Genotyping by amplified fragment length polymorphism analysis reveals persistence and recurrence of infection with Streptococcus anginosus group organisms.
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Streptococcus anginosus, Streptococcus constellatus, and Streptococcus intermedius, commonly referred to as the Streptococcus anginosus group (SAG), are commensal organisms known for their propensity to cause purulent infections which are difficult to eradicate. In this study, we determined the genetic similarities between SAG isolates consecutively recovered from single patients to assess the duration of infection or colonization. A total of 97 SAG isolates recovered from 30 patients were included; 65 (67.0%) of the isolates were abscess related. The isolates were identified by the 16S rRNA reverse line blot hybridization assay as S. anginosus (n = 34), S. constellatus (n = 55), and S. intermedius (n = 8). Amplified fragment length polymorphism (AFLP) analysis of the SAG isolates produced discriminatory and reproducible patterns. Consecutive SAG isolates with identical AFLP types were found in 27 of 30 (90.0%) patients, and consecutive isolates with only a single AFLP type were demonstrated in 21 (70.0%) patients. The median delay between the times of recovery of the first and last isolates of identical AFLP types from each patient was 36 days, and this delay extended for more than 1 year in patients with both colonizing and abscess-related SAG isolates. In six bacteremic patients, paired blood and nonblood SAG isolates showed identical AFLP types. (+info)
Horizontal transfer of segments of the 16S rRNA genes between species of the Streptococcus anginosus group.
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The nature in variation of the 16S rRNA gene of members of the Streptococcus anginosus group was investigated by hybridization and DNA sequencing. A collection of 708 strains was analyzed by reverse line blot hybridization. This revealed the presence of distinct reaction patterns representing 11 different hybridization groups. The 16S rRNA genes of two strains of each hybridization group were sequenced to near-completion, and the sequence data confirmed the reverse line blot hybridization results. Closer inspection of the sequences revealed mosaic-like structures, strongly suggesting horizontal transfer of segments of the 16S rRNA gene between different species belonging to the Streptococcus anginosus group. Southern blot hybridization further showed that within a single strain all copies of the 16S rRNA gene had the same composition, indicating that the apparent mosaic structures were not PCR-induced artifacts. These findings indicate that the highly conserved rRNA genes are also subject to recombination and that these events may be fixed in the population. Such recombination may lead to the construction of incorrect phylogenetic trees based on the 16S rRNA genes. (+info)
Invasive group B streptococcal disease in infants: a 19-year nationwide study. Serotype distribution, incidence and recurrent infection.
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During the period 1984-2002, 472 cases of invasive group B streptococcal (GBS) disease in infants aged 0-90 days in Denmark were registered. The overall incidence was 0.4/1000 live births. Most infants (73%) had early-onset GBS infection with 53% registered within the first day. Serotype III predominated (59%) with other serotypes as follows: Ia (16%), Ib (8%), NT (7%), II (6%), other serotypes (5%). Recurrence of GBS infection was registered in six infants, and the interval with no antibiotic therapy varied from 2 to 39 days. The serotypes of the isolates obtained from first and second episodes were identical (serotype III in five, and serotype Ia in one infant). Paired isolates were indistinguishable by PFGE and antibiotic susceptibility testing. Invasive GBS infections in infants are still a problem in Denmark, and recurrent infections are registered in 1% of these infants. (+info)
Culture results of heart valves resected because of streptococcal endocarditis: insights into duration of treatment to achieve valve sterilization.
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OBJECTIVES: To analyse the culture results of heart valves removed following streptococcal endocarditis in order to gain insight into the duration of treatment required for valve sterilization. PATIENTS AND METHODS: Retrospective review of 131 episodes of streptococcal endocarditis: 94 due to alpha-haemolytic streptococci; 15 due to beta-haemolytic streptococci; 10 due to nutritionally deficient streptococci; eight due to the Streptococcus anginosus group and four due to Streptococcus pneumoniae. Patients had their valves removed during antimicrobial treatment. Culture results were analysed with respect to duration of treatment before surgery. RESULTS: For alpha-haemolytic streptococci, 17 (18%) valves were culture-positive and 77 (82%) culture-negative after a median (range) of 4 (1-20) and 16 (4-58) days of treatment, respectively, P < 0.001. For beta-haemolytic streptococci, two valves (13%) were culture-positive; both patients had received < or = 4 days of treatment. Four patients (40%) with nutritionally deficient streptococci were culture-positive, and had received < or = 8 days of treatment. For the S. anginosus group, two valves (25%) were culture-positive; both patients had received < or = 4 days of treatment before operation. Overall, only one of 131 (0.8%) valves was culture-positive after 14 days of treatment. All valves infected with beta-haemolytic streptococci, nutritionally deficient streptococci and the S. anginosus group, who were treated for more than 8 days before surgery, were culture-negative. CONCLUSIONS: Our findings support current treatment guidelines for endocarditis caused by alpha-haemolytic streptococci. We suggest that the recommended duration of treatment for endocarditis resulting from other streptococci may be excessive and treatment trials evaluating 2 and 4 week regimens are justified. (+info)
Expression of the gtfI gene from Streptococcus sobrinus in Streptococcus anginosus using integration-mediated transformation system.
