Vibrio campbellii Quorum Sensing

Abstract

This study will demonstrate the use of the ATCC Vibrio campbellii Panel (ATCC MP-6) as a nonpathogenic model for AI-2-based quorum sensing pathways. 

Introduction 

In many prokaryotes, cooperative behaviors are regulated through a density-dependent, signal-mediated communication system termed quorum sensing (QS)¹ When a bacterial population reaches a critical threshold, autoinducer signaling molecules (AI) specifically bind to a cognate regulatory protein or activate a 2-component signal transduction system, leading to the regulation of group behaviors. In the marine organism Vibrio campbellii, AI signals (AI-1 and AI-2) and cognate regulators are used to regulate bioluminescence¹ (Figure 1). Since its discovery, AI-2 has proven ubiquitous within interspecies and intraspecies communication, including that of pathogenic microorganisms.² Here, we show a panel of 9 V. campbellii strains displaying wild-type or varying mutational phenotypes for use as a nonpathogenic model in the analysis of AI-2-based QS systems. 

Materials and methods 

Nine V. campbellii strains were phenotypically analyzed for QS proficiency by monitoring the bioluminescence production of genotypically diverse strains that were plated together in pairs on Autoinducer Bioassay Medium.^1,3-6

Results and discussion

Upon analysis of paired strains, it was determined that bioluminescence could be restored in strains lacking regulator and/or AI production if the adjacent strain was proficient in that characteristic (Figure 2A-C, Table 1). Bioluminescence could not be restored in strains lacking part of the luxCDABE operon, which encodes for bioluminescence (Figure 1, Figure 2D, Table 1).

Figure 1. Quorum sensing

 

Figure 2. Bioluminescence

 

Table 1. ATCC Vibrio campbellii panel. (ATCC MP-6)

 

		Autoinducers
		1+, 2+	1+, 2+	1+, 2+	1+, 2+	1+, 2+	1-, 2+	1+, 2-	1+, 2-	1-, 2-
Sensors	ATCC number	700104	700106	BAA-1116	BAA-1117	BAA-1118	BAA-1119	BAA-1120	BAA-1121	BAA-2363
luxA-	700104	-	-	-	-	-	-	-	-	-
1+ , 2-	700106	+	+	+	+	+	+	+	+	+
1+ , 2+	BAA-1116	+	+	+	+	+	+	+	+	+
1- , 2+	BAA-1117	+	+	+	+	+	+	+	+	+
1+ , 2-	BAA-1118	+	+	+	+	+	+	+	+	+
1- , 2+	BAA-1119	+	+	+	+	+	+	+	+	+
1+ , 2+	BAA-1120	+	+	+	+	+	+	+	+	+
1- , 2+	BAA-1121	+	+	+	+	+	+	-	-	-
1+ , 2+	BAA-2363	+	+	+	+	+	-	-	-	-

Sensor 1 = LuxN; Sensor 2 = LuxQ; Autoinducer 1 = AI-1; Autoinducer 1 AI-2; (+) = Light observed; (-) = No light observed.

 

Conclusion

The characterization of these V. campbellii strains illustrates that ATCC MP-6 is well suited as a nonpathogenic model for the analysis of AI-2-based, 2-component regulatory QS pathways. 

References

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