Biomedical subjects

G Berg

Publications and source records attributed to G Berg.

At least 37 records · Page 2Linked to original sources

PubMed2001

Primary angioplasty versus intravenous thrombolysis in acute myocardial infarction: can we define subgroups of patients benefiting most from primary angioplasty? Results from the pooled data of the Maximal Individual Therapy in Acute Myocardial Infarction Registry and the Myocardial Infarction Registry.

OBJECTIVES: We sought to determine the effectiveness of primary angioplasty compared with thrombolysis in clinical practice. BACKGROUND: In clinical practice, primary angioplasty for the treatment of acute myocardial infarction (AMI) has not yet been proven more effective than intravenous thrombolysis, nor have subgroups of patients been identified who would perhaps benefit from primary angioplasty. METHODS: The pooled data of two AMI registries--the Maximal Individual TheRapy in Acute myocardial infarction (MITRA) study and the Myocardial Infarction Registry (MIR)--were analyzed. A total of 9,906 lytic-eligible patients with AMI, with a pre-hospital delay of < or =12 h, were treated with either primary angioplasty (n = 1,327) or thrombolysis (n = 8,579). RESULTS: Despite differences in the patients' characteristics and concomitant diseases between the two groups, the prevalence of adverse risk factors was balanced. Univariate analysis of hospital mortality showed a more favorable course for patients treated with primary angioplasty: 6.4% versus 11.3% (odds ratio [OR] 0.54, 95% confidence interval [CI] 0.43 to 0.67). This was confirmed by logistic regression analysis (multivariate OR 0.58, 95% CI 0.44 to 0.77). Primary angioplasty was associated with a lower mortality in all subgroups analyzed. We observed a significant correlation between mortality and absolute risk reduction (r = 0.82, p < 0.0001) in the different subgroups: as mortality increased, there was an increase in absolute benefit of primary angioplasty compared with thrombolysis. CONCLUSIONS: These large registry data showed the effect of primary angioplasty to be more favorable than thrombolysis for the treatment of patients with AMI in clinical practice. This effect was not restricted to special subgroups of patients. As mortality increased, the absolute benefit of primary angioplasty also increased.

Aged↗

PubMed2001

Gastrostomy tube leak in a patient receiving peritoneal dialysis.

Aggressive nutritional support is imperative to ensure an optimal quality of life in the management of children with end stage renal disease (ESRD). Supplemental enteral feeds using a gastrostomy tube (G-tube) are commonly used for nutritional support to overcome the barrier posed by anorexia. Some of the reported complications of G-tube feeds in children simultaneously receiving peritoneal dialysis include G-tube exit site infection with concomitant peritonitis and G-tube obstruction. We are reporting our experience in managing an 8-year-old Caucasian male with ESRD who, while receiving peritoneal dialysis and G-tube feeds, developed medically intractable peritonitis due to separation of the stomach wall from the anterior abdominal wall, resulting in peritoneal contamination with gastric contents. This complication, which has not previously been reported in patients receiving peritoneal dialysis, had devastating consequences, culminating in the death of our patient.

Child↗

PubMed2001

Prevalence of depressive symptoms in late pregnancy and postpartum.

BACKGROUND: Postnatal depression refers to a non-psychotic depressive episode that begins in or extends into the postpartum period. The aims of this study were to examine the prevalence of depressive symptoms in a pregnant and later postnatal population, to determine the natural course of these symptoms and whether there is an association between antenatal and postnatal depressive symptomatology. METHODS: A longitudinal study with a total population of 1,558 consecutively registered pregnant women in the southeast region of Sweden. Presence of depressive symptoms was measured with the Edinburgh Postnatal Depression Scale on four occasions namely in gestational week 35-36, in the maternity ward, 6-8 weeks and 6 months postpartum. RESULTS: The prevalence of depressive symptoms during late pregnancy was 17%; in the maternity ward 18%; 6-8 weeks postnatally 13%; and 6 months postnatally, 13%. A correlation between antenatal and postnatal depressive symptoms was found (r=0.50, p<0.0001). CONCLUSION: Detection of women at risk for developing postnatal depressive symptoms can be done during late pregnancy. Antenatal care clinics constitute a natural and useful environment for recognition of women with depressive symptoms.

