Severe Cases of COVID-19 and High Association with Causes of Immune Dysregulation: A Systematic Review.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the virus responsible for coronavirus 2019 (COVID-19), which was declared a pandemic in March 2020 by the World Health Organization due the rapid spread representing a global health crisis. The disease is characterized by a wide clinical spectrum ranging from asymptomatic forms until severe viral pneumonia, which can to evolve to severe acute respiratory syndrome, especially in elderly patients and/or with comorbidities. An efficient assembly of the immunological response of the patients becomes fundamental against SARS-CoV-2 infection and it has been demonstrating a significant relationship between the severity of the disease and expression profile of the immune cells and the levels of pro-inflammatory cytokines. This review aims to presents the main immunological mechanisms developed during the infection by SARS-CoV-2 in the evolution of the severe cases of COVID-19. The immune dysregulation of the Th1 cellular response standard, the instability in the production of neutralizing antibodies by plasma B cells, the difference in tropism of CD8+ T cells against virus proteins in early infection, late infection and reinfections, dynamic of alveolar macrophages and pulmonary innate lymphoid cells (TCR γδ) of the natural imune response and the high level of pro-inflammatory cytokines can determine the main cause of breath tissues damages and, consequently, a greater severity of the disease. Therefore, a complete understanding of the main immunological changes involved in SARS-CoV-2 infection can identify possible biomarkers in the evaluation of early prognosis of the severe cases of COVID-19, making possible better therapeutic success to the patients.

Assessment of rSodC, rPknG, rNanH, and rSpaC as Antigens for Diagnostic Tools Against Caseous Lymphadenitis.

Corynebacterium pseudotuberculosis is a bacillus that causes caseous lymphadenitis in small ruminants, leading to great losses to rural producers; thus, an efficient diagnosis is necessary for using disease control measures. This study aimed to evaluate the antigenic potential of four C. pseudotuberculosis recombinant proteins (rSodC, rPknG, rNanH, and rSpaC) against sera of goat and sheep experimentally infected with one of three different C. pseudotuberculosis strains. Goats were infected with CAP76 or CAP21 strain (n = 10), sheep with VD57 strain (n = 6), and a group of not-infected animals (goats and sheep) were kept as a healthy control (healthy n = 12). Sera were collected at 0, 14, 60, 90, 180, or 190 days after inoculation for antigenicity testing using Western blotting and enzyme-linked immunosorbent assay (ELISA) techniques. Cross-reactivity tests with recombinant proteins were performed in goat serum experimentally vaccinated with Nocardia sp. or Rhodococcus equi bacterin. The rSodC protein showed discriminatory antigenic reactivity with a statistically significant difference against three different C. pseudotuberculosis strains evaluated in goats and sheep samples, while rPknG showed statistical significance only against two C. pseudotuberculosis strains evaluated in goats. rSodC was proved to be a strong candidate as a tool for diagnosis of C. pseudotuberculosis infection, once it was able to recognize antibodies against all strains evaluated in goats and sheep.

Development of ELISA Using Recombinant Proteins for the Diagnosis of Mycoplasma hyopneumoniae Infection.

In order to develop a more sensitive and reliable method for detection of serum antibodies against Mycoplasma hyopneumoniae infection in pigs, six recombinant proteins of M. hyopneumoniae (P102, P95, P46, P97 like, Lppt, and hypothetical P987) were used for the standardization of an indirect enzyme-linked immunosorbent assay (ELISA). The proteins were evaluated against 50 sera of the specific pathogen-free and 50 sera of pigs with lesions suggestive of infection. The sensitivity was 88%, 86%, 78%, 74%, 66%, and 60% for the proteins P102, P95, P46, P97 like, Lppt, and hypothetical protein P987, respectively. Moreover, the proteins were used to establish the seroprevalence in two different commercial herds (254 sera pigs from farm considered free of M. hyopneumoniae and 246 from farm with clinical signs of enzootic pneumonia and positive serology for M. hyopneumoniae) and the positive rate was 65.2% for P95, 54.6% for P102, 40.2% for P46, 37.2% for P97 like, 17.4% for the hypothetical P987, and 14% for Lppt protein. In addition, the ELISA with six recombinant proteins was compared to commercial HerdCheck kit using 118 random pig sera samples and the results showed that ELISA with recombinant proteins were more sensitive than the commercial test. These data show that the recombinant proteins P95 and P102 are potential targets to be used in diagnostic tests to detect antibodies against M. hyopneumoniae. Although more studies are necessary, this study provides insights that these recombinant proteins can be useful in epidemiological investigations and as potential biomarkers in differentiating infected animals from those vaccinated.

