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PubMed2000

Fed-batch production of recombinant human calcitonin precursor fusion protein using Staphylococcus carnosus as an expression-secretion system.

A pH-auxostatic fed-batch process was developed for the secretory production of a fusion protein consisting of the pro-part of Staphylococcus hyicus lipase and two synthetic human calcitonin (hCT) precursor repeats under the control of a xylose-inducible promotor from Staphylococcus xylosus. Using glycerol as the energy source and pH-controlled addition of yeast extract resulted in the production of 2000 mg 1(-1) of the fusion protein (420 mg 1(-1) of the recombinant hCT precursor) within 14 h, reaching 45 g 1(-1) cell dry mass with Staphylococcus carnosus in a stirred-tank reactor. Product titer and space-time yield (30 mg calcitonin precursor 1(-1) h(-1)) were thus improved by a factor of 2, and 4.5, respectively, compared to Escherichia coli expression-secretion systems for the production of calcitonin precursors. Two hundred grams of the fusion protein was secreted by the recombinant S. carnosus on a 150-1 scale (scale-up factor of 50) with a minimum use of technical-grade yeast extract (40 mg fusion protein g(-1) yeast extract).

Amino Acids↗

PubMed2006

Different photoresponses of Staphylococcus aureus and Pseudomonas aeruginosa to 514, 532, and 633 nm low level lasers in vitro.

Low Level Light irradiation (LLLI) may proliferate cell growth at certain conditions during a set of photochemical reactions called biostimulation. However, phototoxic inhibitory reactions after irradiating natural or artificially inoculated cells are possible. The purpose of this study was to determine these effects on Pseudomonas aeruginosa and Staphylococcus aureus. Ar ion laser at 514 nm was used to determine the effect of various energy densities of green light on these bacteria. The most effective energy densities of Ar ion laser were chosen to irradiate both bacteria with He-Ne (633 nm) and SHG Nd:YAG (532 nm) lasers to compare the effect of red and green lights on the growth. Irradiation of Pseudomonas aeruginosa for both He-Ne and SHG Nd:YAG lasers in the presence of toluidine blue O or safranine O as photosensitizers was also studied. All energy densities of Ar ion laser showed a proliferative effect on Pseudomonas aeruginosa and inhibitory effect on Staphylococcus aureus. Similarly, SHG Nd:YAG and He-Ne lasers with chosen energy densities were again proliferating for Pseudomonas aeruginosa and inhibitory for Staphylococcus aureus and SHG Nd:YAG was more effective than He-Ne in both cases. Irradiation of Pseudomonas aeruginosa in the presence of both photosensitizers led to the decrease of the cell population compared to the control.

Argon↗

PubMed2006

Expression of TNF-alpha, IL-1beta, and IFN-gamma in Staphylococcus epidermidis slime-positive experimental endophthalmitis is closely related to clinical inflammatory scores.

PURPOSE: The purpose of this study was to investigate the expression of inflammatory cytokines TNF-alpha, IL-1beta, and IFN-gamma in the vitreous after experimentally induced endophthalmitis by a Staphylococcus epidermidis slime-producing strain. METHODS: Seventy-two experimental Lewis rats received an intravitreal injection of 7000 viable organisms of Staphylococcus epidermidis slime-producing ATCC strain 35983, while 72 control rats received an intravitreal injection of sterile normal saline. Eyes were graded daily for signs of clinical inflammation and were removed 6, 12, 24, 48, 72 h, and 7 days after injection. Vitreous was obtained and titers of TNF-alpha, IL-1beta, and IFN-gamma were measured with established enzyme-linked immunosorbent assays. RESULTS: In the experimental group, the clinical inflammatory score reached maximum (4+) within 24 h, while inflammation was almost abolished by day 7 (score 0-0.5+). Statistically increased levels of TNF-alpha and IL-1beta were detected in the experimental vitreous with maximum levels observed at 12 h. IFN-gamma was also detected in the experimental vitreous and reached maximum levels at 48 h. None of the cytokines examined was detected in sera at any time point in experimental or control rats. CONCLUSIONS: The results of this study suggest that Staphylococcus epidermidis experimental endophthalmitis induces the expression of cytokines TNF-alpha, IL-1beta, and IFN-gamma in the vitreous. The time course of those cytokine expression levels is closely associated to the clinical presentation of this endophthalmitis model.

