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Background/Objectives: Staphylococcus lugdunensis is a coagulase-negative staphylococcus (CoNS) commonly found on human skin. Unlike other CoNS, S. lugdunensis has a notable potential to cause severe infections comparable to Staphylococcus aureus. This study aimed to characterize the clinical and microbiological profile of patients with S. lugdunensis skin infections at a single center. Methods: We conducted a retrospective analysis of patient records from the Dermatology Department of the University Hospital of Heraklion, Greece, covering the period from January 2014 to January 2024. Patients' clinical presentations, demographics, infection sites, comorbidities, prior infections, antimicrobial treatments, and therapeutic responses were examined. Specimens were collected, transported, and processed according to standardized microbiological protocols. Bacterial identification and antibiotic susceptibility testing were performed using the Vitek 2 automated system and MALDI-TOF MS, with results interpreted according to Clinical and Laboratory Standards Institute (CLSI) criteria. Results: A total of 123 skin specimens positive for S. lugdunensis were analyzed. The cohort comprised 62 males (50.4%) and 61 females (49.6%), with a mean age of 40.24 ± 20.14 years. Most specimens were collected from pus (84%), primarily from below the waist (66.7%). Hidradenitis suppurativa (26%) was the most common condition associated with S. lugdunensis, followed by folliculitis, abscesses, ulcers, cellulitis, and acne. Co-infections with other bacteria were noted in 49.6% of cases, and 25.2% of infections were nosocomially acquired. The majority of patients (65%) received systemic antibiotics, predominantly amoxicillin/clavulanic acid, cefuroxime axetil, and doxycycline, with a cure rate of 100%. All isolates were susceptible to several antibiotics, though resistance to penicillin (28.5%) and clindamycin (36%) was observed. Conclusions: S. lugdunensis is a significant pathogen in skin infections, capable of causing severe disease. The high cure rate demonstrates the effectiveness of appropriate antibiotic therapy. Continued monitoring and antimicrobial stewardship are essential to manage resistance and ensure effective treatment. [ABSTRACT FROM AUTHOR]

Background/Objectives: Antibiotic (AB) therapy is the first step in managing hidradenitis suppurativa (HS). Knowledge of the local patterns of antimicrobial resistance is paramount for the appropriate selection of antimicrobials. This study aimed to assess the occurrence of antibiotic resistance in patients with HS. Methods: A cross-sectional study was conducted on 103 patients with HS seen at the Dermatology Department at the University Hospital of Heraklion, Heraklion, Crete, Greece, from January 2019 to December 2023, who were not on any antibiotics in the last three months. Results: A total of 103 patients with HS participated in this study. Purulent material from 139 skin lesions of these patients was swabbed, and 79.86% (111/139) tested positive for bacteria. Gram-positive isolates accounted for 73%, whereas Gram-negative isolates comprised 27%. Among the isolates, 85.1% were aerobes, and 14.9% were anaerobic. The most common bacterial families isolated were Staphylococcaceae (48.27%), Enterobacteriaceae (14.94%), and Streptococcaceae (6.89%). The antibiogram profiles of bacterial cultures revealed a 57.1% resistance to levofloxacin and a 53.3% resistance to penicillin in Staphylococcus lugdunensis, whereas Staphylococcus aureus showed a 76.9% resistance to penicillin and a 58.3% resistance to fusidic acid. High resistance rates of 63.5% for tigecycline, 63.3% for ampicillin, and 40.5% for colistin were observed for Gram-negative isolates. Resistances of 62.5%, 61.5%, and 53.8% to erythromycin, clindamycin, and penicillin, respectively, were observed in the anaerobes. Conclusions: Patients with HS displayed considerable resistance to bacterial proliferation. The revised therapeutic guidelines for HS should incorporate the latest insights into bacterial antibiotic resistance. [ABSTRACT FROM AUTHOR]

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.

A patient with dissecting folliculitis of the scalp who did not respond to antibiotic therapy received four monthly sessions of intradermal administration of 100 IU of botulinum toxin A. Four months after treatment, a complete recovery of the affected area of the patient's scalp was observed. A biopsy taken from the affected area showed the presence of Staphylococcus lugdunensis and Staphylococcus aureus resistant to erythromycin. Botulinum toxin A had no effect on the viability or biofilm production of the Staphylococcus strains, indicating that the healing effect of the toxin was associated with the host response alone.

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. Plain Language Summary: 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.

Abstract 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.

Background/Objectives: Staphylococcus lugdunensis is a coagulase-negative staphylococcus (CoNS) commonly found on human skin. Unlike other CoNS, S. lugdunensis has a notable potential to cause severe infections comparable to Staphylococcus aureus. This study aimed to characterize the clinical and microbiological profile of patients with S. lugdunensis skin infections at a single center. Methods: We conducted a retrospective analysis of patient records from the Dermatology Department of the University Hospital of Heraklion, Greece, covering the period from January 2014 to January 2024. Patients’ clinical presentations, demographics, infection sites, comorbidities, prior infections, antimicrobial treatments, and therapeutic responses were examined. Specimens were collected, transported, and processed according to standardized microbiological protocols. Bacterial identification and antibiotic susceptibility testing were performed using the Vitek 2 automated system and MALDI-TOF MS, with results interpreted according to Clinical and Laboratory Standards Institute (CLSI) criteria. Results: A total of 123 skin specimens positive for S. lugdunensis were analyzed. The cohort comprised 62 males (50.4%) and 61 females (49.6%), with a mean age of 40.24 ± 20.14 years. Most specimens were collected from pus (84%), primarily from below the waist (66.7%). Hidradenitis suppurativa (26%) was the most common condition associated with S. lugdunensis, followed by folliculitis, abscesses, ulcers, cellulitis, and acne. Co-infections with other bacteria were noted in 49.6% of cases, and 25.2% of infections were nosocomially acquired. The majority of patients (65%) received systemic antibiotics, predominantly amoxicillin/clavulanic acid, cefuroxime axetil, and doxycycline, with a cure rate of 100%. All isolates were susceptible to several antibiotics, though resistance to penicillin (28.5%) and clindamycin (36%) was observed. Conclusions: S. lugdunensis is a significant pathogen in skin infections, capable of causing severe disease. The high cure rate demonstrates the effectiveness of appropriate antibiotic therapy. Continued monitoring and antimicrobial stewardship are essential to manage resistance and ensure effective treatment.

