Table 1.
Antimicrobial activity of polymyxin B (PMB), prochlorperazine (PCH), chlorpromazine (CHP) and thiethylperazine (THY) monotherapy, and in combination.
|
MIC (mg/L) |
FIC indexd |
|||||||
|---|---|---|---|---|---|---|---|---|
| Isolates | PMB | PCH | CHP | THY | PMB-PCH | PMB-CHP | PMB-THY | |
| Polymyxin-resistant isolates | ||||||||
| P. aeruginosa | FADDI-PA006 muca | 8 | >128 | >128 | >128 | 0.27 | 0.27 | 0.26 |
| FADDI-PA092 | 16 | >128 | >128 | >128 | 0.28 | 0.19 | 0.28 | |
| FADDI-PA067 n/ma (s)b | 16 | >128 | >128 | >128 | 0.28 | 0.19 | 0.19 | |
| FADDI-PA093 | 32 | >128 | >128 | >128 | 0.25 | 0.19 | 0.19 | |
| FADDI-PA066 n/m | 32 | 128 | >128 | >128 | 0.25 | 0.27 | 0.13 | |
| FADDI-PA112 | 16 | >128 | >128 | >128 | 0.19 | 0.31 | 0.31 | |
| FADDI-PA070 n/m | 64 | 128 | >128 | >128 | 0.16 | 0.19 | 0.14 | |
| FADDI-PA071 n/m | >64 | >128 | >128 | >128 | 0.1 | 0.14 | 0.16 | |
| FADDI-PA016 n/m (L)b | >64 | >128 | >128 | >128 | 0.13 | 0.13 | 0.13 | |
| FADDI-PA068 n/m | >64 | >128 | >128 | >128 | 0.13 | 0.08 | 0.14 | |
| FADDI-PA063 muc | >64 | >128 | >128 | >128 | 0.13 | 0.08 | 0.06 | |
| FADDI-PA072 n/m | >64 | >128 | >128 | >128 | 0.16 | 0.27 | 0.28 | |
| FADDI-PA064 n/m | >64 | 64 | 128 | 32 | 0.63 | 1 | 1 | |
| Polymyxin-susceptible isolates | ||||||||
| FADDI-PA002 muc | 0.125 | 128 | >128 | >128 | 0.53 | 0.5 | 0.27 | |
| FADDI-PA005 n/m | 0.25 | 128 | >128 | >128 | 0.52 | 0.56 | 0.52 | |
| FADDI-PA021 muc | 0.25 | >128 | 128 | >128 | 0.5 | 1 | 0.53 | |
| FADDI-PA111 | 1 | >128 | >128 | >128 | 0.51 | 0.56 | 0.53 | |
| FADDI-PA117 | 0.5 | >128 | >128 | >128 | 0.5 | 0.28 | 0.52 | |
| FADDI-PA007 n/m | 0.5 | >128 | >128 | >128 | 0.53 | 0.56 | 1 | |
| FADDI-PA020 muc | 0.5 | >128 | >128 | >128 | 0.53 | 0.56 | 0.28 | |
| FADDI-PA024 | 1 | >128 | >128 | >128 | 0.26 | 0.56 | 0.27 | |
| FADDI-PA019 muc | 1 | 128 | >128 | >128 | 0.52 | 0.31 | 0.27 | |
| Polymyxin-resistant isolates | ||||||||
| A. baumannii | FADDI-AB065 | >64 | 8 | 8 | 4 | 1 | 1 | 1 |
| FADDI-AB148 | 8 | >128 | NAc | NA | 0.13 | NA | NA | |
| FADDI-AB144 | 8 | >128 | NA | NA | 0.13 | NA | NA | |
| Polymyxin-susceptible isolates | ||||||||
| ATCC 17,978 | 0.5 | 128 | NA | NA | 0.28 | NA | NA | |
| ATCC 19,606 | 1 | >128 | >128 | 32 | 0.27 | 0.27 | 0.31 | |
| FADDI-AB146 | 0.5 | 64 | 64 | 32 | 0.51 | 0.51 | 0.27 | |
| Polymyxin-susceptible isolates | ||||||||
| K. pneumoniae | ATCC 700,721 | 0.125 | >128 | >128 | >128 | 0.75 | 0.63 | 0.75 |
| Kp BM1 | 0.125 | >128 | NA | NA | 0.63 | NA | NA | |
| FADDI-KP001 | 1 | >128 | >128 | >128 | 0.38 | 0.25 | 0.19 | |
| FADDI-KP002 | 0.25 | >128 | >128 | >128 | 0.25 | 0.13 | 0.25 | |
a
muc, mucoid; n/m, nonmucoid.
b
S, small colony; L, large colony.
c
NA, not accessed.
d
FIC = FIC INDEX= (MIC polymyxin B in combination with phenothiazine/MIC polymyxin B monotherapy) + (MIC phenothiazine in combination with polymyxin B/MIC phenothiazine monotherapy); synergy FIC < 0.5 [green]; additivity FIC = 0.5–1.0 [yellow]; indifference FIC = 1–4 [not observed]; antagonism FIC ≥ 4 [not observed].