RESUMO

Organic acids (OAs) are a class of feed additives that have prophylactic and inhibitory properties against pathogenic bacteria. In this study, we investigated growth performance, innate immune response, gut microbiota, and disease resistance against Francisella orientalis F1 in Nile tilapia (Oreochromis niloticus) fed different doses of Bacti-nil®Aqua, a blend of short- and medium-chain OAs. For 21 days, 680 juvenile tilapias were fed a control diet or diets supplemented with a 0.3% (D3) or 0.5% (D5) OA blend. The feed conversion rate of fish fed the 0.5% enriched diet was considerably lower (p < 0.05) than that of the fish fed the basal diet. Lysozyme and serum bactericidal activities were significantly elevated following OA administration. After infection, no differences in the diversity and composition of gut microbiota were observed between the groups. After the bacterial challenge, the mortality was significantly lower in group D5 (p < 0.01). The diet supplemented with Bacti-nil®Aqua (Adisseo) improved the immune response and resistance of tilapia juveniles against F. orientalis infection. Thus, this OA blend could serve as a feed additive with good activity against F. orientalis.

Assuntos

RESUMO

Aquaculture is one of the sectors of animal husbandry with the fastest growth rate. However, the increase in the sector's production chain without proper management can result in factors that favor the development of diseases, especially infectious diseases caused by bacteria. Many factors, such as agriculture or industry resides, improper use of antibiotics in animals or humans, have contributed to increased environmental pressure and the appearance of antibiotic-resistant bacteria, while residues from these drugs can remain in the carcasses and in water a risk to public and environmental health. From that, we identified the bacterial genus/species and their bacterial resistance to antibiotics from samples received from fish disease outbreaks for bacteriosis diagnosis between January 2017 and October 2020. Isolated bacteria were subjected to the Kirby and Bauer sensitivity test for five classes of antibiotics (penicillins, fluoroquinolones, aminoglycosides, amphenicols, and tetracyclines). Of the 181 analyzed outbreaks, 232 bacteria were isolated, including Streptococcus spp., Aeromonas spp., Edwardsiella spp., Plesiomonas shigelloides, Pseudomonas aeruginosa, Chromobacterium violaceum, Flavobacterium spp., Citrobacter spp., Enterococcus spp., Vibrio spp., Enterobacter spp., Chryseobacterium meningosepticum. Of the 232 bacteria, 40 strains were classified as multidrug resistant (MDR), with Plesiomonas shigelloides, Aeromonas spp., and Edwardsiella spp. representing more than half of this number (22/total). With several bacteria demonstrating resistance to Brazilian aquaculture-legalized drugs (tetracycline and florfenicol), it is mandatory to research, not only for alternatives to the use of antibiotics, but also for other [...].(AU)

Aquicultura é um dos setores da produção animal com o mais rápido crescimento. Muitos fatores, como resíduos industriais e/ou de agricultura e o uso indevido de antibióticos em animais ou humanos têmc ontribuído para aumentar a pressão ambiental e o aparecimento de bactérias resistentes a antibióticos contribuindo para os resíduos dessas drogas permanecerem nas carcaças e na água, o que é um risco para a saúde pública / ambiental. A partir disso, foram identificados o gênero / espécie de bactérias e sua resistência bacteriana aos antibióticos de amostras recebidas de surtos de doenças em peixes para diagnóstico bacteriológico no período entre janeiro de 2017 e outubro de 2020. As bactérias isoladas foram submetidas ao teste de sensibilidade de Kirby e Bauer para cinco classes de antibióticos (penicilinas, fluoroquinolonas, aminoglicosídeos, anfenicóis e tetraciclinas). Nos 181 surtos analisados, 232 bactérias foram isoladas, sendo estas Streptococcus spp., Aeromonas spp., Edwardsiella spp., Plesiomonas shigelloides, Pseudomonas aeruginosa, Chromobacterium violaceum, Flavobacterium spp.,Citrobacter spp., Enterococcus spp., Vibrio spp., Enterobacter spp., Chryseobacterium meningosepticum dentre outras. Destas 232 bactérias, 40 cepas foram classificadas como multirresistentes (MDR), com Plesiomonas shigelloides, Aeromonas spp. e Edwardsiella spp. representando mais da metade destas (22 / total). Com várias bactérias demonstrando resistência aos medicamentos legalizados na aquicultura brasileira (tetraciclina e florfenicol), torna-se obrigatória a pesquisa, não apenas de alternativas ao uso de antibióticos, mas também de outros medicamentos eficazes contra os principais patógenos circulantes. Além disso, a vigilância sobre a ocorrência de cepas resistentes é necessária levando-se em consideração o aparecimento de bactérias zoonóticas com essa característica, tornando-se um ponto de interesse à saúde pública.(AU)

