Extranodal Multiple Involvement of Enteropathy-Type T-Cell Lymphoma without Expression of CC Chemokine Receptor 7

Enteropathy-type T-cell lymphoma (ETCL) is a rare extranodal lymphoma that tends to disseminate into the intestines and other extranodal organs. We present a case of ETCL with involvement of the lungs and kidneys and report CC chemokine receptor 7 (CCR7) expression of lymphoma cells. A 73-year-old man was admitted to the hospital with a complaint of abdominal pain. Multiple ulcers and perforations were observed in the small intestine, and partial resection of the ileum was performed. Histological examination of the resected specimen revealed diffuse proliferation of atypical large lymphoid cells. The diagnosis was ETCL with dissemination into the lungs and kidney. Lymphoma cells of the small intestine and in pleural effusion were CD3+, CD4+, CD7+, CD8-, CD25-, CD56-, CD103 +/-, and TIA-1+. Rearrangement of the T-cell receptor beta gene was detected, and human T-lymphotropic virus was not integrated. Combination chemotherapy did not result in a sustained response. The results for CCR7 expression of lymphoma cells in the lung and pleural effusion were negative. Therefore we concluded that lymphoma cells did not migrate into the lymph nodes but instead spread into the extranodal organs.     

Staphylococcus aureus, platelets, and the heart

Infective endocarditis (IE) caused by Staphylococcus aureus is serious, burgeoning frequency, and growing increasingly resistant to antibiotics. S. aureus IE is associated with high morbidity and mortality rates in nosocomial and community-acquired settings. S. aureus is the most common, most virulent IE etiologic pathogen. S. aureus IE pathogenesis depends upon complex interaction among the pathogen, platelets, plasma proteins, and vascular endothelial cells. S. aureus coordinates the expression of key virulence factors required for the specific pathogenic phases of IE. Platelets, now appear to play an important role in antimicrobial host defense against S. aureus IE and other endovascular infections. Platelet microbicidal proteins are believed to significantly contribute to the antimicrobial properties of platelets; however, abnormal disposition of native or prosthetic cardiac valves is an important risk factor in S. aureus IE establishment and severity. Thus, the need to define the molecular mechanisms of S. aureus pathogenesis and host defense against IE is urgent. Understanding these mechanisms will yield new approaches for the prevention and treatment of such life-threatening cardiovascular infections due to S. aureus.     

瘦素受体基因Gln223Arg多态性与脑卒中相关性的研究

目的探讨瘦素受体(leptin receptor,LR)基因Gln223Arg位点多态性与脑卒中的相关性。方法采用聚合酶链反应-限制性片段长度多态性分析法检测50例脑卒中患者和50例正常对照者的LR基因Gln223Arg位点多态性,同时记录受试者年龄、性别,并测定血糖、胆固醇(CHO)、低密度脂蛋白(LDL)、收缩压和舒张压等临床指标进行对比分析。结果脑卒中组的瘦素受体基因G和A等位基因频率分别为74.0%和26.0%,正常对照组分别为84.0%和16.0%,两者比较差异有统计学意义(P<0.05)。与对照组基因型比较,基因型中含有等位基因A的各临床指标要高于对照组。结论 LR基因Gln223Arg位点的A等位基因会增加脑卒中的发病风险。     

Update on the epidemiology and management of Staphylococcus aureus, including methicillin-resistant Staphylococcus aureus, in patients with cystic fibrosis

PURPOSE OF REVIEW: Staphylococcus aureus is one of the first and most common pathogens to be isolated from the respiratory tract of patients with cystic fibrosis. The prevalence of respiratory tract colonization/infection with both methicillin-susceptible and methicillin-resistant S. aureus has increased over the past decade. The clinical significance of colonization/infection with these pathogens is variable, leading to numerous therapeutic strategies: primary prophylaxis, eradication, treatment of cystic fiboris pulmonary exacerbations, and treatment of methicillin-resistant S. aureus. RECENT FINDINGS: Studies have demonstrated increased prevalence of S. aureus in clinical laboratories that use selective media. Additionally, small colony variant S. aureus has been associated with persistent infection, co-infection with Pseudomonas aeruginosa, and frequent courses of antibiotics, but this phenotype may be difficult to identify in clinical laboratories. Increased prevalence of methicillin-resistant S. aureus has led to use of oral and inhaled antibiotics in attempts to eradicate this pathogen; these studies have yielded variable results. SUMMARY: The epidemiology of S. aureus in cystic fibrosis has changed. Studies are needed to assess the clinical significance of the increased prevalence of both methicillin-susceptible and methicillin-resistant S. aureus, and whether primary prophylaxis or new treatment/eradication protocols are effective.     

