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Journal of Infection and Public Health 2017Currently, the data on pneumococcal invasive disease in the Indonesian population are limited. In this study, we investigated the serotype distribution and antimicrobial...
Currently, the data on pneumococcal invasive disease in the Indonesian population are limited. In this study, we investigated the serotype distribution and antimicrobial susceptibility of Streptococcus pneumoniae. These samples were isolated from the sputum of adult patients with non-specific clinical symptoms aged 18-87 years in Jakarta, Indonesia, from August to October 2014. Of the 349 sputum specimens, thirteen isolates were identified as S. pneumoniae strains (4%), with two strains each for serotype 19F, 3, and 15A, and one strain each for serotype/serogroup 13, 23A, 6, 34, 17F, 16F, and untypeable. Resistance to tetracycline was most common with only 5 of 13 strains being susceptible. In conclusion, these data provide an initial in the surveillance of invasive pneumococcus in the Indonesia population.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Cross-Sectional Studies; Drug Resistance, Bacterial; Female; Humans; Indonesia; Male; Microbial Sensitivity Tests; Middle Aged; Pneumococcal Infections; Serogroup; Sputum; Streptococcus pneumoniae; Young Adult
PubMed: 28215915
DOI: 10.1016/j.jiph.2017.01.018 -
Clinical Microbiology and Infection :... Jun 2000To follow the evolution of capsular types and resistance of Streptococcus pneumoniae, isolated from deep sites.
OBJECTIVE
To follow the evolution of capsular types and resistance of Streptococcus pneumoniae, isolated from deep sites.
METHODS
More than 100 Belgian laboratories permanently collect S. pneumoniae strains isolated from puncture specimens (blood, cerebrospinal fluid, middle ear fluid, etc.) and forward them to the reference center in Leuven, in order to determine the capsular serogroups and types (SGTs) and their resistance.
RESULTS
From 1994 to 1998, the 5486 S. pneumoniae strains examined belonged to 39 of the 46 currently identified SGTs. The 10 most frequent SGTs accounted for 78.9% of the isolates, and 97% of all isolates belonged to SGTs included in the 23-valent vaccine. Overall mortality of patients with pneumococcal bacteremia or meningitis was 9.7%, and 23.8% in patients over 80 years. From 1994 to 1998, resistance to penicillin (P) increased from 7.6% to 14.2%, to tetracycline (T) from 14.9% to 28.0%, and to erythromycin (E) from 22.9% to 31%. Triple resistance (PTE) increased from 0.9% in 1994 to 6.6% in 1998. Five SGTs (6, 9, 14, 19 and 23) accounted for 50% of the isolates, but for > 90% of the penicillin-resistant or erythromycin-resistant isolates.
CONCLUSIONS
Resistance of S. pneumoniae to penicillin, erythromycin and tetracycline is steadily increasing and is concentrated in five serotypes included in the 23-valent pneumococcal vaccine. Increasing resistance and high mortality of invasive infections are an incentive to vaccinate vulnerable groups.
Topics: Adolescent; Adult; Belgium; Child; Child, Preschool; Drug Resistance, Microbial; Humans; Infant; Microbial Sensitivity Tests; Middle Aged; Pneumococcal Infections; Serotyping; Streptococcus pneumoniae
PubMed: 11168139
DOI: 10.1046/j.1469-0691.2000.00091.x -
Molecular Microbiology Sep 2021Rggs are a group of transcriptional regulators with diverse roles in metabolism and virulence. Here, we present work on the Rgg1518/SHP1518 quorum sensing system of...
Rggs are a group of transcriptional regulators with diverse roles in metabolism and virulence. Here, we present work on the Rgg1518/SHP1518 quorum sensing system of Streptococcus pneumoniae. The activity of Rgg1518 is induced by its cognate peptide, SHP1518. In vitro analysis showed that the Rgg1518 system is active in conditions rich in galactose and mannose, key nutrients during nasopharyngeal colonization. Rgg1518 expression is highly induced in the presence of these sugars and its isogenic mutant is attenuated in growth on galactose and mannose. When compared with other Rgg systems, Rgg1518 has the largest regulon on galactose. On galactose it controls up- or downregulation of a functionally diverse set of genes involved in galactose metabolism, capsule biosynthesis, iron metabolism, protein translation, as well as other metabolic functions, acting mainly as a repressor of gene expression. Rgg1518 is a repressor of capsule biosynthesis, and binds directly to the capsule regulatory region. Comparison with other Rggs revealed inter-regulatory interactions among Rggs. Finally, the rgg1518 mutant is attenuated in colonization and virulence in a mouse model of colonization and pneumonia. We conclude that Rgg1518 is a virulence determinant that contributes to a regulatory network composed of multiple Rgg systems.
