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Kwok-yung Yuen - One of the best experts on this subject based on the ideXlab platform.
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Streptococcus sinensis may react with Lancefield group F antiserum.
Journal of Medical Microbiology, 2004Co-Authors: Patrick C. Y. Woo, Jade L. L. Teng, Kit-wah Leung, Susanna K. P. Lau, Herman Tse, Beatrice H.l. Wong, Kwok-yung YuenAbstract:Lancefield group F streptococci have been found almost exclusively as members of the ‘Streptococcus milleri’ group, although they have been reported very occasionally in some other streptococcal species. Among 302 patients with bacteraemia caused by viridans streptococci over a 6-year period, three cases were caused by Streptococcus sinensis (type strain HKU4T, HKU5 and HKU6). All three patients had infective endocarditis complicating their underlying chronic rheumatic heart diseases. Gene sequencing showed no base differences between the 16S rRNA gene sequences of HKU5 and HKU6 and that of HKU4T. All three strains were Gram-positive, non-spore-forming cocci arranged in chains. All grew on sheep blood agar as α-haemolytic, grey colonies of 0.5–1 mm in diameter after 24 h incubation at 37 °C in ambient air. Lancefield Grouping revealed that HKU5 and HKU6 were Lancefield group F, but HKU4T was non-groupable with Lancefield groups A, B, C, D, F or G antisera. HKU4T was identified by the Vitek system (GPI), API system (20 STREP) and ATB system (ID32 STREP) as 99 % Streptococcus intermedius, 51.3 % S. intermedius and 99.9 % Streptococcus anginosus, respectively. Using the same tests, HKU5 was identified as 87 % Streptococcus sanguinis/Streptococcus gordonii, 59 % Streptococcus salivarius and 99.6 % S. anginosus, respectively, and HKU6 as 87 % S. sanguinis/S. gordonii, 77 % Streptococcus pneumoniae and 98.3 % S. anginosus, respectively. The present data revealed that a proportion of Lancefield group F streptococci could be S. sinensis. Lancefield group F streptococci should not be automatically reported as ‘S. milleri'.
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Streptococcus sinensis may react with Lancefield group F antiserum
2004Co-Authors: Kwok-yung Yuen, Patrick C. Y. Woo, Jade L. L. Teng, Kit-wah Leung, Susanna K. P. Lau, Herman TseAbstract:Lancefield group F streptococci have been found almost exclusively as members of the ‘Streptococcus milleri ’ group, although they have been reported very occasionally in some other streptococcal species. Among 302 patients with bacteraemia caused by viridans streptococci over a 6-year period, three caseswere caused byStreptococcus sinensis (type strain HKU4T, HKU5 and HKU6). All three patients had infective endocarditis complicating their underlying chronic rheumatic heart diseases. Gene sequencing showed no base differences between the 16S rRNA gene sequences of HKU5 andHKU6 and that of HKU4T. All three strains wereGram-positive, non-spore-forming cocci arranged in chains. All grew on sheep blood agar as Æ-haemolytic, grey colonies of 0.5–1 mm in diameter after 24 h incubation at 37 8C in ambient air. Lancefield Grouping revealed that HKU5 and HKU6 were Lancefield group F, but HKU4T was non-groupable with Lancefiel
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Streptococcus sinensis may react with Lancefield group F antiserum.
Journal of medical microbiology, 2004Co-Authors: Patrick C. Y. Woo, Jade L. L. Teng, Kit-wah Leung, Susanna K. P. Lau, Herman Tse, Beatrice H.l. Wong, Kwok-yung YuenAbstract:Lancefield group F streptococci have been found almost exclusively as members of the 'Streptococcus milleri' group, although they have been reported very occasionally in some other streptococcal species. Among 302 patients with bacteraemia caused by viridans streptococci over a 6-year period, three cases were caused by Streptococcus sinensis (type strain HKU4T, HKU5 and HKU6). All three patients had infective endocarditis complicating their underlying chronic rheumatic heart diseases. Gene sequencing showed no base differences between the 16S rRNA gene sequences of HKU5 and HKU6 and that of HKU4T. All three strains were Gram-positive, non-spore-forming cocci arranged in chains. All grew on sheep blood agar as alpha-haemolytic, grey colonies of 0.5-1 mm in diameter after 24 h incubation at 37 degrees C in ambient air. Lancefield Grouping revealed that HKU5 and HKU6 were Lancefield group F, but HKU4T was non-groupable with Lancefield groups A, B, C, D, F or G antisera. HKU4T was identified by the Vitek system (GPI), API system (20 STREP) and ATB system (ID32 STREP) as 99 % Streptococcus intermedius, 51.3 % S. intermedius and 99.9 % Streptococcus anginosus, respectively. Using the same tests, HKU5 was identified as 87 % Streptococcus sanguinis/Streptococcus gordonii, 59 % Streptococcus salivarius and 99.6 % S. anginosus, respectively, and HKU6 as 87 % S. sanguinis/S. gordonii, 77 % Streptococcus pneumoniae and 98.3 % S. anginosus, respectively. The present data revealed that a proportion of Lancefield group F streptococci could be S. sinensis. Lancefield group F streptococci should not be automatically reported as 'S. milleri'.
