Invasive Candida Infections in Neonates after Major Surgery: Current Evidence and New Directions

Clinicopathologic Characterization of Invasive Fungal Intestinal Infections in Pediatric Patients

BACKGROUND

Invasive fungal intestinal infections are rare in pediatric patients with limited studies reported to date.

METHODS

Retrospective study of invasive intestinal fungal infections in pediatric patients. For fungal specification, 18S rRNA gene PCR was performed using formalin-fixed paraffin-embedded tissues.

RESULTS

A total of 19 cases from 18 patients were included (13 males, 72%) with a median age of 20 days (8 days-14 years). About 13 patients (72%) presented within 67 days of birth and 11 patients (61%) were premature and 14 patients (78%) had a significant medical history. The most common location was the jejunum/ileum (56%) followed by the right colon and terminal ileum (22%). In 10 patients, the fungal elements were seen in the mucosa with 3 extending into the submucosa, and only 3 patients showed full-thickness involvement. Tissue necrosis and angioinvasion were seen in 13 (72%) and 8 (44%) patients, respectively. Morphologically, organisms consistent with Candida spp. were seen in 17 patients and with a mucoraceous mold in 1 patient. A 18S rRNA gene sequencing performed in 18 cases identified Candida dubliniensis in 16 cases and Candida spp. in 2 cases. During the study follow-up period, 56% of the patients died.

CONCLUSION

In our experience, most cases were due to Candida spp. and predominantly in premature infants and associated with poor outcomes.

Neonatal Fungemia by Non-Candida Rare Opportunistic Yeasts: A Systematic Review of Literature

Fungal colonization poses a significant risk for neonates, leading to invasive infections such as fungemia. While Candida species are the most commonly identified pathogens, other rare yeasts are increasingly reported, complicating diagnosis and treatment due to limited data on antifungal pharmacokinetics. These emerging yeasts, often opportunistic, underscore the critical need for early diagnosis and targeted therapy in neonates. This systematic review aims to comprehensively analyze all published cases of neonatal fungemia caused by rare opportunistic yeasts, examining geographical distribution, species involved, risk factors, treatment approaches, and outcomes. Searching two databases (PubMed and SCOPUS), 89 relevant studies with a total of 342 cases were identified in the 42-year period; 62% of the cases occurred in Asia. Pichia anomala (31%), Kodamaea ohmeri (16%) and Malassezia furfur (15%) dominated. Low birth weight, the use of central catheters, prematurity, and the use of antibiotics were the main risk factors (98%, 76%, 66%, and 65%, respectively). 22% of the cases had a fatal outcome (80% in Asia). The highest mortality rates were reported in Trichosporon beigelii and Trichosporon asahii cases, followed by Dirkmeia churashimamensis cases (80%, 71%, and 42% respectively). Low birth weight, the use of central catheters, the use of antibiotics, and prematurity were the main risk factors in fatal cases (84%, 74%, 70%, and 67%, respectively). 38% of the neonates received fluconazole for treatment but 46% of them, died. Moreover, the rare yeasts of this review showed high MICs to fluconazole and this should be taken into account when planning prophylactic or therapeutic strategies with this drug. In conclusion, neonatal fungemia by rare yeasts is a life-threatening and difficult-to-treat infection, often underestimated and misdiagnosed.

Virulence factors, antifungal susceptibility and molecular profile in Candida species isolated from the hands of health professionals before and after cleaning with 70% ethyl alcohol-based gel

Fungal infections in neonatal intensive care units (NICU) are mainly related to Candida species, with high mortality rates. They are predominantly of endogenous origin, however, cross-infection transmitted by healthcare professionals' hands has occurred. The aim of this study was to identify Candida species isolated from the hands of healthcare professionals in a NICU before and after hygiene with 70% ethanol-based gel and evaluate virulence factors DNase, phospholipase, proteinase, hemolysin, biofilm biomass production, and metabolic activity. In vitro antifungal susceptibility testing and similarity by random amplified polymorphic DNA (RAPD) were also performed. C. parapsilosis complex was the most frequent species (57.1%); all isolates presented at least one virulence factor; three isolates (Candida parapsilosis complex) were resistant to amphotericin B, two (Candida famata [currently Debaryomyces hansenii] and Candida guilliermondii [currently Meyerozyma guilliermondii]) was resistant to micafungin, and six (Candida parapsilosis complex, Candida guilliermondii [=Meyerozyma guilliermondii], Candida viswanathi, Candida catenulata [currently Diutina catenulata] and Candida lusitaniae [currently Clavispora lusitaniae]) were resistant to fluconazole. Molecular analysis by RAPD revealed two clusters of identical strains that were in the hands of distinct professionals. Candida spp. were isolated even after hygiene with 70% ethanol-based gel, highlighting the importance of stricter basic measures for hospital infection control to prevent nosocomial transmission.