Assuntos

RESUMO

Aquaculture is one of the sectors of animal husbandry with the fastest growth rate. However, the increase in the sector's production chain without proper management can result in factors that favor the development of diseases, especially infectious diseases caused by bacteria. Many factors, such as agriculture or industry resides, improper use of antibiotics in animals or humans, have contributed to increased environmental pressure and the appearance of antibiotic-resistant bacteria, while residues from these drugs can remain in the carcasses and in water a risk to public and environmental health. From that, we identified the bacterial genus/species and their bacterial resistance to antibiotics from samples received from fish disease outbreaks for bacteriosis diagnosis between January 2017 and October 2020. Isolated bacteria were subjected to the Kirby and Bauer sensitivity test for five classes of antibiotics (penicillins, fluoroquinolones, aminoglycosides, amphenicols, and tetracyclines). Of the 181 analyzed outbreaks, 232 bacteria were isolated, including Streptococcus spp., Aeromonas spp., Edwardsiella spp., Plesiomonas shigelloides, Pseudomonas aeruginosa, Chromobacterium violaceum, Flavobacterium spp., Citrobacter spp., Enterococcus spp., Vibrio spp., Enterobacter spp., Chryseobacterium meningosepticum. Of the 232 bacteria, 40 strains were classified as multidrug resistant (MDR), with Plesiomonas shigelloides, Aeromonas spp., and Edwardsiella spp. representing more than half of this number (22/total). With several bacteria demonstrating resistance to Brazilian aquaculture-legalized drugs (tetracycline and florfenicol), it is mandatory to research, not only for alternatives to the use of antibiotics, but also for other [...].

Aquicultura é um dos setores da produção animal com o mais rápido crescimento. Muitos fatores, como resíduos industriais e/ou de agricultura e o uso indevido de antibióticos em animais ou humanos têmc ontribuído para aumentar a pressão ambiental e o aparecimento de bactérias resistentes a antibióticos contribuindo para os resíduos dessas drogas permanecerem nas carcaças e na água, o que é um risco para a saúde pública / ambiental. A partir disso, foram identificados o gênero / espécie de bactérias e sua resistência bacteriana aos antibióticos de amostras recebidas de surtos de doenças em peixes para diagnóstico bacteriológico no período entre janeiro de 2017 e outubro de 2020. As bactérias isoladas foram submetidas ao teste de sensibilidade de Kirby e Bauer para cinco classes de antibióticos (penicilinas, fluoroquinolonas, aminoglicosídeos, anfenicóis e tetraciclinas). Nos 181 surtos analisados, 232 bactérias foram isoladas, sendo estas Streptococcus spp., Aeromonas spp., Edwardsiella spp., Plesiomonas shigelloides, Pseudomonas aeruginosa, Chromobacterium violaceum, Flavobacterium spp.,Citrobacter spp., Enterococcus spp., Vibrio spp., Enterobacter spp., Chryseobacterium meningosepticum dentre outras. Destas 232 bactérias, 40 cepas foram classificadas como multirresistentes (MDR), com Plesiomonas shigelloides, Aeromonas spp. e Edwardsiella spp. representando mais da metade destas (22 / total). Com várias bactérias demonstrando resistência aos medicamentos legalizados na aquicultura brasileira (tetraciclina e florfenicol), torna-se obrigatória a pesquisa, não apenas de alternativas ao uso de antibióticos, mas também de outros medicamentos eficazes contra os principais patógenos circulantes. Além disso, a vigilância sobre a ocorrência de cepas resistentes é necessária levando-se em consideração o aparecimento de bactérias zoonóticas com essa característica, tornando-se um ponto de interesse à saúde pública.