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Analysis of a viridans group strain reveals a case of bacteremia due to Lancefield group G alpha-hemolytic Streptococcus dysgalactiae subsp equisimilis in a patient with pyomyositis and reactive arthritis.
Journal of clinical microbiology, 2003Co-Authors: Patrick C. Y. Woo, Jade L. L. Teng, Kit-wah Leung, Susanna K. P. Lau, Peggy N. L. Lum, Kee-lam Wong, Kui-chun Lam, Kwok-yung YuenAbstract:Streptococcus dysgalactiae is classified by a combination of phenotypic and genotypic characteristics into Lancefield group C alpha-hemolytic Streptococcus dysgalactiae subsp. dysgalactiae and Lancefield group C, group G, and group L beta-hemolytic Streptococcus dysgalactiae subsp. equisimilis. In this study, we report the isolation of a catalase-negative, alpha-hemolytic, optochin- and bacitracin-resistant viridans group strain, which does not grow in 10 or 40% bile, on MacConkey agar or bile esculin agar, or in 6% NaCl, from the blood culture of a 73-year-old woman with pyomyositis and poststreptococcal reactive arthritis. Lancefield Grouping revealed that the strain was a group G streptococcus. The Vitek system (GPI) showed that it was unidentified, and the API system (20 STREP) showed that it was 95.7% S. dysgalactiae subsp. dysgalactiae. 16S rRNA gene sequencing showed that it was a strain of S. dysgalactiae. Based on phylogenetic affiliation with 16S rRNA gene or GroEL amino acid (another bacterial gene, in addition to 16S rRNA gene, that is highly conserved) sequences, the strain is most closely related to Lancefield group C beta-hemolytic S. dysgalactiae subsp. equisimilis. PCR amplification and sequencing of the streptolysin S structural gene (sagA) and M protein gene (emm) hypervariable region showed the presence of these suspected primary virulence factors. Further studies would delineate whether the isolate is just a hemolysin-deficient variant of group G beta-hemolytic S. dysgalactiae subsp. equisimilis or a novel type of S. dysgalactiae. The present case showed that group G alpha-hemolytic S. dysgalactiae subsp. equisimilis can be associated with serious invasive infection and poststreptococcal sequelae.
Patrick C. Y. Woo - One of the best experts on this subject based on the ideXlab platform.
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Streptococcus sinensis may react with Lancefield group F antiserum.
Journal of Medical Microbiology, 2004Co-Authors: Patrick C. Y. Woo, Jade L. L. Teng, Kit-wah Leung, Susanna K. P. Lau, Herman Tse, Beatrice H.l. Wong, Kwok-yung YuenAbstract:Lancefield group F streptococci have been found almost exclusively as members of the ‘Streptococcus milleri’ group, although they have been reported very occasionally in some other streptococcal species. Among 302 patients with bacteraemia caused by viridans streptococci over a 6-year period, three cases were caused by Streptococcus sinensis (type strain HKU4T, HKU5 and HKU6). All three patients had infective endocarditis complicating their underlying chronic rheumatic heart diseases. Gene sequencing showed no base differences between the 16S rRNA gene sequences of HKU5 and HKU6 and that of HKU4T. All three strains were Gram-positive, non-spore-forming cocci arranged in chains. All grew on sheep blood agar as α-haemolytic, grey colonies of 0.5–1 mm in diameter after 24 h incubation at 37 °C in ambient air. Lancefield Grouping revealed that HKU5 and HKU6 were Lancefield group F, but HKU4T was non-groupable with Lancefield groups A, B, C, D, F or G antisera. HKU4T was identified by the Vitek system (GPI), API system (20 STREP) and ATB system (ID32 STREP) as 99 % Streptococcus intermedius, 51.3 % S. intermedius and 99.9 % Streptococcus anginosus, respectively. Using the same tests, HKU5 was identified as 87 % Streptococcus sanguinis/Streptococcus gordonii, 59 % Streptococcus salivarius and 99.6 % S. anginosus, respectively, and HKU6 as 87 % S. sanguinis/S. gordonii, 77 % Streptococcus pneumoniae and 98.3 % S. anginosus, respectively. The present data revealed that a proportion of Lancefield group F streptococci could be S. sinensis. Lancefield group F streptococci should not be automatically reported as ‘S. milleri'.
