Epidemiology and typing of Staphylococcus aureus strains isolated from bloodstream infections

We carried out an epidemiological study covering 2,365,067 patient days of hospitalization between 2000 and 2003. During this time, 413 Staphylococcus aureus bloodstream infections occurred. This corresponds to 15% of the 2,676 bloodstream infections observed during this period in the 31 hospitals in our region of France, which has 2.5 million inhabitants. The incidence of nosocomial S. aureus bloodstream infections was 0.11 per 1,000 days of hospitalization. The prevalence of methicillin-resistant S. aureus (MRSA) strains, of which 13% were nonmultiresistant MRSA (NORSA), was 33%, and this percentage was stable over the 4 years. In contrast, the prevalence of S. aureus strains susceptible to methicillin but resistant to quinolones or susceptible to methicillin but multiresistant to antibiotics (EMSSA strains) increased from 4% in 2000 to 23% in 2003. As previously reported, MRSA strains were mostly recovered from nosocomial bloodstream infections, whereas NORSA strains-generally considered to be responsible for community-acquired infections-were always isolated from nosocomial bloodstream infections. Pulsed-field gel electrophoresis (PFGE) analysis of 109 MRSA strains and 15 EMSSA strains demonstrated clonal diffusion of the three major French MRSA clones and revealed considerable genetic heterogeneity among EMSSA strains. Although no epidemiologically related NORSA strains clustered in particular PFGE groups, the distribution of MRSA strains isolated from bloodstream infections according to the portal of entry (vascular devices, pulmonary, and urinary) was not random for the major PFGE clones, suggesting that each MRSA lineage displays particular virulence features.     

CHRONIC REJECTION: PROSPECTS FOR THERAPEUTIC INTERVENTION IN FIBROPROLIFERATIVE VASCULAR DISEASE

The graft survival rates of sensitized kidney recipients have been shown to be lower than those of nonsensitized patients. Therefore, panel reactive antibody (PRA) and cross-match determination is accepted as mandatory screening for renal transplantation candidates. Our recent previous study showed that simvastatin has a significant immunosuppressive effect in PRA-positive and/or crossmatch-positive patients. We present the long-term pre and post-transplantation outcomes of simvastatin treatment in highly sensitized dialysis patients. Thirty patients were followed for a mean period of 22 months. The PRA and flow cytometric measurements were performed at monthly intervals. Ten patients underwent successful kidney transplantation (eight living-related and two cadaveric). None of the patients developed hyperacute or acute rejection, and there was no graft loss during the 16.1±8.2 months of post-transplantation follow up. Of the 18 patients who stayed on dialysis throughout the study with PRA-positivity, six were lost to follow up and three spontaneously stopped taking the simvastatin. In the latter three cases, the PRA levels rose significantly after the drug was discontinued. Eight of the remaining nine PRA-positive patients showed significant drops in mean PRA level over the study period, and entered the range considered acceptable for transplantation. Only one patient showed persistently high PRA levels throughout the study. In one patient, the drug had to be discontinued because of acute toxic hepatitis. In conclusion, the results indicate that long-term continuous simvastatin therapy is effective in immunized and highly sensitized dialysis patients. Meanwhile, it has a beneficial effect on 1-year graft survival rates in sensitized renal transplantation patients.     

Comparative study of the prevalence of Herpesviridae in an African population and a European population

We have looked for long-term antibodies to Herpesviridae (HSV, VZV, CMV, EBV) in an African population (suburban area of Dakar, Senegal, West Africa) and in a European population (urban area of Bordeaux, France) in order to determine the prevalence of these viruses. The studied sera have been dispatched into 5 age-groups: 6 months to 4 years, 5 years to 9 years, 10 years to 14 years, 15 years to 44 years and greater than 45 years. We note that primary infection with Herpesviridae occurs sooner in life in Africa and that the prevalence rates of these viruses are higher in Africa with the exception of EBV, the prevalence of which is almost identical within the fifth age-group of the African and European populations. The prevalence rates of each individual virus are in agreement with previous studies except for VZV which we describe as the least prevalent virus of the family. The interest of this work is a simultaneous comparison of the prevalence of all viruses of the family Herpesviridae within two different populations.     

The HLA linked iron loading gene in an Afrikaner population.

