) apresentar considerações psicológicas acerca do desemprego e das relações de trabalho no mundo contemporâneo. Os dados necessários para tanto foram coletados junto ao Balcão de Empregos da cidade e, inicialmente, analisados estatística e quantitativamente. Posteriormente, tais dados foram interpretados a partir do referencial teórico de autores que propõem uma leitura crítica das transformações da conjuntura econômica moderna