22 research outputs found
Genotyping of Mycobacterium tuberculosis clinical isolates in two cities of Turkey: Description of a new family of genotypes that is phylogeographically specific for Asia Minor
BACKGROUND: Population-based bacterial genetics using repeated DNA loci is an efficient approach to study the biodiversity and phylogeographical structure of human pathogens, such as Mycobacterium tuberculosis, the agent of tuberculosis. Indeed large genetic diversity databases are available for this pathogen and are regularly updated. No population-based polymorphism data were yet available for M. tuberculosis in Turkey, at the crossroads of Eurasia. RESULTS: A total of 245 DNAs from Mycobacterium tuberculosis clinical isolates from tuberculosis patients residing in Turkey (Malatya n = 147 or Ankara n = 98) were genotyped by spoligotyping, a high-throughput genotyping method based on the polymorphism of the Direct Repeat locus. Thirty-three spoligotyping-defined clusters including 206 patients and 39 unique patterns were found. The ST41 cluster, as designated according to the international SpolDB3 database project, represented one fourth and when gathered to three genotypes, ST53, ST50 and ST284, one half of all the isolates. Out of 34 clinical isolates harboring ST41 which were further genotyped by IS6110 and by MIRU-VNTR typing, a typical 2-copy IS6110-RFLP pattern and a "215125113322" MIRU-VNTR pattern were observed among 21 clinical isolates. Further search in various databases confirms the likely Turkish-phylogeographical specificity of this clonal complex. CONCLUSION: We described a new phylogeographically-specific clone of M. tuberculosis, designated LAM7-TUR. Further investigations to assess its frequency within all regions of Turkey and its phylogeographical origin and phylogenetic position within the global M. tuberculosis phylogenetic tree will shed new light on its endemicity in Asia Minor
The use of microbead-based spoligotyping for Mycobacterium tuberculosis complex to evaluate the quality of the conventional method: Providing guidelines for Quality Assurance when working on membranes
Fil: Abadia, Edgar. CNRS UniversitĂ© Paris-Sud 11 Universud. Institute of Genetics and Microbiology UMR8621; Francia.Fil: Zhang, Jian. CNRS UniversitĂ© Paris-Sud 11 Universud. Institute of Genetics and Microbiology UMR8621; Francia.Fil: Ritacco, Viviana. ANLIS Dr.C.G.MalbrĂĄn. Instituto Nacional de Enfermedades Infecciosas; Argentina.Fil: Kremer, Kristin. National Institute for Public Health and the Environment; Paises Bajos.Fil: Ruimy, Raymond. UniversitĂ© Paris- Diderot & Microbiology Laboratory; Francia.Fil: Rigouts, Leen. Prince Leopold Institute of Tropical Medicine. Mycobacteriology Unit; BĂ©lgica.Fil: Gomes, Harrison Magdinier. Oswaldo Cruz Institute. Laboratory of Molecular Biology applied to Mycobacteria; Brasil.Fil: Elias, Atina Ribeiro. Oswaldo Cruz Institute. Laboratory of Molecular Biology applied to Mycobacteria; Brasil.Fil: Fauville-Dufaux, Maryse. Scientific Institute of Public Health. National Reference Centre of Tuberculosis and Mycobacteria; BĂ©lgica.Fil: Stoffels, Karolien. Scientific Institute of Public Health. National Reference Centre of Tuberculosis and Mycobacteria; BĂ©lgica.Fil: Rasolofo-Razanamparany, Voahangy. Institut Pasteur de Madagascar. UnitĂ© des MycobactĂ©ries; Madagascar.Fil: Garcia de Viedma, Dario. Hospital Gregorio Marañón. Servicio de MicrobiologĂa ClĂnica y Enfermedades Infecciosas; España.Fil: Herranz, Marta. Hospital Gregorio Marañón. Servicio de MicrobiologĂa ClĂnica y Enfermedades Infecciosas; España.Fil: Al-Hajoj, Sahal. King Faisal Specialist Hospital and Research Center. Department of Comparative Medicine; Arabia Saudita.Fil: Rastogi, Nalin. Institut Pasteur de Guadeloupe. UnitĂ© de la Tuberculose et des MycobactĂ©ries - WHO Supranational TB Reference Laboratory; Guadalupe.Fil: Garzelli, Carlo. UniversitĂ di Pisa. Dipartimento di Patologia Sperimentale Biotecnologie Mediche Infettivologia ed Epidemiologia; Italia.Fil: Tortoli, Enrico. Careggi Hospital. Regional Reference Center for Mycobacteria; ItaliaFil: Suffys, Philip N. Oswaldo Cruz Institute. Laboratory of Molecular Biology applied to Mycobacteria; Brasil.Fil: van Soolingen, Dick. National Institute for Public Health and the Environment; Paises Bajos.Fil: Refregier, Guislaine. CNRS UniversitĂ© Paris-Sud 11 Universud. Institute of Genetics and Microbiology UMR8621; Francia.Fil: