Effect of oviposition by Bactrocera dorsalis on the antioxidant activity of orange juice / Efeito da oviposição de Bactrocera dorsalis na atividade antioxidante do suco de laranja

Abstract Among fruits and fruit products, oranges and orange juice are the most widely consumed worldwide. However, the effects of pest infestation of oranges on the quality of orange juice are not yet known. To evaluate the effect of the oriental fruit fly Bactrocera dorsalis on the antioxidant activity of orange juice, we measured changes in the vitamin C (Vc) concentration, total phenol content, and antioxidant activity of orange juice after the introduction of fruit fly eggs. Ten days after the eggs were introduced (larvae removed), the concentration of Vc in orange juice was 18.65 µg/mL, which was 9.16 µg/mL lower than that measured in healthy orange juice. In addition, the total phenol content decreased by 46.519 mg Gallic Acid Equivalents (GAE)/g to 9.748 mg GAE/g. Furthermore, the free-radical scavenging activity decreased from 22.297% to 5.393%. Correlation analysis indicated significant correlations between Vc concentration, total phenol content, and antioxidant activity of orange juice after B. dorsalis infestation. The decrease in Vc concentration, total phenol content and free-radical scavenging activity indicated that B. dorsalis changed the quality of orange juice by affecting the antioxidant activity of the juice after the oranges were infested.

Resumo Entre frutas e produtos de frutas, as laranjas e suco de laranja são os mais consumidos em todo o mundo. No entanto, os efeitos da infestação de laranjas sobre a qualidade do suco de laranja ainda não são conhecidos. Para avaliar o efeito da mosca-das-frutas oriental, Bactrocera dorsalis, sobre a atividade antioxidante do suco de laranja, foram medidas as mudanças na concentração de vitamina C (Vc), no teor de fenol total e na atividade antioxidante do suco de laranja após a introdução de ovos da mosca-das-frutas oriental. Dez dias após a introdução dos ovos (larvas removidas), a concentração de Vc no suco de laranja foi de 18,65 µg/mL, que foi 9,16 µg/mL menor do que a medida em suco de laranja saudável. Além disso, o teor total de fenol diminuiu de 46,519 mg em equivalente de ácido gípico (GAE)/g para 9,748 mg de GAE/g. Ademais, a atividade de eliminação de radicais livres diminuiu de 22,297% para 5,393%. A análise de correlação indicou correlações significativas dentre a concentração de Vc, o conteúdo total de fenol e a atividade antioxidante do suco de laranja após a infestação por B. dorsalis. A diminuição na concentração de Vc, o conteúdo total de fenol e a atividade sequestradora de radicais livres indicaram que B. dorsalis alterou a qualidade do suco de laranja, afetando a atividade antioxidante do suco após a infestação das laranjas.

Biopanning the mimotopes of aflatoxin B1 and their immunogenicity / Panning de mimotopo aflatoxina B1 e sua imunogenicidade

Utilizando um anticorpo monoclonal contra a aflatoxina B1 (AFB1) como ligante, foi identificado um mimotopo específico de aflatoxina B1 após se realizarem quatro ciclos de seleção biológica de 7-peptídeos aleatórios em biblioteca de fago exibida. O mimotopo é denominado P10, e sua sequência de aminoácidos é YRRHEKD. O soro imunológico de ratos Balb/c imunizados com P10 foi especificamente ligado à aflatoxina B1-albumina, indicando que o anticorpo era específico ao AFB1. Esses resultados sugerem que é possível desenvolver a vacina baseada em mimotopo associado à toxina.(AU)

Effect of oviposition by Bactrocera dorsalis on the antioxidant activity of orange juice

