R Köck

Publications of R Köck

• Characteristics of hospital patients colonized with livestock-associated meticillin-resistant Staphylococcus aureus (MRSA) CC398 versus other MRSA clones.

  Authors: R Köck, K Siam, S Al-Malat, J Christmann, F Schaumburg, K Becker, A W Friedrich

  The Journal of hospital infection. 12/2011; 79(4):292-6.

  Meticillin-resistant Staphylococcus aureus (MRSA) associated with the clonal complex (CC) 398 has emerged among livestock and humans exposed to these animals. MRSA CC398 has so far contributedMeticillin-resistant Staphylococcus aureus (MRSA) associated with the clonal complex (CC) 398 has emerged among livestock and humans exposed to these animals. MRSA CC398 has so far contributed relatively little to spread of MRSA and the burden of disease in the healthcare setting. This study aimed to assess whether demographic and clinical differences in patients colonized with MRSA CC398 and those carrying other MRSA clones contribute to the observed differences in transmission and infection rates. Age, sex, length of stay (LOS), diagnoses and medical procedures were assessed in all patients with MRSA admitted to a university hospital in 2008 and 2009. S. aureus protein A gene (spa) typing was performed on the first MRSA isolate from each patient. Patients colonized or infected with MRSA that had spa types indicative of CC398 (MRSA CC398) were compared with patients who had other MRSA clones (MRSA non-CC398). Age (53 vs 59 years), mean LOS (8 vs 13 days) and percentage of patients admitted to an intensive care unit (12% vs 17%) differed significantly between MRSA CC398 and MRSA non-CC398 patients, respectively. The mean numbers and types of diagnoses and medical procedures performed for patients in these two groups also differed significantly. The differences in patient characteristics could explain, at least in part, the relatively low rates of transmission and infection associated with MRSA CC398 in the healthcare setting.

• Virulence factors and genotypes of Staphylococcus aureus from infection and carriage in Gabon.

  Authors: F Schaumburg, U Ateba Ngoa, K Kösters, R Köck, A A Adegnika, P G Kremsner, B Lell, G Peters, A Mellmann, K Becker

  Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases. 04/2011; 17(10):1507-13.

  Staphylococcus aureus isolates from developed countries have been extensively analyzed with respect to their virulence patterns and clonal relatedness but there is only sparse information on theStaphylococcus aureus isolates from developed countries have been extensively analyzed with respect to their virulence patterns and clonal relatedness but there is only sparse information on the molecular diversity of S. aureus isolates from Africa. In particular, little is known about S. aureus isolates from asymptomatic carriers compared with isolates causing infections. From 2008 to 2010, we prospectively collected S. aureus isolates from asymptomatic carriers and infections in Lambaréné, Gabon, Central Africa. For these isolates, we determined major virulence factors, and performed multilocus sequence typing (MLST) and spa typing. Among 163 S. aureus isolates from asymptomatic carriers, we found the MLST clonal complexes (CCs) 5, 6, 7, 8, 9, 15, 25, 30, 45, 88, 101, 121 and 152; 3.7% were methicillin-resistant (MRSA). The clinical isolates were associated with CCs 5, 8, 9, 15, 88, 121 and 152; 11% were MRSA. Sequence types 1 and 88 were significantly associated with infection and sequence type 508 was associated with carriage. Remarkably, there was a high prevalence of Panton-Valentine leukocidin (PVL) -encoding genes both in disease-related isolates (57.4%) and in carrier isolates (40.5%). We found differences in the clonal structure and virulence pattern of Gabonese S. aureus isolates from asymptomatic carriers and infections. Of note, S. aureus isolates from Gabon show a very high prevalence of PVL-encoding genes, which exceeds the rates observed for developed countries.

• Methicillin-resistant Staphylococcus aureus (MRSA): burden of disease and control challenges in Europe.