Adolescent↗

PubMed2001

Evaluation of potential biocontrol rhizobacteria from different host plants of Verticillium dahliae Kleb.

AIMS: A screening approach was developed to assess the potential of rhizobacterial strains to control Verticillium wilt caused by Verticillium dahliae Kleb. METHODS AND RESULTS: Sixty randomly chosen antagonistic bacterial strains originally isolated from rhizosphere of three different host plants of V. dahliae--strawberry, potato and oilseed rape--were evaluated for biocontrol and plant growth promotion by analysing in vitro antagonism towards V. dahliae and other plant pathogenic fungi, production of fungal cell wall-degrading enzymes and plant growth-promoting effects on strawberry seedlings. To test the plant growth-promoting effect, a microplate assay with strawberry seedlings was developed. Although the rhizobacterial strains were isolated from different plants they showed effects on the growth of strawberry seedlings. According to the in vitro biocontrol and plant growth-promoting activity, the three best candidates Pseudomonas putida B E2 (strawberry rhizosphere), Ps. chlororaphis K15 (potato rhizosphere) and Serratia plymuthica R12 (oilseed rape rhizosphere) were selected for greenhouse experiments to verify the in vitro screening results. Under greenhouse conditions the isolates selected according to this strategy were as effective, or more effective than commercial biocontrol agents and may therefore possibly be valuable as antagonists of V. dahliae. CONCLUSIONS: In this study, the screening strategy resulted in a selection of three interesting biocontrol candidates against Verticillium: Ps. putida B E2 (strawberry rhizosphere), Ps. chlororaphis K15 (potato rhizosphere) and Ser. plymuthica R12 (oilseed rape rhizosphere). SIGNIFICANCE AND IMPACT OF THE STUDY: A new combination of in vitro screening methods including a microplate assay with strawberry seedlings to test the plant growth promoting effect which allow to more efficiently select potential biological control agents was developed successfully.

Antibiosis↗

PubMed2001

Screening for thyroid disease of 15-17-year-old schoolchildren in an area with normal iodine intake.

OBJECTIVE: The prevalence of thyroid disease in Swedish schoolchildren is today insufficiently known. The aim of the study was therefore to determine the prevalence of abnormal thyroid function and thyroid autoimmunity in teen-age schoolchildren and to compare the findings with a healthy control group of 60-65-year-old inhabitants from the same community. SETTING: A semirural community of approximately 15,000 inhabitants. DESIGN: Cross-sectional study. MAIN OUTCOME MEASURES: Thyroid volume and serum concentrations of serum thyrotropin (TSH), total and free thyroxine (T4), total and free 3,5,3'-triiodothyronine (T3), and antithyroperoxidase antibodies (TPOAb). RESULTS: Four schoolchildren (7%, 59 screened) had elevated TPOAb concentration, three of the subjects being girls (8%). One girl with a goitre was overtly hypothyroid and one girl showed borderline-high serum TSH concentration suggesting subclinical autoimmune thyroid disease. One euthyroid boy had a goitre and high concentration of TPOAb. The serum free T3 concentration was significantly higher in 15-17-year-old than 60-65-year-old (7.4 vs. 6.4 pmol L(-1), P < 0.001). The concentrations of other thyroid hormones and of TSH in 15-17-year-old did not differ from those of the 60-65-year-old. CONCLUSIONS: We found three cases of thyroid disease in need of immediate attention or later follow-up. The prevalence of autoimmune thyroid disease was high as indicated from TPOAb measurements. Thyroid tests including TPOAb measurement should be performed on wide indications when teenagers seek medical advice. The reference intervals for teen-age children for commonly used first line tests (TSH and free T4) do not differ from those for adults.

