Healthcare workers' hands as a vehicle for the transmission of virulent strains of Candida spp.: A virulence factor approach.

BACKGROUND: Although the majority of Candida infections are thought to come from endogenous sources, the healthcare workers' (HCWs) hands are being increasingly reported as vehicles for the transmission of pathogens. The aim of the present study was to evaluate the susceptibility of yeast isolated from the HCWs' hands and ICU (Intensive Care Unit) surfaces to antifungal agents and to determine the virulence potential and the genetic similarity between the same. METHODS: The susceptibility of yeasts from the HCWs' hands (n = 57) and ICU surfaces (n = 98) to conventional antifungals (fluconazole, voriconazole, amphotericin B and micafungin) was evaluated using the broth microdilution assay accordance with CLSI M27-A3. Additionally, some virulence factors such as adhesion and biofilm capacity on abiotic surfaces and on endothelial cells were evaluated, as well as germ tube formation. The similarity among yeast isolates were evaluated by the RAPD technique using the P4, OPA18 and OPE18 primers. RESULTS: Five species of Candida were found on the HCWs' hands (C. albicans, C. parapsilosis (sensu stricto), C. glabrata, C. tropicalis and C. krusei) and two on ICU surfaces (C. albicans and C. parapsilosis (sensu stricto)). The isolates from hands had higher resistance rates, with C. glabrata having the highest indices (100% FLU; 100% MFG). The similarity of C. albicans from HCWs and ICU surfaces was ≥80% according to the three primers analyzed. Candida spp. from hands had a greater potential for adhesion and biofilm formation on abiotic surfaces (p < 0.05). C. albicans from ICU surfaces had the greatest potential of adhesion on endothelial cells after 2 and 24 h, and presented high filamentation in SEM images and formed more and larger germ tubes (p < 0.05). CONCLUSION: the present study showed the significant virulence potential of yeasts transmitted in the hospital environment for the first time. Additionally, healthy people working in the ICU can carry these yeasts, which are capable of surviving in hospital surfaces, on their hands, offering a risk to patients, especially those who are immunocompromised.

Detection of Candida species resistant to azoles in the microbiota of rheas (Rhea americana): possible implications for human and animal health.

There is growing interest in breeding rheas (Rhea americana) in Brazil. However, there are no data on the yeast microbiota of the gastrointestinal tract of this avian species, and the phenotypic characteristics of these yeasts are not known. Therefore, the aim of this work was to isolate Candida species from the digestive tract of rheas and to evaluate the in vitro antifungal susceptibility and secretion of phospholipases of the recovered isolates. For this purpose, 58 rheas from breeding operations in the cities of Fortaleza and Mossoró, north-eastern Brazil, were used. Samples were gathered from the oropharynx and cloaca of the animals using sterile swabs. Stool samples were collected from their pens by scraping with a scalpel blade. For the primary isolation, the material was seeded onto 2 % Sabouraud dextrose agar supplemented with chloramphenicol (0.5 g l(-1)). The isolates were identified based on morphological and biochemical features. After identification, all the strains were submitted to antifungal susceptibility testing for amphotericin B, itraconazole and fluconazole. The phospholipase activity of the Candida species isolates was also tested by culturing on egg yolk agar. Candida species were isolated from at least one anatomical site in 36/58 birds (14/17 juveniles and 22/41 adults) and in 6/10 faecal samples. Mostly, only a single species was isolated from each collection site (36/56 positive sites), with up to three species being observed only in four cases (4/56). A total of 77 isolates were obtained, belonging to the species Candida parapsilosis sensu lato (19), Candida albicans (18), Candida tropicalis (13), Candida guilliermondii (12), Candida krusei (10) and Candida famata (5). C. albicans was more prevalent in the oropharynx of the juvenile rheas when compared with adult ones (P<0.001). All tested isolates were susceptible to amphotericin B, but 16 isolates were simultaneously resistant to the two azole derivatives (11/18 C. albicans, 1/10 C. krusei, 2/19 C. parapsilosis sensu lato and 2/13 C. tropicalis). C. albicans presented a particularly high resistance rate to fluconazole (15/18) and itraconazole (13/18). Finally, 23/77 strains secreted phospholipases. In summary, healthy rheas carry potentially pathogenic Candida species in their gastrointestinal tract, including azole-resistant strains that secrete phospholipases, and are prone to disseminating them in the environment. Thus, breeding and handling these animals may have some implications for human and animal health.

