The Shadows of Normal Flora on Minor Wounds: A Case Report of an Uncommon Pathogen With Potentially Lethal Consequences.

Staphylococcus lugdunensis is a gram-positive, coagulase-negative organism, typically found in the normal skin flora, predominantly colonizing the perineal region. It has gained recognition as an opportunistic pathogen capable of causing severe infections. This manuscript presents a case study of a 75-year-old female with multiple comorbidities, including hypertension, hyperlipidemia, atrial fibrillation on Xarelto, type 2 diabetes mellitus, hypothyroidism, and a bioprosthetic aortic valve. The patient exhibited symptoms of fever, chills, and lethargy following a dog scratch that resulted in wounds on the left lower extremity. Despite initial negative findings in the drug screen and unremarkable workup for other infectious etiologies, the patient's clinical course revealed the presence of S. lugdunensis in the blood cultures. Timely intervention with broad-spectrum intravenous antibiotics and a six-week course of cefazolin led to significant improvement without recurrence. Staphylococcus lugdunensis, previously considered a relatively benign microorganism, has become a significant player in infectious diseases, particularly causing skin and soft tissue infections and infective endocarditis (IE). It is considered an aggressive pathogen, especially in chronic immunocompromised personnel, with a high potential for morbidity and mortality. S. lugdunensis was found to be the fourth most common cause of IE. The manuscript discusses the epidemiology, clinical presentation, and management of S. lugdunensis infections, emphasizing the importance of early recognition and treatment to prevent potentially fatal outcomes.

An Unusual Case of Cryoglobulinemic Vasculitis and Acute Disseminating Encephalomyelitis in a 21-Year-Old Caucasian Male.

Cryoglobulinemic vasculitis and acute disseminated encephalomyelitis (ADEM) are characterized by damage to either blood vessels or grey matter. For both diseases, infections can be an etiology. In cryoglobulinemic vasculitis, the initial insult causes damage to the glomerulus, and in the case of ADEM, damage leads to a central nervous system demyelinating disorder. Infective endocarditis can be associated with both diseases and can be challenging to diagnose. Individuals on antibiotics may present with negative blood cultures, making underlying infective endocarditis difficult to diagnose. In this report, we describe a 21-year-old male who presented to the hospital after an assault with splenic laceration and was subsequently found to have infective endocarditis associated with cryoglobulinemic vasculitis and ADEM.

Staphylococcus lugdunensis Peritoneal Dialysis-Related Peritonitis: A Matched Comparative Analysis.

Rationale & Objective: Staphylococcus lugdunensis (S lugdunensis) is a coagulase-negative staphylococcus species that has been increasingly recognized to cause serious infections with virulence resembling Staphylococcus aureus (S aureus). No studies have evaluated the characteristics and outcomes of patients with S lugdunensis peritoneal dialysis-related peritonitis compared with those with S aureus peritonitis. We aim to evaluate the clinical course of peritonitis as caused by these organisms. Study Design: A retrospective matched comparative analysis involving a single tertiary center from July 2000 to July 2020. Setting & Participants: Forty-eight episodes of S aureus peritonitis were matched to 19 cases of S lugdunensis peritonitis. Analytical Approach: The cases were individually matched for year of peritonitis, sex, age (±10 years), and Charlson Comorbidity Index (±3). A comparative analysis was performed between the 2 organisms. The outcome includes responses at day 5 of peritonitis and the rate of complete response. Results: There is a higher predilection of diabetes in those with S aureus peritonitis than in those with S lugdunensis (64.6% vs 31.6%; P = 0.03). Patients with S aureus peritonitis also have a much higher total cell count at presentation (4,463.9 ± 5,479.5 vs 1,807.9 ± 3,322.7; P = 0.05); a higher prevalence of poor response at day 5 (50.0% vs 15.8%; P = 0.03); a lower rate of complete response (64.6% vs 94.7%; P = 0.01) and are more prone to relapse with the same organism (29.2% vs 0%, respectively; P = 0.01) as compared to those with S lugdunensis. Limitations: The result of this small retrospective study involving a single center may not be generalizable to other centers. There is also no data for comparative analysis on other coagulase-negative staphylococci such as Staphylococcus epidermidis, which belongs to the same family as S lugdunensis. Conclusions: Although S aureus peritonitis is more virulent with significant morbidity, S lugdunensis can cause similarly serious peritonitis. This largest case series of S lugdunensis peritonitis enabled better characterization of clinical features and outcomes of patients with S lugdunensis peritonitis.

