SEARCH · PubMed Health

Results for “Staphylococcus”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,621 records · Page 90Linked to original sources

PubMed2005

Staphylococcus aureus isolates carrying Panton-Valentine leucocidin genes in England and Wales: frequency, characterization, and association with clinical disease.

Staphylococcus aureus isolates carrying the genes that encode for Panton-Valentine leucocidin (PVL), a highly potent toxin, have been responsible for recent outbreaks of severe invasive disease in previously healthy children and adults in the United States of America and Europe. To determine the frequency of PVL-positive isolates sent to the Staphylococcus Reference Unit (United Kingdom) for epidemiological purposes, we tested 515 isolates of S. aureus, and 8 (1.6%) were positive for the PVL locus. A further 470 isolates were selected to explore the association of PVL-positive S. aureus with clinical disease. Of these, 23 (4.9%) were PVL positive and most were associated with skin and soft tissue infections (especially abscesses). The PVL genes were also detected in isolates responsible for community-acquired pneumonia, burn infections, bacteremia, and scalded skin syndrome. Genotyping by pulsed-field gel electrophoresis and multilocus sequence typing revealed that the PVL-positive isolates were from diverse genetic backgrounds, although one prevalent clone of 12 geographically dispersed methicillin-resistant S. aureus (MRSA) isolates was identified (ST80). All 12 isolates were stapylococcal cassette chromosome mec type IVc, had an agr3 allele, and shared a common toxin gene profile (sea-see, seg-sej, eta, etb, and tst negative but etd positive). ST80 strains with similar genetic characteristics have been responsible for community-acquired infections in France and Switzerland. The remaining PVL-positive isolates were mostly methicillin-sensitive S. aureus and belonged to 12 different sequence types, including ST22 and ST30, which are closely related to the most prevalent MRSA clones in United Kingdom hospitals, EMRSA-15 and EMRSA-16, respectively.

Bacterial Toxins↗

PubMed2005

Use of genotypic identification by sodA sequencing in a prospective study to examine the distribution of coagulase-negative Staphylococcus species among strains recovered during septic orthopedic surgery and evaluate their significance.

A total of 212 coagulase-negative Staphylococcus strains recovered prospectively during 119 surgeries for proven or suspected bone and joint infection (BJI) were identified by sodA sequencing. These strains were identified as 151 Staphylococcus epidermidis isolates, 15 S. warneri isolates, 14 S. capitis isolates, 9 S. hominis isolates, 6 S. lugdunensis isolates, 5 S. haemolyticus isolates, 4 S. caprae isolates, 4 S. pasteuri isolates, 3 S. simulans isolates, and 1 S. cohnii isolate. Only S. epidermidis, S. lugdunensis, S. capitis, and S. caprae were found to be infecting organisms and were involved, respectively, in 35 (81.4%), 3 (7.0%), 3 (7.0%), and 2 (4.6%) cases of BJI.

Adult↗

PubMed2005

Use of an automated multiple-locus, variable-number tandem repeat-based method for rapid and high-throughput genotyping of Staphylococcus aureus isolates.

Fast and reliable genotyping methods that allow real-time epidemiological surveillance would be instrumental to monitoring of the spread of methicillin-resistant Staphylococcus aureus. We describe an automated variable-number tandem repeat-based method for the rapid genotyping of Staphylococcus aureus. Multiplex PCR amplifications with eight primer pairs that target gene regions with variable numbers of tandem repeats were resolved by microcapillary electrophoresis and automatically assessed by cluster analysis. This genotyping technique was evaluated for its discriminatory power and reproducibility with clinical isolates of various origins, including a panel of control strains previously characterized by several typing methods and collections from either long-term carriers or defined nosocomial outbreaks. All steps of this new procedure were developed to ensure a rapid turnaround time and moderate cost. The results obtained suggest that this rapid approach is a valuable tool for the genotyping of S. aureus isolates in real time.

Automation↗

PubMed2005

Mannitol salt agar-cefoxitin combination as a screening medium for methicillin-resistant Staphylococcus aureus.

