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1.
Antifungal susceptibility testing of Candida against fluconazole has been standardized by both the Clinical and Laboratory Standards Institute (CLSI) and the European Committee on Antimicrobial Susceptibility Testing (EUCAST). Both CLSI and EUCAST have developed clinical breakpoint (CBP) criteria for fluconazole, but these differ in both magnitude and target species. Studies using the EUCAST method have also defined wild-type minimum inhibitory concentration (MIC) distributions and epidemiologic cutoff values (ECVs or ECOFFs) for the common species of Candida. The ECVs serve as a sensitive means of discriminating wild-type strains from those with acquired resistance mechanisms and include MICs of 1 μg/mL for C. albicans, 2 μg/mL for C. tropicalis and C. parapsilosis, 32 μg/mL for C. glabrata, and 128 μg/mL for C. krusei. Because the CLSI CBPs may be too insensitive to detect emerging resistance among strains of C. albicans, C. tropicalis, and C. parapsilosis, and bisect the WT MIC distribution of C. glabrata, we sought to establish the wild-type MIC distribution and ECVs for fluconazole and Candida spp. The establishment of the wild-type MIC distributions and ECVs for fluconazole using CLSI methods will be useful in resistance surveillance and may prove to be an important step in the development of species-specific CBPs for this important antifungal agent.  相似文献   

2.
Failure to respond to antifungal therapy could be due to in vitro resistance (intrinsic or developed during therapy) or clinical resistance. In vitro resistance is mostly due to genetic mutations (resistance mechanisms), and it is associated with high minimal inhibitory concentrations (MICs), minimal effective concentrations (MECs), and/or clinical failure. Clinical breakpoints (CBPs) and/or epidemiologic cutoff values (ECVs) are useful to detect the in vitro antifungal resistance when isolates are tested by standardized methods. ECVs are available from the Clinical and Laboratory Standards Institute (CLSI) for Candida spp. versus echinocandins (anidulafungin, caspofungin, and micafungin) and triazoles (fluconazole, posaconazole, and voriconazole). Lately, the CLSI has adjusted to species-specific CBPs for Candida spp. versus fluconazole, similar to those of the European Committee on Antimicrobial Susceptibility Testing (EUCAST), and versus echinocandins. However, the available voriconazole EUCAST and CLSI CBPs differ. In the absence of CBPs, EUCAST and CLSI assigned ECVs for various Aspergillus spp. and triazoles. This article reviews emerging resistance, laboratory detection, and clinical relevance as reported in the literature in the past 3 to 4 years.  相似文献   

3.
Candida ciferrii, which is known as an agent of superficial yeast infection and onychomycosis, has rarely been isolated as an agent of candidemia. Limited reports have suggested different patterns of antifungal sensitivity. We report a rare candidemia case caused by c.ciferrii in an 8-year-old child in which isolated candida species were resistant to amphotericin-B (MIC > 1 μg/ml), fluconazole, (MIC ≥ 64 μg/ml), caspofungin (MIC ≥ 32 μg/ml), and anidulafungin (MIC ≥ 32 μg/ml) but sensitive to voriconazole (MIC ≤ 0.12 μg/ml). As far as we aware, this was the first recorded C. ciferrii candidemia case in children.  相似文献   

4.
The U.S. Clinical and Laboratory Standards Institute (CLSI) and the European Committee of Antimicrobial Susceptibility Testing (AFST-EUCAST) have developed broth microdilution methodologies for testing yeasts and filamentous fungi (molds). The mission of these methodologies is to identify in vitro antifungal resistance, which is accomplished by the use of either clinical breakpoints (CBPs), or to a lesser degree, epidemiologic cutoff values (ECVs). The newly adjusted and species-specific CLSI CBPs for Candida spp. versus fluconazole and voriconazole have ameliorated some of the differences between the two methodologies. In the absence of CBPs for mold testing, CLSI ECVs are available for six Aspergillus species versus the triazoles, caspofungin and amphotericin B. Recently, breakpoints were developed by the EUCAST for certain Aspergillus spp. versus amphotercin B, itraconazole and posaconazole, which to some extent are comparable to ECVs. We summarize these latest accomplishments, which have made possible the harmonization of some susceptibility cutoffs, if not methodologies for some agent/species combinations.  相似文献   

