Halorubrum kocurii sp. nov., an archaeon isolated from a saline lake.

A Gram-negative, non-motile, neutrophilic, rod-shaped, extremely halophilic archaeon, designated strain BG-1(T), was isolated from a salt lake, Lake Bagaejinnor, in Inner Mongolia, China. Strain BG-1(T) was able to grow at 25-55 degrees C, required at least 2.5 M NaCl for growth (with an optimum at 3.4 M NaCl) and grew at pH 6.0-9.0 (with an optimum at pH 7.5). Hypotonic treatment with less than 2.0 M NaCl caused cell lysis. Phylogenetic analysis of the almost-complete 16S rRNA gene sequence positioned the isolate within the genus Halorubrum in the family Halobacteriaceae. Strain BG-1(T) was most closely related to Halorubrum aidingense 31-hong(T) (98.8% sequence similarity), Halorubrum saccharovorum NCIMB 2081(T) (98.6%), Halorubrum lacusprofundi ACAM 34(T) (98.6%) and Halorubrum lipolyticum 9-3(T) (98.4%). However, values for DNA-DNA hybridization between strain BG-1(T) and the most closely related members of the genus Halorubrum were below 40%. Analysis of the polar lipids of strain BG-1(T) revealed the presence of mannosyl-2-sulfate-(1-4)-glycosyl-archaeol, the main glycolipid found in neutrophilic species of the genus Halorubrum. The G+C content of the genomic DNA was 69.4 mol% (T(m)). Comparison of the phenotypic characteristics of the strain with those of Halorubrum species supported the conclusion that BG-1(T) represents a novel species within this genus, for which the name Halorubrum kocurii sp. nov. is proposed. The type strain is BG-1(T) (=CECT 7322(T) =CGMCC 1.7018(T) =JCM 14978(T)).

Aquisalibacillus elongatus gen. nov., sp. nov., a moderately halophilic bacterium of the family Bacillaceae isolated from a saline lake.

A novel moderately halophilic, non-motile, rod-shaped bacterium was isolated from a saline lake, Lake Shangmatala, in the Inner Mongolia Autonomous Region, China. This bacterium, designated SH4sT, was strictly aerobic, catalase-positive and oxidase-negative. It grew at salinities of 3-20 % (w/v) NaCl, with an optimum at 10 % (w/v) NaCl. The cell-wall peptidoglycan was of the A4beta type, based on l-Orn-d-Asp, and the major quinone was a menaquinone with seven isoprene units (MK-7). The major fatty acids were iso-C16:0 and iso-C15:0. The polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, a glycolipid and four different unidentified phospholipids. The DNA G+C content was 45.9 mol%. In a maximum-parsimony phylogenetic tree based on 16S rRNA gene sequences, strain SH4sT was found to belong to the family Bacillaceae and to be most closely related to members of the genera Filobacillus (95.9 % sequence similarity), Piscibacillus (95.7 %) and Tenuibacillus (95.4 %). DNA-DNA hybridization experiments revealed 10 % relatedness (12 %, reciprocally) between strain SH4sT and Filobacillus milosensis DSM 13259T, the sole species of the genus. All of these data show that strain SH4sT represents a novel genus and species in the family Bacillaceae, for which the name Aquisalibacillus elongatus gen. nov., sp. nov. is proposed. The type strain of Aquisalibacillus elongatus is SH4sT (=CCM 7366T =CECT 7149T =DSM 18090T).

Sediminibacillus halophilus gen. nov., sp. nov., a moderately halophilic, Gram-positive bacterium from a hypersaline lake.

