Matthias Imöhl

Prof. Dr. Matthias Imöhl

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Research Focus & Metrics

Academic Career Length

18Years (2009-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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5 May 2015 in BMC Infectious Diseases
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Journal Article
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MLMark van der Linden
Mark van der Linden
SPStephanie Perniciaro
Stephanie Perniciaro
MIMatthias Imöhl
Matthias Imöhl
This study presents an analysis of 1,491 serogroup 23 and 762 serogroup 15 isolates from invasive pneumococcal disease (IPD) in children and adults before and after the general recommendation for childhood pneumococcal conjugate vaccination in Germany in July 2006. Vaccination formulations used were PCV7 (from July 2006), PCV10 (from April 2009) and PCV13 (from December 2009, replacing PCV7). The German National Reference Center for Streptococci (GNRCS) has conducted surveillance of IPD since 1992. Isolates were serotyped and tested for antibiotic susceptibility. Selected isolates were characterized using MLST. In an analysis of 23,957 isolates from IPD in children and adults sent to the GNRCS between July 1992 and June 2014, we found a strongly significant increase of non-PCV13 serotypes in the late vaccination (PCV13) period (2010-2014). Among these, the proportions of serotypes 15A and 23B were the most strongly significantly increasing. After the recommendation for pneumococcal conjugate childhood vaccination in 2006 and the introduction of higher-valent vaccines in 2009, the proportion of 15A increased significantly from 0.5% in the early vaccination period (2007-2010) to 2.4% in the late vaccination period (2010-2014, p=3.14x10-22). The proportion of serotype 23B increased from 0.5% to 2.8% in the same period (p=1.55x10-29). Penicillin non-susceptibility levels of the serotype 15A (47.4%) and serotype 23B (46.5%) isolates were high, with MIC values ranging from 0.12-2 μg/ml (15A) and 0.12-0.5 μg/ml (23B). MLSTs of serotype 23B isolates grouped in two clonal complexes (CC): CC439, with sequence type (ST) 439 as the main representative and CC338 (linked to CC156), with ST1349 as most prevalent clone. Both CCs have been present over almost the whole surveillance period. All penicillin non-susceptible isolates occurred in CC338. Serotype 15A isolates appeared to be more diverse. Six CCs, one group of three STs and two singletons were found among 20 isolates. Most prevalent was CC63, with ST63 as most prominent representative (n=5). Most penicillin non-susceptible isolates were found among CC63 isolates. The prevalence of non-PCV13 serotypes in Germany has increased significantly between July 2007 and June 2014, with 15A and 23B being the most strongly increasing serotypes of all. Both serotypes show a high proportion of penicillin non-susceptibility.

1 April 2010 in Journal of Clinical Microbiology
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MIMatthias Imöhl
Matthias Imöhl
RRRalf René Reinert
Ralf René Reinert
COChristina Ocklenburg
Christina Ocklenburg
MLMark van der Linden
Mark van der Linden
A total of 7,764 isolates from patients with invasive pneumococcal disease (IPD) were collected from 1992 to June 2006. Data on serotypes were available for 5,022 isolates (64.7% of all invasive isolates). Some 54.0% of the isolates originated from adults ≥16 years of age, and 46.0% were from children <16 years of age. The leading serotypes were 14, 23F, 1, 6B, 7F, 3, and 4. The serotypes significantly more common in children were 14, 6B, 19F, and 18C, while among adults, serotypes 3 and 4 were predominant. Serotype 7F was statistically more prevalent among children <4 months old than among the other age groups. Among children aged ≥4 months and <1 year, serotype 19F occurred statistically more frequently; and among children aged ≥1 year to <5 years, serotypes 14, 6B, and 18C were overrepresented. The serotypes predominantly affecting patients younger than the remaining collective of patients were 14, 6B, 19F, and 18C, while patients with IPD caused by serotypes 3, 4, and 9V were older than the collective, on average.

5 February 2013 in BMC Infectious Diseases
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MLMark van der Linden
Mark van der Linden
RRRalf René Reinert
Ralf René Reinert
WKWinfried V. Kern
Winfried V. Kern
MIMatthias Imöhl
Matthias Imöhl
This study presents an analysis of 159 serotype 19A isolates from IPD in children before and after the general recommendation for childhood pneumococcal conjugate vaccination in Germany in July 2006. Vaccination formulations used were PCV7, PCV10 (from April 2009) and PCV13 (from Dec. 2009, replacing PCV7).

