continuous ambulatory peritoneal dialysis ( capd ) is an important treatment option for patients with end - stage renal disease .
although the rate of peritonitis has declined in recent years because of improvements in capd techniques , peritonitis remains the leading cause for discontinuation of capd .
rothia muciliaginosa ( r. mucilaginosa ) is a component of the normal flora of the mouth and respiratory tract and is usually associated with dental plaques , cavities , and periodontal diseases .
it appears that the presence of an indwelling vascular catheter and previous treatment with ciprofloxacin increase the risk of invasive infection with rothia 
 .
although cases of peritoneal dialysis ( pd)-associated peritonitis caused by r. mucilaginosa have been reported worldwide , no korean cases have been reported . to the best of our knowledge ,
this is the first case report of peritonitis due to r. mucilaginosa as a single pathogen in korea .
herein , we describe a case of pd - associated peritonitis caused by r. mucilaginosa that was cured after a 2-week course of intraperitoneal antibiotic therapy .
a 58-year - old korean man , who had been treated with capd for 3 years , was admitted to our hospital because of turbid peritoneal effluent accompanied by constant abdominal pain that began 1 day before his admission .
the underlying causes of his end - stage renal disease were diabetes mellitus and hypertension .
he exchanged dialysis solutions of 2 l per dwell 4 times / d , with the solution remaining in the abdomen for 6 hours and had a urine output of about 200  ml / d . on admission ,
his blood pressure was 120/80  mmhg , heart rate was 72 beats / min , respiratory rate was 18 breaths / min , and body temperature was 37.4c .
his abdomen was diffusely tender with normal bowel sounds , and infection was not found around the catheter exit site .
the laboratory findings showed pd - associated peritonitis : the white blood cell ( wbc ) count of the peritoneal effluent was 1,620/mm with a neutrophil predominance ( 90% ) .
his hemoglobin was 9.9  g / dl , wbc count was 14.510/l , and c - reactive protein was 12.53  mg / dl ( normal : < 0.8  mg / dl ) .
after the peritoneal fluid was sent for bacterial culture , a single 1  g / d dose of cefazolin and a single 1  g / d dose of ceftazidime were given intraperitoneally .
two peritoneal fluid samples were inoculated into a bactec plus aerobic / f culture bottle ( becton dickinson diagnostic instrument system , drogheda , ireland ) and incubated in a bact / alert 3d blood culture system ( biomerieux , marcy l`etoile , france ) .
culture of the peritoneal dialysate revealed streptococcus mitis , which was susceptible to levofloxacin , clindamycin , vancomycin , and tetracycline .
the peritoneal wbc count decreased to 30/mm , and the patients clinical condition improved on the 5 day after starting intraperitoneal cefazolin and ceftazidime .
however , he complained of abdominal pain and turbid peritoneal effluent 3 days after termination of intraperitoneal antibiotics .
the wbc count of the peritoneal effluents was 2,140/mm with a neutrophil predominance ( 80% ) .
we restarted intraperitoneal cefazolin and ceftazidime , and repeated culture of the peritoneal dialysate revealed s. mitis . according to the international society for peritoneal dialysis guidelines , we recommended removal of the pd catheter , but he refused our recommendation .
therefore , we maintained intraperitoneal antibiotics , and the patient improved after intraperitoneal antibiotics for 2 weeks ; however , the patient experienced turbid peritoneal effluent 10 days after cessation of the second round of intraperitoneal antibiotics .
the wbc count of the peritoneal effluents was 2,080/mm with a neutrophil predominance ( 85% ) , and repeated culture of the peritoneal dialysate revealed r. mucilaginosa .
the peritoneal wbc count decreased to 8/mm , and abdominal pain disappeared on the 3 day after starting intraperitoneal cefazolin and ceftazidime .
the patients condition improved , and he was discharged after a 2-week course of intraperitoneal antibiotics ( fig .
