Combining antibiotic with anti-TLR2/TLR13 therapy prevents brain pathology in pneumococcal meningitis

Despite effective antibiotic therapy, brain-destructive inflammation often cannot be avoided in pneumococcal meningitis. The causative signals are mediated predominantly through TLR-recruited myeloid differentiation primary response adaptor 88 (MyD88), as indicated by a dramatic pneumococcal meningitis phenotype of Myd88-/- mice. Because lipoproteins and single-stranded RNA are crucial for recognition of Gram-positive bacteria such as Streptococcus pneumoniae by the host immune system, we comparatively analyzed the disease courses of Myd88-/- and Tlr2-/- Tlr13-/- mice. Their phenotypic resemblance indicated TLR2 and -13 as master sensors of S. pneumoniae in the cerebrospinal fluid. A neutralizing anti-TLR2 antibody (T2.5) and chloroquine (CQ) - the latter applied here as an inhibitor of murine TLR13 and its human ortholog TLR8 - abrogated activation of murine and human primary immune cells exposed to antibiotic-treated S. pneumoniae. The inhibitory effect of the T2.5/CQ cocktail was stronger than that of dexamethasone, the current standard adjunctive drug for pneumococcal meningitis. Accordingly, TLR2/TLR13 blockade concomitant with ceftriaxone application significantly improved the clinical course of pneumococcal meningitis compared with treatment with ceftriaxone alone or in combination with dexamethasone. Our study indicates the importance of murine TLR13 and human TLR8, besides TLR2, in pneumococcal meningitis pathology, and suggests their blockade as a promising antibiotic therapy adjunct.

Nucleic acid sensing Toll-like receptors 3 and 9 play complementary roles in the development of bacteremia after nasal colonization associated with influenza co-infection

Streptococcus pneumoniae can cause mortality in infant, elderly, and immunocompromised individuals owing to invasion of bacteria to the lungs, the brain, and the blood. In building strategies against invasive infections, it is important to achieve greater understanding of how the pneumococci are able to survive in the host. Toll-like receptors (TLRs), critically important components in the innate immune system, have roles in various stages of the development of infectious diseases. Endosomal TLRs recognize nucleic acids of the pathogen, but the impact on the pneumococcal diseases of immune responses from signaling them remains unclear. To investigate their role in nasal colonization and invasive disease with/without influenza co-infection, we established a mouse model of invasive pneumococcal diseases directly developing from nasal colonization. TLR9 KO mice had bacteremia more frequently than wildtype in the pneumococcal mono-infection model, while the occurrence of bacteremia was higher among TLR3 KO mice after infection with influenza in advance of pneumococcal inoculation. All TLR KO strains showed poorer survival than wildtype after the mice had bacteremia. The specific and protective role of TLR3 and TLR9 was shown in developing bacteremia with/without influenza co-infection respectively, and all nucleic sensing TLRs would contribute equally to protecting sepsis after bacteremia.

Streptococcus pneumoniae secretion chaperones PrsA, SlrA, and HtrA are required for competence, antibiotic resistance, colonization, and invasive disease

Streptococcus pneumoniae is a Gram-positive bacterium and a significant health threat with the populations most at risk being children, the elderly, and the immuno-compromised. To colonize and transition into an invasive infectious organism, S. pneumoniae secretes virulence factors that are translocated across the bacterial membrane and destined for surface exposure, attachment to the cell wall, or secretion into the host. The surface exposed protein chaperones PrsA, SlrA, and HtrA facilitate S. pneumoniae protein secretion; however, the distinct roles contributed by each of these secretion chaperones have not been well defined. Tandem Mass-Tagged Mass Spectrometry and virulence, adhesion, competence, and cell wall integrity assays were used to interrogate the individual and collective contributions of PrsA, SlrA, and HtrA to multiple aspects of S. pneumoniae physiology and virulence. PrsA, SlrA, and HtrA were found to play critical roles in S. pneumoniae host cell infection and competence, and the absence of each of these secretion chaperones significantly altered the S. pneumoniae secretome in distinct ways. PrsA and SlrA were additionally found to contribute to cell wall assembly and resistance to cell wall-active antimicrobials and were important for enabling S. pneumoniae host cell adhesion during colonization and invasive infection. These findings serve to further illustrate the pivotal contributions of PrsA, SlrA, and HtrA to S. pneumoniae protein secretion and virulence.