Animals↗

PubMed2001

Experimental treatment of vascular graft infection due to Staphylococcus epidermidis by in situ replacement with a rifampin-bonded polyester graft.

In situ prosthetic graft replacement (ISPGR) of an infected prosthesis raises the risk of recurrent infection in the new graft, especially in cases involving drug-resistant microorganisms. The purpose of this animal study was to evaluate in situ replacement of a vascular graft infected by a highly rifampin-resistant strain of Staphylococcus epidermidis with the use of a rifampin-bonded polyester graft. Antibiotic bonding was obtained by soaking grafts in a high dose of rifampin solution (60 mg/mL). The infrarenal abdominal aorta of 20 dogs was replaced using a polyester prosthesis infected with a highly rifampin-resistant strain of Staphylococcus epidermidis. One week later, the 18 surviving animals were randomized into three groups. Group I (n = 6) did not undergo reoperation. Group II (n = 6) underwent ISPGR using a rifampin-bonded prosthesis. Group III (n = 6) underwent ISPGR using an untreated prosthesis. All surviving animals were killed 28 days after the first procedure. Infectious signs were noted and bacteriological study was carried out on explanted prostheses and various tissue samples. The findings of this experimental study show that soaking a polyester prosthesis in a high-dose rifampin solution can prevent reinfection after in situ replacement of a prosthesis infected by a highly rifampin-resistant Staphylococcus epidermidis.

Anastomosis, Surgical↗

PubMed2003

Subacute necrotizing fasciitis caused by gas-producing Staphylococcus aureus.

Presented here is a case of necrotizing fasciitis that developed bilaterally on the thighs of a 54-year-old diabetic woman following subcutaneous insulin injection. Severe localized pain was the presenting symptom; later, soft-tissue gas appeared. Incisional biopsy, performed on day 10 following admission, confirmed the diagnosis. Staphylococcus aureus was the only pathogen isolated. The disease had a slowly progressive course despite appropriate medical treatment, and recovery of the patient was achieved only after fasciotomy, drainage, and debridement of necrotic tissue was undertaken 4 weeks following admission. Staphylococcus aureus may cause subacute necrotizing fasciitis, and infection with this organism should be considered in cases of soft-tissue infection with gas formation in diabetics. The development of soft-tissue infection at the site of insulin injection should alert physicians to the possibility of infection with Staphylococcus aureus.

Anti-Bacterial Agents↗

PubMed2004

Rapid diagnosis of Staphylococcus aureus bacteremia using S. aureus PNA FISH.

In the study presented here, the performance of the S. aureus PNA FISH assay was evaluated using 285 blood cultures (from 104 patients) that had gram-positive cocci resembling staphylococci on Gram stain. The new molecular test is based on a fluorescence in situ hybridization assay using peptide nucleic acid probes targeting Staphylococcus aureus 16S rRNA and is designed for the rapid identification of Staphylococcus aureus directly from positive blood cultures. The sensitivity, specificity, and positive and negative predictive values of the S. aureus PNA FISH for the rapid identification of Staphylococcus aureus directly from positive blood culture bottles were 100, 99.4, 99.2 and 100%, respectively.

Bacteremia↗

PubMed2000

Molecular epidemiology of methicillin-resistant Staphylococcus aureus in Finland.

This study reports the recent trends in the occurrence of methicillin-resistant Staphylococcus aureus in Finland, with special focus on characterization of the strains linked to interhospital epidemics and local outbreaks. Between 1981 and 1997, the annual number of methicillin-resistant Staphylococcus aureus isolations ranged from 89 to 272. Of all blood isolates of Staphylococcus aureus reported to the National Infectious Disease Register during the period 1995-97 (n = 2049), only six were resistant to methicillin. Between 1992 and 1997, typing analysis by various methods (i.e., antibiogram, phage typing, ribotyping, and pulsed-field gel electrophoresis) identified 18 different strains capable of causing intrahospital outbreaks or interhospital epidemics. These 18 strains were separated into 13 different ribotypes and 14 major pulsed-field gel electrophoresis types. Multiresistance was investigated as a possible marker for epidemicity. Eight of the ten interhospitally spread strains were multiresistant compared to only three of the eight intrahospitally spread outbreak strains. More than one-third of the epidemic and local outbreak strains were suspected to be of foreign origin. The majority (6 of 10) of the epidemics were localized in southern and western Finland, and the largest epidemic, which occurred in the Helsinki metropolitan area, involved over 200 persons. Thus far, the epidemics have remained primarily intracity problems, and only two strains have become endemic.

