Among these strains is a highly virulent subclone
of serotype M1T1 that has exhibited unusual epidemiologic features and virulence, unlike all other streptococcal strains.
A recent report described a myeloma patient in whom all of the malignant plasma cells contained a truncated [gamma] chain, whereas a subclone
of 30% of the cells also contained light chain (4).
The USA300-0114 subclone
has been the predominant one during the community MRSA epidemic in San Francisco (6) and is becoming widely prevalent in communities throughout the United States (7).
, however, exceeded the 4 mg/L NCCLS breakpoint for vancomycin susceptibility (the MIC of vancomycin for all but one subclone
was [less than or equal to] 2 mg/L; for one subclone
it was 4 mg/L) (1).
35) This is not to say that the transcriptional profiles obtained at the population level of resected tumor cells are of no potential value clinically or scientifically, but such findings do highlight the need to think about the idea of heterogeneity and subclones
within a tumor, and the relative extent to which each subclone
contributes to clinically meaningful and treatable parameters.
Separate F-type plasmids have shaped the evolution of the H 30 subclone
of Escherichia coli sequence type 131.
Some cells that are responsive to a drug will acquire new variants that result in the cell becoming resistant to treatment as part of this survival strategy, while other cells are present as a subclone
that lingers in the background waiting for an opportunity to proliferate.
The patient eventually relapsed as a result of the least prevalent subclone
at diagnosis, which developed an additional mutation, proliferating in the absence of the others.
The first strain of this clone belonged to B1 subclone
and was isolated from a blood culture of a patient hospitalized in the internal medicine service.
There are two major clonal evolution patterns found in AML relapse, reflecting either the evolution from the founding to the relapsing clone through acquisition of further mutations, or the expansion of a subclone
of the founding clone with gain of additional mutations.
11) The cell lines used in this study were a monocytic leukemia subclone
(BF24) and (THP89GFP), infected with the HIV-1 strain.
In others, a subclone
derived from the founding clone survives chemotherapy, gains mutations and evolves to become the dominant clone at relapse.