Elvira Richter

Publications of Elvira Richter

• rplC T460C identified as a dominant mutation in linezolid resistant Mycobacterium tuberculosis strains.

  Authors: Patrick Beckert, Doris Hillemann, Thomas A Kohl, Jörn Kalinowski, Elvira Richter, Stefan Niemann, Silke Feuerriegel

  Antimicrobial agents and chemotherapy. 02/2012;

  The ribosomal L3 protein was identified as novel target in linezolid (LZD) resistant Mycobacterium tuberculosis strains. Next-generation-sequencing confirmed rplC T460C as sole mutation in an LZDThe ribosomal L3 protein was identified as novel target in linezolid (LZD) resistant Mycobacterium tuberculosis strains. Next-generation-sequencing confirmed rplC T460C as sole mutation in an LZD resistant M. tuberculosis H37Rv strain selected in vitro. Sequencing analysis revealed the rplC T460C mutation in eight further LZD resistant isolates (three in vitro selected mutants, five patient isolates including isolates from three different patients developing LZD resistance during treatment), but in none of the susceptible control strains (n=84).

• High prevalence of multidrug-resistant tuberculosis, Swaziland, 2009-2010.

  Authors: Elisabeth Sanchez-Padilla, Themba Dlamini, Alexandra Ascorra, Sabine Rüsch-Gerdes, Zerihun Demissie Tefera, Philippe Calain, Roberto de la Tour, Frauke Jochims, Elvira Richter, Maryline Bonnet

  Emerging infectious diseases. 01/2012; 18(1):29-37.

  In Africa, although emergence of multidrug-resistant (MDR) tuberculosis (TB) represents a serious threat in countries severely affected by the HIV epidemic, most countries lack drug-resistant TBIn Africa, although emergence of multidrug-resistant (MDR) tuberculosis (TB) represents a serious threat in countries severely affected by the HIV epidemic, most countries lack drug-resistant TB data. This finding was particularly true in the Kingdom of Swaziland, which has the world's highest HIV and TB prevalences. Therefore, we conducted a national survey in 2009-2010 to measure prevalence of drug-resistant TB. Of 988 patients screened, 420 new case-patients and 420 previously treated case-patients met the study criteria. Among culture-positive patients, 15.3% new case-patients and 49.5% previously treated case-patients harbored drug-resistant strains. MDR TB prevalence was 7.7% and 33.8% among new case-patients and previously treated case-patients, respectively. HIV infection and past TB treatment were independently associated with MDR TB. The findings assert the need for wide-scale intervention in resource-limited contexts such as Swaziland, where diagnostic and treatment facilities and health personnel are lacking.

• Direct drug susceptibility testing of Mycobacterium tuberculosis for rapid detection of multidrug resistance using the Bactec MGIT 960 system: a multicenter study.

  Authors: Salman Siddiqi, Altaf Ahmed, Sunil Asif, Digamber Behera, Mona Javaid, Jasmine Jani, Arora Jyoti, Radhika Mahatre, Dewanand Mahto, Elvira Richter, Camilla Rodrigues, Potharaju Visalakshi, Sabine Rüsch-Gerdes

  Journal of clinical microbiology. 12/2011; 50(2):435-40.

  Conventional indirect drug susceptibility testing of Mycobacterium tuberculosis with liquid medium is well established and offers time-saving and reliable results. This multicenter study was carriedConventional indirect drug susceptibility testing of Mycobacterium tuberculosis with liquid medium is well established and offers time-saving and reliable results. This multicenter study was carried out to evaluate if drug susceptibility testing (DST) can be successfully carried out directly from processed smear-positive specimens (direct DST) and if this approach could offer substantial time savings. Sputum specimens were digested, decontaminated, and concentrated by the laboratory routine procedure and were inoculated in Bactec MGIT 960 as well as Lowenstein-Jensen (LJ) medium for primary isolation. All the processed specimens which were acid-fast bacterium (AFB) smear positive were used for setting up direct DST for isoniazid (INH) and rifampin (RIF). After the antimicrobial mixture of polymyxin B, amphotericin B, nalidixic acid, trimethoprim, and azlocillin (PANTA) was added, the tubes were entered in the MGIT 960 instrument using the 21-day protocol (Bactec 960 pyrazinamide [PZA] protocol). Results obtained by direct DST were compared with those obtained by indirect DST to establish accuracy and time savings by this approach. Of a total of 360 AFB smear-positive sputum specimens set up for direct DST at four sites in three different countries, 307 (85%) specimens yielded reportable results. Average reporting time for direct DST was 11 days (range, 10 to 12 days). The average time savings by direct DST compared to indirect DST, which included time to isolate a culture and perform DST, was 8 days (range, 6 to 9 days). When results of direct DST were compared with those of indirect DST, there was 95.1% concordance with INH and 96.1% with rifampin. These findings indicate that direct DST with the Bactec MGIT 960 system offers further time savings and is a quick method to reliably detect multidrug resistance (MDR) cases.