Abstract Among fruits and fruit products, oranges and orange juice are the most widely consumed worldwide. However, the effects of pest infestation of oranges on the quality of orange juice are not yet known. To evaluate the effect of the oriental fruit fly Bactrocera dorsalis on the antioxidant activity of orange juice, we measured changes in the vitamin C (Vc) concentration, total phenol content, and antioxidant activity of orange juice after the introduction of fruit fly eggs. Ten days after the eggs were introduced (larvae removed), the concentration of Vc in orange juice was 18.65 µg/mL, which was 9.16 µg/mL lower than that measured in healthy orange juice. In addition, the total phenol content decreased by 46.519 mg Gallic Acid Equivalents (GAE)/g to 9.748 mg GAE/g. Furthermore, the free-radical scavenging activity decreased from 22.297% to 5.393%. Correlation analysis indicated significant correlations between Vc concentration, total phenol content, and antioxidant activity of orange juice after B. dorsalis infestation. The decrease in Vc concentration, total phenol content and free-radical scavenging activity indicated that B. dorsalis changed the quality of orange juice by affecting the antioxidant activity of the juice after the oranges were infested.

Resumo Entre frutas e produtos de frutas, as laranjas e suco de laranja são os mais consumidos em todo o mundo. No entanto, os efeitos da infestação de laranjas sobre a qualidade do suco de laranja ainda não são conhecidos. Para avaliar o efeito da mosca-das-frutas oriental, Bactrocera dorsalis, sobre a atividade antioxidante do suco de laranja, foram medidas as mudanças na concentração de vitamina C (Vc), no teor de fenol total e na atividade antioxidante do suco de laranja após a introdução de ovos da mosca-das-frutas oriental. Dez dias após a introdução dos ovos (larvas removidas), a concentração de Vc no suco de laranja foi de 18,65 µg/mL, que foi 9,16 µg/mL menor do que a medida em suco de laranja saudável. Além disso, o teor total de fenol diminuiu de 46,519 mg em equivalente de ácido gípico (GAE)/g para 9,748 mg de GAE/g. Ademais, a atividade de eliminação de radicais livres diminuiu de 22,297% para 5,393%. A análise de correlação indicou correlações significativas dentre a concentração de Vc, o conteúdo total de fenol e a atividade antioxidante do suco de laranja após a infestação por B. dorsalis. A diminuição na concentração de Vc, o conteúdo total de fenol e a atividade sequestradora de radicais livres indicaram que B. dorsalis alterou a qualidade do suco de laranja, afetando a atividade antioxidante do suco após a infestação das laranjas.

Class 1 integrons contributes to antibiotic resistance among clinical isolates of Escherichia coli producing extended-spectrum beta-lactamases.

Objectives: The objective of this study is to determine the prevalence of antibiotic resistance factors, including the production of extended-spectrum beta-lactamases (ESBLs) and the presence of class 1 integrons among Escherichia coli isolated from clinical specimens. Materials and Methods: Bacterial species identifi cation was performed using a VITEK-2 system (VITEK2 GN-card; bioMérieux, France). Antimicrobial susceptibility testing was determined using the disk diffusion method according to the 2010 Clinical and Laboratory Standards Institute guidelines. Polymerase chain reaction (PCR) was used to detect integrons and amplify variable regions of the blaTEM, blaSHV and blaCTX-M genes. Gene cassettes were detected by deoxyribonucleic acid sequencing. Results: In this study, 58% (100/172) of clinical E. coli isolates were identifi ed as ESBL producers. We found that 90% of the ESBL-producing E. coli isolates harbored the blaCTX-M gene, whereas only 59% and 32% possessed the blaTEM and blaSHV genes respectively. The presence of class 1 integrons was based on the detection of the integrase gene by PCR. A total of 69% of the ESBL-producing isolates were integron-positive. Resistance to 10 antibiotics, including quinolones, sulfonamides and -lactam/enzyme inhibitors, was signifi cantly higher in the class 1 integron-positive isolates (P < 0.05). The occurrence of class 1 integrons in blaTEM, blaSHV and blaCTX-M gene carriers was 72.9%, 84.4% and 68.9%, respectively. Class 1 integrons were detected in 61.5% of the isolates with only one ESBL genotype, but in 69.0% and 92.3% of the isolates with two or three different ESBL genotypes, respectively. Conclusions: Our fi ndings indicate that clinical strains of bacteria with multiple ESBL genotypes may have greater opportunities to carry class 1 integrons.