Fluorescent and electrochemical detection of nuclease activity associated with Streptococcus pneumoniae using specific oligonucleotide probes

Streptococcus pneumoniae (S. pneumoniae) represents a significant pathogenic threat, often responsible for community-acquired pneumonia with potentially life-threatening consequences if left untreated. This underscores the pressing clinical need for rapid and accurate detection of this harmful bacteria. In this study, we report the screening and discovery of a novel biomarker for S. pneumoniae detection. We used S. pneumoniae nucleases as biomarker and we have identified a specific oligonucleotide that works as substrate. This biomarker relies on a specific nuclease activity found on the bacterial membrane, forming the basis for the development of both fluorescence and electrochemical biosensors. We observed an exceptionally high sensitivity in the performance of the electrochemical biosensor, detecting as low as 102 CFU mL-1, whereas the fluorescence sensor demonstrated comparatively lower efficiency, with a detection limit of 106 CFU mL-1. Moreover, the specificity studies have demonstrated the biosensors' remarkable capacity to identify S. pneumoniae from other pathogenic bacteria. Significantly, both biosensors have demonstrated the ability to identify S. pneumoniae cultured from clinical samples, providing compelling evidence of the potential clinical utility of this innovative detection system.

In vivo functional immunoprotection correlates for vaccines against invasive bacteria

Vaccination has significantly reduced the incidence of invasive infections caused by several bacterial pathogens, including Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis. However, no vaccines are available for many other invasive pathogens. A major hurdle in vaccine development is the lack of functional markers to quantify vaccine immunity in eliminating pathogens during the process of infection. Based on our recent discovery of the liver as the major organ of vaccine-induced clearance of blood-borne virulent bacteria, we here describe a new vaccine evaluation system that quantitatively characterizes the key features of effective vaccines in shuffling virulent bacteria from the blood circulation to the liver resident macrophage Kupffer cells (KCs) and sinusoidal endothelial cells (LSECs) in mouse septic infection model. This system consists of three related correlates or assays: pathogen clearance from the bloodstream, pathogen trapping in the liver, and pathogen capture by KCs/LSECs. These readouts were consistently associated with the serotype-specific immunoprotection levels of the 13-valent pneumococcal polysaccharide conjugate vaccine (PCV13) against lethal infection of S. pneumoniae, a major invasive Gram-positive pathogen of community-acquired infections in humans. Furthermore, the reliability and sensitivity of these correlates in reflecting vaccine efficacy were verified with whole cell vaccines of Klebsiella pneumoniae and Escherichia coli, two major Gram-negative pathogens in hospital-acquired invasive infections. This system may be used as effective readouts to evaluate the immunoprotective potential of vaccine candidates in the preclinical phase by filling the current technical gap in vaccine evaluation between the conventional in vitro approaches (e.g. antibody production and pathogen neutralization/opsonophagocytosis) and survival of immunized animals.

Pneumococcal population genomics changes during the early time period of conjugate vaccine uptake in southern India

Streptococcus pneumoniae is a major cause of invasive disease of young children in low- and middle-income countries. In southern India, pneumococcal conjugate vaccines (PCVs) that can prevent invasive pneumococcal disease began to be used more frequently after 2015. To characterize pneumococcal evolution during the early time period of PCV uptake in southern India, genomes were sequenced and selected characteristics were determined for 402 invasive isolates collected from children <5 years of age during routine surveillance from 1991 to 2020. Overall, the prevalence and diversity of vaccine type (VT) and non-vaccine type (NVT) isolates did not significantly change post-uptake of PCV. Individually, serotype 1 and global pneumococcal sequence cluster (GPSC or strain lineage) 2 significantly decreased, whereas serotypes 6B, 9V and 19A and GPSCs 1, 6, 10 and 23 significantly increased in proportion post-uptake of PCV. Resistance determinants to penicillin, erythromycin, co-trimoxazole, fluoroquinolones and tetracycline, and multidrug resistance significantly increased in proportion post-uptake of PCV and especially among VT isolates. Co-trimoxazole resistance determinants were common pre- and post-uptake of PCV (85 and 93 %, respectively) and experienced the highest rates of recombination in the genome. Accessory gene frequencies were seen to be changing by small amounts across the frequency spectrum specifically among VT isolates, with the largest changes linked to antimicrobial resistance determinants. In summary, these results indicate that as of 2020 this pneumococcal population was not yet approaching a PCV-induced equilibrium and they highlight changes related to antimicrobial resistance. Augmenting PCV coverage and prudent use of antimicrobials are needed to counter invasive pneumococcal disease in this region.

Identification of pneumococcal serotypes with individual recognition of vaccine types by a highly multiplexed real-time PCR-based MeltArray approach

BACKGROUND

Pneumococcus serotyping is important for monitoring serotype epidemiology, vaccine-induced serotypes replacement and emerging pathogenic serotypes. However, the lack of high-resolution serotyping tools has hindered its widespread implementation.

METHODS

We devised a single-step, multiplex real-time polymerase chain reaction (PCR)-based MeltArray approach termed PneumoSero that can identify 92 serotypes with individual recognition of 54 serotypes, including all 24 currently available vaccine types. The limit of detection (LOD) and the ability to coexisting serotypes were studied, followed by analytical evaluation using 92 reference pneumococcal strains and 125 non-pneumococcal strains, and clinical evaluation using 471 pneumococcus isolates and 46 pneumococcus-positive clinical samples.