• Evaluation of Mycobacterium tuberculosis typing methods in a 4-year study in Schleswig-Holstein, Northern Germany.

  Authors: Andreas Roetzer, Sieglinde Schuback, Roland Diel, Frauke Gasau, Tanja Ubben, Alessia di Nauta, Elvira Richter, Sabine Rüsch-Gerdes, Stefan Niemann

  Journal of clinical microbiology. 12/2011; 49(12):4173-8.

  In order to evaluate the discriminatory power of different methods for genotyping of Mycobacterium tuberculosis complex (MTBC) isolates, we compared the performance of (i) IS6110 DNA fingerprintIn order to evaluate the discriminatory power of different methods for genotyping of Mycobacterium tuberculosis complex (MTBC) isolates, we compared the performance of (i) IS6110 DNA fingerprint typing, (ii) spoligotyping, and (iii) 24-loci mycobacterial interspersed repetitive units-variable number of tandem repeats (MIRU-VNTR) typing in a long-term study on the epidemiology of tuberculosis (TB) in Schleswig-Holstein, the northernmost federal state of Germany. In total, we analyzed 277 MTBC isolates collected from patients between the years 2006 and 2010. The collection comprised a broad spectrum of 13 different genotypes, among which strains of the Haarlem genotype (31%) were most prominent, followed by strains belonging to the Delhi and Beijing lineages (7% and 6%, respectively). On the basis of IS6110 restriction fragment length polymorphism (RFLP) and spoligotyping analyses, 211 isolates had unique patterns (76%) and 66 isolates (24%) were in 20 clusters. MIRU-VNTR combined with spoligotyping analyses revealed 202 isolates with unique patterns (73%) and 75 isolates in 18 clusters (27%). Overall, there was 93.1% concordance between the typing results obtained; 198 strains were identified as unique, and 60 isolates were clustered by both typing combinations (including all 31 isolates with confirmed epidemiological links). Of the remaining 19 isolates with discrepant results, 15 were falsely clustered by MIRU-VNTR (six Beijing genotype strains) and four were clustered by IS6110 RFLP (low IS6110 copy number) only. In conclusion, in the study population investigated, a minority of isolates, especially of the Beijing genotype, clustered by standard 24-loci MIRU-VNTR and without an obvious epidemiological link may require second-line typing by IS6110 RFLP or hypervariable MIRU-VNTR loci.

• Multilocus sequence analysis and rpoB sequencing of Mycobacterium abscessus (sensu lato) strains.

  Authors: Edouard Macheras, Anne-Laure Roux, Sylvaine Bastian, Sylvia Cardoso Leão, Moises Palaci, Valérie Sivadon-Tardy, Cristina Gutierrez, Elvira Richter, Sabine Rüsch-Gerdes, Gaby Pfyffer, Thomas Bodmer, Emmanuelle Cambau, Jean-Louis Gaillard, Beate Heym

  Journal of clinical microbiology. 02/2011; 49(2):491-9.