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Streptococcus sinensis may react with Lancefield group F antiserum
2004Co-Authors: Kwok-yung Yuen, Patrick C. Y. Woo, Jade L. L. Teng, Kit-wah Leung, Susanna K. P. Lau, Herman TseAbstract:Lancefield group F streptococci have been found almost exclusively as members of the ‘Streptococcus milleri ’ group, although they have been reported very occasionally in some other streptococcal species. Among 302 patients with bacteraemia caused by viridans streptococci over a 6-year period, three caseswere caused byStreptococcus sinensis (type strain HKU4T, HKU5 and HKU6). All three patients had infective endocarditis complicating their underlying chronic rheumatic heart diseases. Gene sequencing showed no base differences between the 16S rRNA gene sequences of HKU5 andHKU6 and that of HKU4T. All three strains wereGram-positive, non-spore-forming cocci arranged in chains. All grew on sheep blood agar as Æ-haemolytic, grey colonies of 0.5–1 mm in diameter after 24 h incubation at 37 8C in ambient air. Lancefield Grouping revealed that HKU5 and HKU6 were Lancefield group F, but HKU4T was non-groupable with Lancefiel
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Streptococcus sinensis may react with Lancefield group F antiserum.
Journal of medical microbiology, 2004Co-Authors: Patrick C. Y. Woo, Jade L. L. Teng, Kit-wah Leung, Susanna K. P. Lau, Herman Tse, Beatrice H.l. Wong, Kwok-yung YuenAbstract:Lancefield group F streptococci have been found almost exclusively as members of the 'Streptococcus milleri' group, although they have been reported very occasionally in some other streptococcal species. Among 302 patients with bacteraemia caused by viridans streptococci over a 6-year period, three cases were caused by Streptococcus sinensis (type strain HKU4T, HKU5 and HKU6). All three patients had infective endocarditis complicating their underlying chronic rheumatic heart diseases. Gene sequencing showed no base differences between the 16S rRNA gene sequences of HKU5 and HKU6 and that of HKU4T. All three strains were Gram-positive, non-spore-forming cocci arranged in chains. All grew on sheep blood agar as alpha-haemolytic, grey colonies of 0.5-1 mm in diameter after 24 h incubation at 37 degrees C in ambient air. Lancefield Grouping revealed that HKU5 and HKU6 were Lancefield group F, but HKU4T was non-groupable with Lancefield groups A, B, C, D, F or G antisera. HKU4T was identified by the Vitek system (GPI), API system (20 STREP) and ATB system (ID32 STREP) as 99 % Streptococcus intermedius, 51.3 % S. intermedius and 99.9 % Streptococcus anginosus, respectively. Using the same tests, HKU5 was identified as 87 % Streptococcus sanguinis/Streptococcus gordonii, 59 % Streptococcus salivarius and 99.6 % S. anginosus, respectively, and HKU6 as 87 % S. sanguinis/S. gordonii, 77 % Streptococcus pneumoniae and 98.3 % S. anginosus, respectively. The present data revealed that a proportion of Lancefield group F streptococci could be S. sinensis. Lancefield group F streptococci should not be automatically reported as 'S. milleri'.
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Analysis of a viridans group strain reveals a case of bacteremia due to Lancefield group G alpha-hemolytic Streptococcus dysgalactiae subsp equisimilis in a patient with pyomyositis and reactive arthritis.
Journal of clinical microbiology, 2003Co-Authors: Patrick C. Y. Woo, Jade L. L. Teng, Kit-wah Leung, Susanna K. P. Lau, Peggy N. L. Lum, Kee-lam Wong, Kui-chun Lam, Kwok-yung YuenAbstract:Streptococcus dysgalactiae is classified by a combination of phenotypic and genotypic characteristics into Lancefield group C alpha-hemolytic Streptococcus dysgalactiae subsp. dysgalactiae and Lancefield group C, group G, and group L beta-hemolytic Streptococcus dysgalactiae subsp. equisimilis. In this study, we report the isolation of a catalase-negative, alpha-hemolytic, optochin- and bacitracin-resistant viridans group strain, which does not grow in 10 or 40% bile, on MacConkey agar or bile esculin agar, or in 6% NaCl, from the blood culture of a 73-year-old woman with pyomyositis and poststreptococcal reactive arthritis. Lancefield Grouping revealed that the strain was a group G streptococcus. The Vitek system (GPI) showed that it was unidentified, and the API system (20 STREP) showed that it was 95.7% S. dysgalactiae subsp. dysgalactiae. 16S rRNA gene sequencing showed that it was a strain of S. dysgalactiae. Based on phylogenetic affiliation with 16S rRNA gene or GroEL amino acid (another bacterial gene, in addition to 16S rRNA gene, that is highly conserved) sequences, the strain is most closely related to Lancefield group C beta-hemolytic S. dysgalactiae subsp. equisimilis. PCR amplification and sequencing of the streptolysin S structural gene (sagA) and M protein gene (emm) hypervariable region showed the presence of these suspected primary virulence factors. Further studies would delineate whether the isolate is just a hemolysin-deficient variant of group G beta-hemolytic S. dysgalactiae subsp. equisimilis or a novel type of S. dysgalactiae. The present case showed that group G alpha-hemolytic S. dysgalactiae subsp. equisimilis can be associated with serious invasive infection and poststreptococcal sequelae.
