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1.
J Water Health ; 22(1): 77-96, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38295074

ABSTRACT

Disasters such as the Ahr Valley flood in 2021 make us aware of the importance of functioning healthcare facilities. Their functionality depends on the availability of drinking water. Water safety planning is a long-established method to increase the safety of water utilities. Our work supports the implementation of water safety planning in healthcare facilities during normal operations and emergency situations concerning the water supply. The authors conducted a stakeholder mapping exercise and problem awareness analysis. Based on these results, it was identified what is needed to overcome barriers to water safety planning (WSP). Building on existing procedures, the WSP concept, and latest scientific findings, an event-specific risk assessment method for healthcare facilities was developed and applied in a case study. Based on an analysis of water demand, water-related processes, and infrastructure, potentially necessary components for establishing an emergency supply were identified. For these, based on technical and legal requirements, planning principles were developed, and prototypes of components for emergency water supply were built. They were tested in pilot trials, particularly regarding hygienic safety. For the management of crises in hospitals, a survey was carried out on the command structures used in practice. Finally, recommendations were drawn based on the German Hospital Incident Command System.


Subject(s)
Drinking Water , Water Supply , Risk Assessment , Hospitals , Delivery of Health Care
2.
J Digit Imaging ; 34(1): 182-189, 2021 02.
Article in English | MEDLINE | ID: mdl-33409816

ABSTRACT

Magnetic resonance imaging (MRI) systems and their continuous, failure-free operation is crucial for high-quality diagnostics and seamless workflows. One important hardware component is coils as they detect the magnetic signal. Before every MRI scan, several image features are captured which represent the used coil's condition. These image features recorded over time are used to train machine learning models for classification of coils into normal and broken coils for faster and easier maintenance. The state-of-the-art techniques for classification of time series involve different kinds of neural networks. We leveraged sequential data and trained three models, long short-term memory (LSTM), fully convolutional network (FCN), and the combination of those called LSTMFCN as reported by Karim et al. (IEEE access 6:1662-1669, 2017). We found LSTMFCN to combine the benefits of LSTM and FCN. Thus, we achieved the highest F1-score of 87.45% and the highest accuracy of 99.35% using LSTMFCN. Furthermore, we tackled the high data imbalance of only 2.1% data collected from broken coils by training a Gaussian process (GP) regressor and adding predicted sequences as artificial samples to our broken labelled data. Adding 40 synthetic samples increased the classification results of LSTMFCN to an F1-score of 92.30% and accuracy of 99.83%. Thus, MRI head/neck coils can be classified normal or broken by training a LSTMFCN on image features, successfully. Augmenting the data using GP-generated samples can improve the performance even further.


Subject(s)
Machine Learning , Neural Networks, Computer , Humans , Magnetic Resonance Imaging , Normal Distribution
3.
Article in English | MEDLINE | ID: mdl-28893793

ABSTRACT

Chemotherapy for tuberculosis (TB) is lengthy and could benefit from synergistic adjuvant therapeutics that enhance current and novel drug regimens. To identify genetic determinants of intrinsic antibiotic susceptibility in Mycobacterium tuberculosis, we applied a chemical genetic interaction (CGI) profiling approach. We screened a saturated transposon mutant library and identified mutants that exhibit altered fitness in the presence of partially inhibitory concentrations of rifampin, ethambutol, isoniazid, vancomycin, and meropenem, antibiotics with diverse mechanisms of action. This screen identified the M. tuberculosis cell envelope to be a major determinant of antibiotic susceptibility but did not yield mutants whose increase in susceptibility was due to transposon insertions in genes encoding efflux pumps. Intrinsic antibiotic resistance determinants affecting resistance to multiple antibiotics included the peptidoglycan-arabinogalactan ligase Lcp1, the mycolic acid synthase MmaA4, the protein translocase SecA2, the mannosyltransferase PimE, the cell envelope-associated protease CaeA/Hip1, and FecB, a putative iron dicitrate-binding protein. Characterization of a deletion mutant confirmed FecB to be involved in the intrinsic resistance to every antibiotic analyzed. In contrast to its predicted function, FecB was dispensable for growth in low-iron medium and instead functioned as a critical mediator of envelope integrity.


