Formulation and Validation of Recombinant Antigens CFP10 and ESAT6 for Tuberculosis Diagnosis

Abstract The rapid and accurate diagnosis of tuberculosis (TB), especially considering limited resources, is still a challenge. Development of new methodologies and tests are needed to overcome several disadvantages of the available standard tests. We evaluated the diagnostic potential of two antigens specific for Mycobacterium tuberculosis, the CFP10 and ESAT6 recombinant proteins, and developed stable formulations thereof. Sensitivity and specificity of the delayed-type hypersensitivity (DTH) skin testing and the induction of gamma interferon production (IFN-γ) by lymphocytes, as a non-invasive test, were evaluated using the CFP10 and ESAT6 protein formulations. The recombinant proteins produced by our group presented a high DTH response and the ability to differentiate between tuberculosis infection, BCG vaccination, and the contact with non-tuberculous mycobacteria (NTM). The production of IFN-γ by stimulation with individual and combined proteins was detected in a panel of 40 individuals and showed a specificity of 100% and a sensitivity of 90% when the two proteins were used together. Lyophilized formulations were stable under all conditions, while soluble formulations were stable under freezing at -20 ºC and -80 ºC. The proposed formulations containing the ESAT6 and CFP10 recombinant antigens constitute satisfactory tools for TB testing, suitable to be developed and implemented in a large-scale trial.

Parasite detection in sand from bays on the north coast of São Paulo state, Brazil

Soil contamination by protozoan parasites and soil-transmitted helminths (STH) is common in beach sand due to a number of factors such as pets, pluvial water, garbage, etc. These pathogens may cause many diseases in humans and animals and become a public health problem. Thus, systematic evaluation and inspection are necessary to develop control strategies regarding public contamination. For this purpose, our aims were to evaluate the parasitic profile of sandy soils on an urban beach and an untouched beach and correlate this with environmental and seasonal characteristics in Ubatuba, Brazil, in two seasons (winter and summer). 132 soil samples were collected for parasite analysis utilizing Rugai's method and the sedimentation adapted method. Our results showed positivity in 62% of the samples for at least one parasite in the urban beach and no parasitic structures on the untouched beach. The positivity was higher in summer (85%) than in winter (51.7%). All samples were positive for both, helminths and protozoa. Seasonal influence was noted regarding the presence of STH while for protozoa this influence was not observed. The parasitic structures most found were larvae of hookworms (35%) and Toxocara eggs (31.7%). We also noted the presence of Strongyloides sp, Ascaris lumbricoides, coccidia, Dipylidium caninum, Entamoeba hystolitica/dispar, Endolimax nana, Entamoeba coli, Giardia sp, Toxascaris leonina, Trichuris sp and Dibothricephalus latus. There was a positive correlation between temperature and the presence of STH in the sand samples. Most of the collection sites on the urban beach presented dogs or canine traces and garbage in both seasons. There was an association between the presence of dogs or their traces and parasitic structures. In conclusion, seasonality, urbanization and the presence of pets on beaches can potentially favor environmental contamination by parasites increasing the risk of transmission of zoonotic and parasitic diseases.

Prevalence of intestinal parasites in child day care centers: epidemiological significance

Intestinal parasites are among the most commonly found pathogens in humans and are considered a public health problem. The frequency of intestinal parasites was evaluated in children and staff at two day care centers in the city of Ituiutaba, Brazil and health encouragement activities were developed. For parasite detection in stool samples the Ritchie's technique and the Hoffman-Pons-Janer, Baermann-Moraes, Willis and Ziehl-Neelsen methods were applied. Of 140 children, 88 (62.9%) were positive, where Giardia intestinalis cysts were present in 65 children (51.1%), Entamoeba coli in 22 (17.3%), Endolimax nana in 12 (9.4%), Entamoeba histolytica/E. dispar in 9 (7%), Hymenolepis nana eggs were found in 5 (4%), hookworms in 4 (3.1%), Ascaris lumbricoides and Enterobius vermicularis in 3 (2.3%) and Strongyloides stercoralis, Trichuris trichiura, Cryptosporidium spp. and Iodamoeba butschlii in one child (0.8%). Among the 41 employees examined, 10 (24.3%) were positive, E. coli cysts were found in 6 samples (35.2%) and E. nana in 5 (29.4%), followed by E. histolytica/E. dispar in 4 (23.6%) and G. intestinalis and E. vermicularis eggs in (5.9%). The data show the high frequency of intestinal parasites in fecal samples analyzed and demonstrate the importance of adopting preventive measures such as health and education involving the community

PREVALENCE OF CHAGAS DISEASE AMONG BLOOD DONOR CANDIDATES IN TRIANGULO MINEIRO, MINAS GERAIS STATE, BRAZIL / Prevalência de casos de doença de Chagas em candidatos a doação de sangue na região do Pontal do Triângulo Mineiro, Brasil

Despite public health campaigns and epidemiological surveillance activities, Chagas disease remains a major health problem in Latin America. According to data from the World Health Organization, there are approximately 7-8 million people infected with Trypanosoma cruzi worldwide, a large percentage of which in Latin America. This study aims to examine the serological profile of blood donors in blood banks of Hemominas hematology center, in the town of Ituiutaba, Minas Gerais State, Brazil. The study sample consisted of 53,941 blood donors, which were grouped according to gender and age. Sample collections were performed from January 1991 to December 2011, and 277 donors (0.5%) were considered serologically ineligible due to Chagas disease. Analysis of data showed no significant difference between genders. As for age, the highest proportion of ineligible donors was from 40 to 49 years (30%), and there was a positive correlation between increasing age and the percentage of patients seropositive for Chagas disease. Therefore, adopting strategies that allow the safe identification of donors with positive serology for Chagas disease is essential to reduce or eliminate indeterminate serological results.

A doença de Chagas, apesar das campanhas de saúde pública e das ações de vigilância epidemiológica, ainda constitui-se um sério problema de saúde na América Latina. De acordo com dados divulgados pela Organização Mundial de Saúde, existem cerca de 7 a 8 milhões de pessoas infectadas com Trypanosoma cruzi em todo o mundo, principalmente na América Latina. Este estudo tem por objetivo analisar o perfil sorológico de doadores de sangue dos bancos de sangue do Hemominas de Ituiutaba, Minas Gerais. Os doadores também foram separados de acordo com o sexo e a idade. A amostra do estudo foi composta por 53.941 doadores de sangue durante o período de janeiro de 2001 a dezembro de 2011. Duzentos e setenta e sete doações (0,5%) foram considerados sorologicamente inaptas para a doença de Chagas. Quanto à idade, a maior proporção de doadores impróprios foi de 40 a 49 anos (30%). Os dados não revelaram diferença significativa entre os sexos (p < 0,05). Houve correlação positiva entre o aumento da idade e o percentual de pacientes soropositivos para doença de Chagas. É imprescindível a adoção de estratégias que permitam a identificação segura de um doador com sorologia positiva para doença de Chagas, tentando assim minimizar ou eliminar resultados sorológicos indeterminados.