In Vitro and In Vivo Activity of a Novel Antisense Peptide Nucleic Acid Compound Against Multidrug-Resistant Acinetobacter baumannii

2019 ◽  
Vol 25 (7) ◽  
pp. 961-965 ◽  
Author(s):  
Michael Rose ◽  
Amabel Lapuebla ◽  
David Landman ◽  
John Quale
Keyword(s):  
Nucleic Acid ◽  
Acinetobacter Baumannii ◽  
Peptide Nucleic Acid ◽  
Multidrug Resistant ◽  
Antisense Peptide ◽  
Acid Compound

mazE Antitoxin of Toxin Antitoxin System and fbpA as Reliable Targets to Eradication of Neisseria meningitidis

2018 ◽  
Vol 24 (11) ◽  
pp. 1204-1210 ◽  
Author(s):  
Abbas Maleki ◽  
Sobhan Ghafourian ◽  
Iraj Pakzad ◽  
Behzad Badakhsh ◽  
Nourkhoda Sadeghifard
Keyword(s):  
Nucleic Acid ◽  
Neisseria Meningitidis ◽  
Peptide Nucleic Acid ◽  
Iron Uptake ◽  
Drug Target ◽  
Uptake System ◽  
Bacteriostatic Activity ◽  
In Vivo Analysis ◽  
Antisense Peptide

Background: Neisseria meningitidis is considered as a dangerous pathogen threatening human health. Nowadays, the new drug target is focused. Toxin antitoxin (TA) system is recently identified as an antimicrobial drug target. Also, in N. meningitidis, iron-uptake system could be an interesting target for drug discovery. Methods: In this study, fbpA and mazE genes were chosen as new antimicrobial targets and treated with antisense peptide nucleic acid (PNA). Firstly, they were evaluated by bioinformatics and then analyzed by experimental procedures. Secondly, the functionality was evaluated by stress conditions. Results: Our results interestingly demonstrated that when fbpA and mazE loci of N. meningitidis were targeted by antisense PNA, 8 µM concentration of fbpA-PNA as well as 30 µM concentration of mazE-PNA inhibited the growth of N. meningitides and were found to be bacteriostatic, whereas 10 μM concentration of fbpA-PNA showed bacteriocidal activity. Conclusion: Our findings demonstrated the bactriocidal activity of fbpA-PNA and bacteriostatic activity of mazEPNA. Therefore, mazE and fbpA genes should be potent antimicrobial targets but further analysis including in vivo analysis should be performed.

scholarly journals In VitroandIn VivoActivities of E-101 Solution against Acinetobacter baumannii Isolates from U.S. Military Personnel

2011 ◽  
Vol 55 (7) ◽  
pp. 3603-3608 ◽  
Author(s):  
G. A. Denys ◽  
J. C. Davis ◽  
P. D. O'Hanley ◽  
J. T. Stephens
Keyword(s):  
Acinetobacter Baumannii ◽  
Bactericidal Activity ◽  
Military Personnel ◽  
Multidrug Resistant ◽  
Full Thickness ◽  
Content Type ◽  
Full Thickness Excision ◽  
Time Kill

ABSTRACTWe evaluated thein vitroandin vivoactivity of a novel topical myeloperoxidase-mediated antimicrobial, E-101 solution, against 5 multidrug-resistantAcinetobacter baumanniiisolates recovered from wounded American soldiers. Time-kill studies demonstrated rapid bactericidal activity against allA. baumanniistrains tested in the presence of 3% blood. Thein vitrobactericidal activity of E-101 solution againstA. baumanniistrains was confirmed in a full-thickness excision rat model. Additionalin vivostudies appear warranted.

scholarly journals A Potential Combination Therapy of Berberine Hydrochloride With Antibiotics Against Multidrug-Resistant Acinetobacter baumannii

2021 ◽  
Vol 11 ◽  
Author(s):  
Xiaobo Li ◽  
Yanqing Song ◽  
Lina Wang ◽  
Guangbo Kang ◽  
Ping Wang ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Synergistic Effects ◽  
Multidrug Resistant ◽  
Infection Model ◽  
Berberine Hydrochloride ◽  
Transporter Protein ◽  
Antimicrobial Efficiency ◽  
Global Threat

