The Incidence of R Factors in Bordetella bronchiseptica Isolated from Pigs

Bordetella bronchiseptica strains isolated from the nasal cavities of young pigs in Japan from 1969 to 1972 were surveyed for drug resistance and distribution of R factors. Of 304 strains examined, 71 (23%) were resistant to either one or more of following three drugs, streptomycin (SM), sulfadimethoxine (SA), and aminobenzyl penicillin (APC). Triple (SM.SA.APC)-resistance was most frequent among these resistant strains. Strains of double (SM. SA)- or single (SM)- and (SA)-resistance were also isolated, but were very few in numbers. Of the 71 drug-resistant strains, 61 (86%) were found to carry R factors which were capable of conjugal transfer. All of these R factors had the triple (SM.SA.APC)-resistant markers and were identified as fi^– (no fertility inhibition) type. The (SM.SA.APC)-resistant strains carrying R factors had been isolated from pigs reared on various farms in different districts, and consequently the prevalence of B. bronchiseptica strains carrying R factors was considered to be relatively wide-spread in young pigs.     

Purification and Properties of a Pectin trans-Eliminase in Erwin aroideae Formed in the Presence of Nalidixic Acid

A strain of Erwinia aroideae produces a remarkable amount of pectolytic enzyme when the organism was induced by nalidixic acid for the bacteriocin production. This pectolytic enzyme was purified approximately 60-fold from the induced medium by carboxymethyl-cellulose and Sephadex G–75 gel column chromatographies after batchwise treatment with carboxymethyl- and diethylaminoethyl-celluloses. The purified enzyme was almost homogeneous on sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis, a molecular weight of about 28,000 to 32,000 was determined for this enzyme. The optimum pH of the enzyme activity was about 8.0 to 8.2. The purified enzyme produced reaction products from pectin and methoxylated pectic acid which had a strong absorption at 235 nm indicating a trans-eliminase reaction. Pectin or pectic acid with higher methoxyl content was a good substrate for this enzyme, while no significant activity was observed when pectic acid was a substrate. The limit of degradation of pectin and pectic acid with higher methoxyl content (90% esterified) by the enzyme were 6.5% and 43%, respectively. It was concluded that the enzyme is a new endo-pectin trans-eliminase from bacterial origin.     

Are Additional Trace Elements Necessary in Total Parenteral Nutrition for Patients with Esophageal Cancer Receiving Cisplatin-Based Chemotherapy?

It is known that cisplatin induces the excretion of zinc from the urine and thereby reduces its serum concentration. However, the fluctuation of these trace elements during or after cisplatin-based chemotherapy has not been evaluated. To answer this question, we performed a clinical study in esophageal cancer patients undergoing cisplatin-based chemotherapy. Eighteen patients with esophageal cancer who were not able to swallow food or water orally due to complete stenosis of the esophagus were evaluated. The patients were divided into a control group [total parenteral nutrition (TPN) alone for 28?days, ten cases] and an intervention group (TPN with additional trace elements for 28?days, eight cases). The serum concentrations of zinc, iron, copper, manganese, triiodothyronin (T3), and thyroxin (T4), as alternative indicators of iodine, were measured on days?0, 14, and 28 of treatment, and statistically analyzed on day?28. In the control group, the serum concentration of copper was significantly decreased from 135.4 (day?0) to 122.1???g/ml (day?14), and finally to 110.6???g/ml (day?28, p?=?0.015). The concentration of manganese was also significantly decreased from 1.34 (day?0) to 1.17???g/ml (day?14) and finally to 1.20 (day?28, p?=?0.049). The levels of zinc, iron, T3, and T4 were not significantly changed. In the intervention group, the supplementation with trace elements successfully prevented these decreases in their concentrations. TPN with supplementary trace elements is preferable and recommended for patients who are undergoing chemotherapy in order to maintain the patients?? nutrient homeostasis.     

Bacterial Classification of Fish-Pathogenic Mycobacterium Species by Multigene Phylogenetic Analyses and MALDI Biotyper Identification System

Mycobacterium marinum is difficult to distinguish from other species of Mycobacterium isolated from fish using biochemical methods. Here, we used genetic and proteomic analyses to distinguish three Mycobacterium strains: M. marinum strains MB2 and Europe were isolated from tropical and marine fish in Thailand and Europe, and Mycobacterium sp. 012931 strain was isolated from yellowtail in Japan. In phylogenetic trees based on gyrB, rpoB, and Ag85B genes, Mycobacterium sp. 012931 clustered with M. marinum strains MB2 and Europe, but in trees based on 16S rRNA, hsp65, and Ag85A genes Mycobacterium sp. 012931 did not cluster with the other strains. In proteomic analyses using a Bruker matrix-assisted laser desorption ionization Biotyper, the mass profile of Mycobacterium sp. 012931 differed from the mass profiles of the other two fish M. marinum strains. Therefore, Mycobacterium sp. 012931 is similar to M. marinum but is not the same, suggesting that it could be a subspecies of M. marinum.     

Gingival Fibroblasts as a Promising Source of Induced Pluripotent Stem Cells

Background

Induced pluripotent stem (iPS) cells efficiently generated from accessible tissues have the potential for clinical applications. Oral gingiva, which is often resected during general dental treatments and treated as biomedical waste, is an easily obtainable tissue, and cells can be isolated from patients with minimal discomfort.

Methodology/Principal Findings

We herein demonstrate iPS cell generation from adult wild-type mouse gingival fibroblasts (GFs) via introduction of four factors (Oct3/4, Sox2, Klf4 and c-Myc; GF-iPS-4F cells) or three factors (the same as GF-iPS-4F cells, but without the c-Myc oncogene; GF-iPS-3F cells) without drug selection. iPS cells were also generated from primary human gingival fibroblasts via four-factor transduction. These cells exhibited the morphology and growth properties of embryonic stem (ES) cells and expressed ES cell marker genes, with a decreased CpG methylation ratio in promoter regions of Nanog and Oct3/4. Additionally, teratoma formation assays showed ES cell-like derivation of cells and tissues representative of all three germ layers. In comparison to mouse GF-iPS-4F cells, GF-iPS-3F cells showed consistently more ES cell-like characteristics in terms of DNA methylation status and gene expression, although the reprogramming process was substantially delayed and the overall efficiency was also reduced. When transplanted into blastocysts, GF-iPS-3F cells gave rise to chimeras and contributed to the development of the germline. Notably, the four-factor reprogramming efficiency of mouse GFs was more than 7-fold higher than that of fibroblasts from tail-tips, possibly because of their high proliferative capacity.

Conclusions/Significance

These results suggest that GFs from the easily obtainable gingival tissues can be readily reprogrammed into iPS cells, thus making them a promising cell source for investigating the basis of cellular reprogramming and pluripotency for future clinical applications. In addition, high-quality iPS cells were generated from mouse GFs without Myc transduction or a specific system for reprogrammed cell selection.