Burkhard Springer

Methicillin-resistant Staphylococcus aureus: a new zoonotic agent?

ZusammenfassungStaphylococcus aureus ist ein bedeutender Erreger von Infektionen, die in Krankenhäusern und Pflegeeinrichtungen erworben werden, und bei der Allgemeinbevölkerung. Ein Drittel der Gesamtbevölkerung ist mit Staphylococcus aureus kolonisiert, wobei das Risiko, an einer Infektion durch Staphylococcus aureus zu erkranken bei diesen kolonisierten Personen erhöht ist. Die weltweit zunehmende Antibiotikaresistenz von Staphylococcus aureus schränkt die Behandlungsmöglichkeiten von Infektionen ein und erschwert Kontrollmaßnahmen. Kurz nach Einführung des Methicillins wurde über die ersten Methicillin-resistenten Staphylococcus aureus Isolate (MRSA) berichtet. Während des letzten Jahrzehnts vollzog sich außerdem eine epidemiologische Verschiebung von den bisher dominierenden Krankenhaus assoziierten MRSA Stämmen hin zu in der Gemeinschaft erworbenen MRSA Stämmen (community acquired MRSA, CA-MRSA), welche Infektionen auch bei dem Teil der Bevölkerung hervorrufen, der keine Risikofaktoren durch Krankenhauskontakte hat. Basierend auf neueren Untersuchungen besteht für den Sequenztyp (ST) 398 eine kausale Verbindung zwischen einer MRSA Kolonisation im Viehbestand und der MRSA Besiedlung, sowie dem Auftreten von Infektionen, bei Tierzüchtern. In den Niederlanden wurde eine hohe Besiedlungsrate durch den MRSA ST398 bei Schweinen und Schweinehaltern festgestellt. Weltweite Berichte über den Nachweis von ST398 MRSA verdeutlichen, dass das Auftreten des neuen Subtyps kein spezifisch holländisches Problem darstellt. In Österreich konnte der MRSA Sequenztyp 398 in Staubproben von Schweinezuchtbetrieben und aus Lebensmitteln isoliert werden. Seit dem ersten Auftreten des Sequenztyps ST398 als Infektionserreger beim Menschen in Österreich im Jahre 2006 konnten 21 Humanisolate nachgewiesen werden, wovon allerdings nur ein geringer Teil mit Infektionen assoziiert war. MRSA müssen zukünftig auch als zoonotisches Agens betrachtet werden, wobei der Nutztierbestand ein bedeutendes Reservoir darstellt. Weitergehende Untersuchungen sind nötig, um Kontrollmaßnahmen erarbeiten und implementieren zu können.SummaryStaphylococcus aureus is a major cause of infection in hospitals and the community. One third of the general population is colonized by the bacterium, constituting a risk factor for acquisition of infection with this pathogen. Worldwide, the increasing antibiotic resistance of S. aureus complicates treatment of infection and control measures. Soon after the introduction of methicillin, the first isolates resistant to this antibiotic were reported and named methicillin-resistant S. aureus (MRSA). During the past decade a major change in MRSA epidemiology has been observed: whereas in the past MRSA was almost exclusively regarded a hospital pathogen, the advent of community-acquired MRSA has led to infections in people without hospital-related risk factors. Recent evidence has also identified a link between colonization of livestock and MRSA carriage and infections in people who work with animals. Screening of pigs and pig farmers in the Netherlands revealed high prevalence of MRSA sequence type (ST) 398 and it has become clear that the emergence of ST398 is not just a Dutch problem, as reports on livestock colonization and human infections are appearing worldwide. In Austria, the ST398 lineage has been detected in dust samples from pig breeding facilities and in food samples. Since the first Austrian detection of this emerging lineage in 2006, 21 human isolates, partially associated with infections, have been observed. MRSA has to be regarded as a new emerging zoonotic agent and livestock may constitute a growing reservoir of the ST398 lineage. More information is needed so that control measures to reduce the impact of the emerging MRSA ST398 lineage on public health can be developed and implemented.

Shigellosis in refugees, Austria, July to November 2015.

We report on a cluster of shigellosis including 21 cases in refugees and two in local residents who worked in refugee transit centres, detected in Austria in 2015, between calendar weeks 29 and 47. The species isolated from the cluster cases, including one mixed infection, were S. sonnei (n = 13), S. flexneri (n = 10) and S. boydii (n = 1). Eleven of 18 tested isolates were extended spectrum beta-lactamase (ESBL)-positive, including five of six ciprofloxacin-resistant and three azithromycin-resistant isolates.