In disk diffusion tests, cefoxitin is now considered a better indicator than oxacillin for the presence of the mecA gene in Staphylococcus aureus. A logical extension of this work is the incorporation of cefoxitin into media selective for methicillin-resistant Staphylococcus aureus (MRSA). This paper describes the development and subsequent testing of mannitol salt agar containing 4 mg/liter cefoxitin with a unique collection of well-characterized MRSA strains, including low-level methicillin-resistant strains and an equal number of known mecA-negative S. aureus strains. The agar supported the growth of 96.6% of the mecA-positive strains in the collection and inhibited the growth of 100% of the mecA-negative strains. These results suggest that selective media based on cefoxitin are superior to those based on oxacillin for the detection of MRSA.

Cefoxitin↗

PubMed2005

Partial excision of the chromosomal cassette containing the methicillin resistance determinant results in methicillin-susceptible Staphylococcus aureus.

We report a detailed characterization of methicillin-susceptible Staphylococcus aureus isolates from five French hospitals negative for both the mecA and the ccrAB loci but positive for the IS431::pUB110::IS431::dcs structure, present in some Staphylococcus cassette chromosome mec (SCCmec) types. The presence of SCCmec-associated elements suggests that this unusual resistant phenotype is due to a partial excision of SCCmec from epidemic methicillin-resistant S. aureus. The hypothesis of a genetic relatedness is strengthened by common sequence and spa types and similar susceptibility patterns.

Chromosomes, Bacterial↗

PubMed2006

Evaluation of the IDI-MRSA assay for detection of methicillin-resistant staphylococcus aureus from nasal and rectal specimens pooled in a selective broth.

Rapid detection of methicillin-resistant Staphylococcus aureus (MRSA) by PCR can be performed directly from nasal specimens with the IDI-MRSA assay. To improve the efficiency of screening, we evaluated the performance of the IDI-MRSA assay for the detection of MRSA from pooled and unpooled specimens cultured in a selective broth. Of the 287 specimens evaluated, 71 were culture and PCR positive, 203 were culture and PCR negative, 3 were culture positive and PCR negative, 8 were culture negative and PCR positive, and 2 remained inhibited. A methicillin-susceptible Staphylococcus aureus isolate was recovered from five of the eight specimens with false-positive PCR results. Compared to the results of culture, the sensitivity, specificity, and positive and negative [corrected] predictive values of the IDI-MRSA assay for detection of MRSA from broth were 96%, 96%, 90%, and 98%, respectively. Following implementation of the IDI-MRSA assay, PCR-positive broths were subcultured for evaluation of assay performance. Of the 298 IDI-MRSA assay-positive broths, the results for 103 could not be confirmed by culture. A methicillin-susceptible S. aureus (MSSA) isolate was recovered from 77 of these 103 broths. Repeat testing by the IDI-MRSA assay directly with the MSSA isolates confirmed the original positive PCR result. The positive predictive value of the IDI-MRSA assay fell from 90% during the evaluation phase to 65% postimplementation. The IDI-MRSA assay performed well for the detection of MRSA from a selective broth compared to the performance of the detection of MRSA from culture. However, because of the burden associated with implementation of infection control precautions, cultures remain essential in confirming positive IDI-MRSA results.

Bacterial Typing Techniques↗

PubMed2006

Presence of a novel DNA methylation enzyme in methicillin-resistant Staphylococcus aureus isolates associated with pig farming leads to uninterpretable results in standard pulsed-field gel electrophoresis analysis.

Genomic DNA from methicillin-resistant Staphylococcus aureus isolates recovered from pigs and their caretakers proved resistant to SmaI digestion, leading to uninterpretable results in standard pulsed-field gel electrophoresis. This is the result of a yet unknown restriction/methylation system in the genus Staphylococcus with the recognition sequence CCNGG.

5-Methylcytosine↗

PubMed1979

Susceptibility of Staphylococcus aureus and group A, B, C, and G streptococci to free fatty acids.

The susceptibility of 242 strains of Staphylococcus aureus and 117 strains of streptococci of groups A, B, C, and G to decanoic, dodecanoic, octadeca-9,12-dienoic, and octadeca-9,12,15-trienoic acids was estimated by determination of minimal inhibitory concentrations. S. aureus strains appeared to be generally less susceptible to all four fatty acids than streptococcal strains of all groups. Dodecanoic acid was the most inhibitory fatty acid against both staphylococci and streptococci. Both saturated fatty acids used were more active than the unsaturated acids. Among the unsaturated acids, octadeca-9,12,15-trienoic acid appeared to be more inhibitory for Staphylococcus and Streptococcus strains than octadeca-9,12-dienoic acid. No differences in susceptibility to fatty acids among staphylococcal and streptococcal strains isolated from skin, throat, or other sites were found.