Congenital candidiasis: confirmation of mother-neonate transmission using molecular analysis techniques.

We describe a case of congenital acquired candidiasis in a preterm female delivered through Caesarean section due to the premature rupture of the amniotic membrane. The neonate presented with suspected chorioamnionitis and erythematous desquamative skin. Candida albicans was isolated from the placenta, mouth, groin, and periumbilical lesions. The infant developed candidemia due to Candida albicans and the same yeast was also isolated from a catheter. Culture inoculated with swabs from the mouth and vagina of the mother yielded C. albicans and C. krusei. All C. albicans isolates from the mother and the neonate were visually indistinguishable by molecular typing techniques which included chromosomal karyotyping and restriction endonuclease analysis followed by pulsed-field gel electrophoresis. These findings allowed the clinical condition to be confirmed as congenital acquisition of candidiasis in this case.

[Colonization by yeasts in newborns and healthcare personnel in a neonatal intensive care unit at a university hospital in Bogotá, Colombia]. / Colonización por levaduras en recién nacidos y personal de salud en la unidad de cuidados intensivos neonatales de un hospital universitario en Bogotá, Colombia.

Candida infections in the neonatal intensive care unit (NICU) are associated with high morbidity and mortality rates. The main objective of this work was to determine the risk factors for colonization by Candida species in the newborns in a hospital NICU in Bogota, Colombia, and to evaluate the colonization of intravascular devices and healthcare personnel. Fifty newborns at high risk (low birth-weight, gestational age under 35 weeks, previous exposure to antibiotics and eight days of stay in the NICU) were followed prospectively. Clinical specimens from conjunctiva, nasal orifices, oral cavity, inguinal skin, rectum, intravascular devices, and the resulting watery solution of the washing of hands of healthcare personnel were cultured. Samples were cultured on Sabouraud agar with chloramphenicol (50 ppm). Identification of yeasts was peformed using phenotypic and biochemical tests. A multivariate analysis of the risk factors for colonization in the newborns was performed. Growth of different Candida spp. was found in samples recovered from 38% of the newborns tested. However, no yeasts were obtained in cultures from intravascular devices. About 32% of the samples from healthcare personnel (paediatricians, undergraduate and postgraduate students, professional nurses and nurse assistants), showed presence of yeasts. In the multivariate regression analysis length of stay in the NICU was the only identified risk factor for colonization.

[Candida albicans outbreak in a neonatal intensive care unit]. / Brote de candidemia por Candida albicans en neonatología.

The appearance of Candida albicans in three patients made physicians investigate an outbreak. Outbreak description and microbiologic screening: Case 1 developed C. albicans in the placenta culture and in the blood culture carried out on the 8th day of birth. Four days after this candidemia, C. albicans was recovered in a catheter tip of a second neonate (case 2) and finally five days later other newborn (case 3) developed C. albicans in the hemoculture. After that, the hands of all caregivers as well as case 3's incubator, case 1's mother, and from all nine neonates in the unit were studied with swabs. A wet mount was done to all swabs and then they were cultured in Chromagar Candida and SDA. All C. albicans were studied by RAPD. RAPD study showed that C. albicans recovered from placenta and blood cultures of case 1, the catheter tip of case 2 and the blood culture of case 3, resulted to be identical and these yeasts were related to the C. albicans from the mouth of case 1 mother and the mouth of another colonized newborn. C. albicans was not found in the others swabs. The isolations of identical C. albicans allowed to suppose the horizontal transmission from the case 1, that had acquired it congenitally. Not only isolation of unusual Candida species would be an alert. Despite patients' personal factors to justify a fungal infection, the recovery of C. albicans in a short period of time should warn physicians about the possibility of a horizontal transmission.