Adolescent↗

PubMed2001

Phenotypic and genotypic characterization of antagonistic bacteria associated with roots of transgenic and non-transgenic potato plants.

Rhizobacteria obtained during a risk assessment study from parental and transgenic T4 lysozyme-expressing potato plants were investigated to determine whether or not the strains could be grouped based on the source of isolation, transgenic or non-transgenic plants, respectively. A total of 68 representative bacterial strains of the group of enterics and pseudomonads were investigated by phenotypic profiling (the antagonistic activity towards bacterial and fungal plant pathogens, the production of the plant growth hormone indole-3-acetic acid [auxin], and the sensitivity to T4 lysozyme in vitro) and genotypic profiling by PCR fingerprints using BOX primers. All isolates were identified by fatty acid methyl ester (FAME) analysis. Computer-based analysis of the phenotypic characteristics showed that both, enterics and Pseudomonas strains clustered into six to seven groups at an Euclidian distance of 10. According to their BOX-PCR-generated fingerprints the Pseudomonas strains clustered into seven groups and the enterobacteria into two groups at the same genetic distance level of 10. The majority of groups were heterogeneous and contained isolates from all plant lines. In conclusion, cluster analysis of the phenotypic and genotypic features did not reveal correlations between bacterial isolates and transgenic character of plants.

Cluster Analysis↗

PubMed2001

Helicobacter pylori infection and serum ferritin: A population-based study among 1806 adults in Germany.

OBJECTIVE: Helicobacter pylori may possibly affect the iron metabolism by occult bleeding, impaired absorption of non-hem iron, and by scavenging hem iron or ferritin, as some studies have suggested. The aim of this study was to analyze the association between H. pylori infection and serum ferritin, a marker of the body iron stores. In this analysis, we paid particular attention to the role of dietary iron intake and CagA, an established virulence factor of the agent. METHODS: The analysis is based on a cross-sectional national health and nutrition survey among healthy people in Germany conducted in 1987/1988. The examination included a detailed questionnaire on medical history and lifestyle factors, a 7-day food record, and blood samples. Infection with H. pylori was measured serologically by ELISA and Westernblot. RESULTS: In total, 39.2% of 1806 persons aged 18 to 89 yr included in the study were H. pylori positive, of whom 57.6% had an infection with a CagA-positive H. pylori strain. Age- and sex-adjusted geometric mean of ferritin was 54.5 microg/dl among H. pylori-infected compared with 63.8 microg/dl among uninfected persons. A multiple linear regression model with log-transformed serum ferritin concentration as dependent variable and H. pylori infection and several potential confounding factors as independent variable was fitted. In this model, H. pylori infection was associated with a 17.0% decrease of the serum ferritin concentration (95% CI = 9.8-23.6). The association between H. pylori infection and serum ferritin levels did not vary by gender, age, and iron intake, and it was similar for CagA-positive and CagA-negative H. pylori infections. CONCLUSIONS: The decreased serum ferritin concentration among subjects infected with H. pylori might be induced by the uptake of ferritin in the stomach by H. pylori. Possible health implications of H. pylori-induced low ferritin levels warrant further investigation.

Adolescent↗

PubMed2001

Bulk and rhizosphere soil bacterial communities studied by denaturing gradient gel electrophoresis: plant-dependent enrichment and seasonal shifts revealed.

