Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 37
Filtrar
1.
Methods Mol Biol ; 2387: 17-28, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34643898

RESUMO

Primary isolation of Mycobacterium ulcerans is the separation and growth of the bacterium from a mixed population either in clinical specimen or environmental specimen in pure cultures. It is a crucial activity as it can be used to monitor antimicrobial treatment, surveillance for antimicrobial resistance, and molecular epidemiology studies toward understanding pathogen ecology and transmission as well as pathogen biology. The process involves removal of unwanted fast-growing bacteria using 5% oxalic acid, inoculation on Lowenstein-Jensen medium supplemented with glycerol, and incubation at temperatures between 30 °C and 33 °C.

2.
PLoS Negl Trop Dis ; 15(9): e0009744, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34543293

RESUMO

INTRODUCTION: To date, eleven countries have been validated as having eliminated trachoma as a public health problem, including Ghana in 2018. Surveillance for recrudescence is needed both pre- and post-validation but evidence-based guidance on appropriate strategies is lacking. We explored two potential surveillance strategies in Ghana. METHODOLOGY/PRINCIPAL FINDINGS: Amongst randomly-selected communities enrolled in pre-validation on-going surveillance between 2011 and 2015, eight were identified as having had trachomatous-inflammation follicular (TF) prevalence ≥5% in children aged 1-9 years between 2012 and 2014. These eight were re-visited in 2015 and 2016 and neighbouring communities were also added ("TF trigger" investigations). Resident children aged 1-9 years were then examined for trachoma and had a conjunctival swab to test for Chlamydia trachomatis (Ct) and a dried blood spot (DBS) taken to test for anti-Pgp3 antibodies. These investigations identified at least one community with evidence of probable recent Ct ocular transmission. However, the approach likely lacks sufficient spatio-temporal power to be reliable. A post-validation surveillance strategy was also evaluated, this reviewed the ocular Ct infection and anti-Pgp3 seroprevalence data from the TF trigger investigations and from the pre-validation surveillance surveys in 2015 and 2016. Three communities identified as having ocular Ct infection >0% and anti-Pgp3 seroprevalence ≥15.0% were identified, and along with three linked communities, were followed-up as part of the surveillance strategy. An additional three communities with a seroprevalence ≥25.0% but no Ct infection were also followed up ("antibody and infection trigger" investigations). DBS were taken from all residents aged ≥1 year and ocular swabs from all children aged 1-9 years. There was evidence of transmission in the group of communities visited in one district (Zabzugu-Tatale). There was no or little evidence of continued transmission in other districts, suggesting previous infection identified was transient or potentially not true ocular Ct infection. CONCLUSIONS/SIGNIFICANCE: There is evidence of heterogeneity in Ct transmission dynamics in northern Ghana, even 10 years after wide-scale MDA has stopped. There is added value in monitoring Ct infection and anti-Ct antibodies, using these indicators to interrogate past or present surveillance strategies. This can result in a deeper understanding of transmission dynamics and inform new post-validation surveillance strategies. Opportunities should be explored for integrating PCR and serological-based markers into surveys conducted in trachoma elimination settings.

3.
Front Public Health ; 9: 706651, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34368069

RESUMO

Tuberculosis (TB), an airborne infectious disease caused by Mycobacterium tuberculosis complex (MTBC), remains a global health problem. West Africa has a unique epidemiology of TB that is characterized by medium- to high-prevalence. Moreover, the geographical restriction of M. africanum to the sub-region makes West Africa have an extra burden to deal with a two-in-one pathogen. The region is also burdened with low case detection, late reporting, poor treatment adherence leading to development of drug resistance and relapse. Sporadic studies conducted within the subregion report higher burden of drug resistant TB (DRTB) than previously thought. The need for more sensitive and robust tools for routine surveillance as well as to understand the mechanisms of DRTB and transmission dynamics for the design of effective control tools, cannot be overemphasized. The advancement in molecular biology tools including traditional fingerprinting and next generation sequencing (NGS) technologies offer reliable tools for genomic epidemiology. Genomic epidemiology provides in-depth insight of the nature of pathogens, circulating strains and their spread as well as prompt detection of the emergence of new strains. It also offers the opportunity to monitor treatment and evaluate interventions. Furthermore, genomic epidemiology can be used to understand potential emergence and spread of drug resistant strains and resistance mechanisms allowing the design of simple but rapid tools. In this review, we will describe the local epidemiology of MTBC, highlight past and current investigations toward understanding their biology and spread as well as discuss the relevance of genomic epidemiology studies to TB control in West Africa.


