Nanoparticulate β-Cyclodextrin with Gallium Tetraphenylporphyrin Demonstrates in Vitro and in Vivo Antimicrobial Efficacy against Mycobacteroides abscessus and Mycobacterium avium

Author(s):  
Seoung-Ryoung Choi ◽  
Geoffrey A. Talmon ◽  
Bradley E. Britigan ◽  
Prabagaran Narayanasamy
2018 ◽  
Vol 62 (10) ◽  
Author(s):  
James D. Blanchard ◽  
Valerie Elias ◽  
David Cipolla ◽  
Igor Gonda ◽  
Luiz E. Bermudez

ABSTRACT Nontuberculous mycobacteria (NTM) affect an increasing number of individuals worldwide. Infection with these organisms is more common in patients with chronic lung conditions, and treatment is challenging. Quinolones, such as ciprofloxacin, have been used to treat patients, but the results have not been encouraging. In this report, we evaluate novel formulations of liposome-encapsulated ciprofloxacin (liposomal ciprofloxacin) in vitro and in vivo. Its efficacy against Mycobacterium avium and Mycobacterium abscessus was examined in macrophages, in biofilms, and in vivo using intranasal instillation mouse models. Liposomal ciprofloxacin was significantly more active than free ciprofloxacin against both pathogens in macrophages and biofilms. When evaluated in vivo, treatment with the liposomal ciprofloxacin formulations was associated with significant decreases in the bacterial loads in the lungs of animals infected with M. avium and M. abscessus. In summary, topical delivery of liposomal ciprofloxacin in the lung at concentrations greater than those achieved in the serum can be effective in the treatment of NTM, and further evaluation is warranted.


2001 ◽  
Vol 45 (8) ◽  
pp. 2210-2214 ◽  
Author(s):  
Luiz E. Bermudez ◽  
Clark B. Inderlied ◽  
Peter Kolonoski ◽  
Martin Wu ◽  
Priscilla Aralar ◽  
...  

ABSTRACT The activity of telithromycin, a new ketolide, was evaluated in vitro and in vivo against Mycobacterium avium complex (MAC) strains. The MIC of telithromycin for several M. aviumisolates obtained from the blood of AIDS patients ranged from 16 to >128 μg/ml (MIC at which 90% of isolates are inhibited, >128 μg/ml), and the compound did show activity in the macrophage system at concentrations greater than 8 or 16 μg/ml, but this was dependent on the MAC strain used. Telithromycin was then administered to mice infected with MAC strain 101 for 4 weeks at doses of 100, 200, or 400 mg/kg of body weight/day. Treatment with 100 and 200 mg/kg/day was bacteriostatic, but at 400 mg/kg/day telithromycin was bactericidal for MAC strains. The frequency of the emergence of resistance to telithromycin was low despite prolonged usage (12 weeks). This study demonstrates that telithromycin is active in vivo against MAC and warrants further evaluation.


2007 ◽  
Vol 51 (11) ◽  
pp. 4071-4076 ◽  
Author(s):  
Yoshihisa Kohno ◽  
Hideaki Ohno ◽  
Yoshitsugu Miyazaki ◽  
Yasuhito Higashiyama ◽  
Katsunori Yanagihara ◽  
...  

ABSTRACT The recommended treatments for Mycobacterium avium complex (MAC) infectious disease are combination regimens of clarithromycin (CLR) or azithromycin with ethambutol and rifamycin. However, these chemotherapy regimens are sometimes unsuccessful. Recently developed antimicrobial agents, such as newer fluoroquinolones (FQs) containing C-8 methoxy quinolone (moxifloxacin [MXF] and gatifloxacin [GAT]), are expected to be novel antimycobacterial agents. Here, we evaluated the in vitro and in vivo antimycobacterial activities of three FQs (MXF, GAT, and levofloxacin) and CLR against clinically isolated MAC strains. Subsequently, the in vitro and in vivo synergic activities of FQ-CLR combinations against MAC strains were investigated. CLR and the individual FQs alone showed promising activity against MAC strains in vitro, and the bacterial counts in organs (lungs, liver, and spleen) of MAC-infected mice treated with single agents were significantly reduced compared to control mice. CLR showed the best anti-MAC effect in vivo. When the three FQs were individually combined with CLR in vitro, mild antagonism was observed for 53 to 57% of the tested isolates. Moreover, mice were infected with MAC strains showing mild antagonism for FQ-CLR combinations in vitro, and the anti-MAC effects of the FQ-CLR combinations were evaluated by counting the viable bacteria in their organs and by histopathological examination after 28 days of treatment. Several FQ-CLR combinations exhibited bacterial counts in organs significantly higher than those in mice treated with CLR alone. Our results indicate that the activity of CLR is occasionally attenuated by combination with an FQ both in vitro and in vivo and that this effect seems to be MAC strain dependent. Careful combination chemotherapy using these agents against MAC infectious disease may be required.


