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BACKGROUND: Streptococcus pneumoniae is the most common bacterial cause of community acquired pneumonia and the acute respiratory distress syndrome (ARDS). Some clinical trials have demonstrated a beneficial effect of corticosteroid therapy in community acquired pneumonia, COVID-19, and ARDS, but the mechanisms of this benefit remain unclear. The primary objective of this study was to investigate the effects of corticosteroids on the pulmonary biology of pneumococcal pneumonia in a mouse model. A secondary objective was to identify shared transcriptomic features of pneumococcal pneumonia and steroid treatment in the mouse model and clinical samples. METHODS: We carried out comprehensive physiologic, biochemical, and histological analyses in mice to identify the mechanisms of lung injury in Streptococcus pneumoniae with and without adjunctive steroid therapy. We also studied lower respiratory tract gene expression from a cohort of 15 mechanically ventilated patients (10 with Streptococcus pneumoniae and 5 controls) to compare with the transcriptional studies in the mice. RESULTS: In mice with pneumonia, dexamethasone in combination with ceftriaxone reduced (1) pulmonary edema formation, (2) alveolar protein permeability, (3) proinflammatory cytokine release, (4) histopathologic lung injury score, and (5) hypoxemia but did not increase bacterial burden. Transcriptomic analyses identified effects of steroid therapy in mice that were also observed in the clinical samples. CONCLUSIONS: In combination with appropriate antibiotic therapy in mice, treatment of pneumococcal pneumonia with steroid therapy reduced hypoxemia, pulmonary edema, lung permeability, and histologic criteria of lung injury, and also altered inflammatory responses at the protein and gene expression level. The transcriptional studies in patients suggest that the mouse model replicates some of the features of pneumonia in patients with Streptococcus pneumoniae and steroid treatment. Overall, these studies provide evidence for the mechanisms that may explain the beneficial effects of glucocorticoid therapy in patients with community acquired pneumonia from Streptococcus Pneumoniae.

Background: Haemophilus influenzae community-acquired pneumonia (CAP) is common, and it is equally common to Streptococcus pneumoniae in some settings. The purpose of this study was to provide additional data on patients affected by H. influenzae CAP and their outcomes. Methods: Streptococcus pneumoniae-caused CAP (111 cases) was compared to CAP with H. influenzae (53 cases). Patients were adults (≥ 18 years) from the prospective study "Etiology of community acquired pneumonia in Sweden" (ECAPS), which was established during the years 2016–2018. Results: Cases with H. influenzae CAP were significantly older compared to S. pneumoniae CAP (median 77 vs 70 years, p = 0.037) albeit similar comorbidities. Haemophilus influenzae was generally absent in the bloodstream compared to S. pneumoniae (18% vs 2%, p = 0.01) but clinical presentations were comparable. Only a minority of patients, 34% with H. influenzae and 41% with S. pneumoniae CAP had underlying lung disease. Conclusion: In the light of childhood immunization campaigns against S. pneumoniae and the increasing numbers of pneumococcal vaccinations among the elderly, coupled with an aging population, the incidence of CAP caused by H. influenzae may increase. Further research is needed to understand the impact of H. influenzae CAP and to a development of a vaccine against this emerging microbe. [ABSTRACT FROM AUTHOR]

Background: S. pneumoniae (SPN) is the most common cause of pneumonia. The disease can be effectively prevented through immunisation. Since December 2020, the Malaysian Government has included the 10-valent pneumococcal conjugate vaccine (PCV10) for all infants born on or after 1 January 2020 as part of the National Immunisation Programme (NIP). However, the epidemiology of pneumonia remains poorly understood. To fill the knowledge gap, we established a multicentre surveillance study to understand the burden of pneumococcal pneumonia among young children in Peninsular Malaysia. Methods: MY-Pneumo is a multicentre prospective case–control study conducted in three sentinel sites located in three different states of Peninsular Malaysia – Kuala Lumpur, Pahang, and Kelantan. A cohort of at least 500 incident cases and 500 controls is enrolled beginning in October 2021 and matched for age. Cases are hospitalised children < 5 years with radiologically confirmed pneumonia, and the controls are children without any features suggestive of pneumonia. Clinical samples, including nasopharyngeal swabs (NPS) and urine, are collected according to the study protocol. Biological fluids such as blood, cerebrospinal fluid (CSF) and pleural fluid are obtained from invasive pneumonia disease (IPD) patients, if available. All children are tested for SPN using polymerase chain reaction (PCR) and pneumococcal urine antigen test (PUAT) using BinaxNow. Discussion: Surveillance data, including carriage rate, serotype variations and the phylogeny data structure of SPN among young children in Malaysia during PCV implementation, will be generated from this study. Trends and patterns of pneumococcal serotypes by different regions are important for targeted public health strategies. Our data will provide baseline information for estimating the impact of PCV10 implementation and will influence policymakers' decisions regarding the upgrade from PCV10 to a higher-valency conjugate vaccine in Malaysia. Trial registration: This project was registered at ClinicalTrials.gov (NCT04923035) on 2021, June 11. The study protocol was approved by the International Medical University Joint-Committee on Research & Ethics (4.15/JCM-216/2021) and the Institutional Review Board at sentinel sites (USM/JEPeM/21020190, IREC 2021–114, MREC ID No: 2021128–9769) and University of Southampton's Ethics and Research Governance (ERGo II 64844). [ABSTRACT FROM AUTHOR]

Background: Except for neonates, streptococci other than Streptococcus pneumoniae are a rare cause of acute bacterial meningitis. Streptococcus constellatus is a member of the Streptococcus anginosus group of gram-positive streptococci. It is a commensal microbe of the mucosae of the oral cavity, gastrointestinal tract, and urogenital tract. Rarely, it becomes pathogenic and causes contiguous or distant infections after mucosal damage. This report describes a 19-year-old immunocompetent man who developed bacterial meningitis, lung abscess, and brainstem infarct secondary to Streptococcus constellatus. Case Report: A 19-year-old immunocompetent man presented to the Emergency Department with a 4-week history of headache and neck pain. He was febrile on arrival. Physical examination revealed ataxia, upper-limb discoordination, and a positive Brudzinski sign. Cerebrospinal fluid and blood cultures were positive for Streptococcus constellatus, identified by matrix-assisted laser desorption ionization – time of flight mass spectrometry. Computed tomography of the chest demonstrated a lung abscess measuring 7×3.5×3 cm. A magnetic resonance imaging scan of the head revealed a 1.8×0.7 cm acute infarct in the right pons. The patient was treated initially with intravenous ceftriaxone and vancomycin before culture and sensitivity results, in addition to intravenous dexamethasone. After culture and sensitivities resulted, antibiotics were transitioned to a 4-week course of intravenous penicillin. The patient survived with no neurological consequences upon discharge. Conclusions: Streptococcus constellatus should be suspected as an etiological agent for bacterial meningitis and other rare complications such as brainstem infarction and lung abscess, even in immunocompetent patients. [ABSTRACT FROM AUTHOR]

Cationic ultrashort lipopeptides (USLPs) are promising antimicrobial candidates to combat multidrug-resistant bacteria. Using DICAMs, a newly synthesized family of tripeptides with net charges from -2 to +1 and a fatty amine conjugated to the C-terminus, we demonstrate that anionic and neutral zwitterionic USLPs can possess potent antimicrobial and membranedisrupting activities against prevalent human pathogens such as Streptococcus pneumoniae and Streptococcus pyogenes. The strongest antimicrobials completely halt bacterial growth at low micromolar concentrations, reduce bacterial survival by several orders of magnitude, and may kill planktonic cells and biofilms. All of them comprise either an anionic or neutral zwitterionic peptide attached to a long fatty amine (16-18 carbon atoms) and show a preference for anionic lipid membranes enriched in phosphatidylglycerol (PG), which excludes electrostatic interactions as the main driving force for DICAM action. Hence, the hydrophobic contacts provided by the long aliphatic chains of their fatty amines are needed for DICAM's membrane insertion, while negative-charge shielding by salt counterions would reduce electrostatic repulsions. Additionally, we show that other components of the bacterial envelope, including the capsular polysaccharide, can influence the microbicidal activity of DICAMs. Several promising candidates with good-to-tolerable therapeutic ratios are identified as potential agents against S. pneumoniae and S. pyogenes. Structural characteristics that determine the preference for a specific pathogen or decrease DICAM toxicity have also been investigated. [ABSTRACT FROM AUTHOR]

