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PubMed2005

Genotypic versus phenotypic characterization, with respect to susceptibility and identification, of 17 clinical isolates of Staphylococcus lugdunensis.

OBJECTIVES: To compare different methods for the identification and determination of susceptibility to penicillin and methicillin of Staphylococcus lugdunensis. METHODS: Seventeen clinical isolates of S. lugdunensis (identified by PCR amplification and sequencing of the rpoB gene) were studied using the ATB32-Staph, Crystal, Vitek 2 and Wider commercial systems. The clumping factor test and the tube coagulase test were also performed. Beta-lactamase production was studied by chromogenic methods. Methicillin resistance was phenotypically studied by the MRSA slide latex agglutination test, growth in MRSA agar, and the Vitek 2 and Wider systems (based on oxacillin MIC), and genotypically studied by detection of the mecA gene by PCR. RESULTS: The clumping factor test was negative in 35.3% of strains. All isolates were correctly identified to species level by the ATB32-Staph system. Species misidentification rates were 5.9%, 23.5% and 29.4% with the Crystal, the Vitek 2 and the Wider systems, respectively, mostly as Staphylococcus haemolyticus. Beta-lactamase was present in 11.8% of strains. Whereas 76.5% and 47.1% of strains exhibited oxacillin resistance (MIC range 0.5-2 mg/L) by the Vitek 2 system and the Wider system, respectively, none of the strains was positive in the MRSA slide latex agglutination test or grew in MRSA agar. All strains lacked the mecA gene. CONCLUSIONS: The clumping factor test and some commercial systems may misidentify S. lugdunensis. Oxacillin resistance detected by commercial systems is not indicative of the presence of the mecA gene. These facts, together with beta-lactamase production, may preclude adequate treatment of infections by this virulent coagulase-negative Staphylococcus.

Cross Infection↗

PubMed1997

Staphylococcus epidermidis produces a cell-associated proteinaceous fraction which causes bone resorption by a prostanoid-independent mechanism: relevance to the treatment of infected orthopaedic implants.

Staphylococcus epidermidis is the most commonly isolated coagulase-negative staphylococcus from the skin, gut and upper respiratory tract. Although it is less virulent than Staphylococcus aureus, it has emerged in recent years as an important causative agent of infections associated with metal implants, prosthetic devices and i.v. lines. We have previously demonstrated that a saline wash of S. aureus contained proteins which had potent bone-resorbing activity in vitro. The purpose of this study was to determine whether gently washing S. epidermidis in saline also released osteolytically active proteins. The so-called surface-associated material (SAM) eluted from S. epidermidis in saline was able to induce osteolysis, and activity was heat and trypsin sensitive, suggesting that the active component was proteinaceous. Fractionation studies have suggested that activity is due to a small number of cationic proteins. This SAM-induced bone resorption was not inhibited by the cyclo-oxygenase inhibitor, indomethacin, or the 5-lipoxygenase inhibitors BWA70C and MK886. However, it was partially inhibited by high concentrations of interleukin-1 receptor antagonist and was completely blocked by a neutralizing antibody to tumour necrosis factor-alpha. Thus, the SAM from this organism is a potent osteolytic agent which differs from that of S. aureus SAM in not being inhibited by cyclo-oxygenase inhibitors. As adjunctive therapy is becoming necessary in infectious diseases, either as a result of the side-effects of antibiotics or their lack of efficacy, consideration should be given to the future treatment of bone infections with staphylococci in the light of the different mechanisms of action of the surface proteins produced by these bacteria.

Animals↗

PubMed2003

The role of fibronectin binding proteins in the pathogenesis of Staphylococcus aureus infections.

