Genome-wide analyses of member identification, expression pattern, and protein-protein interaction of EPF/EPFL gene family in Gossypium.

BACKGROUND: Epidermal patterning factor / -like (EPF/EPFL) gene family encodes a class of cysteine-rich secretory peptides, which are widelyfound in terrestrial plants.Multiple studies has indicated that EPF/EPFLs might play significant roles in coordinating plant development and growth, especially as the morphogenesis processes of stoma, awn, stamen, and fruit skin. However, few research on EPF/EPFL gene family was reported in Gossypium. RESULTS: We separately identified 20 G. raimondii, 24 G. arboreum, 44 G. hirsutum, and 44 G. barbadense EPF/EPFL genes in the 4 representative cotton species, which were divided into four clades together with 11 Arabidopsis thaliana, 13 Oryza sativa, and 17 Selaginella moellendorffii ones based on their evolutionary relationships. The similar gene structure and common motifs indicated the high conservation among the EPF/EPFL members, while the uneven distribution in chromosomes implied the variability during the long-term evolutionary process. Hundreds of collinearity relationships were identified from the pairwise comparisons of intraspecifc and interspecific genomes, which illustrated gene duplication might contribute to the expansion of cotton EPF/EPFL gene family. A total of 15 kinds of cis-regulatory elements were predicted in the promoter regions, and divided into three major categories relevant to the biological processes of development and growth, plant hormone response, and abiotic stress response. Having performing the expression pattern analyses with the basic of the published RNA-seq data, we found most of GhEPF/EPFL and GbEPF/EPFL genes presented the relatively low expression levels among the 9 tissues or organs, while showed more dramatically different responses to high/low temperature and salt or drought stresses. Combined with transcriptome data of developing ovules and fibers and quantitative Real-time PCR results (qRT-PCR) of 15 highly expressed GhEPF/EPFL genes, it could be deduced that the cotton EPF/EPFL genes were closely related with fiber development. Additionally, the networks of protein-protein interacting among EPF/EPFLs concentrated on the cores of GhEPF1 and GhEPF7, and thosefunctional enrichment analyses indicated that most of EPF/EPFLs participate in the GO (Gene Ontology) terms of stomatal development and plant epidermis development, and the KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways of DNA or base excision repair. CONCLUSION: Totally, 132 EPF/EPFL genes were identified for the first time in cotton, whose bioinformatic analyses of cis-regulatory elements and expression patterns combined with qRT-PCR experiments to prove the potential functions in the biological processes of plant growth and responding to abiotic stresses, specifically in the fiber development. These results not only provide comprehensive and valuable information for cotton EPF/EPFL gene family, but also lay solid foundation for screening candidate EPF/EPFL genes in further cotton breeding.

Genomic and co-expression network analyses reveal candidate genes for oil accumulation based on an introgression population in Upland cotton (Gossypium hirsutum).

KEY MESSAGE: Integrated QTL mapping and WGCNA condense the potential gene regulatory network involved in oil accumulation. A glycosyl hydrolases gene (GhHSD1) for oil biosynthesis was confirmed in Arabidopsis, which will provide useful knowledge to understand the functional mechanism of oil biosynthesis in cotton. Cotton is an economical source of edible oil for the food industry. The genetic mechanism that regulates oil biosynthesis in cottonseeds is essential for the genetic enhancement of oil content (OC). To explore the functional genomics of OC, this study utilized an interspecific backcross inbred line population to dissect the quantitative trait locus (QTL) interlinked with OC. In total, nine OC QTLs were identified, four of which were novel, and each QTL explained 3.62-34.73% of the phenotypic variation of OC. The comprehensive transcript profiling of developing cottonseeds revealed 3,646 core genes differentially expressed in both inbred parents. Functional enrichment analysis determined 43 genes were annotated with oil biosynthesis processes. Implementation of weighted gene co-expression network analysis showed that 803 differential genes had a significant correlation with the OC phenotype. Further integrated analysis identified seven important genes located in OC QTLs. Of which, the GhHSD1 gene located in stable QTL qOC-Dt3-1 exhibited the highest functional linkages with the other network genes. Phylogenetic analysis showed significant evolutionary differences in the HSD1 sequences between oilseed- and starch- crops. Furthermore, the overexpression of GhHSD1 in Arabidopsis yielded almost 6.78% higher seed oil. This study not only uncovers important genetic loci for oil accumulation in cottonseed, but also provides a set of new candidate genes that potentially influence the oil biosynthesis pathway in cottonseed.

