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P M Daggett

Publications and source records attributed to P M Daggett.

10 recordsLinked to original sources
PubMed1985

A molecular approach to the phylogeny of Acanthamoeba.

Isoenzyme electrophoresis of three different enzyme systems was used to compare 71 strains assigned to the 15 currently recognized species of Acanthamoeba. A phylogenetic (cladistic) analysis of the zymograms indicated an arrangement of strains in 15 distinguishable lineages, but not all corresponding to current taxonomic assignments. Five of the groups corresponded to the recognized species A. castellanii, A. culbertsoni, A. griffini, A. lenticulata and A. royreba. But none of these groups consisted of only strains which had been previously assigned to each respective species. The type-equivalent strains for two species, A. hatchetti and A. tubiashi, were not closely aligned to any other strain and thus are considered to be monotypic. Strains of A. triangularis, A. astronyxis and A. palestinensis occurred together in a single group suggesting possible synonymy; however, on morphologic criteria, the strains assigned to these species are readily distinguishable. Strains assigned to A. polyphaga and A. rhysodes were interspersed throughout the other species groups. The strains of these two species were either misidentified or the species could not be recognized. Two groups previously not recognized as unique formed distinctive clusters which could be considered as new species. The analysis also made it possible to place strains which had previously been identified only to genus into species complexes. These results therefore suggest that previous criteria which have been used to classify Acanthamoeba are not adequate for fully resolving taxa at the species level.

Amoeba↗
PubMed1983

The biochemical identification of vahlkampfiid amoebae.

Isoenzyme electrophoresis of three different enzymes was used to compare 16 strains of vahlkampfiid amoebae and a strain identified as a slime mold. The strain designated as an Echinostelium sp. was found to be an isolate of Naegleria fowleri on the basis of zymogram type and other characters, confirming Cursons & Brown's similar conclusion drawn in 1975. The N. fowleri strains examined expressed the typical zymograms of the species. The N. gruberi strains in this study presented two distinctive groups of patterns that were different from the two previously reported types for N. gruberi. Each of the remaining species studied formed single distinctive groups by which they could be identified.

Acid Phosphatase↗
PubMed1983

Chemically defined media for the cultivation of Naegleria: pathogenic and high temperature tolerant species.

Chemically defined minimal media for the cultivation of high temperature tolerant and pathogenic Naegleria spp. have been developed. A defined minimal medium, identical for N. fowleri and N. lovaniensis, consists of eleven amino acids (arginine, glycine, histidine, isoleucine, leucine, methionine, phenylalanine, proline, threonine, tryptophan, and valine), six vitamins (biotin, folic acid, hemin, pyridoxal, riboflavin, and thiamine), guanosine, glucose, salts, and metals. Three of the four strains of Naegleria fowleri tested (ATCC 30100, ATCC 30863, and ATCC 30896) and two strains of N. lovaniensis (ATCC 30467 and ATCC 30569) could be cultured beyond ten subcultures on this medium. For N. fowleri ATCC 30894 diaminopimelic acid, or lysine, or glutamic acid was also required. Mean generation time was reduced and population density increased for all strains with the introduction of glutamic acid. Glucose could be eliminated from the minimal medium only if glutamic acid was present. Without glucose, mean generation time increased and population density decreased. Diaminopimelic acid could substitute for lysin for ATCC 30894, indicating that Naegleria species may synthesize their lysine via the DAP pathway. Naegleria fowleri ATCC 30100 could be adapted to grow without serine or glycine in the minimal medium with glutamic acid added, but with mean generation time increased and population density decreased. The strain could be grown in the minimal medium in the absence of metals. For growth of N. australiensis ATCC 30958, modification of the medium by increasing metals ten-fold, substituting guanine for guanosine and adding lysine, glutamic acid, and six vitamins (p-aminobenzoic acid, choline chloride, inositol, vitamin B12, nicotinamide, and Ca pantothenate) was required.

Amino Acids↗
PubMed1980

Method for coding data on protozoan strains for computers.

Traditionally, observations on the nature of protozoa have been published in periodicals or books, or remain buried in research notebooks. The retrieval and processing of information on a particular species or strain are dependent solely upon individual investigators. Although various modern methods have been applied to the study of protozoa, no attempt has been made to develop a system with which information on protozoan strains can be stored, retrieved easily, and processed for various analyses by computer technology. Based upon an existing system for encoding data on bacterial strains, a complementary system applicable to protozoan strains was developed and is described herein.

Animals↗
PubMed1979

Starch gel electrophoresis: an effective method for separation of pathogenic and nonpathogenic Naegleria strains.

Isoenzyme electrophoresis of 7 different enzyme systems was used to compare 24 strains of Naegleria fowleri and 6 strains of N. gruberi. The 30 strains could be grouped into 4 distinct categories based upon zymogram patterns. No interstrain band variation in all enzyme systems was demonstrated in pathogenic strains of N. fowleri. Three nonpathogenic high temperature-tolerant strains of Naegleria had similar zymograms. Four of the 5 remaining nonpathogenic Naegleria strains had no interstrain band variation. Based upon zymograms, the 22 pathogenic strains constitute a homogenous species. Similarly the high temperature-tolerant nonpathogenic strains formed a cohesive group. The remaining nonpathogenic strains could be separated into 2 groups.

Acid Phosphatase↗
PubMedDate not supplied

Naegleria and Acanthamoeba infections: review.

Infections caused by small, free-living amebas are still unfamiliar to many clinicians, pathologists, and laboratorians. As of 31 July 1989, more than 140 cases of primary amebic meningoencephalitis caused by Naegleria fowleri and more than 40 cases of granulomatous amebic encephalitis caused by Acanthamoeba species (including two cases in patients with AIDS) and possibly by other free-living amebas had occurred worldwide. The recent increase in acanthamoeba keratitis (more than 200 cases), especially in contact lens wearers, has generated new interest in this group of amebas. Effective treatment is still lacking. Risk factors, clinical manifestations, and laboratory parameters helpful in the recognition of infections of the central nervous system (i.e., granulomatous amebic encephalitis and primary amebic meningoencephalitis) and acanthamoeba keratitis are reviewed.

Acanthamoeba↗