Assuntos
Mycobacterium tuberculosis , Tuberculose Resistente a Múltiplos Medicamentos , Tuberculose , África Ocidental/epidemiologia , Genômica , Humanos , Mycobacterium tuberculosis/genética , Tuberculose/diagnóstico , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico
4.
PLoS One ; 16(8): e0255433, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34437584

RESUMO

Findings from previous comparative genomics studies of the Mycobacterium tuberculosis complex (MTBC) suggest genomic variation among the genotypes may have phenotypic implications. We investigated the diversity in the phenotypic profiles of the main prevalent MTBC genotypes in West Africa. Thirty-six whole genome sequenced drug susceptible MTBC isolates belonging to lineages 4, 5 and 6 were included in this study. The isolates were phenotypically characterized for urease activity, tween hydrolysis, Thiophen-2-Carboxylic Acid Hydrazide (TCH) susceptibility, nitric oxide production, and growth rate in both liquid (7H9) and solid media (7H11 and Löwenstein-Jensen (L-J)). Lineage 4 isolates showed the highest growth rate in both liquid (p = 0.0003) and on solid (L-J) media supplemented with glycerol (p<0.001) or pyruvate (p = 0.005). L6 isolates optimally utilized pyruvate compared to glycerol (p<0.001), whereas L5 isolates grew similarly on both media (p = 0.05). Lineage 4 isolates showed the lowest average time to positivity (TTP) (p = 0.01; Average TTP: L4 = 15days, L5 = 16.7days, L6 = 29.7days) and the highest logCFU/mL (p = 0.04; average logCFU/mL L4 = 5.9, L5 = 5.0, L6 = 4.4) on 7H11 supplemented with glycerol, but there was no significant difference in growth on 7H11 supplemented with pyruvate (p = 0.23). The highest release of nitrite was recorded for L5 isolates, followed by L4 and L6 isolates. However, the reverse was observed in the urease activity for the lineages. All isolates tested were resistant to TCH except for one L6 isolate. Comparative genomic analyses revealed several mutations that might explain the diverse phenotypic profiles of these isolates. Our findings showed significant phenotypic diversity among the MTBC lineages used for this study.

5.
Sci Rep ; 11(1): 13945, 2021 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-34230563

RESUMO

Acute gastroenteritis associated with diarrhea is considered a serious disease in Africa and South Asia. In this study, we examined the trends in the causative pathogens of diarrhea and the corresponding gut microbiota in Ghana using microbiome analysis performed on diarrheic stools via 16S rRNA sequencing. In total, 80 patients with diarrhea and 34 healthy adults as controls, from 2017 to 2018, were enrolled in the study. Among the patients with diarrhea, 39 were norovirus-positive and 18 were rotavirus-positive. The analysis of species richness (Chao1) was lower in patients with diarrhea than that in controls. Beta-diversity analysis revealed significant differences between the two groups. Several diarrhea-related pathogens (e.g., Escherichia-Shigella, Klebsiella and Campylobacter) were detected in patients with diarrhea. Furthermore, co-infection with these pathogens and enteroviruses (e.g., norovirus and rotavirus) was observed in several cases. Levels of both Erysipelotrichaceae and Staphylococcaceae family markedly differed between norovirus-positive and -negative diarrheic stools, and the 10 predicted metabolic pathways, including the carbohydrate metabolism pathway, showed significant differences between rotavirus-positive patients with diarrhea and controls. This comparative study of diarrheal pathogens in Ghana revealed specific trends in the gut microbiota signature associated with diarrhea and that pathogen-dependent dysbiosis occurred in viral gastroenteritis.

6.
Int J Infect Dis ; 109: 294-303, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34273514

RESUMO

OBJECTIVE: We conducted a cross-sectional study in the five administrative regions of Northern Ghana to determine the diversity of Mycobacterium tuberculosis complex (MTBC) sub/lineages and their susceptibility to isoniazid (INH) and rifampicin (RIF). METHODS: Sputum specimens were collected and cultured from 566 pulmonary tuberculosis patients reporting to 17 health facilities from 2015 to 2019. Mycobacterial isolates obtained from solid cultures were confirmed as members of the MTBC by PCR amplification of IS6110 and rpoß and assigned lineages and sub-lineages using spoligotyping. RESULTS: Of 294 mycobacterial isolates recovered, MTBC species identified were: M. tuberculosis sensu stricto (Mtbss) 241 (82.0%), M. africanum 41 (13.9%) and M. bovis four (1.4%) with eight (2.7%) unidentified. The human-adapted lineages (L) identified (N=279) were L1 (8/279, 2.9%), L2 (15/279, 5.4%), L3 (7/279, 2.5%), L4 (208/279, 74.5%), L5 (13/279, 4.7%) and L6 (28/279, 10.0%) with three unidentified lineages. Among the 208 L4, the dominant sub-lineages in the region were the Cameroon 120/208 (57.7%) and Ghana 50/208 (24.0%). We found 4.4% (13/294) and 0.7% (2/294) of the patients infected with MTBC isolates resistant to INH only and RIF only, respectively, with 2.4% (7/294) being infected with MDR strains. Whereas L6 was associated with the elderly, we identified that the Ghana sub-lineage of L4 was associated with both INH and MDR (p<0.05), making them important TB pathogens in Northern Ghana and a growing public health concern.


