Vernix caseosa reveals mechanistic clues linking maternal obesity to atopic dermatitis pathogenesis.

BACKGROUND: Maternal overweight and obesity have been associated with an increased risk of atopic dermatitis (AD) in the offspring, but the underlying mechanisms are unclear. Vernix caseosa (VC) is a proteolipid material covering the fetus produced during skin development. However, whether maternal prepregnancy weight excess influences fetal skin development is unknown. Characterizing the VC of newborns from mothers with prepregnancy overweight and obesity might reveal AD-prone alterations during fetal skin development. OBJECTIVE: We sought to explore AD biomarkers and staphylococcal loads in VC from the offspring of mothers who were overweight/obese (O/O) before pregnancy versus in those from offspring of normal weight mothers. METHODS: The VC of newborns of 14 O/O and 12 normal weight mothers were collected immediately after birth. Biomarkers were determined by ELISA and staphylococcal species by quantitative PCR. RESULTS: The VC from the O/O group showed decreased expression of skin barrier proteins (filaggrin and loricrin) and increased levels of proinflammatory biomarkers (IgA, thymic stromal lymphopoietin [TSLP], S100A8, IL-25, and IL-33). No differences in concentrations of antimicrobial peptides and enzymes were detected. The VC from the O/O group had a lower Staphylococcus epidermidis and Staphylococcus hominis commensal bacterial load, whereas Staphylococcus aureus bacterial load was not significantly different between the 2 groups. Maternal body mass index was negatively correlated with VC filaggrin expression and S epidermidis load and was positively associated with TSLP concentration. One-year follow-up established that the offspring of O/O mothers had a higher incidence of AD that was specifically linked with decreased VC filaggrin expression and lower S epidermidis load. CONCLUSIONS: VC from neonates of mothers with prepregnancy overweight and obesity exhibit skin barrier molecular alterations and staphylococcal dysbiosis that suggest early mechanistic clues to this population's increased risk of AD.

Discovery of a C-S lyase inhibitor for the prevention of human body malodor formation: tannic acid inhibits the thioalcohol production in Staphylococcus hominis.

Human body odor is a result of the bacterial biotransformation of odorless precursor molecules secreted by the underarm sweat glands. In the human axilla, Staphylococcus hominis is the predominant bacterial species responsible for the biotransformation process of the odorless precursor molecule into the malodorous 3M3SH by two enzymes, a dipeptidase and a specific C-S lyase. The current solutions for malodor, such as deodorants and antiperspirants are known to block the apocrine glands or disrupt the skin microbiota. Additionally, these chemicals endanger both the environment and human health, and their long-term use can influence the function of sweat glands. Therefore, there is a need for the development of alternative, environmentally friendly, and natural solutions for the prevention of human body malodor. In this study, a library of secondary metabolites from various plants was screened to inhibit the C-S lyase, which metabolizes the odorless precursor sweat molecules, through molecular docking and molecular dynamics (MD) simulation. In silico studies revealed that tannic acid had the strongest affinity towards C-S lyase and was stably maintained in the binding pocket of the enzyme during 100-ns MD simulation. We found in the in vitro biotransformation assays that 1 mM tannic acid not only exhibited a significant reduction in malodor formation but also had quite low growth inhibition in S. hominis, indicating the minimum inhibitory effect of tannic acid on the skin microflora. This study paved the way for the development of a promising natural C-S lyase inhibitor to eliminate human body odor and can be used as a natural deodorizing molecule after further in vivo analysis.

Extensive perineal ecthyma gangrenosum in leukocyte adhesion deficiency type 1 associated with Staphylococcus hominis bacteremia.

Leukocyte adhesion deficiency (LAD), a disorder of neutrophil function, is characterized by a defect in leukocyte adhesion to the endothelium. Recurrent infections in the skin, soft tissue, gingiva, and lungs due to Staphylococcus aureus, Pseudomonas aeruginosa, and Klebsiella sp. are common in these patients. Ecthyma gangrenosum (EG) is an ulcer of skin and subcutaneous tissue with a black eschar and surrounding erythematous halo secondary to a bacterial infection. Here, we report an unusual presentation of LAD type-1 with extensive EG of perineum secondary to Staphylococcus hominis bacteremia treated successfully with combination of granulocyte transfusion and diversion colostomy.