RESULTS

The LODs varied with serotypes from 50 to 100 copies per reaction and 10 % of the minor serotypes were detectable in samples containing two mixed serotypes. Analytical evaluation presented 100 % accuracy in both 92 reference pneumococcal strains and 125 non-pneumococcal strains. Clinical evaluation of 471 pneumococcus isolates displayed full concordance with Sanger sequencing results. The 46 clinical specimens yielded 45 typeable results and one untypeable result. Of the 45 typeable samples, 41 were of a single serotype and four were of mixed serotypes, all of which were confirmed by Sanger sequencing or separate PCR assays.

CONCLUSION

We conclude that the PneumoSero assay can be implemented as a routine tool for pneumococcal serotyping in standard microbiology laboratories and even in clinical settings.

Design, development, and assessment of a novel multi-peptide vaccine targeting PspC, PsaA, and PhtD proteins of Streptococcus pneumoniae

Pneumococcus is the top cause of diseases such as pneumonia/meningitis, and of secondary infections after viral respiratory diseases like COVID-19/flu. Pneumococcal protein-based vaccines consisting of proteins with various functions in virulence might provide a qualified alternative for present vaccines. In this project, PspC, PsaA, and PhtD proteins were considered to anticipate B/T-cell epitopes using immunoinformatics to develop 4 multi-peptide constructs (C, A, and D individual constructs, and a fusion construct CAD). We tested whether vaccination with CAD is able to elicit more efficient protective responses against infection than vaccination with the individual constructs or combination of C + A + D. Based on the in silico results, the constructs were predicted to be antigenic, soluble, non-toxic, and stable, and also be able to provoke humoral/cellular immune reactions. When mice were immunized with the fusion protein, significantly higher levels of IgG and cytokines were induced in serum. The IgG in the fusion group had an effective bioactivity for pneumococcus clearance utilizing the complement pathway. The mice immunized with fusion protein were the most protected from challenge. This report for the first time presents a novel multi-peptide vaccine composed of immunodominant peptides of PspC, PsaA, and PhtD. In general, the experimental results supported the immunoinformatics predictions.

Global trends in non-susceptibility rates of Streptococcus pneumoniae isolates to ceftriaxone: Data from the antimicrobial testing leadership and surveillance (ATLAS) programme, 2016-21

To understand the global changes in non-susceptibility rates of Streptococcus pneumoniae to ceftriaxone, we conducted a study using the Antimicrobial Testing Leadership and Surveillance database. A total of 15,717 S. pneumoniae isolates were collected from 2016 to 2021. The minimum inhibitory concentrations (MICs) were determined using broth microdilution. The overall susceptibility rates of S. pneumoniae isolates to penicillin, ceftriaxone and ceftaroline were 63.4%, 94.0% and 99.6%, respectively. The geometric mean of MICs and MIC50/MIC90 values of ceftriaxone were higher in Asia than in other continents. China (33.9%), South Korea (33.8%) and Taiwan (27.6%) had the highest ceftriaxone non-susceptibility rates, followed by Turkey, India, Brazil, Malaysia, South Africa and Colombia, with rates between 10% and 20%. During the study period from 2020 to 2021, Asia had the highest MIC90 value (4 mg/L) for ceftriaxone in S. pneumoniae isolates, and the geometric mean of MICs increased from 0.25 mg/L in 2016-2017 to 0.39 mg/L in 2020-2021. Both Asia (from 83.4% to 75.1%) and Latin America (from 94.2% to 86.3%) showed a decreasing trend in ceftriaxone susceptibility rates from 2016 to 2021. In North America, Europe and Oceania, the susceptibility rate was higher than 95%, and there was no obvious change in the rate during the 6 y. Further analysis of the data from Asia revealed that individuals younger than 6 y of age had a lower susceptibility rate to ceftriaxone (71.6% vs. 81.7%, P < 0.05) than patients ≥6 y. The higher non-susceptibility rates of ceftriaxone in S. pneumoniae in Asia may lead to therapeutic challenges in community-acquired pneumonia.

The application of nanopore targeted sequencing for pathogen diagnosis in bronchoalveolar lavage fluid of patients with pneumonia: a prospective multicenter study

OBJECTIVE

To evaluate the value of nanopore targeted sequencing in diagnosing pneumonia pathogens.

METHODS

This large-scale multicentre prospective study performed in 8 hospitals across China from April to October 2022. Hospitalised patients with a diagnosis of pneumonia at admission were included. Complete clinical data were collected, and bronchoalveolar lavage fluid were obtained from each patient. These samples underwent simultaneous testing using conventional microbial testing, metagenomic next-generation sequencing, and nanopore targeted sequencing.