  Mycobacterium abscessus, Mycobacterium bolletii, and Mycobacterium massiliense (Mycobacterium abscessus sensu lato) are closely related species that currently are identified by the sequencing of theMycobacterium abscessus, Mycobacterium bolletii, and Mycobacterium massiliense (Mycobacterium abscessus sensu lato) are closely related species that currently are identified by the sequencing of the rpoB gene. However, recent studies show that rpoB sequencing alone is insufficient to discriminate between these species, and some authors have questioned their current taxonomic classification. We studied here a large collection of M. abscessus (sensu lato) strains by partial rpoB sequencing (752 bp) and multilocus sequence analysis (MLSA). The final MLSA scheme developed was based on the partial sequences of eight housekeeping genes: argH, cya, glpK, gnd, murC, pgm, pta, and purH. The strains studied included the three type strains (M. abscessus CIP 104536(T), M. massiliense CIP 108297(T), and M. bolletii CIP 108541(T)) and 120 isolates recovered between 1997 and 2007 in France, Germany, Switzerland, and Brazil. The rpoB phylogenetic tree confirmed the existence of three main clusters, each comprising the type strain of one species. However, divergence values between the M. massiliense and M. bolletii clusters all were below 3% and between the M. abscessus and M. massiliense clusters were from 2.66 to 3.59%. The tree produced using the concatenated MLSA gene sequences (4,071 bp) also showed three main clusters, each comprising the type strain of one species. The M. abscessus cluster had a bootstrap value of 100% and was mostly compact. Bootstrap values for the M. massiliense and M. bolletii branches were much lower (71 and 61%, respectively), with the M. massiliense cluster having a fuzzy aspect. Mean (range) divergence values were 2.17% (1.13 to 2.58%) between the M. abscessus and M. massiliense clusters, 2.37% (1.5 to 2.85%) between the M. abscessus and M. bolletii clusters, and 2.28% (0.86 to 2.68%) between the M. massiliense and M. bolletii clusters. Adding the rpoB sequence to the MLSA-concatenated sequence (total sequence, 4,823 bp) had little effect on the clustering of strains. We found 10/120 (8.3%) isolates for which the concatenated MLSA gene sequence and rpoB sequence were discordant (e.g., M. massiliense MLSA sequence and M. abscessus rpoB sequence), suggesting the intergroup lateral transfers of rpoB. In conclusion, our study strongly supports the recent proposal that M. abscessus, M. massiliense, and M. bolletii should constitute a single species. Our findings also indicate that there has been a horizontal transfer of rpoB sequences between these subgroups, precluding the use of rpoB sequencing alone for the accurate identification of the two proposed M. abscessus subspecies.

• Rapid molecular detection of extrapulmonary tuberculosis by the automated GeneXpert MTB/RIF system.

  Authors: Doris Hillemann, Sabine Rüsch-Gerdes, Catharina Boehme, Elvira Richter

  Journal of clinical microbiology. 01/2011; 49(4):1202-5.

  In total, 521 nonrespiratory specimens (91 urine, 30 gastric aspirate, 245 tissue, 113 pleural fluid, 19 cerebrospinal fluid [CSF], and 23 stool specimens) submitted to the German National ReferenceIn total, 521 nonrespiratory specimens (91 urine, 30 gastric aspirate, 245 tissue, 113 pleural fluid, 19 cerebrospinal fluid [CSF], and 23 stool specimens) submitted to the German National Reference Laboratory for Mycobacteria (NRL) from May 2009 to August 2010 were comparatively investigated with the new molecular-based GeneXpert MTB/RIF (Xpert) assay system and conventional liquid and solid culture methods. Twenty (3.8%) of the 521 specimens gave no interpretable result. Whereas the sensitivity of the Xpert assay with tissue specimens was 69.0% (20 out of 29 culture-positive cases detected), 100% sensitivity was found with the urine and stool specimens. The combined sensitivity and specificity of the Xpert assay were calculated to be 77.3% and 98.2%, respectively.

• Thr202Ala in thyA is a marker for the Latin American Mediterranean lineage of the Mycobacterium tuberculosis complex rather than para-aminosalicylic acid resistance.

  Authors: Silke Feuerriegel, Claudio Köser, Leona Trübe, John Archer, Sabine Rüsch Gerdes, Elvira Richter, Stefan Niemann

  Antimicrobial agents and chemotherapy. 11/2010; 54(11):4794-8.