Taxonomy of Candida parapsilosis complex isolated from neonates and the role of Hsp90 inhibitors to enhanced the antifungal activity of micafungin

Species from Candida parapsilosis complex are frequently found in neonatal candidemia. The antifungal agents to treat this infection are limited and the occurrence of low in vitro susceptibility to echinocandins such as micafungin has been observed. In this context, the chaperone Hsp90 could be a target to reduce resistance. Thus, the objective of this research was to identify isolates from the C. parapsilosis complex and verify the action of Hsp90 inhibitors associated with micafungin. The fungal identification was based on genetic sequencing and mass spectrometry. Minimal inhibitory concentrations were determined by broth microdilution method according to Clinical Laboratory and Standards Institute. The evaluation of the interaction between micafungin with Hsp90 inhibitors was realized using the checkerboard methodology. According to the polyphasic taxonomy, C. parapsilosis sensu stricto was the most frequently identified, followed by C. orthopsilosis and C. metapsilosis, and one isolate of Lodderomyces elongisporus was identified by genetic sequencing. The Hsp90 inhibitor geladanamycin associated with micafungin showed a synergic effect in 31.25% of the isolates, a better result was observed with radicicol, which shows synergic effect in 56.25% tested yeasts. The results obtained demonstrate that blocking Hsp90 could be effective to reduce antifungal resistance to echinocandins.

Decreased incidence of late-onset sepsis during the SARS-CoV-2 pandemic in Italy: a multicentric study on a cohort of infants requiring major surgery

Changes in the organization of the clinical care wards, requested by the SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) pandemic, have influenced the environmental circulation of other pathogens. The implementation of prevention procedures may have led to a decrease in the incidence of healthcare-associated infections. We aimed to investigate the impact of prevention and control measures for preventing the COVID-19 spread on the incidence of bacterial sepsis and invasive fungal infections in neonates and infants requiring major surgery. We compared the incidence of bacterial and fungal sepsis and their risk factors observed before the SARS-CoV-2 pandemic (from 01/10/2018 to 29/02/2020) with those observed during the pandemic (from 01/03/2020 to 07/05/2021) in 13 level III Neonatal Intensive Care Units in Italy, through a secondary analysis of data, collected during a prospective multicenter study (REF). The patients enrolled were infants within three months of life, hospitalized in the two periods in the participating centers to undergo major surgery. Among 541 enrolled patients, 324 (59.9%) were born in the pre-pandemic period and 217 (40.1%) during the pandemic. The incidence density (ID) of any infection in the pre-pandemic period was 16.0/1000 patient days versus 13.6/1000 patient days in the pandemic period (p < 0.001). One hundred and forty-five (145/324; 44.8%) patients developed at least one episode of bacterial sepsis in the pre-pandemic period, versus 103/217 (31.8%) patients, during the pandemic (p = 0.539). Concerning fungal sepsis, 12 (3.7%) patients had one episode in the pre-pandemic period versus 11 (5.1%) patients during the pandemic (p = 0.516). The most significant differences observed in the use of healthcare procedures were the reduction of CVC days, the reduced use of antibiotics pre-surgery, and that of proton pump inhibitors during the SARS-CoV-2 pandemic compared with the previous period.

CONCLUSIONS

In our cohort of patients with major surgical needs, the reduction of CVC days, pre-surgery antibiotics administration, and current use of proton pump inhibitors, during the SARS-CoV-2 pandemic, led to a decrease in the incidence of late-onset sepsis.

WHAT IS KNOWN

• Most cases of late-onset sepsis in neonates are referred to as central line-associated bloodstream infections. • In adults, the COVID-19 outbreak negatively influenced healthcare-associated infection rates and infection clusters within hospitals.

WHAT IS NEW

• In neonates and infants undergoing major surgery the incidence density of infections was lower in the pandemic period than before. • The most significant differences observed in the use of healthcare procedures were the reduction of CVC days, the reduced use of antibiotics before surgery, and that of proton pump inhibitors during the pandemic compared with previously.