Analysis of the MIR396 gene family and the role of MIR396b in regulating fiber length in cotton.

Cotton fiber is one of the most important natural raw materials in the world textile industry. Improving fiber yield and quality has always been the main goal. MicroRNAs, as typical small noncoding RNAs, could affect fiber length during different stages of fiber development. Based on differentially expressed microRNA in the two interspecific backcross inbred lines (BILs) with a significant difference in fiber length, we identified the miR396 gene family in the two tetraploid cotton genomes and found MIR396b_D13 as the functional precursor to produce mature miR396 during the fiber elongation stage. Among 46 target genes regulated by miR396b, the GROWTH-REGULATING FACTOR 5 gene (GRF5, Gh_A10G0492) had a differential expression level in the two BILs during fiber elongation stage. The expression patterns indicated that the miR396b-GRF5 regulatory module has a critical role in fiber development. Furthermore, virus-induced gene silencing (VIGS) of miR396b significantly produced longer fiber than the wild type, and the expression level of GRF5 showed the reverse trends of the miR396b expression level. The analysis of co-expression network for the GRF5 gene suggested that a cytochrome P450 gene functions as an allene oxide synthase (Gh_D06G0089, AOS), which plays a critical role in jasmonate biosynthetic pathway. In conclusion, our results revealed that the miR396b-GRF5 module has a critical role in fiber development. These findings provide a molecular foundation for fiber quality improvement in the future.

Comprehensive transcriptomic analysis provides new insights into the mechanism of ray floret morphogenesis in chrysanthemum.

BACKGROUND: The ray floret shapes referred to as petal types on the chrysanthemum (Chrysanthemum × morifolium Ramat.) capitulum is extremely abundant, which is one of the most important ornamental traits of chrysanthemum. However, the regulatory mechanisms of different ray floret shapes are still unknown. C. vestitum is a major origin species of cultivated chrysanthemum and has flat, spoon, and tubular type of ray florets which are the three basic petal types of chrysanthemum. Therefore, it is an ideal model material for studying ray floret morphogenesis in chrysanthemum. Here, using morphological, gene expression and transcriptomic analyses of different ray floret types of C. vestitum, we explored the developmental processes and underlying regulatory networks of ray florets. RESULTS: The formation of the flat type was due to stagnation of its dorsal petal primordium, while the petal primordium of the tubular type had an intact ring shape. Morphological differences between the two ray floret types occurred during the initial stage with vigorous cell division. Analysis of genes related to flower development showed that CYCLOIDEA genes, including CYC2b, CYC2d, CYC2e, and CYC2f, were differentially expressed in different ray floret types, while the transcriptional levels of others, such as MADS-box genes, were not significantly different. Hormone-related genes, including SMALL AUXIN UPREGULATED RNA (SAUR), GRETCHEN HAGEN3 (GH3), GIBBERELLIN 2-BETA-DIOXYGENASE 1 (GA2OX1) and APETALA2/ETHYLENE RESPONSIVE FACTOR (AP2/ERF), were identified from 1532 differentially expressed genes (DEGs) in pairwise comparisons among the flat, spoon, and tubular types, with significantly higher expression in the tubular type than that in the flat type and potential involvement in the morphogenesis of different ray floret types. CONCLUSIONS: Our findings, together with the gene interactional relationships reported for Arabidopsis thaliana, suggest that hormone-related genes are highly expressed in the tubular type, promoting petal cell division and leading to the formation of a complete ring of the petal primordium. These results provide novel insights into the morphological variation of ray floret of chrysanthemum.

