In order to characterize the immunogenicity and immunoprotection of the Staphylococcus aureus (S. aureus) surface protein Clumping factor A (ClfA), we amplified clfa genes from S. aureus Newman strain, Wood46 strain and HLJ23-1. The clfa gene from Newman strain was subsequently inserted into pQE-30 vector and the recombinant plasmid was transformed into Escherichia coli strain M15 (pREP4). The recombinant ClfA protein was expressed and purified. Then, we immunized mice with the purified recombinant protein. The antibody level and the concentration of cytokines were measured by enzyme-linked immunosorbent assay. Finally, immunized mice were challenged with S. aureus Newman, Wood46 and HLJ23-1. These results suggested that clfa gene sequences were highly conserved, and the recombinant ClfA was expressed correctly with good antigenicity. The antibody titer and the concentration of cytokines in the immunized groups increased significantly (P < 0.05) compared with control, and the mice in the immunized groups were protected against the challenge strains to some extent. These results showed that the ClfA had high immunogenicity and immunoprotective potential.
Animals ; Coagulase ; genetics ; immunology ; metabolism ; Escherichia coli ; genetics ; metabolism ; Immunization ; Mice ; Recombinant Proteins ; genetics ; immunology ; metabolism ; Staphylococcus aureus ; metabolism ; pathogenicity

OBJECTIVETo investigate the impact of Staphylococcus aureus from infertile men on sperm motility and the relationship between virulence genes and the activity of spermatozoal immobilization.

METHODSWe collected 60 strains of non-repeated Staphylococcus aureus from the semen of 589 infertile males and analyzed the influence of Staphylococcus aureus on sperm motility using the computer-aided sperm analysis system. We selected the strains that apparently decreased sperm motility and detected their virulence genes by PCR.

RESULTSSperm motility was significantly decreased in 17 of the 60 strains of Staphylococcus aureus (P < 0.05). The main virulence genes in these strains were hlg (33.3%), scn (23.3%), cna (20%), hlb (20%), and clfA (18.3%), others including icaA, fnbA, tst, seb, hld, eta and sea. The scn gene carriers accounted for 47.1% in the spermatozal immobilization positive group, significantly higher than 14% in the negative group (P < 0.05). No statistically significant differences were found in the percentages of the carriers of the other virulence genes between the two groups (P > 0.05).

CONCLUSIONInfections of Staphylococcus aureus in male reproductive system can lead to the decrease of sperm motility, which may be associated with the Staphylococcus complement inhibitor encoding gene scn.

Humans ; Infertility, Male ; microbiology ; Male ; Polymerase Chain Reaction ; Semen ; microbiology ; Species Specificity ; Sperm Motility ; Staphylococcal Infections ; Staphylococcus aureus ; pathogenicity ; Virulence ; genetics

BACKGROUND: Various virulence factors and superantigens are encoded by mobile genetic elements. The relationship between clonal background and virulence factors differs in different geographic regions. We compared the distribution and relationship of spa types and virulence genes among methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from a tertiary hospital in 2000-01 and 2007-08. METHODS: In 2000-01 and 2007-08, 94 MRSA strains were collected from 3 intensive care units at a Korean tertiary hospital. We performed spa typing and multiplex PCR for 19 superantigen genes. RESULTS: Relatively frequent spa types were t037 (40.5%), t002, t601, and t2138 in 2000-01, and t2460 (43.9%), t002, t037, t601, t324, and t2139 in 2007-08. We identified 4 novel spa types, 2 of which were designated as t5076 and t5079. Superantigen profiles were closely linked to spa types. For example, sea, sek, and seq superantigen genes were mainly detected in t037 strains. CONCLUSIONS: Major spa types differed depending on study periods, and the distribution of superantigen genes correlated with spa type.
Bacterial Typing Techniques ; DNA, Bacterial/chemistry ; Genotype ; Humans ; Intensive Care Units/statistics & numerical data ; Methicillin-Resistant Staphylococcus aureus/genetics/*isolation & purification/pathogenicity ; Microbial Sensitivity Tests ; Polymerase Chain Reaction ; Staphylococcal Infections/microbiology ; Superantigens/genetics ; Virulence/genetics ; Virulence Factors/*genetics

BACKGROUNDStaphylococcus aureus (S. aureus) remains as an important microbial pathogen resulting in community and nosocomial acquired infections with significant morbidity and mortality. Few reports for S. aureus in lower respiratory tract infections (LRTIs) have been documented. The aim of this study was to explore the molecular epidemiology of S. aureus in LRTIs in China.