Topics: Animals; Bacterial Proteins; Carbohydrate Metabolism; Female; Galactose; Gene Expression Regulation, Bacterial; Humans; Mannose; Mice; Mutation; Pneumococcal Infections; Promoter Regions, Genetic; Quorum Sensing; Streptococcus pneumoniae; Trans-Activators; Virulence; Virulence Factors
PubMed: 34328238
DOI: 10.1111/mmi.14788 -
Proceedings. Biological Sciences Nov 2013More than 90 capsular serotypes of Streptococcus pneumoniae coexist despite competing for nasopharyngeal carriage and a gradient in fitness. The underlying mechanisms...
More than 90 capsular serotypes of Streptococcus pneumoniae coexist despite competing for nasopharyngeal carriage and a gradient in fitness. The underlying mechanisms for this are poorly understood and make assessment of the likely population impact of vaccination challenging. We use an individual-based simulation model to generalize widely used deterministic models for pneumococcal competition and show that in these models short-term serotype-specific and serotype non-specific immunity could constitute the mechanism governing between-host competition and coexistence. We find that non-specific immunity induces between-host competition and that serotype-specific immunity limits a type's competitive advantage and allows stable coexistence of multiple serotypes. Serotypes carried at low prevalence show high variance in carriage levels, which would result in apparent outbreaks if they were highly pathogenic. Vaccination against few serotypes can lead to elimination of the vaccine types and induces replacement by others. However, in simulations where the elimination of the targeted types is achieved only by a combination of vaccine effects and the competitive pressure of the non-vaccine types, a universal vaccine with similar-type-specific effectiveness can fail to eliminate pneumococcal carriage and offers limited herd immunity. Hence, if vaccine effects are insufficient to control the majority of serotypes at the same time, then exploiting the competitive pressure by selective vaccination can help control the most pathogenic serotypes.
Topics: Age Factors; Computer Simulation; Humans; Microbial Interactions; Models, Biological; Nasopharynx; Pneumococcal Infections; Species Specificity; Streptococcus pneumoniae; United Kingdom; Vaccination
PubMed: 24089337
DOI: 10.1098/rspb.2013.1939 -
Journal of Clinical Microbiology Mar 2017Reliable distinction of and viridans group streptococci is important because of the different pathogenic properties of these organisms. Differentiation between and...
Improved Differentiation of Streptococcus pneumoniae and Other S. mitis Group Streptococci by MALDI Biotyper Using an Improved MALDI Biotyper Database Content and a Novel Result Interpretation Algorithm.
Reliable distinction of and viridans group streptococci is important because of the different pathogenic properties of these organisms. Differentiation between and closely related species group streptococci has always been challenging, even when using such modern methods as 16S rRNA gene sequencing or matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry. In this study, a novel algorithm combined with an enhanced database was evaluated for differentiation between and species group streptococci. One hundred one clinical species group streptococcal strains and 188 clinical strains were identified by both the standard MALDI Biotyper database alone and that combined with a novel algorithm. The database update from 4,613 strains to 5,627 strains drastically improved the differentiation of and species group streptococci: when the new database version containing 5,627 strains was used, only one of the 101 species group isolates was misidentified as , whereas 66 of them were misidentified as when the earlier 4,613-strain MALDI Biotyper database version was used. The updated MALDI Biotyper database combined with the novel algorithm showed even better performance, producing no misidentifications of the species group strains as All strains were correctly identified as with both the standard MALDI Biotyper database and the standard MALDI Biotyper database combined with the novel algorithm. This new algorithm thus enables reliable differentiation between pneumococci and other species group streptococci with the MALDI Biotyper.
Topics: Algorithms; Databases, Chemical; Humans; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Streptococcal Infections; Streptococcus mitis; Streptococcus pneumoniae
PubMed: 28053215
DOI: 10.1128/JCM.01990-16 -
Journal of Bacteriology Mar 2021The pneumococcal serine-rich repeat protein (PsrP) is a high-molecular-weight, glycosylated adhesin that promotes the attachment of to host cells. PsrP, its associated...
