Background: In a recent epidemiological study in southern Israel, nontypable Streptococcus pneumoniae isolates were found to be highly associated with sporadic cases of acute conjunctivitis (AC). The purpose of the present study was to evaluate the relative importance in causing AC of the absence of capsule versus genotype properties.
Methods: DNA typing by pulsed-field gel electrophoresis (PFGE) was performed on 148 nontypable organisms isolated from 3 sites: nasopharynx of healthy children, middle-ear fluid, and conjunctiva.
Results: Analysis of the PFGE patterns revealed the presence of 6 clusters; 2 clusters that included 44% of the isolates (65/148) were associated with AC, and the remaining 4 were frequently isolated from the nasopharynx. Multilocus sequence typing, performed on representative isolates of the 2 major clusters, confirmed that the organisms were pneumococci; one is a single-locus variant of sequence type (ST) 448, and the other is related to ST344. Both types appear to be members of pneumococcal lineages that have lost capsular loci. The nontypable isolates showed high rates of resistance to antimicrobial agents.
Conclusions: Our data suggest that the absence of the capsule--along with other, yet-unidentified genetic characteristics--provide S. pneumoniae with a selective virulence advantage in conjunctivitis.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1086/506453 | DOI Listing |
Microorganisms
November 2024
Department of Preventive Veterinary Medicine, Veterinary School, Federal University of Minas Gerais, Belo Horizonte 31270-901, Brazil.
is an important pathogen responsible for cases of high mortality in farmed and wild fish worldwide. In Brazil, this bacterium has been commonly associated with outbreaks in Nile tilapia farms, but other native fish species are also susceptible. Since floating cages are one of the most common culture systems used in the country, the close contact between farmed tilapia and native fish species presents a risk concerning the transmission of this pathogen.
View Article and Find Full Text PDFIJID Reg
December 2024
District Secretary of Health, Bogotá, Colombia.
Objectives: Sentinel surveillance for bacterial pneumonia (SSBP) allows the monitoring of immunopreventable diseases. The results of the SSBP carried out at HOMI, Fundación Hospital pediátrico de la Misericordia, are presented.
Methods: The daily active search for cases was carried out in accordance with the protocol of the Pan American Health Organization from January 2016 to December 2022.
Pediatr Pulmonol
October 2024
Institute for Biomedicine and Glycomics, Griffith University, Gold Coast, Queensland, Australia.
J Infect
November 2024
National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, UK; Department of Respiratory Medicine, Nottingham University Hospitals NHS Trust, Nottingham, UK.
Objectives: We aimed to determine the prevalence of and risk factors for nasopharyngeal and oral pneumococcal carriage in adults with community-acquired pneumonia (CAP), and the relationship between carried and disease-causing serotypes.
Methods: Between 2016 and 2018, nasopharyngeal swabs, oral-fluid, and urine were collected from hospitalised adults recruited into a prospective cohort study of CAP. Pneumococcal carriage was detected by semi-quantitative real-time PCR of direct and culture-enriched nasopharyngeal swabs and culture-enriched oral-fluid.
Eur J Clin Microbiol Infect Dis
November 2024
Department of Pathology and Immunology, Division of Laboratory and Genomic Medicine, Washington University School of Medicine, 425 S. Euclid Ave., Campus Box 8118, St. Louis, MO, 63110, USA.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!