  Single nucleotide polymorphisms (SNPs) involved in the development of resistance represent powerful markers for the rapid detection of first- and second-line resistance in clinical MycobacteriumSingle nucleotide polymorphisms (SNPs) involved in the development of resistance represent powerful markers for the rapid detection of first- and second-line resistance in clinical Mycobacterium tuberculosis complex (MTBC) isolates. However, the association between particular mutations and phenotypic resistance is not always clear-cut, and phylogenetic SNPs have been misclassified as resistance markers in the past. In the present study, we investigated the utility of a specific polymorphism in thyA (Thr202Ala) as a marker for resistance to para-aminosalicyclic acid (PAS). Sixty-three PAS-susceptible MTBC strains comprising all major phylogenetic lineages, reference strain H37Rv, and 135 multidrug-resistant (MDR) strains from Germany (comprising 8 PAS-resistant isolates) were investigated for the presence of Thr202Ala. In both strain collections, the Thr202Ala SNP was found exclusively in strains of the Latin American Mediterranean (LAM) lineage irrespective of PAS resistance. Furthermore, PAS MICs (0.5 mg/liter) for selected LAM strains (all containing the SNP) and non-LAM strains (not containing the SNP), as well as the results of growth curve analyses performed in liquid 7H9 medium in the presence of increasing PAS concentrations (0 to 2.0 mg/liter), were identical. In conclusion, our data demonstrate that the Thr202Ala polymorphism in thyA is not a valid marker for PAS resistance but, instead, represents a phylogenetic marker for the LAM lineage of the M. tuberculosis complex. These findings challenge some of the previous understanding of PAS resistance and, as a consequence, warrant further in-depth investigations of the genetic variation in PAS-resistant clinical isolates and spontaneous mutants.

• Transmission dynamics of pulmonary tuberculosis between autochthonous and immigrant sub-populations.

  Authors: Judit Barniol, Stefan Niemann, Valerie Louis, Bonita Brodhun, Caroline Dreweck, Elvira Richter, Heiko Becher, Walter Haas, Thomas Junghanss

  BMC infectious diseases. 12/2009; 9(1):197.

  ABSTRACT: BACKGROUND: The overall incidence of tuberculosis (TB) in Western Europe has been declining since the 19th Century. However, immigrant sub-groups from high-prevalence countries are slowingABSTRACT: BACKGROUND: The overall incidence of tuberculosis (TB) in Western Europe has been declining since the 19th Century. However, immigrant sub-groups from high-prevalence countries are slowing down this trend. The aim of this study was to describe how immigration influences TB transmission in Germany. For that we prospectively investigated the dynamics of TB transmission between TB high-prevalence immigrant and TB low-prevalence local populations with molecular epidemiological methods and conventional contact investigations. Besides, we assessed transmission in relation to social mixing using an innovative tool that measures the integration of immigrants into the local social environment. METHODS: A prospective study of confirmed culture positive cases of pulmonary TB and their contacts was carried out in a German federal state from 2003 to 2005. Data for the study included: 1) case data routinely collected by the local public health staff and transmitted to the state health office and the national surveillance centre, 2) a study questionnaire designed to capture social interactions of relevance for TB transmission and 3) molecular genotyping data (IS6110 DNA fingerprint and spoligotyping). The proportion of German cases caused by foreign-born cases, and vice versa, was estimated and an integration index was computed using a selected set of questions from the study questionnaire. RESULTS: A total of 749 cases of culture-positive pulmonary tuberculosis voluntarily enrolled in the study, representing 57.8% of all registered cases diagnosed over the study period. Data that included study questionnaire and DNA fingerprinting were available for 41% (n=308) of the study participants. Forty-seven clusters, defined as a least two cases infected by the same TB strains, were identified by molecular methods and included 132 (17%) of the study participants. Epidemiological links were identified for 28% of the clusters by conventional epidemiological data. In mixed clusters, defined as clusters including German and foreign-born individuals, the probability of cases to be caused by foreign-born cases was estimated at 18.3%. We observed a trend to mixed clusters with increasing time spent by immigrants in the host country. This group also presented comparatively higher integration indexes than immigrants in immigrant-only clusters. CONCLUSIONS: Our results confirm the findings of other studies that there is no significant TB transmission from TB high-prevalence immigrant to TB low-prevalence autochthonous population. This may be explained by the good performance of tuberculosis screening programmes for certain groups arriving in Germany from high- prevalence countries, by a low degree of mixing of immigrants with the local population or by a combination of both.

