One example of such a phytochemical might arguably be dodecenal. Due to the nature of this compound having a lipophilic tail and hydrophilic head, the tail can sit itself in the bacteria membrane while the head acts to mix with the water around it. As a consequence, the membrane is affected in such as a way that it gets "dissolved". So, to the experts out there, can bacteria become resistant to this type of phytochemical?
It is very hard to say, but obviously changing the lipidome will take very long time to evolve a resistance against such phytochemicals. Further, it will be interesting to see weather such chemicals acts equally good on Gram +ve bacteria?
Though playing around with lipid bilayer hampers many vital processes, and it is hard to get a resistance against such compounds easily.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3994350/
I conducted antimicrobial susceptibility testing on 24 different strains of bacteria and 1 strain of yeast. What I've found is that the compound works only on Gram positive bacteria. All Gram negative bacteria tested were not affected. This is strange as I've read papers out there reporting MICs against Gram negative bacteria.
The compound you describe has detergent-like properties. Bacteria and other cells can become resistant to membrane-active molecules by increasing expression of efflux pumps or by changing the properties (e.g. selection of phospholipid fatty acyl chains) of their membranes. These types of resistance may not always be due to genetic mutation, but just to changes in gene expression.
An interesting example of bacterial resistance to a membrane-active agent is the resistance of some Gram-negative bacteria to polymyxin and colistin, two similar natural products that supposedly act by disrupting first the outer membrane, then the inner membrane. Polymxin binds to the negative charge on the outer membrane lipopolysaccharide (LPS). Pseudomonas aeruginosa bacteria can become resistant by changing the outer membrane to have positive charge. Acinetobacter baumannii bacteria can become resistant by stopping production of the normal outer membrane LPS and replacing it with inner membrane lipids.
I agree with Adam B Shapiro answer considering that many times the loss of susceptibility to membrane-active molecules detected is rather an adaptation than an acquisition (mutation). So the most important point is to optimize strain preservation and to work only on the second or third cultures from a -80°C pool.
I think it is quite probable that bacteria mutate to develop resistance. Though I have conducted no studies, my gut feeling that bacteria by virtue of their genetic plasticity and multiple and imaginative ways of gene transfer is the best adapted form of life to overcome any obstacle which challenges their survival.
de part les quelque travaux que nous avons menés au labo , il ressort en général, une sensibilité aux huiles essentielles les bactéries de l'environnement proches de la plante. Par ailleurs, les BGN sont plus résistants aux huiles essentielles sauf celle riches en composés phénols
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