The role of MIF, cyclinD1 and ERK in the development of pulmonary hypertension in broilers.

Pulmonary hypertension (PH) is a major disease in the broiler breeding industry. During PH, the pulmonary artery undergoes remodelling, which is caused by pulmonary vascular smooth muscle cell proliferation. CyclinD1 regulates cell proliferation. This study investigated the role of cyclinD1 in the development of PH in broilers, and which bioactivators and signalling pathway are involved in the pathological process. The PH group contained 3-4-week-old broilers with clinical PH, and the healthy group broilers from the same flock without PH. Histopathology indicated pulmonary arterial walls were thicker in the PH group compared with the healthy group. Target gene expressions of macrophage migration inhibitory factor (MIF), extracellular signal-regulated kinase (ERK), and cyclinD1 detected by quantitative real-time PCR were upregulated in the PH group compared with the healthy group. Immunohistochemistry showed MIF, phosphorylated ERK (p-ERK) and cyclinD1 were present on pulmonary vascular walls; MIF was present in the cytoplasm of arterial endothelial cells and smooth muscle cells; p-ERK and cyclinD1 were present in smooth muscle cell cytoplasm. Western blotting demonstrated that MIF, p-ERKand cyclinD1 levels were significantly higher (P < 0.01) in the PH group compared with the healthy group. In summary, increased MIF in PH broiler pulmonary arteries upregulated cyclinD1 via the ERK signalling pathway to induce pulmonary vascular smooth muscle cell proliferation, causing pulmonary artery remodelling and hypertension.

[Genome-wide analysis of the LPAAT gene family in Gossypium raimondii and G. arboreum, and expression analysis of its orthologs in G. hirsutum].

Lysophosphatidic acid acyltransferase (LPAAT) which converts lysophosphatidic acid into phosphatidic acid is a key enzyme in biosynthesis pathway of lipid in plants. In this study, we identified 17 members of the LPAAT gene family from genomic data of G. raimondii-D5 and G. arboreum-A2. Analysis of gene structure, chromosome distribution and phylogenetic evolution of LPAAT genes in diploid Gossypium using bioinformatics approaches showed that these genes can be divided into distinct subfamilies based on the distance of their genetic relationship. Moreover, the gene structures were similar within LPAAT subfamily members. The amino acid sequences encoded by LPAAT family genes contained three conserved motifs, including ΦFPEGTR-G binding site and Φ-NHQS- ΦDΦΦ catalytic site. Phylogenetic analysis of LPAAT gene family demonstrated significant differences in evolution of LPAAT in different species. Finally, expression analysis of G. hirsutum ovules in different stages from RNA-seq and qRT-PCR data indicated that LPAAT gene may play a positive role in oil accumulation. Our studies facilitate understanding of the function of LPAAT gene family in Gossypium and selecting better LPAAT genes for further functional validation.

Changes in the Expression of MIF and Other Key Enzymes of Energy Metabolism in the Myocardia of Broiler Chickens with Ascites Syndrome.

Ascites syndrome (AS) is a metabolic disease observed mainly in fast-growing broilers. The heart is one of the most important target organs of the disease. The goal of this study was to evaluate the metabolic function of the right ventricles in clinical ascitic broilers. HE staining was performed to observe histopathological changes in the right ventricle of the heart, while Western blotting was used to detect the protein expression levels of macrophage migration inhibitory factor (MIF) and phosphorylated AMP-activated protein kinase (p-AMPK), as well as other key enzymes of energy metabolic pathways (i.e., glycolytic pathway: HK2, PFK1, PFK2, and PKM2; the tricarboxylic acid cycle (TCA cycle) pathway: OGDH, IDH2, and CS; and the fatty acid oxidation pathway: CPT-1A and ACC) in myocardial tissue. The histopathological examination of the myocardia of ascitic broilers revealed disoriented myocardial cells in the myofibril structure and a large number of blood cells deposited in the intermyofibrillar vessels, suggesting right heart failure in ascitic broilers. The Western blotting analysis demonstrated significantly increased levels of MIF and p-AMPK in the myocardia of ascitic broilers compared to those of the control group (p < 0.05). Additionally, the protein expression of key enzymes was dramatically increased in the glycolytic and fatty acid oxidation pathways, while the protein expression of key enzymes in the TCA cycle pathway was decreased in the ascitic broiler group. These findings suggest enhanced glycolysis and fatty acid oxidation metabolism, and a diminished TCA cycle, in the myocardia of broiler chickens with ascites syndrome.

