Diferenciação de bactérias do gênero Pseudomonas patogênicas ao cafeeiro por técnicas serológicas

Abstract

Some bacterial diseases have been described causing problems in coffee, whose causal agents are Pseudomonas cichorii, P. syringae pv. garcae, P. s. pv. tabaci and Burkholderia andropogonis, all of them also occurring in Brazil. Attempts to differentiate these bacteria by double diffusion agar (dda) technique with antisera produced against whole cells of P. s. pv. garcae showed cross-reactions, especially among P. s. pv. garcae and P. s. pv. tabaci. Thus, antisera were produced against P. s. pv. garcae (pathotype strain IBSBF-248 -Phytobacteria Culture Collection of Instituto Biológico -IBSBF), using rabbit immunizations with antigens of the protein complex of membranes. These antisera were tested against different kind of antigens (autoclaved cells, cells treated with formaldehyde, capsule polysaccharides, glycoproteins, bacterial membrane proteins and bacterial suspension in 0.85% NaCl) extracted from P. cichorii, P. s. pv. garcae and P. s. pv. tabaci. The results showed that depending on the kind of antigen and the medium used in the double diffusion test (with or without MgCl 2 and/or trypan blue), the antiserum reacted only with P. s. pv. garcae. Thus, these antigens may be used as an auxiliary tool in the rapid diagnosis of bacterial halo blight of coffee in the double diffusion test. KEYWORDS

Ethiopian coffee germplasm is a valuable resistance gene pool to brazilian Pseudomonas syringae PVS garcae and tabaci

“…In the same way as previously reported, in two field studies they identified the mixed infection by both P. syringae pathovars in the same location from similar symptoms in C. arabica leaves (Rodrigues et al, 2017b;Fernandes et al, 2020). However, the correct diagnosis of the bacterial halo blight and bacterial leaf spot can only be made by isolation and characterization of the causal agent or agents by biochemical (Young;Triggs, 1994), serological (Beriam et al, 2017) and/or molecular techniques (Maciel, 2018). It is importance to mention that no study aiming to evaluate different methods of control against bacterial leaf spot, caused by P. syringae pv.…”

Desenvolvimento de metodologia de PCR multiplex para diagnose simultânea de Pseudomonas syringae pv. garcae e Pseudomonas syringae pv. tabaci e influência do nitrogênio no crescimento vegetativo do cafeeiro e severidade da mancha aureolada

“…As tentativas de diagnose via sintomatologia na grande maioria dos casos levam a diagnose errada. O diagnóstico de doenças bacterianas causadoras de manchas foliares é realizado pela diferenciação por morfologia de colônias, fluorescência sob luz ultravioleta, aliadas aos resultados dos testes serológicos e LOPAT (LELLIOTT; BILLING; HAYWARD, et al, 1966;BERIAM et al, 2017). Tais técnicas demandam mais tempo quando comparadas a detecção por biologia molecular.…”