Tp0684, Tp0750, and Tp0792 Recombinant Proteins as Antigens for the Serodiagnosis of Syphilis.

The incidence of syphilis has increased alarmingly over the years. Its diagnosis continues to be a challenge, leading to the search for new alternative and effective methods. The objective of this study was to select and evaluate three Treponema pallidum recombinant proteins for potential use in syphilis serodiagnosis. Bioinformatics analysis was performed with three T. pallidum antigens (Tp0684, Tp0750, and Tp0792) to assess their physical, antigenic, and structural characteristics. The antigens were chemically synthesized, recombinant plasmids were expressed in Escherichia coli BL21 Star™ (DE3), and the recombinant proteins were purified by nickel affinity chromatography. The antigenicity of the recombinant proteins was evaluated by western blotting and enzyme-linked immunosorbent assay (ELISA), using the sera from patients with primary and latent syphilis. In silico analysis indicated the antigenic potential once the exposed B cell epitopes were detected in the evaluated proteins. Sera from patients with primary and latent syphilis specifically recognized rTp0684, rTp0750, and rTp0792 recombinant antigens. Moreover, the rTp0684-ELISA receiver operating characteristic (ROC) analysis showed an area under the ROC curve of 0.99, indicating high diagnostic efficacy with 97.62% specificity and 95% sensitivity. In conclusion, rTp0684 showed better potential as an antigen for the development of syphilis serodiagnosis. Thus, bioinformatic analysis can be an important tool to guide the selection of antigens for serological diagnosis. Supplementary Information: The online version contains supplementary material available at 10.1007/s12088-022-01017-w.

Genomic characterization of SARS-CoV-2 from an indigenous reserve in Mato Grosso do Sul, Brazil.

Background: The COVID-19 pandemic had a major impact on indigenous populations. Understanding the viral dynamics within this population is essential to create targeted protection measures. Methods: A total of 204 SARS-CoV-2 positive samples collected between May 2020 and November 2021 from an indigenous area in Mato Grosso do Sul (MS), Midwestern Brazil, were screened. Samples were submitted to whole genome sequencing using the Nanopore sequencing platform. Clinical, demographic, and phylogenetic data were analyzed. Results: We found the co-circulation of six main SARS-CoV-2 lineages in the indigenous population, with the Zeta lineage being the most prevalent (27.66%), followed by B.1.1 (an ancestral strain) (20.21%), Gamma (14.36%) and Delta (13.83%). Other lineages represent 45.74% of the total. Our phylogenetic reconstruction indicates that multiple introduction events of different SARS-CoV-2 lineages occurred in the indigenous villages in MS. The estimated indigenous population mortality rate was 1.47%. Regarding the ethnicity of our cohort, 64.82% belong to the Guarani ethnicity, while 33.16% belong to the Terena ethnicity, with a slightly higher prevalence of males (53.43%) among females. Other ethnicities represent 2.01%. We also observed that almost all patients (89.55%) presented signs and symptoms related to COVID-19, being the most prevalent cough, fever, sore throat, and headache. Discussion: Our results revealed that multiple independent SARS-CoV-2 introduction events had occurred through time, probably due to indigenous mobility, since the villages studied here are close to urban areas in MS. The mortality rate was slightly below of the estimation for the state in the period studied, which we believe could be related to the small number of samples evaluated, the underreporting of cases and deaths among this population, and the inconsistency of secondary data available for this study. Conclusion: In this study, we showed the circulation of multiple SARS-CoV-2 variants in this population, which should be isolated and protected as they belong to the most fragile group due to their socioeconomic and cultural disparities. We reinforce the need for constant genomic surveillance to monitor and prevent the spread of new emerging viruses and to better understand the viral dynamics in these populations, making it possible to direct specific actions.

Determining reference ranges for immunological cells of healthy indigenous individuals from a region in Brazil.

