An Update on the Epidemiology of Candidemia in Children

Candidemia is a cause of significant morbidity and mortality in neonates and children. Risk factors for candidemia include prolonged stay in the intensive care unit, prior antibiotic therapy, immunosuppression related to malignancy, transplantation, use of immunosuppressants or steroids, neutropenia, need for mechanical ventilation, use of vasopressors, recent surgery (especially gastrointestinal), intravenous catheters and receipt of total parenteral nutrition. Candida albicans followed by C. parapsilosis are the most common species causing candidemia in children. Clinicians must be aware of the risk factors for candidemia and the local epidemiology of Candida species in order to direct antifungal therapy appropriately. Ongoing efforts to minimize health care-associated candidemia through infection control practices, judicious antimicrobial use and antifungal prophylaxis in appropriate situations are important to reducing Candida-associated morbidity and mortality in neonates and children.     

Epidemiology, species distribution, antifungal susceptibility and outcome of nosocomial candidemia in a tertiary care hospital in Italy

Candida is an important cause of bloodstream infections (BSI), causing significant mortality and morbidity in health care settings. From January 2008 to December 2010 all consecutive patients who developed candidemia at San Martino University Hospital, Italy were enrolled in the study. A total of 348 episodes of candidaemia were identified during the study period (January 2008-December 2010), with an incidence of 1,73 episodes/1000 admissions. Globally, albicans and non-albicans species caused around 50% of the cases each. Non-albicans included Candida parapsilosis (28.4%), Candida glabrata (9.5%), Candida tropicalis (6.6%), and Candida krusei (2.6%). Out of 324 evaluable patients, 141 (43.5%) died within 30 days from the onset of candidemia. C. parapsilosis candidemia was associated with the lowest mortality rate (36.2%). In contrast, patients with C. krusei BSI had the highest mortality rate (55.5%) in this cohort. Regarding the crude mortality in the different units, patients in Internal Medicine wards had the highest mortality rate (54.1%), followed by patients in ICU and Hemato-Oncology wards (47.6%).This report shows that candidemia is a significant source of morbidity in Italy, with a substantial burden of disease, mortality, and likely high associated costs. Although our high rates of candidemia may be related to high rates of BSI in general in Italian public hospitals, reasons for these high rates are not clear and warrant further study. Determining factors associated with these high rates may lead to identifying measures that can help to prevent disease.     

Species distribution, antifungal susceptibility and clonal relatedness of Candida isolates from patients in neonatal and pediatric intensive care units at a medical center in Turkey

The aim of this study was to assess species distribution, antifungal susceptibility and clonal relationships among Candida strains isolated from a group of pediatric/neonatal intensive care (PICU/NICU) patients that had a very high mortality rate (76%). The cases of 21 patients (19 with candidemia, 2 with Candida meningitides) treated over a 1-year period in a Turkish hospital PICU and NICU were retrospectively analyzed. Twenty-eight Candida isolates were detected from blood (20), cerebrospinal fluid (CSF) (2) and other specimens (6). Candida species were identified using the API ID 32C System. Susceptibility testing was done (all 28 isolates) for amphotericin B, fluconazole and itraconazole using the broth microdilution method. Arbitrarily primed polymerase chain reaction (AP-PCR) was used for molecular typing of the 3 most common ones; C. albicans (15), C. parapsilosis (6), and C. pelliculosa (4). Electrophoretic karyotyping (EK) was done to check clonal identity obtained by AP-PCR. Of the 20 blood isolates, 8 (40%) were C. albicans, 12 (60%) were non-albicans Candida, and one of the 2 CSF isolates was C. albicans. The overall species distribution was as follows: 15 C. albicans isolates, 6 C. parapsilosis isolates, 4 C. pelliculosa isolates, 2 C. famata isolates and 1 C tropicalis isolate. Amphotericin B had the best antifungal activity with a MIC90 of 0.125 microg/ml, and the rates of susceptibility to fluconazole and itraconazole were 93% and 82%, respectively. AP-PCR revealed 11 genotypes (4 were identical pairs, 7 were distinct) among the 15 C. albicans isolates, 2 genotypes (5 were classified in the same type) among the 6 C. parapsilosis isolates, and 4 separate genotypes for the 4 C. pelliculosa isolates. Karyotyping results correlated well with the AP-PCR findings. As indicated in the previous research, our results confirmed that non-albicans Candida species have become more frequently causative agents for invasive fungal infections in the ICU. Transmission of C. albicans and C. pelliculosa was relatively low, but transmission of C. parapsilosis was high, suggesting that more effective control and very strict treatment protocols are needed for patients having high mortality and invasive fungal infection in ICU.     

