U Eigner

Publications of U Eigner

• Evaluation of a new selective medium, BD BBL CHROMagar MRSA II, for detection of methicillin-resistant Staphylococcus aureus in different specimens.

  Authors: C Wendt, N L Havill, K C Chapin, J M Boyce, R Dickenson, U Eigner, S Schütt, A M Fahr

  Journal of clinical microbiology. 06/2010; 48(6):2223-7.

  The sensitivity of screening for methicillin-resistant Staphylococcus aureus (MRSA) can be improved by adding other specimen sites to nares. We describe an evaluation of a new selective medium, BBLThe sensitivity of screening for methicillin-resistant Staphylococcus aureus (MRSA) can be improved by adding other specimen sites to nares. We describe an evaluation of a new selective medium, BBL CHROMagar MRSA II (CMRSAII), for its ability to detect MRSA from different specimen types. CMRSAII is a chromogenic medium which incorporates cefoxitin for the detection of MRSA. A study was performed at four clinical laboratories with the following specimens: 1,446 respiratory, 694 stool, 1,275 skin, and 948 wound specimens and 688 blood culture bottles containing Gram-positive cocci. The recovery of MRSA on traditional culture media was compared to results with CMRSAII. S. aureus was tested by cefoxitin disk diffusion. CMRSAII was interpreted as positive for MRSA at 24 h (range, 18 to 28 h) based solely on the visualization of mauve-colored colonies and at 48 h (range, 36 to 52 h) based on detection of mauve colonies with subsequent confirmation as S. aureus (by coagulase or latex agglutination testing). MRSA was recovered more frequently on CMRSAII (89.8% at 24 h and 95.6% at 48 h) than on traditional culture plates (83.1% at 24 h and 79.8% at 48 h) for all specimen types combined (P < 0.001). The percent sensitivities of CMRSAII at 24- and 48-h reads, respectively, were 85.5 and 92.4% for respiratory specimens, 87.9% and 98.3% for stool specimens, 88.4% and 96.1% for skin specimens, 92.1% and 94.6% for wound specimens, and 100% and 100% for positive blood cultures. The specificity was 99.8% for respiratory specimens and 100% for all others. In conclusion, CMRSAII is a reliable screening medium for multiple specimen types.

• High Inter-Laboratory Reproducibility of MALDI-TOF Mass Spectrometry-Based Species Identification of Nonfermenting Bacteria.

  Authors: A Mellmann, F Bimet, C Bizet, A. D. Borovskaya, R. R. Drake, U Eigner, A M Fahr, Y. He, E. N. Ilina, M Kostrzewa, T Maier, L Mancinelli, W. Moussaoui, G Prévost, L Putignani, C. L. Seachord, Y. W. Tang, D Harmsen

  Journal of clinical microbiology. 09/2009;

  MALDI-TOF MS has emerged as rapid, cost-effective alternative for bacterial species identification. Identifying 60 blind-coded nonfermenting bacteria samples, this international study (eightMALDI-TOF MS has emerged as rapid, cost-effective alternative for bacterial species identification. Identifying 60 blind-coded nonfermenting bacteria samples, this international study (eight laboratories) achieved 98.75% inter-laboratory reproducibility. Only six of 480 samples were misidentified due to interchanges (4 samples) or contamination (1), or not identified because of insufficient signal intensity (1).

• Direct detection of methicillin-resistant Staphylococcus aureus in clinical specimens by a nucleic acid-based hybridisation assay.

  Authors: M Holfelder, U Eigner, A-M Turnwald, W Witte, M Weizenegger, A Fahr

  Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases. 01/2007; 12(12):1163-7.

  The occurrence of methicillin-resistant Staphylococcus aureus (MRSA) is still increasing worldwide and is associated with significant morbidity, mortality and hospital costs. Screening for MRSA playsThe occurrence of methicillin-resistant Staphylococcus aureus (MRSA) is still increasing worldwide and is associated with significant morbidity, mortality and hospital costs. Screening for MRSA plays a key role in limiting further nosocomial spread of this organism. Control measures require a rapid and sensitive test for direct detection of MRSA carriage. This study evaluated an easy-to-use PCR-hybridisation assay for the direct detection of MRSA in clinical swab specimens. In total, 508 pairs of swabs from 242 patients at risk for MRSA carriage were analysed by the standard culture method and the PCR assay. One swab was used for PCR and culture, while the second was used for culture only. Of the 508 pairs tested, 37 were positive by culture and 35 were positive by PCR. Among the 471 culture-negative specimens, 465 were negative by PCR and six were PCR-positive. The PCR assay had a sensitivity of 94.59%, a specificity of 98.73%, a positive predictive value of 85.37%, and a negative predictive value of 99.57%. The PCR-hybridisation assay enabled reliable detection of MRSA carriage in c. 4 h, thereby allowing its effective use in an MRSA control strategy.

