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1.
Antimicrob Agents Chemother ; 68(5): e0028024, 2024 May 02.
Article in English | MEDLINE | ID: mdl-38587391

ABSTRACT

Testing Plasmodium vivax antimicrobial sensitivity is limited to ex vivo schizont maturation assays, which preclude determining the IC50s of delayed action antimalarials such as doxycycline. Using Plasmodium cynomolgi as a model for P. vivax, we determined the physiologically significant delayed death effect induced by doxycycline [IC50(96 h), 1,401 ± 607 nM]. As expected, IC50(96 h) to chloroquine (20.4 nM), piperaquine (12.6 µM), and tafenoquine (1,424 nM) were not affected by extended exposure.


Subject(s)
Aminoquinolines , Antimalarials , Doxycycline , Piperazines , Plasmodium cynomolgi , Plasmodium vivax , Doxycycline/pharmacology , Antimalarials/pharmacology , Aminoquinolines/pharmacology , Plasmodium vivax/drug effects , Plasmodium cynomolgi/drug effects , Chloroquine/pharmacology , Animals , Malaria, Vivax/drug therapy , Malaria, Vivax/parasitology , Quinolines/pharmacology , Inhibitory Concentration 50 , Humans , Parasitic Sensitivity Tests
2.
J Glob Antimicrob Resist ; 36: 1-3, 2024 Mar.
Article in English | MEDLINE | ID: mdl-37992964

ABSTRACT

OBJECTIVES: Antimicrobial resistance (AMR) including multidrug-resistant (MDR) and extensively drug-resistant (XDR) Pseudomonas aeruginosa has emerged as one of the serious public health threats across the globe. Southeast Asia is a 'hot spot' of antimicrobial-resistant bacteria, including MDR P. aeruginosa. Despite Myanmar being located in Southeast Asia and suffering from a high infectious disease burden, data on MDR and XDR P. aeruginosa from Myanmar are limited. In this communication, we report the draft genome of an XDR P. aeruginosa isolate, MMXDRPA001, that was identified during a routine diagnosis in Myanmar. METHODS: An MMXDRPA001 isolate colonising a hospitalised patient was characterised by antibiotic resistance profiling following standard methods and whole-genome sequencing using an Illumina MiSeq platform. The generated reads were de novo assembled using SPAdes (v.3.9.1). Annotation was performed by Prokka (v.1.14.0). Sequence type, antimicrobial resistance and virulence-related genes were predicted from the sequence. The phylogenetic relationships of all P. aeruginosa isolates were determined using core genome single-nucleotide polymorphisms (SNPs) analysis utilising Snippy (v.4.6.0) and Gubbins (v.2.3.4). RESULTS: P. aeruginosa MMXDRPA001 was resistant to most antipseudomonal ß-lactams, aminoglycosides and quinolones. The assembly comprised 145 contigs totalling 6 808 493 bases of sequence and a total of 6183 coding sequences. The isolate belonged to sequence type (ST) 235, contained carbapenemase-encoding gene blaIMP-1 and was clonally related to a previously reported isolate from Thailand. CONCLUSION: The identification of an international high-risk clone of ST235 XDR isolate in Myanmar, genomically relating to that from a neighbouring country underscores the need for coordinated AMR surveillance throughout healthcare settings in Myanmar and in the Southeast Asia region.


Subject(s)
Pseudomonas Infections , Pseudomonas aeruginosa , Humans , Drug Resistance, Multiple, Bacterial/genetics , Myanmar , Phylogeny , Anti-Bacterial Agents/pharmacology , Pseudomonas Infections/microbiology
3.
Trop Med Infect Dis ; 8(4)2023 Apr 21.
Article in English | MEDLINE | ID: mdl-37104364

ABSTRACT

This study aimed to characterize whole-genome sequencing (WGS) information of Mycobacterium tuberculosis (Mtb) in the Mandalay region of Myanmar. It was a cross-sectional study conducted with 151 Mtb isolates obtained from the fourth nationwide anti-tuberculosis (TB) drug-resistance survey. Frequency of lineages 1, 2, 3, and 4 were 55, 65, 9, and 22, respectively. The most common sublineage was L1.1.3.1 (n = 31). Respective multi-drug resistant tuberculosis (MDR-TB) frequencies were 1, 1, 0, and 0. Four clusters of 3 (L2), 2 (L4), 2 (L1), and 2 (L2) isolates defined by a 20-single-nucleotide variant (SNV) cutoff were detected. Simpson's index for sublineages was 0.0709. Such high diversity suggests that the area probably had imported Mtb from many geographical sources. Relatively few genetic clusters and MDR-TB suggest there is a chance the future control will succeed if it is carried out properly.