Background Growing evidence indicates antimicrobial resistance disproportionately affects individuals living in socially vulnerable areas. This study evaluated the association between the CDC/ATSDR Social Vulnerability Index (SVI) and Streptococcus pneumoniae (SP) antimicrobial resistance (AMR) in the United States. Methods Adult patients ≥18 years with 30-day nonduplicate SP isolates from ambulatory/hospital settings from January 2011 to December 2022 with zip codes of residence were evaluated across 177 facilities in the BD Insights Research Database. Isolates were identified as SP AMR if they were non-susceptible to ≥1 antibiotic class (macrolide, tetracycline, extended-spectrum cephalosporins, or penicillin). Associations between SP AMR and SVI score (overall and themes) were evaluated using generalized estimating equations with repeated measurements within county to account for within-cluster correlations. Results Of 8008 unique SP isolates from 574 US counties across 39 states, the overall proportion of AMR was 49.9%. A significant association between socioeconomic status (SES) theme and SP AMR was detected with higher SES theme SVI score (indicating greater social vulnerability) associated with greater risk of AMR. On average, a decile increase of SES, indicating greater vulnerability, was associated with a 1.28% increased risk of AMR (95% confidence interval [CI],.61%, 1.95%; P =.0002). A decile increase of household characteristic score was associated with a 0.81% increased risk in SP AMR (95% CI,.13%, 1.49%; P =.0197). There was no association between racial/ethnic minority status, housing type and transportation theme, or overall SVI score and SP AMR. Conclusions SES and household characteristics were the SVI themes most associated with SP AMR. [ABSTRACT FROM AUTHOR]

Immune response elicited during pneumococcal carriage has been shown to protect against subsequent colonization and infection by Streptococcus pneumoniae. The study was designed to measure the baseline serotype-specific anti-capsular IgG concentration and opsonic titers elicited in response to asymptomatic carriage in adults with and without type 2-diabetes. Level of IgG to capsular polysaccharide was measured in a total of 176 samples (124 with type 2 diabetes and 52 without type 2 diabetes) against serotype 1, 19F, 9V, and 18C. From within 176 samples, a nested cohort of 39 samples was selected for measuring the functional capacity of antibodies by measuring opsonic titer to serotypes 19F, 9V, and 18C. Next, we measured levels of IgG to PspA in 90 samples from individuals with and without diabetes (22 non-diabetes and 68 diabetes). Our results demonstrated comparable IgG titers against all serotypes between those with and without type 2-diabetes. Overall, we observed higher opsonic titers in those without diabetes as compared to individuals with diabetes for serotypes 19F and 9V. The opsonic titers for 19F and 9V significantly negatively correlated with HbA1c. For 19F, 41.66% (n = 10) showed opsonic titers ≥ 1:8 in the diabetes group as compared to 66.66% (n = 10) in the non-diabetes group. The percentage was 29.6% (n = 7) vs 66.66% (n = 10) for 9V and 70.83% (n = 17) vs 80% (n = 12) for 18C in diabetes and non-diabetes groups respectively. A comparable anti-PspA IgG (p = 0.409) was observed in those with and without diabetes, indicating that response to protein antigen is likely to remain intact in those with diabetes. In conclusion, we demonstrated comparable IgG titers to both capsular polysaccharide and protein antigens in those with and without diabetes, however, the protective capacity of antibodies differed between the two groups. [ABSTRACT FROM AUTHOR]

Streptococcus pneumoniae is a bacterium of great global importance, responsible for more than one million deaths per year. This bacterium is commonly acquired in the first years of life and colonizes the upper respiratory tract asymptomatically by forming biofilms that persist for extended times in the nasopharynx. However, under conditions that alter the bacterial environment, such as viral infections, pneumococci can escape from the biofilm and invade other niches, causing local and systemic disease of varying severity. The polyamine transporter PotABCD is required for optimal survival of the organism in the host. Immunization of mice with recombinant PotD can reduce subsequent bacterial colonization. PotD has also been suggested to be involved in pneumococcal biofilm development. Therefore, in this study we aimed to elucidate the role of PotABCD and polyamines in pneumococcal biofilm formation. First, the formation of biofilms was evaluated in the presence of exogenous polyamines–the substrate transported by PotABCD–added to culture medium. Next, a potABCD-negative strain was used to determine biofilm formation in different model systems using diverse levels of complexity from abiotic surface to cell substrate to in vivo animal models and was compared with its wild-type strain. The results showed that adding more polyamines to the medium stimulated biofilm formation, suggesting a direct correlation between polyamines and biofilm formation. Also, deletion of potABCD operon impaired biofilm formation in all models tested. Interestingly, more differences between wild-type and mutant strains were observed in the more complex model, which emphasizes the significance of employing more physiological models in studying biofilm formation. [ABSTRACT FROM AUTHOR]

β-Lactam antibiotics are a class of antibiotics commonly used to treat bacterial infections. However, the effects of β-lactam antibiotics on term neonatal intestinal flora have not been fully elucidated. Hospitalized full-term newborns receiving β-lactam antibiotics formed the antibiotic group (n = 67), while those without antibiotic treatment comprised the non-antibiotic group (n = 47). A healthy group included healthy full-term newborns (n = 16). Stool samples were collected for 16 S rDNA sequencing to analyze gut microbiota variations. Further investigation was carried out within the β-lactam antibiotic group, exploring the effects of antibiotic use on the newborns' gut microbiota in relation to the duration and type of antibiotic administration, delivery method, and feeding practices. The antibiotic group exhibited significant difference of microbial community composition compared to the other groups. Genera like Klebsiella, Enterococcus, Streptococcus, Alistipes, and Aeromonas were enriched, while Escherichia-Shigella, Clostridium sensu stricto 1, Bifidobacterium, and Parabacteroides were reduced. Klebsiella negatively correlated with Escherichia-Shigella, positively with Enterobacter, while Escherichia-Shigella negatively correlated with Enterococcus and Streptococcus. Regardless of neonatal age, β-lactam antibiotics induced an elevated abundance of Klebsiella and Enterococcus. The impact on gut microbiota varied with the duration and type of antibiotic (cefotaxime or ampicillin/sulbactam). Compared to vaginal delivery, cesarean delivery after β-lactam treatment heightened the abundance of Klebsiella, Enterobacteriaceae_Unclassified, Lactobacillales_Unclassified, and Pectobacterium. Feeding patterns minimally influenced β-lactam-induced alterations. In conclusion, β-lactam antibiotic treatment for neonatal pneumonia and sepsis markedly disrupted intestinal microbiota, favoring Klebsiella, Enterococcus, Streptococcus, Alistipes, and Aeromonas. The impact of β-lactam varied by duration, type, and delivery method, emphasizing heightened disruptions post-cesarean delivery. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the bacterial characteristics of pneumococcal isolates obtained from a tertiary care hospital in Japan. We analyzed the antimicrobial susceptibility, possession of macrolide resistance genes, pneumococcal serogroup/serotype, and sequence type (ST) of pneumococcal isolates from patients aged 15 years or older between 2011 and 2020 at Nagasaki University Hospital. Of the 73 isolates analyzed, 86.3% showed resistance to macrolides, and 28.8%, 46.6%, and 11.0% harbored mefA, ermB, and both, respectively. Of the isolates possessing ermB, 97.6% showed high levels of macrolide resistance [minimal inhibitory concentration (MIC) range, > 16 µg/mL]. Solithromycin (MIC range, 0.03-0.25 µg/mL), regardless of the presence of macrolide resistance genes, and lascufloxacin (MIC range, 0.06-0.5 µg/mL) showed potent in vitro activity against pneumococci. Serotype 19A was the most prevalent (six isolates), followed by serotypes 10A, 15A, and 15B/C (five isolates each). Four serotypes (11A, 19A, 22F, and 23B) and five STs (36, 99, 433, 558, and 3111) were significantly correlated with the presence of macrolide resistance genes. All four isolates with serotype 11A/ST99 and three isolates with serotype 19A/ST3111 harbored both mefA and ermB. No macrolide resistance genes were detected in either of the two isolates with serotype 22F/ST433, while all ten isolates with serogroup 15 (serotypes 15A and 15B/C, five isolates each) possessed ermB alone. Our study revealed the bacterial characteristics of the pneumococcal isolates obtained from our hospital. In vitro activity of solithromycin and lascufloxacin against these isolates was confirmed. [ABSTRACT FROM AUTHOR]