Epidemiology of candidemia in Spain - Multicenter study

The results of the epidemiological study on candidemias with the highest number of cases carried out in Spain is presented. This study is included in the Epidemiological Survey of Candidemia in Europe supported by the ECMM in which another five countries take part. In the Spanish study, 19 hospitals participated, 290 candidemia episodes were analysed (80 in children under 15 years and 210 in adults), 293 strains of yeasts being isolated. Both in children and in adults, the risks factors more frequently observed were the intravenous catheter and previous antibiotic therapy. In adults, the most habitual underlying disease was the solid tumor and, in children, hematological diseases. Candida albicans was the most prevalent species isolated in adults (46.1%) and Candida parapsilosis in children (50%). As part of the therapy, the intravenous line was removed and antifungal treatment was prescribed to 74% and 92.5% of children, respectively and to 43.8% and 73.8% of adults. The antifungal agent of election in adults was fluconazole (54.8%) and liposomal amphotericin B (58.1%) in children. The global mortality of the study was 38.9%, which for ages was major in adults (41.4%) than in children (38.7%). The geographical distribution of the isolated species was homogeneous, C. albicans being the predominant species, with the exception of Galicia and Extremadura where C. parapsilosis was the most frequent.     

念珠菌血症的危险因素和预后分析

目的了解念珠菌血症的临床特点、分布及预后危险因素。方法回顾性调查2012年1月至2014年5月浙江大学医学院附属第一医院所有血培养念珠菌阳性的患者资料,分析其临床特征、治疗和预后等,采用χ2检验或Fisher精确概率法进行预后单因素分析,采用多元Logistic回归进行预后多因素分析。结果 97例念珠菌血症患者入选,其中男性64例,女性33例,平均年龄（59.6±16.8）岁。包括白色念珠菌51例（52.6%）,非白色念珠菌46例（47.4%）,非白色念珠菌中热带念珠菌17例（17.5%）、近平滑念珠菌12例（12.4%）、光滑念珠菌7例（7.2%）、无名念珠菌4例（4.1%）、其他念珠菌6例（6.2%）。念珠菌培养阳性后30 d内死亡37例,30 d病死率为38.1%。Logistic多因素回归分析显示：年龄（OR=1.104,95%CI：1.041~1.170,P=0.001）、血液系统肿瘤（OR=63.256,95%CI：2.898~1380.833,P=0.008）、APACHEⅡ评分（OR=1.176,95%CI：1.053~1.313,P=0.004）、感染性休克（OR=12.032,95%CI：2.389~60.587,P=0.003）及合并细菌性血流感染（OR=26.016,95%CI：4.002~169.127,P=0.001）是其死亡的独立危险因素;而拔除或更换深静脉置管（OR=0.118,95%CI：0.025~0.559,P=0.007）是念珠菌血症死亡的独立保护性因素。结论念珠菌血症患者分布科室范围广、基础疾病重、侵入性操作多。年龄、高APACHEⅡ评分、感染性休克及合并细菌血流感染是影响念珠菌血症死亡的独立危险因素,拔除或更换深静脉置管是念珠菌血症死亡的独立保护性因素。     

