Streptococcus salivarius Causing Multiple Liver Abscesses in a Patient with Situs Inversus

To the Editor:

A 65-year-old man without any clinical history complained of continuous pain in the left upper quadrant of the abdomen and fever of 38°C during the preceding four days. Laboratory data revealed a white blood cell count of 20,800/mm³, total bilirubin 2.6 mg/dL, aspartate transaminase 63U/L, and alanine transaminase 64 U/L. An abdominal computed tomography (CT) scan showed complete situs inversus, with the liver in the left upper quadrant. Multiple liver abscesses were evidenced, mainly in the left lobe (Fig. 1). A CT-guided percutaneous drainage of the two larger abscesses was performed. Empiric antibiotic treatment was started with piperacillin-tazobactam 4.5 g q 6 h and teicoplanin 400 mg q 12 h. Culture of the drained material yielded Streptococcus salivarius sensitive to the employed antibiotics. The same antibiotic treatment was continued for 28 days. The patient recovered uneventfully and was discharged 30 days after admission. Further investigations were performed, discounting a gastrointestinal of the infection and possible immunodeficiency.

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FIG. 1.

Computed tomography views of liver abscesses. (A) Frontal section. Multiple abscesses and situs inversus. (B) Axial section. Multiple abscesses are visible in left lobe.

Streptococcus salivarius is a gram-positive coccus, the principal commensal bacterium of the oral cavity in human beings. When this bacterium enters the blood stream by accident during dental work or when brushing the teeth, it usually manifests an indolent course. However, in neutropenic patients, it acts as an opportunistic pathogen, causing sepsis. S. salivarius has been detected occasionally in the stools of asymptomatic patients. This reveals that these microorganisms can be found in every segment of the gastrointestinal tract, without causing pathology [1,2]. Lee et al. reported one case of bacteremia after colonic endoscopic mucosal resection without symptoms or signs associated with infection [3].

Situs inversus is a congenital condition in which the major visceral organs are reversed from their normal positions. Many people with situs inversus totalis are unaware of their unusual anatomy until they seek medical attention for an unrelated condition [4], as in the case we present.

Kartagener syndrome is characterized by the triad of situs inversus, chronic sinusitis, and bronchiectasis. These patients present a dysfunction of the cilia that are responsible for the position of the internal organs during early embryologic development and the clearance of mucus from the lung. This dysfunction increases susceptibility to lung infections and may cause infertility [4]. Our patient did not present any history of sinusitis or bronchiectasis.

To our knowledge, there is only one case reported in the literature describing the association between situs inversus and common variable immunodeficiency with a tendency to develop lung infections [5], suggesting that the coexistence of situs inversus and liver infection by S. salivarius is a coincidence rather than that situs inversus predisposes to an immunodeficiency state.

In conclusion, S. salivarius is an extremely infrequent cause of bacteremia. Although these infections usually affect neutropenic patients, septic embolization can occur in healthy subjects and be responsible for liver abscesses.