Malassezia furfur colonization of neonates in an intensive care unit

Combinatory Use of hLF(1-11), a Synthetic Peptide Derived from Human Lactoferrin, and Fluconazole/Amphotericin B against Malassezia furfur Reveals a Synergistic/Additive Antifungal Effect

OBJECTIVE

The increasing resistance of Malassezia yeasts against commonly used antifungal drugs dictates the need for novel antifungal compounds. Human lactoferrin-based peptides show a broad spectrum of antimicrobial activities. Various assays were performed to find the optimal growth conditions of the yeasts and to assess cell viability, using media with low lipid content to avoid peptide binding to medium components.

METHODS

In the current study, we tested the antimicrobial susceptibility of 30 strains of M. furfur that cover the known IGS1 genotypic variation.

RESULTS

hLF(1-11) inhibited the growth of all species tested, resulting in minimum inhibitory concentrations (MIC) values ranging from 12.5 to 100 μg/mL. In the combinatory tests, the majority of fractional inhibitory concentration indexes (FIC) for the tested strains of M. furfur were up to 1.0, showing that there is a synergistic or additive effect on the efficacy of the antifungal drugs when used in combination with hLF(1-11).

CONCLUSION

Results showed that hLF(1-11) could be combined with fluconazole or amphotericin for the antimicrobial treatment of resistant strains, enhancing the potency of these antifungal drugs, resulting in an improved outcome for the patient.

Tinea versicolor in a premature infant

Tinea versicolor (TV) is a fungal skin infection that classically affects adolescents and young adults. Occasionally, it may be seen on the face of infants. We report an unusual case of widespread cutaneous TV in a premature infant.

Malassezia furfur Emergence and Candidemia Trends in a Neonatal Intensive Care Unit During 10 Years: The Experience of Fluconazole Prophylaxis in a Single Hospital

BACKGROUND

Because Candida spp is a major cause of mortality and morbidity in preterm infants, fluconazole prophylaxis has been suggested by some experts and hospital policy. In our hospital, fluconazole prophylaxis was used in eligible preterm infants and set as the neonatal intensive care unit (NICU) practice in 2014.

PURPOSE

This study focused on fungal bloodstream infections and aimed to evaluate the benefit and harm of fluconazole prophylaxis.

METHODS/SEARCH STRATEGY

This retrospective, descriptive study involved medical record reviews in our hospital from April 2005 to October 2016. NICU patients were included if Candida species, yeast-like organisms, or Malassezia species were cultured from their venous catheter tips or blood cultures.

FINDINGS/RESULTS

After fluconazole prophylaxis, cases of Candida spp decreased and those of Malassezia furfur emerged. We reviewed 19 cases of catheter-related M furfur colonization and 1 case of M furfur fungemia. The gestational age was 27.3 ± 2.0 weeks and birth weight was 959.2 ± 229.8 g. Hyperalimentation with lipid infusion was used in all cases. All of the neonates survived with antifungal agent use.

IMPLICATIONS FOR PRACTICE

This study highlights that prophylactic fluconazole may be an associated factor of Malassezia colonization; M furfur remains a potential concern for fungemia in the care of premature infants and thus requires our attention.

IMPLICATIONS FOR RESEARCH

Future studies should further investigate the incidence and impact of noncandidal fungal infections with fluconazole prophylaxis use in premature infants.

