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Hanna Soini

Publications and source records attributed to Hanna Soini.

12 recordsLinked to original sources

Isolation and automated ribotyping of Mycobacterium lentiflavum from drinking water distribution system and clinical specimens.

Automated ribotyping as a tool for identifying of nontuberculous mycobacteria was evaluated. We created a database comprising of riboprints of 60 strains, representing 32 species of nontuberculous mycobacteria. It was shown that combined ribopatterns generated after digestion with EcoRI and PvuII were distinguishable between species of both slow-growing and rapid-growing mycobacteria. The findings were in good agreement with the 16S rRNA gene sequencing results, allowing correct identification of Mycobacterium lentiflavum isolated from clinical specimens and from biofilms growing in public water distribution system. The automated ribotyping was powerful in discriminating between M. lentiflavum and closely related species M. simiae and M. palustre. Mycobacterium lentiflavum strains from drinking water biofilms were resistant to two to four antimycobacterial drugs. The drinking water distribution system may, thus, be a source of nontuberculous mycobacteria resistant to multiple drugs.

Biofilms↗

Comparison of two commercially available DNA line probe assays for detection of multidrug-resistant Mycobacterium tuberculosis.

Two commercially available DNA line probe assays, Genotype MTBDR and INNO-LiPA Rif. TB, were evaluated for their abilities to detect resistance to isoniazid (INH) and rifampin (RIF) in 52 Mycobacterium tuberculosis isolates. The test results were compared to those obtained by phenotypic drug susceptibility testing and sequencing. Compared to the results of phenotypic drug susceptibility testing, the Genotype MTBDR test results were concordant for INH for 47 of the 52 (90.4%) isolates, and both the Genotype MTBDR and the INNO-LiPA Rif. TB test results were concordant for RIF for 51 of the 52 (98.1%) isolates. The Genotype MTBDR test results correlated with the sequencing results for 48 of the 52 (92.3%) isolates and the INNO-LiPA Rif. TB results for 50 of the 52 (96.2%) isolates. Both assays are useful for the rapid screening of M. tuberculosis isolates obtained from patients suspected of having multidrug-resistant tuberculosis, but the GenoType MTBDR assay has the advantage of being able to detect resistance to both INH and RIF simultaneously.

Antibiotics, Antitubercular↗

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Journal Article↗

Single-nucleotide polymorphism-based population genetic analysis of Mycobacterium tuberculosis strains from 4 geographic sites.

We studied genetic relationships among 5069 Mycobacterium tuberculosis strains recovered from patients enrolled in 4 population-based studies in the United States and Europe, by analysis of 36 synonymous single-nucleotide polymorphisms (SNPs). All strains were assigned to 1 of 9 major genetic clusters based on sSNP profile. The same 9 genetic clusters were revealed by analysis of 227 nonsynonymous SNPs, 121 intergenic SNPs, and concatenated profiles of 578 SNPs available for a subset of 48 representative strains. IS6110 profiles, spoligotypes, and mycobacterial interspersed repetitive unit patterns were nonrandomly associated with SNP-based phylogenetic lineages, together indicating a strongly clonal population structure. Isolates of the 9 genetic clusters were not distributed with equal frequency in all localities, reflecting geographic subdivision. The SNP-based phylogenetic framework provides new insight into the worldwide evolution of M. tuberculosis and a gateway for investigating genotype-disease phenotype relationships in large samples of strains.

Bacterial Typing Techniques↗

Relating the size of molecularly defined clusters of tuberculosis to the duration of symptoms.

Molecular profiling of Mycobacterium tuberculosis isolates has improved recognition of tuberculosis case clusters, but the determinants of cluster size are unknown. We hypothesized that longer duration of symptoms prior to initiation of tuberculosis therapy would be associated with increased cluster size. All patients with tuberculosis in Harris County, Texas, identified between 10/1/95 and 12/31/97 through a prospective population-based project were interviewed, had their medical records reviewed, and had M. tuberculosis isolates molecularly characterized. There were 506 symptomatic, evaluable patients in 74 clusters, ranging in size from 2 patients (32 clusters) to 61 patients (1 cluster). The median duration of symptoms was 46 days (range, 1-471 days). There was no association between the log-transformed duration of symptoms and cluster size in univariate or multivariate analysis. In multivariate analysis, age and HIV coinfection were inversely related to cluster size, but only weakly. The size of molecularly defined clusters of tuberculosis was not related to the duration of symptoms of most patients who belonged to clusters.

Adult↗

IS6110 restriction fragment length polymorphism of Mycobacterium tuberculosis isolated from patients with pulmonary tuberculosis in Campinas, Brazil: evidence of intercontinental distribution of strains.

