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Biomedical subjects

W D Grant

Publications and source records attributed to W D Grant.

At least 19 recordsLinked to original sources
PubMed2006

Halovivax asiaticus gen. nov., sp. nov., a novel extremely halophilic archaeon isolated from Inner Mongolia, China.

Strain EJ-46T, a novel pleomorphic, aerobic, extremely halophilic member of the Archaea was isolated from sediment of the saline Lake Ejinor, in Inner Mongolia, China. This organism was neutrophilic and required at least 15 % (2.5 M) NaCl for growth. MgCl2 was not required. The isolate was able to grow at pH 6.0-9.0. Optimum growth occurred in media containing 20 % (3.4 M) NaCl at pH 7.0-7.5. Polar lipid analysis revealed the presence of phosphatidylglycerol and phosphatidylglycerol phosphate methyl ester, derived from both C20C20 and C20C25 glycerol diethers. Four glycolipids were detected, one of which may be novel. The DNA G+C content was 60.3 mol%. 16S rRNA gene analysis revealed that strain EJ-46T was a member of the phylogenetic group defined by the family Halobacteriaceae, and the highest 16S rRNA gene similarity values of 94.9 and 94.8 % were obtained with the haloalkaliphilic species of the genus Natronococcus, Natronococcus occultus and Natronococcus amylolyticus, respectively. Based on the phenotypic, genotypic and phylogenetic analyses, it is proposed that the novel isolate should be classified as representing a new genus and species, for which the name Halovivax asiaticus gen. nov., sp. nov. is proposed. The type strain is EJ-46T (=CGMCC 1.4248T = CECT 7098T).

China↗
PubMed2006

Gracilibacillus orientalis sp. nov., a novel moderately halophilic bacterium isolated from a salt lake in Inner Mongolia, China.

Three Gram-positive, moderately halophilic, spore-forming rods, designated XH-63T, XH-62 and EJ-15, were isolated from two salt lakes located near Xilin Hot and Ejinor, in Inner Mongolia, China. The strains were strictly aerobic and motile, with spherical, terminal and deforming endospores. They grew at pH 5.0-9.0 (optimal growth at pH 7.5), between 4 and 45 degrees C (optimal growth at 37 degrees C) and at salinities of 1-20% (w/v) total salts, growing optimally at 10% (w/v) salts. They had meso-diaminopimelic acid in the cell wall peptidoglycan and DNA G + C contents of 36.1-37.1 mol%. The polar lipid pattern of strain XH-63T, selected as the representative strain, consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, and a phospholipid and two amino phospholipids of unknown structure. This strain possessed anteiso-C(15:0) and anteiso-C(17:0) as the major fatty acids (altogether representing 72.5% of total) and MK-7 as the major menaquinone. 16S rRNA gene analysis of the three strains showed that they were within the Gracilibacillus cluster, with highest sequence similarity (95.4-95.8%) with Gracilibacillus dipsosauri. Based on a combination of phenotypic, chemotaxonomic and phylogenetic features, it is proposed that the three isolates represent a novel species of the genus Gracilibacillus, Gracilibacillus orientalis sp. nov. The type strain is strain XH-63T (= CCM 7326T = AS 1.4250T = CECT 7097T).

Bacillaceae↗
PubMed2006

Halostagnicola larsenii gen. nov., sp. nov., an extremely halophilic archaeon from a saline lake in Inner Mongolia, China.

Strain XH-48(T) was isolated from the sediment of Lake Xilinhot, a saline lake in Inner Mongolia (China). The organism is pleomorphic, neutrophilic and requires at least 2.5 M (15 %) NaCl, but not MgCl(2), for growth; it exhibits optimal growth at 3.4 M (20 %) NaCl. The G+C content of its DNA is 61 mol%. 16S rRNA gene sequence analysis revealed that strain XH-48(T) is a member of the family Halobacteriaceae, but there were low levels of similarity with other members of this family. The highest sequence similarity values (94.5 and 93.3 %) were obtained with the 16S rRNA genes of Natrialba aegyptiaca and Natrialba asiatica, respectively. Polar lipid analyses revealed that strain XH-48(T) contains phosphatidylglycerol and phosphatidylglyceromethylphosphate, derived from both C(20)C(20) and C(20)C(25) glycerol diethers, and two unidentified glycolipids. On the basis of the data obtained, the novel isolate cannot be classified within any recognized genus. Strain XH-48(T) should be placed within a novel genus and species within the family Halobacteriaceae, order Halobacteriales, for which the name Halostagnicola larsenii gen. nov., sp. nov. is proposed. The type strain of Halostagnicola larsenii is strain XH-48(T) (=DSM 17691(T)=CGMCC 1.5338(T)=JCM 13463(T)=CECT 7116(T)).

