Historic methicillin-resistant Staphylococcus aureus: expanding current knowledge using molecular epidemiological characterization of a Swiss legacy collection.

BACKGROUND: Few methicillin-resistant Staphylococcus aureus (MRSA) from the early years of its global emergence have been sequenced. Knowledge about evolutionary factors promoting the success of specific MRSA multi-locus sequence types (MLSTs) remains scarce. We aimed to characterize a legacy MRSA collection isolated from 1965 to 1987 and compare it against publicly available international and local genomes. METHODS: We accessed 451 historic (1965-1987) MRSA isolates stored in the Culture Collection of Switzerland, mostly collected from the Zurich region. We determined phenotypic antimicrobial resistance (AMR) and performed whole genome sequencing (WGS) using Illumina short-read sequencing on all isolates and long-read sequencing on a selection with Oxford Nanopore Technology. For context, we included 103 publicly available international assemblies from 1960 to 1992 and sequenced 1207 modern Swiss MRSA isolates from 2007 to 2022. We analyzed the core genome (cg)MLST and predicted SCCmec cassette types, AMR, and virulence genes. RESULTS: Among the 451 historic Swiss MRSA isolates, we found 17 sequence types (STs) of which 11 have been previously described. Two STs were novel combinations of known loci and six isolates carried previously unsubmitted MLST alleles, representing five new STs (ST7843, ST7844, ST7837, ST7839, and ST7842). Most isolates (83% 376/451) represented ST247-MRSA-I isolated in the 1960s, followed by ST7844 (6% 25/451), a novel single locus variant (SLV) of ST239. Analysis by cgMLST indicated that isolates belonging to ST7844-MRSA-III cluster within the diversity of ST239-MRSA-III. Early MRSA were predominantly from clonal complex (CC)8. From 1980 to the end of the twentieth century, we observed that CC22 and CC5 as well as CC8 were present, both locally and internationally. CONCLUSIONS: The combined analysis of 1761 historic and contemporary MRSA isolates across more than 50 years uncovered novel STs and allowed us a glimpse into the lineage flux between Swiss-German and international MRSA across time

Limits of professional secrecy: medical confidentiality in England and Germany in the nineteenth and early twentieth centuries

Among patients as well as doctors it is commonly held that confidentiality has been the foundation of the therapeutic relationship since the introduction of the Hippocratic oath. Nevertheless, medical confidentiality is a controversial issue, for example in current debates on HIV/AIDS, especially with regard to the question whether sexual contacts of patients infected with HIV should be warned by doctors. Consequentialist arguments are used to justify a breach of confidence to protect other people's health, as well as to defend absolute secrecy to maintain mutual trust between patient and doctor. This article discusses the history of the debates on medical confidentiality from the nineteenth century onwards in England and Germany. Comparing the debates in these two countries shows that the issue was not confined to national borders. Furthermore, we demonstrate that the debates depended not merely on ethical arguments, but were strongly influenced by public health policies, in particular regarding venereal disease prevention, by legislation, politics and the status of the medical profession. Differences in legislation and in the social standing of the medical profession in England and Germany in particular distinguish the development of the debates in the two countries

Quality of MALDI-TOF Mass Spectra in Routine Diagnostics: Results from an International External Quality Assessment including 36 Laboratories from 12 countries using 47 challenging bacterial strains.

MALDI-TOF MS is a widely used method for bacterial species identification. Incomplete databases and mass spectral quality (MSQ) still represent major challenges. Important proxies for MSQ are: number of detected marker masses, reproducibility, and measurement precision. We aimed to assess MSQs across diagnostic laboratories and the potential of simple workflow adaptations to improve it. For baseline MSQ assessment, 47 diverse bacterial strains which are challenging to identify by MALDI-TOF MS, were routinely measured in 36 laboratories from 12 countries, and well defined MSQ features were used. After an intervention consisting of detailed reported feedback and instructions on how to acquire MALDI-TOF mass spectra, measurements were repeated and MSQs were compared. At baseline, we observed heterogeneous MSQ between the devices, considering the median number of marker masses detected (range = [5, 25]), reproducibility between technical replicates (range = [55%, 86%]), and measurement error (range = [147 parts per million (ppm), 588ppm]). As a general trend, the spectral quality was improved after the intervention for devices which yielded low MSQs in the baseline assessment: for 4/5 devices with a high measurement error, the measurement precision was improved (p-values<0.001, paired Wilcoxon test); for 6/10 devices, which detected a low number of marker masses, the number of detected marker masses increased (p-values<0.001, paired Wilcoxon test). We have identified simple workflow adaptations, which, to some extent, improve MSQ of poorly performing devices and should be considered by laboratories yielding a low MSQ. Improving MALDI-TOF MSQ in routine diagnostics is essential for increasing the resolution of bacterial identification by MALDI-TOF MS, which is dependent on the reproducible detection of marker masses. The heterogeneity identified in this EQA requires further study