Susanna K. P. Lau - One of the best experts on this subject based on the ideXlab platform.
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Streptococcus sinensis may react with Lancefield group F antiserum.
Journal of Medical Microbiology, 2004Co-Authors: Patrick C. Y. Woo, Jade L. L. Teng, Kit-wah Leung, Susanna K. P. Lau, Herman Tse, Beatrice H.l. Wong, Kwok-yung YuenAbstract:Lancefield group F streptococci have been found almost exclusively as members of the ‘Streptococcus milleri’ group, although they have been reported very occasionally in some other streptococcal species. Among 302 patients with bacteraemia caused by viridans streptococci over a 6-year period, three cases were caused by Streptococcus sinensis (type strain HKU4T, HKU5 and HKU6). All three patients had infective endocarditis complicating their underlying chronic rheumatic heart diseases. Gene sequencing showed no base differences between the 16S rRNA gene sequences of HKU5 and HKU6 and that of HKU4T. All three strains were Gram-positive, non-spore-forming cocci arranged in chains. All grew on sheep blood agar as α-haemolytic, grey colonies of 0.5–1 mm in diameter after 24 h incubation at 37 °C in ambient air. Lancefield Grouping revealed that HKU5 and HKU6 were Lancefield group F, but HKU4T was non-groupable with Lancefield groups A, B, C, D, F or G antisera. HKU4T was identified by the Vitek system (GPI), API system (20 STREP) and ATB system (ID32 STREP) as 99 % Streptococcus intermedius, 51.3 % S. intermedius and 99.9 % Streptococcus anginosus, respectively. Using the same tests, HKU5 was identified as 87 % Streptococcus sanguinis/Streptococcus gordonii, 59 % Streptococcus salivarius and 99.6 % S. anginosus, respectively, and HKU6 as 87 % S. sanguinis/S. gordonii, 77 % Streptococcus pneumoniae and 98.3 % S. anginosus, respectively. The present data revealed that a proportion of Lancefield group F streptococci could be S. sinensis. Lancefield group F streptococci should not be automatically reported as ‘S. milleri'.
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Streptococcus sinensis may react with Lancefield group F antiserum
2004Co-Authors: Kwok-yung Yuen, Patrick C. Y. Woo, Jade L. L. Teng, Kit-wah Leung, Susanna K. P. Lau, Herman TseAbstract:Lancefield group F streptococci have been found almost exclusively as members of the ‘Streptococcus milleri ’ group, although they have been reported very occasionally in some other streptococcal species. Among 302 patients with bacteraemia caused by viridans streptococci over a 6-year period, three caseswere caused byStreptococcus sinensis (type strain HKU4T, HKU5 and HKU6). All three patients had infective endocarditis complicating their underlying chronic rheumatic heart diseases. Gene sequencing showed no base differences between the 16S rRNA gene sequences of HKU5 andHKU6 and that of HKU4T. All three strains wereGram-positive, non-spore-forming cocci arranged in chains. All grew on sheep blood agar as Æ-haemolytic, grey colonies of 0.5–1 mm in diameter after 24 h incubation at 37 8C in ambient air. Lancefield Grouping revealed that HKU5 and HKU6 were Lancefield group F, but HKU4T was non-groupable with Lancefiel
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Streptococcus sinensis may react with Lancefield group F antiserum.