Assuntos
Mycobacterium tuberculosis , Preparações Farmacêuticas , Tuberculose Resistente a Múltiplos Medicamentos , Idoso , Antituberculosos/farmacologia , Antituberculosos/uso terapêutico , Estudos Transversais , Genótipo , Gana/epidemiologia , Humanos , Testes de Sensibilidade Microbiana , Epidemiologia Molecular , Mycobacterium tuberculosis/genética , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/epidemiologia
7.
Int J Infect Dis ; 106: 13-22, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33667696

RESUMO

OBJECTIVE: To retrospectively investigate the cause of recurring tuberculosis (rcTB) among participants with pulmonary TB recruited from a prospective population-based study conducted between July 2012 and December 2015. METHODS: Mycobacterium tuberculosis complex isolates obtained from rcTB cases were characterized by standard mycobacterial genotyping tools, whole-genome sequencing, and phylogenetic analysis carried out to assess strain relatedness. RESULTS: The majority (58.3%, 21/36) of study participants with rcTB episodes had TB recurrence within 12 months post treatment. TB strains with isoniazid (INH) resistance were found in 19.4% (7/36) of participants at the primary episode, of which 29% (2/7) were also rifampicin-resistant. On TB recurrence, an INH-resistant strain was found in a larger proportion of participants, 27.8% (10/36), of which 40% (4/10) were MDR-TB strains. rcTB was attributed to relapse (same strain) in 75.0% (27/36) of participants and 25.0% (9/36) to re-infection. CONCLUSION: Our findings indicate that previous unresolved infectiondue to inadequate treatment, may be the major cause of rcTB.


Assuntos
Genômica , Habitação , Mycobacterium tuberculosis/genética , Tuberculose/epidemiologia , Tuberculose/transmissão , Adulto , Antituberculosos/uso terapêutico , Feminino , Gana/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Mycobacterium tuberculosis/fisiologia , Filogenia , Recidiva , Estudos Retrospectivos , Tuberculose/tratamento farmacológico , Sequenciamento Completo do Genoma
8.
PLoS One ; 16(3): e0238898, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33730036

RESUMO

CONTEXT: Available molecular epidemiological data from recent studies suggest significant genetic variation between the different lineages of Mycobacterium tuberculosis complex (MTBC) and the MTBC lineages might have adapted to different human populations. AIM: This study sought to determine the population structure of clinical MTBC isolates from the Volta Region of Ghana. METHODS: The MTBC isolates obtained from collected sputum samples were identified by PCR detecting of IS6110 and genotyped using spoligotyping. Non-tuberculous mycobacterial isolates were characterized by amplification of the heat shock protein 65 (hsp65) gene and sequencing. The drug susceptibility profiles of the MTBCs determined using GenoType MTBDRplus. RESULTS: One hundred and seventeen (117, 93.6%) out of 125 mycobacterial positive isolates were characterized as members of the MTBC of which M. tuberculosis sensu stricto (MTBss) and M. africanum (MAF) were respectively 94 (80.3%) and 23 (19.7%). In all, 39 distinct spoligotype patterns were obtained; 26 for MTBss and 13 for MAF lineages. Spoligotyping identified 89 (76%) Lineage 4, 16 (13.6%) Lineage 5, 7 (6.0%) Lineage 6, 3 (2.6%) Lineage 2, 1(0.9%) Lineage 3 and 1 (0.9%) Lineage 1. Among the Lineage 4 isolates, 62/89 (69.7%) belonged to Cameroon sub-lineage, 13 (14.7%) Ghana, 8 (9.0%) Haarlem, 2 (2.2%) LAM, 1 (1.1%) Uganda I, 1 (1.1%) X and the remaining two (2.2%) were orphan. Significant localization of MAF was found within the Ho municipality (n = 13, 29.5%) compared to the more cosmopolitan Ketu-South/Aflao (n = 3, 8.3%) (p-value = 0.017). Eight (8) non-tuberculous mycobacteria were characterized as M. abscessus (7) and M. fortuitum (1). CONCLUSION: We confirmed the importance of M. africanum lineages as a cause of TB in the Volta region of Ghana.


Assuntos
Mycobacterium/genética , Tuberculose/epidemiologia , Adulto , Antituberculosos/farmacologia , DNA Bacteriano/genética , DNA Bacteriano/metabolismo , Feminino , Genótipo , Gana/epidemiologia , Humanos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Mycobacterium/efeitos dos fármacos , Mycobacterium/isolamento & purificação , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/isolamento & purificação , Micobactérias não Tuberculosas/genética , Micobactérias não Tuberculosas/isolamento & purificação , Prevalência , Escarro/microbiologia , Tuberculose/microbiologia , Tuberculose/patologia
9.
Microb Genom ; 7(2)2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33555243

RESUMO

Human tuberculosis (TB) is caused by members of the Mycobacterium tuberculosis complex (MTBC). The MTBC comprises several human-adapted lineages known as M. tuberculosis sensu stricto, as well as two lineages (L5 and L6) traditionally referred to as Mycobacterium africanum. Strains of L5 and L6 are largely limited to West Africa for reasons unknown, and little is known of their genomic diversity, phylogeography and evolution. Here, we analysed the genomes of 350 L5 and 320 L6 strains, isolated from patients from 21 African countries, plus 5 related genomes that had not been classified into any of the known MTBC lineages. Our population genomic and phylogeographical analyses showed that the unclassified genomes belonged to a new group that we propose to name MTBC lineage 9 (L9). While the most likely ancestral distribution of L9 was predicted to be East Africa, the most likely ancestral distribution for both L5 and L6 was the Eastern part of West Africa. Moreover, we found important differences between L5 and L6 strains with respect to their phylogeographical substructure and genetic diversity. Finally, we could not confirm the previous association of drug-resistance markers with lineage and sublineages. Instead, our results indicate that the association of drug resistance with lineage is most likely driven by sample bias or geography. In conclusion, our study sheds new light onto the genomic diversity and evolutionary history of M. africanum, and highlights the need to consider the particularities of each MTBC lineage for understanding the ecology and epidemiology of TB in Africa and globally.