Clinical microbiology of neonatal candidiasis in Hungary

The occurrence of Candida spp. was investigated during a three-year period in two neonatal intensive care units, Budapest, Hungary. The species distribution among the 41 analysed cases was the following: C. albicans (30/41, 73%), C. parapsilosis (10/41, 24%) and C. glabrata (1/41, 3%). All of the isolates were susceptible to the tested drugs. There was a significant difference in the birth weight, the gestational age <30 weeks and the occurrence of caesarean section between the C. albicans and the C. parapsilosis groups of the cases. Respiratory tract colonization was the same (76-77%) in the extremely low birth weight (ELBW) and the very low birth weight (VLBW) groups. Comparing the ELBW, VLBW, and >1500 g birth weight groups, significant difference was found in the parenteral nutrition, the gestation weeks <36 or <30, the polymicrobial infection and the transfusion. The ratio of C. albicans, C. parapsilosis and C. glabrata was 9:7:1 in ELBW group; 6:3:0 in VLBW group and 15:1:0 in >1500 g group. The mortality rate for C. parapsilosis was higher than for C. albicans.     

Candidemia in the Pediatric Intensive Care Unit: What’s Different from Candidemia in Adults?

Candida species bloodstream infections have been associated with high morbidity and mortality, especially in patients hospitalized in a pediatric intensive care unit (PICU). The incidence of such infections is rising because of malignancies, prolonged PICU stay, and the use of broad-spectrum antibiotics. Although Candida albicans remains the most frequently isolated species, non-albicans Candida species have shown an increased frequency. Treatment with fluconazole or an echinocandin should be considered in patients at high risk for candidemia or as initial treatment for non-neutropenic patients with candidemia, in addition to the removal of intravascular catheters. Treatment with a lipid formulation of amphotericin B or caspofungin is suggested for neutropenic patients. Early diagnosis, prompt therapy, and prevention are the cornerstones of controlling infection and improving outcome. Although there are some differences between children and adults with candidemia, especially in antifungal drug therapy and outcome, in general the incidence, risk factors, species variation, diagnostic methods, and management are similar.     

念珠菌血症时甘露聚糖抗原及其IgG抗体检测诊断价值的临床研究

目的评价念珠菌甘露聚糖抗原（M抗原）及甘露聚糖IgG抗体（M-IgG抗体）检测诊断念珠菌血症的价值。方法收集2013年5月～2014年1月我院住院患者及健康体检人群共107例,包括念珠菌血症组（念珠菌血培养阳性患者）13例、危险因素组（临床诊断侵袭性念珠菌病或接受化疗恶性疾病、留置深静脉置管等侵袭性念珠菌病感染高危患者）63例和对照组（健康体检人群）31例。通过ELISA方法检测甘露聚糖抗原及甘露聚糖IgG抗体,比较3组人群检测阳性情况及持续时间,计算两种方法的灵敏度、特异度、阴性预测值、阳性预测值、ROC曲线下面积及Kappa值。结果白念珠菌和光滑念珠菌为念珠菌血症的主要念珠菌病原,均为5例。念珠菌血症的7／14菌株（1例患者合并2种念珠菌感染）来自重症医学科,其次为感染内科（2／14株）。除1例死亡病例外,余12例患者进行了M抗原和M—IgG抗体监测。首次M抗原检测中,4例阳性,1例可疑阳性;首次M-IgG抗体检测中,11例阳性,1例可疑阳性。经抗真菌治疗,监测14d,M-IgG抗体持续阳性时间长于M抗原。甘露聚糖抗原在诊断念珠菌血症的敏感度41．7％,特异度98．8％,阴性预测值92．4％,阳性预测值100％。甘露聚糖IgG抗体在诊断念珠菌血症的敏感度91．7％,特异度52．8％,阴性预测值100％,阳性预测值27．5％。M抗原、M抗原并M—IgG抗体作为念珠菌血症时诊断实验的ROC曲线下面积均为0．708（95％CI：0．517—0．900）,两者的Kappa值分别为0．520和0．559。结论甘露聚糖抗原在诊断念珠菌血症时的特异度较高,甘露聚糖IgG抗体在诊断念珠菌血症的敏感性较高,两者的联合检测可以适当提高检测的敏感度及特异度,有助于念珠菌血症的诊断。     

