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Table 3 Screening of liposomal formulations for antibacterial activity

From: Assessment of free fatty acids and cholesteryl esters delivered in liposomes as novel class of antibiotic

ID SE MRSA VRE ENC PACF PA AB
TL CR TL CR TL CR TL CR TL CR TL CR TL CR
PA1 64 −11 62 75 53 −89 −14 −80 4 32 20 13 23 −93
PA3 67 3 69 82 99 −63 14 −56 84 92 28 5 0 −91
PA4 100 8 32 62 99 −90 −10 6 3 15 41 45 35 −59
PA6 66 −11 42 59 65 −85 7 −48 12 34 −17 −22 46 −58
SA1 15 −14 63 63 −76 −91 22 −72 0 10 −7 18 28 −76
SA3 −28 −8 64 72 83 −78 22 −93 70 93 27 7 26 −60
SA4 100 7 38 64 100 −99 −18 −11 12 19 44 47 31 −63
SA6 5 −61 46 50 −25 −86 −30 −143 −16 27 −22 −25 29 −81
OA1 32 −21 62 79 40 −142 56 −60 22 38 −1 8 17 −77
OA3 50 −49 80 83 50 −41 −66 −117 87 93 −9 4 14 −92
OA4 31 −26 59 79 55 −58 −7 −25 12 17 52 45 31 −84
OA6 −10 0 66 59 −12 −18 44 30 11 25 −25 −21 1 −72
LA1 5 −27 49 70 25 −156 −31 −121 8 46 −6 12 18 −70
LA3 100 −57 55 83 18 −62 −37 −399 97 93 12 1 29 −61
LA4 86 −32 60 79 94 −101 89 −103 10 20 5 45 0 −75
LA6 9 −37 45 57 45 −156 −140 −135 2 25 −34 −26 22 −81
AA1 −37 51 48 73 66 −14 79 34 −1 44 −5 6 31 −85
AA3 72 94 50 82 −8 −40 −6 8 91 94 −17 −8 34 −57
AA4 65 36 85 84 89 43 95 54 15 18 51 47 33 −55
AA6 45 −69 45 58 33 −91 −1 −131 −8 14 −29 −20 34 −55
DA1 22 2 72 −42 −10 −11 34 42 38 −90 19 −91 −1 −76
DA3 −34 42 55 95 98 −105 35 15 71 94 −9 10 24 −77
DA4 15 1 28 54 −29 44 11 80 18 36 14 30 5 −67
DA6 10 18 44 55 −11 −40 −13 −14 −18 28 −32 −13 9 −71
CP1 85 99 74 74 −14 −7 36 70 27 43 −10 −19 21 −83
CP2 71 100 67 74 −15 3 15 9 87 66 −5 −6 15 −90
CP3 77 99 42 54 −44 5 5 39 86 86 24 28 4 −87
CP5 62 100 65 71 −6 7 9 58 82 63 −19 −9 15 −75
CO1 19 43 53 57 −11 −26 29 24 34 20 −9 −5 24 −69
CO3 10 100 59 70 62 −6 −34 −22 99 95 −25 −18 4 −78
CO4 −20 14 38 90 84 16 29 29 12 18 11 50 35 −56
CL1  NT NT 64 67  NT  NT  NT  NT 95 72 −41 −26 NT   NT
CL3 100 52 65 47 21 −39 94 36 100 88 45 23 16 −82
CL4  NT NT 80 68 NT NT NT NT 84 33 −22 0  NT  NT
CA1 74 10 59 54 −16 −27 45 29 82 24 11 −4 19 −70
CA3 −44 11 60 65 11 −43 50 19 100 93 −20 −24 24 −72
CA4 53 94 53 87 31 100 47 −1 72 25 8 42 13 −68
  1. Test lipids (see Table 1 for abbreviations) prepared in carrier liposomes formulations #1–6 with unique phospholipid composition (TL) and carrier liposomes without test lipid (CR) were screened against bacterial strains relevant to healthcare associated infections (SE multidrug-resistant Staphylococcus epidermidis ATCC 700566, MRSA methicillin resistant Staphylococcus aureus ATCC 33591, VRE vancomycin resistant Enterococcus faecalis ATCC 700802, ENC Enterococcus cloacae ATCC 49141, PA Pseudomonas aeruginosa ATCC 9027, PACF Pseudomonas aeruginosa, cystic fibrosis isolate [16], AB Acinetobacter baumanii ATCC 19606). All test lipids where employed at 64 μg/mL. The corresponding carrier lipid concentrations were about 10–12 times higher for fatty acid formulations and 4–5 times higher for cholesteryl ester formulations. Bacterial growth was quantified based on relative fluorescence units (RFU) of the DNA probe Syto 9. Italics 80–95 % growth inhibition; Bolded and in italics >95 % growth inhibition. Data represent means of the % inhibition compared to untreated bacteria from two independent experiments conducted each in triplicate. ID Liposome identification, for example PA1 stands for palmitic acid prepared in carrier liposomes # 1
  2. NT not tested