scholarly journals Streptococcus pneumoniae Nasopharyngeal Carriage among PCV-10-Vaccinated HIV-1-Infected Children with Maintained Serological Memory in Ethiopia

Pathogens ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 159
Author(s):  
Mahlet Lemma ◽  
Yonas Bekele ◽  
Stefan Petkov ◽  
Moa Hägglund ◽  
Beyene Petros ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Geometric Mean ◽  
Upper Respiratory Tract ◽  
Nasopharyngeal Carriage ◽  
High Coverage ◽  
Highly Pathogenic ◽  
Specific Igg ◽  
Upper Respiratory ◽  
Protective Threshold ◽  
Hiv 1

Streptococcus pneumoniae (S. pneumoniae) vaccines have substantially reduced the burden of invasive pneumococcal diseases (IPDs) worldwide. Despite high coverage with S. pneumoniae vaccination, upper-respiratory-tract colonization by S. pneumoniae is still common. We assessed maintenance of serological responses to S. pneumoniae serotypes included in PCV-10 by ELISA in HIV-1-infected children (n = 50) and age-matched controls (n = 50) in Ethiopia. We isolated S. pneumoniae in nasopharyngeal swabs and determined S. pneumoniae serotype by whole genome sequencing (WGS). Comparable levels of S. pneumoniae serotype-specific IgG concentrations were detected in plasma of HIV-1-infected children and matched controls, with geometric mean concentrations (GMCs) consistently higher than the protective threshold for PCV-10 serotypes of 0.35 μg/mL. We isolated S. pneumoniae from 38 (out of 97) nasopharyngeal swabs, 25 from HIV-1-infected children and 13 from controls. WGS based serotyping revealed 22 known S. pneumoniae serotypes and 2 nontypeable (NT) isolates. Non-PCV-10 serotypes represented >90% of isolates. We showed that HIV-1-infected children and matched controls in Ethiopia carry a level of maintained serological memory to PCV-10 considered protective for IPDs. We identified a higher proportion of nasopharyngeal carriage with highly pathogenic S. pneumoniae non-PCV strains among HIV-1-infected children compared to controls.

scholarly journals Isolation of an obligately anaerobic Streptococcus pneumoniae from blood culture

1977 ◽  
Vol 6 (2) ◽  
pp. 181-182
Author(s):  
j a Yatabe ◽  
K L baldwin ◽  
W J Martin
Keyword(s):  
Streptococcus Pneumoniae ◽  
Tract Infection ◽  
Blood Culture ◽  
Respiratory Tract ◽  
Respiratory Tract Infection ◽  
Upper Respiratory Tract Infection ◽  
Upper Respiratory Tract ◽  
Obligately Anaerobic ◽  
Upper Respiratory

An obligately anaerobic strain of Streptococcus pneumoniae was isolated from blood culture in a 14-month-old child with an upper respiratory tract infection.

scholarly journals Upper respiratory tract colonization with Streptococcus pneumoniae in adults

2020 ◽  
Vol 19 (4) ◽  
pp. 353-366 ◽  
Author(s):  
Adriano Arguedas ◽  
Krzysztof Trzciński ◽  
Katherine L. O’Brien ◽  
Daniela M. Ferreira ◽  
Anne L. Wyllie ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Respiratory Tract ◽  
Upper Respiratory Tract ◽  
Upper Respiratory ◽  
Respiratory Tract Colonization

scholarly journals Identification of Pneumococcal Factors Affecting Pneumococcal Shedding Shows that thedltLocus Promotes Inflammation and Transmission

mBio ◽  
2019 ◽  
Vol 10 (3) ◽  
Author(s):  
M. Ammar Zafar ◽  
Alexandria J. Hammond ◽  
Shigeto Hamaguchi ◽  
Weisheng Wu ◽  
Masamitsu Kono ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Respiratory Tract ◽  
Capsular Polysaccharide ◽  
Inflammatory Responses ◽  
Transposon Mutagenesis ◽  
Respiratory Pathogen ◽  
Invasive Infection ◽  
Upper Respiratory Tract ◽  
Content Type ◽  
Upper Respiratory