The bacterial rhizosphere communities of three host plants of the pathogenic fungus Verticillium dahliae, field-grown strawberry (Fragaria ananassa Duch.), oilseed rape (Brassica napus L.), and potato (Solanum tuberosum L.), were analyzed. We aimed to determine the degree to which the rhizosphere effect is plant dependent and whether this effect would be increased by growing the same crops in two consecutive years. Rhizosphere or soil samples were taken five times over the vegetation periods. To allow a cultivation-independent analysis, total community DNA was extracted from the microbial pellet recovered from root or soil samples. 16S rDNA fragments amplified by PCR from soil or rhizosphere bacterium DNA were analyzed by denaturing gradient gel electrophoresis (DGGE). The DGGE fingerprints showed plant-dependent shifts in the relative abundance of bacterial populations in the rhizosphere which became more pronounced in the second year. DGGE patterns of oilseed rape and potato rhizosphere communities were more similar to each other than to the strawberry patterns. In both years seasonal shifts in the abundance and composition of the bacterial rhizosphere populations were observed. Independent of the plant species, the patterns of the first sampling times for both years were characterized by the absence of some of the bands which became dominant at the following sampling times. Bacillus megaterium and Arthrobacter sp. were found as predominant populations in bulk soils. Sequencing of dominant bands excised from the rhizosphere patterns revealed that 6 out of 10 bands resembled gram-positive bacteria. Nocardia populations were identified as strawberry-specific bands.

Bacteria↗

PubMed2001

Comparison of antifungal activities and 16S ribosomal DNA sequences of clinical and environmental isolates of Stenotrophomonas maltophilia.

In recent years, the gram-negative bacterium Stenotrophomonas maltophilia has become increasingly important in biotechnology and as a nosocomial pathogen, giving rise to a need for new information about its taxonomy and epidemiology. To determine intraspecies diversity and whether strains can be distinguished based on the sources of their isolation, 50 S. maltophilia isolates from clinical and environmental sources, including strains of biotechnological interest, were investigated. The isolates were characterized by in vitro antagonism against pathogenic fungi and the production of antifungal metabolites and enzymes. Phenotypically the strains showed variability that did not correlate significantly with their sources of isolation. Clinical strains displayed remarkable activity against the human pathogenic fungus Candida albicans. Antifungal activity against plant pathogens was more common and generally more severe from the environmental isolates, although not exclusive to them. All isolates, clinical and environmental, produced a range of antifungal metabolites including antibiotics, siderophores, and the enzymes proteases and chitinases. From 16S ribosomal DNA sequencing analysis, the isolates could be separated into three clusters, two of which consisted of isolates originating from the environment, especially rhizosphere isolates, and one of which consisted of clinical and aquatic strains. In contrast to the results of other recent investigations, these strains could be grouped based on their sources of isolation, with the exception of three rhizosphere isolates. Because there was evidence of nucleotide signature positions within the sequences that are suitable for distinguishing among the clusters, the clusters could be defined as different genomovars of S. maltophilia. Key sequences on the 16S ribosomal DNA could be used to develop a diagnostic method that differentiates these genomovars.

Antibiosis↗

PubMed2001

Outcomes following coronary artery bypass grafting and percutaneous transluminal coronary angioplasty in the stent era: a prospective study of all 9890 consecutive patients operated on in Scotland over a two year period.

OBJECTIVE: To determine current outcomes of percutaneous transluminal coronary angioplasty (PTCA) and coronary artery bypass grafting (CABG). DESIGN: The Scottish coronary revascularisation register provided prospectively collected data on case mix and in-hospital complications for all revascularisation procedures between April 1997 and March 1999 (4775 PTCA; 5115 CABG). Linkage to routine hospital discharge and death data provided follow up information on survival and repeat revascularisation. RESULTS: Stents were used in 51% of PTCA procedures. CABG patients were older, had more severe coronary disease, and had greater comorbidity. PTCA was more likely to be undertaken as an urgent or emergency procedure. Perioperative death and urgent surgery followed 0.3% and 0.6% of PTCA procedures, respectively. Case fatality rates were higher following CABG, with 6.7% dead within two years compared with 3.4% following PTCA. PTCA was more often followed by readmission for ischaemic heart disease, repeat angiography, or revascularisation: 22.8% of patients had repeat revascularisation within two years, compared with 1.8% following CABG. CONCLUSIONS: The severity of coronary heart disease was greater than in previously published registry studies and randomised trials. Despite this, overall survival figures were comparable and repeat revascularisation rates lower, particularly following PTCA. Perioperative death and urgent surgery following PTCA were also lower. These favourable outcomes may be attributable, in part, to increased use of bail out and elective stenting.