Background/Objectives: Antibiotic (AB) therapy is the first step in managing hidradenitis suppurativa (HS). Knowledge of the local patterns of antimicrobial resistance is paramount for the appropriate selection of antimicrobials. This study aimed to assess the occurrence of antibiotic resistance in patients with HS. Methods: A cross-sectional study was conducted on 103 patients with HS seen at the Dermatology Department at the University Hospital of Heraklion, Heraklion, Crete, Greece, from January 2019 to December 2023, who were not on any antibiotics in the last three months. Results: A total of 103 patients with HS participated in this study. Purulent material from 139 skin lesions of these patients was swabbed, and 79.86% (111/139) tested positive for bacteria. Gram-positive isolates accounted for 73%, whereas Gram-negative isolates comprised 27%. Among the isolates, 85.1% were aerobes, and 14.9% were anaerobic. The most common bacterial families isolated were Staphylococcaceae (48.27%), Enterobacteriaceae (14.94%), and Streptococcaceae (6.89%). The antibiogram profiles of bacterial cultures revealed a 57.1% resistance to levofloxacin and a 53.3% resistance to penicillin in Staphylococcus lugdunensis, whereas Staphylococcus aureus showed a 76.9% resistance to penicillin and a 58.3% resistance to fusidic acid. High resistance rates of 63.5% for tigecycline, 63.3% for ampicillin, and 40.5% for colistin were observed for Gram-negative isolates. Resistances of 62.5%, 61.5%, and 53.8% to erythromycin, clindamycin, and penicillin, respectively, were observed in the anaerobes. Conclusions: Patients with HS displayed considerable resistance to bacterial proliferation. The revised therapeutic guidelines for HS should incorporate the latest insights into bacterial antibiotic resistance.

PurposeTo present a case of periorbital and orbital necrotizing fasciitis (PONF) from an odontogenic source with a distinct microbiologic profile and highlight the need for emergent multidisciplinary management.ObservationsA 39-year-old man presented with periorbital swelling, pain, and erythema following facial trauma. Imaging revealed peri-dental collections, accompanying maxillary sinusitis, and pre- and post-septal involvement. Immediate surgical debridement of necrotic tissue along with broad-spectrum antibiotics were pursued for management. Cultures grew multiple organisms, most notably Streptococcus milleri group and Staphylococcus lugdunensis.Conclusions and importancePONF is a rare yet potentially fatal disease. Streptococcus milleri group and a fulminant course are to be suspected when the source is odontogenic. Timely multidisciplinary surgical debridement and medical management with intravenous antibiotics is critical for best outcomes.

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. [ABSTRACT FROM AUTHOR]

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 β-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. [ABSTRACT FROM AUTHOR]

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.

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. [ABSTRACT FROM AUTHOR]

ABSTRACT 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.

Aims: The aim of the study was to investigate the prevalence, antibiogram and associated risk factors of Staphylococcus lugdunensis among healthy people. Methodology and results: A total of 200 nasal samples were collected from participants. The swabs were cultured on mannitol salt agar and incubated at 37 °C for 24 h. Isolates were diagnosed based on phenotypic, biochemical reactions and molecular methods. All identified isolates were screened for susceptibility to ten different antibiotics. Based on Gram stain and biochemical tests, 65 out of 200 (32.5%) were identified as S. lugdunensis. Twenty-nine of 65 (34.5%) were from males and 36 of 65 (31%) were from females (p=0.603). The highest prevalence was observed in the age group of 31-40 years (40%; 16/41) and the least prevalence rate was among the age group of =51 (15.4%; 2/13) (p=0.533). No statistically significant difference in the prevalence of S. lugdunensis was observed among people according to their family member size (p=0.472). Additionally, a slight difference in the carriage rate of S. lugdunensis was observed among the people who had Coronavirus disease (Covid-19) infection (31%) and the people who had no previous infection with it (33.6%) (p=0.697). Also, no statistically significant difference (p=0.992) in the nasal carriage rate of S. lugdunensis was observed among smokers (32.5%; 12/37) and nonsmokers (32.5%; 53/163). All isolates were 100% susceptible to doxycycline, linezolid and chloramphenicol; 99% to oxacillin; 92% to ciprofloxacin; 91% to amikacin; 89% to nitrofurans and vancomycin; 83% to meropenem; and 75% to erythromycin. Also, 15.4% of the isolates were multidrug resistant. Conclusion, significance and impact of study: Results revealed that the prevalence of nasal S. lugdunensis was high among people with no specific associated risk factor. Also, a high rate of antibiotic resistance was observed with a high rate of multidrug resistance. Hence, education programs and improving hygienic measures are necessary to prevent the spread of multidrug resistance to S. lugdunensis. This can help as an effective measure to control bacterial infections. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. 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. 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). Strong biofilm production in S. lugdunensis isolates was associated with relapse in PJI. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