• Spread of ampicillin/vancomycin-resistant Enterococcus faecium of the epidemic-virulent clonal complex-17 carrying the genes esp and hyl in German hospitals.

  Authors: I Klare, C Konstabel, S Mueller-Bertling, G Werner, B Strommenger, C Kettlitz, S Borgmann, B Schulte, D Jonas, A Serr, A M Fahr, U Eigner, W Witte

  European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology. 01/2006; 24(12):815-25.

  The incidence of vancomycin-resistant Enterococcus faecium isolation was low (<or=5%) in German hospitals before 2003. Within the second half of 2003 and the first half of 2004, however, increasingThe incidence of vancomycin-resistant Enterococcus faecium isolation was low (<or=5%) in German hospitals before 2003. Within the second half of 2003 and the first half of 2004, however, increasing frequencies of up to 14% were noticed in several hospitals in southwestern Germany. This increase was attributed mainly to the occurrence and spread of epidemic-virulent ampicillin/vancomycin-resistant, vanA- and vanB-positive E. faecium clones, most of which exhibited the virulence factors enterococcal surface protein (esp) and bacteriocin activity and some which exhibited hyaluronidase (hyl). E. faecium possessing hyaluronidase was initially found in U.S. hospitals and recently detected in several European hospitals and, subsequently, in German hospitals as well. Ampicillin/vancomycin-resistant E. faecium clones originating mainly from southwestern German hospitals were characterized by multilocus sequence typing since different sequence types (STs) belonging to the clonal complex-17 are currently disseminated worldwide. Multilocus sequence typing revealed that, in 1998 and 1999, ampicillin/vancomycin-resistant E. faecium clone ST-117 was prevalent in various German hospitals, while in 2003 and 2004, clone ST-203 dominated in several hospitals located in southwestern Germany. Both sequence types display single-locus variants of ST-78, which was frequently recorded in various Italian hospitals between 2000 and 2003, and all of these STs belong to the clonal complex-17. Expression of linezolid resistance was observed in ampicillin/glycopeptide-resistant E. faecium strains (VanA type) from two tertiary hospitals in southwestern Germany due to mutations in domain V of the 23S rDNA (G2576T). While in one hospital the resistance emerged during linezolid therapy, in the other hospital resistance was caused by transfer of an identical linezolid/ampicillin/glycopeptide-resistant E. faecium strain. In conclusion, it is very important to monitor the occurrence of epidemic-virulent clonal complex-17 strains of E. faecium to prevent their spread in hospitals, especially if they are resistant to glycopeptides and linezolid.

• Evaluation of a rapid direct assay for identification of bacteria and the mec A and van genes from positive-testing blood cultures.

  Authors: U Eigner, M Weizenegger, A M Fahr, W Witte

  Journal of clinical microbiology. 11/2005; 43(10):5256-62.

  We performed the first evaluation of a DNA strip assay (GenoType blood culture; Hain Lifescience, Nehren, Germany) for the detection of the most relevant bacterial sepsis pathogens directly fromWe performed the first evaluation of a DNA strip assay (GenoType blood culture; Hain Lifescience, Nehren, Germany) for the detection of the most relevant bacterial sepsis pathogens directly from positive BACTEC blood culture bottles (Becton Dickinson, Heidelberg, Germany). The test comprises two panels, one for the direct species identification of important gram-positive cocci and the other for gram-negative rods. Additionally, detection of the mec A and the van genes are implemented. The GenoType assay was validated regarding its analytical sensitivity with blood cultures spiked with reference strains. Approximately 10(4) CFU per ml were detected. Analytical specificity was calculated with a test panel of 212 reference strains. Of the strains tested, 99% were correctly identified. Additionally, 279 consecutive blood cultures signaled positive by BACTEC were processed directly, in comparison to conventional methods. The GenoType assays were performed according to Gram stain morphology. A total of 243 (87.1%) of the 279 organisms isolated were covered by specific probes. A total of 152 organisms were gram-positive cocci, of which 148 (97.4%) were correctly identified by the GenoType assay. Ninety-one organisms were gram-negative rods, of which 89 (97.8%) were correctly identified. Concerning mec A gene detection, GenoType assay correctly detected 12 of 13 methicillin-resistant Staphylococcus aureus isolates. One Enterococcus faecium isolate with a positive van A gene isolated was correctly differentiated by the assay. All results were available 4 h after the results of microscopic analysis. The evaluated GenoType blood culture assay showed fast and reliable results in detecting the most important sepsis pathogens and the mec A and van genes directly from positive blood culture bottles.

• Analysis of the comparative workflow and performance characteristics of the VITEK 2 and Phoenix systems.