Morais et al. conducted a pioneering study with Brazilian indigenous populations to determine reference values for immunologic cells from healthy adult individuals. The main findings included a higher relative median for T lymphocyte subsets in females than males, and T CD3+, T CD4+, and T CD8+ relative values were statistically different when compared with Brazilian populations from other Brazilian regions. The relative medians of CD3+, CD4+, and CD8+ T cells were significantly higher in women than in men in a healthy indigenous population. Demographic and ethnic diversity of the Brazilian population can be associated with quantitative modifications in the immunologic cells of healthy individuals. OBJECTIVE: The establishment of reference values for a subset of leukocytes is common in clinical practice, and ethnic variations are strongly associated with disease development. In Brazil, indigenous people are vulnerable to infections, and few studies have described the health and disease conditions of this population. This study aimed to provide reference values for immunological cell subsets in indigenous Brazilians living in the state of Mato Grosso do Sul. METHODS: Flow cytometry and 4-color combinations of monoclonal antibodies were used to characterize cells. A total of 115 healthy adults, mostly females (72%), were included in the study. The results are presented as mean and median (2.5%-97.5% percentiles) for T and B lymphocytes, CD4+ T cells, CD8+ T cells, Natural Killer cells, monocytes, and dendritic cells, providing an average immunological profile for the population in question. RESULTS: The relative medians of CD3+, CD4+, and CD8+ T cells were significantly higher in women than in men in a healthy indigenous population. CONCLUSION: To our knowledge, cell reference data from indigenous Brazilians are unknown in the literature. The immune cell results presented in this pioneering study will contribute to the clinical and laboratory evaluation of the Brazilian indigenous population, especially given the important differences when compared with other Brazilian ethnic groups.

Seroprevalence Of SARS-COV-2 infection in asymptomatic indigenous from the largest Brazilian periurban area.

This study assessed the seroprevalence of SARS-CoV-2 in 496 asymptomatic individuals from Mato Grosso do Sul, located in Dourados, the largest periurban indigenous area in Brazil, from January 25 to February 4, 2021. The volunteers participated before receiving their first dose of the CoronaVac inactivated vaccine. For screening, blood samples were collected and analyzed using SARS-CoV-2 rapid tests and the enzyme-linked immunosorbent assay (ELISA). We observed varying trends in total anti-SARS-CoV-2 antibodies across different variables. Seropositivity among the participants tested was 63.70% (316/496) using the rapid test and 52.82% (262/496) were positive using the ELISA method. The majority of participants identified with the Guarani-Kaiowá ethnic group, with 66.15% (217/328), and other ethnic groups with 58.84% (193/328). The median age of the subjects was 30.5 years, with 79.57% (261/328) being femaleThis research showed the elevated seroprevalence of SARS-CoV-2 antibodies in asymptomatic Brazilians. The findings indicate a high seropositivity rate among the asymptomatic indigenous population of Midwest Brazil. This underscores the overlooked status of these communities and underscores the need for targeted national initiatives that emphasize the protection of vulnerable ethnic groups in the fight against COVID-19.

The first year of the COVID-19 pandemic in an indigenous population in Brazil: an epidemiological study.

This cross-sectional observational study that describes the epidemiological data of the first year of the COVID-19 pandemic in the Mato Grosso do Sul State, aimed to demonstrate the differences between indigenous and non-indigenous populations, characterize confirmed cases of COVID-19 according to risk factors related to ethnicity, comorbidities and their evolution and to verify the challenges in facing the disease in Brazil. SIVEP-Gripe and E-SUS-VE, a nationwide surveillance database in Brazil, from March 2020 to March 2021 in Mato Grosso do Sul state, were used to compare survivors and non-survivors from indigenous and non-indigenous populations and the epidemiological incidence curves of these populations. A total of 176,478, including 5,299 indigenous people, were confirmed. Among the indigenous population, 52.5% (confidence interval [CI] 51.2-53.9) were women, 38% (CI 36.7-39.4) were 20-39 years old, 56.7% were diagnosed by rapid antibody tests, 12.3% (CI 95%:11.5-13.2) had at least one comorbidity, and 5.3% (CI 95%:4.7-5.9) were hospitalized. In the non-indigenous patients, 56.8% were confirmed using RT-PCR, 4.4% (CI 95%:4.3-4.5) had at least one comorbidity, and 8.0% (CI 95%:7.9-8.2) were hospitalized. The majority of non-survivors were ≥60 years old (65.1% indigenous vs. 74.1% non-indigenous). The mortality in indigenous people was more than three times higher (11% vs. 2.9%). Indigenous people had a lower proportion of RT-PCR diagnoses; deaths were more frequent in younger patients and were less likely to be admitted to hospital. Mass vaccination may have controlled the incidence and mortality associated with COVID-19 in this population during the period of increased viral circulation.

