TY - JOUR
T1 - Single cell analysis of drug susceptibility of mycobacterium abscessus during macrophage infection
AU - Brzostek, Joanna
AU - Fatin, Amierah
AU - Chua, Wen Hui
AU - Tan, Hui Yi
AU - Dick, Thomas
AU - Gascoigne, Nicholas R.J.
N1 - Funding Information:
Funding: This research was supported by NUS, the Singapore Ministry of Health’s National Medical Research Council under its CBRG/0064/2014 to N.R.J.G. and by the Cystic Fibrosis Foundation (DICK17XX00) and the National Institute of Allergy and Infectious Diseases of the National Institutes of Health (R01AI132374) to T.D.
Publisher Copyright:
© 2020 by the authors. Licensee MDPI, Basel, Switzerland.
PY - 2020/10
Y1 - 2020/10
N2 - Mycobacterium abscessus is an emerging health risk to immunocompromised individuals and to people with pre-existing pulmonary conditions. As M. abscessus possesses multiple mechanisms of drug resistance, treatments of M. abscessus are of poor efficacy. Therefore, there is an urgent need for new therapeutic strategies targeting M. abscessus. We describe an experimental system for screening of compounds for their antimicrobial activity against intracellular M. abscessus using flow cytometry and imaging flow cytometry. The assay allows simultaneous analysis of multiple parameters, such as proportion of infected host cells, bacterial load per host cell from the infected population, and host cell viability. We verified the suitability of this method using two antibiotics with known activity against M. abscessus: clarithromycin and amikacin. Our analysis revealed a high degree of infection heterogeneity, which correlated with host cell size. A higher proportion of the larger host cells is infected with M. abscessus as compared to smaller host cells, and infected larger cells have higher intracellular bacterial burden than infected smaller cells. Clarithromycin treatment has a more pronounced effect on smaller host cells than on bigger host cells, suggesting that heterogeneity within the host cell population has an effect on antibiotic susceptibility of intracellular bacteria.
AB - Mycobacterium abscessus is an emerging health risk to immunocompromised individuals and to people with pre-existing pulmonary conditions. As M. abscessus possesses multiple mechanisms of drug resistance, treatments of M. abscessus are of poor efficacy. Therefore, there is an urgent need for new therapeutic strategies targeting M. abscessus. We describe an experimental system for screening of compounds for their antimicrobial activity against intracellular M. abscessus using flow cytometry and imaging flow cytometry. The assay allows simultaneous analysis of multiple parameters, such as proportion of infected host cells, bacterial load per host cell from the infected population, and host cell viability. We verified the suitability of this method using two antibiotics with known activity against M. abscessus: clarithromycin and amikacin. Our analysis revealed a high degree of infection heterogeneity, which correlated with host cell size. A higher proportion of the larger host cells is infected with M. abscessus as compared to smaller host cells, and infected larger cells have higher intracellular bacterial burden than infected smaller cells. Clarithromycin treatment has a more pronounced effect on smaller host cells than on bigger host cells, suggesting that heterogeneity within the host cell population has an effect on antibiotic susceptibility of intracellular bacteria.
KW - Drug screen
KW - Mycobacterium abscessus
KW - Single cell analysis
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U2 - 10.3390/antibiotics9100711
DO - 10.3390/antibiotics9100711
M3 - Article
AN - SCOPUS:85092742057
SN - 2079-6382
VL - 9
SP - 1
EP - 13
JO - Antibiotics
JF - Antibiotics
IS - 10
M1 - 711
ER -