Tuberculosis (TB) is a major concern in developing countries. In Brazil, few genotyping studies have been conducted to verify the number of IS6110 copies present in local prevalent strains of Mycobacterium tuberculosis, the distribution and clustering of strains. IS6110 DNA fingerprinting was performed on a sample of M. tuberculosis isolates from patients with AFB smear-positive pulmonary TB, at a hospital in Brazil. The IS6110 profiles were analyzed and compared to a M. tuberculosis database of the Houston Tuberculosis Initiative, Houston, US. Seventy-six fingerprints were obtained from 98 patients. All M. tuberculosis strains had an IS6110 copy number between 5-21 allowing for differentiation of the isolates. Human immunodeficiency virus infection was confirmed in nearly half the patients of whom data was available. Fifty-eight strains had unique patterns, while 17 strains were grouped in 7 clusters (2 to 6 strains). When compared to the HTI database, 6 strains matched isolates from El Paso, Ciudad de Juarez, Houston, and New York. Recently acquired infections were documented in 19% of cases. The community transmission of infection is intense, since some clustered strains were recovered during the four-year study period. The intercontinental dissemination of M. tuberculosis strains is suspected by demonstration of identical fingerprints in a distant country.

Bacterial Typing Techniques↗

Molecular detection of resistance to antituberculous therapy.

Drug-resistant tuberculosis is becoming increasingly common and represents a worldwide threat. Therefore, new approaches for the rapid susceptibility testing of Mycobacterium tuberculosis are needed to replace traditional culture-based methods. This article presents the genetic background of drug resistance in tubercle bacillus, and the methods currently available for genotypic susceptibility testing.

Antitubercular Agents↗

PFGE and pertactin gene sequencing suggest limited genetic variability within the Finnish Bordetella parapertussis population.

The outer-membrane protein pertactin (Prn) of Bordetella pertussis, Bordetella parapertussis and Bordetella bronchiseptica is believed to function as an adhesin and is an important immunogen. The emergence of B. pertussis and B. bronchiseptica Prn variants has been reported. The aim of this study was to determine whether similar variation is found in B. parapertussis Prn and to characterize Finnish clinical B. parapertussis isolates that were collected in 1982-2000. Of 76 B. parapertussis isolates studied, seven (9 %) were found to have silent and non-silent nucleotide changes. In addition, one (1 %) had eight PQP repeats instead of nine. Three closely related B. parapertussis XbaI PFGE patterns were found. Genetic variation of B. parapertussis was found to be very limited, suggesting that B. parapertussis is a stable organism that is well-adapted to its own ecological niche.

Bacterial Outer Membrane Proteins↗

Characterization of Finnish Mycobacterium tuberculosis isolates by spoligotyping.

The molecular epidemiology of tuberculosis (TB) in Finland was studied by spoligotyping 380 Mycobacterium tuberculosis isolates. The isolates were obtained during a 1-year study period from July 2000 to June 2001 and represented 90% of new M. tuberculosis findings by culture in the whole country during the study period. The spoligotyping results were compared to the World Spoligotyping Database of the Institut Pasteur de Guadeloupe, which contains data from >14,000 M. tuberculosis isolates obtained worldwide. A total of 138 different spoligotypes were identified among the 380 M. tuberculosis isolates. Thirty-eight (10%) isolates had unique spoligotypes, while 342 (90%) isolates belonged to 100 shared types. The four most common spoligotypes caused approximately one-third of the Finnish TB cases. Forty-seven of the 138 (34.1%) spoligotypes and 61 (16.1%) of the 380 M. tuberculosis isolates had spoligotypes that had not been previously reported. Only four (1.1%) patients were infected with an isolate belonging to the Beijing genotype. The characterization of Finnish M. tuberculosis isolates by spoligotyping shows that ubiquitous spoligotypes were common, but many spoligotypes specific to Finland were also found. However, Beijing family isolates were rarely encountered, although this spoligotype is predominant in our eastern and southern neighbors.

Bacterial Typing Techniques↗

Mycobacterium simiae pseudo-outbreak resulting from a contaminated hospital water supply in Houston, Texas.

Various species of nontuberculous mycobacteria are known to cause nosocomial pseudo-outbreaks, but there have been no detailed reports of nosocomial Mycobacterium simiae pseudo-outbreaks. From April 1997 through February 2001, we recovered 65 M. simiae isolates from 62 patients at a community teaching hospital in Houston, Texas. The organism was grown in various water samples obtained in the hospital building and in professional building 1 but not in professional building 2, which has a separate water supply system. Thirty-one environmental and human outbreak-related M. simiae isolates had indistinguishable or closely related patterns on pulsed-field gel electrophoresis and were considered clonal. M. simiae can be a cause of nosocomial pseudo-outbreaks. The reservoir for this pseudo-outbreak was identified as a contaminated hospital water supply.

Adolescent↗

Evaluation of genotype and LiPA MYCOBACTERIA assays for identification of Finnish mycobacterial isolates.

Two DNA strip assays, INNO-LiPA MYCOBACTERIA and GenoType Mykobakterien, were evaluated for identification of 81 Finnish mycobacterial isolates. The LiPA assay correctly identified 89.4% of the 66 isolates studied, and the GenoType assay identified 95.1% of 81 isolates. The GenoType assay had a wider selection of species and less stringent temperature requirements.

Bacterial Typing Techniques↗