Identification, Typing, Antifungal Resistance Profile, and Biofilm Formation ofCandida albicansIsolates from Lebanese Hospital Patients

Abstract

As leading opportunistic fungal pathogens identification and subtyping of Candida species are crucial in recognizing outbreaks of infection, recognizing particularly virulent strains, and detecting the emergence of drug resistant strains. In this study our objective was to compare identification of Candida albicans by the hospitals through the use of conventional versus identification based on the ITS (Internal Transcribed Spacer) and to assess biofilm forming capabilities, drug resistance patterns and correlate these with MLST typing. ITS typing revealed a 21.2% hospital misidentification rate. Multidrug resistance to three drugs out of four tested was detected within 25% of the isolates raising concerns about the followed treatment regimens. Drug resistant strains as well as biofilm formers were phylogenetically related, with some isolates with significant biofilm forming capabilities being correlated to those that were multidrug resistant. Such isolates were grouped closely together in a neighbor-joining tree generated by MLST typing indicating phylogenetic relatedness, microevolution, or recurrent infection. In conclusion, this pilot study gives much needed insight concerning C. albicans isolates circulating in Lebanese hospitals and is the first study of its kind correlating biofilm formation, antifungal resistance, and evolutionary relatedness.

Antifungal Susceptibility Patterns ofCandidaSpecies Recovered from Endotracheal Tube in an Intensive Care Unit

“…The pathogenicity of Candida species is attributed to certain virulence factors, mostly production of biofilm [17, 18]. Candida species are now recognized as major agents of hospital-acquired infection.…”

Comparison of Various Methods Used to Detect Biofilm Production of Candida Species

“…Our study showed XTT reduction assay is less time consuming and accurate method for the detection of biofilm production [3,9,11,15].…”

Differences by Resistotyping Between C. albicans Strains Isolated from the Oral Cavity of HIV+ and Seronegative Patients

“…A broad range of fungi-typing techniques currently exist with variations in throughput, cost, processing time and discriminatory power. What method is chosen will depend largely on the epidemiological data needed and available laboratory infrastructure (10,12,27 (9,(28)(29)(30). However, molecular biology methods are more expensive than phenotypic methods and are often only available in research or epidemiological reference laboratories (19,30).…”

“…Candida species is a possible cause for increased antifungal resistance with consequent treatment failure and persistent infection. This suggests that oral candidiasis in HIV+ patients may be caused by different clones of the same species (12,14). Little data is available on the presence of C. albicans clones with different resistance profiles colonizing the oral cavity of HIV+ subjects.…”