METHODSA multicenter study of the molecular epidemiology of S. aureus in LRTIs was conducted in 21 hospitals in Beijing, Shanghai and twelve other provinces from November 2007 to February 2009. All the collected S. aureus strains were classified as minimum inhibitory concentration (MIC), mecA gene, virulence genes Panton-Valentine Leukocidin (PVL) and γ-hemolysin (hlg), staphylococcal cassette chromosome mec (SCCmec) type, agr type, and Multilocus Sequence Typing (MLST).

RESULTSTotally, nine methicillin-sensitive S. aureus (MSSA) and 29 methicillin-resistant S. aureus (MRSA) strains were isolated after culture from a total of 2829 sputums or bronchoalveolar lavages. The majority of MRSA strains (22/29) had a MIC value of ≥ 512 µg/ml for cefoxitin. The mecA gene acting as the conservative gene was carried by all MRSA strains. PVL genes were detected in only one S. aureus strain (2.63%, 1/38). The hlg gene was detected in almost the all S. aureus (100% in MSSA and 96.56% in MRSA strains). About 75.86% of MRSA strains carried SCCmec III. Agr type 1 was predominant (78.95%) among the identified three agr types (agr types 1, 2, and 3). Totally, ten sequence type (ST) of S. aureus strains were detected. A new sequence type (ST1445) was found besides confirming ST239 as the major sequence type (60.53%). A dendrogram generated from our own MLST database showed all the bootstrap values ≤ 50%.

CONCLUSIONOur preliminary epidemiology data show SCCmec III, ST239 and agr type 1 of S. aureus as the predominant strains in LRTIs in Mainland of China.

Alleles ; Anti-Bacterial Agents ; therapeutic use ; China ; epidemiology ; Drug Resistance, Bacterial ; genetics ; Humans ; Microbial Sensitivity Tests ; Prospective Studies ; Respiratory Tract Infections ; epidemiology ; Staphylococcal Infections ; epidemiology ; Staphylococcus aureus ; drug effects ; pathogenicity

The present study was carried out to genotypically characterize Staphylococcus aureus (S. aureus) isolated from bovine mastitis cases. A total of 37 strains of S. aureus were isolated during processing of 552 milk samples from 140 cows. The S. aureus strains were characterized phenotypically, and were further characterized genotypically by polymerase chain reaction using oligonucleotide primers that amplified genes encoding coagulase (coa), clumping factor (clfA), thermonuclease (nuc), enterotoxin A (entA), and the gene segments encoding the immunoglobulin G binding region and the X region of protein A gene spa. All of the isolates yielded an amplicon with a size of approximately 1,042 bp of the clfA gene. The amplification of the polymorphic spa gene segment encoding the immunoglobulin G binding region was observed in 34 isolates and X-region binding was detected in 26 isolates. Amplification of the coa gene yielded three different products in 20, 10, and 7 isolates. The amplification of the thermonuclease gene, nuc, was observed in 36 out of 37 isolates. All of the samples were negative for the entA gene. The phenotypic and genotypic findings of the present strategies might provide an understanding of the distribution of the prevalent S. aureus clones among bovine mastitis isolates, and might aid in the development of steps to control S. aureus infections in dairy herds.
Animals ; Bacterial Proteins/chemistry/genetics ; Cattle ; Coagulase/chemistry/genetics ; DNA, Bacterial/chemistry/genetics ; Endonucleases/chemistry/genetics ; Female ; Mastitis, Bovine/*microbiology ; Micrococcal Nuclease/chemistry/genetics ; Milk/microbiology ; Polymerase Chain Reaction/veterinary ; Staphylococcal Infections/microbiology/*veterinary ; Staphylococcus aureus/*genetics/pathogenicity ; Virulence Factors/chemistry/*genetics

