OBJECTIVETo study the proteomic change in lymphocytes of rabbits with scald injury and Staphylococcus aureus (SA) invasion.

METHODSTwenty-four rabbits were divided into four groups as follows: control group, scald group, scald with SA invasion 2 hs group, and scald with SA invasion 6 hs group, according to random number table, with 6 rabbits in each group. Except for rabbits in control group (sham scald at 37 degrees C), rabbits in the other 3 groups were subjected to 30% TBSA full-thickness scald. Rabbits in SA invasion 2 and 6 hs groups were injected with 2 mL (1.0 x 10(8) CFU/mL) SA suspension, which was in the log growth phase, via auricle vein 18 hs and 22 hs after injury. Whole blood samples were collected from carotid artery of rabbits in 4 groups 24 hs after scald. Lymphocytes were isolated and its extracted proteins were analyzed by two-dimensional gel electrophoresis coupled with mass spectroscopy.

RESULTSAbout 1030 protein spots of lymphocytes were detected in each group. Compared with that of control group, 19 protein spots were found to be differentially expressed in the other 3 groups, and 11 spots (10 proteins) were identified. Expression levels of cofilin, cyclophilin A, ubiquitin, nucleoside diphosphate kinase, glutamate dehydrogenase and annexin 1 were down-regulated, but expression level of peroxiredoxin was up-regulated obviously.

CONCLUSIONSThere is obvious proteomic change in lymphocytes of scalded rabbits or of scalded rabbits invaded by SA, and it may relate to immune suppression and sepsis after injury.

Animals ; Burns ; metabolism ; microbiology ; Lymphocytes ; metabolism ; Male ; Proteome ; Rabbits ; Staphylococcal Infections ; etiology ; metabolism

OBJECTIVETo investigate whether S. aureus could activate NF-κB signaling pathway in human osteoblasts.

METHODSImmunoblot and electrophoretic mobility shift assay were used to detect the degradation of I-κBα and activation of NF-κB in human osteoblasts following infection with S.aureus, respectively, and there were investigated the activated state of NF-κB signaling pathway in human osteoblasts. In addition, enzyme-linked immunosorbent assay was used to measure the secretion of IL-6 in culture supernatants, which was represented as one of important cytokines in osteomyelitis, and an inhibitor of NF-κB, SN50, which was added to human osteoblasts culture prior to 1 hour at 50 µmol/L before the infection of S.aureus, was used to determine whether S.aureus-activated NF-κB signaling pathway regulates IL-6 secretion of human osteoblasts.

RESULTSS.aureus could induce the degradation of I-κBα (I-κBα(15 min)/I-κBα(0 min) = 0.409 ± 0.245 and I-κBα(30 min)/I-κBα(0 min) = 0.061 ± 0.010) and activation of NF-κB in human osteoblasts in a time and dose-dependent manner following infection. In addition, the secretion of IL-6 in the supernatants of human osteoblasts ((2.17 ± 0.11) µg/L) was suppressed by 50 µmol/L SN50 compared to without the addition of SN50 ((3.58 ± 0.31) µg/L) (F = 174.25, P < 0.05).

CONCLUSIONSS.aureus could activate NF-κB signaling pathway in human osteoblasts, which could regulate cytokines secretions of human osteoblasts.

Cells, Cultured ; Humans ; Interleukin-6 ; secretion ; NF-kappa B ; metabolism ; Osteoblasts ; metabolism ; Signal Transduction ; Staphylococcal Infections ; metabolism

Humans ; Interferon-gamma ; metabolism ; Interleukin-12 Subunit p40 ; metabolism ; Meningitis, Bacterial ; blood ; cerebrospinal fluid ; Multiple Sclerosis, Relapsing-Remitting ; blood ; cerebrospinal fluid ; Staphylococcal Infections ; blood ; cerebrospinal fluid