Neutrophils are the first leukocytes to be recruited to sites of inflammation in response to chemotactic factors released by activated macrophages and pulmonary epithelial and endothelial cells in bacterial pneumonia, a common cause of acute respiratory distress syndrome (ARDS). Although neutrophilic inflammation facilitates the elimination of pathogens, neutrophils also may cause bystander tissue injury. Even though the presence of neutrophils in alveolar spaces is a key feature of acute lung injury and ARDS especially from pneumonia, their contribution to the pathogenesis of lung injury is uncertain. The goal of this study was to elucidate the role of neutrophils in a clinically relevant model of bacterial pneumonia. We investigated the effect of reducing neutrophils in a mouse model of pneumococcal pneumonia treated with antibiotics. Neutrophils were reduced with anti-lymphocyte antigen 6 complex locus G6D (Ly6G) monoclonal antibody 24 h before and immediately preceding infection. Mice were inoculated intranasally with Streptococcus pneumoniae and received ceftriaxone 12 h after bacterial inoculation. Neutrophil reduction in mice treated with ceftriaxone attenuated hypoxemia, alveolar permeability, epithelial injury, pulmonary edema, and inflammatory biomarker release induced by bacterial pneumonia, even though bacterial loads in the distal air spaces of the lung were modestly increased as compared with antibiotic treatment alone. Thus, when appropriate antibiotics are administered, lung injury in the early phase of bacterial pneumonia is mediated in part by neutrophils. In the early phase of bacterial pneumonia, neutrophils contribute to the severity of lung injury, although they also participate in host defense. NEW & NOTEWORTHY: Neutrophil accumulation is a key feature of ARDS, but their contribution to the pathogenesis is still uncertain. We investigated the effect of reducing neutrophils in a clinically relevant mouse model of pneumococcal pneumonia treated with antibiotics. When appropriate antibiotics were administered, neutrophil reduction with Ly6G antibody markedly attenuated lung injury and improved oxygenation. In the early phase of bacterial pneumonia, neutrophils contribute to the severity of lung injury, although they also participate in host defense. [ABSTRACT FROM AUTHOR]

Background: Parenteral penicillin G (PENG) and oral amoxicillin (AMOX) are recommended as treatment for pediatric community‐acquired pneumonia (CAP). With recent epidemiologic penicillin susceptibility data for Streptococcus pneumoniae, the most common etiology of CAP, the objective of this study was to evaluate optimal dosing regimens of PENG and AMOX based on population pharmacokinetics linked to current susceptibility data. Methods: Using NONMEM v7.3, Monte Carlo simulations (N = 10,000) were conducted for AMOX 15 mg/kg/dose PO every 8 h (standard‐dose), AMOX 45 mg/kg/dose PO every 12 h (high‐dose), and PENG 62,500 units/kg/day IV every 6 h using six virtual subjects with ages spanning 3 months to 15 years old. The probability of target attainment (PTA) was determined for both serum and epithelial lining fluid (ELF) to achieve free drug concentrations above the minimum inhibitory concentration (%fT>MIC) across the population of pneumococci for 30%–50% of the dosing interval. Results: In 2018, all 21 (100%) pneumococcal isolates were susceptible to both PENG and AMOX based on Clinical and Laboratory Standards Institute (CLSI; MIC at 2 mg/L) breakpoints, and 15 of 21 (71%) were susceptible based on EUCAST (MIC at 0.5 mg/L) breakpoints. As compared to CLSI, EUCAST breakpoints consistently achieved higher PTA for all antibiotic regimens. At 50% fT>MIC in the serum at the susceptible MICs, standard‐dose AMOX achieved >4% PTA (CLSI) and >86% PTA (EUCAST); high‐dose AMOX achieved >73% PTA (CLSI) and >99% PTA (EUCAST); and PENG achieved 0% PTA (using CLSI) and 100% PTA (using EUCAST). Standard‐dose AMOX, high‐dose AMOX, and PENG achieved >71%, >93%, and 100% PTA, respectively, in the serum at 30%–50% fT>MIC when each patient was stochastically linked to an MIC based on the frequency distribution of national susceptibility data. The PTA was consistently lower in ELF as compared with serum for all regimens. Conclusion: Based on the recent rates of resistance, antibiotic doses evaluated provide appropriate exposure for pediatric CAP based on the serum and ELF data associated with predicted clinical and microbiologic success for pneumococcus. High‐dose AMOX may still be required to treat pediatric CAP, especially if using CLSI breakpoints. Ongoing surveillance for resistance is essential. [ABSTRACT FROM AUTHOR]

To study the epidemiology and microbiological landscape in patients (≤21 yrs) diagnosed with endophthalmitis across a multi-tier ophthalmology network in India. This cross-sectional hospital-based study included 1,041 patients (≤21 yrs) diagnosed with endophthalmitis, between April 2012 and May 2022. The data were collected using an electronic medical record system. Bacteria (24%) was the most common etiology followed by fungus (2%). The majority of the patients were male (66%) with a mean age of 8.37 ± 5.99 years. The most common age group was middle childhood (6-11 years) with 365 (35.06%) patients. The patients were more commonly from the lower socio-economic status (60.81%) and urban geography (49%). The common cause of endophthalmitis was trauma (59.33%) and amongst the 279 culture positive eyes, the predominant bacteria isolated was Streptococcus pneumoniae followed by Bacillus species and fungus included predominantly Aspergillus and Candida species. The most common surgical intervention performed was intraocular antibiotics (74%) followed by pars plana vitrectomy (52%). The most common etiology of endophthalmitis in children is bacterial and traumatic in nature and presented from the lower socio-economic status. A half of the eyes warranted a vitreo-retinal surgical intervention. A cross-sectional study on the microbiological landscape in pediatric endophthalmitis showed that the most common cause of endophthalmitis was trauma and the predominant bacteria isolated was Streptococcus spp. and Bacillus spp. Additionally, majority of the patients were from the lower socio-economic status and urban geography and the most common surgical intervention performed was injection of intraocular antibiotics. [ABSTRACT FROM AUTHOR]

To review the etiology and antibiotic susceptibility patterns of infectious endophthalmitis over 11 years in different age groups Microbiology records of culture-positive endophthalmitis cases from January 2011 and December 2021 were reviewed for the age groups 0–30, 31–60, and >60 years. Additionally, data was also analysed for trends in antibiotic susceptibility between different age groups. A total of 5590 patients were clinically diagnosed with endophthalmitis. Of these, 1316 (23.5%) patients were culture positive comprising of 1097 bacteria (83.3%) and 219 fungal (16.6%). Gram-positive bacteria predominated the culture-proven bacterial endophthalmitis group with 709 cases (62.6%). Streptococcus pneumoniae (9.3%) was the most prevalent organism in the age group between 0 and 30 years, while Staphylococcus epidermidis (6%) was the most prevalent organism in the age group of 31–60 years. In comparison, Pseudomonas aeruginosa (4.1%) was the most abundant organism in the age group >60 years. Interestingly, Aspergillus flavus (13.24%) was the predominant fungal pathogen in all age groups. There was an increasing trend in antibiotic resistance from younger to older age groups and this pattern was observed for almost all drugs tested except vancomycin and amikacin. While infection can occur at any age, the etiology also seems to vary. This study helps us understand the demography of endophthalmitis along with choice of empirical antibiotics that would influence treatment outcomes. Although vancomycin currently holds good for the treatment for gram-positive infections, gram-negative infections calls for an immediate need for newer drugs or advanced treatment options. [ABSTRACT FROM AUTHOR]

Background Viridans group streptococci (VGS) bloodstream infection (BSI) frequently occurs in cancer patients receiving chemotherapy, and is associated with infective endocarditis (IE) in up to 20% of cases in the general population. Objectives In cancer patients receiving chemotherapy with VGS BSI, we aimed to: (i) determine the incidence of infective complications including IE, (ii) assess the utility of echocardiography in this patient population, (iii) determine the duration and type of antimicrobial therapy received for monomicrobial infections, and (iv) determine the evolution of antimicrobial resistance. Methods VGS BSIs (excluding Streptococcus pneumoniae and Streptococcus pseudopneumoniae) in cancer patients receiving chemotherapy were identified from a statewide public pathology database between 2013 and 2022 at our tertiary centre. Medical records were accessed for clinical, microbiological and radiological data. Results Of 581 patient episodes screened, 183 episodes involving 171 patients met inclusion criteria. Of these, 51% were bone marrow transplantation (BMT) patients, 40% were non-BMT haematology patients, and 8% were solid organ malignancy patients. The median age was 55 years, and 96% were neutropenic at the time of blood culture collection. A transthoracic echocardiogram was performed for 71% of episodes, and one patient met modified Duke's criteria for definite IE, although this diagnosis was not suspected on clinical grounds. Other complications were uncommon. Benzylpenicillin resistance was rare (2.9%) and did not change over time. Most episodes (75%) were treated with piperacillin/tazobactam. For monomicrobial BSIs, the median antibiotic duration was 5 days (IQR 2–7) post-neutropenia resolution. Conclusions Infective complications and antimicrobial resistance are rare in cancer patients with VGS BSI. This may provide a safe opportunity to limit both investigations (e.g. echocardiogram) and prolonged exposure to broad-spectrum antimicrobials. [ABSTRACT FROM AUTHOR]