ABSTRACT Importance Staphylococcus lugdunensis (S. lugdunensis) is a coagulase‐negative staphylococcus (CoNS), found commonly as skin flora in humans. While most species of CoNS are clinically benign, S. lugdunensis can exhibit a similar virulence to that of S. aureus. However, there is scant data concerning S. lugdunensis infection in the pediatric population. Objective To ascertain local S. lugdunensis infection rates and sensitivity patterns in the pediatric population. Methods A retrospective analysis was undertaken of all S. lugdunensis isolates across a 6‐year period from 2015 to 2020. Data were collected from electronic patient notes and laboratory records. Matrix‐assisted laser desorption ionization and time of flight mass spectrometry were used to identify isolates. Results Ninety‐six isolates of S. lugdunensis were identified from 86 patients. Of these, 34 isolates were treated as an infection. Twenty‐three (67.6%) were found to have skin as the primary source of infection. While the observed number was small, central nervous system (CNS) sources of S. lugdunensis infection appear to be a significant source: all three isolates cultured from cerebrospinal fluid were clinically managed as infection. All three were associated with ventriculoperitoneal (VP) shunt infection. No cases of S. lugdunensis infective endocarditis were identified. About 18.6% of S. lugdunensis isolates were resistant to flucloxacillin. Interpretation S. lugdunensis is an uncommon but significant cause of infection in the pediatric population and appears to be a rising cause of CNS infection, particularly when associated with VP shunts. Flucloxacillin is recommended locally as the first choice of antibiotic.

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. [ABSTRACT FROM AUTHOR]

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 β-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.

Background/purpose: Staphylococcus lugdunensis is a Gram-positive coagulase-negative bacterium and is recognized as a critical pathogenic species recently. Here, we aimed to evaluate the cefoxitin disk diffusion (CDD), oxacillin agar dilution (OAD), and mecA PCR for detecting oxacillin-resistant S. lugdunensis (ORSL) isolates. Methods: Multilocus sequence typing (MLST) analysis was performed to determine the clonality of 117 S. lugdunensis isolates isolated between May 2009 and Jul 2014. CDD, OAD, and mecA PCR were used to identify oxacillin-resistant S. lugdunensis (ORSL). Results: MLST results showed that the most common sequence type (ST) of our S. lugdunensis isolates was ST6 (35.9%) followed by ST3 (28.2%), ST27 (17.9%), and ST4 (6.8%). CDD and OAD showed that 39 and 43 isolates were ORSL, respectively. 4 ST3 CDD-susceptible S. lugdunensis (OSSL) isolates had MIC values ≥ 4 for oxacillin. mecA PCR results showed that 43 OAD-resistant S. lugdunensis and 3 OAD-susceptible ST27 S. lugdunensis had the mecA gene. Therefore, OAD was used as the gold standard to evaluate the performance of CDD and mecA PCR for identifying ORSL. The overall sensitivity, specificity, and accuracy of CCD for ORSL detection was 90.7%, 100%, and 96.8%, respectively. The sensitivity, specificity, and accuracy of mecA PCR for identifying ORSL was 100%, 95.9%, and 97.44%, respectively. Conclusion: Our results indicate that OAD shows higher accuracy for ORSL detection compared with CDD and mecA PCR.

Objectives: To describe Staphylococcus lugdunensis prosthetic joint infection (PJI) management and outcome.Methods: Adults with proven S. lugdunensis PJI were included in a multicentric retrospective cohort. Determinants for failure were assessed by logistic regression and treatment failure-free survival curve analysis (Kaplan-Meier).Results: One hundred and eleven patients were included (median age 72.4 [IQR, 62.7-79.4] years), with a knee (n = 71, 64.0%) or hip (n = 39, 35.1%) PJI considered as chronic in 77 (69.4%) cases. Surgical management consisted in debridement, antibiotic with implant retention (DAIR; n = 60, 54.1%), two-stage (n = 28, 25.2%) or one-stage (n = 15, 13.5%) exchange. Total duration of antimicrobial therapy was 13.1 (IQR, 11.8-16.9) weeks. After a median follow-up of 99.9 (IQR, 53.9-178.1) weeks, 22 (19.8%) S. lugdunensis-related treatment failures were observed. Independent determinants for outcome were diabetes (OR, 3.741; p = 0.036), sinus tract (OR, 3.846; p = 0.032), DAIR (OR, 3.749; p = 0.039) and rifampin-based regimen (OR, 0.319; p = 0.043). Twenty-four (40.0%) of the 60 DAIR-treated patients experienced treatment failure, with hip location (OR, 3.273; p = 0.048), delay from prosthesis implantation (OR, 1.012 per month; p = 0.019), pre-surgical CRP level >115 mg/L (OR, 4.800; p = 0.039) and mobile component exchange (OR, 0.302; p = 0.069) constituting additional determinants of outcome.Conclusions: Staphylococcus lugdunensis PJI are difficult-to-treat infections, with pivotal roles of an optimal surgical management. [ABSTRACT FROM AUTHOR]