Decanoic Acids↗

PubMed2026

Staphylococcus aureus urease is controlled by a complex regulatory network to promote dissemination during CAUTI.

UNLABELLED: Catheter-associated urinary tract infections (CAUTIs) are one of the most common hospital-associated infections in the United States, accounting for >1 million cases annually. One CAUTI pathogen, Staphylococcus aureus, is commonly found persisting asymptomatically in the bladder of catheterized individuals, increasing these individuals' risk of developing infection. Importantly, S. aureus is not only associated with severe symptoms during CAUTI, including bacteremia and septic shock, but it also produces a common uropathogen-associated virulence factor, urease. Despite its importance, urease has only been well-studied in another uropathogen, Proteus mirabilis. While previous studies identified three S. aureus urease regulators, including CodY, CcpA, and Agr, the environmental signals required for expression and activity, and the enzyme's contribution to CAUTI have not been explored. In this study, we demonstrate that post-exponential growth and growth in the urinary tract environment significantly induce S. aureus urease expression and activity. Additionally, we identify SigB, SaeR, and SrrA as novel regulators of urease, and further explore the role of CodY, CcpA, and Agr-previously implicated in urease expression-in urease regulation in the urinary tract environment. Impactfully, we found that the urease promoters of clinical isolates contain genomic changes that enhance urease expression. Furthermore, urease contributes to biofilm formation under catheterized urinary tract-like conditions in vitro and dissemination from the bladder to the kidneys in a mouse CAUTI model. Together, our data not only provide insight into the regulatory pathway controlling S. aureus urease but also emphasize the importance of studying these mechanisms in a model that mimics the urinary environment. IMPORTANCE: In this study, we investigate how regulatory pathways coordinate the expression and activity of urease in response to environmental signals present within the catheterized urinary tract. We show that growth during the post-exponential phase and in conditions that mimic the urinary tract increases urease expression and activity. This finding challenges the dogma that Staphylococcus aureus is a "weak" urease producer. We also identified three novel regulators of S. aureus urease-SigB, SrrA, and SaeR-and show that their respective activation signals can modulate urease expression. Additionally, single-nucleotide changes identified in the urease regulatory pathway of clinical urinary catheter-associated isolates enhance urease expression. Finally, urease promotes biofilm formation under conditions that mimic the catheterized urinary tract and dissemination during catheter-associated urinary tract infections (CAUTIs). Our study provides insight into the complex regulatory mechanisms controlling urease in the urinary tract and highlights the role urease plays in S. aureus CAUTI.

Urease↗

PubMed2025

Comprehensive genomic analysis of antibiotic resistance plasmids in animal-associated Staphylococcus aureus in France.

UNLABELLED: In Staphylococcus aureus, an animal pathogen and zoonotic agent, plasmids play a pivotal role in the acquisition and spread of antibiotic resistance genes (ARGs). This study investigated the plasmid content of 329 S. aureus isolates from livestock and companion animals collected in France between 2010 and 2021. Plasmids (n = 211) were identified from 139 isolates. The major families identified-rep7a, rep20, and rep10-were associated with specific resistance genes (str, cat, blaZ, erm(C)) and exhibited widespread horizontal transfer across different S. aureus sequence types (STs) and animal hosts. In temporal analysis, the rep7a/str and rep7a/cat plasmids circulating in horses were progressively replaced by a rep7a plasmid carrying both str and cat genes. The study also highlighted the presence of mosaic plasmids, which combined elements from different bacterial species/genera, confirming the broad host range of S. aureus plasmids and their ability to acquire ARGs from diverse sources. Moreover, the occurrence of hybrid plasmids (carrying multiple rep genes) underscores the plasticity of these vectors of ARGs. This study emphasizes the need to investigate the mechanisms driving the spread and persistence of antibiotic-resistant plasmids in S. aureus, with a view to developing strategies aimed at combating antibiotic resistance. IMPORTANCE: The spread of antibiotic resistance in Staphylococcus aureus is a growing concern, particularly in animals that can serve as reservoirs for resistant strains. This study highlights the crucial role of plasmids in transmitting resistance genes among different animal hosts and S. aureus lineages. The characterization of 329 isolates collected over 10 years revealed how certain plasmid families are associated with specific resistance genes and how they evolve over time. The occurrence of mosaic and hybrid plasmids further underscores the ability of S. aureus to acquire resistance from diverse bacterial sources. These findings provide key insights into the mechanisms shaping antibiotic resistance in this pathogen and emphasize the fact that understanding plasmid-driven resistance is essential for developing effective interventions to limit the spread of multidrug-resistant S. aureus in both veterinary and human medicine.

