The Proteases of American Foulbrood Scales

American Foulbrood in honeybees and its causative agent, Paenibacillus larvae

“…1). One characteristic of P. larvae is that it secretes highly active extracellular proteases during vegetative growth and infection (Dancer and Chantawannakul, 1997;Holst, 1946;Holst and Sturtevant, 1940;Hrabak and Martinek, 2007). It is tempting to speculate that some of these proteases are responsible for the disruption of the epithelial barrier integrity by degrading cell-cell and cell-matrix junctional structures thereby allowing P. larvae to invade the hemocoel.…”

Endophytic actinomycetes isolated from Aquilaria crassna Pierre ex Lec and screening of plant growth promoters production

“…The reaction was mixed with 1 ml of 1 M NaOH and then the absorbance at 440 nm was measured. One unit of enzyme activity is determined as 0.01 of absorbance increase at 440 nm (Dancer and Chantawannakul 1997).…”

Paenibacillus larvae and American Foulbrood – long since known and still surprising

“…In contrast to earlier studies suggesting that penetration of the midgut epithelium by P. larvae occurs via phagocytosis (Davidson, 1973;Gregorc and Bowen, 1998) FISH analysis revealed that P. larvae rather used the paracellular route for crossing the midgut epithelium and entering the haemocoel (Yue et al, 2008). Numerous studies in the past had shown that P. larvae secretes highly active extracellular proteases during the process of infection (Holst and Sturtevant, 1940;Holst, 1946;Dancer and Chantawannakul, 1997). However, the function of these proteases remained elusive (Chantawannakul and Dancer, 2001).…”