4.
Trop Med Infect Dis ; 7(12)2022 Dec 19.
Article in English | MEDLINE | ID: mdl-36548703

ABSTRACT

Mycobacterium tuberculosis complex (MTBC) is divided into 9 whole genome sequencing (WGS) lineages. Among them, lineages 1−4 are widely distributed. Multi-drug resistant tuberculosis (MDR-TB) is a major public health threat. For effective TB control, there is a need to obtain genetic information on lineages of Mycobacterium tuberculosis (Mtb) and to understand distribution of lineages and drug resistance. This study aimed to describe the distribution of major lineages and drug resistance patterns of Mtb in Upper Myanmar. This was a cross-sectional study conducted with 506 sequenced isolates. We found that the most common lineage was lineage 2 (n = 223, 44.1%). The most common drug resistance mutation found was streptomycin (n = 44, 8.7%). Lineage 2 showed a higher number of MDR-TB compared to other lineages. There were significant associations between lineages of Mtb and drug resistance patterns, and between lineages and geographical locations of Upper Myanmar (p value < 0.001). This information on the distribution of Mtb lineages across the geographical areas will support a lot for the better understanding of TB transmission and control in Myanmar and other neighboring countries. Therefore, closer collaboration in cross border tuberculosis control is recommended.

5.
Microbiol Resour Announc ; 11(11): e0078122, 2022 Nov 17.
Article in English | MEDLINE | ID: mdl-36227116

ABSTRACT

We report here the complete genome sequence of Mycobacterium tuberculosis strain Colonial S-type 1 (CS1), which has been responsible for ongoing outbreaks of tuberculosis in New Zealand over the past 30 years. CS1 appears to be highly transmissible, with greater rates of progression to active disease, compared to other circulating M. tuberculosis strains; therefore, comparison of its genomic content is of interest.

6.
Parasitol Int ; 89: 102589, 2022 Aug.
Article in English | MEDLINE | ID: mdl-35470066

ABSTRACT

The absence of a routine continuous in vitro cultivation method for Plasmodium vivax, an important globally distributed parasite species causing malaria in humans, has restricted investigations to field and clinical sampling. Such a method has recently been developed for the Berok strain of P. cynomolgi, a parasite of macaques that has long been used as a model for P. vivax, as these two parasites are nearly indistinguishable biologically and are genetically closely related. The availability of the P. cynomolgi Berok in routine continuous culture provides for the first time an opportunity to conduct a plethora of functional studies. However, the initial cultivation protocol proved unsuited for investigations requiring extended cultivation times, such as reverse genetics and drug resistance. Here we have addressed some of the critical obstacles to this, and we propose a set of modifications that help overcome them.


Subject(s)
Malaria, Vivax , Malaria , Parasites , Plasmodium cynomolgi , Animals , Macaca/parasitology , Malaria/parasitology , Malaria, Vivax/parasitology , Plasmodium vivax
7.
PLOS Glob Public Health ; 2(6): e0000588, 2022.
Article in English | MEDLINE | ID: mdl-36962394

