The role of male hormones in bacterial infections: enhancing Staphylococcus aureus virulence through testosterone-induced Agr activation.

Staphylococcus aureus is a notorious pathogen predominantly involved in skin and soft tissue infections, exhibiting a distinct innate sex bias. This study explores the influence of testosterone on the virulence of S. aureus and elucidates its underlying mechanisms. Utilizing a skin abscess model in intact and castrated male mice, we assessed the effects of testosterone on S. aureus pathogenicity. Compared to controls, castrated mice showed significantly reduced abscess sizes and decreased bacterial loads, highlighting the role of testosterone in modulating the severity of S. aureus infections. In vitro experiments revealed that testosterone enhances the hemolytic activity, cytotoxicity, and oxidative stress resistance of S. aureus. Real-time quantitative PCR analysis showed a significant upregulation of the genes encoding α-hemolysin (hla) and phenol-soluble modulin (psmα). Importantly, testosterone treatment significantly enhanced the expression of the accessory gene regulator (Agr) quorum-sensing system components (agrC, agrA, agrB, agrD), while the SaeRS system (saeR, saeS, and sbi) exhibited only slight changes. Gene knockout experiments revealed that deletion of agrC, rather than saeRS and agrBD, abolishes the testosterone-induced enhancement of hemolysis and gene expression, underscoring the key role of AgrC. Molecular docking simulations indicated a direct interaction between testosterone and AgrC protein, with a strong binding affinity at the active site residue SER201. This study provides new insights into the mechanistic basis of how testosterone enhances the pathogenicity of S. aureus, potentially contributing to increased male susceptibility to S. aureus infections and offering a targeted approach for therapeutic interventions.

Fatal Renal Abscess Caused by Porphyromonas gingivalis and Subcapsular Hemorrhage, Japan.

A 61-year-old man in Japan with abdominal pain was suspected of having a renal tumor. Despite initial treatment, his condition rapidly deteriorated, leading to death. Postmortem examination revealed a renal abscess and sepsis caused by Porphyromonas gingivalis. This case underscores the need to consider atypical pathogens in renal masses.

Renal abscess in a Lionhead rabbit due to Encephalitozoon cuniculi and Escherichia coli: A case report.

Background: In rabbits, renal abscesses (pus-filled sores) are rare and diagnosis remains challenging. Therefore, in this study, we aimed to determine the clinical manifestation and diagnostic tests associated with renal abscess identification in rabbits. Case Description: A four-and-a-half-year-old castrated male Lionhead rabbit with a history of poor appetite and abdominal distension was admitted to the animal hospital. Blood analysis, radiography, ultrasonography, and computed tomography scans revealed a kidney abscess found within the renal parenchyma, with severe loss of the cortex and medulla, extending toward the capsule. Consequently, the rabbit underwent nephrectomy. The enlarged right kidney was surgically removed. Histopathological examination of the affected kidney showed severe necrosis and ischemic zones, atrophy of the renal tubules, and prominent heterophils with mixed inflammatory cell infiltrates. Immunohistochemistry and polymerase chain reaction confirmed Encephalitozoon cuniculi and Escherichia coli infections, respectively. Conclusion: This report provides novel insights into the diagnosis of renal abscesses in Lionhead rabbits.

Subcutaneous and paraspinal tuberculous abscesses in a patient with Crohn's disease.

This case involves a man with longstanding Crohn's disease on azathioprine therapy who developed a rare manifestation of tuberculosis, presenting as a subcutaneous tuberculous abscess and tuberculous spondylitis. The patient's immunocompromised state due to azathioprine raised the risk for opportunistic infections. The unique aspects include the absence of disseminated tuberculosis and the development of tuberculous paraspinal and subcutaneous abscesses in a patient with Crohn's disease. The case underscores the importance of vigilance for rare infections in immunosuppressed individuals and highlights the need for tuberculosis screening before initiating immunosuppressive therapies. The patient was successfully treated with antituberculous medication, emphasising the importance of a tailored approach in managing such cases.

Recurrent subcutaneous abscesses and pneumonia in a toddler with a novel pathogenic variation in IL-17RA gene.

