Candida parapsilosis bloodstream infections in neonatal intensive care unit patients: epidemiologic and laboratory confirmation of a common source outbreak.

BACKGROUND: Candida parapsilosis is a common cause of sporadic and epidemic infections in neonatal intensive care units (NICUs). When a cluster of C. parapsilosis bloodstream infections occurred in NICU patients in a hospital in Louisiana, it provided us with the opportunity to conduct an epidemiologic investigation and to apply newly developed molecular typing techniques. METHODS: A case-patient was defined as any NICU patient at Louisiana State University Medical Center, University Hospital, with a blood culture positive for C. parapsilosis during July 20 to 27, 1991. To identify risk factors for C. parapsilosis bloodstream infection, a cohort study of all NICU infants admitted during July 17 to 27, 1991, was performed. Electrophoretic karyotyping was used to assess the relatedness of C. parapsilosis isolates. RESULTS: The receipt of liquid glycerin given as a suppository was identified as a risk factor (relative risk, 31.2; 95% confidence intervals, 4.3 to 226.8). Glycerin was supplied to the NICU in a 16-oz multidose bottle. Bottles used at the time of the outbreak were not available for culture. All six available isolates from four case-patients had identical chromosomal banding patterns; six University Hospital non-outbreak isolates had different banding patterns. CONCLUSIONS: This study demonstrates the utility of combined epidemiologic and laboratory techniques in identifying a novel common source for a C. parapsilosis bloodstream infection outbreak and illustrates that extreme caution should be exercised when using multidose medications in more than one patient.

Mucormycosis caused by Rhizopus microsporus var. microsporus: cellulitis in the leg of a diabetic patient cured by amputation.

Mucormycosis accompanied the development of bacterial infection in the leg of a diabetic African-American man. Local injury, diabetic ketoacidosis, renal insufficiency, and antimicrobial therapy were factors that contributed to the pathogenesis of the mucormycosis. The cellulitis was caused in part by Rhizopus microsporus var. microsporus and was cured by amputation. We report this unusual case of mucormycosis to emphasize the value of fungal identification, to illustrate a dramatic and successful clinical result, and to draw attention to an apparent role for bacterial infection and its treatment in the pathogenesis of mucormycosis. It is the third case report of mucormycosis in a human in which R. microsporus var. microsporus was definitively identified as the etiologic agent.

Nosocomial Malassezia pachydermatis bloodstream infections in a neonatal intensive care unit.

Malassezia pachydermatis, a lipophilic yeast, has been described to cause sporadic nosocomial bloodstream infections (BSI). Nosocomial outbreaks of M. pachydermatis BSI have never been described. A cluster of M. pachydermatis BSIs in the neonatal intensive care unit at Louisiana State University Medical Center, University Hospital provided the opportunity to investigate the epidemiology of this organism and apply molecular epidemiologic typing techniques. A case-patient was defined as any neonatal intensive care unit patient in University Hospital with a blood culture positive for M. pachydermatis from January 1, 1989, through August 15, 1991. Five patients met the case definition. Case-patients were premature as estimated by gestational age and required prolonged hospitalization. Case-patients received parenteral nutrition and intravenous lipids for twice as many days as randomly selected controls. No environmental source of M. pachydermatis was identified; however, infants on each side of a previously identified M. pachydermatis-colonized infant became colonized with M. pachydermatis during a 20-day period. Chromosomal analysis of five M. pachydermatis blood isolates from two case-patients had identical banding patterns. These data show that M. pachydermatis can cause nosocomial BSI outbreaks, that premature infants receiving parenteral nutrition and/or lipids may be at greatest risk and that transmission is most likely from person to person, probably via the hands of medical personnel.

Mycobacterium chelonae causing otitis media in an ear-nose-and-throat practice.

Seventeen cases of otitis media caused by Mycobacterium chelonae were detected among patients seen at a single ear-nose-and-throat (ENT) office (Office A) in Louisiana between May 5 and September 15, 1987. All the patients had a tympanotomy tube or tubes in place or had one or more tympanic-membrane perforations, with chronic otorrhea that was unresponsive to standard therapy with antimicrobial agents. Middle-ear exploration in six patients revealed abundant granulation tissue; multiple granulomas and acid-fast bacilli were demonstrated on a section of tissue from one patient with a nonhealing mastoidectomy incision. Thirteen of the 14 ear isolates obtained from patients seen in Office A had the same unusual pattern of high-level resistance to aminoglycosides. M. chelonae and other nontuberculous mycobacteria were recovered from several sources of water in Office A, as well as in another ENT office (Office B) in a neighboring city that was visited by the index patient. Only one additional case was detected in Office B during the same period. Otologic instruments in Office A were cleaned in an ultrasonic bath with tap water and a liquid detergent; the contents of the bath were changed only once weekly. Instruments in Office B were placed in boiling water between patient examinations. This outbreak establishes M. chelonae as an agent of otitis media and underscores the need for high-level disinfection or sterilization of ENT instruments between examinations to prevent the transmission of this organism to patients in the office setting.

Nosocomial invasive Saksenaea vasiformis infection.

Saksenaea vasiformis is a zygomycete fungus found in soils worldwide; however, it is rarely documented as a cause of human disease. We describe what, to our knowledge, is the first nosocomial infection caused by S. vasiformis and the first documentation that this organism exists in Louisiana. The infection developed at an arterial catheter site in an otherwise healthy young man treated with high-dose corticosteroids and antibiotics for serious head trauma and caused a "cheesy" yellow necrosis of skin, muscle, tendon, and fascia. Resolution of the process occurred following removal of the arterial catheter and without antifungal therapy. The organism was isolated from deep surgical specimens on routine media but did not produce its characteristic sporangia until grown on Czapek's solution agar. It is recommended that zygomycete isolates not identifiable by routine procedures be grown on media that permit Saksenaea to sporulate.

Pityrosporum isolate from the upper respiratory tract.

A 49-year-old white man experienced maxillary sinus osteitis after removal of a portion of the maxilla containing root tips from a previous molar tooth extraction. After the patient had received long-term antibiotic therapy for that infection, a yeast-like organism was observed on smears from the patient's left nasal passage and its surgically enlarged communication with the maxillary sinus. The fungus has appeared on all subsequent smears, but early attempts to culture the organism were unsuccessful. A lipophilic yeast-like fungus, morphologically similar to the organisms seen on the direct smears and consistent with the genus Pityrosporum, was isolated in culture at this facility. Electron microscopy of the organism revealed cellular morphologic features believed to be unique to the Pityrosporum genus, thereby confirming the identity of the isolate as a member of that genus.