Salmonellosis in Austria: situation and trends

ZusammenfassungSalmonellen zählen in vielen Teilen der Welt zu den häufigsten bakteriellen Durchfallerregern. Die meisten Infektionen werden von gesunden Tieren über kontaminierte Lebensmittel auf den Menschen übertragen. In Österreich sind wir nach wie vor mit einer 1989 begonnenen Salmonellen-Epidemie konfrontiert, deren Ursache ein sprunghafter Anstieg von Salmonella enterica spp. enterica serovar Enteriditis, einem vorwiegend bei Eiern und Geflügel vorkommenden Serovar, darstellt. Durch Salmonella-Impfungen von Lege- und Masthühnern sowie durch verstärkte Ausbruchserhebungen konnte die Zahl der humanen Salmonellosen in der Zeit von 2002 bis 2007 mehr als halbiert werden. Die Resistenzsituation bei Salmonellen war in den letzten Jahren stabil. Resistenzen gegen Ciprofloxacin und Resistenzen gegen Cephalosporine der dritten Gene ration (Cefotaxim) traten nach wie vor nur sehr vereinzelt auf.SummaryNon-typhoidal Salmonella spp. are a major cause of human gastroenteritis in many parts of the world. Most of these infections are zoonotic and are transmitted from healthy carrier animals to humans through contaminated food. In Austria we are facing an ongoing salmonellosis epidemic that started in 1989. The main cause of the epidemic is a massive increase of infections due to S. enterica subsp. enterica serovar Enteritidis (S. Enteritidis), a serotype prevalent in poultry, particularly in eggs. The introduction of vaccination of laying hens and broilers, together with intensified outbreak investigation efforts, has led to a remarkable decrease of human salmonella isolates. Since 2002 the number of isolates received by the National Reference Center for Salmonella (NRCS) has been reduced by more than 50%. Overall rates of antibiotic resistance in salmonella have remained stable over the past years. In Austria, high levels of resistance to ciprofloxacin and third-generation cephalosporins (cefotaxime) are still extremely rare.

Whole genome sequence-based serogrouping of Listeria monocytogenes isolates.

Whole genome sequencing (WGS) is currently becoming the method of choice for characterization of Listeria monocytogenes isolates in national reference laboratories (NRLs). WGS is superior with regards to accuracy, resolution and analysis speed in comparison to several other methods including serotyping, PCR, pulsed field gel electrophoresis (PFGE), multilocus sequence typing (MLST), multilocus variable number tandem repeat analysis (MLVA), and multivirulence-locus sequence typing (MVLST), which have been used thus far for the characterization of bacterial isolates (and are still important tools in reference laboratories today) to control and prevent listeriosis, one of the major sources of foodborne diseases for humans. Backward compatibility of WGS to former methods can be maintained by extraction of the respective information from WGS data. Serotyping was the first subtyping method for L. monocytogenes capable of differentiating 12 serovars and national reference laboratories still perform serotyping and PCR-based serogrouping as a first level classification method for Listeria monocytogenes surveillance. Whole genome sequence based core genome MLST analysis of a L. monocytogenes collection comprising 172 isolates spanning all 12 serotypes was performed for serogroup determination. These isolates clustered according to their serotypes and it was possible to group them either into the IIa, IIc, IVb or IIb clusters, respectively, which were generated by minimum spanning tree (MST) and neighbor joining (NJ) tree data analysis, demonstrating the power of the new approach.

Draft Genome Sequence of a 94-Year-Old Listeria monocytogenes Isolate, SLCC208

ABSTRACT We report here the draft genome sequence of Listeria monocytogenes strain SLCC208 from Seeligers historical Special Listeria Culture Collection, initially cultured from a human case in France in 1921. This is, to our knowledge, the oldest L. monocytogenes isolate available and may be useful for comparative genomic studies of L. monocytogenes.

Letter to the editor: Salmonella Stanley outbreaks – a prompt to reevaluate existing food regulations

To the editor: In a recent Eurosurveillance issue, Kinross et al. [1] describe a cross-border outbreak of Salmonella Stanley in the European Union, which could be traced back to a contamination in the turkey production chain. The aetiological clone is mono-resistant to nalidixic acid and characterised by a novel pulsed-field gel electrophoresis (PFGE) type. We agree with Kinross et al. that the exchange of molecular data has to be improved to speed up outbreak investigations. However, although control measures were adequate to contain the multistate outbreak, they were not sufficient to eradicate the new clone, seeing as two outbreaks that occurred in Germany 12 months and Austria 16 months later [2] were caused by kebab contaminated with the newly described Salmonella Stanley outbreak clone. Rather, there is a considerable risk that the clone will become endemic in the turkey or poultry production chain in Europe.