ABSTRACT

Tuberculosis (TB) remains a significant cause of morbidity and mortality in Myanmar. The fourth National TB Prevalence Survey was conducted in 2017-2018 to determine the actual burden of TB not only at the national level but also for three subnational strata (the states, regions other than Yangon, and the Yangon region) and develop a more efficacious country strategy on TB care and control. One hundred and thirty eight clusters were selected by population proportionate sampling. Adult (≥15 years of age) residents having lived for 2 weeks or more in the households of the selected clusters were invited to participate in the survey. The survey participants were screened for TB by a questionnaire and digital chest X-ray (CXR) after providing written informed consent. Individuals with a positive symptom screen and/or chest X-ray suggestive of TB were asked to provide sputum samples to test for Mycobacterium tuberculosis (Mtb) by Ziehl-Neelsen direct light microscopy, Xpert MTB/RIF Ultra (Xpert), and culture (Ogawa media). Bacteriologically confirmed TB cases were defined by an expert panel. Of 75 676 eligible residents, 66 480 (88%) participated, and 10 082 (15%) screened positive for TB. Among these, 322 participants were defined as bacteriologically confirmed TB cases. Cough lasting for two weeks or longer, one of the criteria used for screening for symptoms, could detect only 14% (45/322) of the study cases. The estimated prevalence of bacteriologically confirmed adult pulmonary TB was 468 (95% CI: 391-546) per 100,000. The prevalence was much higher among males, the older age group, urban Yangon and remote villages. In-depth interview with the participants on TB treatment showed that none of them was diagnosed in a TB health centre (primary care facilities). The prevalence of TB in Myanmar is still high due to challenges such as uncontrolled urbanization, an ageing population, migration, and poor access to health facilities in remote areas. New screening and diagnostic tools might help to detect more TB patients. There is a need to lay greater emphasis on multisectoral approaches, decentralization and the integration of basic TB services into primary care facilities.

8.
Emerg Infect Dis ; 27(11): 2847-2855, 2021 11.
Article in English | MEDLINE | ID: mdl-34670644

ABSTRACT

Multidrug resistance is a major threat to global elimination of tuberculosis (TB). We performed phenotypic drug-susceptibility testing and whole-genome sequencing for 309 isolates from 342 consecutive patients who were given a diagnosis of TB in Yangon, Myanmar, during July 2016‒June 2018. We identified isolates by using the GeneXpert platform to evaluate drug-resistance profiles. A total of 191 (62%) of 309 isolates had rifampin resistance; 168 (88%) of these rifampin-resistant isolates were not genomically related, indicating the repeated emergence of resistance in the population, rather than extensive local transmission. We did not detect resistance mutations to new oral drugs, including bedaquiline and pretomanid. The current GeneXpert MTB/RIF system needs to be modified by using the newly launched Xpert MTB/XDR cartridge or line-probe assay. Introducing new oral drugs to replace those currently used in treatment regimens for multidrug-resistant TB will also be useful for treating TB in Myanmar.


Subject(s)
Mycobacterium tuberculosis , Tuberculosis, Multidrug-Resistant , Drug Resistance, Bacterial , Genomics , Humans , Microbial Sensitivity Tests , Myanmar/epidemiology , Mycobacterium tuberculosis/genetics , Rifampin , Tuberculosis, Multidrug-Resistant/diagnosis , Tuberculosis, Multidrug-Resistant/drug therapy , Tuberculosis, Multidrug-Resistant/epidemiology
9.
Trop Med Infect Dis ; 6(3)2021 Jul 14.
Article in English | MEDLINE | ID: mdl-34287379

ABSTRACT

BACKGROUND: This is the first survey to use the World Health Organization (WHO) methodology to document the magnitude and main drivers of tuberculosis (TB) patient costs in order to guide policies on cost mitigation and to produce a baseline measure for the percentage of TB-affected households experiencing catastrophic costs in Myanmar. METHODS: A nationally representative cross-sectional survey was administered to 1000 TB patients in health facilities from December 2015 to February 2016, focusing on costs of TB treatment (direct and indirect), household income, and coping strategies. A total cost was estimated for each household by extrapolating reported costs and comparing them to household income. If the proportion of total costs exceeded 20% of the annual household income, a TB-affected household was deemed to have faced catastrophic costs. RESULTS: 60% of TB-affected households faced catastrophic costs in Myanmar. On average, total costs were USD 759, and the largest proportion of this total was accounted for by patient time (USD 365), followed by food costs (USD 200), and medical expenses (USD 130). Low household wealth quintile and undergoing MDR-TB treatment were both significant predictors for households facing catastrophic costs. CONCLUSIONS: The high proportion of TB-affected households experiencing catastrophic costs suggests the need for TB-specific social protection programs in patient-centered healthcare. The survey findings have led the government and donors to increase support for MDR-TB patients. The significant proportion of total spending attributable to lost income and food or nutritional supplements suggests that income replacement programs and/or food packages may ameliorate the burdensome costs.