Detection of Treponema pallidum in whole blood samples of patients with syphilis by the polymerase chain reaction.

Syphilis is caused by the bacterium Treponema pallidum. The diagnosis is based on clinical data and serological analysis; however, the sensitivity and specificity of such tests may vary depending on the type of test and stage of the infection. In order to overcome this premise, this study utilized the polymerase chain reaction (PCR) for the detection of T. pallidum DNA in whole blood samples of patients with syphilis. The blood samples from patients with or without symptoms of syphilis, but with positive results in enzyme-linked immunosorbent assay (ELISA), were included in this study. A venereal disease research laboratory (VDRL) test was performed for all collected sera samples. For PCR, the T. pallidum DNA was extracted from the collected blood samples and a specific primer set was designed to amplify 131 nucleotides of polA (Tp0105). The specificity of the primers was evaluated with the DNA of 17 different pathogens. From a total of 314 blood samples reactive in ELISA, 58.2% (183/314) of the samples were reactive in the VDRL test. In the PCR, 54% (168/314) of the ELISA-reactive samples were positive. In both tests (VDRL and PCR) 104 samples were positive. Of 104 positive samples for both tests, 71 were at the latent stage. Based on these results, it can be concluded that PCR with the designed set of primers can be utilized as a diagnostic method for T. pallidum detection in blood samples of patients with syphilis, especially those with latent infection. In addition, it can be utilized as a supplement for serological methods to improve the diagnosis of syphilis.

The Association of Bacterin and Recombinant Proteins Induces a Humoral Response in Sheep against Caseous Lymphadenitis.

In this study, we investigated the capacity of the recombinant proteins SpaC, NanH, SodC, and PLD of C. pseudotuberculosis to trigger protective humoral and cellular immune responses against experimentally induced C. pseudotuberculosis infection in sheep. The antigens were produced in a heterologous system and were purified by affinity chromatography. Nine sheep were randomly divided into three groups, which were immunized as follows: Group 1 (control)-a mix of adjuvants composed of the inactivated T1 strain of C. pseudotuberculosis and commercial Montanide™ISA 61 VG (T1M); Group 2-rSpaC, rSodC, rPLD, and T1M; Group 3-rNanH, rSodC, rPLD, and T1M. All groups were immunized twice (on days 0 and 30) and challenged on day 90 of the experiment. Humoral and cellular immune responses were evaluated by Enzyme-Linked Immunosorbent Assay (ELISA) to quantify the IgG antibodies and interferon-gamma (IFN-y). Both vaccine formulations with recombinant proteins (groups 2 and 3) could induce a significant humoral IgG immune response in sheep. The proteins rSodC, rPLD, and rNanH were more immunogenic, inducing significant levels of IgG antibodies after the first dose of the vaccine or after the challenge, maintaining constant levels until the end of the experiment. However, it was not possible to differentiate between the cellular responses induced by the vaccines. This lack of effectiveness points toward the need for further studies to improve the efficacy of this subunit-based vaccine approach.

Comparative Proteomic Analyses Between Biofilm-Forming and Non-biofilm-Forming Strains of Corynebacterium pseudotuberculosis Isolated From Goats.

Caseous lymphadenitis (CLA) is a chronic disease that affects small ruminants and causes economic losses in the associated breeding system. The causative agent of CLA is Corynebacterium pseudotuberculosis, a Gram-positive bacterium that exhibits tropism for external and internal lymph nodes and induces abscess formation in the host. Bacterial communities often produce a biofilm matrix that serves various functions, including protection against hostile environmental conditions, antibiotics, and the host immune response. Although biofilm formation has been reported for C. pseudotuberculosis, not all strains demonstrate this property in culture. In this work, we report the first comparative proteomic analysis of one biofilm-forming (CAPJ4) and one biofilm-non-forming strain (CAP3W) of C. pseudotuberculosis isolated from goats. Bacterial whole cell protein extracts were obtained for mass spectrometry analyses. Using LC-MS/MS, our studies reveal three and four proteins exclusively found in the CAPJ4 and CAP3W proteome, respectively. In addition, label-free quantitative analysis identified 40 proteins showing at-least 2-fold higher values in CAPJ4 compared CAP3W proteome Notably, CAPJ4 differentially synthesized the penicillin-binding protein, which participates in the formation of peptidoglycans. CAPJ4 also exhibited upregulation of N-acetylmuramoyl-L-alanine amidase and galactose-1-phosphate uridylyltransferase, which are involved in biofilm formation and exopolysaccharide biosynthesis. Here, we demonstrate that biofilm formation in C. pseudotuberculosis is likely associated with specific proteins, some of which were previously shown to be associated with virulence and biofilm formation in other organisms. Our findings may drive studies related to the bacterial mechanisms involved in the biofilm formation, in addition to providing targets for the treatment of CLA.