A Gram-positive, moderately halophilic bacterium, designated strain EN8d(T), was isolated from sediment from Lake Erliannor in the Inner Mongolia Autonomous Region, China. Cells were facultatively anaerobic, rod-shaped and motile and did not display endospore formation. Isolate EN8dT grew in a complex medium supplemented with 0-20 % (w/v) marine salts (optimally at 5-7.5 %, w/v). Phylogenetic analysis based on 16S rRNA gene sequence comparisons showed that strain EN8dT was a member of the family Bacillaceae, belonging to a cluster with Thalassobacillus (96.3 % gene sequence similarity) and Halobacillus (95.0-96.0 %), albeit emerging as an independent lineage from members of these two genera. Strain EN8dT contained cell-wall peptidoglycan based on meso-diaminopimelic acid and possessed MK-7 as the major respiratory isoprenoid quinone. The major fatty acids were anteiso-C15:0 and anteiso-C17:0. The polar lipid pattern consisted of diphosphatidylglycerol, phosphatidylglycerol and an unidentified glycolipid. The DNA G+C content was 47.5 mol%. Strain EN8dT could be clearly differentiated from its phylogenetic neighbours on the basis of several phenotypic, genotypic and chemotaxonomic features. Therefore strain EN8dT is considered to represent a novel genus and species, for which the name Sediminibacillus halophilus gen. nov., sp. nov. is proposed. The type strain of Sediminibacillus halophilus is EN8dT (=CCM 7364T =CECT 7148T =CGMCC 1.6199T =DSM 18088T).

Conjunctivitis outbreak among divers.

In March 2006, an outbreak of conjunctivitis that occurred over a six day period among twenty-nine individuals who partook in recreational scuba diving trips on two boats off Vitu Levu Island, Fiji. We investigated the likelihood that a communal container used to store diving masks facilitated the spread of conjunctivitis among individuals. The diagnosis of conjunctivitis was based on clinical assessment by a physician. Transmission of conjunctivitis from person to person was documented with eventual identification of the index case, the dive master, a Fijian resident. Topical antibiotics were dispensed accordingly and detergent and bleach were used as mask cleaning agents in an effort to control the outbreak. Follow up surveys were mailed to all twenty-nine participants. Ultimately, fourteen cases of conjunctivitis were documented (46.7%). Eleven cases were verified during the six days in Fiji, two upon arrival back in the U.S., and one case of familial transmission in the U.S. All but two cases resolved within one week. Unknown to these divers was a coincidental, generalized outbreak of acute haemorrhagic conjunctivitis among the Fijian Residents. The communal container used to store diving masks was the likely vector for the spread of infectious conjunctivitis, the first such documented outbreak involving communal diving equipment.

Halorubrum luteum sp. nov., isolated from Lake Chagannor, Inner Mongolia, China.

A novel halophilic archaeon, strain CGSA15(T), was isolated from water of Lake Chagannor in China. The strain grew optimally at 33-37 degrees C, pH 9.5-10.0 and 4.0-4.3 M NaCl. The major polar lipids were phosphatidylglycerol and phosphatidylglycerol phosphate methyl ester. The genomic DNA G+C content of strain CGSA15(T) was 60.2 mol%. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain CGSA15(T) was a member of the genus Halorubrum and was related most closely to Halorubrum alkaliphilum AS 1.3528(T) (96.1 % similarity) and Halorubrum tibetense AS 1.3239(T) (96.9 %). Levels of DNA-DNA relatedness between strain CGSA15(T) and Hrr. alkaliphilum AS 1.3528(T) and Hrr. tibetense AS 1.3239(T) were 36.7 and 28.9 %, respectively. According to the phenotypic and genotypic data presented, strain CGSA15(T) is considered to represent a novel species of the genus Halorubrum, for which the name Halorubrum luteum sp. nov. is proposed. The type strain is CGSA15(T) (=CGMCC 1.6783(T) =CECT 7303(T)).

Halorubrum ejinorense sp. nov., isolated from Lake Ejinor, Inner Mongolia, China.

A novel halophilic archaeon, strain EJ-32T, was isolated from water from Lake Ejinor in Inner Mongolia, China. The taxonomy of strain EJ-32T was studied by using a polyphasic approach. On the basis of 16S rRNA gene sequence similarities, strain EJ-32T was shown to be phylogenetically related to Halorubrum coriense (97.9%), Halorubrum trapanicum (97.9%), Halorubrum sodomense (97.8%), Halorubrum tebenquichense (97.8%), Halorubrum xinjiangense (97.6%), Halorubrum terrestre (97.4%), Halorubrum distributum (97.1%) and Halorubrum saccharovorum (96.4%). Strain EJ-32T was found to be neutrophilic, non-motile and Gram-negative. It grew in medium containing saturation concentrations of NaCl and did not require magnesium for optimal growth. The G+C content of the DNA is 64.0 mol%. Values for DNA-DNA hybridization with respect to phylogenetically related Halorubrum species were

Salsuginibacillus kocurii gen. nov., sp. nov., a moderately halophilic bacterium from soda-lake sediment.

