A linear B-cell epitope on the class 3 outer-membrane protein of Neisseria meningitidis recognized after vaccination with the Norwegian group B outer-membrane vesicle vaccine.

The class 3 outer-membrane protein (OMP) of Neisseria meningitidis is a potential target for bactericidal and opsonic antibodies in humans. Synthetic peptides spanning the class 3 OMP from the vaccine strain 44/76 (B:15:P1.7,16:L3,7) were synthesized on pins and screened with serum obtained from Norwegian adolescents immunized with a meningococcal serogroup B outer-membrane vesicle (OMV) vaccine.

Emergence of a new virulent clone within the electrophoretic type 5 complex of serogroup B meningococci in Norway.

An increase in B:15:P1.12 meningococci among isolates from patients with Neisseria meningitidis infection in Norway in recent years led to further characterization of such strains. Between 1987 and 1992, B:15:P1.

Contamination pattern of Listeria monocytogenes and other Listeria spp. in a salmon slaughterhouse and smoked salmon processing plant.

A smoked salmon processing plant including a smokehouse and a slaughterhouse was examined for the occurrence of Listeria monocytogenes and other Listeria spp. From a total of 475 samples the overall frequency of L. monocytogenes was 16%, while other Listeria spp.

Detection of rifampin resistance among isolates of Mycobacterium tuberculosis from Mozambique.

Rifampin resistance in respiratory isolates of Mycobacterium tuberculosis from Mozambique was detected by screening for point mutations using polymerase chain reaction (PCR) and DNA sequence analysis. The target template was a 350-bp fragment of rpoB encoding the beta-subunit of the RNA polymerase. Of the 66 strains studied, 38 were rifampin resistant by susceptibility testing with the radiometric method, 3 were intermediately resistant, and 25 were susceptible to rifampin.

Characterization of strains of Neisseria meningitidis recovered from complement-sufficient and complement-deficient patients in the Western Cape Province, South Africa.

Complement deficiency has been associated with increased susceptibility to meningococcal disease. In order to determine whether special meningococcal strains caused disease in complement-deficient (CD) patients, 17 Neisseria meningitidis strains recovered from patients in the Western Cape Province, South Africa, known to be CD were compared with 124 routine isolates obtained from patients living in the same area. Serogrouping of the strains from the CD subjects revealed that the common serogroups, particularly serogroup B, predominated.

Genotypic Diversity among Bacillus cereus and Bacillus thuringiensis Strains.

Twenty-four strains of Bacillus cereus were analyzed by pulsed-field gel electrophoresis (PFGE) and compared with 12 Bacillus thuringiensis strains. In addition, the 36 strains were examined for variation in 15 chromosomal genes encoding enzymes (by multilocus enzyme electrophoresis [MEE]). The genome of each strain had a distinct NotI restriction enzyme digestion profile by PFGE, and the 36 strains could be assigned to 27 multilocus genotypes by MEE.

Phenotypic and genotypic changes in a new clone complex of Neisseria meningitidis causing disease in The Netherlands, 1958-1990.

To characterize the phenotypic and genotypic changes that occurred in a new clone lineage of Neisseria meningitidis (lineage III) in the Netherlands, the electrophoretic type (ET) was determined for 79 serogroup B isolates of serotype 4 or subtype P1.4 (or both) obtained between 1958 and 1990 from patients with systemic meningococcal disease. Thirty-five previously described isolates were also included.

Asymptomatic carriage of Neisseria meningitidis in a randomly sampled population.

To estimate the extent of meningococcal carriage in the Norwegian population and to investigate the relationship of several characteristics of the population to the carrier state, 1,500 individuals living in rural and small-town areas near Oslo were selected at random from the Norwegian National Population Registry. These persons were asked to complete a questionnaire and to volunteer for a bacteriological tonsillopharyngeal swab sampling. Sixty-three percent of the selected persons participated in the survey.

Characteristics of serogroup A Neisseria meningitidis strains isolated in the Central African Republic in February 1992.

A severe epidemic of serogroup A meningococcus meningitis occurred in the northwest Central African Republic from January to March 1992. Strains from 24 patients were characterized using serotyping, testing of susceptibility to antibiotics, and multilocus enzyme electrophoresis. In 23 of the 24 patients the causal strain was found to be 4:P1.

A new variant of serosubtype P1.16 in Neisseria meningitidis from Norway, associated with increased resistance to bactericidal antibodies induced by a serogroup B outer membrane protein vaccine.

Based on differences in reaction pattern with monoclonal antibodies against the P1.16 epitope, a new variant of the class 1 protein in Neisseria meningitidis serogroup B was identified in Norway. A single amino acid deletion was revealed when the part of the gene region encoding the second variable region of the protein was sequenced.

Antigenic and epidemiologic properties of the ET-37 complex of Neisseria meningitidis.

A special collection of 336 Neisseria meningitidis strains was established that spanned the genetic variability, as defined by multilocus enzyme electrophoresis, of the ET-37 complex (228 strains isolated in different continents between the 1960s and the 1980s) and of other serogroup C meningococci (108 strains). Of the strains in the ET-37 complex, 90% were serogroup C and 10% were serogroup B. Most ET-37 complex strains were serotype 2a and serosubtype P1.

Meningococcal disease in The Netherlands, 1958-1990: a steady increase in the incidence since 1982 partially caused by new serotypes and subtypes of Neisseria meningitidis.