5.
Denture stomatitis is often treated with antifungal agents but recurrences or new episodes are common, and certain episodes can be resistant. New triazoles, such as posaconazole and voriconazole, may represent useful alternatives for management. In vitro activities of amphotericin B, nystatin, miconazole, fluconazole, itraconazole, posaconazole and voriconazole against 150 oral Candida (101 C. albicans, 18 C. tropicalis, 12 C. glabrata, 11 C. guilliermondii, 4 C. parapsilosis, 2 Saccharomyces cerevisiae, 1 C. dubliniensis and 1 C. krusei) from 100 denture wearers were tested by the CLSI M27-A3 method. Resistant isolates were retested by Sensititre YeastOne and Etest. Most antifungal agents were very active. However, 4 C. glabrata (33.3%), 2 C. tropicalis (11.1%), 6 C. albicans (5.6%) and 1 C. krusei were resistant to itraconazole. Posaconazole was active against 143 yeast isolates (95.3%): 6 C. albicans (5.9%) and 1 C. tropicalis (5.6%) were resistant. Geometric mean MICs were 0.036 μg/ml for C. parapsilosis, 0.062 μg/ml for C. albicans, 0.085 μg/ml for C. tropicalis, 0.387 μg/ml for C. guilliermondii and 0.498 μg/ml for C. glabrata. Voriconazole was active against 148 isolates (98.7%) with geometric mean MICs ranging from 0.030 μg/ml for C. parapsilosis, 0.042 μg/ml for C. albicans, 0.048 μg/ml for C. tropicalis, 0.082 μg/ml for C. guilliermondii, to 0.137 μg/ml for C. glabrata. Only 2 C. albicans (2%) were resistant to voriconazole showing cross-resistance to other azoles. Posaconazole and voriconazole have excellent in vitro activities against all Candida isolates and could represent useful alternatives for recalcitrant or recurrent candidiasis.  相似文献   

6.
The antibacterial effects of tea polyphenols (TPP) extracted from Korean green tea (Camellia sinensis) against clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) were evaluated. Characterization of the minimal inhibitory concentration (MIC) of oxacillin for 30 S. aureus strains isolated from patients treated with oxacillin identified 13 strains with an oxacillin MIC ≥ 4 μg/mL as methicillin-resistant Staphylococcus aureus (MRSA) (range: 8 to 512 μg/mL), while 17 strains were methicillin-susceptible Staphylococcus aureus (MSSA) (range: 0.25–0.5 μg/mL). The MICs of TPP ranged from 50 to 180 μg/mL for both the MSSA and the MRSA strains. The MICs of oxacillin for each of the 13 MRSA strains were reduced between 8- and 128-fold when these strains were coincubated with sub-MIC (≤0.5× MIC) levels of TPP, demonstrating that the combination of TPP plus oxacillin was synergistic for all of the clinical MRSA isolates. Two-dimensional polyacrylamide gel electrophoresis identified 14 extracellular proteins of MRSA-13 down-regulated and 3 proteins up-regulated by exposure to TPP. These studies demonstrate that TPP can differentially stimulate the expression of various proteins in these bacteria and synergize the bactericidal activity of oxacillin for MRSA.  相似文献   

7.
Antifungal susceptibility testing of Candida has been standardized and refined and now may play an important role in managing Candida infections. Important new developments include the establishment of species-specific epidemiological cutoff values (ECVs) for the systemically active antifungal agents and both common and uncommon species of Candida. The clinical breakpoints (CBPs) for fluconazole, voriconazole, and the echinocandins have been revised to provide species-specific interpretive criteria for the six most common species that not only are predictive of clinical outcome but also provide a more sensitive means of identifying those strains with acquired or mutational resistance mechanisms. Collaborative work by the CLSI and EUCAST organizations has made major advances in the harmonization of these two international standards. The impact of the recent changes in the CBPs on commercial MIC methods does not appear to be major but additional studies with well defined resistant populations are necessary to confirm the ability of these systems to detect emerging resistance.  相似文献   

