TY - JOUR
T1 - In vitro susceptibility of Thai Pythium insidiosum isolates to antibacterial agents
AU - Worasilchai, Navaporn
AU - Chindamporn, Ariya
AU - Plongla, Rongpong
AU - Torvorapanit, Pattama
AU - Manothummetha, Kasama
AU - Chuleerarux, Nipat
AU - Permpalung, Nitipong
N1 - Funding Information:
This study was funded by a Ratchadapiseksompotch Award from the Faculty of Medicine, Chulalongkorn University (grant number RA62/113). The funder had no role in study design, data collection and interpretation, or the decision to submit the work for publication. We thank Nongnuch Vanittanakom, Professor of Microbiology, Faculty of Medicine, Chiang Mai University, for P. insidiosum isolates.
Publisher Copyright:
Copyright © 2020 American Society for Microbiology. All Rights Reserved.
PY - 2020
Y1 - 2020
N2 - Human pythiosis is a life-threatening human disease caused by Pythium insidiosum. In Thailand, vascular pythiosis is the most common form and carries a mortality rate of 10 to 40%, despite aggressive treatment with radical surgery, antifungal agents, and immunotherapy. Itraconazole and terbinafine have been the mainstay of treatment, until recently, based on case report data showing potential synergistic effects against Brazilian P. insidiosum isolates. However, the synergistic effects of itraconazole and terbinafine against Thai P. insidiosum isolates were not observed. This study tested the in vitro susceptibilities of 27 Thai human P. insidiosum isolates (clade II, n = 17; clade IV, n = 10), 12 Thai environmental P. insidiosum isolates (clade II, n = 4; clade IV, n = 8), and 11 non-Thai animal P. insidiosum isolates (clade I, n = 9; clade II, n = 2) to antibiotics in eight antibacterial classes to evaluate alternative effective treatments. Tetracycline and macrolide antibiotics demonstrated in vitro activity against Thai P. insidiosum isolates, with doxycycline MICs (1 to 16 μg/ml), minocycline MICs (1 to 4 μg/ml), tigecycline MICs (1 to 4 μg/ml), azithromycin MICs (1 to 16 μg/ml), and clarithromycin MICs (0.125 to 8 μg/ml) being the lowest, on average. Synergistic effects of tetracyclines and macrolides were also observed.
AB - Human pythiosis is a life-threatening human disease caused by Pythium insidiosum. In Thailand, vascular pythiosis is the most common form and carries a mortality rate of 10 to 40%, despite aggressive treatment with radical surgery, antifungal agents, and immunotherapy. Itraconazole and terbinafine have been the mainstay of treatment, until recently, based on case report data showing potential synergistic effects against Brazilian P. insidiosum isolates. However, the synergistic effects of itraconazole and terbinafine against Thai P. insidiosum isolates were not observed. This study tested the in vitro susceptibilities of 27 Thai human P. insidiosum isolates (clade II, n = 17; clade IV, n = 10), 12 Thai environmental P. insidiosum isolates (clade II, n = 4; clade IV, n = 8), and 11 non-Thai animal P. insidiosum isolates (clade I, n = 9; clade II, n = 2) to antibiotics in eight antibacterial classes to evaluate alternative effective treatments. Tetracycline and macrolide antibiotics demonstrated in vitro activity against Thai P. insidiosum isolates, with doxycycline MICs (1 to 16 μg/ml), minocycline MICs (1 to 4 μg/ml), tigecycline MICs (1 to 4 μg/ml), azithromycin MICs (1 to 16 μg/ml), and clarithromycin MICs (0.125 to 8 μg/ml) being the lowest, on average. Synergistic effects of tetracyclines and macrolides were also observed.
KW - Antibacterial agents
KW - Pythium insidiosum
KW - Susceptibility profile
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U2 - 10.1128/AAC.02099-19
DO - 10.1128/AAC.02099-19
M3 - Article
C2 - 32015039
AN - SCOPUS:85082401634
SN - 0066-4804
VL - 64
JO - Antimicrobial agents and chemotherapy
JF - Antimicrobial agents and chemotherapy
IS - 4
M1 - e02099-19
ER -