The pneumococcal serine-rich repeat protein (PsrP) is a high-molecular-weight, glycosylated adhesin that promotes the attachment of to host cells. PsrP, its associated glycosyltransferases (GTs), and dedicated secretion machinery are encoded in a 37-kb genomic island that is present in many invasive clinical isolates of PsrP has been implicated in establishment of lung infection in murine models, although specific roles of the PsrP glycans in disease progression or bacterial physiology have not been elucidated. Moreover, enzymatic specificities of associated glycosyltransferases are yet to be fully characterized. We hypothesized that the glycosyltransferases that modify PsrP are critical for the adhesion properties and infectivity of Here, we characterize the putative locus glycosyltransferases responsible for PsrP glycosylation. We also begin to elucidate their roles in virulence. We show that four glycosyltransferases within the locus are indispensable for biofilm formation, lung epithelial cell adherence, and establishment of lung infection in a mouse model of pneumococcal pneumonia. PsrP has previously been identified as a necessary virulence factor for many serotypes of and studied as a surface glycoprotein. Thus, studying the effects on virulence of each glycosyltransferase (GT) that builds the PsrP glycan is of high importance. Our work elucidates the influence of GTs We have identified at least four GTs that are required for lung infection, an indication that it is worthwhile to consider glycosylated PsrP as a candidate for serotype-independent pneumococcal vaccine design.
Topics: Adhesins, Bacterial; Animals; Bacterial Proteins; Female; Glycosyltransferases; Humans; Lung; Mice; Mice, Inbred BALB C; Pneumococcal Infections; Streptococcus pneumoniae; Virulence
PubMed: 33468592
DOI: 10.1128/JB.00389-20 -
International Journal of Infectious... Jan 2016The aim of this study was to determine the distribution of serotypes and the antimicrobial susceptibilities of Streptococcus pneumoniae clinical isolates causing...
OBJECTIVE
The aim of this study was to determine the distribution of serotypes and the antimicrobial susceptibilities of Streptococcus pneumoniae clinical isolates causing invasive and non-invasive disease in children aged ≤60 days in hospitals in Mexico.
METHODS
A 15-year retrospective study was conducted for the period 2000 to 2014. Pneumococcal clinical isolates were serotyped by Quellung reaction, and antimicrobial susceptibility testing was performed with the broth microdilution method.
RESULTS
A total of 126 pneumococcal isolates were collected. Pneumonia was the most frequent diagnosis (40.5%), followed by meningitis (29.4%), septicemia (16.7%), and other clinical entities, including otitis media and conjunctivitis (13.5%). The most frequent serotypes before the introduction of heptavalent pneumococcal conjugate vaccine (PCV7) were 19F, 23F, 7F, and 35B. Serotypes 3, 6A, 10A, 12F, and 15A/B increased after the introduction of PCV7. Serotype 19A was isolated most frequently in the pneumonia and meningitis cases only after the introduction of PCV7, and it displayed a high resistance to penicillin.
CONCLUSIONS
Although the number of infections in infants aged ≤60 days was low, such infections were not unusual events. New vaccination strategies should be evaluated to limit the risks in this age group.
Topics: Female; Humans; Infant; Infant, Newborn; Male; Microbial Sensitivity Tests; Pneumococcal Infections; Retrospective Studies; Serotyping; Streptococcus pneumoniae
PubMed: 26673859
DOI: 10.1016/j.ijid.2015.12.001 -
BMC Microbiology Aug 2014The polysaccharide capsule is a major virulence factor of the important human pathogen Streptococcus pneumoniae. However, S. pneumoniae strains lacking capsule do occur.
BACKGROUND
The polysaccharide capsule is a major virulence factor of the important human pathogen Streptococcus pneumoniae. However, S. pneumoniae strains lacking capsule do occur.
RESULTS
Here, we report a nasopharyngeal isolate of Streptococcus pneumoniae composed of a mixture of two phenotypes; one encapsulated (serotype 18C) and the other nonencapsulated, determined by serotyping, electron microscopy and fluorescence isothiocyanate dextran exclusion assay.By whole genome sequencing, we demonstrated that the phenotypes differ by a single nucleotide base pair in capsular gene cpsE (C to G change at gene position 1135) predicted to result in amino acid change from arginine to glycine at position 379, located in the cytoplasmic, enzymatically active, region of this transmembrane protein. This SNP is responsible for loss of capsule production as the phenotype is transferred with the capsule operon. The nonencapsulated variant is superior in growth in vitro and is also 117-fold more adherent to and more invasive into Detroit 562 human epithelial cells than the encapsulated variant.Expression of six competence pathway genes and one competence-associated gene was 11 to 34-fold higher in the nonencapsulated variant than the encapsulated and transformation frequency was 3.7-fold greater.
