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Reta MA, Said HM, Maningi NE, Wubetu GY, Agonafir M, Fourie PB. Genetic diversity of Mycobacterium tuberculosis strains isolated from spiritual holy water site attendees in Northwest Ethiopia. A cross-sectional study. New Microbes New Infect 2024; 59:101235. [PMID: 38590765 PMCID: PMC11000200 DOI: 10.1016/j.nmni.2024.101235] [Citation(s) in RCA: 0] [Impact Index Per Article: 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: 10/25/2023] [Revised: 03/04/2024] [Accepted: 03/07/2024] [Indexed: 04/10/2024] Open
Abstract
Background The genetic diversity of Mycobacterium tuberculosis complex (MTBC) strains was characterized among isolates from individuals with pulmonary tuberculosis (PTB) symptoms attended holy water sites (HWSs) in the Amhara region, Ethiopia. Methods A cross-sectional study was done from June 2019 to March 2020 to describe the genetic diversity and drug-resistance profiles of MTBC isolates. Sputum specimens were collected and cultured in the Löwenstein-Jensen culture medium. Line Probe Assay, MTBDRplus VER 2.0, and MTBDRsl VER 2.0 were used to detect first-and second-line anti-TB drug-resistance patterns. A spoligotyping technique was utilized to characterize the genetic diversity. Statistical analysis was performed using STATA 15. Results Of 560 PTB-symptomatic participants, 122 (21.8%) were culture-positive cases. Spoligotyping of 116 isolates revealed diverse MTBC sublineages, with four major lineages: Euro-American (EA) (Lineage 4), East-African-Indian (EAI) (Lineage 3), Ethiopian (ETH) (Lineage 7), East Asian (EA) (Lineage 2). The majority (96.6%) of the isolates were EA (lineage 4) and EAI, with proportions of 54.3% and 42.2%, respectively. A total of 31 spoligotype patterns were identified, 26 of which were documented in the SITVIT2 database. Of these, there were 15 unique spoligotypes, while eleven were grouped with 2-17 isolates. SIT149/T3-ETH (n = 17), SIT26/CAS1-DELHI (n = 16), SIT25/CAS1-DELHI (n = 12), and SIT52/T2 (n = 11) spoligotypes were predominant. A rare spoligotype pattern: SIT41/Turkey and SIT1/Beijing, has also been identified in North Shewa. The overall clustering rate of sub-lineages with known SIT was 76.4%.Of the 122 culture-positive isolates tested, 16.4% were resistant to rifampicin (RIF) and/or isoniazid (INH). Multidrug-resistant TB (MDR-TB) was detected in 12.3% of isolates, five of which were fluoroquinolones (FLQs) resistant. SIT149/T3-ETH and SIT21/CAS1-KILI sublineages showed a higher proportion of drug resistance. Conclusions Diverse MTBC spoligotypes were identified, with the T and CAS families and EA (lineage 4) predominating. A high prevalence of drug-resistant TB, with SIT149/T3-ETH and CAS1-KILI sublineages comprising a greater share, was observed. A study with large sample size and a sequencing method with stronger discriminatory power is warranted to understand better the genetic diversity of circulating MTBC in this cohort of study, which would help to adopt targeted interventions.
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Affiliation(s)
- Melese Abate Reta
- Department of Medical Microbiology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
- Department of Medical Laboratory Science, College of Health Sciences, Woldia University, Woldia, Ethiopia
| | - Halima M. Said
- National Institute for Communicable Diseases (NICD), Centre for Tuberculosis, Johannesburg, South Africa
| | - Nontuthuko Excellent Maningi
- Department of Microbiology, School of Life Sciences, College of Agriculture, Engineering and Science, University of Kwazulu Natal, Durban, South Africa
| | - Gizachew Yismaw Wubetu
- Amhara Public Health Institute (APHI), Bahir Dar, Ethiopia
- Centre for Innovative Drug Development and Therapeutic Trials for Africa (CDT-Africa), College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
| | - Mulualem Agonafir
- Department of Microbial, Cellular and Molecular Biology, Addis Ababa University, Addis Ababa, Ethiopia
| | - P. Bernard Fourie
- Department of Medical Microbiology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
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Nyazema KB, Shey BA, Sei CJ, Peters RP, Maningi NE, Fischer GW, Bernard Fourie P. In vitro evaluation of the binding activity of novel mouse IgG1 opsonic monoclonal antibodies to Mycobacterium tuberculosis and other selected mycobacterial species. J Clin Tuberc Other Mycobact Dis 2024; 35:100435. [PMID: 38601919 PMCID: PMC11004620 DOI: 10.1016/j.jctube.2024.100435] [Citation(s) in RCA: 0] [Impact Index Per Article: 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] [Indexed: 04/12/2024] Open
Abstract
Antimicrobial resistance alongside other challenges in tuberculosis (TB) therapeutics have stirred renewed interest in host-directed interventions, including the role of antibodies as adjunct therapeutic agents. This study assessed the binding efficacy of two novel IgG1 opsonic monoclonal antibodies (MABs; GG9 & JG7) at 5, 10, and 25 µg/mL to live cultures of Mycobacterium tuberculosis, M. avium, M. bovis, M. fortuitum, M. intracellulare, and M. smegmatis American Type Culture Collection laboratory reference strains, as well as clinical susceptible, multi-drug resistant, and extensively drug resistant M. tuberculosis strains using indirect enzyme-linked immunosorbent assays. These three MAB concentrations were selected from a range of concentrations used in previous optimization (binding and functional) assays. Both MABs bound to all mycobacterial species and sub-types tested, albeit to varying degrees. Statistically significant differences in MAB binding activity were observed when comparing the highest and lowest MAB concentrations (p < 0.05) for both MABs GG9 and JG7, irrespective of the M. tuberculosis resistance profile. Binding affinity increased with an increase in MAB concentration, and optimal binding was observed at 25 µg/mL. JG7 showed better binding activity than GG9. Both MABs also bound to five MOTT species, albeit at varied levels. This non-selective binding to different mycobacterial species suggests a potential role for GG9 and JG7 as adjunctive agents in anti-TB chemotherapy with the aim to enhance bacterial killing.
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Affiliation(s)
- Kudzai B. Nyazema
- Department of Medical Microbiology, Faculty of Health Sciences, University of Pretoria, South Africa
| | - Bong-Akee Shey
- Department of Medical Microbiology, Faculty of Health Sciences, University of Pretoria, South Africa
| | - Clara J. Sei
- Vaccine and Antibody Development, Longhorn Vaccines and Diagnostics, Gaithersburg, MD, USA
| | - Remco P.H. Peters
- Department of Medical Microbiology, Faculty of Health Sciences, University of Pretoria, South Africa
- Foundation for Professional Development, Research Unit, East London, South Africa
| | - Nontuthuko E. Maningi
- Department of Medical Microbiology, Faculty of Health Sciences, University of Pretoria, South Africa
- Department of Microbiology, School of Life Sciences, University of KwaZulu-Natal, South Africa
| | - Gerald W. Fischer
- Vaccine and Antibody Development, Longhorn Vaccines and Diagnostics, Gaithersburg, MD, USA
| | - P. Bernard Fourie
- Department of Medical Microbiology, Faculty of Health Sciences, University of Pretoria, South Africa
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Reta MA, Maningi NE, Wubetu GY, Olorunju SAS, Fourie PB. Spiritual Holy Water Sites in Ethiopia: Unrecognized High-Risk Settings for Transmission of Pulmonary Tuberculosis. Int J Microbiol 2024; 2024:3132498. [PMID: 38623557 PMCID: PMC11018379 DOI: 10.1155/2024/3132498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 03/24/2024] [Accepted: 03/28/2024] [Indexed: 04/17/2024] Open
Abstract
Ethiopia is a high-tuberculosis (TB) burden country with 157 new cases per 100,000 people, with 23,800 TB-related deaths in 2020. In Ethiopia, TB patients have different healthcare-seeking behaviors. They frequently visit spiritual places, such as holy water sites (HWSs), to seek treatment for their illness spiritually. This study examined the prevalence of pulmonary TB (PTB) and drug susceptibility profiles of Mycobacterium tuberculosis (MTB) isolates among spiritual HWS attendees in Northwest Ethiopia. A cross-sectional study was conducted from June 2019 to March 2020. Sputum samples were collected, processed, and cultured using Löwenstein-Jensen (LJ) culture medium. Second-generation line probe assays (LPAs), GenoType®MTBDRplus VER2.0 and GenoType®MTBDRsl VER2.0, were used to detect anti-TB drug-resistant isolates. STATA 17 was utilized to perform descriptive statistics, bivariate, and multivariate regression analyses. Of 560 PTB-symptomatic participants, 21.8% ((95% confidence interval (95 CI): 18.4-25.2%)) were culture-positive, resulting in a point prevalence of 1,183/100,000 attendees. Amongst HWS attendees, culture-positive TB occurred most commonly in persons 18-33 years of age (28.5% (95 CI 23.4-34.3%)). Other participant characteristics significantly associated with culture-positive PTB were as follows: rural residents (adjusted odds ratio (aOR) 2.65; 95 CI 1.38-5.10), married participants (aOR 2.43; 95 CI 1.28-4.63), family members >5 per household (aOR 1.84; 95 CI 1.04-3.24), and sharing living space (aOR 10.57; 95 CI 3.60-31.13). Also, among 438 participants followed for 12 months after showing negative TB culture results while at the HWS, 6.8% (95 CI 4.4-9.4%) developed or contracted culture-positive TB post-residency at the HWSs. Of the 122 tested isolates, 20 (16.4%) were isoniazid (INH) and/or rifampicin (RIF) resistant. Multidrug-resistant (MDR) TB was detected in 15 cases (12.3%), five of which were fluoroquinolones (FLQs) resistant. The findings from this study should raise a concern about HWSs as potential high-risk settings for TB transmission. It is recommended that appropriate control measures be instituted that include compulsory TB testing and tightened infection control at HWSs, where an increased risk exists for transmission of TB.