• Drug-susceptibility testing in TB: current status and future prospects.

  Authors: Elvira Richter, Sabine Rüsch-Gerdes, Doris Hillemann

  Expert review of respiratory medicine. 10/2009; 3(5):497-510.

  The rising number of resistant and multidrug-resistant Mycobacterium tuberculosis strains and the emergence of extensively drug-resistant strains substantiate the urgent demand for rapid and reliableThe rising number of resistant and multidrug-resistant Mycobacterium tuberculosis strains and the emergence of extensively drug-resistant strains substantiate the urgent demand for rapid and reliable techniques for the detection of drug-resistant TB. In recent years, a multitude of techniques for rapid drug-susceptibility testing have been designed and evaluated. Two different strategies for the assessment of drug resistance can be followed; phenotypic determination has been common practice for years, whereas more recently the genetic detection of mutations that confer for drug resistance has been established. Novel liquid culture-based drug-susceptibility testing techniques have been evaluated; several of them have proved their reliability and accuracy, while others need more evaluation or a different performance due to biosafety risks. Among the molecular tests, line-probe assays seem to be the most promising tools for a rapid and very specific and sensitive detection of multidrug-resistant M. tuberculosis.

• Feasibility of the GenoType(R) MTBDRsl Assay for fluoroquinolone, amikacin/capreomycin, and ethambutol resistance testing of Mycobacterium tuberculosis strains and in clinical specimens.

  Authors: Doris Hillemann, Sabine Rüsch-Gerdes, Elvira Richter

  Journal of clinical microbiology. 05/2009;

  The new GenoType(R) MTBDRsl assay (Hain Lifescience, Germany) was tested on 106 clinical isolates and directly on 64 sputum specimens for its capability to detect resistance to fluorquinolones,The new GenoType(R) MTBDRsl assay (Hain Lifescience, Germany) was tested on 106 clinical isolates and directly on 64 sputum specimens for its capability to detect resistance to fluorquinolones, injectable drugs (amikacin or capreomycin), and ethambutol in Mycobacterium tuberculosis strains. In total, 63 strains harboring fluoroquinolone, amikacin/capreomycin, or ethambutol resistance and 43 fully susceptible strains were comparatively analyzed with the new MTBDRsl assay, DNA sequencing and conventional drug susceptibility testing in liquid and solid media. No discrepancies were obtained in comparison with DNA sequencing results. Fluoroquinolone resistance was detected in 29 of the 32 (90.6 %), amikacin/capreomycin resistance in 39/39 of 46/45 (84.8 %/86.7 %), and ethambutol resistance in 36 of 52 (69.2 %) resistant strains. A total of 64 sputum specimens (42 smear-positive, 12 scanty, and 10 smear-negative) were tested with the new MTBDRsl assay and the results were compared with conventional drug susceptibility testing. Fluoroquinolone resistance was detected in 8 of the 9 (88.9 %), amikacin/capreomycin resistance in 6/7 of 8 (75.0 %/87.5 %), and ethambutol resistance in 10 of 26 (38.5 %) resistant strains. No mutation was detected in susceptible strains. The new GenoType(R) MTBDRsl assay represents a reliable tool for the detection of fluoroquinolone and amikacin/capreomycin resistance and to a lower extent also ethambutol resistance. In combination with a molecular test for detection of rifampicin and isoniazid resistance the potential for the detection of extensively resistant TB within one to two days can be postulated.

• In vitro-selected linezolid-resistant Mycobacterium tuberculosis mutants.

  Authors: Doris Hillemann, Sabine Rüsch-Gerdes, Elvira Richter

  Antimicrobial agents and chemotherapy. 03/2008; 52(2):800-1.