Sola, Christophe. CNRS UniversitĂ© Paris-Sud 11 Universud. Institute of Genetics and Microbiology UMR8621; Francia.Background: The classical spoligotyping technique, relying on membrane reverse line-blot hybridization of the spacers of the Mycobacterium tuberculosis CRISPR locus, is used world-wide (598 references in Pubmed on April 8th, 2011). However, until now no inter-laboratory quality control study had been undertaken to validate this technique. We analyzed the quality of membrane-based spoligotyping by comparing it to the recently introduced and highly robust microbead-based spoligotyping. Nine hundred and twenty-seven isolates were analyzed totaling 39,861 data points. Samples were received from 11 international laboratories with a worldwide distribution. Methods: The high-throughput microbead-based Spoligotyping was performed on CTAB and thermolyzate DNA extracted from isolated Mycobacterium tuberculosis complex (MTC) strains coming from the genotyping participating centers. Information regarding how the classical Spoligotyping method was performed by center was available. Genotype discriminatory analyses were carried out by comparing the spoligotypes obtained by both methods. The non parametric U-Mann Whitney homogeneity test and the Spearman rank correlation test were performed to validate the observed results. Results: Seven out of the 11 laboratories (63 %), perfectly typed more than 90% of isolates, 3 scored between 80-90% and a single center was under 80% reaching 51% concordance only. However, this was mainly due to discordance in a single spacer, likely having a non-functional probe on the membrane used. The centers using thermolyzate DNA performed as well as centers using the more extended CTAB extraction procedure. Few centers shared the same problematic spacers and these problematic spacers were scattered over the whole CRISPR locus (Mostly spacers 15, 14, 18, 37, 39, 40). Conclusions: We confirm that classical spoligotyping is a robust method with generally a high reliability in most centers. The applied DNA extraction procedure (CTAB or thermolyzate) did not affect the results in this study. However performance was center-dependent, suggesting that training is a key component in quality assurance of spoligotyping. Overall, no particular spacer yielded a higher degree of deviating results, suggesting that errors
The use of microbead-based spoligotyping for Mycobacterium tuberculosis complex to evaluate the quality of the conventional method: Providing guidelines for Quality Assurance when working on membranes
Contains fulltext :
124321.pdf (publisher's version ) (Open Access)BACKGROUND: The classical spoligotyping technique, relying on membrane reverse line-blot hybridization of the spacers of the Mycobacterium tuberculosis CRISPR locus, is used world-wide (598 references in Pubmed on April 8th, 2011). However, until now no inter-laboratory quality control study had been undertaken to validate this technique. We analyzed the quality of membrane-based spoligotyping by comparing it to the recently introduced and highly robust microbead-based spoligotyping. Nine hundred and twenty-seven isolates were analyzed totaling 39,861 data points. Samples were received from 11 international laboratories with a worldwide distribution. METHODS: The high-throughput microbead-based Spoligotyping was performed on CTAB and thermolyzate DNA extracted from isolated Mycobacterium tuberculosis complex (MTC) strains coming from the genotyping participating centers. Information regarding how the classical Spoligotyping method was performed by center was available. Genotype discriminatory analyses were carried out by comparing the spoligotypes obtained by both methods. The non parametric U-Mann Whitney homogeneity test and the Spearman rank correlation test were performed to validate the observed results. RESULTS: Seven out of the 11 laboratories (63%), perfectly typed more than 90% of isolates, 3 scored between 80-90% and a single center was under 80% reaching 51% concordance only. However, this was mainly due to discordance in a single spacer, likely having a non-functional probe on the membrane used. The centers using thermolyzate DNA performed as well as centers using the more extended CTAB extraction procedure. Few centers shared the same problematic spacers and these problematic spacers were scattered over the whole CRISPR locus (Mostly spacers 15, 14, 