Journal of medical microbiology, 2004Co-Authors: Patrick C. Y. Woo, Jade L. L. Teng, Kit-wah Leung, Susanna K. P. Lau, Herman Tse, Beatrice H.l. Wong, Kwok-yung YuenAbstract:Lancefield group F streptococci have been found almost exclusively as members of the 'Streptococcus milleri' group, although they have been reported very occasionally in some other streptococcal species. Among 302 patients with bacteraemia caused by viridans streptococci over a 6-year period, three cases were caused by Streptococcus sinensis (type strain HKU4T, HKU5 and HKU6). All three patients had infective endocarditis complicating their underlying chronic rheumatic heart diseases. Gene sequencing showed no base differences between the 16S rRNA gene sequences of HKU5 and HKU6 and that of HKU4T. All three strains were Gram-positive, non-spore-forming cocci arranged in chains. All grew on sheep blood agar as alpha-haemolytic, grey colonies of 0.5-1 mm in diameter after 24 h incubation at 37 degrees C in ambient air. Lancefield Grouping revealed that HKU5 and HKU6 were Lancefield group F, but HKU4T was non-groupable with Lancefield groups A, B, C, D, F or G antisera. HKU4T was identified by the Vitek system (GPI), API system (20 STREP) and ATB system (ID32 STREP) as 99 % Streptococcus intermedius, 51.3 % S. intermedius and 99.9 % Streptococcus anginosus, respectively. Using the same tests, HKU5 was identified as 87 % Streptococcus sanguinis/Streptococcus gordonii, 59 % Streptococcus salivarius and 99.6 % S. anginosus, respectively, and HKU6 as 87 % S. sanguinis/S. gordonii, 77 % Streptococcus pneumoniae and 98.3 % S. anginosus, respectively. The present data revealed that a proportion of Lancefield group F streptococci could be S. sinensis. Lancefield group F streptococci should not be automatically reported as 'S. milleri'.
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Analysis of a viridans group strain reveals a case of bacteremia due to Lancefield group G alpha-hemolytic Streptococcus dysgalactiae subsp equisimilis in a patient with pyomyositis and reactive arthritis.
Journal of clinical microbiology, 2003Co-Authors: Patrick C. Y. Woo, Jade L. L. Teng, Kit-wah Leung, Susanna K. P. Lau, Peggy N. L. Lum, Kee-lam Wong, Kui-chun Lam, Kwok-yung YuenAbstract:Streptococcus dysgalactiae is classified by a combination of phenotypic and genotypic characteristics into Lancefield group C alpha-hemolytic Streptococcus dysgalactiae subsp. dysgalactiae and Lancefield group C, group G, and group L beta-hemolytic Streptococcus dysgalactiae subsp. equisimilis. In this study, we report the isolation of a catalase-negative, alpha-hemolytic, optochin- and bacitracin-resistant viridans group strain, which does not grow in 10 or 40% bile, on MacConkey agar or bile esculin agar, or in 6% NaCl, from the blood culture of a 73-year-old woman with pyomyositis and poststreptococcal reactive arthritis. Lancefield Grouping revealed that the strain was a group G streptococcus. The Vitek system (GPI) showed that it was unidentified, and the API system (20 STREP) showed that it was 95.7% S. dysgalactiae subsp. dysgalactiae. 16S rRNA gene sequencing showed that it was a strain of S. dysgalactiae. Based on phylogenetic affiliation with 16S rRNA gene or GroEL amino acid (another bacterial gene, in addition to 16S rRNA gene, that is highly conserved) sequences, the strain is most closely related to Lancefield group C beta-hemolytic S. dysgalactiae subsp. equisimilis. PCR amplification and sequencing of the streptolysin S structural gene (sagA) and M protein gene (emm) hypervariable region showed the presence of these suspected primary virulence factors. Further studies would delineate whether the isolate is just a hemolysin-deficient variant of group G beta-hemolytic S. dysgalactiae subsp. equisimilis or a novel type of S. dysgalactiae. The present case showed that group G alpha-hemolytic S. dysgalactiae subsp. equisimilis can be associated with serious invasive infection and poststreptococcal sequelae.
Jade L. L. Teng - One of the best experts on this subject based on the ideXlab platform.
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Streptococcus sinensis may react with Lancefield group F antiserum.