Animals↗

PubMed2024

Adaptation for Staphylococcus aureus to hosts via insertion mutation in the accessory gene regulator agrC gene: decreased virulence and enhanced persistence capacity.

UNLABELLED: Staphylococcus aureus is an important human pathogen due to its vast array of virulence factors regulated by multiple regulatory mechanisms, including the accessory gene regulator. In this study, two S. aureus strains were simultaneously isolated from the blood of a febrile patient, belonging to the same clone, designated as 23H with a complete hemolytic phenotype, and 23B, exhibiting an incomplete hemolytic phenotype. The genomic comparison between strains 23B and 23H revealed that 23B had a single adenine base insertion at position 923 in the agrC gene, leading to a functional loss of the encoded AgrC. Experimental findings showed that strain 23B had decreased hemolytic activity, lower cytotoxicity against human alveolar epithelial A549 cells and in the Galleria mellonella model, and a reduced ability to survive intracellularly after infecting macrophages, in comparison to 23H. Conversely, 23B exhibited enhanced biofilm formation, greater adherence to A549 cells, and increased persistence in the face of vancomycin and daptomycin treatment. Transcriptomic analysis revealed that 23B upregulated surface protein-encoding genes while simultaneously reducing the expression levels of virulence factors, highlighting the intricate regulatory adjustments facilitating its persistence and reducing pathogenic potential. ATP assay results indicated that 23B maintained elevated ATP levels during the exponential phase yet exhibited reduced levels in the stationary phase when compared with 23H. Our findings suggested that the mutation in the agrC gene of S. aureus results in diminished virulence but markedly enhances persistence. This mutated strain warrants clinical attention because it may lead to treatment failures and persist in patients. IMPORTANCE: In clinical antimicrobial therapy, bacterial strains often develop resistance to antimicrobial agents. Additionally, mutations in their gene regulatory networks can increase their persistence, especially in immunocompromised patients. This study identified an insertion mutation in the accessory gene regulator, agrC gene, carried by a Staphylococcus aureus strain isolated from the blood of a febrile patient, leading to the functional loss of AgrC. Further research revealed that despite the reduced virulence of the mutated strain, it significantly bolstered the capacity to adapt and endure within the host during prolonged infections. This was evidenced by increased adhesion and biofilm formation capabilities, development of antimicrobial tolerance, and decreased ATP levels linked to persistence. Therefore, monitoring these mutations in S. aureus is crucial clinically, as they can complicate treatment strategies.

Staphylococcus aureus↗

PubMed2026

In-host adaptation of Staphylococcus aureus during recurrent prosthetic joint infections: a retrospective longitudinal study.

UNLABELLED: The aim of this study was to characterize the in vivo evolution of Staphylococcus aureus strains involved in recurrent prosthetic joint infections (PJIs) both phenotypically and genomically. We conducted a monocentric retrospective study in a 1,437-bed French teaching hospital between 2013 and 2021. All patients presenting a recurrent S. aureus-related PJI-defined as at least two strains isolated from distinct clinical samples more than 90 days apart-of the knee, hip, or shoulder were included. Clinical data were reviewed, and all isolates underwent phenotypic characterization, including antimicrobial susceptibility testing, growth rate determination, biofilm production assays, metabolic profiling (API 50 CH), and virulence evaluation using the Galleria mellonella infection model. Whole-genome sequencing (WGS) was performed for all strains, followed by analyses of core-genome multilocus sequence typing (cgMLST), resistome, virulome, and mobilome composition, and single-nucleotide polymorphisms (SNPs). Thirteen patients met inclusion criteria, yielding 55 S. aureus isolates. Eight patients experienced recurrent infections caused by genetically closely related strains throughout the clinical course (median: three strains per patient; range: 2-6), whereas five patients were infected by genetically distinct strains. At baseline, isolates were genetically diverse and susceptible to methicillin and rifampicin; two showed fluoroquinolone resistance due to grlA and/or gyrA mutations. In one patient (patient C), a recurrent isolate acquired an rpoB S486L mutation, conferring rifampicin resistance after rifampicin exposure. Due to the limited sample size, it is difficult to draw definitive conclusions from the phenotypic analyses. This study highlights the adaptive evolution of S. aureus during chronic PJIs and underscores the need for further research to better understand intra-host dynamics in long-standing infections. IMPORTANCE: This study conducted in a 1,437-bed French teaching hospital analyzed the genomic and phenotypic evolution of 55 Staphylococcus aureus strains recovered in recurrent PJIs from 13 patients. The first strains showed high genotypic diversity across 12 different sequence types. Among the 13 patients, only eight experienced a true recurrence with the same strain, while five were contaminated with a different strain of S. aureus, indicating a new infection. Moreover, this study underscores the complex within-host evolution of S. aureus and highlights the phenotypical and genotypical adaptation during chronic infection.