Impaired macrophage migration inhibitory factor-AMP-activated protein kinase activation and ischemic recovery in the senescent heart.

BACKGROUND: Elderly patients are more sensitive than younger patients to myocardial ischemia, which results in higher mortality. We investigated how aging affects the cardioprotective AMP-activated protein kinase (AMPK) signaling pathway. METHODS AND RESULTS: Ischemic AMPK activation was impaired in aged compared with young murine hearts. The expression and secretion of the AMPK upstream regulator, macrophage migration inhibitory factor (MIF), were lower in aged compared with young adult hearts. Additionally, the levels of hypoxia-inducible factor 1alpha, a known transcriptional activator of MIF, were reduced in aged compared with young hearts. Ischemia-induced AMPK activation in MIF knockout mice was blunted, leading to greater contractile dysfunction in MIF-deficient than in wild-type hearts. Furthermore, intramyocardial injection of adenovirus encoding MIF in aged mice increased MIF expression and ischemic AMPK activation and reduced infarct size. CONCLUSIONS: An impaired MIF-AMPK activation response in senescence thus may be attributed to an aging-associated defect in hypoxia-inducible factor 1alpha, the transcription factor for MIF. In the clinical setting, impaired cardiac hypoxia-inducible factor 1alpha activation and consequent reduced MIF expression may play an important role in the increased susceptibility to myocardial ischemia observed in older cardiac patients.

Quantitative Trait Locus Analysis and Identification of Candidate Genes for Micronaire in an Interspecific Backcross Inbred Line Population of Gossypium hirsutum × Gossypium barbadense.

Cotton is the most important fiber crop and provides indispensable natural fibers for the textile industry. Micronaire (MIC) is determined by fiber fineness and maturity and is an important component of fiber quality. Gossypium barbadense L. possesses long, strong and fine fibers, while upland cotton (Gossypium hirsutum L.) is high yielding with high MIC and widely cultivated worldwide. To identify quantitative trait loci (QTLs) and candidate genes for MIC in G. barbadense, a population of 250 backcross inbred lines (BILs), developed from an interspecific cross of upland cotton CRI36 × Egyptian cotton (G. barbadense) Hai7124, was evaluated in 9 replicated field tests. Based on a high-density genetic map with 7709 genotyping-by-sequencing (GBS)-based single-nucleotide polymorphism (SNP) markers, 25 MIC QTLs were identified, including 12 previously described QTLs and 13 new QTLs. Importantly, two stable MIC QTLs (qMIC-D03-2 on D03 and qMIC-D08-1 on D08) were identified. Of a total of 338 genes identified within the two QTL regions, eight candidate genes with differential expression between TM-1 and Hai7124 were identified. Our research provides valuable information for improving MIC in cotton breeding.

Glucocorticoid-induced MIF expression by human CEM T cells.

