Dissemination of blaOXA-23 in Acinetobacter spp. in China: main roles of conjugative plasmid pAZJ221 and transposon Tn2009.

Production of the OXA-23 carbapenemase is the most common reason for the increasing carbapenem resistance in Acinetobacter spp. This study was conducted to reveal the genetic basis of blaOXA-23 dissemination in Acinetobacter spp. in China. A total of 63 carbapenem-resistant OXA-23-producing Acinetobacter sp. isolates, representing different backgrounds, were selected from 28 hospitals in 18 provinces for this study. Generally, two patterns of plasmids carrying blaOXA-23 were detected according to S1-nuclease pulsed-field gel electrophoresis and Southern blot hybridization. A ca. 78-kb plasmid, designated pAZJ221, was found in 23 Acinetobacter baumannii and three Acinetobacter nosocomialis isolates, while a novel ca. 50-kb plasmid was carried by only two other A. baumannii isolates. Three of these isolates had an additional copy of blaOXA-23 on the chromosome. Transformation of the two plasmids succeeded, but only pAZJ221 was conjugative. Plasmid pAZJ221 was sequenced completely and found to carry no previously known resistance genes except blaOXA-23. The blaOXA-23 gene of the remaining 35 isolates was chromosome borne. The blaOXA-23 genetic environments were correlated with Tn2009 in 57 isolates, Tn2008 in 5 isolates, and Tn2006 in 1 isolate. The MIC values for the carbapenems with these isolates were not significantly associated with the genomic locations or the copy numbers of blaOXA-23. Overall, these observations suggest that the plasmid pAZJ221 and Tn2009 have effectively contributed to the wide dissemination of blaOXA-23 in Acinetobacter spp. in China and that horizontal gene transfer may play an important role in dissemination of the blaOXA-23 gene.

Effects of Supplementing Tributyrin on Meat Quality Characteristics of Foreshank Muscle of Weaned Small-Tailed Han Sheep Lambs.

This experiment aimed to evaluate the effects of supplementing tributyrin (TB) on the meat quality characteristics of foreshank muscle of weaned lambs. A total of 30 healthy weaned Small-Tailed Han female lambs with body weights ranging from 23.4 to 31.6 kg were selected and randomly divided into five groups, and each group consisted of 6 lambs. The control group was fed a basic total mixed ration, while other groups were fed the same ration supplemented with 0.5, 1.0, 2.0, and 4.0 g/kg TB, respectively. The experiment lasted 75 d, including 15 d of adaptation. Foreshank muscle obtained at the same position from each lamb was used for chemical analysis and sensory evaluation. The results showed that supplementing TB increased the muscle contents of ether extract (p = 0.029), calcium (p = 0.030), phosphorus (p = 0.007), and intermuscular fat length (p = 0.022). Besides, TB increased the muscle pH (p = 0.001) and redness (p < 0.001) but reduced the lightness (p < 0.001), drip loss (p = 0.029), cooking loss (p < 0.001), shear force (p = 0.001), hardness (p < 0.001), cohesiveness (p < 0.001), springiness (p < 0.001), gumminess (p < 0.001), and chewiness (p < 0.001). In addition, TB increased the muscle content of inosine-5'-phosphate (p = 0.004). Most importantly, TB increased the muscle contents of essential amino acids (p < 0.001). Furthermore, TB increased the saturated fatty acids level in the muscle (p < 0.001) while decreasing the unsaturated fatty acids content (p < 0.001). In conclusion, supplementing TB could influence the meat quality of foreshank muscle of weaned lambs by modifying the amino acid and fatty acid levels.

Sublingual immunotherapy for experimental allergic conjunctivitis in a murine model induced by Dermatophagoides farinae allergen.

BACKGROUND: Sublingual immunotherapy (SLIT) is a clinically effective treatment in allergic conjunctivitis (AC); however, the mechanism of the underlying pharmacodynamics remains unclear. Here, we investigate the efficacy and the mechanism of a sublingually administered Dermatophagoides farinae (Der f) vaccine in a murine AC model. METHODS: A murine model of AC caused by Der f extract was developed in BALB/c mice by repeated application of allergen. Sensitized mice were SLIT treated by Der f drops and subsequently analyzed for AC symptoms, histopathological and immunological parameters. RESULTS: In this study, Der f extract successfully induced the symptoms of AC in BALB/c mice. In these sensitized mice, clinical symptoms (scratching behavior, lacrimation, conjunctival hyperemia and edema), immunological and histopathological findings (inflammatory cell infiltration) were very similar to those in human AC. SLIT treatment of sensitized mice markedly reduced the clinical and histopathological symptoms and decreased the expression levels of total immunoglobulin E (IgE), Der f-specific IgE and T helper cell 2 (Th2) cytokine interleukin-4, with a significant increase in Der f-specific IgG4 and Th1 cytokine interferon-γ. CONCLUSIONS: SLIT with Der f drops is a potentially effective means of immunotherapy for Der f-induced AC by modulating the Th2-biased allergic immune response.