Assuntos
Farmacorresistência Bacteriana , Mycobacterium tuberculosis/classificação , Tuberculose/microbiologia , Sequenciamento Completo do Genoma/métodos , África Oriental , África Ocidental , Evolução Molecular , Genoma Bacteriano , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/isolamento & purificação , Filogenia , Filogeografia
10.
Tuberc Res Treat ; 2020: 1097581, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32832153

RESUMO

Introduction: The convergence of TB and HIV dual epidemics is a major public health challenge in Ghana as well as many developing countries. Treatment outcome monitoring is a vital part of the surveillance needed to successfully eliminate TB. The impact of HIV status and demographic and treatment-related factors on adverse TB treatment outcome has not been studied in the Greater Accra Regional Hospital. This study determined factors associated with TB treatment outcome in patients with TB-HIV coinfection and TB-only infection in the hospital. Method: A cross-sectional study was carried out in the Greater Accra Regional Hospital. We reviewed TB treatment cards of patients who received treatment for tuberculosis in the hospital from 2008 to 2016. Data on treatment outcome and sociodemographic and clinical characteristics were extracted on TB-only-infected and TB/HIV-coinfected patients. The chi-squared test and binary and multiple logistic regression models were used to assess factors associated with adverse treatment outcome. Results: Out of the 758 patient records analyzed, 174 (22.9%) were TB-HIV-coinfected patients. Overall treatment success for all TB patients was 88.1% (668/758). About 11.9% (90/758) of the patients had an adverse treatment outcome, including treatment failure 0.9% (7/758), defaulting 0.9% (7/758), and death 10.0% (76/758). TB-HIV-coinfected patients' treatment success was 78.1% (136/174). TB-only patients' treatment success was 91.4% (532/582). Independent predictors of adverse treatment outcome were found to be as follows: being HIV positive (aOR: 3.85, 95% CI: 2.19-6.75; p < 0.01); aged 65 and above (aOR: 1.76, 95% CI: 1.44-1.54; p = 0.01); and previously failed TB treatment (aOR: 5.02, 95% CI: 2.09-28.87; p < 0.01). Conclusion: Treatment outcome for TB-HIV-coinfected patients is below the WHO target. HIV status, age, and category of patient of the TB patients were associated with adverse treatment outcome. Strengthening the TB/HIV collaborative efforts by stakeholders is required for good treatment outcomes.

11.
PLoS One ; 15(7): e0236016, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32649692

RESUMO

Cholera remains a major global public health threat and continuous emergence of new Vibrio cholerae strains is of major concern. We conducted a molecular epidemiological study to detect virulence markers and antimicrobial resistance patterns of V. cholerae isolates obtained from the 2012-2015 cholera outbreaks in Ghana. Archived clinical isolates obtained from the 2012, 2014 and 2015 cholera outbreaks in Ghana were revived by culture and subjected to microscopy, biochemical identification, serotyping, antibiotic susceptibility testing, molecular detection of distinct virulence factors and Multi-Locus Variable-Number of Tandem-Repeat Analysis (MLVA). Of 277 isolates analysed, 168 (60.6%) were confirmed to be V. cholerae and 109 (39.4%) isolates constituted other bacteria (Escherichia coli, Aeromonas sobria, Pseudomonas aeruginosa, Enterobacter cloacae and Enterococci faecalis). Serotyping the V. cholerae isolates identified 151 (89.9%) as Ogawa, 3 (1.8%) as Inaba and 14 (8.3%) as non-O1/O139 serogroup. The O1 serogroup isolates (154/168, 91.7%) carried the cholera toxin ctxB gene as detected by PCR. Additional virulence genes detected include zot, tcpA, ace, rtxC, toxR, rtxA, tcpP, hlyA and tagA. The most common and rare virulence factors detected among the isolates were rtxC (165 isolates) and tcpP (50 isolates) respectively. All isolates from 2014 and 2015 were multidrug resistant against the selected antibiotics. MLVA differentiated the isolates into 2 large unique clones A and B, with each predominating in a particular year. Spatial analysis showed clustering of most isolates at Ablekuma sub-district. Identification of several virulence genes among the two different genotypes of V. cholerae isolates and resistance to first- and second-line antibiotics, calls for scaleup of preventive strategies to reduce transmission, and strengthening of public health laboratories for rapid antimicrobial susceptibility testing to guide accurate treatment. Our findings support the current WHO licensed cholera vaccines which include both O1 Inaba and Ogawa serotypes.