Fungemia in cancer patients in Brazil: Predominance of non-albicans species

The objective of this study was to characterize the epidemiology of candidemia in cancer patients in the city of Rio de Janeiro, Brazil. An 18-month survey of fungemia in patients with cancer was undertaken in three Hospitals in Rio de Janeiro. Forty-three episodes of candidemia were identified in 43 patients, 43 of which were episodes of candidemia; in ten cases the strains were not available for further identification of species and were excluded from this analysis. The overall distribution of fungi causing fungemia was: Candida albicans (5), Candida tropicalis (16), Candida parapsilosis (6), Candida guilliermondii (4), Candida lusitaniae (1) and Candida stellatoidea (1). Antifungal prophylaxis had been administered before the episode of fungemia in only six patients (18.2%): oral itraconazole in three patients and oral nistatin, low dose intravenous amphotericin B and oral fluconazole in one patient each. There was no difference in the presence of risk factors, clinical characteristics or in the outcome between albicans and non-albicans species, nor between Candida tropicalis and other non-albicans species. There was a clear predominance of non-albicans species, regardless of the underlying disease, antifungal prophylaxis or the presence of neutropenia. This revised version was published online in June 2006 with corrections to the Cover Date.     

Recent changes in candidemia trends in a tertiary hospital (2011–2018)

BackgroundThe epidemiology of candidemia has changed over the last decades and varies widely among geographic areas.AimsWe examined in children (aged 0–14) with candidemia the trends in the incidence rate of this infection, as well as the clinical characteristics of the patients, in order to optimize the prognosis and the control measures of this serious disease.MethodsA retrospective cohort study of candidemia in the period 2011–2018 in the neonatal intensive care unit (NICU), pediatric ICU (PICU) and pediatric wards of a tertiary hospital, was conducted. The clinical course, Candida species isolated, antifungal susceptibility, outcome and incidence rates were analyzed and compared.ResultsWe diagnosed 68 episodes of candidemia in 62 children, 48% occurred in the NICU, 31% in the PICU and 21% in pediatric wards. Candida albicans was the most frequent species isolated in NICU infants (53%), and Candida parapsilosis predominated among PICU patients (59%) and pediatric wards (50%). One third of NICU infants had invasive candidiasis (IC), most of them having extremely low birth weight (ELBW) (35%). All isolates were susceptible to the antifungal administered. Over time, the incidence of candidemia decreased in the PICU (from 2.2 to 0.3 episodes/1000 patient-days, OR = 0.6; 95%CI 0.5–0.8), whereas in the NICU and in the wards remained stable. Mortality occurred mostly in NICU patients (26%), predominated in ELBW infants and did not change over time.ConclusionsThe higher incidence and mortality of candidemia and IC observed in preterm infants requires a continuous evaluation of practices and diagnostic methods which will allow improving the prognosis of this most vulnerable population.     

血培养分离出212株念珠菌的菌种分布及耐药性分析

目的分析血培养分离出的念珠菌的菌种分布及耐药分析,为临床念珠菌血症的诊治提供理论依据。方法回顾性分析2017年1月—2020年12月期间,本院血培养分离出的念珠菌的菌种分布、药敏试验结果及患者血培养分离出念珠菌前后96 h内的G试验结果。结果血培养中分离出念珠菌314例,阳性率2.1%,其中非重复分离株212例。检出率最高的是近平滑念珠菌(72株,34.0%),其次是白念珠菌(55株,25.9%)和光滑念珠菌(28株,13.2%)。念珠菌检出率最高的科室为ICU(62株,29.2%),其次是新生儿科(39株,18.4%)和血液科(20株,9.4%)。检出的212株念珠菌除一株近平滑念珠菌为两性霉素B的非野生株,其余均为两性霉素B的野生株。白念珠菌对唑类药物的敏感率超过90%。但光滑念珠菌和热带念珠菌对唑类药物的敏感性较低。血培养分离出念珠菌的前后96 h内,G试验的阳性率为73.7%。结论本院念珠菌检出率前3位分别是近平滑念珠菌、白念珠菌和光滑念珠菌。光滑念珠菌、热带念珠菌对唑类药物敏感性比较低,在经验用药时需要合理选择抗真菌药物。G试验对念珠菌血症有较高的价值,需要对结果进行动态监测。     