Staphylococcus lugdunensis is a coagulase-negative staphylococcus species that has been increasingly recognized to cause serious infections with virulence resembling Staphylococcus aureus. No studies have evaluated the characteristics and outcomes of patients with S lugdunensis peritoneal dialysis-related peritonitis compared those with S aureus peritonitis. This largest retrospective matched comparative analysis of S lugdunensis peritonitis enabled better characterization of clinical features and outcomes of patients with S lugdunensis. Our result suggested that although S. aureus peritonitis is more virulent with significant morbidity, S lugdunensis can cause similarly serious peritonitis. Regardless, S lugdunensis remains susceptible to most antibiotics and penicillin group, penicillin G in particular, can be considered as the first line antibiotic.

Clinical Disease and Outcomes of Invasive Staphylococcus lugdunensis Infection in a University Hospital in Saudi Arabia.

Background Staphylococcus lugdunensis is a pathogen that can cause various diseases in humans, of which bacteremia and infective endocarditis have been described most extensively. In Saudi Arabia, reports of S. lugdunensis infection are extremely rare, and no studies have reported S. lugdunensis antibiotic susceptibility. The objective of this study was to determine S. lugdunensis clinical disease, potential risk factors, susceptibility pattern, and 30-day mortality. Methods A retrospective study was performed at King Abdulaziz University Hospital in Jeddah, Saudi Arabia, from January 1, 2015, to December 31, 2022. Patients ≥14 years old were included. All variables, such as age, sex, body mass index (BMI), clinical manifestations, source of infection, antimicrobial susceptibility, antimicrobial given, duration of treatment, and 30-day mortality, were obtained from electronic health charts. Results Twenty-five patients with S. lugdunensis infection were identified, with a median age of 58 years and all had comorbidities (mean: 2, range 1-10). The patients had a median BMI of 28, and most patients were either overweight (28%, n = 7) or obese (48%, n = 12). The 30-day mortality was only 8% (n = 2). S. lugdunensis was most often cultured from wound swabs (72%, n = 18) and blood (20%, n = 5). The majority (68%, n = 17) of infections were community-acquired. Antibiotic susceptibility to vancomycin was 100% (n = 25), oxacillin 72% (n = 18), and clindamycin and trimethoprim-sulfamethoxazole 64% (n = 16) each. The mean Charlson comorbidity index was significantly higher (p-value = 0.027) among the deceased patients (6.00 ± 2.12) than those that survived (1.83 ± 1.77). Conclusion S. lugdunensis can cause clinically significant disease, especially in patients with multiple comorbidities, and a higher Charlson comorbidity index was found in patients who died.

Staphylococcus lugdunensis Endocarditis Causing Secondary Splenic Abscess: A Potentially Lethal Complication.

Infective endocarditis is a potentially life-threatening condition caused by a bacterial infection of the heart valves. The incidence of splenic abscess associated with infective endocarditis varies between 1-10% of cases, and its presence may indicate a severe form of the disease. We present a 24-year-old man diagnosed with infective endocarditis who was found to have a splenic abscess upon further evaluation. The patient was initially managed conservatively with targeted antibiotics, but after unsuccessful percutaneous drainage, a splenectomy was performed. The patient underwent mitral valve replacement surgery and made a good recovery. The patient's case highlights the importance of considering a secondary abscess in the management of infective endocarditis. This complication can easily be missed and cause significant morbidity. This case underscores the importance of early diagnosis and effective collaboration between various healthcare professionals to achieve the best possible outcome for patients with infective endocarditis and its associated complications.

