Carbon nanotube compared with carbon black: effects on bacterial survival against grazing by ciliates and antimicrobial treatments.
The ingestion and digestion of Escherichia coli by the ciliated protozoan, Tetrahymena thermophila, was investigated after an initial exposure to either water-soluble single-walled carbon nanotubes (SWNT) or to carbon black (CB). Both SWNT and CB were internalised and visible in food vacuoles of ciliates. When presented with E. coli expressing green-fluorescent protein (GFP), these ciliates internalised bacteria as well. However, ciliates that had first internalised SWNT but not CB subsequently externalised or egested vesicle-like structures with fluorescent bacteria inside. These egested bacteria were viable and less susceptible than planktonic E. coli to killing either by the antibiotic, chloramphenicol or the disinfectant, glutaraldehyde. These results suggest that SWNT can alter the intracellular trafficking of vesicles within ciliates, leading to bacterial prey being packaged externally and protected for a time from environmental killing, which could have implications for sewage treatment and for public health.
Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada.
Tiffany S Y
TS
Chan
Fatima
F
Nasser
Christine H
CH
St-Denis
Himadri S
HS
Mandal
Parnian
P
Ghafari
Nacima
N
Hadjout-Rabi
Niels
N
C Bols
Xiaowu Shirley
XS
Tang
D000890:Anti-Infective Agents / Q000633:toxicity*; D002452:Cell Count; D002701:Chloramphenicol / Q000633:toxicity; D018920:Coculture Techniques; D004202:Disinfectants / Q000633:toxicity; D054750:Ecotoxicology; D004926:Escherichia coli / Q000187:drug effects; D005976:Glutaral / Q000633:toxicity; D049452:Green Fluorescent Proteins / Q000378:metabolism; D050296:Microbial Viability / Q000187:drug effects; D037742:Nanotubes, Carbon / Q000633:toxicity*; D053260:Soot / Q000633:toxicity*; D016808:Tetrahymena thermophila / Q000187:drug effects* / Q000382:microbiology* / Q000502:physiology; D014617:Vacuoles / Q000382:microbiology
D000890:Anti-Infective Agents; D004202:Disinfectants; D037742:Nanotubes, Carbon; D053260:Soot; D049452:Green Fluorescent Proteins; D002701:Chloramphenicol; D005976:Glutaral