Cellulitis caused by Roseomonas mucosa in a child: a case report

BACKGROUND

Roseomonas mucosa (R. mucosa) is a pink-pigmented, Gram-negative short rod bacterium. It is isolated from moist environments and skin, resistant to multiple drugs, including broad-spectrum cephalosporins, and a rare cause of infection with limited reports. R. mucosa mostly causes catheter-related bloodstream infections, with even fewer reports of skin and soft tissue infections.

CASE PRESENTATION

A 10-year-old boy received topical steroid treatment for sebum-deficient eczema. A few days before the visit, he was bitten by an insect on the front of his right lower leg and scratched it due to itching. The day before the visit, redness, swelling, and mild pain in the same area were observed. Based on his symptoms, he was diagnosed with cellulitis. He was treated with sulfamethoxazole/trimethoprim, and his symptoms improved. Pus culture revealed R. mucosa.

CONCLUSIONS

We report a rare case of cellulitis caused by R. mucosa. Infections caused by rare organisms that cause opportunistic infections, such as R. mucosa, should be considered in patients with compromised skin barrier function and regular topical steroid use. Gram stain detection of organisms other than Gram-positive cocci should be considered.

Peritonitis caused by Roseomonas mucosa after ventriculoperitoneal shunt revision: a case report

Ventriculoperitoneal shunt (VPS) is an adequate treatment for congenital hydrocephalus or chronic hydrocephalus in adults. Yet, it is a surgery associated with a significant rate of complications amongst neurosurgical procedures, with frequent shunt obstructions and infections. We report the first-ever case of peritonitis caused by Roseomonas mucosa, shortly after the revision of a VPS ventricular catheter. Hardware removal and proper antibiotic therapy led to the patient's recovery. Roseomonas mucosa is an opportunistic skin pathogen with an antibiotic resistance profile to many beta-lactamines and a tropism for indwelling catheters and post-operative period. Nowadays, it should be taken into account in case of infection of indwelling catheters and for some implantable medical devices.

A nosocomial cluster of Roseomonas mucosa bacteremia possibly linked to contaminated hospital environment

Roseomonas, a genus of pink-pigmented glucose non-fermentative bacteria, has been associated with various primary and hospital-acquired human infections; however, to our knowledge, its nosocomial transmission has never been reported. Clinical and epidemiological investigations were carried out after two cases of R. mucosa bacteremia occurred in our hospital in 2018. Environmental samples were taken of environmental surfaces prone to water contamination in the wards and cultured. The two clinical isolates and all environmental isolates that showed growth of pink colonies were identified using matrix-assisted laser desorption/ionization time of flight mass spectrometry and 16S rRNA gene sequencing. Pulse-field gel electrophoresis (PFGE) was performed and fingerprinting software was used to analyze the DNA restriction patterns and determine their similarity. Two patients who developed R. mucosa bacteremia had received care from the same treatment team. Of 126 environmental samples, five showed growth of R. mucosa. Using 80% similarity as the cut-off, PFGE analysis revealed that the isolates from the two patients' blood cultures and three environmental isolates belonged to the same clone. The hospital water environment was contaminated with the same clone of R. mucosa that caused bacteremia in the two patients, suggesting nosocomial transmission linked to contaminated environment. Increased vigilance is needed to monitor the emergence of Roseomonas in healthcare settings.

Roseomonas mucosa infective endocarditis in patient with systemic lupus erythematosus: case report and review of literature

Background

Roseomonas mucosa, as a Gram-negative coccobacilli, is an opportunistic pathogen that has rarely been reported in human infections. Here we describe a case of bacteremia in an infective endocarditis patient with systemic lupus erythematosus (SLE).

Case presentations

A 44-year-old female patient with SLE suffered bacteremia caused by Roseomonas mucosa complicated with infective endocarditis (IE). The patient started on treatment with piperacillin-tazobactam and levofloxacin against Roseomonas mucosa, which was switched after 4 days to meropenem and amikacin for an additional 2 weeks. She had a favorable outcome with a 6-week course of intravenous antibiotic therapy.

Discussion and conclusions

Roseomonas mucosa is rarely reported in IE patients; therefore, we report the case in order to improve our ability to identify this pathogen and expand the range of known bacterial causes of infective endocarditis.

Differing Virulence of Healthy Skin Commensals in Mouse Models of Infection

Introduction: As therapies for atopic dermatitis (AD) based on live biotherapeutic products (LBP) are developed, the potential displacement of biotherapeutic strains, and species to mucosal sites where they are not naturally found is of investigative interest. However, formal assessment of the toxicity potential of healthy skin commensal organisms has not been reported in the literature. Our previous research indicates that topical application of live Roseomonas mucosa to treat AD was associated with clinical benefit on the skin, but the effects of exposure via inhalation, eye inoculation, and ingestion were unknown.

Methods: Herein we report our findings from mice inoculated with commensal strains of R. mucosa, coagulase negative Staphylococci (CNS), and Pseudomonas aeruginosa. Bacterial isolates were collected under clinical trial NCT03018275, however these results do not represent an interventional clinical trial.