8.
The aim of this study was to determine liver and kidney concentrations of selenium in wild boars from the northwest part of Poland, depending on season of the year, age, sex, and body weight. Altogether, samples of livers and kidneys from 172 wild boars that were shot in 2005–2008 were investigated. Liver and kidney concentrations of selenium were determined using spectrofluorometric method. In all the animals studied, selenium concentration was several times lower in the liver than in the kidneys. Selenium concentration averaged 0.19 μg/g wet weight (w.w.) in the liver and 1.20 μg/g w.w. in kidneys. The present study showed that season (P ≤ 0.05), age (P ≤ 0.01), and body weight (P ≤ 0.01) have a significant effect on selenium concentration in the liver of wild boars. Liver selenium concentration was the highest in spring (0.23 μg/g w.w.) and the lowest in autumn (0.16 μg/g w.w). Young animals (up to 1 year of age) and those with the lowest body weight (up to 20 kg) were characterized by a slightly lower selenium concentration in the liver compared to older and heavier animals. No significant differences were found in organ selenium concentration between males and females. According to biochemical criteria for the diagnosis of selenium deficiency in pig liver, which were used to evaluate selenium concentration in the liver of wild boars, no individuals were found to have optimal levels. Considering that in Se deficiency higher selenium concentrations are found in kidneys than in the liver, it can be presumed that the wild boars had Se deficiency. However, this is difficult to state conclusively because there are no reference values for this species.  相似文献   

9.
The dry weight per unit biovolume of 810 single, living cells of the ubiquitous soil algae Klebsormidium flaccidum from 80 experiments were determined using a Mach–Zehnder double-beam interference microscope. Different substrates such as agarized nutrient solution, different soils, and slag heap material, different pH values, temperatures and light intensities were used and cells from both growth and stationary phase were measured. The total possible range of dry weight with respect to carbon per unit biovolume (C/ubv) values was 93–226 fg μm−3. The mean value of all data was 147 fg μm−3, which concurs with the average value as taken from literature data of several planktonic algal species and groups within the respective size range (cell volume 300–1,000 μm3). We could show that C/ubv is suitable to quantify environmental stress conditions: C/ubv values ≤140 fg μm−3 are characteristic of cells grown under optimum conditions, and values ≥160 fg μm−3 reflect quantitatively graded stress situations. We propose integrating the microscope interferometric method using K. flaccidum as a test organism into a soil test system to determine the prevailing environmental conditions.  相似文献   

10.
The Alternaria mycotoxin tenuazonic acid (TA) was quantified in fruit juices (n = 50), cereals (n = 12) and spices (n = 38) using a recently developed stable isotope dilution assay (SIDA). [13 C6,15 N]-TA was used as the internal standard. Method validation revealed low limits of detection (LODs) of 0.15 μg/kg (fruit juices), 1.0 μg/kg (cereals) and 17 μg/kg (spices). The respective limits of quantitation were about three times higher. Recovery was about 100% for all matrices. The precision (relative standard deviation of replicate analyses of naturally contaminated samples) was 4.2% (grape juice; 1.7 μg/kg), 3.5% (whole wheat flour; 36 μg/kg) and 0.9% (curry powder; 215 μg/kg). The median content of TA in the analyzed samples was 1.8 μg/kg (fruit juices), 16 μg/kg (cereals) and 500 μg/kg (spices). Positive samples amounted to 86% (fruit juices), 92% (cereals) and 87% (spices).  相似文献   

11.
Deficiencies in Cu, Se, and Zn impair one or more biochemical functions, and excess are associated with toxicity. Baseline studies on the Ghanaian population are scanty. The study was undertaken to determine whether significant rural/urban differences in the serum levels of Cu, Se, and Zn did exist. Forty males/60 females from rural and 50 males/50 females from urban Ghanaian communities were sampled. Serum Cu, Se, and Zn were determined using flame atomic absorption spectrometry. Cu level for rural and urban subjects was 997 ± 333 and 979 ± 290 μg/L, respectively (p = 0.68). However, Cu levels were significantly higher in the rural females (1,063 ± 367 μg/L) than the rural males (898 ± 249 μg/L; p = 0.0085). Se levels for rural/urban subjects were 97 ± 36 and 87 ± 31 μg/L, respectively (p = 0.03). Zn levels in the rural/urban subjects were 312 ± 218 and 150 ± 102 μg/L, respectively (p = 0.002). Additionally, Zn was significantly higher in rural females (428 ± 204 μg/L) than the urban females (166 ± 103 μg/L; p = 0.0002). Finally, Zn was significantly higher in rural females (428 ± 204 μg/L) than males (172 ± 116 μg/L; p = 0.0028). In conclusion, Cu, Se, and Zn were higher in the rural group compared to the urban group, and the generally low Zn levels were confirmed in another cohort follow-up study.  相似文献   

12.

