RESUMO
An outbreak of Campylobacter upsaliensis in four Brussels day care centers (A, B-1, B-2, and C) affected 44 children. Diarrhea was the major symptom. From January 1991 to June 1992, the outbreak strain was isolated from 3, 1, and 21 (of 68) children in centers A, B-1, and B-2, respectively, and from 19 of 22 children in center C, IgG, IgM, and IgA antibodies were detected by Western blotting of serum specimens of 9 of 10 and 13 of 16 children in centers B-2 and C, respectively. Strains were typed by biotyping, DNA restriction-based and antibiotic susceptibility typing, whole cell protein and plasmid analysis, restriction fragment length polymorphism (RFLP), and polymerase chain reaction (PCR). On the basis of RFLP and PCR typing, the strains could be divided into two strongly related clonal variants: One was isolated only from the children of center A and the second only from children in the other day care centers.
Assuntos
Infecções por Campylobacter/epidemiologia , Campylobacter/genética , Creches , Surtos de Doenças , Antibacterianos/farmacologia , Bélgica , Western Blotting , Campylobacter/classificação , Campylobacter/isolamento & purificação , Infecções por Campylobacter/imunologia , Infecções por Campylobacter/transmissão , Pré-Escolar , Variação Genética , Genótipo , Humanos , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Lactente , Testes de Sensibilidade Microbiana , Fenótipo , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , População UrbanaRESUMO
The nucleotide sequence of the region between the 16S and 23S rRNA genes of the facultative anaerobic bacterium Gardnerella vaginalis has been determined, together with the 5' proximal 500 nucleotides of the 23S rRNA gene. Regions suited for the development of specific, probe-confirmable polymerase chain reaction (PCR) assays were selected. PCR assays were evaluated with respect to sensitivity and specificity, the latter in comparison with a number of G. vaginalis reference strains and closely related species like Bifidobacterium spp. In an initial diagnostic study it appeared that the PCR test detected G. vaginalis in 40% of women irrespective of their clinical status. Ten out of 11 patients suffering from bacterial vaginosis as defined on the basis of clinical parameters were carrying G. vaginalis.
Assuntos
Gardnerella vaginalis/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , Vaginose Bacteriana/diagnóstico , Sequência de Bases , DNA Bacteriano/análise , DNA Ribossômico/análise , DNA Ribossômico/genética , Ácidos Graxos/análise , Feminino , Gardnerella vaginalis/química , Gardnerella vaginalis/genética , Humanos , Recém-Nascido , Dados de Sequência Molecular , Fenótipo , Gravidez , Complicações Infecciosas na Gravidez/diagnóstico , RNA Ribossômico/química , RNA Ribossômico/genética , RNA Ribossômico 16S/química , RNA Ribossômico 16S/genética , RNA Ribossômico 23S/química , RNA Ribossômico 23S/genética , Especificidade da EspécieRESUMO
The applicability of polymerase chain reaction (PCR)-mediated DNA typing, with primers complementary to dispersed repetitive DNA sequences and arbitrarily chosen DNA motifs, to study the epidemiology of campylobacter infection was evaluated. With a single PCR reaction and simple gel electrophoresis, strain-specific DNA banding patterns were observed for Campylobacter jejuni and C. upsaliensis. DNA from multiple strains isolated during an outbreak of C. jejuni meningitis generated identical banding patterns and could be distinguished from randomly isolated strains. Strains from a community outbreak of C. upsaliensis, that were all identical by conventional typing methods, could be divided into two genetically different groups. This report illustrates that PCR fingerprinting can be successfully applied in epidemiological investigations of campylobacter infections.
Assuntos
Infecções por Campylobacter/microbiologia , Campylobacter/classificação , Impressões Digitais de DNA , DNA Bacteriano/análise , Animais , Técnicas de Tipagem Bacteriana , Sequência de Bases , Bélgica/epidemiologia , Campylobacter/genética , Infecções por Campylobacter/epidemiologia , Campylobacter jejuni/classificação , Campylobacter jejuni/genética , Creches , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/microbiologia , Primers do DNA/química , DNA Bacteriano/química , Surtos de Doenças , Enterite/epidemiologia , Enterite/microbiologia , França/epidemiologia , Humanos , Lactente , Meningites Bacterianas/epidemiologia , Meningites Bacterianas/microbiologia , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Polimorfismo Genético , PrevalênciaRESUMO
The application of polymerase chain reaction (PCR) fingerprinting assays enables discrimination between species and strains of microorganisms. PCR primers aiming at arbitrary sequences in combination with primers directed against the repetitive extragenic palindrome (REP) or enterobacterial repetitive intergenic consensus (ERIC) motifs generate isolate-specific DNA banding patterns. Analysis of these PCR fingerprints obtained for 33 isolates of Campylobacter jejuni, 30 isolates of Campylobacter coli, and 8 isolates of Campylobacter lari revealed that besides generation of isolate-specific fragments, species-specific DNA fragments of identical size were synthesized. It appeared that these DNA fragments could be used as species-specific probes, since they are unique for the pattern which they are deriving from. The probes do not cross-react with amplified DNA originating from a large panel of nonrelated microorganisms. Moreover, these probes displayed species specificity, as they reacted with a single restriction fragment on Southern blots containing DNA from C. jejuni, C. coli, and C. lari and other Campylobacter species. This combination of PCR fingerprinting and probe hybridization results in a highly specific identification assay and provides an example of specific test development without the prior need for DNA sequence information. The principle of the procedure holds great promise for the rapid isolation of DNA probes which, in combination with a general PCR assay, may lead to efficient typing and detection procedures for a multitude of medically important nonviral microorganisms.