PURPOSE OF REVIEW: Staphylococcus aureus produces two closely-related fibronectin-binding proteins (FnBPs) that facilitate attachment by this versatile pathogen. Recent studies of staphylococcal FnBP have increased our understanding of the molecular mechanisms that are critical in bacterial-host cell interactions and in infection. RECENT FINDINGS: This review will summarize current knowledge of the role of the FnBPs of Staphylococcus aureus in the pathogenesis of infection. The FnBPs, which facilitate attachment of this pathogen to host cells and to fibronectin-coated biomaterials, are important mediators of infection in experimental endocarditis. In addition, recent vaccine studies utilizing FnBP derivatives have shown partial protection in animals. FnBPs also act as invasins permitting uptake of the staphylococcus by cultured non-professional phagocytes using host fibronectin to bridge with integrins on the cell surface. However, the precise role of FnBP in tissue invasion and the relevance of intracellular invasion in disease remain to be elucidated. SUMMARY: FnBP is one of many adhesins expressed by S. aureus that influence host tissue adherence by binding to host fibronectin. FnBP-based vaccine strategies and novel anti-adherence tools based upon FnBP derivatives are in the early stages of investigation but may show promise in preventing staphylococcal infections.

Adhesins, Bacterial↗

PubMedDate not supplied

Vancomycin intermediate-resistant Staphylococcus aureus (VISA).

Methicillin-resistant Staphylococcus aureus (MRSA) has been an infectious disease problem since the early 1980s and until recently was uniformly susceptible to vancomycin, the drug known as the "last resort." Recent reports indicate that Staphylococcus aureus has continued to mutate and has developed intermediate resistance to vancomycin (VISA). This article lists some of the potential clinical manifestations of Staphylococcus aureus as well as a possible explanation of the phenomenon of antibiotic resistance. The reported cases of VISA are reviewed, and intervention strategies for prevention and control are discussed.

DNA, Bacterial↗

PubMed1992

Relatedness of strains of methicillin-resistant coagulase-negative Staphylococcus colonizing hospital personnel and producing bacteremias in a neonatal intensive care unit.

The emergence of methicillin-resistant coagulase-negative Staphylococcus as a major bacterial pathogen in neonatal intensive care units has stimulated interest in the epidemiology of spread of the organism. During a 12-month "epidemic" of bacteremias with methicillin-resistant coagulase-negative Staphylococcus we compared the characteristics of bacteremic and personnel nasally-carried strains by traditional and biomolecular methods. Sixty-two percent of neonatal intensive care unit nurses were colonized with methicillin-resistant coagulase-negative Staphylococcus with similar speciation to bacteremic strains. Inspection of plasmid profiles revealed a moderate degree of similarity between bacteremic and colonizing strains although genomic DNA restriction patterns showed diversity. Ribotype patterns were highly conserved (90%) in personnel strains. A 2.6-kilobase plasmid DNA probe hybridized to similarly sized plasmids and larger plasmids in one-half of the strains. We hypothesize that related methicillin-resistant strains may be transferred among personnel and neonates in the neonatal intensive care unit. Epidemiologic studies of coagulase-negative staphylococci should consider multiple molecular techniques to relate strains.

Bacteremia↗

PubMed2006

Self-reinforced ciprofloxacin-releasing polylactide-co-glycolide 80/20 inhibits attachment and biofilm formation by Staphylococcus epidermidis: an in vitro study.

