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Category: Clinical Microbiology
Mixed Mycotic Infections, Page 1 of 2
< Previous page | Next page > /docserver/preview/fulltext/10.1128/9781555817947/9781555812447_Chap17-1.gif /docserver/preview/fulltext/10.1128/9781555817947/9781555812447_Chap17-2.gifAbstract:
In considering the question of mixed mycotic infections, one is faced with a number of issues related to the specific pathogenic strategies that have developed in different species and related to the phylogenetic levels of unrelatedness. First, one must consider, where relevant, the issues of commensalism, opportunism, and infection. Second, one must consider exactly what is meant by mixed colonization, or mixed infection, as it relates to genetic relatedness. Mixing can occur between kingdoms (e.g., bacteria and fungi), between genera within a kingdom (e.g., Aspergillus spp. And Candida spp.), between species within a genus (e.g., C. albicans and C. tropicalis), between strains within a species, and between substrains within a strain, a result of microevolution. Each of these combinations is relevant since each involves combinations of genetically distinct organisms with potentially different phenotypes, even at the substrain level. In this context, colonizing populations can also contain mixed phenotypes that are quite stable but which may be the result of high-frequency phenotypic switching systems that involve epigenetic mechanisms rather than genetic change at the level of DNA sequence. The intention of this chapter is to consider all of the levels of genetic and phenotypic mixing.
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The levels of genetic relatedness (or unrelatedness) basic to mixed infections. In the scheme, mixing based on genetic differences (upper triangle) is separated from mixing due to epigenetic switching (lower triangle).
The levels of genetic relatedness (or unrelatedness) basic to mixed infections. In the scheme, mixing based on genetic differences (upper triangle) is separated from mixing due to epigenetic switching (lower triangle).
Primary culture from the vaginal canal in which the bacterial colony (B) alters the morphology of closely associated C. albicans colonies by inducing hypha and pseudohypha formation. Altered portions of colonies (arrowheads) and an entirely altered colony (arrow) are indicated. The changes are not hereditary (Soll and Lockhart, unpublished observation).
Primary culture from the vaginal canal in which the bacterial colony (B) alters the morphology of closely associated C. albicans colonies by inducing hypha and pseudohypha formation. Altered portions of colonies (arrowheads) and an entirely altered colony (arrow) are indicated. The changes are not hereditary (Soll and Lockhart, unpublished observation).
Dendrogram generated from the S ABs computed for every pair in a set of test isolates that included identical, highly related, and unrelated isolates, originally analyzed by Pujol et al. ( 65 ). This set of isolates has been separated into three clusters and outliers (strains not in clusters). The unrelated and highly related ranges of S ABs are arbitrarily set between 0.57 and 0.80 and between 0.90 and 0.99, respectively ( 78 ). Strains were fingerprinted by Southern blot analysis with the complex probe Ca3.
Dendrogram generated from the S ABs computed for every pair in a set of test isolates that included identical, highly related, and unrelated isolates, originally analyzed by Pujol et al. ( 65 ). This set of isolates has been separated into three clusters and outliers (strains not in clusters). The unrelated and highly related ranges of S ABs are arbitrarily set between 0.57 and 0.80 and between 0.90 and 0.99, respectively ( 78 ). Strains were fingerprinted by Southern blot analysis with the complex probe Ca3.
Collections of clonal C. albicans isolates, each from a primary sample from two patients (P2 and P3), were DNA fingerprinted with the complex probe Ca3 and incorporated into a mixed dendrogram that includes a more general collection of unrelated isolates. Note how the P2 and P3 collections cluster at very high S ABs and exhibit microevolution in each case.
Collections of clonal C. albicans isolates, each from a primary sample from two patients (P2 and P3), were DNA fingerprinted with the complex probe Ca3 and incorporated into a mixed dendrogram that includes a more general collection of unrelated isolates. Note how the P2 and P3 collections cluster at very high S ABs and exhibit microevolution in each case.