18 July 2017 in PLOS ONE
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MIMatthias Imöhl
Matthias Imöhl
CFChristina Fitzner
Christina Fitzner
SPStephanie Perniciaro
Stephanie Perniciaro
MLMark van der Linden
Mark van der Linden
A nationwide laboratory-based surveillance study of invasive S. pyogenes infections was conducted in Germany. Invasive isolates (n = 719) were obtained between 2009 and 2014. Most isolates were obtained from blood (92.1%). The proportions of isolates from cerebrospinal fluid, pleural fluid, synovial fluid and peritoneal fluid were 3.9%, 1.8%, 1.7% and 0.6%, respectively. The most common emm types were emm 1 (31.8%), emm 28 (15.4%) and emm 89 (14.5%). The most common superantigen genes (speA, speC, speG, speH, speI, speJ, speK, speL, speM, ssa) identified from S. pyogenes were speG (92.1%), speJ (50.9%), and speC (42.0%). Significant associations of superantigen genes with underlying conditions or risks were observed in speG, speH, speJ, and speK. Significant associations between emm types or superantigen genes with clinical complications were observed in emm type 3 and in superantigen gene speA 1–3. Most frequent clinical manifestations included sepsis 59.4%, STSS 6.3%, meningitis 5.4%, and necrotizing fasciitis 5.0% (significantly associated with emm1).

1 June 2011 in FEMS Immunology & Medical Microbiology
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Journal Article
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MIMatthias Imöhl
Matthias Imöhl
MLMark van der Linden
Mark van der Linden
RRRalf René Reinert
Ralf René Reinert
KRKlaus Ritter
Klaus Ritter

14 February 2015 in BMC Infectious Diseases
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Journal Article
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MIMatthias Imöhl
Matthias Imöhl
JMJens Möller
Jens Möller
RRRalf René Reinert
Ralf René Reinert
SPStephanie Perniciaro
Stephanie Perniciaro
MLMark van der Linden
Mark van der Linden
OAOrhan Aktas
Orhan Aktas
Long-term complications and a case mortality rate of 7.5% make meningitis caused by Streptococcus pneumoniae a serious clinical threat. In 2006, a general pneumococcal conjugate vaccination (PCV) recommendation was issued for all children under 2 years in Germany. Here, we investigate serotype changes in meningitis cases after this vaccine recommendation. The German National Reference Center for Streptococci (NRCS) has conducted surveillance for invasive pneumococcal disease (IPD) in Germany since 1992. Pneumococcal isolates were serotyped by the Neufeld’s Quellung reaction and antibiotic susceptibility was tested using the broth microdilution method. Of 22,204 IPD isolates sent to the NRCS from July 1992 to June 2013, 3,086 were meningitis cases. Microbiological and statistical investigations were performed to characterize and quantify all meningitis cases, focusing on changes reflecting implementation of the national PCV recommendation. 1,766 isolates (57.2% of meningitis cases) were from adults (≥16 years) and 1,320 isolates (42.8%) originated from children (<16 years). Overall, the leading serotypes were 14 (9.7%), 7F (7.8%), 3 (6.9%), 19F (5.7%) and 23F (5.0%). Among children, serotypes 14 (16.2%), 7F (8.9%) and 19F (7.1%) were most common, whereas among adults, serotypes 3 (9.6%), 7F (6.9%), 22F (5.0%), 23F (4.9%) and 14 (4.8%) were most prevalent. After the introduction of general PCV7/10/13 vaccination a significant decrease for most vaccine serotypes was observed. Generally, the differences in antibiotic nonsusceptibility between children <16 years and adults ≥16 were low. For macrolides in the pre-PCV7 period, a significantly higher proportion of resistant isolates was found in children (25.1%), compared to the post-vaccination period (9.7%; p<0.0001). Implementation of the pneumococcal conjugate vaccines broadly reduced vaccine-type meningitis cases. Changes in serotype prevalence must be continuously monitored to observe future trends concerning pneumococcal meningitis.