We have observed the efficiency of antibiotic-releasing polylactide-co-glycolide (PLGA) 80/20 in preventing Staphylococcus epidermidis attachment and biofilm formation in vitro. The aim of the present study was to evaluate the effect of self-reinforced (SR) implants with enhanced antibiotic release on bacterial attachment and biofilm formation rates, and also on growth inhibition of Staphylococcus epidermidis. Cylindrical SR-PLGA+AB specimens (length 30 mm, diameter 3 mm) were examined by scanning electron microscopy (SEM) for attachment of S. epidermidis ATCC 35989 on biomaterial surface and formation of biofilm, after incubating with bacterial suspension of ca. 10 cfu/mL for 1, 3, 7, 14 and 21 days. SR-PLGA and SR-PLGA+AB implants were tested on agar plates by measuring the inhibition distance around implants. On the surface of SR-PLGA+AB, at days 1, 3, 7, 14 and 21, the percentage of areas with not a single bacteria attached, was 88.6%, 71.1%, 73.7%, 73.7%, and 68.4%, respectively. On the areas where bacteria were detected, the number of bacterial cells remained low during whole study period, and no significant increase by time was seen. There was no biofilm observed on 97-99% of the examined areas during the whole study period on SR-PLGA+AB. In agar plates, the SR-PLGA+AB showed inhibition of bacterial growth, with (mean) 53.2 mm diameter of inhibition area with peeled implants and 50.5 mm with non-peeled implants. There was no inhibition seen around implants without ciprofloxacin. Bioabsorbable ciprofloxacin-releasing self-reinforced PLGA (SR-PLGA+AB) was superior to plain SR-PLGA in preventing bacterial attachment, biofilm formation, and also the growth of Staphylococcus epidermidis.

Anti-Infective Agents↗

PubMed1990

Staphylococcus schleiferi subsp. coagulans subsp. nov., isolated from the external auditory meatus of dogs with external ear otitis.

A new subspecies, Staphylococcus schleiferi subsp. coagulans, was isolated from the external auditory meatus of dogs suffering from external ear otitis and is described on the basis of studies of 21 strains. Phenotypic studies showed that these strains are more closely related to Staphylococcus intermedius than to other staphylococci, but DNA hybridization studies indicated that they are closely related to Staphylococcus schleiferi N850274T. On the basis of biochemical distinctiveness (positive test tube coagulase test and different carbohydrate reactions) and the etiological importance (frequent isolation from otitis specimens from dogs) of these strains, we propose to classify them as a subspecies of S. schleiferi. The strains of this new subspecies are coagulase tube test, beta-hemolysin, and heat-stable nuclease positive but clumping factor negative. A simple scheme for the differentiation of S. schleiferi subsp. coagulans from the other coagulase-positive staphylococci is presented. The type strain is GA211 (= JCM 7470).

Animals↗

PubMed1995

Staphylococcus pulvereri sp. nov., isolated from human and animal specimens.

A new coagulase-negative species of the genus Staphylococcus, Staphylococcus pulvereri, was isolated from human and animal specimens. The complete 16S rRNA sequence of the type strain of S. pulvereri, NT215, was determined and compared with the sequences of 16S rRNAs from the other staphylococci. Strains of S. pulvereri were differentiated from other novobiocin-resistant Staphylococcus species by their biochemical activities, cell wall composition, and levels of genetic relatedness. The type strain of this species is NT215 (= PCM 2443T).

Animals↗

PubMed1992

Evaluation of a ribosomal RNA gene probe for the identification of species and subspecies within the genus Staphylococcus.

To evaluate a 16S rRNA gene probe for the identification of staphylococcal species and subspecies, we have augmented previous studies involving 12 staphylococcal species by analysing the remaining 16 species currently classified in the genus Staphylococcus. HindIII- and EcoRI-restricted DNA of isolates from validly described species of Staphylococcus was probed with radiolabelled plasmid pBA2 containing 16S rDNA from Bacillus subtilis. The Dice coefficient was used to assess similarity between the 74 HindIII- and the 81 EcoRI-hybridization patterns obtained from a total of 271 isolates belonging to 31 staphylococcal taxa (28 species, of which three include two subspecies). The use of HindIII yielded a better discrimination of the staphylococci than the use of EcoRI. All of the isolates belonging to the same species or subspecies, except S. hyicus isolates, were recovered as homogeneous clusters using their HindIII hybridization patterns. The phenotypically close taxa were clearly distinguished. Thus, the method presented in this study constitutes a powerful tool for the identification of taxa within the genus Staphylococcus.

Bacterial Typing Techniques↗

PubMed2007

dnaJ gene sequence-based assay for species identification and phylogenetic grouping in the genus Staphylococcus.