A toddler presented with recurrent subcutaneous abscesses, otitis media and pneumonia, requiring frequent hospitalisations and intravenous antimicrobials. He also had oral thrush and difficulty in gaining weight; hence, an underlying inborn error of immunity (IEI) was strongly suspected. The complete haemogram showed leucocytosis with neutrophilic predominance. Both erythrocyte sedimentation rate and C reactive protein were elevated. Klebsiella pneumoniae was isolated from blood culture. The dihydrorhodamine-123 assay was negative, and the immunoglobulin profile showed an increased IgG level. Whole exome sequencing revealed a novel homozygous pathogenic variation in the IL-17RA gene (c.2563G>A, p. Asp855Asn). He showed remarkable improvement following intravenous colistin and fluconazole with complete resolution of abscesses. Thus, it is prudent to consider the possibility of IL-17RA deficiency in children with a history of recurrent abscesses, skin ulcerations and pneumonia after excluding the common groups of IEI.

Case Report: Multiple Metastatic Primary Multidrug-Resistant Tubercular Abscesses.

This case report presents an atypical manifestation of tuberculosis in a 21-year-old male who presented with multiple subcutaneous swellings in the bilateral heel, left elbow, and base of the left third finger for the previous 6 months. The patient also experienced loss of appetite and unintentional weight loss. Despite initial suspicion of bacterial abscesses, antibiotics did not lead to significant improvement. Further investigations revealed an elevated erythrocyte sedimentation rate and findings suggestive of osteomyelitis on imaging. Gene Xpert testing confirmed multidrug-resistant Mycobacterium tuberculosis as the causative agent. The patient was prescribed a bedaquiline-based multidrug-resistant tuberculosis regimen, which resulted in reduction in swelling size. This report highlights the challenges in diagnosing and managing complex cases of primary multiple tubercular abscesses, especially with drug-resistant strains, emphasizing the importance of timely diagnosis and multidisciplinary management for successful outcomes.

Disseminated tuberculosis complicated by intramuscular abscesses, meningoencephalitis, and hemophagocytic lymphohistiocytosis: a case report.

BACKGROUND: As disseminated extrapulmonary tuberculosis infection can involve multiple systems and result in atypical clinical manifestations that mimic other diseases, the diagnosis may be difficult, especially in elderly patients. Delaying treatment can adversely affect the prognosis. And to achieve better prognosis, early detection and diagnosis are necessary, as well as early initiation of comprehensive treatment. CASE PRESENTATION: We present the case of a 78-year-old man with disseminated tuberculosis who developed the uncommon complication of urinary retention due to a psoas abscess, meningoencephalitis, and the rare secondary hemophagocytic lymphohistiocytosis syndrome. The patient achieved a favorable outcome following targeted therapy with antitubercular medications. CONCLUSIONS: This case highlights that disseminated extrapulmonary tuberculosis infection can present with a variety of manifestations, and may exhibit many rare and complex clinical presentations. Prompt and accurate diagnosis and treatment play a crucial role in improving prognosis for the patients with persistent fever.

Late-Onset Mesh Infection Manifesting as Preperitoneal Abscess and Cutaneous Fistula Post-TEP Inguinal Hernia Repair: A Case Report.

BACKGROUND Endoscopic inguinal hernia repair has become the preferred technique currently. The use of mesh to facilitate a tension-free reinforcement has become the standard of care during endoscopic totally extraperitoneal (TEP), laparoscopic transabdominal pre-peritoneal, and open inguinal hernia repair. Although uncommon, late-developing mesh infections, defined as those occurring in the surgical site months or years after the procedure, can lead to severe complications. To achieve the best possible outcome for the patient, prompt imaging and a multidisciplinary approach to management, including complete surgical removal of the contaminated mesh and proper antibiotic therapy, are crucial. CASE REPORT A 39-year-old woman presented with a 1-month history of intermittent fever, progressive lower abdominal pain and fullness, and purulent discharge from the abdominal wall. Her medical history was significant for an endoscopic right TEP inguinal hernia repair performed 3 years earlier, which involved the use of an anatomic mesh and titanium screws. Physical examination and ultrasound findings revealed a large preperitoneal abscess with cutaneous fistulization, secondary to a deep-seated mesh infection. Pseudomonas aeruginosa was identified as the causative pathogen. She underwent a 2-step surgical procedure, including an initial fistulectomy followed by endoscopic abscess drainage and surgical excision of the infected mesh, combined with antimicrobial therapy, resulting in an excellent clinical response and complete resolution. This strategy also allowed for an effective assessment of the abdominal wall integrity. CONCLUSIONS This case underscores the importance of considering late-developing mesh infections in patients presenting with abdominal symptoms who have previously undergone TEP hernia repair, even years after the initial surgery.

