Highlighting the Potency of Biosurfactants Produced by Pseudomonas Strains as Anti-Legionella Agents

Table 5

Antibacterial spectrum of lipopeptide mixtures produced by Pseudomonas strains.

		MIC of lipopeptide mixtures (mg/ml)
		DSS73	MFAD21c	MFAF88	MFAH4a	MFAO2	PfA7b
Gram positive	B. subtilis LMG 28342	-	-	-	-	-	-
	E. faecalis V583	-	-	-	-	-	-
	L.  ivanovii Li4pVS2	-	-	-	-	-	-
	L. monocytogenes EGDe ATCC BAA-679	-	-	-	-	-	-
Gram negative	A. hydrophila LMG 2844	-	-	-	-	-	-
	E. coli LMG 2092	-	-	-	-	-	-
	F. breve LMG 4011	-	-	-	-	-	-
	K. pneumoniae 050283	-	-	-	-	-	-
	P. aeruginosa LMG 1242	-	-	-	-	-	-
	P. aeruginosa UCBPP-PA14	-	-	-	-	-	-
	S. enterica J18	-	-	-	-	-	-
	L. bozemanii ATCC 33217	0.09	0.14	0.61	0.19	0.38	0.20
	L. dumoffii ATCC 33279	0.09	0.14	0.30	0.19	0.38	0.20
	L. feeleii ATCC 35072	0.09	0.14	0.15	0.19	0.04	0.20
	L. longbeachae ATCC 33484	0.18	0.14	0.30	0.19	0.19	0.20
	L. micdadei ATCC 33218	0.18	0.27	0.30	0.19	0.19	0.20
	L. pneumophila ATCC 33155 (Sg 3)	0.18	0.27	0.61	0.38	0.38	0.40
	L. pneumophila ATCC 33215 (Sg 6)	0.36	0.27	0.61	0.38	0.38	0.40
	L. pneumophila ATCC 33216 (Sg5)	0.18	0.27	0.30	0.38	0.19	0.40
	L. pneumophila ATCC Baa74 130b	0.36	0.27	0.61	0.76	0.38	0.40
	L. pneumophila Corby (Sg1)	0.18	0.27	0.61	0.38	0.38	0.40
	L. pneumophila Lens CIP 108286 (Sg 1)	0.36	0.54	0.61	0.76	0.38	0.40

-: no growth of inhibition was detected even with undiluted lipopeptide mixture (0.72 mg/ml for the DSS73 mixture, 1.08 mg/ml for the MFAD21c mixture, 0.76 mg/ml for the MFAH4a mixture, 0.76 mg/ml for the MFAO2 mixture, 1.6 mg/ml for the PfA7b mixture, and 1.22 mg/ml for the MFAF88 mixture).
Bacteria (10⁶ CFU/ml) were incubated in BYE or BHI medium with two-fold dilutions of lipopeptide mixtures. Results correspond to the MIC after incubation for 24h or 96 h at 37°C depending on the tested strain and are the mean of three independent experiments.
Bacterial strains were obtained from various culture collections: ATCC: American Type Culture Collection, CIP: Collection Institut Pasteur, France, and LMG: BCCM/LMG Bacteria Collection, Ghent University, Belgium. The Corby strain was kindly provided by the Centre National de Référence des Légionelles (Lyon, France). Other strains were from the laboratory culture collection. Sg: serogroup.