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Affiliation(s)
- Melese Abate Reta
- Research Centre for Tuberculosis and Department of Medical Microbiology, Faculty of Health Sciences, University of Pretoria, Prinshof, Pretoria 0084, South Africa
- Department of Medical Laboratory Science, College of Health Sciences, Woldia University, P.O. Box 400, Woldia, Ethiopia
| | - Nontuthuko Excellent Maningi
- Department of Microbiology, School of Life Sciences, College of Agriculture, Engineering and Science, University of KwaZulu-Natal, Durban, South Africa
| | - Gizachew Yismaw Wubetu
- Amhara Public Health Institute, Bahir Dar, Ethiopia
- Centre for Innovative Drug Development and Therapeutic Trials for Africa (CDT-Africa), College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
| | - Steve A. S. Olorunju
- South African Medical Research Council, Biostatistics Unit, Pretoria, South Africa
| | - P. Bernard Fourie
- Research Centre for Tuberculosis and Department of Medical Microbiology, Faculty of Health Sciences, University of Pretoria, Prinshof, Pretoria 0084, South Africa
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Reta MA, Maningi NE, Fourie PB. Patterns and profiles of drug resistance-conferring mutations in Mycobacterium tuberculosis genotypes isolated from tuberculosis-suspected attendees of spiritual holy water sites in Northwest Ethiopia. Front Public Health 2024; 12:1356826. [PMID: 38566794 PMCID: PMC10985251 DOI: 10.3389/fpubh.2024.1356826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2023] [Accepted: 02/26/2024] [Indexed: 04/04/2024] Open
Abstract
Purpose This study examined the patterns and frequency of genetic changes responsible for resistance to first-line (rifampicin and isoniazid), fluoroquinolones, and second-line injectable drugs in drug-resistant Mycobacterium tuberculosis (MTB) isolated from culture-positive pulmonary tuberculosis (PTB) symptomatic attendees of spiritual holy water sites (HWSs) in the Amhara region. Patients and methods From June 2019 to March 2020, a cross-sectional study was carried out. A total of 122 culture-positive MTB isolates from PTB-suspected attendees of HWSs in the Amhara region were evaluated for their drug resistance profiles, and characterized gene mutations conferring resistance to rifampicin (RIF), isoniazid (INH), fluoroquinolones (FLQs), and second-line injectable drugs (SLIDs) using GenoType®MTBDRplus VER2.0 and GenoType®MTBDRsl VER2.0. Drug-resistant MTB isolates were Spoligotyped following the manufacturer's protocol. Results Genetic changes (mutations) responsible for resistance to RIF, INH, and FLQs were identified in 15/122 (12.3%), 20/122 (16.4%), and 5/20 (25%) of MTB isolates, respectively. In RIF-resistant, rpoB/Ser531Lue (n = 12, 80%) was most frequent followed by His526Tyr (6.7%). Amongst INH-resistant isolates, katG/Ser315Thr1 (n = 19, 95%) was the most frequent. Of 15 MDR-TB, the majority (n = 12, 80%) isolates had mutations at both rpoB/Ser531Leu and katG/Ser315Thr1. All 20 INH and/or RIF-resistant isolates were tested with the MTBDRsl VER 2.0, yielding 5 FLQs-resistant isolates with gene mutations at rpoB/Ser531Lue, katG/Ser315Thr1, and gyrA/Asp94Ala genes. Of 20 Spoligotyped drug-resistant MTB isolates, the majority (n = 11, 55%) and 6 (30%) were SIT149/T3-ETH and SIT21/CAS1-Kili sublineages, respectively; and they were any INH-resistant (mono-hetero/multi-). Of 15 RIF-resistant (RR/MDR-TB) isolates, 7 were SIT149/T3-ETH, while 6 were SIT21/CAS1-Kili sublineages. FLQ resistance was detected in four SIT21/CAS1-Kili lineages. Conclusion In the current study, the most common gene mutations responsible for resistance to INH, RIF, and FLQs were identified. SIT149/T3-ETH and SIT21/CAS1-Kili constitute the majority of drug-resistant TB (DR-TB) isolates. To further understand the complete spectrum of genetic changes/mutations and related genotypes, a sequencing technology is warranted.
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Affiliation(s)
- Melese Abate Reta
- Department of Medical Microbiology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
- Department of Medical Laboratory Science, College of Health Sciences, Woldia University, Woldia, Ethiopia
| | - Nontuthuko Excellent Maningi
- Department of Microbiology, School of Life Sciences, College of Agriculture, Engineering and Science, University of KwaZulu-Natal, Durban, South Africa
| | - P. Bernard Fourie
- Department of Medical Microbiology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
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Agonafir M, Belay G, Maningi NE, Feleke A, Reta MA, Olifant SL, Hassen MS, Girma T, Fourie PB. Genetic diversity of Mycobacterium tuberculosis isolates from the central, eastern and southeastern Ethiopia. Heliyon 2023; 9:e22898. [PMID: 38125463 PMCID: PMC10731068 DOI: 10.1016/j.heliyon.2023.e22898] [Citation(s) in RCA: 0] [Impact Index Per Article: 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: 09/23/2022] [Revised: 11/13/2023] [Accepted: 11/22/2023] [Indexed: 12/23/2023] Open
Abstract
Introduction The population structure of Mycobacterium tuberculosis complex (MTBC) in Ethiopia is diverse but dominated by Euro-American (Lineage 4) and East-African-Indian (Lineage 3) lineages. The objective of this study was to describe the genetic diversity of MTBC isolates in Central, Eastern and Southeastern Ethiopia. Methods A total of 223 MTBC culture isolates obtained from patients referred to Adama and Harar TB reference laboratories were spoligotyped. Demographic and clinical characteristics were collected. Results Six major lineages: Euro-American (Lineage 4), East-African-Indian (Lineage 3), East Asian (Lineage 2), Indo-Oceanic (Lineage 1), Mycobacterium africanum (Lineage 5 and Lineage 6) and Ethiopian (Lineage 7) were identified. The majority (94.6 %) of the isolates were Euro-American and East-African-Indian, with proportions of 75.3 % and 19.3 %, respectively. Overall, 77 different spoligotype patterns were identified of which 42 were registered in the SITVIT2 database. Of these, 27 spoligotypes were unique, while 15 were clustered with 2-49 isolates. SIT149/T3_ETH (n = 49), SIT53/T1 (n = 33), SIT21/CAS1_Kili (n = 24) and SIT41/Turkey (n = 11) were the dominant spoligotypes. A rare Beijing spoligotype pattern, SIT541, has also been identified in Eastern Ethiopia. The overall clustering rate of sub-lineages with known SIT was 71.3 %. Age group (25-34) was significantly associated with clustering. Conclusion We found a heterogeneous population structure of MTBC dominated by T and CAS families, and the Euro-American lineage. The identification of the Beijing strain, particularly the rare SIT541 spoligotype in Eastern Ethiopia, warrants a heightened surveillance plan, as little is known about this genotype. A large-scale investigation utilizing a tool with superior discriminatory power, such as whole genome sequencing, is necessary to gain a thorough understanding of the genetic diversity of MTBC in the nation, which would help direct the overall control efforts.
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Affiliation(s)
- Mulualem Agonafir
- Department of Microbial, Cellular and Molecular Biology, College of Natural Sciences, Addis Ababa University, Ethiopia
| | - Gurja Belay
- Department of Microbial, Cellular and Molecular Biology, College of Natural Sciences, Addis Ababa University, Ethiopia
| | - Nontuthuko E. Maningi
- Department of Medical Microbiology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Adey Feleke
- Department of Microbial, Cellular and Molecular Biology, College of Natural Sciences, Addis Ababa University, Ethiopia
| | - Melese Abate Reta
- Department of Medical Microbiology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
- Department of Medical Laboratory Sciences, College of Health Sciences, Woldia University, Woldia, Ethiopia
| | - Sharon L. Olifant
- Department of Medical Microbiology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | | | - Tewodros Girma
- Harar Health Research and Regional Laboratory, Harar, Ethiopia
| | - P. Bernard Fourie
- Department of Medical Microbiology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
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Mensah E, Fourie PB, Peters RPH. Antimicrobial effects of Medicines for Malaria Venture Pathogen Box compounds on strains of Neisseria gonorrhoeae. Antimicrob Agents Chemother 2023; 67:e0034823. [PMID: 37791750 PMCID: PMC10648949 DOI: 10.1128/aac.00348-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 08/02/2023] [Indexed: 10/05/2023] Open
Abstract
Therapeutic options for Neisseria gonorrhoeae are limited due to emerging global resistance. New agents and treatment options to treat patients with susceptible and multi-extensively drug-resistant N. gonorrhoeae is a high priority. This study used an in vitro approach to explore the antimicrobial potential, as well as synergistic effects of Medicine for Malaria Venture (MMV) Pathogen Box compounds against ATCC and clinical N. gonorrhoeae strains. Microbroth dilution assay was used to determine pathogen-specific minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the Pathogen Box compounds against susceptible and resistant N. gonorrhoeae strains, with modification, by adding PrestoBlue HS Cell Viability Reagent. A checkerboard assay was used to determine synergy between the active compounds and in conjunction with ceftriaxone. Time-kill kinetics was performed to determine if the compounds were either bactericidal or bacteriostatic. The Pathogen Box compounds: MMV676501, MMV002817, MMV688327, MMV688508, MMV024937, MMV687798 (levofloxacin), MMV021013, and MMV688978 (auranofin) showed potent activity against resistant strains of N. gonorrhoeae at an MIC and MBC of ≤10 µM. Besides the eight compounds, MMV676388 and MMV272144 were active against susceptible N. gonorrhoeae strains, also at MIC and MBC of ≤10 µM. All the compounds were bactericidal and were either synergistic or additive with fractional inhibitory concentration index ranging between 0.40 and 1.8. The study identified novel Pathogen Box compounds with potent activity against N. gonorrhoeae strains and has the potential to be further investigated as primary or adjunctive therapy to treat gonococcal infections.
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Affiliation(s)
- Eric Mensah
- Department of Medical Microbiology, University of Pretoria, Pretoria, South Africa
| | - P. Bernard Fourie
- Department of Medical Microbiology, University of Pretoria, Pretoria, South Africa
| | - Remco P. H. Peters
- Department of Medical Microbiology, University of Pretoria, Pretoria, South Africa
- Foundation for Professional Development, Research Unit, East London, South Africa
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Agonafir M, Belay G, Feleke A, Maningi N, Girmachew F, Reta M, Fourie PB. Profile and Frequency of Mutations Conferring Drug-Resistant Tuberculosis in the Central, Southeastern and Eastern Ethiopia. Infect Drug Resist 2023; 16:2953-2961. [PMID: 37201127 PMCID: PMC10187580 DOI: 10.2147/idr.s408567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 05/05/2023] [Indexed: 05/20/2023] Open
Abstract
Purpose Advances in molecular tools that assess genes harboring drug resistance mutations have greatly improved the detection and treatment of drug-resistant tuberculosis (DR-TB). This study was conducted to determine the frequency and type of mutations that are responsible for resistance to rifampicin (RIF), isoniazid (INH), fluoroquinolones (FLQs) and second-line injectable drugs (SLIDs) in Mycobacterium tuberculosis (MTB) isolates obtained from culture-positive pulmonary tuberculosis (TB) patients in the central, southeastern and eastern Ethiopia. Patients and Methods In total, 224 stored culture-positive MTB isolates from pulmonary TB patients referred to Adama and Harar regional TB laboratories between August 2018 and January 2019 were assessed for mutations conferring RIF, INH, FLQs and SLIDs resistance using GenoType®MTBDRplus (MTBDRplus) and GenoType®MTBDRsl (MTBDRsl). Results RIF, INH, FLQs and SLIDs resistance-conferring mutations were identified in 88/224 (39.3%), 85/224 (38.0%), 7/77 (9.1%), and 3/77% (3.9%) of MTB isolates, respectively. Mutation codons rpoB S531L (59.1%) for RIF, katG S315T (96.5%) for INH, gyrA A90V (42.1%) for FLQs and WT1 rrs (100%) for SLIDs were observed in the majority of the isolates tested. Over a 10th of rpoB mutations detected in the current study were unknown. Conclusion In this study, the most common mutations conferring drug resistance to RIF, INH, FLQs were identified. However, a significant proportion of RIF-resistant isolates manifested unknown rpoB mutations. Similarly, although few in number, all SLID-resistant isolates had unknown rrs mutations. To further elucidate the entire spectrum of mutations, tool such as whole-genome sequencing is imperative. Furthermore, the expansion of molecular drug susceptibility testing services is critical for tailoring patient treatment and preventing disease transmission.