Expression and Immobilization of Tannase for Tannery Effluent Treatment from Lactobacillus plantarum and Staphylococcus lugdunensis: A Comparative Study.

Agro-industrial discharges have higher concentrations of tannins and have been a significant cause of pollution to water bodies and soil surrounding the agro-industries. So in this study, toxic tannic acid is into commercially valuable gallic acid from the tannery effluent using immobilized microbial tannase. Tannase genes were isolated from Lactobacillus plantarum JCM 1149 (tanLpl) and Staphylococcus lugdunensis MTCC 3614 (tanA). Further, these isolated tannese genes were cloned and expressed in BL 21 host using pET 28a as an expression vector,  and immobilized in sodium alginate beads. Vegetable tannery effluent was treated by tannase-immobilized beads at 25 °C and 37 °C, where liberated gallic acid was analyzed using TLC and NMR to confirm the tannin reduction. Further, both immobilized tannases exhibited excellent reusability up to 15 cycles of regeneration without significant reduction in their activity. Moreover, we also showed that immobilized tannases tanLpl and tanA activity remained unaffected compared to the free enzyme in the presence of metal ions. Further, tanA activity remained unaffected over a wide range of pH, and tanLpl showed high thermal stability. Thus, immobilized tannase tanLpl and tanA provide a possible solution for tannery effluent treatment depending upon industry requirements and reaction composition/effluent composition, one can choose a better-immobilized tannase among the two as per the need-based requirement.

Molecular characterization of lugdunin inactivation mechanisms and their association with Staphylococcus lugdunensis genetic types.

BACKGROUND AND PURPOSE: Our previous studies showed that lugdunin activities are associated with Staphylococcus lugdunensis genotypes, and most isolates do not exhibit lugdunin activity. As a continuation of our previous analysis, we focused on the reasons for defects in lugdunin production in S. lugdunensis clinical isolates. METHODS: A comparative analysis of 36 S. lugdunensis whole genome sequencing data revealed three major mutation types, unknown deletion mechanism that caused most of lug operon genes lost, mobile genetic element (MGE) insertion, and nonsense mutations, which potentially damaged lugdunin production. A total of 152 S. lugdunensis clinical isolates belonging to lugdunin nonproducers were further examined for the above three mutation types. PCR products were sequenced to examine these variations. RESULTS: Forty-six of the 152 isolates were CRISPR-Cas IIC isolates, including 26 ST27, 14 ST4, and 6 ST29 isolates; further investigation confirmed that all of their lug operons had lost almost all lug operon genes except lugM. An IS256 insertion in lugA was identified in 16 isolates, and most isolates (15 over 16) belonged to ST3. In addition, three nonsense mutations caused by single nucleotide substitutions (an adenine deletion in lugB at the 361th and 1219th nucleotides and an adenine deletion in lugC at the 1612nd nucleotide) that were frequently observed among 36 S. lugdunensis whole genome sequencing data were further observed in our clinical isolates. These three nonsense mutations were frequently found in most of CRISPR-Cas IIIA strains, especially in ST6 isolates. CONCLUSION: Our findings suggest that the mechanisms affecting lugdunin production are associated with S. lugdunensis molecular types.

Infective Endocarditis Caused by Staphylococcus lugdunensis.

Staphylococcus lugdunensis, a minor species of coagulase-negative staphylococci, has attracted attention because of its formidable pathogenicity. We present a case of infective endocarditis (IE) caused by S. lugdunensis in a 72-year-old woman with a history of breast cancer and metastases who presented with fever. Two of two blood culture bottles were positive for gram-positive cocci. Transesophageal echocardiography revealed vegetation attached to the right cusp of the aortic valve and an abscess in the annulus, which was less evident on transthoracic echocardiography. This case underscores the importance of considering S. lugdunensis as a potential cause of IE.