Nosocomial Bloodstream Candida Infections in a Tertiary-Care Hospital in South Brazil: A 4-Year Survey

The aims of this study were to evaluate the epidemiology of nosocomial candidemia in a tertiary hospital in South Brazil and the in vitro antifungal susceptibility of isolates. Blood strains from 108 patients were identified by PCR-based method. Some 30.5 % of candidemia were caused by Candida tropicalis, 28.7 % were due to Candida albicans, 24.1 % with Candida parapsilosis sensu stricto, 8.3 % with Candida glabrata sensu lato, 1.8 % involved Candida krusei and 6.6 % with other species. Candidemia was more common in intensive care unit settings (66 %). In vitro susceptibility to antifungal drugs was determined by a microdilution method; and new species-specific clinical breakpoints for fluconazole and voriconazole were applied. Overall susceptibility rates were 100 % for itraconazole, 91 % for fluconazole, 98 % for voriconazole and 99 % for amphotericin B. Fluconazole resistance was mostly among C. parapsilosis sensu stricto isolates (26.9 %). Most of the findings reported here agreed with epidemiological features common to other tertiary hospitals in Brazil; but also revealed some peculiarities, such as a high frequency of C. tropicalis associated with candidemia. Besides, high rate of fluconazole resistance among C. parapsilosis stricto sensu isolates was obtained when applying the new species-specific clinical breakpoints.     

Species distribution and antifungal susceptibility profile of Candida spp. bloodstream isolates from Latin American hospitals

From March 1999 to March 2000, we conducted a prospective multicenter study of candidemia involving five tertiary care hospitals from four countries in Latin America. Yeast isolates were identified by classical methods and the antifungal susceptibility profile was determined according to the National Committee for Clinical Laboratory Standards microbroth assay method. During a 12 month-period we were able to collect a total of 103 bloodstream isolates of Candida spp. C. albicans was the most frequently isolated species accounting for 42% of all isolates. Non-albicans Candida species strains accounted for 58% of all episodes of candidemia and were mostly represented by C. tropicalis (24.2%) and C. parapsilosis (21.3%). It is noteworthy that we were able to identify two cases of C. lusitaniae from different institutions. In our casuistic, non-albicans Candida species isolates related to candidemic episodes were susceptible to fluconazole. Continuously surveillance programs are needed in order to identify possible changes in the species distribution and antifungal susceptibility patterns of yeasts that may occurs after increasing the use of azoles in Latin American hospitals.     

A genome sequence survey shows that the pathogenic yeast Candida parapsilosis has a defective MTLa1 allele at its mating type locus

Candida parapsilosis is responsible for ca. 15% of Candida infections and is of particular concern in neonates and surgical intensive care patients. The related species Candida albicans has recently been shown to possess a functional mating pathway. To analyze the analogous pathway in C. parapsilosis, we carried out a genome sequence survey of the type strain. We identified ca. 3,900 genes, with an average amino acid identity of 59% with C. albicans. Of these, 23 are predicted to be predominantly involved in mating. We identified a genomic locus homologous to the MTLa mating type locus of C. albicans, but the C. parapsilosis type strain has at least two internal stop codons in the MTLa1 open reading frame, and two predicted introns are not spliced. These stop codons were present in MTLa1 of all eight C. parapsilosis isolates tested. Furthermore, we found that all isolates of C. parapsilosis tested appear to contain only the MTLa idiomorph at the presumptive mating locus, unlike C. albicans and C. dubliniensis. MTLalpha sequences are present but at a different chromosomal location. It is therefore likely that all (or at least the majority) of C. parapsilosis isolates have a mating pathway that is either defective or substantially different from that of C. albicans.     