ABSTRACTHost-to-host transmission is a necessary but poorly understood aspect of microbial pathogenesis. Herein, we screened a genomic library of mutants of the leading respiratory pathogenStreptococcus pneumoniaegenerated by mariner transposon mutagenesis (Tn-Seq) to identify genes contributing to its exit or shedding from the upper respiratory tract (URT), the limiting step in the organism’s transmission in an infant mouse model. Our analysis focused on genes affecting the bacterial surface that directly impact interactions with the host. Among the multiple factors identified was thedltlocus, which addsd-alanine onto lipoteichoic acids (LTA) and thereby increases Toll-like receptor 2-mediated inflammation and resistance to antimicrobial peptides. The more robust proinflammatory response in the presence ofd-alanylation promotes secretions that facilitate pneumococcal shedding and allows for transmission. Expression of thedltlocus is controlled by the CiaRH system, which senses cell wall stress in response to antimicrobial activity, including in response to lysozyme, the most abundant antimicrobial along the URT mucosa. Accordingly, in alysM−/−host, there was no longer an effect of thedltlocus on pneumococcal shedding. Thus, our findings demonstrate how a pathogen senses the URT milieu and then modifies its surface characteristics to take advantage of the host response for transit to another host.IMPORTANCEStreptococcus pneumoniae(the pneumococcus) is a common cause of respiratory tract and invasive infection. The overall effectiveness of immunization with the organism’s capsular polysaccharide depends on its ability to block colonization of the upper respiratory tract and thereby prevent host-to-host transmission. Because of the limited coverage of current pneumococcal vaccines, we carried out an unbiasedin vivotransposon mutagenesis screen to identify pneumococcal factors other than its capsular polysaccharide that affect transmission. One such candidate was expressed by thedltlocus, previously shown to addd-alanine onto the pneumococcal lipoteichoic acid present on the bacterial cell surface. This modification protects against host antimicrobials and augments host inflammatory responses. The latter increases secretions and bacterial shedding from the upper respiratory tract to allow for transmission. Thus, this study provides insight into a mechanism employed by the pneumococcus to successfully transit from one host to another.

scholarly journals Type I Interferon Signaling Is a Common Factor Driving Streptococcus pneumoniae and Influenza A Virus Shedding and Transmission

mBio ◽  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Tonia Zangari ◽  
Mila B. Ortigoza ◽  
Kristen L. Lokken-Toyli ◽  
Jeffrey N. Weiser
Keyword(s):  
Streptococcus Pneumoniae ◽  
Respiratory Tract ◽  
Influenza A Virus ◽  
Influenza A ◽  
Common Factor ◽  
Type I ◽  
Upper Respiratory Tract ◽  
Content Type ◽  
Infant Mouse ◽  
Upper Respiratory

