Comparative study of different methods of diagnosis of invasive fungal infection in immunocompromised patients

Fungal infection is still a major cause of morbidity and mortality in cancer patients. Our study was conducted on 50 patients attending Al-Hussein university hospital complaining from different types of cancer were suffering from low grade fever, night sweat, weight loss, lassitude and easy fatigability. The cases were matched with 10 healthy controls of the same age and sex. Blood samples were collected and cultured to isolate fungal pathogens using conventional methods and BACTEC system. Positive cases were subcultured on Sabouraud dextrose Agar [SDA]. We describe a multiplex polymerase chain reaction [PCR] based approach to the detection and identification of pathogenic fungi which has potential for the diagnosis of invasive mycoses. PCR allowed the detection [universal PCR] and identification [species-specific PCR] of a fungal pathogen within 6 h from blood samples. Fungal isolates detected and identified using conventional and confirmatory methods were 7 cases [14%], while fungal isolates detected using PCR were 8 cases [18%]. Sensitivity and specificity of conventional methods in relation to PCR was; sensitivity [87.5%] and specificity [98.1%]. In our study Candida species were the only fungal pathogens with different frequency; Candida albicans [4 isolates], Candida tropicalis [2 isolates], Candida glabrata [1 isolate] and Candida parapsilosis [1 isolate]

Candidemia in neonates

Neonatal fungal sepsis is a risky condition that needs effort for early diagnosis and management Clinical diagnosis of sepsis is not easy, because symptoms and signs are not specific, and complication of clinical conditions can occur rapidly, even in asymptomatic newborn infants, long before blood culture results are available. The aim of this work was to study risk factors for neonatal candidemia and evaluate the role of molecular biology in rapid diagnosis of neonatal sepsis using Polymerase Chain Reaction technique. One hundred neonates were studied. Twelve cases showed infection with yeast species [12% of neonates]. Three yeast species were isolated from blood of neonates. Candida albicans was the predominant species, and was isolated from 10 cases representing 83.3% of the total yeast isolates, while Non albicans Candida was isolated from two cases only, representing 16.7% of the total yeast isolates. They were identified as Candida parapsilosis and Debaryomyces hansenii which also known as Candida famata. Low birth weight and preterm delivery were significantly increasing the incidence of neonatal fungal sepsis. Detection of candidemia in neonatal blood was carried out by polymerase chain reaction [PCR] for universal yeast to amplify the V3 region of the large subunit ribosomal DNA. Analysis of neonatal cases showed that there is a perfect correlation between molecular and microbiological data in all infected cases. This means that PCR for universal yeast is recommended to be used for confirmation of fungemia in neonates, long before blood culture results are available