• [Antibiotic drug-resistant tuberculosis]

  Authors: Ulf Greinert, Doris Hillemann, Christoph Lange, Elvira Richter

  Medizinische Klinik (Munich, Germany : 1983). 01/2008; 102(12):957-66.

  Tuberculosis remains to be one of the most important infectious diseases worldwide. Among the estimated 9 million new cases that are anually recorded, antibiotic drug resistance of MycobacteriumTuberculosis remains to be one of the most important infectious diseases worldwide. Among the estimated 9 million new cases that are anually recorded, antibiotic drug resistance of Mycobacterium tuberculosis has become an increasing problem. Cases of multidrug resistance (MDR), by definition resistance against at least isoniazid and rifampin, are reported worldwide. Moreover, cases of extensively drug-resistant tuberculosis (XDR-TB) with additional resistance to fluoroquinolones and aminoglycosides are also emerging. Patients who are infected with MDR-TB strains need a carefully selected antibiotic combination therapy consisting of four to six alternative drugs according to the results of in vitro drug susceptibility testing. The duration of treatment against MDR-TB is cost-intensive, and is generally recommended for 18 months beyond the first time of sustained culture negativity. Patient adherence to the therapy is essential. As adverse effects of MDR-TB therapy are common, treatment of these patients should be guided by experienced physicians.

• Mycobacterium alsiense, a novel, slowly growing species isolated from two patients with pulmonary disease.

  Authors: Elvira Richter, Enrico Tortoli, Arno Fischer, Oliver Hendricks, Regina Engel, Doris Hillemann, Sabine Schubert, Jette E Kristiansen

  Journal of clinical microbiology. 12/2007; 45(11):3837-9.

  A previously undescribed, slowly growing Mycobacterium species was isolated from pulmonary specimens of two patients, one from Denmark and one from Italy. The isolates showed unique 16S rRNA internalA previously undescribed, slowly growing Mycobacterium species was isolated from pulmonary specimens of two patients, one from Denmark and one from Italy. The isolates showed unique 16S rRNA internal transcribed spacers and hsp65 sequences: the 16S rRNA was most closely related to Mycobacterium szulgai and Mycobacterium malmoense.

• Evaluation of the GenoType MTBDRplus assay for rifampin and isoniazid susceptibility testing of Mycobacterium tuberculosis strains and clinical specimens.

  Authors: Doris Hillemann, Sabine Rüsch-Gerdes, Elvira Richter

  Journal of clinical microbiology. 09/2007; 45(8):2635-40.

  The new GenoType MTBDRplus assay (Hain Lifescience GmbH, Nehren, Germany) was tested with 125 clinical isolates and directly with 72 smear-positive sputum specimens for its ability to detect rifampinThe new GenoType MTBDRplus assay (Hain Lifescience GmbH, Nehren, Germany) was tested with 125 clinical isolates and directly with 72 smear-positive sputum specimens for its ability to detect rifampin (RMP) and isoniazid (INH) resistance in Mycobacterium tuberculosis complex (MTBC) strains. In total, 106 RMP(r)/INH(r), 10 RMP(s)/INH(r), and 80 RMP(s)/INH(s) MTBC strains were comparatively analyzed with the new and the old MTBDR assays. Besides the detection of mutations within the 81-bp hot spot region of rpoB and katG codon 315, the GenoType MTBDRplus assay is designed to detect mutations in the regulatory region of inhA. The applicability of the new assay directly to specimens was shown, since 71 of 72 results for smear-positive sputa and all 125 results for clinical isolates were interpretable and no discrepancies compared with the results of real-time PCR or DNA sequencing were obtained. In comparison to conventional drug susceptibility testing, both assays were able to identify RMP resistance correctly in 74 of 75 strains (98.7%) and 30 of 31 specimens (96.8%). The misidentification of RMP resistance was obtained for two strains containing rpoB P533L mutations. Compared to the old MTBDR assay, the new GenoType MTBDRplus assay enhanced the rate of detection of INH resistance from 66 (88.0%) to 69 (92.0%) among the 75 INH-resistant strains and 36 (87.8%) to 37 (90.2%) among the 41 specimens containing INH-resistant strains. Thus, the new GenoType MTBDRplus assay represents a reliable and upgraded tool for the detection of INH and RMP resistance in strains or directly from smear-positive specimens.