Journal of Medical Microbiology, 2004Co-Authors: Patrick C. Y. Woo, Jade L. L. Teng, Kit-wah Leung, Susanna K. P. Lau, Herman Tse, Beatrice H.l. Wong, Kwok-yung YuenAbstract:Lancefield group F streptococci have been found almost exclusively as members of the ‘Streptococcus milleri’ group, although they have been reported very occasionally in some other streptococcal species. Among 302 patients with bacteraemia caused by viridans streptococci over a 6-year period, three cases were caused by Streptococcus sinensis (type strain HKU4T, HKU5 and HKU6). All three patients had infective endocarditis complicating their underlying chronic rheumatic heart diseases. Gene sequencing showed no base differences between the 16S rRNA gene sequences of HKU5 and HKU6 and that of HKU4T. All three strains were Gram-positive, non-spore-forming cocci arranged in chains. All grew on sheep blood agar as α-haemolytic, grey colonies of 0.5–1 mm in diameter after 24 h incubation at 37 °C in ambient air. Lancefield Grouping revealed that HKU5 and HKU6 were Lancefield group F, but HKU4T was non-groupable with Lancefield groups A, B, C, D, F or G antisera. HKU4T was identified by the Vitek system (GPI), API system (20 STREP) and ATB system (ID32 STREP) as 99 % Streptococcus intermedius, 51.3 % S. intermedius and 99.9 % Streptococcus anginosus, respectively. Using the same tests, HKU5 was identified as 87 % Streptococcus sanguinis/Streptococcus gordonii, 59 % Streptococcus salivarius and 99.6 % S. anginosus, respectively, and HKU6 as 87 % S. sanguinis/S. gordonii, 77 % Streptococcus pneumoniae and 98.3 % S. anginosus, respectively. The present data revealed that a proportion of Lancefield group F streptococci could be S. sinensis. Lancefield group F streptococci should not be automatically reported as ‘S. milleri'.
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Streptococcus sinensis may react with Lancefield group F antiserum
2004Co-Authors: Kwok-yung Yuen, Patrick C. Y. Woo, Jade L. L. Teng, Kit-wah Leung, Susanna K. P. Lau, Herman TseAbstract:Lancefield group F streptococci have been found almost exclusively as members of the ‘Streptococcus milleri ’ group, although they have been reported very occasionally in some other streptococcal species. Among 302 patients with bacteraemia caused by viridans streptococci over a 6-year period, three caseswere caused byStreptococcus sinensis (type strain HKU4T, HKU5 and HKU6). All three patients had infective endocarditis complicating their underlying chronic rheumatic heart diseases. Gene sequencing showed no base differences between the 16S rRNA gene sequences of HKU5 andHKU6 and that of HKU4T. All three strains wereGram-positive, non-spore-forming cocci arranged in chains. All grew on sheep blood agar as Æ-haemolytic, grey colonies of 0.5–1 mm in diameter after 24 h incubation at 37 8C in ambient air. Lancefield Grouping revealed that HKU5 and HKU6 were Lancefield group F, but HKU4T was non-groupable with Lancefiel
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Streptococcus sinensis may react with Lancefield group F antiserum.
Journal of medical microbiology, 2004Co-Authors: Patrick C. Y. Woo, Jade L. L. Teng, Kit-wah Leung, Susanna K. P. Lau, Herman Tse, Beatrice H.l. Wong, Kwok-yung YuenAbstract:Lancefield group F streptococci have been found almost exclusively as members of the 'Streptococcus milleri' group, although they have been reported very occasionally in some other streptococcal species. Among 302 patients with bacteraemia caused by viridans streptococci over a 6-year period, three cases were caused by Streptococcus sinensis (type strain HKU4T, HKU5 and HKU6). All three patients had infective endocarditis complicating their underlying chronic rheumatic heart diseases. Gene sequencing showed no base differences between the 16S rRNA gene sequences of HKU5 and HKU6 and that of HKU4T. All three strains were Gram-positive, non-spore-forming cocci arranged in chains. All grew on sheep blood agar as alpha-haemolytic, grey colonies of 0.5-1 mm in diameter after 24 h incubation at 37 degrees C in ambient air. Lancefield Grouping revealed that HKU5 and HKU6 were Lancefield group F, but HKU4T was non-groupable with Lancefield groups A, B, C, D, F or G antisera. HKU4T was identified by the Vitek system (GPI), API system (20 STREP) and ATB system (ID32 STREP) as 99 % Streptococcus intermedius, 51.3 % S. intermedius and 99.9 % Streptococcus anginosus, respectively. Using the same tests, HKU5 was identified as 87 % Streptococcus sanguinis/Streptococcus gordonii, 59 % Streptococcus salivarius and 99.6 % S. anginosus, respectively, and HKU6 as 87 % S. sanguinis/S. gordonii, 77 % Streptococcus pneumoniae and 98.3 % S. anginosus, respectively. The present data revealed that a proportion of Lancefield group F streptococci could be S. sinensis. Lancefield group F streptococci should not be automatically reported as 'S. milleri'.
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Analysis of a viridans group strain reveals a case of bacteremia due to Lancefield group G alpha-hemolytic Streptococcus dysgalactiae subsp equisimilis in a patient with pyomyositis and reactive arthritis.