Aerobiosis↗
PubMed2006

Halorubrum orientale sp. nov., a halophilic archaeon isolated from Lake Ejinor, Inner Mongolia, China.

A motile, pleomorphic, red-pigmented archaeon, strain EJ-52T, was isolated from water from Lake Ejinor, a saline lake in Inner Mongolia, China. Analysis of the almost-complete 16S rRNA gene sequence showed that the isolate was phylogenetically related to species of the genus Halorubrum, being most closely related to Halorubrum saccharovorum ATCC 29252T (96.1% sequence similarity), Halorubrum lacusprofundi JCM 8891T (95.9%), Halorubrum tibetense AS 1.3239T (95.2%), Halorubrum alcaliphilum AS 1.3528T (95.2%) and Halorubrum vacuolatum JCM 9060T (95.1%). The polar lipids of strain EJ-52T were C20C20 derivatives of phosphatidylglycerol phosphate and phosphatidylglycerol phosphate methyl ester and a sulfated diglycosyl diether. Strain EJ-52T requires at least 2.5 M NaCl for growth and grows optimally at 3.4 M NaCl. The strain grows at 25-50 degrees C, with optimal growth occurring at 35-45 degrees C. Mg2+ is not required. The DNA G+C content is 64.2 mol%. On the basis of the data obtained in this study, strain EJ52T represents a novel species, for which the name Halorubrum orientale sp. nov. is proposed. The type strain is EJ-52T (=CECT 7145T=JCM 13889T=CGMCC 1.6295T).

Base Composition↗
PubMed2006

Natrinema ejinorense sp. nov., isolated from a saline lake in Inner Mongolia, China.

A Gram-negative, non-motile, neutrophilic, pleomorphic and extremely halophilic archaeon, strain EJ-57T, was isolated from saline Lake Ejinor in Inner Mongolia, China. Strain EJ-57T was able to grow at 25-50 degrees C, required at least 1.8 M NaCl for growth (optimum at 3.4 M NaCl) and grew over a pH range from 6.0 to 8.5 (optimum at pH 7.0). Hypotonic treatment with less than 1.5 M NaCl caused cell lysis. Analysis of the almost complete 16S rRNA gene sequence indicated that the isolate represented a member of the genus Natrinema in the family Halobacteriaceae. Strain EJ-57T was most closely related to Natrinema versiforme JCM 10478T (96.2% sequence similarity), Natrinema pallidum NCIMB 777T (95.9% sequence similarity), Natrinema altunense JCM 12890T (95.8% sequence similarity) and Natrinema pellirubrum NCIMB 786T (95.5 % sequence similarity). However, DNA-DNA hybridization experiments showed that strain EJ-57T was not related to these species, with levels of DNA-DNA relatedness equal to or below 39%. The major polar lipids of the isolate were C20C20 and C20C25 derivatives of phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester and the disulfated glycolipid S2-DGA-1. The G+C content of the genomic DNA was 64.7 mol%. Comparative analysis of phenotypic characteristics between strain EJ-57T and recognized Natrinema species supported the conclusion that EJ-57T represents a novel species within this genus, for which the name Natrinema ejinorense sp. nov. is proposed. The type strain is EJ-57T (=CECT 7144T=JCM 13890T=CGMCC 1.6202T).

Base Composition↗
PubMed2004

Life at low water activity.

