Bacterial Infections in Adult HIV-Infected Patients

Abstract

Purpose: The purpose of this article is to critically review articles published from the pre-HAART era to the present on bacterial infections in adult HIV-infected patients. Method: Literature search on bacterial infections in HIV-infected patients yields predominantly small case series from single centers, many of which are retrospectively collected. Results: Variations in case selection limit the utility of these articles for assessing the epidemiology and clinical features of a particular infection. Nonetheless, numerous articles indicate that certain bacterial infections occur most often when CD4 cell counts are < 200/mm³. In the pre-HAART era, others suggest that PcP prophylaxis with TMP/SMX and MAC prophylaxis with macrolides reduced rates of several bacterial infections. Since the advent of HAART, however, some articles suggest that the incidence of various infections has declined and that withdrawal of OI prophylaxis in patients who have had HAART restoration of CD4 cell counts has not led to an increase in certain bacterial infections. Conclusion: This review suggests that bacterial infections may have declined in the HAART era, as multicenter cohort studies have shown to be the case with AIDS-associated OIs. Nonetheless, preventive measures such as pneumococcal vaccination and smoking cessation remain effective strategies.     

IL-18 Upregulates the Production of Key Regulators of Osteoclastogenesis from Fibroblast-Like Synoviocytes in Rheumatoid Arthritis

Recent data have demonstrated the importance of IL-18 in the induction and perpetuation of chronic inflammation in experimental arthritis. The aim of the present study was to elucidate whether IL-18 has any indirect effects on osteoclastogenesis by regulating the production of molecules from fibroblast-like synoviocytes (FLS) in rheumatoid arthritis (RA). Human FLS were isolated from RA synovial tissue and cultured in vitro for three to five passages. The expression of IL-18 receptor was determined by RT-PCR. The levels of soluble receptor activator of nuclear factor κB ligand (RANKL), osteoprotegerin (OPG), macrophage colony-stimulating factor (M-CSF), and granulocyte-macrophage colony-stimulating factor (GM-CSF) in culture supernatants were determined by ELISA. Membrane-bound RANKL expression was analyzed by flow cytometry. Both α and β chains of IL-18 receptor were confirmed in cultured FLS. IL-18 upregulated membrane-bound RANKL expression and soluble RANKL production by FLS in both time- and dose-dependent manners. In addition, IL-18 enhanced production of M-CSF, GM-CSF, and OPG from cultured FLS in a dose-dependent manner. IL-18 also increased the ratio of RANKL/OPG, suggesting that the net effect of IL-18 on FLS favors for the induction of osteoclast formation and bone resorption. In conclusion, IL-18 upregulates the production of key regulators of osteoclastogenesis from FLS in RA.     

细菌性阴道病患者阴道茵群特征的非培养分析

细菌性阴道病( bacterial vaginosis,BV)是一种阴道菌群失调所致的常见病,许多阴道菌群为厌氧菌,培养条件要求苛刻,很难纯培养和分离鉴定.本研究旨在通过非培养方法,明确BV患者阴道菌群特征.根据Amsel标准和Nugent评分筛选BV患者和健康育龄期妇女各30例,提取细菌基因组DNA,构建细菌16Sr...     

Proinflammatory Cytokines in the Treatment of Bacterial and Fungal Infections

Mortality due to severe bacterial infections has not been markedly effected by the introduction of new antimicrobial drugs over the last 30-40 years. This has emphasized the need for development of new therapeutic strategies to combat sepsis. The outcome of an infection depends on two factors: the growth of the microorganisms (including the effect of antibacterial drugs), and the host's defensive response to the invading organism. It is known that injection of bacterial products into experimental animals leads to enhanced nonspecific resistance to a variety of microorganisms. The discovery of the specific mediators responsible for modulation of host defense has created new possibilities for the development of alternative treatment strategies. Molecules such as interleukins, interferons, tumor necrosis factors and hematopoietic growth factors have become available in recombinant form, and their therapeutic potential in various infectious diseases has been tested in various experimental models of infections. Initial data in various patient groups indicate that adjunctive therapy with recombinant proinflammatory cytokines may have beneficial effects in the treatment of bacterial and fungal infections.     