Skin Colonization by Malassezia spp. in hospitalized neonates and infants in a tertiary care centre in North India

Malassezia, a skin colonizer, is associated with multiple skin disorders in adults, and cephalic pustulosis and folliculitis in children. It can cause fungemia in infants and neonates. The time and pattern of colonization, risk factors associated with colonization and causing fungemia in children, are not well understood. The prospective cohort study was conducted to determine the rate of Malassezia species colonization and associated factors in hospitalized neonates and infants. Consecutive 50 neonates and infants admitted in neonatal and pediatric intensive care units were studied. The skin swabs were collected on the day of admission and every fifth day, thereafter, till the patient was discharged or died. Putative risk factors for the colonization of Malassezia species were recorded. Isolates were identified by phenotypic methods and sequencing of the D1 and D2 region of rDNA. Neonates were not colonized at the time of entry in neonatal ICU or at birth. Nineteen (38 %) neonates were colonized with Malassezia species during their hospital stay. Among the infants, three (6 %) came to ICU with Malassezia colonization and 26 (52 %) acquired Malassezia during ICU stay. Mechanical ventilation, duration of hospital stay, central venous catheterization, and antifungal therapy were the significantly associated factors for colonization. Malassezia furfur was the most common species isolated from the skin of infants and neonates. Colonization by Malassezia species in infants and neonates in a hospital is not uncommon and can be a potential source of nosocomial infection.

Colonization of neonate skin by Malassezia species: relationship with neonatal cephalic pustulosis

BACKGROUND

Colonization of neonate skin by Malassezia species and their causative role in neonatal cephalic pustulosis is unclear.

OBJECTIVES

We sought to determine the skin colonization by Malassezia in healthy newborns, and to investigate its association with neonatal cephalic pustulosis.

METHODS

Samples for Malassezia colonization were taken from cheeks and scalps of 104 neonates between 24 and 72 hours after birth, and again 2 or 4 weeks later. Pustules were sampled with concomitant nonlesional skin cultures if neonatal cephalic pustulosis was diagnosed.

RESULTS

Malassezia colonization increased significantly with age of the neonate (5% at the first week, 30% at 2-4 weeks). In all, 26 patients were given the diagnosis of neonatal cephalic pustulosis during follow-up. No correlation was found between the severity of the disease and Malassezia isolation. Skin colonization of patients with neonatal cephalic pustulosis (20.8%) was not higher than colonization of healthy newborns (37%).

LIMITATIONS

Not all of the neonates were examined by the authors at the second visit.

CONCLUSIONS

Malassezia colonization increases after the first week of life. No correlation was found between neonatal cephalic pustulosis and Malassezia.

Skin colonization by Malassezia in neonates and infants

OBJECTIVE

To identify the timing, pattern, and determinants of colonization of neonates by Malassezia.

DESIGN

Prospective observational study.

SETTING

A neonatal medical and surgical unit consisting of 10 special care, 10 high-dependency, 10 intensive care, and 10 surgical cots.

PARTICIPANTS

All neonates (< or = 28 days of age) or infants (> 28 days of age) admitted to the unit during the 20-week period from October 1995 to March 1996.

METHODS

All infants or neonates were swabbed on the day of admission and every third day thereafter and risk factors were collected for every day on the unit.

RESULTS

During the study period, 245 neonates and 42 infants were sampled for their entire duration of stay on the unit. Of these, 41 infants (97.6%) were colonized with Malassezia on admission to the unit and thereafter, as assessed by subsequent samples. Within the neonate population, 78 (31.8%) became colonized, but none were colonized immediately after birth. Univariate analysis showed that many factors appeared to be significantly associated with colonization in the neonates, including use of ventilation, presence of central venous catheters, use of parenteral nutrition, and use of antibacterial or antifungal drugs. However, when the data were analyzed by multivariate logistic regression to control for confounding variables, only gestational age and length of stay on the unit were found to be significantly associated with colonization.

CONCLUSION

Colonization of infants is not as unusual as previously thought and many infants have established a cutaneous Malassezia commensal flora by the age of 3 to 6 months. Factors that predispose to colonization in neonates may not be the same as those that predispose to infection.