A Gram-positive, endospore-forming, alkali-tolerant, moderately halophilic bacterium, designated strain CH9d(T), was isolated from the sediment of Lake Chagannor in the Inner Mongolia Autonomous Region, China. The cells were rod-shaped and motile. Isolate CH9d(T) grew at pH 5.8-10.0 (optimally at pH 8.5), at salinities of 3-20 % (w/v) marine salts (optimally at 10.0 %, w/v) and between 20 and 50 degrees C (optimally at 37 degrees C). The cell wall contained meso-diaminopimelic acid and the major respiratory isoprenoid quinone was MK-7. The predominant cellular fatty acids of strain CH9d(T) were anteiso-C(15 : 0), anteiso-C(17 : 0), iso-C(17 : 0) and iso-C(15 : 0) and its polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and two unknown phospholipids. The G+C content of the DNA was 44.7 mol%. Strain CH9d(T) exhibited a 16S rRNA gene sequence similarity value of only 91 % with respect to Thalassobacillus devorans DSM 16966(T) and showed values below 91 % with respect to members of the genera Bacillus, Halobacillus and Marinococcus. Strain CH9d(T) could be clearly differentiated from its closest phylogenetic neighbours on the basis of several phenotypic, genotypic and chemotaxonomic features. Therefore, data from the polyphasic study support the placement of strain CH9d(T) in a novel genus and species, for which the name Salsuginibacillus kocurii gen. nov., sp. nov. is proposed. The type strain is CH9d(T) (=CCM 7365(T)=CECT 7154(T)=CGMCC 1.6287(T)=DSM 18087(T)).

Bacillus chagannorensis sp. nov., a moderate halophile from a soda lake in Inner Mongolia, China.

A Gram-positive, moderately halophilic, spore-forming bacterium, designated strain CG-15(T), was isolated from a soda lake, Lake Chagannor, in the Inner Mongolia Autonomous Region, China. The cells were found to be motile short rods with ellipsoidal, terminal and deforming endospores. Strain CG-15(T), a facultatively anaerobic bacterium, grew at pH 5.8-11.0 (optimally at pH 8.5), at 6-40 degrees C (optimally at 37 degrees C) and at salinities of 3-20 % (w/v) total salts (optimally at 7 % w/v). On the basis of the results of 16S rRNA gene sequence analysis, strain CG-15(T) was shown to belong to the genus Bacillus (phylum Firmicutes), showing the greatest phylogenetic similarity with respect to Bacillus saliphilus (96.0 %). The DNA G+C content of the novel isolate was found to be 53.8 mol%. The major cellular fatty acids of strain CG-15(T) were anteiso-C(15 : 0), iso-C(15 : 0) and anteiso-C(17 : 0), and its polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and three different unidentified phospholipids. The analysis of the quinones showed that MK-7 was the major menaquinone. The peptidoglycan type was A1gamma, with meso-diaminopimelic acid as the diagnostic diamino acid. On the basis of the data from this polyphasic study, strain CG-15(T) represents a novel species of the genus Bacillus, for which the name Bacillus chagannorensis sp. nov. is proposed. The type strain is CG-15(T) (=CCM 7371(T)=CECT 7153(T)=CGMCC 1.6292(T)=DSM 18086(T)).

Halopiger xanaduensis gen. nov., sp. nov., an extremely halophilic archaeon isolated from saline Lake Shangmatala in Inner Mongolia, China.