Assuntos
Cólera/epidemiologia , Vibrio cholerae/metabolismo , Antibacterianos/farmacologia , Cólera/diagnóstico , Cólera/microbiologia , Toxina da Cólera/genética , Toxina da Cólera/metabolismo , Surtos de Doenças , Farmacorresistência Bacteriana Múltipla/genética , Gana/epidemiologia , Humanos , Testes de Sensibilidade Microbiana , Filogenia , Sorogrupo , Sequências de Repetição em Tandem/genética , Vibrio cholerae/classificação , Vibrio cholerae/isolamento & purificação , Vibrio cholerae/patogenicidade , Virulência/genética
12.
Front Med (Lausanne) ; 7: 161, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32509791

RESUMO

Whole genome sequencing (WGS) is progressively being used to investigate the transmission dynamics of Mycobacterium tuberculosis complex (MTBC). We used WGS analysis to resolve traditional genotype clusters and explored the spatial distribution of confirmed recent transmission clusters. Bacterial genomes from a total of 452 MTBC isolates belonging to large traditional clusters from a population-based study spanning July 2012 and December 2015 were obtained through short read next-generation sequencing using the illumina HiSeq2500 platform. We performed clustering and spatial analysis using specified R packages and ArcGIS. Of the 452 traditional genotype clustered genomes, 314 (69.5%) were confirmed clusters with a median cluster size of 7.5 genomes and an interquartile range of 4-12. Recent tuberculosis (TB) transmission was estimated as 24.7%. We confirmed the wide spread of a Cameroon sub-lineage clone with a cluster size of 78 genomes predominantly from the Ablekuma sub-district of Accra metropolis. More importantly, we identified a recent transmission cluster associated with isoniazid resistance belonging to the Ghana sub-lineage of lineage 4. WGS was useful in detecting unsuspected outbreaks; hence, we recommend its use not only as a research tool but as a surveillance tool to aid in providing the necessary guided steps to track, monitor, and control TB.

13.
Genes (Basel) ; 11(2)2020 01 27.
Artigo em Inglês | MEDLINE | ID: mdl-32012697

RESUMO

In Ghana, gap-junction protein ß 2 (GJB2) variants account for about 25.9% of familial hearing impairment (HI) cases. The GJB2-p.Arg143Trp (NM_004004.6:c.427C>T/OMIM: 121011.0009/rs80338948) variant remains the most frequent variant associated with congenital HI in Ghana, but has not yet been investigated in clinical practice. We therefore sought to design a rapid and cost-effective test to detect this variant. We sampled 20 hearing-impaired and 10 normal hearing family members from 8 families segregating autosomal recessive non syndromic HI. In addition, a total of 111 unrelated isolated individuals with HI were selected, as well as 50 normal hearing control participants. A restriction fragment length polymorphism (RFLP) test was designed, using the restriction enzyme NciI optimized and validated with Sanger sequencing, for rapid genotyping of the common GJB2-p.Arg143Trp variant. All hearing-impaired participants from 7/8 families were homozygous positive for the GJB2-p.Arg143Trp mutation using the NciI-RFLP test, which was confirmed with Sanger sequencing. The investigation of 111 individuals with isolated non-syndromic HI that were previously Sanger sequenced found that the sensitivity of the GJB2-p.Arg143Trp NciI-RFLP testing was 100%. All the 50 control subjects with normal hearing were found to be negative for the variant. Although the test is extremely valuable, it is not 100% specific because it cannot differentiate between other mutations at the recognition site of the restriction enzyme. The GJB2-p.Arg143Trp NciI-RFLP-based diagnostic test had a high sensitivity for genotyping the most common GJB2 pathogenic and founder variant (p.Arg143Trp) within the Ghanaian populations. We recommend the adoption and implementation of this test for hearing impairment genetic clinical investigations to complement the newborn hearing screening program in Ghana. The present study is a practical case scenario of enhancing genetic medicine in Africa.


Assuntos
Conexinas/genética , Perda Auditiva/diagnóstico , Perda Auditiva/genética , Adulto , Conexinas/metabolismo , Análise Custo-Benefício/métodos , Surdez/genética , Família , Feminino , Gana/epidemiologia , Perda Auditiva Neurossensorial/genética , Homozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Mutação/genética , Linhagem , Polimorfismo de Fragmento de Restrição/genética
14.
PLoS One ; 14(3): e0209395, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30830912

