Genotyping analysis of colonizing candidal isolates from very-low-birthweight infants in a neonatal intensive care unit

Oral nystatin prophylaxis to prevent systemic fungal infection in very low birth weight preterm infants: a randomized controlled trial

Background

Systemic fungal infection (SFI) is one of leading causes of morbidity and mortality in very low birth weight (VLBW) preterm infants. Because early diagnosis of SFI is challenging due to nonspecific manifestations, prophylaxis becomes crucial. This study aimed to assess effectiveness of oral nystatin as an antifungal prophylaxis to prevent SFI in VLBW preterm infants.

Methods

A prospective, open-labelled, randomized controlled trial was performed in a neonatal intensive care unit (NICU) of an academic hospital in Indonesia. Infants with a gestational age ≤ 32 weeks and/or birth weight of ≤ 1500 g with risk factors for fungal infection were assessed for eligibility and randomized to either an intervention group (nystatin) or control group. The intervention group received 1 ml of oral nystatin three times a day, and the control group received a dose of 1 ml of sterile water three times a day. The incidence of fungal colonization and SFI were observed and evaluated during the six-week study period. Overall mortality rates and nystatin-related adverse drug reactions during the study period were also documented.

Results

A total of 95 patients were enrolled. The incidence of fungal colonization was lower among infants in nystatin group compared to those in control group (29.8 and 56.3%, respectively; relative risk 0.559; 95% confidence interval 0.357–0.899; p-value = 0.009). There were five cases of SFI, all of which were found in the control group (p-value = 0.056). There was no difference in overall mortality between the two groups. No adverse drug reactions were noted during the study period.

Conclusions

Nystatin is effective and safe as an antifungal prophylactic medication in reducing colonization rates in the study population. Whilst the use of nystatin showed a potential protective effect against SFI among VLBW preterm infants, there was no statistical significant difference in SFI rates between groups.

Trial registration

NCT03390374. Registered 4 January 2018 - Retrospectively registered.

2016 guidelines for the use of antifungal agents in patients with invasive fungal diseases in Taiwan

The Infectious Diseases Society of Taiwan, Medical Foundation in Memory of Dr. Deh-Lin Cheng, Foundation of Professor Wei-Chuan Hsieh for Infectious Diseases Research and Education, and CY Lee's Research Foundation for Pediatric Infectious Diseases and Vaccines have updated the guidelines for the use of antifungal agents in adult patients with invasive fungal diseases in Taiwan. This guideline replaces the 2009 version. Recommendations are provided for Candida, Cryptococcus, Aspergillus and Mucormycetes. The focus is based on up-to-date evidence on indications for treatment or prophylaxis of the most common clinical problems. To support the recommendations in this guideline, the committee considered the rationale, purpose, local epidemiology, and key clinical features of invasive fungal diseases to select the primary and alternative antifungal agents. This is the first guideline that explicitly describes the quality and strength of the evidence to support these recommendations. The strengths of the recommendations are the quality of the evidence, the balance between benefits and harms, resource and cost. The guidelines are not intended nor recommended as a substitute for bedside judgment in the management of individual patients, the advice of qualified health care professionals, and more recent evidence concerning therapeutic efficacy and emergence of resistance. Practical considerations for individualized selection of antifungal agents include patient factors, pathogen, site of infection and drug-related factors, such as drug-drug interaction, drug-food intervention, cost and convenience. The guidelines are published in the Journal of Microbiology, Immunology and Infection and are also available on the Society website.

Oral colonization: a possible source for candidemia in low-weight neonates

OBJECTIVE

To check the oral colonization in neonates at high-risk and to associate these cases with candidemia.

SUBJECTS AND METHODS

This study was conducted in the NICU. For six months, 125 high-risk neonates were investigated for oral colonization and septicemia by yeasts. From this total, 19 neonates had yeasts on the oral mucosae and 12 neonates developed fungemia. All of the 12 neonates with fungemia were included in the amount of 19 who have presented oral colonization by yeasts.

RESULTS

There was a species concordance between the yeasts of the oral mucosae and the blood in 6 neonates (50%) among the 12 neonates with oral colonization and septicemia at the same time. The yeasts isolated in these 6 cases regarding the species concordance were Candida albicans (5 cases, 83.4%) and Candida parapsilosis (1 case, 16.6%). All of the cases involving an association were confirmed by PFGE. All of the strains of yeasts involved in oral colonization and also blood presented the same karyotype. A total of 66.6% of the patients with strains in agreement progressed to death.

CONCLUSION

The results indicate the relevance of monitoring the oral microbiota, as a possible source of fungal infection, and assisting to develop appropriate therapeutic strategy.

