1
|
Nguyen TK, Peyrusson F, Siala W, Pham NH, Nguyen HA, Tulkens PM, Van Bambeke F. Activity of Moxifloxacin Against Biofilms Formed by Clinical Isolates of Staphylococcus aureus Differing by Their Resistant or Persister Character to Fluoroquinolones. Front Microbiol 2021; 12:785573. [PMID: 34975808 PMCID: PMC8715871 DOI: 10.3389/fmicb.2021.785573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 11/19/2021] [Indexed: 11/13/2022] Open
Abstract
Staphylococcus aureus biofilms are poorly responsive to antibiotics. Underlying reasons include a matrix effect preventing drug access to embedded bacteria, or the presence of dormant bacteria with reduced growth rate. Using 18 clinical isolates previously characterized for their moxifloxacin-resistant and moxifloxacin-persister character in stationary-phase culture, we studied their biofilm production and matrix composition and the anti-biofilm activity of moxifloxacin. Biofilms were grown in microtiter plates and their abundance quantified by crystal violet staining and colony counting; their content in polysaccharides, extracellular DNA and proteins was measured. Moxifloxacin activity was assessed after 24 h of incubation with a broad range of concentrations to establish full concentration-response curves. All clinical isolates produced more biofilm biomass than the reference strain ATCC 25923, the difference being more important for those with high relative persister fractions to moxifloxacin, most of which being also resistant. High biofilm producers expressed icaA to higher levels, enriching the matrix in polysaccharides. Moxifloxacin was less potent against biofilms from clinical isolates than from ATCC 25923, especially against moxifloxacin-resistant isolates with high persister fractions, which was ascribed to a lower concentration of moxifloxacin in these biofilms. Time-kill curves in biofilms revealed the presence of a moxifloxacin-tolerant subpopulation, with low multiplication capacity, whatever the persister character of the isolate. Thus, moxifloxacin activity depends on its local concentration in biofilm, which is reduced in most isolates with high-relative persister fractions due to matrix effects, and insufficient to kill resistant isolates due to their high MIC.
Collapse
Affiliation(s)
- Tiep K. Nguyen
- Pharmacologie cellulaire et moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
- Department of Pharmaceutical Industry, Hanoi University of Pharmacy, Hanoi, Vietnam
| | - Frédéric Peyrusson
- Pharmacologie cellulaire et moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Wafi Siala
- Pharmacologie cellulaire et moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Nhung H. Pham
- Department of Microbiology, Bach Mai Hospital, Hanoi, Vietnam
| | - Hoang A. Nguyen
- The National Center for Drug Information and Adverse Drug Reactions Monitoring, Hanoi University of Pharmacy, Hanoi, Vietnam
| | - Paul M. Tulkens
- Pharmacologie cellulaire et moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Françoise Van Bambeke
- Pharmacologie cellulaire et moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
- *Correspondence: Françoise Van Bambeke,
| |
Collapse
|
2
|
Nguyen TK, Peyrusson F, Dodémont M, Pham NH, Nguyen HA, Tulkens PM, Van Bambeke F. The Persister Character of Clinical Isolates of Staphylococcus aureus Contributes to Faster Evolution to Resistance and Higher Survival in THP-1 Monocytes: A Study With Moxifloxacin. Front Microbiol 2020; 11:587364. [PMID: 33329458 PMCID: PMC7719683 DOI: 10.3389/fmicb.2020.587364] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Accepted: 10/16/2020] [Indexed: 12/26/2022] Open
Abstract
Staphylococcus aureus may cause relapsing infections. We previously showed that S. aureus SH1000 surviving intracellularly to bactericidal antibiotics are persisters. Here, we used 54 non-duplicate clinical isolates to assess links between persistence, resistance evolution, and intracellular survival, using moxifloxacin throughout as test bactericidal antibiotic. The relative persister fraction (RPF: percentage of inoculum surviving to 100× MIC moxifloxacin in stationary phase culture for each isolate relative to ATCC 25923) was determined to categorize isolates with low (≤10) or high (>10) RPF. Evolution to resistance (moxifloxacin MIC ≥ 0.5 mg/L) was triggered by serial passages at 0.5× MIC (with daily concentration readjustments). Intracellular moxifloxacin maximal efficacy (Emax) was determined by 24 h concentration-response experiments [pharmacodynamic model (Hill-Langmuir)] with infected THP-1 monocytes exposed to moxifloxacin (0.01 to 100× MIC) after phagocytosis. Division of intracellular survivors was followed by green fluorescence protein dilution (FACS). Most (30/36) moxifloxacin-susceptible isolates showed low RPF but all moxifloxacin-resistant (n = 18) isolates harbored high RPF. Evolution to resistance of susceptible isolates was faster for those with high vs. low RPF (with SOS response and topoisomerase-encoding genes overexpression). Intracellularly, moxifloxacin Emax was decreased (less negative) for isolates with high vs. low RPF, independently from resistance. Moxifloxacin intracellular survivors were non-dividing. The data demonstrate and quantitate persisters in clinical isolates of S. aureus, and show that this phenotype accelerates resistance evolution and is associated with intracellular survival in spite of high antibiotic concentrations. Isolates with high RPF may represent a possible cause of treatment failure not directly related to resistance in patients receiving active antibiotics.