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Affiliation(s)
- Mulualem Agonafir
- Department of Microbial, Cellular and Molecular Biology, College of Natural and Computational Sciences, Addis Ababa University, Addis Ababa, Ethiopia
- Correspondence: Mulualem Agonafir, Department of Microbial, Cellular and Molecular Biology, College of Natural and Computational Sciences, Addis Ababa University, P.O. Box 34738, Addis Ababa, Ethiopia, Tel +251911446959, Email
| | - Gurja Belay
- Department of Microbial, Cellular and Molecular Biology, College of Natural and Computational Sciences, Addis Ababa University, Addis Ababa, Ethiopia
| | - Adey Feleke
- Department of Microbial, Cellular and Molecular Biology, College of Natural and Computational Sciences, Addis Ababa University, Addis Ababa, Ethiopia
| | - Nontuthuko Maningi
- Department of Medical Microbiology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | | | - Melese Reta
- Department of Medical Microbiology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
- Department of Medical Laboratory Sciences, College of Health Sciences, Woldia University, Woldia, Ethiopia
| | - P Bernard Fourie
- Department of Medical Microbiology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
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Reta MA, Tamene BA, Abate BB, Mensah E, Maningi NE, Fourie PB. Mycobacterium tuberculosis Drug Resistance in Ethiopia: An Updated Systematic Review and Meta-Analysis. Trop Med Infect Dis 2022; 7:tropicalmed7100300. [PMID: 36288041 PMCID: PMC9611116 DOI: 10.3390/tropicalmed7100300] [Citation(s) in RCA: 6] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 09/10/2022] [Accepted: 09/20/2022] [Indexed: 11/07/2022] Open
Abstract
Background: Tuberculosis (TB) remains a significant global public health issue, despite advances in diagnostic technologies, substantial global efforts, and the availability of effective chemotherapies. Mycobacterium tuberculosis, a species of pathogenic bacteria resistant to currently available anti-TB drugs, is on the rise, threatening national and international TB-control efforts. This systematic review and meta-analysis aims to estimate the pooled prevalence of drug-resistant TB (DR-TB) in Ethiopia. Materialsand Methods: A systematic literature search was undertaken using PubMed/MEDLINE, HINARI, the Web of Science, ScienceDirect electronic databases, and Google Scholar (1 January 2011 to 30 November 2020). After cleaning and sorting the records, the data were analyzed using STATA 11. The study outcomes revealed the weighted pooled prevalence of any anti-tuberculosis drug resistance, any isoniazid (INH) and rifampicin (RIF) resistance, monoresistance to INH and RIF, and multidrug-resistant TB (MDR-TB) in newly diagnosed and previously treated patients with TB. Results: A total of 24 studies with 18,908 patients with TB were included in the final analysis. The weighted pooled prevalence of any anti-TB drug resistance was 14.25% (95% confidence interval (CI): 7.05–21.44%)), whereas the pooled prevalence of any INH and RIF resistance was found in 15.62% (95%CI: 6.77–24.47%) and 9.75% (95%CI: 4.69–14.82%) of patients with TB, respectively. The pooled prevalence for INH and RIF-monoresistance was 6.23% (95%CI: 4.44–8.02%) and 2.33% (95%CI: 1.00–3.66%), respectively. MDR-TB was detected in 2.64% (95%CI: 1.46–3.82%) of newly diagnosed cases and 11.54% (95%CI: 2.12–20.96%) of retreated patients with TB, while the overall pooled prevalence of MDR-TB was 10.78% (95%CI: 4.74–16.83%). Conclusions: In Ethiopia, anti-tuberculosis drug resistance is widespread. The estimated pooled prevalence of INH and RIF-monoresistance rates were significantly higher in this review than in previous reports. Moreover, MDR-TB in newly diagnosed cases remained strong. Thus, early detection of TB cases, drug-resistance testing, proper and timely treatment, and diligent follow-up of TB patients all contribute to the improvement of DR-TB management and prevention. Besides this, we urge that a robust, routine laboratory-based drug-resistance surveillance system be implemented in the country.
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Affiliation(s)
- Melese Abate Reta
- Department of Medical Microbiology, Faculty of Health Sciences, University of Pretoria, Prinshof 0084, South Africa
- Department of Medical Laboratory Science, College of Health Sciences, Woldia University, Woldia P.O. Box 400, Ethiopia
- Correspondence:
| | - Birhan Alemnew Tamene
- Department of Medical Laboratory Science, College of Health Sciences, Woldia University, Woldia P.O. Box 400, Ethiopia
| | - Biruk Beletew Abate
- Department of Nursing, College of Health Sciences, Woldia University, Woldia P.O. Box 400, Ethiopia or
| | - Eric Mensah
- Department of Medical Microbiology, Faculty of Health Sciences, University of Pretoria, Prinshof 0084, South Africa
| | - Nontuthuko Excellent Maningi
- Department of Microbiology, School of Life Sciences, College of Agriculture, Engineering and Science, University of Kwazulu Natal, Durban 4041, South Africa
| | - P. Bernard Fourie
- Department of Medical Microbiology, Faculty of Health Sciences, University of Pretoria, Prinshof 0084, South Africa
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Reta MA, Alemnew B, Abate BB, Fourie PB. Prevalence of drug resistance-conferring mutations associated with isoniazid- and rifampicin-resistant Mycobacterium tuberculosis in Ethiopia: a systematic review and meta-analysis. J Glob Antimicrob Resist 2021; 26:207-218. [PMID: 34214698 DOI: 10.1016/j.jgar.2021.06.009] [Citation(s) in RCA: 3] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 05/26/2021] [Accepted: 06/06/2021] [Indexed: 10/21/2022] Open
Abstract
OBJECTIVES Globally, the incidence and mortality of tuberculosis (TB) are declining; however, low detection of drug-resistant disease threatens to reverse current progress toward global TB control. Multiple rapid molecular diagnostic tests have recently been developed to detect genetic mutations in Mycobacterium tuberculosis (Mtb) known to confer drug resistance. However, their utility depends on the frequency and distribution of resistance-associated mutations in the pathogen population. This review aimed to assess the prevalence of gene mutations associated with rifampicin (RIF)- and isoniazid (INH)-resistant Mtb in Ethiopia. METHODS We searched the literature in PubMed/MEDLINE, Web of Science, Scopus and Cochrane Library. Data analysis was conducted in Stata 11. RESULTS Totally, 909 (95.8%) of 949 INH-resistant Mtb isolates had detectable gene mutations: 95.8% in katG315 and 5.9% in the inhA promoter region. Meta-analysis resulted in an estimated pooled prevalence of katGMUT1(S315T1) of 89.2% (95% CI 81.94-96.43%) and a pooled prevalence of inhAMUT1(C15T) of 77.5% (95% CI 57.84-97.13%). Moreover, 769 (90.8%) of 847 RIF-resistant strains had detectable rpoB gene mutations. Meta-analysis resulted in a pooled prevalence of rpoBMUT3(S531L) of 74.2% (95% CI 66.39-82.00%). CONCLUSION RIF-resistant Mtb were widespread, particularly those harbouring rpoB(S531L) mutation. Similarly, INH-resistant Mtb with katG(S315T1) and inhA(C15T) mutations were common. Tracking S531L, S315T1 and C15T mutations among RIF- and INH-resistant isolates, respectively, would be diagnostically and epidemiologically valuable. Rapid diagnosis of RIF- and INH-resistant Mtb would expedite modification of TB treatment regimens, and proper timely infection control interventions could reduce the risk of development and transmission of multidrug-resistant TB.
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Affiliation(s)
- Melese Abate Reta
- Department of Medical Microbiology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa; Department of Medical Laboratory Sciences, College of Health Sciences, Woldia University, Woldia, Ethiopia.
| | - Birhan Alemnew
- Department of Medical Laboratory Sciences, College of Health Sciences, Woldia University, Woldia, Ethiopia
| | - Biruk Beletew Abate
- Department of Nursing, College of Health Sciences, Woldia University, Woldia, Ethiopia
| | - P Bernard Fourie
- Department of Medical Microbiology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
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Mboneni TA, Eales OO, Mosina NL, Fourie PB. Molecular detection of Mycobacterium tuberculosis in poor-quality cough specimens. J Med Microbiol 2020; 69:1179-1182. [PMID: 32755530 DOI: 10.1099/jmm.0.001239] [Citation(s) in RCA: 0] [Impact Index Per Article: 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] [Indexed: 11/18/2022] Open
Abstract
Clinical specimens unfit for laboratory processing represent missed opportunities for diagnosing tuberculosis. Poor-quality cough specimens (n=61) from presumptive tuberculosis cases were cultured and GeneXpert MTB/RIF (Xpert) successfully performed on samples transferred by flocked swab into PrimeStore molecular transport medium (PS-MTM). Mycobacterium tuberculosis was grown in culture from 13 (21.3 %) and Xpert reported 15 (24.2 %) positive, of which 10 concordant. RT-PCR of PS-MTM samples showed enhanced sensitivity; three positives were missed by Xpert, five by culture and three more detected for a total of 21 positives (34.4 %).
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Affiliation(s)
- Tondani A Mboneni
- Department of Medical Microbiology, University of Pretoria, Pretoria, South Africa
| | - Owen O Eales
- Department of Family Medicine, University of Pretoria, Pretoria, South Africa
| | - Ntsoaki L Mosina
- Department of Genetics, University of Pretoria, Pretoria, South Africa
| | - P Bernard Fourie
- Department of Medical Microbiology, University of Pretoria, Pretoria, South Africa
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11
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Ongole JJ, Rossouw TM, Fourie PB, Stoltz AC, Hugo J, Marcus TS. Sustaining essential healthcare in Africa during the COVID-19 pandemic. Int J Tuberc Lung Dis 2020; 24:643-645. [PMID: 32553005 DOI: 10.5588/ijtld.20.0214] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
| | | | | | - A C Stoltz
- Division of Infectious Diseases, Department of Internal Medicine, University of Pretoria, Pretoria, South Africa, ,
| | - J Hugo
- Departments of Family Medicine
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Sei CJ, Shey BA, Schuman RF, Rikhi N, Muema K, Rodriguez JD, Daum LT, Fourie PB, Fischer GW. Erratum to “Opsonic monoclonal antibodies enhance phagocytic killing activity and clearance of Mycobacterium tuberculosis from blood in a quantitative qPCR mouse model” [Heliyon 5 (9), (September 2019), e02260]. Heliyon 2019; 5:e02627. [PMID: 31720450 PMCID: PMC6838979 DOI: 10.1016/j.heliyon.2019.e02627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Accepted: 10/07/2019] [Indexed: 11/24/2022] Open
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13
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Sei CJ, Shey BA, Schuman RF, Rikhi N, Muema K, Rodriguez JD, Daum LT, Fourie PB, Fischer GW. Opsonic monoclonal antibodies enhance phagocytic killing activity and clearance of Mycobacterium tuberculosis from blood in a quantitative qPCR mouse model. Heliyon 2019; 5:e02260. [PMID: 31517107 PMCID: PMC6734336 DOI: 10.1016/j.heliyon.2019.e02260] [Citation(s) in RCA: 0] [Impact Index Per Article: 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: 06/14/2019] [Revised: 07/26/2019] [Accepted: 08/05/2019] [Indexed: 11/29/2022] Open
Abstract
Background Patients with impaired immunity often have rapid progression of tuberculosis (TB) which can lead to highly lethal Mycobacterium tuberculosis (MTB) sepsis. Opsonic monoclonal antibodies (MABs) directed against MTB that enhance phagocytic killing activity and clearance of MTB from blood may be useful to enhance TB immunity. Methods BALB/c mice were immunized with ethanol-killed MTB (EK-MTB) and MABs were produced and screened by ELISA for binding to killed and live Mycobacterium smegmatis (SMEG) and MTB. MAB opsonophagocytic killing activity (OPKA) was examined using SMEG with HL60 and U-937 cells and MTB with U-937 cells. Clearance of MTB from blood was evaluated in Institute of Cancer Research (ICR) mice given opsonic anti-MTB MABs or saline (control) 24 h prior to intravenous infusion with 108 CFUs gamma-irradiated MTB (HN878). MTB levels in murine blood collected 0.25, 4 and 24 h post-challenge were assessed by qPCR. MAB binding to peptidoglycan (PGN) was examined by ELISA using PGN cell wall mixture and ultra-pure PGN. Results Two MABs (GG9 and JG7) bound to killed and live SMEG and MTB (susceptible and resistant), and promoted OPKA with live MTB. MAB JG7 significantly enhanced OPKA of MTB. Both MABs significantly enhanced clearance of killed MTB from murine blood at 4 and 24 h as measured by qPCR. These opsonic MABs bound to PGN, a major cell wall constituent. Conclusions Anti-MTB MABs that promote bactericidal phagocytic activity of MTB and enhance clearance of killed MTB from the blood, may offer an immunotherapeutic approach for treatment of MTB bacteremia or sepsis, and augment treatment of multi-drug resistant (MDR) or extensively drug resistant (XDR) TB.