A comparative analysis of the CVP structure of nonprofit teaching and for-profit non-teaching hospitals.

Due to the market turbulence facing the hospital industry, the financial viability of teaching hospitals has been severely threatened. Their missions of education, research, and patient care even strengthen this crisis. Therefore, the objective of this study is to conduct a comparative analysis of the cost, volume, and profit (CVP) structure between large nonprofit urban teaching hospitals and small for-profit rural/suburban non-teaching hospitals. The following two hypotheses were developed: (1) large nonprofit urban teaching hospitals tend to have higher fixed cost, lower variable cost, lower total revenue adjusted by case mix index (CMI), and lower return on total assets (ROA); and (2) small for-profit rural/suburban non-teaching hospitals tend to have lower fixed cost, higher variable cost, higher total revenue adjusted by CMI, and higher ROA. Using 117 teaching hospitals and 102 non-teaching hospitals selected from the Medicare Cost Report database in 2005, the results from multiple regression indicated that large nonprofit teaching hospitals located in urban areas are more likely to have higher fixed cost and lower variable cost. While such cost structure doesn't necessarily affect their total revenue adjusted by CMI, it does lead to a lower return on hospitals' total assets. The results support our hypotheses in terms of fixed cost percentage, variable cost percentage, and ROA, but not total revenue adjusted by CMI. The results suggest that cost structure is significantly associated with hospitals' performance. Also, as teaching hospitals' portfolios of services and programs increase (e.g., provision of uncompensated care to Medicare and Medicaid patients and doing research), it becomes strategically necessary and critical to manage the allocation of resources or investments into the fixed capital that supports the business.

Effect of Dietary Forage: Concentrate Ratio on Pre-Caecal and Total Digestive Tract Digestibility of Diverse Feedstuffs in Donkeys as Measured by the Mobile Nylon Bag Technique.

The domestic donkey is a unique equid species with specific nutritional requirements, however, limited laboratory evidences are available to address the digestibility contribution of the prececum in relation to the total digestive tract. In the present study, six caecum-fistulated adult female Xinjiang donkeys served as the experimental animals in a 3 × 3 Latin square design, and mobile nylon bag technique was applied to determine the effect of dietary F:C ratio on pre-caececum and total digestive tract digestibility of rice straw, alfalfa hay, corn meal, and soybean meal. The dietary treatments included: (1) HF, a high-fiber ration (F:C = 80:20), (2) MF, a medium-fiber ration (F:C = 55:45), and (3), LF, a low-fiber ration (F:C = 35:65). The experiment consisted of three consecutive Latin square periods, and each period lasted 25 days. In each period, the animals were administrated naso-gastrically nylon bags (38 µm pore size) containing aforementioned feeds. After 1.5 h intubation, the bags were checked once an hour and collected at the ileo-caecal junction (small intestine bag, D1) and in the feces (fecal bag, D2). Regardless whatever feeds were introduced, the percentage of bag collected (BC) was quadratically (HF) or linearly (MF and LF) increased against different fixed bag collection time. The highest BC occurred in MF (73.8%), but no significant difference was observed between HF (62.3%) and LF (50.8%). The lowest mean bag retention time was observed in HF (2.7 h), and no significant difference occurred between MF (4.6 h) and LF (5.0 h) diets. For each feed, D1 and D2 digestibility for DM, CP, NDF, and ADF did not differ among three dietary treatments (p > 0.05). Regardless of whatever diets were fed to the donkeys, D2 digestibility for DM and CP among the feeds ranked as: soybean meal > corn meal > alfalfa hay > rice straw (p < 0.01). D1 digestibility for DM among the feeds ranked as: corn meal > soybean meal > alfalfa hay > rice straw (p < 0.01). D1 digestibility for CP among the feeds ranked as: soybean meal > corn meal > alfalfa hay > rice straw (p < 0.01). In summary, dietary forage: concentrate ratio did not affect pre-caecal or total tract nutrient digestibility. The fiber level in feeds was the main limiting factor to affect the digestibility contribution of the pre-caecum in relation to the total digestive tract.

Effect of Dietary Forage/Concentrate Ratio on Nutrient Digestion and Energy and Protein Metabolism in Adult Donkeys.