Strain SH-6(T) was isolated from the sediment of Lake Shangmatala, a saline lake in Inner Mongolia (China). Cells were pleomorphic. The organism was neutrophilic and required at least 2.5 M (15 %) NaCl, but not MgCl(2), for growth; optimal growth occurred at 4.3 M (25 %) NaCl. The G+C content of its DNA was 63.1 mol%. 16S rRNA gene sequence analysis revealed that strain SH-6(T) is a member of the family Halobacteriaceae, but there was a low level of similarity with other members of this family. Highest sequence similarity (94.6 %) was obtained with the 16S rRNA genes of the type strains of Natronolimnobius innermongolicus and Natronolimnobius baerhuensis. Polar lipid analyses revealed that strain SH-6(T) contains phosphatidylglycerol and phosphatidylglyceromethylphosphate, derived from both C(20)C(20) and C(20)C(25) glycerol diethers together with the glycolipid S(2)-DGD-1. On the basis of the data obtained, the new isolate could not be classified in any recognized genus. Strain SH-6(T) is thus considered to represent a novel species in a new genus within the family Halobacteriaceae, order Halobacteriales, for which the name Halopiger xanaduensis gen. nov., sp. nov. is proposed. The type strain of Halopiger xanaduensis is SH-6(T) (=CECT 7173(T)=CGMCC 1.6379(T)=JCM 14033(T)).

Halovivax ruber sp. nov., an extremely halophilic archaeon isolated from Lake Xilinhot, Inner Mongolia, China.

A Gram-negative, pleomorphic, extremely halophilic archaeon, designated strain XH-70(T), was isolated from the saline Lake Xilinhot, in Inner Mongolia, China. It formed small (0.9-1.5 mm), red-pigmented, elevated colonies on agar medium. The strain required at least 2.5 M NaCl and 5 mM Mg(2+) for growth. The 16S rRNA gene sequence analysis indicated that strain XH-70(T) belongs to the family Halobacteriaceae, showing 99.5 % similarity to the type strain of Halovivax asiaticus and 94.7 and 94.6 % similarity, respectively, to the type strains of Natronococcus amylolyticus and Natronococcus occultus. Polar lipid analysis supported the placement of strain XH-70(T) in the genus Halovivax. DNA-DNA hybridization studies (32 % with Halovivax asiaticus CGMCC 1.4248(T)), as well as biochemical and physiological characterization, allowed strain XH-70(T) to be differentiated from Halovivax asiaticus. A novel species, Halovivax ruber sp. nov., is therefore proposed to accommodate this strain. The type strain is XH-70(T) (=CGMCC 1.6204(T)=DSM 18193(T)=JCM 13892(T)).

Aquisalimonas asiatica gen. nov., sp. nov., a moderately halophilic bacterium isolated from an alkaline, saline lake in Inner Mongolia, China.

Two novel moderately halophilic, Gram-negative rods (strains CG12(T) and CG13) were isolated from Lake Chagannor in Inner Mongolia Autonomous Region, China. They were strictly aerobic and motile. They grew at pH 6.0-10.8 (optimally at pH 7.5-8.5), at 20-50 degrees C (optimally at 37 degrees C) and at salinities of 1-20 % (w/v) total salts (optimally at 7-10 %, w/v). Phylogenetic analysis of the two strains, based on a comparison of their 16S rRNA genes, led to their classification within the class Gammaproteobacteria, the closest recognized type strain being Alkalispirillum mobile DSM 12769(T), with which they were found to share 94.4-94.6 % sequence similarity. On the basis of DNA-DNA hybridization data (showing 100 and 99 % relatedness for each other), the two isolates were found to be members of the same species. The DNA G+C contents of strains CG12(T) and CG13 were found to be 63.6 and 64.0 mol%, respectively. The major cellular fatty acids of strain CG12(T), selected as the representative strain, were C(18 : 1)omega7c, C(16 : 0) and C(12 : 0), and its polar lipids consisted of phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, a phosphoglycolipid and six unidentified phospholipids. On the basis of the polyphasic evidence from this study, strains CG12(T) and CG13 represent a novel genus and species, for which the name Aquisalimonas asiatica gen. nov., sp. nov. is proposed. The type strain of Aquisalimonas asiatica is CG12(T) (=CCM 7368(T)=CECT 7151(T)=CGMCC 1.6291(T)=DSM 18102(T)).

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).

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).

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)).

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).

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).

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.

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.

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.

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.