Staphylococcus aureus↗

PubMed1977

Comparison of coagulase, deoxyribonuclease (DNase), and heat-stable nuclease tests for identification of Staphylococcus aureus.

One thousand and thirty-five clinical isolates of the genus staphylococcus were used to compare the coagulase test with the deoxyribonuclease (DNase) and heat-stable nuclease tests as methods for identifying Staphylococcus aureus. Conflicting results were obtained with 65 isolates when the coagulase test was compared with the DNase test but with only one isolate when the coagulase test was compared with the heat-stable nuclease test. The heat-stable nuclease test produced reliable results after four hours' incubation and was considered a satisfactory substitute for the coagulase test in the clinical laboratory.

Bacteriological Techniques↗

PubMed2002

Detection of methicillin and mupirocin resistance in Staphylococcus aureus isolates using conventional and molecular methods: a descriptive study from a burns unit with high prevalence of MRSA.

AIMS: To compare conventional phenotypic methods for the detection of methicillin and mupirocin resistance in Staphylococcus aureus in routine laboratory practice with reference to an established molecular method. METHODS: This study was conducted on a selection of 65 isolates of methicillin resistant Staphylococcus aureus (MRSA) from a burns unit in India which is endemic for MRSA. The Kirby-Bauer and modified Stokes disc diffusion tests and the Vitek breakpoint minimum inhibitory concentration (MIC) were performed on all isolates using the presence of the mecA gene as the reference standard. Gel based and colorimetric polymerase chain reaction (PCR) assays were evaluated as molecular methods for the diagnosis of MRSA. A commercial latex agglutination test, the Mastalex, was assessed for the detection of penicillin binding protein 2a (PBP2a), the mecA gene product. Conventional disc diffusion and molecular methods were investigated for the detection of mupirocin resistance. RESULTS: Fifty one of 65 isolates were positive for the mecA gene. All three phenotypic methods showed high sensitivity (> 96.2%), whereas the specificity varied: 50% for Kirby-Bauer, 87.5% for modified Stokes, and 93.3% for Vitek. The colorimetric PCR was less cumbersome than the gel based PCR; there was complete concordance between both systems. The Mastalex kit showed good correlation with PCR. One isolate was found to be mupirocin resistant and harboured the mupA gene. CONCLUSIONS: The specificity of routine laboratory tests for MRSA detection was variable. mecA gene detection, the "gold standard" to confirm ambiguous results, is difficult to perform in routine diagnostic laboratories. The Mastalex kit for the detection of PBP2a is an alternative that could be used in most laboratories. High level mupirocin resistance can be confirmed with genotypic methods.

Anti-Bacterial Agents↗

PubMed1979

Increase in the in vitro susceptibility of Staphylococcus aureus to antimicrobial agents in the presence of Candida albicans.

In experiments with mixed cultures of Staphylococcus aureus and Candida albicans both in the absence and in the presence of 5-fluorocytosine (5-FC), we have observed that (1) there is an inhibition of S. aureus growth in mixed cultures with C. albicans in media supplemented with 1 microgram/mL of 5-fc and that 5-FC has no effect on staphylococci in pure cultures; (2) this inhibition occurred with clinically isolated and laboratory strains and could be reversed by specific metabolites; (3) Staphylococcus aureus was inhibited by filtrates of C. albicans cultures treated with 5-FC and this seemed to be favored by some C. albicans filterable product which can affect the cell wall and the permeability of the staphylococcal cells since they become sensitive to 5-FC; (4) nine other commonly used antimicrobials showed an increased inhibitory activity against S. aureus in mixed cultures with C. albicans; and (5) there is a decrease in the number of precipitating antigens of S. aureus and of the activity of alpha toxin when this species was grown with both C. albicans and 5-FC. Our results indicate that the susceptibility of some species to antimicrobials could be significantly modified in the presence of other species. One cannot exclude that a similar phenomenon could happen in hosts under treatment with antibiotics against infection.