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Affiliation(s)
- Clara J Sei
- Longhorn Vaccines and Diagnostics, Gaithersburg, MD, 20878, USA
| | - Bong-Akee Shey
- Department of Medical Microbiology, University of Pretoria, Prinshof, Pretoria, South Africa
| | | | - Nimisha Rikhi
- Longhorn Vaccines and Diagnostics, Gaithersburg, MD, 20878, USA
| | - Kevin Muema
- Longhorn Vaccines and Diagnostics, Gaithersburg, MD, 20878, USA
| | | | - Luke T Daum
- Longhorn Vaccines and Diagnostics, San Antonio, TX, 78209, USA
| | - P Bernard Fourie
- Department of Medical Microbiology, University of Pretoria, Prinshof, Pretoria, South Africa
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14
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Daum LT, Fourie PB, Peters RPH, Rodriguez JD, Worthy SA, Khubbar M, Bhattacharyya S, Gradus MS, Mboneni T, Marubini EE, Helm C, Chambers JP, Fischer GW. Xpert(®) MTB/RIF detection of Mycobacterium tuberculosis from sputum collected in molecular transport medium. Int J Tuberc Lung Dis 2018; 20:1118-24. [PMID: 27393549 DOI: 10.5588/ijtld.15.0990] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The Xpert(®) MTB/RIF assay is widely used for Mycobacterium tuberculosis detection. However, specimen transport remains a challenge. PrimeStore Molecular Transport Medium(®) (PS-MTM) inactivates specimens and stabilizes DNA/RNA at ambient temperature for subsequent molecular detection. OBJECTIVE To compare the detection of M. tuberculosis concentrations in PS-MTM using Xpert and real-time polymerase chain reaction (RT-PCR), and smear-positive sputum specimens collected using a flocked swab. METHODS Dilutions of M. tuberculosis in PS-MTM and phosphate buffered saline (PBS) were analyzed using the Xpert assay and commercial RT-PCR. Smear-positive (1+ to 3+) sputum specimens (n = 17) were transferred by flocked swab into PS-MTM and PBS, and were compared to standard 1.0 ml sputum Xpert analysis. RESULTS Using the Xpert assay, cycle threshold values from high M. tuberculosis concentrations in PS-MTM (>10(3) colony forming units [cfu]/ml) were increased compared to control. In contrast, M. tuberculosis samples containing <10(3) cfu/ml, i.e., low concentrations, suspended in PS-MTM resulted in detection down to 10 cfu/ml. Xpert detection efficiency in PS-MTM treated samples (63.2%) was improved compared to PBS controls (34.9%). Xpert detected M. tuberculosis in all sputum specimens collected by flocked swabs in PS-MTM, and correlated with routine Xpert detection. CONCLUSIONS PS-MTM enhances M. tuberculosis detection at low concentrations of M. tuberculosis, and provides a simplified and efficient collection method for Xpert detection.
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Affiliation(s)
- L T Daum
- Longhorn Vaccines and Diagnostics, San Antonio, Texas, USA
| | - P B Fourie
- University of Pretoria, Pretoria, South Africa
| | - R P H Peters
- University of Pretoria, Pretoria, Anova Health Institute, Johannesburg, South Africa
| | - J D Rodriguez
- Longhorn Vaccines and Diagnostics, San Antonio, Texas, USA
| | - S A Worthy
- Longhorn Vaccines and Diagnostics, San Antonio, Texas, USA
| | - M Khubbar
- City of Milwaukee Health Department Laboratory, Milwaukee, Wisconsin, USA
| | - S Bhattacharyya
- City of Milwaukee Health Department Laboratory, Milwaukee, Wisconsin, USA
| | - M S Gradus
- City of Milwaukee Health Department Laboratory, Milwaukee, Wisconsin, USA
| | - T Mboneni
- University of Pretoria, Pretoria, South Africa
| | | | - C Helm
- Longhorn Vaccines and Diagnostics, San Antonio, Texas, USA
| | - J P Chambers
- University of Texas at San Antonio, San Antonio, Texas, USA
| | - G W Fischer
- Longhorn Vaccines and Diagnostics, San Antonio, Texas, USA
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15
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Omar SV, Peters RPH, Ismail NA, Jonkman K, Dreyer AW, Said HM, Gwala T, Ismail N, Fourie PB. Field evaluation of a novel preservation medium to transport sputum specimens for molecular detection of Mycobacterium tuberculosis in a rural African setting. Trop Med Int Health 2016; 21:776-82. [PMID: 27098085 DOI: 10.1111/tmi.12701] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVES To assess the performance of an innovative method of transporting sputum to centralised facilities for molecular detection of Mycobacterium tuberculosis: using a swab to inoculate sputum in a transport medium, PrimeStore(®) Molecular Transport Medium (PS-MTM). METHODS Two sputum specimens were obtained from suspected patients with tuberculosis (TB) at rural healthcare facilities in South Africa. A swab was taken from each specimen and placed into PS-MTM, prior to it being processed by either liquid culture or Xpert MTB/RIF assay (Xpert). RESULTS A total of 141 patients (including 47 with laboratory-confirmed TB) were included in this analysis. M. tuberculosis was detected at 29% by culture and 29% by Xpert, whereas 31% tested positive by IS6110 real-time PCR of PS-MTM from the culture and 36% from the Xpert-paired specimen. Concordance between the method under evaluation with culture was 82% (McNemar, P = 0.55) and 84% (McNemar, P = 0.05) for Xpert. Stratified by culture result, the detection rate by IS6110 real-time PCR of PS-MTM was similar to Xpert for patients with positive culture (P = 0.32), but significantly higher if culture was negative (P = 0.008). CONCLUSIONS These results suggest that swab collection of sputum into PS-MTM for transport is a promising method for diagnosis of TB in rural healthcare settings, thereby potentially improving the options available for molecular diagnosis of TB in countries incapable of applying decentralised high-tech molecular testing.
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Affiliation(s)
- Shaheed V Omar
- Department of Medical Microbiology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa.,Centre for Tuberculosis, National TB Reference Laboratory, National Institute for Communicable Diseases, National Health Laboratory Service, Johannesburg, South Africa
| | - Remco P H Peters
- Department of Medical Microbiology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa.,Anova Health Institute, Johannesburg, South Africa
| | - Nazir A Ismail
- Department of Medical Microbiology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa.,Centre for Tuberculosis, National TB Reference Laboratory, National Institute for Communicable Diseases, National Health Laboratory Service, Johannesburg, South Africa
| | | | - Andries W Dreyer
- Centre for Tuberculosis, National TB Reference Laboratory, National Institute for Communicable Diseases, National Health Laboratory Service, Johannesburg, South Africa
| | - Halima M Said
- Centre for Tuberculosis, National TB Reference Laboratory, National Institute for Communicable Diseases, National Health Laboratory Service, Johannesburg, South Africa
| | - Thabisile Gwala
- Centre for Tuberculosis, National TB Reference Laboratory, National Institute for Communicable Diseases, National Health Laboratory Service, Johannesburg, South Africa
| | - Nabila Ismail
- Centre for Tuberculosis, National TB Reference Laboratory, National Institute for Communicable Diseases, National Health Laboratory Service, Johannesburg, South Africa
| | - P Bernard Fourie
- Department of Medical Microbiology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
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16
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Hennig S, Svensson EM, Niebecker R, Fourie PB, Weiner MH, Bonora S, Peloquin CA, Gallicano K, Flexner C, Pym A, Vis P, Olliaro PL, McIlleron H, Karlsson MO. Population pharmacokinetic drug-drug interaction pooled analysis of existing data for rifabutin and HIV PIs. J Antimicrob Chemother 2016; 71:1330-40. [PMID: 26832753 DOI: 10.1093/jac/dkv470] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 12/04/2015] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVES Extensive but fragmented data from existing studies were used to describe the drug-drug interaction between rifabutin and HIV PIs and predict doses achieving recommended therapeutic exposure for rifabutin in patients with HIV-associated TB, with concurrently administered PIs. METHODS Individual-level data from 13 published studies were pooled and a population analysis approach was used to develop a pharmacokinetic model for rifabutin, its main active metabolite 25-O-desacetyl rifabutin (des-rifabutin) and drug-drug interaction with PIs in healthy volunteers and patients who had HIV and TB (TB/HIV). RESULTS Key parameters of rifabutin affected by drug-drug interaction in TB/HIV were clearance to routes other than des-rifabutin (reduced by 76%-100%), formation of the metabolite (increased by 224% in patients), volume of distribution (increased by 606%) and distribution to the peripheral compartment (reduced by 47%). For des-rifabutin, clearance was reduced by 35%-76% and volume of distribution increased by 67%-240% in TB/HIV. These changes resulted in overall increased exposure to rifabutin in TB/HIV patients by 210% because of the effects of PIs and 280% with ritonavir-boosted PIs. CONCLUSIONS Given together with non-boosted or ritonavir-boosted PIs, rifabutin at 150 mg once daily results in similar or higher exposure compared with rifabutin at 300 mg once daily without concomitant PIs and may achieve peak concentrations within an acceptable therapeutic range. Although 300 mg of rifabutin every 3 days with boosted PI achieves an average equivalent exposure, intermittent doses of rifamycins are not supported by current guidelines.