Neutrophils play an essential role in the innate immune response to infection. Neutrophils migrate from the vasculature into the tissue in response to infection. Recently, a neutrophil cell surface receptor, CD177, was shown to help mediate neutrophil migration across the endothelium through interactions with PECAM1. We examined a publicly available gene array dataset of CD177 expression from human neutrophils following pulmonary endotoxin instillation. Among all 22,214 genes examined, CD177 mRNA was the most upregulated following endotoxin exposure. The high level of CD177 expression is also maintained in airspace neutrophils, suggesting a potential involvement of CD177 in neutrophil infiltration under infectious diseases. To determine the role of CD177 in neutrophils in vivo, we constructed a CD177-genetic knockout mouse model. The mice with homozygous deletion of CD177 have no discernible phenotype and no significant change in immune cells, other than decreased neutrophil counts in peripheral blood. We examined the role of CD177 in neutrophil accumulation using a skin infection model with Staphylococcus aureus. CD177 deletion reduced neutrophil counts in inflammatory skin caused by S. aureus. Mechanistically we found that CD177 deletion in mouse neutrophils has no significant impact in CXCL1/KC- or fMLP-induced migration, but led to significant cell death. Herein we established a novel genetic mouse model to study the role of CD177 and found that CD177 plays an important role in neutrophils.
Animals ; Disease Models, Animal ; GPI-Linked Proteins ; genetics ; Gene Expression Regulation ; Genetic Therapy ; Humans ; Immunity, Innate ; genetics ; Inflammation ; genetics ; microbiology ; pathology ; Isoantigens ; genetics ; Mice ; Mice, Knockout ; Neutrophils ; metabolism ; pathology ; Platelet Endothelial Cell Adhesion Molecule-1 ; metabolism ; Receptors, Cell Surface ; genetics ; Staphylococcus aureus ; pathogenicity ; Transcriptional Activation

In the present study, Staphylococcus (S.) hyicus strains isolated in Russia (n = 23) and Germany (n = 17) were investigated for the prevalence of the previously described genes sheta and shetb. Sheta was detected in 16 S. hyicus strains. Sheta-positive strains were mainly found among strains isolated from exudative epidermitis, and frequently together with the exfoliative toxin-encoding genes exhD and exhC. Partial sequencing of sheta in a single S. hyicus strain revealed an almost complete match with the sheta sequence obtained from GenBank. None of the S. hyicus strains displayed a positive reaction with the shetb-specific oligonucleotide primer used in the present study. According to the present results, the exotoxin encoding gene sheta seems to be distributed among S. hyicus strains in Russia and Germany. The toxigenic potential of this exotoxin, which does not have the classical structure of a staphylococcal exfoliative toxin, remains to be elucidated.
Animals ; Cattle ; Cattle Diseases/epidemiology/microbiology ; DNA Primers ; Dog Diseases/epidemiology/microbiology ; Dogs ; Epidermitis, Exudative, of Swine/epidemiology ; Exfoliatins/*genetics/immunology ; Germany ; Pneumonia/epidemiology/veterinary ; Russia ; Staphylococcal Infections/immunology/veterinary ; Staphylococcus aureus/genetics/*pathogenicity ; Swine ; Swine Diseases/epidemiology ; Virulence/*genetics ; Virulence Factors/genetics/immunology

Staphylococcus aureus may perform an crucial function in atopic dermatitis (AD), via the secretion of superantigens, including staphylococcal enterotoxins (SE) A or B, and toxic shock syndrome toxin-1 (TSST-1). Dysregulated cytokine production by keratinocytes (KCs) upon exposure to staphylococcal superantigens (SsAgs) may be principally involved in the pathophysiology of AD. We hypothesized that lesional KCs from AD may react differently to SsAgs compared to nonlesional skin or normal skin from nonatopics. We conducted a comparison of HLA-DR or CD1a expression in lesional skin as opposed to that in nonlesional or normal skin by immunohistochemistry (IHC). We also compared, using ELISA, the levels of IL-1alpha, IL-1beta, and TNF-alpha secreted by cultured KCs from lesional, nonlesional, and normal skin, after the addition of SEA, SEB and TSST-1. IHC revealed that both HLA-DR and CD1a expression increased significantly in the epidermis of lesional skin versus nonlesional or normal skin in quite a similar manner. IL-1alpha, IL-1beta, and TNF-alpha secretion was also significantly elevated in the cultured KCs from lesional skin after the addition of SsAgs. Our results indicated that KCs from lesional skin appear to react differently to SsAgs and increased proinflammatory cytokine production in response to SsAgs may contribute to the pathogenesis of AD.
Tumor Necrosis Factor-alpha/biosynthesis/genetics ; *Superantigens/administration & dosage/immunology ; Staphylococcus aureus/*immunology/pathogenicity ; Male ; Keratinocytes/immunology/*microbiology ; Interleukin-1/biosynthesis/genetics ; Inflammation Mediators/metabolism ; Humans ; HLA-DR Antigens/metabolism ; Enterotoxins/administration & dosage/immunology ; Dermatitis, Atopic/etiology/immunology/*microbiology ; DNA, Complementary/genetics ; Case-Control Studies ; Base Sequence ; Bacterial Toxins/administration & dosage/immunology ; Antigens, CD1/metabolism ; Adult