Immunology of diseases associated with Malassezia species

Malassezia species are members of the human cutaneous commensal flora, in addition to causing a wide range of cutaneous and systemic diseases in suitably predisposed individuals. Studies examining cellular and humoral immune responses specific to Malassezia species in patients with Malassezia-associated diseases and healthy controls have generally been unable to define significant differences in their immune response. The use of varied antigenic preparations and strains from different Malassezia classifications may partly be responsible for this, although these problems can now be overcome by using techniques based on recent work defining some important antigens and also a new taxonomy for the genus. The finding that the genus Malassezia is immunomodulatory is important in understanding its ability to cause disease. Stimulation of the reticuloendothelial system and activation of the complement cascade contrasts with its ability to suppress cytokine release and downregulate phagocytic uptake and killing. The lipid-rich layer around the yeast appears to be pivotal in this alteration of phenotype. Defining the nonspecific immune response to Malassezia species and the way in which the organisms modulate it may well be the key to understanding how Malassezia species can exist as both commensals and pathogens.

Colonization and infection associated with Malassezia and Candida species in a neonatal unit

The objectives of this study were to determine, in neonates of < 1250 g birthweight (N = 57), the initial time of skin colonization by Malassezia furfur, rate of colonization by Candida spp., and whether skin colonization by these yeasts was predictive of central line colonization or fungaemia. By age two weeks, 51% of neonates were culture-positive for M. furfur on umbilical or groin skin. During hospitalization, positive skin cultures for M. furfur or Candida spp. were obtained in 70% and 37% of neonates, respectively. Risk factors associated with positive skin cultures were mechanical ventilation and three or more episodes of suspected sepsis. Eight of the 52 infants with central venous catheters, had positive blood cultures withdrawn from the lines; five (62%) of these had positive skin surveillance cultures. Although positive skin cultures for M. furfur, Candida spp., or both were commonly observed in this population, they were not predictive of positive central line cultures or systemic illness.

The use of karyotyping in the systematics of yeasts

The use of electrophoretic karyotyping in systematics of yeasts is discussed. New data are provided on the karyotypes of the medically important fungi Hortaea werneckii, Filobasidiella (= Cryptococcus) neoformans, and Malassezia species. Hortaea werneckii has twelve to eighteen bands of chromosomal DNA, ranging in size between 500 and 2300 kb. The karyotypes of Filobasidiella neoformans consist of seven to fourteen bands of chromosomal DNA. The varieties neoformans and bacillispora cannot be separated by their karyotypes, and no obvious correlation was found with serotypes, geography or habitat. All strains of Malassezia pachydermatis studied have similar karyotypes consisting of five bands, whereas in M. furfur, four different karyotypes are prevalent. However, each of these karyotypes is stable.

Fungal gut colonization with Candida or Pityrosporum sp. and serum Candida antigen in preterm neonates with very low birth weights

To evaluate the diagnostic value of gut colonization by yeasts and of candida antigen in serum for predicting fungal infection in very premature neonates, faecal and serum samples were obtained biweekly from 27 newborn babies treated at our neonatal intensive care unit. Altogether 82 sets of serum and faecal samples were obtained. 17 babies were followed for > or = 4 weeks. Blood cultures, both by routine and lysis centrifugation techniques, were performed for bacteria and fungi if infection was suspected. All children were given systemic broad-spectrum antibiotic treatment. Five of the children died, all without evidence of fungal infection. No systemic antifungal treatments were given. Quantitative faecal cultures demonstrated Candida albicans in 3 (11%) (10(3)-10(5) colony forming units/g) and Pityrosporum sp. in 8 (30%) of the preterm neonates. Candida antigen in titre 4 was detected in 1/82 serum samples. The child subsequently died with no other evidence of candida infection. In 56 full term neonates treated at the intensive care unit during the same period and tested by 1 set of samples, faecal colonization with Candida sp. was detected in 2 (4%) and with Pityrosporum sp. in 4 (15%). None were positive for candida antigen. Fungal gut colonization did not lead to clinical infection in the preterm neonates studied. The false positivity rate of the candida antigen test was low (0.7%). The predictive value of the test could not be determined in this study group with no systemic fungal infections. The role of pityrosporum as an inducer of neonatal infections remains to be evaluated.