Overcoming taxonomic challenges in DNA barcoding for improvement of identification and preservation of clariid catfish species

DNA barcoding without assessing reliability and validity causes taxonomic errors of species identification, which is responsible for disruptions of their conservation and aquaculture industry. Although DNA barcoding facilitates molecular identification and phylogenetic analysis of species, its availability in clariid catfish lineage remains uncertain. In this study, DNA barcoding was developed and validated for clariid catfish. 2,970 barcode sequences from mitochondrial cytochrome c oxidase I (COI) and cytochrome b (Cytb) genes and D-loop sequences were analyzed for 37 clariid catfish species. The highest intraspecific nearest neighbor distances were 85.47%, 98.03%, and 89.10% for COI, Cytb, and D-loop sequences, respectively. This suggests that the Cytb gene is the most appropriate for identifying clariid catfish and can serve as a standard region for DNA barcoding. A positive barcoding gap between interspecific and intraspecific sequence divergence was observed in the Cytb dataset but not in the COI and D-loop datasets. Intraspecific variation was typically less than 4.4%, whereas interspecific variation was generally more than 66.9%. However, a species complex was detected in walking catfish and significant intraspecific sequence divergence was observed in North African catfish. These findings suggest the need to focus on developing a DNA barcoding system for classifying clariid catfish properly and to validate its efficacy for a wider range of clariid catfish. With an enriched database of multiple sequences from a target species and its genus, species identification can be more accurate and biodiversity assessment of the species can be facilitated.

An audit of transmucosal immediate-release fentanyl prescribing at a university hospital

Transmucosal Immediate-Release Fentanyl（TIRF）can be a key-drug for breakthrough cancer pain. Prescription audit is needed because there are concerns about tolerance or serious adverse events including respiratory suppression and addiction due to inappropriate use of these drugs. The aim of this audit study is to evaluate appropriateness of TIRF prescriptions, reasons of violation, and adverse events in the real-world setting. A retrospective chart review was conducted in 31 patients who had breakthrough cancer pain and were treated with TIRF. A 2-step algorithm was generated：baseline pain and administration situation of other opioid rescues. TIRF was prescribed appropriately in six patients（19.4％）. Reasons of violation were as follows：prescriptions only for using same drug with around-the-clock opioids（fentanyl transdermal patches, <i>n</i>＝19）, and patients could take oral medicines and use of morphine or oxycodone rescues would be preferable（<i>n</i>＝12）. TIRF was initiated with a minimum dose in all patients and no serious adverse events were observed. Although TIRF was used widely for breakthrough cancer pain, prescription was not necessarily done appropriately. Detailed assessment of breakthrough cancer pain and consideration of the use the other rescue medication would be required.