RESUMO

BACKGROUND: Bovine tuberculosis (bTB) caused by Mycobacterium bovis is a re-emerging problem in both livestock and humans. The association of some M. bovis strains with hyper-virulence, MDR-TB and disseminated disease makes it imperative to understand the biology of the pathogen. METHODS: Mycobacterium bovis (15) among 1755 M. tuberculosis complex (MTBC) isolated between 2012 and 2014 were characterized and analyzed for associated patient demography and other risk factors. Five of the M. bovis isolates were whole-genome sequenced and comparatively analyzed against a global collection of published M. bovis genomes. RESULTS: Mycobacterium bovis was isolated from 3/560(0.5%) females and 12/1195(1.0%) males with pulmonary TB. The average age of M. bovis infected cases was 46.8 years (7-72years). TB patients from the Northern region of Ghana (1.9%;4/212) had a higher rate of infection with M. bovis (OR = 2.7,p = 0.0968) compared to those from the Greater Accra region (0.7%;11/1543). Among TB patients with available HIV status, the odds of isolating M. bovis from HIV patients (2/119) was 3.3 higher relative to non-HIV patients (4/774). Direct contact with livestock or their unpasteurized products was significantly associated with bTB (p<0.0001, OR = 124.4,95% CI = 30.1-508.3). Two (13.3%) of the M. bovis isolates were INH resistant due to the S315T mutation in katG whereas one (6.7%) was RIF resistant with Q432P and I1491S mutations in rpoB. M. bovis from Ghana resolved as mono-phyletic branch among mostly M. bovis from Africa irrespective of the host and were closest to the root of the global M. bovis phylogeny. M. bovis-specific amino acid mutations were detected among MTBC core genes such as mce1A, mmpL1, pks6, phoT, pstB, glgP and Rv2955c. Additional mutations P6T in chaA, G187E in mgtC, T35A in Rv1979c, S387A in narK1, L400F in fas and A563T in eccA1 were restricted to the 5 clinical M. bovis from Ghana. CONCLUSION: Our data indicate potential zoonotic transmission of bTB in Ghana and hence calls for intensified public education on bTB, especially among risk groups.


Assuntos
Infecções por HIV/epidemiologia , Mycobacterium bovis/genética , Tuberculose Pulmonar/epidemiologia , Tuberculose Pulmonar/microbiologia , Sequenciamento Completo do Genoma/métodos , Adolescente , Adulto , Idoso , Animais , Bovinos , Criança , Comorbidade , DNA Bacteriano/genética , Farmacorresistência Bacteriana , Feminino , Gana , Humanos , Masculino , Pessoa de Meia-Idade , Epidemiologia Molecular , Mutação , Mycobacterium bovis/classificação , Mycobacterium bovis/isolamento & purificação , Filogenia , Tuberculose Bovina/epidemiologia , Tuberculose Bovina/transmissão , Adulto Jovem
15.
PLoS One ; 14(2): e0211822, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30730937

RESUMO

BACKGROUND: Diabetes Mellitus (DM) is a known risk factor for tuberculosis (TB) but little is known on TB-Diabetes Mellitus (TBDM) co-morbidity in Sub-Saharan Africa. METHODS: Consecutive TB cases registered at a tertiary facility in Ghana were recruited from September 2012 to April 2016 and screened for DM using random blood glucose and glycated hemoglobin (HbA1c) level. TB patients were tested for other clinical parameters including HIV co-infection and TB lesion location. Mycobacterial isolates obtained from collected sputum samples were characterized by standard methods. Associations between TBDM patients' epidemiological as well as microbiological variables were assessed. RESULTS: The prevalence of DM at time of diagnosis among 2990 enrolled TB cases was 9.4% (282/2990). TBDM cases were significantly associated with weight loss, poor appetite, night sweat and fatigue (p<0.001) and were more likely (p<0.001) to have lower lung cavitation 85.8% (242/282) compared to TB Non-Diabetic (TBNDM) patients 3.3% (90/2708). We observed 22.3% (63/282) treatment failures among TBDM patients compared to 3.8% (102/2708) among TBNDM patients (p<0.001). We found no significant difference in the TBDM burden attributed by M. tuberculosis sensu stricto (Mtbss) and Mycobacterium africanum (Maf) and (Mtbss; 176/1836, 9.6% and Maf; 53/468, 11.3%, p = 0.2612). We found that diabetic individuals were suggestively likely to present with TB caused by M. africanum Lineage 6 as opposed to Mtbss (odds ratio (OR) = 1.52; 95% confidence interval (CI): 0.92-2.42, p = 0.072). CONCLUSION: Our findings confirms the importance of screening for diabetes during TB diagnosis and highlights the association between genetic diversity and diabetes. in Ghana.


Assuntos
Coinfecção , Complicações do Diabetes , Infecções por HIV , HIV-1 , Mycobacterium tuberculosis , Tuberculose , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Coinfecção/diagnóstico , Coinfecção/epidemiologia , Coinfecção/microbiologia , Coinfecção/virologia , Complicações do Diabetes/diagnóstico , Complicações do Diabetes/epidemiologia , Complicações do Diabetes/microbiologia , Complicações do Diabetes/virologia , Feminino , Gana/epidemiologia , Infecções por HIV/diagnóstico , Infecções por HIV/epidemiologia , Infecções por HIV/microbiologia , Infecções por HIV/virologia , Humanos , Masculino , Pessoa de Meia-Idade , Tuberculose/diagnóstico , Tuberculose/epidemiologia , Tuberculose/microbiologia , Tuberculose/virologia
16.
PLoS Negl Trop Dis ; 12(12): e0007027, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30550537

