Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases
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Clin. Microbiol. Infect. · Sep 2012
Evolution of French Bordetella pertussis and Bordetella parapertussis isolates: increase of Bordetellae not expressing pertactin.
Bordetella pertussis and Bordetella parapertussis are closely related bacterial agents of whooping cough. Whole-cell pertussis (wP) vaccine was introduced in France in 1959. Acellular pertussis (aP) vaccine was introduced in 1998 as an adolescent booster and was rapidly generalized to the whole population, changing herd immunity by specifically targeting the virulence of the bacteria. ⋯ Since the introduction of the aP vaccines there has been a steady increase in the number of B. pertussis and B. parapertussis isolates collected that are lacking expression of pertactin. These isolates seem to be as virulent as those expressing all virulence factors according to animal and cellular models of infection. Whereas wP vaccine-induced immunity led to a monomorphic population of B. pertussis, aP vaccine-induced immunity enabled the number of circulating B. pertussis and B. parapertussis isolates not expressing virulence factors to increase, sustaining our previous hypothesis.
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Clin. Microbiol. Infect. · Sep 2012
How to discriminate contamination from bloodstream infection due to coagulase-negative staphylococci: a prospective study with 654 patients.
Coagulase-negative staphylococci (CoNS) are frequent contaminants of blood cultures. We aimed to evaluate the systemic inflammatory response syndrome (SIRS) criteria in patients with CoNS bacteraemia for discrimination between true bloodstream infection (BSI) and contamination. Prospective evaluation was carried out of clinical and laboratory parameters in adults with at least one positive blood culture with CoNS at the University Hospital of Basel between 2003 and 2007. ⋯ The probability of BSI increased with each additional SIRS criterion, ranging from 42.4% in patients with only one SIRS criterion to 56.7% for those with two criteria, and 72.3% for patients with three SIRS criteria. A positive blood culture with CoNS most likely represents true BSI if the patient has at least three SIRS criteria or two SIRS criteria and a central venous catheter. These simple bedside criteria may guide decision to treat, decreasing the use of glycopeptides.