Butyricimonas faecihominis: an atypically resistant bacterium implicated in abscess formation - a case report.

BACKGROUND: This case report presents a unique instance of abscesses with an uncommon pathogen isolated from blood cultures. CASE PRESENTATION: We present the case of a perianal abscess in a 50-year-old man with a history of cocaine abuse and bilateral hip replacements. The rapid progression led to septic shock and multi-organ failure, requiring intensive care unit admission, surgery including protective transversostomy. Blood cultures showed growth of Butyricimonas spp. with resistance to penicillin and piperacillin-tazobactam. The immediate switch to meropenem led to a significant improvement in the patient's condition. The patient was discharged after 40 days of hospitalization in good general condition and the reversal of the transversostomy was performed six months later. CONCLUSION: The identification of Butyricimonas faecihominis, a rarely reported pathogen, emphasizes the challenges of diagnosing and treating unusual infections. This case emphasizes the importance of rapid microbiological diagnosis, interdisciplinary collaboration, and targeted antibiotic therapy in the treatment of abscesses and sepsis.

MALDI TIMS IMS Reveals Ganglioside Molecular Diversity within Murine S. aureus Kidney Tissue Abscesses.

Gangliosides play important roles in innate and adaptive immunity. The high degree of structural heterogeneity results in significant variability in ganglioside expression patterns and greatly complicates linking structure and function. Structural characterization at the site of infection is essential in elucidating host ganglioside function in response to invading pathogens, such as Staphylococcus aureus (S. aureus). Matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI IMS) enables high-specificity spatial investigation of intact gangliosides. Here, ganglioside structural and spatial heterogeneity within an S. aureus-infected mouse kidney abscess was characterized. Differences in spatial distributions were observed for gangliosides of different classes and those that differ in ceramide chain composition and oligosaccharide-bound sialic acid. Furthermore, integrating trapped ion mobility spectrometry (TIMS) allowed for the gas-phase separation and visualization of monosialylated ganglioside isomers that differ in sialic acid type and position. The isomers differ in spatial distributions within the host-pathogen interface, where molecular patterns revealed new molecular zones in the abscess previously unidentified by traditional histology.

Bi-institutional analysis of microbiological spectrum and therapeutic management of parotid abscesses.

BACKGROUND: A parotid abscess (PA) is a complication of an acute bacterial parotitis with a potentially life-threatening course. To date, data on the diagnosis and therapy of PA is sparse and mostly consists of case reports or case series. Therefore, this study aimed at comprehensively analyzing the microbiological spectrum and the therapeutic management in a bi-institutional setting. METHODS: A retrospective clinical chart review was performed to identify all patients surgically treated for PA at two tertiary care centers in Germany. Data on demographics, clinical management and microbiological data including species identification, pathogenicity, type of antibiotic therapy, adjustment of antibiotics, antibiotic sensitivity testing, and smear test results were extracted. Intervention-related variables and etiology were analyzed for their statistical association with outcome variables. RESULTS: Overall, 85 patients were included. Most patients (92.9%) underwent surgical incision. Around half of the patients (45.9%) were treated under local anesthesia. No facial nerve palsy was observed. The most frequently detected pathogens were Streptococci (n = 23), followed by Staphylococcus aureus (n = 6) including one case of methicillin-resistant Staphylococcus aureus. Most patients (68.2%) received an aminopenicillin ± beta-lactamase inhibitor as empiric antibiotic therapy. In 6 cases the antibiotic therapy was modified after receiving the antibiogram. Four patients (5.2%) presented with recurrent PA. Etiology was idiopathic (42.4%), followed by tumorous (12.9%), obstructive, and immunosuppressive (each 11.8%). Patients with a dental focus (p = 0.007) had a longer duration of hospitalization. CONCLUSION: The results show that the surgical therapy of PA under local anesthesia is safe. A dental examination should routinely be performed to rule out a dental focus. Obtaining a microbiological specimen in order to modify antibiotic therapy if necessary and a histopathological specimen to rule out a tumorous etiology is obligate.

