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early recognition and timely intervention is key to the successful treatment and better prognosis of the patients . in recent years
, its management has been enhanced by imaging techniques , and the use of percutaneous drainage and improvement in microbiological characterization have allowed the use of most appropriate antibiotic therapy .
major underlying conditions include biliary tract disease , malignancy , and disorders of the colon .
sigmoid diverticulitis as the source of hepatic abscess is uncommon.[13 ] the  streptococcus milleri group 
( smg ) of bacteria is frequently linked to abscess.[47 ] members of this group are now actually classified into three distinct species ; streptococcus intermedius , streptococcus constellatus , and streptococcus anginosus .
the first case of streptococcus milleri hepatic abscess was reported in 1975 . since then they have been identified as one of the important pathogens of liver abscess.[811 ] smg bacteremia from a sigmoid diverticular source leading to hepatic and intra - abdominal abscess is rarely reported .
we present a case report in which our patient had streptococcus anginosus bacteremia with hepatic and intraabdominal abscesses .
a 71-year - old caucasian male with a past medical history of hypertension , arthritis , benign prostatic hypertrophy , and osteoarthritis presented to the emergency room with complaints of intermittent fever , chills , generalized weakness , myalagia , and malaise of two weeks duration .
he denied diarrhea , melena , any recent travels , or any sick contacts . on physical examination ,
patient had a temperature of 36.7c , was hypotensive initially with systolic blood pressure in the 70s-80s ; however , with aggressive fluid resuscitation , his blood pressure came up and was recorded as 98/52 on admission .
no significant tenderness , guarding or rigidity was elicited in the right upper quadrant of abdomen .
initial laboratory testing revealed a wbc count of 36.61000 with bands of 7% ; creatinine was 2.1 , bun 54 , ast 84 , alt 51 , alkaline phosphatase 182 , total bilirubin 2.5 , direct bilirubin 1.3 , albumin 1.7 , total protein 5.5 , pt 15.1 , ptt 38 , and inr 1.5 .
patient was started on empiric intravenous antibiotics with ampicillin - sulbactam , and blood and urine cultures were sent .
in view of his complaint of intermittent right - sided sub costal pain and a negative chest x - ray , abdominal ultrasound was obtained .
interestingly , the ultrasound revealed heterogenous liver masses and associated partial main portal vein thrombosis . to further characterize these findings ,
the ct scan showed multiple low - density liver lesions with enhancing rims as well as perihepatic fluid collections suggestive of multiple hepatic abscesses .
the finding of diverticulosis raised the possibility of diverticulitis as the source of infection ; however , this could not be determined convincingly .
after consultation with the surgeon and radiologist , ct guided drain was placed in the largest hepatic abscess with a view aimed at interval follow up of the lesions . in the meantime patient 's blood culture revealed streptococcus anginosus ( 2/2 ) , susceptible to penicillins .
patient continued to do well with mild discomfort intermittently in the right subcostal/ right upper abdominal quadrant .
repeat blood cultures did not show any growth and the cultures from hepatic abscess drain showed no growth as well .
surprisingly , a repeat ct scan done 6 days after the drain was placed showed that there was overall increased size of the intraparenchymal and extrahepatic abscesses .
the sigmoid colon was noted to be completely adherent to the bladder with extensive fibrolytic area .
the patient underwent sigmoid resection with primary anastomosis , repair of the colovesical fistula , enterolysis , and drainage of multiple intraabdominal abscesses .
ct scan of the abdomen showing multiple liver abscesses patient 's postoperative course was unremarkable .
he showed gradual recovery . a repeat ct scan of the abdomen and pelvis done 6 days post surgery showed improvement in liver lesions .
patient was discharged home on hospital day 24 to complete a total 4-week course of amoxicillin - clavulanate . a follow - up
ct scan done about 3 months later did not show any intra - abdominal or hepatic abscess .
smg has been known by a variety of names , and in the past has been regarded as a single species that is loosely synonymous with streptococcus anginosus .
the organisms are regularly encountered in clinical specimens and typically produce small colonies on culture with variable hemolytic properties and variable carriage of lancefield group antigens including f , c , g , and a. because many phenotypic tests for the characterization of these species yield similar result , identification of isolates can be difficult .
s. anginosus and s. constellatus both belong to lancefiled group f , but s. constellatus is  hemolytic while s. anginosus is non - hemolytic.s .
whitley et al . was the first group to differentiate the smg species through a biochemical scheme .
they found that s intermedius produce -glucosidase , -glucodidase , -d fucosidase , -n - acetylgalactosaminadase , -n - acetyglucosaminadase , and sialadase with 4 methylumbelliferl linked fluorogenic subsilates .
although biochemical evaluation first enabled smg isolates into 3 species , smg can now be distinguished through pcr amplified 16 s r rna gene sequences followed by species - specific hybridization probes .
members of the smg group are part of the normal flora of human mucous membranes and are infrequent pathogens . however , these organisms are frequently isolated from purulent infections of the mouth and internal organs including brain , liver , lungs , and spleen and from cases of appendicitis , peritonitis , endocarditis , meningitis , and infections of the skin and soft tissue .
smg bacteria are usually opportunistic in nature with some reports suggesting its association with patients having multiple co morbid illness , neoplasm , and diabetes .
smg as a causative organism in hepatic abscess have been reported in the literature.[811 ] in a study evaluating 29 cases of bactericidal with smg in north yorkshire hepatic abscess was found to be the source in 14% of the cases . in a prospective study , s. milleri was associated with 51% cases of hepatic abscess , the species isolated were s. intermedus and s. constellatus .
biliary stone disease , obstructive malignancy affecting the biliary tree , stricture , and congenital diseases are common inciting conditions .
liver abscess may also develop from hematogenous dissemination of organisms in association with systemic bacteremia such as endocarditis and pyelonephritis .
local spread of bacteria can also occur from contiguous sites of infection within the peritoneal cavity .
infections in the portal bed can result in a localized septic thrombophlebitis , which can lead to liver abscess .
previously , rupture of appendicitis with subsequent spread via portal system was the most common pathway to progress to liver abscess .
however , with advanced surgical management and antibiotics , this is less frequently seen nowadays .
although intra - abdominal infection is a potential source of hepatic abscess , there are only some cases listing sigmoid diverticulitis as the source for liver abscess . in our case ,
the patient was an elderly male with hypertension , arthritis , benign prostatic hypertrophy , and osteoarthritis .
there has been no particular link between any of these conditions to streptococcus anginosus or smg , however , presence of multiple medical problems predisposes to infection with this group of organisms .
the patient had bacteremia with s. anginosus ; the primary source of the infection was sigmoid diverticulitis which was spread hematogenously as well as contiguously , resulting in multiple intra - abdominal abscess and hepatic abscess .
the patient had a satisfactory recovery on oral antibiotics after undergoing sigmoid resection and removal of the source .
in conclusion , bacteremia with s. milleri ( s. intermedius , s. constellatus , and s. anginosus ) should alert the clinicians for abscess as a potential source of infection .
intraabdominal sources of infection should be looked for in the absence of any obvious source .
it is important to be aware of diverticulitis as a possible cause of liver abscess .
progression of intra - abdominal abscess despite drainage of hepatic abscess and institution of broad - spectrum antibiotics should raise the suspicion of diverticular source as the possible source of infection .
pyogenic liver abscess secondary to dissemination from sigmoid diverticulitis is rare . 
 streptococcus anginosus has been linked to abscesses but has been rarely reported from a sigmoid diverticulitis source . 
 we report a case of liver abscess in which the source was confounding but eventually was traced to sigmoid diverticulitis on laparotomy .