Recombinational exchanges at the capsular polysaccharide biosynthetic locus lead to frequent serotype changes among natural isolates of Streptococcus pneumoniae.

Serotype 19F variants of the major Spanish multiresistant serotype 23F clone of Streptococcus pneumoniae have been proposed to have arisen by recombinational exchanges at the capsular biosynthetic locus. Members of the Spanish multiresistant serotype 23F clone and the serotype 19F variants were confirmed to be essentially identical in overall genotype, as they were indistinguishable by REP-PCR, and had identical sequences at three polymorphic housekeeping genes. Eight serotype 19F variants were studied and all had large recombinational replacements at the capsular biosynthetic locus.

Simultaneous persistence of methicillin-resistant and methicillin-susceptible clones of Staphylococcus aureus in a neonatal ward of a Warsaw hospital.

Fifty-seven methicillin-resistant Staphylococcus aureus (MRSA) isolates from babies (N = 31), carriers amongst health care workers (N = 16; 10% of all staff members) and the environment (N = 10); 39 MSSA isolates, from babies (N = 18), health care workers (N = 5) and environment (N = 16) were analysed. The strains were from the neonatal ward of a teaching hospital in Warsaw and were collected over a period of 16 months (1993/1994). The isolates were characterized by phage-typing, arbitrary-primed polymerase chain reaction (AP PCR), DNA repeat polymorphism within the protein A gene and the resistance pattern to antimicrobial agents.

Two clones of methicillin-resistant Staphylococcus aureus in Poland.

OBJECTIVE: To evaluate relatedness among methicillin-resistant Staphylococcus aureus (MRSA) strains isolated in Poland. METHODS: Ninety-three MRSA hospital isolates were collected from different regions in Poland from 1990 to 1992. Strains were analyzed with respect to heterogeneity of methicillin resistance, phage types, resistance patterns, crystal violet staining, chromosomal DNA SmaI restriction patterns by PFGE, ERIC1 and ERIC2 AP-PCR types and DNA repeat polymorphism within the protein A gene.

Binding of extracellular matrix proteins by enterococci.

Forty-four enterococcal strains isolated from human clinical specimens were investigated for binding of 125I-labeled fibronectin, vitronectin, thrombospondin, lactoferrin, and collagen type I and IV, and for cell surface hydrophobicity. Most strains expressed low binding of iodine-labeled human fibronectin, collagen I and IV, and higher binding of human vitronectin, human lactoferrin, and human thrombospondin. Bacteria grown in Todd-Hewitt broth exhibited increased binding to vitronectin and thrombospondin.

Apoptosis of monocytes and prolonged survival of granulocytes as a result of phagocytosis of bacteria.

Monocytes and granulocytes were incubated with suspensions of Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, or Salmonella enteritidis and, after being washed free of bacteria, cultured for up to 48 h. Every few hours, samples of cultured cells were taken for DNA isolation. Monocytes which phagocytosed bacteria showed features of apoptotic cells, as determined by light microscopy and DNA fragmentation detected by gel electrophoresis.

Carriage of antibiotic-resistant Streptococcus pneumoniae by children in eastern and central Europe--a multicenter study with use of standardized methods.

With use of standardized techniques, a study of nasopharyngeal pneumococcal carriage in children in six Central and Eastern European cities was undertaken during the winter of 1993-1994. Nasopharyngeal swab specimens were collected from 954 children (predominantly under the age of 5 years) who were hospitalized or attending outpatient clinics or day-care centers. Susceptibility of isolates was determined by disk diffusion (on Mueller-Hinton agar with 5% sheep blood).

Susceptibility testing of Haemophilus influenzae--an international collaborative study in quality assessment.

In order to compare the prevalence of antibiotic resistance in different geographical areas, it is necessary to ensure that agreement is achieved between laboratories on the assignment of strains to 'susceptible' and 'resistant' categories. An international quality assessment study, involving 15 laboratories in eight countries, was performed to investigate the standard of performance of the susceptibility testing of Haemophilus influenzae. One hundred and fifty strains of H.

Phenotyping methods in epidemiological analysis of epidemic Staphylococcus aureus strains.

One hundred and fifty hospital Staphylococcus aureus strains isolated on Polish hospitals during an outbreaks were used to evaluate usefulness of S. aureus phenotyping methods. According to the expression of resistance to methicillin (a marker of resistance to all beta-lactam antibiotics) all strains were classified as homogeneously of heterogeneously resistant to methicillin (methicillin resistant S.

Characterization of two different clusters of clonally related methicillin-resistant Staphylococcus aureus strains by conventional and molecular typing.

