Phenotypic and genomic characterization of pneumococcus-like streptococci isolated from HIV-seropositive patients.

Accurate differentiation between pneumococci and other viridans streptococci is essential given their differences in clinical significance. However, classical phenotypic tests are often inconclusive, and many examples of atypical reactions have been reported. In this study, we applied various phenotypic and genotypic methods to discriminate between a collection of 12 streptococci isolated from the upper respiratory tract of HIV-seropositive individuals in 1998 and 1999.

Immunogenicity of fractional doses of tetravalent a/c/y/w135 meningococcal polysaccharide vaccine: results from a randomized non-inferiority controlled trial in Uganda.

Background: Neisseria meningitidis serogroup A is the main causative pathogen of meningitis epidemics in sub-Saharan Africa. In recent years, serogroup W135 has also been the cause of epidemics. Mass vaccination campaigns with polysaccharide vaccines are key elements in controlling these epidemics.

Carriage of Streptococcus pneumoniae in healthy Norwegian children attending day-care centres.

An observational study to examine Streptococcus pneumoniae carriage in Norwegian children was initiated after two cases of pneumococcal meningitis, caused by the England(14)-9 clone, occurred in one day-care centre in Oslo. All children recruited from the day-care centre where the cases occurred were vaccinated with a seven-valent pneumococcal conjugate vaccine; the other participants who attended three other day-care centres nearby were not. The children were followed for 9 months, and three samplings took place.

Pharyngeal carriage of Neisseria meningitidis in 2-19-year-old individuals in Uganda.

In southern Uganda, only sporadic cases of serogroup A meningococcal disease have been reported since 2000. As part of an immunogenicity study of the tetravalent meningococcal polysaccharide vaccine, nasopharyngeal swab samples were collected twice, 4 weeks apart, from 2-19-year-old healthy individuals in Mbarara, Uganda. Only 15 (2.

Systemic pneumococcal disease in Norway 1995-2001: capsular serotypes and antimicrobial resistance.

A total of 4624 pneumococcal isolates from episodes of systemic pneumococcal disease were received at the Norwegian Institute of Public Health during the period 1995-2001. All isolates were serotyped and tested for susceptibility to benzylpenicillin, lincomycin, erythromycin, tetracycline and trimethroprim sulphamethoxazole. The proportion of strains resistant to these antimicrobial agents remained stable at a low level, ranging from 0.

Antibody specificities and effect of meningococcal carriage in icelandic teenagers receiving the Norwegian serogroup B outer membrane vesicle vaccine.

Antibody specificities of pre- and postvaccination serum samples from 40 (53%) teenagers who received three doses of the Norwegian Neisseria meningitidis serogroup B vaccine (B:15:P1.7,16) during a previous trial in Iceland (Perkins et al., J.

Molecular characteristics of Neisseria meningitidis strains isolated in Burkina Faso in 2001.

In the course of an epidemic of meningitis in Burkina Faso in 2001, 27 cerebrospinal fluid samples from patients in 7 districts were forwarded to Norway for isolation and characterization of the causative agents. Neisseria meningitidis was isolated from 13 (48%) samples. The isolates were analysed using serological and genetic methods.

Do HIV-seropositive patients become colonised with drug-resistant microorganisms?

The aim of the present study was to investigate whether HIV-infected patients, a group that is supposedly at risk for infection with antibiotic-resistant microbes, really does so, and to assess possible risk factors for acquiring these organisms. During the period from January 1998 to July 1999, samples of normal flora were obtained from 107 HIV-infected patients attending an outpatient clinic in Oslo, Norway. The samples were cultured for Streptococcus pneumoniae, Haemophilus influenzae, Escherichia coli, coagulase-negative staphylococci and Candida spp.

Emerging antibiotic resistance in Salmonella typhimurium in Norway.

The antimicrobial resistance of 809 Salmonella Typhimurium isolates collected from humans in Norway between 1975 and 1998 was studied. The material was subdivided into domestic and foreign isolates according to whether the patient had recently travelled abroad or not. In imported isolates the largest increase in resistance was in 1996 when 35% of the isolates were multi-resistant.

Genomic rearrangements in neisseria meningitidis strains of the ET-5 complex.

A physical map of the chromosome of Neisseria meningitidis strain 44/76, which belongs to the epidemic clone ET-5, was constructed. DNA fragments obtained after SfiI and NheI digestion were resolved by pulsed field gel electrophoresis (PFGE). The overall arrangement of 26 genetic markers localized on the 2.

Induction of antigen-specific T cell responses in human volunteers after intranasal immunization with a whole-cell pertussis vaccine.

We have studied the ability of an intranasally administered whole-cell pertussis vaccine (WCP) without adjuvant to induce antigen-specific T cell responses in humans. Six adult volunteers were given a vaccine dose (corresponding to 250 microg protein) by nasal spray four times at weekly intervals, and peripheral blood mononuclear cells were assayed for antigen-specific proliferative T cell responses. All six vaccinees had a WCP-specific response, which in four of them remained elevated throughout the 2 month study.

Outbreak of meningococcal disease in western Norway due to a new serogroup C variant of the ET-5 clone: effect of vaccination and selective carriage eradication.

A new sulphonamide resistant (SR) C: 15:P1.7,16 meningococcal strain, a variant of the ET-5 clone, dominated in an outbreak of 22 cases in western Norway commencing in 1995. The first eight patients were 15-21 years old from the Nordhordland area, initiating a carrier study in the local high schools.