Impact of clonal lineages on susceptibility of Staphylococcus lugdunensis to chlorhexidine digluconate and chloride benzalkonium.

BACKGROUND: Little is known about susceptibility of Staphylococcus lugdunensis to antiseptics. The objective of this study was to evaluate, at the molecular and phenotypic level, the susceptibility of 49 clinical S. lugdunensis strains (belonging to the seven clonal complexes [CCs] defined by multilocus sequence typing) to two antiseptics frequently used in healthcare settings (chlorhexidine digluconate [CHX] and chloride benzalkonium [BAC]). RESULTS: The minimum inhibitory concentrations (MICs), by broth microdilution method, varied for BAC from 0.25 mg/L to 8 mg/L (MIC50 = 1 mg/L, MIC90 = 2 mg/L) and for CHX from 0.5 mg/L to 2 mg/L (MIC50 = 1 mg/L, MIC90 = 2 mg/L). The BAC and CHX minimum bactericidal concentrations (MBCs) varied from 2 mg/L to 8 mg/L (MBC50 = 4 mg/L, MBC90 = 8 mg/L) and from 2 mg/L to 4 mg/L (MBC50 and MBC90 = 4 mg/L), respectively. A reduced susceptibility to CHX (MIC = 2 mg/L) was observed for 12.2% of the strains and that to BAC (MIC ≥ 4 mg/L) for 4.1%. The norA resistance gene was detected in all the 49 isolates, whereas the qacA gene was rarely encountered (two strains; 4.1%). The qacC, qacG, qacH, and qacJ genes were not detected. The two strains harboring the qacA gene had reduced susceptibility to both antiseptics and belonged to CC3. CONCLUSION: The norA gene was detected in all the strains, suggesting that it could belong to the core genome of S. lugdunensis. S. lugdunensis is highly susceptible to both antiseptics tested. Reduced susceptibility to BAC and CHX was a rare phenomenon. Of note, a tendency to higher MICs of BAC was detected for CC3 isolates. These results should be confirmed on a larger collection of strains.

Searching for Virulence Factors among Staphylococcus lugdunensis Isolates from Orthopedic Infections: Correlation of ß-hemolysin, hemolysin III, and slush Genes with Hemolytic Activity and Synergistic Hemolytic Activity.

Staphylococcus lugdunensis is an emerging high-virulent pathogen. Here, the presence and expression of virulence genes (icaA, fbl, vwbl, fbpA, slush A, B and C, and genes of the putative ß-hemolysin and hemolysin III) and the ability to induce synergistic hemolytic activity and hemolysis after 24, 48 and 72 h were investigated in a collection of twenty-two S. lugdunensis clinical isolates. The collection of isolates, mainly from implant orthopedic infections, had previously been grouped by ribotyping/dendrogram analysis and studied for biofilm matrices, biomasses and antibiotic resistances. Two isolates, constituting a unique small ribogroup sharing the same cluster, exhibited an amplicon size of the slush operon (S. lugdunensis synergistic hemolysin) which was shorter than the expected 977 bp. This outcome can predict the genetic lineage of the S. lugdunensis strains. One isolate (cra1342) presented two deletions: one of 90 bp in slush A and the other of 91 bp in slush B. Another isolate (N860314) showed a single 193 bp deletion, which encompassed part of the slush B terminal sequence and most of slush C. The isolate N860314 was devoid of hemolytic activity after 24 h, and the first consideration was that the deleted region deals with the coding of the active enzymatic site of the slush hemolysin. On the other hand, cra1342 and N860314 isolates with different slush deletions and with hemolytic activity after 24 and 48 h, respectively, could have replaced the hemolytic phenotype through other processes.

From Obscurity To Spotlight: Staphylococcus lugdunensis-Induced Infective Endocarditis, a Profound Case Unraveling.