The domestic donkey is a unique equid species with specific nutritional requirements; however, limited feeding studies have been addressed so far to understand nutrient digestion and metabolism in donkeys. In the present study, six adult female Xinjiang donkeys (180 ± 10 kg live weight) were applied in a 3 × 3 Latin square design to investigate the effect of the forage/concentrate ratio (F/C) in three experimental diets on N and energy balance within 12 weeks. Rice straw and alfalfa hay were chosen as forage ingredients, and the diets included the following: (1) a high-fiber (HF) ration (F/C = 80:20), (2) a medium-fiber (MF) ration (F/C = 55:45), and (3) a low-fiber (LF) ration (35:45). After the fixed amount of diets were daily allowed to the animals, total feces and urine were collected to determine total tract digestibility, N and energy balance. As a result, dry matter intake did not differ among the three diet groups. Decreasing the dietary F/C significantly promoted protein digestibility and decreased fiber digestibility. The N and energy balance analysis showed that increasing the F/C remarkably (p < 0.01) decreased N retention through the increase in N excretion in urine, and the highest N loss relative to N intake was observed in MF. Meanwhile, decreasing the F/C linearly increased the conversion efficiency of digestible energy to metabolizable energy. Taken together, the results obtained in the present study implicated that the dietary forage level should not be less than 55% to maintain greater N and energy utilization in feeding practice, otherwise, a donkey's N utilization might be highly discounted.

Differential effects of dihydropyridine calcium antagonists on doxorubicin-induced nephrotoxicity in rats.

The aim of this study was to compare the roles of dihydropyridine calcium antagonists nifedipine, nitrendipine, amlodipine on doxorubicin (DXR)-induced nephrotoxicity in rats using biochemical, histopathological and immunohistochemical approaches. Male Sprague-Dawley rats were randomly divided into five experimental groups: control; DXR; DXR+nifedipine (15 mg/kg); DXR+nitrendipine (10 mg/kg); DXR+amlodipine (5 mg/kg). Results showed that treatment with DXR alone caused significant changes in the levels of urinary protein, serum creatinine (SCr), and blood urea nitrogen (BUN). Co-administration with amlodipine effectively reversed the effect of DXR on these parameters. In contrast, nifedipine and nitrendipine either had no effect or worsened DXR induced changes in the levels of urinary protein, SCr and BUN. Furthermore, DXR treatment caused significant increases in the levels of malondialdehyde (MDA), nitric oxide (NO), nitric oxide synthase (NOS) and significant decreases in the levels of reduced glutathione (GSH), glutathione-S-transferase (GST), and superoxide dismutase (SOD). These effects were significantly reduced by co-administration with amlodipine but not affected by nifedipine and worsened by nitrendipine. In addition to the biochemical changes, histopathological studies showed that DXR caused significant structural damages in the kidneys. Glomerular cell apoptosis, a decrease in Bcl-2 expression and an increase in Bax expression were observed in all rats treated with DXR. Co-administration with amlodipine effectively reversed the effect of DXR while nifedipine and nitrendipine had no effect. In conclusion, this study clearly indicated that amlodipine protected against DXR-induced nephrotoxicity while nifedipine and nitrendipine had no effect.

Emergence of cfr-harbouring coagulase-negative staphylococci among patients receiving linezolid therapy in two hospitals in China.

This study reports on the emergence of cfr-harbouring coagulase-negative staphylococci (CoNS) among patients who received linezolid therapy in two hospitals in Hangzhou, China. The mechanisms of resistance and transmission were analysed for these resistant isolates. Eight Staphylococcus capitis isolates, one Staphylococcus epidermidis isolate and one Staphylococcus hominis isolate, obtained from patients who had received linezolid therapy in two hospitals in Hangzhou, China, were confirmed as linezolid resistant, with MICs ranging from 8 to >256 mg l(-1). The linezolid usage data of the ten patients before isolation of the linezolid-resistant CoNS were collected. PFGE analysis showed that the eight S. capitis isolates from the two hospitals belonged to the same clone. Nine of the linezolid-resistant CoNS isolates carried the cfr gene, which was located on plasmids of a similar size. A 5.3 kb fragment containing the cfr gene, revealing 99 % identity to the sequence of the cfr-harbouring plasmid pSS-01 reported previously, was determined by PCR mapping for all cfr-positive isolates, and the cfr gene was flanked by two copies of IS256-like elements. Thus, these results document the emergence of linezolid-resistant CoNS isolates carrying the cfr gene in Hangzhou, China. Effective nosocomial infection control strategies and the judicious use of antibiotics will be required to prevent further spread of this resistance mechanism.