Surveillance of yeast colonization and drug regimen of a bone marrow transplant patient infected with two strains of C. tropicalis in the blood and a variety of yeasts in other body locations. The origins of samples are indicated as follows: ur, urine; bl, blood; sk-b, skin blister; th, throat; st, stool. The major colony phenotypes were the following: sw, smooth white; ie, irregular edge; F, fuzzy; bh, bumpy halo. The names of the yeast colonies before identification and DNA fingerprinting are presented under “Major Colony Phenotype and Strain” (in parentheses) and with the identified species and strains. The identified species and strain, for example, C.alb-1, refer to species and strain number in order of isolation. Low-dosage (hatched bar) and maximum-dosage (solid bars) drug regimens are indicated. 5-FC, flucytosine. Modified from reference 86 .
Surveillance of yeast colonization and drug regimen of a bone marrow transplant patient infected with two strains of C. tropicalis in the blood and a variety of yeasts in other body locations. The origins of samples are indicated as follows: ur, urine; bl, blood; sk-b, skin blister; th, throat; st, stool. The major colony phenotypes were the following: sw, smooth white; ie, irregular edge; F, fuzzy; bh, bumpy halo. The names of the yeast colonies before identification and DNA fingerprinting are presented under “Major Colony Phenotype and Strain” (in parentheses) and with the identified species and strains. The identified species and strain, for example, C.alb-1, refer to species and strain number in order of isolation. Low-dosage (hatched bar) and maximum-dosage (solid bars) drug regimens are indicated. 5-FC, flucytosine. Modified from reference 86 .
The basic bud-hypha transition in C. albicans. (A) A budding cell in which the mother and daughter cell have in turn budded and are separating; (B) a cell forming a germ tube. Note the bud scars on the mother cell.
The basic bud-hypha transition in C. albicans. (A) A budding cell in which the mother and daughter cell have in turn budded and are separating; (B) a cell forming a germ tube. Note the bud scars on the mother cell.
Colony morphologies in the switching system in C. albicans 3153A. (A) Original smooth; (B) star; (C) ring; (D) wrinkle; (E) mottled; (F) hat; (G) fuzzy; (H) revertant smooth. Reprinted from reference 72 with permission.
Colony morphologies in the switching system in C. albicans 3153A. (A) Original smooth; (B) star; (C) ring; (D) wrinkle; (E) mottled; (F) hat; (G) fuzzy; (H) revertant smooth. Reprinted from reference 72 with permission.
Isolates from sequential episodes of recurrent vaginal candidiasis caused by a single strain. (A) The original large-colony phenotype in episode 1. (B) The small- and medium-sized-colony phenotype in episode 2. DNA fingerprinting with probe Ca3 demonstrated that all colonies represented the same strain. Plating experiments demonstrated that smalland medium-sized-colony phenotype cells switched back to the large- colony phenotype. Reprinted from reference 82 .
Isolates from sequential episodes of recurrent vaginal candidiasis caused by a single strain. (A) The original large-colony phenotype in episode 1. (B) The small- and medium-sized-colony phenotype in episode 2. DNA fingerprinting with probe Ca3 demonstrated that all colonies represented the same strain. Plating experiments demonstrated that smalland medium-sized-colony phenotype cells switched back to the large- colony phenotype. Reprinted from reference 82 .
Summary of carriage of Candida spp. in 17 body locations of 52 healthy young women a
Summary of carriage of Candida spp. in 17 body locations of 52 healthy young women a
Proportions of posthysterectomy patients carrying bacteria and yeast a
Proportions of posthysterectomy patients carrying bacteria and yeast a
Species and intensities of carriage in healthy individuals over 70 years of age a
Species and intensities of carriage in healthy individuals over 70 years of age a
Microevolution in commensal and pathogenic populations revealed by C1 fingerprinting of C. albicans a
Microevolution in commensal and pathogenic populations revealed by C1 fingerprinting of C. albicans a