In order to explain a threefold increase in the incidence of meningococcal disease in the Netherlands during the 1980s, we serotyped and subtyped Neisseria meningitidis isolates recovered between 1958 and 1990 from > 3,000 patients with systemic disease. No single strain could be held responsible for the increase. Apart from the newly introduced strain B:4:P1.

Epidemiological analysis of Candida albicans strains by multilocus enzyme electrophoresis.

Genotypic diversity in a collection of 98 isolates of Candida albicans was assessed by multilocus enzyme electrophoresis. Four of the 10 enzyme loci studied were polymorphic. The electrophoretic patterns observed were compatible with those expected for a diploid organism.

Expression of an inaccessible P1.7 subtype epitope on meningococcal class 1 proteins.

Dot-blot analysis of whole-cell suspensions of meningococci showed that 81% of B:15:P1.16 strains from patients reacted with a monoclonal antibody (MAb) against subtype P1.7.

Differentiation of Moraxella nonliquefaciens, M. lacunata, and M. bovis by using multilocus enzyme electrophoresis and hybridization with pilin-specific DNA probes.

Genetic relationships among strains of Moraxella nonliquefaciens, M. lacunata, and M. bovis were studied by using multilocus enzyme electrophoresis and DNA-DNA hybridization.

Clonal and antigenic analysis of serogroup A Neisseria meningitidis with particular reference to epidemiological features of epidemic meningitis in the People's Republic of China.

Representative strains of serogroup A Neisseria meningitidis were chosen from all major meningitis epidemics worldwide since 1960 and subjected to analysis for the electrophoretic variation of 15 cytoplasmic allozymes and four outer membrane proteins. The 290 strains defined 84 unique electrophoretic types which were classified in nine subgroups. Tests with monoclonal antibodies specific for conserved pilin epitopes showed that the class I, IIa, and IIb epitopes were uniform within the subgroups.

Transmission of Neisseria meningitidis among asymptomatic military recruits and antibody analysis.

Following the occurrence of a case of systemic meningococcal disease in a military camp in Norway, throat cultures and blood samples were collected from 33 healthy individuals belonging to the same troop as the patient (troop A) and from 29 individuals from a different troop (troop B) in the same camp. Serological studies showed that 91% of the recruits had bactericidal antibodies against the disease-causing strain. The isolates of Neisseria meningitidis recovered from the throat cultures were serogrouped, serotyped, and assigned to a clone on the basis of an analysis of the electrophoretic mobilities of 14 metabolic enzymes.

[Genotypes of Neisseria meningitidis strains isolated from patients in the Czech Republic].

A group of 75 strains of Neisseria meningitidis isolated from patients with meningococcal meningitis in the Czech Republic during 1980-1988 was characterized by assessment of serogroups, serotypes, serosubtypes and genotypes. Twelve strains belonged into serogroup A, 27 into serogroup B and 36 into serogroup C. The most frequently found serotype was 4, subserotype P1.

Ongoing group B Neisseria meningitidis epidemic in São Paulo, Brazil, due to increased prevalence of a single clone of the ET-5 complex.

Beginning in 1988, the incidence of meningococcal disease in the area of greater São Paulo began to surpass the upper confidence limit of an 8-year average incidence (from 1979 to 1986), thus characterizing a new epidemic in the region of greater São Paulo. This epidemic, which extended to 1990, was different from previous epidemics in that it was caused by serogroup B. The increased incidence of meningococcal disease was paralleled by an increased prevalence of a single group B clone, B:4:P1.

Differentiation of Listeria monocytogenes isolates by using plasmid profiling and multilocus enzyme electrophoresis.

Three hundred and seven Listeria monocytogenes isolates from various origins (clinical sources, raw chicken, seafoods, dairy and meat products and processing environments) were screened for plasmids. The overall frequency of L. monocytogenes isolates containing plasmids was 77%.

Emergence of a new clone of serogroup C Neisseria meningitidis in São Paulo, Brazil.

Serogroup C isolates of Neisseria meningitidis recovered from 121 patients with meningitis or septicemia in Greater São Paulo, Brazil, between 1976 and 1990 were analyzed with respect to serotype and multilocus enzyme genotype. The distribution of serotypes has changed since 1989 when serotype 2b started to replace serotype 2a. There were 48 distinct multilocus genotypes (electrophoretic types [ETs]) and 13 distinct complexes.

Molecular polymorphism and epidemiology of Neisseria meningitidis immunoglobulin A1 proteases.

Neisseria meningitidis is one of several important bacterial pathogens that secrete a specific protease capable of cleaving human immunoglobulin A1 (IgA1) in the hinge region. To obtain further information on this putative virulence factor, we examined the IgA1 protease and iga gene region of 133 isolates of N. meningitidis assigned to 88 multilocus enzyme genotypes and representing major epidemics and carrier strains from 19 countries.

Resident colonic Escherichia coli strains frequently display uropathogenic characteristics.

Bacterial factors associated with long-term persistence in the colon have not been defined. Individual Escherichia coli strains in the colonic flora of 13 schoolgirls with asymptomatic bacteriuria were identified by electromorphic typing of chromosomally encoded enzymes and defined as resident or transient. The strains were characterized as to serotype, receptor specificity, and adherence to the human colonic epithelial cell line HT-29.