Aplicación de las técnicas de tipificación molecular al estudio de brotes hospitalarios de candidemia

Candidemia is an infectious complication mainly affecting hospitalized patients, particularly those admitted to intensive care units. Patient mortality can reach up to 40%. Candidemia is typically nosocomially-acquired, and horizontal transmission of Candida spp. can lead to the presence of outbreaks of candidemia. Genotyping of isolates of Candida causing candidemia can help us to understand the source of the infection, detect the hospital wards with active Candida spp. transmission and, consequently, improve the prevention of the infection. Several genotyping tools have been used for the molecular characterization of Candida isolates involved in outbreaks of candidemia. Genotyping procedures based on microsatellites are reproducible and show a high discriminatory power. Microsatellites are recommended for the study of outbreaks of candidemia. In most hospital outbreaks of candidemia, patients admitted to intensive care units are involved, mostly neonatal patients. The role of genotyping Candida isolates causing candidemia for the study of nosocomial outbreaks of candidemia is reviewed, as well as the patients more commonly affected by epidemic strains.     

Fungemia in acute leukemia patients: a single institution's experience

A retrospective study was conducted in 22 episodes of candidemia in 445 patients with acute leukemia (AL) (incidence 4.9%) observed at our Institution between February 1996 and November 2003 to evaluate the variables related to the onset and outcome of infection. Of 22 patients, 20 (90.9%) had refractory/relapsed AL. C. albicans was responsible for 7/22 of the fungemia cases (32%) and C. non albicans for 15/22 (68%). The median absolute neutrophil count was 0.1 x10(9)/L (range 0.04-0.3) at the time of the candidemia diagnosis. The fungemia responded to antifungal therapy in 15/22 (68.1%) patients; among patients with a positive outcome of the fungemia, in 14/15 (93.3%) the neutrophil count recovered within 7 days after the diagnosis of candidemia (p < 0.05). The mortality rate due to candidemia was 31.9% (1/7: 14.2% and 6/15: 40% in the C. albicans and C. non albicans groups, respectively). In our experience the determinants of a positive outcome of fungemia were infection by the C. albicans species and recovery of the neutrophil count.     

Nosocomial Candidemia; Risk Factors and Prognosis Revisited; 11 Years Experience from a Norwegian Secondary Hospital

The aim of the study was to review the epidemiology and prognosis of candidemia in a secondary hospital, and to examine the intra-hospital distribution of candidemia patients. Study design is a retrospective cohort study. Trough 2002–2012, 110 cases of candidemia were diagnosed, giving an incidence of 2, 6/100000 citizens/year. Overall prognosis of candidemia was dismal, with a 30 days case fatality rate of 49% and one year case fatality rate of 64%. Candidemia was a terminal event in 55% of 30 days non-survivors, defined as Candida blood cultures reported positive on the day of death or thereafter (39%), or treatment refrained due to hopeless short-term prognosis (16%). In terminal event candidemias, advanced or incurable cancer was present in 29%. Non-survivors at 30 days were 9 years (median) older than survivors. In 30 days survivors, candidemia was not recognised before discharge in 13% of cases. No treatment were given and no deaths or complications were observed in this group. Candidemia patients were grouped into 8 patient categories: Abdominal surgery (35%), urology (13%), other surgery (11%), pneumonia (13%), haematological malignancy (7%), intravenous drug abuse (4%), other medical (15%), and new-borns (3%). Candidemia was diagnosed while admitted in the ICU in 46% of patients. Urology related cases were all diagnosed in the general ward. Multiple surgical procedures were done in 60% of abdominal surgery patients. Antibiotics were administered prior to candidemia in 87% of patients, with median duration 17 (1–108) days. Neutropenia was less common than expected in patients with candidemia (8/105) and closely associated to haematological malignancy (6/8). Compared with previous national figures the epidemiology of invasive candidiasis seems not to have changed over the last decade.     

