“broad taxonomic group” isn’t quite right. The situation is that names can’t be reused within the scope of a nomenclatural code. But you can have the same name used once in the domain of the zoological code (ICZN) and once within the domain of the botanical code (ICN, formerly ICBN). The zoological code covers animals, and the botanical code plants, algae, and fungi; protists are semi-arbitrarily divided between the two codes based on the old procrustean dichotomy. Some protist groups have names under both codes; for example, the family Amoebidiidae is closer to animals than to fungi, and therefore has a name with the ICZN suffix -idae; it used to be considered a fungal group, with the name Amoebidiaceae, using the ICBN suffix -aceae.
Bacteria used to be covered by the botanical code, but are now covered by the bacteriological code (ICNP). There is also the viral code (ICTV), and PhyloCode, which is an alternative, unranked, scheme, applicable to all life. I don’t know offhand how the ICNP and ICTV interact with the ICZN and ICN; however the requirement the viral genera end with the suffix -virus reduces the risk of a conflict. (I could imagine a plant generic name ending in -virus by coincidence, but the IPNI database doesn’t contain any examples; the nearest occurrence is the epithet virusana/um.)