Synergistic effect of ultrasound and antibiotics against Chlamydia trachomatis-infected human epithelial cells in vitro.
To investigate whether or not the combined ultrasound and antibiotic treatment is effective against chlamydial infection, a new ultrasound exposure system was designed to treat chlamydia-infected cells. First, the minimum inhibitory concentrations of antibiotics against Chlamydia trachomatis were determined. Infected cultures were treated with antibiotics then sonicated at intensity of 0.15 or 0.44 W/cm(2) with or without Bubble liposomes. After 48 or 72 h after infection, chlamydial inclusions were stained and examined by fluorescence microscopy. The internalization of dextran-fluorescein conjugates by ultrasound irradiation with Bubble liposomes was observed by fluorescence microscopy. The results showed that application of nanobubble-enhanced ultrasound caused no significant effect on cell viability and chlamydial infectivity. However, Doxycycline (1/2 MIC) or CZX (1.0 μg/ml) in combination with nanobubble-enhanced ultrasound dramatically reduced the number of inclusions compared with that administered with antibiotics only. Bubble dose-dependent synergy was also observed. After ultrasound irradiation at intensity of 0.44 W/cm(2) on the presence of Bubble liposomes, 10% of HeLa cells were observed to have internalized the dextran molecules. This study suggests the possibility of using nanobubble-enhanced ultrasound to deliver antibiotic molecules into cells to eradiate intracellular bacteria, such as chlamydiae, without causing much damage to the cells itself.
Ikeda-Dantsuji
Yurika
Y
Department of Anatomy, Fukuoka University School of Medicine, Fukuoka, Japan.
Feril
Loreto B
LB
Tachibana
Katsuro
K
Ogawa
Koichi
K
Endo
Hitomi
H
Harada
Yoshimi
Y
Suzuki
Ryo
R
Maruyama
Kazuo
K
D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D015296:Ceftizoxime / Q000737:chemistry / Q000494:pharmacology; D002460:Cell Line; D002690:Chlamydia Infections / Q000188:drug therapy* / Q000382:microbiology / Q000473:pathology; D002692:Chlamydia trachomatis / Q000187:drug effects* / Q000302:isolation & purification; D004305:Dose-Response Relationship, Drug; D004318:Doxycycline / Q000737:chemistry / Q000494:pharmacology; D004847:Epithelial Cells / Q000187:drug effects* / Q000382:microbiology / Q000473:pathology; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D008826:Microbial Sensitivity Tests; D014465:Ultrasonics
D000900:Anti-Bacterial Agents; D015296:Ceftizoxime; D004318:Doxycycline