Staphylococcus lugdunensis endophthalmitis is an uncommon intraocular infection with potentially visually devastating consequences. S. lugdunensis endophthalmitis have been reported following cataract surgery, trauma, intravitreal injections of anti-vascular endothelial growth factor agents and dexamethasone implant. We report four cases of postoperative S. lugdunensis endophthalmitis after cataract extraction (three patients) and combined pars plana vitrectomy and cataract extraction (one patient). The onset of presentation of endophthalmitis was acute (within 2 weeks) in two patients, subacute (2 to 6 weeks) in one patient, and chronic (more than 6 weeks) in one patient. All patients had presenting visual acuity (VA) of hand motions or worse and were treated with pars plana vitrectomy with intravitreal antibiotics. The final VA was 20/50 in two patients, 4/200 in one patient with pre-existing myopic maculopathy, and no light perception in one patient with retinal detachment. In antibiotic susceptibility testing, S. lugdunensis isolates were resistant to penicillin (3/4, 75%), but all were susceptible to vancomycin, oxacillin, teicoplanin, tigecycline, and sulfamethoxazole-trimethoprim. S. lugdunensis may be associated with acute or chronic endophthalmitis. Favorable visual outcomes can be achieved with prompt diagnosis and management. [ABSTRACT FROM AUTHOR]

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 is a part of the normal skin flora. However, this organism can be a pathogen in certain situations such as advanced age or immunosuppression. Further study regarding situations in which this bacterium becomes a pathogen is warranted.

Importance: Staphylococcus lugdunensis (S. lugdunensis) is a coagulase‐negative staphylococcus (CoNS), found commonly as skin flora in humans. While most species of CoNS are clinically benign, S. lugdunensis can exhibit a similar virulence to that of S. aureus. However, there is scant data concerning S. lugdunensis infection in the pediatric population. Objective: To ascertain local S. lugdunensis infection rates and sensitivity patterns in the pediatric population. Methods: A retrospective analysis was undertaken of all S. lugdunensis isolates across a 6‐year period from 2015 to 2020. Data were collected from electronic patient notes and laboratory records. Matrix‐assisted laser desorption ionization and time of flight mass spectrometry were used to identify isolates. Results: Ninety‐six isolates of S. lugdunensis were identified from 86 patients. Of these, 34 isolates were treated as an infection. Twenty‐three (67.6%) were found to have skin as the primary source of infection. While the observed number was small, central nervous system (CNS) sources of S. lugdunensis infection appear to be a significant source: all three isolates cultured from cerebrospinal fluid were clinically managed as infection. All three were associated with ventriculoperitoneal (VP) shunt infection. No cases of S. lugdunensis infective endocarditis were identified. About 18.6% of S. lugdunensis isolates were resistant to flucloxacillin. Interpretation: S. lugdunensis is an uncommon but significant cause of infection in the pediatric population and appears to be a rising cause of CNS infection, particularly when associated with VP shunts. Flucloxacillin is recommended locally as the first choice of antibiotic. [ABSTRACT FROM AUTHOR]

Although Staphylococcus haemolyticus and Staphylococcus lugdunensis are members of the normal human flora, they also can cause infection. Here, we present the draft genomes of five strains of S. lugdunensis and one strain of S. haemolyticus isolated from transurethral catheterized urine samples from different females experiencing lower urinary tract symptoms., Competing Interests: The authors declare no conflict of interest.

Staphylococcus lugdunensis is a coagulase-negative bacteria of the Staphylococcus family. It is a highly invasive organism with similar virulence to Staphylococcus aureus . It is commonly associated with bacteremia and infections of the skin, soft tissues, joints, and bones. Those with indwelling medical devices are at the highest risk of infection due to biofilm formation. Instances of native joint infections are exceedingly rare. We describe a case of a 72-year-old female with multiple comorbidities presenting with native right knee joint septic arthritis from S. lugdunensis . Due to treatment noncompliance secondary to latent social determinants of health, she faced a complicated and protracted clinical course that was treated with inpatient intravenous antibiotics and outpatient oral doxycycline. Few cases of native joint infections with S. lugdunensis have been documented, and to our knowledge, the impact of treatment noncompliance on the sequelae of septic arthritis with this organism has not been reported. Socioeconomic factors and comorbidities have been shown to increase a patient's risk for an extended joint infection with S. lugdunensis., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Howson et al.)

Background: Coagulase-negative staphylococci (CoNS) are biofilm-producing pathogens whose role in periprosthetic joint infection (PJI) is increasing. There is little data on the prognosis and treatment considerations in the setting of PJI. We sought to evaluate the clinical characteristics, outcomes, and complications in these patients.Methods: This is a retrospective cohort study of adult patients at a single tertiary medical center from 2009 to 2020 with culture-proven CoNS PJI after total knee arthroplasty, as diagnosed by Musculoskeletal Infection Society criteria. The primary outcome was treatment success, with failure defined as recurrent CoNS PJI, recurrent PJI with a new pathogen, and/or chronic oral antibiotic suppression at one year postoperatively.Results: We identified 55 patients with a CoNS total knee arthroplasty PJI with a mean follow-up of 29.8 months (SD: 16.3 months). The most commonly isolated organism was Staphylococcus epidermidis (n = 36, 65.5%). The overall prevalence of methicillin resistance was 63%. Surgical treatment included surgical debridement, antibiotics, and implant retention in 25 (45.5%) cases and two-stage revision (22 articulating and eight static antibiotic-impregnated spacers). At one-year follow-up, only 47% of patients had successful management of their infection. The surgical debridement, antibiotics, and implant retention cohort had the higher rate of treatment failure (60.0%) compared to two-stage revision (46.7%).Conclusion: These results indicate a poor rate of success in treating CoNS PJI. This likely represents the interplay of inherent virulence through biofilm formation and decreased antibiotic efficacy. [ABSTRACT FROM AUTHOR]

Purpose: To present a case of periorbital and orbital necrotizing fasciitis (PONF) from an odontogenic source with a distinct microbiologic profile and highlight the need for emergent multidisciplinary management. Observations: A 39-year-old man presented with periorbital swelling, pain, and erythema following facial trauma. Imaging revealed peri-dental collections, accompanying maxillary sinusitis, and pre- and post-septal involvement. Immediate surgical debridement of necrotic tissue along with broad-spectrum antibiotics were pursued for management. Cultures grew multiple organisms, most notably Streptococcus milleri group and Staphylococcus lugdunensis. Conclusions and Importance: PONF is a rare yet potentially fatal disease. Streptococcus milleri group and a fulminant course are to be suspected when the source is odontogenic. Timely multidisciplinary surgical debridement and medical management with intravenous antibiotics is critical for best outcomes.

