Breakthrough bacteremia due to Clostridium tertium in a patient with neutropenic fever, and identification by MALDI-TOF mass spectrometry

Abstract

Clostridium tertium is rare in a human clinical specimen and its pathogenicity is often uncertain. However, the organism has been increasingly recognized as a cause of bacteremia and other infections in immunocompromised patients, especially those with hematologic malignancies. The diagnosis and treatment of C. tertium are difficult due to its growth pattern, micromorphology, and antibiotic resistance. The organism can easily be misidentified as Gram-positive aerobic rods such as Bacillus species, usually considered as a contaminant. Furthermore, it is not covered by empirical treatment with many broad-spectrum antibiotics. Here we report a case of breakthrough bacteremia due to C. tertium that occurred in a patient with acute leukemia and neutropenic fever, who was treated with an empirical regimen of ceftazidime and amikacin. The bacterium was rapidly identified by new mass spectrometry technology (MALDI-TOF MS) and the patient recovered under meropenem and vancomycin treatment, without complications.

Postoperative Clostridium tertium septicemia in a non-neutropenic pediatric patient

“…[6,10] However, fatal cases of C. tertium bacteremia have been reported [2,5,8] and we believe that treatment must be initiated upon the identification of the bacterium in blood cultures. To date, although most documented cases have involved neutropenic patients, [2,[5][6][7][9][10][11] cases involving non-neutropenic patients have also been described. [2,4,7,8] Salvador et al [11] reported that C. tertium could be rapidly identified using a novel mass spectrometry technology (matrix assisted laser desorption ionization timeof-flight).…”

“…To date, although most documented cases have involved neutropenic patients, [2,[5][6][7][9][10][11] cases involving non-neutropenic patients have also been described. [2,4,7,8] Salvador et al [11] reported that C. tertium could be rapidly identified using a novel mass spectrometry technology (matrix assisted laser desorption ionization timeof-flight). In this case, we believe that C. tertium was the cause of septicemia because the organism was independently cultured and that the bacterium identified in the anal wound cultures was different.…”

Comparative genomics identifies potential virulence factors inClostridium tertiumandC. paraputrificum

“…For C. paraputrificum, the pathogenic effect on its hosts has been historically attributed to the action of chitinases [22], whereas for C. tertium, sialidase production is more important [20]. However, misidentification during routine microbiological testing means that the virulence factors from these species have not been studied exhaustively [23]. The draft genomes for C. tertium and C. paraputrificum were recently published [24,25], where exploratory phylogenetic analysis (to differentiate genomes from their closest relatives) and virulencerelated factors and antimicrobial resistance genes were predicted by in silico analysis exclusively.…”

Combinational approach using in situ hybridization targeting 23S ribosomal RNA genes and blood cultures for bacterial identification in patients with neutropenia and fever

“…Several available diagnostic tools such as the detection of serum biomarkers (e.g. procalcitonin (PCT), interleukin (IL)-6, and IL-8) [3][4][5], polymerase chain reaction (PCR) [6,7], or mass spectrometry [8,9] could improve the management of FN. Although PCR analysis and mass spectrometry have the advantage of obtaining direct evidence of bacteria, the former could be susceptible to contamination with bacterial DNA [10][11][12][13][14], whereas the latter demonstrates insufficient diagnostic accuracy.…”

“…Although PCR analysis and mass spectrometry have the advantage of obtaining direct evidence of bacteria, the former could be susceptible to contamination with bacterial DNA [10][11][12][13][14], whereas the latter demonstrates insufficient diagnostic accuracy. However, both methods might be useful for identifying causal bacteria from positive blood culture samples [7][8][9]. However, a strategy based on these tools has not been standardized for the management of FN.…”