[Assessment of available and currently applied typing methods including genome-based methods for zoonotic pathogens with a focus on Salmonella enterica]. / Bestandsaufnahme der verfügbaren und aktuell eingesetzten Typisierungsmethoden einschließlich genombasierter Verfahren von Zoonoseerregern am Beispiel von Salmonella enterica.

BACKGROUND: In recent years, whole genome sequencing (WGS) in combination with bioinformatic analyses has become state of the art in evaluating the pathogenicity/resistance potential and relatedness of bacteria. WGS analysis thus represents a central tool in the investigation of the resistance and virulence potential of pathogens, as well as their dissemination via outbreak clusters and transmission chains within the framework of molecular epidemiology. In order to gain an overview of the available genotypic and phenotypic methods used for pathogen typing of Salmonella and Shiga toxin-producing and enterohemorrhagic Escherichia coli (STEC/EHEC) in Germany at state and federal level, along with the availability of WGS-based typing and corresponding analytical methods, a survey of laboratories was conducted. METHODS: An electronic survey of laboratories working for public health protection and consumer health protection was conducted from February to June 2020. RESULTS AND CONCLUSION: The results of the survey showed that many of the participating laboratories provide a wide range of phenotypic and molecular methods. Molecular typing is most commonly used for species identification of Salmonella. In many cases, WGS-based methods have already been established at federal and state institutions or are in the process of being established. The Illumina sequencing technology is the most widely used technology. The survey confirms the importance of molecular biology and whole genome typing technologies for laboratories in the diagnosis of bacterial zoonotic pathogens.

[Assessment of available and currently applied typing methods of zoonotic pathogens using the example of Shiga toxin-producing and enterohemorrhagic Escherichia coli (STEC/EHEC)]. / Bestandsaufnahme der verfügbaren und aktuell eingesetzten Typisierungsmethoden von zoonotischen Erregern am Beispiel von Shiga Toxin-bildenden bzw. enterohämorrhagischen Escherichia coli (STEC/EHEC).

INTRODUCTION: In order to improve patient care and to increase food safety within the framework of One Health, the project "Integrated Genomic Surveillance of Zoonotic Agents (IGS-Zoo)" aims to develop concepts for a genomic surveillance of Shiga toxin(Stx)-producing and enterohemorrhagic Escherichia coli (STEC/EHEC) in Germany. METHODS: An online survey was conducted to assess the currently available and applied STEC/EHEC typing methods in the federal laboratories of veterinary regulation, food control, and public health service. RESULTS: Twenty-six questionnaires from 33 participants were evaluated with regard to STEC/EHEC. The number of STEC/EHEC-suspected samples that the laboratories process per year ranges between 10 and 3500, and out of these they obtain between 3 and 1000 pathogenic isolates. Currently the most frequently used typing method is the determination of Stx- and intimin-coding genes using polymerase chain reaction (PCR). Whole genome sequencing (WGS) is currently used by eight federal state laboratories, and nine are planning to implement it in the future. The most common obstacle for further typing of STEC/EHEC is that isolation from sample material is often unsuccessful despite apparent PCR detection of the stx genes. DISCUSSION: The results of the survey should facilitate the integration of the analysis methods developed in the project and emphasize the target groups' individual needs for corresponding training concepts.

Molecular Assessment of Staphylococcus Aureus Strains in STAT3 Hyper-IgE Syndrome Patients.

Hyper-IgE syndromes (HIES) are a group of inborn errors of immunity (IEI) caused by monogenic defects such as in the gene STAT3 (STAT3-HIES). Patients suffering from HIES show an increased susceptibility to Staphylococcus aureus (S. aureus) including skin abscesses and pulmonary infections. To assess if the underlying immune defect of STAT3-HIES patients influences the resistance patterns, pathogenicity factors or strain types of S. aureus. We characterized eleven S. aureus strains isolated from STAT3-HIES patients (n = 4) by whole genome sequencing (WGS) to determine presence of resistance and virulence genes. Additionally, we used multi-locus sequence typing (MLST) and protein A (spa) typing to classify these isolates. Bacterial isolates collected from this cohort of STAT3-HIES patients were identified as common spa types in Germany. Only one of the isolates was classified as methicillin-resistant S. aureus (MRSA). For one STAT3 patient WGS illustrated that infection and colonization occurred with different S. aureus isolates rather than one particular clone. The identified S. aureus carriage profile on a molecular level suggests that S. aureus strain type in STAT3-HIES patients is determined by local epidemiology rather than the underlying immune defect highlighting the importance of microbiological assessment prior to antibiotic treatment.

