What is Different About Serotype 1 Pneumococci?

Ritchie, Neil D.; Mitchell, Tim; Evans, Tom

doi:10.2217/fmb.11.146

Cited by 56 publications

(67 citation statements)

References 115 publications

(122 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…For example, although serotype 6D has been isolated in several regions, it is characteristically prevalent in Asian countries but nearly absent in the United States (197); serotype 1 is less prevalent in southeast Asia but causes epidemics in central Africa during the end of the dry season (201). In addition, in contrast to the 15% difference in the United States and Europe (198), PPV23 coverage in Asia was estimated to be only about 5% greater than that of PCV13 owing to the relatively high prevalence of serotype 6A (200).…”

Section: Effect Of Pneumococcal Conjugate Vaccines: Serotype Replacemmentioning

confidence: 99%

Pneumococcal Capsules and Their Types: Past, Present, and Future

et al. 2015

View full text Add to dashboard Cite

SUMMARY Streptococcus pneumoniae (the pneumococcus) is an important human pathogen. Its virulence is largely due to its polysaccharide capsule, which shields it from the host immune system, and because of this, the capsule has been extensively studied. Studies of the capsule led to the identification of DNA as the genetic material, identification of many different capsular serotypes, and identification of the serotype-specific nature of protection by adaptive immunity. Recent studies have led to the determination of capsular polysaccharide structures for many serotypes using advanced analytical technologies, complete elucidation of genetic basis for the capsular types, and the development of highly effective pneumococcal conjugate vaccines. Conjugate vaccine use has altered the serotype distribution by either serotype replacement or switching, and this has increased the need to serotype pneumococci. Due to great advances in molecular technologies and our understanding of the pneumococcal genome, molecular approaches have become powerful tools to predict pneumococcal serotypes. In addition, more-precise and -efficient serotyping methods that directly detect polysaccharide structures are emerging. These improvements in our capabilities will greatly enhance future investigations of pneumococcal epidemiology and diseases and the biology of colonization and innate immunity to pneumococcal capsules.

show abstract

Section: Effect Of Pneumococcal Conjugate Vaccines: Serotype Replacemmentioning

confidence: 99%

Pneumococcal Capsules and Their Types: Past, Present, and Future

et al. 2015

View full text Add to dashboard Cite

show abstract

“…Serotypes with higher invasive indices can cause endemic disease, for example in the African meningitis belt [28][29][30], as well as localized outbreaks [31][32][33]. We identified only nine total pneumococci with serotypes associated with a higher invasiveness index (three at the beginning of the Hajj and six at the end).…”

Section: Discussionmentioning

confidence: 99%

Impact of the hajj on pneumococcal transmission

Memish

Assiri

Almasri

et al. 2015

Clinical Microbiology and Infection

View full text Add to dashboard Cite

Over two million Muslim pilgrims assemble annually in Mecca and Medina, Saudi Arabia, to complete the Hajj. The large number of people in a crowded environment increases the potential for pneumococcal carriage amplification. We evaluated pneumococcal carriage prevalence with four cross-sectional studies conducted at beginning-Hajj (Mecca) and end-Hajj (Mina) during 2011 and 2012. A questionnaire was administered and a nasopharyngeal swab was collected. The swab was tested for pneumococcus, serotype and antibiotic resistance. A total of 3203 subjects (1590 at beginning-Hajj and 1613 at end-Hajj) originating from 18 countries in Africa or Asia were enrolled. The overall pneumococcal carriage prevalence was 6.0%. There was an increase in carriage between beginning-Hajj and end-Hajj cohorts for: overall carriage (4.4% versus 7.5%, prevalence ratio (PR) 1.7, 95% CI 1.3-2.3), and carriage of 23-valent pneumococcal polysaccharide vaccine serotypes (2.3% versus 4.1%, PR 1.8, 95% CI 1.2-2.7), 13-valent pneumococcal conjugate vaccine (PCV) serotypes (1.1% versus 3.6%, PR 3.2, 95% CI 1.9-5.6), 10-valent PCV serotypes (0.6% versus 1.6%, PR 2.6, 95% CI 1.2-5.3), antibiotic non-susceptible isolates (2.5% versus 6.1%, PR 2.5, 95% CI 1.7-3.6) and multiple non-susceptible isolates (0.6% versus 2.2%, PR 3.8, 95% CI 1.8-7.9). Fifty-two different serotypes were identified, most commonly serotypes 3 (17%), 19F (5%) and 34 (5%). These results suggest that the Hajj may increase pneumococcal carriage-particularly conjugate vaccine serotypes and antibiotic non-susceptible strains, although the exact mechanism remains unknown. The Hajj may therefore provide a mechanism for the global distribution of pneumococci.

show abstract

“…Such strains had an early growth advantage in the blood [43] and an impaired ability to activate the NLRP3 inflammasome [44]. Interestingly, some serotype 1 strains express a non-hemolytic PLY [45;46], perhaps in part explaining its propensity for invasiveness [47]. The lack of PLY hemolytic activity appears to enable pneumococcus to escape innate immune surveillance, highlighting previous data showing the importance of PLY in promoting early bacterial clearance [41].…”

Section: Factors That Govern Colonization: a Prelude To Pneumoniamentioning

confidence: 99%

Current concepts in host–microbe interaction leading to pneumococcal pneumonia

Vernatter

Pirofski

2013

Current Opinion in Infectious Diseases

View full text Add to dashboard Cite

Purpose of review Infection with Streptococcus pneumoniae (pneumococcus) results in colonization, which can lead to local or invasive disease, of which pneumonia is the most common manifestation. Despite the availability of pneumococcal vaccines, pneumococcal pneumonia is the leading cause of community and in-hospital pneumonia in the United States and globally. This article discusses new insights into the pathogenesis of pneumococcal disease. Recent findings The host-microbe interactions that determine whether pneumococcal colonization will result in clearance or invasive disease are highly complex. This paper focuses on new information in three areas that bear on the pathogenesis of pneumococcal disease: 1) factors that govern colonization, the prelude to invasive disease, including effects on colonization and invasion of capsular serotype, pneumolysin, surface proteins that regulate complement deposition, biofilm formation and agglutination; 2) the effect of co-infection with other bacteria and viruses on pneumococcal growth and virulence, including the synergistic effect of influenza; and 3) the contribution of the host inflammatory response to the pathogenesis of pneumococcal pneumonia, including the effects of pattern recognition molecules, cells that enhance and modulate inflammation, and therapies that modulate inflammation, such as statins. Summary Recent research on pneumococcal pathogenesis reveals new mechanisms by which microbial factors govern the ability of pneumococcus to progress from the state of colonization to disease and host inflammatory responses contribute to the development of pneumonia. These mechanisms suggest that therapies which modulate the inflammatory response could hold promise for ameliorating damage due to the inflammatory response in pneumococcal disease.

show abstract

What is Different About Serotype 1 Pneumococci?

Cited by 56 publications

References 115 publications

Pneumococcal Capsules and Their Types: Past, Present, and Future

Pneumococcal Capsules and Their Types: Past, Present, and Future

Impact of the hajj on pneumococcal transmission

Current concepts in host–microbe interaction leading to pneumococcal pneumonia

Contact Info

Product

Resources

About