Collapse
Affiliation(s)
- Tiep K Nguyen
- Pharmacologie Cellulaire et Moléculaire, Louvain Drug Research Institute, Université catholique de Louvain (UCLouvain), Brussels, Belgium.,Department of Pharmaceutical Industry, Hanoi University of Pharmacy, Hanoi, Vietnam
| | - Frédéric Peyrusson
- Pharmacologie Cellulaire et Moléculaire, Louvain Drug Research Institute, Université catholique de Louvain (UCLouvain), Brussels, Belgium
| | - Magali Dodémont
- Centre National de Référence des Staphylocoques, Laboratoire Hospitalier Universitaire de Bruxelles (LHUB-ULB) Site Anderlecht, Hôpital Erasme - Cliniques Universitaires de Bruxelles, Brussels, Belgium
| | - Nhung H Pham
- Department of Microbiology, Bach Mai Hospital, Hanoi, Vietnam.,Microbiology Department, Hanoi Medical University, Hanoi, Vietnam
| | - Hoang A Nguyen
- The National Center for Drug Information and Adverse Drug Reactions Monitoring, Hanoi University of Pharmacy, Hanoi, Vietnam
| | - Paul M Tulkens
- Pharmacologie Cellulaire et Moléculaire, Louvain Drug Research Institute, Université catholique de Louvain (UCLouvain), Brussels, Belgium
| | - Françoise Van Bambeke
- Pharmacologie Cellulaire et Moléculaire, Louvain Drug Research Institute, Université catholique de Louvain (UCLouvain), Brussels, Belgium
| |
Collapse
|
3
|
Nguyen HA, Soize S, Manceau PF, Vudang L, Pierot L. Persistent Blood Flow inside the Woven EndoBridge Device More Than 6 Months after Intracranial Aneurysm Treatment: Frequency, Mechanisms, and Management-A Retrospective Single-Center Study. AJNR Am J Neuroradiol 2020; 41:1225-1231. [PMID: 32527839 DOI: 10.3174/ajnr.a6593] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 04/14/2020] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Due to its high safety and great efficacy, flow disruption with the Woven EndoBridge (WEB) device is increasingly used to treat intracranial aneurysms. We recently identified patients with intracranial aneurysm treated with the WEB who presented with residual blood flow inside the device ("contrast-in-WEB" phenomenon) more than 6 months posttreatment. This series reports the frequency and underlying mechanisms and discusses management of this phenomenon. MATERIALS AND METHODS All patients presenting with the contrast-in-WEB phenomenon in the prospectively collected data base of patients with aneurysm treated with the WEB were retrospectively collected and analyzed. RESULTS From June 2011 to February 2019, one hundred twenty-seven patients with 133 aneurysms were treated with the WEB and had DSA follow-up at 6 months or later. Eight patients (6.3%) presented with the phenomenon. All aneurysms were wide-neck bifurcation aneurysms, including 7 unruptured and 1 ruptured aneurysm located at the MCA (5 aneurysms), anterior communicating artery (2 aneurysms), and basilar artery (1 aneurysm). All except 1 patient received dual-antiplatelet therapy preprocedure. All except 1 patient received dual-antiplatelet therapy postoperatively for at least 1 month. The most likely mechanism of the phenomenon is the absence of intradevice thrombosis related to perioperative dual-antiplatelet medication. The phenomenon is also likely associated with a low risk of bleeding except when there is residual blood flow against the aneurysm wall or in the dome. CONCLUSIONS Contrast-in-WEB is a relatively rare phenomenon possibly induced by dual-antiplatelet therapy continued post-WEB procedure. In most cases, no additional treatment is required.
Collapse
Affiliation(s)
- H A Nguyen
- From the Department of Radiology (H.A.N., L.V.), Bach Mai Hospital, Hanoi, Vietnam
- Department of Neuroradiology (H.A.N., S.S., P.-F.M., L.P.), Hôpital Maison-Blanche, Reims, France
| | - S Soize
- Department of Neuroradiology (H.A.N., S.S., P.-F.M., L.P.), Hôpital Maison-Blanche, Reims, France
| | - P-F Manceau
- Department of Neuroradiology (H.A.N., S.S., P.-F.M., L.P.), Hôpital Maison-Blanche, Reims, France
| | - L Vudang
- From the Department of Radiology (H.A.N., L.V.), Bach Mai Hospital, Hanoi, Vietnam
| | - L Pierot
- Department of Neuroradiology (H.A.N., S.S., P.-F.M., L.P.), Hôpital Maison-Blanche, Reims, France.
| |
Collapse
|
4
|
Vu DH, Nguyen DA, Delattre IK, Ho TT, Do HG, Pham HN, Dao XC, Tran NT, Nguyen GB, Van Bambeke F, Tulkens PM, Nguyen HA. Determination of optimal loading and maintenance doses for continuous infusion of vancomycin in critically ill patients: Population pharmacokinetic modelling and simulations for improved dosing schemes. Int J Antimicrob Agents 2019; 54:702-708. [PMID: 31600554 DOI: 10.1016/j.ijantimicag.2019.09.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2019] [Revised: 09/25/2019] [Accepted: 09/28/2019] [Indexed: 10/25/2022]
Abstract
OBJECTIVES Despite extensive clinical use, limited data are available on optimal loading and maintenance doses of vancomycin in critically ill patients. This study aimed to develop a rational approach for optimised dosage of vancomycin given in a continuous infusion in critically ill patients. METHODS Vancomycin pharmacokinetic (PK) data (total serum concentrations) were obtained from 55 intensive care unit (ICU) patients (Bach Mai Hospital, Hanoi, Vietnam) receiving a 20 mg/kg loading dose followed by continuous infusion stratified by creatinine clearance (CLCr). Population PK modelling and Monte Carlo simulations were performed using a nonlinear mixed-effects modelling (NONMEM) program for a target of 20-30 mg/L to optimise efficacy and minimise nephrotoxicity. RESULTS A two-compartment model with first-order elimination best fitted the PK data with central and peripheral volumes of distribution of 1.01 and 2.39 L/kg, respectively (allometric scaling to a 70 kg standard subject). The population total clearance of 3.63 L/h was only explained by renal function in the covariate and final model. The simulations showed that a 25-mg/kg loading dose infused over 90 minutes was optimal to reach the target range. The optimal maintenance dose for low renal function (CLCr < 45 mL/min) was 1000-1500 mg/day. For augmented renal clearance (CLCr > 130 mL/min) the dose should be up to 3500 mg/day or even 4500 mg/day to achieve adequate exposure. These simulated maintenance doses were larger than previously proposed for non-ICU patients. CONCLUSION Large loading and maintenance doses of vancomycin are generally needed in critically ill patients. Because of high interindividual variability in vancomycin PK, drug monitoring may still be necessary.
