Staphylococcus epidermidis is a ubiquitous human skin commensal that has emerged as a major cause of foreign-body infections. Eleven genes encoding putative cell-wall-anchored proteins were identified by computer analysis of the publicly available S. epidermidis unfinished genomic sequence. Four genes encode previously described proteins (Aap, Bhp, SdrF and SdrG), while the remaining seven have not been characterized. Analysis of primary sequences of the S taphylococcus e pidermidis s urface (Ses) proteins indicates that they have a structural organization similar to the previously described cell-wall-anchored proteins from S. aureus and other Gram-positive cocci. However, not all of the Ses proteins are direct homologues of the S. aureus proteins. Secondary and tertiary structure predictions suggest that most of the Ses proteins are composed of several contiguous subdomains, and that the majority of these predicted subdomains are folded into β -rich structures. PCR analysis indicates that certain genes may be found more frequently in disease isolates compared to strains isolated from healthy skin. Patients recovering from S. epidermidis infections had higher antibody titres against some Ses proteins, implying that these proteins are expressed during human infection. Western blot analyses of early-logarithmic and late-stationary in vitro cultures suggest that different regulatory mechanisms control the expression of the Ses proteins.
Introduction: Mandibular deformity can be caused by congenital anomalies, trauma and tumors ect. leading to impairment of aesthetic and function such as communication, swallowing and mastication.To assess the clinical value of the computer-assisted design and computer-assisted manufactured(CAD/CAM) technology and evaluate the clinical experience of manufactured artificial bone precision to repair the mandibular asymmetrical deformity. Methods: From July 2013 to August 2016, computer-assisted 3D printing technology was applied in 72 patients with mandibular asymmetrical deformity in Craniofacial Department, Ninth People’s Hospital,Shanghai Jiao Tong University School of Medicine. The measurement data was conducted and compared with three-dimensional CT result during the 6months of follow-up. To evaluate the effectiveness of the surgery, the distance between the corresponding three anatomical points on the mandible to the mid-sagittal plane were measured and compared by asymmetic ratio Q value and the patients satisfaction survey was carried out. The measurements of mean discrepancy of corresponding three anatomical points between the virtual design and post operative CT during the 6 months of follow up. Results: The patients’ mandibular asymmetry was improved, the asymmetrical ratio Q value decreases from 13.57%±8.73% to 9.01%±8.18% (P<0.001) with high patients’ satisfaction score (score=4.78, Score 5=Completely satisfied). The mean deviation of the preoperative design and postoperative CT was 1.43±0.12mm, basically similar with the preoperative simulation. Pre-designed implant also decreased the intraoperative time with the mean value of 2.15±0.27 h.All patients were treated successfully without serious complications. Conclusion: Three-dimensional design of patients’ specific artificial bone implant in repair of mandibular asymmetrical deformity is a valuable technology, by relying on quantitative design and preoperative simulation using the customized CAD/CAM technology, making the complex reconstruction simple and improve the accuracy of surgery,ultimately improve the facial symmetry. The patients showed high satisfaction rate with low surgical complications and long-term efficacy.
Staphylococcus aureus is one of the major pathogens causing mastitis in dairy herds. The colonization of dairy cows and subsequent contamination of raw milk by S. aureus, especially strains exhibiting multidrug resistance and biofilm-forming and toxin-producing abilities, remains an important issue for both dairy farmers and public health. In this study, we investigated the prevalence, antimicrobial susceptibility, biofilm formation, and genetic diversity of S. aureus from subclinical bovine mastitis in dairy farms located in southern Xinjiang, China. Sixty-five isolates from 84 subclinical mastitic milk samples were identified as S. aureus. The resistance rates to penicillin, erythromycin, clindamycin, tetracycline, gentamicin, linezolid, rifampicin, quinupudin-dafupudin, ciprofloxacin, norfloxacin, and chloramphenicol were 58.5, 44.6, 40.0, 18.5, 12.3, 10.8, 9.2, 6.2, 4.6, 4.6, and 1.5%, respectively. All isolates were susceptible to cefoxitin, sulfamethoxazole-trimethoprim, and vancomycin. Isolates from farm A showed a significantly higher resistance rate to tetracycline (16.9%) than those from farm B (1.5%). The most frequently detected virulence factors were hla (96.9%, 63/65) and hlb (100.0%, 65/65). The percentage rates of the staphylococcal enterotoxin genes sea, sec, sed, seg, seh, sei, and sej in S. aureus isolates were 4.6, 33.8, 27.7, 3.1, 41.5, 41.5, and 7.7%, respectively. The percentage rate of the sec gene in isolates from farm B (30.8%) was significantly higher than that of farm A (3.1%). The percentage rates of the tsst and pvl genes in S. aureus isolates were 26.2 and 40.0%. The percentage rate of the pvl gene in isolates from farm B (32.3%) was significantly higher than that of farm A (7.7%). The adhesion molecules fnbA, fnbB, clfA, clfB, and cna were detected in 21 (32.3%), 23 (35.4%), 65 (100.0%), 65 (100.0%), and 65 (100.0%) isolates, respectively. The percentage rates of the icaA, sarA, tcaR, ccp, luxS, and sigB genes in S. aureus isolates were 69.2, 100.0, 86.2, 95.4, 84.6, and 100.0%, respectively. The fnbB and icaA genes were more frequently detected in isolates from farm A (29.2 and 40.0%, respectively) than those from farm B (6.2 and 29.2%, respectively). The luxS gene was more often found in isolates from farm B (50.8%) than those from farm A (33.8%). Using the microplate method, 61.5, 26.2, and 10.8% of the isolates showed weak, moderate, and strong biofilm-forming abilities, respectively. Different clonal complex (CC) and spa-types were identified, including CC81, CC398, CC88, CC5405, and CC5406. Importantly, in this study we report for the first time 41 new sequence types (ST) among 44 distinct ST. These results indicated high genetic diversity of S. aureus involved in subclinical bovine mastitis in southern Xinjiang, China. The results also showed that S. aureus from subclinical bovine mastitis cases in southern Xinjiang, China, were mainly resistant to β-lactams, erythromycin, and clindamycin. Also, biofilm- and adhesion-related genes, which are increasingly known as important virulence factors in the pathogenesis of S. aureus infections, were detected at a high rate. This study could help identify predominant clones and provide surveillance measures to decrease or eliminate S. aureus contamination in raw milk of dairy cows with subclinical mastitis.