In the last few years, many attempts have been made to use conserved gene sequences for identification and for phylogenetic studies of Staphylococcus species. In an effort to identify a more reliable approach, a dnaJ gene sequence-based database was created. In this study, an approximately 883 bp portion of the dnaJ gene sequence from 45 staphylococcal type strains was compared with 16S rRNA and other conserved gene (hsp60, sodA and rpoB) sequences available in public databases. Nucleotide sequence comparisons revealed that the staphylococcal dnaJ gene showed higher discrimination (mean similarity 77.6 %) than the 16S rRNA (mean similarity 97.4 %), rpoB (mean similarity 86 %), hsp60 (mean similarity 82 %) and sodA (mean similarity 81.5 %) genes. Analysis of the dnaJ gene sequence from 20 Staphylococcus isolates representing two clinically important species showed <1 % sequence divergence. Phylogenetic data obtained from the dnaJ gene sequence were in general agreement with those of 16S rRNA gene sequence analysis and DNA-DNA reassociation studies. In conclusion, the dnaJ gene sequence-based assay is an effective alternative to currently used methods, including 16S rRNA gene sequencing, for identification and taxonomical analysis of Staphylococcus species.

Bacterial Typing Techniques↗

PubMed1994

Genotyping of Staphylococcus epidermidis by small-fragment restriction endonuclease analysis and pulsed-field gel electrophoresis of genomic restriction fragments.

Small-fragment restriction endonuclease analysis (SF-REA) was established as a typing tool for Staphylococcus epidermidis. A total of 60 isolates comprising 48 epidemiologically nonrelated strains and 12 putatively linked isolates from 7 patients in 2 wards were analyzed. Nonrelated isolates were characterized by unique fingerprints when DNA was cleaved with EcoRI or ClaI, electrophoretically separated in a polyacrylamide gel, and silver stained. Three blood culture isolates from one patient in an intensive care unit, 4 isolates obtained from a child over a span of 2 weeks, and 5 isolates from 5 newborns in the same ward were grouped into 3 DNA pattern types, indicating identity of sequential isolates from 2 patients and nosocomial transmission of one Staphylococcus epidermidis strain between 5 babies. Results from pulsed-field gel electrophoresis of SmaI and SacII DNA digests and conventional marker systems such as antibiogram and plasmid profile were in accordance with these interpretations, whereas slight variation was observed in the biotypes of several strains. From the results of this study, we conclude that SF-REA is a precise and efficient method for the genotypic characterization of Staphylococcus epidermidis strains that can be used as a rapid and reliable typing tool.

Adult↗

PubMed1997

Detection and specificity of anti-Staphylococcus intermedius secretory IgA in human tears.

PURPOSE: Secretory IgA (sIgA) is the predominant immunoglobulin present in tears that protects the ocular surface against various antigens. Staphylococcus intermedius is a member of the normal ocular microbiota. METHODS: The presence and the specificity of immunoglobulin A to S. intermedius was determined by fluorescent assay, ELISA and western blots. RESULTS: Three immunodominant antigens of S. intermedius were detected of 145, 127 and 61 kDa. Staphylococcus intermedius-specific IgA cross reacted with Staphylococcus aureus but not with Gram negative bacteria. CONCLUSIONS: This indicates that specific IgA may play an important role in the protection of the eye by limiting the levels of Gram positive normal microbiota and defending against the more pathogenic S. aureus.

Antibodies, Bacterial↗

PubMed2006

Isolation from poultry litter and characterization [corrected] of Staphylococcus spp. capable of growth in high phosphate conditions [corrected].