Infective endocarditis (IE) represents a grave infection characterized by endocardial inflammation and valve impairment due to diverse pathogens. Staphylococcus lugdunensis, a coagulase-negative organism, has garnered increasing recognition as a significant etiological agent of IE. This bacterium is renowned for its aggressive tissue infections encompassing bone and joint, bloodstream, and IE sites. Particularly noteworthy is the rapid devastation and abscess formation it induces on heart valves, resulting in elevated mortality rates. The pathogen's affinity for von Willebrand factor facilitates its attachment to cardiac valves and blood vessels, thereby exacerbating its virulence. This abstract provides a comprehensive overview of S. lugdunensis-triggered IE. We present a compelling case involving a 66-year-old female afflicted by IE attributed to this microorganism, illuminating the clinical manifestations and challenges linked to the ailment. Moreover, we scrutinize previously reported instances of S. lugdunensis-related IE spanning from 1993 to 2022, accentuating the escalating importance of this pathogen in disease causality. The deleterious consequences of S. lugdunensis-induced IE emanate from its distinctive clinical attributes, necessitating tailored diagnostic strategies and treatment considerations. Given the gravity and swift progression of the infection, healthcare professionals play a pivotal role in administering timely and efficacious management for afflicted patients. Further research is imperative to enhance diagnostic modalities and explore therapeutic approaches aimed at effectively combating this formidable and life-threatening infection.

Lugdunin production and activity in Staphylococcus lugdunensis isolates are associated with its genotypes.

Lugdunin produced by Staphylococcus lugdunensis has been shown to have broad inhibitory activity against Gram-positive bacteria; however, lugdunin activity among S. lugdunensis isolates and its association with different agr, SCCmec, and sequence types remain unclear. We used matrix-assisted laser desorption ionization-time-of-flight mass spectrometry to identify S. lugdunensis and collected 202 S. lugdunensis samples for further assays. Agar spot tests were performed to characterize S. lugdunensis lugdunin production and activity. Multilocus sequence typing, SCCmec, and agr genotyping were performed on S. lugdunensis. In all, 91 Staphylococcus aureus strains with varying vancomycin susceptibilities were used to examine lugdunin activity in S. lugdunensis. In total, 48 S. lugdunensis strains (23.8%) were found to be oxacillin-resistant S. lugdunensis (ORSL), whereas 154 (76.2%) were classified as oxacillin-sensitive S. lugdunensis (OSSL). Moreover, 16 (33.3%) ORSL and 35 (22.7%) OSSL strains showed antibacterial activity against S. aureus. Our data showed that most lugdunin-producing ORSL strains (14/48, 29.2%) were of ST3-SCCmec V-agr II genotypes, whereas most lugdunin-producing OSSL strains (15/154, 9.7%) were of ST3-agr II, followed by ST1-agr I (10/154, 6.5%). Our data also revealed that lugdunin exhibited weak inhibitory activity against the VISA ST239 isolate. In addition, we observed that ST239 VSSA was more resistant to lugdunin than ST5, ST59, and ST45 VSSA. Taken together, our data pioneered the epidemiology of lugdunin production in S. lugdunensis isolates and revealed its association with genotypes. However, further molecular and bioinformatics investigations are needed to elucidate the regulatory mechanisms of lugdunin production and activity. IMPORTANCE Lugdunin is active against both methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci by dissipating their membrane potential. However, the association of lugdunin activity with the genotypes of Staphylococcus lugdunensis has not been addressed. Here, we show the high prevalence of lugdunin-producing strains among ST1 (83.3%), ST2 (66.7%), and ST3 (53.3%) S. lugdunensis. Moreover, we identified the antibacterial activity of lugdunin-producing strains against VISA and hVISA. These results shed light on the potential application of lugdunin for the treatment of drug-resistant pathogens.

fbl-typing and Antimicrobial Resistance Analysis of Staphylococcus lugdunensis.