Ongoing surveillance after pneumococcal conjugate vaccination (PCV) deployment is essential to inform policy decisions and monitor serotype replacement. We report serotype and disease severity trends in 3,719 adults hospitalized for pneumococcal disease in Bristol and Bath, United Kingdom, during 2006-2022. Of those cases, 1,686 were invasive pneumococcal disease (IPD); 1,501 (89.0%) had a known serotype. IPD decreased during the early COVID-19 pandemic but during 2022 gradually returned to prepandemic levels. Disease severity changed throughout this period: CURB65 severity scores and inpatient deaths decreased and ICU admissions increased. PCV7 and PCV13 serotype IPD decreased from 2006-2009 to 2021-2022. However, residual PCV13 serotype IPD remained, representing 21.7% of 2021-2022 cases, indicating that major adult PCV serotype disease still occurs despite 17 years of pediatric PCV use. Percentages of serotype 3 and 8 IPD increased, and 19F and 19A reemerged. In 2020-2022, a total of 68.2% IPD cases were potentially covered by PCV20. [ABSTRACT FROM AUTHOR]

Objective: The main goal of this current study was to assess the prevalence of these infections in the outpatient setting as well as in hospitalized patients at Mohammed V hospital in Meknes, Morocco. Method: The epidemiological and microbiological characteristics of respiratory infections mentioned in the registers of the laboratory of microbiology at Mohammed V hospital, Meknes, were collected on pre-established exploitation sheets for each case throughout a 3-year period (2017-2019). Results: A total of 7863 patients diagnosed with respiratory infections were admitted to various hospital departments. During 2017, the percentage of hospitalized patients was equivalent to 33.6% of cases, and during the year 2018, this percentage increased by roughly 4.61% before decreasing by 10.03% in 2019. Males were the most affected with a proportion of 61%, while females did not exceed 31%. The pulmonology department had the highest proportion of hospitalized patients (62.60%), followed by the medicine department (14.63%), and gastroenterology (13.55%). The seasonal distribution peaks in spring with a percentage of 37.6%. According to the bacteriological examination, 20 patients (5.42%) had a bacterial respiratory infection. The biochemical classification of the isolated bacterial species revealed the presence of three bacterial species with a high isolation frequency of Streptococcus pneumoniae (85%), followed by Escherichia coli (10%) and Staphylococcus aureus (5%). Conclusion: Respiratory infections are widespread throughout the spring season, with male being the most affected. Monitoring and characterization of epidemiological and microbiological data are still required to prevent and mitigate the burden of these infections on patients, healthcare systems, and society. [ABSTRACT FROM AUTHOR]

Disruption of the alveolar barrier can trigger acute lung injury. This study elucidated the association of methyltransferase‐like 3 (METTL3) with Streptococcus pneumoniae (SP)‐induced apoptosis and inflammatory injury of alveolar epithelial cells (AECs). AECs were cultured and then infected with SP. Furthermore, the expression of METTL3, interleukin (IL)‐10, IL‐6, tumor necrosis factor‐alpha (TNF‐α), monocyte chemoattractant protein‐1 (MCP‐1), long noncoding RNA nuclear paraspeckle assembly transcript 1 (NEAT1), mucin 19 (MUC19), N6‐methyladenosine (m6A), and NEAT1 after m6A modification were detected by qRT‐PCR, Western blot, and enzyme‐linked immunosorbent, m6A quantification, and methylated RNA immunoprecipitation‐qPCR analyses, respectively. Moreover, the subcellular localization of NEAT1 was analyzed by nuclear/cytosol fractionation assay, and the binding between NEAT1 and CCCTC‐binding factor (CTCF) was also analyzed. The results of this investigation revealed that SP‐induced apoptosis and inflammatory injury in AECs and upregulated METTL3 expression. In addition, the downregulation of METTL3 alleviated apoptosis and inflammatory injury in AECs. METTL3‐mediated m6A modification increased NEAT1 and promoted its binding with CTCF to facilitate MUC19 transcription. NEAT1 or MUC19 overexpression disrupted their protective role of silencing METTL3 in AECs, thereby increasing apoptosis and inflammatory injury. In conclusion, this is the first study to suggest that METTL3 aggravates SP‐induced cell damage via the NEAT1/CTCF/MUC19 axis. [ABSTRACT FROM AUTHOR]

Maintaining the molecular size (MS) of Streptococcus pneumoniae capsular polysaccharide within specified range is essential for manufacture of conjugate vaccines, either through physical or acid hydrolysis before use in the conjugation process. Polysaccharide MS typically reduced, with high-pressure homogenization as an approach, for preserving their chemical structure. When the average MS of Pneumococcal capsular polysaccharide serotype-1(CPS1) exceeds 1200 kDa during fermentation, using a high-pressure homogenizer to reduce its MS to 150–250 kDa can become extremely difficult. Even after multiple homogenization cycles, obtaining polysaccharide of the required size can be challenging. Moreover, exceeding a certain number of homogenization cycles can negatively impact the stability, yield, and conjugation efficiency. To control polysaccharide MS, we conducted a design of experiments (DOE) study focused on the optimization of the fermentation process, employing serotype-1 as a represntative case. The successful optimization of these CPPs was achieved in a consistent and reproducible manner. Systematic evaluation by DOE based process optimization has provided valuable insights into precise polysaccharide manufacturing control of polysaccharide MS. Our findings confirm that maintaining Hy-Soy™ at 20-30 g/L and yeast extract at 1–3 g/L in the fermentation media, with a feed concentration of 2–3.5 g/L/H and 0.1–0.5 VVM of air, consistently yields polysaccharide with MS of < 1200 kDa. This strategy that can be extended to other S. pneumoniae serotype polysaccharide production.Article Highlights: Maintaining a consistant average molecular size of pneumococcal CPS-1 is important for conjugate vaccine formulations. Media optimization was done using a DOE approach to ensure the reproducible production of CPS-1 with controlled MS. Specifications and design space parameters were established and validated to produce polysaccharide with desired molecular size. [ABSTRACT FROM AUTHOR]

Streptococcus pneumoniae is a significant pathogen causing infectious diseases, including pneumonia, otitis media, septicemia, and meningitis. The introduction of multivalent vaccines has coincided with a remarkable decrease in the number of pneumococcal-related deaths. Despite this, pneumococcal infection remains a significant cause of death among children under 5 years old and adults aged 65 or older at a global level. Therefore, early detection of S. pneumoniae infection is crucial for prognosis of pneumococcal infection patients. In this study, we evaluated the utility of a real-time multienzyme isothermal rapid amplification (MIRA) assay for detecting S. pneumoniae and other non-S. pneumoniae bacterial species. A primer–probe set targeting the S. pneumoniae lytA gene was designed, followed by optimization of parameters for the MIRA assay. At the same time, we validated the real-time MIRA assay for detecting S. pneumoniae using 79 clinical isolates identified by VITEK MS. The results showed a detection sensitivity and specificity of 100%. These results demonstrate that the designed real-time MIRA assay is a promising, rapid, simple, and reliable method for detecting S. pneumoniae infection in resource-limited areas. It has great potential for application in detecting not only S. pneumoniae but also other non-S. pneumoniae bacterial species. [ABSTRACT FROM AUTHOR]

Introduction Methodology Results Conclusion Allergic fungal rhinosinusitis (AFRS) is a severe phenotype of chronic rhinosinusitis with nasal polyposis (CRSwNP), characterised by localised and exaggerated type 2 inflammation. While fungal antigenic stimulation of unregulated Th2‐mediated inflammation is the core pathophysiological mechanism, the direct and synergistic role of bacteria in disease modification is a pervasive hypothesis. We set out to define the microenvironment of AFRS to elucidate virulent organisms that may be implicated in the pathophysiology of AFRS.We undertook a cross‐sectional study of AFRS patients and non‐fungal CRSwNP patients. Demographics, disease severity, culture and microbiome sequences were analysed. Multimodality microbiome sequencing included short‐read next‐generation sequencing (NGS) on the Illumina Miseq (16S rRNA and ITS) and full‐length 16S rRNA sequencing on the Oxford Nanopore Technologies GridION (ONT).Thirty‐two AFRS and 29 non‐fungal CRSwNP patients (NF) were included in this study. Staphylococcus aureus was the dominant organism cultured and sequenced in both AFRS and NF groups (AFRS 27.54%; NF 18.04%; p = .07). Streptococcus pneumoniae (AFRS 12.31%; NF 0.98%; p = .03) and Haemophilus influenzae (AFRS 15.03%; NF 0.24%; p = .005) were significantly more abundant in AFRS. Bacterial diversity (Shannon's index) was considerably lower in AFRS relative to NF (AFRS 0.6; NF 1.0, p = .008). Aspergillus was the most cultured fungus in AFRS (10/32, 31.3%). The AFRS sequenced mycobiome was predominantly represented by Malassezia (43.6%), Curvularia (18.5%) and Aspergillus (16.8%), while the NF mycobiome was nearly exclusively Malassezia (84.2%) with an absence of Aspergillus or dematiaceous fungi.A low diversity, dysbiotic microenvironment dominated by Staphylococcus aureus, Streptococcus pneumoniae and Haemophilus influenzae characterised the bacterial microbiome of AFRS, with a mycobiome abundant in Malassezia, Aspergillus and Curvularia. While Staphylococcus aureus has been previously implicated in AFRS through enterotoxin superantigen potential, Streptococcus pneumoniae and Haemophilus influenzae are novel findings that may represent alternate cross‐kingdom pathophysiological mechanisms. [ABSTRACT FROM AUTHOR]