• First linezolid-resistant clinical isolates of Mycobacterium tuberculosis.

  Authors: Elvira Richter, Sabine Rüsch-Gerdes, Doris Hillemann

  Antimicrobial agents and chemotherapy. 05/2007; 51(4):1534-6.

  Linezolid resistance was found in 4 (1.9%) of 210 multidrug-resistant Mycobacterium tuberculosis strains. The MICs of linezolid were 4 microg/ml (one strain) and 8 microg/ml (three strains). Since noLinezolid resistance was found in 4 (1.9%) of 210 multidrug-resistant Mycobacterium tuberculosis strains. The MICs of linezolid were 4 microg/ml (one strain) and 8 microg/ml (three strains). Since no mutations were detected in potential target genes, the mechanism of resistance remains unclear.

• Use of the BACTEC Mycobacteria Growth Indicator Tube 960 automated system for recovery of Mycobacteria from 9,558 extrapulmonary specimens, including urine samples.

  Authors: Doris Hillemann, Elvira Richter, Sabine Rüsch-Gerdes

  Journal of clinical microbiology. 12/2006; 44(11):4014-7.

  The BACTEC Mycobacteria Growth Indicator Tube 960 (MGIT 960) system was applied for recovery of mycobacteria from extrapulmonary specimens and compared with solid media (Löwenstein-Jensen andThe BACTEC Mycobacteria Growth Indicator Tube 960 (MGIT 960) system was applied for recovery of mycobacteria from extrapulmonary specimens and compared with solid media (Löwenstein-Jensen and Stonebrink). A total of 9,558 specimens were investigated, comprising 3,074 body fluids, 1,878 tissues, and 2,069 urine samples, from which the recovery of mycobacteria was not yet established for MGIT 960. In total, the MGIT 960 was able to detect 446 (90.3%) of the 494 isolates of Mycobacterium tuberculosis complex (MTBC) and 223 (86.0%) out of the 259 isolates of nontuberculous mycobacteria (NTM). In comparison to this, culture on solid medium revealed 358 (72.6%) MTBC isolates and 164 (66.8%) NTM isolates. While 136 (27.6%) of the MTBC isolates and 95 (19.2%) of the NTM isolates were recovered from the MGIT 960 only, 48 (9.7%) of the MTBC isolates and 36 (13.9%) NTM isolates grew only on solid media. Thus, the overall sensitivities for the recovery of mycobacteria from extrapulmonary specimens with MGIT 960 and solid media were 88.8% and 69.3%, respectively. However, the efficiency of the MGIT 960 system can be maximized with additional culture on solid media.

• Evaluation of the GenoType Mycobacterium Assay for identification of mycobacterial species from cultures.

  Authors: Elvira Richter, Sabine Rüsch-Gerdes, Doris Hillemann

  Journal of clinical microbiology. 06/2006; 44(5):1769-75.

  A new commercially available DNA strip assay (GenoType Mycobacterium CM/AS; Hain Lifescience, Nehren, Germany) was evaluated for the ability to differentiate mycobacterial species. The test is basedA new commercially available DNA strip assay (GenoType Mycobacterium CM/AS; Hain Lifescience, Nehren, Germany) was evaluated for the ability to differentiate mycobacterial species. The test is based on a PCR technique targeting a 23S rRNA gene region, followed by reverse hybridization and line probe technology. The GenoType CM is capable of identifying 23, the GenoType AS a further 14, species either alone or in combination with one or more species. Both tests were evaluated with 156 mycobacterial strains composed of 61 validly published species including different subspecies, 6 not validly published species, and 3 strains other than mycobacterial species. All strains were precharacterized by sequencing of the 5' region of the 16S rRNA gene and biochemical tests. In total, results for 151 strains were interpretable. Concordant results were obtained for 137 (92.6%) of 148 mycobacterial strains with the CM assay and 133 (89.9%) of 148 mycobacterial strains with the AS assay, and all three non-Mycobacterium species were identified.

