Several European countries reported outbreaks of severe disease caused by Streptococcus pyogenes in the late 1980s. This marked a departure from the previous decades, where very few such outbreaks were noted. These changes in disease occurrence formed part of a global phenomenon, the reasons for which have yet to be explained. Results of surveillance activities for invasive S. pyogenes infection within Europe over the past fifteen years identified further increases in many countries. However, variations in surveillance methods between countries preclude robust comparisons being made, illustrating the need for a unified surveillance strategy across Europe. This was finally embodied in the Strep-EURO programme, introduced in 2002.
The detection of toxigenicity among Corynebacterium diphtheriae and Corynebacterium ulcerans strains is the most important test for the microbiological diagnosis of diphtheria. Difficulties with current methods, in particular the Elek test, are well documented. We therefore describe a modified Elek test which provides an accurate result after only 16 h of incubation, in contrast to 48 h for the conventional test.
Aims-To assess the performance of the polymerase chain reaction (PCR) when used to screen rapidly large numbers of corynebacteria for toxin production; and to determine the incidence of false positive PCR results with non-toxigenic Corynebacterium diphtheriae isolates. Methods-Eighty seven recent British isolates of corynebacteria were assayed by PCR. All isolates were assayed from both blood and telilurite agar within a five day period. Thirty three non-toxigenic isolates of C diphtheriae from six countries were also tested by PCR and by the Elek immunodiffusion assay. Results-There was complete concordance between the results of PCR and traditional methods on the recent British isolates, with one exception: an Elek positive "C ulcerans" isolate, which was PCR positive from tellurite but not from blood agar. One of the thirty three (3%) nontoxigenic isolates of C diphtheriae was PCR positive. Conclusions-These results suggest that PCR compares favourably with traditional methods for the detection of toxigenic corynebacteria and that it represents a powerful new tool in the diagnosis of an old disease.
A collection of 54 isolates of invasive Streptococcus pneumoniae of serotypes 3 and 14 and serogroups 6, 9, 19, and 23 was investigated. Multilocus enzyme electrophoresis and pulsed-field gel electrophoresis suggested that two clones were represented in the collection, one of serotype 14 isolates, most of which were resistant to erythromycin, and one of serotype 9V isolates, in which resistance to penicillin (MIC, 1 g/ml), cefotaxime, and co-trimoxazole was common. Among other isolates there was only a limited correlation between genetic relatedness measured by multilocus enzyme electrophoresis and expression of the same capsule type. However, isolates with highly related pulsed-field gel electrophoresis patterns always shared the same serotype and highly related allele profiles. Calculation of the index of association suggests a freely recombining population structure with epidemic spread of successful clones.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.