CARD 2023: expanded curation, support for machine learning, and resistome prediction at the Comprehensive Antibiotic Resistance Database.

The Comprehensive Antibiotic Resistance Database (CARD; card.mcmaster.ca) combines the Antibiotic Resistance Ontology (ARO) with curated AMR gene (ARG) sequences and resistance-conferring mutations to provide an informatics framework for annotation and interpretation of resistomes. As of version 3.2.4, CARD encompasses 6627 ontology terms, 5010 reference sequences, 1933 mutations, 3004 publications, and 5057 AMR detection models that can be used by the accompanying Resistance Gene Identifier (RGI) software to annotate genomic or metagenomic sequences. Focused curation enhancements since 2020 include expanded ß-lactamase curation, incorporation of likelihood-based AMR mutations for Mycobacterium tuberculosis, addition of disinfectants and antiseptics plus their associated ARGs, and systematic curation of resistance-modifying agents. This expanded curation includes 180 new AMR gene families, 15 new drug classes, 1 new resistance mechanism, and two new ontological relationships: evolutionary_variant_of and is_small_molecule_inhibitor. In silico prediction of resistomes and prevalence statistics of ARGs has been expanded to 377 pathogens, 21,079 chromosomes, 2,662 genomic islands, 41,828 plasmids and 155,606 whole-genome shotgun assemblies, resulting in collation of 322,710 unique ARG allele sequences. New features include the CARD:Live collection of community submitted isolate resistome data and the introduction of standardized 15 character CARD Short Names for ARGs to support machine learning efforts.

Drug Resistance in Hepatitis C Virus: Future Prospects and Strategies to Combat It.

Induction of highly pathogenic hepatitis C virus (HCV) causes chronic hepatitis round the world. This virus is easily prone to developing resistance against antiviral drugs because of two viral polymerases that do not possess the proofreading and overlapping reading frame abilities. There is more than one explanation for how this virus builds up resistance against antiviral drug treatments. Assays are now available to detect HCV-resistant variants, based on phenotypic and genotypic assays, and next generation sequencing. But these assays are of a little value at baseline, because they are not influential enough for making therapeutic decisions in HCV patients. Moreover, HCV monitoring is now an essential part of clinical practice. Special patients, such as those with thalassemia, renal transplant due to renal failure, and the patients undergoing hemodialysis, are at higher risk for acquiring this infection. Management of HCV infection in these patient groups is complicated by multiple side effects, including flu-like symptoms, neutropenia, fever, and neuropsychiatric disorders, thus limiting the use of ribavirin and coexisting iron overload. In HCV patients suffering from depression, the treatment may be discontinued because of some defects in neurochemical pathways caused by interferon, which can enhance the level of depression in these patients. In addition, obesity has been found to be a marker of failure of HCV treatment. There will be many resistance tolerant HCV treatment options available in the near future.