The serum ferritin concentration was used as a screening test to identify the presence of iron overload in 599 Afrikaans subjects (300 males and 299 females) living in the South Western Cape, South Africa. Seventeen of the males with concentrations greater than 400 micrograms/l were reevaluated three and five years later. Serum ferritin concentrations were measured again and further diagnostic procedures were carried out. These included an assessment of alcohol intake and measurements of serum gamma glutamyltransferase, the percentage saturation of transferrin, and HLA-A,-B,-C, and -DR loci typing on the subjects as well as their families. Liver biopsies were performed on some affected subjects. Of the original 16 index subjects, four were diagnosed as homozygous for the HLA linked iron loading gene which is responsible for the clinical disease idiopathic haemochromatosis. Six appeared to be heterozygotes, three were heterozygotes who were also abusing alcohol, and two did not fit into any of the diagnostic groups. The calculated gene frequency was 0.082, with an expected heterozygote frequency of 0.148. The fact that no females were identified in the study suggested that the diagnostic criteria for homozygosity (serum ferritin greater than 400 micrograms/l and % saturation greater than 60%) were set too high. The data were therefore recalculated for the 300 males; when this was done the gene frequency was 0.115 and the heterozygote frequency 0.024. Two subjects were diagnosed as homozygotes in the study of family members and 37 as heterozygotes (33 definite and four probable). Both the homozygotes and nine of the heterozygotes showed mild to moderate disturbances of iron metabolism. There was considerable overlap between the phenotype expression in these nine heterozygotes and the homozygotes, probably as a result of setting the threshold for the serum ferritin concentrations at the relatively high value of 400 microgram/ml. By doing this a small subset of heterozygotes with biochemical abnormalities was identified. The results of the present pilot study suggest a high frequency of the HLA linked iron loading gene in the Afrikaner population of South Western Cape.     

Production of nisin-like bacteriocins by Lactococcus lactis strains isolated from vegetables

Four bacteriocin producing lactic acid bacteria isolated from vegetables were identified as Lactococcus lactis strains on the basis of physiological and biochemical characteristics, carbohydrate fermentation patterns and analysis of total soluble protein pattern by SDS PAGE. The bacteriocins had a wide spectrum of activity as antagonism was detected not only towards a variety of lactic acid bacteria, but also to Staphylococcus aureus and Listeria monocytogenes. These bacteriocins were resistant to heating at 121 °C for 15 minutes and showed highest activity at low pH (<5.0). They were inactivated by the proteolytic enzymes α-chymotrypsin and proteinase K, but not by lipase, α-amylase, catalase or lysozyme. These bacteriocinogenic Lactococcus strains were all immune to the bacteriocins produced as well as to commerical nisin. Bacteriocin producer culture supernatants showed a high degree (70 or 100%) of cross-reactivity in the nisin ELISA, suggesting similarity of the produced bacteriocins to nisin. The potential application of bacteriocin producing lactococci of vegetable origin for safety assurance of vegetable foods and controlling vegetable fermentations is discussed.     

糖尿病视网膜病血清层粘蛋白的变化及意义

目的：探讨糖尿病微血管病变血管基膜和细胞外基质的关系。方法：放射免疫法检测86例2型糖尿病患者视网膜病变三个不同时期血清层粘蛋白（LN）的含量变化;无视网膜病变组（NDR）32组,单纯期视网膜病变组（BDR）24例,增殖期视网膜病变组（PDR）30例。同时检测正常对照组20名,分别与以上三组的结果比较。结果：血清LN水平在三组患者之间存在显著性差异,BDR和PDR高于NDR组和正常对照组,PDR组高于BDR组,差异均有显著性（P＜0．01）。血清LN水平与年龄和诊断病程均呈正相关（P＜0．05和P＜0．01）,与空腹血糖和餐后血糖亦呈正相关（P＜0．01和P＜0．01）。结论L：血清LN含量变化能够反映微血管病变的严重程度,对糖尿病微血管病变的诊断和治疗、预后判断有较好的指导作用。     

Genetic abnormalities detected by comparative genomic hybridization in a human endometriosis-derived cell line

Comparative genomic hybridization (CGH) was used in parallel with fluorescence in-situ hybridization (FISH) and conventional karyotyping to perform a genome-wide survey of DNA gains and losses in the endometriosis-derived permanent cell line, FbEM-1. The cytogenetic analysis showed a complex karyotype with numerical changes and multiple chromosome aberrations, including the der(1) complement marker exhibiting a large homogenous staining region (HSR). The chromosomal rearrangement interpreted as der(5) t(5;6)(q34;p11) was found in the majority of the metaphases indicating a clonal abnormality. Repeated CGH experiments demonstrated over-representation of chromosomes 1, 2, 3, 5, 6p, 7, 16, 17q, 20, 21q and 22q, while chromosomes 6q, 9, 11p, 12, 13q, 18 and X were under-represented. Using DNA from the original endometriotic tissues, including a peritoneal implant and ovarian endometrioma, CGH analysis revealed loss of DNA copy number on 1p, 22q and chromosome X, while gain was found on chromosomal arms 6p and 17q. FISH analysis confirmed that the gain at 17q includes amplification of the proto-oncogene HER-2/neu in 16% of the FbEM-1 nuclei and in 12% of cells from the primary ovarian endometrioma tissue. These findings demonstrate that FbEM-1 cells share certain molecular cytogenetic features with the original tissue and suggest that chromosomal instability is important in the development of endometriosis.     

