Yeast-like microorganisms in eye infections

Etiological agents of fungal endophthalmitis: diagnosis and management

Endophthalmitis caused by fungi is commonly diagnosed around the world in apparently healthy and immunocompromised individuals. An accurate clinical diagnosis for endophthalmitis confirmed by laboratory techniques is essential for early treatment with antifungal drugs, such as amphotericin B, imidazoles, and other antifungals. Here, we review endophthalmitis caused by fungi according to its classification into endogenous fungal endophthalmitis (EFE) and exogenous fungal endophthalmitis (EXFE). EFE is caused by endogenously acquired fungi, whereas the traumatic implantation of opportunistic fungal pathogens is the main feature of EXFE. We highlight the most important etiologies causing endophthalmitis and the steps required for a rapid diagnosis and management.

Candida parapsilosis, an emerging fungal pathogen

SUMMARY

Candida parapsilosis is an emerging major human pathogen that has dramatically increased in significance and prevalence over the past 2 decades, such that C. parapsilosis is now one of the leading causes of invasive candidal disease. Individuals at the highest risk for severe infection include neonates and patients in intensive care units. C. parapsilosis infections are especially associated with hyperalimentation solutions, prosthetic devices, and indwelling catheters, as well as the nosocomial spread of disease through the hands of health care workers. Factors involved in disease pathogenesis include the secretion of hydrolytic enzymes, adhesion to prosthetics, and biofilm formation. New molecular genetic tools are providing additional and much-needed information regarding C. parapsilosis virulence. The emerging information will provide a deeper understanding of C. parapsilosis pathogenesis and facilitate the development of new therapeutic approaches for treating C. parapsilosis infections.

Otomycoses of candidal origin in eastern Slovakia

Mycological analysis of swabs and scraping samples from the external ear canals of 40 patients with clinically diagnosed otomycosis (10 neonates, 30 adults) revealed the presence of fungi as etiological agents. They were investigated microscopically using 20 % potassium hydroxide, and by cultivation on Sabouraud's glucose agar. The Candida species were identified using the germ-tube test, micromorphology observations of colonies on rice agar, and particularly by the commercial kit AUXAcolor. The following Candida species were identified in the aural material examined: C. albicans (n = 21; 52.5 %), C. parapsilosis (11; 27.5), C. tropicalis (3; 7.5), C. krusei (3; 7.5), C. guilliermondii (2; 5.0). The above yeasts were present in samples together with Staphylococcus epidermidis (31), S. aureus (16), alpha-hemolytic streptococci (14), Neisseria spp. (14), Proteus mirabilis (3), Pseudomonas aeruginosa (3), Escherichia coli (1) and Haemophilus influenzae (1). The most frequent predisposing factors for otomycosis were swimming in public pools and/or bath, spa and diabetes mellitus.

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.

Candida--agent of the diaper dermatitis?

Occurrence of Candida spp. was determined in a population of 60 infants, 1-15-month-old, with diaper dermatitis, admitted to a neonatal intensive care unit in Hospital Saca (Kosice, Slovakia). Specimens were obtained from the perianal, pubic, inguinal, or gluteal areas that showed signs of secondary infection as manifested by erythema, oozing, vesiculopustular lesions, and pus formation. The most frequently isolated species was C. albicans (41), followed by C. parapsilosis (8), C. tropicalis (4), C. pulcherrima (4), C. guilliermondii (2), and C. zeylanoides (1). Other organisms present in the mixed culture from the diaper area were Staphylococcus aureus (6), Escherichia coli (3), and 2 strains of each group B and D streptococci, and Proteus mirabilis. Infants diapered exclusively in disposable diapers showed less rash than those diapered exclusively or sometimes in cloth diapers.