11.
Trop Med Infect Dis ; 5(4)2020 Sep 30.
Article in English | MEDLINE | ID: mdl-33007895

ABSTRACT

Worldwide, studies investigating the relationship between the lineage of Mycobacterium tuberculosis (MTB) across geographic areas has empowered the "End TB" program and understand transmission across national boundaries. Genomic diversity of MTB varies with geographical locations and ethnicity. Genomic diversity can also affect the emergence of drug resistance. In Myanmar, we still have limited genetic information about geographical, ethnicity, and drug resistance linkage to MTB genetic information. This study aimed to describe the geno-spatial distribution of MTB and drug resistance profiles in Myanmar-Thailand border areas. A cross-sectional study was conducted with a total of 109 sequenced isolates. The lineages of MTB and the potential associated socio-demographic, geographic and clinical factors were analyzed using Fisher's exact tests. p value of statistically significance was set at < 0.05. We found that 67% of the isolates were lineage 1 (L1)/East-African-Indian (EAI) (n = 73), followed by lineage 2 (L2)/Beijing (n = 26), lineage 4 (L4)/European American (n = 6) and lineage 3 (L3)/Delhi/Central Asian (n = 4). "Gender", "type of TB patient", "sputum smear grading" and "streptomycin resistance" were significantly different with the lineages of MTB. Sublineages of L1, which had never been reported elsewhere in Myanmar, were detected in this study area. Moreover, both ethnicity and lineage of MTB significantly differed in distribution by patient location. Diversity of the lineage of MTB and detection of new sublineages suggested that this small area had been resided by a heterogeneous population group who actively transmitted the disease. This information on distribution of lineage of MTB can be linked in the future with those on the other side of the border to evaluate cross-border transmission.

12.
PLoS Pathog ; 16(2): e1008287, 2020 02.
Article in English | MEDLINE | ID: mdl-32032366

ABSTRACT

Our inability to predict which mutations could result in antibiotic resistance has made it difficult to rapidly identify the emergence of resistance, identify pre-existing resistant populations, and manage our use of antibiotics to effectively treat patients and prevent or slow the spread of resistance. Here we investigated the potential for resistance against the new antitubercular nitroimidazole prodrugs pretomanid and delamanid to emerge in Mycobacterium tuberculosis, the causative agent of tuberculosis (TB). Deazaflavin-dependent nitroreductase (Ddn) is the only identified enzyme within M. tuberculosis that activates these prodrugs, via an F420H2-dependent reaction. We show that the native menaquinone-reductase activity of Ddn is essential for emergence from hypoxia, which suggests that for resistance to spread and pose a threat to human health, the native activity of Ddn must be at least partially retained. We tested 75 unique mutations, including all known sequence polymorphisms identified among ~15,000 sequenced M. tuberculosis genomes. Several mutations abolished pretomanid and delamanid activation in vitro, without causing complete loss of the native activity. We confirmed that a transmissible M. tuberculosis isolate from the hypervirulent Beijing family already possesses one such mutation and is resistant to pretomanid, before being exposed to the drug. Notably, delamanid was still effective against this strain, which is consistent with structural analysis that indicates delamanid and pretomanid bind to Ddn differently. We suggest that the mutations identified in this work be monitored for informed use of delamanid and pretomanid treatment and to slow the emergence of resistance.


Subject(s)
Antitubercular Agents/pharmacology , Bacterial Proteins , Drug Resistance, Bacterial , Mutation , Mycobacterium tuberculosis , Nitroimidazoles/pharmacology , Nitroreductases , Oxazoles/pharmacology , Protein Engineering , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Drug Resistance, Bacterial/drug effects , Drug Resistance, Bacterial/genetics , Mycobacterium tuberculosis/genetics , Mycobacterium tuberculosis/metabolism , Nitroreductases/genetics , Nitroreductases/metabolism , Polymorphism, Genetic
15.
ACS Infect Dis ; 5(2): 239-249, 2019 02 08.
Article in English | MEDLINE | ID: mdl-30485737

