Recovery of uncommon bacteria from blood: association with neoplastic disease

Abstract

Table 6 is a summary of the organisms discussed with a listing of the environmental source, the endogenous source, the predisposing factors including neoplasms, and the postulated mechanisms by which the organism can gain access to the circulation. The evidence considered indicates that the entrance of one of these microorganisms into the bloodstream of a human being depends on the presence of multiplicity of predisposing factors. In the majority of cases of bacteremia due to one of these unusual organisms, two or more predisposing factors are present. Certain predisposing factors, such as cancer chemotherapy or intravenous catheterization, often provide a barrier break, while others, such as liver disease, may render the host immune system less capable of clearing organisms from the circulation. For organisms such as Campy-lobacter, Listeria, and Salmonella spp., attributes that allow the invasion of a healthy host are present and seem to be enhanced by the simultaneous presence of a predisposing condition, such as liver disease, in the host. Although somewhat fragmentary, a number of individual case reports describe bacteremia due to one of these organisms occurring weeks to years after surgery and after other therapeutic measures had effected a supposed cure of a cancer. It may be speculated that cancer patients, even after a cure, are still susceptible to bloodstream invasion by one of the aforementioned organisms by virtue of the presence of one or more predisposing metabolic, physiologic, or immunologic factors, even though these factors may be cryptic. The predominance of hematologic malignancies among cases of bacteremia due to these unusual organisms is also apparent. Although, as pointed out by Keusch (169), the reduction in the performance of immune function in hematologic malignancies compared with solid tumors is likely to be responsible, other associations of certain organisms with specific neoplasms warrant further examination. The frequency of bloodstream infections of Salmonella typhimurium and Capno-cytophaga canimorsus in Hodgkin's disease patients seems likely due to a particular mechanism which infection by these species is favored. The specific nature of these mechanisms remains to be determined. The recovery of any unusual bacterium from blood should warrant a careful consideration of the possibility of underlying disease, especially cancer. Microbiologists should advise clinicians of the unusual nature of the identified organism and provide the counsel that certain neoplastic processes, often accompanied by neutropenia, render the human host susceptible to invasion by almost any bacterium. The recovery of such organisms as C. septicum or S. bovis should prompt the clinician to aggressively seek to identify an occult neoplasm if one has not yet been diagnosed.

Association of tannase-producing Staphylococcus lugdunensis with colon cancer and characterization of a novel tannase gene

“…Many studies have reported the association of Streptococcus (St.) bovis endocarditis with colon cancer. [1][2][3][4] However, this association has not been investigated. Streptococcus bovis has been divided by biotype into three types, I, II/1, and II/2, although it has recently been reclassifi ed both genetically and biochemically.…”

Prospective case-cohort study of intestinal colonization with enterococci that produce extracellular superoxide and the risk for colorectal adenomas or cancer

“…Intestinal colonization, bloodstream infection, and endocarditis with Streptococcus bovis, an organism remotely related to enterococci via a shared group D antigen, has been strongly associated with colorectal cancer (89). S. bovis, however, does not produce detectable extracellular O 2 ⅐ (25), and is an infrequent human commensal (53,55).…”

Streptococcus infantarius and colonic cancer: Identification and purification of cell wall proteins putatively involved in colorectal inflammation and carcinogenesis in rats

“…doi:10.1016/j.ics.2005.11.081 hepatobiliary cancer, and the Streptococcus bovis/S. equinus complex with colorectal cancer [3].…”

“…They are encountered in 2.5% to 15% of individuals but can get pathogenic and then cause bacteriemia and endocarditis. Epidemiological studies showed that half of the patients affected by S. bovis/ S. equinus bacteriemia and/or endocarditis had an intestinal disease and among them 50% presented a colorectal cancer [3].…”