Comamonas kerstersii Bacteremia of Unknown Origin

Bacteremia caused by Comamonas kerstersii in a patient with acute perforated appendicitis and localized peritonitis: case report and literature review

Comamonas kerstersii (C. kerstersii) is a Gram-negative bacterium that was initially thought to be non-pathogenic to humans and is abundant in the environment. In recent years, with the availability of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) that enable fast and accurate bacterial identification, there have been increasing number of reports of human infections caused by C. kerstersii, indicating that this organism has emerged as human pathogen. In fact, most clinical isolates of C. kerstersii are recovered from peritoneal liquid, and bacteremia has been infrequently reported. Here, we report a case of bacteremia caused by C. kerstersii in a 28-year-old male patient with acute perforated appendicitis and localized peritonitis and present a comprehensive review of C. kerstersii infections in pathogenic diagnosis and clinical treatment as well as prognosis, thus providing a better understanding of C. kerstersii-related infections.

The Emergence of the Genus Comamonas as Important Opportunistic Pathogens

Comamonas spp. are non-fermenting Gram-negative bacilli. They were first discovered in 1894, and since then, twenty-four species have been characterized. The natural habitat of these bacteria is soil, wastewater/sludge, fresh water such as ponds and rivers, and the animal intestinal microbiome. They were also isolated from industrial settings, such as activated sludge and polluted soil, and from the hospital environment and clinical samples, such as urine, pus, blood, feces, and kidney. Comamonas spp. are associated with environmental bioremediation and are considered an important environmental bacterium rather than a human pathogen. However, in the 1980s, they became a concern when several human infections associated with these species were reported. Here, the Comamonas genus was examined in terms of its members, identification techniques, and pathogenicity. Seventy-seven infection cases associated with these microorganisms that have been discussed in the literature were identified and investigated in this project. All relevant information regarding year of infection, country of origin, patient information such as age, sex, underlying medical conditions if any, type of infection caused by the Comamonas species, antibiotic susceptibility testing, treatment, and outcomes for the patient were extracted from case reports. The findings suggest that even though Comamonas spp. are thought of as being of low virulence, they have caused harmful health conditions in many healthy individuals and even death in patients with underlying conditions. Antimicrobial treatment of infections associated with these species, in general, was not very difficult; however, it can become an issue in the future because some strains are already resistant to different classes of antibiotics. Therefore, these pathogens should be considered of such importance that they should be included in the hospital screening programs.

Maternal peripartum bacteremia caused by intrauterine infection with Comamonas kerstersii: A case report

BACKGROUND

Comamonas kerstersii (C. kerstersii) infections have considered as non-pathogenic to humans, however due to new techniques such as matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF-MS), more cases have been identified.

CASE SUMMARY

This is the first report of a maternal patient with a C. kerstersii bacteremia following caesarean section. Due to the severity of the patient’s condition; high fever and rapidly progressing organ damage, the patient was transferred to the intensive care unit. C. kerstersii was detected by metagenomic next-generation sequencing testing. Based on the drug sensitivity test, appropriate antibiotic treatment was given and the patient recovered fully.

CONCLUSION

This case report confirms that the detection via MALDI-TOF-MS and metagenomic next-generation sequencing testing provides a reliable basis for the diagnosis of this rare bacterial infection.