Streptococcus bovis endocarditis as a presenting manifestation of idiopathic ulcerative colitis

[Descriptive analysis of diseases associated with Streptococcus bovis bacteremia]

BACKGROUND AND OBJECTIVE

It is well-known the relationship between Streptococcus bovis (S. bovis) bacteremia and colon cancer, liver cirrhosis and others neoplasms. However, a study protocol to rule out these underlying diseases has not been carried out yet. Our objective was to describe S. bovis bacteremia and associated diseases.

PATIENTS AND METHOD

Multicenter, retrospective cohort study. S. bovis bacteremias episodes between 2001 and 2009 were included. Mean variables: colon neoplasm, non-colonic neoplasm or liver cirrhosis. Epidemiologist aspects, bacteremia related variables, personal and familiar history and clinical and analytical data were collected.

RESULTS

Ninety three patients were included. One out of four individuals had a colon neoplasm. Fifty seven per cent were concomitant cases with bacteremia and six cases were diagnosed after bacteremia (time bacteremia-diagnosis of neoplasm [months], median [Q1-Q3], 2.6 [1-11]). Fourteen (15%) patients were diagnosed with any non-colonic neoplasm (mainly biliary and pancreatic [6 cases] or esophagus-gastric [3 cases]). There were three patients (21%) with concomitant bacteremia non-colonic neoplasm and two after it (1.2 and 10.4 months). Twenty-one (23%) patients suffered from liver cirrhosis.

CONCLUSIONS

Patients with S. bovis bacteremia must undergo a study designed to rule out underlying diseases. We suggest that this study should include: a colonic evaluation, ideally by colonoscopy, a liver evaluation by serum chemistry, an abdominal ultrasound scan or a method of liver fibrosis assessment, a gastroscopy and an evaluation of biliary and pancreatic areas by magnetic resonance imaging.

Streptococcus bovis endocarditis, a silent sign for colonic tumour

AIM

An association between colonic carcinoma and Streptococcus bovis endocarditis/bacteraemia was first suggested in 1951. This knowledge has great clinical implications, yet we found scant awareness amongst general surgical trainees. The aim of this article was to review the evidence available in the literature and explore the pathophysiology behind this association.

METHOD

The literature was reviewed, between 1950 and 2008, using Pubmed, Embase and Ovid database searches. We utilized different combinations of the keywords: Streptococcus bovis, endocarditis, septicaemia and colon cancer/carcinoma. Quality assessment was determined using the Oxford Centre for Evidence-based Medicine Levels of Evidence (May 2001). Studies were selected based on their relevance to the aims to be addressed.

RESULTS

We included nine case reports and found 24 studies demonstrating an association between S. bovis bacteraemia/endocarditis and colon cancer; the reported incidence in studies was variable (6-67%). The majority of studies (20) were retrospective analysis of data; only four studies were prospective. A total of 12 of 24 studies also reported an association with extra-colonic malignancy (1-22%) and 12 with liver disease (3-57%). Eight studies relevant to the pathophysiology of this association were identified.

CONCLUSION

Streptococcus bovis endocarditis and/or bacteraemia is an early clue to the likely presence of colorectal cancer. Whilst further studies are required to determine the precise pathophysiology, clinicians should be aware of this association. It is advisable to investigate rigorously for colon cancer in all patients presenting with S. bovis endocarditis/bacteraemia; such patients may also present with liver disease or, occasionally, extra-colonic malignancy.