Genetic diversity and iron metabolism of Staphylococcus hominis isolates originating from bovine quarter milk, rectal feces, and teat apices.

Staphylococcus hominis, a member of the non-aureus staphylococci (NAS) group, is part of the human and animal microbiota. Although it has been isolated from multiple bovine-associated habitats, its relevance as a cause of bovine mastitis is currently not well described. To successfully colonize and proliferate in the bovine mammary gland, a bacterial species must be able to acquire iron from host iron-binding proteins. The aims of this study were (1) to assess the genetic diversity of S. hominis isolated from bovine quarter milk, rectal feces, and teat apices, and (2) to investigate the capacity of bovine S. hominis isolates belonging to these different habitats to utilize ferritin and lactoferrin as iron sources. To expand on an available collection of bovine S. hominis isolates (2 from quarter milk, 8 from rectal feces, and 19 from teat apices) from one commercial dairy herd, a subsequent single cross-sectional quarter milk sampling (n = 360) was performed on all lactating cows (n = 90) of the same herd. In total, 514 NAS isolates were recovered and identified by MALDI-TOF mass spectrometry; the 6 most prevalent NAS species were S. cohnii (33.9%), S. sciuri (16.7%), S. haemolyticus (16.3%), S. xylosus (9.6%), S. equorum (9.4%), and S. hominis (3.5%). A random amplified polymorphic DNA (RAPD) analysis was performed on 46 S. hominis isolates (19 from quarter milk, 8 from rectal feces, and 19 from teat apices). Eighteen distinct RAPD fingerprint groups were distinguished although we were unable to detect the presence of the same RAPD type in all 3 habitats. One S. hominis isolate of a distinct RAPD type unique to a specific habitat (8 from quarter milk, 3 from rectal feces, and 4 from teat apices) along with the quality control strain Staphylococcus aureus ATCC 25923 and 2 well-studied Staphylococcus chromogenes isolates ("IM" and "TA") were included in the phenotypical iron test. All isolates were grown in 4 types of media: iron-rich tryptic soy broth, iron-rich tryptic soy broth deferrated by 2,2'-bipyridyl, and deferrated tryptic soy broth supplemented with human recombinant lactoferrin or equine spleen-derived ferritin. The growth of the different strains was modified by the medium in which they were grown. Staphylococcus chromogenes TA showed significantly lower growth under iron-deprived conditions, and adding an iron supplement (lactoferrin or ferritin) resulted in no improvement in growth; in contrast, growth of S. chromogenes IM was significantly recovered with iron supplementation. Staphylococcus hominis strains from all 3 habitats were able to significantly utilize ferritin but not lactoferrin as an iron source to reverse the growth inhibition, in varying degrees, caused by the chelating agent 2,2'-bipyridyl.

Mixed bacterial-fungal infection following total hip arthroplasty: A case report.

Prosthetic infection is one of the severe postoperative complications of arthroplasty. Mixed bacterial-fungal prosthetic infection is rare but can be disastrous. This case was a 76-year-old female suffered from prosthetic infection following total hip replacement due to femoral neck fracture and underwent multiple debridements. The culture of periprosthetic tissue was bacteriologically sterile following the first debridement, while the Staphylococcus hominis was identified in the second debridement in the previous hospitalization where fungal infection had not been considered. Thus the pathogen spectrum of anti-infection therapy failed to contain fungus. Ultimately, the culture result of our sampled periprosthetic tissue during the third debridement was Candida albicans without bacterium in our hospital. The fungal prosthetic infection was successfully treated by a two-stage revision with antifungal drugs. Accurate diagnosis and standardized treatment is the key to the therapy of infection after hip arthroplasty, especially for mixed bacterial-fungal prosthetic infection.

Characterizing a Novel Staphylococcal Cassette Chromosome mec with a Composite Structure from a Clinical Strain of Staphylococcus hominis, C34847.

Staphylococcal cassette chromosome mec (SCCmec) has predominantly been described in methicillin-resistant Staphylococcus aureus. However, studies have indicated that coagulase-negative staphylococci (CoNS) carry a larger diversity of SCC elements. We characterized a composite SCCmec element carrying an uncharacterized ccr1 and type A mec gene combination, in conjunction with a secondary element bearing ccr4, from a clinical strain of Staphylococcus hominis. The element's complex structure points to a high degree of recombination occurring in SCCmec in CoNS.

