Numerous isolates of both subspecies of Staphylococcus cohnii were found in the environment of the intensive-care unit of a pediatric hospital. These isolates carried in their cells many plasmids, up to fourteen, of a wide range of sizes (< 2 to > 56 kb). Striking was the occurrence of large plasmids not very common in staphylococci. These were present in > 80% of S. cohnii isolates. Fifty-two different plasmid profiles were found in 79 investigated isolates belonging to S. cohnii ssp. cohnii and S. cohnii ssp. urealyticus. Isolates similar in plasmid profiles were grouped in antibiotic-resistance clusters established for 9 antibiotics (gentamicin, ciprofloxacin, clindamycin, erythromycin, tetracycline, chloramphenicol, mupirocin, trimethoprim-sulfamethoxazole, vancomycin) using the method of unweighted pair group mathematical averages (UPGMA). Many isolates were multiresistant to antibiotics and produced bacteriocins.

We have analysed the isolates of Staphylococcus cohnii found in the intensive care unit of a pediatric teaching hospital: in the environment, 159 isolates; on the skin of hospitalized premature infants, 26; and on the skin of ward personnel, 49. Sixteen phenotypic features were used to characterize the isolates at metabolic, biologic and antibiotic resistance level. All selected attributes were treated as equivalent, and numerical analysis of all isolates was performed on this basis. Each isolate was described with a zero-one sequence, then dendrograms were created, indicating similarities inside the group of isolates. This method proved the phenotypic diversity of S. cohnii isolated in the hospital. Among them, almost 65% showed distinct patterns (on the basis of 16 traits) and there were no large clusters created by identical or very similar isolates. The results of these investigations suggest that owing to its diversity S. cohnii may be perfectly adaptive to hospital habitat conditions, and undergoes alteration in the hospital environment by an exchange of genetic material with species selected under the effect of antibiotic pressure. In this way this species, which is rarely associated with human infections, becomes a reservoir of antibiotic resistance genes in the hospital environment. 1 Key words: Staphylococcus cohnii , human skin flora, hospital environment, resistance genes reservoir.

Two microsatellite tandem repeated tetramers, (GACA) 4 and (CAAT) 4 , were used for Proteus mirabilis strain differentiation. The microsatellite-based PCR tests were applied for the examination of interstrain diversity for 87 P. mirabilis strains. Forty-six of the investigated strains were clinical isolates (5 were hospital isolates and 39 were outpatient clinic isolates); 42 strains were derived from the Kauffmann-Perch collection of laboratory strains. Fingerprinting done with the tetramers had a high discrimination ability [0.992 and 0.940 for (GACA) 4 and (CAAT) 4 , respectively]. The distributions of clinical isolates among well-defined laboratory strains, determined by numerical analysis (unweighted pair-group method with arithmetic averages; Dice similarity coefficient), proved their genetic similarity to reference strains in the Kauffmann-Perch collection. This analysis also indicated that it is possible to estimate some phenotypic properties of P. mirabilis clinical isolates solely on the basis of microsatellite fingerprinting.Proteus spp. are mobile gram-negative bacteria common in both the natural environment and animal or human intestinal tracts. Proteus spp. are also known etiologic agents for meningitis and numerous bacteremias (8,(20)(21)(22)(23)43). Urinary tract infections are among the most frequent bacterial infections (19), and Proteus mirabilis strains are one of the most common causes of urinary tract infections (7%), third after Escherichia coli (52%) and Enterococcus spp.(12%) (11). Such infections occur commonly among patients with structural defects of the urinary tract (6,38,39). The presence of P. mirabilis rods within a urease-induced bladder stone matrix was visualized recently (24). Moreover, some results suggest a possible etiopathogenic role of P. mirabilis in rheumatoid arthritis (9, 31), and some nosocomial transmission events have been reported (31). Because of the increasing spread and clinical significance of P. mirabilis rods (13,15,30,31,32), studies of effective methods for epidemiological investigations are of great importance.Out of the numerous types of simple sequence repeats proposed as tools for very sensitive bacterial fingerprinting (25,27,48,50,51,54), many microsatellites have been described as being useful for microbial differentiation, especially below the level of species (1,10,26,28,33,34,47,48,49,53).Most of the molecular fingerprinting methods applied for the differentiation of Proteus (35,36,44), however, are not sensitive enough for more detailed interstrain differentiation. In particular, no specific method allowing for P. mirabilis differentiation, especially below the serotype level, has been described so far.In this study, we have focused on microsatellite-based methods supplying patterns specific for particular P. mirabilis strains. The aim of the study was to verify how effective microsatellites are for P. mirabilis fingerprinting; in particular, we examined whether tandem tetramer-based PCR is applicable to Proteus strain differentiation or typing...

In this study, we found Lewis X (Le(x)) determinants on 68% of Helicobacter pylori isolates from patients with chronic gastroduodenal diseases. Anti-Le(x) IgG were detected more frequently in the sera from dyspeptic children and adults (45 and 46%), with or without proved (culture) H. pylori infection, than in the sera from healthy individuals (14% and 25%). In contrast, the prevalence of anti-Le(x) IgM was higher in the groups of healthy individuals than in the groups of dyspeptic patients. Moreover, anti-Le(x) monoclonal antibody of IgM class enhanced the uptake of Le(x)(+) but not Le(x)(-) H. pylori isolates by phagocytes. In the sera from some dyspeptic patients, we detected Le(x)-anti-Le(x) IgG immune complexes (Le(x) ICs). There was a great difference between children and adults as regards the presence of Le(x) ICs. The immune complexes were found in the sera from nine out of 29 (27%) H. pylori-infected and three out of eight (37%) uninfected adult dyspeptic patients. In comparison, Le(x)-anti-Le(x) IgG ICs were detected only for two out of 18 (11%) H. pylori-infected children. Le(x) ICs were not found in the sera from healthy individuals. Our results suggest that anti-Le(x) IgM may play a protective role in H. pylori infections. In contrast, anti-Le(x) IgG and particularly Le(x)-anti-Le(x) IgG ICs might contribute to the pathogenesis of chronic H. pylori infections.

The averaged genomic similarities based on multilocus randomly amplified polymorphic DNA (RAPD) were calculated for eight species representing three sections of the genus Vicia: faba, bithynica and narbonensis. The frequency of appearance of the sequences corresponding to 25 decamers selected at random from genomes of different Fabace species was checked, and a high correlation with the frequency observed for Vicia allowed us to assume their similar weight in typing Vicia species. The RAPD-based similarity coefficients compared with those related to whole genome hybridization with barley rDNA and those based on restriction fragment length polymorphism (RFLP) revealed similar interspecies relationships. The averaged RAPD-based similarity coefficient (Pearson’s) was 0.68 for all the species, and was sectionspecific: 0.43 (bithynica), 0.50 (faba) and 0.73 (narbonensis). The averaged similarity coefficient for V. serratifolia (0.63) placed it apart from the rest (0.75) of its section. The results correspond to the interspecies relationships built upon non-genetic data. The averaged similarity coefficient for particular RAPD was related to the presence and type of tandemly repeated motif in a primer: 0.7–0.8 for heterodimers (GC, AG, CA, GT, CT), 0.5–0.6 for homodimers (CC, GG) and 0.6 for no repeat, indicating the sensitivity of diversity range to the type of target sequences.