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Affiliation(s)
- Stefanie Hennig
- School of Pharmacy, University of Queensland, Brisbane, Australia Department of Pharmaceutical Bioscience, Uppsala University, Uppsala, Sweden
| | - Elin M Svensson
- Department of Pharmaceutical Bioscience, Uppsala University, Uppsala, Sweden
| | - Ronald Niebecker
- Department of Pharmaceutical Bioscience, Uppsala University, Uppsala, Sweden
| | - P Bernard Fourie
- Department of Medical Microbiology, University of Pretoria, Pretoria, South Africa
| | - Marc H Weiner
- Department of Medicine, University of Texas Health Science Center and Veterans Administration Medical Center, San Antonio, TX, USA
| | - Stefano Bonora
- Unit of Infectious Diseases, Department of Medical Sciences, University of Torino, Torino, Italy
| | - Charles A Peloquin
- College of Pharmacy and Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA
| | | | - Charles Flexner
- Johns Hopkins Adult AIDS Clinical Trials Unit, Division of Clinical Pharmacology, Baltimore, MD, USA
| | - Alex Pym
- Tuberculosis Research Unit, Medical Research Council and KwaZulu-Natal Research Institute for Tuberculosis and HIV (K-RITH), Durban, South Africa
| | - Peter Vis
- Janssen Infectious Diseases BVBA, Beerse, Belgium
| | - Piero L Olliaro
- Special Programme for Research and Training in Tropical Diseases (TDR), World Health Organization (WHO), Geneva, Switzerland
| | - Helen McIlleron
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Mats O Karlsson
- Department of Pharmaceutical Bioscience, Uppsala University, Uppsala, Sweden
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Daum LT, Peters RPH, Fourie PB, Jonkman K, Worthy SA, Rodriguez JD, Ismail NA, Omar SV, Fischer GW. Molecular detection of Mycobacterium tuberculosis from sputum transported in PrimeStore(®) from rural settings. Int J Tuberc Lung Dis 2016; 19:552-7. [PMID: 25868023 DOI: 10.5588/ijtld.14.0769] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
SETTING Mopani District, South Africa. OBJECTIVE To explore remote, molecular detection of Mycobacterium tuberculosis from sputum transported using PrimeStore(®) Molecular Transport Medium (PS-MTM) compared to settings where microscopy or Xpert(®) MTB/RIF is used as the baseline test. DESIGN Two sputum specimens were collected from patients with cough of ⩾ 2 weeks at clinics in rural South Africa. Shortly after expectoration and before processing using Xpert, microscopy and liquid culture, a flocked swab was swirled in each of these specimens and placed in PS-MTM. Swabs were stored and transported to the United States at ambient temperature for real-time PrimeMix(®) polymerase chain reaction (PM-PCR). RESULTS Of 132 patients, 23 (17%) were positive on microscopy, 39 (30%) on Xpert and 44 (33%) by PS-MTM/PM-PCR. Concordance of PS-MTM/PM-PCR with positive microscopy and Xpert was respectively 96% and 85%. Of 107 microscopy-negative samples, 22 (21%) were positive using PS-MTM/PM-PCR, while 11/91 (12%) Xpert-negative samples were PS-MTM/PM-PCR-positive. PS-MTM/PM-PCR positivity was significantly higher than smear microscopy positivity (P < 0.001), but similar to Xpert (P = 0.33). CONCLUSION PCR testing of specimens transported in PS-MTM would enhance TB diagnosis in settings where smear microscopy is the baseline diagnostic test, and could provide an alternative in settings where Xpert testing is not available.
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Affiliation(s)
- L T Daum
- Longhorn Vaccines & Diagnostics, San Antonio, Texas, USA
| | - R P H Peters
- Anova Health Institute, Johannesburg, South Africa; Department of Medical Microbiology, University of Pretoria, South Africa; Department of Medical Microbiology, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - P B Fourie
- Department of Medical Microbiology, University of Pretoria, South Africa
| | - K Jonkman
- Anova Health Institute, Johannesburg, South Africa
| | - S A Worthy
- Longhorn Vaccines & Diagnostics, San Antonio, Texas, USA
| | - J D Rodriguez
- Longhorn Vaccines & Diagnostics, San Antonio, Texas, USA
| | - N A Ismail
- National Institute for Communicable Diseases, National TB Reference Laboratory, Sandringham, South Africa
| | - S V Omar
- National Institute for Communicable Diseases, National TB Reference Laboratory, Sandringham, South Africa
| | - G W Fischer
- Longhorn Vaccines & Diagnostics, San Antonio, Texas, USA
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Rustomjee R, Lockhart S, Shea J, Fourie PB, Hindle Z, Steel G, Hussey G, Ginsberg A, Brennan MJ. Novel licensure pathways for expeditious introduction of new tuberculosis vaccines: A discussion of the adaptive licensure concept. Tuberculosis (Edinb) 2014; 94:178-82. [DOI: 10.1016/j.tube.2013.11.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Revised: 11/06/2013] [Accepted: 11/07/2013] [Indexed: 10/25/2022]
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20
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Daum LT, Fourie PB, Bhattacharyya S, Ismail NA, Gradus S, Maningi NE, Omar SV, Fischer GW. Next-generation sequencing for identifying pyrazinamide resistance in Mycobacterium tuberculosis. Clin Infect Dis 2013; 58:903-4. [PMID: 24336821 DOI: 10.1093/cid/cit811] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Luke T Daum
- Longhorn Vaccines and Diagnostics, San Antonio, Texas
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21
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Hickey AJ, Misra A, Fourie PB. Dry Powder Antibiotic Aerosol Product Development: Inhaled Therapy for Tuberculosis. J Pharm Sci 2013; 102:3900-7. [DOI: 10.1002/jps.23705] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2013] [Accepted: 07/24/2013] [Indexed: 11/12/2022]
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22
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Lewis JJ, Chihota VN, van der Meulen M, Fourie PB, Fielding KL, Grant AD, Dorman SE, Churchyard GJ. "Proof-of-concept" evaluation of an automated sputum smear microscopy system for tuberculosis diagnosis. PLoS One 2012; 7:e50173. [PMID: 23209666 PMCID: PMC3510232 DOI: 10.1371/journal.pone.0050173] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Accepted: 10/22/2012] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND "TBDx" is an innovative smear microscopy system that automatically loads slides onto a microscope, focuses and digitally captures images and then classifies smears as positive or negative using computerised algorithms. OBJECTIVES To determine the diagnostic accuracy of TBDx, using culture as the gold standard, and compare this to a microscopist's diagnostic performance. METHODS This study is nested within a cross-sectional study of tuberculosis suspects from South African gold mines. All tuberculosis suspects had one sputum sample collected, which was decontaminated prior to smear microscopy, liquid culture and organism identification. All slides were auramine-stained and then read by both a research microscopist and by TBDx using fluorescence microscopes, classifying slides based on the WHO classification standard of 100 fields of view (FoV) at 400× magnification. RESULTS Of 981 specimens, 269 were culture positive for Mycobacterium tuberculosis (27.4%). TBDx had higher sensitivity than the microscopist (75.8% versus 52.8%, respectively), but markedly lower specificity (43.5% versus 98.6%, respectively). TBDx classified 520/981 smears (53.0%) as scanty positive. Hence, a proposed hybrid software/human approach that combined TBDx examination of all smears with microscopist re-examination of TBDx scanty smears was explored by replacing the "positive" result of slides with 1-9 AFB detected on TBDx with the microscopist's original reading. Compared to using the microscopist's original results for all 981 slides, this hybrid approach resulted in equivalent specificity, a slight reduction in sensitivity from 52.8% to 49.4% (difference of 3.3%; 95% confidence interval: 0.2%, 6.5%), and a reduction in the number of slides to be read by the microscopist by 47.0%. DISCUSSION Compared to a research microscopist, the hybrid software/human approach had similar specificity and positive predictive value, but sensitivity requires further improvement. Automated microscopy has the potential to substantially reduce the number of slides read by microscopists.
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Affiliation(s)
- James J Lewis
- London School of Hygiene and Tropical Medicine, London, United Kingdom.
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Abstract
A new efficacious tuberculosis (TB) vaccine has the potential to dramatically assist control efforts for the global TB epidemic. Good progress has been made with the clinical development of new TB vaccine candidates with twelve being actively tested in clinical trials. However, there are many challenges that need to be addressed before a new vaccine is licensed for public use. The diversity of risk in populations needs to be factored into clinical development plans, specific but feasible clinical endpoints need to be agreed upon, and TB vaccines need to be effective in both uninfected and infected populations. An achievable efficacy target needs to be set while standardisation of trial outcomes and critical choices based on the vaccine development pipeline need to be made. Alternative routes of vaccine administration should be thoroughly explored, sufficient adequately prepared trial sites for performing TB vaccine assessments are required and creative use of study designs should be used to expedite progress towards licensure while at the same time containing costs. Lastly, there needs to be sufficient funding to support TB vaccine development. These challenges can be met through commitment by all role-players within the TB vaccine arena and with support from external stakeholders.
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Affiliation(s)
- Hassan Mahomed
- South African TB Vaccine Initiative, University of Cape Town, Cape Town, South Africa.
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Abstract
Clofazimine, a lipophilic riminophenazine antibiotic, possesses both antimycobacterial and anti-inflammatory activities. However, its efficacy has been demonstrated only in the treatment of leprosy, not in human tuberculosis, despite the fact that this agent is impressively active in vitro against multidrug-resistant strains of Mycobacterium tuberculosis. Recent insights into novel targets and mechanisms of antimicrobial and anti-inflammatory activity coupled with the acquisition of innovative drug delivery technologies have, however, rekindled interest in clofazimine as a potential therapy for multidrug- and extensively multidrug-resistant tuberculosis in particular, as well as several autoimmune diseases. The primary objective of this review is to critically evaluate these recent developments and to assess their potential impact on improving the therapeutic efficacy and versatility of clofazimine.
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Affiliation(s)
- Moloko C Cholo
- Medical Research Council Unit for Inflammation and Immunity, Department of Immunology, Faculty of Health Sciences, University of Pretoria and Tshwane Academic Division of the National Health Laboratory Service, Pretoria, South Africa.
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Misra A, Hickey AJ, Rossi C, Borchard G, Terada H, Makino K, Fourie PB, Colombo P. Inhaled drug therapy for treatment of tuberculosis. Tuberculosis (Edinb) 2011; 91:71-81. [DOI: 10.1016/j.tube.2010.08.009] [Citation(s) in RCA: 129] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2010] [Revised: 08/12/2010] [Accepted: 08/29/2010] [Indexed: 11/16/2022]
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Mahapatra A, Mativandlela SPN, Binneman B, Fourie PB, Hamilton CJ, Meyer JJM, van der Kooy F, Houghton P, Lall N. Activity of 7-methyljuglone derivatives against Mycobacterium tuberculosis and as subversive substrates for mycothiol disulfide reductase. Bioorg Med Chem 2007; 15:7638-46. [PMID: 17888665 DOI: 10.1016/j.bmc.2007.08.064] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [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: 07/23/2007] [Revised: 08/23/2007] [Accepted: 08/31/2007] [Indexed: 10/22/2022]
Abstract
The naphthoquinone 7-methyljuglone (5-hydroxy-7-methyl-1,4-naphthoquinone) has previously been isolated and identified as an active component of root extracts of Euclea natalensis which displays antitubercular activity. Herein, a series of synthetic and plant-derived naphthoquinone derivates of the 7-methyljuglone scaffold have been prepared and evaluated for antibacterial activity against Mycobacterium tuberculosis. Several of these compounds have been shown to operate as subversive substrates with mycothiol disulfide reductase. The absence of a direct correlation between antitubercular activity and subversive substrate efficiency with mycothiol disulfide reductase, might be a consequence of their non-specific reactivity with multiple biological targets (e.g. other disulfide reductases).
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Affiliation(s)
- Anita Mahapatra
- Department of Botany, Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria 0002, South Africa
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Garcia-Contreras L, Fiegel J, Telko MJ, Elbert K, Hawi A, Thomas M, VerBerkmoes J, Germishuizen WA, Fourie PB, Hickey AJ, Edwards D. Inhaled large porous particles of capreomycin for treatment of tuberculosis in a guinea pig model. Antimicrob Agents Chemother 2007; 51:2830-6. [PMID: 17517845 PMCID: PMC1932523 DOI: 10.1128/aac.01164-06] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Capreomycin is used for the treatment of multidrug-resistant tuberculosis (MDR-TB), but it is limited therapeutically by its severe side effects. The objectives of the present studies were (i) to design low-density porous capreomycin sulfate particles for efficient pulmonary delivery to improve local and systemic drug bioavailability and capacity to reduce the bacillary load in the lungs in a manner similar to that achieved with intramuscular injections; (ii) to determine pharmacokinetic parameters after pulmonary administration of these capreomycin particles; and (iii) to evaluate the efficacy of these particles in treating animals in a small-aerosol-inoculum guinea pig model of TB. Capreomycin particles were manufactured by spray drying and characterized in terms of size and drug content. Pharmacokinetic parameters were determined by noncompartmental methods with healthy guinea pigs after administration of capreomycin particles by insufflation. The efficacy of the particles was evaluated by histopathological analysis and in terms of wet organ weight and bacterial burden in TB-infected animals. Lungs of animals receiving a 14.5-mg/kg dose of capreomycin particles showed significantly lower wet weights and smaller bacterial burdens than those of animals receiving any other treatment. These results were supported by histopathological analysis. The feasibility of inhaling capreomycin in a novel powder form, with the ultimate objective of the treatment of MDR-TB, is demonstrated by pharmacokinetic and pharmacodynamic studies with guinea pigs. If applied to humans with MDR-TB, such a therapeutic approach might simplify drug delivery by eliminating injections and might reduce adverse effects through lowering the dose.