Assuntos

RESUMO

Aquaculture is one of the sectors of animal husbandry with the fastest growth rate. However, the increase in the sector's production chain without proper management can result in factors that favor the development of diseases, especially infectious diseases caused by bacteria. Many factors, such as agriculture or industry resides, improper use of antibiotics in animals or humans, have contributed to increased environmental pressure and the appearance of antibiotic-resistant bacteria, while residues from these drugs can remain in the carcasses and in water a risk to public and environmental health. From that, we identified the bacterial genus/species and their bacterial resistance to antibiotics from samples received from fish disease outbreaks for bacteriosis diagnosis between January 2017 and October 2020. Isolated bacteria were subjected to the Kirby and Bauer sensitivity test for five classes of antibiotics (penicillins, fluoroquinolones, aminoglycosides, amphenicols, and tetracyclines). Of the 181 analyzed outbreaks, 232 bacteria were isolated, including Streptococcus spp., Aeromonas spp., Edwardsiella spp., Plesiomonas shigelloides, Pseudomonas aeruginosa, Chromobacterium violaceum, Flavobacterium spp., Citrobacter spp., Enterococcus spp., Vibrio spp., Enterobacter spp., Chryseobacterium meningosepticum. Of the 232 bacteria, 40 strains were classified as multidrug resistant (MDR), with Plesiomonas shigelloides, Aeromonas spp., and Edwardsiella spp. representing more than half of this number (22/total). With several bacteria demonstrating resistance to Brazilian aquaculture-legalized drugs (tetracycline and florfenicol), it is mandatory to research, not only for alternatives to the use of antibiotics, but also for other drugs effective against the main circulating bacterial pathogens. In addition, vigilance over the occurrence of resistant bacteria is necessary, considering the appearance of zoonotic bacteria with multi-resistant characteristics, becoming a public health concern.(AU)

Aquicultura é um dos setores da produção animal com o mais rápido crescimento. Muitos fatores, como resíduos industriais e/ou de agricultura e o uso indevido de antibióticos em animais ou humanos têm contribuído para aumentar a pressão ambiental e o aparecimento de bactérias resistentes a antibióticos contribuindo para os resíduos dessas drogas permanecerem nas carcaças e na água, o que é um risco para a saúde pública / ambiental. A partir disso, foram identificados o gênero / espécie de bactérias e sua resistência bacteriana aos antibióticos de amostras recebidas de surtos de doenças em peixes para diagnóstico bacteriológico no período entre janeiro de 2017 e outubro de 2020. As bactérias isoladas foram submetidas ao teste de sensibilidade de Kirby e Bauer para cinco classes de antibióticos (penicilinas, fluoroquinolonas, aminoglicosídeos, anfenicóis e tetraciclinas). Nos 181 surtos analisados, 232 bactérias foram isoladas, sendo estas Streptococcus spp., Aeromonas spp., Edwardsiella spp., Plesiomonas shigelloides, Pseudomonas aeruginosa, Chromobacterium violaceum, Flavobacterium spp., Citrobacter spp., Enterococcus spp., Vibrio spp., Enterobacter spp., Chryseobacterium meningosepticum dentre outras. Destas 232 bactérias, 40 cepas foram classificadas como multirresistentes (MDR), com Plesiomonas shigelloides, Aeromonas spp. e Edwardsiella spp. representando mais da metade destas (22 / total). Com várias bactérias demonstrando resistência aos medicamentos legalizados na aquicultura brasileira (tetraciclina e florfenicol), torna-se obrigatória a pesquisa, não apenas de alternativas ao uso de antibióticos, mas também de outros medicamentos eficazes contra os principais patógenos circulantes. Além disso, a vigilância sobre a ocorrência de cepas resistentes é necessária levando-se em consideração o aparecimento de bactérias zoonóticas com essa característica, tornando-se um ponto de interesse à saúde pública.(AU)

Assuntos

RESUMO

Streptococcus agalactiae is an invasive multi-host pathogen that causes invasive diseases mainly in newborns, elderly, and individuals with underlying health complications. In fish, S. agalactiae causes streptococcosis, which is characterized by septicemia and neurological signs, and leads to great economic losses to the fish farming industry worldwide. These bacteria can be classified into different serotypes based on capsular antigens, and into different sequence types (ST) based on multilocus sequence typing (MLST). In 2015, serotype III ST283 was identified to be associated with a foodborne invasive disease in non-pregnant immunocompetent humans in Singapore, and the infection was related to raw fish consumption. In addition, a serotype III strain isolated from tilapia in Brazil has been reported to be resistant to five antibiotic classes. This specific serotype can serve as a reservoir of resistance genes and pose a serious threat to public health. Thus, new approaches for the control and treatment of S. agalactiae infections are needed. In the present study, 24 S. agalactiae serotype III complete genomes, isolated from human and fish hosts, were compared. The core genome was identified, and, using bioinformatics tools and subtractive criteria, five proteins were identified as potential drug targets. Furthermore, 5,008 drug-like natural compounds were virtually screened against the identified targets. The ligands with the best binding properties are suggested for further in vitro and in vivo analysis.