Candida parapsilosis and the neonate: epidemiology, virulence and host defense in a unique patient setting

Invasive candidiasis is a common problem in premature infants that leads to high morbidity and mortality. Although Candida albicans has historically been the most prominent species involved in these infections and has therefore been the subject of the most study, Candida parapsilosis is increasing in frequency, and neonates are disproportionately affected. This article reviews unique aspects of the epidemiology of this organism as well as strategies for prophylaxis against invasive candidiasis in general. Additionally, important differences between C. parapsilosis and C. albicans are coming to light related to virulence determinants and interactions with components of host immunity. These developments are reviewed while highlighting the significant gaps in our understanding that remain to be elucidated.

Bovine lactoferrin prevents invasive fungal infections in very low birth weight infants: a randomized controlled trial

BACKGROUND

Lactoferrin is a mammalian milk glycoprotein involved in innate immunity. Recent data show that bovine lactoferrin (bLF) prevents late-onset sepsis in preterm very low birth weight (VLBW) neonates.

METHODS

This is a secondary analysis of data from a multicenter randomized controlled trial where preterm VLBW neonates randomly received bLF (100 mg/day; group A1), bLF + Lactobacillus rhamnosus GG (10(6) colony-forming units per day; group A2), or placebo (group B) for 6 weeks. Here we analyze the incidence rates of fungal colonization, invasive fungal infection (IFI), and rate of progression from colonization to infection in all groups.

RESULTS

This study included 472 neonates whose clinical, nutritional, and demographical characteristics were similar. Overall, the incidence of fungal colonization was comparable (17.6%, 16.6%, and 18.5% in A1, A2, and B, respectively; P = .89 [A1] and .77 [A2]). In contrast, IFIs were significantly decreased in A1 and A2 (0.7% and 2.0%, respectively) compared with B (7.7%; P = .002 [A1] and .02 [A2]), and this was significantly true both in <1000 g (0.9% [A1] and 5.6% [A2], vs 15.0%) and in 1001 to 1500 g infants (0% and 0% vs 3.7%). The progression rate colonization-infection was significantly lower in the bLF groups: 3.7% (A1) and 12% (A2), vs 41.9%; P < .001 (A1) and P = .02 (A2). No IFI-attributable deaths occurred in the treatment groups, versus 2 in placebo. No adverse effects or intolerances occurred.

CONCLUSIONS

Prophylactic oral administration of bLF reduces the incidence of IFI in preterm VLBW neonates. No effect is seen on colonization. The protective effect on IFI is likely due to limitation of ability of fungal colonies to progress toward invasion and systemic disease in colonized infants.

Microsatellite multilocus genotyping clarifies the relationship of Candida parapsilosis strains involved in a neonatal intensive care unit outbreak

Microsatellite typing of 25 Candida parapsilosis isolates from a described outbreak in a neonatal intensive care showed 2 large groups of blood isolates that were related to hand isolates from specific hospital staff, not infant-colonizing isolates. These results demonstrate the power of this typing tool in clarifying epidemiologic associations.

Recent advances in prevention of sepsis in the premature neonates in NICU

Sepsis-related morbidity and mortality are major problems in NICU. Preterm neonates display clinical characteristics that make them prone to infections. Due to the high frequency of severe neurodevelopmental sequelae in survivors, the best possible strategy to manage sepsis in NICU is to prevent them. Hygiene, cohorting, stewardship on use of H2-blockers, steroids and broad-spectrum antibiotic are mandatory, as well as proper management of central venous accesses and surgical devices. In addition, clinical research offers the opportunity of adopting pharmacological preventative strategies such as use of palivizumab to prevent RSV infection, use of fluconazole to prevent fungal sepsis, use of probiotics and lactoferrin to enhance the innate immunity, and use of pagibaximab to prevent staphylococcal sepsis.

Candida parapsilosis: a review of its epidemiology, pathogenesis, clinical aspects, typing and antimicrobial susceptibility

The Candida parapsilosis family has emerged as a major opportunistic and nosocomial pathogen. It causes multifaceted pathology in immuno-compromised and normal hosts, notably low birth weight neonates. Its emergence may relate to an ability to colonize the skin, proliferate in glucose-containing solutions, and adhere to plastic. When clusters appear, determination of genetic relatedness among strains and identification of a common source are important. Its virulence appears associated with a capacity to produce biofilm and production of phospholipase and aspartyl protease. Further investigations of the host-pathogen interactions are needed. This review summarizes basic science, clinical and experimental information about C. parapsilosis.

