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Mechanism of NanR transcriptional activation of sialic acid metabolism in Streptococcus pneumoniae.

In Streptococcus pneumoniae, the RpiR transcriptional regulator NanR (SpNanR) senses sialic acid in the environment and upregulates transcription of the nan and sia A operons to increase uptake and metabolism of sialic acid. The molecular basis of this activation is unknown. Here, we demonstrate that SpNanR binds N-acetylmannosamine-6-phosphate, a metabolite of sialic acid catabolism. SpNanR exists in a dimer-tetramer equilibrium, and N-acetylmannosamine-6-phosphate binding strongly stabilizes the tetramer. Crystal structures and site-specific substitutions demonstrate that N-acetylmannosamine…

A rare case of Streptococcus pneumoniae infection in a giant pancreatic pseudocyst.

BACKGROUND: Pancreatic pseudocysts are known sequelae of acute and chronic pancreatitis and are typically sterile. Superinfection is not uncommon, but isolation of Streptococcus pneumoniae is exceedingly rare. CASE PRESENTATION: We report a 32-year-old immunocompetent male with a background of chronic alcohol-related pancreatitis presenting with worsening abdominal pain and early satiety. Imaging revealed a large pseudocyst. Laparoscopic transgastric cystogastrostomy with cholecystectomy was performed, and culture of aspirated cyst fluid yielded Streptococcus pneumoniae. The patient recovered…

Acute Respiratory Infections Due to Antibiotic-nonsusceptible Streptococcus pneumoniae in US Adults.

BACKGROUND: We aimed to estimate the burden of antibiotic-nonsusceptible nonbacteremic pneumonia and sinusitis due to Streptococcus pneumoniae (pneumococcus) in US adults (aged ≥18 years). METHODS: We estimated antibiotic-nonsusceptible pneumococcal sinusitis and nonbacteremic pneumonia incidence as products of pneumococcal pneumonia and sinusitis incidence rates, serotype distribution, and serotype-specific antimicrobial nonsusceptibility prevalences from 2016 through 2019. Nonsusceptibility was considered by antibiotic class and guideline-recommended agents. We estimated pneumonia and sinus…

YWHAZ acts as a regulatory node in Streptococcus pneumoniae-induced pulmonary inflammation.

BACKGROUND: Tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein zeta (YWHAZ, 14-3-3ζ), a key regulator of intracellular signaling and inflammatory responses, has not been investigated in Streptococcus pneumoniae (S.pn) infection. METHODS: We first employed Western blotting to detect the expression and activation of YWHAZ in murine RAW264.7 macrophages and a mouse model of S.pn pneumonia. A small-molecule inhibitor BV02 was used to pharmacologically block YWHAZ function both in vitro and in vivo. Subsequent evaluations included the production of inflammatory cytokines via EL…

Transcriptomic analysis of Streptococcus pneumoniae serotype 1 reveals serotype-specific gene regulation.

Streptococcus pneumoniae (Sp) is an opportunistic pathogen that colonizes the mucosal surfaces of the human upper respiratory tract. While transcriptomic studies of Sp have become more common, most have focused on laboratory-adapted strains such as D39 or TIGR4. These strains, though widely used in research, may not fully capture the biology of clinical isolates, particularly the hypervirulent serotype 1 (S1). S1 is clinically significant due to its association with invasive disease, epidemic outbreaks and a distinct global distribution, particularly in regions with a high pneumococcal disease…

Coinfection with SARS-CoV-2 among patients with Streptococcus pneumoniae in Casablanca.

BACKGROUND: During the COVID-19 pandemic caused by SARS-CoV-2, coinfections with Streptococcus pneumoniae have emerged as a significant public health concern. The impact of these coinfections on disease severity and mortality rates remains underexplored. This study aims to address this gap by analyzing the clinical outcomes of patients coinfected with S. pneumoniae and SARS-CoV-2 at CHU Ibn Rochd in Casablanca, Morocco, between 2020 and 2022. METHODS: A cohort of 120 hospitalized patients diagnosed with S. pneumoniae infection was studied retrospectively and prospectively. Clinical and demogr…

Complicated Thoracic Empyema of Serotype 23F Streptococcus pneumoniae in an Adult Patient.