In the face of increasing antimicrobial tolerance and resistance there is a global obligation to optimise oral antimicrobial dosing strategies including narrow spectrum penicillins, such as penicillin-V. We conducted a randomised, crossover study in healthy volunteers to characterise the influence of probenecid on penicillin-V pharmacokinetics and estimate the pharmacodynamics against Streptococcus pneumoniae. Twenty participants took six doses of penicillin-V (250 mg, 500 mg or 750 mg four times daily) with and without probenecid. Total and free concentrations of penicillin-V and probenecid were measured at two timepoints. A pharmacokinetic model was developed, and the probability of target attainment (PTA) calculated. The mean difference (95% CI) between penicillin-V alone and in combination with probenecid for serum total and free penicillin-V concentrations was significantly different at both timepoints (total: 45 min 4.32 (3.20–5.32) mg/L p < 0.001, 180 min 2.2 (1.58–3.25) mg/L p < 0.001; free: 45 min 1.15 (0.88–1.42) mg/L p < 0.001, 180 min 0.5 (0.35–0.76) mg/L p < 0.001). There was no difference between the timepoints in probenecid concentrations. PTA analysis shows probenecid allows a fourfold increase in MIC cover. Addition of probenecid was safe and well tolerated. The data support further research into improved dosing structures for complex outpatient therapy and might also be used to address penicillin supply shortages. [ABSTRACT FROM AUTHOR]

Introduction: Bacteria frequently encounter nutrient limitation in nature. The ability of living in this nutrient shortage environment is vital for bacteria to preserve their population and important for some pathogenic bacteria to cause infectious diseases. Usually, we study how bacteria survive after nutrient depletion, a total starvation condition when bacteria almost cease growth and try to survive. However, nutrient limitation may not always lead to total starvation. Methods: Bacterial adaptation to nutrient shortage was studied by determining bacterial growth curves, intracellular pH, intracellular amino acid contents, gene transcription, protein expression, enzyme activity, and translation and replication activities. Results: No exogenous supply of methionine results in growth attenuation of Streptococcus pneumoniae, a human pathogen. In this paper, we refer to this inhibited growth state between ceased growth under total starvation and fullspeed growth with full nutrients as semi-starvation. Similar to total starvation, methionine semi-starvation also leads to intracellular acidification. Surprisingly, it is intracellular acidification but not insufficient methionine synthesis that causes growth attenuation under methionine semi-starvation. With excessive glutamine supply in the medium, intracellular methionine level was not changed, while bacterial intracellular pH was elevated to ~ 7.6 (the optimal intracellular pH for pneumococcal growth) by glutamine deamination, and bacterial growth under semi-starvation was restored fully. Our data suggest that intracellular acidification decreases translation level and glutamine supply increases intracellular pH to restore translation level, thus restoring bacterial growth. Discussion: This growth with intracellular pH adjustment by glutamine is a novel strategy we found for bacterial adaptation to nutrient shortage, which may provide new drug targets to inhibit growth of pathogenic bacteria under semi-starvation. [ABSTRACT FROM AUTHOR]

Streptococcus pneumoniae is a major pathogen responsible for severe complications in patients with prior influenza A virus (IAV) infection. We have previously demonstrated that S. pneumoniae exhibits increased intracellular survival within IAV-infected cells. Fluoroquinolones (FQs) are widely used to treat pneumococcal infections. However, our prior work has shown that S. pneumoniae can develop intracellular FQ persistence, a phenomenon triggered by oxidative stress within host cells. This persistence allows the bacteria to withstand high FQ concentrations. In this study, we show that IAV infection enhances pneumococcal FQ persistence during intracellular survival within pneumocytes, macrophages, and neutrophils. This enhancement is partly due to increased oxidative stress induced by the viral infection. We find that this phenotype is particularly pronounced in autophagy-proficient host cells, potentially resulting from IAV-induced blockage of autophagosome-lysosome fusion. Moreover, we identified several S. pneumoniae genes involved in oxidative stress response that contribute to FQ persistence, including sodA (superoxide dismutase), clpL (chaperone), nrdH (glutaredoxin), and psaB (Mn+2 transporter component). Our findings reveal a novel mechanism of antibiotic persistence promoted by viral infection within host cells. This underscores the importance of considering this phenomenon when using FQs to treat pneumococcal infections, especially in patients with concurrent influenza A infection. [ABSTRACT FROM AUTHOR]

Background Streptococcus pneumoniae serotype 3 remains a problem globally. Malawi introduced 13-valent pneumococcal conjugate vaccine (PCV13) in 2011, but there has been no direct protection against serotype 3 carriage. We explored whether vaccine escape by serotype 3 is due to clonal expansion of a lineage with a competitive advantage. Methods The distribution of serotype 3 Global Pneumococcal Sequence Clusters (GPSCs) and sequence types (STs) globally was assessed using sequences from the Global Pneumococcal Sequencing Project. Whole-genome sequences of 135 serotype 3 carriage isolates from Blantyre, Malawi (2015–2019) were analyzed. Comparative analysis of the capsule locus, entire genomes, antimicrobial resistance, and phylogenetic reconstructions were undertaken. Opsonophagocytosis was evaluated using serum samples from vaccinated adults and children. Results Serotype 3 GPSC10-ST700 isolates were most prominent in Malawi. Compared with the prototypical serotype 3 capsular polysaccharide locus sequence, 6 genes are absent, with retention of capsule polysaccharide biosynthesis. This lineage is characterized by increased antimicrobial resistance and lower susceptibility to opsonophagocytic killing. Conclusions A serotype 3 variant in Malawi has genotypic and phenotypic characteristics that could enhance vaccine escape and clonal expansion after post-PCV13 introduction. Genomic surveillance among high-burden populations is essential to improve the effectiveness of next-generation pneumococcal vaccines. [ABSTRACT FROM AUTHOR]

Recent phylogenetic profiling of pneumococcal serotype 3 (Pn3) isolates revealed a dynamic interplay among major lineages with the emergence and global spread of a variant termed clade II. The cause of Pn3 clade II dissemination along with epidemiological and clinical ramifications are currently unknown. Here, we sought to explore biological characteristics of dominant Pn3 clades in a mouse model of pneumococcal invasive disease and carriage. Carriage and virulence potential were strain dependent with marked differences among clades. We found that clinical isolates from Pn3 clade II are less virulent and less invasive in mice compared to clade I isolates. We also observed that clade II isolates are carried for longer and at higher bacterial densities in mice compared to clade I isolates. Taken together, our data suggest that the epidemiological success of Pn3 clade II could be related to alterations in the pathogen's ability to cause invasive disease and to establish a robust carriage episode. [ABSTRACT FROM AUTHOR]

Conventional macrolide-lincosamide-streptogramin B-ketolide (MLSBK) antibiotics are unable to counter the growing challenge of antibiotic resistance that is conferred by the constitutive methylation of rRNA base A2058 or its G2058 mutation, while the presence of unmodified A2058 is crucial for high selectivity of traditional MLSBK in targeting pathogens over human cells. The absence of effective modes of action reinforces the prevailing belief that constitutively antibiotic-resistant Staphylococcus aureus remains impervious to existing macrolides including telithromycin. Here, we report the design and synthesis of a novel series of macrolides, featuring the strategic fusion of ketolide and quinolone moieties. Our effort led to the discovery of two potent compounds, MCX-219 and MCX-190, demonstrating enhanced antibacterial efficacy against a broad spectrum of formidable pathogens, including A2058-methylated Staphylococcus aureus, Streptococcus pneumoniae, Streptococcus pyogenes, and notably, the clinical Mycoplasma pneumoniae isolates harboring A2058G mutations which are implicated in the recent pneumonia outbreak in China. Mechanistic studies reveal that the modified quinolone moiety of MCX-190 establishes a distinctive secondary binding site within the nascent peptide exit tunnel. Structure-activity relationship analysis underscores the importance of this secondary binding, maintained by a sandwich-like π–π stacking interaction and a water–magnesium bridge, for effective engagement with A2058-methylated ribosomes rather than topoisomerases targeted by quinolone antibiotics. Our findings not only highlight MCX-219 and MCX-190 as promising candidates for next-generation MLSBK antibiotics to combat antibiotic resistance, but also pave the way for the future rational design of the class of MLSBK antibiotics, offering a strategic framework to overcome the challenges posed by escalating antibiotic resistance. [ABSTRACT FROM AUTHOR]

