Occurrence and Molecular Characteristics of Extended-Spectrum Beta-Lactamase-Producing Enterobacterales Recovered From Chicken, Chicken Meat, and Human Infections in Sao Paulo State, Brazil

This study aimed to investigate the phylogenetic diversity and epidemiology of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae from chicken, chicken meat, and human clinical isolates in Sao Paolo, Brazil, and characterize their respective ESBL-encoding plasmids. Three hundred samples from chicken cloaca, chicken meat, and clinical isolates were phenotypically and genotypically assessed for ESBL resistance. Isolates were identified by MALDI TOF-MS and further characterized by MLST analysis and phylogenetic grouping. ESBL genes were characterized and their location was determined by I-Ceu-I-PFGE and Southern blot, conjugation, transformation, and PCR-based replicon typing experiments. Thirty-seven ESBL-producing isolates (28 E. coli and 9 K. pneumoniae) that were positive for the blaCTX–M–1 or blaCTX–M–2 gene groups were obtained. Two isolates were negative in the transformation assay, and the chromosomal location of the genes was deduced by Southern blot. The blaCTX–M genes identified were carried on plasmid replicon-types X1, HI2, N, FII-variants, I1 and R. The E. coli isolates belonged to nine sequence types, while the K. pneumoniae isolates belonged to four sequence types. The E. coli isolates belonged to phylotype classification groups A, B1, D, and F. This study demonstrated that isolates from cloacal swabs, chicken meat, and human feces had genetic diversity, with a high frequency of blaCTX–M–15 among chickens, chicken meat, and human feces. Thus, this reinforces the hypothesis that chickens, as well as their by-products, could be an important source of transmission for ESBL-producing pathogens to humans in South America

VÍRUS DA BRONQUITE INFECCIOSA AVIÁRIA: PERFIS DE IMUNOGENICIDADE E NOVOS PATOTIPOS NO BRASIL – REVISÃO DE LITERATURA

A bronquite infecciosa das galinhas (BIG) é uma doença infecciosa causada pelo coronavírus aviário (vírus da bronquite infecciosa – VBI) que está amplamente disseminada entre as criações avícolas comerciais na maior parte do mundo. O VBI apresenta alta capacidade de variabilidade genética, o que se traduz pelo aparecimento de alterações marcantes na composição, estrutura e propriedades antigênicas de suas proteínas. Diante disso, este trabalho tem por objetivo realizar uma revisão bibliográfica sobre os novos patotipos desses vírus que surgiram nas últimas décadas abordando principalmente seus perfis de imunogenicidade. Com o aparecimento de variantes antigênicas e biológicas entre as estirpes do VBI nos últimos anos, ocorreu o surgimento de diferentes genótipos, sorotipos e patotipos deste vírus o que proporcionou um aumento nas falhas vacinais contra esta doença

Vírus da bronquite infecciosa aviária: Perfis de imunogenicidade e novos patotipos no brasil – revisão de literatura

Infectious bronchitis of chickens (BIG) is an infectious disease caused by avian coronavirus (IBV) that is widely disseminated among commercial poultry farms in most parts of the world. IBV has a high genetic variability, which is reflected by the appearance of marked changes in the composition, structure and antigenic and biological properties of its proteins. Therefore, the objective of this work is to carry out a bibliographical review on the new genotypes, antigenic types and IBV pathotype that have been isolated in the last decades in Brazil, mainly addressing their immunogenicity profiles. With the appearance of antigenic and biological variants among IBV strains in the last years, different genotypes, serotypes and pathophyses of this virus occurred, which resulted in an increase in vaccine failures against this disease and the need to develop new vaccine preparations which provide both antibody and T cell mediated responses, especially in the mucosal compartment, and which result in a more effective protection status against Brazilian VBI variants.A bronquite infecciosa das galinhas (BIG) é uma doença infecciosa causada pelo coronavírus aviário (vírus da bronquite infecciosa – VBI) que está amplamente disseminada entre as criações avícolas comerciais na maior parte do mundo. O VBI apresenta alta capacidade de variabilidade genética, o que se traduz pelo aparecimento de alterações marcantes na composição, estrutura e propriedades antigênicas de suas proteínas. Diante disso, este trabalho tem por objetivo realizar uma revisão bibliográfica sobre os novos patotipos desses vírus que surgiram nas últimas décadas abordando principalmente seus perfis de imunogenicidade. Com o aparecimento de variantes antigênicas e biológicas entre as estirpes do VBI nos últimos anos, ocorreu o surgimento de diferentes genótipos, sorotipos e patotipos deste vírus o que proporcionou um aumento nas falhas vacinais contra esta doença

Memory immune responses and protection of chickens against a nephropathogenic infectious bronchitis virus strain by combining live heterologous and inactivated homologous vaccines

In this study, we evaluated antibody and cell-mediated immune (CMI) responses in the mucosal and systemic compartments and protection against challenge with a nephropathogenic Brazilian (BR-I) strain of infectious bronchitis virus (IBV) in chickens submitted to a vaccination regime comprising a priming dose of heterologous live attenuated Massachusetts vaccine followed by a booster dose of an experimental homologous inactivated vaccine two weeks later. This immunization protocol elicited significant increases in serum and lachrymal levels of anti-IBV IgG antibodies and upregulated the expression of CMI response genes, such as those encoding CD8? chain and Granzyme homolog A in tracheal and kidney tissues at 3, 7, and 11 days post-infection in the vaccinated chickens. Additionally, vaccinated and challenged chickens showed reduced viral loads and microscopic lesion counts in tracheal and kidney tissues, and their antibody and CMI responses were negatively correlated with viral loads in the trachea and kidney. In conclusion, the combination of live attenuated vaccine containing the Massachusetts strain with a booster dose of an inactivated vaccine, containing a BR-I IBV strain, confers effective protection against infection with nephropathogenic homologous IBV strain because of the induction of consistent memory immune responses mediated by IgG antibodies and TCD8 cells in the mucosal and systemic compartments of chickens submitted to this vaccination regime.Made available in DSpace on 2019-09-05T00:53:12Z (GMT). No. of bitstreams: 1 MemoryImmuneResponses.pdf: 1114140 bytes, checksum: 2bc1aede5399360765eefa6dccd0b2e5 (MD5) Previous issue date: 2019bitstream/item/201566/1/Memory-Immune-Responses.pd

A liquid-phase-blocking concanavalin A enzyme-linked immunosorbent assay for the detection of antibodies against Newcastle disease virus in serum of free-ranging pigeons

A competitive liquid-phase-blocking concanavalin A enzyme-linked immunosorbent assay (LPB-ConA-ELISA) was developed in the current study. The assay used ConA as a capture reagent, and the sera of specific pathogen-free chickens immunized with nonpurified Newcastle disease virus (NDV) suspension as detector antibodies, to detect and quantify specific antiviral antibodies in serum samples from free-ranging pigeons. The comparison between the LPB-ConA-ELISA and the hemagglutination inhibition (HI) test for the detection of antibodies in serum samples from 107 pigeons showed significant correlation between the assays (r = 0.875), a high sensitivity (100%), specificity (95.8%), accuracy (96.3%) for the ELISA, and good agreement ( = 0.83) between the 2 assays. The results of this study suggest that the LPB-ConA-ELISA could be a useful alternative to HI test in the serodiagnosis of NDV in pigeons, or other species of birds.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq