Antibacterial activities of the leaf extracts of Eugenia uniflora Linn. (Synonym Stenocalyx michelli Linn.) Myrtaceae

The aqueous, organic, and volatile oil extracts of leaves of Eugenia uniflora Linn. Family Myrtaceae were investigated for antibacterial properties using agar dilution techniques. The aqueous extract was the most active against the organisms compared to the organic and volatile oil extracts. The extracts were found to inhibit Gram positive Staphylococcus aureus and Bacillus subtilis and Gram negative Escherichia coli and Shigella dysentcriae. Pseudomonas aeruginosa, Klebsiella pneumoniac, and Salmonella typhi were not inhibited.     

Effectiveness of a hospital-wide selective screening programme for methicillin-resistant Staphylococcus aureus (MRSA) carriers at hospital admission to prevent hospital-acquired MRSA infections

Screening of potential MRSA-positive patients at hospital admission is recommended in German and international guidelines. This policy has been shown to be effective in reducing the frequency of nosocomial MRSA transmissions in the event of an outbreak, but the influence of screening on reducing hospital-acquired MRSA infections in a hospital setting where MRSA is endemic is not yet well-documented. This study describes the effect of hospital-wide screening of defined risk groups in a 700-bed acute care hospital during a period of 19 months. In a cohort study with a 19-month control period, the frequencies of hospital-acquired MRSA infections were compared with and without screening. In the control period, there were 119 MRSA-positive patients, of whom 48 had a hospital-acquired MRSA infection. On the basis of this frequency, a predicted total of 73.2 hospital-acquired MRSA infections was calculated for the screening period, but only 52% of the expected number (38 hospital-acquired MRSA infections) were observed, i.e., 48% of the predicted number of hospital-acquired MRSA infections were prevented by the screening programme. The screening programme was performed with minimal effort and can therefore be recommended as an effective measure to help prevent hospital-acquired MRSA infections.     

Staphylococcus aureus Bacteremia in Patients with Hematological Malignancies and/or Agranulocytosis

ABSTRACT. A total of 6 253 cases of Staphylococcus aureus bacteremia, including 274 (4.4%) endocarditis cases, were registered in Denmark in the period 1975–1984. Patients with hematological malignancies and/or agranulocytosis accounted for 479 of the bacteremia cases. The incidence of endocarditis in this group of patients was only 0.4% as compared to 4.7% in other patients with staphylococcal bacteremia (p<0.01). The lower incidence of endocarditis complicating bacteremia in these patients may justify a shorter course of therapy than usually recommended for suspected endocarditis. Patients with hematological malignancies and other patients with agranulocytosis had a higher mortality (49 and 46%, respectively) than other patients with S. aureus bacteremia (33%). The highest mortality was found in patients with multiple myeloma (71%, p<0.01), the lowest in patients with acute lymphocytic leukemia (28%, p<0.01). The higher mortality in these patients may indicate that empiric antibiotic regimens in granulocytopenic patients should include a specific anti-staphylococcal agent.     

Modulation of cytokine production from an EpiOcular corneal cell culture model in response to Staphylococcus aureus superantigen

The present study investigated the hypothesis that Staphylococcus aureus enterotoxin B (SEE) produces epithelial cell death and releases inflammatory cytokines that produce stromal infiltration during contact lens induced peripheral ulceration. Epithelial cells were incubated with different doses of SEB for various time periods. Culture supernatants were assayed for cytokines IL- lo, IL-6 and chemotactic agents IL-8 and LTB,. SEE induced the production of IL- I p and IL-8. Epithelial cells exposed for longer periods (48 h) with low concentrations of SEB produced significantly higher levels (N0.02) of IL-Ip and IL-8 (P<0.05) compared t o a 24 h exposure. SEB did not induce the production o f IL-6 and     

Control of endemic methicillin-resistant Staphylococcus aureus—recent advances and future challenges

Although the exact burden of disease caused by methicillin-resistant Staphylococcus aureus (MRSA) remains largely unknown, most experts agree that MRSA infections are an important clinical and public health problem. Thousands of reports have been published during the last four decades concerning epidemiological and microbiological aspects of MRSA, but uncertainty remains about the best approach to prevent and control this worldwide plague, especially endemic MRSA. Epidemiological methods, e.g., risk scores for targeted screening upon admission, rapid molecular tests and pre-emptive isolation of high-risk patients, new decontamination regimens and restriction of certain antibiotic classes, are all promising approaches that may decrease MRSA cross-transmission; however, further evidence is needed before these strategies can be implemented on a wide scale. Control of community MRSA is an additional challenge for the future, requiring improved surveillance and contact tracing, as well as education and treatment of both infected cases and colonised contacts. This review summarises recent advances and studies that address these issues. Overall, it seems that there is no level of MRSA prevalence for which active control measures are no longer warranted.     