Candidal urinary tract infections caused by non-albicans Candida species

The incidence of non-albicans Candida and non-Candida species isolated from the urine of patients admitted to various departments of the Faculty Hospital of the Medical Faculty of Safárik University in Kosice was examined. From a total of 94 samples of analyzed urine 58 strains of C. albicans and 36 strains of yeasts belonging to 6 species of non-albicans Candida and non-Candida spp. were detected: C. parapsilosis (n = 23), C. tropicalis (6), C. krusei (3), C. robusta (2), C. catenulata (1) and Cryptococcus neoformans (1). In relation to the diagnosis, the yeasts were isolated from patients suffering from a kidneys disease, epididymitis, diabetes, neoplastic diseases, urogenital anomalies, obstructive uropathy, cystitis, prostatitis, hemolytic-uremic syndrome, and others.

Causative agents of nosocomial mycoses

In the last few years mycoses have been caused by fungi formerly considered to be harmless for humans. They cause diseases of plants and insects; some of them are also used in the industry. They are now usually called "emerging fungi". We investigated this flora with respect to their potential to cause infections in hospitals. These fungi are present in the air, on medical objects and instrumentation, in the respiratory tract and on the hands of hospital staff; other sources have been identified in the use of iatrogenic methods. Mycotic diseases, their risk factors, their clinical pictures, and spectra of agents were analyzed in 1990-2000; the results were compared with data in the literature. Transplantations were the most frequent risk factors, fungemia and abscess the most frequent clinical picture and filamentous fungi (genera Absidia, Acremonium, Alternaria, Apophysomyces, Aspergillus, Bipolaris, Cladophialophora, Cunninghamella, Exserohilum, Fusarium, Chaetomium, Chrysosporium, Lecythophora, Ochroconis, Paecilomyces, Pythium, Rhizopus, Scedosporium, Scopulariopsis) were the most frequent agents of nosocomial infections. These filamentous fungi and also some yeasts (genera Candida, Cryptococcus, Trichosporon) bring about different clinical syndromes in both immunocompromised and immunocompetent patients.

Characterization of Cryptococcus neoformans var. neoformans serotype A and A/D in samples from Egypt

The cryptococcal polysaccharide antigen was detected in 10 cerebrospinal fluid (CSF) and 23 serum samples from cryptococcal meningitis and intestinal cryptococcosis by the cryptococcal antigen latex agglutination system (CALAS). CALAS titers in CSF and serum samples of cryptococcal meningitis ranged over 8-2048 and 32-2048, respectively, while in cases of intestinal cryptococcosis, serum titers ranged over 8-2048. The isolates of yeast Cryptococcus neoformans were determined to be of serotype A or of the A/D pair. The total leukocyte count and biochemical parameters in CSF were significantly increased as indicators of microbial infection. Furthermore, the in vitro change of the teleomorph (sexual state) to the anamorph (asexual state) was also detected and the teleomorph state changed in vivo to the encapsulated anamoph state which is more virulent during infection in vivo than the yeast-like noncapsulated form. Two primers for internal transcribed spacer (ITS) regions of ribosomal DNA were used for molecular detection of C. neoformans. After PCR amplification, a DNA band of 415 bp, visualized on agarose gel, indicated the presence of C. neoformans cells in the tested CSF and serum samples. The primer sensitivity was also characterized using purified yeast chromosomal DNA as template; it was about 20 pg or more chromosomal DNA which represents about 10 cells of C. neoformans. The primers were also specific for ITS regions of C. neoformans and gave negative results with Candida albicans and E. coli chromosomal DNA templates.

Fungal diseases of the respiratory tract

The proportion of Candida and non-Candida species in the clinical material from patients with respiratory-tract diseases was determined. C. albicans was isolated in 102 cases. An additional 89 strains of yeasts, isolated in association with respiratory diseases, belonged to 10 non-albicans Candida spp. and Cryptococcus spp. The prevailing species, which occurred in 47 cases, was C. parapsilosis. C. tropicalis, C. glabrata, and C. guilliermondii were isolated in 12, 10, and 9 cases, respectively. Four strains of C. krusei and three strains of C. lusitaniae and one strain each of C. freyschussii, C. robusta, C. zeylanoides, and Cryptococcus neoformans were also isolated.