L-arginine metabolism as pivotal interface of mutual host-microbe interactions in the gut.

L-arginine (L-arg) is a versatile amino acid and a central intestinal metabolite in mammalian and microbial organisms. Thus, L-arg participates as precursor of multiple metabolic pathways in the regulation of cell division and growth. It also serves as a source of carbon, nitrogen, and energy or as a substrate for protein synthesis. Consequently, L-arg can simultaneously modify mammalian immune functions, intraluminal metabolism, intestinal microbiota, and microbial pathogenesis. While dietary intake, protein turnover or de novo synthesis usually supply L-arg in sufficient amounts, the expression of several key enzymes of L-arg metabolism can change rapidly and dramatically following inflammation, sepsis, or injury. Consequently, the availability of L-arg can be restricted due to increased catabolism, transforming L-arg into an essential amino acid. Here, we review the enzymatic pathways of L-arg metabolism in microbial and mammalian cells and their role in immune function, intraluminal metabolism, colonization resistance, and microbial pathogenesis in the gut.

Increased zinc levels facilitate phenotypic detection of ceftazidime-avibactam resistance in metallo-ß-lactamase-producing Gram-negative bacteria.

Ceftazidime-avibactam is one of the last resort antimicrobial agents for the treatment of carbapenem-resistant, Gram-negative bacteria. Metallo-ß-lactamase-producing bacteria are considered to be ceftazidime-avibactam resistant. Here, we evaluated a semi-automated antimicrobial susceptibility testing system regarding its capability to detect phenotypic ceftazidime-avibactam resistance in 176 carbapenem-resistant, metallo-ß-lactamase-producing Enterobacterales and Pseudomonas aeruginosa isolates. Nine clinical isolates displayed ceftazidime-avibactam susceptibility in the semi-automated system and six of these isolates were susceptible by broth microdilution, too. In all nine isolates, metallo-ß-lactamase-mediated hydrolytic activity was demonstrated with the EDTA-modified carbapenemase inactivation method. As zinc is known to be an important co-factor for metallo-ß-lactamase activity, test media of the semi-automated antimicrobial susceptibility testing system and broth microdilution were supplemented with zinc. Thereby, the detection of phenotypic resistance was improved in the semi-automated system and in broth microdilution. Currently, ceftazidime-avibactam is not approved as treatment option for infections by metallo-ß-lactamase-producing, Gram-negative bacteria. In infections caused by carbapenem-resistant Gram-negatives, we therefore recommend to rule out the presence of metallo-ß-lactamases with additional methods before initiating ceftazidime-avibactam treatment.

[The Development of General Practices in Ambulatory Care in the Last Decades - An Analysis of the Physicians' Registry of Bavaria]. / Entwicklung der hausärztlichen Versorgung innerhalb der letzten Jahrzehnte ­ eine Analyse des Basisdatensatzes der Kassenärztlichen Vereinigung Bayerns.

AIM OF THE STUDY: There is an increasing shortage of general practitioners (GPs) in Germany. An in-depth understanding of the variation regarding the characteristics of the GPs in the last decades might help to optimize primary health care. The aim of the analysis of the characteristic features of GPs as preserved by the registry of the Bavarian Association of Statutory Health Insurance of Physicians (KVB) was to delineate the time interval between passing the medical state examination and establishment of one's own private practice, the development of group practices and employments, and the number of additional qualifications. METHODS: The physicians' registry of the KVB was used to analyse the time intervals, additional qualifications, and development of group practices and employments. Data were analysed descriptively. RESULTS: The time interval from passing the medical state examination and establishing one's own private practice increased remarkably since the 70s from 5 years to 12 years on average. There was an increasing trend towards group practices. The number of newly established practices remained constant around 200 practices per year. Beyond that, there was an increasing trend towards employment in practices. The number of additional qualifications decreased over time, which was in particular true of complementary medicine and sports medicine. CONCLUSIONS: The period of vocational traineeship should be organised efficiently to decrease the length of training. Young GPs should be motivated and receive incentives to establish their own private practice. However, it is also necessary to facilitate employment in the practices.

