A comparison of conventional and molecular microbiology in detecting differences in pneumococcal colonization in healthy children and children with upper respiratory illness

Ogami, Masashi; Hotomi, Muneki; Togawa, Akihisa; Yamanaka, Noboru

doi:10.1007/s00431-010-1208-5

Cited by 10 publications

(7 citation statements)

References 26 publications

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“…While we used a selective medium to prevent overgrowth of undesirable bacteria, we may have been unable to detect low-density carriers. In fact, Ogami et al reported that real-time PCR increased significantly detection of carriage in healthy children when compared to culture alone [42]. The same rationale is plausible for detection of carriage in adults.…”

Section: Discussionmentioning

confidence: 98%

Low Prevalence of Pneumococcal Carriage and High Serotype and Genotype Diversity among Adults over 60 Years of Age Living in Portugal

et al. 2014

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Pneumococcal disease is frequent at the extremes of age. While several studies have looked at colonization among young children, much less is known among the elderly. We aimed to evaluate pneumococcal carriage among elderly adults living in Portugal. Between April 2010 and December 2012, nasopharyngeal and oropharyngeal swabs of adults over 60 years of age, living in an urban area (n = 1,945) or in a rural area (n = 1,416), were obtained. Pneumococci were isolated by culture-based standard procedures, identified by optochin susceptibility, bile solubility and PCR screening for lytA and cpsA, and characterized by antibiotype, serotype, and MLST. Associations between pneumococcal carriage, socio-demographic and clinical characteristics were evaluated by univariate analysis and multiple logistic regression. The global prevalence of carriage was 2.3% (95% CI: 1.8–2.8). In the multiple logistic regression analysis, smoking, being at a retirement home, and living in a rural area increased the odds of being a pneumococcal carrier by 4.4-fold (95% CI: 1.9–9.2), 2.0-fold (95% CI: 1.1–3.6) and 2.0-fold (95% CI: 1.2–3.5), respectively. Among the 77 pneumococcal isolates, 26 serotypes and 40 STs were identified. The most prevalent serotypes were (in decreasing order) 19A, 6C, 22F, 23A, 35F, 11A, and 23B, which accounted, in total, for 60.0% of the isolates. Most isolates (93.5%) had STs previously described in the MLST database. Resistance to macrolides, non-susceptibility to penicillin and multidrug resistance were found in 19.5%, 11.7%, and 15.6% of the isolates, respectively. We conclude that the prevalence of pneumococcal carriage in the elderly, in Portugal, as determined by culture-based methods, is low. Serotype and genotype diversity is high. Living in a rural area, in a retirement home, and being a smoker increased the risk of pneumococcal carriage. This study contributes to the establishment of a baseline that may be used to monitor how novel pneumococcal vaccines impact on colonization among the elderly.

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Section: Discussionmentioning

confidence: 98%

Low Prevalence of Pneumococcal Carriage and High Serotype and Genotype Diversity among Adults over 60 Years of Age Living in Portugal

et al. 2014

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“…According to this data, multiplex real-time PCR has the potential to reveal a different distribution of serotypes circulating in the population compared to culture-positive cases. A recent study comparing conventional and molecular microbiology in detecting differences in pneumococcal colonisation among healthy carriers and ill children showed that real-time PCR was superior to bacterial culture in identifying a great number of pneumococcal serotypes in both groups of patients, healthy nasopharyngeal carriers and children with upper respiratory illness [30].…”

Section: Discussionmentioning

confidence: 99%

Serotype 3 is a common serotype causing invasive pneumococcal disease in children less than 5 years old, as identified by real-time PCR

Selva

Ciruela

Esteva

et al. 2011

Eur J Clin Microbiol Infect Dis

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Serotype 3 is one of the most often detected pneumococcal serotypes in adults and it is associated with serious disease. In contrast, the isolation of serotype 3 by bacterial culture is unusual in children with invasive pneumococcal disease (IPD). The purpose of this study was to learn the serotype distribution of IPD, including culture-negative episodes, by using molecular methods in normal sterile samples. We studied all children<5 years of age with IPD admitted to two paediatric hospitals in Catalonia, Spain, from 2007 to 2009. A sequential real-time polymerase chain reaction (PCR) approach was added to routine methods for the detection and serotyping of pneumococcal infection. Among 257 episodes (219 pneumonia, 27 meningitis, six bacteraemia and five others), 33.5% were identified by culture and the rest, 66.5%, were detected exclusively by real-time PCR. The most common serotypes detected by culture were serotypes 1 (26.7%) and 19A (25.6%), and by real-time PCR, serotypes 1 (19.8%) and 3 (18.1%). Theoretical coverage rates by the PCV7, PCV10 and PCV13 vaccines were 10.5, 52.3 and 87.2%, respectively, for those episodes identified by culture, compared to 5.3, 31.6 and 60.2% for those identified only by real-time PCR. Multiplex real-time PCR has been shown to be useful for surveillance studies of IPD. Serotype 3 is underdiagnosed by culture and is important in paediatric IPD.

