# Early Detection and Identification of Methylobacterium radiotolerans Bacteremia in an Early T-Cell Precursor Acute Lymphoblastic Leukemia Patient: A Rare Infection and Literature Review

## TL;DR

A rare case of Methylobacterium radiotolerans infection in a leukemia patient is reported, highlighting the need for specialized culture methods for accurate detection.

## Contribution

Demonstrates that Myco/F Lytic culture vials are more effective for isolating M. radiotolerans compared to conventional methods.

## Key findings

- M. radiotolerans was successfully isolated using Myco/F Lytic culture vials in a leukemia patient.
- Conventional culture methods failed to reliably detect M. radiotolerans in this case.
- Targeted antimicrobial therapy based on susceptibility testing resolved the infection.

## Abstract

(1) Background: Methylobacterium radiotolerans (M. radiotolerans) is a fastidious, aerobic, Gram-negative bacillus primarily found in environmental sources such as soil and sewage, with rare clinical isolation. Its identification remains challenging due to poor growth with conventional culture methods. (2) Case presentation: A 42-year-old male patient with early T-cell precursor acute lymphoblastic leukemia (ETP-ALL) presented with M. radiotolerans bacteremia during hospitalization. The organism was successfully isolated from peripheral blood using the Myco/F Lytic culture vial (Becton, Dickinson and Company, Lincoln, MT, USA). Comparative analysis demonstrated markedly superior growth of M. radiotolerans in Myco/F Lytic culture vials compared with Plus Aerobic/F Lytic and Lytic/10 Anaerobic/F culture vials (Becton, Dickinson and Company, Lincoln, MT, USA). Antimicrobial susceptibility testing, performed with the epsilometer test (E-test) and Bauer–Kirby disk diffusion (BK) method, guided the selection of an appropriate therapeutic regimen. The patient’s infection was ultimately controlled following targeted antimicrobial therapy. (3) Conclusions: M. radiotolerans demonstrates a distinct growth preference for the Myco/F Lytic culture medium. This observation highlights the importance of considering alternative culture media in cases of rare or fastidious bacterial infections that cannot be reliably detected using conventional Plus Aerobic/F Lytic or Lytic/10 Anaerobic/F culture vials, which are typically employed for clinical isolation of aerobic and anaerobic bacteria.