Clinical microbiology of early-onset and late-onset neonatal sepsis, particularly among preterm babies

Prematurity has got special challenge for clinicians and also other medical staff, such as microbiologists. Immature host defense mechanisms support early-onset sepsis, which can be very serious with very high mortality. While the past decade has been marked by a significant decline in early-onset group B streptococcal (GBS) sepsis in both term and preterm neonates, the overall incidence of early-onset sepsis has not decreased in many centers, and several studies have found an increase in sepsis due to gram-negative organisms. With increasing survival of these more fastidious preterm infants, late-onset sepsis or specially nosocomial bloodstream infection (BSI) will continue to be a challenging complication that affects other morbidities, length of hospitalization, cost of care, and mortality rates. Especially the very low birthweight (VLBW) infants sensitive to serious systemic infection during their initial hospital stay. Sepsis caused by multiresistant organisms and Candida spp. are also increasing in incidence, has become the most common cause of death among preterm infants. This review focuses on the clinical microbiology of neonatal sepsis, particularly among preterm babies, summarizing the most frequent bacterial and fungal organisms causing perinatally acquired and also nosocomial sepsis.

Candida parapsilosis fungemia in neonates: genotyping results suggest healthcare workers hands as source, and review of published studies

An outbreak of Candida parapsilosis fungemia involving 17 neonatal intensive care unit (NICU) patients was studied. There were 14 blood culture and nine colonizing isolates from other sites available. The hands of NICU healthcare workers (HCW) yielded eight isolates. Screening of the isolates by random amplified polymorphic DNA (RAPD) method showed only three profiles. Typing by restriction fragment length polymorphism (RFLP) revealed all blood isolates were RFLP subtype VII-1. Among the nine infant colonizing isolates, there were four different RFLP subtypes; four of the isolates were subtype VII-1. Seven of the eight isolates from HCW were RFLP subtype VII-1. The majority of infant colonizers were not found in the blood, suggesting a possible direct spread of the epidemic subtype VII-1 strain from HCW hands to infant blood. The source of the infant colonizing strains is unclear, but non-VII-1 strains may be largely of maternal origin and VII-1 strains from HCW. These findings reinforce prior studies that have implicated HCW hands as the source of nosocomial, including neonatal, fungemia.

Early-onset neutropenia is a risk factor for Candida colonization in very low-birth-weight neonates

Neutropenia is a major risk factor for bacterial colonization and sepsis in preterm neonates in the neonatal intensive care unit (NICU), but little is known about its relationships with candidal colonization (CC) in these settings. We performed a case-control study on neonates with birth weight of <1500 g admitted to our NICU during a 7-year period (1996-2003, N = 585). Through database search, infants with early-onset neutropenia (EON) (n = 68, group A) were identified and 1:1 matched with controls without EON (n = 68, group B). Microbiologic data from weekly surveillance cultures were examined to determine the presence and intensity of CC. Groups A and B were similar clinically and demographically. All group A neonates recovered from EON before the 8th day of life. Incidence of CC in the 1st month of life (at least 1 site) was significantly higher in group A (61.8% versus 35.3%, P = 0.002) and was not modified by treatment with recombinant granulocyte colony-stimulating factor. The same was true of CC intensity, expressed as the number of sites affected (P = 0.002). Incidence of candidal sepsis, mortality rates, and relative frequencies of the various subspecies of Candida among the isolates did not significantly differ between the 2 groups. In conclusion, EON in preterm neonates is a significant, independent risk factor for CC. Larger, prospective, adequately powered studies should verify whether increased CC related to neutropenia may translate into a similar increased occurrence of candidal sepsis in these settings.

Type and number of sites colonized by fungi and risk of progression to invasive fungal infection in preterm neonates in neonatal intensive care unit

AIMS

Retrospective cohort study to assess if different patterns of Candida colonization determine different risks of progression to invasive fungal infection (IFI) in preterm neonates in NICU.

METHODS

Weekly surveillance cultures from all neonates weighing at birth <1500 g admitted over a 6-year period were reviewed. Infants with available results from at least 3 cultures/week and from at least 4 different sites were enrolled and identified by the number of sites involved [1-2 (low-grade), 3 or more (high-grade)] and type (low-risk, if colonization was recovered from skin, stool, ear canal swab, gastric aspirate, nasopharynx secretions, endotracheal tube; high-risk, from urine, catheter tip, drains, surgical devices). Progression rates from colonization to IFI were calculated for each subgroup. Univariate analysis was performed looking for significant associations between IFI and a number of risk factors, including the different subgroups of colonization. Multiple logistic regression assessed all significantly (P<0.05) associated risk factors.

