Antimicrobial resistance profile of Aeromonas spp. isolated from asymptomatic Colossoma macropomum cultured in the Amazonas State, Brazil.

Bacterial diseases are important factors that limit productivity in aquaculture. To reduce negative economic impacts, fish farmers use antimicrobials, often indiscriminately, and this action has led to bacterial resistance to drugs. The objectives of this study were to isolate and identify the main putative pathogenic bacterial species in tambaqui (Colossoma macropomum), establish the profile of resistance to antimicrobials by the methods of disc diffusion, and determine the minimum inhibitory concentration (MIC) values. Two hundred and ninety asymptomatic fish were collected between March and November 2015 from ten fish farms in the Amazonas state (Brazil). Of the total strains recovered from tambaqui, seven were identified as Aeromonas spp. by sequencing the 16S rRNA gene. These seven isolates showed resistance to ampicillin, 28% to erythromycin, and 28% to sulfonamide. Additionally, the seven isolates showed a MIC higher than the range evaluated for amoxicillin, penicillin, novobiocin, tylosin tartrate, and clindamycin, and 85% showed resistance to erythromycin. The results of this study indicate the need to increase the awareness of fish farmers and, most importantly, the government, about the lack of drug regulations for use in aquaculture, and good management practices, so the indiscriminate prophylactic and systemic use of antimicrobials be inhibited.

Antimicrobial resistance profile of Aeromonas spp. isolated from asymptomatic Colossoma macropomum cultured in the Amazonas State, Brazil / Perfil de resistência antimicrobiana de Aeromonas spp. isoladas de Colossoma macropomum assintomáticos no Estado do Amazonas, Brasil

Bacterial diseases are important factors that limit productivity in aquaculture. To reduce negative economic impacts, fish farmers use antimicrobials, often indiscriminately, and this action has led to bacterial resistance to drugs. The objectives of this study were to isolate and identify the main putative pathogenic bacterial species in tambaqui (Colossoma macropomum), establish the profile of resistance to antimicrobials by the methods of disc diffusion, and determine the minimum inhibitory concentration (MIC) values. Two hundred and ninety asymptomatic fish were collected between March and November 2015 from ten fish farms in the Amazonas state (Brazil). Of the total strains recovered from tambaqui, seven were identified as Aeromonas spp. by sequencing the 16S rRNA gene. These seven isolates showed resistance to ampicillin, 28% to erythromycin, and 28% to sulfonamide. Additionally, the seven isolates showed a MIC higher than the range evaluated for amoxicillin, penicillin, novobiocin, tylosin tartrate, and clindamycin, and 85% showed resistance to erythromycin. The results of this study indicate the need to increase the awareness of fish farmers and, most importantly, the government, about the lack of drug regulations for use in aquaculture, and good management practices, so the indiscriminate prophylactic and systemic use of antimicrobials be inhibited.

As doenças bacterianas são fatores importantes que limitam a produtividade na aquicultura. Para reduzir os impactos econômicos negativos, os piscicultores utilizam antimicrobianos, muitas vezes de forma indiscriminada, e essa ação tem levado à resistência bacteriana aos medicamentos. Os objetivos deste estudo foram isolar e identificar as principais bactérias com potencial putativo para o tambaqui (Colossoma macropomum), e estabelecer o perfil de resistência a antimicrobianos pelos métodos de difusão em disco e valores de concentração inibitória mínima (CIM). Duzentos e noventa peixes assintomáticos foram coletados entre março e novembro de 2015, em dez pisciculturas do estado do Amazonas (Brasil). Do total de cepas recuperadas de tambaqui, sete foram identificadas como Aeromonas spp. pelo sequenciamento do gene 16S rRNA. Esses sete isolados apresentaram resistência à ampicilina, 28% à eritromicina e 28% à sulfonamida. Além disso, os sete isolados apresentaram CIM superior à faixa avaliada para amoxicilina, penicilina, novobiocina, tartarato de tilosina e clindamicina, e 85% apresentaram resistência à eritromicina. Os resultados deste estudo indicam a necessidade de aumentar a conscientização dos piscicultores e, principalmente, do poder público, a falta de regulamentação de medicamentos para uso na aquicultura e sobre as boas práticas de manejo, para que o uso profilático e sistêmico de antimicrobianos de forma indiscriminada seja inibido.

Qualidade da carne de tambaqui abatido com diferentes classes de pesos / Meat quality of tambaqui slaughtered at different weights

A pesquisa teve como objetivo avaliar a qualidade da carne de tambaqui com diferentes pesos de abate. Foram utilizados vinte e quatro tambaquis, entre 1,0 e 3,5 kg. O peso ao abate não afetou o pH da carne (6,42), a cor para luminosidade (L*), intensidade de vermelho (a*) e amarelo (b*), respectivamente, com médias de 62,00; 2,86 e 15,57; e os atributos sensoriais aparência (7,41), sabor (7,25), textura (7,40) e aceitação global (7,24). A perda de peso por gotejamento e descongelamento e a capacidade de retenção de água da carne de tambaqui foram afetados (P<0,01) pelo peso ao abate. Embora o peso de abate do tambaqui entre 1,0 e 1,5 kg apresente maiores perdas de água, as demais características qualitativas da carne não foram comprometidas.(AU)

The experiment was conducted to evaluate the meat quality of tambaqui slaughtered at different weights. Twenty-four animals were slaughtered at body weights ranging from 1.0 to 3.5 kg. The slaughter weight did not affect meat pH (6.42), luminosity (L*), red color intensity (a*) or yellow color intensity (b*) (means of 62.0, 2.86 and 15.57, respectively), nor the sensory attributes appearance (7.41), flavor (7.25), texture (7.40), and overall acceptance (7.24). Weight loss by dripping and defrosting and the water holding capacity of tambaqui meat were affected (P<0.01) by slaughter weight. Although a slaughter weight of tambaqui between 1.0 and 1.5 kg was associated with further water loss, the other meat quality traits were not compromised.(AU)

Qualidade da carne de tambaqui abatido com diferentes classes de pesos / Meat quality of tambaqui slaughtered at different weights

A pesquisa teve como objetivo avaliar a qualidade da carne de tambaqui com diferentes pesos de abate. Foram utilizados vinte e quatro tambaquis, entre 1,0 e 3,5 kg. O peso ao abate não afetou o pH da carne (6,42), a cor para luminosidade (L*), intensidade de vermelho (a*) e amarelo (b*), respectivamente, com médias de 62,00; 2,86 e 15,57; e os atributos sensoriais aparência (7,41), sabor (7,25), textura (7,40) e aceitação global (7,24). A perda de peso por gotejamento e descongelamento e a capacidade de retenção de água da carne de tambaqui foram afetados (P<0,01) pelo peso ao abate. Embora o peso de abate do tambaqui entre 1,0 e 1,5 kg apresente maiores perdas de água, as demais características qualitativas da carne não foram comprometidas.

The experiment was conducted to evaluate the meat quality of tambaqui slaughtered at different weights. Twenty-four animals were slaughtered at body weights ranging from 1.0 to 3.5 kg. The slaughter weight did not affect meat pH (6.42), luminosity (L*), red color intensity (a*) or yellow color intensity (b*) (means of 62.0, 2.86 and 15.57, respectively), nor the sensory attributes appearance (7.41), flavor (7.25), texture (7.40), and overall acceptance (7.24). Weight loss by dripping and defrosting and the water holding capacity of tambaqui meat were affected (P<0.01) by slaughter weight. Although a slaughter weight of tambaqui between 1.0 and 1.5 kg was associated with further water loss, the other meat quality traits were not compromised.