Sepsis and Hepatapostema Secondary to Chromobacterium Violaceum Infection on Lower Limb Skin: A Case Report

Abstract

Background: Chromobacterium violaceum (C. violaceum) is a Gram-negative bacterium capable of causing severe infections in both humans and specific animals. Despite its infrequency, C. violaceum infections exhibit a notably high mortality rate. The timely and precise detection of this pathogen stands as a critical factor in achieving effective diagnosis and treatment. Traditional diagnostic approaches possess limitations, particularly in terms of their time-consuming nature and the range of pathogens they can identify. Metagenomic next-generation sequencing (mNGS) testing has emerged as a highly promising diagnostic tool for infectious diseases.

Methods: Within this case report, we present a patient who developed a C. violaceum infection subsequent to a lower limb infection, leading to the progression of sepsis, a liver abscess, septic shock, multi-organ dysfunction, and altered mental status. Samples of the patient's blood and tissue from the lower limb skin are collected, and the infection is swiftly diagnosed through mNGS, allowing for the immediate initiation of suitable treatment.

Results: The mNGS results revealed the patient's infection with C. violaceum. Subsequent conventional bacterial culture results were concordant with the mNGS findings. Following comprehensive management measures, including prompt and effective anti-infective treatment, the patient achieved cure and was successfully discharged.

Conclusion: This case underscores the significance of employing advanced diagnostic methodologies like mNGS for the early detection of uncommon pathogens such as C. violaceum. The expedited diagnosis and timely intervention hold the potential to substantially enhance patient outcomes in cases of severe infections instigated by this bacterium.

Keywords: chromobacterium violaceum; hepatapostema; infection; liver; liver abscess; metagenomic next-generation sequencing; sepsis.

Figure 1

This patient’s left lower limb. (A and B) Upon admission to our hospital. Ulceration of the left lower extremity 10 cm above the ankle joint, and an oval skin gangrene about 5 cm in diameter was seen 10 cm above the ankle joint of the left lower extremity. (C) Intraoperative clearance on August 24, 2022. (D) Post-implantation on September 1, 2022.

Figure 2

Abdominal CT images of the patient. Abdominal CT image results showed multiple hypodense foci in the liver and a small amount of fluid in the abdominal cavity. (A and B) Abdominal CT on August 19, 2022. (C and D) Abdominal CT on August 21, 2022.

Figure 3

(A) Blood specimens were cultured for Chromobacterium violaceum by general bacteriophage culture. (B) Blood samples were tested by next-generation sequencing (NGS) on August 21, 2022, and Chromobacterium violaceum was detected. (C) Tissue samples confirmed Chromobacterium violaceum, with Next-Generation Sequencing (NGS) on August 24, 2022.