ABSTRACT This study was conducted in a commercial apple orchard (Malus domestica) with high woolly apple aphid (Eriosoma lanigerum) incidence, which is highly harmful to apple culture and infects the trunk, branch, roots, shoot, and fruit. Although the fungus Beauveria bassiana is widely reported as a control agent, there is no evidence of its control action against this pest. This case study was conducted under natural infestation conditions to evaluate the effective action of B. bassiana in E. lanigerum nymph mortality and aimed to evaluate the control potential of E. lanigerum treated with different formulation doses based on B. bassiana strain ICBBb252. The experimental unit consisted of ten plants in four randomized blocks, where one colony per plant was previously marked in an orchard (2500 plants/ha). The treatments consisted of applying the formulate in 100, 200, and 300 mL/ha dosages at a 109 spore/mL concentration and one control group; 10, 20, 30, and 40 days after application, the treatments were evaluated by counting the number of colonies alive. The control of woolly apple aphids by B. bassiana strain ICBBb252 was more effective at 200 and 300 mL/ha dosages and has no phytotoxic effects on plants.

O estudo teve como objetivo avaliar a suscetibilidade antimicrobiana de 109 amostras de Escherichia coli (E. coli) de origem ambiental frente a antibióticos e caracterizar esses isolados quanto ao grau de patogenicidade in vivo, verificando-se uma possível relação entre esta variável e a suscetibilidade aos princípios ativos testados. Os isolados foram submetidos ao teste de disco-difusão para 14 antibióticos. Entre 16.5% a 90% das amostras foram sensíveis, 1-28.5% apresentaram grau de suscetibilidade intermediário e entre 9-78% das E. coli analisadas foram resistentes. Os maiores percentuais de resistência foram encontrados para a classe das quinolonas e das tetraciclinas (>75%), e de sensibilidade para a classe dos anfenicóis (68.8%). Por meio da inoculação em pintinhos de um dia de idade, os isolados foram classificados como sendo de patogenicidade alta (2.7%), intermediária (10.1%), baixa (42.2%) e apatogênicos (45%). Foi observada uma ampla variação no perfil de suscetibilidade das amostras frente aos antimicrobianos. Verificou-se também que a maioria apresentou potencial patogênico (55%), sendo, portanto, consideradas APEC (E. coli patogênica para aves). Não foi observada relação entre a patogenicidade e a suscetibilidade aos antimicrobianos (P≤0.05).

The study aimed to evaluate the antimicrobial susceptibility of 109 samples of Escherichia coli (E. coli) of environmental origin and to characterize these isolates according to the degree of pathogenicity in vivo, verifying a possible relationship between this variable and susceptibility to the active principles tested. The isolates were subjected to disc diffusion test to 14 antibiotics. From 16.5% to 90% of the samples were sensitive; 1 - 28.5% showed intermediate degree of susceptibility and between 9 to 78% of E. coli analyzed were resistant. The highest resistance percentages were seen in the class of quinolones and tetracyclines (>75%), and for sensitivity in the class of amphenicols (68.8%). By inoculating 1- day - old chicks, the isolates were classified as highly pathogenic (2.7%), intermediate (10.1%), low (42.2%) and apathogenic (45%). It was observed a wide variation in the susceptibility profile of isolates in relation to antimicrobials. It was also found that most of the samples had pathogenic potential (55%), thus being considered as APEC (avian pathogenic E. coli). No relationship between pathogenicity and antimicrobial susceptibility (P≤0.05) was observed.