Aged↗

PubMed2001

Is hydrogen peroxide an EDHF in human radial arteries?

In human radial arteries, a nitric oxide/prostanoid-independent mechanism that has the pharmacological characteristics of an EDHF contributes to endothelium-dependent relaxation. H2O2 can act as an EDHF in some vascular beds. We examined the hypothesis that endogenously produced H2O2 mediated the nitric oxide/prostanoid-independent relaxation to carbachol in radial arteries obtained from patients undergoing coronary artery bypass surgery. Superoxide levels, measured by chemiluminescence, were similar in radial and internal mammary arteries, but immunohistochemical staining for Cu/Zn superoxide dismutase (SOD) was lower in endothelium from radial arteries. In organ chamber studies, neither addition of catalase nor addition of SOD to the bathing fluid modified nitric oxide/prostanoid-independent relaxations to carbachol in radial arteries. However, nitric oxide-dependent vasorelaxation was enhanced in the presence of SOD. Thus the nitric oxide/prostanoid-independent relaxation to carbachol is not due to H2O2 and, unlike nitric oxide-mediated vasorelaxation, is not attenuated by superoxide. Blood vessels showing EDHF-mediated relaxations resistant to oxidative stress may provide favorable outcomes in revascularization surgery.

Biological Factors↗

PubMed2001

The use of health-care resources in obesity-hypoventilation syndrome.

OBJECTIVE: To document health-care utilization (ie, physician claims and hospitalizations) in patients with obesity-hypoventilation syndrome (OHS), for 5 years prior to the diagnosis and for 2 years after the diagnosis and initiation of treatment. DESIGN: Retrospective observational cohort study. SETTING: University-based sleep disorders center in Manitoba, Canada. PATIENTS AND CONTROL SUBJECTS: Twenty OHS patients (mean [+/- SD] age, 52.7 +/- 9.5 years; body mass index [BMI], 47.3 +/- 11.0 kg/m(2); PaCO(2), 59.7 +/- 13.8 mm Hg; PaO(2), 51.6 +/- 12.4 mm Hg) were matched to two sets of control subjects. First, each case was matched to 15 general population control subjects (GPCs) by age, gender, and geographic location, and, second, each case was matched to a single obese control subject (OBC) who was matched using the same criteria as for the GPCs, plus the measurement of BMI. MEASUREMENTS AND RESULTS: In the 5 years before diagnosis, the 20 OHS patients had (mean +/- SE) 11.2 +/- 1.8 physician visits per patient per year vs 5.7 +/- 0.8 (p < 0.01) visits for OBCs and 4.5 +/- 0.4 (p < 0.001) visits for GPCs. OHS patients generated higher fees, $623 +/- 96 per patient per year for the 5 years prior to diagnosis compared to $252 +/- 34 (p < 0.001) for OBCs and $236 +/- 25 (p < 0.001) for GPCs. OHS patients were much more likely to be hospitalized than were subjects in either control group in the 5 years prior to diagnosis (odds ratio [OR] vs GPCs, 8.6) (95% confidence interval [CI], 5.9 to 12.7); OR vs OBCs, 4.9 (95% CI, 2.3 to 10.1). In the 2 years after diagnosis and the initiation of treatment (usually continuous positive airway pressure or bilevel positive airway pressure), there was a significant linear reduction in physician fees. In the 2 years after the initiation of treatment, there was a 68.4% decrease in days hospitalized per year (5 years before treatment, 7.9 days per patient per year; after 2 years of treatment, 2.5 days per patient per year [p = 0.01]). CONCLUSIONS: OHS patients are heavy users of health care for several years prior to evaluation and treatment of their sleep breathing disorder; there is a substantial reduction in days hospitalized once the diagnosis is made and treatment is instituted.