OBJECTIVE: To investigate the influences of staphylococcus aureus in planktonic and biofilm forms on the expression of lysozyme, SLPI and gp340 in the human sinonasal explant model. METHOD: Mucosa samples from ethmoid sinus were collected from ten patients of cerebrospinal fluid leak and were cultured with and without S. aureus biofilms and planktonic cells. After the infection, the explant model was confirmed by CLSM, and the secretion of lysozyme, SLPI and gp340 was detected by enzyme-linked immunosorbent assay (ELISA) at 8, 16, and 24 h after S. aureus challenge. Expressions of lysozyme, SLPI and gp340 in mRNA and protein levels after 24 h S. aureus challenge were detected using RT-PCR, immunohistochemistry and Western bolt assay respectively. RESULT: The secretion of lysozyme, SLPI and gp340 in the explant model was observed with a trend to increase in a time-dependent manner. At 8 and 16 h after S. aureus challenge, the secretion of lysozyme, SLPI and gp340 in biofilms group was significantly higher than these in planktonic cells group and control group (P<0. 05). S. aureus biofilms enhanced the mRNA expressions of lysozyme, SLPI and gp340 significantly compared with planktonic cells and controls, and the mRNA expressions in the explant model challenged by planktonic cells were significantly higher than controls (P < 0.05). Although the Western bolt assay showed no differences between the lysozyme expression in the planktonic cells group and control group (P > 0.05), the biofilms enhanced the expressions of lysozyme, SLPI and gp340 significantly compared with planktonic cells and controls (P < 0.05). CONCLUSION S. aureus biofilm induced the expressions of lysozyme, SLPI and gp340 to a higher level than planktonic cells, indicating that S. aureus biofilm was an influencing factor on the innate immune system.
Biofilms ; Enzyme-Linked Immunosorbent Assay ; Ethmoid Sinus ; metabolism ; microbiology ; Humans ; Immunity, Innate ; Muramidase ; metabolism ; RNA, Messenger ; metabolism ; Receptors, Cell Surface ; metabolism ; Secretory Leukocyte Peptidase Inhibitor ; metabolism ; Staphylococcal Infections ; metabolism ; Tissue Culture Techniques

Necrotizing fasciitis (NF) is a deep infection of the subcutaneous tissue that progressively destroys fascia and fat; it is associated with systemic toxicity, a fulminant course, and high mortality. NF most frequently develops from trauma that compromises skin integrity, and is more common in patients with predisposing medical conditions such as diabetes mellitus, atherosclerosis, alcoholism, renal disease, liver disease, immunosuppression, malignancy, or corticosteroid use. Most often, NF is caused by polymicrobial pathogens including aerobic and anaerobic bacteria. NF caused by Staphylococcus aureus as a single pathogen, however, is rare. Here we report a case of NF that developed in a healthy woman after an isolated shoulder sprain that occurred without breaking a skin barrier, and was caused by Staphylococcus aureus as a single pathogen.
*Arm ; Coagulase/metabolism ; Fasciitis, Necrotizing/*etiology/microbiology/pathology/surgery ; Female ; Humans ; Middle Aged ; Shoulder Joint/*injuries ; Sprains and Strains/*complications ; Staphylococcal Infections/*etiology/microbiology ; Staphylococcus aureus/enzymology/isolation & purification

In this paper, we review the results of previous studies and summarize the effects of various factors on the regulation of bone metabolism in traumatic bone infections. Infection-related bone destruction incorporates pathogens and iatrogenic factors in the process of bone resorption dominated by the skeletal and immune systems. The development of bone immunology has established a bridge of communication between the skeletal system and the immune system. Exploring the effects of pathogens, skeletal systems, immune systems, and antibacterials on bone repair in infectious conditions can help improve the treatment of these diseases.
Anti-Bacterial Agents/administration & dosage* ; Bone and Bones/metabolism* ; Cellular Microenvironment ; Humans ; Immune System/immunology* ; Lymphocyte Subsets/immunology* ; Osteitis/microbiology* ; Osteoblasts/physiology* ; Osteoclasts/physiology* ; Staphylococcal Infections

AIMTo explore the changes of rat platelet phospholipase A2 (PLA2) mRNA content in bacteria infected rat and study the cDNA and amino acid sequences of the PLA2 structure to lay a good foundation for the development of new antibiotics.

METHODSThe PLA2 mRNA level in blood was determined by RT-PCR. The DNA sequence was cloned and analyzed.

RESULTSAfter injection of bacteria in rats, the mRNA level of PLA2 in blood increased markedly. The cDNA and amino acid sequence were highly homologous to other PLA2 cDNA from different tissues of the rat.

CONCLUSIONPlatelet PLA2 in blood responded quickly to bacteria infection in gene level. Therefore, the PLA2 protein was produced increasingly which was shown to control the infection with bacteria. Although there are little difference between PLA2 cDNA cloned from blood and other sources in DNA and amino acid sequences, the catalytic site for enzymatic activity and basic structure are identical.

Amino Acid Sequence ; Animals ; Base Sequence ; Cloning, Molecular ; DNA, Complementary ; metabolism ; Male ; Molecular Sequence Data ; Phospholipases A ; blood ; genetics ; metabolism ; Phospholipases A2 ; RNA, Messenger ; metabolism ; Rats ; Rats, Wistar ; Staphylococcal Infections ; blood ; Staphylococcus aureus

OBJECTIVETo explore the cellular immunology mechanism of infective endocarditis (IE), we investigated the effects of Staphylococcus aureus (S. aureus) on MCSF-1 and its receptor (c-fms) gene expression in cardiac valves.