RESULTS

A total of 218 patients were included. Among the 168 cases of pulmonary infection, 246 strains of pathogens were confirmed. Nanopore targeted sequencing outperformed conventional microbial testing, identifying more pathogens with a sensitivity increase of 47.9% (77.2% vs. 29.3%). Metagenomic next-generation sequencing had a sensitivity of 82.9%. Total of 70.1% patients had consistent results in both metagenomic next-generation sequencing and nanopore targeted sequencing. Nanopore targeted sequencing exhibited significantly higher sensitivity in detecting Pneumocystis jiroveci, cytomegalovirus, Mycobacterium tuberculosis, Nontuberculous mycobacteria, Streptococcus pneumoniae, and Mycoplasma pneumoniae compared to conventional microbial testing. However, metagenomic next-generation sequencing demonstrated higher sensitivity than nanopore targeted sequencing for Aspergillus (88.5% vs. 53.8%). Regarding the detection of co-infections, nanopore targeted sequencing displayed significantly higher sensitivity than conventional microbial testing (76.7% vs. 28.7%) and was on par with metagenomic next-generation sequencing (76.7% vs. 82.9%).

CONCLUSION

Nanopore targeted sequencing performs equally well as metagenomic next-generation sequencing in bronchoalveolar lavage fluid for pathogen diagnosis in pneumonia, both methods showing higher sensitivity than conventional microbial testing. Nanopore targeted sequencing can be considered a reliable method for diagnosing pathogens in pneumonia.

Validation and comprehensive analysis of Streptococcus pneumoniae IgG WHO enzyme-linked immunosorbent assay in an Indian reference laboratory

Monitoring serotype-specific IgG levels against pneumococci is crucial for assessing immunity, vaccine efficacy, and evaluating vaccination programs. The WHO ELISA for pneumococci is a standardized assay ensuring consistency in testing and comparability of results across laboratories. It involves a rigorous testing process to confirm accurate, precise and reliable detection of antibodies. We validated the protocol for 13 pneumococcal serotypes by assessing its specificity, reproducibility (coefficient of variation ≤15%), repeatability (coefficient of variation ≤20%), accuracy, lower limit of quantification, stability, and robustness. We found these parameters were within acceptable ranges and showed excellent performance. Our findings imply that the method employed is appropriate for evaluating 13 valent pneumococcal conjugate vaccine which is introduced in the national immunization program by comparing pre-and post-vaccination IgG response.

Pathogen spectrum of community acquired pneumonia in people living with HIV (PLWH) in the German CAPNETZ-Cohort

OBJECTIVES

The objective of this study was to identify the pathogen spectrum of community acquired pneumonia in people living with HIV (PLWH), and to compare it with a matched HIV negative group in order to reassess therapeutic strategies for PLWH.

METHODS

Seventy-three (n = 73) PLWH (median CD4 3-6 months before CAP: 515/µl; SD 309) with community acquired pneumonia (CAP) were matched with 218 HIV-negative CAP controls in a prospective study design. Pathogen identifications used blood culture, samples from the upper and lower respiratory tract (culture and multiplex PCR) and urinary pneumococcal and legionella antigen test.

RESULTS

Although the vaccination rate among PLWH with CAP was significantly higher (pneumococcal vaccination: 27.4 vs. 8.3%, p < 0.001; influenza vaccination: 34.2 vs. 17.4%, p = 0.009), pneumococci were found most frequently as pathogen among both PLWH (n = 19/21.3%) and controls (n = 34/17.2%; p = 0.410), followed by Haemophilus influenzae (PLWH, n = 12/13.5%, vs. controls, n = 25 / 12.6%; p = 0.850). Staphylococcus aureus was found equally in 20.2 and 19.2% in PLWH and controls, but infection or colonization could not be distinguished. Mortality during 6-month follow-up was significantly higher for PLWH (5/73, or 6.8%) versus controls (3/218, or 1.4%), however with lower case numbers than previously reported. Typical HIV-associated pathogens such as Pneumocystis jirovecii were found only exceptionally.

CONCLUSIONS

Our study underscores the persistent clinical burden of CAP for PLWH. From pathogen perspective, empirical antibiotic treatment for CAP in PLWH on antiretroviral therapy should cover pneumococci and Haemophilus influenzae and may be adopted from valid common recommendations.