Whole-Genome Analysis Reveals That Bacteriophages Promote Environmental Adaptation of Staphylococcus aureus via Gene Exchange,Acquisition, and Loss

The study of bacteriophages is experiencing a resurgence owing to their antibacterial efficacy, lack of side effects, and low production cost. Nonetheless, the interactions between Staphylococcus aureus bacteriophages and their hosts remain unexplored. In this study, whole-genome sequences of 188 S. aureus bacteriophages—20 Podoviridae, 56 Herelleviridae, and 112 Siphoviridae—were obtained from the National Center for Biotechnology Information (NCBI, USA) genome database. A phylogenetic tree was constructed to estimate their genetic relatedness using single-nucleotide polymorphism analysis. Comparative analysis was performed to investigate the structural diversity and ortholog groups in the subdividing clusters. Mosaic structures and gene content were compared in relation to phylogeny. Phylogenetic analysis revealed that the bacteriophages could be distinguished into three lineages (I–III), including nine subdividing clusters and seven singletons. The subdividing clusters shared similar mosaic structures and core ortholog clusters, including the genes involved in bacteriophage morphogenesis and DNA packaging. Notably, several functional modules of bacteriophages 187 and 2368A shared more than 95% nucleotide sequence identity with prophages in the S. aureus strain RJ1267 and the Staphylococcus pseudintermedius strain SP_11306_4, whereas other modules exhibited little nucleotide sequence similarity. Moreover, the cluster phages shared similar types of holins, lysins, and DNA packaging genes and harbored diverse genes associated with DNA replication and virulence. The data suggested that the genetic diversity of S. aureus bacteriophages was likely due to gene replacement, acquisition, and loss among staphylococcal phages, which may have crossed species barriers. Moreover, frequent module exchanges likely occurred exclusively among the subdividing cluster phages. We hypothesize that during evolution, the S. aureus phages enhanced their DNA replication in host cells and the adaptive environment of their host.     

Association between nasal carriage of Staphylococcus aureus and infection in liver transplant recipients.

We reviewed the records of 87 patients who underwent liver transplantation and who were screened by use of nasal swabs on the day before surgery. Twenty-four patients harbored methicillin-susceptible Staphylococcus aureus (MSSA), and 8 harbored methicillin-resistant S. aureus (MRSA). MSSA infection occurred in 3 (12.5%) of 24 MSSA carriers and in 2 (3.2%) of 63 noncarriers (nonsignificant). In contrast, MRSA infection occurred more frequently in MRSA carriers (7 [87.5%] of 8) than in MRSA noncarriers (8 [10.1%] of 79; P<.001). Nasal carriage of MRSA is associated with a very high risk of MRSA infection in liver transplant recipients.     

Polymorphisms in Beta-2 Adrenergic Receptor Gene and Association with Tuberculosis

Purpose

Genetic susceptibility for tuberculosis in human has been previously demonstrated. Polymorphisms in genes involved in immune responses may alter the susceptibility of individuals to tuberculosis. Polymorphisms of beta-2 adrenergic receptor (ADRB2) gene can be possibly an important risk factor in tuberculosis. In this study, the association between rs1042713 (Arg16Gly +46A>G) and rs1042714 (Gln27Glu +79C>G) polymorphisms in ADRB2 gene and tuberculosis was evaluated.

Methods

Genotype distributions of the rs1042713 (Arg16Gly +46A>G) and rs1042714 (Gln27Glu +79C>G) polymorphisms in ADRB2 gene in 106 patients with pulmonary tuberculosis and 88 healthy subjects were studied by PCR–RFLP method in an Iranian population.

Results

The frequency of rs1042713*G and rs1042714*G alleles in ADRB2 gene in tuberculosis patients was significantly different from healthy controls [odds ratio (OR) 0.176, 95% confidence interval (CI) 0.065–0.48, P value <0.001 and OR 0.45, 95% CI 0.247–0.825, P value = 0.009, respectively]. There were no significant differences in haplotype analysis between the patients and control subjects.

Conclusion

The association was reported between rs1042713 and rs1042714 polymorphisms in ADRB2 gene and tuberculosis for the first time. rs1042713*G and rs1042714*G polymorphisms in ADRB2 gene makes people more susceptible to develop the disease.

     

Association between biomass formation and the prognosis of infective endocarditis due to Staphylococcus aureus

IntroductionThe aim of this study was to evaluate the association between biomass formation and the clinical characteristics and prognosis of Staphylococcus aureus infective endocarditis (IE).MethodsWe prospectively studied 209 S. aureus strains causing IE. Biomass formation was examined using the crystal violet assay and quantified spectrophotometrically. The average (SD) optical density of the biomass was compared for each clinical, microbiological (methicillin-resistance, vancomycin MIC ≥ 1.5 μg/ml) and molecular (clonal complex, agr type and agr dysfunction) variable according to their presence or absence. The primary clinical endpoints studied were in-hospital death, severe sepsis, persistent bacteraemia, symptomatic peripheral embolisms and prosthetic valve IE.ResultsMean age was 66.1 years, 61.5% of patients were male and the median age-adjusted Charlson comorbidity index was 5 points (IQR 3–8). In-hospital mortality was 37.3%. Strains belonging to CC5 and CC22 had optical biomass densities [mean (SD) 1.573 (1.14) vs 0.942 (0.98) p < 0.001 and 1.720 (0.94) vs 1.028 (1.04) p = 0.001, respectively]. Strains belonging to CC5 and CC22 had significantly higher optical biomass densities [1.369 (1.18) vs 0.920 (0.93) p = 0.008]. No statistically significant differences were found in the clinical endpoints studied.ConclusionsHigh biomass production was associated with CC5 and CC22 but not with higher hospital mortality, septic complications, type of endocarditis, methicillin-resistance, elevated vancomycin MIC or agr dysfunction.     

Staphylococcus aureus and MRSA in Austrian hospitals, 1995

In 1996, 327 acute care hospitals and other health care institutions in Austria were asked by the Federal Ministry of Health and Consumer Protection to report the number of inpatient episodes in 1995 in which Staphylococcus aureus (SA) was cultured. The m