Anti-Bacterial Agents↗

PubMed2002

Comparison of the bactericidal activities and post-antibiotic effects of the Des-F(6)-quinolone BMS-284756, levofloxacin, and ciprofloxacin against methicillin-susceptible and methicillin-resistant Staphylococcus aureus.

The bactericidal activities and post-antibiotic effects of BMS-284756 (T-3811ME), levofloxacin, and ciprofloxacin were evaluated against a methicillin-susceptible and a methicillin-resistant Staphylococcus aureus strain. Minimum inhibitory concentrations (MICs), minimum bactericidal concentrations, post-antibiotic effects, and post-antibiotic sub-MIC effects were determined and time-kill studies were performed for BMS-284756, levofloxacin, and ciprofloxacin. At 4-times and 10-times the MIC, time-kill kinetics over 3 h and over 24 h were similar for all three quinolones when effects were considered as multiples of the MIC. All three quinolones achieved a 3 log10 reduction in cfu/ml within 2 h. At 10-times the MIC, the post-antibiotic effects of BMS-284756, levofloxacin, and ciprofloxacin were 1.6-2.6 h for the methicillin-susceptible Staphylococcus aureus strain and 1.5-1.9 h for the methicillin-resistant Staphylococcus aureus strain. When actual concentrations were considered, BMS-284756 achieved results comparable to levofloxacin and ciprofloxacin at concentrations nearly 10-fold less. When relating the pharmacokinetic properties of the three quinolones to their in vitro activities, the resulting Cmax/MIC and AUC/MIC ratios were. respectively, 120-240.7 and 1,321.7-2,643 for BMS-284756, 22.8 and 190 for levofloxacin, and 5.9-11.9 and 54.8-109.6 for ciprofloxacin. The greater in vitro activity and favorable human pharmacokinetics of BMS-284756 may translate to improved clinical effectiveness of this agent compared to currently marketed quinolones.

Anti-Infective Agents↗

PubMedDate not supplied

Persistent wound infection after herniotomy associated with small-colony variants of Staphylococcus aureus.

A small-colony variant (SCV) of Staphylococcus aureus was cultured from a patient with a persistent wound infection (abscess and fistula) 13 months after herniotomy. The strain was nonhemolytic, nonpigmented and grew only anaerobically on Schaedler agar. As it was coagulase-negative, it was initially misidentified as a coagulase-negative Staphylococcus. In further analysis, however, the microorganism was shown to be an auxotroph that reverted to normal growth and morphology in the presence of menadione and hemin (Schaedler agar) and could be identified as a SCV of Staphylococcus aureus. Surgery and antibiotic treatment of the patient with flucloxacillin and rifampicin for 4 weeks resulted in healing of the chronic wound infection.

Abdominal Abscess↗

PubMed1995

Characterisation of a synergohymenotropic toxin produced by Staphylococcus intermedius.

Staphylococcal synergohymenotropic (SHT) toxins damage membranes of host defence cells and erythrocytes by the synergy of two secreted and non-associated proteins: class S and class F components. Whereas Panton-Valentine leucocidin (PVL), gamma-hemolysin and Luk-M from Staphylococcus aureus are members of this toxin family, a new bi-component toxin (LukS-I + LukF-I) from Staphylococcus intermedius, a pathogen for small animals, was characterised and sequenced. It is encoded as a luk-I operon by two cotranscribed genes, like PVL, LukS-I + LukF-I shares a strong leukotoxicity of various PMNs, but only slight haemolytic properties on rabbit erythrocytes. When intradermally injected into rabbit skin, a 100 ng dose caused acute inflammatory reaction leading to tissue necrosis. The new SHT seemed to be largely distributed among various Staphylococcus intermedius strains.

Amino Acid Sequence↗

PubMed1990

Isolation of a plasmid from "canine" Staphylococcus epidermidis mediating constitutive resistance to macrolides and lincosamides.

