共查询到20条相似文献,搜索用时 15 毫秒
1.
W. Zhang X. Shen H. Zhang C. Wang Q. Deng L. Liu Y. Yang 《European journal of clinical microbiology & infectious diseases》2009,28(7):861-864
To investigate the molecular epidemiological analysis of methicillin-resistant Staphylococcus aureus (MRSA) isolates from
five pediatric hospitals in China. Seventy-three MRSA isolates were analyzed by a combination of different genotyping methods,
including multilocus sequence typing (MLST), SCCmec and spa typing. Panton-Valentine Leukocin (PVL) gene was also detected.
The prevalent strains were ST239-MRSA-III and ST1-MRSA clones in the northern region; ST239-MRSA-III, ST910-MRSA-IV and ST88-MRSA
in the eastern region; and ST59-MRSA in the southern region. Only the ST910-MRSA-IV clone has been found in China until now,
and it is closely related to ST30-MRSA-IV. All MRSA isolates were found to be resistant to penicillin and azithromycin, and
multidrug resistance was observed. The cases of necrotic pneumonia, severe skin and subcutaneous tissue infection and lymphadenitis
resulted from PVL gene-positive MRSA. There were several novel genetic types of MRSA. Antimicrobial susceptibility tests showed
high resistance of many antimicrobials and multiple drugs. 相似文献
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3.
Molecular cloning and expression of the epidermolytic toxin A gene of Staphylococcus aureus 总被引:7,自引:0,他引:7
The gene coding for serotype A of epidermolytic (exfoliative) toxin has been cloned from Staphylococcus aureus in Escherichia coli phage lambda and plasmid vectors. The coding sequence for eta was localised by subcloning and transposon Tn5 mutagenesis experiments. The eta gene was probably expressed from its natural promoter in E. coli. The protein synthesised in E. coli was located predominantly in the periplasm. It was immunochemically indistinguishable from the toxin purified from S. aureus culture supernatants and had the same molecular weight. Furthermore, subcutaneous injection of this material caused epidermal splitting (the Nikolsky reaction) showing that it was biologically active. An eta shuttle plasmid was transformed into protoplasts of S. aureus. The level of expression of toxin in strain 8325-4 was shown to be dependent on the integrity of the agr gene which is known to be required for the expression of several exoproteins. 相似文献
4.
Biomaterials-centered infections are serious complications associated with the use of implants. The infection risk of biomaterials varies between different materials and is determined by the chemical composition of materials, the host proteins and the type of bacteria. In this study we measured the initial adhesion of Staphylococcus aureus onto polystyrene derivatives containing carboxylate and sulfonate groups. Five polymers were synthesized and characterized. We studied the role of the host protein fibronectin in promoting adhesion of Staphylococcus aureus. Fibronectin adsorption was comparable on all the tested polymers (pKd=7.2±0.2) whereas bacterial adhesion was dependent on surfaces chemical compositions. Polymers substituted with sulfonate groups showed the most important inhibition of initial bacterial adhesion. 相似文献
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6.
Raju Sunagar Shripad A. Patil R. Kelmani Chandrakanth 《Research in microbiology》2010,161(10):854-860
The protective effect of bacteriophage was assessed against experimental Staphylococcus aureus lethal bacteremia in streptozotocin (STZ) induced-diabetic and non-diabetic mice. Intraperitoneal administrations of S. aureus (RCS21) of 2 × 108 CFU caused lethal bacteremia in both diabetic and non-diabetic mice. A single administration of a newly isolated lytic phage strain (GRCS) significantly protected diabetic and non-diabetic mice from lethal bacteremia (survival rate 90% and 100% for diabetic and non-diabetic bacteremic groups versus 0% for saline-treated groups). Comparison of phage therapy to oxacillin treatment showed a significant decrease in RCS21 of 5 and 3 log units in diabetic and non-diabetic bacteremic mice, respectively. The same protection efficiency of phage GRCS was attained even when the treatment was delayed up to 4 h in both diabetic and non-diabetic bacteremic mice. Inoculation of mice with a high dose (1010 PFU) of phage GRCS alone produced no adverse effects attributable to the phage per se. These results suggest that phages could constitute valuable prophylaxis against S. aureus infections, especially in immunocompromised patients. 相似文献
7.