Collapse
Affiliation(s)
- Dinh H Vu
- National Drug Information and Adverse Drug Reaction Monitoring Center, Hanoi University of Pharmacy, Hanoi, Vietnam.
| | - Duy A Nguyen
- National Drug Information and Adverse Drug Reaction Monitoring Center, Hanoi University of Pharmacy, Hanoi, Vietnam
| | - Isabelle K Delattre
- Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Trong T Ho
- National Drug Information and Adverse Drug Reaction Monitoring Center, Hanoi University of Pharmacy, Hanoi, Vietnam
| | - Hong G Do
- Department of Pharmacy, Bach Mai Hospital, Hanoi, Vietnam
| | - Hong N Pham
- Department of Microbiology, Bạch Mai Hospital, Hanoi, Vietnam
| | - Xuan C Dao
- Intensive Care Unit, Bạch Mai Hospital, Hanoi, Vietnam
| | - Nhan T Tran
- Department of Pharmacy, Bach Mai Hospital, Hanoi, Vietnam
| | - Gia B Nguyen
- Intensive Care Unit, Bạch Mai Hospital, Hanoi, Vietnam
| | - Françoise Van Bambeke
- Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Paul M Tulkens
- Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Hoang A Nguyen
- National Drug Information and Adverse Drug Reaction Monitoring Center, Hanoi University of Pharmacy, Hanoi, Vietnam
| |
Collapse
|
5
|
Bayraktarov E, Ehmke G, O'Connor J, Burns EL, Nguyen HA, McRae L, Possingham HP, Lindenmayer DB. Do Big Unstructured Biodiversity Data Mean More Knowledge? Front Ecol Evol 2019. [DOI: 10.3389/fevo.2018.00239] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
6
|
Wong RJ, Nguyen MT, Trinh HN, Chan C, Huynh A, Ly MT, Nguyen HA, Nguyen KK, Torres S, Yang J, Liu B, Garcia RT, Bhuket T, Baden R, Levitt B, da Silveira E, Gish RG. Hepatitis B surface antigen loss and sustained viral suppression in Asian chronic hepatitis B patients: A community-based real-world study. J Viral Hepat 2017; 24:1089-1097. [PMID: 28581644 DOI: 10.1111/jvh.12736] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 05/09/2017] [Indexed: 12/19/2022]
Abstract
Community-based real-world outcomes on effectiveness of antiviral therapies for chronic hepatitis B virus (CHB) in Asians are limited. Whether hepatitis B surface antigen (HBsAg) loss correlates with undetectable virus and alanine aminotransferase (ALT) normalization on treatment or what predicts risk of seroreversion or detectable virus after stopping therapy is unclear. We aim to evaluate rates and predictors of HBsAg loss, seroconversion, ALT normalization and undetectable HBV DNA, including HBsAg seroreversion or re-emergence of HBV DNA among Asian CHB patients. We retrospectively evaluated 1072 CHB adults on antiviral therapy at two community gastroenterology clinics from 1997 to 2015. Rates of HBsAg loss, ALT normalization, achieving undetectable HBV DNA and developing surface antibody (anti-HBs) were stratified by HBeAg status. Following HBsAg loss, HBsAg seroreversion or re-emergence of detectable HBV DNA was analysed. With median treatment of 76.7 months, the overall rate of HBsAg loss was 4.58%, with similar HBsAg loss rates between HBeAg-positive and HBeAg-negative patients (4.44% vs 4.71%, P=.85) in a predominantly Asian population (98.1%). Among HBsAg loss patients, 33.3% developed anti-HBs, 95.8% achieved undetectable virus and 66.0% normalized ALT. No significant baseline or on-treatment predictors of HBsAg loss were observed. While six patients who achieved HBsAg loss had seroreversion with re-emergence of HBsAg positivity, viral load remained undetectable, demonstrating the sustainability of viral suppression. Among a large community-based real-world cohort of Asian CHB patients treated with antiviral therapy, rate of HBsAg loss was 4.58%. Despite only 33.3% of HBsAg loss patients achieving anti-HBs, nearly all patients achieved sustained undetectable virus.