  Authors: R Köck, K Becker, B Cookson, J E van Gemert-Pijnen, S Harbarth, J Kluytmans, M Mielke, G Peters, R L Skov, M J Struelens, E Tacconelli, A Navarro Torné, W Witte, A W Friedrich

  Euro surveillance : bulletin européen sur les maladies transmissibles = European communicable disease bulletin. 01/2010; 15(41):19688.

  Methicillin-resistant Staphylococcus aureus (MRSA) isa major cause of healthcare- and community-associated infections worldwide. Within the healthcare setting alone, MRSA infections are estimated toMethicillin-resistant Staphylococcus aureus (MRSA) isa major cause of healthcare- and community-associated infections worldwide. Within the healthcare setting alone, MRSA infections are estimated to affect more than 150,000 patients annually in the European Union (EU), resulting in attributable extra in-hospital costs of EUR 380 million for EU healthcare systems. Pan-European surveillance data on bloodstream infections show marked variability among EU Member States in the proportion of S. aureus that are methicillin-resistant, ranging from less than 1% to more than 50%. In the past five years, the MRSA bacteraemia rates have decreased significantly in 10 EU countries with higher endemic rates of MRSA infections. In addition to healthcare-associated infections, new MRSA strains have recently emerged as community and livestock-associated human pathogens in most EU Member States. The prevention and control of MRSA have therefore been identified as public health priorities in the EU. In this review, we describe the current burden of MRSA infections in healthcare and community settings across Europe and outline the main threats caused by recent changes in the epidemiology of MRSA. Thereby, we aim at identifying unmet needs of surveillance, prevention and control of MRSA in Europe.

• Prevalence and molecular characteristics of methicillin-resistant Staphylococcus aureus (MRSA) among pigs on German farms and import of livestock-related MRSA into hospitals.

  Authors: R Köck, J. Harlizius, N. Bressan, R. Laerberg, L Wieler, W Witte, R Deurenberg, A Voss, K Becker, A Friedrich

  European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology. 09/2009;

  The aim of this study was to evaluate the prevalence and molecular characteristics of methicillin-resistant Staphylococcus aureus (MRSA) among pigs and estimate the impact of this animal reservoir onThe aim of this study was to evaluate the prevalence and molecular characteristics of methicillin-resistant Staphylococcus aureus (MRSA) among pigs and estimate the impact of this animal reservoir on human healthcare. Nasal swabs were derived from 1,600 pigs at 40 German farms. The MRSA were characterized using S. aureus protein A (spa) typing, multilocus sequence typing (MLST) and detection of toxin genes. In a retrospective case control study, we compared risk factors for the carriage of MRSA between patients carrying spa types found among regional pigs and patients with other MRSA molecular types. Pigs carrying MRSA were identified on 70% of the farms (spa types t011, t034, t108, t1451 and t2510, all associated with MLST sequence type ST398). Contact to pigs and cattle were independent risk factors for the carriage of these spa types in patients at hospital admission. Our results indicate that livestock represents a relevant reservoir for the import of MRSA into regional German hospitals.

• Cross-border comparison of the admission prevalence and clonal structure of meticillin-resistant Staphylococcus aureus.

  Authors: R Köck, L Brakensiek, A Mellmann, F Kipp, M Henderikx, D Harmsen, I Daniels-Haardt, C von Eiff, K Becker, M G R Hendrix, A W Friedrich

  The Journal of hospital infection. 02/2009;