A. Vainio S. Koskela A. Virolainen J. Vuopio S. Salmenlinna 《European journal of clinical microbiology & infectious diseases》2011,30(6):789-797
Laboratory-based surveillance of methicillin-resistant Staphylococcus aureus (MRSA) monitors the baseline occurrence of different genotypes and identifies strains and transmission chains responsible
for outbreaks. The consequences of substituting pulsed-field gel electrophoresis (PFGE) with spa typing as a first-line typing method were analyzed by typing 589 strains isolated between 1997 and 2006, with a focus on
both short- and long-term correspondence between the PFGE and spa typing results. The study, covering these ten years, included all Finnish MRSA blood isolates and representatives of the
two most prevalent MRSA strains (PFGE types FIN-4 and FIN-16) in Finland. In addition, all sporadic isolates from 2006 were
included. spa typing was more expensive but approximately four times faster to perform than PFGE. Nearly 90% of FIN-4 and FIN-16 isolates
showed consistent spa types, t172 and t067, respectively. spa typing predicted the PFGE result of the blood isolates by a Wallace coefficient of 0.9009, recognized internationally successful
strains (t041, t067) to be common also in Finland, and identified a separate cluster of isolates, also related in time and
place among the FIN-4 strains. Additional typing by another method was needed to provide adequate discrimination or to characterize
isolates with a newly recognized spa type in Finland. 相似文献
8.
David C. Coleman John P. Arbuthnott Harriet M. Pomeroy T. Harry Birkbeck 《Microbial pathogenesis》1986,1(6):549-564
The beta-lysin determinant (Hlb) from Staphylococcus aureus CN6708 was cloned in Escherichia coli K-12 using the bacteriophage replacement vector lambda L47.1. The Hlb determinant was localised to a 1250 base pair DNA sequence by cloning fragments from a Hlb+ recombinant phage into the plasmid vectors pACYC184 and pBR322 in E. coli K-12, and by the subsequent construction and analysis of several sub-clones, in vitro deletion and Tn5 insertion mutations. E. coli cells harbouring Hlb+ plasmids expressed readily detectable levels of beta-lysin and sphingomyelinase activity, which were located in the cytoplasm. Two polypeptides of molecular weight 38,000 and 33,000 which were encoded by the Hlb determinant were detected in E. coli minicells, but only the 33,000 dalton protein was detected in immunoblotting experiments with specific anti-beta-lysin serum. Hybridisation analysis with probes made from the cloned Hlb determinant and from DNA of the staphylokinase-converting phage phi 13, indicated that bacteriophage conversion of S. aureus to loss of beta-lysin activity is due to insertion of phi 13 DNA into or adjacent to the beta-lysin determinant. A shuttle plasmid was used to transfer the cloned Hlb determinant into a beta-lysin negative strain of S. aureus where the wild-type chromosomal determinant was inactivated by lysogenic conversion. Beta-lysin activity was readily detected in supernatants of S. aureus harbouring the cloned determinant. 相似文献
9.
B. Quintero M. Araque C. van der Gaast-de Jongh F. Escalona M. Correa S. Morillo-Puente S. Vielma P. W. M. Hermans 《European journal of clinical microbiology & infectious diseases》2011,30(1):7-19
Streptococcus pneumoniae and Staphylococcus aureus cause significant morbidity and mortality worldwide. We investigated both the colonization and co-colonization characteristics
for these pathogens among 250 healthy children from 2 to 5 years of age in Merida, Venezuela, in 2007. The prevalence of S. pneumoniae colonization, S. aureus colonization, and S. pneumoniae–S. aureus co-colonization was 28%, 56%, and 16%, respectively. Pneumococcal serotypes 6B (14%), 19F (12%), 23F (12%), 15 (9%), 6A (8%),
11 (8%), 23A (6%), and 34 (6%) were the most prevalent. Non-respiratory atopy was a risk factor for S. aureus colonization (p = 0.017). Vaccine serotypes were negatively associated with preceding respiratory infection (p = 0.02) and with S. aureus colonization (p = 0.03). We observed a high prevalence of pneumococcal resistance against trimethoprim–sulfamethoxazole (40%), erythromycin
(38%), and penicillin (14%). Semi-quantitative measurement of pneumococcal colonization density showed that children with
young siblings and low socioeconomic status were more densely colonized (p = 0.02 and p = 0.02, respectively). In contrast, trimethoprim–sulfamethoxazole- and multidrug-resistant-pneumococci colonized children