Serotype-specific quantification of residual free polysaccharide in multivalent pneumococcal conjugate vaccines

The Streptococcus pneumoniae bacteria has over 100 known serotypes that display a continuous change in prevalence by patients' age and geographical location and therefore necessitate continued efforts toward development of new vaccines with broader protection. Glycoconjugate vaccines have been instrumental in reducing global morbidity and mortality caused by Streptococcus pneumoniae infections. In these vaccines, the bacterial polysaccharide is conjugated to a carrier protein to enhance immunogenicity. To ensure well defined immunogenicity and stability of conjugated vaccines, reliable quantification of non-conjugated (free) polysaccharide is a critical, albeit challenging step during vaccine clinical dosing, release and stability monitoring. Multivalent preparations of Cross-reactive material 197 (CRM197)- conjugated pneumococcal polysaccharide materials often contain only nanogram levels of each individual free polysaccharide at final container concentrations. We have developed a novel method for the separation of free polysaccharides from conjugated material that requires no sample derivatization, employing instead an approach of quantitative immunoprecipitation of CRM197 with 3 different monoclonal antibodies and magnetic beads. A mix of antibodies against both linear and conformational epitopes enables successful removal of conjugates regardless of the protein folded state. The remaining free polysaccharide is subsequently measured in a serotype-specific ELISA.

Distinct baseline immune characteristics associated with responses to conjugated and unconjugated pneumococcal polysaccharide vaccines in older adults

Pneumococcal infections cause serious illness and death among older adults. The capsular polysaccharide vaccine PPSV23 and conjugated alternative PCV13 can prevent these infections; yet, underlying immunological responses and baseline predictors remain unknown. We vaccinated 39 older adults (>60 years) with PPSV23 or PCV13 and observed comparable antibody responses (day 28) and plasmablast transcriptional responses (day 10); however, the baseline predictors were distinct. Analyses of baseline flow cytometry and bulk and single-cell RNA-sequencing data revealed a baseline phenotype specifically associated with weaker PCV13 responses, which was characterized by increased expression of cytotoxicity-associated genes, increased frequencies of CD16+ natural killer cells and interleukin-17-producing helper T cells and a decreased frequency of type 1 helper T cells. Men displayed this phenotype more robustly and mounted weaker PCV13 responses than women. Baseline expression levels of a distinct gene set predicted PPSV23 responses. This pneumococcal precision vaccinology study in older adults uncovered distinct baseline predictors that might transform vaccination strategies and initiate novel interventions.

Serotype-Dependent Inhibition of Streptococcus pneumoniae Growth by Short-Chain Fatty Acids

Streptococcus pneumoniae (pneumococcus) is an opportunistic pathogen that can cause severe infectious diseases such as pneumonia, meningitis, and otitis media. Despite the availability of antibiotics and pneumococcal vaccines against some invasive serotypes, pneumococcal infection remains a tremendous clinical challenge due to the increasing frequency of infection by antimicrobial resistant, nonencapsulated, and/or non-vaccine serotype strains. Short-chain fatty acids (SCFAs), which are produced at various mucosal sites in the body, have potent antimicrobial activity, including inhibition of pathogen growth and/or bacterial biofilm formation. In this study, we investigated the antimicrobial activity of SCFAs (acetate, propionate, and butyrate) against various serotypes pneumococci. Propionate generally inhibited the growth of S. pneumoniae serotypes included in the pneumococcal conjugate vaccine (PCV) 13, except for serotypes 3 and 7F, though butyrate and acetate showed no or low inhibition, depending on the serotypes. Of note, butyrate showed strong inhibition against serotype 3, the most prevalent invasive strain since the introduction of the PCV. No SCFAs showed inhibitory effects against serotype 7F. Remarkably, the nonencapsulated pneumococcal strain had more sensitivity to SCFAs than encapsulated parental strains. Taken together, these results suggest that propionate showing the most potent inhibition of pneumococcal growth may be used as an alternative treatment for pneumococcal infection, and that butyrate could be used against serotype 3, which is becoming a serious threat.

Combined deficient response to polysaccharide-based and protein-based vaccines predicts a severe clinical phenotype

OBJECTIVES

Antibody response on polysaccharide- and protein-based vaccines is useful to test B cell functionality. As only few studies have explored the value of studying immune response to both vaccines, we evaluated the clinical value of anti-polysaccharide and anti-protein Luminex-based multiplex assays in context of primary immunodeficiency (PID) diagnosis.

METHODS

A 10-plex Luminex-based assay detecting antibodies to ten pneumococcal polysaccharide (PnPS) serotypes [present in unconjugated Pneumovax, not in 13-valent pneumococcal conjugated vaccine (PCV)] and a 5-plex assay detecting antibodies to five protein antigens (present in DTap/Tdap) were clinically validated in healthy individuals (n=99) and in retrospective (n=399) and prospective (n=108) patient cohorts. Clinical features of individuals with impaired response to PnPS and/or proteins were compared to those with normal response.

RESULTS

Antigen-specific antibody thresholds were determined in healthy individuals. Individuals with impaired anti-PnPS responses and deficient immunoglobulin levels suffered more from autoimmune diseases and had lower B cell levels compared to individuals with impaired anti-PnPS response with normal immunoglobulin levels. Individuals with combined impaired response to PnPS and proteins showed more severe clinical manifestations compared to individuals with isolated impaired response to PnPS or proteins. Eight of the 11 individuals with severely impaired responses to both PnPS and proteins had common variable immunodeficiency. Evaluation of the anti-PnPS response to four serotypes not contained in 20-valent PCV was comparable to evaluation to ten serotypes not contained in 13-valent PCV.