Resumen: Introducción y objetivo: Staphylococcus lugdunensis pertenece al grupo de los estafilococos coagulasa negativos. El objetivo del estudio es revisar las características clínicas y microbiológicas de los pacientes diagnosticados de una infección cutánea por S. lugdunensis. Material y métodos: Estudio observacional retrospectivo de todos los casos de infecciones cutáneas en las que se aisló S. lugdunensis diagnosticados entre 2009 y 2016 en el Servicio de Microbiología del Hospital San Jorge de Huesca. Resultados: Se incluyeron 16 pacientes. La localización más frecuente fue la zona inguinoperineal (n = 6, 37,5%) y la forma de presentación más habitual fueron las pústulas (n = 5, 31,3%). El 87,6% de los pacientes (n = 14) mostraron buena respuesta al tratamiento; sin embargo, 3 pacientes recurrieron. De ellos, 2 estaban en tratamiento con un anti-TNF. Conclusión: S. lugdunensis debería considerarse el posible agente causal de la infección cuando se aísla tanto en piel como en tejido celular subcutáneo, especialmente en pacientes que están recibiendo tratamiento biológico. Abstract: Introduction and objective: Staphylococcus lugdunensis belongs to the group of coagulase-negative staphylococci. The aim of this report was to review the clinical and microbiologic features of cases of S. lugdunensis skin infections. Material and methods: Observational study of all cases of skin infections in which S. lugdunensis was isolated by the microbiology department of Hospital General San Jorge in Huesca, Spain, between 2009 and 2016. Results: We studied the cases of 16 patients. The most frequent site of infection was the inguinal-perineal region (n = 6, 37.5%), and pustules were the most common presentation (n = 5, 31.3%). Response to treatment was good in 87.6% of the patients (n = 14). However, infection recurred in 3 patients, 2 of whom were on anti-TNF therapy. Conclusions: S. lugdunensis should be considered a possible cause of infection when it is isolated in both skin and subcutaneous tissues, especially in patients on biologic therapies.

Objectives: To evaluate the in vitro activity of dalbavancin compared with vancomycin, daptomycin and other agents against a large collection of coagulase-negative staphylococci (CoNS) isolates. Methods: A total of 5088 CoNS causing clinically significant infection were consecutively collected from 122 medical centres in the USA and Europe over 6 years (2014–2019). Isolates were tested for susceptibility by the reference broth microdilution method. Species identification was confirmed by MALDI-TOF. Most isolates were from bloodstream infections (BSIs) (53.5%) or skin/skin structure infections (28.5%). Results: Staphylococcus epidermidis was the most common species overall (54.6%) and for BSI (61.3%). The second most common species were Staphylococcus lugdunensis overall (12.3%) and Staphylococcus hominis for BSI (14.7%). Dalbavancin (MIC50/90, 0.03/0.06 mg/L) inhibited >99.9% of CoNS isolates at ≤0.25 mg/L (susceptible breakpoint for Staphylococcus aureus per CLSI). All species were inhibited at ≤0.25 mg/L dalbavancin, except some S. epidermidis (>99.9%) and Staphylococcus warneri (98.9%) isolates. Staphylococcus capitis and Staphylococcus simulans exhibited the lowest dalbavancin MIC50/90 values (0.015/0.03 mg/L) and Staphylococcus haemolyticus and Staphylococcus saprophyticus the highest (MIC50/90, 0.06/0.12 mg/L); 47.8% of S. epidermidis and 34.7% of S. haemolyticus exhibited decreased susceptibility to vancomycin (MIC ≥ 2 mg/L) and 23.2% of S. capitis and 28.4% of S. warneri showed decreased susceptibility to daptomycin (MIC ≥ 1 mg/L). Conclusion: Antimicrobial susceptibility varied widely among CoNS species. Dalbavancin inhibited >99.9% and 99.1% of isolates at the US-FDA and EUCAST breakpoints, respectively. Clinical studies of dalbavancin for treatment of CoNS infections should be considered based on these in vitro data.

