Naturally occurring plasmids exhibiting incompatibility with members of incompatibility groups I and P

Abstract

From a group of naturally occurring antibiotic resistance plasmids, a number of plasmids were identified which were incompatible with members of incompatibility group P and also incompatibility group Ia or Iy. These plasmids also exhibited strong entry exclusion with members of group P only and showed a host range which resembled that of plasmids of group I rather than those of group P. Segregants of a number of these plasmids appeared to have lost some of the incompatibility and/or surface exclusion functions. Studies of nucleic acid homology indicated that these plasmids were very similar to one another. They exhibited 15 to 20% nucleic acid homology with representatives of the la and Iy groups, yet showed less than 2% homology with the group P plasmid RP4.

Plasmid-controlled resistance to copper in Escherichia coli

“…pRJ1004 was found to exhibit incompatibility with plasmids belonging to the Incll group (R144drd-3, R648, and R64drd-11) and with the IncK plasmid R387. The detection of plasmids which exhibit incompatibility with members of two different incompatibility groups has been reported by numerous workers (8,14,15). According to the theory of Datta and Hedges (8), pRJ1004 may be a hybrid plasmid formed after 13/13 a Expressed as the number of transconjugants per donor cell, obtained in 30-min matings (unless otherwise stated).…”

Identification and classification of bacterial plasmids.

“…repB/O: inclrep functions. pULB2406 was constructed by cloning a PstI fragment of 1.6 kb from the IncB/O plasmid pMU700 (45) in the PstI site of pBR322. The PstI fragment was subcloned from pMU602 (36), a miniplasmid derived from plasmid pMU700.…”

Molecular genetic analysis of bacterial plasmid promiscuity

“…There are exceptions, e.g. : (a) R906 (alias Rt¢16 ), isolated from Bordetella bronchiseptica, is transmissible to E. coli, Citrobacter freundii, Salmonella typhimurium, Y. enterocolitica but not to Shigella flexneri, S. sonnei, Proteus mirabilis, P. vulgaris, P. rettgeri, K. pneumoniae and P. aeruginosa [17,18]; (b) pAVI, isolated from one strain of A. calcoaceticus and transmissible between some strains of A. calcoaceticus is unable to transfer to other strains of A. calcoaceticus or to E. coli, to P. aeruginosa, to P. mirabilis or to Klebsiella [19]; (c) pMU700-pMU707, isolated from E. coli, are unable to transfer to P. aeruginosa or to P. mirabilis [20]; (d) pHH502, isolated from E. coli, is not transmissible to P. mirabilis, P. aeruginosa or to A. calcoaceticus [21]. With a derivative of pHH502 it has been established that reduced host range may be associated with a lack of a functional IncP-1 replication system since despite its possession of a IncP-1 origin of replication it lacks the essential replication protein trfA [22].…”