CONCLUSIONS

Multiplexed assessment of anti-PnPS and anti-protein responses combined with immunoglobulin quantification provides useful clinical information to support PID diagnosis.

Cold-inducible RNA-binding protein induces inflammatory responses via NF-κB signaling pathway in normal human bronchial epithelial cells infected with streptococcus pneumoniae

BACKGROUND

Community-acquired pneumonia causes significant illness and death worldwide, requiring further investigation and intervention. The invasion of Streptococcus pneumoniae (S. pneumoniae, S.p) can lead to serious conditions like meningitis, sepsis, or pneumonia. Extracellular Cold-inducible RNA-binding protein (eCIRP) acts as a damage-associated molecular pattern that triggers inflammatory responses and plays an important role in both acute and chronic inflammatory diseases. It remains unclear whether CIRP is involved in the process of S. pneumoniae infection in normal human bronchial epithelial cells (BEAS-2B).

METHODS

Cell counting kit (CCK)-8 assay was used to detect the activity of BEAS-2B cells. The subcellular localization of CIRP was detected by immunofluorescence. The mRNA and protein levels of CIRP, nuclear factor kappa-B (NF-κB) p65, toll like receptor-4 (TLR4), interleukin-6 (IL-6) were detected using quantitative real-time PCR (PCR) and Western Blot (WB). The protein expressions of CIRP, IL-1β, IL-6, tumor necrosis factor-α (TNF-α) and monocyte chemoattractant protein-1 (MCP-1) were assessed by enzyme-linked immunosorbent assay (ELISA).

RESULTS

CIRP affects the activity of BEAS-2B cells induced by S. pneumoniae infection. After infection, CIRP translocates from the nucleus to the cytoplasm, thereby inducing the production of pro-inflammatory cytokines (IL-1β, IL-6, TNF-α, and MCP-1). Additionally, the NF-κB p65 protein increases in infected cells but decreases with si-CIRP interference. Treatment with TLR4 neutralizing antibodies or NF-κB inhibitor effectively reduces the expressions of IL-1β, IL-6, TNF-α, and MCP-1.

CONCLUSIONS

The infection with S. pneumoniae upregulates CIRP expression and translocates it from the nucleus to the cytoplasm in BEAS-2B cells, leading to the release of proinflammatory factors via activation of NF-κB signaling pathway. CIRP as a key mediator in S. pneumoniae-induced inflammation offers potential targets for therapeutic intervention against community-acquired pneumonia.

Compliance with recommended pneumococcal vaccination schedule in patients treated for rheumatoid arthritis: A retrospective cohort study in the Veterans Affairs population

INTRODUCTION

Invasive pneumococcal disease (IPD) is a leading cause of death. Rheumatoid arthritis (RA) patients are at risk of IPD due to immunosuppressant medications. Up until 2022, two pneumococcal vaccines, the 13-valent Pneumococcal conjugate vaccine (PCV13) and pneumococcal polysaccharide vaccine (PPSV23), were recommended. Despite the recommendation change to give a single 20-valent PCV vaccine (PCV20), some still require multiple vaccinations. There is a need to identify barriers to vaccine uptake.

METHODS

We conducted a retrospective cohort study to assess the on-time vaccination rates for PCV13 and PPSV23 in treated RA patients between 2010 and 2018 using national Veterans Affairs data. Patients > 18 years of age diagnosed with RA and newly initiated on RA treatment were included. Pneumococcal vaccine compliance was assessed by measuring on-time receipt of PCV13 and PPSV23 vaccinations. We identified factors using multivariate logistic regression and described the occurrence of these factors using descriptive statistics.

RESULTS

A total of 39,243 patients were included in the study. Most patients were white (75.8 %), male (85.4 %), on methotrexate therapy (41.4 %). The average age was 62.3 years. The proportion of patients considered vaccine compliant is 43.9 %. The primary independent risk factors for vaccine non-compliance were black/African American race (Odds Ratio [OR] 1.26, 95 % Confidence Interval [CI] 1.19-1.34) or missing/unknown race (OR 1.45, 95 % CI 1.31-1.61), missing/unknown ethnicity (OR 1.21, 1.02-1.43), never married (OR 1.10, 95 % CI 1.02-1.19) or widowed (OR 1.23, 95 % CI 1.12-1.34), diagnosed with congestive heart failure (OR 1.10, 95 % CI 1.00-1.22), or dementia (OR 1.48, 95 % CI 1.16-1.91). The proportion of patients who were non-compliant in patients who were vaccine naïve was 32.1 % and the non-compliance rate for non-naïve patients was 65.3 %.