The coagulase-negative staphylococcal (CoNS) species Staphylococcus lugdunensis is unique in causing serious infections in humans that resemble those of Staphylococcus aureus rather than those of other CoNS species. The colonization and invasion of host tissue presupposes the presence of adherence factors, but only a few proteins mediating adhesion of S. lugdunensis to biotic surfaces are known yet. Here, we report on the functionality of the S. lugdunensis enolase (SlEno), which performs two distinct roles, first, as the metabolic enzyme of the glycolysis, and second, as an adherence factor to the extracellular matrix (ECM) of cells. Phylogenetic analyses of the SlEno confirmed their high conservation to enolases of other species and revealed a closer relationship to Staphylococcus epidermidis than to S. aureus. Using matrix-assisted laser desorption/ionization time of flight mass spectrometry and Western blot experiments, we identified SlEno to be located in the cytoplasm as well as on the cell surface of S. lugdunensis. Recombinantly generated and surface-associated SlEno showed the usual enolase activity by catalyzing the conversion of 2-phosphoglycerate to phosphoenolpyruvate but, in addition, also displayed strong binding to immobilized laminin, fibronectin, fibrinogen, and collagen type IV in a dose-dependent manner. We also showed a strong binding of SlEno to plasminogen (Plg) and observed a tissue plasminogen activator (tPA)-dependent conversion of Plg to plasmin (Pln) whereby the Plg activation significantly increased in the presence of SlEno. This interaction might be dependent on lysines of the SlEno protein as binding to Plg was inhibited by ε-aminocaproic acid. Furthermore, the enhanced activation of the Plg/Pln system by SlEno enabled S. lugdunensis to migrate through a fibrin matrix. This migration was about 10-fold higher than without exogenously added SlEno. Finally, we observed a significantly higher clearance of S. lugdunensis by freshly prepared granulocytes and in the presence of anti-SlEno antibodies. In conclusion, these data demonstrate for the first time a moonlighting function of the S. lugdunensis enolase, which is an underrated virulence factor for colonization and invasion of tissues. Hence, SlEno might be a potential vaccine candidate to prevent severe infections caused by this pathogen. [ABSTRACT FROM AUTHOR]

Objectives: Coagulase-negative staphylococci (CNS) are commensal skin microbiota but may also cause septicemia, endocarditis, and systemic infections. Staphylococcus lugdunensis, is a member of CNS, but their antibiotic susceptibility test should be evaluated as Staphylococcus aureus not as CNS. We aimed to investigate S.lugdunensis and selected CNS strains by simple biochemical method and determination of their susceptibilities to antibiotics. Methods: A total of 251 CNS isolates were collected from blood culture bottles sent to Istanbul Faculty of Medicine Department of Medical Microbiology, between 2018 and 2019. PYR (pyrrolidonyl arylamidase) and ODC (ornithine decarboxylase) tests were performed on total of CNS isolates and API Staph was used for identification of the isolates giving positive result in both or either of these two tests. Disk diffusion method was used for the determination of antibiotic susceptibility of the isolates. S. aureus ATCC 25923 and S S.lugdunensis ATCC® 49576 strains were used as quality control strains in disc diffusion method, and biochemical tests, respectively. Results: Twenty three out of 251 CNS isolates were positive in each or both of PYR and ODC tests. We detected the first S.lugdunensis isolate from eye vitreous fluid of patient developed a postoperative endophthalmitis in Turkey. This isolate gave dual positive with ODC, PYR, and API Staph. Other 22 CNS isolates were from blood cultures and distributed as follows; 14 Staphylococcus haemolyticus and three Staphylococcus chromogenes isolates were PYR positive and ODC negative and five Staphylococcus epidermidis isolates were ODC positive and PYR negative. All isolates except S.lugdunensis were resistant to penicillin (95.7%) and 20 (87.0%) isolates were found to be methicillin resistant. Conclusions: ODC and PYR are cost effective tests and easily applicable for accurate identification of S.lugdunensis, and eliminating of opportinistic pathogens such as S. epidermidis, S. haemolyticus, and S. chromogenes from other CNS species in postoperative endophthalmitis and pateints with malignancies. Linezolid was very effective (100%) on four selected CNS species. [ABSTRACT FROM AUTHOR]

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Abstract Background Staphylococcus lugdunensis is a coagulase-negative Staphylococcus species, which are weak pathogenic bacteria generally. However, the acute and severe pathogenicity of Staphylococcus lugdunensis infective endocarditis may be due to the rapid growth of large vegetation and consequent valve destruction. Case presentation The patient was an 81-year-old male who visited our hospital with chief complaints of low back pain and high fever. Four years before this visit, he had undergone aortic valve replacement for aortic regurgitation. He was found to be hypotensive. Although there is no heart murmur on auscultation and echocardiography revealed negative findings with aortic valve, a blood test showed increases in the white blood cell count and C-reactive protein concentration. On the next day, Gram-positive cocci were detected in a blood culture and echocardiography detected a large vegetation on the prosthetic valve with increased flow velocity. Therefore, he underwent redo aortic valve replacement emergently. Staphylococcus lugdunensis was identified in blood samples and vegetation culture. Consequently, the patient was treated with antibiotics for 5 weeks after the operation and discharged home. Conclusions We experienced rapidly progressive prosthetic valve endocarditis caused by Staphylococcus lugdunensis. Hence, Staphylococcus lugdunensis infective endocarditis requires aggressive treatment, and the pathogenicity of this coagulase-negative Staphylococcus with high drug susceptibility should not be underestimated.

Abstract Background Staphylococcus lugdunensis is a coagulase-negative Staphylococcus part of the commensal skin flora but emerge as an important opportunistic pathogen. Because iron limitation is a crucial stress during infectious process, we performed phenotypic study and compared proteomic profiles of this species incubated in absence and in presence of the iron chelator 2,2′-dipyridyl (DIP). Results No modification of cell morphology nor cell wall thickness were observed in presence of DIP. However iron-limitation condition promoted biofilm formation and reduced the ability to cope with oxidative stress (1 mM H2O2). In addition, S. lugdunensis N920143 cultured with DIP was significantly less virulent in the larvae of Galleria mellonella model of infection than that grown under standard conditions. We verified that these phenotypes were due to an iron limitation by complementation experiments with FeSO4. By mass spectrometry after trypsin digestion, we characterized the first iron-limitation stress proteome in S. lugdunensis. Among 1426 proteins identified, 349 polypeptides were differentially expressed. 222 were more and 127 less abundant in S. lugdunensis incubated in iron-limitation condition, and by RT-qPCR, some of the corresponding genes have been shown to be transcriptionally regulated. Our data revealed that proteins involved in iron metabolism and carriers were over-expressed, as well as several ABC transporters and polypeptides linked to cell wall metabolism. Conversely, enzymes playing a role in the oxidative stress response (especially catalase) were repressed. Conclusions This phenotypic and global proteomic study allowed characterization of the response of S. lugdunensis to iron-limitation. We showed that iron-limitation promoted biofilm formation, but decrease the oxidative stress resistance that may, at least in part, explained the reduced virulence of S. lugdunensis observed under low iron condition.