Macrophage migration inhibitory factor (MIF) is an upstream activator of the immune response that counter-regulates the immunosuppressive effects of glucocorticoids. While MIF is released by cells in response to diverse microbial and invasive stimuli, evidence that glucocorticoids in low concentrations also induce MIF secretion suggests an additional regulatory relationship between these mediators. We investigated the expression of MIF from the human CEM T cell line, which exists in two well-characterized, glucocorticoid-sensitive (CEM-C7) and glucocorticoid-resistant (CEM-C1) variant clones. Dexamethasone in low concentrations induced MIF secretion from CEM-C7 but not CEM-C1 T cells by a bell-shaped dose response that was similar to that reported previously for the release of MIF by monocytes/macrophages. Glucocorticoid stimulation of CEM-C7 T cells was accompanied by an MIF transcriptional response, which by promoter analysis was found to involve the GRE and ATF/CRE transcription factor binding sites. These data support a glucocorticoid-mediated MIF secretion response by T cells that may contribute to the regulation of the adaptive immune response.

The effects of fluoride on neuronal function occurs via cytoskeleton damage and decreased signal transmission.

It has been reported that fluoride exposure may cause serious public health problems, particularly neurotoxicity. However, the underlying mechanisms remain unclear. This study used Neuro-2A cells to investigate the effects of fluoride on the cytoskeleton. The Neuro-2A cells were exposed to 0, 1, 2, 4 and 6 mM sodium fluoride (NaF) for 24 h. Cell viability and lactate dehydrogenase (LDH) release were examined. It was observed that exposure to NaF reduced cell viability, disrupted cellular membrane integrity, and high levels of LDH were released. The observed changes occurred in a dose response manner. Morphologic observations showed that cell became rounded and were loosely adherent following exposure to NaF. Axon spines and normal features disappeared with high dose NaF treatment. The expression of MAP2 and synaptophysin decreased, particularly at 4 mM and 6 mM (P < 0.05) for MAP2. These results corroborate the morphologic observations. The content of glutamate and NMDAR (glutamate receptor) protein were assessed to help understand the relationship between synapses and neurotransmitter release using ELISA and Western-blot. Compared with the control, glutamate and NMDAR expression declined significantly at 4 mM and 6 mM (P < 0.05) group. Finally, the ultrastructural changes observed with increasing doses of NaF were: disappearance of synapses, mitochondrial agglutination, vacuole formation, and cellular edema. Taken together, NaF exposure disrupted cellular integrity and suppressed the release of neurotransmitters, thus effecting neuronal function. These findings provide deeper insights into roles of NaF in neuron damage, which could contribute to a better understanding of fluoride-induced neurotoxicity.

RNA-Seq-Mediated Transcriptome Analysis of a Fiberless Mutant Cotton and Its Possible Origin Based on SNP Markers.

As the longest known single-celled trichomes, cotton (Gossypium L.) fibers constitute a classic model system to investigate cell initiation and elongation. In this study, we used a high-throughput transcriptome sequencing technology to identify fiber-initiation-related single nucleotide polymorphism (SNP) markers and differentially expressed genes (DEGs) between the wild-type (WT) Upland cotton (G. hirsutum) Xuzhou 142 and its natural fuzzless-lintless mutant Xuzhou 142 fl. Approximately 700 million high-quality cDNA reads representing over 58 Gb of sequences were obtained, resulting in the identification of 28,610 SNPs--of which 17,479 were novel--from 13,960 expressed genes. Of these SNPs, 50% of SNPs in fl were identical to those of G. barbadense, which suggests the likely origin of the fl mutant from an interspecific hybridization between Xuzhou 142 and an unknown G. barbadense genotype. Of all detected SNPs, 15,555, 12,750, and 305 were classified as non-synonymous, synonymous, and pre-terminated ones, respectively. Moreover, 1,352 insertion/deletion polymorphisms (InDels) were also detected. A total of 865 DEGs were identified between the WT and fl in ovules at -3 and 0 days post-anthesis, with 302 candidate SNPs selected from these DEGs for validation by a high-resolution melting analysis and Sanger sequencing in seven cotton genotypes. The number of genotypic pairwise polymorphisms varied from 43 to 302, indicating that the identified SNPs are reliable. These SNPs should serve as good resources for breeding and genetic studies in cotton.

Integrative transcriptome, proteome, phosphoproteome and genetic mapping reveals new aspects in a fiberless mutant of cotton.