CONCLUSIONS

Providers should identify barriers to pneumococcal vaccination in RA patients to improve compliance. Efforts to increase vaccination should be tailored to specific high-risk groups.

Invasive Pneumococcal Disease and Potential Impact of Pneumococcal Conjugate Vaccines Among Adults, Including Persons Experiencing Homelessness-Alaska, 2011-2020

BACKGROUND

Adults aged ≥65 years, adults with certain underlying medical conditions, and persons experiencing homelessness are at increased risk for invasive pneumococcal disease (IPD). Two new pneumococcal conjugate vaccines, 15-valent pneumococcal conjugate vaccine (PCV15) and 20-valent pneumococcal conjugate vaccine (PCV20), were recently approved for use in US adults. We describe the epidemiology of IPD among Alaska adults and estimate the proportion of IPD cases potentially preventable by new vaccines.

METHODS

We used statewide, laboratory-based surveillance data to calculate and compare IPD incidence rates and 95% confidence intervals (CIs) among Alaska adults aged ≥18 years during 2011-2020 and estimate the proportion of IPD cases that were caused by serotypes in PCV15 and PCV20.

RESULTS

During 2011-2020, 1164 IPD cases were reported among Alaska adults for an average annual incidence of 21.3 cases per 100 000 adults per year (95% CI, 20.1-22.5). Incidence increased significantly during the study period (P < .01). IPD incidence among Alaska Native adults was 4.7 times higher than among non-Alaska Native adults (95% CI, 4.2-5.2). Among adults experiencing homelessness in Anchorage, IPD incidence was 72 times higher than in the general adult population (95% CI, 59-89). Overall, 1032 (89%) Alaska adults with IPD had an indication for pneumococcal vaccine according to updated vaccination guidelines; 456 (39%) and 700 (60%) cases were caused by serotypes in PCV15 and PCV20, respectively.

CONCLUSIONS

Use of PCV15 and PCV20 could substantially reduce IPD among adults in Alaska, including Alaska Native adults and adults experiencing homelessness.

Household air pollution and pneumococcal density related to nasopharyngeal inflammation in mothers and children in Ethiopia: A cross-sectional study

BACKGROUND

Three billion people in low- and middle-income countries are exposed to household air pollution as they use biomass fuel for cooking. We investigated the associations between solid fuel use and nasopharyngeal (NP) inflammation, as well as the associations between high pneumococcal density and NP inflammation, in mothers and children in rural and urban Ethiopia.

MATERIALS AND METHODS

Sixty pairs of mothers (median age, 30 years; range, 19-45 years) with a child (median age, 9 months; range, 1-24 months) were included from rural Butajira (n = 30) and urban Addis Ababa (n = 30) in Ethiopia. The cohort was randomly selected from a previous study of 545 mother/child pairs included 2016. Questionnaire-based data were collected which included fuel type used (solid: wood, charcoal, dung or crop waste; cleaner: electricity, liquefied petroleum gas). Nasopharyngeal (NP) samples were collected from all mothers and children and analyzed for the levels of 18 cytokines using a Luminex immunoassay. Pneumococcal DNA densities were measured by a real-time multiplex PCR and a high pneumococcal density was defined as a cyclic threshold (Ct) value ≤ 30.

RESULTS

Mothers from rural areas had higher median CXCL8 levels in NP secretions than those from urban areas (8000 versus 1900 pg/mL; p < 0.01), while rural children had slightly higher IL-10 levels than those from the urban area (26 vs 13 pg/mL; p = 0.04). No associations between fuel type and cytokine levels were found. However, a high pneumococcal density was associated with higher levels of cytokines in both mothers (CCL4, CXCL8, IL-1β, IL-6 and VEGF-A) and children (CCL4, CXCL8, IL-1β, IL-6 and IL-18).

CONCLUSIONS

No significant associations were found between solid fuel use and NP inflammation in Ethiopian mothers and children, but the inflammatory activity was higher in individuals living in the rural compared to the urban area. In addition, high cytokine levels were associated with high pneumococcal density in both mothers and children, indicating a significant impact of NP pathogens on inflammatory mediator levels in upper airways.

Antimicrobial resistance of Streptococcus pneumoniae from invasive pneumococcal diseases in Latin American countries: a systematic review and meta-analysis

Background

Invasive pneumococcal disease has declined since pneumococcal conjugate vaccine introduction in Latin America and the Caribbean (LAC). However, serotype distribution and antimicrobial resistance patterns have changed.

Methods

We conducted a systematic review to evaluate the frequency of antimicrobial resistance of Streptococcus pneumoniae from invasive disease in LAC. Articles published between 1 January 2000, and 27 December 2022, with no language restriction, were searched in major databases and gray literature. Pairs of reviewers independently selected extracted data and assessed the risk of bias in the studies. The quality of antimicrobial resistance (AMR) studies was evaluated according to WHO recommendations (PROSPERO CRD42023392097).