sparsely (p = 0.03 and p = 0.01, respectively). Our data form an important basis to monitor the future impact of pneumococcal vaccination on bacterial
colonization, as well as to recommend a rationalized and restrictive antimicrobial use in our community. 相似文献
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P. Munro R. Clément J.-P. Lavigne C. Pulcini E. Lemichez L. Landraud 《European journal of clinical microbiology & infectious diseases》2011,30(8):965-972
Staphylococcus aureus, a major causative agent of human infection, produces a large array of virulence factors, including various toxins. Among
them, the host RhoA GTPase ADP-ribosylating EDIN toxins are considered as potential virulence factors. Using the polymerase
chain reaction (PCR) assay, we analyzed the virulence profile of 256 S. aureus isolates from various clinical sites of infections. We developed specific primers to detect the three isoforms of edin-encoding genes. We found a prevalence of 14% (36 bacteria) of edin-encoding genes among these clinical isolates. Strikingly, we found that 90% of all edin-bearing S. aureus isolates carried the type-C allele. Both the spa types and the profile of virulence factors of these edin-positive isolates are highly variable. Notably, we show for the first time that edin-C-positive isolates were more frequently recovered from deep-seated infections than other types of infections. Our present
work, thus, strongly suggests that the presence of edin-C is a risk factor of S. aureus dissemination in tissues and, thus, represents a predictive marker for a pejorative evolution of staphylococcal infections. 相似文献
12.
T. Stenholm A. J. Hakanen S. Salmenlinna S. Pihlasalo H. H?rm? P. E. H?nninen P. Huovinen J. Vuopio P. Kotilainen 《European journal of clinical microbiology & infectious diseases》2011,30(10):1237-1243
The aim of this study was to evaluate a new type of assay for the phenotypic detection of methicillin-resistant Staphylococcus aureus (MRSA). The assay is based on a point-of-care compatible two-photon excitation fluorescence detection technology (TPX). A collection of 243 epidemic MRSA isolates was tested in addition to 138 sporadic MRSA and 101 negative control strains. The assay proved to be both sensitive (97.9%) and specific (94.1%) in the identification of MRSA, with adequate positive (98.4%) and negative (92.2%) predictive values. The time required for obtaining a positive test result was less than 14 h for 99.0% of the MRSA true-positive samples. After a test run, the selectively enriched reaction mixtures may be recovered and further studied by molecular or standard phenotypic methods. The main benefits of the TPX methodology include a simple assay procedure, low reagent consumption, and a high-throughput capacity. 相似文献
13.
Thomas B. Buxton J. Peter Rissing Jack A. Horner Kent M. Plowman David F. Scott Terry J. Sprinkle Gary K. Best 《Microbial pathogenesis》1990,8(6)
We contrasted the collagen-binding potential of the experimental osteomyelitis pathogen, Staphylococcus aureus strain SMH, to several other strains. These included Cowan 1 (binder), Wood 46 (non-binder) and six capsular variants. These measurements were made using an 125I-collagen binding assay. Formalin-killed S. aureus SMH strongly bound commercial type I iodinated collagen (dissociation contant, Kd = 2 × 10−9 m). The extent of binding was similar to Cowan 1. Binding was saturable and not inhibited by 100 m
solutions of
-glucose,
-galactose,
-mannose, methyl-α-
-fucopyranoside,
-hydroxyproline or
-glycine.
-lactose gave moderate inhibition of binding to collagen, and
-fucose was strongly inhibitory. Trypsinized SMH did not bind collagen. None of four Ruthenium-red-staining staphylococci (encapsulated) avidly bound type I collagen. The encapsulated Smith strain, for example, did not bind to collagen but its capsule-negative variant, Smith compact, showed extensive binding. Three of five non-encapsulated S. aureus were strong collagen binders. These data suggest that the prototype bone pathogen binds to the major protein component of bone's extracellular matrix. Collagen-binding is promoted by protein adhesin(s), not capsule. The latter, in fact, appeared to interfere with this interaction. Binding was inhibited by solutions containing the simple monosaccharide,
-fucose. 相似文献
14.