  Authors: U Eigner, A Schmid, U Wild, D Bertsch, A M Fahr

  Journal of clinical microbiology. 09/2005; 43(8):3829-34.

  The VITEK 2 (bioMérieux, Marcy L'Etoile, France) and the Phoenix systems (BD Diagnostic Systems, Sparks, Md.) are automated instruments for rapid organism identification and susceptibility testing.The VITEK 2 (bioMérieux, Marcy L'Etoile, France) and the Phoenix systems (BD Diagnostic Systems, Sparks, Md.) are automated instruments for rapid organism identification and susceptibility testing. We evaluated the workflow, the time to result, and the performance of identification and susceptibility testing of both instruments. A total of 307 fresh clinical isolates were tested: 141 Enterobacteriaceae, 22 nonfermenters, 93 Staphylococcus spp., and 51 Enterococcus spp. Manipulation time was measured in batches, each with seven isolates, for a total of 39 batches. The mean (+/- standard deviation [SD]) manipulation time per batch was 20.9 +/- 1.8 min for Phoenix and 10.6 +/- 1.0 min for VITEK 2 (P < 0.001). Mean (+/-SD) time to result for all bacterial groups was 727 +/- 162 min for Phoenix and 506 +/- 120 min for VITEK 2 (P < 0.001). Concerning identification, Phoenix and VITEK 2 yielded the same results for nonfermenters (100%), staphylococci (97%), and enterococci (100%). For 140 Enterobacteriaceae strains evaluated, 135 (96%) were correctly identified by Phoenix and 137 (98%) by VITEK 2 (P = 0.72). The overall category agreement for all isolates was 97.0% for both instruments. The minor error rate, major error rate, and very major error rate for all bacterial isolates tested were 3.0, 0.3, and 0.6 and 2.8, 0.2, and 1.7 for Phoenix and VITEK 2, respectively (P values of 0.76, 0.75, and 0.09). The VITEK 2 system required less manual manipulation time and less time than the Phoenix system to yield results.

• Evaluation of a new molecular system for simultaneous identification of four Enterococcus species and their glycopeptide resistance genotypes.

  Authors: U Eigner, A Fahr, M Weizenegger, W Witte

  Journal of clinical microbiology. 07/2005; 43(6):2920-2.

  We compared the performances of a new DNA-based strip assay and the VITEK 2 system for identification of 105 enterococcal strains and differentiation of their van gene-associated resistance levels.We compared the performances of a new DNA-based strip assay and the VITEK 2 system for identification of 105 enterococcal strains and differentiation of their van gene-associated resistance levels. Both methods provided excellent results. The molecular assay showed advantages in time to result for identification of van-associated genes.

• Evaluation of a new chromogenic medium for the isolation and presumptive identification of Salmonella species from stool specimens.

  Authors: U Eigner, R Reissbrodt, R Hammann, A M Fahr

  European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology. 09/2001; 20(8):558-65.

  The performance of BBL CHROMagar Salmonella (Becton Dickinson, France), a new selective chromogenic medium for the isolation and presumptive identification of Salmonella spp., was evaluated. On thisThe performance of BBL CHROMagar Salmonella (Becton Dickinson, France), a new selective chromogenic medium for the isolation and presumptive identification of Salmonella spp., was evaluated. On this medium, which is a modification of CHROMagar Salmonella (CHROMagar Microbiology, France) with enhanced selectivity, the colonies of Salmonella are stained in mauve (rose-violet), while those of other organisms appear in blue-green or are not stained by any of the chromogens of the medium. The medium was evaluated with a total of 176 strains of Salmonella and other organisms, consisting of 18 reference strains and 158 clinical isolates. All Salmonella strains except subspecies IIIa and IIIb strains and Salmonella Gallinarum yielded typical mauve colonies. During the evaluation with 107 known positive and 332 unknown stool specimens in a clinical laboratory, a total of 115 and 105 Salmonella isolates were obtained on BBL CHROMagar Salmonella and Hektoen enteric agar, respectively. From the known positive stool specimens, 92 true positive cultures were obtained on BBL CHROMagar Salmonella and 89 on Hektoen enteric agar, yielding sensitivities of 86 and 83%, respectively. From the unknown stool specimens, a total of 27 Salmonella isolates were obtained, with 23 isolated from BBL CHROMagar Salmonella and 16 from Hektoen enteric agar by direct plating (sensitivity 85 and 59%, specificity 99 and 97%, respectively). Seroagglutination tests could be performed directly from BBL CHROMagar Salmonella. Compared to conventional isolation media, the time needed for confirmatory biochemical and serological tests was shortened by about 1 day when BBL CHROMagar Salmonella was used. On the basis of these results, the medium can be recommended for the primary isolation and presumptive identification of Salmonella spp. from clinical stool specimens.