The association of Streptococcus bovis bacteremia and gastrointestinal diseases: a retrospective analysis

There is a well-established association between Streptococcus bovis bacteremia (SBB) and colorectal cancer. However, SBB is also frequently associated with chronic liver disease and has been described with other gastrointestinal disorders. The aim of the study was to evaluate the prevalence of gastrointestinal disease in patients with SBB. Retrospective analysis of the microbiology database at Jackson Memorial Medical Center, Miami, Florida, between 1992 and 2002, was performed. Patients' clinical records were reviewed, with special focus on underlying gastrointestinal disease or other major comorbidities. Thirty-eight patients (83%) were adults and eight (17%) were pediatric patients. Nineteen patients presented with gastrointestinal disorders associated with SBB (41%). Nine adult patients (19%) had end-stage liver disease (five female). Six patients had alcohol-induced liver disease (one with concomitant chronic hepatitis C), with the remaining three cases related to autoimmune hepatitis, primary biliary cirrhosis, and nonalcoholic steatohepatitis. Colonic neoplasms (adenocarcinoma in 3 and adenomatous polyps in 3) were found in 6 of 10 adult patients in whom colonoscopic evaluation was performed. Seven adult patients had acquired immunodeficiency syndrome (AIDS) (18%). Mortality in the patients with AIDS and SBB was high (71%). No significant association with gastrointestinal diseases was found in the pediatric population. Bacteremia due to S. bovis in adults is frequently associated with hepatic dysfunction (1:4), colonic neoplasms (1:6), and AIDS (1:6). This association was valid for our adult population only. SBB is an early clue to the likely presence of these serious underlying conditions and warrants rigorous investigation when recognized.

Prevalence of liver disease in patients with Streptococcus bovis bacteraemia

BACKGROUND

The relationship between Streptococcus bovis bacteraemia and gastrointestinal disease (mainly colon cancer) is well known. Patients with advanced liver disease are prone to bacteraemia. Less attention has been paid to the association between liver disease and Streptococcus bovis bacteraemia in the literature.

AIMS

To evaluate the prevalence of liver disease in patients with S. bovis bacteraemia.

PATIENTS AND METHODS

Twenty-two episodes of S. bovis bacteraemia in 20 adults (13 males and seven females, with a median age of 61 years, range 32-94 years) were detected in a single hospital over a 7-year period. Ten of them had endocarditis. Patients' clinical records were reviewed, with special focus on underlying liver and gastrointestinal disease.

RESULTS

Eleven patients (55%) had a chronic liver disease. Nine of them were cirrhotics. Ten patients had a history of chronic alcohol abuse, and four patients had hepatitis C virus antibodies (associated with alcohol abuse in three cases). Large bowel disease was present in six out of 13 evaluable patients (adenocarcinoma in three cases). Patients with liver disease were younger than patients without it. Mortality related to S. bovis bacteraemia was particularly high among patients with advanced liver disease (Child-Pugh state C). Bacteraemia recurred two times in one alcoholic cirrhotic, who was diagnosed as having a Dukes-B colon cancer 4.5 years after the first episode of S. bovis bacteraemia.

CONCLUSIONS

In our area, S. bovis bacteraemia is frequently associated with chronic liver disease. Liver disease may be a predisposing factor for S. bovis bacteraemia.

Recovery of uncommon bacteria from blood: association with neoplastic disease

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.

Development of a DNA probe for Streptococcus bovis by using a cloned amylase gene

Streptococcus bovis is a normal inhabitant of the rumen but has been implicated as a causative agent for ruminal lactic acidosis and related problems. While rarely isolated from humans, S. bovis has been identified as a causative agent for endocarditis, meningitis, and septicemia. Recent reports have also suggested a correlation between human colonic carcinoma and increased levels of S. bovis. Identification of S. bovis strains of human origin has been problematic because of variations in results of biochemical tests compared with results for ruminal strains. We have tested a cloned amylase gene from the ruminal strain S. bovis JB1 as a potential DNA probe for rapid and accurate identification of S. bovis strains from all sources. DNAs from strains identified as S. bovis, of both human and ruminal origin, were found to hybridize with the probe under stringent conditions. The probe also hybridized with variants of S. bovis that did not grow on starch. The probe did not hybridize with DNA isolated from other bacteria of human colonic and ruminal origin, including Bacteroides thetaiotaomicron, Bacteroides ruminicola, Butyrivibrio fibrisolvens, and Enterococcus faecalis but did demonstrate hybridization with Streptococcus salivarius.