Biofilm: The invisible culprit in catheter-induced candidemia

Candidemia is the most common form of invasive fungal infection associated with several risk factors, and one of them is the use of medical devices, to which microbial biofilms can attach. Candidemia related to the use of peripheral intravascular and central venous catheters (CVC) is referred to as Candida catheter-related bloodstream infection, with more than 90% being related to CVC usage. The infection is associated with a higher morbidity and mortality rate than nosocomial bacterial infections. Candida spp. can protect themselves from the host immune system and antifungal drugs because of the biofilm structure, which is potentiated by the extracellular matrix (ECM). Candida albicans and Candida parapsilosis are the most pathogenic species often found to form biofilms associated with catheter usage. Biofilm formation of C. albicans includes four mechanisms: attachment, morphogenesis, maturation and dispersion. The biofilms formed between C. albicans and non-albicans spp. differ in ECM structure and composition and are associated with the persistence of colonization to infection for various catheter materials and antifungal resistance. Efforts to combat Candida spp. biofilm formation on catheters are still challenging because not all patients, especially those who are critically ill, can be recommended for catheter removal; also to be considered are the characteristics of the biofilm itself, which readily colonizes the permanent medical devices used. The limited choice and increasing systemic antifungal resistance also make treating it more difficult. Hence, alternative strategies have been developed to manage Candida biofilm. Current options for prevention or therapy in combination with systemic antifungal medications include lock therapy, catheter coating, natural peptide products and photodynamic inactivation.

Updates in Laboratory Identification of Invasive Fungal Infection in Neonates

Invasive fungal infection (IFI) in immunocompromised neonates is significantly associated with high morbidity and mortality and has become the third most common infection in Neonatal Intensive Care Units. The early diagnosis of IFI for neonatal patients is difficult because of the lack of specific symptoms. The traditional blood culture remains the gold standard in clinical diagnosis for neonatal patients but it requires a long duration, which delays treatment initiation. Detections of fungal cell-wall components are developed for early diagnosis but the diagnostic accuracy in neonates needs to be improved. PCR-based laboratory methods, such as real-time PCR, droplet digital PCR, and the cationic conjugated polymer fluorescence resonance energy transfer (CCP-FRET) system, distinguish the infected fungal species by their specific nucleic acids and show a high sensitivity and specificity. Particularly, the CCP-FRET system, which contains a cationic conjugated polymer (CCP) fluorescent probe and pathogen-specific DNA labeled with fluorescent dyes, could identify multiple infections simultaneously. In the CCP-FRET system, the CCP and fungal DNA fragments can self-assemble into a complex with an electrostatic interaction and the CCP triggers the FRET effect under ultraviolet light to make the infection visible. Here, we summarize the recent laboratory methods for neonatal IFI identification and provide a new perspective for early clinical fungal diagnosis.

Neonatal Brain Abscess with Serratia marcescens after Intrauterine Infection: A Case Report

Brain abscesses are a possible complication of bacterial sepsis or central nervous system infection but are uncommon in the neonatal period. Gram-negative organisms often cause them, but Serratia marcescens is an unusual cause of sepsis and meningitis in this age group. This pathogen is opportunistic and frequently responsible for nosocomial infections. Despite the existing antibiotics and modern radiological tools, mortality and morbidity remain significant in this group of patients. We report an unusual unilocular brain abscess in a preterm neonate caused by Serratia marcescens. The infection had an intrauterine onset. The pregnancy was achieved through assisted human reproduction techniques. It was a high-risk pregnancy, with pregnancy-induced hypertension, imminent abortion, and required prolonged hospitalization of the pregnant woman with multiple vaginal examinations. The infant was treated with multiple antibiotic cures and percutaneous drainage of the brain abscess associated with local antibiotic treatment. Despite treatment, evolution was unfavorable, complicated by fungal sepsis (Candida parapsilosis) and multiple organ dysfunction syndrome.

