Study of the antibacterial effects of chitosans on Bacillus cereus (and its spores) by atomic force microscopy imaging and nanoindentation Export

@article{citeulike:4209381, abstract = {Bacillus cereus is a Gram-positive, spore-forming bacterium that is widely distributed in nature. Its intrinsic thermal resistance coupled with the extraordinary resistance against common food preservation techniques makes it one of the most frequent food poisoning microorganisms causing both intoxications and infections. In order to control B. cereus growth/sporulation, and hence minimize the aforementioned hazards, several antimicrobial compounds have been tested. The aim of this work was to assess by atomic force microscopy (AFM) the relationship between the molecular weight (MW) of chitosan and its antimicrobial activity upon both vegetative and resistance forms of B. cereus. The use of AFM imaging studies helped us to understand how chitosans with different MW act differently upon B. cereus . Higher MW chitosans (628 and 100 kDa) surrounded both forms of B. cereus cells by forming a polymer layer – which eventually led to the death of the vegetative form by preventing the uptake of nutrients yet didn't affect the spores since these can survive for extended periods without nutrients. Chitooligosaccharides (COS) (<3 kDa) on the other hand, provoked more visible damages in the B. cereus vegetative form – most probably due to the penetration of the cells by the COS. The use of COS by itself on B. cereus spores wasn't enough for the destruction of large number of cells, but it may well weaken the spore structure and its ability to contaminate, by inducing exosporium loss.}, author = {Fernandes, Jo\~{a}o C. and Eaton, Peter and Gomes, Ana M. and Pintado, Manuela E. and Xavier}, citeulike-article-id = {4209381}, citeulike-linkout-0 = {http://dx.doi.org/10.1016/j.ultramic.2009.03.015}, citeulike-linkout-1 = {http://linkinghub.elsevier.com/retrieve/pii/S0304399109000552}, day = {19}, doi = {10.1016/j.ultramic.2009.03.015}, issn = {03043991}, journal = {Ultramicroscopy}, keywords = {afm, air, bacillus, cereus}, month = {March}, posted-at = {2009-03-23 13:31:24}, priority = {2}, title = {Study of the antibacterial effects of chitosans on Bacillus cereus (and its spores) by atomic force microscopy imaging and nanoindentation}, url = {http://dx.doi.org/10.1016/j.ultramic.2009.03.015}, year = {2009} }

TY - JOUR ID - citeulike:4209381 L3 - citeulike-article-id:4209381 N2 - Bacillus cereus is a Gram-positive, spore-forming bacterium that is widely distributed in nature. Its intrinsic thermal resistance coupled with the extraordinary resistance against common food preservation techniques makes it one of the most frequent food poisoning microorganisms causing both intoxications and infections. In order to control B. cereus growth/sporulation, and hence minimize the aforementioned hazards, several antimicrobial compounds have been tested. The aim of this work was to assess by atomic force microscopy (AFM) the relationship between the molecular weight (MW) of chitosan and its antimicrobial activity upon both vegetative and resistance forms of B. cereus. The use of AFM imaging studies helped us to understand how chitosans with different MW act differently upon B. cereus . Higher MW chitosans (628 and 100 kDa) surrounded both forms of B. cereus cells by forming a polymer layer – which eventually led to the death of the vegetative form by preventing the uptake of nutrients yet didn’t affect the spores since these can survive for extended periods without nutrients. Chitooligosaccharides (COS) (<3 kDa) on the other hand, provoked more visible damages in the B. cereus vegetative form – most probably due to the penetration of the cells by the COS. The use of COS by itself on B. cereus spores wasn’t enough for the destruction of large number of cells, but it may well weaken the spore structure and its ability to contaminate, by inducing exosporium loss. JF - Ultramicroscopy SN - 03043991 TI - Study of the antibacterial effects of chitosans on Bacillus cereus (and its spores) by atomic force microscopy imaging and nanoindentation KW - afm KW - air KW - bacillus KW - cereus AU - Fernandes, João AU - Eaton, Peter AU - Gomes, Ana AU - Pintado, Manuela AU - Xavier PY - 2009/03/19/ UR - http://dx.doi.org/10.1016/j.ultramic.2009.03.015 ER -