METHODSThirty-two rabbits were divided into 4 groups: mitral or tricuspid valve artificial lesions with 5 x 10(4) CFU or 5 x 10(6) CFU S. aureus injection. Control rabbits (n = 7) received 5 x 10(6) CFU S. aureus injection. IE after operation were confirmed by naked eyes and electron microscope observations. MCSF-1, c-fms in mitral and tricuspid valves were detected by RT-PCR.

RESULTSTwenty-six rabbits survived the operation and 14 rabbits developed IE (2 with 5 x 10(4) CFU and 12 with 5 x 10(6) CFU S. aureus injection) one day post operation. S. aureus injection alone did not induce IE. Compared to control rabbits, MCSF-1 mRNA was significantly upregulated and c-fms mRNA significantly downregulated after 5 x 10(4) CFU S. aureus injection with heart valve artificial lesion in mitral valves or tricuspid valves. MCSF-1 expression in mitral valves was further increased while remained unchanged in tricuspid valve after 5 x 10(6) CFU S. aureus injection compared to that in 5 x 10(4) CFU S. aureus injection group.

CONCLUSIONHigh dose bacterial invasion and heart valves lesion were the main factors for inducing infective endocarditis. Development of infective endocarditis was associated with valve MCSF-1/c-fms expression changes in this rabbit model.

Animals ; Endocarditis, Bacterial ; metabolism ; microbiology ; Macrophage Colony-Stimulating Factor ; biosynthesis ; genetics ; Mitral Valve ; metabolism ; RNA, Messenger ; biosynthesis ; Rabbits ; Receptor, Macrophage Colony-Stimulating Factor ; biosynthesis ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Staphylococcal Infections ; metabolism ; microbiology ; Staphylococcus aureus

OBJECTIVETo investigate α-toxin-induced apoptosis of umbilical vein endothelial cells and explore its role in vertical infection of Staphylococcus aureus L-form.

METHODSHUV-EC-C cells exposed to different concentrations (0, 10, 30, 90, and 270 ng/ml) of α-toxin for different time lengths (0, 2, 4, 6, and 8 h) were examined for apoptosis using flow cytometry with Annexin V-PI staining. The levels of tumor necrosis factor-α (TNF-α) and the activities of, caspase-3 and caspase-8 in the cell culture were detected by ELISA and colorimetric method, respectively. α-Toxin-induced cell apoptosis was also analyzed in HUV-EC-C cells treated with a neutralizing antibody of TNF-α or with the inhibitory peptides of caspase-3 (zDEVD-FMK) and caspase-8 (zIETD-fmk).

RESULTSα-Toxin induced apoptosis of HUV-EC-C cells in a dose- and time-dependent manner and caused significantly enhanced expression of TNF-α and the activation of both caspase-3 and caspase-8. Inhibition of TNF-α with its neutralizing antibody and the inhibitory peptides of caspase-3 or -8 all significantly decreased α-toxin-induced cell apoptosis, and the caspase-3 inhibitor completely blocked α-toxin-induced cell apoptosis.

CONCLUSIONα-Toxin-induced apoptosis is partially mediated by the extrinsic cell death pathway of TNF-α and caspase-8 and plays an important role in the vertical infection of S. aureus L-form to affect fetal growth and development.

Apoptosis ; Bacterial Toxins ; toxicity ; Caspase 3 ; metabolism ; Caspase 8 ; metabolism ; Cells, Cultured ; Human Umbilical Vein Endothelial Cells ; cytology ; Humans ; L Forms ; Staphylococcal Infections ; Staphylococcus aureus ; Tumor Necrosis Factor-alpha ; metabolism

Clindamycin resistance in Staphylococcus species can be either constitutive or inducible. Inducible resistance cannot be detected by the conventional antimicrobial susceptibility test. In this study, we determined the prevalence of inducible clindamycin resistance in staphylococcal isolates at a Korean tertiary care hospital. Between February and September 2004, 1,519 isolates of Staphylococcus aureus and 1,043 isolates of coagulase-negative staphylococci (CNS) were tested for inducible resistance by the D-zone test. Overall, 17% of MRSA, 84% of MSSA, 37% of MRCNS, and 70% of MSCNS were susceptible to clindamycin. Of the erythromycin non-susceptible, clindamycin-susceptible isolates, 32% of MRSA, 35% of MSSA, 90% of MRCNS, and 94% of MSCNS had inducible clindamycin resistance. Inducible clindamycin resistance in staphylococci was highly prevalent in Korea. This study indicates importance of the D-zone test in detecting inducible clindamycin resistance in staphylococci to aid in the optimal treatment of patients.
Staphylococcus aureus/metabolism ; Staphylococcal Infections/*metabolism ; Prevalence ; *Microbial Sensitivity Tests ; Korea ; Humans ; Drug Resistance, Multiple, Bacterial ; *Drug Resistance, Microbial ; Clindamycin/*pharmacology ; Anti-Infective Agents/*pharmacology ; Anti-Bacterial Agents/*pharmacology