We report a case of thoracic empyema in a 61-year-old male patient, a heavy smoker with malignancy undergoing chemotherapy. The patient's clinical symptoms included shortness of breath, productive cough, fever, and chest pain. This patient had never received antibiotics before. Streptococcus pneumoniae was isolated from a bedside culture of empyema fluid collected through thoracentesis. The empyema fluid was cultured on chocolate agar plates and in aerobic and anaerobic culture bottles. The isolate was identified as serotype 23F, a vaccine strain with sequence type 17532. The isolate was resis…

Large-scale global molecular epidemiology of antibiotic resistance determinants in Streptococcus pneumoniae.

Streptococcus pneumoniae is a leading pathogen in terms of deaths attributable to or associated with antimicrobial resistance globally. Thus, monitoring antibiotic resistance determinants constitutes a key aspect of surveillance efforts for this microbe. Leveraging publicly available whole-genome sequencing (WGS) data, we aimed to investigate the presence and distribution patterns of antibiotic resistance determinants in S. pneumoniae with a focus on multidrug resistance (MDR) and serotype distribution. Metadata and genomes were obtained from the National Center for Biotechnology Information P…

A global epidemic serotype 14 Streptococcus pneumoniae switching to non-vaccine types.

Streptococcus pneumoniae infection is a leading cause of bacterial pneumonia worldwide, contributing to both invasive pneumococcal diseases and non-invasive diseases. Following the introduction of pneumococcal conjugate vaccines (PCV7, PCV10, and PCV13), a significant decrease in the prevalence of vaccine-type pneumococci has been observed, while the prevalence of non-vaccine-type (NVT) pneumococci has increased. This shift has been evident in both disease incidence and nasopharyngeal carriage. Serotype switching refers to the alteration or exchange of the serotype-related cps gene locus that …

Glucose affects capsular polysaccharides synthesis via CcpA and HPr in Streptococcus pneumoniae.

Streptococcus pneumoniae is a conditionally pathogenic bacteria that colonizes the nasopharynx of 27% to 65% of children and 10% of adults. Capsular polysaccharides are the most critical virulence factor of S. pneumoniae, and nonencapsulated strains are usually non-pathogenic. Previous studies have shown that glucose regulates capsule synthesis. To investigate the mechanism of carbon metabolism regulatory factors CcpA and HPr regulating capsule synthesis in the presence of glucose as the sole carbon source, we constructed deletion mutants (D39ΔccpA and ΔptsH) and complemented strains (D39ΔccpA…

Serotype replacement and mobile genetic elements in Streptococcus pneumoniae: a systematic review.

Streptococcus pneumoniae causes otitis media and severe diseases including pneumonia, meningitis and bacteraemia. The rise of antimicrobial resistance (AMR) in S. pneumoniae, facilitated by mobile genetic elements (MGEs), complicates infection treatment. While pneumococcal conjugate vaccine (PCV) deployment has reduced disease burden, non-vaccine serotypes (NVTs) have increased and now cause invasive disease. Although PCV reduced the overall AMR incidence, AMR prevalence among NVT pneumococci has increased, creating dual challenges of MGE-driven AMR spread and serotype replacement. In this rev…

[Protective effect of Streptococcus salivarius K12 against Mycoplasma pneumoniae infection in mice].

OBJECTIVES: To investigate the protective effect of the probiotic bacterium Streptococcus salivarius K12 (K12) against Mycoplasma pneumoniae (Mp) infection in mice. METHODS: Forty male BALB/c mice were randomized into normal control group, K12 treatment group, Mp infection group, and K12 pretreatment prior to Mp infection group. The probiotic K12 was administered daily by gavage for 14 days before Mp infection induced by intranasal instillation of Mp. Three days after Mp infection, the mice were euthanized for analysis of bronchoalveolar lavage fluid (BALF) cell counts and serum levels of sec

Role of the polyamine transporter PotABCD during biofilm formation by Streptococcus pneumoniae.

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 th…

Коэффициенты вакцинации от пневмонии и гриппа у онкологических пациентов - данные из Германии.

