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This study compares the susceptibility patterns of Staphylococcus aureus and Escherichia coli isolated from patients with hospital-acquired and outpatient infections. A total of 902 isolates of S. aureus and 1,114 of E. coli were collected in five different Estonian medical centers between January 1997 and November 1997. Strains were grouped into two different categories, depending on whether they had been obtained from inpatients or outpatients. Compared to S. aureus strains isolated from inpatients, the strains from outpatients were significantly more resistant to erythromycin (25.3% vs. 17.9%), tetracycline (33.5% vs. 22.4%) and trimethoprim-sulfamethoxazole (13.9% vs. 7.9%). The overall prevalence of oxacillin-resistant S. aureus was 10.4%, with no significant differences noted between isolates recovered from inpatients and outpatients. In the case of E. coli, significantly more isolates from inpatients (42.8%) than from outpatients (34.4%) were ampicillin-resistant. Inpatient isolates of E. coli were also more resistant to cefotaxime (9.3%) and nitrofurantoin (11.2%) than outpatient strains (0% and 3.1%, respectively). Analysis showed remarkable co-resistance among both inpatient and outpatient strains of S. aureus and E. coli. Multiple resistant S. aureus and E. coli strains represented 15.1% and 17.3%, respectively of the organisms examined in this study. With respect to E. coli, significantly more multiresistant isolates were found in inpatient than outpatient isolates (20.4% vs. 8.9%). Our results indicate that the distinction between community-acquired and hospital infections due to S. aureus and E. coli may not be valid in Estonia.

The presence and composition of amniotic fluid (AF) microflora, as well as AF glucose concentration and white blood cell (WBC) count, were investigated in 22 consecutive asymptomatic women with intact membranes at mid-gestation. AF was retrieved by trans-abdominal amniocentesis. Three of the 22 women (13.6%) had microorganisms in their AF: Chlamydia trachomatis in 2 and both Corynebacterium group absolute nonfermenter (ANF) group and Propionibacterium spp. in 1. No differences were found in clinical characteristics, glucose concentration or WBC count in patients with and without microorganisms in their AF.

The prevalence of metronidazole and clarithromycin resistance of Helicobacter pylori strains under different growth conditions (microaerophilic or anaerobic preincubation) was tested in 56 patients suffering from gastritis and peptic ulcer. vacA subtypes were detected in 46 H. pylori strains and were subsequently compared with the antibiotic resistance pattern. From 56 isolates, 26 proved resistant and 30 sensitive to metronidazole. The patients with peptic ulcer and gastritis were infected with both metronidazole-sensitive and metronidazole-resistant strains. In anaerobic preincubation all the strains were sensitive to metronidazole (MIC < 8 mg/l). All the strains were clarithromycin-sensitive (MIC < 2 mg/l). In the patients with gastritis and peptic ulcer s1 was the predominant vacA subtype. Comparison of vacA subtypes with the diagnoses revealed no correlation; different virulence factors such as vacA subtypes and antibiotic resistance to metronidazole in a microaerophilic milieu proved unrelated.

Effects on aqueous extracts of medicinal plants on ten Helicobacter pylori strains were studied by the salt aggregation test to determine the possibility to modulate their cell surface hydrophobicity and by an agar diffusion assay for detection of antimicrobial activity. It was established that aqueous extracts of bearberry and cowberry leaves enhance cell aggregation of all H. pylori strains tested by the salt aggregation test, and the extract of bearberry possessed a remarkable bacteriostatic activity. Pure tannic acid showed a result similar to that of bearberry and cowberry extracts which contained a large amount of tannins. In contrast, extracts of wild camomile and pineapple-weed, which blocked aggregation of H. pylori, contained small amounts of tannins and did not reveal any antimicrobial activity. Tannic acid seems to be the component of bearberry and cowberry aqueous extracts with the highest activity to decrease cell surface hydrophobicity as well as in antibacterial activity against H. pylori.

In a 1-month prospective case-matched study we found Acinetobacter baumannii was a prevailing microbe simultaneously colonizing respiratory tract and skin of neurointensive care unit patients who stayed in our neurointensive care unit for more than 3 d. A. baumannii was not isolated from healthy case-matched controls. Based on their phenotypic properties and the results of amplified ribosomal DNA restriction analysis the 12 strains of Acinetobacter spp. isolated were identified as belonging to DNA group 2 (A. baumannii). For epidemiological typing, Biolog system results of 95-carbon source oxidation, antibiograms and restriction endonuclease analysis were used. One predominant A. baumannii strain was found in all colonized patients, skin and respiratory tract were found mainly to be colonized with the same strain. The starting point of A. baumannii colonization seemed to vary with the individual patient. Environmental strains were different from patients' strains: they were metabolically more active, more resistant and had a different restriction endonuclease analysis profile.