BACKGROUND: A broad variety of infections, ranging from skin infections to infective endocarditis can be caused by Staphylococcus lugdunensis. Bacterial virulence is often related to virulence genes, so we sought to investigate the relationship between virulence genes and the pathogenicity of S. lugdunensis and to explore an appropriate typing method to distinguish different pathogenic phenotypes of S. lugdunensis. METHODS: We describe the distribution of several virulence genes in different infection types in an attempt to find the relationship between virulence genes and pathogenicity. Subsequently, we make the Matrix-Assisted Laser Desorption/Ionization-Time-of-Flight Mass Spectrometry (MALDI-TOF MS) dendrogram and fbl-typing were performed using BioNumerics software, tried to compare the correlation between different methods and the different infectious diseases, and antimicrobial resistance of the strains, in order to obtain the epidemic characteristics and antimicrobial resistance information of S. lugdunensis based on a molecular approach. RESULTS: The results of virulence genes showed that the seven virulence genes we have described existed in most strains, and there was no significant correlation between virulence gene distribution and infection type. Compared with the MALDI-TOF MS dendrogram, we found that fbl-typing could better correspond to the pathogenic phenotype, with better recognition and reproducibility. In the phylogenetic tree constructed in the fbl R-region, we found a tendency for some infection types to be distributed in clusters, new type 3 was the most dominant fbl-type, followed by fbl47b. Bone and joint infection isolates and ear infection isolates were significantly clustered together, in addition, all the oxacillin-resistant isolates were concentrated in fbl-type fbl45j and fbl47b. CONCLUSIONS: In this study, we found no significant correlation between virulence genes from S. lugdunensis isolates and the site of infection. The fbl-typing has the characteristics of convenient operation, low cost, high repeatability, and is preferable to indicate the pathogenic phenotype. Based on fbl-typing, we described the epidemiological characteristics of S. lugdunensis in a hospital and supplemented the data for fbl-typing. We recommend that fbl-typing method be extended and supplemented.

Staphylococcus lugdunensis Infective Endocarditis With Mitral Valve Vegetations in a Hemodialysis Patient With Recurrent Arteriovenous Fistula Cannulation: A Case Report.

Infective endocarditis is a severe medical condition that occurs when the endocardium of the heart gets infected by different microorganisms, including coagulase-negative staphylococci such as Staphylococcus lugdunensis. The source of infection is often related to procedures done in the groin area, such as femoral catheterization for cardiac catheterization, vasectomy, or central line placement in an already infected mitral or aortic valve. Herein, we are discussing a case of a 55-year-old female with a past medical history of end-stage renal disease on hemodialysis with a history of recurrent cannulation of her arteriovenous (AV) fistula. She presented with fever, myalgia, and generalized weakness, and was later found to have Staphylococcus lugdunensis bacteremia and infective endocarditis with mitral valve vegetations, for which the patient was transferred to the mitral valve specialized center for mitral valve replacement. This case acts as a reminder to consider recurrent cannulation of the AV fistula as one of the potential ports of entry of Staphylococcus lugdunensis to the body.

Staphylococcus lugdunensis, a Not So Infrequent Pathogen in Orthopedic Surgery.

