Transfusion‐transmitted CMV infection – current knowledge and future perspectives

Transmission of human cytomegalovirus (CMV) via transfusion (TT‐CMV) may still occur and remains a challenge in the treatment of immunocompromised CMV‐seronegative patients, e.g. after stem cell transplantation, and for low birthweight infants. Measures to reduce the risk of TT‐CMV have been evaluated in clinical studies, including leucocyte depletion of cellular blood products and/or the selection of CMV‐IgG‐negative donations. Studies in large blood donor cohorts indicate that donations from newly CMV‐IgG‐positive donors should bear the highest risk for transmitting CMV infections because they contain the highest levels of CMV‐DNA, and early CMV antibodies cannot neutralise CMV. Based on this knowledge, rational strategies to reduce the residual risk of TT‐CMV using leucoreduced blood products could be designed. However, there is a lack of evidence that CMV is still transmitted by transfusion of leucoreduced units. In low birthweight infants, most (if not all) CMV infections are caused by breast milk feeding or congenital transmission rather than by transfusion of leucoreduced blood products. For other patients at risk, no definitive data exist about the relative importance of alternative transmission routes of CMV compared to blood transfusion. As a result, only the conduction of well‐designed studies addressing strategies to prevent TT‐CMV and the thorough examination of presumed cases of TT‐CMV will achieve guidance for the best transfusion regimen in patients at risk.     

Molecular identification of sympatric chromosomal forms of Anopheles gambiae and further evidence of their reproductive isolation

Three chromosomal forms of Anopheles gambiae s.s., designated as Bamako, Mopti and Savanna, were studied for diagnostic PCR assays based on the analysis of the X-linked ribosomal DNA (rDNA). The study was performed on a 1.3 kb fragment containing part of the 28S coding region and part of the intergenic spacer region. The amplified material was cut with fourteen restriction enzymes to detect Restriction Fragment Length Polymorphisms (RFLPs). The enzymes Tru 9I and Hha I produced patterns of DNA bands which differentiated Mopti from Savanna and Bamako; moreover, a distinct 'hybrid' pattern was recognized in the F1 female progeny from the cross of Mopti with either one of the other two chromosomal forms. The diagnostic significance of the PCR-RFLP assay was verified on 203 karyotyped females from field samples collected in two villages in Mali and one village in Burkina Faso. Agreement was observed between the chromosomal and the molecular identifications. No 'hybrid' molecular patterns were detected even among carriers of rare heterokaryotypes hypothetically produced by crosses between Mopti and Savanna. The results confirm previous observations indicating barriers to gene flow within An. gambiae s.s. and supporting the specific status of the taxonomic units proposed on cytogenetic ground.     

Dissemination of extended-spectrum β-lactamase-producing <Emphasis Type="Italic">Klebsiella pneumoniae</Emphasis> and <Emphasis Type="Italic">Escherichia coli</Emphasis> in Thai hospitals

Fifty clinical isolates of Klebsiella pneumoniae and Escherichia coli with reduced susceptibility to third-generation cephalosporins, collected from 11 hospitals in Thailand, were studied. All isolates were found to produce extended-spectrum β-lactamase (ESBL), as judged by double-disk synergy and combination disk methods. Most ESBL-producing K. pneumoniae isolates were resistant to ceftazidime (94%) and aztreonam (90%). In contrast, most ESBL-producing E. coli isolates were resistant to ceftriaxone (95%) and cefotaxime (74%). Plasmid DNA was isolated and β-lactamase genes were identified by PCR and sequencing. We found that SHV-12 and CTX-M-14 were the main ESBLs responsible for resistance in K. pneumoniae and E. coli, respectively. SHV-27, SHV-28, and CTX-M-14 were detected in three, two, and four K. pneumoniae isolates, respectively. A high genetic diversity among ESBL-producing K. pneumoniae and E. coli isolates was observed. In addition, the finding of a few isolates that produced identical restriction patterns on pulsed field gel electrophoresis (PFGE) suggests the clonal spread of resistant bacteria within the hospital.     

Intérêt du Télos dans l'évaluation de la laxité chronique antérieure du genou en pré- et en postopératoire

The objective of our work is to clarify the contribution of knee arthrometer in the diagnosis of the anterior laxity of the knee, to look for the factors of escalation of this pathology, to estimate the objective results and outcomes following of the anterior cruciate ligament surgery. It is about a retrospective study which concerned 78 patients presenting the anterior chronic laxity of the knee, investigated, treated and followed in the M.-T.-Kassab Institute of Orthopaedics over a period of 10 years. The average age of our patients was of 27.6 years with a male ascendancy. The anterior cruciate ligament surgery was realized according to the technique of Kenneth-Jones under arthroscopy. The arthrometer has been used to determine the outcome 6 months after the surgery. Before the surgery, the average anterior translation of the tibia was 15.3 mm, 95% of the patients had 8 mm previous absolute laxity, while the differential was about 4 mm in 87% of the cases in which comparative study could be made. There was a statistically significant correlation between the Lachman's test, the internal meniscus injuries and the delay accident — surgery with the anterior knee laxity in the arthrometer. The postoperative average laxity was bout 8.2 mm and earning was proportional to the importance of the initial tibial translation. The present study demonstrates that arthrometer tests may be an objective complement for the clinical exam, with a diagnostic, previous and therapeutic purpose.