Lack of genomic evidence of AI-2 receptors suggests a non-quorum sensing role for luxS in most bacteria

BMC Microbiology

Table 3 A literature survey of the relationship between the presence of the luxS gene and QS-2 dependent behavior in bacterial species without a luxP- or a lsrB-gene homolog in their genome for which the presence of a QS-2 system was claimed

	Talk^a	Listen^a		Answer^b
Strain	*luxS*	*luxP*	*lsrB*	AI-2 related phenotype	Chemical compl.^c	References
Actinomyces naeslundii	+	-	-	C	+/DPD	[115]
Bacillus subtilis	+	-	-	C	+/SN	[116]
Bifidobacterium adolescentis	+	-	-	nd	nd	This work
Bifidobacterium longum	+	-	-	nd	nd	[11]
Campylobacter jejuni	+	-	-	C	nd	[117]
				C	nd	[118]
Clostridium perfringens	+	-	-	C	+/SN	[119]
Enterococcus faecalis	+	-	-	nd	nd	[120]
Pectobacterium carotovora	+	-	-	C	nd	[121]
				C	nd	[122]
Escherichia blattae	+	-	nd	nd	nd	[43]
Photobacterium profundum	+	-	-	nd	nd	[123]
Porphyromonas gingivalis	+	-	-	C	nd	[124]
				C	nd	[125]
				C	nd	[46]
				C	+/SN	[126]
				C	+/SN	[127]
Pseudomonas aeruginosa	-	-	-	C	+/SN	[128]
Serratia marcescens	+	- ^d	- ^d	C	+/SN	[129]
Shewanella spp.	+	-	-	C	nd	[130]
Staphyoycoccus epidermis	+	-	-	C	+/SN	[131]
Streptococcus anginosus	+	-	- ^e	C	+/DPD	[132]
				C	Interference	[133]
Streptococcus gordonii	+	-	- ^e	C	nd	[46]
Streptococcus pneumoniae	+	-	-	C	nd	[134]

A more detailed description of the findings of the papers cited herein is available as additional file 1 (Table 1s).
^a +: positive (>50% protein identity); (+): positive (<50% protein identity); -: negative (<30% protein identity); nd: not determined;
^b nd: not determined; C: claimed;
^c +: successful complementation; -: unsuccessful complementation; nd: not determined; AI-2: complementation with pure autoinducer; DPD: complementation with precursor; SN: complementation with co-culture or conditioned supernatants of luxS-positive strain;
^d Hypothesized based on Serratia proteomaculans sequence;
^e Hypothesized on the basis of more than 10 known Streptococcus complete genomes belonging to the species S. pneumoniae, S. mutans, S. pyogenes, S. agalactiae, S. suis, S. equis and S. zooepidemicus.

ISSN: 1471-2180