The coagulase-negative staphylococcal (CoNS) species Staphylococcus lugdunensis is unique in causing serious infections in humans that resemble those of Staphylococcus aureus rather than those of other CoNS species. The colonization and invasion of host tissue presupposes the presence of adherence factors, but only a few proteins mediating adhesion of S. lugdunensis to biotic surfaces are known yet. Here, we report on the functionality of the S. lugdunensis enolase (SlEno), which performs two distinct roles, first, as the metabolic enzyme of the glycolysis, and second, as an adherence factor to the extracellular matrix (ECM) of cells. Phylogenetic analyses of the SlEno confirmed their high conservation to enolases of other species and revealed a closer relationship to Staphylococcus epidermidis than to S. aureus. Using matrix-assisted laser desorption/ionization time of flight mass spectrometry and Western blot experiments, we identified SlEno to be located in the cytoplasm as well as on the cell surface of S. lugdunensis. Recombinantly generated and surface-associated SlEno showed the usual enolase activity by catalyzing the conversion of 2-phosphoglycerate to phosphoenolpyruvate but, in addition, also displayed strong binding to immobilized laminin, fibronectin, fibrinogen, and collagen type IV in a dose-dependent manner. We also showed a strong binding of SlEno to plasminogen (Plg) and observed a tissue plasminogen activator (tPA)-dependent conversion of Plg to plasmin (Pln) whereby the Plg activation significantly increased in the presence of SlEno. This interaction might be dependent on lysines of the SlEno protein as binding to Plg was inhibited by ε-aminocaproic acid. Furthermore, the enhanced activation of the Plg/Pln system by SlEno enabled S. lugdunensis to migrate through a fibrin matrix. This migration was about 10-fold higher than without exogenously added SlEno. Finally, we observed a significantly higher clearance of S. lugdunensis by freshly prepared granulocytes and in the presence of anti-SlEno antibodies. In conclusion, these data demonstrate for the first time a moonlighting function of the S. lugdunensis enolase, which is an underrated virulence factor for colonization and invasion of tissues. Hence, SlEno might be a potential vaccine candidate to prevent severe infections caused by this pathogen.

ABSTRACT Staphylococcus lugdunensis is a coagulase-negative Staphylococcus that emerges as an important opportunistic pathogen. However, little is known about the regulation underlying the transition from commensal to virulent state. Based on knowledge of S. aureus virulence, we suspected that the agr quorum sensing system may be an important determinant for the pathogenicity of S. lugdunensis. We investigated the functions of the transcriptional regulator AgrA using the agrA deletion mutant. AgrA played a role in cell pigmentation: ΔargA mutant colonies were white while the parental strains were slightly yellow. Compared with the wild-type strain, the ΔargA mutant was affected in its ability to form biofilm and was less able to survive in mice macrophages. Moreover, the growth of ΔagrA was significantly reduced by the addition of 10% NaCl or 0.4 mM H2O2 and its survival after 2 h in the presence of 1 mM H2O2 was more than 10-fold reduced. To explore the mechanisms involved beyond these phenotypes, the ΔagrA proteome and transcriptome were characterized by mass spectrometry and RNA-Seq. We found that AgrA controlled several virulence factors as well as stress-response factors, which are well correlated with the reduced resistance of the ΔagrA mutant to osmotic and oxidative stresses. These results were not the consequence of the deregulation of RNAIII of the agr system, since no phenotype or alteration of the proteomic profile has been observed for the ΔRNAIII mutant. Altogether, our results highlighted that the AgrA regulator of S. lugdunensis played a key role in its ability to become pathogenic. IMPORTANCE Although belonging to the natural human skin flora, Staphylococcus lugdunensis is recognized as a particularly aggressive and destructive pathogen. This study aimed to characterize the role of the response regulator AgrA, which is a component of the quorum-sensing agr system and known to be a major element in the regulation of pathogenicity and biofilm formation in Staphylococcus aureus. In the present study, we showed that, contrary to S. aureus, the agrA deletion mutant produced less biofilm. Inactivation of agrA conferred a white colony phenotype and impacted S. lugdunensis in its ability to survive in mice macrophages and to cope with osmotic and oxidative stresses. By global proteomic and transcriptomic approaches, we identified the AgrA regulon, bringing molecular bases underlying the observed phenotypes. Together, our data showed the importance of AgrA in the opportunistic pathogenic behavior of S. lugdunensis allowing it to be considered as an interesting therapeutic target.

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El Staphylococcus lugdunensis se manifiesta más como Staphylococcus aureus que como un típico estafilococo coagulasa negativa, especialmente por su gran virulencia y capacidad para producir infecciones supuradas. Debido al protagonismo creciente de esta especie, es propósito de esta investigación destacar la significación clínica y los aspectos microbiológicos para el diagnóstico de pacientes con dicha infección.

