Kytococcus schroeteri Bacteremia in a Patient with Hairy Cell Leukemia: A Case Report and Review of the Literature

Recombinant mannan-binding lectin magnetic beads increase pathogen detection in immunocompromised patients

The microbiological diagnosis of infection for hematological malignancy patients receiving chemotherapy or allogeneic hematopoietic stem cell transplantation (allo-HSCT) patients relies primarily on standard microbial culture, especially blood culture, which has many shortcomings, such as having low positive rates, being time-consuming and having a limited pathogenic spectrum. In this prospective observational self-controlled test accuracy study, blood, cerebrospinal fluid (CSF), and bronchoalveolar lavage fluid (BALF) samples were collected from chemotherapy or allo-HSCT patients with clinical symptoms of infections who were hospitalized at Peking University First Hospital. Possible pathogens were detected by the method based on recombinant mannan-binding lectin (MBL) magnetic bead enrichment (M1 method) and simultaneously by a standard method. The analytical sensitivity of M1 method was close to that of standard culture method. Besides, the turn-around time of M1-method was significantly shorter than that of standard culture method. Moreover, the M1 method also added diagnostic value through the detection of some clinically relevant microbes missed by the standard method. M1 method could significantly increase the detection efficiency of pathogens (including bacteria and fungi) in immunocompromised patients. KEY POINTS: • The detection results of M1-method had a high coincidence rate with that of standard method • M1 method detected many pathogens which had not been found by standard clinic method.

Periprosthetic joint infection caused by kytococcus schroeteri: The first reported case and a review of the literature

Oftentimes, Gram-positive cocci are the cause for periprosthetic joint infections (PJI). Most of these infections include bacteria such as Staphylococcus aureus, Staphylococcus epidermidis or other coagulase-negative staphylococci. We here present the first case of a PJI caused by Kytococcus schroeteri. While being a Gram-positive coccus, it is very rarely the cause for infections in the human body. K. schroeteri is part of the micrococcus branch and often encountered as a symbiotic bacterium living on the skin. Regarding its pathogenic potential, not a lot is known since less than a few dozen human infections have been reported worldwide. Furthermore, many of the cases reported are either associated with implanted material, especially heart valves, or associated with patients whose immune response is deficient. Only 3 reports of osteoarticular infections are described so far.

Circulating microbial content in myeloid malignancy patients is associated with disease subtypes and patient outcomes

Although recent work has described the microbiome in solid tumors, microbial content in hematological malignancies is not well-characterized. Here we analyze existing deep DNA sequence data from the blood and bone marrow of 1870 patients with myeloid malignancies, along with healthy controls, for bacterial, fungal, and viral content. After strict quality filtering, we find evidence for dysbiosis in disease cases, and distinct microbial signatures among disease subtypes. We also find that microbial content is associated with host gene mutations and with myeloblast cell percentages. In patients with low-risk myelodysplastic syndrome, we provide evidence that Epstein-Barr virus status refines risk stratification into more precise categories than the current standard. Motivated by these observations, we construct machine-learning classifiers that can discriminate among disease subtypes based solely on bacterial content. Our study highlights the association between the circulating microbiome and patient outcome, and its relationship with disease subtype.

Insight into Kytococcus schroeteri Infection Management: A Case Report and Review

Background: Kytococcus schroeteri is a member of normal skin microflora, which can cause lethal infections in immunosuppressed hosts. In this review we attempted to draw patterns of its pathogenicity, which seem to vary regarding host immune status and the presence of implantable devices. Evidence suggests this pathogen houses many resistance-forming proteins, which serve to exacerbate the challenge in curing it. Available information on K. schroeteri antibacterial susceptibility is scarce. In this situation, a novel, genome-based antibiotic resistance analysis model, previously suggested by Su et al., could aid clinicians dealing with unknown infections. In this study we merged data from observed antibiotic resistance patterns with resistance data demonstrated by DNA sequences. Methods: We reviewed all available articles and reports on K. schroeteri, from peer-reviewed online databases (ClinicalKey, PMC, Scopus and WebOfScience). Information on patients was then subdivided into patient profiles and tabulated independently. We later performed K. schroeteri genome sequence analysis for resistance proteins to understand the trends K. schroeteri exhibits. Results: K. schroeteri is resistant to beta-lactams, macrolides and clindamycin. It is susceptible to aminoglycosides, tetracyclines and rifampicin. We combined data from the literature review and sequence analysis and found evidence for the existence of PBP, PBP-2A and efflux pumps as likely determinants of K. schroeteri. Conclusions: Reviewing the data permits the speculation that baseline immune status plays a role in the outcome of a Kytococcal infection. Nonetheless, our case report demonstrates that the outcome of a lower baseline immunity could still be favorable, possibly using rifampicin in first-line treatment of infection caused by K. schroeteri.

Postoperative Hardware-Related Infection from Kytococcus schroeteri: Its Association with Prosthetic Material and Hematological Malignancies-A Report of a Case and Review of Existing Literature

Introduction

Kytococcus schroeteri is an infrequently isolated Gram-positive coccus often encountered as a commensal bacterium. Only eighteen cases of human infection associated with this organism have been previously reported. Most of these cases involved patients with implanted prosthetic materials or patients with immunosuppressive conditions. It has been described in prosthetic valve endocarditis and in select patients with hematologic diseases but only one prior report as being involved in osteoarticular infections.

Case Presentation

We describe a case of postsurgical osteoarticular hardware-related infection by K. schroeteri and discuss a possible association with implanted prosthetic material.

Conclusion

Other clinical presentations of K. schroeteri, including reported infection syndromes, antimicrobial susceptibility profiles, and treatment outcomes, are also reviewed.