• Use of the genotype MTBDR assay for rapid detection of rifampin and isoniazid resistance in Mycobacterium tuberculosis complex isolates.

  Authors: Doris Hillemann, Michael Weizenegger, Tanja Kubica, Elvira Richter, Stefan Niemann

  Journal of clinical microbiology. 09/2005; 43(8):3699-703.

  A commercially available DNA strip assay (Genotype MTBDR; Hain Lifescience, Nehren, Germany) was evaluated for its ability to detect mutations conferring resistance to rifampin (RMP) and isoniazidA commercially available DNA strip assay (Genotype MTBDR; Hain Lifescience, Nehren, Germany) was evaluated for its ability to detect mutations conferring resistance to rifampin (RMP) and isoniazid (INH) in clinical Mycobacterium tuberculosis complex isolates. A total of 103 multidrug-resistant (MDR; i.e., at least resistant to RMP and INH) and 40 fully susceptible strains isolated in Germany in 2001 in which resistance mutations have been previously defined by DNA sequencing and real-time PCR analysis were investigated. The Genotype MTBDR assay identified 102 of the 103 MDR strains with mutations in the rpoB gene (99%) and 91 strains (88.4%) with mutations in codon 315 of katG. All 40 susceptible strains showed a wild-type MTBDR hybridization pattern. The concordance between the MTBDR assay and the DNA sequencing results was 100%. Compared to conventional drug susceptibility testing, the sensitivity and specificity were 99 and 100% for RMP resistance and 88.4 and 100% for INH resistance, respectively. In conclusion, the MTBDR assay is a rapid and easy-to-perform test for the detection of the most common mutations found in MDR M. tuberculosis strains that can readily be included in a routine laboratory work flow.

• Usefulness of the GenoType MTBC assay for differentiating species of the Mycobacterium tuberculosis complex in cultures obtained from clinical specimens.

  Authors: Elvira Richter, Michael Weizenegger, Anne-Marie Fahr, Sabine Rüsch-Gerdes

  Journal of clinical microbiology. 10/2004; 42(9):4303-6.

  A novel DNA strip assay, GenoType MTBC, was evaluated for differentiation of Mycobacterium tuberculosis complex species from 77 positive liquid cultures in clinical practice. Species identificationA novel DNA strip assay, GenoType MTBC, was evaluated for differentiation of Mycobacterium tuberculosis complex species from 77 positive liquid cultures in clinical practice. Species identification (M. tuberculosis [71 strains], Mycobacterium bovis subsp. bovis [5 strains], and Mycobacterium africanum subtype I [1 strain]) results were identical to conventional results. The sensitivity was slightly higher for this test than for the AccuProbe assay.

• Clinical evaluation of the semiautomated BDProbeTec ET System for the detection of Mycobacterium tuberculosis in respiratory and nonrespiratory specimens.

  Authors: Sabine Rüsch-Gerdes, Elvira Richter

  Diagnostic microbiology and infectious disease. 05/2004; 48(4):265-70.

  The reliability of the BDProbeTec ET assay, a semiautomated system for the direct detection of Mycobacterium tuberculosis complex in clinical specimens was evaluated by comparing results obtained byThe reliability of the BDProbeTec ET assay, a semiautomated system for the direct detection of Mycobacterium tuberculosis complex in clinical specimens was evaluated by comparing results obtained by the system to those obtained by conventional culture methods and clinical data of the patients. Out of 1131 (735 respiratory and 396 nonrespiratory) specimens, 42 were smear- and 125 culture-positive. After resolution of discrepant results the overall sensitivity, specificity, and positive and negative predictive values for the BDProbeTec ET assay were 90.3, 96.9, 78.3, and 98.9%, respectively. For smear-positive specimens, all values were 100%, while the values for smear-negative specimens were 86.1, 96.9, 70.1, and 98.8%, respectively. All 28 nontuberculous mycobacteria were negative with the BDProbeTec ET system. The data demonstrate that the BDProbeTec ET assay is a highly sensitive and specific technique for the rapid (within 5 h) detection of M. tuberculosis complex in respiratory and nonrespiratory specimens.