Purpose of Review

Resistance to antifungal drugs amongst Candida species is a growing concern, and azole resistance may be emerging in Cryptococcus species. This review provides a contemporary perspective, relevant to the clinical mycology laboratory, of antifungal susceptibility testing of these fungi, focussing on the challenges of phenotypic and genotypic methodologies to detect drug resistance.

Recent Findings

Standardised CLSI and EUCAST broth microdilution (BMD) susceptibility testing methods are the benchmark to determine clinical breakpoints (CBPs) and/or epidemiological cut-off values (ECVs) MICs for Candida and Cryptococcus spp. Commercial methods may be used but caution is required when employing BMD CBPs/ECVs to interpret results. Species-specific CBPs/ECVs for Candida spp. generally correlate well with predicting likelihood of therapeutic failure or of presence of a drug resistance mechanism with the exception of the echinocandins where the presence of specific FKS gene mutations and not the MIC correlates most accurately with clinical outcome. The relationship of presence of one or more mechanisms of azole resistance and drug MICs is uncertain. Next generation sequencing technology is offering insights into the relationships between susceptibility results obtained by phenotypic and genotypic methods. For Cryptococcus spp., CBPs are not established but species- and genetic type-specific EVCs are useful for guiding therapy where clinically indicated. Isolates of genotype VGII appear to exhibit the highest MICs.

Summary

Antifungal susceptibility testing of yeasts is important to detect drug resistance. For Candida spp., MICs have clinical utility for the azoles but detecting echinocandin resistance by genotypic methods is preferred. For Cryptococcus spp., ECVs are useful in guiding therapy.
  相似文献   

13.
The purpose of the study was to determine the concentration of trace elements present in scalp hair sample of schizophrenic patients and to find out the relationship between trace elements level and nutritional status or socioeconomic factors. The study was conducted among 30 schizophrenic male patients and 30 healthy male volunteers. Patients were recruited from Bangabandhu Sheikh Mujib Medical University by random sampling. Hair trace element concentrations were determined by flame atomic absorption spectroscopy and analyzed by independent t test, Pearson’s correlation analysis, regression analysis, and analysis of variance (ANOVA). Mn, Zn, Ca, Cu, and Cd concentrations of schizophrenic patients were 3.8 ± 2.31 μg/gm, 171.6 ± 59.04 μg/gm, 396.23 ± 157.83 μg/gm, 15.40 ± 5.68 μg/gm, and 1.14 ± 0.89 μg/gm of hair sample, while those of control subjects were 4.4 ± 2.32 μg/gm, 199.16 ± 27.85 μg/gm, 620.9 ± 181.55 μg/gm, 12.23 ± 4.56 μg/gm, and 0.47 ± 0.32 μg/gm of hair sample, respectively. The hair concentration of Zn and Ca decreased significantly (p = 0.024; p = 0.000, respectively) and the concentration of Cu and Cd increased significantly (p = 0.021; p = 0.000, respectively) in schizophrenic patients while the concentration of Mn (p = 0.321) remain unchanged. Socioeconomic data reveals that most of the patients were poor, middle-aged and divorced. Mean body mass indices (BMIs) of the control group (22.26 ± 1.91 kg/m2) and the patient group (20.42 ± 3.16 kg/m2) were within the normal range (18.5−25.0 kg/m2). Pearson’s correlation analysis suggested that only Ca concentration of patients had a significant positive correlation with the BMI (r = 0.597; p = 0.000) which was further justified from the regression analysis (R 2 = 44%; t = 3.59; p = 0.002) and one-way ANOVA test (F = 3.62; p = 0.015). A significant decrease in the hair concentration of Zn and Ca as well as a significant increase in the hair concentration of Cu and Cd in schizophrenic patients than that of its control group was observed which may provide prognostic tool for the diagnosis and treatment of this disease. However, further work with larger population is suggested to examine the exact correlation between trace element level and the degree of disorder.  相似文献   

