02345nas a2200253   4500000000100000000000100001008004100002260007000043653001800113653002000131653002500151653002000176100001400196700001400210700001200224700001400236700001300250700001200263245010000275300001200375490000800387520168200395022001402077       2014                            d  c12/2014bSchlütersche Verlagsgesellschaft mbH & Co. KGaHannover10aCampylobacter10aphage treatment10aresistance mechanism10aphage  receptor1 aS Orquera1 aS Hertwig1 aT Alter1 aJ Hammerl1 aA Jirova1 aG Gölz00aDevelopment of transient phage resistance in Campylobacter coli against the group II phage CP84  a141-1470 v1283 a Recently, there is a growing interest in the use of bacteriophages for pre- and  post-harvest applications to reduce foodborne pathogens (including Campylobacter)  along the food chain. Quantitative Campylobacter reductions of up to  three log10 units have been achieved by phage application. However, possible  phage resistance might limit this approach. In Campylobacter (C.) jejuni, phage  resistance mechanisms have been described in detail but data on these mechanisms  in C. coli are still missing.  To study phage resistance in C. coli, strain NCTC 12668 was infected with the  lytic phage CP84, belonging to group II of Campylobacter phages. Resistant and  sensitive clones were analysed using phenotypic and genotypic assays. C. coli  clones acquired only transient resistance against CP84. The resistance led to  cross-protection to one out of five other group II phages tested. Phage resistance  was apparently neither caused by large genomic rearrangements nor by a CRISPR  system. Binding assays demonstrated that CP84 could not adsorb to resistant C. coli clones suggesting a bacterial phage receptor to be involved in resistance.  However, phage resistant C. coli clones did not reveal an altered motility or modified  flaA sequence.  Considering the loss of binding capacity and the reversion to a phage sensitive  phenotype we hypothesize that acquired resistance depends on temporal phase  variable switch-off modifications of the phage receptor genes, even though the  resistance mechanism could not be elucidated in detail. We further speculate that  even closely related phages of the same group use different bacterial receptors  for binding on C. coli.   a0005-9366