Collapse
Affiliation(s)
- R J Wong
- Division of Gastroenterology and Hepatology, Alameda Health System - Highland Hospital, Oakland, CA, USA
| | - M T Nguyen
- Silicon Valley Research Institute, San Jose, CA, USA
| | - H N Trinh
- San Jose Gastroenterology, San Jose, CA, USA
| | - C Chan
- Division of Gastroenterology and Hepatology, Alameda Health System - Highland Hospital, Oakland, CA, USA
| | - A Huynh
- Silicon Valley Research Institute, San Jose, CA, USA
| | - M T Ly
- Silicon Valley Research Institute, San Jose, CA, USA
| | - H A Nguyen
- San Jose Gastroenterology, San Jose, CA, USA
| | - K K Nguyen
- San Jose Gastroenterology, San Jose, CA, USA
| | - S Torres
- Division of Gastroenterology and Hepatology, Alameda Health System - Highland Hospital, Oakland, CA, USA
| | - J Yang
- San Jose Gastroenterology, San Jose, CA, USA
| | - B Liu
- Division of Gastroenterology and Hepatology, Alameda Health System - Highland Hospital, Oakland, CA, USA
| | - R T Garcia
- San Jose Gastroenterology, San Jose, CA, USA
| | - T Bhuket
- Division of Gastroenterology and Hepatology, Alameda Health System - Highland Hospital, Oakland, CA, USA
| | - R Baden
- Division of Gastroenterology and Hepatology, Alameda Health System - Highland Hospital, Oakland, CA, USA
| | - B Levitt
- San Jose Gastroenterology, San Jose, CA, USA
| | | | - R G Gish
- Division of Gastroenterology and Hepatology, Department of Medicine, Stanford University Medical Center, Stanford, CA, USA.,Hepatitis B Foundation, Doylestown, PA, USA
| |
Collapse
|
7
|
de Assis PL, Yeo I, Gloppe A, Nguyen HA, Tumanov D, Dupont-Ferrier E, Malik NS, Dupuy E, Claudon J, Gérard JM, Auffèves A, Arcizet O, Richard M, Poizat JP. Strain-Gradient Position Mapping of Semiconductor Quantum Dots. Phys Rev Lett 2017; 118:117401. [PMID: 28368631 DOI: 10.1103/physrevlett.118.117401] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Indexed: 06/07/2023]
Abstract
We introduce a nondestructive method to determine the position of randomly distributed semiconductor quantum dots (QDs) integrated in a solid photonic structure. By setting the structure in an oscillating motion, we generate a large stress gradient across the QDs plane. We then exploit the fact that the QDs emission frequency is highly sensitive to the local material stress to map the position of QDs deeply embedded in a photonic wire antenna with an accuracy ranging from ±35 nm down to ±1 nm. In the context of fast developing quantum technologies, this technique can be generalized to different photonic nanostructures embedding any stress-sensitive quantum emitters.
Collapse
Affiliation(s)
- P-L de Assis
- Institut NEEL, CNRS, Univ. Grenoble Alpes, France
- Departamento de Física, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - I Yeo
- Institut NEEL, CNRS, Univ. Grenoble Alpes, France
- INAC-PHELIQS, "Nanophysique et semiconducteurs" group, CEA, Univ. Grenoble Alpes, France
| | - A Gloppe
- Institut NEEL, CNRS, Univ. Grenoble Alpes, France
| | - H A Nguyen
- Institut NEEL, CNRS, Univ. Grenoble Alpes, France
| | - D Tumanov
- Institut NEEL, CNRS, Univ. Grenoble Alpes, France
| | | | - N S Malik
- INAC-PHELIQS, "Nanophysique et semiconducteurs" group, CEA, Univ. Grenoble Alpes, France
| | - E Dupuy
- INAC-PHELIQS, "Nanophysique et semiconducteurs" group, CEA, Univ. Grenoble Alpes, France
| | - J Claudon
- INAC-PHELIQS, "Nanophysique et semiconducteurs" group, CEA, Univ. Grenoble Alpes, France
| | - J-M Gérard
- INAC-PHELIQS, "Nanophysique et semiconducteurs" group, CEA, Univ. Grenoble Alpes, France
| | - A Auffèves
- Institut NEEL, CNRS, Univ. Grenoble Alpes, France
| | - O Arcizet
- Institut NEEL, CNRS, Univ. Grenoble Alpes, France
| | - M Richard
- Institut NEEL, CNRS, Univ. Grenoble Alpes, France
| | - J-Ph Poizat
- Institut NEEL, CNRS, Univ. Grenoble Alpes, France
| |
Collapse
|
8
|
Pham KC, Tran HTT, Van Doan C, Le PH, Van Nguyen AT, Nguyen HA, Hong HA, Cutting SM, Phan TN. Protection of Penaeus monodon against white spot syndrome by continuous oral administration of a low concentration of Bacillus subtilis spores expressing the VP28 antigen. Lett Appl Microbiol 2017; 64:184-191. [PMID: 27992657 DOI: 10.1111/lam.12708] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Revised: 10/19/2016] [Accepted: 12/12/2016] [Indexed: 11/28/2022]
Abstract
In this study, Bacillus subtilis spores expressing a chimeric protein, CotB-VP28, were used as a probiotic vaccine to protect black tiger shrimps (Penaeus monodon) against white spot syndrome virus (WSSV) infection. Oral administration of pellets coated with CotB-VP28 spores (at ≥1 × 109 CFU per g pellet) to shrimps induced immune-relating phenoloxydase activity (PO) in shrimps after 14 days of feeding (prior challenge) and at day 3 post challenge (1·26 and 1·70 fold increase respectively). A 75% protection rate was obtained by continuous feeding of the spore-coated pellets at ≥1 × 109 CFU per g for 14 days prior to WSSV challenge and during all the postchallenge period. Even when the amount of CotB-VP28 spores in feed pellets was reduced down to ≥5 × 107 CFU per g and ≥1 × 106 CFU per g, relatively high protection rates of 70 and 67·5%, respectively, were still obtained. By contrast, feeding pellets without spores (untreated group) and with naked spores (PY79 group) at ≥1 × 109 CFU per g could not protect shrimps against WSSV. These data suggest that supplementation of CotB-VP28 spores at low dose of ≥1 × 106 CFU per g could be effective as a prophylactic treatment of WSS for black tiger shrimps. SIGNIFICANCE AND IMPACT OF THE STUDY This study reports the protective efficacy of Bacillus subtilis CotB-VP28 spores on black tiger shrimps (Penaeus monodon) against white spot syndrome virus infection. Oral administration of pellets coated with CotB-VP28 spores (≥1 × 109 CFU per g) conferred 75% protection after white spot syndrome virus challenge. Even after reducing CotB-VP28 spores in feed pellets to ≥1 × 106 CFU per g, 67·5% protections was still obtained. These data indicate that supplementation of CotB-VP28 spores at a low dose of ≥1 × 106 CFU per g could be effective in prophylaxis against white spot syndrome in black tiger shrimps.
