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Resistance Data Human Medicine


Resistance trends vary between microorganism-antibiotic combinations. While resistance rates are decreasing for methicillin in Staphylococcus aureus and penicillin in Streptococcus pneumoniae, increasing trends have been observed for quinolones and third/fourth generation cephalosporins in Enterobacterales (e.g. E. coli and K. pneumoniae). However, these upward trends have flattened out in recent years. As clearly visible in the animated graph below, higher resistance rates are also reflected in an increase in the burden of disease.

Resistance rates of a selection of highly resistant microorganisms in Switzerland



Burden of a selection of antibiotic-resistant bacteria in Switzerland

Estimation of infections, disability-adjusted life-years (DALYs) and attributable deaths caused by a selection of 16 antibiotic-resistant bacteria in Switzerland 2010-2019. The bubble size is proportional to the number of DALYs.


Microorganism Specific Resistances (Graphics)



Database Query (Table)

Inspect the most relevant resistance data of Switzerland in a tabular view and customize the query according to your preferences.


Carbapenem Resistance

Carbapenem-resistant Enterobacterales

Although on a relatively low-level, numbers of carbapenem-resistant Enterobacterales have constantly increased during the last years.

Carbapenem-resistant Enterobacterales (CRE)

Carbapenems are broad spectrum antibiotics, used for severe infections with some multidrug-resistant microorganisms, in particular extended-spectrum betalactamase-producing Enterobacterales. Resistance to this class of reserve antibiotics  is therefore crucial to survey. ANRESIS analyses carbapenem resistance in Enterobacterales continuously and publishes data on this web-site.

Carbapenem non-susceptibility can be mediated via different mechanisms such as permeability defects, efflux pumps or by the production of carbapenemase enzymes. The resistance mechanism cannot be predicted from the resistance test alone, genomic analyses are needed. Due to their multiresistance and their rapid spread a separate focus is laid on the carbapenemase-producing enterobacterales (see next section).

Temporal Course of CRE in Switzerland

CRE Distribution of Microorganisms

Carbapenemase Producers

Enterobacterales which are in possession of carbapenemase enzymes (the so-called carbapenemase-producing Enterobacterales or CPE) are particularly resistant to numerous other antibiotic classes than carbapenems. Due to this multresistance and due to their rapid spread, they pose a particular threat. The reporting of CPE has therefore been declared as mandatory by the Swiss government on January 2017 and since January 2019 all CPE isolates must be sent to the National Reference Centre for Emerging Antibiotic Resistance (NARA) for a detailed analysis of the resistance mechanisms and for early detection of outbreaks. An overview on CPE was published in EUROSURVEILLANCE in 2021.

CPE are classified according to the amino acid sequence similarities of their carbapenemases. The most prevalent CPE genotypes in Switzerland are currently OXA-48 and NDM. ANRESIS publishes the actual CPE data quarterly on this Website. Of note, these data cannot be compared directly to data before 2019 due to a change in the reporting system. All of the following graphs are based on data from NARA.

Regional Distribution of CPE in Switzerland

Close by ANRESIS

INterface For Empirical antimicrobial ChemoTherapy

INFECT is an interactive web application which is directed particularly towards health professionals. It gives a fast and intuitive access to ANRESIS resistance data and connects them with the latest national treatment guidelines. The INFECT project has been developed with support from the Federal Office of Public Health and the Institute for Infectious Diseases Bern.


Resistance to new antibiotics

In this section resistance data on new reserve antibiotics are shown. Graphics are updated on a monthly basis. All isolates from all sites from 2020 onwards are considered. Doubles according to the ANRESIS algorithm and results with n<5 are excluded. Results are reported as delivered by laboratories and may be biased due to varying testing strategies. Data are provided for surveillance purposes and are not intended to be used for therapeutic decisions solely.


MIC / DD Distributions
MIC / DD Distributions

Quantitative resistance data (disc diffusion (DD) or minimal inhibitory concentration (MIC)) should be preferred over categorical resistance data (s, i, r) for several reasons. Among others, quantitative data allow detection of slow, gradual development of resistance, they help clinicians to decide whether treatment can be modified by administering higher dosage and they allow reclassification of resistance categories after changes in breakpoint definitions to detect susceptibility trends over a longer period of time.

Within this submenu we graphically depict the distribution of disc diffusion and MIC data of clinical samples collected within ANRESIS. Of note, qualitative resistance data are not delivered for all resistance tests. For wildtype distributions please refer to EUCAST.



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