Introduction: The oropharyngeal microbiome plays an important role in protection against infectious agents when in balance. Despite use of vaccines and antibiotic therapy to prevent respiratory tract infections, they remain one of the major causes of mortality and morbidity in Low- and middleincome countries. Hence the need to explore other approaches to prevention by identifying microbial biomarkers that could be leveraged to modify the microbiota in order to enhance protection against pathogenic bacteria. The aim of this study was to analyze the oropharyngeal microbiome (OPM) of schoolchildren in Côte d’Ivoire presenting symptoms of upper respiratory tract infections (URTI) for better prevention strategy. Methods: Primary schools’ children in Korhogo (n = 37) and Abidjan (n = 39) were followed for six months with monthly oropharyngeal sampling. Clinical diagnostic of URT infection was performed and nucleic acid extracted from oropharyngeal swabs were used for 16S rRNA metagenomic analysis and RT-PCR. Results: The clinical examination of children’s throat in Abidjan and Korhogo identified respectively 17 (43.59%) and 15 (40.54%) participants with visible symptoms of URTIs, with 26 episodes of infection in Abidjan and 24 in Korhogo. Carriage of Haemophilus influenzae (12%), Streptococcus pneumoniae (6%) and SARS-CoV-2 (6%) was confirmed by PCR. A significant difference in alpha diversity was found between children colonized by S. pneumoniae and those that were not (p = 0.022). There was also a significant difference in alpha diversity between children colonised with H. influenzae and those who were not (p = 0.017). No significant difference was found for SARS-CoV-2. Sphingomonas, Ralstonia and Rothia were significantly enriched in non-carriers of S. pneumoniae; Actinobacillus was significantly enriched in non-carriers of H. influenzae; Actinobacillus and Porphyromonas were significantly enriched in non-carriers of SARS-CoV-2 (p < 0.001). Discussion: Nearly 40% of children showed clinical symptoms of infection not related to geographical location. The OPM showed an imbalance during H. influenzae and S. pneumoniae carriage. This study provides a baseline understanding of microbiome markers in URTIs in children for future research, to develop targeted interventions aimed at restoring the microbial balance and reducing the symptoms associated with RTIs. [ABSTRACT FROM AUTHOR]

Competence for natural transformation is a central driver of genetic diversity in bacteria. In the human pathogen Streptococcus pneumoniae, competence exhibits a populational character mediated by the stress-induced ComABCDE quorum-sensing (QS) system. Here, we explore how this cell-to-cell communication mechanism proceeds and the functional properties acquired by competent cells grown under lethal stress. We show that populational competence development depends on self-induced cells stochastically emerging in response to stresses, including antibiotics. Competence then propagates through the population from a low threshold density of self-induced cells, defining a biphasic Self-Induction and Propagation (SI&P) QS mechanism. We also reveal that a competent population displays either increased sensitivity or improved tolerance to lethal doses of antibiotics, dependent in the latter case on the competence-induced ComM division inhibitor. Remarkably, these surviving competent cells also display an altered transformation potential. Thus, the unveiled SI&P QS mechanism shapes pneumococcal competence as a health sensor of the clonal population, promoting a bet-hedging strategy that both responds to and drives cells towards heterogeneity. Stress exposure shapes survival mechanisms in bacteria. Here, the authors show that individual pneumococcal cells react to stress by competence self-induction, which may propagate to non-competent cells, promoting multilevel heterogeneity and favouring survival. [ABSTRACT FROM AUTHOR]

This study investigated the antibacterial properties of Coptis rhizome, a plant traditionally used for respiratory infections, against Streptoccus pneumonia (S. pneumoniae), for which there has been minimal empirical evidence of effectiveness. The study particularly examined autolysis, indirectly associated with antibacterial resistance, when using Coptis rhizome for bacterial infections. In our methodology, Coptis rhizome was processed with ethanol and distilled water to produce four different extracts: CRET30, CRET50, CRET70, and CRDW. The antibacterial activity of these extracts were tested through Minimum Inhibitory Concentration (MIC) assays, disk diffusion tests, and time-kill assays, targeting both standard (ATCC 49619) and resistant (ATCC 70067) strains. The study also evaluated the extracts' biofilm inhibition properties and monitored the expression of the lyt gene, integral to autolysis. The results prominently showed that the CRET70 extract demonstrated remarkable antibacterial strength. It achieved an MIC of 0.125 µg/mL against both tested S. pneumoniae strains. The disk diffusion assay recorded inhibition zones of 22.17 mm for ATCC 49619 and 17.20 mm for ATCC 70067. Impressively, CRET70 resulted in a 2-log decrease in bacterial numbers for both strains, showcasing its potent bactericidal capacity. The extract was also effective in inhibiting 77.40% of biofilm formation. Additionally, the significant overexpression of the lytA gene in the presence of CRET70 pointed to a potential mechanism of action for its antibacterial effects. The outcomes provided new perspectives on the use of Coptis rhizome in combating S. pneumoniae, especially significant in an era of escalating antibiotic resistance. [ABSTRACT FROM AUTHOR]

Purpose: To assess performance of Etest®, Vitek®2 and BD Phoenix™ to determine the susceptibility of Streptococcus pneumoniae strains to penicillin, ampicillin and cefotaxime. Methods: Sixty unique S. pneumoniae challenge strains were selected to cover a wide range of penicillin, ampicillin and cefotaxime minimal inhibitory concentrations (MICs). Strains were analyzed in four different Belgian laboratories. Etest® benzylpenicillin (BEN), ampicillin/amoxicillin (AMP) and cefotaxime (CTA) (bioMérieux), Vitek®2 AST-ST03 (bioMérieux) and BD Phoenix™ SMIC/ID-11 testing were each performed in two different labs. Results were compared to Sensititre® broth microdilution (BMD) (Thermo Fisher Scientific) results. MIC results were interpreted using EUCAST non-meningitis breakpoints (v 13.0). Results: Essential agreement (EA) was ≥ 90% for all methods compared to BMD, except for Etest® BEN on Oxoid plate (58.3%), Etest® AMP (both on Oxoid (65.8%) and BD BBL plate (84.2%)). Categorical agreement (CA) for penicillin was only ≥ 90% for Vitek®2, for other methods CA ranged between 74 and 84%. CA for AMP was for all methods < 90% (range 75.8–88.3%) and CA for CTA was between 87 and 90% for all methods except for Etest on Oxoid plate (79.2%). Conclusions: Our study indicates that Vitek®2 and BD Phoenix™ are reliable for providing accurate pneumococcal susceptibility results for BEN, AMP and CTA. Using Etest BEN or AMP on Oxoid plate carries a risk of underestimating the MIC and should be interpreted with caution, especially when the obtained MIC is 1 or 2 doubling dilutions below the S or R clinical breakpoint. [ABSTRACT FROM AUTHOR]

Streptococcus pneumoniae infection is a major public health concern with high morbidity and mortality rates. This study aimed to evaluate the serotype distribution, antimicrobial resistance changes, clonal composition, and virulence factors of S. pneumoniae isolates causing pneumococcal disease in northeast China from 2000 to 2021. A total of 1,454 S. pneumoniae isolates were included, with 568 invasive strains and 886 non-invasive strains. The patients from whom the S. pneumoniae were isolated ranged in age from 26 days to 95 years, with those ≤ 5 years old comprising the largest group (67.19%). 19 F, 19 A, 23 F, 14, and 6B were the most common serotypes, of which 19 A and 19 F were the main serotypes of invasive and non-invasive S. pneumoniae, respectively. CC271 was the most common multilocus sequence type. Serotype 14 had the lowest expression of cbpA, rrgA, and psrP genes, but expression levels of 19 A and 19 F genes were similar. All isolates were sensitive to ertapenem, moxifloxacin, linezolid, and vancomycin but highly resistant to macrolides, tetracyclines, and cotrimoxazole. Simultaneous resistance to erythromycin, clindamycin, tetracyclines, and trimethoprim/sulfamethoxazole was common pattern among multidrug-resistant isolates. Non-invasive S. pneumoniae had higher resistance to β-lactam antibiotics than invasive strains. 19 A and 19 F were the main strains of penicillin-resistant S. pneumoniae. The resistance rate of β-lactam antibiotics decreased from 2017 to 2021 compared to previous periods. Including PCV13 in the national immunization program can reduce the morbidity and mortality rates of pneumococcal disease effectively. [ABSTRACT FROM AUTHOR]