ЦЕЛИ: Из-за иммунодепрессии, связанной с болезнями или терапией, онкологические пациенты страдают значительно более высокой заболеваемостью и смертностью в результате инфекций, передаваемых такими респираторными патогенами, как пневмония Стрептококка и вирус гриппа. Хотя Постоянный комитет Германии по вакцинации (НТИКО) выносит конкретные рекомендации в отношении вакцинации от этих патогенов, данные о коэффициентах вакцинации этой группы населения, подверженной высокому риску, отсутствуют. МЕТОДЫ: Для получения информации о показателях вакцинации от пневмонии стрептокококка и вируса гриппа у о

Совпадение в аннотации оригинала
OBJECTIVES: Due to disease- or therapy-associated immunosuppression, oncological patients suffer from significantly higher morbidity and mortality due to infections transmitted by respiratory pathogens such as Streptococcus pneumoniae and influenza virus. Although the German Standing Committee on Vaccination (STIKO) provides specific recommendations for vacc…

Trends in Streptococcus pneumoniae Antimicrobial Resistance in US Children: A Multicenter Evaluation.

BACKGROUND: Antimicrobial resistance (AMR) poses a significant challenge for treating pneumococcal disease. This study assessed AMR trends in Streptococcus pneumoniae from US children. METHODS: We evaluated antibiotic resistance, defined as facility antimicrobial susceptibility reports of intermediate/resistant, in 30-day nonduplicate S pneumoniae isolates from children (<18 years of age) with invasive (blood or cerebrospinal fluid/neurological) or noninvasive (respiratory or ear/nose/throat) isolates at 219 US hospital inpatient/outpatient settings in the BD Insights Research Database (Janua…

Penicillin-Susceptible Streptococcus pneumoniae Meningitis in Adults: Does the Ceftriaxone Dosing Matter?

The recommended empiric ceftriaxone dosing regimen for acute bacterial meningitis in adults is 2 g every 12 h. After penicillin-susceptible Streptococcus pneumoniae is isolated as a causative microorganism, the ceftriaxone dose may be continued or reduced to a single dose of 2 g every 24 h, per institutional preference. There is no clear guidance that indicates the superiority of one regimen over the other. The objective of this study was to evaluate the susceptibility of S. pneumoniae in the cerebral spinal fluid (CSF) of patients with meningitis and the relationship between ceftriaxone dose …

Multiplex PCR to Streptococcus pneumoniae serotype identification directly in cerebrospinal fluid samples.

Streptococcus pneumoniae causes invasive diseases of significant public health concern, such as meningitis. The culture of cerebrospinal fluid (CSF) samples, the standard technique for meningitis diagnoses, is not always positive. Consequently, meaningful information about the etiological agent is lost, which can compromise effective epidemiological surveillance and the improvement of immunization policies. This study aims to standardize a method to genotype pneumococcus in the CSF samples which could mitigate the absence of isolated strains, and also evaluate the prediction of this assay. We …

The Role of luxS in the Middle Ear Streptococcus pneumoniae Isolate 947.

The LuxS protein, encoded by luxS, is required for the production of autoinducer 2 (AI-2) in Streptococcus pneumoniae. The AI-2 molecule serves as a quorum sensing signal, and thus regulates cellular processes such as carbohydrate utilisation and biofilm formation, as well as impacting virulence. The role of luxS in S. pneumoniae biology and lifestyle has been predominantly assessed in the laboratory strain D39. However, as biofilm formation, which is regulated by luxS, is critical for the ability of S. pneumoniae to cause otitis media, we investigated the role of luxS in a middle ear isolate,…

Host-Mediated Copper Stress Is Not Protective against Streptococcus pneumoniae D39 Infection.

Metal ions are required by all organisms for the chemical processes that support life. However, in excess they can also exert toxicity within biological systems. During infection, bacterial pathogens such as Streptococcus pneumoniae are exposed to host-imposed metal intoxication, where the toxic properties of metals, such as copper, are exploited to aid in microbial clearance. However, previous studies investigating the antimicrobial efficacy of copper in vivo have reported variable findings. Here, we use a highly copper-sensitive strain of S. pneumoniae, lacking both copper efflux and intrace…

Antimicrobial Activity of Peptide-Coupled Antisense Peptide Nucleic Acids in Streptococcus pneumoniae.

Streptococcus pneumoniae is the most common cause of community-acquired pneumonia and is responsible for multiple other infectious diseases, such as meningitis and otitis media, in children. Resistance to penicillins, macrolides, and fluoroquinolones is increasing and, since the introduction of pneumococcal conjugate vaccines (PCVs), vaccine serotypes have been replaced by non-vaccine serotypes. Antisense peptide nucleic acids (PNAs) have been shown to reduce the growth of several pathogenic bacteria in various infection models. PNAs are frequently coupled to cell-penetrating peptides (CPPs) t…