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“…Second, despite the higher sensitivity of culture-independent approaches, molecular methods can be subjected to confounding, especially when used directly to analyse carriage specimens [17,22,23]. (17) 19F (15) a 19F (10), cpsA+ (4) 19F (8), cpsA+ (9) 14 (13) 14 1114 1114 (13) 6A (12) 6A (12) b 6 (11), cpsA+ (1) 6 (9), cpsA+ (3) 15C (10) 15C 1015B/C (8), cpsA+ (1) 15B/C (4), cpsA+ (6) 23F (8) 23F 723F 723F (8) 16F (6) 16F 416F 416F (6) 17F (6) 17F 617F (5), cpsA+ (1) 17F (4), cpsA+ (2) 6 (5) c -6 (2) 6 (5) 19A (5) 19A 5 1) 18 (318B (1), 18C 118 (3) 18(2) 23A 323A 323A 323A 1, Previous studies reported on the considerable variation and false positivity when using multiplex PCR [22,23], yet many findings of the BEPCR method were confirmed by the culture methodologies. Moreover, other technologies, such as microarray and real-time PCR, are more sensitive [22,24] and the combination of microarray with a culture amplification step was identified as one of the best methods to serotype pneumococci in carriage studies [22].…”

Section: Resultsmentioning

confidence: 99%

“…Due to the large size and the multitude of differences in the country, regarding cultural, socioeconomic and even climatic characteristics, evaluation of the impact on the use of these vaccines needs to be based on regional data obtained from the pre-vaccine era. Furthermore, while different methods have already been proposed to evaluate pneumococcal carriage [5][6][7], none is universally adopted.…”

Section: Introductionmentioning

confidence: 99%

Pneumococcal nasopharyngeal carriage among children in Brazil prior to the introduction of the 10-valent conjugate vaccine: a culture- and PCR-based survey

et al. 2017

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We performed two different approaches (broth enrichment step prior to culture (BEC) and PCR (BEPCR)) for detecting Streptococcus pneumoniae from nasopharyngeal specimens collected from 242 children aged <6 years attending one hospital (n = 140) and one childcare centre (n = 102) in a major urban area in Brazil. These specimens were collected immediately before the introduction of the 10-valent pneumococcal conjugate vaccine (PCV10) and the 13-valent vaccine (PCV13) for routine use in Brazil. Results were compared with previous findings obtained with direct culture (DC) on a selective medium. Colonisation prevalence was 58·3% (n = 141), being higher among children attending the childcare centre (62·7% vs. 55%). The culture-based methods (DC and BEC) enabled the detection of S. pneumoniae in 119 (49·2%) and 115 (47·5%) children, respectively. The PCR-based method (BEPCR) was more sensitive and 137 (56·6%) carriers were identified. Twenty-six serogroups/serotypes were identified, predominantly 6B, 19F, 14, 6A, 15C and 23F. Multiple colonisation was observed in 13 (5·4%) children. The estimated serotypes coverage of available PCVs was 40·4% for the 10-valent (included in the Brazilian immunisation programme) and 55·8% for the 13-valent (only available in private clinics). The use of robust approaches to obtain a more realistic insight about the asymptomatic carrier status is of paramount importance to estimate and assess the impact of vaccine implementation. The combination between culture-based and molecular methods constitutes a suitable strategy.

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A comparison of conventional and molecular microbiology in detecting differences in pneumococcal colonization in healthy children and children with upper respiratory illness

Cited by 10 publications

References 26 publications

Low Prevalence of Pneumococcal Carriage and High Serotype and Genotype Diversity among Adults over 60 Years of Age Living in Portugal

Low Prevalence of Pneumococcal Carriage and High Serotype and Genotype Diversity among Adults over 60 Years of Age Living in Portugal

Serotype 3 is a common serotype causing invasive pneumococcal disease in children less than 5 years old, as identified by real-time PCR

Pneumococcal nasopharyngeal carriage among children in Brazil prior to the introduction of the 10-valent conjugate vaccine: a culture- and PCR-based survey

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