List of three important viruses of Mollicutes:- 1. Mycoplasma Viruses 2. Acholeplasma Viruses 3. Spiroplasma Viruses.
Mollicutes: Virus # 1. Mycoplasma Viruses:
Gourlay (1980) first isolated a virus from an unknown bovine source which infected Mycoplasma bovirhinis host cells and designed it as Br-1. In 1983, they further isolated a virus from spontaneous plaques on Mycoplasma hyorhinis lawn, successfully propagated this virus on M. hyorhinis cells, and named it Hr-1.
A new mycoplasma virus was isolated by Dybvig (1987) from Mycoplasma pulmonis cell which they designated P-1. P-1 was successfully propagated on the cells of M. pulmonis.
Mycoplasma viruses are considered to be filamentous, isometric and short-tailed phage-like in appearance. Some of them are enveloped viruses. Unfortunately, none of the mycoplasm viruses could have been grown in sufficient quantities to allow characterization of their structures and replication cycles.
The knowledge about mycoplasma viruses available so far seems full of confusing data and they still await more attentions of virologists.
Mollicutes: Virus # 2. Acholeplasma Viruses:
The first Acholeplasma virus was isolated by Gourlay (1970) in England from the filtrate of Acholeplasma laidlawii strain and designated L1. In the next few years, Gourlay isolated and characterized two additional viruses, designated L2 and L3, from A. laidlawii strains. Each of the three viruses was found to be morphologically and serologically different from the others.
Subsequently in 1972, Liska in Czechoslovakia isolated other Acholeplasma virus from an unknown strain of A. laidlawii and designated L172, and from strain of A. modicum and designated M1. O1 Acholeplasma virus has been isolated from an A. oculi strain by Ichimaru and Nakamaru (1983) in Japan. Further studies with respect to the molecular biology of these viruses were initially focussed on L1 and later shifted to L2 and the unique lysogenic cycle of L2 became apparent.
Mollicutes: Virus # 3. Spiroplasma Viruses:
Cole (1973) first reported virus-like particles in Spiroplasma cultures during ultrastructural characterization of Spiroplasma cells. Three different morphological forms of these virus-like particles were reported and designated C1, C2 and C3.
Two of these VLPs (C1 and C3) were subsequently propagated and characterized. In 1984, Bove and coworkers isolated a fourth morphological type of Spiroplasma virus in France and designated SpV4.