AIMS: To isolate and characterize micro-organisms from poultry litter capable of growing under phosphate concentrations typical of poultry litter. METHODS AND RESULTS: Poultry litter extracts were plated onto brain-heart infusion medium (BHI) containing an additional 0.75 mol l(-1) phosphate (BHI-P). Colonies were screened for the presence of inclusion granules with five being selected for further study. All strains displayed identical biochemical characteristics consistent with Staphylococcus spp. and grouped with Staphylococcus spp. by comparative 16S rDNA analysis. Thus all five strains were identified as such. All strains displayed elevated intracellular phosphate levels when cultured in BHI-P broth (0.417-0.600 microg phosphate mg(-1) protein) vs BHI broth (0.075-0.093 microg phosphate mg(-1) protein). When grown using an austere semi-defined medium or BHI-P, Staph. sp. #7 displayed similar elevated intracellular phosphate levels compared with growth in BHI. CONCLUSIONS: Poultry litter contains novel Staphylococcus spp. capable of robust growth when exposed to phosphate levels comparable with that typically found in poultry litter. Data suggest intracellular phosphate levels in these strains increase in response to increasing phosphate in the medium or austere medium conditions. Intracellular phosphate did not reach levels comparable with known hyper-accumulating micro-organisms. SIGNIFICANCE AND IMPACT OF THE STUDY: These data suggest poultry litter possesses a resident microflora that thrives and accumulates intracellular phosphate in response to high phosphate conditions.

Animals↗

PubMed2000

Identification of a novel antigen from Staphylococcus epidermidis.

A genomic DNA library of Staphylococcus epidermidis NCTC 11047 was constructed, using the Lambda Zap Express cloning vector, and screened with serum collected from a patient with S. epidermidis endocarditis. Sequence analysis of a 30 kDa cloned protein, termed staphylococcal secretory antigen, SsaA, identified a novel protein not previously reported in S. epidermidis. SsaA showed strong homology with two other staphylococcal proteins: SceB from Staphylococcus carnosus and a staphyloxanthin biosynthesis protein from Staphylococcus aureus. Further investigation revealed SsaA to be a highly antigenic protein that was expressed in vivo and could be recovered from whole cells and from the culture supernatant. A combination of Western blot analysis and PCR screening identified SsaA or a homologue in 103/103 staphylococcal strains. SsaA-like genes were not detected in other Gram-positive bacteria of medical importance or a number of Gram-negative organisms. Elevated anti-SsaA IgG antibody levels were detected in sera of five patients with S. epidermidis endocarditis but not in patients with other S. epidermidis infections, endocarditis of other aetiologies or patients with no evidence of infection. The expression of SsaA during episodes of S. epidermidis endocarditis suggests a virulence role specific to the pathogenesis of this infectious disease.

Amino Acid Sequence↗

PubMed2006

Meningoencephalitis associated with Staphylococcus warneri in a dog.

A case of meningoencephalitis in a dog caused by Staphylococcus warneri is reported here. The history and clinical signs were suggestive of possible central nervous system infection. Analysis of cerebrospinal fluid documented a neutrophilic pleocytosis (890 cells/mul) and the presence of occasional intracellular cocci. Staphylococcus warneri was isolated from the microbiological culture of the cerebrospinal fluid. Treatment consisted of intravenous antibiotics, supportive care and anticonvulsants for the generalised seizures that developed after admission. Histological assessment confirmed the location and extension of bacterial meningoencephalitis. Thrombotic meningoencephalitis associated with Staphylococcus warneri infection has not, to the authors' knowledge, been previously reported in dogs.

Animals↗

PubMed1993

[Effect of the passage and storage of strains, and inoculum size on the change of zone pattern types and sizes produced by protease of methicillin resistant Staphylococcus aureus].