Multidrug-resistant (MDR) Acinetobacter baumannii strains can cause severe infections in intensive care units, and are rapidly developing resistance to the last-resort of existing antibiotics, posing a major global threat to health care system. Berberine hydrochloride (BBH), a kind of isoquinoline alkaloids extracted from Berberis and other plants, has been widely used as an antibacterial medicine for its reliable therapeutic efficiency. The in vitro synergistic effects of BBH with antibiotics against MDR A. baumannii were determined. BBH alone had weak antimicrobial activity (e.g., MIC≥256 mg/L) against MDR A. baumannii. However, it dramatically increased the susceptibility of MDR strains against antibiotics with FICI values <0.5, even reversed their resistance to antibiotics (e.g., tigecycline, sulbactam, meropenem and ciprofloxacin). In vivo study has suggested BBH with sulbactam had stronger antimicrobial efficiency than monotherapy in a neutropenic murine thigh infection model. The antibiotic-sensitizing mechanism of action of BBH was evaluated as well. BBH boosted adeB gene expression and bound to the AdeB transporter protein, resulting in low uptake of BBH, which may contribute to less extrusion of antibiotics by the AdeABC pump. Knockout of the adeB gene increased uptake of BBH and diminished the antibiotic sensitization and synergistic effects between antibiotics and BBH in MDR strains. Together, BBH effectively re-sensitizes this MDR pathogen to a range of antibiotics that have become barely effective due to antibiotic resistance, which indicates BBH may be a promising therapeutic adjuvant candidate to combat MDR A. baumannii.

A Peptide Nucleic Acid Targeting Nuclear Rad51 Sensitizes Myeloma Cells to Melphalan Chemotoxicity Both in Vitro and in Vivo

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3529-3529
Author(s):  
David Alagpulinsa ◽  
Srinivas Ayyadevara ◽  
Shmuel Yaccoby ◽  
Robert shmookler Reis
Keyword(s):  
Cell Cycle ◽  
Nucleic Acid ◽  
Tumor Growth ◽  
Peptide Nucleic Acid ◽  
Dna Lesions ◽  
Prolonged Treatment ◽  
Mrna Levels ◽  
Qrt Pcr

Abstract Multiple myeloma (MM) cells are characterized by extensive genomic heterogeneity, which contributes to patient differences in prognosis and response to treatment. We previously reported that MM cells have elevated homologous recombination (HR) rates and expression of RAD51 and its paralogs, promoting genomic instability and disease progression that are reversed by RAD51 siRNA. We now examine the roles of HR and RAD51 in resistance to melphalan, one of the most widely used drugs for MM chemotherapy. The drug induces a variety of DNA lesions, with DNA interstrand crosslinks (ICL) accounting for most of the drug’s cytotoxicity. RAD51 is a central protein in the HR pathway and its overexpression may contribute to chemoresistance by enabling repair of DNA lesions induced by DNA damaging agents such as melphalan. MM cell sensitivity to melphalan correlates directly with melphalan-induced RAD51 foci, and high RAD51 expression predicts poor event-free and overall survival of MM patients. Activity of the Rad51 promoter increases >850-fold in cancer cells compared to normal cells, and tumor cells are selectively killed by a construct in which PRad51 drives expression of diphtheria toxin. In this study, we tested whether inhibiting RAD51 expression with a peptide nucleic acid (PNA) would inhibit MM cell growth and/or sensitize MM cells to melphalan. PNAs are DNA or RNA mimics in which a polymer of (2-amino­ethyl) glycine replaces the nucleic acid’s sugar-phosphate backbone. PNAs are highly specific, binding DNA with higher affinity than RNA or DNA, and they are quite stable to degradation both in vitro and in vivo. We designed a PNA to target the promoter region of the RAD51 gene (PNArad51), encompassing the transcription start site. To enhance cellular uptake and nuclear delivery without transfection, we conjugated the PNA to a nuclear localization signal rich in basic residues (PKKKRKVR). As a control we employed a scrambled PNA (PNAmt) with the same nucleotide composition but not targeting any genomic sequences. We used qRT-PCR to assess the effect of PNA on RAD51 mRNA expression and that of melphalan on mRNA levels of RAD51 and its paralogs (RAD51B, RAD51B, RAD51C, RAD51D, XRCC2 and XRCC3) and BRCA1. Propidium iodide staining and flow cytometry were used to examine the cell-cycle effects of melphalan. γH2AX and RAD51 foci were quantitated using confocal immuno­fluorescence microscopy, and MM cell viability was assessed with the WST-1 assay. To examine the in vivo consequences of PNA ± melphalan for tumor growth, we injected H929 MM cells expressing luciferase into rabbit bone fragments implanted in SCID-rab mice, as previously described by us,. Total RNA extracted from cells recovered from the rabbit bones was analyzed by qRT-PCR to determine the in vivo effect of PNA on expression of RAD51. Melphalan treatment (10 µM) significantly induced expression of RAD51 and its paralogs, particularly RAD51 and XRCC3 (p≤0.01). Melphalan caused cell-cycle arrest, predominantly in the S-phase (55%, significantly elevated over vehicle alone, 17%; p<0.0001), the period in which HR is most active, and during which ICLs are converted into double strand breaks (DSBs) on encountering DNA replication forks. PNArad51 (10 µM) significantly reduced expression of RAD51 (~60%, p<0.001) relative to PNAmt. Pretreatment with PNArad51 inhibited melphalan-induced RAD51 focus formation, far more than PNAmt pretreatment (21% compared to 66%, p<0.0001) whereas the number of γH2AX foci increased (66%) relative to PNAmt (39%; p<0.0001). Consequently, pretreatment with PNArad51 produced synergistic synthetic lethality with melphalan, reducing the IC50 of melphalan by 4.5-fold. PNArad51 alone caused significant cytotoxicity compared to PNAmt (p<0.05). In the SCID-rab mouse model, a two-week treatment with PNArad51 alone or in combination with melphalan resulted in significant inhibition of tumor volume (p≈0.01 and p<0.05, respectively) compared to PNAmt, although the combination of PNAmt plus melphalan was ineffectual. Prolonged treatment (4 weeks) with PNArad51 ± melphalan (but not PNAmt + melphalan) reduced tumor growth compared to PNAmt treatment, although this was not statistically significant (p>0.05). These results highlight the importance of RAD51 in the response of MM cells to melphalan, and indicate for the first time the potential for RAD51-targeted PNA in tumor chemosensitization. Disclosures No relevant conflicts of interest to declare.