CONCLUSIONS
We identified a new single point mutation in capsule gene cpsE of a clinical S. pneumoniae serotype 18C isolate sufficient to cause loss of capsule expression resulting in the co-existence of the encapsulated and nonencapsulated phenotype. The mutation caused phenotypic changes in growth, adherence to epithelial cells and transformability. Mutation in capsule gene cpsE may be a way for S. pneumoniae to lose its capsule and increase its colonization potential.
Topics: Bacterial Adhesion; Bacterial Capsules; Bacterial Proteins; Cell Line; DNA Mutational Analysis; DNA Transformation Competence; Epithelial Cells; Genome, Bacterial; Humans; Mutant Proteins; Nasopharynx; Pneumococcal Infections; Point Mutation; Sequence Analysis, DNA; Streptococcus pneumoniae; Transformation, Genetic
PubMed: 25163487
DOI: 10.1186/s12866-014-0210-x -
Genome Biology and Evolution May 2016Streptococcus pneumoniae is a commensal human pathogen and the causative agent of various invasive and noninvasive diseases. Carriage of the pneumococcus in the...
Streptococcus pneumoniae is a commensal human pathogen and the causative agent of various invasive and noninvasive diseases. Carriage of the pneumococcus in the nasopharynx is thought to be mediated by biofilm formation, an environment where isogenic populations frequently give rise to morphological colony variants, including small colony variant (SCV) phenotypes. We employed metabolic characterization and whole-genome sequencing of biofilm-derived S. pneumoniae serotype 22F pneumococcal SCVs to investigate diversification during biofilm formation. Phenotypic profiling revealed that SCVs exhibit reduced growth rates, reduced capsule expression, altered metabolic profiles, and increased biofilm formation compared to the ancestral strain. Whole-genome sequencing of 12 SCVs from independent biofilm experiments revealed that all SCVs studied had mutations within the DNA-directed RNA polymerase delta subunit (RpoE). Mutations included four large-scale deletions ranging from 51 to 264 bp, one insertion resulting in a coding frameshift, and seven nonsense single-nucleotide substitutions that result in a truncated gene product. This work links mutations in the rpoE gene to SCV formation and enhanced biofilm development in S. pneumoniae and therefore may have important implications for colonization, carriage, and persistence of the organism. Furthermore, recurrent mutation of the pneumococcal rpoE gene presents an unprecedented level of parallel evolution in pneumococcal biofilm development.
Topics: Bacterial Proteins; Biofilms; Biological Evolution; Genome, Bacterial; Humans; Mutation; Pneumococcal Infections; Streptococcus pneumoniae
PubMed: 27190203
DOI: 10.1093/gbe/evw072 -
PloS One 2018Streptococcus pneumoniae is the leading cause of community-acquired pneumonia in all ages worldwide, and with ever-increasing antibiotic resistance, the understanding of...
Streptococcus pneumoniae is the leading cause of community-acquired pneumonia in all ages worldwide, and with ever-increasing antibiotic resistance, the understanding of its pathogenesis and spread is as important as ever. Recently, we reported the presence of a Low Molecular Weight Tyrosine Phosphatase (LMWPTP) Spd1837 in the pneumococcus. This protein is encoded in an operon, OM001 with two other genes, with previous work implicating this operon as important for pneumococcal virulence. Thus, we set out to investigate the role of the individual genes in the operon during pneumococcal pathogenesis. As LMWPTPs play a major role in capsular polysaccharide (CPS) biosynthesis in many bacteria, we tested the effect of mutating spd1837 and its adjacent genes, spd1836 and spd1838 on CPS levels. Our results suggest that individual deletion of the genes, including the LMWPTP, did not modulate CPS levels, in multiple conditions, and in different strain backgrounds. Following in vivo studies, Spd1836 was identified as a novel virulence factor during pneumococcal invasive disease, in both the lungs and blood, with this protein alone responsible for the effects of operon's role in virulence. We also showed that a deletion in spd1836, spd1838 or the overall OM001 operon reduced survival in human saliva during the conditions that mimic transmission compared to the wildtype strain. With studies suggesting that survival in human saliva may be important for transmission, this study identifies Spd1836 and Spd1838 as transmission factors, potentially facilitating the spread of the pneumococcus from person to person. Overall, this study hopes to further our understanding of the bacterial transmission that precedes disease and outbreaks.
Topics: Animals; Blotting, Western; Electrophoresis, Polyacrylamide Gel; Female; Genes, Bacterial; Humans; Mice; Operon; Polysaccharides; Saliva; Streptococcus pneumoniae; Virulence; Virulence Factors
PubMed: 29293606
DOI: 10.1371/journal.pone.0190402