Topic
Diplococcus
About: Diplococcus is a research topic. Over the lifetime, 169 publications have been published within this topic receiving 2457 citations.
Papers published on a yearly basis
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Papers
TL;DR: The biology, microbiology, and epidemiology of this exclusive human pathogen, which causes significant morbidity and mortality in children and young adults worldwide through epidemic or sporadic meningitis and/or septicemia is described.
Abstract: Neisseria meningitidis (the meningococcus) causes significant morbidity and mortality in children and young adults worldwide through epidemic or sporadic meningitis and/or septicemia. In this review, we describe the biology, microbiology, and epidemiology of this exclusive human pathogen. N.meningitidis is a fastidious, encapsulated, aerobic gram-negative diplococcus. Colonies are positive by the oxidase test and most strains utilize maltose. The phenotypic classification of meningococci, based on structural differences in capsular polysaccharide, lipooligosaccharide (LOS) and outer membrane proteins, is now complemented by genome sequence typing (ST). The epidemiological profile of N. meningitidis is variable in different populations and over time and virulence of the meningococcus is based on a transformable/plastic genome and expression of certain capsular polysaccharides (serogroups A, B, C, W-135, Y and X) and non-capsular antigens. N. meningitidis colonizes mucosal surfaces using a multifactorial process involving pili, twitching motility, LOS, opacity associated, and other surface proteins. Certain clonal groups have an increased capacity to gain access to the blood, evade innate immune responses, multiply, and cause systemic disease. Although new vaccines hold great promise, meningococcal infection continues to be reported in both developed and developing countries, where universal vaccine coverage is absent and antibiotic resistance increasingly more common.
382 citations
TL;DR: If an isolated strain of gram-positive diplococci grows with typical colonies on blood agar and diffusely in serum broth, the final diagnosis of S. pneumonia becomes a matter of differentiating between this and other species of α-haemolytic streptococci.
Abstract: Publisher Summary This chapter discusses the diagnosis, serology, and epidemiology of Streptococcus pneumonia that is a species of the genus Streptococcus of the family Streptococcaceae. Pneumococci are gram-positive, capsulated, lanceolate diplococci often arranged in short, straight chains; typically, they grow diffusely in serum broth and give rise to smooth colonies surrounded by narrow zones of α-haemolysis on blood agar. They are facultative anaerobes and some strains are carbon dioxide dependent upon isolation from clinical specimens. They are killed by heat at 60°C for 30 minutes, easily lysed, soluble in bile, sensitive to optochin, and many types are virulent for mice. Fluid specimens and swabs are inoculated onto blood agar and into serum broth. The cultures are incubated at 37°C. On blood agar, typical pneumococcal colonies may be observed as round, flat, smooth, translucent, often with a central pitting, and with a greenish discoloration of the surrounding medium. If an isolated strain of gram-positive diplococci grows with typical colonies on blood agar and diffusely in serum broth, the final diagnosis of S. pneumonia becomes a matter of differentiating between this and other species of α-haemolytic streptococci.
317 citations
TL;DR: The pathogenicity of B catarrhalis was evident from purulence of sputum, fever, blood leucocytosis, and patchy pulmonary shadowing on chest radiographs.
94 citations
TL;DR: The sputum Gram's stain is proposed as a sensitive and reliable indicator to guide therapy and predict outcome in adults with community-acquired pneumonia.
Abstract: Expectorated sputum Gram's stain was correlated with clinical presenting data, cultures, serological data, and response to antibiotic therapy in 89 patients admitted with community-acquired pneumonia. The finding of Gram-positive diplococci on Gram's stain correlated with brief antecedent illness, Streptococcus pneumoniae growing from cultures, and a rapid response to single-agent antibiotic therapy. Patients with no predominant pathogen on Gram's stain were clinically indistinguishable from those with Gram-positive diplococci except for a longer antecedent illness, lack of growth of pathogens from cultures, and more prolonged response to antibiotic therapy. Sputum cytological findings and transtracheal cultures were useful in patients with no Gram-positive diplococci on Gram's stain. The sputum Gram's stain is proposed as a sensitive and reliable indicator to guide therapy and predict outcome in adults with community-acquired pneumonia. ( JAMA 1982;247:642-645)
87 citations
85 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 2 |
| 2020 | 3 |
| 2019 | 1 |
| 2017 | 1 |
| 2016 | 7 |
| 2015 | 5 |