High frequency of conjugation in Lactobacillus mediated by an aggregation-promoting factor

Reniero, R.; Cocconcelli, Piersandro; Bottazzi, V.; Morelli, L.

doi:10.1099/00221287-138-4-763

Cited by 126 publications

(117 citation statements)

References 29 publications

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“…These include Bacillus thuringiensis (Andrup et al, 1993), Lactobacillus plantarum (Reniero et al, 1992), Lactococcus lactis The clumping phenomenon is clearly visible. Aggregation substance was detected by reacting the cells/clumps with a polyclonal antiserum directed against pAD1-encoded aggregation substance and decorating the bound antibodies with a commercial preparation of goat (anti-rabbit) antibodies conjugated to gold particles (10 nm diameter).…”

Section: I Detection By Observation Of a Bacterial Clumping Reactionmentioning

confidence: 99%

The sex pheromone system of Enterococcus faecalis

Wirth¹

1994

European Journal of Biochemistry

120

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The sex pheromone system of Enterococcus faecalis was discovered by observing a clumping reaction of E. faecalis strains during conjugative transfer of plasmids. It was found that only a special type of E. faecalis plasmids, the so-called sex pheromone plasmids, are transferred via this mechanism. Various experiments, especially by the group of D. B. Clewell, led to the formulation of a model describing how the sex pheromone system works. Small linear peptides, the so-called sex pheromones, are excreted by strains not possessing the corresponding sex pheromone plasmid. Donor strains harboring the plasmid do not produce the corresponding sex pheromone; they react to the presence of the peptide by production of a plasmid-encoded adhesin, the so-called aggregation substance. This adhesin allows contact between the non-motile mating partners ; after conjugative transfer of the plasmid, the former recipient possesses and replicates the new plasmid. Thereby the population of E. faecalis strains is shifted to a high percentage of donor strains. This is especially true because a donor strain will still excrete sex pheromones corresponding to plasmids it does not harbor; therefore, such a strain can also function as recipient for other sex pheromone plasmids it does not possess.Various aspects of this unique plasmid collection mechanism have been studied during the last few years. The data indicate that, with the exception of pAM373, all sex pheromone plasmids possess one DNA region which is highly similar to and codes for the adhesin. It is also becoming more and more clear that regulatory functions/proteins are not conserved between different sex pheromone plasmids. Induction of adhesin synthesis needs the action of a regulatory cascade composed of unique features; at the moment we are just beginning to understand this cascade. By sequencing the first structural gene for one of those adhesins, we realized that the aggregation substance might act also as an adhesin for eucaryotic cells, probably by interaction with integrins. At least in the case of the in vitro cultured pig kidney tubulus cell line LLC-PK, this idea could be verified. An interesting aspect of the sex pheromone system of E. faecalis is its evolution. I will discuss the idea that two different components, both of which well might contribute to virulence of the opportunistic pathogenic bacterium, were combined in the species E. faecalis to result in this unique plasmid collection system.Enterococcus faecalis belongs to the bacterial genus Enterococcus which at the moment contains more than 15 valid species. The genus was established in 1984 when 'Streptococcus faecalis' and 'Streptococcus faecium' were transferred from the taxionomically unclearly defined group 'Streptococcus' in the new genus (Schleifer and Kilpper-Balz, 1984). Because of this some of the older literature cited in Abbreviations. ASA1, ASA373, ASCIO and ASPl, aggregation substance encoded by sex pheromone plasmids pAD1, pAM373, pCFlO and pPD1, respectively; ORFX, gene product of ogx (or€ ...

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Section: I Detection By Observation Of a Bacterial Clumping Reactionmentioning

confidence: 99%

The sex pheromone system of Enterococcus faecalis

Wirth¹

1994

European Journal of Biochemistry

120

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“…A homologous APF protein was originally identified in L. gasseri and suggested to be an aggregation-promoting factor (Reniero et al, 1992). However, Apf1 was recently described as an S-layer protein (Ventura et al, 2002).…”

Section: Prediction Of the Protein Functionsmentioning

confidence: 99%

Phage display reveals 52 novel extracellular and transmembrane proteins from Lactobacillus reuteri DSM 20016T

et al. 2003

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Extracellular and transmembrane proteins are important for the binding of bacteria to intestinal surfaces and for their interaction with the host. The aim of this study was to identify genes encoding extracellular and transmembrane proteins from the probiotic bacterium Lactobacillus reuteri by construction and screening of a phage display library. This library was constructed by insertion of randomly fragmented DNA from L. reuteri into the phagemid vector pG3DSS, which was previously developed for screening for extracellular proteins. After affinity selection of the library, the L. reuteri inserts were sequenced and analysed with bioinformatic tools. The screening resulted in the identification of 52 novel genes encoding extracellular and transmembrane proteins. These proteins were classified as: transport proteins; enzymes; sensor-regulator proteins; proteins involved in host/microbial interactions; conserved hypothetical proteins; and unconserved hypothetical proteins. Further characterization of the extracellular and transmembrane proteins identified should contribute to the understanding of the probiotic properties of L. reuteri.

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“…Direct evidence for the involvement of extracellular proteins in the adhesion process of Axospirillum to abiotic surfaces has been provided (Dufrhe et al, 1996a, b;Dufrkne & Rouxhet, 1996). Extracellular proteins were suggested or demonstrated to directly participate in aggregation of various bacterial species from diverse environments (Eggset et a/., 1983;Calleja, 1984;Reniero et al, 1992;Wang et al, 1994;Marsh & Bradshaw, 1995;Ma et al, 1996;Wai et al, 1996).…”

Section: S B U R D M a N A N D Othersmentioning

confidence: 99%

Aggregation in Azospirillum brasilense: effects of chemical and physical factors and involvement of extracellular components

et al. 1998

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A medium for consistent induction of aggregation of Azospirillum brasilense cells was developed and used to study the effects of chemical and physical factors as well as extracellular components involved in this phenomenon. Growth of A. brasilense strain Cd in a high C:N medium using fructose and ammonium chloride as C and N sources, respectively, resulted in flocculation visible to the naked eye after 24 h. No cell aggregates were formed after 72 h growth in low C:N medium. Aggregating cells, but not cells grown under low C : N, accumulated high amounts of poly-/?-hydroxybutyrate and the cell envelope contained a well-defined electron-dense layer outside the outer membrane. Suspending the aggregates in 0 2 or 0 5 M urea was the only treatment effective for disrupting aggregates. The concentration of exopolysaccharide produced by four different strains of A. brasilense, differing in their capacity to aggregate, strongly correlated with the extent of aggregation. Electrophoretic protein profiles from different fractions of aggregating and non-aggregating cells were compared. Differences were observed in the pattern of low-molecular-mass proteins and in the polar flagellin that has previously been proposed to be involved in adhesion processes. However, a mutant lacking both lateral and polar flagella showed the strongest aggregation. The involvement of polysaccharides andlor proteins in aggregation of A. brasilense is discussed.

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High frequency of conjugation in Lactobacillus mediated by an aggregation-promoting factor

Cited by 126 publications

References 29 publications

The sex pheromone system of Enterococcus faecalis

The sex pheromone system of Enterococcus faecalis

Phage display reveals 52 novel extracellular and transmembrane proteins from Lactobacillus reuteri DSM 20016T

Aggregation in Azospirillum brasilense: effects of chemical and physical factors and involvement of extracellular components

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