New solution of beauty problem by Staphylococcus hominis: Relevance between skin microbiome and skin condition in healthy subject.

BACKGROUND/AIMS: Recently, it was suggested that skin microbiome is related to some skin disease. The possibility of affecting the skin might be high, but there were few reports of the influence on the skin condition in healthy subjects. Our aim was to evaluate the relationship between skin condition and skin microbiome in healthy subjects. METHODS: Experiment 1: 293 Japanese healthy women were divided into two groups, good skin properties and poor skin properties by 14 skin physiology parameter values on the cheek using noninvasive method. Differences of abundance of bacterial species on the cheek between the two groups were evaluated. Experiment 2: 11 Japanese healthy women were applied Staphylococcus hominis (S. hominis) on half-side of cheek for eight times in 1 month. Difference of change of physiology parameter values comparing to placebo side was evaluated. RESULTS: Experiment 1: Multiple skin bacterial species were found to be significantly relevant in 14 physiology parameters. The abundance of S. hominis on the cheek with good skin properties group was significantly higher than poor skin properties group. Experiment 2: The application of S. hominis improved significantly the conspicuous pore number, melanin index, and the wrinkle count compared to placebo side. CONCLUSION: We found many skin bacterial species that might improve the skin condition in healthy women. In particular, S. hominis might have the potential to improve multiple skin beauty problems.

Staphylococcal species less frequently isolated from human clinical specimens - are they a threat for hospital patients?

BACKGROUND: Coagulase-negative staphylococci belonging to S. haemolyticus, S. hominis subsp. hominis, S. simulans, and S. warneri are often described as etiological factors of infections. Staphylococci are a phylogenetically coherent group; nevertheless, there are differences among the species which may be important to clinicians. METHODS: We investigated selected virulence factors and antibiotic resistance that were phenotypically demonstrated, the presence and expression of genes encoding the virulence factors, and the type of the SCCmec cassette. RESULTS: The differences between the tested species were revealed. A great number of isolates produced a biofilm and many of them contained single icaADBC operon genes. Clear differences between species in the lipolytic activity spectrum could be related to their ability to cause various types of infections. Our studies also revealed the presence of genes encoding virulence factors homologous to S. aureus in the analysed species such as enterotoxin and pvl genes, which were also expressed in single isolates of S. simulans and S. warneri. S. haemolyticus and S. hominis subsp. hominis isolates were resistant to all clinically important antibiotics including ß-lactams. The identified SCCmec cassettes belonged to IV, V, VII, and IX type but most of the detected cassettes were non-typeable. Among the investigated species, S. hominis subsp. hominis isolates accumulated virulence genes typical for S. aureus in the most efficient way and were widely resistant to antibiotics. CONCLUSIONS: Our results clearly indicated significant differences between the tested species, which might be a result of the horizontal gene transfer (HGT) and can lead to the formation and selection of multi-drug resistant strains as well as strains with new virulence features. Such strains can have a new clinical relevance.

Comparison of the etiological relevance of Staphylococcus haemolyticus and Staphylococcus hominis.

The study was performed to assess potential differences in the etiological relevance of two coagulase-negative staphylococci (CoNS), Staphylococcus haemolyticus and Staphylococcus hominis, in an observational single-center study. Over a 5-year interval, patients in whom there was detected S. haemolyticus or S. hominis of presumed etiological relevance were assessed for the primary endpoint death during hospital stay and the secondary endpoint transfer to an intensive care unit (ICU) after the detection of S. haemolyticus or S. hominis. Patients with S. haemolyticus or S. hominis died in 11.3% (50 out of 444) and 9.5% (60 out of 631) of cases, respectively, and were transferred to ICU after S. haemolyticus and S. hominis detection in 8.7% (19 out of 219) and 11.7% (44 out of 377) of cases, respectively. There was no significance for species-related influence on the primary outcome parameter (P > 0.1), while ICU transfers were more likely for patients with S. hominis detections (P = 0.016). Delayed diagnosis of both CoNS species was associated with an increased probability of death (P = 0.009). The study revealed comparable morbidity caused by S. haemolyticus and S. hominis identified in a clinically relevant context.

Multifactorial mechanisms of the pathogenesis of methicillin-resistant Staphylococcus hominis isolated from bloodstream infections.