Collapse
Affiliation(s)
- K-C Pham
- Key Laboratory of Enzyme and Protein Technology, VNU University of Science, Hanoi, Vietnam.,Department of Biochemistry, Institute of New Technology, Hanoi, Vietnam
| | - H T T Tran
- Faculty of Aquaculture, Can Tho University, Can Tho, Vietnam
| | - C Van Doan
- Southern Monitoring Center for Aquaculture Environment and Epidemic, Research Institute for Aquaculture No. 2, Ho Chi Minh City, Vietnam
| | - P H Le
- Southern Monitoring Center for Aquaculture Environment and Epidemic, Research Institute for Aquaculture No. 2, Ho Chi Minh City, Vietnam
| | - A T Van Nguyen
- Key Laboratory of Enzyme and Protein Technology, VNU University of Science, Hanoi, Vietnam
| | - H A Nguyen
- ANABIO Research & Development JSC, Hanoi, Vietnam
| | - H A Hong
- School of Biological Sciences, Royal Holloway University of London, Egham, UK
| | - S M Cutting
- School of Biological Sciences, Royal Holloway University of London, Egham, UK
| | - T-N Phan
- Key Laboratory of Enzyme and Protein Technology, VNU University of Science, Hanoi, Vietnam
| |
Collapse
|
9
|
Wong RJ, Nguyen MT, Trinh HN, Huynh A, Ly MT, Nguyen HA, Nguyen KK, Yang J, Garcia RT, Levitt B, da Silveira E, Gish RG. Community-based real-world treatment outcomes of sofosbuvir/ledipasvir in Asians with chronic hepatitis C virus genotype 6 in the United States. J Viral Hepat 2017; 24:17-21. [PMID: 27677786 DOI: 10.1111/jvh.12609] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Accepted: 08/23/2016] [Indexed: 01/08/2023]
Abstract
Sofosbuvir/ledipasvir (SOF/LDV) is the first all-oral ribavirin-free treatment approved for chronic hepatitis C virus (HCV) genotype 6, offering a safe and highly efficacious treatment option. Large studies evaluating real-world outcomes of this regimen are lacking. We aim to evaluate real-world treatment outcomes for HCV genotype 6. A retrospective cohort study evaluated 65 adults (age ≥18) with chronic HCV genotype 6 treated with SOF/LDV without ribavirin at a community gastroenterology clinic in the United States from November 2014 to May 2016. Rates of undetectable virus at week 4 on treatment, at end of treatment (EOT) and SVR12 were stratified by the presence of cirrhosis and prior treatment (treatment naïve vs treatment experienced). Among 65 patients with chronic HCV genotype 6 treated with SOF/LDV (52.3% male, mean age 66.3 years [SD 9.7], 41.5% cirrhosis and 15.4% treatment experienced), 97.3% had undetectable virus at week 4 on treatment, 96.9% had undetectable virus at EOT and 95.3% achieved SVR12. SVR12 was 100% in females vs 91.2% in males, P=.096, and 92.3% in patients with cirrhosis vs 97.4% in those without cirrhosis, P=.347. Resistance testing of treatment failures was attempted but unsuccessful due to lack of conforming primers to define the possible resistance mutations. Among the largest U.S. community-based real-world cohort of Asian chronic HCV genotype 6 patients treated with all-oral SOF/LDV without ribavirin, SVR12 was similar to SVR12 reported in clinical trials, confirming the safety and effectiveness of this regimen and validating current HCV genotype 6 treatment guideline recommendations.