Rett syndrome is now considered to be a neurodevelopmental disease. Its cause is unknown, but it has been suggested that neuronal growth factors and neurotransmitters play important roles. We measured levels of brain-derived neurotrophic factor and glial cell line-derived neurotrophic factor in cerebrospinal fluid, and nerve growth factor and brain-derived neurotrophic factor in serum in child and adolescent patients with Rett syndrome. Levels of brain-derived neurotrophic factor and glial cell line-derived neurotrophic factor in cerebrospinal fluid were below the limit of sensitivity of the methods used. Serum levels of nerve growth factor and brain-derived neurotrophic factor did not differ from control values. In Rett syndrome, the normal serum levels of nerve growth factor together and previously reported low levels of the factor in cerebrospinal fluid indicate that the latter may reflect low levels of nerve growth factor in the central nervous system.

Several studies indicate that xylitol (X) consumption is associated with certain biochemical changes in dental plaque and whole saliva. In making X-containing saliva stimulants more cost-effective and palatable, manufacturers may use maltitol syrup (MS, which normally contains some sorbitol and higher polyols) or polydextrose (PD, a polysaccharide molecule with a mass > 22 kDa) as bulking agents. Combinations of X with MS and PD have not been tested regarding their salivary effects. One hundred and eighty-eight young subjects (mean age, 22 years) of both sexes were divided into three groups of equal size for a 4-month study. The subjects in one group used X-MS dragees (in 7 daily episodes; 8 g X per day), while the subjects in another group used X-PD dragées in as many daily episodes (8 g X per day). Subjects in the third (comparison) group did not receive saliva stimulants. Paraffin-stimulated whole saliva samples were collected at baseline, after 2 months, and at endpoint. The usage of X-MS was associated with a significant (P < 0.05) reduction in the salivary sucrase activity. After 4 months, the activity of enzymes hydrolyzing N(alpha)-benzoyl-DL-arginyl-p-nitroaniline was significantly reduced in all groups, while the levels of free sialic acid were reduced in group X-PD only (P < 0.05). These salivary changes most likely reflected microbial shifts in the oral cavity and suggest that information from saliva studies may be of avail when deciding which bulking agents should be used in xylitol-based saliva stimulants.

The adhesion of microbes on host cells is of decisive importance in the development of Gram-negative microbe-induced infections and can be influenced by the surface hydrophobicity of the microbial cell. The hydrophobicity of 155 Escherichia coli strains of different origin was determined by the salt aggregation test (SAT). Among the strains isolated from faecal samples of healthy persons only 16.7% showed aggregative properties, whereas among the strains isolated from the urine of patients with pyelonephritis and the faecal samples of calves and pigs with diarrhoea some 40.0%-60.0% were aggregative. The influence of aqueous extracts prepared from bearberry leaves, St. John's wort herbs, wild camomile and marigold flowers on hydrophobicity of 40 E. coli and 20 Acinetobacter baumannii strains was investigated. The decoctions of bearberry and St. John's wort increased remarkably the hydrophobicity of both microbial species. The infusions of wild camomile and marigold completely blocked the aggregative properties of the investigated strains. Bactericidal action was relatively low in the case of bearberry and St. John's wort and completely lacking in the case of wild camomile and marigold. Thus, one of the probable and potentially important action mechanisms of the four medicinal plants studied is their ability to influence the surface characteristics of the microbial cells and thereby their putative virulence properties.

Cell surface properties of 78 strains of Acinetobacter baumannii of different origin (lower respiratory tract, wound, blood and environment) were investigated. The bacterial adhesion to collagen, fibronectin, fibrinogen and vitronectin was detected by particle agglutination assays. Salt aggregation tests were used to determine the cell surface hydrophobicity of isolated A. baumannii strains. We found that A. baumannii strains originating from patients with wound infection and bacteraemia showed significantly lower aggregative properties compared to respiratory and environmental strains. Electron microscopic investigations revealed more fimbriated bacterial cells among the highly aggregative A. baumannii strains. This study demonstrates that the investigated A. baumannii strains can be divided into two different groups according to their cell surface properties and source of isolation, whereas the majority of strains, from the lower respiratory tract and the hospital environment expressed strong adhesive properties.

