Biochemical analyses demonstrated a leukocytosis and neutrophilia; haemoglobin (Hb) 11.9 g/dL, white blood cell count (WCC) 13.9 × 10⁹/L, neutrophils 11.4 × 10⁹/L. An acute phase response was evident with C-reactive protein (CRP) 131 mg/L. A mixed cholestatic and hepatic picture of hepatic enzymes with alkaline phosphatase (ALP) 340 U/L, alanine aminotransferase (ALT) 240 U/L and gamma-glutamyl-transferase (γGT) 381 U/L was demonstrated; total bilirubin was 351 μmol/L. Hepatic synthetic function was preserved with albumin 30 g/L and prothrombin time (PT) of 13.8 seconds. A clinical diagnosis of cholangitis was made on the basis of Charcot's triad (abdominal pain, fever and jaundice), and empirical antibiotic therapy (oral ciprofloxacin 500 mg bd) was commenced.

An ultrasound of the biliary tree was performed demonstrating dilatation of the common bile duct to 1.5 cm with visualization of at least one stone in the lumen of the duct. Intrahepatic duct dilatation was also noted. Blood cultures confirmed a Lactococcus lactis cremoris septicaemia. The organism was sensitive to tazobactam/piperacillin and co-amoxiclav. In light of these results, antibiotic therapy was changed to intravenous tazobactam/piperacillin 4.5 g tds.

The patient proceeded to endoscopic retrograde cholangiopancreatogram (ERCP) where an impacted common bile duct stone was identified. Unfortunately, this was not amenable to endoscopic removal despite sphincterotomy; however two biliary stents were inserted with good drainage.

Empirical antibiotic therapy for cholangitis is targeted towards gut organisms, particularly Gram-negative organisms. Commonly (including in our unit), ciprofloxacin is considered to be an appropriate empirical therapy. This is backed up by reports of an 85% clinical cure rate in trials [13]. The Tokyo Consensus group [13] failed to recommend a single specific empirical treatment, therefore local antibiotic guidelines will continue to direct empirical therapy. In the presence of positive microbiological investigations, there is a clear consensus that agents should be changed for more appropriate treatment according to sensitivity.

Biliary drainage reduces mortality and speeds recovery from cholangitis and is therefore a vital part of management [14]. The Tokyo guidelines recognize that this must be done in an emergency setting for patients with severe cholangitis and as promptly as practical in other patients. Endoscopic drainage is the preferred modality [15].

Lactococcus lactis cremoris is a Gram-positive coccus, formerly classified as Streptococcus cremoris but now recognized as a member of the genus Lactococcus [3]. This species is commonly regarded as non-pathogenic in immunocompetent adults, however we report the thirteenth case to our knowledge of this pathogen causing clinically significant infection. Previously, four cases of bacterial endocarditis [4,6,9,11], one of septicaemia [7], two liver abscesses [3,5] and one each of necrotizing pneumonitis [10], septic arthritis [8], deep neck infection [2], cerebellar abscess [4] and canaliculitis [1] have been reported. Of these, it appears that nine were immunocompetent patients. All bar one of the case reports were in adults (Table ​(Table11).