Collapse
Affiliation(s)
- R J Wong
- Division of Gastroenterology and Hepatology, Alameda Health System - Highland Hospital, Oakland, CA, USA
| | - M T Nguyen
- Silicon Valley Research Institute, San Jose, CA, USA
| | - H N Trinh
- San Jose Gastroenterology, San Jose, CA, USA
| | - A Huynh
- Silicon Valley Research Institute, San Jose, CA, USA
| | - M T Ly
- Silicon Valley Research Institute, San Jose, CA, USA
| | - H A Nguyen
- San Jose Gastroenterology, San Jose, CA, USA
| | - K K Nguyen
- San Jose Gastroenterology, San Jose, CA, USA
| | - J Yang
- San Jose Gastroenterology, San Jose, CA, USA
| | - R T Garcia
- San Jose Gastroenterology, San Jose, CA, USA
| | - B Levitt
- San Jose Gastroenterology, San Jose, CA, USA
| | | | - R G Gish
- Division of Gastroenterology and Hepatology, Stanford Health Care, Stanford, CA, USA.,National Viral Hepatitis Roundtable, San Francisco, CA, USA
| |
Collapse
|
10
|
Vutien P, Trinh HN, Nguyen K, Garcia RT, Nguyen HA, Levitt BS, Nguyen L, Ha NB, Ahmed A, Daugherty T, Garcia G, Nguyen MH. Precore and basal core promoter mutations in Asian American patients with hepatitis B e antigen-positive chronic hepatitis B. Aliment Pharmacol Ther 2013; 37:464-72. [PMID: 23278246 DOI: 10.1111/apt.12193] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Revised: 10/19/2012] [Accepted: 12/05/2012] [Indexed: 01/04/2023]
Abstract
BACKGROUND Prior studies have shown that precore mutations abolish and basal core promoter (BCP) mutations down-regulate hepatitis B e antigen (HBeAg) production. Thus, the presence of precore and BCP mutations in HBeAg-positive patients indicates an infection with a mixed viral population of wild-type and precore and/or BCP mutant hepatitis B virus (HBV). To date, there has been limited study of the prevalence and clinical significance of precore and BCP mutations in patients with HBeAg-positive chronic hepatitis B. AIM To determine the prevalence, predictors and clinical characteristics of mixed wild-type and precore/BCP HBV infection, through a cross-sectional study, in a US cohort of patients with chronic hepatitis B. METHODS We conducted a retrospective study of 828 chronic hepatitis B patients with HBV genotype and mutation panel testing seen at three US gastroenterology and liver clinics from June 2005 to September 2009. RESULTS A majority of our patients (92.3%) were either Vietnamese or Chinese American. In the HBeAg-positive cohort, 17% of patients had precore mutations only, 28% had BCP mutations only and 5% had both BCP and precore mutations. On multivariate analyses, HBV genotype C, increasing age, lower HBV DNA level and an ALT quotient >2 were independent predictors for the presence of precore and/or BCP mutations. CONCLUSIONS The current distinction and management recommendations for HBeAg-positive vs. HBeAg-negative patients with chronic hepatitis B should be reassessed. Additional biomarkers and treatment endpoints should be studied for their usefulness in predicting continued viral suppression after treatment discontinuation.
Collapse
Affiliation(s)
- P Vutien
- Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Sheen E, Trinh HN, Nguyen TT, Do ST, Tran P, Nguyen HA, Nguyen KK, Garcia RT, Nguyen MH. The efficacy of entecavir therapy in chronic hepatitis B patients with suboptimal response to adevofir. Aliment Pharmacol Ther 2011; 34:767-74. [PMID: 21806648 DOI: 10.1111/j.1365-2036.2011.04785.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
BACKGROUND An increasing number of patients with chronic hepatitis B (CHB) have experienced treatment failure to adefovir (ADV) and their management poses a growing challenge. Very limited data are available on the efficacy of entecavir (ETV) in patients previously treated with ADV. AIM To examine the effect of ETV monotherapy on HBV DNA and ALT levels in CHB patients previously treated with ADV, but switched to ETV due to suboptimal response. METHODS Study candidates were enrolled from five community gastroenterology clinics in the U.S. Each completed at least 12 months of ETV treatment after being previously treated with ADV and experiencing suboptimal response. Primary and secondary outcome measurements were complete viral suppression (CVS, HBV DNA <100 IU/mL) and biochemical response (BR, ALT < 40 U/L), respectively. RESULTS A total of 60 patients were included in this analysis. Twelve were lamivudine (LAM)-experienced and none were LAM-resistant. At time of switch to ETV, no patients had experienced CVS. The CVS rate was 68% after 12 months of ETV therapy. The BR rate was 67% at switch to ETV and 80% after 12 months. There was no significant difference in response rates between LAM-experienced and naïve patients. Among the eight patients with ADV resistance, each achieved CVS after 12 months of ETV therapy and seven achieved BR. CONCLUSIONS In patients with suboptimal response to adefovir, complete viral suppression and biochemical response can be achieved in the majority by 12 months after switching to entecavir, including patients with prior exposure to lamivudine and those with adefovir resistance.
Collapse
Affiliation(s)
- E Sheen
- Department of Medicine, Stanford University Medical Center, Stanford, CA, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Nguyen MH, Garcia RT, Trinh HN, Nguyen HA, Nguyen KK, Nguyen LH, Levitt B. Prevalence of hepatitis B virus DNA polymerase mutations in treatment-naïve patients with chronic hepatitis B. Aliment Pharmacol Ther 2009; 30:1150-8. [PMID: 19785624 DOI: 10.1111/j.1365-2036.2009.04151.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND One of the most important factors in treatment failure using nucleos(t)ide analogues in chronic hepatitis B is anti-viral resistance. Primary drug resistance refers to amino acid changes in the hepatitis B virus polymerase/reverse transcriptase (rt) that result in reduced susceptibility to anti-viral agents. Pre-existing drug resistance mutations may occur in untreated patients and may affect their treatment outcomes. AIM To determine the prevalence of hepatitis B DNA polymerase mutations in treatment-naïve patients. METHODS We used a direct PCR sequencing test to detect DNA polymerase mutations in 472 consecutive treatment-naïve patients at two community gastroenterology clinics in Northern California. RESULTS A majority of patients were Asians (>95%), had either genotype B or C (95%) and had no evidence of cirrhosis or liver cancer (94%). Mean age was 45 +/- 13 and mean hepatitis B virus DNA was 5.3 +/- 1.8 log(10) IU/mL. Most patients did not have any detectable mutations (82.4%). Some (16.7%) had mutations of unknown clinical significance (rtV207M/L/I) and only 4 patients had rtA181A/S, rtA194S or M250I. CONCLUSIONS No rtM204V/I or rtN236T mutations were observed in our study. Less than 1% of our patients had mutations that can be associated with primary resistance to existing anti-viral therapies for hepatitis B virus.