Two major types of environment provide habitats for the most xerophilic organisms known: foods preserved by some form of dehydration or enhanced sugar levels, and hypersaline sites where water availability is limited by a high concentration of salts (usually NaCl). These environments are essentially microbial habitats, with high-sugar foods being dominated by xerophilic (sometimes called osmophilic) filamentous fungi and yeasts, some of which are capable of growth at a water activity (a(w)) of 0.61, the lowest a(w) value for growth recorded to date. By contrast, high-salt environments are almost exclusively populated by prokaryotes, notably the haloarchaea, capable of growing in saturated NaCl (a(w) 0.75). Different strategies are employed for combating the osmotic stress imposed by high levels of solutes in the environment. Eukaryotes and most prokaryotes synthesize or accumulate organic so-called 'compatible solutes' (osmolytes) that have counterbalancing osmotic potential. A restricted range of bacteria and the haloarchaea counterbalance osmotic stress imposed by NaCl by accumulating equivalent amounts of KCl. Haloarchaea become entrapped and survive for long periods inside halite (NaCl) crystals. They are also found in ancient subterranean halite (NaCl) deposits, leading to speculation about survival over geological time periods.

Adaptation, Physiological↗
PubMed2004

Isolation of haloarchaea that grow at low salinities.

Summary Archaea, the third domain of life, were long thought to be limited to environmental extremes. However, the discovery of archaeal 16S rRNA gene sequences in water, sediment and soil samples has called into question the notion of Archaea as obligate extremophiles. Until now, none of these novel Archaea has been brought into culture, a critical step for discovering their ecological roles. We have cultivated three novel halophilic Archaea (haloarchaea) genotypes from sediments in which the pore-water salinity was close to that of sea water. All previously reported haloarchaeal isolates are obligate extreme halophiles requiring at least 9% (w/v) NaCl for growth and are typically the dominant heterotrophic organisms in salt and soda lakes, salt deposits and salterns. Two of these three newly isolated genotypes have lower requirements for salt than previously cultured haloarchaea and are capable of slow growth at sea-water salinity (2.5% w/v NaCl). Our data reveal the existence of Archaea that can grow in non-extreme conditions and of a diverse community of haloarchaea existing in coastal salt marsh sediments. Our findings suggest that the ecological range of these physiologically versatile prokaryotes is much wider than previously supposed.

Base Sequence↗
PubMed2003

Low back pain in Australian adults: the economic burden.

This paper reports the results of a "cost-of-illness" study of low back pain (LBP) in Australian adults. It estimates the direct cost of LBP in 2001 to be AU dollars 1.02 billion. Approximately 71% of this amount is for treatment by chiropractors, general practitioners, massage therapists, physiotherapists and acupuncturists. However, the direct costs are minor compared to the indirect costs of AU dollars 8.15 billion giving a total cost of AU dollars 9.17 billion. LBP in Australian adults represents a massive health problem with a significant economic burden. This burden is so great that it has compelling and urgent ramifications for health policy, planning and research. This study identifies that research should concentrate on both direct but particularly the indirect costs including cost-effective management regimes that encourage an early return to duties.

Adult↗
PubMed2001

Natrialba hulunbeirensis sp. nov. and Natrialba chahannaoensis sp. nov., novel haloalkaliphilic archaea from soda lakes in Inner Mongolia Autonomous Region, China.

Two haloalkaliphilic archaeal strains, X21T and C112T, were isolated from soda lakes in Inner Mongolia Autonomous Region, China. Their morphology, physiology, biochemical features, polar lipid composition and 16S rRNA genes were characterized in order to elucidate their taxonomy. According to these data, strains X21T and C112T belong to the genus Natrialba, although there are clear differences with respect to their physiology and polar lipid composition between the two strains and the type species, Natrialba asiatica. On the basis of low DNA-DNA hybridizations, these two strains should be considered as new species of genus Natrialba. The names Natrialba hulunbeirensis sp. nov. (type strain X21T = AS 1.1986T = JCM 10989T) and Natrialba chahannaoensis sp. nov. (type strain C112T = AS 1.1977T = JCM 10990T) are proposed.

Base Composition↗
PubMed2001

Are fluid-based cytologies superior to the conventional Papanicolaou test? A systematic review.