14.
Candida-associated denture stomatitis has a high rate of recurrence. Candida biofilms formed on denture acrylic are more resistant to antifungals than planktonic yeasts. Histatins, a family of basic peptides secreted by the major salivary glands in humans, especially histatin 5, possess significant antifungal properties. We examined antifungal activities of histatin 5 against planktonic or biofilm Candida albicans and Candida glabrata. Candida biofilms were developed on poly(methyl methacrylate) discs and treated with histatin 5 (0.01–100 μM) or fluconazole (1–200 μM). The metabolic activity of the biofilms was measured by the XTT reduction assay. The fungicidal activity of histatin 5 against planktonic Candida was tested by microdilution plate assay. Biofilm and planktonic C. albicans GDH18, UTR-14 and 6122/06 were highly susceptible to histatin 5, with 50% RMA (concentration of the agent causing 50% reduction in the metabolic activity; biofilm) of 4.6 ± 2.2, 6.9 ± 3.7 and 1.7 ± 1.5 μM, and IC50 (planktonic cells) of 3.0 ± 0.5, 2.6 ± 0.1 and 4.8 ± 0.5, respectively. Biofilms of C. glabrata GDH1407 and 6115/06 were less susceptible to histatin 5, with 50% RMA of 31.2 ± 4.8 and 62.5 ± 0.7 μM, respectively. Planktonic C. glabrata was insensitive to histatin 5 (IC50 > 100 μM). Biofilm-associated Candida was highly resistant to fluconazole in the range 1–200 μM; e.g. at 100 μM only ~20% inhibition was observed for C. albicans, and ~30% inhibition for C. glabrata. These results indicate that histatin 5 exhibits antifungal activity against biofilms of C. albicans and C. glabrata developed on denture acrylic. C. glabrata is significantly less sensitive to histatin 5 than C. albicans.  相似文献   

15.
There are few studies on Tibetan youth’s blood lead level (BLL) and environmental pollution in China. The objective of this project was to conduct a preliminary investigation on the blood lead level of Tibetan youth. Chinese Han youth’s BLL was also investigated as a control group. A total of 846 Tibetan youth and 785 Han youth were tested for BLL from September to October in 2007. Both of the mean BLL (6.4 μg/dL) and the frequency of high BLL (≥10 μg/dL) of Tibetan youth (7.7%, 65 of 846) were lower than those of Han youth (6.7 μg/dL; 13.2%, 104 of 785). But they are still higher compared with the BLL of youth in developed countries (1.1 μg/dL; USA 2005 census). The BLL of boys was significantly higher than that of girls, both in Tibetan and Han youth (p = 0.033 and p = 0.000, respectively). The study shows that Chinese Han and Tibetan youth's lead poisoning prevention and treatment lags far behind developed countries. These findings have implications for environmental health policy.  相似文献   

16.
Tecoma stans is a tropical plant from the Americas. Antioxidant activity and both phenolic compound and flavonoid total content were determined for callus tissue of T. stans cultured in either a set photoperiod or in darkness. Callus lines from three explant types (hypocotyls, stem, and leaf) were established on B5 culture medium supplemented with 0.5 μM 2,4-D and 5.0 μM kinetin. While leaf-derived callus grew slower under a 16-h photoperiod (specific growth rate, μ = 0.179 d−1, t D = 3.9 d) than in darkness (μ = 0.236 d−1, t D = 2.9 d), it accumulated the highest amount (p < 0.05) of both phenolics (86.6 ± 0.01 mg gallic acid equivalents/g) and flavonoids (339.6 ± 0.06 mg catechin equivalents/g). Similarly, antioxidant activity was significantly higher (p < 0.05) when callus was cultured in period light than when grown in extended darkness. Antioxidant activity measured with a 2,20-azinobis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS)-based assay was 350.5 ± 15.8 mmol Trolox/g extract for callus cultured under a defined photoperiod compared to 129.1 ± 7.5 mmol Trolox/g extract from callus cultured in darkness. Content of phenolic compounds and flavonoids was in agreement with a better antioxidant power (EC50 = 450 μg extract/mg 1,1-diphenyl-2-picrylhydrazyl) and antiradical efficiency. Results of the present study show that calli of T. stans are a source of compounds with antioxidant activity that is favored by culture under a set photoperiod.  相似文献   

17.
The purpose of this study was to develop and validate a rapid, sensitive, and specific reversed-phase high-performance liquid chromatography method for the quantitative determination of native tenofovir (TNF) for various applications. Different analytical performance parameters such as linearity, precision, accuracy, limit of quantification (LOQ), limit of detection (LOD), and robustness were determined according to International Conference on Harmonization (ICH) guidelines. A Bridge™ C18 column (150 × 4.6 mm, 5 μm) was used as stationary phase. The retention time of TNF was 1.54 ± 0.03 min (n = 6). The assay was linear over the concentration range of 0.1–10 μg/mL. The proposed method was sensitive with LOD and LOQ values equal to 50 and 100 ng/mL, respectively. The method was accurate with percent mean recovery from 95.41% to 102.90% and precise as percent RSD (relative standard deviation) values for intra-day, and inter-day precision were less than 2%. This method was utilized for the estimation of molar absorptivity of TNF at 259 nm (ε 259 = 12,518 L/mol/cm), calculated from linear regression analysis. The method was applied for determination of percentage of encapsulation efficiency ( 22.93 ± 0.04%), drug loading (12.25 ± 1.03%), in vitro drug release profile in the presence of enzyme (43% release in the first 3 h) and purification analysis of hyaluronic acid-based nanomedicine.  相似文献   