Abstract Background: Staphylococcus lugdunensis is a coagulase-negative staphylococci that is considered normal skin microbiota. It has been described as a cause of soft tissue infections but is not a common micro-organism as the cause of orthopedic surgery-related infections. This study describes the characteristics, treatment, and results of musculoskeletal infection by Staphylococcus lugdunensis treated in our institution. Methods: We performed a descriptive, retrospective observational study. Clinical records of all musculoskeletal infections treated in our department between 2012 and 2020 were reviewed. We selected those patients with a positive monomicrobial culture for Staphylococcus lugdunensis. Risk factors for infection, patient's medical records, previous surgery performed, time from surgery to infection, culture antibiogram, antibiotic and surgical treatment for the infection, and recovery rate were registered for the analysis. Results: Of the 1,482 patients with musculoskeletal infections diagnosed in our institution, 22 had a monomicrobial positive culture of Staphylococcus lugdunensis after an orthopedic surgery representing 1.5% of all orthopedic infections. Ten patients underwent arthroplasty, six underwent fractures synthesis, three had foot surgeries, two had anterior cruciate ligament reconstructions, and one had spine surgery. All patients needed surgery and antibiotic treatment with a mean of two surgeries. The most used antibiotic scheme was levofloxacin-rifampicin. The mean follow-up was 36 months. Ninety-six percent of the patients achieved a complete clinical and analytical recovery. Conclusions: Although musculoskeletal infections caused by Staphylococcus lugdunensis are not common, we have observed a statistically significant incidence increase of Staphylococcus lugdunensis in recent years. If managed with appropriately aggressive surgical treatment and correct antibiotic therapy, good results can be obtained.

Staphylococcus lugdunensis infective endocarditis with perforation of the sinus of Valsalva: a case report.

Background: Staphylococcus lugdunensis endocarditis is a rare but fulminant disease. Case summary: A 74-year-old female with a history of asymptomatic severe aortic valve stenosis and permanent atrial fibrillation presented with acute onset of fever (39.0°C). Electrocardiogram showed diffuse ST-segment elevation. She was hospitalized for further analysis. All blood cultures were positive for Staphylococcus lugdunensis and antibiotic treatment was started. Transthoracic echocardiography (TTE) showed known aortic valve stenosis without clear signs of endocarditis. The following day, a transoesophageal echocardiogram (TEE) showed a new moderate aortic valve regurgitation, new pericardial effusion (PE), and a thickened sinus of Valsalva (SOV) consistent with endocarditis with paravalvular involvement. Positron emission tomography-computed tomography was consistent with aortic valve endocarditis with paravalvular expansion. The patient was transferred to a tertiary referral centre for surgical treatment. On admission, patient was in shock and a second TTE revealed a new systolic and diastolic flow through the SOV to the right ventricle indicating SOV perforation. Additionally, there was flow in the PE suggestive of perforation of one of the cardiac chambers or large vessels. Emergent surgery showed extended infection with SOV perforation and a large perforation of the right ventricle. Ultimately, patient died during the operation because of extensive infection and refractory shock. Conclusion: Staphylococcus lugdunensis endocarditis is a severe disease with poor response to conventional anti-microbial treatment, destructive complications requiring surgery, and has a high mortality risk.

Novel biochemical aspects of lugdulysin, a Staphylococcus lugdunensis metalloprotease that inhibits formation and disrupts protein biofilm of methicillin-resistant Staphylococcus aureus.

Staphylococcus lugdunensis produces lugdulysin, a metalloprotease that may contribute to its virulence. This study aimed to evaluate the biochemical aspects of lugdulysin and investigate its effect on Staphylococcus aureus biofilms. The protease was isolated and characterized for its optimal pH and temperature, hydrolysis kinetics, and influence of metal cofactor supplementation. The protein structure was determined via homology modeling. The effect on S. aureus biofilms was assessed by the micromethod technique. The protease optimal pH and temperature were 7.0 and 37 °C, respectively. EDTA inhibited protease activity, confirming it as a metalloprotease. Lugdulysin activity was not recovered by divalent ion supplementation post-inhibition, and supplementation with divalent ions did not change enzymatic activity. The isolated enzyme was stable for up to 3 h. Lugdulysin significantly inhibited the formation and disrupted preestablished protein-matrix MRSA biofilm. This preliminary study indicates that lugdulysin has a potential role as a competition mechanism and/or modulation of staphylococcal biofilm.

Improvise, Adapt & Overcome: Successful Surgery-Sparing Prosthetic Hip Infection Antibiotic Suppression During COVID-19 Crisis.