Collapse
Affiliation(s)
- M H Nguyen
- Division of Gastroenterology and Hepatology, Stanford University Medical Center, Stanford, CA 94304, USA.
| | | | | | | | | | | | | |
Collapse
|
13
|
Olsson E, Tuyet LTN, Nguyen HA, Stålsby Lundborg C. Health professionals' and consumers' views on the role of the pharmacy personnel and the pharmacy service in Hanoi, Vietnam--a qualitative study. J Clin Pharm Ther 2002; 27:273-80. [PMID: 12174029 DOI: 10.1046/j.1365-2710.2002.00421.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
OBJECTIVES To explore the views of health professionals and consumers concerning (i) the role of the pharmacy personnel and (ii) the pharmacy service in Hanoi, Vietnam. METHOD A qualitative approach influenced by both content analysis and phenomenography was used. The different groups of participants were selected by purposive sampling, whereas the representatives from each group were selected based on availability. Data were collected by means of face-to-face interviews. Pre-tested, semi-structured interview guides were used. The interviews were tape-recorded and transcribed. The analysis followed commonly applied procedures in qualitative research. The views of the respondents were categorized and described concerning the main issues. RESULTS A total of 21 interviews were conducted with six pharmacists, five medical doctors, five pharmacy students and five pharmacy customers. An interpreter was used in 16 cases. The role of the pharmacy personnel was viewed in three different ways, as: counsellor, doctor's assistant or businessman. It was also believed that sometimes the pharmacy personnel might play a double role--both as doctor and pharmacist. They were considered to have a passive or active role in the provision of information to the customers. Some of the subjects put emphasis on the quality of the information given, and some others considered the information given at the pharmacies as merely a reiteration of the doctor's instruction. Concerning the pharmaceutical field in general, three different categories could be discerned, which describe the interviewee's perspective on the main actors influencing pharmacy practice: a mutual, a central and an individual perspective. CONCLUSION This study describes different ways of viewing the role of the pharmacy personnel and the pharmacy service in Hanoi. The estimation of the impact of the different views on the pharmacy profession in Hanoi requires another kind of study.
Collapse
Affiliation(s)
- E Olsson
- Department Public Health Sciences, IHCAR, Karolinska Institute, Stockholm, Sweden.
| | | | | | | |
Collapse
|
14
|
Nguyen HA, Tomita T, Hirota M, Kaneko J, Hayashi T, Kamio Y. DNA inversion in the tail fiber gene alters the host range specificity of carotovoricin Er, a phage-tail-like bacteriocin of phytopathogenic Erwinia carotovora subsp. carotovora Er. J Bacteriol 2001; 183:6274-81. [PMID: 11591670 PMCID: PMC100113 DOI: 10.1128/jb.183.21.6274-6281.2001] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Carotovoricin Er is a phage-tail-like bacteriocin produced by Erwinia carotovora subsp. carotovora strain Er, a causative agent for soft rot disease in plants. Here we studied binding and killing spectra of carotovoricin Er preparations for various strains of the bacterium (strains 645Ar, EC-2, N786, and P7) and found that the preparations contain two types of carotovoricin Er with different host specificities; carotovoricin Era possessing a tail fiber protein of 68 kDa killed strains 645Ar and EC-2, while carotovoricin Erb with a tail fiber protein of 76 kDa killed strains N786 and P7. The tail fiber proteins of 68 and 76 kDa had identical N-terminal amino acid sequences for at least 11 residues. A search of the carotovoricin Er region in the chromosome of strain Er indicated the occurrence of a DNA inversion system for the tail fiber protein consisting of (i) two 26-bp inverted repeats inside and downstream of the tail fiber gene that flank a 790-bp fragment and (ii) a putative DNA invertase gene with a 90-bp recombinational enhancer sequence. In fact, when a 1,400-bp region containing the 790-bp fragment was amplified by a PCR using the chromosomal DNA of strain Er as the template, both the forward and the reverse nucleotide sequences of the 790-bp fragment were detected. DNA inversion of the 790-bp fragment also occurred in Escherichia coli DH5alpha when two compatible plasmids carrying either the 790-bp fragment or the invertase gene were cotransformed into the bacterium. Furthermore, hybrid carotovoricin CGE possessing the tail fiber protein of 68 or 76 kDa exhibited a host range specificity corresponding to that of carotovoricin Era or Erb, respectively. Thus, a DNA inversion altered the C-terminal part of the tail fiber protein of carotovoricin Er, altering the host range specificity of the bacteriocin.