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Gabriels GA, McIlleron H, Smith PJ, Folb PI, Fourie PB. Modification to improve efficiency of sampling schedules for BA/BE testing of FDC anti-tuberculosis drugs. Int J Tuberc Lung Dis 2007; 11:181-8. [PMID: 17263289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/13/2023] Open
Abstract
SETTING The assessment of rifampicin (RMP) containing fixed-dose combination (FDC) formulations using in vivo bioequivalence testing is widely accepted. It would be advantageous for both the drug regulatory authorities and drug manufacturers, for optimum minimum blood testing time intervals that encompass all anti-tuberculosis active constituents in the FDC to be established. OBJECTIVE To determine the optimum blood sampling schedule for testing novel FDC anti-tuberculosis drugs, isoniazid, RMP, pyrazinamide and ethambutol DESIGN The results of 12 different single-dose, two-way cross-over designs are presented. The studies determined the bioavailability and bioequivalence of RMP-containing FDCs, and conformed with the requirements of the South African national drug regulatory authority for each of the active constituents. RESULTS The pharmacokinetic parameters to determine bioavailability and the Hauschke method to determine bioequivalence revealed that a six-point time protocol, namely 0, 1, 2, 4, 6 and 8 h, provides a good approximation of the area under the curve, and that an 11-point time protocol of 0, 0.25, 0.5, 1, 1.5, 2, 2.5, 3, 4, 6 and 8 h provided information comparable to the conventional 15 time-points for FDCs containing up to four drugs. CONCLUSION The findings provide concrete economic benefit and convenience for quality assurance testing of existing and novel FDCs.
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Affiliation(s)
- G A Gabriels
- Division of Clinical Pharmacology, Department of Medicine, Faculty of Health Sciences, University of Cape Town, Rondebosch, South Africa.
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Bapela NB, Lall N, Fourie PB, Franzblau SG, Van Rensburg CEJ. Activity of 7-methyljuglone in combination with antituberculous drugs against Mycobacterium tuberculosis. Phytomedicine 2006; 13:630-5. [PMID: 16987644 DOI: 10.1016/j.phymed.2006.08.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The recent increase in the incidence of tuberculosis with the emergence of multidrug-resistant (MDR) cases has lead to the search for new drugs that are effective against MDR strains of Mycobacterium tuberculosis and can augment the potential of existing drugs against tuberculosis. In the present study, we investigated the activities of a naphthoquinone, 7-methyljuglone, isolated from the roots of Euclea natalensis alone and in combination with other antituberculous drugs against extracellular and intracellular M. tuberculosis. Combinations of 7-methyljuglone with isoniazid or rifampicin resulted in a four to six-fold reduction in the minimum inhibitory concentration of each compound. Fractional inhibitory concentration (FIC) indexes obtained were 0.2 and 0.5, respectively, for rifampicin and isoniazid, suggesting a synergistic interaction between 7-methyljuglone and these anti-TB drugs. The ability of 7-methyljuglone to enhance the activity of isoniazid and rifampicin against both extracellular and intracellular organisms suggests that 7-methyljuglone may serve as a promising compound for development as an anti-tuberculous agent.
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Affiliation(s)
- N B Bapela
- Department of Pharmacology, University of Pretoria, PO Box 2034, Pretoria, 0001, South Africa
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Sirgel FA, Fourie PB, Donald PR, Padayatchi N, Rustomjee R, Levin J, Roscigno G, Norman J, McIlleron H, Mitchison DA. The Early Bactericidal Activities of Rifampin and Rifapentine in Pulmonary Tuberculosis. Am J Respir Crit Care Med 2005; 172:128-35. [PMID: 15805182 DOI: 10.1164/rccm.200411-1557oc] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.9] [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: 11/16/2022] Open
Abstract
RATIONALE Comparison of the early bactericidal activity (EBA) of rifapentine and its pharmacokinetics with those of rifampin to determine the cause of poor clinical response and regrowth between doses, leading to rifamycin monoresistance at relapse. OBJECTIVES Determination of the dose size of rifapentine that gives sufficient drug exposure to prevent regrowth. METHODS EBA study over initial 5 days of treatment of 123 patients, half at Durban and half at Cape Town, who received single rifapentine doses of 300, 600, 900, or 1,200 mg rifapentine or five daily doses of 150, 300, or 600 mg rifampin, with a pharmacokinetic study on 58 patients measuring standard parameters for each dose size of rifamycin and their desacetyl metabolites. RESULTS The EBAs for both rifamycins were similar, with a linear relationship to log dose at lower doses and a curvilinear response at higher doses giving a plateau at 1,136 mg rifapentine. The area under the concentration-time curve (AUC) divided by the minimal inhibitory concentration (MIC) agreed well for both rifamycins on the assumption that the only free 2% of free rifapentine and the 14% of free rifampin after plasma binding were active in the lesions. CONCLUSIONS Only the free proportions of the rifamycins were active in lesions. From consideration of the pulse size and the duration of the postantibiotic lag, a 1,200-mg dose of rifapentine seemed necessary to improve response and to prevent regrowth between doses, and hence rifamycin monoresistance.
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Affiliation(s)
- Frik A Sirgel
- Department of Cellular and Molecular Medicine, St. George's Hospital Medical School, Cranmer Terrace, London SW17 0RE, United Kingdom
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Johnson JL, Nunn AJ, Fourie PB, Ormerod LP, Mugerwa RD, Mwinga A, Chintu C, Ngwira B, Onyebujoh P, Zumla A. Effect of Mycobacterium vaccae (SRL172) immunotherapy on radiographic healing in tuberculosis. Int J Tuberc Lung Dis 2004; 8:1348-54. [PMID: 15581204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/01/2023] Open
Abstract
OBJECTIVE Controlled trials have failed to show an effect of Mycobacterium vaccae immunotherapy on treatment outcome and mortality in patients with tuberculosis (TB); however, several studies have suggested improvement in radiographic clearing and resolution of cavitary disease. METHODS To assess the effect of M. vaccae immunotherapy on radiographic healing in pulmonary TB, chest X-rays from three randomized placebo-controlled trials of M. vaccae given as a single injection during the first 2 weeks of treatment were interpreted by a single, masked assessor using a standard scheme. Endpoints were the overall degree of radiographic improvement or deterioration and changes in cavitary disease at the end of antituberculosis treatment and follow-up. RESULTS Of 1018 patients (478 HIV-infected; 540 HIV-uninfected) with an end of treatment or end of follow-up X-ray analyzed, 496 received M. vaccae and 522 received placebo. There was no difference in radiographic improvement or deterioration or cavitary disease at the end of treatment or follow-up comparing the M. vaccae and placebo groups. Results were similar comparing HIV-infected and HIV-uninfected patients. CONCLUSION Adjunctive immunotherapy of drug-susceptible pulmonary TB with M. vaccae during the first 2 weeks of treatment did not improve radiographic responses to treatment or resolution of cavitary disease.
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Affiliation(s)
- J L Johnson
- Division of Infectious Diseases, Case Western Reserve University School of Medicine and University Hospitals of Cleveland, Cleveland, Ohio 44106-5083, USA.
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Donald PR, Sirgel FA, Venter A, Parkin DP, Seifart HI, van de Wal BW, Maritz JS, Fourie PB. Early bactericidal activity of antituberculosis agents. Expert Rev Anti Infect Ther 2004; 1:141-55. [PMID: 15482107 DOI: 10.1586/14787210.1.1.141] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [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: 11/08/2022]
Abstract
The early bactericidal activity (EBA) of an antituberculosis agent is arbitrarily defined as the fall in log(10) colony forming units (cfu) of Mycobacterium tuberculosis per ml sputum per day during the first 2 days of treatment. Determining the EBA is an important preliminary step in the clinical evaluation of an antituberculosis agent. We review the results of eight published studies of the EBA of different antituberculosis agents, the impact of these results on our understanding of the actions of the respective agents, the clinical characteristics and sputum findings of patients included in these studies, and explore sources of variation in the EBA results. Patients in these studies had a mean age of 31-36 years, a mean weight of 50-57 kg, 67% were male and 56% had lung involvement covering an area of more than one lung, and 90% had multicavitary disease. None of these findings were related to EBA in any study. The mean log(10) cfu per ml sputum in the first specimen was 6.474. This was related to radiological extent of disease and cavity size in one study (p < 0.001) and, in the case of isoniazid to EBA with a rise in EBA of 0.094 (95% CL 0.029-0.158) for each tenfold rise in cfu counts/ml sputum. The overall variation in EBA in these studies was 0.0303, that due to laboratory processing of specimens was 0.0011, and due to patient characteristics and sputum sampling 0.0212. The EBA is a reproducible investigation that has contributed significantly to our knowledge of the actions and characteristics of both established and new antituberculosis agents. The greatest source of variation in EBA results appears to be that due to interpatient variation in disease characteristics and sputum sampling.
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Affiliation(s)
- P R Donald
- Department of Paediatrics and Child Health, Faculty of Health Sciences, University of Stellenbosch, PO Box 19063, Tygerberg, 7505, South Africa
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Abstract
Health services in Africa are being overburdened by a continuous increase of cases of tuberculosis (TB), largely resulting from the large pool of infected individuals becoming co-infected with HIV. To help deal with the situation, TB treatment schedules need to be shorter and simpler, with minimal contact between the patient and the service provider required, if the problems of non-compliance and of ineffective service provision are to be overcome. Various drugs not marketed for use in the treatment of TB are currently under investigation for their potential roles in the simplification or shortening of treatment schedules. These mainly include the long-acting rifamycins and the fluoroquinolones. Furthermore, new drug development is focused on an understanding of the host-pathogen interaction leading to infection, latency and disease. Of these, latency is least understood. The use of molecular diversity and combinatorial chemistry, proteomics, and the use of the whole genome to discover drug targets are expected to produce new lead compounds for turning into drugs to treat active, latent and multi-drug-resistant TB more effectively in the foreseeable future.
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Affiliation(s)
- A Mwinga
- University Teaching Hospital, Lusaka, Zambia.
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Bopape MC, Steel HC, Cockeran R, Matlola NM, Fourie PB, Anderson R. Antimicrobial activity of clofazimine is not dependent on mycobacterial C-type phospholipases. J Antimicrob Chemother 2004; 53:971-4. [PMID: 15117926 DOI: 10.1093/jac/dkh215] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [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: 11/12/2022] Open
Abstract
We have used a phospholipase C (PLC)-deletion mutant (plcABC) of the H37Rv strain of Mycobacterium tuberculosis (MTB), as well as a plcA-insertion mutant of Mycobacterium smegmatis, to investigate the possible involvement of PLCs in clofazimine-mediated inhibition of mycobacterial K(+) transport and growth. Inactivation of the PLCs of MTB and insertion of the plcA gene into M. smegmatis resulted in a substantial reduction and increase in hydrolysis of phosphatidylcholine (PC), respectively. However, both the mutant and wild-type strains of MTB and M. smegmatis were equally sensitive to the inhibitory effects of clofazimine on K(+) uptake and growth. These observations demonstrate that the PLCs of MTB are not involved in the antimicrobial activity of clofazimine.