Flow Cytometry Study of Lymphocyte Subsets in Malnourished and Well-Nourished Children with Bacterial Infections

Protein-energy malnutrition is the primary cause of immune deficiency in children across the world. It has been related to changes in peripheral T-lymphocyte subsets. The aim of the present study was to evaluate the effects of infection and malnutrition on the proportion of peripheral-lymphocyte subsets in well-nourished non-bacterium-infected (WN), well-nourished bacterium-infected (WNI), and malnourished bacterium-infected (MNI) children by flow cytometry. A prospectively monitored cohort of 15 MNI, 12 WNI, and 17 WN children was studied. All the children were 3 years old or younger and had only bacterial infections. Results showed a significant decrease in the proportion of T CD3⁺ (P < 0.05 for relative and P < 0.03 for absolute values), CD4⁺ (P < 0.01 for relative and absolute values), and CD8⁺ (P < 0.05 for relative values) lymphocyte subsets in WNI children compared to the results seen with WN children. Additionally, B lymphocytes in MNI children showed significant lower values (CD20⁺ P < 0.02 for relative and P < 0.05 for absolute values) in relation to the results seen with WNI children. These results suggest that the decreased proportions of T-lymphocyte subsets observed in WNI children were associated with infection diseases and that the incapacity to increase the proportion of B lymphocyte was associated with malnutrition. This low proportion of B lymphocytes may be associated with the mechanisms involved in the immunodeficiency of malnourished children.     

男女婚后心理特征及性别差异

采用自评与配偶互评方式，用“婚后心理评定量表”和“家庭关系量表”测量婚后男女心理行为特征。结果显示：婚后女性在家庭中表现优于男性；而对婚姻的失望程度高于男性。这与女性在婚前对婚姻的期望值和理想化程度较高有关。男性婚后表现欠佳，与婚前追求女性有较好的表现，婚后放松对自己要求有关。在“能否忍让对方缺点”的项目中发现，无论男女都存在对自己优点估计过高，缺点估计低的主观性。以上特点应引起咨询工作者的注意。     

Molecular Detection of Culture-Confirmed Bacterial Bloodstream Infections with Limited Enrichment Time

Conventional blood culturing using automated instrumentation with phenotypic identification requires a significant amount of time to generate results. This study investigated the speed and accuracy of results generated using PCR and pyrosequencing compared to the time required to obtain Gram stain results and final culture identification for cases of culture-confirmed bloodstream infections. Research and physician-ordered blood cultures were drawn concurrently. Aliquots of the incubating research blood culture fluid were removed hourly between 5 and 8 h, at 24 h, and again at 5 days. DNA was extracted from these 6 time point aliquots and analyzed by PCR and pyrosequencing for bacterial rRNA gene targets. These results were then compared to those of the physician-ordered blood culture. PCR and pyrosequencing accurately identified 92% of all culture-confirmed cases after a mean enrichment time of 5.8 ± 2.9 h. When the time needed to complete sample processing was included for PCR and pyrosequencing protocols, the molecular approach yielded results in 11.8 ± 2.9 h compared to means of 27.9 ± 13.6 h to obtain the Gram stain results and 81.6 ± 24.0 h to generate the final culture-based identification. The molecular approach enabled accurate detection of most bacteria present in incubating blood culture bottles on average about 16 h sooner than Gram stain results became available and approximately 3 days sooner than the phenotypic identification was entered in the Laboratory Information System. If implemented, this more rapid molecular approach could minimize the number of doses of unnecessary or ineffective antibiotics administered to patients.     

Resistance to Bacterial and Parasitic Infections in the Nutritionally Compromised Host

Tuberculosis, a bacterial disease prevalent since ancient times, continues to cause the most deaths globally compared with all other diseases. The causative agent Mycobacterium tuberculosis is responsible for different types of tuberculosis in humans; however, pulmonary tuberculosis is the most common and causes the most deaths. Mycobacterium tuberculosis is an intracellular pathogenic bacterium, which has developed sophisticated mechanisms to survive inside host mononuclear phagocytes and thus evade the host immune system. This is attributed primarily to an inadequate immune response toward infecting bacteria, which results in temporary growth inhibition rather than death and subsequently allows the bacteria to multiply immensely, leading to full-blown disease in an individual. This disease has become a challenge due to poor diagnosis, a low-efficiency tuberculosis vaccine (Mycobacterium bovis Bacillus Calmette-Guèrin [BCG]), a long-term antibacterial chemotherapy regimen (approximately 6 months), and an emergence of multiple drug resistant strains of Mycobacterium tuberculosis especially in people with human immune deficiency virus (HIV) infection, for whom researchers worldwide must develop effective short-term chemotherapy and an effective vaccine. In this review different aspects of vaccines in tuberculosis are discussed, and these include the traditional BCG vaccine, the modern auxotrophic vaccine, the subunit or acellular vaccine; and a DNA vaccine. We discuss also the potential of mycobacterial lipids as a vaccine or as an adjuvant in the future. Since complete genome information of Mycobacterium tuberculosis H37Rv and bioinformatics tools are available, it is possible to develop new strategies for a better and effective tuberculosis vaccine, which can replace the traditional BCG vaccine.