A small plasmid of 2.5 kB mediating constitutive resistance to macrolide-lincosamide-(ML)antibiotics could be detected in a "canine" Staphylococcus epidermidis-culture. This plasmid, designated as pSES 1, was identified by interspecies protoplast transformation into Staphylococcus aureus RN 4220. A detailed restriction map of pSES 1 could be constructed using the restriction endonucleases Acc I, Bcl I, Cfo I, Cla I, Hind III, Hinf I, Mbo I, Sst I and Taq I. This map allowed structural comparisons of pSES 1 with plasmids from "human" Staphylococcus- and Bacillus-species, also mediating macrolide-lincosamide resistance (MLR). On the basis of its restriction map, pSES 1 proved to be similar to the plasmids pNE 131 from "human" S. epidermidis, pE 194 from "human" S. aureus and pIM 13 from B. subtilis.

Animals↗

PubMed1991

Nasal carriage of methicillin-resistant Staphylococcus aureus by hospital staff in north Jordan.

The nasal carriage of methicillin-resistant Staphylococcus aureus was detected in 550 hospital staff members of four hospitals in north Jordan. Of the 109 (19.8%) individuals tested who were nasal carriers of S. aureus, only 32 (5.8%) were found to be carriers of methicillin-resistant Staphylococcus aureus. The carriers were four doctors, 23 nurses, three laboratory technicians, one maid and an administrator. It was noted that 25 (78.1%) of these carriers were in constant contact with patients in operating theatres, surgical wards or intensive care units. It was not clear whether the carriers were short- or long-term carriers, or whether they were persistent sources of methicillin-resistant Staphylococcus aureus. Decontamination of these carriers was considered among other control measures to avoid the dangerous outcome of hospital outbreaks caused by this potential pathogen.

Female↗

PubMed1991

Cloning and expression of various staphylococcal genes encoding urease in Staphylococcus carnosus.

The urease genes from Staphylococcus xylosus C2a, Staphylococcus aureus U500, and S. aureus Newman were cloned in Staphylococcus carnosus using the plasmid vectors pCA43 and pCA44. The resulting respective recombinant plasmids pUra 402, pUraUH66, and pUra17 contained chromosomal DNA fragments with sizes of 5.6, 5.8, and 6.8 kb, respectively. Investigations on urease expression of the donor and recombinant strains in media with various nitrogen sources revealed that S. xylosus C2a produced urease constitutively at the highest specific activity. All of the recombinant strains had significantly lower urease activities than their DNA-donor strains. The nickel-dependence of urease was demonstrated in S. aureus U500 by a plate diffusion assay.

Cloning, Molecular↗

PubMed1992

Cloning and sequencing of a plasmid-mediated erythromycin resistance determinant from Staphylococcus xylosus.

A 2.3-kb DNA fragment cloned from plasmid pCH200, the largest (52 kb) of four plasmids detected in Staphylococcus xylosus, was found to confer resistance to 14-membered ring macrolides in Bacillus subtilis and Staphylococcus aureus. DNA-sequence analysis of the fragment revealed the presence of an open-reading frame, the deduced product of which was identical to one of the two ATP-binding domains encoded by the macrolide/streptogramin-B-resistance gene msrA of Staphylococcus epidermidis. The observation that a polypeptide homologous to the C-terminus of MsrA is capable of mediating erythromycin resistance in the absence of the N-terminal region is of significance both to the evolution and functional activity of members of the ATP-binding transport super-gene family.

Amino Acid Sequence↗

PubMed1992

Co-transfer of vancomycin and other resistance genes from Enterococcus faecalis NCTC 12201 to Staphylococcus aureus.

Conjugative transfer, in the apparent absence of plasmid DNA, of high-level vancomycin resistance from Enterococcus faecalis NCTC 12201 to Staphylococcus aureus B111 has been demonstrated in vivo and in vitro. Selection of transconjugants on media containing erythromycin or chloramphenicol may result in the transfer of resistance to erythromycin, chloramphenicol, gentamicin, streptomycin and vancomycin though these are capable of separate transfer. Vancomycin resistance has not been transmitted from staphylococcus to staphylococcus though transfer of erythromycin and of chloramphenicol resistance has been achieved.

Conjugation, Genetic↗

PubMed1994

Emerging chloramphenicol resistance in Staphylococcus lentus from mink following chloramphenicol treatment: characterisation of the resistance genes.