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Affiliation(s)
- M C Bopape
- Tuberculosis Research Lead Programme, Medical Research Council, Pretoria, South Africa
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Pillai G, Ellard GA, Smith PJ, Fourie PB. The potential use of urinary excretion data for assessing the relative bioavailability of rifampicin in fixed dose combination anti-tuberculosis formulations. Int J Tuberc Lung Dis 2001; 5:691-5. [PMID: 11495257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023] Open
Abstract
SETTING The perceived need for simple, non-invasive methods of assessing the relative bioavailability of rifampicin in fixed-dose combination (FDC) anti-tuberculosis formulations. OBJECTIVE To compare the performance of methods based on urinary excretion data with those utilising plasma concentration-time profiles to assess the relative bioavailability of rifampicin in combined and single-drug formulations. DESIGN A two-period randomised crossover bioequivalence study in healthy male volunteers with a 1 week washout period between treatments. Plasma rifampicin concentrations were measured at 0, 1, 2, 4, 6 and 8 hours after each drug administration using a high performance liquid chromatography (HPLC) method. The rifampicin and desacetylrifampicin content of complete urinary collections made from 0-4 and 4-8 hours after dosage were determined using both the HPLC and a much simpler colorimetric procedure. RESULTS There was good agreement between the relative bioavailability of the formulations using plasma and urinary excretion data, although the precision of the urinary-based estimates was slightly less than those derived from the plasma findings. There was also good agreement between the HPLC and colorimetric estimates of the combined urinary excretion of rifampicin plus desacetylrifampicin. CONCLUSIONS Urinary excretion data may be used for ongoing quality control to confirm that commercial combined rifampicin-containing formulations that were initially shown to be satisfactory continue to be so.
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Affiliation(s)
- G Pillai
- Department of Pharmacology, University of Durban Westville, South Africa.
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Webber LM, Swanevelder C, Grabow WO, Fourie PB. Evaluation of a rapid test for HIV antibodies in saliva and blood. S Afr Med J 2000; 90:1004-7. [PMID: 11081107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023] Open
Abstract
OBJECTIVE To test whole blood and saliva for HIV antibodies (anti-HIV) using a rapid test strip capillary flow immunoassay, and to correlate the test strip results with blood specimen results obtained from routine diagnostic anti-HIV assays. DESIGN A prospective pilot study of selected HIV-positive and HIV-negative individuals, children and medico-legal cases from Gauteng, South Africa. METHODS Whole blood specimens taken from every individual and medico-legal case (total study population 153) and saliva specimens taken from 76 selected cases were tested for anti-HIV using the respective Hema-Strip HIV-1/2, Sero-Strip HIV-1/2 and Saliva-Strip HIV-1/2 (Saliva Diagnostic Systems Inc.) rapid test strip methodology. All results were correlated with the currently recommended anti-HIV assays. RESULTS The whole blood test strip results correlated 100% with the traditional diagnostic results. Only two saliva test strip results tested false-negative, both from marasmic and severely dehydrated babies, while the other results were in concordance. All test strip results on postmortem blood and saliva were fully concordant with the diagnostic assay results. CONCLUSION The anti-HIV test strip methodology for whole blood and saliva specimens is rapid, reliable and easy to perform and interpret. Saliva specimens can be readily collected from any individual, and there is a reduction in hazard risk. Anti-HIV saliva testing using the test strip methodology is recommended for South Africa, particularly in high-risk situations such as the paediatric and forensic medicine settings. A large field study obtaining specimens from different regions in South Africa is advised.
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Affiliation(s)
- L M Webber
- Department of Medical Virology, University of Pretoria
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Weyer K, Fourie PB, Dürrheim D, Lancaster J, Haslöv K, Bryden H. Mycobacterium bovis as a zoonosis in the Kruger National Park, South Africa. Int J Tuberc Lung Dis 1999; 3:1113-9. [PMID: 10599016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023] Open
Abstract
SETTING The Kruger National Park (KNP), Mpumalanga Province, South Africa. OBJECTIVE The prevalence of tuberculosis caused by Mycobacterium bovis exceeds 70% in African buffalo in the southern region of the KNP. Inter-species transmission (lion, cheetah, baboon, antelope) has also been confirmed. Regular culling of emaciated buffalo and processing of meat and hides constitute routine control policy. Following extensive media coverage of the problem, public health concerns about the transmission of M. bovis to humans, including visitors to the KNP, prompted this investigation. DESIGN The study was designed to determine the prevalence of infection and/or active disease due to M. bovis among KNP employees selected from three defined risk groups based on occupation category. RESULTS Of 206 persons screened for active disease by sputum bacteriology, two persons with disease due to M. tuberculosis were identified. No isolate of M. bovis was found. Differential skin testing using three antigens failed to show any degree of M. bovis infection risk, even among high risk occupations. Reasons for these results are discussed. CONCLUSIONS Bovine tuberculosis was not indicated as an occupational zoonosis in the KNP, nor was aerosol transmission implicated as a mechanism for human infection. Concerns about the public health implications of tuberculosis in buffalo in the KNP have therefore not been validated.
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Affiliation(s)
- K Weyer
- National Tuberculosis Research Programme, Medical Research Council, Pretoria, South Africa.
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Fourie PB, Spinaci S. Structures required, roles and responsibilities in maintaining laboratories for quality assurance of anti-tuberculosis fixed-dose combinations in accordance with the IUATLD/WHO statement. Int J Tuberc Lung Dis 1999; 3:S368-70; discussion S381-7. [PMID: 10593720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023] Open
Abstract
Combining rifampicin in the same tablet with isoniazid, with or without pyrazinamide, is known to affect the bioavailability of the drug. It is also known that many fixed-dose combination (FDC) preparations exist in the market which are of inferior quality, but are unknowingly used extensively in tuberculosis treatment programmes in low-income countries with high tuberculosis caseloads. This has led to joint statements by the International Union Against Tuberculosis and Lung Disease and the World Health Organization (WHO) pointing out that anti-tuberculosis FDCs should only be used in National Tuberculosis Programmes if the bioavailability of at least the rifampicin component has been demonstrated. Through the FDC Quality Assurance Project launched by the WHO in 1997, a strategy was proposed which aimed to provide specific guidance to ensure the improved quality of such preparations, and in particular the bioavailability of the rifampicin component. A crucial component of drug quality assurance is to ensure that the infrastructure and logistics required to carry out the operational aspects of quality assurance are adequate and sustainable. This paper describes the structures and management responsibilities required to meet this objective, based on general WHO guidelines for the quality assurance of pharmaceuticals.
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Affiliation(s)
- P B Fourie
- National Tuberculosis Research Programme, Medical Research Council, Pretoria, South Africa.
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Pillai G, Fourie PB, Padayatchi N, Onyebujoh PC, McIlleron H, Smith PJ, Gabriels G. Recent bioequivalence studies on fixed-dose combination anti-tuberculosis drug formulations available on the global market. Int J Tuberc Lung Dis 1999; 3:S309-16; discussion S317-21. [PMID: 10593710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023] Open
Abstract
SETTING Concern has been expressed about the bioavailability of rifampicin in some fixed-dose combination (FDC) anti-tuberculosis formulations. OBJECTIVE To evaluate the relative bioavailability of rifampicin in various FDC formulations currently in use in tuberculosis control programmes in the global market. DESIGN A two-period randomised crossover bioequivalence study in healthy male volunteers, with a 1 week washout period between treatments. Plasma rifampicin concentrations were measured at 0, 1, 2, 4, 6, 8 and 12 hours after each drug administration. RESULTS The AUC0-8, AUC0-12 and Cmax for rifampicin in seven of 10 FDC formulations was not found to be bioequivalent to the reference administered as loose (separate) formulations. This was confirmed using parametric and non-parametric statistical methods. CONCLUSIONS The poor relative bioavailability of rifampicin from some FDCs has been documented. The implications for tuberculosis programmes are extremely serious and warrant urgent attention.
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Affiliation(s)
- G Pillai
- Department of Pharmacology, University of Durban Westville, South Africa.
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McIlleron H, Gabriels G, Smith PJ, Fourie PB, Ellard GA. The development of a standardised screening protocol for the in vivo assessment of rifampicin bioavailability. Int J Tuberc Lung Dis 1999; 3:S329-35; discussion S351-2. [PMID: 10593713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023] Open
Abstract
SETTING The prerequisite for in vivo bioavailability testing of rifampicin in fixed-dose combination (FDC) formulations is widely accepted. However, many smaller drug regulatory authorities and drug manufacturers have difficulty implementing costly and cumbersome testing procedures. OBJECTIVE To test whether a simplified blood sampling schedule can be used for the determination of drug bioequivalence in randomised, single dose, crossover studies of FDCs and appropriate reference formulations. METHOD The results of three bioavailability and bioequivalence studies of different rifampicin-containing FDCs were analysed. The relationship between the number of time points employed and precision of estimated relative bioavailability was explored. The relative bioavailabilities of the drug components in the test FDCs were calculated using maximal concentration and area under the curve estimates based on an extended blood sampling schedule of up to 15 time points over 48 hours, and a contracted sampling scheme with only six blood samples over 8 hours. RESULTS Estimates of relative bioavailability calculated using the contracted blood sampling protocol were closely similar to those derived using the extended sampling schedules. CONCLUSION Considerable cost and convenience benefits can be gained by using the contracted sampling schedule with only a minor reduction in the precision of the estimation of relative rifampicin bioavailability.
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Affiliation(s)
- H McIlleron
- Department of Pharmacology, University of Cape Town Medical School, Observatory, South Africa.
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Fourie PB. Proposed minimum registration requirements for fixed-dose combination anti-tuberculosis drugs. Int J Tuberc Lung Dis 1999; 3:S362-7; discussion S381-7. [PMID: 10593719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023] Open
Abstract
Registration requirements for combined pharmaceutical preparations have been published before, but not specifically for fixed-dose combination (FDC) anti-tuberculosis preparations. With tuberculosis being a high priority disease world-wide and concerns being raised over substandard FDC anti-tuberculosis preparations being marketed on a wide scale, specific guidelines for industry seem to be indicated. This is predominantly necessitated by the fact that rifampicin bioavailability can be adversely affected when put in combination with isoniazid and pyrazinamide, and by the need for standardisation of the formulations to only a few essential combinations in order to better control quality. This paper proposes certain minimum requirements to be met when standardising dose in the combinations and when ensuring bioavailability of the preparations. Nine rifampicin-containing combinations are listed as essential. Furthermore, bioavailability testing of the rifampicin component only by a restricted assay protocol of six sample times over 8 hours is advocated, whilst in vitro procedures for other actives in the combination would suffice for registration purposes.
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Affiliation(s)
- P B Fourie
- National Tuberculosis Research Programme, Medical Research Council, Pretoria, South Africa.