MRSA eradication in dermatologic outpatients - theory and practice.

BACKGROUND: The dissemination of methicillin resistant staphylococcus aureus (MRSA) is an increasing challenge in medical care. Apart from hospital acquired MRSA, there has also been an increase in community acquired and livestock associated MRSA. While the risks of MRSA (e. g. wound infections) and consequences (e. g. rejection of patients) are well known, there are little data on the effectiveness of eradication procedures. PATIENTS AND METHODS: 32 patients with proven MRSA colonization were monitored during eradication for the following aspects: (1) localization of MRSA (swabs from hairline, anterior nares, throat, axillae, groins, perineum, and wounds, if present), (2) presence of eradication-impairing factors, (3) length of time needed for eradication, (4) cost of eradication, (5) molecular fingerprint and risk assessment (spa-types). RESULTS: We describe the successful eradication of MRSA in all 32 patients. Most positive nasal swabs were obtained from the anterior nares and the throat and only rarely from the hairline or axillae. The greater the number of positive swabs, the more time was needed for eradication. In most patients (37.5%), eradication with topical antiseptics was successful. The average time for eradication was 12.97 (± 7.6) days. Twelve patients required systemic antibiotic therapy. Treatment costs associated with the use of systemic antibiotics were significantly higher. The most frequent spa types were t032 and t003. CONCLUSIONS: We report successful MRSA eradication in outpatients. Systemic antibiotics are unnecessary in the majority of patients. A combined anti-MRSA strategy for inpatients and outpatients is recommended.

Evidence for cost reduction based on pre-admission MRSA screening in general surgery.

Colonization with methicillin-resistant Staphylococcus aureus (MRSA) is a risk factor for MRSA infection causing increased costs in patient's care and treatment. To evaluate cost efficiency, pre-admission MRSA screening and subsequent MRSA decolonization of patients admitted to the Department of General Surgery at the University Hospital of Münster were determined. In 2004, 2054 (89.3%) out of the total of 2299 hospital-admitted patients were screened for MRSA (1769 elective and 530 direct admissions); 1536 patients underwent pre-admission MRSA screening (86.8% of the 1769 elective admissions), of whom seven patients (0.5%) were MRSA-positive and five of these were successfully decolonized before admission. In case of direct admissions, i.e., emergency cases or transferral from other hospitals, 2.4% and 8.6% were MRSA-positive, respectively. There were 25 patients MRSA positive during their hospital stay, two of these were nosocomially acquired, which represent 0.1 nosocomial MRSA cases in 1000 in-patients. The average MRSA carrier was (65+/-15 years) older than the other patients (55+/-17 years), had a significantly higher rate of pulmonary disease, coronary heart disease and certain infections; and had a longer hospital stay (27 versus 10 days, p<0.05). The total costs of the MRSA screening were approximately 20,000 euro. Since the estimated costs for handling MRSA treatment and isolation during a hospital stay are 6000-10,000 euro for each affected patient, we estimated that approximately 20,000 euro could be saved by detecting and successfully decolonizing a total of five patients through pre-admission screening. In this calculation, additional costs due to the increased morbidity and mortality of MRSA carriers and the possible spread of MRSA through unrecognized colonization were not included. In conclusion, pre-admission screening for MRSA is an effective method to reduce the hospital burden of MRSA-colonized patients and the savings due to consistent decolonization before elective admission outweigh the costs of screening.