Prognostic factors of combined viral load and CD4+ cell count responses under triple antiretroviral therapy, Aquitaine cohort, 1996-1998

OBJECTIVE: To describe the viroimmunologic response and its prognostic factors 6 months after initiating triple antiretroviral therapy in a cohort of HIV-1-infected patients. METHODS: Positive virologic response during follow-up (VL+) was defined as plasma HIV RNA level <500 copies/ml and positive immunologic response (CD4+) as an increase of CD4+ count of at least 50 cells/mm3. Four categories of response were defined: VL+/CD4+; VL+/CD4-; VL-/CD4+ and VL-/CD4-. Prognostic factors were studied through a polytomous logistic regression (VL-/CD4-, as reference). RESULTS: Baseline characteristics of the 478 studied patients were: 22% at AIDS stage, 77% pretreated, median CD4+ cell count 195/mm3 and HIV RNA level 4.42 log. At 6 months 37.5% were VL+/CD4+; 15.7% VL+/CD4-; 23.8% VL-/CD4+ and 23.0% VL-/CD4-. Baseline HIV RNA level was associated to a higher risk of VL-/CD4+ response. More advanced age was associated with a higher risk of isolated immunologic failure (VL+/CD4-), whereas pretreatment and saquinavir therapy were associated with a lower frequency of positive virologic response independently of immunologic response. CONCLUSION: HIV-RNA level, pretreatment, and saquinavir therapy were already known to be linked to therapeutic response. Based on our results, a high baseline HIV-RNA level is associated with isolated immunologic response; moreover, age should be of importance in treatment decision.     

Simultane Messungen der lokalen Myokarddurchblutung mit W?rmeleitmessern und 85Krypton-Clearance

Zusammenfassung Bei Hunden wurde die Durchblutung im Myokard des linken Ventrikels gleichzeitig und am gleichen Ort mit zwei Methoden gemessen. Eine Methode war die fortlaufende Registrierung des Wärmeabtransports durch das Blut von einer geheizten Stelle einer Wärmeleitsonde. Die andere war eine Modifikation der intraarteriellen ⁸⁵Krypton-Clearance-Technik.Als Wärmeleitsonden wurden zwei Bautypen verwendet, von denen einer vorwiegend für Langzeitmessungen am wachen und frei beweglichen Tier verwendet wird, während der zweite Bautyp im wesentlichen für akute Experimente geeignet ist.Die Beziehung zwischen der Änderung der Wärmetransportzahl und den ⁸⁵KrWerten war nicht linear und nicht in allen Versuchen gleich. Der unterschiedliche Verlauf der Beziehung zwischen beiden Meßgrößen bei steigender Durchblutung wird durch die von Ort zu Ort verschiedene Vascularisierung erklärt. Es zeigt sich aber, daß der Wärmetransport mit der ⁸⁵Kr-Methode in ml Blut/g Gewebe · min geeicht werden kann, wenn eine Reihe von Voraussetzungen beachtet werden, welche im einzelnen beschrieben sind.Es wird bei kombinierter Verwendung beider Methoden möglich, die lokale Myokarddurchblutung fortlaufend in ml/g · min zu registrieren.

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Summary In dogs the regional blood flow of the myocardium of the left ventricle was measured simultaneously on the same site by two methods. One was the continuous recording of heat clearance from a heated junction of a thermocouple of a heat clearance probe. The other methode was a modification of the intra-arterial ⁸⁵Krypton clearance technique.Two types of heat clearance probes were used. One is predominantly suitable for long term measurements in conscious and freely moving animals whereas the other type is used essentially in acute experiments.The relation between the heat clearance and the ⁸⁵Krypton clearance was not linear and not the same in all experiments. The different slopes of the curves are explained by the different vascularisation of the chosen measuring sites. It can be seen however, that the heat transport can be calibrated by the ⁸⁵Kr-method in ml blood/g tissue · min if the described assumptions are fulfilled. By the combined use of both methods it is possible to record regional myocardial blood flow continuously in ml/g · min.

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