RESUMO

BACKGROUND: Validation of elimination of trachoma as a public health problem is based on clinical indicators, using the WHO simplified grading system. Chlamydia trachomatis (Ct) infection and anti-Ct antibody responses (anti-Pgp3) have both been evaluated as alternative indicators in settings with varying levels of trachoma. There is a need to evaluate the feasibility of using tests for Ct infection and anti-Pgp3 antibodies at scale in a trachoma-endemic country and to establish the added value of the data generated for understanding transmission dynamics in the peri-elimination setting. METHODOLOGY/PRINCIPAL FINDINGS: Dried blood spots for serological testing and ocular swabs for Ct infection testing (taken from children aged 1-9 years) were integrated into the pre-validation trachoma surveys conducted in the Northern and Upper West regions of Ghana in 2015 and 2016. Ct infection was detected using the GeneXpert PCR platform and the presence of anti-Pgp3 antibodies was detected using both the ELISA assay and multiplex bead array (MBA). The overall mean cluster-summarised TF prevalence (the clinical indicator) was 0.8% (95% CI: 0.6-1.0) and Ct infection prevalence was 0.04% (95%CI: 0.00-0.12). Anti-Pgp3 seroprevalence using the ELISA was 5.5% (95% CI: 4.8-6.3) compared to 4.3% (95%CI: 3.7-4.9) using the MBA. There was strong evidence from both assays that seropositivity increased with age (p<0.001), although the seroconversion rate was estimated to be very low (between 1.2 to 1.3 yearly events per 100 children). CONCLUSIONS/SIGNIFICANCE: Infection and serological data provide useful information to aid in understanding Ct transmission dynamics. Elimination of trachoma as a public health problem does not equate to the absence of ocular Ct infection nor cessation in acquisition of anti-Ct antibodies.


Assuntos
Chlamydia trachomatis/isolamento & purificação , Tracoma/microbiologia , Anticorpos Antibacterianos/sangue , Criança , Pré-Escolar , Chlamydia trachomatis/genética , Chlamydia trachomatis/imunologia , Feminino , Gana/epidemiologia , Humanos , Lactente , Masculino , Reação em Cadeia da Polimerase/métodos , Saúde Pública , Estudos Soroepidemiológicos , Testes Sorológicos/métodos , Tracoma/sangue , Tracoma/epidemiologia , Tracoma/transmissão
17.
J Med Microbiol ; 67(12): 1718-1727, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30388066

RESUMO

PURPOSE: Differentiation of the Mycobacterium tuberculosis complex (MTBc) from non-tuberculous mycobacteria (NTM) is important for tuberculosis diagnosis and is a prerequisite for reliable phenotypic drug-resistance testing. We evaluated the performance of the rapid MPT64 antigen identification test for the detection of Mycobacterium africanum lineage 5 (MAF L5). METHODOLOGY: Smear-positive tuberculosis patients' sputa were included prospectively. Culture was performed on Löwenstein-Jensen medium and, when positive, the MPT64 test and the classical para-nitro benzoic acid susceptibility and heat-labile catalase (PNB/catalase) identification tests were performed. The MPT64 test was repeated 14 days after an initially negative first testing. Direct spoligotyping was performed for MTBc lineage determination. RESULTS: In total, 333 isolates were tested for all of the methods. Three hundred and twenty-two (96.7 %) were pure MTBc, by agreement between spoligotyping and PNB/catalase, and 11 were NTM or a mixture of MTBc/NTM. The MPT64 test conducted on day zero of culture-positivity correctly identified most of the pure MTBc isolates (93.2 %, 300/322), but it failed to detect 24 % of the L5 isolates (18/75) versus 2 % (4/202) of the L4 ones [OR=15.6 (5.3-45.8), P<0.0001], with improved sensitivity for L5 detection on repeat testing after 14 days. The L5-wide non-synonymous single-nucleotide polymorphism in the mpt64 gene may explain the poor performance of the MPT64 test for L5. CONCLUSION: The MPT64 test has a lower sensitivity for detecting L5 isolates of the MTBc, and can be considered as a first-screening test that should be confirmed by another identification method when it produces negative results in countries with L5. Given the microbiological bias in both the isolation and identification of MAF lineages, diagnostics with high sensitivity for direct testing on clinical material are preferable.


Assuntos
Antígenos de Bactérias/isolamento & purificação , Técnicas de Tipagem Bacteriana/métodos , Mycobacterium tuberculosis/classificação , Mycobacterium tuberculosis/isolamento & purificação , Tuberculose/diagnóstico , Regulação Bacteriana da Expressão Gênica , Humanos , Polimorfismo de Nucleotídeo Único , Sensibilidade e Especificidade , Tuberculose/microbiologia
18.
Int J Mycobacteriol ; 7(3): 222-227, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30198500