Anti-Bacterial Agents↗

PubMed2000

Assessing and analysing contamination of a dairy products processing plant by Staphylococcus aureus using antibiotic resistance and PFGE.

A dairy product processing plant was studied for 2.5 years to examine contamination with Staphylococcus aureus and try to correlate the source of contamination. Cultures were submitted to an antibiotic susceptibility test (AST) and characterised by Pulsed-field Gel Electrophoresis (PFGE) analysis. Results showed that 35.2% (19/51) of food handlers were asymptomatic carriers of S. aureus, and that 90.4% (19/21) of raw milk sampled was contaminated. Staphylococcus aureus was isolated from only 10 samples among more than 3200 investigated dairy products. No S. aureus contamination was found on machinery. The AST analysis demonstrated sensitivity of tested S. aureus to oxacillin, cephalothin, vancomycin, gentamicin, and sulfamethoxazole/trimethoprim. AST analysis generated eight different phenotypic profiles, but did not allow us to identify the source of contamination in seven of ten final products. PFGE analysis proved to be a sensitive method as it generated 42 different DNA banding profiles among the 48 S. aureus investigated, demonstrating a lack of predominance of endemic strains in the plant, contrary to suggestions raised by antibiotic resistance typing. Based on PFGE genotyping, S. aureus strains isolated from four contaminated final products were similar to four S. aureus isolated from raw milk. Five final products contained S. aureus different from all other strains collected, and one showed similarity to a strain isolated from a food handler. These results suggest contamination by raw milk as the main source of contamination of the final dairy products.

Animals↗

PubMed2005

Synergic interaction between pomegranate extract and antibiotics against Staphylococcus aureus.

We evaluated the interaction between Punica granatum (pomegranate) methanolic extract (PGME) and antibiotics against 30 clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA). Susceptibility testing of the isolates to PGME and antibiotics was performed by the broth dilution method. Synergic activity was detected between PGME and the 5 antibiotics tested, chloramphenicol, gentamicin, ampicillin, tetracycline, and oxacillin, ranging from 38% to 73%. For some isolates, PGME did not interfere with the action of any of the antibiotics tested. The bactericidal activity of PGME (0.1 x MIC) in combination with ampicillin (0.5 x MIC) was assessed using chosen isolates by time-kill assays, and they confirmed the synergic activity. Using this combination, cell viability was reduced by 99.9% and 72.5% in MSSA and MRSA populations, respectively. PGME increased the post-antibiotic effect (PAE) of ampicillin from 3 to 7 h. In addition, PGME demonstrated the potential to either inhibit the efflux pump NorA or to enhance the influx of the drug. The detection of in vitro variant colonies of S. aureus resistant to PGME was low and they did not survive. In conclusion, PGME dramatically enhanced the activity of all antibiotics tested, and thus, offers an alternative for the extension of the useful lifetime of these antibiotics.

Anti-Bacterial Agents↗

PubMed1999

Staphylococcus lugdunensis pulmonary valve endocarditis in a patient on chronic hemodialysis.

We describe a case of Staphylococcus lugdunensis pulmonary valve endocarditis in a 65-year-old woman on chronic hemodialysis and provide a review of previously reported cases. The patient presented with fever and altered mental status, but had no other localizing symptoms or signs; coagulase-negative staphylococcus (subsequently identified as S. lugdunensis) was isolated from two sets of blood cultures. Transthoracic and transesophageal echocardiograms showed a large (2.3 x 3.1 cm) vegetation on the pulmonary valve with moderate valvular insufficiency. The patient was treated with 6 weeks of antibiotic therapy and is stable 4 months following the completion of therapy; no surgical intervention was performed. Of the 28 previously reported cases of S. lugdunensis endocarditis, only 1 had previously survived with medical therapy alone. This is the 3rd case report of S. lugdunensis endocarditis in a patient on hemodialysis; the presumed portal of entry in this and previously reported cases was the vascular access device. Endocarditis due to this organism is characterized by a high mortality, rapid tissue destruction, and a predilection for native valves. Because the clinical outcome is much more favorable with valvular replacement, speciation of the organism assumes great importance in defining the therapeutic approach.

Aged↗