Results: Our tested R. mucosa isolates did not display significant infection or inflammation. However, neutropenic mice inoculated with CNS had infection without major inflammation in pulmonary models. In contrast, systemic infection generated hepatic and splenic pathology for P. aeruginosa and CNS, which was worsened by the presence of neutropenia.

Discussion: Our results suggest that LBP derived from bacteria without significant infectivity histories, such as R. mucosa, may represent safer options than known pathobionts like P. aeruginosa and Staphylococcus spp. Overall, these results suggest that topically applied LBP from select skin commensals are likely to present safe therapeutic options and reinforce our prior clinical findings.

Roseomonas mucosa bacteremia in a neutropenic child: A case report and literature review

Roseomonas species is rarely found to be pathogenic to humans and there are few clinical cases that have been described in the literature. We report a case of Roseomonas mucosa bacteremia that involved a 9-year-old Japanese boy who was in a condition of febrile neutropenia caused by chemotherapy for cerebellar medulloblastoma. Conventional phenotyping failed to identify the organism; however, genetic analysis using 16S rDNA sequencing confirmed the pathogen to be R. mucosa. The patient recovered following treatment by meropenem without any complications. A literature review of pediatric cases of Roseomonas bacteremia identified 12 other documented cases, and these revealed that a common clinical situation for the infection is an immunocompromised state with malignancy and/or an indwelling intravenous catheter. Because of the low number of cases, the overall picture of Roseomonas bacteremia in children remains to be elucidated; however, the prognosis of the infection appears to be satisfactory.

Endogenous endophthalmitis due to Roseomonas mucosa presenting as a subretinal abscess

Background

Endogenous bacterial endophthalmitis is an infrequently reported entity. Although Roseomonas mucosa has been reported to cause systemic infections in immunosuppressed individuals, ocular infection due to Roseomonas has been rarely reported in literature previously.

Findings

A 74-year-old diabetic was diagnosed to have Klebsiella urinary tract infection and septicemia following which he developed ocular pain and redness. Further investigation revealed endophthalmitis with subretinal abscess and retinal detachment. The patient underwent pars plana vitrectomy with drainage of the abscess and silicone oil tamponade. The subretinal aspirate was found to contain R. mucosa confirmed on culture and PCR.

Conclusion

Microbiological evaluation of the subretinal purulent material revealed pink-colored colonies. Nested PCR was positive for detection of the eubacterial genome as well as for detection of the Mycobacterium tuberculosis genome (Ref)-targeting MPB64 gene. PCR examination of the subretinal pus sample ruled out M. tuberculosis and confirmed R. mucosa. The occurrence of Roseomonas endogenous endophthalmitis presenting as a subretinal abscess has not yet been reported in English literature so far to the best of our knowledge.

Two Cases of Bacteremia Due to Roseomonas mucosa

Roseomonas is a genus of pink-pigmented nonfermentative bacilli. These slow-growing, gram-negative cocobacilli form pink-colored colonies on sheep blood agar. They differ from other pink-pigmented nonfermenters, including Methylobacterium, in morphology, biochemical characteristics, and DNA sequence. Roseomonas strains are rarely isolated in clinical laboratories; therefore, we report two cases in order to improve our ability to identify these pathogens. We isolated two strains of Roseomonas mucosa from the venous blood cultures of two patients, an 84-yr-old woman with common bile duct obstruction and a 17-yr-old male with acute myeloid leukemia who had an indwelling central-venous catheter for chemotherapy. The isolated strains were confirmed as R. mucosa by 16S rRNA sequencing.

Infectious Spondylitis with Bacteremia Caused by Roseomonas mucosa in an Immunocompetent Patient

Roseomonas are a gram-negative bacteria species that have been isolated from environmental sources. Human Roseomonas infections typically occur in immunocompromised patients, most commonly as catheter-related bloodstream infections. However, Roseomonas infections are rarely reported in immunocompetent hosts. We report what we believe to be the first case in Korea of infectious spondylitis with bacteremia due to Roseomonas mucosa in an immunocompetent patient who had undergone vertebroplasty for compression fractures of his thoracic and lumbar spine.

A case of bacterial peritonitis caused by Roseomonas mucosa in a patient undergoing continuous ambulatory peritoneal dialysis

Bacterial peritonitis remains a life-threatening complication of peritoneal dialysis (PD). Roseomonas is a bacterial genus of pink-pigmented, oxidized, gram-negative coccobacilli that was first named in 1993. Importantly, Roseomonas mucosa exhibits antibiotic resistance, with significant resistance to cephalosporin, which is often selected as an empirical antibiotic regimen for peritonitis in PD patients. We herein report the case of a PD patient with bacterial peritonitis caused by Roseomonas mucosa that was fortunately identified using 16S rRNA gene sequencing and successfully treated with ciprofloxacin. Given that Roseomonas demonstrates resistance to a variety of antibiotics. The administration of empiric antibiotic therapy based on the recommendation of the International Society of Peritoneal Dialysis guidelines occasionally fails, leading to the aggravation of bacterial peritonitis. Hence, nephrologists should consider Roseomonas as one of the potential causative organisms of peritonitis, especially when gram-negative bacilli are resistant to cephalosporin and cannot be identified using standard laboratory methods.