Objective To investigate the clinical epidemiological characteristics and drug resistance of methicillin-resistant Staphylococcus aureus(MRSA) and to instruct rational administration. Methods A retrospective observational study was carried out in the hospital from 2001 to 2007 years(2003 was not covered for the SARS attack),specimens isolated from sputum,urine and blood of the patients were investigated and the distribution of the type,resistance and epidemiological characteristics of MRSA were evaluated. Results ①3 745 (15.2%) Staphylococcus aureus were isolated.Staphylococcus aureus was in the second place in Staphylococci infection.Among them,MRSA was 3 480(97.2%),MSSA 274(7.3%).3 360(89.5%) MRSA were isolated from specimens of the patients above 60 years old.2 718 (78.1%) MRSA specimens were isolated from the hospital-acquired patients.762(21.9%) MRSA specimens were isolated from the community-acquired patients.Distributions of specimens were obtained 3 303 (94.9%) MRSA from sputum,71(2.0%) MRSA from urine and 106 (3.0%) MRSA from blood.②The detection rate of MRSA increased from 7.3% in 2001 to 17.1% in 2007. The yearly increasing tendency was notable(χ2=115.176,P=0.000).But the detection rate of MSSA did not change significantly.③Through 2001 to 2007,the average drug-resistance rate of MRSA to 20 commonly-used antibiotics was 79.9%,83.2%,78.4%,80.6%,77.1%,79.6%. MRSA had resistance to most antibiotic except vancocin.The top of them were penicillins,cephalosporins,macrolides,Ciprofloxacin.the drug-resistance rates of MRSA were above 80%.But the resistance to sulfamethoxine decreased yearly with 77.8%,69.7%,45.2%,31.6%,13.5%,3.8%. Conclusion The most impotant issues of nosocomial infections still are the increasing detection rate of MRSA and multidrug resistance to antibiotics.It is impotant to make the strategy of rational administration and to control and prevent nosocomial infection.
Streptococcus uberis is a common cause of mastitis. The pathogenicity among different strains of S. uberis and the resultant host immune responses remain to be elucidated. Herein, we document immune responses among three strains of S. uberis, and preliminary explore whether and how intestinal immunity plays a role in host anti-infection processes. Mice have been proved to be effective experimental animals for bovine mastitis, so utilizing a mouse intramammary infection model, we assay immune responses and gut flora changes of three S. uberis strains by histopathologic examination, RT-PCR, Western blot, and 16s ribosomal DNA sequencing. We find that the immune responses among the three sequence-type (ST) S. uberis strains may be linked to the hasA/B and lbp virulence genes, and the beta diversity of the intestine may be independent of the ST of S. uberis. Twenty phyla and 30 genera of intestinal flora were identified, with Verrucomicrobia and Akkermansia being the most prominent phylum and genus, respectively. These bacteria have strong anti-inflammatory and protective effects against S. uberis challenge. These data provide a foundation for further studies to elucidate gut flora function and exploration of therapeutic targets for mastitis.
Epidemic methicillin-resistant Staphylococcus aureus (MRSA) imposes an increasing impact on public health. Due to multi-antibiotics resistance in MRSA strains, there is an urgent need to develop novel therapeutics such as effective monoclonal antibodies (mAbs) against MRSA infections. Staphylococcus aureus surface protein A (SasA), a large surface-located protein (~240 kDa), is one of MSCRAMMs (microbial surface components recognizing adhesive matrix molecules) and a potential target for immunotherapeutic approaches against S. aureus infections. In the present study, we analyzed the sequence of SasA with bioinformatics tools and generated a protective monoclonal antibody (2H7) targeting the conserved domain of SasA. 2H7 was shown to recognize wild-type S. aureus and promote opsonophagocytic killing of S. aureus. In both sepsis and peritoneal infection models, prophylactic administration of 2H7 improved the survival of BALB/c mice challenged by S. aureus strain USA300 and ST239 (prevalent MRSA clones in North America and Asian countries, respectively) and enhanced bacterial clearance in kidneys. Additionally, 2H7 prophylaxis prevented the formation of intraperitoneal abscess in a murine model of peritoneal infection and therapeutic administration of 2H7 showed protective efficacy in a murine sepsis model. Our results presented here provide supporting evidences that an anti-SasA mAb might be a potential component in an antibody-based immunotherapeutic treatment of MRSA infections.
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