scholarly journals Pharmacokinetics and Pharmacodynamics of Minocycline against Acinetobacter baumannii in a Neutropenic Murine Pneumonia Model

2017 ◽  
Vol 61 (5) ◽  
Author(s):  
Jian Zhou ◽  
Kimberly R. Ledesma ◽  
Kai-Tai Chang ◽  
Henrietta Abodakpi ◽  
Song Gao ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Multidrug Resistant ◽  
Time Curve ◽  
Content Type ◽  
Concentration Time ◽  
Dose Linearity ◽  
Unit Reduction ◽  
The Relationship

ABSTRACT Multidrug-resistant (MDR) Acinetobacter baumannii is increasingly more prevalent in nosocomial infections. Although in vitro susceptibility of A. baumannii to minocycline is promising, the in vivo efficacy of minocycline has not been well established. In this study, the in vivo activity of minocycline was evaluated in a neutropenic murine pneumonia model. Specifically, we investigated the relationship between minocycline exposure and bactericidal activity using five A. baumannii isolates with a broad range of susceptibility (MIC ranged from 0.25 mg/liter to 16 mg/liter). The pharmacokinetics of minocycline (single dose of 25 mg/kg of body weight, 50 mg/kg, 100 mg/kg, and a humanized regimen, given intraperitoneally) in serum and epithelial lining fluid (ELF) were characterized. Dose linearity was observed for doses up to 50 mg/kg and pulmonary penetration ratios (area under the concentration-time curve in ELF from 0 to 24 h [AUCELF,0–24]/area under the concentration time curve in serum from 0 to 24 h [AUCserum,0–24]) ranged from 2.5 to 2.8. Pharmacokinetic-pharmacodynamics (PK-PD) index values in ELF for various dose regimens against different A. baumannii isolates were calculated. The maximum efficacy at 24 h was approximately 1.5-log-unit reduction of pulmonary bacterial burdens from baseline. The AUC/MIC ratio was the PK-PD index most closely correlating to the bacterial burden (r 2 = 0.81). The required AUCELF,0–24/MIC for maintaining stasis and achieving 1-log-unit reduction were 140 and 410, respectively. These findings could guide the treatment of infections caused by A. baumannii using minocycline in the future. Additional studies to examine resistance development during therapy are warranted.

scholarly journals In vitro and In vivo Activity of Theaflavin–Epicatechin Combinations versus Multidrug-Resistant Acinetobacter baumannii

2017 ◽  
Vol 6 (3) ◽  
pp. 435-442 ◽  
Author(s):  
Jonathan W. Betts ◽  
Michael Hornsey ◽  
David W. Wareham ◽  
Roberto M. La Ragione
Keyword(s):  
Acinetobacter Baumannii ◽  
Multidrug Resistant
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