Explore chapters and articles related to this topic
Bloodstream Infections
Published in Firza Alexander Gronthoud, Practical Clinical Microbiology and Infectious Diseases, 2020
A positive blood culture does not always represent infection. Especially if the blood culture was not aseptically collected, contamination can easily occur. Common blood culture contaminants are skin flora such as coagulase-negative staphylococci, diptheroids, Bacillus spp. and Propionibacterium acnes. Less commonly, viridans streptococci can be found as contaminants.. To audit blood culture collection practices in hospitals, a generally accepted rule is that contaminants should be cultures in less than 3% of all blood cultures collected.
Practice Paper 9: Answers
Published in Anthony B. Starr, Hiruni Jayasena, David Capewell, Saran Shantikumar, Get ahead! Medicine, 2016
Anthony B. Starr, Hiruni Jayasena, David Capewell
Viridans streptococci are a large group of bacterial organisms that are usually commensals in the oral cavity. They are the most common cause of bacterial endocarditis, being responsible for approximately 60% of cases. Individuals with pre-existing valvular disease are at risk of viridans streptococcal endocarditis following invasive dental procedures such as tooth extraction. Antibiotic treatment is usually with intravenous benzylpenicillin, with the addition of gentamicin if resistant bacteria are present. Patients with known valvular heart disease should always receive prophylactic antibiotics prior to any invasive procedure.
Streptococcus mitis
Published in Peter M. Lydyard, Michael F. Cole, John Holton, William L. Irving, Nino Porakishvili, Pradhib Venkatesan, Katherine N. Ward, Case Studies in Infectious Disease, 2010
Peter M. Lydyard, Michael F. Cole, John Holton, William L. Irving, Nino Porakishvili, Pradhib Venkatesan, Katherine N. Ward
The viridans streptococci are increasingly important causes of sepsis and pneumonia in neutropenic persons and sepsis and meningitis in neonates. Their portal of entry is the oral mucosa and oral mucositis is a predisposing factor as are profound neutropenia and administration of trimethoprim-sulfamethoxazole or quinolines. Treatment is the administration of appropriate antibiotics and blood cultures are usually negative after 24 hours of therapy.
16S rRNA is a valuable tool in finding bacterial aetiology of community-acquired pleural empyema–a population-based observational study in South Sweden
Published in Infectious Diseases, 2022
Jakob Hjertman, Jonas Bläckberg, Oskar Ljungquist
In total, 291 patients were included in the study with 429 pleural samples. The median age was 69 years and 63% (n = 184) were men. For the majority, 105 patients (36%), the bacterial aetiology was viridans streptococci, out of which 80% was Streptococcus anginosus. S. pneumoniae were found in samples of 42 patients (14%). Anaerobic bacteria were seen in 34 patients (12%), of which Fusobacterium nucleatum were most commonly found (n = 12). For 26 patients (9%), a combination of viridans streptococci and anaerobic bacteria were found. S. aureus or Enterobacterales were found in a minority of pleural samples, 20 patients (6.9%) and 14 patients (4.8%), respectively. A minimum of 2 bacteria were found in 61 patients (21%). A detailed list of bacterial aetiology is presented in Table 1.
Etiology, drug sensitivity profiles and clinical outcome of bloodstream infections: A retrospective study of 784 pediatric patients with hematological and neoplastic diseases
Published in Pediatric Hematology and Oncology, 2019
Senmin Chen, Sixi Liu, Xiuli Yuan, Huirong Mai, Junrong Lin, Feiqiu Wen
Resistance patterns of CoNS, K. pneumoniae, E. coli, viridans streptococci, S. aureus, Acinetobacter baumannii, and Pseudomonas in patients are summarized in Table 2. The response rates of the Gram-negative bacteria to piperacillin/tazobactam, imipenem, meropenem, and amikacin were high. E. coli showed higher levels of beta-lactam and 4-fluoro-quinolone resistance compared to K. pneumoniae. Low levels of antibiotic resistance were observed in Pseudomonas aeruginosa. All Gram-positive bacteria were susceptible to vancomycin, which was empirically added to the antibiotic therapy in patients with persistent fever. CoNS were often resistant to a variety of antibiotics, including penicillin, amoxicillin, erythromycin, azithromycin, and cotrimoxazole, but was only relatively sensitive to gentamicin, rifampicin, and levofloxacin. Viridans streptococci showed high levels of resistance to macrolides.
The cultivable bacterial flora of the esophagus in subjects with esophagitis
Published in Scandinavian Journal of Gastroenterology, 2018
Elisabeth Norder Grusell, Gunnar Dahlén, Magnus Ruth, Henrik Bergquist, Mogens Bove
This study compared the cultivable bacterial flora of the esophagus in subjects with GERD and EoE as well as to that of healthy volunteers examined in a previously published study using the same technique. This was performed in order to evaluate if there are differences that might be involved in the pathophysiological mechanisms of these diseases. The study demonstrated that the esophagus of subjects with both GERD and EoE most often was colonized with bacteria, commonly in sparse or very sparse amounts. The most common bacterial species were viridans streptococci. Subjects with EoE were found to have significantly more species than GERD subjects in the upper and lower esophagus.