RESUMO

Background: Sputum culture is limited to centralized facilities. Thus, samples require transportation from peripheral laboratories to these facilities, compromising specimen quality since it is difficult to maintain cold chain. We evaluated OMNIgene SPUTUM Reagent (OMS) for transporting sputum samples for tuberculosis (TB) testing. The study was carried out at Noguchi Memorial Institute for Medical Research using sputa from Korle Bu Teaching Hospital and La General Hospital in Ghana. Methods: In a laboratory-based controlled experiment (CE), sputum contaminants were determined on blood agar before treatment with OMS and N-acetyl-L-cysteine-sodium hydroxide (NALC-NaOH). TB testing included smear microscopy, culture, and Xpert MTB/RIF. Afterward, two peripheral laboratories were trained to transport sputum samples with OMS without cold chain. Positivity, negativity, and contamination rates were compared between both methods using Chi-square and Fisher's exact tests. Cohen's Kappa was also used to determine agreements. Results: Among 104 sputum samples analyzed in the CE, 93 (89.4%) had bacterial growth on blood agar before decontamination, while 6 (5.8%) and 5 (4.8%) contaminated after NALC-NaOH and OMS treatment, respectively. Contamination was high with NALC-NaOH (12.8%) than OMS (4.3%) on Lowenstein-Jensen media (P < 0.001), but mycobacterial positivity was comparable: NALC-NaOH of 74.5% and OMS of 78.7%. Smear positivity after NALC-NaOH treatment was 89.4% and OMS was 75.9% (P = 0.491). All except one of the samples tested positive by Xpert MTB/RIF after both treatment. Sixteen samples were evaluated in the field experiment and 81.3% yielded positive culture, and no contamination on LJ was observed. Conclusion: Our findings indicate that OMS works well as a transport and decontaminating reagent of samples for TB testing.


Assuntos
Descontaminação/métodos , Indicadores e Reagentes/química , Mycobacterium tuberculosis/isolamento & purificação , Manejo de Espécimes/métodos , Escarro/microbiologia , Técnicas Bacteriológicas/métodos , Gana , Humanos , Laboratórios Hospitalares , Refrigeração , Sensibilidade e Especificidade , Transportes , Tuberculose/diagnóstico
19.
Sci Rep ; 8(1): 11269, 2018 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-30050166

RESUMO

Mycobacterium africanum (Maf) causes a substantial proportion of human tuberculosis in some countries of West Africa, but little is known on this pathogen. We compared the genomes of 253 Maf clinical isolates from Ghana, including N = 175 Lineage 5 (L5) and N = 78 Lineage 6 (L6). We found that the genomic diversity of L6 was higher than in L5 despite the smaller sample size. Regulatory proteins appeared to evolve neutrally in L5 but under purifying selection in L6. Even though over 90% of the human T cell epitopes were conserved in both lineages, L6 showed a higher ratio of non-synonymous to synonymous single nucleotide variation in these epitopes overall compared to L5. Of the 10% human T cell epitopes that were variable, most carried mutations that were lineage-specific. Our findings indicate that Maf L5 and L6 differ in some of their population genomic characteristics, possibly reflecting different selection pressures linked to distinct ecological niches.


Assuntos
Variação Genética , Genoma Bacteriano , Genômica , Genótipo , Mycobacterium/genética , Tuberculose/microbiologia , Gana , Humanos , Mycobacterium/classificação , Mycobacterium/isolamento & purificação
20.
PLoS Negl Trop Dis ; 12(6): e0006560, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29870529

RESUMO

BACKGROUND: Buruli ulcer (BU), a necrotizing skin infection caused by Mycobacterium ulcerans is the third most important mycobacterial disease globally after tuberculosis and leprosy in immune competent individuals. This study reports on the retrospective analyses of microbiologically confirmed Buruli ulcer (BU) cases in seventy-five health facilities in Ghana. METHOD/PRINCIPAL FINDINGS: Pathological samples were collected from BU lesions and transported either through courier services or by car directly to the laboratory. Samples were processed and analysed by IS2404 PCR, culture and Ziehl-Neelsen staining for detection of acid-fast bacilli. From 2008 to 2016, we analysed by PCR, 2,287 samples of 2,203 cases from seventy-five health facilities in seven regions of Ghana (Ashanti, Brong Ahafo, Central, Eastern, Greater Accra, Northern and Volta). The mean annual positivity rate was 46.2% and ranged between 14.6% and 76.2%. The yearly positivity rates from 2008 to 2016 were 52.3%, 76.2%, 56.7%, 53.8%, 41.2%, 41.5%, 22.9%, 28.5% and 14.6% respectively. Of the 1,020 confirmed cases, the ratio of female to male was 518 and 502 respectively. Patients who were 15 years of age and below accounted for 39.8% of all cases. The median age was 20 years (IQR = 10-43). Ulcerative lesions were 69.2%, nodule (9.6%), plaque (2.9%), oedema (2.5%), osteomyelitis (1.1%), ulcer/oedema (9.5%) and ulcer/plaque (5.2%). Lesions frequently occurred on the lower limbs (57%) followed by the upper limbs (38%), the neck and head (3%) and the least found on the abdomen (2%). CONCLUSIONS/SIGNIFICANCE: Our findings show a decline in microbiological confirmed rates over the years and therefore call for intensive education on case recognition to prevent over-diagnosis as BU cases decline.


Assuntos
Úlcera de Buruli/diagnóstico , Mycobacterium ulcerans/isolamento & purificação , Adolescente , Adulto , Úlcera de Buruli/complicações , Úlcera de Buruli/epidemiologia , Úlcera de Buruli/microbiologia , Criança , Pré-Escolar , Técnicas de Laboratório Clínico , Feminino , Gana/epidemiologia , Instalações de Saúde , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Mycobacterium ulcerans/genética , Osteomielite/microbiologia , Reação em Cadeia da Polimerase/métodos , Estudos Retrospectivos , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...