Accuracy of conventional identification methods used for Enterobacteriaceae isolates in three Nigerian hospitals

Background Enterobacteriaceae are ubiquitously present in nature and can be found in the intestinal tract of humans and animals as commensal flora. Multidrug-resistant Enterobacteriaceae are increasingly reported and are a threat to public health implicating a need for accurate identification of the isolates to species level. In developing countries, identification of bacteria basically depends on conventional methods: culture and phenotypic methods that hamper the accurate identification of bacteria. In this study, matrix-assisted desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) technique was compared to conventional identification techniques. Materials and Methods In total, 147 Enterobacteriaceae isolates were collected from March to May 2015 from three medical microbiology laboratories of hospitals in Edo state, Nigeria, after being tested according to the individual laboratories standard operating procedures. All isolates were stored at −20°C until tested centrally by MALDI-TOF MS. Results One hundred and forty five (98.6%) isolates had a MALDI Biotyper best score > or =2.0, indicating a secure genus and probable species identification; and 2(1.36%) isolates had a best score <2.0 indicating probable genus identification. Isolates with best scores of > or =2.0 comprised nine genera and 10 species, respectively. A total of 57.2% and 33.1% of isolates identified had agreement between MALDI-TOF MS and conventional techniques for identification at genus and species level, respectively, when analyzing bacteria with MALDI Biotyper best scores > or =2.0. Conclusion The results of our study show that the applied conventional identification techniques for Enterobacteriaceae in the investigated Nigerian hospitals are not very accurate. Use of state-of-the-art identification technologies for microorganisms is necessary to guarantee comparability of bacteriological results.

Characterization of a community-acquired-MRSA USA300 isolate from a river sample in Austria and whole genome sequence based comparison to a diverse collection of USA300 isolates.

The increasing emergence of multi-resistant bacteria in healthcare settings, in the community and in the environment represents a major health threat worldwide. In 2016, we started a pilot project to investigate antimicrobial resistance in surface water. Bacteria were enriched, cultivated on selective chromogenic media and species identification was carried out by MALDI-TOF analysis. From a river in southern Austria a methicillin resistant Staphylococcus aureus (MRSA) was isolated. Whole genome sequence analysis identified the isolate as ST8, spa type t008, SCCmecIV, PVL and ACME positive, which are main features of CA-MRSA USA300. Whole genome based cgMLST of the water isolate and comparison to 18 clinical MRSA USA300 isolates from the Austrian national reference laboratory for coagulase positive staphylococci originating from 2004, 2005 and 2016 and sequences of 146 USA300 isolates arbitrarily retrieved from the Sequence Read Archive revealed a close relatedness to a clinical isolate from Austria. The presence of a CA-MRSA USA300 isolate in an aquatic environment might pose a public health risk by serving as a potential source of infection or a source for emergence of new pathogenic MRSA clones.

Letter to the editor: Livestock-associated meticillin-resistant Staphylococcus aureus (LA-MRSA), Austria, 2013

To the editor: In their article titled ‘Livestock-associated meticillin-resistant Staphylococcus aureus (LA-MRSA) among human MRSA isolates, European Union/ European Economic Area countries, 2013’, Kinross et al. recently reported on the occurrence of LA-MRSA in humans [1]. The results were obtained by an ECDC initiated study documenting the identification of LA-MRSA (i.e. CC398 and ‘other’ LA-MRSA) in European Union/ European Economic Area countries (EU/EEA) countries and the MRSA subtyping capacity and availability in EU/EEA national or regional reference laboratories. ECDC National Focal Points for Antimicrobial Resistance (AMR) were invited to designate a primary and alternate contact person with expertise in molecular surveillance of MRSA for public health purposes and with access to data for the survey in their respective countries; 27 of 30 EU/EEA countries responded to this request for data.

Use of antibiotics in Austria / Antibiotikaeinsatz in Österreich

Summary In 2015, 119.2 t of active ingredients of antibiotics were used in Austria in human medicine (70.4 t; 59.1%), for food animals (48.8 t; 40.9%) and in plant production (0.002 t; < 0.1%). During the last five years, consumption of antibiotics increased in human medicine by 3.8% (2011: 67.8 t; 2015: 70.4 t). In hospitals, it increased by 17.3%, from 19.7 t in 2011 to 23.1 t active ingredients in 2015. In the community, measured in kg active ingredient, it increased by 0.3% from 2011 to 2015. Consumption in defined daily dose (DDD) per 100,000 inhabitants per year decreased by 3.6%. Our numbers for the community (2015: 17.0 DDD) contradict AURES reports and a recent ECDC report, which claim a consumption of 14.0 DDD/1000 inhabitants per day in primary care in Austria, based on the social insurance company’s sales data. Declining pharmacy sales prices due to an increase in market shares for cheap generic drugs as well as increase in deductibles for insured people falsely suggest low consumption. In food animals, the antibiotic consumption decreased by 8.7%, from 53.4 t to 48.8 t. In plant production, the annual usage fluctuated considerably and decreased by 95.3%, from 47.2 kg in 2010 to 2.2 kg in 2015.