  Since patient exchange between hospitals sharing a common catchment area might favour regional spread of meticillin-resistant Staphylococcus aureus (MRSA), the reliable detection of patientsSince patient exchange between hospitals sharing a common catchment area might favour regional spread of meticillin-resistant Staphylococcus aureus (MRSA), the reliable detection of patients colonised at admission is crucial. This, hospitals in the Dutch-German border area EUREGIO MRSA-net aim at synchronising their local MRSA standards in order to prevent unidentified inter-hospital as well as cross-border spread. This assumes enhanced knowledge of MRSA prevalence and risk factors associated with MRSA carriage at admission. We conducted nasal MRSA screening of all inpatients admitted to 39 German hospitals (in the period 1 November to 30 November 2006) and to one Dutch hospital (in the period 1 July to 30 September 2007) in the EUREGIO MRSA-net. A total of 390 MRSA cases were detected among 25 540 patients screened. The admission prevalence was 1.6 MRSA/100 patients (6.5% of all S. aureus) in the German and 0.5 MRSA/100 patients (1.4% of all S. aureus) in the Dutch part of the border region. Overall, the predominating S. aureus protein A gene (spa) sequence types were t003, t032 and t011. One isolate (t044) carried Panton-Valentine leukocidin (PVL) encoding genes. Altogether, 79% and 67% of all MRSA patients in the German and Dutch regions respectively, were identifiable by the classical nosocomial risk factors assessed. In patients lacking all risk factors assessed, spa types t011 and t034 were predominant (P<0.001).

• EUREGIO MRSA-net Twente/Münsterland--a Dutch-German cross-border network for the prevention and control of infections caused by methicillin-resistant Staphylococcus aureus.

  Authors: A W Friedrich, I Daniels-Haardt, R Köck, F Verhoeven, A Mellmann, D Harmsen, J. E. van Gemert-Pijnen, K Becker, M G R Hendrix

  Euro surveillance : bulletin européen sur les maladies transmissibles = European communicable disease bulletin. 09/2008; 13(35).

  Methicillin-resistant Staphylococcus aureus (MRSA) is associated with increased mortality and morbidity and a leading cause of hospital-acquired infections. Community-acquired (CA)-MRSA are a growingMethicillin-resistant Staphylococcus aureus (MRSA) is associated with increased mortality and morbidity and a leading cause of hospital-acquired infections. Community-acquired (CA)-MRSA are a growing concern worldwide. In the last 10 years, an increase in the MRSA rate from 2% to approximately 23% has been observed in Germany, while a rate under 5% has been recorded for many years in the Netherlands and Scandinavia. In the Netherlands in particular, MRSA rates have become very low in stationary care due to a consistent 'search and destroy' policy. The main focus in Germany lies on hospital-acquired MRSA, whereas the Netherlands focus on the control of the importation of MRSA cases from abroad and on CA-MRSA. As MRSA in hospitals and in the community can be a problem in cross-border health care, the European Union-funded EUREGIO MRSA-net project was established in the bordering regions Twente/Achterhoek, the Netherlands and Münsterland, Germany. The main aim of the project is the creation of a network of the major health care providers in the EUREGIO and the surveillance and prevention of MRSA infections. A spa-typing network was established in order to understand the regional and cross-border dissemination of epidemic and potentially highly virulent MRSA genotypes. As the reduction of differences in health care quality is an important prerequisite for cross-border health care, a transborder quality group comprising hospitals, general practitioners, public health authorities, laboratories, and insurerance companies has been established since 2005 equalising the quality criteria for the control of MRSA on both sides of the border.

• Urease genes in non-O157 Shiga toxin-producing Escherichia coli: mostly silent but valuable markers for pathogenicity.

  Authors: A W Friedrich, R Lukas, A Mellmann, R Köck, W Zhang, W Mathys, M Bielaszewska, H Karch

  Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases. 06/2006; 12(5):483-6.

  The distribution of ureC was investigated among 294 Escherichia coli isolates, comprising 72 strains from the E. coli standard reference collection (ECOR), 62 strains from the diarrhoeagenic E. coliThe distribution of ureC was investigated among 294 Escherichia coli isolates, comprising 72 strains from the E. coli standard reference collection (ECOR), 62 strains from the diarrhoeagenic E. coli (DEC) collection, and 160 clinical isolates of Shiga toxin-producing E. coli (STEC). The ureC gene was more frequent among STEC isolates harbouring eae than among those lacking eae (p < 0.0001). All clinical STEC isolates of serogroups O111 and O145 contained ureC, but only two of 294 isolates expressed urease activity. The silencing of urease expression could not be linked to a stop codon in ureD. The frequent occurrence of ure genes in eae-positive STEC isolates makes them valuable markers for virulence.