Diabetes mellitus and candidiases

Patients in various clinical states of diabetes mellitus (according to the recommendation of the American Diabetes Association) as a primary diagnosis were examined for fungal infections by Candida species. Candida spp. were detected in urine, in the material taken from the mouth cavity, nails, skin lesions, ears and eyes, by cultivation on the Sabouraud agar, CHROMagar Candida, and by saccharide assimilation. In the group of diabetics with symptoms of oral candidiasis and denture stomatitis C. albicans was identified in 8 cases, C. tropicalis in 3, C. parapsilosis in 2; 1 strain of C. guilliermondii was also isolated. In patients with urinary tract infections the presence of C. albicans was shown in 12 cases; C. parapsilosis was detected in 6 cases and two strains of each C. tropicalis and C. krusei were also isolated. In patients with leg ulcers C. albicans (25 cases), C. parapsilosis (5), C. tropicalis (3) and one strain of each C. krusei and C. robusta were isolated. Otomycosis was associated with one strain of C. albicans, C. parapsilosis, C. tropicalis and C. guilliermondii. C. albicans was most frequently associated with onychomycosis, paronychia and endophthalmitis; C. parapsilosis was the second most rated yeast.     

Live imaging of disseminated candidiasis in zebrafish reveals role of phagocyte oxidase in limiting filamentous growth

Candida albicans is a human commensal and a clinically important fungal pathogen that grows in both yeast and hyphal forms during human infection. Although Candida can cause cutaneous and mucosal disease, systemic infections cause the greatest mortality in hospitals. Candidemia occurs primarily in immunocompromised patients, for whom the innate immune system plays a paramount role in immunity. We have developed a novel transparent vertebrate model of candidemia to probe the molecular nature of Candida-innate immune system interactions in an intact host. Our zebrafish infection model results in a lethal disseminated disease that shares important traits with disseminated candidiasis in mammals, including dimorphic fungal growth, dependence on hyphal growth for virulence, and dependence on the phagocyte NADPH oxidase for immunity. Dual imaging of fluorescently marked immune cells and fungi revealed that phagocytosed yeast cells can remain viable and even divide within macrophages without germinating. Similarly, although we observed apparently killed yeast cells within neutrophils, most yeast cells within these innate immune cells were viable. Exploiting this model, we combined intravital imaging with gene knockdown to show for the first time that NADPH oxidase is required for regulation of C. albicans filamentation in vivo. The transparent and easily manipulated larval zebrafish model promises to provide a unique tool for dissecting the molecular basis of phagocyte NADPH oxidase-mediated limitation of filamentous growth in vivo.     

儿童重症监护病房医院感染暴发白色念珠菌血流感染4例分析

摘要 目的：探讨儿童重症监护病房白色念珠菌血流感染暴发的临床表现、危险因素、控制措施等,为预防和控制院内白色念珠菌血流感染暴发提供科学依据。方法：以2018年7月我院儿童重症监护病房发生的4例白色念珠菌血流感染暴发患儿为研究对象,分析患儿临床情况、临床特征、危险因素、暴发原因以及采取的预防控制措施。结果：4例医院感染暴发白色念珠菌血流感染患儿均存在基础疾病、有机械通气史、存在中心静脉或动脉置管、静脉或动脉置管前后均使用碘伏消毒、曾使用广谱抗生素、输血制品,白色念珠菌血流感染后最突出的临床表现均是发热。药敏方面,医院感染暴发的4例白色念珠菌感染患儿对唑类及5-氟胞嘧啶均耐药,但对两性霉素B均敏感。经拔除血管置管、减少或者避免广谱抗菌药的应用,根据药敏使用卡泊芬净及两性霉素B抗真菌等积极治疗,1例患儿放弃治疗后死亡,3例患儿顺利出院。通过Fisher确切概率法分析可知,留置中心静脉或动脉置管是儿童重症监护病房发生医院感染暴发白色念珠菌血流感染的危险因素（P<0.05）。结论：留置中心静脉或动脉置管是儿童重症监护病房发生医院感染暴发白色念珠菌血流感染的危险因素,医院感染暴发白色念珠菌血流感染患儿最突出的临床表现是发热,唑类及5-氟胞嘧啶耐药的患儿使用卡泊芬净及两性霉素B可能获得较好的治疗效果。