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We have constructed a Streptococcus anginosus transformant expressing the gtfI gene from Streptococcus sobrinus, using a previously developed integration-mediated transformation system to introduce foreign genes onto the oral streptococcal chromosome, and attempted to evaluate the gene expression. In this system, one cloning plasmid and three pACYC184 derivatives, anchor, heterodimer, and integration plasmids were used for the construction of a series of integrants via homologous recombination. A portion of S. sobrinus gtfI gene devoid of approximately 1 kb of the 5'-region derived from pMD39 was cloned into the integration plasmid and introduced onto the S. anginosus chromosome. Next, the polymerase chain reaction product corresponding to 2.0 kb of the 5'-region of the gtfI gene from S. sobrinus chromosome was further cloned into the cloning plasmid, and the intact gtfI gene was reconstructed following integration. The final S. anginosus integrant successfully secreted the enzymatically active gtfI gene products and extracellular enzyme was characterized. This enzyme produced water-insoluble glucans and glucan-forming activity was stimulated by the addition of dextranT10. When this integrant was grown in Todd-Hewitt broth supplemented with sucrose, the integrant adhered to the glass surface in vitro and this integrant exhibited the different colony morphology on Mitis-Salivarius agar plates compared to S. sobrinus and S. anginosus. These observations strongly suggest that the construction of S. anginosus integrant expressing S. sobrinus gtfI gene using this transformation system may be an effective means of analysis of cariogenic biofilm formation. (+info)
Spontaneous cervical paraspinal and epidural giant abscess in a child--case report--.
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A 10-year-old girl presented with a very rare paraspinal and spinal epidural abscess manifesting as fever, and neck pain and stiffness. Initially, she was treated under a diagnosis of meningitis for 3 weeks. However, she developed monoparesis of the right upper extremity, and was referred for neurosurgery. Magnetic resonance imaging revealed an epidural and paraspinal lesion intensely enhanced by gadolinium. The patient underwent urgent surgery for C2-3 laminectomy and abscess drainage, followed by broad spectrum antibiotic therapy. She was discharged and followed up in the outpatient clinic. Two months later, the paraspinal abscess recurred with great increase in size. A second operation was performed and 150 ml pus was drained. Streptococcus anginosus was grown in the culture. The patient fully recovered after long-term targeted antibiotic therapy. Such abscesses are very rare in children, especially in the cervical region. The correct diagnosis can be difficult to establish but early treatment is essential for a good prognosis. (+info)
Homogeneous enzymatic assay for L-cysteine with betaC-S lyase.
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We have developed a new enzymatic assay for determining L-cysteine concentration. The method involves the use of betaC-S lyase from Streptococcus anginosus, which catalyzes the alpha,beta-elimination of L-cysteine to hydrogen sulfide, pyruvate, and ammonia. The production of pyruvate is measured by D-lactate dehydrogenase and NADH. The decrease in NADH was proportional to the L-cysteine concentration up to 1.0 mM. When serum samples were used, within-day and day-to-day coefficient variations were below 4%. This method is simple, and can easily and reliably be used for accurate determination of L-cysteine concentration in serum or other samples. (+info)
Rapid differentiation between members of the anginosus group and Streptococcus dysgalactiae subsp. equisimilis within beta-hemolytic group C and G streptococci by PCR.
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Based on a pair of primers developed initially for differentiating the anginosus group from other viridans streptococci, the PCR reported here can also differentiate between members of the anginosus group and Streptococcus dysgalactiae subsp. equisimilis among beta-hemolytic group C and G streptococci. The resulting 742-bp PCR product was specific for members of the anginosus group, although a smaller, nonspecific product (361 bp) was generated from S. dysgalactiae subsp. equisimilis. Restriction digestion of the amplicon with XbaI and BsmI further differentiated Streptococcus anginosus from Streptococcus constellatus within the anginosus group. (+info)