x - ray showed a poorly defined , surface - based lesion arising from the proximal shaft of the left clavicle .
computed tomography scan revealed osteolytic bony destruction and soft tissue mass formation suggesting a malignant bone tumor , such as a chondrosarcoma or osteogenic sarcoma with pathologic fracture in the proximal portion of the left clavicle ( fig .
pd - associated peritonitis caused by r. mucilaginosa is rare , and this coccus has not been reported as the single causative pathogen of pd - associated peritonitis in korea . here , we report a case of peritonitis due to r. mucilaginosa that recovered after intraperitoneal antibiotic therapy . a malignant bone tumor on the left clavicle was coincidentally found .
r. mucilaginosa is a gram - positive , coagulase - negative , encapsulated , non  spore - forming coccus considered part of the commensal flora of the oral cavity and upper respiratory tract in humans .
r. mucilaginosa appears to be an opportunistic pathogen in immunocompromised patients and has been implicated in serious infections such as septicemia , endocarditis , meningitis , pneumonia , and osteomyelitis .
although cases of pd - associated peritonitis caused by r. mucilaginosa have been reported previously , there are no prior reports in korea . to the best of our knowledge ,
this is the first case report of pd - associated peritonitis due to r. mucilaginosa in korea .
the most common risk factors for rothia infection are indwelling catheter , leukemia , cancer , cardiac valvular heart disease , intravenous drug abuse , severe neutropenia , and previous treatment with ciprofloxacin .
r. mucilaginosa is usually associated with the formation of dental plaque and tooth cavities . in our case
, the patient did not have any recent history of dental work ; however , he had a history of treatment with ciprofloxacin 2 months earlier and had a malignant bone tumor on the left clavicle . therefore , this patient was at high risk for pd - associated peritonitis related to atypical organisms such as rothia .
recommendations for treatment of r. mucilaginosa - induced peritonitis were not included in the international society for peritoneal dialysis guidelines .
however , based on previous literature , all patients with pd - associated peritonitis caused by r. mucilaginosa recovered after intraperitoneal antibiotic therapy including ampicillin , rifampin , vancomycin , and cefazolin .
it was reported that a patient with human immunodeficiency virus was successfully treated with intraperitoneal vancomycin .
another patient who had recently lost a renal allograft and was still on immunosuppressive therapy developed coagulase - negative staphylococcal bacteremia and culture - negative peritonitis treated with ceftriaxone and ofloxacin with removal of pd catheter .
two months later , she was back on pd and had another episode of peritonitis , which grew r. mucilaginosa .
it responded well to intraperitoneal vancomycin with resolution of symptoms in 2 days . in our case
, we did not perform an antibiotic sensitivity test because of the absence of clinical laboratory standard institute guidelines for this organism .
such antibiotics could be helpful to treat r. mucilaginosa - induced peritonitis if sensitivity test results are not available . in summary
, we report a case of pd - associated peritonitis caused by r. mucilaginosa that was cured after a 2-week course of intraperitoneal antibiotic therapy .
intraperitoneal antibiotics should therefore be considered as treatment for pd - associated peritonitis caused by r. mucilaginosa .
 rothia muciliaginosa ( r. mucilaginosa ) is a facultative , gram - positive coccus that is considered to be part of the normal flora of the mouth and respiratory tract . 
 there are sporadic reports of the organism causing endocarditis in patients with heart valve abnormalities , as well as meningitis , septicemia , and pneumonia associated with intravenous drug abuse . 
 however , it is an unusual pathogen in cases of peritoneal dialysis ( pd)-associated peritonitis . 
 although r. mucilaginosa is generally susceptible to penicillin , ampicillin , cefotaxime , imipenem , rifampicin , and glycopeptides , there are no guidelines for the treatment of pd - associated peritonitis . herein , we report a case of pd - associated peritonitis due to r. mucilaginosa that was resolved with intraperitoneal antibiotic treatment . 
Introduction
Case report
Discussion
Conflicts of interest