traditionally , the neisseria species has two potential pathogenic strains ; neisseria meningitidis and neisseria gonorrhoeae . the remainder of neisseria species , including neisseria mucosa , are considered normal flora colonizing the respiratory tract , living in symbiosis . one analysis showed that the majority of people are colonized by one to two of these neisseria species . specifically , neisseria mucosa is increasingly found to cause a multitude of diseases , in particular peritonitis . part of the difficulty in associating disease with other species of neisseria , such as neisseria mucosa , is the fact that they do not contain the typical virulence factors . the established pathogens neisseria meningitidis and neisseria gonorrhoeae derive much of their virulence from attaching to mucosal surfaces . however , the lack of these virulence factors does not necessarily make the other neisseria species benign . the advent of chronic ambulatory peritoneal dialysis ( capd ) has permitted significant patient autonomy with the concomitant risk of bacterial peritonitis . the typical culprits are gram - positive species , such as staphylococcus species and streptococcus species . we performed a pubmed literature search using the terms neisseria mucosa , peritonitis , and chronic ambulatory peritoneal dialysis . this yielded very few published cases of capd patients afflicted by neisseria mucosa peritonitis . in this clinical vignette , we add another case of capd associated with neisseria mucosa peritonitis . the patient was a 28 year - old hispanic man with a history of end stage renal disease due to hypertensive disease since the age of 10 years , complicated by malignant hypertension . his surgical history was remarkable for a remotely failed renal transplant requiring an allograft nephrectomy . he had been on hemodialysis for about a decade since , and transitioned to peritoneal dialysis just six months prior to presenting to our facility with sepsis due to new - onset peritonitis . in the outpatient clinic , the patient had been diagnosed with external cheek cellulitis that responded to a short course of empiric cephalexin . he overcame this only to experience three days of abdominal pain near his dialysis catheter . the pain was constant and severe pain , worsened by draining and filling during dialysis sessions . he denied any fevers , chills , nausea , vomiting , diarrhea , oropharyngeal and genitourinary complaints or decrease in recent ultrafiltration . exam was remarkable for a blood pressure of 167/99 mmhg , heart rate of 107 beats per minute and abdominal tenderness to palpation diffusely with the catheter exit site clear dry and intact without exudate or erythema . he quickly underwent peritoneal fluid examination , revealing an absolute neutrophil count of 14,458 cells / mm , confirming the diagnosis of bacterial peritonitis . his gram stain revealed gram - negative diplococci and subsequent chocolate agar plated cultures grew neisseria species , not gonorrhoeae or meningitidis . further biochemical speciation ( via rapid nh system by remel , thermo fisher scientific inc . , waltham , usa ) showed neisseria mucosa to be the etiology of the patient s bacterial peritonitis . given this is typically nonpathogenic , further susceptibility was not performed . the patient was placed on empiric intraperitoneal vancomycin 1 gram and cefepime 1 gram therapy and later transitioned to oral ciprofloxacin 500 mg daily for two weeks . during the hospitalization , the likely source of neisseria mucosa contamination of the dialysis port was the oral cellulitis . the transmission from the oral site to catheter site is supported by the well - known colonization of the oropharyngeal tract . capd seems to be associated with an increased risk for neisseria mucosa , particularly in cases of peritonitis . in general , this case adds to the current literature highlighting the importance of considering all types of disease caused by traditionally - benign neisseria mucosa species . although , nongonococcal and nonmeningococcal neisseria strains are usually benign and infections are rare , they may cause a variety of disease . this case highlights the danger of neisseria mucosa peritonitis in patients undergoing capd , and is the fourth reported case . the rarity of case reports and lack of the established pathogenic factors of nongonococcal and nonmeningococcal neisseria may limit recognition of these infections . this makes the association with clinical disease complex , and further investigation regarding their pathogenicity is warranted . in previously described case reports of nongonococcal and nonmeningococcal neisseria , our patient was also successfully treated with ciprofloxacin . given the increasing frequency of infections by nongonococcal and nonmeningococcal neisseria , guidelines regarding appropriate antimicrobial therapy should be established . further case reports should also establish the safety of preserving the peritoneal dialysis catheters , as in our patient s case .