G. I. Andriesse S. Elberts A. Vrolijk C. Verhulst J. A. J. W. Kluytmans 《European journal of clinical microbiology & infectious diseases》2011,30(2):259-264
In this study, we evaluated a fourth-generation agglutination assay (Staph Plus; DiaMondiaL[DML]) for the rapid identification
of Staphylococcus aureus. First, comparison with three third-generation assays (Slidex Staph Plus, bioMérieux; Staphaurex Plus, Murex Diagnostics;
Pastorex Staph-Plus, Sanofi Diagnostics Pasteur) was performed on a predefined strain collection: 265 coagulase-negative staphylococci
(CNS), 266 methicillin-resistant S. aureus (MRSA) and 262 methicillin-susceptible S. aureus (MSSA) strains (“strain study”). Second, patient material-derived strains (883 CNS, 847 MSSA and 135 MRSA) were tested concurrently
with both the DML and Slidex assays (“daily practice study”). In the strain study, the overall sensitivity and specificity
of the DML, Slidex, Staphaurex and Pastorex assays were 99.2% and 100%, 98.1% and 100%, 95.2% and 100%, and 98.2% and 98.8%,
respectively. Using the respective tests, the result was indeterminate in 0.0%, 0.6%, 0.4% and 1.5% of the strains. Overall,
the sensitivity of the DML and Slidex assays were comparable in both sub-studies. However, in MRSA strains, the sensitivity
of the DML assay was significantly lower than the Slidex assay. The specificity of the Slidex assay was significantly higher
than the DML assay. However, the percentage of indeterminate results was much higher for the Slidex than the DML assay. In
conclusion, the presumptive identification of S. aureus by the DML assay proved to be equal to third-generation latex agglutination assays. 相似文献
15.
Previously we observed that Staphylococcus aureus phagocytized by cultured bovine endothelial cells do not proliferate intracellularly, but are cytotoxic to bovine endothelial cells. To investigate S. aureus virulence factors which may be produced intracellularly and cause lysis of endothelial cells, we tested S. aureus mutants defective in production of one or more potential virulence factors and corresponding parent strains for cytotoxicity to endothelial cell monolayers subsequent to being ingested. Following incubation of endothelial cell monolayers with S. aureus for 3.5 h, cultures were supplemented with lysostaphin to destroy extracellular but not intracellular S. aureus. At subsequent times, viability of endothelial cells was assayed by retention of 3H-adenine and the number of intracellular S. aureus was measured. The cytotoxic activity of S. aureus culture supernatants was also characterized. The results indicate that S. aureus α-hemolysin is cytotoxic to bovine endothelial cells and plays an important role in the damage suffered by bovine endothelial cell monolayers following ingestion of S. aureus. Ingestion of α-hemolysin-producing S. aureus by endothelial cells in vivo might be expected to result in destruction of endothelium followed by development of platelet-fibrin vegetations. This possible sequence of events is compatible with the frequently fulminant course of S. aureus endocarditis. 相似文献
16.
V. Saegeman J. Flamaing J. Muller W. E. Peetermans J. Stuyck J. Verhaegen 《European journal of clinical microbiology & infectious diseases》2011,30(8):943-949
The screening for and diagnosis of bacteriological infections often involves the collection and transportation of swab samples.
The Copan ESwab was compared with the dry cotton Copan swab for methicillin-resistant Staphylococcus aureus (MRSA) screening (n = 200 paired samples) and with the Amies agar gel swab (Copan) for the sampling of burn and orthopaedic wounds (n = 203 paired samples) in terms of Gram staining and bacterial recovery. Gram stains performed with ESwab liquid showed significantly
more Gram-negative rods, streptococci, Gram-positive cocci, Gram-positive rods, polymorphonuclear cells, lymphocytes and red
blood cells than Gram stains from dry swabs. Bacterial recovery was significantly higher with ESwab (p < 0.01, for both MRSA screening and wounds, quantitative/semi-quantitative method). This lead to a slightly higher detection
rate of MRSA (128 vs. 124 MRSA-positive ESwabs and dry swabs, respectively, p = 0.50) and a higher detection rate of coagulase-negative Staphylococcus spp. (44 isolates with ESwab vs. 29 with Amies gel swab, p = 0.001) and Enterococcus spp. (15 isolates with ESwab vs. 7 isolates with Amies gel swab, p = 0.005) with ESwab (quantitative method). We confirmed that ESwab has a high performance for Gram stains and a higher bacterial
recovery than dry and Amies gel swabs when using clinical samples for MRSA screening and wound sampling. 相似文献
17.