To investigate the molecular mechanisms of fiber initiation in cotton (Gossypium spp.), an integrated approach combining transcriptome, iTRAQ-based proteome and genetic mapping was taken to compare the ovules of the Xuzhou 142 wild type (WT) with its fuzzless-lintless (fl) mutant at -3 and 0 day post-anthesis. A total of 1,953 mRNAs, 187 proteins, and 131 phosphoproteins were differentially expressed (DE) between WT and fl, and the levels of transcripts and their encoded proteins and phosphoproteins were highly congruent. A functional analysis suggested that the abundance of proteins were mainly involved in amino sugar, nucleotide sugar and fatty acid metabolism, one carbon pool for folate metabolism and flavonoid biosynthesis. qRT-PCR, Western blotting, and enzymatic assays were performed to confirm the regulation of these transcripts and proteins. A molecular mapping located the lintless gene li3 in the fl mutant on chromosome 26 for the first time. A further in-silico physical mapping of DE genes with sequence variations between fl and WT identified one and four candidate genes in the li3 and n2 regions, respectively. Taken together, the transcript abundance, phosphorylation status of proteins at the fiber initiation stage and candidate genes have provided insights into regulatory processes underlying cotton fiber initiation.

Severe burn injury in late pregnancy: a case report and literature review.

The management of serious burn injuries during pregnancy is an unsolved clinical problem because of the low incidence of this disease. Although it has been documented that the effect of burns on fetal and maternal survival is detrimental, there have been conflicting reports among the different burn centers regarding the mortality of burned pregnant women and the management of burn patients during pregnancy. We report a case of severe burn in late pregnancy treated at our burn center. Additionally, we searched and summarized the literature concerning the management of pregnant patients to provide useful information for their treatment.

In vitro evaluation of antiviral activity of tea seed saponins against porcine reproductive and respiratory syndrome virus.

BACKGROUND: Porcine reproductive and respiratory syndrome virus (PRRSV) is one of the major swine pathogens. This virus causes immune suppression and other secondary infections, leading to significant economic losses in the swine industry. Tea seed saponins (TS) are a natural extract from tea seeds with anti-cancer, anti-inflammatory and antiviral activity. In this study, we demonstrated that TS possessed anti-PRRSV activity. METHODS: MTT assay and trypan blue staining were used to evaluate the cytotoxicity and antiviral ability of TS in cell culture. Apoptosis was measured to assess the safety of TS on Marc-145 cells. Time-of-addition assay, entry inhibition assay and virucidal assay were used to assess the antiviral action of TS. The effect of TS on host cellular gene expression was analysed by real-time PCR. Absolute quantification RT-PCR and western blot were used to study the inhibitory effect of TS on PRRSV N gene and protein expression. RESULTS: Our results showed that 50% cytotoxic concentrations (CC50) and 50% effective concentration (EC50) of TS were 59.86 ±0.3841 µg/ml and 24.29 ±1.194 µg/ml, respectively. The maximum non-cytotoxic concentration of TS on Marc-145 cells was 30 µg/ml. TS inhibited PRRSV-induced cell apoptosis and effectively inhibited PRRSV replication by reducing the expression of host cellular gene PABP, and significantly inhibited virus N gene/protein expression. CONCLUSIONS: TS possessed anti-PRRSV activity in vitro and could serve as a potential antiviral drug for PRRSV prevention and control.

Sodium tanshinone IIA sulfonate inhibits the meq, ul49 and VP22 expression of Marek's disease virus.