18.
The sialic acid/glycosaminoglycan ratio was determined in 35 coronary artery ectasia patients and 35 control subjects to determine the possible role of fluoride in the etiology of the disease. The coronary artery ectasia patients and controls were selected from subjects who underwent coronary angiography. The mean serum sialic acid level was significantly lower in patients with coronary artery ectasia (CAE) than in controls (340.3 ± 28.6 vs. 427.0 ± 15.9 μg/mL, respectively; p < 0.001). The mean serum glycosaminoglycan level was significantly higher in patients with CAE than in controls (5,013.1 ± 158.6 vs. 3,833.6 ± 237.1 μg/mL, respectively; p < 0.001). The sialic acid/glycosaminoglycan ratio in patients with coronary artery ectasia was significantly lower than in controls (0.068 ± 0.007 vs. 0.111 ± 0.005; p < 0.001). There was more than 38.7% reduction in this ratio in patients with CAE when compared with controls. We demonstrated that chronic fluoride exposure has an important role in pathogenesis of coronary artery ectasia.  相似文献   

19.
The aim of this study was to investigate the respiratory function disorders that could be related to dust exposure during the production of copper mine in copper mineworkers (CMWs). The study included 75 male CMWs (mean age, 32.0 ± 7.1 years, 58.6% smokers) and 75 male age- and smoking status-matched healthy control subjects. Serum Cu level was significantly higher in the CMW group (0.80 ± 0.62 μg/ml) than the control group (0.60 ± 0.39 μg/ml) (p = 0.017). Significant negative correlations were found between serum Cu level and forced expiratory volume in first second (r = −0.600; p < 0.001) and between serum Cu level and forced vital capacity (r = −0.593; p = <0.001) in CMWs. Serum Cu level was significantly higher in the restrictive type pulmonary function disorders group (1.36 ± 0.62 μg/ml) than obstructive type (0.90 ± 0.55 μg/ml) and normal pulmonary function pattern group (0.53 ± 0.43 μg/ml) (p < 0.001). Patients with radiological parenchymal abnormalities had significantly higher serum copper levels than those without abnormalities (1.53 ± 0.52 vs. 0.71 ± 0.52 μg/ml, respectively; p = 0.002). In conclusion, result of the study has shown a negative association between pulmonary functions disorders and radiological abnormalities and serum Cu levels in CMWs.  相似文献   

20.
This study was conducted to determine the effects of dietary supplementation with Cr nicotinate and Cr chloride and their optimum inclusion rate on performance, carcass traits, meat oxidative stability, serum metabolites, hematological parameters, and liver chromium concentration in heat-stressed broilers. A total number of 420, 1-day-old male broiler chicks were randomly assigned to seven treatments with four replicates of 15 chicks. The dietary treatments consisted of the basal diet supplemented with 0 (control), 500, 1,000, and 1,500 μg/kg Cr in the form of Cr nicotinate and Cr chloride. Chicks were raised for 6 weeks in heat stress condition (33 ± 2°C). Supplements of organic and inorganic Cr particularly at 1,500 μg/kg incorporation increased feed consumption (P < 0.05) and body mass gain of broilers (P < 0.01). Cr supplementation increased carcass yield and decreased abdominal fat (P < 0.01). Supplementation of 1,500 μg/kg Cr nicotinate (P < 0.05) enhanced liver Cr concentration. Storage time increased lipid oxidation of meat (P < 0.01). Cr decreased lipid oxidation of breast and thigh muscles over 2 (P < 0.01) or 6 (P < 0.05) days of storage time. Birds fed 1,500 μg/kg Cr nicotinate, had lower concentration of serum glucose and triglyceride at 21 days (P < 0.05). Hematological parameters tested at 21 and 42 days, were not influenced. The results suggested that dietary Cr supplementation regardless of its source have a positive effect on productive, and carcass traits, also enhances oxidative stability of refrigerated meat in broilers reared under heat stress conditions.  相似文献   

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