Results

From 8,600 records identified, 103 studies were included, with 49,660 positive samples of S. pneumoniae for AMR analysis processed. Most studies were from Brazil (29.1%) and Argentina (18.4%), were cross-sectional (57.3%), reported data on AMR from IPD cases (52.4%), and were classified as moderate risk of bias (50.5%). Resistance to penicillin was 21.7% (95%IC 18.7-25.0, I2: 95.9), and for ceftriaxone/cefotaxime it was 4.7% (95%IC 3.2-6.9, I2: 96.1). The highest resistance for both penicillin and ceftriaxone/cefotaxime was in the age group of 0 to 5 years (32.1% [95%IC 28.2-36.4, I2: 87.7], and 9.7% [95%IC 5.9-15.6, I2: 96.9] respectively). The most frequent serotypes associated with resistance were 14 for penicillin and 19A for ceftriaxone/cefotaxime.

Conclusion

Approximately one-quarter of invasive pneumococcal disease isolates in Latin America and the Caribbean displayed penicillin resistance, with higher rates in young children. Ongoing surveillance is essential to monitor serotype evolution and antimicrobial resistance patterns following pneumococcal conjugate vaccine introduction.

The epidemiology and the pathogen distribution of pediatric dacryocystitis in Chinese population 2017-2022

BACKGROUND

Dacryocystitis is a common disease in pediatric ophthalmology. Analysis of basic information, flora distribution, and characteristics of information on drug-resistant bacteria in children with dacryocystitis for 6 years, providing evidence for ophthalmologic infection prevention and clinical management strategies.

METHODS

A retrospective cohort study was conducted to evaluate the demographics of dacryocystitis in children and microbiological characteristics of secretion cultures, and to analyze the basic information, distribution of pathogenic bacteria, drug resistance, and to plot trendsand distribution pie charts according to the years.

RESULTS

This study recruited 5791 specimens. Decreased incidence of dacryocystitis from 2020 to 2022 (including the COVID-19 pandemic). The age of highest incidence of dacryocystitis is infancy, followed by the neonatal period, and the incidence decreased with age. Streptococcus pneumoniae had the highest percentage in 2017, and the overall trend was decreasing, the difference was statistically significant (p < 0.001); Streptococcus mitis showed an overall increasing trend, with the highest incidence in 2022 and the lowest in 2017, with a statistically significant difference (p < 0.001); Haemophilus influenzae was the most common gram-negative bacteria with an overall decreasing trend (p < 0.001); The incidence of Catamoeba and Stenotrophomonas varied from year to year, with statistically significant differences (p = 0.010, p = 0.033, respectively). Methicillin-resistant Staphylococcus aureus (MRSA) had the lowest incidence in 2017 and 2022 the highest incidence in 2022, with a statistically significant difference in incidence between years (p = 0.003); β-lactamase-positive was the most common type of resistance, and MRSA was the second, with statistically significant differences between years (p = 0.003, p < 0.001, respectively). Streptococcus pneumoniae is a common etiologic agent of dacryocystitis in all age groups.

CONCLUSIONS

Dacryocystitis in children is significantly associated with age characteristics and infection-related pathogens, and infection prevention and control can help reduce the infection of related pathogens and the increase of new drug-resistant strains. Close monitoring of changes in pathogen distribution in ocular secretion cultures can help in early intervention and treatment of infectious dacryocystitis.

Co-occurrence of bacteria and viruses and serotype distribution of Streptococcus pneumoniae in the nasopharynx of Tanzanian children below 2 years of age following introduction of the PCV13

Introduction

Pneumococcal conjugate vaccines have reduced severe disease attributed to vaccine-type pneumococci in children. However, the effect is dependent on serotype distribution in the population and disease development may be influenced by co-occurrence of viral and bacterial pathogens in the nasopharynx.

Methods

Following introduction of the 13-valent pneumococcal conjugate vaccine (PCV13) in Tanzania we performed repeated cross-sectional surveys, including 775 children below 2 years of age attending primary healthcare centers. All children were sampled from nasopharynx and pneumococci were detected by single-target PCR. Pneumococcal serotypes/groups and presence of viruses and other bacteria were determined by two multiplex PCR assays.

Results

The prevalence of PCV13 vaccine-type pneumococci decreased by 50%, but residual vaccine-types were still detected in 21% of the children 2 years after PCV13 introduction. An increase in the non-vaccine-type 15 BC was observed. Pneumococci were often co-occurring with Haemophilus influenzae, and detection of rhino/enterovirus was associated with higher pneumococcal load.

Discussion

We conclude that presence of residual vaccine-type and emerging non-vaccine-type pneumococci in Tanzanian children demand continued pneumococcal surveillance. High co-occurrence of viral and bacterial pathogens may contribute to the disease burden and indicate the need of multiple public health interventions to improve child health in Tanzania.