Staphylococcus hominis is a species of the coagulase-negative staphylococci. It has been designated as a potential pathogen but so far the pathogenic mechanisms of this bacterium have not been determined. We studied 30 clinical isolates of methicillin-resistant S. hominis, which were previously examined for biofilm forming properties. The results of this study revealed that all these S. hominis strains had the ability to adhere to HeLa cells. Over 40% of the S. hominis strains invaded epithelial cells. The invasion index ranged from 0 to 41.5%. All isolates exhibited the cytotoxic activity of extracellular factors, which caused the destruction of epithelial cells. More than 90% of these methicillin-resistant strains contained at least one aminoglycosides resistance gene. The ant(4')-I gene was found in 63% of the isolates, aac(6')/aph(2″) in 20% and aph(3')-IIIa in 47%. Two strains were assigned to SCCmec type VIII and three to SCCmec type III. The remaining isolates (83%) harboured a non-typeable SCCmec type. The mec complex A was predominant in this species. The results indicate that the pathogenicity of S. hominis may be multifactorial, involving adhesion, invasion and the activity of extracellular toxins, which cause damage to the host epithelium.

Clinical significance of positive Raoultella Ornithinolytica and Staphylococcus hominis cultures in a post lobectomy patient. A case report.

Raoultella Ornithinolytica (RO) is an encapsulated, Gram- negative, nonmotile aerobic rob which was reclassified from Klepsiella genus belonging in the family of Enterobacteriaceae. It is a rare human infection and few cases have been reported in post thoracotomy patients. Here we present a case of a left lower lobectomy patient that was complicated by pleural effusion and high fever with positive sputum cultures of Raoultella Ornithinolytica and positive pleural fluid cultures of Staphylococcus hominis. It is related with aquatic life poisoning. There are few cases reported and even fewer postoperatively. The infection is rare in human therefore the bacteria is still underreported.

Complete genome sequence of Staphylococcus hominis FSEL1 isolated from chicken skin in South Korea.

Staphylococcus hominis FSEL1 has been isolated from chicken skin. The complete genome sequence of the bacterium comprised one chromosome and two plasmids of 2.44 Mbp. A total of 2,273 CDS, 2,473 genes, 19 rRNAs, 62 tRNAs, and 1 tmRNA were predicted to be present within the genome.

Effect of Salicylic Acid on the gene expression of FnbA and FnbB genes in Staphylococcus hominis.

BACKGROUND: Staphylococcus hominis is an opportunistic pathogen that expresses surface proteins, which are adhesive proteins that play a major role in biofilm formation. Biofilm is a protective layer that provides S. hominis bacteria with greater antibiotic resistance and promotes its adherence to biomedical surfaces, facilitating its entry into the bloodstream. OBJECTIVE: This research aimed to investigate the activity of Salicylic Acid (SA) and its effect on the gene expression of biofilm genes (FnbA and FnbB genes). METHODS: A total of 150 blood specimens were collected from patients. The specimens were cultured in broth media of the BacT/ALERT® system and subcultured on blood and chocolate agar. Bacteria were detected using the VITEK2 system. FnbA and FnbB genes were detected using PCR. The broth microdilution method performed the minimum inhibitory concentration (MIC) of Salicylic acid (SA) on S. hominis isolates with both genes. Detection of the gene expression levels of FnbA and FnbB genes was assessed using Real-Time PCR(RT-PCR). RESULTS: The results showed that out of the 150 specimens collected, 35 were S. hominis. The detection of S. hominis bacteria was performed by PCR amplification of two genes FnbA and FnbB and showed 100% and 17.14% of isolates were positive for genes FnbA and FnbB, respectively. The expression of FnbA and FnbB genes was decreased in samples treated with SA compared with untreated ones. CONCLUSION: In conclusion, there is a significant impact of SA on the prevention of biofilm formation of S. hominis through the suppression of gene expression, specifically FnbA and FnbB. This could enhance susceptibility to antimicrobial treatments. However, more research is required to determine whether SA leads to the selection of resistant bacteria.

Pseudoaneurysm of the left ventricular free wall occurring after cardiac surgery of endocarditis affecting mitral and aortic valves: a case report.