The DNA fragments of 28 distinct isolates of methicillin-resistant Staphylococcus aureus (MRSA) originating from different hospitals in Warsaw and Lodz, were studied. They were obtained by cleavage with restriction endonuclease SmaI and subsequently analysed by pulsed-field electrophoresis. Sixteen different patterns were seen and clusters of related strains were clearly distinguishable.

Bacterial resistance in eastern Europe--selected problems.

The profile of infection and pattern of bacterial resistance in Eastern Europe is distinct from that observed in other parts of the world. Several Polish investigations have reported that environmental pollution may increase the risk of respiratory disease. Studies from Hungary and Romania have documented a dramatic increase in the proportion of Streptococcus pneumoniae strains resistant to antibiotics.

[Use of western-blotting technique and computer analysis for comparing cellular antigens of coagulase-negative staphylococci].

Western-Blotting technique and computer programme have been used to analyse cellular antigenic patterns of coagulase-negative staphylococci mainly of S. epidermidis and S. saprophyticus species.

[Evaluation of different methods for detecting resistance of staphylococcus aureus strains to methicillin].

Resistance to methicillin of 70 Staphylococcus aureus isolates from infection and 6 standard strains was evaluated by screening and disc diffusion techniques. Amongst wild S. aureus isolates 28 were identified as methicillin-susceptible (MSSA), 18 as heterogeneously resistant and 24 as homogeneously resistant to methicillin (MRSA).

Comparison of simple methods of methicillin-resistance detection and evaluation of some properties of methicillin-resistant Staphylococcus aureus strains.

Population analysis of methicillin-resistant Staphylococcus aureus and determination of their sensitivity to antimicrobial agents were performed. It was found, that the methicillin-resistant strains belonged to resistance classes II and III. All methicillin-resistant S.

[Evaluation of susceptibility to antibiotics of Staphylococcus aureus strains resistant to methicillin].

Methicillin-resistant strains of Staphylococcus aureus (MRSA) constitute a serious diagnostic and therapeutic problem. Over 500 strains of Staphylococcus aureus were tested for susceptibility to methicillin. By application of a screening method, 13.

[Evaluation of usefulness of the PYR-Wellcome test for identifying microorganisms from the genus enterococcus].

The study was aimed at evaluation of usefulness of PYR-Wellcome test in bacteriological diagnostic. Results of identification of enterococcal strains by application of the above test were performed on 157 strains of Enterococcus spp., 15 strains of Streptococcus pyogenes and 12 of Streptococcus bovis.

Staphylococcal lipase affects phagocytosis of Staphylococcus aureus by human granulocytes and monocytes.

The rate of immunological and non-immunological phagocytosis of staphylococci by lipase pre-treated human granulocytes and monocytes was compared. It was found that the effect of this enzyme on two types of cells is opposite. Lipase decreases phagocytosis by granulocytes and increases by monocytes.

Lipase versus teichoic acid and alpha-toxin as antigen in an enzyme immunoassay for serological diagnosis of Staphylococcus aureus infections.

Titres of IgG antibodies to Staphylococcus aureus lipase were analysed in 448 sera from patients suspected of having Staphylococcus aureus infections and the results compared to those for the routinely used staphylococcal antigens teichoic acid and alpha-toxin. The results indicated that determination of serum antibodies to lipase is a sensitive assay for serological diagnosis of staphylococcal infections and increased sensitivity may be achieved by selection of optimal antigen combinations.

[Humoral response to Staphylococcus aureus antigens evaluated by the western blotting method].

Cellular antigens extracted from the cells of four Staphylococcus aureus strains from different kinds of infections (sepsis, osteomyelitis, furunculosis) were analysed by the western blotting technique. Antibiotic sensitivity pattern of the strains was compared. One isolate was found to be MRSA strain.

[Preparation of Staphylococcus aureus antigens for evaluation of their immunological reactivity with the human sera by the western blot method].

Extracellular antigens as well as cell wall extracts of 4 S. aureus strains isolated from different kinds of infection were analysed by Western-Blott technique. Materials obtained in two systems of bacteria cultivation (with and without aeration) were compared.

[The role of surface structures of Streptococcus agalactiae in adhesion to epithelial cells].

Induced mutants of S. agalactiae which differed in surface structures were used for the study. The aim of using them was to try to correlate the presence of defined structures or surface properties with the ability of group B streptococci to attach to epithelial cells.

Role of Staphylococcus saprophyticus in human infection.

Biological properties of Staphylococcus saprophyticus strains isolated from urinary tract infection and respiratory tract secretions were investigated. The majority of S. saprophyticus strains exhibit moderate surface hydrophobic properties, as measured by Hydrophobic Interaction Chromatography.