The phrase "a previous strain" is correct and usable in written English.
It can be used when referring to an earlier version or type of something, often in contexts related to biology, music, or any field where variations or changes occur over time.
Example: "The researchers compared the new virus to a previous strain to understand its mutations."
Alternatives: "an earlier variant" or "a prior version".
The message didn't seem to sink in after the emergence, in 1996, of a previous strain of avian influenza, one that did kill people.
B3 NEW TRACES OF ANTHRAX -- A month after the Morgan mail-processing center on the West Side of Manhattan was thought to be free of anthrax, postal officials said traces from a previous strain were found on one of the center's high-speed mail-sorting machines.
The fact that the swine flu pandemic disproportionately affected the young is a known feature [ 8, 26], with research suggesting that people over 60 had some acquired resistance from exposure to a previous strain [ 27].
In a departure from previous strain theory, our model predicts that the different dominant repertoires can exhibit partial overlap; the extent of the overlap increases with transmission intensity and this, in turn, influences observed epidemiological patterns (particularly age-serology profiles).
Finally, it is interesting to highlight the results obtained for patients 1 and 3. From patient 1, we isolated a previous hypermutator strain in 2004 (1a) and a subsequent hypermutator strain in 2007 1bb) (Table 1).
The GS1.11-26 stralsoaccomplishedished complete attenuation of D-xylose with an ethanol yield of 0.46 g/g D-xylose, whereas the previous strain BWY10Xyl left a substantial amount of D-xylose unfermented.
Acquisition of resistance was defined as the isolation of a resistant organism in a patient with a previous sensitive strain or prior negative cultures.
The whole genome sequencing has been proposed as a sort of "gold standard" for strain typing in M. tuberculosis since it clarifies previous strain typing approaches used for phylogenetic and epidemiologic studies and provides more detailed genomic variation information.
Unlike the case with the previous strain, which killed six people, there is no evidence that this strain affects human beings, the officials said.
These changes are enough to make those who suffered from - and became immune to - the previous strain susceptible to the new one.
Even a short heating episode can be dangerous especially when it is repeated before the wood has completely relaxed from the previous strain [31].
