First reportedNocardia otitidiscaviarum infection in an AIDS patient in Italy

Nocardiosis is a well-described infection in immunocompromised patients, and has been rarely documented in patients with AIDS.Nocardia asteroides is the most frequently isolated etiologic agent. Rare cases are due toN. brasiliensis andN. otitidiscaviarum. This work describes the first case of nocardiosis in Italy caused byN. otitidiscaviarum in an AIDS patient. A 31 year-old intravenous drug abuser with a diagnosis of full-blown AIDS, presented with high fever and lymphadenitis with a fistula draining copious purulent discharge. Broad-spectrum antibiotic therapy was initiated, but the patient did not show any improvement. Direct examination of the pus revealed numerous gram positive rods. When culturedN. otitidiscavarium was isolated and identified by morphological and biochemical tests.     

Effect ofNocardia rubra cell-wall skeleton on cancer prevention in humans

Summary The retired workers at the chemical weapons plant in Japan are regarded as a high-risk group for cancers. Under the Cancer Preventive Program,Nocardia rubra cell-wall skeleton (N-CWS) was administered to 80 workers directly involved in the production of sulfur mustard and 66 workers engaged in work related to sulfur mustard production. Untreated workers whose age, sex, duties and duration of work at this factory were individually matched to the N-CWS-treated workers were used as controls. During a 4.5-year observation period, development of cancers was found in 7 treated workers and 17 untreated controls. After elimination of the influence of the difference in smoking level, the incidence of subjects who developed cancers was compared statistically between the N-CWS-treated workers and the untreated controls and a significant suppression of development of cancers was noted in the N-CWS-treated workers. Thus, it was concluded that the administration of N-CWS could prevent cancer development in humans.     

Production of L-tartaric acid by immobilized bacterial cells Nocardia tartaricans

Nocardia tartaricans converted sodium cis-epoxysuccinate to L-tartrate. The highest cis-epoxysuccinate hydrolase activity (37.7 U mg^–1) was obtained with 0.02% (w/v) sodium deoxycholate, but this inactivated the cells. Immobilized N. tartaricans in pectate gel showed higher enzyme activity (51 U mg ^–1) compare to the free cells (8.9 U mg ^–1). After 450 days, the immobilized cells still possessed 0.65 U mg ^–1, i.e. 30% of the initial enzyme activity.     

Clinical isolates of <Emphasis Type="Italic">Nocardia brasiliensis</Emphasis> from Japan exhibit variable susceptibility to the antibiotic imipenem

Clinical isolates of Nocardia brasiliensis from Japan were classified into two groups based on their susceptibility to the carbapenem antibiotic, imipenem (IPM). Of 33 strains tested, 10 belonged to an IPM susceptible group, with MIC of from 0.25 to 2 εg/ml and a MIC₈₀ value of 1.5 εg/ml for this antibiotic. The remaining 23 strains belonged to an IPMresistant group with MIC and MIC₈₀ values of 8–16 εg/ml and >16 εg/ml, respectively. The type strain of N. brasiliensis belonged to this resistant group. Analysis of 16S rDNA genes sequences showed that the IPM susceptible group had characteristic single nucleotide substitutions at positions 103 (T), 381 (A), and 456 (A), in contrast to the IPM resistant group. This grouping, however, was not associated with their clinical manifestation.     

The biological macromolecule Nocardia rubra cell-wall skeleton as an avenue for cell-based immunotherapy

Promoting the antitumor effects of cell-based immunotherapy for clinical application remains a difficult challenge. Nocardia rubra cell-wall skeleton (N-CWS) is an immunotherapeutic agent for cancers that have been proven to possess the ability to activate immune response without showing toxicity. However, its effects on immune cells that are derived from tumor patients and cultured in vitro remain unclear. As expected, N-CWS can enhance the proliferation and viability of cytokine-induced killer (CIK) cells, dendritic cells (DCs), and natural killer (NK) cells. The maturation of DCs and specific cytotoxicity against NK cells and CIK cells were consistently promoted. The TUNEL-staining and the Annexin V/propidium iodide assay revealed that after treatment with N-CWS, the stimulated CIK/NK cells could induce DNA breaks in tumor cells. Furthermore, quantitative real-time polymerase chain reaction and western blot analysis showed upregulation of proapoptotic biomarkers (caspase-3 and caspase-9) and a downregulation of the antiapoptotic biomarker Bcl-2 in the tumor cells of the N-CWS-treated group, indicating that N-CWS could induce hepatocellular carcinoma cell apoptosis via CIK/NK cells. Finally, CIK/NK cells could notably suppress the invasion and migration of tumor cells in the presence of N-CWS. Our study provides evidence that N-CWS could significantly increase the growth of CIK cells, DCs, and NK cells, particularly due to its robust antitumor activities by inducing apoptosis, and attenuate the invasion and migration of tumor cells.     

Analysis of the expression of outer-membrane proteins in Neisseria meningitidis in iron-replete and iron-deficient media

Fusions to the beta-lactamase (bla) gene were employed to analyze the presence of localization information in the mature part of OmpC, a major pore-forming outer membrane protein in Escherichia coli K-12. Six translational ompC-bla gene fusions were constructed, the shortest of them containing only part of the ompC signal sequence and the largest approximately 90% of the sequence encoding mature OmpC protein. Export of the hybrid proteins to a non-cytoplasmic location was a prerequisite for ampicillin resistance. Localization of the hybrid proteins by cell fractionation and solid phase iodination of whole cells suggested that the exported hybrid proteins possibly interacted with the outer membrane in vivo. No specific sequence of the mature OmpC protein, however, was found to promote this interaction.     

