Increase in methicillin-susceptible Staphylococcus aureus bloodstream infections in Switzerland: a nationwide surveillance study (2008-2021).

PURPOSE An increasing burden of Staphylococcus aureus bloodstream infections (BSI), despite a decrease in the percentage of methicillin-resistant S. aureus (MRSA), was described recently in other European countries. The main aim of this study was to analyse recent temporal trends of S. aureus, methicillin-susceptible S. aureus (MSSA) and MRSA BSI for Switzerland as well as the different linguistic regions within Switzerland. An additional aim was to estimate potential differences among patient-based and epidemiological risk factors. METHODS A retrospective observational study was conducted in Switzerland over a period of 14 years (2008-2021). Trends in S. aureus, MSSA and MRSA BSI were analysed by applying linear regression models. RESULTS Staphylococcus aureus BSI increased by + 30% from 19.7 to 25.6 cases per 100,000 inhabitants between 2008 and 2021 (P < 0.01) in Switzerland. Thereof, MSSA increased by + 37% from 17.8 to 24.4 cases per 100,000 inhabitants (P < 0.01). MRSA decreased from 1.9 to 1.2 cases per 100,000 inhabitants (P < 0.01), which was driven by decreasing incidence in the French-speaking region. MSSA BSI increased significantly (P < 0.01) in both linguistic regions. A further stratification revealed that incidence increased the most in male patients of the age group ≥ 80 years of the German-speaking region. CONCLUSION The increasing health burden of MSSA BSI in Switzerland indicates that not only proportions of resistant microorganisms but also total BSI incidences should be monitored. In addition, data stratification revealed that the increase was mainly driven by an increasing incidence in elderly males of the German-speaking region

Polyclonal Proliferation of Large Granular Lymphocytes during Cytomegalovirus Primary Infection in a Human Immunodeficiency Virus—Infected Patient Receiving Antiretroviral Therapy

We report the first case of a patient infected with HIV in whom polyclonal CD8+/CD57- T lymphocyte large granular lymphocyte (LGL) proliferation was observed in association with cytomegalovirus primary infection. Because the differential diagnosis of an increased number of LGLs includes both monoclonal LGL leukemia and polyclonal proliferation of LGL, patients in whom LGL proliferation is detected always need close hematological and clinical observation to determine whether therapeutic intervention is necessar

Antibiotic resistance surveillance of Klebsiella pneumoniae complex is affected by refined MALDI-TOF identification, Swiss data, 2017 to 2022.

BackgroundModern laboratory methods such as next generation sequencing and MALDI-TOF allow identification of novel bacterial species. This can affect surveillance of infections and antimicrobial resistance. From 2017, increasing numbers of medical microbiology laboratories in Switzerland differentiated Klebsiella variicola from Klebsiella pneumoniae complex using updated MALDI-TOF databases, whereas many laboratories still report them as K. pneumoniae or K. pneumoniae complex.AimOur study explored whether separate reporting of K. variicola and the Klebsiella pneumoniae complex affected the ANRESIS surveillance database.MethodsWe analysed antibiotic susceptibility rates and specimen types of K. variicola and non-K. variicola-K. pneumoniae complex isolates reported by Swiss medical laboratories to the ANRESIS database (Swiss Centre for Antibiotic Resistance) from January 2017 to June 2022.ResultsAnalysis of Swiss antimicrobial resistance data revealed increased susceptibility rates of K. variicola compared with species of the K. pneumoniae complex other than K. variicola in all six antibiotic classes tested. This can lead to underestimated resistance rates of K. pneumoniae complex in laboratories that do not specifically identify K. variicola. Furthermore, K. variicola strains were significantly more often reported from blood and primarily sterile specimens than isolates of the K. pneumoniae complex other than K. variicola, indicating increased invasiveness of K. variicola.ConclusionOur data suggest that refined differentiation of the K. pneumoniae complex can improve our understanding of its taxonomy, susceptibility, epidemiology and clinical significance, thus providing more precise information to clinicians and epidemiologists

Retrospective data analysis for definition of multidrug resistance in gram-negative bacteria - a consensus proposal.