Cohort Studies↗

PubMed2001

[Acquired partial lipodystrophy. Insulin resistance, hepatic lipase activity and small and dense LDL particles].

Partial lipodystrophy (PLD) is an infrequent condition characterized by symmetric loss of subcutaneous adipose tissue in the upper or lower part of the body, although occasionally it affects only the extremities. In all cases it appears along with acantosis nigricans (AN), insulin resistance and impairment in the metabolism of lipids and carbohydrates. The case depicted pertains to a 49 year old female with no family history involving loss of adipose tissue in face and upper body. No fat in lower part of body was observed. The patient showed facial thinning at age 8, AN at 11 and gestational diabetes during her fourth pregnancy at 33. At present, the patient presents severe hyperglycemia and hyperinsulinemia with a marked insulin resistance. Type IV hyperlipoproteinemia (OMS), declined C-HDL and Apo A1 and low C-LDL but with a high proportion of small and dense LDL particles were present. Non esterified fatty acids were high. Lipoprotein lipase and hepatic lipase activities are in the lower limit and increased respectively. Fraction C3 of the complement was diminished. No mutations were observed either in codons 170, 809 and 972 of the IRS-1 receptor or in codon 276 of the adrenergic beta 2 gene.

Female↗

PubMed2001

Radial artery hypertrophy occurs in coronary atherosclerosis and is independent of blood pressure.

Endothelial dysfunction, believed to underlie the structural changes of atherosclerosis, is a systemic phenomenon. Despite this, the radial artery has been considered as devoid of atherosclerosis and is commonly used as a conduit in coronary artery bypass grafting (CABG). Recently, histological study has shown intimal hyperplasia and other structural changes consistent with early atherosclerosis in the radial artery. The objective of the present study was to determine if structural changes in the radial artery could be detected in vivo in patients with coronary atherosclerosis. Using high resolution echo-tracking, measurements of radial artery internal diameter, wall thickness and wall cross-sectional area were made in 25 patients awaiting CABG and in 20 controls. Digital and brachial blood pressures were also recorded. Mean arterial pressures did not differ between the patient and control groups. All measures of wall thickness were greater in the patient than the control group. Neither current arterial pressures nor past history of hypertension correlated with wall thickness. Using a model of analysis of covariance, coronary artery disease was the best single predictor of intima-media thickness, R(2)=48%, n=44, P<0.0005. We concluded that increased radial artery wall thickness can be demonstrated in vivo in patients with coronary atherosclerosis. This is a novel observation which seems to be independent of blood pressure, and is consistent both with the hypothesis of systemic endothelial dysfunction leading to systemic structural changes and also to the recent histological evidence for atherosclerotic changes in this vessel.

Adult↗

PubMed2001

Short-term functional outcome of hospitalised first-ever strokes in Finnmark, Norway in 1998-1999. Results from the Finnmark Stroke Register.

Data on the functional outcome, prevalence of risk factors and comorbidity of stroke were collected in the population-based Finnmark Stroke Register in northern Norway. Findings for hospitalised first-ever strokes (n = 125) during the first registration year (1998-1999) are presented here. The median age of the patients was 70 years for men and 79 years for women. Cerebral infarctions comprised 81.6% of the strokes. Patients were severely handicapped: at discharge from hospital about 46% of those 75 years or older and about 21% of those younger than 75 years had severe disability by Rankin Scale. Women were more impaired than men. After hospitalisation, 45% of those 75 years or older and 21% of those younger than 75 years were sent to nursing home. The prevalence of risk factors and comorbidity was high: 29% of men (52% of women) had high blood pressure, 22% of men (25% of women) had atrial fibrillation, 22% of both men and women had diabetes, and 50% of men and 33% of women were current smokers. In conclusion, stroke victims in Finnmark were left with severe disability and need intensive rehabilitation. The prevalence of treatable risk factors was high; thus, primary and secondary prevention is the key to reduce the individual and social burden of stroke.