OBJECTIVE: We compared fluid-based cytologies (FBC) with conventional Papanicolaou (Pap) tests (CT) to determine if either is superior. STUDY DESIGN: This was a systematic review of original research reports evaluating both CT and FBC with respect to specimen adequacy, comparison with a reference standard, or both. Two reviewers independently reviewed the titles, abstracts, and full articles to determine inclusion status, with differences resolved by consensus with a third author. Risk differences (RD) between occurrence rates for FBC and CT were used for the specimen adequacy data. Sensitivity and specificity were pooled independently and weighted by the inverse of the variance using a random effects model. DATA SOURCES: Studies published between 1985 and November 1999 were identified from MEDLINE, Best Evidence, EMBASE, Biological Abstracts/RRM, and The Cochrane Library. OUTCOMES MEASURED: Sensitivity, specificity, area under the receiver operating characteristic curve (AuROC), and the proportion of satisfactory, unsatisfactory, and "satisfactory but limited by" test results were measured. RESULTS: There was no significant difference in AuROC (P = .37). FBC specimens were more likely to be satisfactory (RD=0.06; 95% confidence interval [CI], 0.03-0.09) or to have absent endocervical cells (RD=0.06; 95% CI, 0.02-0.10) but had 10% fewer "satisfactory but limited by - other" reports (RD = -0.10; 95% CI, -0.14 to -0.06). There was no difference in unsatisfactory Pap test results. CONCLUSIONS: For most women there is no reason to replace CT with FBC. For women at high risk of cervical cancer or who are screened infrequently, the possible increase in FBC sensitivity may outweigh the potential harms from additional false positives.

Confidence Intervals↗
PubMed2000

Halomonas magadii sp. nov., a new member of the genus Halomonas, isolated from a soda lake of the East African Rift Valley.

A number of novel alkaliphilic organotrophic bacteria have been isolated from several saline and alkaline East African soda lakes. The new isolates grow at pH values between 7.0 and 11.0, with pH optima for growth between 9.0 and 10.0. Growth occurs at total salts concentration between 0% and 20% (w/v) with optimum at 0%-7% (w/v). Phylogenetic analyses based on 16S rDNA sequence comparison indicate that these isolates are related (>96% similarity) to members of the Halomonadaceae within the gamma-3 subdivision of the Proteobacteria. These analyses indicate that existing species within the Halomonadaceae fell within three main groups, one group comprising the type species of Halomonas, Halomonas elongata, and a number of other known species including one soda lake isolate. A second group constituting most of the remaining known species of Halomonas and related Chromohalobacter spp. includes 3 soda lake isolates with high DNA-DNA homologies. The third group included Halomonas halodenitrificans, Halomonas desiderata, Halomonas cupida, and 13 soda lake isolates. Phenotypic comparisons indicated that the majority of soda lake strains shared similar morphological, phenotypic, and chemotaxonomic properties to known strains of Halomonas but grew under alkaline conditions. The 3 soda lake isolates with high DNA-DNA homologies were, however, significantly different in antibiotic sensitivity pattern and in the utilization of several substrates, were unable to reduce nitrite, and showed low DNA-DNA homologies with known halomonads in the same group. We propose that these isolates comprise a new species of the genus Halomonas that we name Halomonas magadii sp. nov. The type strain is strain 21 MI (NCIMB 13595).

Africa↗
PubMed1999

Novel plasmids from alkaliphilic halomonads.

Seventeen alkaliphilic halomonads were examined for the presence of plasmids. Of these, eight strains harbored one or more from 5.3 to 33 kb in size, the first plasmids to be identified from an alkaliphilic halomonad source. Restriction and hybridization analysis revealed three strains that maintained an identical 5.9-kb plasmid which we named pAH1, two that had an identical 33-kb plasmid, and three others, of which one carried two plasmids of 5.3 and 15 kb, the former being designated pAH2. The two final strains maintained plasmids of 15 and 20.5 kb. Restriction mapping of both pAH1 and pAH2 indicated that they have a number of unique restriction sites and are of a small enough size to make them suitable for vector construction.

DNA, Archaeal↗
PubMed1999

Novel archaeal phylotypes from an East African alkaline saltern.

