The epidemiological impact of viral diseases, combined with the emergence and reemergence
of some viruses, and the difficulties in identifying effective therapies, have encouraged
several studies to develop new therapeutic strategies for viral infections. In this context, the use of immunotherapy
for the treatment of viral diseases is increasing. One of the strategies of immunotherapy
is the use of antibodies, particularly the monoclonal antibodies (mAbs) and multi-specific antibodies,
which bind directly to the viral antigen and bring about activation of the immune system. With current
advancements in science and technology, several such antibodies are being tested, and some are already
approved and are undergoing clinical trials. The present work aims to review the status of mAb
development for the treatment of viral diseases.
This study discussed the use of antimicrobials in the commercial chicken production system and the possible factors influencing the presence of Extended-spectrum β-lactamase (ESBL)/AmpC producers strains in the broiler production chain. The aim of this study was to perform longitudinal monitoring of ESBL-producing and fosfomycin-resistant Escherichia coli from poultry farms in southern Brazil (Paraná and Rio Grande do Sul states) and determine the possible critical points that may be reservoirs for these strains. Samples of poultry litter, cloacal swabs, poultry feed, water, and beetles (Alphitobius sp.) were collected during three distinct samplings. Phenotypic and genotypic tests were performed for characterization of antimicrobial resistant strains. A total of 117 strains were isolated and 78 (66%) were positive for ESBL production. The poultry litter presented ESBL positive strains in all three sampled periods, whereas the cloacal swab presented positive strains only from the second period. The poultry litter represents a significant risk factor mainly at the beginning poultry production (odds ratio 6.43, 95% confidence interval 1–41.21, p < 0.05). All beetles presented ESBL positive strains. The predominant gene was blaCTX–M group 2, which occurred in approximately 55% of the ESBL-producing E. coli. The cit gene was found in approximately 13% of the ESBL-producing E. coli as AmpC type determinants. A total of 19 out of 26 fosfomycin-resistant strains showed the fosA3 gene, all of which produced ESBL. The correlation between fosA3 and blaCTX–M group 1 (blaCTX–M55) genes was significant among ESBL-producing E. coli isolated from Paraná (OR 3.66, 95% CI 1.9–9.68) and these genetic determinants can be transmitted by conjugation to broiler chicken microbiota strains. Our data revealed that poultry litter and beetles were critical points during poultry production and the presence of fosfomycin-resistant strains indicate the possibility of risks associated with the use of this antimicrobial during production. Furthermore, the genetic determinants encoding CTX-M and fosA3 enzymes can be transferred to E. coli strains from broiler chicken microbiota, thereby creating a risk to public health.
It is known that chicken litter is home to many pathogenic and antimicrobial resistant bacteria, and in many cases, it is reused without prior treatment in the creation of subsequent batches. Thus, the work aimed to verify whether Escherichia coli strains that produce Extended Spectrum Beta-lactamases (ESBL) isolated from chicken beds in the state of Paraná, were able to transfer their genes to E. coli isolates from the intestinal microbiota of one day old chicks. For this study, four strains of E. coli producing ESBL were used, presenting the blaCTX-M1 gene isolated from chicken litter, to be the plasmid donors, and three strains isolated from chicks newly arrived at the shed, which showed resistance to only gentamicin. For the conjugation assays, the donor and recipient strains were used in a proportion of 1: 2 respectively, and the transconjugants selected for resistance to gentamicin and cefotaxime in specific concentrations. Transconjugant colonies were selected and their phylogenetic groups identified by the PCR technique. Of the 12 conjugations performed, three presented transconjugants harboring the blaCTX-M1 gene, indicating that there is a possibility that this gene could be transferred to E. coli of the microbiota. Thus, in the environment of the farms, the transmission of plasmids of resistance from bacteria present in the chicken litter to bacteria from the microbiota of the newly arrived chicks may occur. The fact that chicken litter is reused without proper treatment contributes to the maintenance and dissemination of genetic determinants for ESBL in broiler chickens.
Direitos para esta edição cedidos à Atena Editora pelos autores. Open access publication by Atena Editora Todo o conteúdo deste livro está licenciado sob uma Licença de Atribuição Creative Commons. Atribuição-Não-Comercial-NãoDerivativos 4.0 Internacional (CC BY-NC-ND 4.0).O conteúdo dos artigos e seus dados em sua forma, correção e confiabilidade são de responsabilidade exclusiva dos autores, inclusive não representam necessariamente a posição oficial da Atena Editora. Permitido o download da obra e o compartilhamento desde que sejam atribuídos créditos aos autores, mas sem a possibilidade de alterá-la de nenhuma forma ou utilizá-la para fins comerciais. Todos os manuscritos foram previamente submetidos à avaliação cega pelos pares, membros do Conselho Editorial desta Editora, tendo sido aprovados para a publicação com base em critérios de neutralidade e imparcialidade acadêmica.A Atena Editora é comprometida em garantir a integridade editorial em todas as etapas do processo de publicação, evitando plágio, dados ou resultados fraudulentos e impedindo que interesses financeiros comprometam os padrões éticos da publicação. Situações suspeitas de má conduta científica serão investigadas sob o mais alto padrão de rigor acadêmico e ético.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.