ABSTRACT The dynamics underlying respiratory contagion (the transmission of infectious agents from the airways) are poorly understood. We investigated host factors involved in the transmission of the leading respiratory pathogen Streptococcus pneumoniae. Using an infant mouse model, we examined whether S. pneumoniae triggers inflammatory pathways shared by influenza A virus (IAV) to promote nasal secretions and shedding from the upper respiratory tract to facilitate transit to new hosts. Here, we show that amplification of the type I interferon (IFN-I) response is a critical host factor in this process, as shedding and transmission by both IAV and S. pneumoniae were decreased in pups lacking the common IFN-I receptor (Ifnar1−/− mice). Additionally, providing exogenous recombinant IFN-I to S. pneumoniae-infected pups was sufficient to increase bacterial shedding. The expression of IFN-stimulated genes (ISGs) was upregulated in S. pneumoniae-infected wild-type (WT) but not Ifnar1−/− mice, including genes involved in mucin type O-glycan biosynthesis; this correlated with an increase in secretions in S. pneumoniae- and IAV-infected WT compared to Ifnar1−/− pups. S. pneumoniae stimulation of ISGs was largely dependent on its pore-forming toxin, pneumolysin, and coinfection with IAV and S. pneumoniae resulted in synergistic increases in ISG expression. We conclude that the induction of IFN-I signaling appears to be a common factor driving viral and bacterial respiratory contagion. IMPORTANCE Respiratory tract infections are a leading cause of childhood mortality and, globally, Streptococcus pneumoniae is the leading cause of mortality due to pneumonia. Transmission of S. pneumoniae primarily occurs through direct contact with respiratory secretions, although the host and bacterial factors underlying transmission are poorly understood. We examined transmission dynamics of S. pneumoniae in an infant mouse model and here show that S. pneumoniae colonization of the upper respiratory tract stimulates host inflammatory pathways commonly associated with viral infections. Amplification of this response was shown to be a critical host factor driving shedding and transmission of both S. pneumoniae and influenza A virus, with infection stimulating expression of a wide variety of genes, including those involved in the biosynthesis of mucin, a major component of respiratory secretions. Our findings suggest a mechanism facilitating S. pneumoniae contagion that is shared by viral infection.

scholarly journals Strategy using a new antigenic test for rapid diagnosis of Streptococcus pneumoniae infection in respiratory samples from children consulting at hospital

2020 ◽  
Author(s):  
Cyrille H Haddar ◽  
Johan MD J ◽  
Anne Carricajo ◽  
Paul O Verhoeven ◽  
Florence Grattard ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Antimicrobial Treatment ◽  
Cell Wall Polysaccharide ◽  
Upper Respiratory Tract ◽  
Pneumococcal Infections ◽  
Vaccination Programs ◽  
X Ray ◽  
Upper Respiratory ◽  
Pcr Assays ◽  
The Impact

Abstract Background. Despite vaccination programs, Streptococcus pneumoniae remains among the main microorganisms involved in bacterial pneumonia, notably in terms of severity. The prognosis of pneumococcal infections is conditioned in part by the precocity of the diagnosis. The aim of this study was to evaluate the impact of a Rapid Diagnostic Test (RDT) targeting cell wall polysaccharide of Streptococcus pneumoniae and performed directly in respiratory samples, on the strategy of diagnosis of respiratory pneumococcal infections in children. Results. Upper-respiratory tract samples from 196 children consulting at hospital for respiratory infection were tested for detecting S. pneumoniae using a newly-designed RDT (PneumoResp, Biospeedia), a semi-quantitative culture and two PCR assays. If positive on fluidized undiluted specimen, the RDT was repeated on 1:100-diluted sample. The RDT was found highly specific when tested on non-S. pneumoniae strains. By comparison to culture and PCR assays, the RDT on undiluted secretions exhibited a sensitivity (Se) and negative predictive value (NPV) of more than 98%. By comparison to criteria of S. pneumoniae pneumonia combining typical symptoms, X-ray image, and culture ≥ 107 CFU/ml, the Se and NPV of RDT on diluted specimens were 100% in both cases. Conclusions. In case of negative result, the excellent NPV of RDT on undiluted secretions allows excluding S. pneumoniae pneumonia. In case of positive result, the excellent sensitivity of RDT on diluted secretions for the diagnosis of S. pneumoniae pneumonia allows proposing a suitable antimicrobial treatment at day 0.

Discrimination of Streptococcus pneumoniae from other upper respiratory tract streptococci by arbitrarily primed PCR

1995 ◽  
Vol 28 (6) ◽  
pp. 567-572 ◽  
Author(s):  
Trudy O. Messmer ◽  
Carolyn M. Black ◽  
Richard R. Facklam
Keyword(s):  
Streptococcus Pneumoniae ◽  
Respiratory Tract ◽  
Upper Respiratory Tract ◽  
Upper Respiratory ◽  
Arbitrarily Primed Pcr
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