A nasal whole-cell pertussis vaccine induces specific systemic and cross-reactive mucosal antibody responses in human volunteers.

A whole-cell pertussis vaccine, each dose consisting of 250 microg of protein, was given intranasally four times at weekly intervals to six adult volunteers. All vaccinees responded with increases in nasal fluid IgA antibodies to Bordetella pertussis whole-cell antigen. Three vaccinees with high nasal antibody responses also developed increased serum IgA and IgG antibodies to this antigen.

Low occurrence of antibiotic resistance in Escherichia coli and staphylococci isolated from blood cultures in two Norwegian hospitals in 1991-92 and 1995-96.

The aim of this study was to investigate the antibiotic resistance rates of major bacterial pathogens causing bloodstream infections in two very different types of hospital in Norway. We examined all Escherichia coli and staphylococci (330 isolates) causing bloodstream infections from one general county hospital and one specialist national cancer hospital during the periods 1991-92 and 1995-96. Minimal inhibitory concentrations (MICs) were determined using the E-test.

A mouse model utilising human transferrin to study protection against Neisseria meningitidis serogroup B induced by outer membrane vesicle vaccination.

We have previously developed a mouse model based on transient bacteraemia in normal B10.M mice to evaluate the protective efficacy of outer membrane vesicle vaccines against serogroup B meningococci. To obtain a course of infection similar to that observed in man, we have in this work modified the mouse model by administration of human holo-transferrin upon bacterial challenge.

Identification of nasopharyngeal carriage of an outbreak strain of Neisseria meningitidis by pulsed-field gel electrophoresis versus phenotypic methods.

The clustering of four cases of meningococcal disease during a 3-month period in a small community with 2233 inhabitants prompted an interventional carrier survey in persons < 19 years old and in family members of the patients. The aims of the survey were to identify the nasopharyngeal carriers and the carriage rate of the outbreak strain, to offer chemoprophylaxis to those carrying the outbreak strain, and to study the discriminatory power of phenotypic methods versus pulsed-field gel electrophoresis (PFGE) on carrier isolates during an outbreak. A high percentage of the population in the age group 0-19 years (73.

Clonal distribution of invasive Neisseria meningitidis isolates from the Norwegian county of Telemark, 1987 to 1995.

Forty-two Neisseria meningitidis isolates were obtained from patients with meningococcal disease in the Norwegian county of Telemark (January 1987 to March 1995), and all were compared by PCR amplicon restriction endonuclease analysis (PCR-AREA) of the dhps gene, chromosomal DNA fingerprinting, and serological analysis. PCR-AREA divided the isolates into 11 classes, of which 4, comprising 15, 8, 6, and 2 isolates, were clonal while the remaining 8 classes were genetically heterogeneous or contained only 1 isolate. Three of the four clonal classes could be tentatively equated with recognized epidemic clones (ET5, ET37, and cluster A4) on the basis of their phenotypic characteristics, while the remaining clone appears to be new.

Effect of aluminium hydroxide and meningococcal serogroup C capsular polysaccharide on the immunogenicity and reactogenicity of a group B Neisseria meningitidis outer membrane vesicle vaccine.

Three different formulations of an outer membrane vesicle (OMV) vaccine against group B meningococcal disease have been prepared and tested for immunogenicity and reactogenicity in adult volunteers. The vaccines were prepared with or without aluminium hydroxide and serogroup C-polysaccharide (C-ps). Doses from 12.

Polymerase chain reaction for case ascertainment of meningococcal meningitis: application to the cerebrospinal fluids collected in the course of the Norwegian meningococcal serogroup B protection trial.

To improve the diagnosis of systemic meningococcal disease we used a nested polymerase chain reaction (nPCR) test to detect meningococcal DNA in cerebrospinal fluid (CSF) samples from patients. The nPCR test was based on the gene coding for the PorA outer membrane protein, a major antigen of Neisseria meningitidis, which is the basis for determining the subtype of the strains. The method was tested on CSF samples from 87 patients with various disease aetiology, including 37 patients with systemic meningococcal disease.

Serotypes and subtypes of Neisseria meningitidis: results of an international study comparing sensitivities and specificities of monoclonal antibodies.

An international study supported by the World Health Organization comparing monoclonal antibodies for serotyping and serosubtyping of Neisseria meningitidis strains was performed and the results were assessed in 1992. A collection of 6 serotype-specific (1, 2a, 2b, 4, 14, and 15) and 12 serosubtype-specific (P1.1, P1.

[All persons without spleen should be given pneumococcal vaccine].

Splenectomized individuals run increased risk of developing overwhelming septicemia from encapsulated bacteria, especially Streptococcus pneumoniae. Polyvalent pneumococcal polysaccharide vaccine should be given to all splenectomized individuals above two years of age. Antipneumococcal antibody levels should be measured three to five years after the first vaccination, and persons with low antibody levels should be revaccinated.

[High incidence and mortality of systemic pneumococcal disease among persons without spleen].

We surveyed 472 cases of culture-confirmed systemic pneumococcal disease that were reported to the Norwegian Notification System for Infectious Diseases during a 12-month period in 1992-93. The clinicians in charge of the patients filled in a questionnaire providing information on underlying disease and outcome for 461 (98%) of the patients. Eight of these patients were splenectomized; all of them more than ten years before.

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.