Journal of clinical microbiology, 2003Co-Authors: Patrick C. Y. Woo, Jade L. L. Teng, Kit-wah Leung, Susanna K. P. Lau, Peggy N. L. Lum, Kee-lam Wong, Kui-chun Lam, Kwok-yung YuenAbstract:Streptococcus dysgalactiae is classified by a combination of phenotypic and genotypic characteristics into Lancefield group C alpha-hemolytic Streptococcus dysgalactiae subsp. dysgalactiae and Lancefield group C, group G, and group L beta-hemolytic Streptococcus dysgalactiae subsp. equisimilis. In this study, we report the isolation of a catalase-negative, alpha-hemolytic, optochin- and bacitracin-resistant viridans group strain, which does not grow in 10 or 40% bile, on MacConkey agar or bile esculin agar, or in 6% NaCl, from the blood culture of a 73-year-old woman with pyomyositis and poststreptococcal reactive arthritis. Lancefield Grouping revealed that the strain was a group G streptococcus. The Vitek system (GPI) showed that it was unidentified, and the API system (20 STREP) showed that it was 95.7% S. dysgalactiae subsp. dysgalactiae. 16S rRNA gene sequencing showed that it was a strain of S. dysgalactiae. Based on phylogenetic affiliation with 16S rRNA gene or GroEL amino acid (another bacterial gene, in addition to 16S rRNA gene, that is highly conserved) sequences, the strain is most closely related to Lancefield group C beta-hemolytic S. dysgalactiae subsp. equisimilis. PCR amplification and sequencing of the streptolysin S structural gene (sagA) and M protein gene (emm) hypervariable region showed the presence of these suspected primary virulence factors. Further studies would delineate whether the isolate is just a hemolysin-deficient variant of group G beta-hemolytic S. dysgalactiae subsp. equisimilis or a novel type of S. dysgalactiae. The present case showed that group G alpha-hemolytic S. dysgalactiae subsp. equisimilis can be associated with serious invasive infection and poststreptococcal sequelae.
Kit-wah Leung - One of the best experts on this subject based on the ideXlab platform.
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Streptococcus sinensis may react with Lancefield group F antiserum.
Journal of Medical Microbiology, 2004Co-Authors: Patrick C. Y. Woo, Jade L. L. Teng, Kit-wah Leung, Susanna K. P. Lau, Herman Tse, Beatrice H.l. Wong, Kwok-yung YuenAbstract:Lancefield group F streptococci have been found almost exclusively as members of the ‘Streptococcus milleri’ group, although they have been reported very occasionally in some other streptococcal species. Among 302 patients with bacteraemia caused by viridans streptococci over a 6-year period, three cases were caused by Streptococcus sinensis (type strain HKU4T, HKU5 and HKU6). All three patients had infective endocarditis complicating their underlying chronic rheumatic heart diseases. Gene sequencing showed no base differences between the 16S rRNA gene sequences of HKU5 and HKU6 and that of HKU4T. All three strains were Gram-positive, non-spore-forming cocci arranged in chains. All grew on sheep blood agar as α-haemolytic, grey colonies of 0.5–1 mm in diameter after 24 h incubation at 37 °C in ambient air. Lancefield Grouping revealed that HKU5 and HKU6 were Lancefield group F, but HKU4T was non-groupable with Lancefield groups A, B, C, D, F or G antisera. HKU4T was identified by the Vitek system (GPI), API system (20 STREP) and ATB system (ID32 STREP) as 99 % Streptococcus intermedius, 51.3 % S. intermedius and 99.9 % Streptococcus anginosus, respectively. Using the same tests, HKU5 was identified as 87 % Streptococcus sanguinis/Streptococcus gordonii, 59 % Streptococcus salivarius and 99.6 % S. anginosus, respectively, and HKU6 as 87 % S. sanguinis/S. gordonii, 77 % Streptococcus pneumoniae and 98.3 % S. anginosus, respectively. The present data revealed that a proportion of Lancefield group F streptococci could be S. sinensis. Lancefield group F streptococci should not be automatically reported as ‘S. milleri'.
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Streptococcus sinensis may react with Lancefield group F antiserum
2004Co-Authors: Kwok-yung Yuen, Patrick C. Y. Woo, Jade L. L. Teng, Kit-wah Leung, Susanna K. P. Lau, Herman TseAbstract:Lancefield group F streptococci have been found almost exclusively as members of the ‘Streptococcus milleri ’ group, although they have been reported very occasionally in some other streptococcal species. Among 302 patients with bacteraemia caused by viridans streptococci over a 6-year period, three caseswere caused byStreptococcus sinensis (type strain HKU4T, HKU5 and HKU6). All three patients had infective endocarditis complicating their underlying chronic rheumatic heart diseases. Gene sequencing showed no base differences between the 16S rRNA gene sequences of HKU5 andHKU6 and that of HKU4T. All three strains wereGram-positive, non-spore-forming cocci arranged in chains. All grew on sheep blood agar as Æ-haemolytic, grey colonies of 0.5–1 mm in diameter after 24 h incubation at 37 8C in ambient air. Lancefield Grouping revealed that HKU5 and HKU6 were Lancefield group F, but HKU4T was non-groupable with Lancefiel
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Streptococcus sinensis may react with Lancefield group F antiserum.