ABSTRACT Clustered regularly interspaced short palindromic repeats (CRISPRs) and CRISPR-associated (Cas) genes (CRISPR-Cas) are present in many bacterial genomes with functions beyond adaptive immunity. We aimed to characterize the CRISPR-Cas system in the pathogenic Gram-positive bacterium Staphylococcus lugdunensis and determine its association with sequence types (STs) determined by multilocus sequence typing (MLST) and oxacillin susceptibility. Primers were designed to detect and sequence types IIIA and IIC CRISPR-Cas in 199 S. lugdunensis isolates. MLST and oxacillin susceptibility tests were also performed on the isolates. We found that 84 S. lugdunensis isolates had type IIIA CRISPR-Cas, while 46 had type IIC. The results showed a strong association between STs and CRISPR-Cas types. The ST1, ST6, ST12, and ST15 isolates had type IIIA CRISPR-Cas systems, and the ST4, ST27, and ST29 isolates had type IIC CRISPR-Cas. Interestingly, of 83 isolates containing type IIIA CRISPR-Cas, 17 (20.5%) were oxacillin-resistant S. lugdunensis (ORSL), and all of these ORSL isolates belonged to ST6 cluster 1. Moreover, spacers 23 and 21 were found in 16 and 17 ORSL isolates, respectively. In contrast, all 46 isolates with type IIC CRISPR-Cas were susceptible to oxacillin. Our results showed that 41.3% of CRISPR-Cas IIIA spacers were homologous to plasmids and 20.2% were homologous to phages. However, in type IIC CRISPR-Cas, 11.8% and 39.9% of spacers showed sequence homology with plasmids and phages, respectively. In conclusion, we found that the distribution and composition of the CRISPR-Cas system in S. lugdunensis was associated with STs and oxacillin susceptibility. IMPORTANCE CRISPR-Cas systems have been characterized as playing several biological roles in many bacterial genomes. Moreover, CRISPR-Cas systems are useful for epidemiological, diagnostic, and evolutionary studies of pathogenic bacteria. However, the characteristics of CRISPR-Cas systems in Staphylococcus lugdunensis have been rarely reported. In this study, we revealed that type IIIA CRISPR-Cas was dominant in S. lugdunensis isolates, followed by type IIC CRISPR-Cas. Moreover, the composition of CRISPR-Cas spacers was strongly associated with multilocus sequence typing and oxacillin susceptibility of S. lugdunensis. These results advance our understanding of the evolution of CRISPR-Cas systems; however, the biological functions of CRISPR-Cas systems in S. lugdunensis remain to be further characterized.

Staphylococcus lugdunensis endophthalmitis is an uncommon intraocular infection with potentially visually devastating consequences. S. lugdunensis endophthalmitis have been reported following cataract surgery, trauma, intravitreal injections of anti-vascular endothelial growth factor agents and dexamethasone implant. We report four cases of postoperative S. lugdunensis endophthalmitis after cataract extraction (three patients) and combined pars plana vitrectomy and cataract extraction (one patient). The onset of presentation of endophthalmitis was acute (within 2 weeks) in two patients, subacute (2 to 6 weeks) in one patient, and chronic (more than 6 weeks) in one patient. All patients had presenting visual acuity (VA) of hand motions or worse and were treated with pars plana vitrectomy with intravitreal antibiotics. The final VA was 20/50 in two patients, 4/200 in one patient with pre-existing myopic maculopathy, and no light perception in one patient with retinal detachment. In antibiotic susceptibility testing, S. lugdunensis isolates were resistant to penicillin (3/4, 75%), but all were susceptible to vancomycin, oxacillin, teicoplanin, tigecycline, and sulfamethoxazole-trimethoprim. S. lugdunensis may be associated with acute or chronic endophthalmitis. Favorable visual outcomes can be achieved with prompt diagnosis and management.

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., Competing Interests: Declaration of competing interest We have no conflicts of interest to declare., (Copyright © 2024. Published by Elsevier B.V.)

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.

Background  Coronary artery embolism is an infrequent cause of type 2 myocardial infarction which can be due to arterial thromboembolism or septic embolism. While systemic embolization is one of the most acknowledged and threatened complications of infective endocarditis, coronary localization of the emboli causing acute myocardial infarction is exceedingly rare occurring in <1% of cases. Case summary  A 52-year-old man with a history of Bentall procedure and redo aortic valve replacement due to prosthetic degeneration (11 years prior to the current presentation) presented to the emergency department with high-grade fever and myalgias. Shortly after his arrival, he experienced typical chest pain and an electrocardiogram demonstrated signs of inferior ST-elevation myocardial infarction: coronary angiography showed a lesion of presumed embolic origin at the level of the mid-distal circumflex coronary artery which was treated with embolectomy. Transthoracic and transoesophageal echocardiography highlighted the presence of a periaortic abscess. The final diagnosis of infective endocarditis as the cause of septic coronary artery embolization was confirmed with a Positron Emission Tomography-Computed Tomography (PET-CT) exam and by the growth of Staphylococcus lugdunensis on repeated blood cultures. The patient underwent successful redo Bentall surgery the good outcome was confirmed at 1-month follow-up. Discussion  Type 2 myocardial infarction caused by coronary embolism is a rare presentation of infective endocarditis and requires a high level of suspicion for its diagnosis. Prosthetic heart valves are a predisposing factor for infective endocarditis: aortic root abscess requires surgery as it rarely regresses with antibiotic therapy. [ABSTRACT FROM AUTHOR]