Background: We have previously shown that asthma-like airways inflammation may be induced by topical exposure to respiratory tract pathogens such as S. pneumoniae (SP) in concert with epithelial alarmins such as IL-33. Details of the pathogenesis of this murine surrogate remain however unexplored. Methods: Airways inflammation was induced by repeated, intranasal exposure of Il-4−/−, Rag1−/− and Rag2−/−Il2rg−/− mice (in which B lymphocyte IgE switching, adaptive and innate immunity are respectively ablated) as well as wild type mice to inactivated SP, IL-33 or both. Airways pathological changes were analysed, and the subsets and functions of locally accumulated ILC2s investigated by single cell RNA sequencing and flow cytometry. Results: In the presence of IL-33, repeated exposure of the airways to inactivated SP caused marked eosinophil- and neutrophil-rich inflammation and local accumulation of ILC2s, which was retained in the Il-4−/− and Rag1−/− deficient mice but abolished in the Rag2−/−Il2rg−/− mice, an effect partly reversed by adoptive transfer of ILC2s. Single cell sequencing analysis of ILC2s recruited following SP and IL-33 exposure revealed a Klrg1+Ly6a+subset, expressing particularly elevated quantities of the pro-inflammatory cytokine IL-6, type 2 cytokines (IL-5 and IL-13) and MHC class II molecules, promoting type 2 inflammation as well as involved in neutrophil-mediated inflammatory responses. Conclusion: Local accumulation of KLRG1+Ly6a+ ILC2s in the lung tissue is a critical aspect of the pathogenesis of airways eosinophilic and neutrophil-rich inflammation induced by repeated exposure to SP in the presence of the epithelial alarmin IL-33. [ABSTRACT FROM AUTHOR]

Studies examining time to positivity (TTP) of blood cultures as a risk factor for death have shown conflicting results. The study objective was to examine the effect of TTP on all-cause-30-day case-fatality among a population-based cohort of patients with bloodstream infections (BSI). A retrospective cohort study including all residents of Queensland, Australia with incident monomicrobial BSI managed in the publicly funded healthcare system from 2000 to 2019 was performed. Clinical, TTP and all-cause 30-day case-fatality information was obtained from state-wide sources. A cohort of 88 314 patients was assembled. The median TTP was 14 hours, with 5th, 25th, 75th, and 95th percentiles of 4, 10, 20, and 53 hours, respectively. The TTP varied significantly by BSI aetiology. The 30-day all-cause case-fatality rate was 2606/17 879 (14.6%), 2834/24 272 (11.7%), 2378/20 359 (11.7%), and 2752/22 431 (12.3%) within the first, second, third, and fourth TTP quartiles, respectively (p < 0.0001). After adjustment for age, sex, onset, comorbidity, and focus of infection, TTP within 10 hours (first quartile) was associated with a significantly increased risk for death (odds ratio 1.43; 95% CI, 1.35–1.50; p < 0.001). After adjustment for confounding variables (odds ratio; 95% CI), TTP within the first quartile for Staphylococcus aureus (1.56; 1.41–1.73), Streptococcus pneumoniae (1.91; 1.49–2.46), β-hemolytic streptococci (1.23; 1.00–1.50), Pseudomonas species (2.23; 1.85–2.69), Escherichia coli (1.37; 1.23–1.53), Enterobacterales (1.38; 1.16–1.63), other Gram-negatives (1.68; 1.36–2.06), and anaerobes (1.58; 1.28–1.94) increased the risk for case-fatality. This population-based analysis provides evidence that TTP is an important determinant of mortality among patients with BSI. [ABSTRACT FROM AUTHOR]

Blumea balsamifera L. essential oil (EO) has been known for its diverse antimicrobial activities. This study aimed to determine the antibacterial activity of Blumea balsamifera EO against two strains of pathogenic bacteria (Streptococcus pyogenes and Streptococcus pneumoniae) through in vitro and in silico methods. The phytochemical screening of the EO and other physicochemical properties (DFT, ADMET, and drug-likeness) were determined using standard protocols. In vitro results show that the EO possesses promising antibacterial properties with inhibition zone diameters (IZDs) of 10 ± 2 and 18 ± 2 mm, respectively, for S. pyogenes and S. pneumoniae; MICs 2.50 and 1.25 μL.mL-1; MBC/MIC ratios 1 and 2. GC-MS characterization of the EO identified 17 constituents (1-17). The binding affinity of the compounds against the target proteins are in the following order: 16-P0C0C7 (-9.4 kcal.mol-1) > 4-P0C0C7 (-9.3 kcal.mol-1) > 15-P0C0C7 ≈ 17-P0C0C7 (-9.2 kcal.mol-1); 3-Q8DQF8 (-9.0 kcal.mol-1) > 4-Q8DQF8 (-8.9 kcal.mol-1) > 15-Q8DQF8 (-8.7 kcal.mol-1); 16-6LU7 (-9.0 kcal.mol-1) ≈ 17-6LU7 (-9.1 kcal.mol-1). The phytochemicals potentiality derived from quantum calculation were 3 (3.40 Debye), 15 (2.47 Debye), and 5 (2.03 Debye). The suitability for physicochemical and pharmacokinetic applications was assessed via reference to Lipinski's rule of five and Pires' interpretations, respectively. The analysis shows that (+)-2-Bornanone (3; 58.00 %) was the primary bioactive component responsible for the observable antibacterial activities given by its predominant content and favorable predictions. Compound 3 could further be investigated for its antibacterial activity by isolating and characterizing its pure form. [ABSTRACT FROM AUTHOR]

Antimicrobial resistance (AMR) is a significant global public health threat. This review presents the most recent in-depth review of the situation of the main AMR types in relation to the most commonly prescribed antibiotics in the World Health Organization (WHO) African Region. Underlying genes of resistance have been analyzed where possible. A search to capture published research data on AMR from articles published between 2016 and 2020 was done using PubMed and Google Scholar, with rigorous inclusion/exclusion criteria. Out of 48003 articles, only 167 were included. Among the tested gram-negative bacteria species, Klebsiella spp. remain the most tested, and generally the most resistant. The highest overall phenotypic resistance for imipenem was reported in E. coli, whereas for meropenem, E. coli and Haemophilus spp. showed an equal resistance proportion at 2.5%. For gram-positive bacteria, Streptococcus pneumoniae displayed high resistance percentages to trimethoprim/sulfamethoxazole (64.3%), oxacillin (32.2%), penicillin (23.2%), and tetracycline (28.3%), whereas Staphylococcus aureus contributed to 22.8% and 10% resistance to penicillin and oxacillin, respectively. This review shows that AMR remains a major public health threat. The present findings will help public health decision-makers in developing efficient preventive strategies and adequate policies for antibiotic stewardship and surveillance in line with the global action plan for AMR. [ABSTRACT FROM AUTHOR]

In previous studies, it was demonstrated that Corynebacterium pseudodiphtheriticum 090104, isolated from the human nasopharynx, modulates respiratory immunity, improving protection against infections. Here, the antagonistic effect of the 090104 strain on respiratory pathogens, including Streptococcus pneumoniae, Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii, was explored. In a series of in vitro studies, the capacity of C. pseudodiphtheriticum 090104, its bacterium-like particles, and its culture supernatants to coaggregate, inhibit the growth, and change the virulent phenotype of pathogenic bacteria was evaluated. The results showed that the 090104 strain was able to exert a bacteriostatic effect on K. pneumoniae and S. pneumoniae growth. In addition, C. pseudodiphtheriticum 090104 coaggregated, inhibited biofilm formation, and induced phenotypic changes in all the respiratory pathogens evaluated. In conclusion, this work demonstrated that, in addition to its beneficial effects exerted by host–microbe interactions, C. pseudodiphtheriticum 090104 can enhance protection against respiratory pathogens through its microbe–microbe interactions. The mechanisms involved in such interactions should be evaluated in future research. [ABSTRACT FROM AUTHOR]

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Epithelial cells are the first point of contact for bacteria entering the respiratory tract. Streptococcus pneumoniae is an obligate human pathobiont of the nasal mucosa, carried asymptomatically but also the cause of severe pneumoniae. The role of the epithelium in maintaining homeostatic interactions or mounting an inflammatory response to invasive S. pneumoniae is currently poorly understood. However, studies have shown that chromatin modifications, at the histone level, induced by bacterial pathogens interfere with the host transcriptional program and promote infection. Here, we uncover a histone modification induced by S. pneumoniae infection maintained for at least 9 days upon clearance of bacteria with antibiotics. Di-methylation of histone H3 on lysine 4 (H3K4me2) is induced in an active manner by bacterial attachment to host cells. We show that infection establishes a unique epigenetic program affecting the transcriptional response of epithelial cells, rendering them more permissive upon secondary infection. Our results establish H3K4me2 as a unique modification induced by infection, distinct from H3K4me3 or me1, which localizes to enhancer regions genome-wide. Therefore, this study reveals evidence that bacterial infection leaves a memory in epithelial cells after bacterial clearance, in an epigenomic mark, thereby altering cellular responses to subsequent infections and promoting infection. Here, Chevalier et al show that Streptococcus pneumoniae induces the histone modifications H3K4me2 in epithelial cells, where it persists beyond bacterial clearance and affects cell responses to secondary infection. [ABSTRACT FROM AUTHOR]