BACKGROUND: Our previous studies have demonstrated that sodium tanshinone IIA sulfonate (STS), a natural compound derived from Salviae Miltiorrhizae Radix et Rhizoma (Danshen), could effectively inhibit Marek's disease virus (MDV) infection both in vitro and in vivo, but the underlying mechanisms remain unclear. The main objective of the study was to explore the effect of STS on the meq, ul49 and VP22 expression of MDV in vitro. METHODS: Quantitative real-time PCR (qRT-PCR) was used to analyse the effect of STS on meq and ul49 expression at both the DNA and messenger RNA (mRNA) level, and the effect of STS on VP22 was assessed by immunofluorescence assay and western blotting. RESULTS: The DNA and mRNA copy numbers of meq and ul49 significantly decreased in the groups treated with STS compared with MDV control (P<0.05), which indicated that STS could inhibit the expression of meq and ul49 at both the DNA and mRNA level. Moreover, the expression of VP22 encoded by ul49 was also significantly inhibited (P<0.05). CONCLUSIONS: STS possessed anti-MDV activity in chicken embryo fibroblasts. Its antiviral mechanisms may be ascribed to inactivating MDV directly, disturbing meq and ul49 replication and inhibiting the expression of VP22 encoded by ul49. These results suggested that STS is a promising natural compound to be further developed as an antiviral agent against MDV infection.

Epidemiological and genetic diversity of Staphylococcus aureus causing bloodstream infection in Shanghai, 2009-2011.

OBJECTIVES: Staphylococcus aureus or methicillin-resistant Staphylococcus aureus (MRSA) has been an important pathogen causing bloodstream infections. Our study aimed to investigate the epidemiological and genetic diversity of clinical S. aureus isolates from patients with bloodstream infection in four hospitals of Shanghai from 2009 to 2011. METHODS: A collection of S. aureus isolates causing bloodstream infection from four hospitals in the central part of Shanghai was carried out. Antimicrobial susceptibility testings of collected isolates were performed according to the Clinical and Laboratory Standards Institute (CLSI) guidelines, and spa-type, multi-locus sequence typing, agr type and toxin gene profiling were performed to explore the molecular diversity. Moreover, MRSA strains were also characterized by Staphylococcal cassette chromosome mec (SCCmec) typing. RESULTS: The drugs such as linezolid, teicoplanin and vancomycin were efficacious for treating S. aureus including MRSA bloodstream infection. Methicillin-sensitive Staphylococcus aureus (MSSA) strains displayed distinct diversity in molecular characterization and toxin genes, and three virulent MSSA strains encoding at least five toxins were detected. Five community-associated MRSA (CA-MRSA) strains were found, but the majority (88.7%) of MRSA strains belonged to two epidemic clones (ST239-MRSA- III and ST5-MRSA- II) with different toxin gene profiles among patients with bloodstream infection. CONCLUSIONS: Healthcare-associated MRSA (HA-MRSA) strains were still the main pathogen causing bloodstream infections in spite of the emergence of CA-MRSA strains in hospital setting.

[Multi-center clinical trial of FLAMIGEL (hydrogel dressing) for the treatment of residual burn wound].

OBJECTIVE: To evaluate the effect of FLAMIGEL (hydrogel dressing) on the repair of residual burn wound. METHODS: Sixty burn patients with residual wounds hospitalized in 6 burn units from November 2011 to May 2012 were enrolled in the multi-center, randomized, and self-control clinical trial. Two residual wounds of each patient were divided into groups T (treated with FLAMIGEL) and C (treated with iodophor gauze) according to the random number table. On post treatment day (PTD) 7 and 14, wound healing rate was calculated, with the number of completely healed wound counted. The degree of pain patient felt during dressing change was evaluated using the visual analogue scale (VAS). The mean numbers of wounds with score equal to zero, more than zero and less than or equal to 3, more than 3 and less than or equal to 6, more than 6 and less than or equal to 10 were recorded respectively. Wound secretion or exudate samples were collected for bacterial culture, and the side effect was observed. Data were processed with repeated measure analysis of variance, t test, chi-square test, and nonparametric rank sum test. RESULTS: Wound healing rate of groups T, C on PTD 7 was respectively (67 ± 24)%, (45 ± 25)%, and it was respectively (92 ± 16)%, (72 ± 23)% on PTD 14. There was statistically significant difference in wound healing rate on PTD 7, 14 between group T and group C (F = 32.388, P < 0.01). Ten wounds in group T and four wounds in group C were healed completely on PTD 7, with no significant difference between them (χ(2) = 0, P > 0.05). Forty-two wounds in group T and seven wounds in group C healed completely on PTD 14, with statistically significant difference between them (χ(2) = 42.254, P < 0.01). Patients in group T felt mild pain during dressing change for 37 wounds, with VAS score higher than zero and lower than or equal to 3. Evident pain was observed in patients of group C during dressing change for 43 wounds, and it scored higher than 3 and less than or equal to 6 by VAS evaluation. There was statistically significant difference in mean number of wounds with different grade of VAS score between group T and group C (Z = -4.638, P < 0.01). Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, E. coli, Baumanii, and Staphylococcus epidermidis were all detected in both groups, but there was no statistical difference between group T and group C (χ(2) = 0.051, P > 0.05). No side effect was observed in either of the two groups during the whole trial. CONCLUSIONS: FLAMIGEL can accelerate the healing of residual burn wounds and obviously relieve painful sensation during dressing change.