Subject(s)
Antitubercular Agents/pharmacology , Bacterial Proteins/genetics , Cell Wall/drug effects , Drug Resistance, Multiple, Bacterial/genetics , Gene Expression Regulation, Bacterial , Mycobacterium tuberculosis/drug effects , Serine Proteases/genetics , Adenosine Triphosphatases/genetics , Adenosine Triphosphatases/metabolism , Bacterial Proteins/metabolism , Cell Wall/genetics , Cell Wall/metabolism , Ethambutol/pharmacology , Galactans/biosynthesis , Gene Expression Profiling , Humans , Ion Pumps/deficiency , Ion Pumps/genetics , Isoniazid/pharmacology , Ligases/genetics , Ligases/metabolism , Mannosyltransferases/genetics , Mannosyltransferases/metabolism , Membrane Transport Proteins/genetics , Membrane Transport Proteins/metabolism , Meropenem , Microbial Sensitivity Tests , Mycobacterium tuberculosis/genetics , Mycobacterium tuberculosis/metabolism , Mycolic Acids/metabolism , Peptidoglycan/biosynthesis , Rifampin/pharmacology , Serine Proteases/metabolism , Thienamycins/pharmacology , Vancomycin/pharmacology
4.
J Bacteriol ; 197(19): 3182-90, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26216844

ABSTRACT

UNLABELLED: Mycobacterium tuberculosis persists inside granulomas in the human lung. Analysis of the metabolic composition of granulomas from guinea pigs revealed that one of the organic acids accumulating in the course of infection is acetate (B. S. Somashekar, A. G. Amin, C. D. Rithner, J. Troudt, R. Basaraba, A. Izzo, D. C. Crick, and D. Chatterjee, J Proteome Res 10:4186-4195, 2011, doi:http://dx.doi.org/10.1021/pr2003352), which might result either from metabolism of the pathogen or might be provided by the host itself. Our studies characterize a metabolic pathway by which M. tuberculosis generates acetate in the cause of fatty acid catabolism. The acetate formation depends on the enzymatic activities of Pta and AckA. Using actyl coenzyme A (acetyl-CoA) as a substrate, acetyl-phosphate is generated and finally dephosphorylated to acetate, which is secreted into the medium. Knockout mutants lacking either the pta or ackA gene showed significantly reduced acetate production when grown on fatty acids. This effect is even more pronounced when the glyoxylate shunt is blocked, resulting in higher acetate levels released to the medium. The secretion of acetate was followed by an assimilation of the metabolite when other carbon substrates became limiting. Our data indicate that during acetate assimilation, the Pta-AckA pathway acts in concert with another enzymatic reaction, namely, the acetyl-CoA synthetase (Acs) reaction. Thus, acetate metabolism might possess a dual function, mediating an overflow reaction to release excess carbon units and resumption of acetate as a carbon substrate. IMPORTANCE: During infection, host-derived lipid components present the major carbon source at the infection site. ß-Oxidation of fatty acids results in the formation of acetyl-CoA. In this study, we demonstrate that consumption of fatty acids by Mycobacterium tuberculosis activates an overflow mechanism, causing the pathogen to release excess carbon intermediates as acetate. The Pta-AckA pathway mediating acetate formation proved to be reversible, enabling M. tuberculosis to reutilize the previously secreted acetate as a carbon substrate for metabolism.


Subject(s)
Acetates/metabolism , Carbon/metabolism , Mycobacterium tuberculosis/metabolism , Acetyl Coenzyme A/metabolism , Animals , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Gene Deletion , Gene Expression Regulation, Bacterial/physiology , Guinea Pigs , Mycobacterium tuberculosis/genetics , Phosphates/metabolism
5.
J Clin Microbiol ; 52(1): 244-50, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24197890

ABSTRACT

Mycobacterium abscessus, which consists of the two subspecies M. abscessus subspecies abscessus and M. abscessus subspecies bolletii, can produce rough or smooth colony morphologies. Here we analyzed 50 M. abscessus isolates cultured from the respiratory specimens of 34 patients, 28 (82%) of whom had cystic fibrosis (CF), with respect to their colony morphologies and antibiotic susceptibilities. The overall proportions of occurrences of the two morphotypes were similar, with specimens from 50% of the patients showing a rough and 38% showing a smooth morphotype. A total of 12% of the specimens from the patients showed both morphotypes simultaneously. At the subspecies level, the proportions of rough and smooth morphotypes differed substantially; 88% of rough morphotypes belonged to M. abscessus subspecies abscessus, and 85% of smooth morphotypes belonged M. abscessus subspecies bolletii. Inducible clarithromycin resistance due to the Erm(41) methylase, as well as high-level resistance to clarithromycin due to mutations within the rrl gene, occurred independently of the morphotype. The MIC50s of amikacin and cefoxitin were identical for the two morphotypes, whereas the MIC50s of tigecycline were 0.25 µg/ml for the rough morphotype and 2.0 µg/ml for the smooth morphotype. Our results show that the smooth morphotype was more dominant in respiratory specimens from CF patients than previously thought. With respect to resistance, colony morphology did not affect the susceptibility of Mycobacterium abscessus to the first-line antibiotics clarithromycin, amikacin, and cefoxitin.


Subject(s)
Mycobacterium Infections, Nontuberculous/microbiology , Mycobacterium/isolation & purification , Mycobacterium/physiology , Anti-Bacterial Agents/pharmacology , Humans , Microbial Sensitivity Tests , Mycobacterium/drug effects , Mycobacterium/growth & development , Respiratory Tract Infections/microbiology
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