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Ellard GA, Fourie PB. Rifampicin bioavailability: a review of its pharmacology and the chemotherapeutic necessity for ensuring optimal absorption. Int J Tuberc Lung Dis 1999; 3:S301-8; discussion S317-21. [PMID: 10593709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023] Open
Abstract
The World Health Organization encourages the use of fixed dose combinations (FDCs) of rifampicin (RMP) and isoniazid together with pyrazinamide or pyrazinamide plus ethambutol for the treatment of tuberculosis. The main advantages of such FDCs are the simplification of procurement and prescribing practices and the protection they afford against the potential selection of RMP-resistant strains of Mycobacterium tuberculosis. There is convincing evidence, however, that the rifampicin absorption from FDCs manufactured under suboptimal conditions may be significantly impaired, and this appears to be especially problematic with combined formulations of rifampicin, isoniazid and pyrazinamide. In view of the marked dose-dependence of rifampicin's bacterial sterilizing action, it is therefore essential that tuberculosis control programmes only use rifampicin-containing FDCs with proven rifampicin bioavailability. The comprehensive literature on the pharmacology of rifampicin is reviewed, together with the methods employed for determining it and its most important metabolite, desacetyl-rifampicin, in either serum or urine. By contrast, published information concerning the absorption of rifampicin from currently marketed combined formulations and on laboratory methods for precisely assessing their bioavailability is very sparse. There is therefore a crucial need to establish the quality of currently marketed rifampicin-containing FDCs in studies using adequate numbers of volunteers, precise analytical techniques and sophisticated statistical techniques.
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Affiliation(s)
- G A Ellard
- Department of Medical Microbiology, St. George's Hospital Medical School, London, UK
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Schilke K, Weyer K, Bretzel G, Amthor B, Brandt J, Sticht-Groh V, Fourie PB, Haas WH. Universal pattern of RpoB gene mutations among multidrug-resistant isolates of Mycobacterium tuberculosis complex from Africa. Int J Tuberc Lung Dis 1999; 3:620-6. [PMID: 10423225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/13/2023] Open
Abstract
SETTING Multidrug-resistant tuberculosis (MDR-TB) presents an increasing burden in Southern Africa. Rapid diagnostic tests for drug resistance to rifampicin have been developed based on mutation analysis of the rpoB gene. However, geographic differences of underlying mutations have recently been suggested. OBJECTIVE Drug-resistant strains of Mycobacterium tuberculosis complex from Africa were analysed for geographic differences in frequency and location of rpoB mutations. DESIGN A random sample of rifampicin-resistant strains was collected from 87 patients with pulmonary MDR-TB treated in 12 hospitals from six different regions of South Africa. In addition, 18 isolates of M. tuberculosis complex from Namibia, Sierra Leone, and Uganda, including 13 isolates of M. africanum, were analyzed. Point mutations were detected by direct sequence analysis of the rpoB gene. RESULTS Missense mutations were identified for 91 isolates (87%). Double mutations were present in eight (8%) MDR-TB isolates, two of which carried one mutation outside a previously described diagnostic region. We found no geographic differences regarding the frequency and pattern of single rpoB gene mutations. CONCLUSION Our results confirm that molecular genetic analysis of rifampicin resistance based on a core region within the rpoB gene is universally applicable to strains of M. tuberculosis complex from different geographic regions.
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Affiliation(s)
- K Schilke
- Department of General Pediatrics, Children's Hospital, University of Heidelberg, Germany
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Fourie PB, Becker PJ, Festenstein F, Migliori GB, Alcaide J, Antunes M, Auregan G, Beyers N, Carvalho JM, Cruz JR, Fanning EA, Gie R, Huong ND, Leitch AG. Procedures for developing a simple scoring method based on unsophisticated criteria for screening children for tuberculosis. Int J Tuberc Lung Dis 1998; 2:116-23. [PMID: 9562121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
OBJECTIVE To develop a scoring system for screening children for tuberculosis (TB) and for selecting suspects for further investigation in tuberculosis control programmes. Application of the score model, which would not require sophisticated or expensive technology, would be directed towards resource-poor countries with high prevalences of tuberculosis, where health care workers have to deal with diagnostic problems away from district hospitals or diagnostic facilities. DESIGN Based on contributions from members of an IUATLD task group from 10 countries on the use of diagnostic criteria in childhood tuberculosis, criteria were selected to be used as elements in a score model. Data were collected by standardised questionnaire on 879 subjects aged under 15 years. Of these, 794 were considered probable or confirmed cases of tuberculosis by the diagnosing doctors. From each record, the criteria/procedures used in the diagnosis of probable/confirmed TB and regarded by the doctors as relevant criteria were selected. Bacteriology, histology and chest radiography were used either singly or collectively as the definitive reference (gold standard) against which the more subjective criteria (symptoms, clinical signs, skin test) would be evaluated. The latter criteria cited as relevant were then ranked and further explored for inclusion in the score model. The relative importance of each criterion to every other criterion on the list was expressed as weights, determined by employing a logarithmic least squares method to solve the ratio scale estimation problem which underlies decision-making involving more than one criterion. The resultant values were then assigned to each criterion in the final score model. RESULTS The five clinical criteria thought to be most relevant as predictors of disease in children were history of contact with a case of tuberculosis, positive skin test, persistent cough, low weight for age, and unexplained/prolonged fever. In selecting the optimal cut-off points for the model at which tuberculosis would be suspected, low sensitivity and specificity (below 70%) but reasonably good positive predictive values (60%-77%) were obtained, depending on age group and epidemiological setting. In low tuberculosis prevalence settings, heavy reliance is placed by the model on a history of contact with a household case of tuberculosis and on a positive skin test, both of which have to be true. For high prevalence settings, more or less equal weighting is assigned to all five elements. Case contact and skin tests are less important, with low body weight, prolonged fever and cough being more indicative of tuberculosis. CONCLUSION The model provides for epidemiological differences between target populations and should prove successful as a screening tool to select children for further investigation by radiography and bacteriology.
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Affiliation(s)
- P B Fourie
- MRC National Tuberculosis Research Programme, Pretoria, South Africa
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Haas WH, Schilke K, Brand J, Amthor B, Weyer K, Fourie PB, Bretzel G, Sticht-Groh V, Bremer HJ. Molecular analysis of katG gene mutations in strains of Mycobacterium tuberculosis complex from Africa. Antimicrob Agents Chemother 1997; 41:1601-3. [PMID: 9210694 PMCID: PMC163968 DOI: 10.1128/aac.41.7.1601] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.0] [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: 02/04/2023] Open
Abstract
A sample of 124 isoniazid (INH)-resistant and 88 susceptible strains of Mycobacterium tuberculosis complex from south, central, and west Africa was analyzed by direct sequence analysis and PCR-restriction fragment length polymorphism analysis of their catalase-peroxidase (katG) genes. Point mutations at codon 315 were found in the genomes of 64% of INH-resistant strains, but no complete deletions were identified. Mutations at codon 463 were independent of INH resistance and were linked to the geographic origins of the strains.
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Affiliation(s)
- W H Haas
- Department of General Pediatrics, Children's Hospital, Heidelberg University, Germany.
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McGregor MM, Olliaro P, Wolmarans L, Mabuza B, Bredell M, Felten MK, Fourie PB. Efficacy and safety of rifabutin in the treatment of patients with newly diagnosed pulmonary tuberculosis. Am J Respir Crit Care Med 1996; 154:1462-7. [PMID: 8912765 DOI: 10.1164/ajrccm.154.5.8912765] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.6] [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: 02/03/2023] Open
Abstract
The efficacy and safety of rifabutin (RBT) and rifampicin (RMP) were compared in 298 patients with newly diagnosed pulmonary tuberculosis. In the initial 8-wk phase, all patients received isoniazid 400 mg/d, ethambutol 1200 mg/d, and pyrazinamide 2 g/d and were randomly allocated to receive either RMP 600 mg/d or RBT 300 mg/d. In the 16-wk continuation phase, patients received intermittent treatment (twice weekly) with isoniazid 600 mg/d, ethambutol 2400 mg/d and either RMP 600 mg/d or RBT 300 mg/d. Two hundred twenty-five (RMP = 118; RBT = 107) patients completed the 24-wk treatment period (evaluable patient population). Bacteriologic conversion rates in the RMP and RBT groups were 87.7 versus 92.0% at Week 8, 99.1 versus 99.0% at Week 12, 93.5 versus 93.8% at Week 24, and 89.8 versus 95.3% at the last valid observation. The mean time to first bacteriologic conversion was 14.1 wk in the RMP group and 14.3 wk in the RBT group. None of these differences was significant. Adverse events were reported by four patients (five events) in the RMP group and six patients (six events) in the RBT group. Those events thought to be associated with RMP were increased SGOT and leucopenia and, with RBT, increased SGOT and thrombocytopenia. Two hundred four patients entered the follow-up phase, and, of these, 95 (RMP = 49; RBT = 46) completed the scheduled 24-mo period. The overall rate of relapse was 3.8% (4/106) for the RMP group and 5.1% (5/98) for the RBT group. These differences were not significant. All relapsed patients, except for two who could not be traced, were successfully retreated. We conclude that the efficacy and tolerability of RBT is equivalent to that of RMP in the treatment of newly diagnosed uncomplicated tuberculosis, and that RBT can be effectively administered in a part-daily, part-intermittent dosage schedule.
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Affiliation(s)
- M M McGregor
- MRC National Tuberculosis Research Programme, Pretoria, South Africa
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Weyer K, Fourie PB. Tuberculosis control in South Africa--time for a new paradigm? S Afr Med J 1996; 86:563-4; author reply 564-5. [PMID: 8711562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
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Adhikari M, Wesley AG, Fourie PB. Intravenous immunoglobulin prophylaxis in neonates on artificial ventilation. S Afr Med J 1996; 86:542-5. [PMID: 8711553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The efficacy of the prophylactic use of intravenous immunoglobulin (Ig) was evaluated in a double-blind placebo-controlled trial of 21 pairs of ventilated neonates weighing more than 1,500 g. Each infant received 0.4 g/kg/day of intravenous Ig or a similar volume of placebo daily for 5 days. Criteria used to assess the efficacy of intravenous Ig were the number of infections, the duration of ventilation therapy and time to clinical recovery. There were no significant differences in the treated and placebo groups with regard to the frequency of positive blood cultures (28.6% and 14.3%), endotracheal cultures (57.1% and 66.7%) and abnormal white cell counts (52.4% and 57.1%). On entry to the study there was no significant difference in IgG levels between the treated (974.5 mg/dl; SD 575.3) and placebo groups (818 mg/dl; SD 516.9). However, on day 6 the treated group had a mean level of 1,400.3 mg/dl (SD 426.7) versus 710.9 mg/dl (SD 377.4) in the placebo group (P < 0.05). Clinical improvement occurred within 3 days in both groups. Ventilatory support was required for 11.8 days (SD 8.3) in the treated and 11.8 days (SD 7.3) in the placebo group. Both groups required 3-4 antibiotic treatments over a period of 14-15 days. Two patients died in the treated and 4 in the placebo group, with 1 infant in each group developing bronchopulmonary dysplasia. The patients who recovered did so within 14 days. Analyses of subgroups of patients with different diagnoses revealed no differences except a trend suggesting fewer infections in term babies treated with intravenous Ig. The organisms cultured in the intravenous Ig groups were Pseudomonas, Klebsiella, Escherichia coli and Staphylococcus and in the placebo group Pseudomonas, Klebsiella and Enterobacter. The above has shown that, except for a trend in the older neonates, intravenous Ig is not of prophylactic benefit in ventilated neonates. Newer adjuncts in immunotherapy such as hyperimmune gammaglobulin or monoclonal antibodies may prove of greater value in the treatment of neonatal sepsis.
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Affiliation(s)
- M Adhikari
- Department of Paediatrics and Child Health, University of Natal, Durban
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