BACKGROUND: Infective endocarditis remains a serious condition. Left ventricular pseudoaneurysm may complicate the clinical course of infective endocarditis or occur postoperatively. CASE PRESENTATION: We describe a case of a pseudoaneurysm of the left ventricular lateral wall which developed one month following cardiac surgery of active endocarditis affecting aortic and mitral valves. The diagnosis was established by transthoracic echocardiography and computed tomography angiography of the chest. Urgent cardiac surgery is performed with excision of the pseudoaneurysm and direct closure of the defect. The patient had a complete recovery and was discharged on the twelfth postoperative day. CONCLUSIONS: Left ventricular pseudoaneurysms are rare but potentially fatal. The symptoms revealing such complications are very diverse. Surgical treatment can be offered to younger patients.

Rapid methicillin resistance detection and subspecies discrimination in Staphylococcus hominis clinical isolates by MALDI-TOF MS.

PURPOSE: Staphylococcus hominis is a coagulase-negative opportunistic pathogen responsible for implanted medical device infections. Rapid identification and virulence factors detection are crucial for appropriate antimicrobial therapy. We aimed to search protein biomarker peaks for rapid classification of antibiotic resistance and subspecies of S. hominis using MALDI-TOF MS. METHODS: S. hominis clinical isolates (n = 148) were screened for subspecies differentiation by novobiocin resistance. Biofilm composition and formation were determined by detachment assay and crystal violet staining, respectively. Antibiotic susceptibility was performed by the broth microdilution method. The search for potential biomarkers peaks was enabled by ClinProTools 3.0, flexAnalysis 3.4, and Biotools 3.2 for statistical analysis, peak visualization, and protein/peptide alignment, respectively. RESULTS: Of 148 isolates, 12.16% were classified as S. hominis subsp. novobiosepticus, 77.77% were biofilm producers, and ˃ 50% were multidrug-resistant. Two potential biomarker peaks, 8975 m/z and 9035 m/z were detected for the discrimination of methicillin resistance with a sensitivity of 96.72%. The following peaks were detected for subspecies differentiation: 2582 m/z, 2823 m/z, and 2619 m/z with 88.89-98.28% of sensitivity. CONCLUSIONS: We found potential biomarker peaks to predict methicillin resistance and discriminate S. hominis subspecies during routine MALDI-TOF MS identification in a clinical setting to enable better antibiotic treatment.

Antibiotic resistance and mecA characterization of Staphylococcus hominis from filarial lymphedema patients in the Ahanta West District, Ghana: A cross-sectional study.

Background and Aim: Filarial infections affect over 150 million people in the tropics. One of the major forms of filarial pathologies is lymphedema; a condition where the immune response is significantly altered, resulting in changes in the normal flora. Staphylococcus hominis, a human skin commensal, can also be pathogenic in immunocompromised individuals. Therefore, there is the possibility that S. hominis could assume a different behavior in filarial lymphedema patients. To this end, we investigated the levels of antibiotic resistance and extent of mecA gene carriage in S. hominis among individuals presenting with filarial lymphedema in rural Ghana. Method: We recruited 160 individuals with stages I-VII lymphedema, in a cross-sectional study in the Ahanta West District of the Western Region of Ghana. Swabs from lymphedematous limb ulcers, pus, and cutaneous surfaces were cultured using standard culture-based techniques. The culture isolates were subjected to Matrix-Assisted Laser Desorption/Ionization Time of Flight (MALDI-TOF) mass spectrometry for bacterial identification. Antimicrobial susceptibility testing (AST) was performed using the Kirby-Bauer method. mecA genes were targeted by polymerase chain reaction for strains that were cefoxitin resistant. Results: In all, 112 S. hominis were isolated. The AST results showed resistance to chloramphenicol (87.5%), tetracycline (83.3%), penicillin (79.2%), and trimethoprim/sulphamethoxazole (45.8%). Of the 112 strains of S. hominis, 51 (45.5%) were resistant to cefoxitin, and 37 (72.5%) of the cefoxitin-resistant S. hominis haboured the mecA gene. Conclusion: This study indicates a heightened level of methicillin-resistant S. hominis isolated among filarial lymphedema patients. As a result, opportunistic infections of S. hominis among the already burdened filarial lymphedema patients in rural Ghana may have reduced treatment success with antibiotics.

Infective Endocarditis Presenting With Non-ST Elevation Myocardial Infarction: A Case Report.

