Endophthalmitis involving an Arthrobacter-like organism following intraocular lens implantation

Corneal Deposits: A Presentation of Arthrobacter Keratitis

Introduction

Infectious keratitis, an inflammatory condition of the cornea, poses a significant public health concern globally. Bacterial keratitis, the most common type, primarily involves Staphylococcus aureus and Pseudomonas aeruginosa. Timely diagnosis and treatment are crucial to prevent vision loss.

Case Presentation

This case report presents a 78-year-old male patient with a burning sensation persisting for 1 week. The patient was diagnosed with keratitis caused by Arthrobacter, a Gram-positive coccobacillus commonly found in the environment. While the literature reports a few cases of Arthrobacter species keratitis, limited data exist regarding its clinical course and outcomes. Treatment with ciprofloxacin eye drops resulted in complete resolution of symptoms and a clear cornea upon final follow-up.

Conclusion

Arthrobacter, a rare causative agent of keratitis, requires early suspicion for accurate diagnosis and treatment. Despite the limited literature on Arthrobacter keratitis, this case highlights the importance of considering uncommon pathogens in corneal infections. Further research is necessary to understand the prevalence and clinical course of Arthrobacter keratitis.

Infection or Contamination with Rothia, Kocuria, Arthrobacter and Pseudoglutamicibacter-a Retrospective Observational Study of Non-Micrococcus Micrococcaceae in the Clinic

Rothia, Kocuria, Arthrobacter, and Pseudoglutamicibacter are bacterial species within the family Micrococcaeae. Knowledge of human infections due to these bacteria is limited. This study aimed to examine features of infections caused by non-Micrococcus Micrococcaeae (NMM). Findings of NMM from blood cultures and other sterile cultures from 2012 to 2021 were identified from the records of the Department of Clinical Microbiology in Region Skåne, Lund, Sweden. Medical records were retrospectively reviewed. True infection was defined as having signs of infection, no other more likely pathogen, and no other focal infection, together with two positive blood cultures or one positive blood culture and an intravascular device. A total of 197 patients with findings of NMM in blood cultures were included. Among adult patients with bacteremia, 29 patients (22%) were considered to have a true infection. Adults with true infection were significantly more likely to have malignancy (69%), leukopenia (62%), and treatment with chemotherapeutics (66%) compared to patients with contaminated samples (24%, 3%, and 8%, respectively) (P < 0.001). A total of 31 patients had findings of NMM in other sterile cultures, and infections were considered true in joints (n = 4), a pacemaker (n = 1), and peritoneal dialysis fluid (n = 1). Infections due to NMM occur but are rare. Growth of NMM in blood cultures should be suspected to be a true infection mainly in immunocompromised patients.

Arthrobacter woluwensis Bacteremia: A Clinical and Genomic Report

Arthrobacter woluwensis is a Gram-positive, aerobic Actinobacteria that is widely distributed in the environment worldwide. Little is known about A. woluwensis infection and it is commonly mis-identified by culturing with commercial kits. To date, only six cases of bacteremia caused by A. woluwensis have been reported in the literature. Herein, we report a case of Arthrobacter woluwensis bacteremia in an immunocompromised host. In this case report, the results of antimicrobial susceptibility testing showed that this clinical isolate of A. woluwensis is sensitive to vancomycin, teicoplanin, but resistant to penicillin, cephalosporin and ciprofloxacin. Additionally, whole genome sequencing analysis identified common subunits of the urease system.

Arthrobacter woluwensisSubacute Infective Endocarditis: Case Report and Review of the Literature

We report a case of endocarditis due to Arthrobacter woluwensis and review the published reports of Arthrobacter species isolated from human clinical samples. A 39-year-old injection drug user presented with fever and a new heart murmur. A. woluwensis was isolated from blood cultures, and a diagnosis of subacute infective endocarditis of the native mitral valve was made. The patient was successfully treated with a 6-week course of intravenous teicoplanin. From our review of the literature, we were able to retrieve data on 41 cases of Arthrobacter species isolated from human clinical samples. However, Arthrobacter species was documented as a cause of human disease on only 5 other occasions (2 cases of bacteremia, 1 case of postoperative endophthalmitis, 1 case of a Whipple disease-like syndrome, and 1 case of phlebitis). Because of the difficulty of identifying Arthrobacter strains by conventional biochemical assays, it is likely that infections with these coryneform bacteria are underreported.

Whipple's syndrome (uveitis, B27-negative spondylarthropathy, meningitis, and lymphadenopathy) associated with Arthrobacter sp. infection

OBJECTIVE

To report an unusual case of Whipple's disease, including uveitis, seronegative spondylarthropathy, meningitis, and lymphadenopathy, associated with an Arthrobacter sp. infection.

DESIGN

Interventional case report.

PATIENT AND INTERVENTION

A 60-year-old white man presenting with severe chronic uveitis and systemic inflammatory manifestations was treated efficiently for Whipple's disease after histopathologic analysis of vitreous and inguinal adenopathy biopsy specimens. The authors performed a retrospective, laboratory-based evaluation of stored tissue specimens.

MEASUREMENTS

Molecular analysis based on 16S ribosomal RNA gene amplification was applied to pretreatment biopsy specimens of inguinal lymph node to identify a causative bacterial agent.

RESULTS

Tropheryma whippelii genome was not detected in these specimens. However, an amplification product was obtained after the first polymerase chain reaction run and subsequently was sequenced. It corresponded to an Arthrobacter sp., a gram-positive agent presenting diagnostic patterns and therapeutic management similar to those of Whipple's disease caused by T. whippelii.

CONCLUSION

The absence of T. whippelii identification by molecular amplification during a clinically and histologically oriented Whipple's syndrome should not rule out the diagnosis. Arthrobacter infection may represent a new bacterial etiology of systemic inflammatory disorders involving the eye and associated with periodic acid-Schiff-positive inclusions.

Characteristics of Arthrobacter cumminsii, the most frequently encountered Arthrobacter species in human clinical specimens

During a 2-year period, 10 strains of Arthrobacter cumminsii were isolated in or received by a Swiss routine clinical bacteriology laboratory, and 5 further isolates were referred to a Swedish bacteriology reference center over a 5-year period, making A. cumminsii the most frequently encountered Arthrobacter species in these two laboratories. The present report outlines the clinical features of the 15 A. cumminsii strains and presents an extended biochemical characterization of this microorganism. A. cumminsii exhibits a unique cellular fatty acid pattern with the consistent presence of C14:0i and C14:0 fatty acids as well as relatively large amounts of C16:0i and C16:0 fatty acids usually not seen in other Arthrobacter spp. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis was found to be a useful tool for confirmation of the identification of A. cumminsii. The MICs of 39 antimicrobial agents were determined, and it was demonstrated that aminoglycosides and quinolones had only weak activities against A. cumminsii strains, in contrast to their activities against most other coryneform bacteria. As a result of the extended characterization of A. cumminsii, an emended description of this species is presented. Due to the lack of A. cumminsii in established identification systems, it is most likely that this species is underdiagnosed in many routine clinical bacteriology laboratories.