MAIN RESULTS

In the 405 eligible infants, overall colonization rate was 42.9%, IFI rate 9.9%, overall progression rate to IFI 0.23, the latter being significantly higher in high-grade or high-risk than in low-grade or low-risk colonized infants (0.59 vs. 0.18, P=0.001; 0.44 vs. 0.11, P<0.001, respectively). Infants with concomitant high-grade + high-risk colonization had 4-fold higher risk of progression than any other colonized infant, and 7-fold higher risk than infants concomitantly low-grade + low-risk colonized (P<0.001). At multivariate analysis, high-grade and high-risk colonization (P=0.001 for both), birth weight (P=0.02) and presence of central venous line (P=0.04) remained independent predictors of IFI.

CONCLUSIONS

Density and severity of fungal colonization condition the progression to IFI in preterm infants in NICU, and certain patterns of colonization are independent predictors of IFI. Increased culture surveillance and prophylactic measures should be addressed to preterm colonized infants in NICU featuring the most risky colonization patterns.

Assessment of Candida glabrata strain relatedness by pulsed-field gel electrophoresis and multilocus sequence typing

In this study, 80 Candida glabrata isolates from intensive care unit and human immunodeficiency virus (HIV)-infected patients were typed by multilocus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE), and mating type class determination. Among the 25 patients with multiple isolates, 19 patients (76%) contained multiple isolates exhibiting identical or highly related PFGE and MLST genotypes, which may indicate the maintenance or microvariation of one C. glabrata strain in each patient. However, isolates from six patients (24%) displayed different sequence types, PFGE genotypes, or mating type classes, which may indicate colonization with more than one clone over time or strain replacement. High correlations among PFGE genotypes, sequence types, and mating types were found (P < 0.01). MLST exhibited less discriminatory power than PFGE with BssHII. The genotypes, sequence types, and mating type classes were independent of anatomic sources, drug susceptibility, and HIV infection status.

Prevention of catheter-related bloodstream infections in the neonatal intensive care setting

Nosocomial infection causes substantial morbidity and mortality among neonates treated in the neonatal intensive care setting. Colonization and subsequent infection of central venous catheters leading to catheter-related bloodstream infection is among the most common causes of nosocomial sepsis in this patient population. Prevention of catheter-related bloodstream infection is a major challenge and numerous strategies have been attempted in this context with varying success. Given the dynamic epidemiology of nosocomial infection among neonates and the emergence of antimicrobial resistance, novel prevention strategies are urgently required.

Risk factors for progression to invasive fungal infection in preterm neonates with fungal colonization

OBJECTIVE

Colonization by Candida spp is a major risk factor for development of fungal sepsis, but little is known about the variables associated with progression to invasive disease in already colonized neonates. We investigated such variables in a large number of colonized preterm neonates in an NICU.

SETTING

This study was conducted in the Department of Neonatology and the NICU at Sant'Anna Hospital in Torino, Italy.

DESIGN AND PATIENTS

A database search of clinical charts and weekly surveillance cultures was used to identify all neonates with birth weights < 1500 g (very low birth weight) who were admitted to our NICU during 1998-2005 and were colonized (> or = 1 site) by Candida spp during their stay, as well as infants with invasive fungal infection. The association between a number of factors with progression to invasive fungal infection was evaluated. Those shown to be significantly associated by univariate analysis were cross-checked by logistic regression.

RESULTS

Colonization occurred in 201 infants (32.1% of very low birth weight admitted neonates), and invasive fungal infection occurred in 51 (8.1%) of them, with an overall progression rate of 0.25. At univariate analysis, 10 factors (namely low birth weight, low gestational age, use of third-generation cephalosporins, endotracheal intubation, duration of stay in the NICU, bacterial sepsis, colonization of central venous catheter, of endotracheal tube, of gastric aspirate, or in > or = 3 [multiple] sites) were associated with an increased risk of progression, whereas prophylaxis with fluconazole was associated to a decreased risk. After logistic regression, only colonization of central venous catheter and colonization in multiple sites remained significantly associated with invasive fungal infection. Fluconazole prophylaxis remained an independent protective factor.

CONCLUSIONS

Central venous catheter colonization and multiple-site colonization are independent risk factors and predictors of progression to fungal sepsis in preterm very low birth weight neonates colonized by Candida spp during their stay in the NICU. Fluconazole prophylaxis is an independent protective factor. These findings can be used to improve the surveillance, prophylaxis, or preemptive measures in neonates at high risk.

Molecular evidence of congenital candidiasis associated with maternal candidal vaginitis

A premature newborn born to a mother with candidal vaginitis developed congenital invasive candidiasis. The isolates of Candida albicans from the bloodstream and the oral cavity of the neonate and the vagina of the mother shared a common genotype, which provide direct evidence of the association of congenital candidiasis with candidal vaginitis in the mother.