Molecular epidemiologic analysis of Staphylococcus aureus isolated from four burn centers.

Staphylococcus aureus has been a major cause of hospital-acquired infections. Methicillin-resistant Staphylococcus aureus (MRSA) has emerged since 1980s as an epidemiologic problem in hospitals. This old pathogen brings a new challenge to all physicians and bacteriologists. Hence, effective measures of MRSA control are in critical need. S. aureus or MRSA is one of the leading causes of infection among burn centers, resulting in a number of poor outcomes and even death. The present study performed a molecular epidemiologic analysis of S. aureus isolated from four burn centers in the southeast of China. A total of 85 isolates were collected, and molecular characters were determined for further investigation. In this study, the prevalent clone of MRSA among four burn centers was found to be SCCmec III (spa-type t030, agr I), which is resistant to 4 kinds of antimicrobials including erythromycin, clindamycin, kanamycin and mupirocin. Discrepancy between mecA detection and conventional tests used for MRSA identification was observed unintentionally. Our data demonstrated that the overall prevalence rate of MRSA was 55.3%, and drugs such as sulfamethoxazole/trimethoprim, linezolid and fusidic acid are efficient antibiotic options for treating S. aureus or MRSA infections among four burn centers studied in present investigation.

[Analysis of the molecular epidemiology and distribution of pathogenic bacteria in burn wards of Ruijin Hospital from 2004 to 2006].

OBJECTIVE: To analyse the distribution, drug resistance and epidemiology of pathogenic bacteria in the burn wards of Ruijin Hospital. METHODS: Seventeen strains of Methicillin resistant staphylococcus aureus (MRSA), 52 strains of Pseudomonas aeruginosa (PA), and 11 strains of Acinetobacter baumannii (AB) isolated from the wound secretion, venous catheters, blood, urine and stool etc. were collected from burn patients hospitalized in our department from January 2004 to December 2006. The distribution and the drug resistance profile of bacteria were analyzed, and the homology analysis was performed by randomly amplified polymorphic DNA (RAPD). RESULTS: MRSA, PA and AB were the major strains in our burn wards in recent years, of which Staphylococcus aureus (SA) was the most dominant. During these 3 years, MRSA accounted for 77% (63/82), 85% (63/74), and 75% (74/99), respectively, for SA isolated in this period. MRSA was resistant to Amikacin, Gentamicin, Erythromycin, Clindamycin and Levofloxacin; PA was resistant to Amikacin, Gentamicin, Piperacillin, Ceftazidime, Cefoperazone, Aztreonam and Imipenem; AB was resistant to Amikacin, Gentamicin, Piperacillin, Ceftazidime, Imipenem and Ciprofloxacin. Three bacteria were found to belong to the same type in the RAPD homology analysis. CONCLUSIONS: There are many kind of multi-drug resistant pathogenic bacteria for nosocomial infection in our burn wards. To control the spread of infection due to above-mentioned 3 bacteria is the focus of nosocomial infection control.