Prevalence and factors associated with Trichomonas vaginalis infection in indigenous Brazilian women.

There is a scarcity of studies on the prevalence of Trichomonas vaginalis (TV) in indigenous populations of Brazil. We conducted a cross-sectional study between January and December 2018, on indigenous women living nearby an urban center of the Midwest region of Brazil and determined the prevalence of TV. Factors associated with TV infection and a comparison of molecular and direct microscopy diagnoses were determined. 241 indigenous women aged above 18 years participated in the study. Cervical and vaginal brush samples were collected to diagnose TV through polymerase chain reaction (PCR). Direct microscopy for detection of TV, and cellular changes was performed. A sociodemographic and behavioral questionnaire was applied at the beginning of the study. All the data were analyzed using Statistical Package for the Social Sciences. The result obtained showed that 27.8% [95% CI: 22.2-33.9] were positive for TV on PCR, while 7.41% [95% CI: 4.1-11] showed positive on direct microscopy. Direct microcopy also found 21 (8.71%) and 8 (3.31%) women infected with Gardnerella vaginalis and Candida albicans, respectively. In addition, 10 women presented atypical squamous cells of unknown significance and 14 lesions suggestive of HPV. Single women, under the age of 30 and who do not use condoms, were found to have a greater chance of getting TV infection. The high prevalence TV found in this population is comparable to highly vulnerable populations, as prisoners, sex workers and women in regions with low socioeconomic levels, moreover, seems to be an underdiagnosis of this infection. Therefore, a routine test program, as well as a review of the diagnostic method used, is encouraged for proper management.

Gestational outcomes in women infected by Zika virus during pregnancy in Mato Grosso do Sul, Brazil: A cross-sectional study.

OBJECTIVES: This study aimed to describe the demographic and clinical parameters of women infected by Zika virus who had infants with stigmata of Congenital Zika Syndrome (CZS) versus those who had normal-appearing infants at birth, thereby providing further details on the clinical caveats of neonatal ZIKV infection. METHODOLOGY: This cross-sectional study was performed in the state of Mato Grosso do Sul, Central-West region of Brazil, and included 117 mother-infant pairs who were interviewed and 120 gestational outcomes. All mothers had laboratory confirmation by qRT-PCR of ZIKV infection during pregnancy. RESULTS: The prevalence of congenital abnormalities related to ZIKV was 2.69 cases per 10,000 live births during this period. Exanthem was the main clinical finding, observed in 92.5% of the mothers in this study. Regarding the timing of ZIKV infection, the first trimester was the most frequent time of infection among mothers of infants with CZS (54.55%) (p=0.0007). The case fatality rate was 5% (n=6). Among the 23 children who were classified as having CZS, 13 (56.52%) of them presented with microcephaly. Only 13 (56.52%) children with CZS were tested by qRT-PCR for ZIKV infection at birth, five (38%) were positive. CONCLUSIONS: This study highlights the congenital alterations of ZIKV infection during pregnancy in an epidemic burst, demonstrating that the alterations found in other studies are similar to the present research.

Cochlospermum regium (Schrank) pilger leaf extract inhibit methicillin-resistant Staphylococcus aureus biofilm formation.