Candidosis en pacientes HIV o con otras inmunodeficiencias secundarias en hospitales de la ciudad de Tucumán (Argentina) / Candidosis in HIV patients or with other secondary immunodeficiencies detected in hospitals of the city of Tucumán (Argentina)

Con el objeto de conocer las especies causantes de candidosis humanas en pacientes HIV positivos o con otras inmunodeficiencias secundarias y la incidencia de especies con capacidad de resistencia a antifúngicos, se estudiaron 76 aislamientos de Candida procedentes de 61 casos de candidosis superficiales y profundas de niños y adultos. Obtenidas desde piel, anexos, mucosas, abscesos, catéteres y secreciones diversas, entre otras. La identificación de las especies fue realizada por estudios de características morfológicas, cromogénicas y bioquímicas (CHROMagar , Candifast, API 20 y API 32). Los resultados revelan predominio de especies noalbicans (52.7 por ciento), obteniéndose las siguientes frecuencias de aislamientos: C.albicans (47,3 por ciento), C. parapsilosis: 15,8 por ciento, C. glabrata: 13,2 por ciento, C. krusei: 11,8 por ciento, C. tropicalis: 10,6 por ciento y C. dubliniensis: 1,3 por ciento. Algunas de ellas pueden presentar resistencia primaria o secundaria a algunos antifúngicos de uso habitual, por lo cual es necesario incluir estudios de sensibilidad a estos, para una mejor conducta terapéutica.

In order to find out species causing human candidosis in positive HIV patients or in individuals suffering from other secondary immunodeficiencies and the incidence of species bearing a resistance ability to antifungal agents, 76 Candida isolations obtained from 61 cases of superficial and deep candidosis in children and adults were studied. Samples were collected from skin, annexa, mucosities, abscesses, catheters and diverse secretions, among others. The identification of species was carried out through studies on morphological, chromogenic and biochemical characteristics (CHROMagar, Candifast, API 20 and API 32). Results reveal a predominance of non-albican species (52,7 percent), and the following frequencies of isolation: C.albicans (47.3 percent), C. parapsilosis: 15.8 percent, C.glabrata: 13.2 percent, C. krusei: 11.8 percent, C. tropicalis: 10.6 percent and C. dubliniensis: 1.3 percent. Some of them may exhibit some primary or secondary resistance to certain antifungal agents of common use, this is why it is necessary to include studies on sensitivity of them so as to attain a better therapeutical behaviour.

Candida isolated from vaginal mucosa of mothers and oral mucosa of neonates: occurrence and biotypes concordance.

BACKGROUND: The common occurrence of Candida spp. on the vaginal mucosa of pregnant women suggests this as the source of neonatal candidiasis. METHODS: This study investigated the occurrence of yeasts on the vaginal mucosa of 100 mothers at the time of birth, and on the oral mucosa of their respective neonates, all full-term, on the 1st, 3rd, and 9th days after birth by vaginal (72 cases) and cesarean (28 cases) routes. In each case where concordance at the level of species was found between the isolate from the mother and that from the neonate, tests were made to check for concordance between the genotypic and phenotypic profiles (susceptibility to killer toxins, serotyping, proteinase and phospholipase production, and susceptibility to antifungal agents). RESULTS: For the vaginal-route group, yeasts were recovered from the vaginal mucosa of 47.2% of the mothers and from 25% of the neonates. For the cesarean-route group, these rates were 46.4% and 3.6%, respectively. Species found most frequently in the samples from the mothers and the neonates were, respectively C. albicans and C. guilliermondii. For the vaginal-route group, the rate of mother/neonate concordance at the level of species was 23.5% and no cases of concordance for the cesarean births. Of these cases with species concordance, there was concordance between the genotypic and phenotypic profiles in 6% (2 cases). CONCLUSION: The vaginal mucosa was not the main route of transmission of the Candida species to the neonate, because there was concordance between the genotypic and phenotypic profiles in only 6% (2 cases).

[Endemic tendencies and bacterial resistance markers in third-level hospitals in Bogotá, Colombia]. / Canales endémicos y marcadores de resistencia bacteriana, en instituciones de tercer nivel de Bogota, Colombia.