18, 37, 39, 40). CONCLUSIONS: We confirm that classical spoligotyping is a robust method with generally a high reliability in most centers. The applied DNA extraction procedure (CTAB or thermolyzate) did not affect the results in this study. However performance was center-dependent, suggesting that training is a key component in quality assurance of spoligotyping. Overall, no particular spacer yielded a higher degree of deviating results, suggesting that errors occur randomly either in the process of re-using membranes, or during the reading of the results and transferring of data from the film to a digital file. Last, the performance of the microbead-based method was excellent as previously shown by Cowan et al. (J. Clin. Microbiol. 2004) and Zhang et al. (J. Med. Microbiol. 2009) and demonstrated the proper detection of spacer 15 that is known to occasionally give weak signals in the classical spoligotyping
Three-Year Population-Based Evaluation of Standardized Mycobacterial Interspersed Repetitive-Unit-Variable-Number Tandem-Repeat Typing of Mycobacterium tuberculosisâż
Standardized mycobacterial interspersed repetitive-unit-variable-number tandem repeat (MIRU-VNTR) typing based on 15 and 24 loci recently has been proposed for Mycobacterium tuberculosis genotyping. So far, this optimized system has been assessed in a single, 1-year population-based study performed in Germany (M. C. Oelemann, R. Diel, V. Vatin, W. Haas, S. Rusch-Gerdes, C. Locht, S. Niemann, and P. Supply, J. Clin. Microbiol. 45:691-697, 2007). Here, we evaluated these optimized formats in a much larger population-based study conducted during 39 months in the Brussels capital region of Belgium. Isolates from 807 patients were genotyped. The resolution power, cluster, and lineage identification by the standardized MIRU-VNTR sets were compared to those obtained using standardized IS6110-restriction fragment length polymorphism (RFLP), spoligotyping, and a previous 12-MIRU-VNTR-locus set. On a subset representing 77% of the cases during a 16-month period, a high concordance was observed between unique isolates or strain clusters as defined by standardized MIRU-VNTR and IS6110-RFLP (i.e., more than five IS6110 bands). When extended to the entire population-based collection, the discriminatory subset of 15 loci decreased the strain-clustering rate by almost twofold compared to that of the old 12-locus set. The addition of the nine ancillary MIRU-VNTR loci and/or spoligotyping only slightly further decreased this strain-clustering rate. Familial, social, and/or geographic proximity links were found in 48% of the clusters identified, and well-known risk factors for tuberculosis transmission were identified. Finally, an excellent correspondence was determined between our MIRU-VNTR-spoligotyping strain identifications and external reference strain lineages included in the MIRU-VNTRplus database and identified by, e.g., large sequence polymorphisms. Our results reinforce the proposal of standardized MIRU-VNTR typing as a new reference genotyping method for the epidemiological and phylogenetic screening of M. tuberculosis strains
Utilisation du kit Lipa Mycobacteria pour l'identification des mycobactéries
The test consists in the PCR amplification of the DNA region coding for the 16S~23S rRNA
space! of Mycobacterium species followed by the hybridization and the stringent wash of the
amplified product with species specific probes immobilized on a strip. Thirteen different probes
are placed on the strip enabling the specific identification of the most frequent mycobacterial
strains isolated in clinical samples.
One hundred twenty strains isolated from clinical specimens on Lowenstein-Jensen medium
were included in the evaluation study. Lipa. identification of all the 120 strains was in agreement
with identification obtained by other methods like classical bacteriological tests) Gen Probe
hybridization tests, species specific PCRs. PeR-restriction fragment length polymorphism
analysis ofthe fup65 gene (PRA) and, in some cases, DNA sequencing of an amplified fragment
ofthe 168 rRNA gene.
On the other hand, 35 early growing Bactec cultures from clinical specimens, taken at a GI as
low as 9, were analysed by Lips Mycobacteria. 69 % ofthem could be identified on the aliquot
taken when the GI was between 9 to 50. The remaining cultures could be identified on an
aliquot ofBaetec mediwn taken one or 2 days later.