A total of 26 staphylococcal strains isolated from mink with urinary tract infections as well as from the environment of the mink were examined for antibiotic resistance and prevalence of plasmids mediating resistance to the antibiotics applied for prophylactic or therapeutic purposes. Chloramphenicol resistance (Cmr) which occurred in fourteen of the eighteen Staphylococcus lentus strains, but in none of the Staphylococcus intermedius and Staphylococcus xylosus strains, was shown to be mediated by small plasmids of 3.6 to 4.6 kb. On the basis of restriction endonuclease mapping and hybridization experiments, four different types of Cmr plasmids, designated pSCS14-17, could be distinguished. All these plasmids conferred Cmr by encoding the Cm-inactivating enzyme chloramphenicol acetyltransferase (CAT). In all four types of Cmr plasmids from S. lentus, the expression of the cat gene was inducible with Cm, as demonstrated by enzymatic assay and polyacrylamide gel electrophoresis.

Animals↗

PubMed1984

Incidence, adherence, and antibiotic resistance of coagulase-negative Staphylococcus species causing human disease.

Fifty-two isolates of coagulase-negative Staphylococcus species recovered from the blood or intravenous catheters of patients with clinically significant disease were compared to 60 similar isolates from patients who were presumably colonized. All isolates were identified and evaluated for ability to adhere to smooth surfaces, and resistance to anti-staphylococcal penicillins. S. epidermidis, S. hominis, and S. haemolyticus were the most frequently occurring species, representing 65%, 15%, and 10%, respectively, of disease isolates and 57%, 25%, and 8% of colonizers. The seven other species recovered accounted for only 10% of the total in both groups. Differences in isolation rates of each species within the two groups were not significant and were reflective of their reported incidence in the normal flora. All species of coagulase-negative Staphylococcus (except S. capitis and S. cohnii, which were isolated in very small numbers) were capable of adhering to smooth surfaces. S. hominis disease isolates were all capable of adherence, and the difference between the disease isolates and colonizers was statistically significant (p less than 0.02). This was not true for any other species that was analyzed nor for all isolates considered as a whole. Resistance to anti-staphylococcal penicillins was documented for all coagulase-negative Staphylococcus species, and was more frequent in S. epidermidis disease isolates than colonizers (p less than 0.05). No correlation was found between resistance to antistaphylococcal penicillins and ability to adhere.

Adhesiveness↗

PubMed2004

Ciprofloxacin and levofloxacin resistance among methicillin-sensitive Staphylococcus aureus isolates from keratitis and conjunctivitis.

PURPOSE: The majority of Staphylococcus aureus isolated from ocular infections are methicillin sensitive (MSSA). Fluoroquinolone resistance among methicillin- resistant Staphylococcus aureus is well known but not among MSSA. In this study we investigate the emergence of fluoroquinolone (ciprofloxacin, levofloxacin) resistance among methicillin-sensitive Staphylococcus aureus isolates from keratitis and conjunctivitis. DESIGN: Cross-sectional study. METHODS: Minimal inhibitory concentration susceptibility profiles for 1230 S. aureus isolates from keratitis and conjunctivitis were analyzed. Historical and current rates of emerging fluoroquinolone resistance for methicillin-resistant (MRSA) and methicillin-sensitive isolates (MSSA) were evaluated. Sensitivity patterns for vancomycin and gentamicin were also documented. RESULTS: Ciprofloxacin resistance among corneal and conjunctival S. aureus isolates during the first 6 years after its introduction (baseline) (1990-1995) was 8% and ranged from 3% to 11%. The rate for the most recent 6 years (current) (1996-2001) was 20.7%. Baseline ciprofloxacin resistance for MSSA isolates was 2% vs 55.8% for MRSA. The current resistance rate for MSSA is 5% vs 83.7% for MRSA. The general resistance rate from January 2000 to December 2001 for levofloxacin was 25.5% vs 33.2% for ciprofloxacin (P =.13). The levofloxacin-resistance rate for MSSA was 4.7% vs 11.9% for ciprofloxacin (P =.05). In MRSA isolates, a higher resistance rate was found for ciprofloxacin (95.7%) vs levofloxacin (82.1%) (P =.04). No resistance for vancomycin was documented for any of the S. aureus isolates. Gentamicin susceptibility for MSSA was 99% and MRSA was 86%. CONCLUSIONS: Ciprofloxacin and levofloxacin resistance among methicillin-sensitive S. aureus corneal and conjunctival isolates is increasing. This is of concern because it narrows treatment choices for the management of these common ocular infections.

Anti-Infective Agents↗