Purification and characterization of a novel phytase from Nocardia sp. MB 36

Phytase from Nocardia sp. MB 36 was purified (9.65-fold) to homogeneity by acetone precipitation, ion exchange, and molecular sieve chromatography. Native polyacrylamide gel electrophoresis (PAGE) and zymogram analysis showed a single active protein in the purified enzyme preparation. Sodium dodecyl sulfate (SDS)-PAGE analysis showed that phytase was a monomeric protein with a molecular weight of approximately 43 kDa. Phytase exhibited activity and stability over a broad pH range (2–8) and elevated temperatures (50–80°C), and utilized several phosphate compounds as substrates. Phytase was extremely resistant to pepsin and trypsin. Various metal ions viz. Fe²⁺, Co²⁺, and Mn²⁺, and NH₄⁺, ethylenediaminetetraacetic acid or EDTA and phenylmethylsulfonyl fluoride or PMSF had no influence on activity, while Ca²⁺ and Zn²⁺ enhanced activity by 15 % and 3.58 %, respectively. SDS caused significant reduction in enzyme activity (41.8 %), while 2,3-butanedione did so moderately (15.9 %). Features of Nocardia sp. MB 36 phytase suggest a potential for animal feed applications.     

Nocardiosis in Mediterranean bivalves: First detection of Nocardia crassostreae in a new host Mytilus galloprovincialis and in Ostrea edulis from the Gulf of Naples (Italy)

In this work M. galloprovincialis and O. edulis specimens were surveyed for a pathological study in the Gulf of Naples (Mediterranean sea, Campania Region, southern Italy). Clusters of Nocardia sp.-like cells were observed in histological slides. PCR amplification, sequencing and in situ hybridization were carried out in order to corroborate Nocardia species identification for both hosts. Blast results showed a 99% of maximum identity with Nocardia crassostreae sequences in Genbank. This is the first report of N. crassostreae in the new host M. galloprovincialis and, in a new area, the Mediterranean Sea.     

Biodegradation of Aliphatic and Aromatic Hydrocarbons by Nocardia sp. H17-1

We investigated the biodegradation of hydrocarbon components by Nocardia sp. H17-1 and the catabolic genes involved in the degradation pathways of both aliphatic and aromatic hydrocarbons. After 6 days of incubation, the aliphatic and aromatic fractions separated from Arabian light oil were degraded 99.0 ± 0.1% and 23.8 ± 0.8%, respectively. Detection of the catabolic genes involved in the hydrocarbon degradation indicated that H17-1 possessed the alkB genes for n-alkane biodegradation and catA gene for catechol 1,2-dioxygenase. However, H17-1 had neither the C23O gene for the degradation of aromatic hydrocarbons nor the catechol 2,3-dioxygenase activity. The investigation of the genes involved in the biodegradation of hydrocarbons supported the low degradation activity of H17-1 on the aromatic fractions.     

诺卡氏菌烈性噬菌体vB_Ncarnea_KYD1的分离纯化与基因组分析

【背景】诺卡氏菌是一种广泛分布的好氧放线菌,可在人体内引起局部或播散性感染,尤其是在免疫功能低下的个体中。诺卡氏菌感染在临床上较难鉴定,而且不断有新型诺卡氏菌种被发现。不同类型、不同地域的诺卡氏菌具有流行差异和抗生素敏感性差异,阻碍了适当治疗方式的选择。利用病灶处的宿主菌分离得到噬菌体来控制诺卡氏菌感染的这种方法在近年来受到了各界的关注。【目的】尝试从环境中分离出能够用于临床治疗的针对诺卡氏菌的烈性噬菌体,并研究其基因组学特征。【方法】利用双层平板法分离得到目标噬菌体,观察其噬菌斑形态,并对噬菌体进行分离纯化,在透射电镜下鉴定其特征。提取噬菌体DNA进行全基因组测序与注释,并与数据库内已知噬菌体基因组进行比较,同时构建系统进化树以进行遗传进化分析。【结果】本文以肉色诺卡氏菌为宿主,从环境样本中分离出一株烈性噬菌体vB_Ncarnea_KYD1,在双层平板上可形成直径<2 mm的透亮均匀的噬菌斑。基因组分析表明,vB_Ncarnea_KYD1DNA为环状,大小为66 621 bp,共发现102个蛋白质编码区(coding sequence,CDS)及一个tRNA-Ser编码序列。透射电镜观察与系统进化树综合分析可以确定,vB_Ncarnea_KYD1为长尾噬菌体科的一个新属。其在进化过程中经历了复杂的基因重组过程。暂未发现毒力因子相关基因与抗性基因,具备实用价值。【结论】从环境水体中分离出一株烈性肉色诺卡氏菌噬菌体vB_Ncarnea_KYD1,通过电镜观察与基因组分析可知,此株噬菌体为长尾噬菌体,基因组中暂未发现不利于临床应用的相关基因,是一株相对安全的烈性诺卡氏菌噬菌体。研究结果丰富了国内噬菌体资源库,并为后续诺卡氏菌感染疾病的治疗提供支持。