In comparison to the other identification methods. Lipa Mycobacteria gives results by far faster
than bacteriological tests and is easier to perfonn than PRA and DNA sequencing. It takes
longer to perform than the Gen Probe hybridization test (lh30 PeR plus 3h30 hybridizationwashing procedure versus 2h for the Gen Probe test), but it allows, in the same procedure, identification of 9 different mycobacterial species though Gen Probe hyridiution only identifies 1 or maximum 2 species. Lipa Mycobacteria is also usable on early growing Bactec cultures
Population-Based Molecular Epidemiological Study of Tuberculosis in Malatya, Turkeyâż
This investigation describes drug resistance patterns and genotyping data on a total of 145 Mycobacterium tuberculosis strains isolated between 2000 and 2004 in Malatya, Turkey. Drug susceptibility results indicated a total of 20% resistant and 4.8% of multidrug-resistant isolates. Spoligotyping resulted in 25 unique patterns and 120 strains in 19 clusters (2 to 33 strains per cluster). When the results were compared to an international spoligotyping database, 19 of 25 unique patterns matched existing shared spoligotype international types (SITs). This led to the description of 38 SITs with 139 strains and 6 orphan patterns (not previously reported). Five of the SITs (SIT759, SIT1936, SIT1937, SIT1938, and SIT2285) were newly created. The most prevalent spoligotype was SIT41 (LAM7-TUR) with 33 (23.9%) isolates. The repartition of strains according to major M. tuberculosis clades (in decreasing order) was as follows: ill-defined T clade (45.7%) > Latin American and Mediterranean (LAM; 29%) > Haarlem (15.9%). Strains belonging to Central Asian (CAS), East-African Indian (EAI), Beijing, and Africanum clades were absent in this setting. IS6110-restriction fragment length polymorphism (RFLP) resulted in 19 clusters (52 strains), with a final clustering rate of 35.9% and a recent transmission rate of 22.8%. Typing based on mycobacterial interspersed repetitive units (MIRUs) permitted us to identify 65 patterns (23 orphan patterns and 42 patterns that matched existing MIRU international types in an updated database). The combination of the three typing methods allowed us to calculate a final clustering rate of 22% and a significantly lower transmission rate of 13.1%. The discrimination achieved by IS6110-RFLP/MIRUs was not significantly improved by adding spoligotyping results (1.4%). We conclude that our patient population is infected by diverse M. tuberculosis populations; however, the majority of the ongoing transmission is due to âevolutionary recentâ tuberculosis lineages belonging to principal genetic group 2 (PGG2; Haarlem and LAM) and PGG3 (ill-defined T clade), and most of it is attributable to the LAM7-TUR sublineage with an enhanced phylogeographical specificity for Turkey. An absence of lineages belonging to PGG1 clones (EAI, CAS, and Beijing, essentially found in Central, South, and Southeast Asia), is noteworthy
Submandibular lymphadenitis caused by Mycobacterium interjectum: contribution of new diagnostic tools.
Mycobacterium interjectum is a rare causative agent of cervical lymphadenitis. We describe a 2-year-old girl with suspected tuberculous cervical lymphadenitis. Sequencing of the 16S rRNA gene allowed the correct identification of Mycobacterium interjectum. As yet, only nine case reports of infections due to M. interjectum in children have been reported in the literature, and in all of them a correct identification could only be obtained using gene sequencing
Characteristics of the 58 MDR-TB patients in strain-clusters and results of epidemiological investigation.
<p>Legend: Yâ=âyes; Nâ=âno, Uâ=âunknown; ââ=ânot applicable.</p
Evolution of the resistance profile of serial isolates obtained from 24 patients.
<p>For these 24 MDR-TB patients out of 37 with multiple isolates, resistance to additional drugs was observed during treatment. Legend: âȘâ=âSusceptible, âȘâ=âResistant, âTest not performed, I: Isoniazid, R: Rifampicin, E: Ethambutol, Z: Pyrazinamid, Rb: Rifabutin, Ofl: Ofloxacin, Amk: Amikacin, Thio: Thioamide, Cap: Capreomycin NAâ=âNot Applicable as less than 2 isolates were FLP profiled, so no conclusion possible.</p