三种实验性IgA肾病模型的比较

目的探讨建立一种理想的IgA肾病（IgAN）动物模型方法。方法分别采用葡聚糖G200、大肠杆菌外膜蛋白和金葡菌的细胞膜20肽抗原决定簇诱导小鼠IgA肾病模型。用分子生物学和病理学方法对3组IgAN模型小鼠进行鉴定和比较。结果（1）葡聚糖组尿蛋白增高，伴有血尿；免疫荧光显示部分肾小球大量IgA沉积；光镜下肾小球系膜细胞增多，肝和脾可见弥漫性的粉染物质沉积；电镜下肾小球系膜区少量低电子密度的致密沉积物，肝和脾可见淀粉丝样物质沉积。（2）大肠杆菌外膜蛋白组尿蛋白增高，伴有血尿；免疫荧光显示肾小球有少量IgA沉积；光镜下肾小球系膜细胞轻度增多，间质炎细胞浸润明显；电镜下肾小球系膜区无电子致密沉积物。（3）金葡菌细胞膜20肽抗原决定簇组尿蛋白增高，伴有血尿；免疫荧光显示多数肾小球均可见大量IgA沉积；光镜下肾小球系膜细胞增多，伴系膜基质轻度增生；电镜下肾小球系膜区和基底膜的内皮细胞下可见高电子密度的致密沉积物。结论金葡菌细胞膜20肽抗原决定簇组诱导的IgAN模型从临床表现和病理学变化与人IgAN极其相似，是3种IgAN模型中最理想的IgAN模型。     

Distribution of the exfoliative toxin D gene in clinical Staphylococcus aureus isolates in France

Exfoliative toxin D (ETD) was identified recently as a new exfoliative toxin serotype. Like other exfoliative toxins, ETD induces intra-epidermal cleavage through the granular layer of the epidermis of neonatal mice. The distribution of ETD production was investigated in Staphylococcus aureus isolates from infected and colonised patients in France. The etd gene was found in 55 (10.5%) of 522 isolates tested. Isolates responsible for bullous impetigo and generalised staphylococcal scalded skin syndrome did not harbour etd, but etd was significantly more frequent in isolates causing cutaneous abscesses and furuncles. Most etd- and Panton-Valentine leukocidin-positive strains belonged to the clone of community-acquired methicillin-resistant S. aureus spreading currently throughout France.     

Possible role of IL-2 deficiency for hypogammaglobulinaemia in patients with common variable immunodeficiency.

Common variable immunodeficiency (CVID) patients are unable to produce specific immunoglobulins after antigen contact in vivo. The aim of this study was to investigate whether in some cases of CVID a decreased de novo synthesis of IL-2 might be the cause of immunodeficiency and whether this deficiency can be corrected by IL-2 supplementation in vitro. Mononuclear cells from 17 CVID patients and from 10 healthy controls were cultured with monoclonal anti-CD3 antibody OKT3, pokeweed mitogen (PWM) or tetanus toxoid (TT) to stimulate IL-2 synthesis. In parallel, in vitro IgG and IgM synthesis was stimulated with Staphylococcus aureus Cowan I (SAC), PWM or TT in the presence or absence of IL-2. While lymphocytes of 11 out of 17 patients produced low to normal amounts of IL-2 upon stimulation with anti-CD3, only three patients showed low IL-2 production in response to PWM and five in response to TT. Regarding immunoglobulin synthesis in vitro, five patients completely failed to produce IgM or IgG upon stimulation with PWM, SAC or TT irrespective of the addition of IL-2. By contrast, four patients did not show any defect in vitro and synthesized normal amounts of IgM and IgG with any of the three stimuli. Finally, eight patients could be reconstituted for PWM-, SAC- and TT-induced IgM and/or IgG synthesis in vitro, by adding IL-2 to the culture system. This enhancing effect of IL-2 could be blocked by adding anti-IL-2 receptor antibodies to the cultures. Our findings indicate that a defective IL-2 synthesis after antigen stimulation may be one reason for the impaired immunoglobulin production in some cases of CVID.