For many microorganisms, including Clostridium difficile, mucosal association is an important factor influencing intestinal colonisation and subsequent infection. Inhibition of adhesion of C. difficile to intestinal mucosa could be a new promising strategy for prevention and treatment of antibiotic-associated diarrhoea. We investigated the possibilities of influencing the adhesion of C. difficile by xylitol and bovine colostrum whey. Caco-2 cells and C. difficile cells were incubated with 1%, 5% and 10% solutions of xylitol and colostrum. Our study revealed that both xylitol and colostrum inhibited the adhesion of C. difficile to Caco-2 cells. Inhibition by xylitol was dose-dependent. When compared to the control, the count of adherent C. difficile decreased 3.4 times when treated with 1% xylitol, 12 times when 5% xylitol was applied, and 18.7 times when treated with 10% xylitol. The inhibition of adherence by colostrum was partially dose-dependent: 3.1 times in the case of 1%, and 5.5 times in the cases of 5% and 10% colostrum. Further experimental and clinical studies are needed for the application of xylitol and colostrum in the treatment and prophylaxis of pseudomembraneous colitis.

Our aim was to study the initial microbial colonization of the newborns by comparing it with their mothers' vaginal microflora. Nineteen mother-newborn pairs were examined at delivery. We found a close association, both qualitative and quantitative, between the individually different microflora of a mother's vagina and that of her newborn. The degree of contamination of the newborn significantly correlated with the counts of microorganisms found in the vagina of mothers. In 85% of investigated individual mother-newborn pairs we revealed similar predominant microorganisms. There were no cases of the mothers and their newborns harbouring similar potentially pathogenic prevailing microorganisms.

The quantitative relations of various groups of microbes, the biological properties of lactobacilli in the luminal and mucosal microfloras of the gastrointestine of rats after having received kanamycin and after starvation, of conventional and germfree mice after irradiation and of piglets of different ages were compared. It was revealed that there exists a positive correlation between the mucosal and the lumenal microfloras which remains considerably stable under different conditions. Nevertheless, in case of irradiation or starvation influencing the gastrointestine microflora, the mucosal microflora gets more changed and the translocation of microbes through the mucosa into blood circulation takes place. The mucosal lactoflora of piglets is formed during the first (1-5) days of life on account of microbes with well-expressed antagonistic activity and lysozyme resistance.

Output of bacterial metabolites reflects not only the number but the metabolic activity of certain microorganisms. In case of excess of a substrate one can observe the increased output of metabolite(s) without the overgrowth of intestinal bacteria. This matter is used for detection of malabsorption of some carbohydrates (lactose, glucose) by increased excretion of hydrogen in expired air. Another group of so-called breath tests (14C-cholylglycine, 14C-xylose) is designed to detect the bacterial overgrowth in the small intestine by measuring the rise of the concentration of 14CO2 in alveolar air. All the tests basing on the decomposition of the test substance by intestinal bacteria, have some limitations. Little is known about the microorganisms decomposing the different test substances. Significant correlations between the urinary phenols (p-cresol, phenol) and certain groups of mucosal flora (staphylococci, bacteroides) of the small intestine of rats could be found. Therefore one suggests that elucidating the origin of a bacterial metabolite is still possible in some instances, although very complicated. In conclusion, the authors refer to several reasons for failure to obtain correlations between the output of the metabolite(s) and data of bacteriological investigation.

Due to the emotional stress before the take off the lactoflora of 24 cosmonouts shows distinct changes regarding the spectrum of different species of Lactobacilli. Compared to long-time flights after short-time flights even stronger alterations are observed. The reason is that the disturbances which take place before the take-off as to the short space of time cannot be balanced by the macroorganism. Additionally, after a certain adaptive period the factors of the space travel begin to act. There are characteristic individual particularities regarding the number of Lactobacilli in the saliva and the feces of the cosmonouts.

Lactobacilli can belong to the gut flora or to the flora associating with gastrointestinal epithelial surfaces. They play an important role within the microbial defense mechanisms taking part in the colonization resistance and in the decontamination of the host. Lactobacilli affect the immune response. They accelerate the revival of the small intestinal epithelial cells. Those strains of lactobacilli with distinct antagonistic properties with lysozyme activity and resistance against lysozyme often develop a compact glycocalyx. They are endowed with a high adhesion capacity. The intestinal lactoflora consists of several species with different defense properties.