Lack of Utility of Serotyping Multiple Colonies for Detection of Simultaneous Nasopharyngeal Carriage of Different Pneumococcal Serotypes

Huebner, Robin E.; Dagan, Ron; Porath, N; Wasas, Avril; Klugman, Keith P.

doi:10.1097/00006454-200010000-00019

Cited by 97 publications

(98 citation statements)

References 14 publications

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“…Although the presence of carriage with multiple serotypes has been described [23][24][25], infections caused by multiple serotypes have been reported only sporadically [20,21,26,27]. Recently, five out of 366 patients with pneumococcal CAP had pneumonia caused by two serotypes based on a multiplex immunoassay for 14 serotypes in urine samples [28].…”

Section: Discussionmentioning

confidence: 99%

Diagnostic accuracy of a serotype-specific antigen test in community-acquired pneumonia

et al. 2013

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Our aim was to evaluate the diagnostic accuracy and clinical utility of a serotype-specific urinary antigen detection multiplex assay for identification of 13 pneumococcal serotypes (1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F and 23F) in urine of patients with community-acquired pneumonia.Adult patients with clinical suspicion of community-acquired pneumonia were included. In addition to standard diagnostic procedures, a urine sample was collected to perform the urinary antigen detection test. Demographic, clinical, radiological and microbiological data were collected.Among 1095 community-acquired pneumonia patients Streptococcus pneumoniae was identified as causative pathogen in 257 (23%), when using conventional diagnostic methods and in 357 (33%) when urinary antigen detection was added. Of the 49 bacteraemic episodes caused by one of the 13 serotypes covered by the urinary antigen detection, 48 were detected by the urinary antigen detection, indicating a sensitivity of 98%. Of the 77 community-acquired pneumonia episodes with a ''non-urinary antigen detection'' causative pathogen, none had a positive urinary antigen detection result, indicating a specificity of 100%.Addition of the urinary antigen detection test to conventional diagnostic methods increased the prevalence of S. pneumoniae community-acquired pneumonia by 39%. Using bacteraemic episodes as reference sensitivity and specificity of the urinary antigen detection was 98% and 100%, respectively. @ERSpublications Addition of urinary antigen detection test to conventional diagnostic methods increases prevalence of S. pneumoniae CAP http://ow.ly/nSA1l

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Section: Discussionmentioning

confidence: 99%

Diagnostic accuracy of a serotype-specific antigen test in community-acquired pneumonia

et al. 2013

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“…However, identification of simultaneous carriage of multiple serotypes is laborious, and the yield varies according to the method used (24). Serotyping of multiple colonies is time- consuming, and if the second serotype constitutes 4 to 27% of the population, 11 to 59 randomly picked CFU would have to be subcultured and serotyped for identification of the two serotypes (24). An immunoblot method designed to detect multiple serotypes in carriage studies was used in a study in Navajo and White Mountain Apache reservations.…”

Section: Discussionmentioning

confidence: 99%

Phenotypic and Genotypic Characterization of Streptococcus pneumoniae Strains Colonizing Children Attending Day-Care Centers in Norway

et al. 2008

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A cross-sectional study of nasopharyngeal colonization with Streptococcus pneumoniae was performed among 573 children attending 29 day-care centers (DCCs) in Norway prior to the start of mass vaccination with the heptavalent pneumococcal conjugate vaccine (PCV-7). A sensitive sampling method was employed, including transport in an enrichment broth and serotyping of pneumococci directly from the broth, in addition to traditional single-colony isolation from blood agar plates. The prevalence of carriage was high, peaking at 88.7% in 2-year-olds. More than one serotype was isolated from 12.7% of the carriers. Of 509 isolates obtained, 227 (44.6%) belonged to the PCV-7 serotypes. Penicillin nonsusceptibility was rare (1.8% of the isolates). Nonsusceptibility to erythromycin (5.9%), clindamycin (2.0%), and tetracycline (5.5%) was associated with PCV-7 serotypes (P < 0.001). Multilocus sequence typing was performed on the whole strain collection, revealing 102 sequence types (STs), of which 31 (30.4%) were novel. Eleven isolates (2.2%) belonged to the England 14 -9 clone, and 19 isolates (3.7%) belonged to, or were single-locus variants of, the Portugal 19F -21 clone. The pneumococcal populations within the DCCs were composed of a majority of isolates with STs shared between the DCCs and a minority of isolates with STs unique for each DCC. The highest numbers of different STs, including novel STs, were found within the most frequent serotypes. Our study indicates that carriage of S. pneumoniae is highly prevalent among children in Norwegian DCCs, with a genetically diverse pneumococcal population consisting of unique microepidemic DCC populations.

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“…This is especially problematic given that for many nasopharyngeal carriage studies to achieve statistical significance, sample sizes of Ն100 pneumococcal carriers are required (10). As Huebner et al report, if the less common serotype represents only 5% of the total pneumococcal population, 59 colonies from each specimen would need to be serotyped to have a 95% probability of picking the second pneumococcal type (10). The need to develop a method that would allow a feasible analysis of minority strains in a pneumococcal population is confirmed by studies on the carriage of multiple pneumococcal capsular types (9,10,24).…”

Section: Discussionmentioning

confidence: 99%

Serotyping Streptococcus pneumoniae by Multiplex PCR

2003

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The capsule is a major virulence factor of pneumococci, and it was shown that some capsular variants are associated with antimicrobial resistance and certain types of disease. Moreover, pneumococcal capsular typing has received renewed interest since the availability of conjugate vaccines, which include serotypes frequently associated with pediatric disease. Our aim was to develop a simple, reliable, and economical method for detecting epidemiologically important serotypes present in the proposed 11-valent conjugate vaccine. We designed primers based on the sequences available for the capsular types 1, 3, 4, 6B, 14, 18C, 19F, 19A, and 23F and combined them into seven multiplex PCRs. The method involves streamlined DNA template preparation and agarose gel electrophoresis to analyze the amplification products. A total of 446 pneumococci selected from among isolates colonizing the nasopharynx of children attending day care centers in Lisbon, Portugal, were typed both by conventional immunological techniques and by multiplex PCR. Capsular types identified by the PCR method invariably produced results concordant with the conventional serotyping technique. Even when the method presented does not fully type an isolate, the PCR data can guide the experimenter when using immunological serotyping. Multiplex PCR for the analysis of pneumococci provides an accurate, expeditious, and cost-effective way of reducing the number of strains that have to be serotyped by conventional immunological techniques.

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Lack of Utility of Serotyping Multiple Colonies for Detection of Simultaneous Nasopharyngeal Carriage of Different Pneumococcal Serotypes

Cited by 97 publications

References 14 publications

Diagnostic accuracy of a serotype-specific antigen test in community-acquired pneumonia

Diagnostic accuracy of a serotype-specific antigen test in community-acquired pneumonia

Phenotypic and Genotypic Characterization of Streptococcus pneumoniae Strains Colonizing Children Attending Day-Care Centers in Norway

Serotyping Streptococcus pneumoniae by Multiplex PCR

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