ABSTRACT

Respiration is a promising target for the development of new antimycobacterial agents, with a growing number of compounds in clinical development entering this target space. However, more candidate inhibitors are needed to expand the therapeutic options available for drug-resistant Mycobacterium tuberculosis infection. Here, we characterize a putative respiratory complex III (QcrB) inhibitor, TB47: a pyrazolo[1,5- a]pyridine-3-carboxamide. TB47 is active (MIC between 0.016 and 0.500 µg/mL) against a panel of 56 M. tuberculosis clinical isolates, including 37 multi-drug-resistant and two extensively drug-resistant strains. Pharmacokinetic and toxicity studies showed promising profiles, including negligible CYP450 interactions, cytotoxicity, and hERG channel inhibition. Consistent with other reported QcrB inhibitors, TB47 inhibits oxygen consumption only when the alternative oxidase, cytochrome bd, is deleted. A point mutation in the qcrB cd2-loop (H190Y, M. smegmatis numbering) rescues the inhibitory effects of TB47. Metabolomic profiling of TB47-treated M. tuberculosis H37Rv cultures revealed accumulation of steps in the TCA cycle and pentose phosphate pathway that are linked to reducing equivalents, suggesting that TB47 causes metabolic redox stress. In mouse infection models, a TB47 monotherapy was not bactericidal. However, TB47 was strongly synergistic with pyrazinamide and rifampicin, suggesting a promising role in combination therapies. We propose that TB47 is an effective lead compound for the development of novel tuberculosis chemotherapies.


Subject(s)
Antitubercular Agents/pharmacology , Electron Transport Complex III/antagonists & inhibitors , Extensively Drug-Resistant Tuberculosis/drug therapy , Mycobacterium tuberculosis/drug effects , Tuberculosis, Multidrug-Resistant/drug therapy , Animals , Antitubercular Agents/pharmacokinetics , Female , Metabolomics , Mice , Mice, Inbred BALB C , Microbial Sensitivity Tests , Pyridines/pharmacology
16.
N Z Med J ; 131(1487): 15-22, 2018 12 14.
Article in English | MEDLINE | ID: mdl-30543607

ABSTRACT

New Zealand has a low burden of multi-drug resistant TB (MDR-TB), but with increased mobility within the population, rapid detection and treatment of MDR-TB is a priority from the public health point of view. Mycobacterium Reference Laboratory in LabPLUS, Auckland City Hospital receives referred Mycobacterium tuberculosis complex (MTBC) isolates from all over New Zealand for second-line drug susceptibility testing (DST) and 24-loci MIRU VNTR genotyping. Between 2002 and 2013, 38 multidrug resistant Mycobacterium tuberculosis (MDR-TB) isolates were recorded by culture-based DST. A retrospective study revealed that in 12 of these 38 MDR-TB isolates (28%) there was a discrepancy between the genotypic and the phenotypic results. In order to address this, whole genome sequencing (WGS) was performed on the discrepant MDR-TB isolates. Reported here are the additional information on the drug resistant markers from WGS, which shed light on the discordance between results from the culture-based DST and the molecular diagnostic tests. These results underscore the utility of WGS in a reference mycobacterium laboratory in New Zealand to supplement other molecular tests and to assist in a rapid but accurate diagnosis and appropriate management of MDR-TB.


Subject(s)
Drug Resistance, Multiple, Bacterial/genetics , Mycobacterium tuberculosis/drug effects , Mycobacterium tuberculosis/genetics , Whole Genome Sequencing , Antitubercular Agents/pharmacology , Humans , Isoniazid/pharmacology , Microbial Sensitivity Tests , New Zealand , Phenotype , Rifampin/pharmacology
18.
Data Brief ; 21: 354-357, 2018 Dec.
Article in English | MEDLINE | ID: mdl-30364728

ABSTRACT

This article contains microbiome data from the upper respiratory tract of patients living with HIV/TB, HIV and TB from Meiktila, a town in Myanmar where there is a high incidence of HIV and TB. Microbiomes were compared for HIV/TB infected and healthy adults from the same population. We collected nasopharyngeal and oropharyngeal swabs from a total of 33 participants (Healthy {5}, HIV/TB {8}, HIV {14}, and TB {6}). DNA was extracted from the swabs and subjected to custom single step 16s rRNA sequencing on an Illumina MiSeq platform. The sequencing data is available via http://www.ncbi.nlm.nih.gov/bioproject/ PRJNA432583.

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