Enzymatic Hydrolysis of Pneumococcal Capsular Polysaccharide Renders the Bacterium Vulnerable to Host Defense Cellular Microbiology: Pathogen-Host Cell Molecular Interactions

This study aimed to evaluate the protective role of a glycoside hydrolase, Pn3Pase, targeting the CPS of type 3 S. pneumoniae, which is one of the most virulent serotypes. We have assessed the ability of Pn3Pase to degrade the capsule on a live type 3 strain. Through in vitro assays, we observed that Pn3Pase treatment increases the bacterium's susceptibility to phagocytosis by macrophages and complement-mediated killing by neutrophils. We have demonstrated that in vivo Pn3Pase treatment reduces nasopharyngeal colonization and protects mice from sepsis caused by type 3 S. pneumoniae. Due to the increasing shifts in serotype distribution, the rise in drug-resistant strains, and poor immune responses to vaccine-included serotypes, it is necessary to investigate approaches to combat pneumococcal infections. This study evaluates the interaction of pneumococcal CPS with the host at molecular, cellular, and systemic levels and offers an alternative therapeutic approach for diseases caused by S. pneumoniae through enzymatic hydrolysis of the CPS.
Source: Infection and Immunity - Category: Infectious Diseases Authors: Tags: Cellular Microbiology: Pathogen-Host Cell Molecular Interactions Source Type: research

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Conclusion: According to WHO-recommended thresholds for interpreting cost-effectiveness, introduction of PCV-13 for children under 5 years in the Islamic Republic of Iran would be cost-effective. PMID: 31774134 [PubMed - in process]
Source: Eastern Mediterranean Health Journal - Category: Middle East Health Tags: East Mediterr Health J Source Type: research
Outbreaks of severe pneumococcal disease occur sporadically and can affect large numbers of individuals, although they are less frequent compared to the pre-antibiotic era.1 The responsible pathogen, Streptococcus pneumoniae, is a Gram-positive bacterium that commonly colonises the nasopharyngeal tract, especially in young children. Occasionally, however, it can invade locally to cause mucosal infections including sinusitis, otitis media or pneumonia. Rarely, invasion of the bloodstream can lead to more serious infections, including septicaemia and meningitis.
Source: Journal of Infection - Category: Infectious Diseases Authors: Source Type: research
Outbreaks of severe pneumococcal disease occur sporadically and can affect large numbers of individuals, although they are less frequent compared to the pre-antibiotic era.1 The responsible pathogen, Streptococcus pneumoniae, is a Gram-positive bacterium that commonly colonises the nasopharyngeal tract, especially in young children. Occasionally, however, it can invade locally to cause mucosal infections including sinusitis, otitis media or pneumonia. Rarely, invasion of the bloodstream can lead to more serious infections, including septicaemia and meningitis.
Source: Journal of Infection - Category: Infectious Diseases Authors: Source Type: research
Streptococcus pneumoniae is the leading cause of bacterial infections in children, including meningitis, bacteremia, bacteremic pneumonia, empyema, and mucosal infections such as otitis media and non-bacteremic pneumonia. After the implementation of pneumococcal conjugate vaccines (PCVs), worldwide, the burden of invasive pneumococcal diseases (IPDs) and non-invasive pneumococcal diseases due to vaccine serotypes (VTs) greatly decreased in children.1 However, since 2015, several European countries have reported an increased incidence of IPDs due to non-vaccine serotypes (NVTs), which seemed variable across countries in ter...
Source: The Journal of Pediatrics - Category: Pediatrics Authors: Tags: European Paediatric Association Source Type: research
ConclusionsAny difference in price between PHiD-CV and PCV13 is expected to be the key driver of vaccine choice for preventing childhood pneumococcal disease in Turkey. At price parity, PHiD-CV use is likely to be a dominant strategy over the use of PCV13.
Source: Value in Health Regional Issues - Category: International Medicine & Public Health Source Type: research
ConclusionThe ongoing NIP in Algeria is projected to reduce the impact and economic toll of pneumococcal disease in Algeria. If an NIP were also introduced in Tunisia, a commensurate impact would be expected. PCV NIPs are highly cost-effective, highly impactful public health interventions.FundingPfizer.
Source: Infectious Diseases and Therapy - Category: Infectious Diseases Source Type: research
CONCLUSION: The results from this study suggest that our NTHi AOM coinfection model is useful for assessing protein vaccines. PMID: 30136923 [PubMed - as supplied by publisher]
Source: Journal of Medical Microbiology - Category: Microbiology Authors: Tags: J Med Microbiol Source Type: research
Publication date: Available online 14 August 2018Source: Microbial PathogenesisAuthor(s): Min Yong Jwa, Eun Byeol Ko, Hyun Young Kim, Sun Kyung Kim, Soyoung Jeong, Ho Seong Seo, Cheol-Heui Yun, Seung Hyun HanAbstractStreptococcus pneumoniae is a major respiratory pathogen that can cause pneumonia, meningitis, and otitis media. Although capsular polysaccharide-based vaccines are commercially available, there is a need for broad-spectrum, serotype-independent, and cost-effective vaccines. Recently, an intranasal vaccine formulated with gamma-irradiated nonencapsulated S. pneumoniae whole cells has been developed and its immu...
Source: Microbial Pathogenesis - Category: Infectious Diseases Source Type: research
Calvin Green, Christine Ann Moore, Akhilesh Mahajan, Kailash BajajJournal of Global Infectious Diseases 2018 10(3):159-162 Streptococcus pneumoniae is a bacterium responsible for a spectrum of diseases including lobar pneumonia, meningitis, otitis media, and sinusitis. Invasive pneumococcal disease is responsible for significant morbidity and mortality across the world. Concerted efforts led to the development of two vaccinations, Pneumova × 23 and Prevnar 13, for the prevention of pneumococcal disease. The Advisory Committee on Immunization Practices of the US Centers for Disease Control and Prevention provides vacc...
Source: Journal of Global Infectious Diseases - Category: Infectious Diseases Authors: Source Type: research
In this study, we describe a simple method to produce PspA of clade 4 from an Escherichia coli expression system using hydroxylapatite and ion-exchange chromatography. Using this method, we successfully expressed soluble PspA4 in 10 L of autoinducing culture medium, with a wet-cell yield of 19 g/L and a final PspA4 concentration of 22.8 mg/L. Additionally, we improved PspA4 purity from 17% to 70% in a single step through the use of hydroxylapatite, resulting in acquisition of recombinant PspA4 (>95% purity) at a final yield of 43% from the starting cell-lysis solution. We subsequently verified the secondary struct...
Source: Protein Expression and Purification - Category: Biochemistry Source Type: research
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