2013 ◽  
Vol 82 (1) ◽  
pp. 405-412 ◽  
Author(s):  
Sasha J. Rose ◽  
Luiz E. Bermudez

ABSTRACTMycobacterium aviumsubsp.hominissuisis an opportunistic human pathogen that has been shown to form biofilmin vitroandin vivo. Biofilm formationin vivoappears to be associated with infections in the respiratory tract of the host. The reasoning behind howM. aviumsubsp.hominissuisbiofilm is allowed to establish and persist without being cleared by the innate immune system is currently unknown. To identify the mechanism responsible for this, we developed anin vitromodel using THP-1 human mononuclear phagocytes cocultured with establishedM. aviumsubsp.hominissuisbiofilm and surveyed various aspects of the interaction, including phagocyte stimulation and response, bacterial killing, and apoptosis.M. aviumsubsp.hominissuisbiofilm triggered robust tumor necrosis factor alpha (TNF-α) release from THP-1 cells as well as superoxide and nitric oxide production. Surprisingly, the hyperstimulated phagocytes did not effectively eliminate the cells of the biofilm, even when prestimulated with gamma interferon (IFN-γ) or TNF-α or cocultured with natural killer cells (which have been shown to induce anti-M. aviumsubsp.hominissuisactivity when added to THP-1 cells infected with planktonicM. aviumsubsp.hominissuis). Time-lapse microscopy and the TUNEL (terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling) assay determined that contact with theM. aviumsubsp.hominissuisbiofilm led to early, widespread onset of apoptosis, which is not seen until much later in planktonicM. aviumsubsp.hominissuisinfection. Blocking TNF-α or TNF-R1 during interaction with the biofilm significantly reduced THP-1 apoptosis but did not lead to elimination ofM. aviumsubsp.hominissuis. Our data collectively indicate thatM. aviumsubsp.hominissuisbiofilm induces TNF-α-driven hyperstimulation and apoptosis of surveilling phagocytes, which prevents clearance of the biofilm by cells of the innate immune system and allows the biofilm-associated infection to persist.


Tubercle ◽  
1988 ◽  
Vol 69 (3) ◽  
pp. 187-192 ◽  
Author(s):  
Hajime Saito ◽  
Katsumasa Sato ◽  
Haruaki Tomioka

2021 ◽  
Author(s):  
Farhad Safari ◽  
Shahla Mirzaeei ◽  
Ghobad Mohammadi

Purpose: The present investigation aimed to prepare Vancomycin-loaded nanoparticles (VAN-NPs) using chitosan (CS) and tripolyphosphate (TPP) besides exploring the effects of changing CS/TPP ratio on the physicochemical properties, corneal permeation, and ocular delivery of the prepared NPs. Methods: Different pre-formulations were prepared using the modified ionic gelation process, then were characterized in terms of size distribution. Optimized formulations were furtherly evaluated by some characteristic tools such as Fourier-transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA). The in vitro antimicrobial efficacy and drug release amounts along with the Ex-vivo corneal permeation of NPs through the sheep cornea were investigated. Quantification was performed using High-Performance Liquid Chromatography. Results: Spherical and uniformly distributed NPs were developed with a mean particle size varied between 215–290 nm. FTIR spectroscopy confirmed that the CS/TPP cross-linking has taken place without affecting the pharmacologically active moiety of the drug. The obtained zeta potential values were in the range of +34 to +37 mV, which could ensure the stability of formulations. TGA analysis indicated enhanced thermal stability for the encapsulated drug compared to the plain drug. Formulations indicated suitable antimicrobial efficacy while releasing more than 90% of the drug during 24 h. NPs offered a 10-fold enhancement in corneal permeation compared to the drug solution. Conclusions: Although further in vivo evaluation is still required to completely confirm the efficacy of the formulations, the enhanced release and corneal permeation of the drug suggest that the prepared NPs are suitable for ocular delivery of VAN.


1998 ◽  
Vol 36 (7) ◽  
pp. 1859-1863 ◽  
Author(s):  
Martine Pestel-Caron ◽  
Robert D. Arbeit

IS1245 is an insertion element widely prevalent among isolates of Mycobacterium avium. We used PvuII Southern blots to analyze IS1245 polymorphisms among 159M. avium isolates (141 clinical isolates from 40 human immunodeficiency virus-infected patients plus 18 epidemiologically related environmental isolates) that represented 40 distinct M. avium strains, as resolved by previous studies by pulsed-field gel electrophoresis (PFGE). All 40 strains carried DNA homologous to IS1245 and thus were typeable. Twenty-five (63%) strains had ≥10 copies of the element, 6 (15%) had 4 to 9 copies, and 9 (23%) had only 1 to 3 copies. Among the last group of nine strains (each of which was distinct by PFGE analysis), IS1245typing resolved only four patterns and thus provided poor discriminatory power. To evaluate the in vivo stability of IS1245, we analyzed 32 strains for which sets of 2 to 19 epidemiologically related isolates were available. For 19 (59%) of these sets, all isolates representing the same strain had indistinguishable IS1245 patterns. Within eight (25%) sets, one or more isolates had IS1245 patterns that differed by one or two fragments from the modal pattern for the isolates of that strain. Five (16%) sets included isolates whose patterns differed by three or more fragments; on the basis of IS1245 typing those isolates would have been designated distinct strains. IS1245 was stable during in vitro passage, suggesting that the variations observed represented natural translocations of the element. IS1245 provides a useful tool for molecular strain typing of M. avium but may have limitations for analyzing strains with low copy numbers or for resolving extended epidemiologic relationships.


Sign in / Sign up

Export Citation Format

Share Document