Chryseobacterium meningosepticum infections in a dialysis unit.

BACKGROUND: Chryseobacterium species are Gram-negative bacteria with an unusual antibiotic profile. Chryseobacterium meningosepticum is the species most commonly encountered as a human pathogen. OBJECTIVES: To study the microbiological, clinical and therapeutic features of C. meningosepticum infections in patients on dialysis, at Sri Jayewardenepura General Hospital (Teaching) (SJGH), and to trace the source of infections. DESIGN: A retrospective descriptive study. SETTING: Dialysis unit of SJGH. PATIENT: population Patients who underwent long term haemodialysis (HD) and manual intermittent peritoneal dialysis (IPD) in the dialysis unit. METHODS: Clinical and microbiological records of patients with C. meningosepticum infections over a period of 2 years were reviewed retrospectively. Environmental screening was carried out to detect a possible source of infection. RESULTS: Thirty five episodes of infection due to C. meningosepticum in 33 patients on HD and IPD were detected. There were 30 episodes of peritonitis, four of bacteraemia and one of asymptomatic colonization of a PD catheter. Isolates were resistant to aminoglycosides, chephalosporins and aztreonam, and sensitive to cotrimoxazole, vancomycin and rifampicin. They showed variable sensitivity to imipenem and ciprofloxacin. All except one patient had a favourable outcome. C. meningosepticum was cultured from a sink in the dialysis unit, but the original source of the organism was not known. CONCLUSION: C. meningosepticum could be an important pathogen in a dialysis unit, and fluoroquinolones and vancomycin are effective as empiric therapy.

Microbiological aspects of peritonitis in patients undergoing chronic peritoneal dialysis at the dialysis unit of Sri Jayawardenapura General Hospital.

BACKGROUND: Peritoneal dialysis (PD) is an established form of therapy in the management of end stage renal disease. Peritonitis is the main complication of PD. OBJECTIVES: To study the incidence and microbial aetiology of peritonitis in patients undergoing chronic PD at the dialysis unit of Sri Jayewardenapura General Hospital (SJGH); to assess the diagnostic value of the Gram's stain; and to study the relationship of the total white cell count of effluent to peritonitis. DESIGN: A prospective study over three months. SETTING: Dialysis unit of SJGH. PATIENT POPULATION: The study involved 18 patients undergoing manual intermittent peritoneal dialysis (IPD), 4 patients undergoing chronic ambulatory peritoneal dialysis (CAPD), and 1 patient undergoing nocturnal intermittent peritoneal dialysis (NIPD). MEASUREMENTS: Clinical presentation of patients with peritonitis; total and differential white blood cell counts of effluent samples; Gram stain and culture of the centrifuged deposit to determine microbial aetiology; incidence of peritonitis in different categories of dialysis. RESULTS: 32 samples were examined from patients on IPD, and 17 from patients on CAPD. In IPD most episodes were due to Gram negative organisms whereas in CAPD most episodes were due to Gram positive organisms. Sensitivity of Gram's stain in relation to culture was 32.4%. 98% of effluent samples had white blood cell counts of > 100/ml and none showed neutrophil counts of < 49%. CONCLUSIONS: The incidence of IPD associated peritonitis was 11.1 episodes per patient year, and the incidence of CAPD associated peritonitis was 14 episodes per patient year. Flavobacterium spp. were the predominant organisms in IPD associated peritonitis, whereas CAPD associated peritonitis was commonly caused by coagulase negative staphylococci. Gram's stain was not useful in the initial identification of the causative agent, but the white cell and neutrophil counts were found to be sensitive indicators of peritonitis.

The isolation of Burkholderia cepacia in a hospital setting in Sri Lanka.

INTRODUCTION: Burkholderia cepacia is widely prevalent in nature. The natural habitat of this organism is soil, water and vegetation, but the hospital environment remains the main source of infection. It causes a wide variety of infections in hospitalised patients. Since there are no reports of its prevalence in Sri Lanka, a data retrieval and analysis was undertaken to determine its incidence among patients at Sri Jayawardenepura General Hospital (SJGH). OBJECTIVE: To determine the prevalence, morphological characteristics, biochemical profile and antibiotic susceptibility pattern of B cepacia in a Sri Lankan tertiary care hospital. METHODS: Relevant clinical data were retrieved from all isolates of B cepacia from SJGH for 12 months from October 1996. Standard procedures were used to isolate the organism from clinical specimens. API 20E was employed for biochemical identification. Antibiotic susceptibility tests was carried out using the modified Kirby Bauer method. RESULTS: B cepacia was isolated from 17 patients. 16 of them were hospitalised and were from the medical, surgical, and intensive care units. All were in a compromised state of health. The organism was isolated from a variety of specimens which included swabs of surgical wounds, chronic ulcers, sputum, bronchial lavage, endotracheal aspirate, urine, peritoneal fluid and blood. Blood agar, MacConkey agar and cystine lactose electrolyte deficient medium supported the growth of all strains. They were motile Gram negative rods. All strains were oxidase positive. Strains gave variable results with other biochemical tests. Antibiograms too were variable. All strains were sensitive to ceftazidime, and the majority of the strains were sensitive to the other third generation cephalosporines. All strains were resistant to four or more antimicrobial agents included in the study. Of the 17 patients from whom B cepacia was isolated, only 9 seem to have had actual infection; others were probably instances of colonisation or contamination. CONCLUSIONS: The present report confirms the prevalence and importance of B cepacia as a hospital pathogen in Sri Lanka. Hospital laboratories should be equipped to isolate, identify and perform antibiotic sensitivity test on these strains. Antibiotic susceptibility testing is necessary as the patterns seem to differ among strains. The multiple drug resistant nature of the organism warrants strict infection control measures to prevent spread in a hospital setting.