AIM OF THE STUDY The main objective of this study was to propose a common definition of multidrug-resistant gram-negative organisms (GN-MDRO), which may be used for epidemiological surveillance and benchmarking. METHODS In this retrospective data analysis, we used interpreted qualitative susceptibility data (SIR) from blood culture isolates of different gram-negative microorganisms from the ANRESIS database from 2017-2021. We first analysed testing algorithms used by different Swiss laboratories and investigated cross-resistance patterns within antibiotic groups. Comparing these data with existing international definitions, we developed two different GN-MDRO definitions, an extended one for surveillance purposes (ANRESIS-extended) and a more stringent one for clinical purposes, aimed primarily at the identification of difficult-to-treat GN-MDRO (ANRESIS-restricted). Using these novel algorithms, the rates of invasive GN-MDRO identified in our national dataset were compared with international and national definitions: the European Centre for Disease Prevention and Control (ECDC) definition, the Commission for Hospital Hygiene and Infection (KRINKO) definition and the definition proposed by the University Hospital Zurich. RESULTS SIR data of a total of 41,785 Enterobacterales, 2,919 , and 419 spp. isolates were used for the analyses. Five antibiotic categories were used for our MDRO definition: aminoglycosides, piperacillin-tazobactam, third- and fourth-generation cephalosporins, carbapenems and fluoroquinolones. Large differences were found between the testing algorithms of the different laboratories. Cross-resistance analysis within an antibiotic group revealed that the substance most likely to be effective against a particular gram-negative bacterium was not preferentially tested (e.g. amikacin for the aminoglycosides). For all bacterial species tested, the highest rates of multidrug-resistant isolates were found using the ECDC-MDR definition, followed by the ANRESIS-extended definition. The number of MDR-Enterobacterales identified using the ANRESIS-restricted definition (n = 627) was comparable to those identified using the KRINKO (n = 622) and UHZ definitions (n = 437). However, the isolates classified as MDR-Enterobacterales according to the KRINKO, UHZ and ANRESIS-restricted definitions (total n = 870) differed considerably. Only 242 of the isolates (27.8%) were uniformly classified as MDRO according to the KRINKO, UHZ and ANRESIS-restricted definitions. Comparable findings were made for Klebsiella spp. and Pseudomonas aeruginosa. CONCLUSIONS The application of different MDRO definitions leads to significant differences in not only MDRO rates but also the isolates that are eventually classified as MDRO. Therefore, defining a nationwide MDRO algorithm is crucial if data are compared between hospitals. The definition of a minimal antibiotic susceptibility testing panel would improve comparability further

Dislocation creep of dry quartz

International audienceSmall-scale shear zones within the Permian Truzzo meta-granite developed during the Alpine orogeny at amphibolite facies conditions. In these shear zones magmatic quartz deformed by dislocation creep and recrystallized dynamically by grain boundary migration with minor subgrain rotation recrystallization to a grain size of around 250–750 μm, consistent with flow at low differential stresses. Fourier transform infrared (FTIR) spectroscopy reveals very low water contents in the interior of recrystallized grains (in the form of discrete OH peaks, ~20 H/10 6 Si and very little broad band absorption, <100 H/10 6 Si). The spectral characteristics are comparable to those of dry Brazil quartz. In FTIR spectra, magmatic quartz grains show a broad absorption band related with high water concentrations only in those areas where fluid inclusions are present while other areas are dry. Drainage of fluid inclusions and synkinematic growth of hydrous minerals indicates that a hydrous fluid has been available during deformation. Loss of intragranular water during grain boundary migration recrystallization did not result in a microstructure indicative of hardening. These FTIR measurements provide the first evidence that quartz with extremely low intragranular water contents can deform in nature by dislocation creep at low differential stresses. Low intragranular water contents in naturally deformed quartz may not be necessarily indicative of a high strength, and the results are contrary to implications taken from deformation experiments where very high water contents are required to allow dislocation creep in quartz. It is suggested that dislocation creep of quartz in the Truzzo meta-granite is possible to occur at low differential stresses because sufficient amounts of intergranular water ensure a high recovery rate by grain boundary migration while the absence of significant amounts of intragranular water is not crucial at natural conditions