OBJECTIVE: Determining antimicrobial resistance profiles and endemic channels in 14 third-level hospitals. METHODS: A high complexity hospital network was created between 2001 and 2003 in Bogotá, Colombia, comprising 14 hospitals belonging to the Bogotá Bacterial Resistance Control Group (BBRCG) and a database was established from participating institutions' microbiology laboratory data (using automated and manual methods) using BacLink 2.0 and Whonet 5.3. Isolate susceptibility profiles were determined according to NCCLS (2003). A descriptive analysis was made of the different resistance markers and such resistance's endemic channel was determined for all hospitals using a 25% to 75% range for every month during the study period. RESULTS: 84,664 isolates were analysed, the most frequently found being Escherichia coli, Staphylococcus aureus, coagulase negative Staphylococcus, Klebsiella pneumoniae and Pseudomonas aeruginosa. S. aureus resistance to oxacillin in 2001, 2002 and 2003 was 41%, 48% and 48%, respectively, Staphylococcus coagulasa negative resistance to oxacillin 75%, 73% and 72%, E. faecium resistance to vancomycin was 14%, 9%, 3%, K. pneumoniae resistance to third-generation cephalosporins 37%, 25% and 23%, P. aeruginosa resistance to imipenem 24%, 22% and 17%, P. aeruginosa resistance to ciprofloxacin 46%, 46% and 35% and A. baumannii resistance to imipenem 11%, 29% and 39%, respectively. The problem of bacterial resistance became evident in the endemic channels; this was centred on the presence of oxacillin-resistant S. aureus and a marked increase in A. baumanni resistance to imipenem. CONCLUSIONS: High resistance levels were observed in epidemiologic impact markers, especially in Intensive Care Units.

Canales Endémicos y Marcadores de Resistencia Bacteriana, en Instituciones de Tercer nivel de Bogota, Colombia / Endemic channels and bacterial resistance markers in third-level hospitals in Bogotá, Colombia

Objetivo: Determinar los perfiles de resistencia bacteriana y los canales endémicos en 14 instituciones de tercer nivel. Métodos: Población. Bogotá-Colombia, 14 hospitales pertenecientes al Grupo para el Control de la Resistencia Bacteriana de Bogotá (GREBO). A partir de la información obtenida de los laboratorios de microbiología de los centros participantes (métodos automatizados y manuales), se creó una base de datos usando los programas BacLink 2.0 y Whonet 5.3, durante los años 2001, 2002 y 2003. Los perfiles de susceptibilidad fueron hallados acordes a las normas de la nCCLS (2003). Se realizó un análisis descriptivo de los diferentes marcadores de resistencia y se determinó el canal endémico de la resistencia para los hospitales, utilizando los puntos entre los percentiles 25 y 75 por ciento, para cada mes durante el periodo de estudio. Resultados: Se analizaron 84664 aislamientos. Los más frecuentes fueron Escherichia coli, Staphylococcus aureus, Staphylococcus coagulasa negativo, Klebsiella pneumoniae y Pseudomonas aeruginosa. La resistencia para los años 2001, 2002 y 2003 fue respectivamente: S. aureus meticilino resistente: 41 por ciento, 48 por ciento, 48 por ciento; Staphylococcus coagulasa negativo resistente a oxacilina: 75 por ciento, 73 por ciento, 72 por ciento; E. faecium vancomicina resistente: 14 por ciento, 9 por ciento, 3 por ciento; K. pneumoniae resistente a cefalosporinas de tercera generación: 37 por ciento, 25 por ciento, 23 por ciento; P. aeruginosa resistente a imipenem: 24 por ciento, 22 por ciento, 17 por ciento; P. aeruginosa resistente a ciprofloxacina: 46 por ciento, 46 por ciento, 35 por ciento, A. baumannii resistente a imipenem: 11 por ciento, 29 por ciento, 39 por ciento. Los canales endémicos evidenciaron la problemática de la resistencia bacteriana, esta se centró en la presencia de S. aureus meticilino resistente y en el marcado incremento de la resistencia de A. baumanni a imipenem. Conclusiones: Se destacan los altos porcentajes de resistencia para todos los marcadores de impacto epidemiológico a nivel hospitalario especialmente en Unidades de Cuidado Intensivo.

Neonatal candidiasis in Venezuela: clinical and epidemiological aspects.

A prospective study of the clinical and epidemiological aspects of Candida spp. sepsis was performed to assess the frequency, etiology, and risk factors in the neonatology service of the Pediatrics Hospital "Dr. Elías Toro" (2002-2003). Forty four out of 128 neonatal intensive care patients, with clinical sepsis and suspected fungal etiology, were chosen randomly for this study. Infant blood, urine, gastrointestinal tract, oral and skin samples were cultured. Samples were also taken from health care worker hands and the environment. The antifungal susceptibility patterns of the isolates were evaluated. The prevalence of Candida spp. from the clinical samples was: C. albicans (72.06%), C. parapsilosis (13.24%), C. tropicalis (10.29 %), C. guilliermondii (2.94%), and C. glabrata (1.47%). Due to the similarity of the susceptibility pattern of some isolates from infants and health care workers, we speculate a horizontal nosocomial infection. Statistical analysis revealed the following significant risk factors associated with Candida spp. isolation: prolonged hospitalization (p < 0.05), missing prenatal birth control (p < 0.05), and parenteral nutrition (p < 0.05). Blood cultures were all negative for bacteria and only 2.90% were positive for Candida spp. All 44 neonates receiving empirical therapy with amphotericin B (0.5-1.0 mg/k/day) evolved satisfactorily.