ETHNOPHARMACOLOGICAL RELEVANCE: Cochlospermum regium, known as "algodãozinho", is an important plant belonging to Brazilian biodiversity used in traditional medicine to treat infections, wounds and skin conditions. AIM OF THE STUDY: To assess the effects of aqueous and ethanolic extracts from C. regium leaves on methicillin-resistant Staphylococcus aureus planktonic cells and biofilm formation. MATERIAL AND METHODS: The phytochemical characterization of the extracts was carried out by quantification of flavonoids, phenols and tannins and HPLC-DAD. Minimum inhibitory concentrations, cell viability, and enzyme activity inhibition were determined in planktonic cells exposed to C. regium extracts. The effect of the extracts on biofilms was assessed by quantifying colony-forming units (CFUs) and the extracellular matrix, and by visualizing the biofilm structure using scanning electron microscopy. RESULTS: Leaf extract contents showed high concentration of phenols and the gallic and ellagic acids were identified. The extracts showed potent antimicrobial activities at concentrations ranging from 62.5-250 µg/mL, and decreased coagulase activity. In addition, the extracts prevented biofilm formation, and the aqueous extract completely inhibited its formation. CONCLUSIONS: C. regium extracts stand out as promising alternative treatments for the prevention and treatment of methicillin-resistant Staphylococcus aureus infections.

rSodC is a potential antigen to diagnose Corynebacterium pseudotuberculosis by enzyme-linked immunoassay.

Caseous lymphadenitis (CL) is a chronic infectious disease that affects sheep and goats. Many serological tests have been developed to detect the disease; one of the most widely used is the enzyme-linked immunosorbent assay (ELISA), due to its advantages, which include acceptable cost-effectiveness, applicability, sensitivity and specificity. ELISA formulations using recombinant proteins can exhibit significant sensitivity and specificity when using a single purified antigen. DTxR, Trx, TrxR, LexA, SodC, SpaC, NanH, and PknG recombinant proteins can be considered target proteins for ELISA development due to its extracellular or on the cell surface location, which allows a better recognition by the immune system. Therefore, the objectives of this study were to evaluate the antigenic reactivity of Corynebacterium pseudotuberculosis recombinant proteins in goat and sheep serum. Of eight proteins evaluated, rSodC was selected for validation assays with small ruminant serum samples from the semiarid region of the state of Bahia, Brazil. Validation assays with goat serum samples showed that ELISA-rSodC presented sensitivity and specificity of 96% and 94%, respectively. Validation assays with sheep serum showed that ELISA-rSodC exhibited sensitivity and specificity of 95% and 98%, respectively. Analysis of 756 field serum samples showed that rSodC identified 95 positive samples (23%) in goats and 75 positive samples (21%) in sheep. The ELISA with recombinant SodC protein developed in this study discriminated positive and negative serum samples with high levels of sensitivity and specificity. This formulation is promising for epidemiological surveys and CL control programs.Trial registration AEC No 4958051018. 12/18/2018, retrospectively registered.

Descriptive analysis of syphilis cases reported in Mato Grosso do Sul, Brazil identifies failure in treatment.

INTRODUCTION: Syphilis infection remains an alarming public health problem worldwide. METHODS: This study analyzed syphilis cases listed in the Information System on Diseases of Compulsory Declaration (SINAN) of Mato Grosso do Sul state in Brazil between January 2013 and December 2014. RESULTS: Most of the evaluated syphilis cases would have been preventable through public education, particularly congenital syphilis in children of previously diagnosed mothers and infection by untreated sexual partners. CONCLUSIONS: The incidence rate of syphilis could be reduced by improving prevention through counselling on the risk of infection, improving access to condoms, and increasing the frequency of diagnostic tests.

Recombinant polypeptide of Mycobacterium leprae as a potential tool for serological detection of leprosy.

Current prevention methods for the transmission of Mycobacterium leprae, the causative agent of leprosy, are inadequate as suggested by the rate of new leprosy cases reported. Simple large-scale detection methods for M. leprae infection are crucial for early detection of leprosy and disease control. The present study investigates the production and seroreactivity of a recombinant polypeptide composed of various M. leprae protein epitopes. The structural and physicochemical parameters of this construction were assessed using in silico tools. Parameters like subcellular localization, presence of signal peptide, primary, secondary, and tertiary structures, and 3D model were ascertained using several bioinformatics tools. The resultant purified recombinant polypeptide, designated rMLP15, is composed of 15 peptides from six selected M. leprae proteins (ML1358, ML2055, ML0885, ML1811, ML1812, and ML1214) that induce T cell reactivity in leprosy patients from different hyperendemic regions. Using rMLP15 as the antigen, sera from 24 positive patients and 14 healthy controls were evaluated for reactivity via ELISA. ELISA-rMLP15 was able to diagnose 79.17% of leprosy patients with a specificity of 92.86%. rMLP15 was also able to detect the multibacillary and paucibacillary patients in the same proportions, a desirable addition in the leprosy diagnosis. These results summarily indicate the utility of the recombinant protein rMLP15 in the diagnosis of leprosy and the future development of a viable screening test.