Ambulatory specialist costs and morbidity of coordinated and uncoordinated patients before and after abolition of copayment: A cohort analysis.

To strengthen the coordinating function of general practitioners (GPs) in the German healthcare system, a copayment of €10 was introduced in 2004. Due to a perceived lack of efficacy and a high administrative burden, it was abolished in 2012. The present cohort study investigates characteristics and differences of GP-coordinated and uncoordinated patients in Bavaria, Germany, concerning morbidity and ambulatory specialist costs and whether these differences have changed after the abolition of the copayment. We performed a retrospective routine data analysis, using claims data of the Bavarian Association of the Statutory Health Insurance Physicians during the period 2011-2012 (with copayment) and 2013-2016 (without copayment), covering 24 quarters. Coordinated care was defined as specialist contact only with referral. Multinomial regression modelling, including inverse probability of treatment weighting, was used for the cohort analysis of 500 000 randomly selected patients. Longitudinal regression models were calculated for cost estimation. Coordination of care decreased substantially after the abolition of the copayment, accompanied by increasing proportions of patients with chronic and mental diseases in the uncoordinated group, and a corresponding decrease in the coordinated group. In the presence of the copayment, uncoordinated patients had €21.78 higher specialist costs than coordinated patients, increasing to €24.94 after its abolition. The results indicate that patients incur higher healthcare costs for specialist ambulatory care when their care is uncoordinated. This effect slightly increased after abolition of the copayment. Beyond that, the abolition of the copayment led to a substantial reduction in primary care coordination, particularly affecting vulnerable patients. Therefore, coordination of care in the ambulatory setting should be strengthened.

Prescribers' compliance with summary of product characteristics of dabigatran, rivaroxaban and apixaban-A European comparative drug utilization study.

Despite a tremendous increase of direct oral anticoagulants (DOACs) prescriptions in recent years, only few data is available analysing prescribers' adherence to Summary of Product Characteristics (SmPC). We aimed to assess adherence to registered indications, contraindications, special warnings/precautions, and potential drug-drug interactions for three DOAC compounds (dabigatran, rivaroxaban, and apixaban) in six databases of five European countries (The Netherlands, United Kingdom, Spain, Denmark, and Germany). We included adult patients (≥18 years) initiating DOACs between 2008 and 2015. For several SmPC items, broad definitions were used due to ambiguous SmPC terms or lacking data in some databases. Within the study period, a DOAC was initiated in 407 576 patients (rivaroxaban: 240 985 (59.1%), dabigatran: 95 303 (23.4%), and apixaban: 71 288 (17.5%)). In 2015, non-valvular atrial fibrillation was the most common indication (>60% in most databases). For the whole study period, a substantial variation between the databases was found regarding the proportion of patients with at least one contraindication (inter-database range [IDR]: 8.2%-55.7%), with at least one special warning/precaution (IDR: 35.8%-75.2%) and with at least one potential drug-drug interaction (IDR: 22.4%-54.1%). In 2015, the most frequent contraindication was "malignant neoplasm" (IDR: 0.7%-21.3%) whereas the most frequent special warning/precaution was "prescribing to the elderly" (≥75 years; IDR: 25.0%-66.4%). The most common single compound class interaction was "concomitant use of non-steroidal anti-inflammatory drugs" (IDR: 3.0%-25.3%). Contraindications, special warnings/precautions, and potential drug-drug interactions were present in a relevant number of new DOAC users. Due to broad definitions used for some SmPC terms, overall proportions for contraindications are prone to overestimation. However, for unambiguous SmPC terms documented in the databases sufficiently, the respective estimates can be considered valid. Differences between databases might be related to "true" differences in prescription behaviour, but could also be partially due to differences in database characteristics.