Influence of the hospital environment on yeast colonization in nursing students.

Fungemias have increased in recent decades, with high indices of morbidity and mortality. The agents of fungal infection isolated most often are yeasts, which can be acquired by direct contact with already colonized individuals. The present study aimed to detect yeast colonization in nursing students, and to study the possible influence of the hospital environment on colonization. The nasal cavities and hands of 22 students were sampled before and after a 62-day hospital training period. The yeast colonies that developed were identified using standard techniques. In total, 47 yeast samples were isolated, which were part of the normal flora of 15 (68%) students. Candida albicans was the species isolated most often (P < 0.05), comprising 59.6% of all isolates. The hospital environment affected colonization, as following the training period there was a significant increase in the number of microorganisms isolated, and also replacement of less virulent species by C. albicans. Our results are important because hospital infections of fungal origin are emerging today, and cross-transmission appears to be an important factor. In this situation, prophylactic measures are necessary to control the nosocomial microbial flora and thus reduce the incidence of hospital infections.

Transmisión nosocomial de Candida albicans en recién nacidos / Nosocomial transmission of Candida albicans in newborn infants

Candida spp. colonization in neonates occurs due to vertical or horizontal transmission. Preliminary studies determined that Candida albicans is the principal agent of these infections. In order to establish nosocomial transmission, 26 Candida albicans strains isolated from patients with candidosis hospitalized during a 18-month period in 2 neonatal intensive care units (NICU) from a pediatric hospital were studied. Fourteen isolates from patients and health care workers, involved in possible outbreaks of an intensive care unit (UCI) and a NICU from another pediatric hospital were also studied. All Candida albicans strains were genotyped by Southern blot hybridization with 27A. Isolates for outbreak confirmation were also hybridized with another specific Candida albicans probe, Ca3. Hybridization patterns demonstrated horizontal transmission in all the units studied. In a NICU, transmission among 4 patients during a 10-month period could be established and in the other NICU, 3 cases of transmission among 2 patients each were demonstrated in periods of 2 to 20 days. The outbreak studies showed the same strain isolated from 2 nurses and from one patient at the NICU and at the ICU identical strains were found in 3 patients. In this study, hybridization with Ca3 in addition to 27A probe did not increase discrimination power among isolates. Genotypic analysis allows, not only, determination of transmission and persistence of strains during prolonged periods or in sporadic outbreaks, but also facilitates necessary epidemiological decisions for optimizing nosocomial fungal infection control measures.

Transmisión nosocomial de Candida albicans en recién nacidos / Nosocomial transmission of Candida albicans in newborn infants

Candida spp. colonization in neonates occurs due to vertical or horizontal transmission. Preliminary studies determined that Candida albicans is the principal agent of these infections. In order to establish nosocomial transmission, 26 Candida albicans strains isolated from patients with candidosis hospitalized during a 18-month period in 2 neonatal intensive care units (NICU) from a pediatric hospital were studied. Fourteen isolates from patients and health care workers, involved in possible outbreaks of an intensive care unit (UCI) and a NICU from another pediatric hospital were also studied. All Candida albicans strains were genotyped by Southern blot hybridization with 27A. Isolates for outbreak confirmation were also hybridized with another specific Candida albicans probe, Ca3. Hybridization patterns demonstrated horizontal transmission in all the units studied. In a NICU, transmission among 4 patients during a 10-month period could be established and in the other NICU, 3 cases of transmission among 2 patients each were demonstrated in periods of 2 to 20 days. The outbreak studies showed the same strain isolated from 2 nurses and from one patient at the NICU and at the ICU identical strains were found in 3 patients. In this study, hybridization with Ca3 in addition to 27A probe did not increase discrimination power among isolates. Genotypic analysis allows, not only, determination of transmission and persistence of strains during prolonged periods or in sporadic outbreaks, but also facilitates necessary epidemiological decisions for optimizing nosocomial fungal infection control measures.(AU)

Epidemiology of nosocomial candidiasis: the importance of molecular typing.