High detection rate of new cases of multibacillary leprosy in Mato Grosso do Sul, Brazil: an observational study from 2001-2015.

Leprosy remains a public health problem in Brazil, and the Mato Grosso do Sul State (MS) had the seventh highest rate of detection of new cases in the country in 2015 (26.59 per 100,000 inhabitants) which was classified as very high. This work aimed to determine the epidemiological characteristics of leprosy in MS. Descriptive statistics were performed with data from the Information System on Diseases of Compulsory Declaration (SINAN) between 2001 and 2015, with all patients included in the system serving as the sample. Clinical forms of multibacillary (MB) leprosy predominated in MS during the study period, with a clear positive trend from 2009 to 2015 and a peak in the detection rate of new cases (NCDR) in 2014 corresponding to 40.39 per 100,000 population (p<0.001). The most affected groups were men (56.7%) aged 20-59 years (70.52%), an economically active population. We observed that Northern MS had the highest overall NCDR in the State. In cities bordering other countries, NCDRs were significantly lower than in those of other analyzed cities. There was no dependency ratio correlating NCDRs in cities with higher or lower indexes with basic care coverage (p=0.799) and human development index (p=0.887). In conclusion, the large number of patients with MB leprosy indicates that the diagnosis of leprosy is delayed in MS, perhaps due to difficulties related to diagnostic methods. This situation contributes to the continuing prevalence of leprosy in MS.

Determining reference ranges for immunological cells of healthy indigenous individuals from a region in Brazil

ABSTRACT Objective The establishment of reference values for a subset of leukocytes is common in clinical practice, and ethnic variations are strongly associated with disease development. In Brazil, indigenous people are vulnerable to infections, and few studies have described the health and disease conditions of this population. This study aimed to provide reference values for immunological cell subsets in indigenous Brazilians living in the state of Mato Grosso do Sul. Methods Flow cytometry and 4-color combinations of monoclonal antibodies were used to characterize cells. A total of 115 healthy adults, mostly females (72%), were included in the study. The results are presented as mean and median (2.5%-97.5% percentiles) for T and B lymphocytes, CD4+ T cells, CD8+ T cells, Natural Killer cells, monocytes, and dendritic cells, providing an average immunological profile for the population in question. Results The relative medians of CD3+, CD4+, and CD8+ T cells were significantly higher in women than in men in a healthy indigenous population. Conclusion To our knowledge, cell reference data from indigenous Brazilians are unknown in the literature. The immune cell results presented in this pioneering study will contribute to the clinical and laboratory evaluation of the Brazilian indigenous population, especially given the important differences when compared with other Brazilian ethnic groups.

Detection of Treponema pallidum in whole blood samples of patients with syphilis by the polymerase chain reaction

ABSTRACT Syphilis is caused by the bacterium Treponema pallidum. The diagnosis is based on clinical data and serological analysis; however, the sensitivity and specificity of such tests may vary depending on the type of test and stage of the infection. In order to overcome this premise, this study utilized the polymerase chain reaction (PCR) for the detection of T. pallidum DNA in whole blood samples of patients with syphilis. The blood samples from patients with or without symptoms of syphilis, but with positive results in enzyme-linked immunosorbent assay (ELISA), were included in this study. A venereal disease research laboratory (VDRL) test was performed for all collected sera samples. For PCR, the T. pallidum DNA was extracted from the collected blood samples and a specific primer set was designed to amplify 131 nucleotides of polA (Tp0105). The specificity of the primers was evaluated with the DNA of 17 different pathogens. From a total of 314 blood samples reactive in ELISA, 58.2% (183/314) of the samples were reactive in the VDRL test. In the PCR, 54% (168/314) of the ELISA-reactive samples were positive. In both tests (VDRL and PCR) 104 samples were positive. Of 104 positive samples for both tests, 71 were at the latent stage. Based on these results, it can be concluded that PCR with the designed set of primers can be utilized as a diagnostic method for T. pallidum detection in blood samples of patients with syphilis, especially those with latent infection. In addition, it can be utilized as a supplement for serological methods to improve the diagnosis of syphilis.