CASE: A 79-year-old active male presented during the first COVID-19 pandemic surgery moratorium with late Staphylococcus lugdunensis periprosthetic total hip arthroplasty infection. Due to the unprecedented circumstances, novel treatment of IV and oral antibiotic suppression was trialed without preceding surgical intervention. At latest follow-up, the patient has two-year revision-free survival with normalization of inflammatory markers and MRI findings, and resolution of clinical symptoms. CONCLUSION: We report a novel surgery-sparing treatment for periprosthetic hip infection. Judicious caution should be used in the application of similar therapies, as host and organism characteristics likely contributed substantially to the success of this case.

Biofilm formation is associated with poor outcome in prosthetic joint infections caused by Staphylococcus lugdunensis.

BACKGROUND: Staphylococcus lugdunensis has been described as a pathogen of increasing importance in prosthetic joint infections (PJI). Our aim was to describe the clinical presentation of PJI caused by S. lugdunensis, and to correlate the biofilm-forming ability of the bacterial isolates to clinical outcome. METHOD: S. lugdunensis isolates from PJI episodes during 2015-2019 were included and analysed for biofilm formation using a microtiter plate assay. Medical records from the corresponding patients were reviewed. RESULTS: We identified 36 patients with PJI caused by S. lugdunensis during the study period. Early postoperative PJIs were most frequent (n = 20, 56%). Surgical intervention was performed in a majority of the patients (n = 33, 92%), and the dominating type of antibiotic treatment was a combination of rifampicin and ciprofloxacin (n = 27, 75%). The treatment success-rate was 81% (n = 29). All isolates causing PJI were able to form biofilm in vitro. Biofilm formation was significantly stronger in isolates causing relapsing vs non-relapsing PJI (mean OD550 3.1 ± 0.23 vs 1.14 ± 0.73 p = .001) and strong biofilm formation was also associated with late acute hematogenic PJI (mean OD550 1.8 ± 0.93 vs. 0.93 ± 0.81, p = .01). CONCLUSION: Strong biofilm production in S. lugdunensis isolates was associated with relapse in PJI.

Characterization of oxacillin-resistant Staphylococcus lugdunensis isolated from sterile body fluids in a medical center in Taiwan: A 12-year longitudinal epidemiological study.

BACKGROUND: In this study, our objective was to characterize Staphylococcus lugdunensis isolated from sterile body fluids (SBFs) in a medical center in Taiwan between 2009 and 2020. METHODS: We used MALDI-TOF MS, disk diffusion testing, agar dilution assay, SCCmec typing, and antibiotic resistance gene screening to identify and investigate the characteristics of oxacillin-resistant S. lugdunensis (ORSL). RESULTS: A total of 438 S. lugdunensis isolates were collected and 146 (33.3%) isolates were identified as ORSL. SCCmec type V was dominant (65.7%) in our ORSL isolates, followed by SCCmec type II (18.5%), and type IV (8.9%). After 2013, a slight increase in SCCmec types IV and V was revealed. Moreover, all ORSL isolates with type II and untypable SCCmec were highly resistant to oxacillin (MIC >32 µg/mL), compared to ORSL that had SCCmec types IV, V, and VT. All 146 ORSL isolates were resistant to penicillin and susceptible to teicoplanin and vancomycin. High resistance rates of ORSL to clindamycin (43.2%), erythromycin (43.2%), gentamicin (78.1%) and tetracycline (46.6%) was observed. Moreover, only two (1.4%) and six (4.1%) ORSL isolates were resistant to trimethoprim/sulfamethoxazole and ciprofloxacin, respectively. The erythromycin-resistant ORSL isolates mostly exhibited constitutive MLSB resistant phenotype (61/63, 96.8%) and contained either ermC alone (27/63, 42.9%) or a combination of ermC with ermA (28/63, 44.4%). CONCLUSION: Our present study showed a stable rate of ORSL from SBFs during 2009-2020. Moreover, teicoplanin, vancomycin, trimethoprim/sulfamethoxazole, and ciprofloxacin were shown to be highly efficient for the treatment of ORSL in vitro.