PubMed Health⌕ Search

Biomedical subjects

Christa Cuny

Publications and source records attributed to Christa Cuny.

4 recordsLinked to original sources
PubMed2005

Molecular characterization of methicillin-resistant Staphylococcus aureus strains from pet animals and their relationship to human isolates.

OBJECTIVES: Methicillin-resistant Staphylococcus aureus (MRSA) isolates from pet animals were characterized and compared with human isolates from clonal complexes most prevalent in Central Europe. METHODS: S. aureus isolates were investigated for their in vitro susceptibility to antimicrobial agents by broth microdilution. Resistance genes and the Panton-Valentine leucocidin gene lukF-lukS were identified by PCR. All isolates were characterized by SmaI macrorestriction analysis and spa typing to assess their genomic relationships. Representative isolates were additionally analysed by multilocus sequence typing and PCR-directed SCCmec typing. RESULTS: All pet isolates carried the resistance genes mecA and erm(C) and proved to be resistant to beta-lactams and MLS(B) antibiotics. In addition, all isolates were resistant to fluoroquinolones. None of the pet isolates carried the Panton-Valentine leucocidin gene lukF-lukS. Macrorestriction analysis revealed that the pet MRSA isolates exhibited four closely related SmaI fragment patterns. Moreover, all isolates revealed spa type t032. Further analysis of representatives of the different PFGE types revealed the presence of multilocus sequence type ST22 in combination with a type IV SCCmec element. Thus, molecular typing results were similar for pet strains and human ST22 reference strains. CONCLUSIONS: Based on their strain characteristics, the MRSA isolates from pets investigated in this study closely resembled ST22 MRSA isolates which are widely disseminated in German hospitals. The results of this study indicate that cross-transmission of MRSA between pet animals and humans might have occurred.

Animals↗
PubMed2002

Intercenter reproducibility of binary typing for Staphylococcus aureus.

The reproducibility of the binary typing (BT) protocol developed for epidemiological typing of Staphylococcus aureus was analyzed in a biphasic multicenter study. In a Dutch multicenter pilot study, 10 genetically unique isolates of methicillin-resistant S. aureus (MRSA) were characterized by the BT assay as presented by van Leeuwen et al. [J. Clin. Microbiol. 2001 39 (1) 328]. The BT assay, including a standardized DNA extraction protocol was performed in duplicate in eleven medical microbiology laboratories. Two different hybridization detection procedures were applied and a prelabeled DNA sample as process control was included. Only three laboratories accurately identified all strains. Divergence in technical procedures resulted in misinterpretation due to an increasing number of faint or absent hybridization signals in combination with high background staining. The binary type of the process control was determined correctly by all participating laboratories. The feasibility of the BT protocol was related directly to the skill of the laboratory personnel. On the basis of the national study, we concluded that the DNA extraction protocol needed modification to improve DNA yield and purity. Subsequently, seven European laboratories participated in an international study to determine the reproducibility of the modified BT protocol. Each center was asked to analyze 10 DNA samples previously extracted from 10 MRSA strains (phase 1) and, additionally, to analyze 10 MRSA strains, using the standardized or their in-house DNA isolation protocol (phase 2). A prelabeled DNA process control sample was included again. The binary types of all DNA samples were identified correctly by all but one laboratories. This latter laboratory diverged from the protocol by adding an excess of labeled DNA to the hybridization mixture, resulting in a high background and, therefore, noninterpretable BT results. All centers produced identical BT results for the process control. Five of the seven centers correctly identified the binary types of all 10 MRSA strains in phase 2 of the international study. Three of these centers used their in-house DNA extraction protocol. Divergence from the standard BT protocol in the remaining two centers resulted in no interpretable BT data for the 10 MRSA strains. The study demonstrated that each center that followed the BT protocol to the letter could generate reproducible results, irrespective whether or not an in-house DNA isolation protocol was used. The current BT protocol thus represents a simple method generating robust, reproducible genotype data for S. aureus strains.

Bacterial Typing Techniques↗
PubMed1997

Increasing incidence and widespread dissemination of methicillin-resistant Staphylococcus aureus (MRSA) in hospitals in central Europe, with special reference to German hospitals.

OBJECTIVE: to present data on prevalence and interregional spread of methicillin-resistant Staphylococcus aureus (MRSA) in Germany. METHODS: A nationwide collection of MRSA isolates from nosocomial infections in 143 hospitals was established from isolates (n=4368) sent to a microbiological reference center during 1993--95. As chosen by distinguishable resistance phenotypes at each time of occurrence during the study period, 1830 isolates were subjected to molecular typing by means of Smal macrorestriction patterns, PCR for RNA gene spacer patterns, and PCR for patterns of DNA stretches flanked by the ERIC-2 sequence and flanked by Tn916 and ribosomal binding site. In addition, data from a multicenter study on the incidence of antibiotic resistance have been analyzed (32 centers, 637 S. aureus isolates). RESULTS: In 1995 the prevalence of MRSA among S. aureus isolates was 8.7% overall in central Europe (including Germany), in comparison to 1.7% in 1990. From 1993 until now, a continuous interregional dissemination of six epidemic strains, which were identified by molecular typing, was recorded. Besides these epidemic strains, 15 MRSA strains were identified which could not be allocated to the epidemic MRSA or to the known clonal groups of the species S. aureus. MRSA from three cases of sporadic nosocomial infections exhibited characteristics of the clonal group of S. aureus with the capacity for toxic shock syndrome formation. The pattern of one MRSA corresponded to those of the S. aureus group exhibiting phage pattern 94,96. CONCLUSIONS: The prevalence of MRSA has increased in central Europe (and Germany) during the last 5 years, to 8.7%. The main source of infection with MRSA is obviously interregional dissemination of epidemic strains. At the same time, the mecA gene has been acquired by strains previously sensitive to methicillin.

Journal Article↗