Conjugative plasmids isolated from bacteria in marine environments show various degrees of homology to each other and are not closely related to well-characterized plasmids

Abstract

Mercury resistance plasmids were exogenously isolated, i.e., recovered after transfer to a model recipient bacterium, from marine air-water interface, bulk water, and biofilm communities during incubation in artificial seawater without added nutrients. Ninety-five plasmids from different environments were classified by restriction endonuclease digestion, and 12 different structural plasmid groups were revealed. The plasmid types isolated from different habitats and from different sampling occasions showed little similarity to each other based on their restriction endonuclease patterns, indicating high variation and possibly a low transfer between microhabitats and/or a different composition of the microbial communities at different sites and times. With another approach in which probes derived from one of the isolated plasmids and a mercury resistance (mer) probe from Tn501 were used, similarities between plasmids from several different groups were found. The plasmids were further tested for their incompatibility by use of the collection of inc/rep probes (B/

Comparison of the plasmid types obtained by two distantly related recipients in biparental exogenous plasmid isolations from soil

“…However, plasmid pAKD1, isolated from both recipients from the StendS soil, hybridized with the repPL probe of plasmid R751. As shown in other studies [3,4] the lack of hybridization with environmental plasmids is common with these probes, and indicates that most of these plasmids belong to yet uncharacterized groups of BHR plasmids. Considering the BHR character of 12 out of 16 plasmids, factors other than limitations in host range must have caused the large di¡erence in plasmid types obtained in the two recipients.…”

“…In order to study the occurrence of self-transferable plasmids in various natural habitats, di¡erent approaches of exogenous plasmid isolation have been used in recent years [2^9]. Several authors have suggested that the use of di¡erent recipients in parallel may widen the range of plasmids captured by this method [3,4,9,10].…”

Piggery manure used for soil fertilization is a reservoir for transferable antibiotic resistance plasmids

“…Although we obtained a cultivation-independent angle at MGE that confer resistance towards amoxicillin, sulfadiazine and tetracycline, we are aware of the fact that this is probably only a small segment of the extant mobile gene pool. A much broader spectrum of environmental BHR plasmids could be obtained using alternative recipients (Top et al, 1994;Dahlberg et al, 1997;Drønen et al, 1999).…”

Genomics of IncP-1 antibiotic resistance plasmids isolated from wastewater treatment plants provides evidence for a widely accessible drug resistance gene pool

“…The main advantages of this method are its direct selection for transferable plasmids and its independence from culturing plasmid hosts. This approach has been successfully used by several groups to isolate a wide diversity of plasmids that encode Hg R or antibiotic resistance, or the ability to degrade a specific organic compound, from various environments (Bale et al, 1987(Bale et al, , 1988Fry & Day, 1990;Top et al, 1995;Lilley et al, 1996;Dahlberg et al, 1997;Drnen et al, 1998Drnen et al, , 1999Smit et al, 1998;Stuart-Keil et al, 1998;Dröge et al, 2000;Schneiker et al, 2001;Heuer et al, 2002;van Overbeek et al, 2002;Smalla et al, 2006;Ono et al, 2007). All of the six plasmids from WWTP described in detail in this review, and pKJK5 from barley rhizosphere (Bahl et al, 2007), were obtained using this method with selection on antibiotic resistance.…”