Unusual Cutibacterium acnes splenic abscess with bacteremia in an immunocompetent man: phylotyping and clonal complex analysis.

BACKGROUND: Cutibacterium acnes is an anaerobic bacterium mostly implicated in cutaneous and body-implant infections. Splenic abscess is a rare entity and C. acnes abscesses have only exceptionally been reported. We describe a spontaneous splenic C. acnes abscess in an immunocompetent man with no predisposing factors or identified portal of entry. His isolates were subjected to single-locus sequence typing (SLST) to explore their genetic relatedness and better understand this rare infection. CASE PRESENTATION: A splenic abscess was diagnosed on a computed-tomography scan in a 74-year-old man with chronic abdominal pain. No risk factor was identified. Abscess-drained pus and post-drainage blood cultures grew C. acnes. SLST of abscess and blood isolates showed that they belonged to the same C. acnes SLST type C1 found in normal skin and rarely in inflammatory skin disease. Specific virulence factors could not be identified. CONCLUSION: C. acnes abscesses are extremely rare and can develop in immunocompetent patients without an identifiable portal of entry. Molecular typing of clinical isolates can help confirm infection (versus contamination) and enables genetic background comparisons. Further research is needed to understand C. acnes tropism and virulence.

Adherence and metal-ion acquisition gene expression increases during infection with Treponema phagedenis strains from bovine digital dermatitis.

Digital dermatitis (DD) is an ulcerative foot lesion on the heel bulbs of dairy cattle. DD is a polymicrobial disease with no precise etiology, although Treponema spirochetes are found disproportionally abundant in diseased tissue. Within Treponema, several different species are found in DD; however, the species Treponema phagedenis is uniformly found in copious quantities and deep within the skin layers of the active, ulcerative stages of disease. The pathogenic mechanisms these bacteria use to persist in the skin and the precise role they play in the pathology of DD are widely unknown. To explore the pathogenesis and virulence of Treponema phagedenis, newly isolated strains of this species were investigated in a subcutaneous murine abscess model. In the first trial, a dosage study was conducted to compare the pathogenicity of different strains across three different treponemes per inoculum (TPI) doses based on abscess volumes. In the second trial, the expression levels of 11 putative virulence genes were obtained to gain insight into their involvement in pathogenesis. During the RT-qPCR analysis, it was determined that genes encoding for two metal-ion import lipoproteins and two adherence genes were found highly upregulated during infection. Conversely, two genes involved in motility and chemotaxis were found to not be significantly upregulated or utilized during infection. These results were supported by gene expression data from natural M2 lesions of dairy cattle. This gene expression analysis could highlight the preference in strategy for T. phagedenis to persist and adhere in the host rather than engage in motility and disseminate.

Mediastinal actinomycosis masquerading as a mass: a case of progressive dysphagia in an immunocompromised patient.

Actinomycosis is a rare endogenous infection characterised by indolent progression, contiguous spreading, abscess formation and draining sinuses. Here, we present a case of Schaalia odontolytica causing a mediastinal abscess that is unique in its acuity and location. Our patient presented with worsening dysphagia, and CT of her chest revealed a new mass in the posterior mediastinum displacing the oesophagus. Oesophagram revealed mild motility disorder, but no masses or ulcers within the oesophagus. Oesophagogastroduodenoscopy with endoscopic ultrasound revealed extrinsic compression of the oesophagus. Fine-needle aspiration of the mass yielded purulent fluid, which was cultured. A single colony of S. odontolytica was isolated. Initially, medical treatment was favoured, but as she developed worsening dysphagia, the abscess was drained. She continued on long-term antibiotic therapy after drainage and had complete resolution of the abscess at 1 year.