DNA has been extracted on site from the brines of the final crystallizing pond of an alkaline saltern at Lake Magadi, Kenya. Amplification of 16S rRNA genes followed by cloning, sequencing, and phylogenetic analysis has revealed the presence of two distinct new archaeal lineages. The majority of cloned sequences showed greater than 95% identity to each other, but only 88%-90% similarity to any cultivated haloalkaliphilic Archaea, and form a distinct cluster within the known Haloarchaea. Two cloned genes showed close similarity to each other but only 76% similarity to any known archaeal sequence, and therefore represent a distinct phylotype only distantly related to the euryarchaeotal branch of the Archaea.

Africa, Eastern↗
PubMed1999

Lipid membranes from halophilic and alkali-halophilic Archaea have a low H+ and Na+ permeability at high salt concentration.

The influence of pH and the salt concentration on the proton and sodium ion permeability of liposomes formed from lipids of the halophile Halobacterium salinarum and the haloalkaliphile Halorubrum vacuolatum were studied. In contrast with liposomes formed from Escherichia coli lipids, liposomes formed from halophilic lipids remained stable up to 4M of NaCl and KCl. The proton permeability of the liposomes from lipids of halophiles was independent of the salt concentration and was essentially constant between pH 7 and pH 9. The sodium ion permeability increased with the salt concentration but was 10- to 100 fold lower than the proton permeability. It is concluded that the membranes of halophiles are stable over a wide range of salt concentrations and at elevated pH values and are well adapted to the halophilic conditions.

Archaea↗
PubMed1999

Structure determination of an exopolysaccharide from an alkaliphilic bacterium closely related to Bacillus spp.

An exopolysaccharide obtained from an alkaliphilic bacterium closely related to Bacillus spp. was found to contain D-galactopyranuronic acid (GalpA), 2,4-diacetamido-2,4,6-trideoxy-D-glucopyranose (QuipNAc4NAc), 2-acetamido-2-deoxy D-mannopyranuronic acid (ManpNAcA) and one uncommon unit of D-galactopyranuronic acid with the carboxyl group amide-linked to glycine [GalpA(Gly)]. The polysaccharide was studied by one-dimensional and two-dimensional 1H-NMR and 13C-NMR spectroscopy both on native polysaccharide and on monosaccharides and oligosaccharides obtained from methanolysis and from anhydrous HF solvolysis. The following linear structure of the repeating unit was established: -->3)-alpha-D-GalpA(Gly)-(1-->4)-beta-D-ManpNAcA-(1-->4)-alp ha-D-Galp A-(1-->3)-alpha-D-QuipNAc4NAc-(1-->. A preliminary phylogenetic assignment for the bacterium is also reported.

Bacillus↗
PubMed1998

Recognizing occupational disease--taking an effective occupational history.

Occupational exposures contribute to the morbidity and mortality of many diseases. However, occupational diseases continue to be underrecognized even though they are responsible for an estimated 860,000 illnesses and 60,300 deaths each year. Family physicians can play an important role in improving the recognition of occupational disease, preventing progressive illness and disability in their own patients, and contributing to the protection of other workers similarly exposed. This role can be maximized if physicians raise their level of suspicion for workplace disease, develop skills in taking occupational histories and establish routine access to occupational health resources.

Adult↗
PubMed1998

Microbial diversity of soda lakes.

Soda lakes are highly alkaline extreme environments that form in closed drainage basins exposed to high evaporation rates. Because of the scarcity of Mg2+ and Ca2+ in the water chemistry, the lakes become enriched in CO3(2-) and Cl-, with pHs in the range 8 to > 12. Although there is a clear difference in prokaryotic communities between the hypersaline lakes where NaCl concentrations are > 15% w/v and more dilute waters, i.e., NaCl concentrations about 5% w/v, photosynthetic primary production appears to be the basis of all nutrient recycling. In both the aerobic and anaerobic microbial communities the major trophic groups responsible for cycling of carbon and sulfur have in general been identified. Systematic studies have shown that the microbes are alkaliphilic and many represent separate lineages within accepted taxa, while others show no strong relationship to known prokaryotes. Although alkaliphiles are widespread it seems probable that these organisms, especially those unique to the hypersaline lakes, evolved separately within an alkaline environment. Although present-day soda lakes are geologically quite recent, they have probably existed since archaean times, permitting the evolution of independent communities of alkaliphiles since an early period in the Earth's history.

Archaea↗