Modern epidemiology studies now require that nosocomial pathogens be characterized to the subspecies level whenever possible to better define infectious processes and modes of transmission. In general, if isolates are classified as different by at least one molecular typing method, they may be assumed to represent different strains and to reflect independent infections. If the isolates are the same, it may be assumed that cross infection has occurred or that the patients were infected by exposure to a common source. Typing methods may also be used to address clinical problems related to distinguishing reinfection versus relapse of an infection, and to examine the development of antifungal resistance among fungal pathogens during the course of antifungal therapy. Determining DNA fingerprints of sequential isolates from patients undergoing antifungal therapy has been useful in demonstrating the potential for the development of antifungal resistance in previously susceptible strains and for detecting the substitution of a more resistant strain for a more susceptible strain in the face of intense antimicrobial pressure. In order to be useful as an epidemiological typing method, a DNA fingerprinting system must effectively distinguish between genetically unrelated strains, identify the same strain in separate samples, and reflect genetic relatedness or unrelatedness (genetic distance) among strains.

[Nosocomial transmission of Candida albicans in newborn infants]. / Transmisión nosocomial de Candida albicans en recién nacidos.

Candida spp. colonization in neonates occurs due to vertical or horizontal transmission. Preliminary studies determined that Candida albicans is the principal agent of these infections. In order to establish nosocomial transmission, 26 Candida albicans strains isolated from patients with candidosis hospitalized during a 18-month period in 2 neonatal intensive care units (NICU) from a pediatric hospital were studied. Fourteen isolates from patients and health care workers, involved in possible outbreaks of an intensive care unit (UCI) and a NICU from another pediatric hospital were also studied. All Candida albicans strains were genotyped by Southern blot hybridization with 27A. Isolates for outbreak confirmation were also hybridized with another specific Candida albicans probe, Ca3. Hybridization patterns demonstrated horizontal transmission in all the units studied. In a NICU, transmission among 4 patients during a 10-month period could be established and in the other NICU, 3 cases of transmission among 2 patients each were demonstrated in periods of 2 to 20 days. The outbreak studies showed the same strain isolated from 2 nurses and from one patient at the NICU and at the ICU identical strains were found in 3 patients. In this study, hybridization with Ca3 in addition to 27A probe did not increase discrimination power among isolates. Genotypic analysis allows, not only, determination of transmission and persistence of strains during prolonged periods or in sporadic outbreaks, but also facilitates necessary epidemiological decisions for optimizing nosocomial fungal infection control measures.

Molecular typing of Candida albicans strains isolated from nosocomial candidemia.

Yeasts of the genus Candida have been recognized as important microorganisms responsible for nosocomial fungemia. Six blood-stream and two intravenous central catheter C. albicans strains were isolated from eight patients and studied by electrophoretic karyotyping of chromosomal DNA by pulsed-field gel electrophoresis. Seven chromosomal DNA profiles were identified. Two patients showed isolates with the same profile, suggesting nosocomial transmission. Karyotyping of C. albicans revealed an excellent discriminatory power among the isolates and may therefore be useful in the study of nosocomial candidemia.

Outbreak of Candida bloodstream infections associated with retrograde medication administration in a neonatal intensive care unit.

An outbreak of candidemia involving five infants receiving total parenteral nutrition in the neonatal intensive care unit was investigated. Cultures of the intravenous fluids demonstrated that the retrograde medication syringe fluids were significantly more likely to be contaminated with Candida than were other fluids being administered to the infants (p less than 0.001). Candidemia was significantly associated with total parenteral nutrition (p = 0.04) and retrograde medication administration (p = 0.02). A survey of nursing practice found that reuse of the retrograde syringes was the most likely cause of contamination. Molecular typing showed that the strains of Candida albicans that were isolated from the bloodstream were also found in the retrograde syringes and that at least three strains of C. albicans and one strain each of Candida tropicalis and Candida parapsilosis were involved. In vitro growth curves demonstrated that Candida species had a selective growth advantage versus bacteria in the total parenteral nutrition fluid. An in vitro simulation of the retrograde medication administration system suggested that the outbreak probably developed after the frequency of changing intravenous tubing was decreased from every 24 hours to every 72 hours. The outbreak was terminated by using syringes only once and resuming intravenous tubing changes every 24 hours. Retrograde medication administration in association with total parenteral nutrition may increase the risk of Candida line infection.