Infectious endocarditis (IE) is a rare disease characterized by infection of the endocardial surface of the heart. IE predominately involves the left-sided valves; however, right-sided valvular IE has increased in incidence with intravenous drug use. Treatment of IE is centered on targeted antibiotic therapy and management of complications, including septic embolization, which can affect all of the major arterial beds. Acute coronary syndrome secondary to septic embolization can be difficult to identify and carries an increased risk of morbidity and mortality. Care is further complicated by a lack of formal guidelines from any organization to inform management. We present a case of Staphylococcus hominis endocarditis complicated by coronary artery embolization and non-ST elevation myocardial infarction at the time of presentation to the emergency department, followed by a discussion of available treatment modalities.

The abundance of the potential pathogen Staphylococcus hominis in the air microbiome in a dental clinic and its susceptibility to far-UVC light.

The dental clinic air microbiome incorporates microbes from the oral cavity and upper respiratory tract (URT). This study aimed to establish a reliable methodology for air sampling in a dental clinic setting and quantify the abundance of culturable mesophilic aerobic bacteria present in these samples using regression modeling. Staphylococcus hominis, a potentially pathogenic bacterium typically found in the human oropharynx and URT, was consistently isolated. S. hominis was the most abundant species of aerobic bacteria (22%-24%) and comprised 60%-80% of all Staphylococcus spp. The study also assessed the susceptibility of S. hominis to 222 nm-far-UVC light in laboratory experiments, which showed an exponential surface inactivation constant of k = 0.475 cm2 /mJ. This constant is a critical parameter for future on-site use of far-UVC light as a technique for reducing pathogenic bacterial load in dental clinics.

Integrated genomic and functional analyses of human skin-associated Staphylococcus reveals extensive inter- and intra-species diversity.

Human skin is stably colonized by a distinct microbiota that functions together with epidermal cells to maintain a protective physical barrier. Staphylococcus, a prominent genus of the skin microbiota, participates in colonization resistance, tissue repair, and host immune regulation in strain specific manners. To unlock the potential of engineering skin microbial communities, we aim to fully characterize the functional diversity of this genus within the context of the skin environment. We conducted metagenome and pan-genome analyses of isolates obtained from distinct body sites of healthy volunteers, providing a detailed biogeographic depiction of staphylococcal species that colonize our skin. S. epidermidis, S. capitis, and S. hominis were the most abundant species present in all volunteers and were detected at all body sites. Pan-genome analysis of these three species revealed that the genus-core was dominated by central metabolism genes. Species-specific core genes were enriched in host colonization functions. The majority (~68%) of genes were detected only in a fraction of isolate genomes, underscoring the immense strain-specific gene diversity. Conspecific genomes grouped into phylogenetic clades, exhibiting body site preference. Each clade was enriched for distinct gene-sets that are potentially involved in site tropism. Finally, we conducted gene expression studies of select isolates showing variable growth phenotypes in skin-like medium. In vitro expression revealed extensive intra- and inter-species gene expression variation, substantially expanding the functional diversification within each species. Our study provides an important resource for future ecological and translational studies to examine the role of shared and strain-specific staphylococcal genes within the skin environment.

Competition between skin antimicrobial peptides and commensal bacteria in type 2 inflammation enables survival of S. aureus.

During inflammation, the skin deploys antimicrobial peptides (AMPs) yet during allergic inflammation it becomes more susceptible to Staphylococcus aureus. To understand this contradiction, single-cell sequencing of Il4ra-/- mice combined with skin microbiome analysis reveals that lower production of AMPs from interleukin-4 receptor α (IL-4Rα) activation selectively inhibits survival of antibiotic-producing strains of coagulase-negative Staphylococcus (CoNS). Diminished AMPs under conditions of T helper type 2 (Th2) inflammation enable expansion of CoNS strains without antibiotic activity and increase Staphylococcus aureus (S. aureus), recapitulating the microbiome on humans with atopic dermatitis. This response is rescued in Camp-/- mice or after topical steroids, since further inhibition of AMPs enables survival of antibiotic-producing CoNS strains. In conditions of Th17 inflammation, a higher expression of host AMPs is sufficient to directly inhibit S. aureus survival. These results show that antimicrobials produced by the host and commensal bacteria each act to control S. aureus on the skin.