Genetic Identification of Methicillin-Resistant Staphylococcus aureus Nasal Carriage and Its Antibiogram among Kidney Dialysis Patients at a Tertiary Care Hospital in AL-Karak, Jordan

Background. Methicillin-resistant Staphylococcus aureus (MRSA) is a major bacterial pathogen. Aim. The present study aimed to determine the incidence of MRSA infections among kidney dialysis patients and the antibiotic susceptibility patterns and investigate the prevalence of mecA gene among MRSA isolates. Materials and Methods. A total of 83 nasal sterile cotton swabs samples were obtained from hemodialysis patients from Al-Karak Governmental Hospital, Al-Karak, Jordan. Collected and cultured on nutrient agar and mannitol salt agar and incubating at 37°C for 24–48 hours, Staphylococcus aureus (S. aureus) strains were identified by gram stain, coagulase test, and catalase tests. The MRSA isolates were tested for the presence of MecA and SCCmec genes using the Xpert SA Nasal Complete assay real-time PCR. Factors such as age and gender were included in the study. The antibiotic profile tested by using the disc diffusion method tested all MRSA isolates. Results. This study showed that 10.8% of the cultures’ growth was S. aureus and 9.6% of all the patients were infected with MRSA, with no relationship between the number and frequency of MRSA according to the patient’s gender or age. All MRSA (100%) isolates have both genes (MecA genes and SCCmec genes), and all samples were resistant to oxacillin, ceftazidime, cefoxitin, aztreonam, and ampicillin. Conclusion. The MRSA prevalence was determined among kidney dialysis patients in the hospital. All positive samples were resistant to oxacillin, ceftazidime, cefoxitin, aztreonam, and ampicillin, which is a very rare finding, and this will give the scientists and doctors a dangerous indication about health-care centers in the Al-Karak city of Jordan.

Prophylaxis of Invasive Fungal Infection in Neonates: A Narrative Review for Practical Purposes

Candida albicans is the most frequent cause of invasive fungal disease in preterm and/or low birth weight neonates, followed by Candida parapsilosis, whilst infections from other species are rare. Considering the severity of the disease, associated with poor clinical signs and diagnostic difficulties, primary prophylaxis becomes relevant. This paper summarizes the pathogenesis and clinical presentation of invasive candidiasis in neonates, focusing on prophylaxis. For late onset invasive disease, e.g., those occurring after the 3rd (or 7th according to some definitions) day of life possible approaches are the use of fluconazole, recommended in case of weight <1000 g or <1500 g if the local incidence of invasive candidiasis is higher than 2%, or the use of nystatin (for patients < 1500 g). Micafungin must be used in case of colonization by Candida auris, or in centers with a high prevalence of this pathogen. Concurrently, correct management of the central venous catheter and isolation procedures, with special regard to patients colonized by resistant strains, are fundamental. Other approaches such as reduced use of H₂ blockers and broad-spectrum antibiotics (e.g., 3rd generation cephalosporins or carbapenems) and promotion of breast feeding proved useful. Reduction of early-onset infections (those occurring in the first 3 days of life) can also be obtained by treating maternal vulvo-vaginal candidiasis, which can represent a fastidious problem during pregnancy. In this case, topic azoles (the only recommendable treatment) can represent a kind of "prophylaxis" of early neonatal candidiasis. However, it must always be remembered that prophylaxis reduces the risk of invasive candidiasis but can not completely eliminate its occurrence, with the parallel risk of selecting for antifungal-resistant strains. Clinicians must maintain a high level of suspicion to start an appropriate therapy and strict epidemiological surveillance to identify the occurrence of clusters and the appearance of strains resistant to prophylaxis.

Characterization of nanomaterials synthesized from Spirulina platensis extract and their potential antifungal activity

Nowadays, fungal infections increase, and the demand of novel antifungal agents is constantly rising. In the present study, silver, titanium dioxide, cobalt (II) hydroxide and cobalt (II,III) oxide nanomaterials have been synthesized from Spirulina platensis extract. The synthesis mechanism has been studied using GCMS and FTIR thus confirming the involvement of secondary metabolites, mainly amines. The obtained products have been analysed using XRD, SEM, TGA and zeta potential techniques. The findings revealed average crystallite size of 15.22 nm with 9.72 nm for oval-shaped silver nanoparticles increasing to 26.01 nm and 24.86 nm after calcination and 4.81 nm for spherical-shaped titanium dioxide nanoparticles which decreased to 4.62 nm after calcination. Nanoflake shape has been observed for cobalt hydroxide nanomaterials and for cobalt (II, III) oxide with crystallite size of 3.52 nm and 13.28 nm, respectively. Silver nanoparticles showed the best thermal and water dispersion stability of all the prepared structures. Once subjected to three different Candida species (C. albicans, C. glabrata, and C. krusei) silver nanoparticles and cobalt (II) hydroxide nanomaterials showed strong antifungal activity at 50 μg/mL with minimum inhibitory concentration (MIC) values. After light exposition, MIC values for nanomaterials decreased (to 12.5 μg/mL) for C. krusei and increased (100 μg/mL) for C. albicans and C. glabrata.

