A recent taxonomic study confirmed the synonymy of Rhodococcus equi (Magnusson 1923) Goodfellow and Alderson 1977 and Corynebacterium hoagii (Morse 1912) Eberson 1918. As a result, both R. equi and C. hoagii were reclassified to Rhodococcus hoagii comb. nov. in application of the principle of priority of the Prokaryotic Code. Being R. equi a well-known animal and zoonotic human pathogen, and the name solidly established in the veterinary and medical literature, we and others argued that the nomenclatural change may cause error and confusion and be potentially perilous. We have now additionally found that the nomenclatural type of the basonym C. hoagii, ATCC 7005^T, does not correspond with the original description of C. hoagii in the early literature. Its inclusion as the C. hoagii type on the Approved Lists 1980 results in a change in the characters of the taxon and in C. hoagii clearly designating two different bacteria. Moreover, ATCC 7005, the only strain in circulation under the name C. hoagii, does not have a well documented history; it is unclear why it was deposited as C. hoagii and a possible mixup with a Corynebacterium (Rhodococcus) equi isolate is a reasonable assumption. We therefore request the rejection of Rhodococcus hoagii as a nomen ambiguum, nomen dubium and nomen perplexum in addition to nomen periculosum, and conservation of the name Rhodococcus equi, according to Rules 56ab of the Code.

Grapevine trunk diseases (GTDs) attack the vine's wood, devastating vineyards worldwide. Chile is the world's fourth largest wine exporter, and Cabernet Sauvignon leads the red wine varieties. Botryosphaeria dieback is an important GTDs and Diplodia seriata is one of the main pathogenic species. Biocontrol studies of these pathogens are commonly carried out at different incubation times but at a single temperature. This study aimed to evaluate the biocontrol effect of native Chilean bacteria against D. seriata isolates at different temperatures. We analyzed the biocontrol effects of Pseudomonas sp. GcR15a, Pseudomonas sp. AMCR2b and Rhodococcus sp. PU4, with three D. seriata isolates (PUCV 2120, PUCV 2142 and PUCV 2183) at 8, 22 and 35°C. Agar plug diffusion and double plate methods were used to evaluate the effect of diffusible and volatile organic compounds (DOC and VOC), and an in vivo test was performed with Cabernet Sauvignon cuttings. Pseudomonas strains showed the most significant inhibition in the DOC assay, and a demelanizing activity was observed. Rhodococcus sp. PU4 showed VOC biocontrol potential at high temperatures (35°C). In vivo, a biocontrol effect was observed against two D. seriata isolates, while the PUCV 2142 isolate proved to be more resistant to being controlled. The biocontrol ability at low temperatures is promising for effective control in the field, where infections occur primarily in winter.