T. M?lk?nen E. Ruotsalainen C. W. Thorball A. J?rvinen 《European journal of clinical microbiology & infectious diseases》2011,30(11):1417-1424
The soluble form of urokinase-type plasminogen activator receptor (suPAR) is a new inflammatory marker. High suPAR levels
have been shown to associate with mortality in cancer and in chronic infections like HIV and tuberculosis, but reports on
the role of suPAR in acute bacteremic infections are scarce. To elucidate the role of suPAR in a common bacteremic infection,
the serum suPAR levels in 59 patients with Staphylococcus aureus bacteremia (SAB) were measured using the suPARnostic™ ELISA assay and associations to 1-month mortality and with deep infection
focus were analyzed. On day three, after the first positive blood culture for S. aureus, suPAR levels were higher in 19 fatalities (median 12.3; range 5.7–64.6 ng/mL) than in 40 survivors (median 8.4; range 3.7–17.6 ng/mL,
p = 0.002). This difference persisted for 10 days. The presence of deep infection focus was not associated with elevated suPAR
levels as compared to patients with no deep infection focus. suPAR was found to be prognostic for mortality in receiver operator
characteristic (ROC) curve analysis, which was not observed for serum C-reactive protein (CRP); the area under the curve (AUC)
for suPAR was 0.754 (95% confidence interval [CI], 0.615–0.894, p = 0.003) and for CRP, it was 0.596 (95% CI, 0.442–0.750, p = 0.253). The optimal suPAR cut-off value in predicting 1-month mortality was 9.25 ng/mL. In conclusion, our study demonstrates
that the new promising biomarker, serum suPAR concentration, was able to predict mortality in SAB. 相似文献
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D. Youssef B. Bailey A. El-Abbassi M. Vannoy T. Manning J. P. Moorman A. N. Peiris 《European journal of clinical microbiology & infectious diseases》2012,31(3):281-286
Methicillin resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa (P. aeruginosa) infections are frequently associated with hospitalization and increased healthcare costs. Vitamin D deficiency may contribute
to increased costs for patients with these infections and there is evidence that vitamin D may have an antimicrobial role.
To evaluate the role of vitamin D deficiency in the costs incurred with these infections, we studied the relationship of serum
25(OH)D levels to healthcare costs in veterans in the southeastern United States. Patients with both infections were vitamin
D deficient to a similar extent and so were combined for further analysis. Vitamin D deficient patients had higher costs and
service utilization than those who were not vitamin D deficient. Those with vitamin D deficiency had higher inpatient costs
compared to the non-deficient group, and this difference was across most categories except for the number of inpatient hospitalizations
or total number of days as an inpatient. Vitamin D deficiency was not significantly related to outpatient cost or service
utilization parameters. We conclude that vitamin D deficiency is intimately linked to adverse healthcare costs in veterans
with MRSA and P. aeruginosa infections. Vitamin D status should be assayed in patients with these infections. 相似文献
20.
Filleron A Chiron R Reverdy ME Jean-Pierre H Dumitrescu O Aleyrangues L Counil F Jumas-Bilak E Marchandin H 《European journal of clinical microbiology & infectious diseases》2012,31(4):599-604
Glycopeptide-intermediate S. aureus (GISA), particularly heterogeneous GISA (hGISA), remain difficult to detect in the routine practice of medical microbiology.
Novel tools have been evaluated comparatively to the population analysis profile-area under the curve (PAP-AUC) reference
method for detecting GISA/hGISA. Among them, the Etest GRD showed relatively high specificity (85.8–97%) and negative predictive
value (97%) but lower sensibility (57–95%) and positive predictive value (30.8%). We investigated the utility of the Etest
GRD for detecting GISA/hGISA among 180 strains isolated from 106 cystic fibrosis (CF) patients. Etest GRD was performed on
all isolates, and those exhibiting a GISA/hGISA phenotype were further tested by PAP-AUC and other agar routine assays for
GISA/hGISA detection. The Etest GRD allowed the detection of 15 GISA/hGISA strains, of which eight were confirmed by the reference
method. Despite the 3.9% level of false positive results, the Etest GRD constitutes a useful routine tool for detecting GISA/hGISA
overlooked by other routine assays, two strains being detected by the Etest GRD only. GISA/hGISA represented 7.7% of MRSA
and 2.1% of MSSA, and were found in 4.7% of CF patients colonized/infected by S. aureus, which is the highest rate reported to date in this population. 相似文献