Aged↗

PubMed2000

Observation of hot-electron pressure in the vibration dynamics of metal nanoparticles

We investigate the vibration dynamics of ellipsoidal silver nanoparticles, using time-resolved optical pump-probe spectroscopy. When excited with femtosecond laser pulses, the particles execute anisotropic shape oscillations. We show that these vibrations are triggered by the thermal expansion of the optically heated particles. The time dependence of the vibrations indicates that this expansion is caused by two mechanisms: The lattice anharmonicity and the extremely large pressure of the hot conduction electrons.

Journal Article↗

PubMed2000

Estrogen effects on postural balance in postmenopausal women without vasomotor symptoms: a randomized masked trial.

OBJECTIVE: To assess whether estrogen treatment given to postmenopausal women without vasomotor symptoms improves balance more than placebo. METHODS: Forty healthy postmenopausal women without vasomotor symptoms were randomized to transdermal 17beta-estradiol (E2) 50 microg/day for 14 weeks or identical transdermal placebo patches. Postural balance was measured with dynamic posturography before and after 4, 12, and 14 weeks of therapy. In this test, the visual, vestibular, and somatosensory systems were provoked with increasing difficulty and body sway was measured with a dual forceplate. A low score showed large sway and a score of 100 showed no sway at all. RESULTS: Thirty-eight women completed the study. Both groups had normal balance for their ages and near maximum scores in the three easier balance tests at baseline. In the most difficult test, both groups improved their postural balance significantly (from 13 to 32 and from 22 to 39, respectively) after 4 weeks. Thereafter, no change was seen. One problem was low statistical power, but the relative change in balance did not differ between groups. The comparison did not show even a minute advantage of E2 over placebo, so a study with higher power would probably not have shown a more pronounced effect of estrogen than placebo. The change over time did not differ between groups, which indicates a significant learning effect. CONCLUSION: In women without vasomotor symptoms, estrogen therapy did not seem to increase postural balance significantly more than placebo. However, we could not rule out that estrogens affect postural balance in women with vasomotor symptoms.

Administration, Cutaneous↗

PubMed2000

Salt adaptation in pseudomonads: characterization of glucosylglycerol-synthesizing isolates from brackish coastal waters and the rhizosphere.

The compatible solute glucosylglycerol (GG) is widespread among cyanobacteria, but, until now, has been reported for only two species of heterotrophic bacteria. About 120 bacterial isolates from coastal regions of the Baltic Sea were screened by HPLC for their ability to synthesize GG. Positive isolates (26) were grouped by SDS-PAGE of whole-cell proteins and representative strains of each group were investigated by sequencing their 16S rRNA genes and phenotypic characterization. All GG-synthesizing isolates were shown to belong to the genus Pseudomonas (sensu stricto) and were assigned to 4 distinct groups, although none of the GG-synthesizing isolates could be unambiguously assigned to described species. The identity of GG was verified by 13C NMR analysis and enzymatic digestion with alpha- and beta-glucosidases. Besides GG, salt adapted cultures of the aquatic isolates accumulated the dipeptide N-acetylglutaminylglutamine amide (NAGGN) and glutamate. The accumulation of noncharged compatible solutes was also tested in previously identified pseudomonads isolated from the rhizosphere of oilseed rape and potato. The majority of these strains were fluorescent species of the genus Pseudomonas and accumulated trehalose and NAGGN when grown under salt stress conditions. However, rhizosphere isolates of Stenotrophomonas maltophilia synthesized GG and trehalose or only trehalose in a strain-dependent manner. These data indicate that the ability to synthesize GG is widely distributed among slightly or moderately halotolerant pseudomonads.

Bacterial Proteins↗