Collapse
Affiliation(s)
- H A Nguyen
- Department of Molecular and Cell Biology, Graduate School of Agricultural Science, Tohoku University, 1-1 Tsutsumi-dori Amamiya-machi, Aoba-ku, Sendai 981-8555, Japan
| | | | | | | | | | | |
Collapse
|
15
|
Abstract
We evaluated the behavioral and neural toxicity of the artemisinin antimalarial compound, arteether (AE), using a novel radial-arm maze procedure. We have previously shown that AE can produce a distinctive pattern of neurotoxicity in the brainstem and that auditory nuclei are particularly vulnerable. Thus, we assessed performance which depended upon auditory processing. We trained rats to choose one of eight arms of a radial maze, depending upon which arm served as the source of a white noise stimulus. Correct responses produced food reinforcement while incorrect choices had no programmed consequences. When the task was acquired, AE (25 mg/kg/day; n=7) or oil vehicle (n=7) was administered (intramuscularly) for seven consecutive days. Behavioral sessions were conducted during the days of drug administrations and for 7 days following drug administrations. Subsequently, histopathology was conducted and a quantitative assessment of the nucleus trapezoideus was made. AE produced a progressive deficit in performance on the maze task. That is, accuracy decreased, choice latency increased, and the number of trials completed decreased. Moreover, the greatest deficits were observed during the period following drug administrations. AE-treated rats revealed marked damage in the nucleus trapezoideus. The damage included chromatolysis, necrosis, and gliosis. Vehicle-treated rats did not show performance deficits or neuropathology. These results extend earlier studies and show that AE can produce damage in the n. trapezoideus of rats, which is associated with performance deficits on a complex auditory task. Thus, the auditory radial-arm maze task is a useful tool for assessing AE-induced toxicity.
Collapse
Affiliation(s)
- R F Genovese
- Division of Neurosciences and Pathology, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD 20910-7500, USA.
| | | | | |
Collapse
|
16
|
Affiliation(s)
- H A Nguyen
- Department of Medicine, Veterans Affairs Medical Center and University of Minnesota, MN 55417, USA
| | | |
Collapse
|
17
|
Abstract
Besides a series of known sterols and triterpenoids, 2-methyl-5-(Z-nonadec-14-enyl)resorcinol and 5-(Z-nonadec-14-enyl)resorcinol have been isolated from leaves of Ardisia silvestris. The last mentioned diphenol has also been obtained from roots of Ardisia gigantifolia. The structures of these resorcinol derivatives were elucidated.
Collapse
Affiliation(s)
- H A Nguyen
- Institute of Chemistry, National Centre for Scientific Research of Vietnam, Nghia Do, Tu Liem, Hanoi
| | | | | | | | | | | |
Collapse
|
18
|
Abstract
In the present study, we examined the expression and distribution of both hyaluronan and its cell-surface receptor (CD44) during lung development in the mouse. Hyaluronan was detected by a specific binding probe, termed b-PG, which is a biotinylated mixture of proteoglycan and link protein from cartilage. Using this probe in an enzyme-linked assay, the amount of hyaluronan in relation to protein content was found to decrease as lung development progressed. In addition, histochemical staining of the embryonic lungs revealed that during early stages, relatively large amounts of hyaluronan were present in the interstitium. However, as development progressed, much of this was lost, and in the adult, hyaluronan was restricted to the regions surrounding the major blood vessels, bronchi, and bronchioles. In contrast to hyaluronan, the amount of CD44 increased as a function of development, as determined by the rat monoclonal antibody, KM-201. Histochemical staining with this antibody showed that the receptor was primarily associated with macrophages and to a lesser extent with adult bronchial and bronchiolar epithelium, vascular smooth muscle, and endothelial cells. As development progressed, the macrophages expressing CD44 increased in number, and this increase was temporarily correlated with the decrease in hyaluronan content. In addition, histochemical staining revealed that some of these macrophages contained hyaluronan in their cytoplasm, suggesting that macrophages had internalized hyaluronan from the extracellular matrix. This possibility was further supported by the fact that when newborn mice were injected with the KM-201 monoclonal antibody, which blocks the interaction between hyaluronan and the receptor, the number of hyaluronan-containing macrophages in the lungs decreased while the concentration of hyaluronan increased. Taken together, these results suggest that macrophages can internalize hyaluronan during lung development and could possibly play a significant role in its removal.
Collapse
Affiliation(s)
- C B Underhill
- Department of Anatomy and Cell Biology, Georgetown Medical Center, Washington, DC 20007
| | | | | | | |
Collapse
|
19
|
Abstract
The hyaluronan receptor belongs to the polymorphic family of CD44 glycoproteins, which have been implicated in a variety of cellular functions including adhesion to hyaluronan and collagen, the binding of lymphocytes to high endothelial cells during extravasation, and conferring metastatic potential to carcinoma cells. Here, we demonstrate that the receptor also participates in the uptake and degradation of hyaluronan by both transformed fibroblasts (SV-3T3 cells) and alveolar macrophages. These cells were incubated with isotopically labeled hyaluronan for various periods of time, and the extent of degradation was determined by either molecular-sieve chromatography or centrifugation through Centricon 30 microconcentrators. The macrophages degraded the hyaluronan at a faster rate than the SV-3T3 cells, which may reflect the fact that they contained a greater number of receptors. More importantly, in both cell types, the degradation of hyaluronan was specifically blocked by antibodies directed against the receptor. However, the receptor by itself did not have the ability to degrade hyaluronan, since preparations of SV-3T3 membranes containing the receptor did not break down hyaluronan. Subsequent experiments revealed that macrophages can internalize fluorescein-tagged hyaluronan, and this process was blocked by antibodies against the receptor. Furthermore, the subsequent degradation of hyaluronan was inhibited by agents that block the acidification of lysosomes (chloroquine and NH4Cl). Thus, the most likely explanation for these results is that the receptor mediates the uptake of hyaluronan into the cell where it can be degraded by acid hydrolases in lysosomes. The ability of cells expressing the receptor to degrade hyaluronan may be important during tissue morphogenesis and cell migration.
Collapse
Affiliation(s)
- M Culty
- Department of Anatomy and Cell Biology, Georgetown Medical Center, Washington, DC 20007
| | | | | |
Collapse
|