Protease produced by Staphylococcus aureus precipitates digests of casein in standard methods caseinate agar (SMCA) plate, and the various sizes of A to E precipitation types were produced depending on strains of inoculated Staphylococcus aureus, as previously reported. To evaluate these phenomena for epidemiological use, we investigated the effects of bacterial passage, storage and dosage on zonal pattern and the size of precipitation rings. Methicillin resistant Staphylococcus aureus (MRSA) was found to produce variable types and sizes of precipitation rings depending upon the inoculated strains. After 5, 30 and 50 passages in heart infusion broth (HIB), each of the strains randomly selected from MRSA strains showed that the precipitation pattern of A to E produced the same types and sizes of precipitation rings. The storage effects were assessed by comparing those strains in different storage time. The strain stored for 1 and 3 years at room temperature in HIB contained 0.8% agar produced the same pattern of precipitation rings at that of the freshly isolated one. Finally, the dosage of inoculated bacteria was examined. Overnight broth (HIB) cultures of MRSA were directly inoculated in SMCA plates, and were found to produce almost the same size of precipitation rings (reproducible within 3 mm). These findings indicated that protease digestion on SMCA plate provides a rapid, sensitive, and specific assay that can supplement the currently available modalities for typing of MRSA strains.

Agar↗

PubMed1997

[Coagulase typing of Staphylococcus aureus in the geriatric wards after introduction of preventive measures of hospital infection].

In the early 1980's methicillin-resistant Staphylococcus aureus (MRSA) was reported as a major pathogenic organism of geriatric hospital infection in Japan. At the same time in our geriatric wards, including 190 beds, MRSA infection was prevalent. In the early 1980's in our geriatric wards minocycline was one of the most sensitive antibiotics to MRSA isolated in our wards and used frequently against MRSA pneumonias and bacteremia. In the late 1980's resistant strains of MRSA to minocycline rapidly increased because vancomycin was not allowed to introduced for treatment of MRSA before 1991 in Japan. At the same period the predominant coagulase type changed from type II to type VII. To decrease minocycline-resistant strains to MRSA after 1987, use of minocycline was limited. Moreover since Oct. 1991 to decrease nosocomial infections some active preventive measures against hospital infection, including limited use of 2nd and 3rd cephems, were taken. In this study changing patterns of coagulase type of Staphylococcus aureus were discussed. At least 4 years was needed to find out that the predominant coagulase type changed from type VII to type II again in 1991. In this study about 22 antimicrobial agents MICs of 313 strains of Staphylococcus aureus isolated between March 1992 and June 1993 were determined and compared with the data of MICs before introduction of preventive measures. The pattern of susceptibility to MINO was in part improved. Thus the some sensitive strains of S. aureus were observed again in our geriatric wards. Interestingly indeed it took approximately 5 years to find out the emergence of sensitive strains to MINO since limitation of use of MINO in 1987.

Bacterial Typing Techniques↗

PubMed1998

[Immunoglobulin production by human peripheral B cells against Staphylococcus aureus].

Immunoglobulin (Ig) production by human B cells in thymus-independent (TI) and -dependent (TD) immune response against Staphylococcus aureus was investigated in vitro. Highly purified human peripheral B cells were cultured either in the presence of formalinized Cowan I strain Staphylococcus aureus (SAC) or with anti-CD3 stimulated T cells, and Ig content in supernatants was analyzed after 10 days of culture by specific sandwich ELISA. When activated with SAC in the absence of T cells, B cells produced minimal amounts of Ig. In the presence of interleukin-2 (IL-2) or supplemental recombinant CD40 ligand plus IL-2, Ig production by SAC-induced B cells was dramatically enhanced. When cultured with T cells stimulated with low concentrations of anti-CD3 or when cultured with smaller numbers of T cells, B cells produced large amounts of Ig, whereas T cells stimulated with higher concentrations of anti-CD3 or large numbers of T cells failed to induce effective Ig secretion by B cells. These findings suggest that TI immune response against Staphylococcus aureus is strongly enhanced in the presence of activated T cells in an antigen non-specific manner, indicating its critical role in the local humoral immune defense. Moreover, it is indicated that the secretion of Ig induced by TD antigens participates in the immune defense against Staphyloccocus aureus dependent on activated T cell/B cell ratio or an impact of CD3 stimulation on T cells.

Antibodies, Bacterial↗