Partial atlE sequencing of Staphylococcus epidermidis strains from prosthetic joint infections.

Partial atlE sequencing (atlE nucleotides 2782 to 3114 [atlE(2782-3114)]) was performed in 41 Staphylococcus epidermidis isolates from prosthetic joint infections (PJIs) and 44 isolates from skin as controls. The atlE(2782-3114) allele 1 (type strain sequence) was significantly more frequent in PJI strains (38/41 versus 29/44 in controls; P = 0.0023). Most PJI strains were positive for mecA, icaA/icaD, and IS256, and most belonged to the sequence type 27 subgroup, suggesting the involvement of few related clones.

Polymorphism of the cell wall-anchoring domain of the autolysin-adhesin AtlE and its relationship to sequence type, as revealed by multilocus sequence typing of invasive and commensal Staphylococcus epidermidis strains.

We sequenced the adhesin-cell wall-anchoring domain of the atlE gene of 49 invasive and commensal Staphylococcus epidermidis strains. We identified 22 alleles, which could be separated into two main groups: group 1 (alleles 1 and 6 to 16, 32/49 strains) and group 2 (alleles 2 to 5 and 17 to 22, 17/49 strains). Allele 1 (the type strain sequence) was by far the most prevalent (21 of 49 strains). Multilocus sequence typing showed a clear relationship between the atlE allele and the sequence type (ST), with the "nosocomial" ST27 clone and closely related STs expressing group 1 alleles.

[Prevalence and characteristics of Guillain-Barré syndromes associated with Campylobacter jejuni and cytomegalovirus in greater Paris]. / Prévalence et caractéristiques des syndromes de Guillain-Barré associés à Campylobacter jejuni et au cytomégalovirus en région parisienne.

AIM OF THE STUDY: We aimed to study prevalence and features of Campylobacter jejuni and cytomegalovirus (CMV)-associated Guillain-Barré syndromes (GBS) in a French care unit. PATIENTS AND METHODS: We studied 264 patients with GBS admitted at Raymond Poincaré hospital (Garches) between 1996 and 2001. Clinical data were obtained prospectively. Sera were collected at patients entry and tested retrospectively for anti-C. jejuni, anti-CMV and antigangliosides GM1 et GM2 antibodies. RESULTS: GBS associated with a serological evidence for a recent C. jejuni infection were the more frequent (58/264, 22%); they affected predominantly men of mature years (mean age: 51.3 years; sex-ratio M/F: 1.76), mostly after a gastrointestinal illness (52%); they were often pure motor forms (57%), were severe (mechanical ventilation: 40%) and associated to an anti-GM1 IgG and/or IgM response (44%). GBS cases involving a primary CMV infection were less frequent (40/264, 15%), but were severe too (mechanical ventilation: 37.5%); they occurred preferentially in young women (mean age: 35.9 years; sex-ratio MF: 0.82), often after respiratory tract symptoms (28%) or an influenza-like syndrome (15%) and were frequently associated with sensory loss (73%) and with an anti-GM2 IgM response (47%). CONCLUSION: C. jejuni and CMV proved to be major triggering agents of GBS in France. They are associated with distinct presentations, which are both severe.

Use of genotypic identification by sodA sequencing in a prospective study to examine the distribution of coagulase-negative Staphylococcus species among strains recovered during septic orthopedic surgery and evaluate their significance.

A total of 212 coagulase-negative Staphylococcus strains recovered prospectively during 119 surgeries for proven or suspected bone and joint infection (BJI) were identified by sodA sequencing. These strains were identified as 151 Staphylococcus epidermidis isolates, 15 S. warneri isolates, 14 S. capitis isolates, 9 S. hominis isolates, 6 S. lugdunensis isolates, 5 S. haemolyticus isolates, 4 S. caprae isolates, 4 S. pasteuri isolates, 3 S. simulans isolates, and 1 S. cohnii isolate. Only S. epidermidis, S. lugdunensis, S. capitis, and S. caprae were found to be infecting organisms and were involved, respectively, in 35 (81.4%), 3 (7.0%), 3 (7.0%), and 2 (4.6%) cases of BJI.

Use of sodA sequencing for the identification of clinical isolates of coagulase-negative staphylococci.

This study evaluated the possible advantages provided by a genotypic method over commercially available biochemical systems for the identification of clinical isolates of coagulase-negative staphylococci (CNS). Partial sequencing of the sodA gene was performed for 168 coagulase-negative clinical isolates of staphylococci identified previously with the ID32 STAPH system. Of these, 101 (60.1%) were identified to the species level with ID32 STAPH, while 67 (39.9%) were misidentified or not identified with certainty. Sequencing of sodA proved useful for resolving all ambiguities or inconclusive identifications generated by the commercially available biochemical identification system.

Modification of the ProC Global assay using dilution of patient plasma in factor V-depleted plasma as a screening assay for factor V Leiden mutation.

The activated protein C (APC) resistant-factor V (factor V Leiden) has emerged as the most common inherited risk factor for thrombosis in the Caucasian population. Beside DNA analysis, the laboratory diagnosis is often based on the detection of a poor anticoagulant response to exogenous APC. The ProC Global assay (Dade Behring, Marburg, Germany) is a global clotting assay, which was primarily developed to evaluate the functionality of the protein C anticoagulant pathway. It is based on the ability of endogenous APC, generated by activation of protein C by an extract from Agkistrodon contortrix contortrix venom, to prolong an activated partial thromboplastin time. It was previously found to be highly sensitive for the factor V Leiden mutation and for protein C deficiency, but only moderately sensitivity for protein S deficiency. Here, we evaluated the performance of a modification of the ProC Global assay using a 1 : 5 pre-dilution of patient plasma in factor V-depleted plasma in the screening of the factor V Leiden mutation-related APC resistance. For that purpose, we investigated selected frozen plasma samples from 341 patients with a history of venous thromboembolism. The sensitivity for the factor V Leiden mutation of the modified assay was found to be 100%, as all the carriers of that mutation (five homozygotes and 77 heterozygotes) had a decreased response to the assay, i.e. a normalized ratio below 0.80. Its specificity was also 100% since none of the other tested patients had a decreased response, i.e. isolated protein C (n = 3) or protein S deficiency (n = 50), or without any abnormality of the protein C pathway (n = 143), even those on oral anticoagulant treatment (n = 76). However, it would be preferable that each laboratory defines both its reference range and its cut-off level. Finally, even if larger-scale multicentre studies are needed before definite recommendations could be made, these results suggest that the ProC Global performed using a 1 : 5 pre-dilution of the patient plasma in factor V-depleted plasma could be validly used as a screening assay of the factor V Leiden mutation-related APC resistance in patients with a history of thrombosis.