Streptococcus pneumoniae (S. pneumoniae) represents a major human bacterial pathogen leading to high morbidity and mortality in children and the elderly. Recent research emphasizes the role of extracellular vesicles (EVs) in bacterial pathogenicity. However, the contribution of S. pneumoniae EVs (pEVs) to host-microbe interactions has remained unclear. Here, we observed that S. pneumoniae infections in mice led to severe lung injuries and alveolar epithelial barrier (AEB) dysfunction. Infections of S. pneumoniae reduced the protein expression of tight junction protein OCLN (occludin) and activated macroautophagy/autophagy in lung tissues of mice and A549 cells. Mechanically, S. pneumoniae induced autophagosomal degradation of OCLN leading to AEB impairment in the A549 monolayer. S. pneumoniae released the pEVs that could be internalized by alveolar epithelial cells. Through proteomics, we profiled the cargo proteins inside pEVs and found that these pEVs contained many virulence factors, among which we identified a eukaryotic-like serine-threonine kinase protein StkP. The internalized StkP could induce the phosphorylation of BECN1 (beclin 1) at Ser93 and Ser96 sites, initiating autophagy and resulting in autophagy-dependent OCLN degradation and AEB dysfunction. Finally, the deletion of stkP in S. pneumoniae completely protected infected mice from death, significantly alleviated OCLN degradation in vivo, and largely abolished the AEB disruption caused by pEVs in vitro. Overall, our results suggested that pEVs played a crucial role in the spread of S. pneumoniae virulence factors. The cargo protein StkP in pEVs could communicate with host target proteins and even hijack the BECN1 autophagy initiation pathway, contributing to AEB disruption and bacterial pathogenicity. Abbreviations: AEB: alveolarepithelial barrier; AECs: alveolar epithelial cells; ATG16L1: autophagy related 16 like 1; ATP:adenosine 5'-triphosphate; BafA1: bafilomycin A1; BBB: blood-brain barrier; CFU: colony-forming unit; co-IP: co-immunoprecipitation; CQ:chloroquine; CTRL: control; DiO: 3,3′-dioctadecylox-acarbocyanineperchlorate; DOX: doxycycline; DTT: dithiothreitol; ECIS: electricalcell-substrate impedance sensing; eGFP: enhanced green fluorescentprotein; ermR: erythromycin-resistance expression cassette; Ery: erythromycin; eSTKs: eukaryotic-like serine-threoninekinases; EVs: extracellular vesicles; HA: hemagglutinin; H&E: hematoxylin and eosin; HsLC3B: human LC3B; hpi: hours post-infection; IP: immunoprecipitation; KD: knockdown; KO: knockout; LAMP1: lysosomal associated membrane protein 1; LC/MS: liquid chromatography-mass spectrometry; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MVs: membranevesicles; NC:negative control; NETs:neutrophil extracellular traps; OD: optical density; OMVs: outer membrane vesicles; PBS: phosphate-buffered saline; pEVs: S.pneumoniaeextracellular vesicles; protK: proteinase K; Rapa: rapamycin; RNAi: RNA interference; S.aureus: Staphylococcusaureus; SNF:supernatant fluid; sgRNA: single guide RNA; S.pneumoniae: Streptococcuspneumoniae; S.suis: Streptococcussuis; TEER: trans-epithelium electrical resistance; moi: multiplicity ofinfection; TEM:transmission electron microscope; TJproteins: tight junction proteins; TJP1/ZO-1: tight junction protein1; TSA: tryptic soy agar; WB: western blot; WT: wild-type [ABSTRACT FROM AUTHOR]

Antibiotic persistence is a phenomenon, where a small fraction of a bacterial population expresses a phenotypic variation that allows them to survive antibiotic treatment, which is lethal to the rest of the population. These cells are called persisters cells, and their occurrence has been associated with recurrent disease. Streptococcus agalactiae is a human pathobiont, able to cause invasive infections, and recurrent infections have been reported to occur in both newborns and adults. In this study, we demonstrated that S. agalactiae NEM316 can form persister cells when exposed to antibiotics from different classes. The frequency of persister cell formation was dependent on bacterial growth phase and the class of antibiotics. The ability to form persister cells in response to penicillin was shown to be a general trait among different clinical S. agalactiae isolates, independent of sero- and sequence-type. Taken together, this study shows the existence of antibiotic tolerant S. agalactiae persister cells, which may explain why this bacterial species frequently persists after treatment of invasive infection and can be associated with recurrent disease. [ABSTRACT FROM AUTHOR]

Introduction: Community-acquired pneumonia (CAP) is a global health concern, with 25% of cases attributed to Streptococcus pneumoniae (Spn). Viral infections like influenza A virus (IAV), respiratory syncytial virus (RSV), and human metapneumovirus (hMPV) increase the risk of Spn, leading to severe complications due to compromised host immunity. Methods: We evaluated the efficacy of an anti-PhtD monoclonal antibody (mAb) cocktail therapy (PhtD3 + 7) in improving survival rates in three viral/bacterial coinfection models: IAV/Spn, hMPV/Spn, and RSV/Spn. Results: The PhtD3 + 7 mAb cocktail outperformed antiviral mAbs, resulting in prolonged survival. In the IAV/Spn model, it reduced bacterial titers in blood and lungs by 2-4 logs. In the hMPV/Spn model, PhtD3 + 7 provided greater protection than the hMPV-neutralizing mAb MPV467, significantly reducing bacterial titers. In the RSV/Spn model, PhtD3 + 7 offered slightly better protection than the antiviral mAb D25, uniquely decreasing bacterial titers in blood and lungs. Discussion: Given the threat of antibiotic resistance, our findings highlight the potential of anti-PhtD mAb therapy as an effective option for treating viral and secondary pneumococcal coinfections. [ABSTRACT FROM AUTHOR]

Pleural empyema is a serious complication of pneumonia in children. Negative bacterial cultures commonly impede optimal antibiotic therapy. To improve bacterial identification, we developed a molecular assay and evaluated its performance compared with bacterial culture. Our multiplex-quantitative PCR to detect Streptococcus pneumoniae, Streptococcus pyogenes, Staphylococcus aureus and Haemophilus influenzae was assessed using bacterial genomic DNA and laboratory-prepared samples (n = 267). To evaluate clinical performance, we conducted the Molecular Assessment of Thoracic Empyema (MATE) observational study, enrolling children hospitalised with empyema. Pleural fluids were tested by bacterial culture and multiplex-qPCR, and performance determined using a study gold standard. We determined clinical sensitivity and time-to-organism-identification to assess the potential of the multiplex-qPCR to reduce the duration of empiric untargeted antibiotic therapy. Using spiked samples, the multiplex-qPCR demonstrated 213/215 (99.1%) sensitivity and 52/52 (100%) specificity for all organisms. During May 2019–March 2023, 100 children were enrolled in the MATE study; median age was 3.9 years (IQR 2–5.6). A bacterial pathogen was identified in 90/100 (90%) specimens by multiplex-qPCR, and 24/100 (24%) by bacterial culture (P <0.001). Multiplex-qPCR identified a bacterial cause in 68/76 (90%) culture-negative specimens. S. pneumoniae was the most common pathogen, identified in 67/100 (67%) specimens. We estimate our multiplex-qPCR would have reduced the duration of untargeted antibiotic therapy in 61% of cases by a median 20 days (IQR 17.5–23, range 1–55). Multiplex-qPCR significantly increased pathogen detection compared with culture and may allow for reducing the duration of untargeted antibiotic therapy. [ABSTRACT FROM AUTHOR]

Ovoid-shaped bacteria, such as Streptococcus pneumoniae (pneumococcus), have two spatially separated peptidoglycan (PG) synthase nanomachines that locate zonally to the midcell of dividing cells. The septal PG synthase bPBP2x:FtsW closes the septum of dividing pneumococcal cells, whereas the elongasome located on the outer edge of the septal annulus synthesizes peripheral PG outward. We showed previously by sm-TIRFm that the septal PG synthase moves circumferentially at midcell, driven by PG synthesis and not by FtsZ treadmilling. The pneumococcal elongasome consists of the PG synthase bPBP2b:RodA, regulators MreC, MreD, and RodZ, but not MreB, and genetically associated proteins Class A aPBP1a and muramidase MpgA. Given its zonal location separate from FtsZ, it was of considerable interest to determine the dynamics of proteins in the pneumococcal elongasome. We found that bPBP2b, RodA, and MreC move circumferentially with the same velocities and durations at midcell, driven by PG synthesis. However, outside of the midcell zone, the majority of these elongasome proteins move diffusively over the entire surface of cells. Depletion of MreC resulted in loss of circumferential movement of bPBP2b, and bPBP2b and RodA require each other for localization and circumferential movement. Notably, a fraction of aPBP1a molecules also moved circumferentially at midcell with velocities similar to those of components of the core elongasome, but for shorter durations. Other aPBP1a molecules were static at midcell or diffusing over cell bodies. Last, MpgA displayed nonprocessive, subdiffusive motion that was largely confined to the midcell region and less frequently detected over the cell body. [ABSTRACT FROM AUTHOR]