Clinical and Microbiological Characteristics of Neonates with Candidemia and Impacts of Therapeutic Strategies on the Outcomes

Neonatal candidemia is associated with significant morbidities and a high mortality rate. We aimed to investigate the clinical characteristics of Candida bloodstream infections in neonates and the impact of therapeutic strategies on the outcomes. We identified all the neonates with candidemia from a medical center in Taiwan over an 18-year period (2003−2021) and analyzed them. Clinical isolates were confirmed by DNA sequencing, and antifungal susceptibility testing was performed. The prognostic factors associated with clinical treatment failure (30-day, all-cause mortality and persistent candidemia > 72 h after antifungal agents) and in-hospital mortality were analyzed using logistic regression modeling. A total of 123 neonates with 139 episodes of candidemia were included in the study. The median (IQR) gestational age and birth weight of the neonates with candidemia were 29.0 (26.0−35.0) weeks and 1104.0 (762.0−2055) g, respectively. The most common Candida spp. was Candida albicans (n = 57, 41.0%), followed by C. parapsilosis (n = 44, 31.7%), Candida guilliermondii (n = 12, 8.6%), and C. glabrata (n = 11, 7.9%). The overall susceptibility to fluconazole was 81.3%, and the resistant rates against other antifungal agents were less than 3%. The cumulative mortality rate at 7 and 30 days after the first episode of candidemia was 11.3% and 32.3%, respectively. The overall in-hospital mortality rate was 42.3%. The treatment outcomes did not change over the study period and were not affected by delayed initiation of antifungal agents. Multivariate analysis showed that delayed catheter removal (odds ratio [OR], 5.54; 95% confidence interval [CI]: 1.93−15.86, p = 0.001), septic shock (OR, 7.88; 95% CI: 2.83−21.93, p < 0.001), and multiple chronic comorbidities (OR, 8.71; 95% CI: 1.82−41.81, p = 0.007) were independently associated with the final in-hospital mortality. We concluded that the overall mortality of neonatal candidemia has remained consistently high over the past decade. Prompt early catheter removal and an aggressive treatment strategy for neonatal candidemia with septic shock would be critical to improving patient outcomes.

Candida albicans: A Major Fungal Pathogen of Humans

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Characteristics of Invasive Pulmonary Fungal Diseases Diagnosed by Pathological Examination

Objective

To explore the characteristics of invasive pulmonary fungal disease and the spectrum of pathogens causing invasive pulmonary fungal disease diagnosed by pathological examination using fungal stains.

Methods

Patients with an invasive pulmonary fungal disease diagnosed by histopathological analysis through the use of fungal stains (including Grocott's methenamine silver and periodic acid-Schiff stains) were included in this study. The clinical records, radiological reports, pathology, and fungal culture results were reviewed.

Results

Forty-eight invasive pulmonary fungal disease patients diagnosed by histopathological analysis in the Tianjin Haihe Hospital (including 8 cases obtained by pulmonary resection, 35 cases by fiberoptic bronchoscopic biopsy, and 5 cases by percutaneous lung biopsy) were included. There were 24 male and 24 female patients, aged 21–80 years (53 ± 13 years). There were 37 cases of pulmonary aspergillosis, 4 cases of pulmonary cryptococcosis, 2 cases of pulmonary mucormycosis, and 5 in which pathogens were not determined due to limited tissue availability. Among 48 cases, 32 specimens were submitted to fungal culture. No fungus was detected in culture, although 26 cases of fungus infections were diagnosed by histopathological analysis. Only 3 cases were consistent between histopathological and culture results. In 3 cases, the pathogen was identified as Aspergillus spp. by the histopathological analysis, while the contrasting fungal culture results identified Candida albicans.

Conclusion

Candida albicans pneumonia was rare, while aspergillosis was common in invasive pulmonary fungal disease diagnosed by histopathological analysis. The majority of patients with an invasive pulmonary fungal disease were culture-negative. Although culture can clarify the fungal pathogen species, it has low sensitivity. Pathological examination with fungal stains has its advantages in diagnosing fungal disease; therefore, more attention should be paid to the role of pathological examination in the diagnosis of fungal disease.