Journal of medical microbiology, 2004Co-Authors: Patrick C. Y. Woo, Jade L. L. Teng, Kit-wah Leung, Susanna K. P. Lau, Herman Tse, Beatrice H.l. Wong, Kwok-yung YuenAbstract:Lancefield group F streptococci have been found almost exclusively as members of the 'Streptococcus milleri' group, although they have been reported very occasionally in some other streptococcal species. Among 302 patients with bacteraemia caused by viridans streptococci over a 6-year period, three cases were caused by Streptococcus sinensis (type strain HKU4T, HKU5 and HKU6). All three patients had infective endocarditis complicating their underlying chronic rheumatic heart diseases. Gene sequencing showed no base differences between the 16S rRNA gene sequences of HKU5 and HKU6 and that of HKU4T. All three strains were Gram-positive, non-spore-forming cocci arranged in chains. All grew on sheep blood agar as alpha-haemolytic, grey colonies of 0.5-1 mm in diameter after 24 h incubation at 37 degrees C in ambient air. Lancefield Grouping revealed that HKU5 and HKU6 were Lancefield group F, but HKU4T was non-groupable with Lancefield groups A, B, C, D, F or G antisera. HKU4T was identified by the Vitek system (GPI), API system (20 STREP) and ATB system (ID32 STREP) as 99 % Streptococcus intermedius, 51.3 % S. intermedius and 99.9 % Streptococcus anginosus, respectively. Using the same tests, HKU5 was identified as 87 % Streptococcus sanguinis/Streptococcus gordonii, 59 % Streptococcus salivarius and 99.6 % S. anginosus, respectively, and HKU6 as 87 % S. sanguinis/S. gordonii, 77 % Streptococcus pneumoniae and 98.3 % S. anginosus, respectively. The present data revealed that a proportion of Lancefield group F streptococci could be S. sinensis. Lancefield group F streptococci should not be automatically reported as 'S. milleri'.
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Analysis of a viridans group strain reveals a case of bacteremia due to Lancefield group G alpha-hemolytic Streptococcus dysgalactiae subsp equisimilis in a patient with pyomyositis and reactive arthritis.
Journal of clinical microbiology, 2003Co-Authors: Patrick C. Y. Woo, Jade L. L. Teng, Kit-wah Leung, Susanna K. P. Lau, Peggy N. L. Lum, Kee-lam Wong, Kui-chun Lam, Kwok-yung YuenAbstract:Streptococcus dysgalactiae is classified by a combination of phenotypic and genotypic characteristics into Lancefield group C alpha-hemolytic Streptococcus dysgalactiae subsp. dysgalactiae and Lancefield group C, group G, and group L beta-hemolytic Streptococcus dysgalactiae subsp. equisimilis. In this study, we report the isolation of a catalase-negative, alpha-hemolytic, optochin- and bacitracin-resistant viridans group strain, which does not grow in 10 or 40% bile, on MacConkey agar or bile esculin agar, or in 6% NaCl, from the blood culture of a 73-year-old woman with pyomyositis and poststreptococcal reactive arthritis. Lancefield Grouping revealed that the strain was a group G streptococcus. The Vitek system (GPI) showed that it was unidentified, and the API system (20 STREP) showed that it was 95.7% S. dysgalactiae subsp. dysgalactiae. 16S rRNA gene sequencing showed that it was a strain of S. dysgalactiae. Based on phylogenetic affiliation with 16S rRNA gene or GroEL amino acid (another bacterial gene, in addition to 16S rRNA gene, that is highly conserved) sequences, the strain is most closely related to Lancefield group C beta-hemolytic S. dysgalactiae subsp. equisimilis. PCR amplification and sequencing of the streptolysin S structural gene (sagA) and M protein gene (emm) hypervariable region showed the presence of these suspected primary virulence factors. Further studies would delineate whether the isolate is just a hemolysin-deficient variant of group G beta-hemolytic S. dysgalactiae subsp. equisimilis or a novel type of S. dysgalactiae. The present case showed that group G alpha-hemolytic S. dysgalactiae subsp. equisimilis can be associated with serious invasive infection and poststreptococcal sequelae.
