Fax +41 61 306 12 34 E-Mail karger@karger.ch www.karger.com Abstracts Med Princ Pract 2006;15:401–404 DOI: 10.1159/000094278 Abstracts of Theses Approved for the MSc Degree at the Faculty of Medicine, Health Sciences Center, Kuwait University gal susceptibility profile. The results of the study suggest that the combined detection of mannan and antimannan antibodies or mannan and  -D -glucan may contribute to the early and sensitive diagnosis of invasive candidiasis in referral diagnostic laborato- ries. Z.U. Khan (supervisor) A.S. Mustafa (co-supervisor) 2 Molecular Detection of Resistance to Ethambutol in Ethambutol-Resistant Clinical Mycobacterium tuberculosis Isolates from Kuwait A.-A. Jaber Al-Rawdhan Department of Microbiology, Faculty of Medicine, Kuwait University Introduction and Objectives: Ethambutol (EMB) is a bacteri- cidal first-line drug for the treatment of tuberculosis (TB). Mono- resistance to EMB in clinical Mycobacterium tuberculosis isolates is rare and is mediated by mutations in several genes, notably embB (arabinosyl transferase) and iniA (isoniazid-inducible) genes. Most EMB-resistant M. tuberculosis strains contain muta- tions at embB codons 306, 406 and 497, the embC-embA inter- genic region (IGR) and iniA codon 501. This study aimed to de- velop simple PCR-restriction fragment length polymorphism (RFLP) and/or DNA sequencing methods for rapid screening of EMB-resistant strains carrying mutations at the above codon po- sitions. The developed methods were then applied to detect resis- tance-associated mutations in 50 EMB-resistant M. tuberculosis isolates from Kuwait. Materials and Methods: The M. tuberculo- sis H37Rv and well-characterized mutant strains with specific mutations were used as references. Fifty phenotypically docu- mented EMB-resistant and 25 pan-susceptible M. tuberculosis isolates recovered from TB patients in Kuwait during 2000–2003 were analyzed. Mutations at embB codons 306 and 497 and iniA codon 501 were detected by PCR-RFLP. Direct DNA sequencing was used to confirm the results of RFLP as well as for the detec- tion of mutations at embB codon 406 and embC-embA IGR. The genotypic relatedness among isolates carrying similar mutations was performed by genetic group analysis and fingerprinting by double repetitive element PCR. Results: The PCR-RFLP methods were successfully developed for the detection of mutations at embB codons 306 and 497 and iniA codon 501. The analysis of 50 EMB-resistant M. tuberculosis isolates showed that 21 (42%) con- tained a mutation indicative of EMB resistance. Fifteen, two and 1 Diagnostic Evaluation of Candida Antigens, Antibodies and DNA in Patients with Candidiasis Fasahat Fakhar Alam Department of Microbiology, Faculty of Medicine, Kuwait University An integrated approach for the diagnosis of invasive candi- diasis has been evaluated employing three currently available di- agnostic assays, namely Platelia Candida Ag for the detection of mannan, Platelia Candida Ab for the detection of anti-mannan antibodies and Fungitell for the detection of (1,3)- -D -glucan. The findings have been analyzed in relation to blood culture and semi-nested PCR (snPCR) results. The study groups included 27 patients with culture-proven candidemia, 39 patients with clini- cally suspected invasive candidiasis, 10 patients with Candida vaginitis and 30 healthy controls. The tests were performed ac- cording to the instructions provided in the kit, and the cut-off value for each positive test was determined using mean + 3 stan- dard deviations of the control sera. In candidemia patients, the sensitivity and negative predictive values (NPV) for the assays were as follows: Platelia mannan 84 and 86%, anti-mannan anti- body 56 and 68%,  -D -glucan 75 and 67%, and Candida snPCR 88 and 88%, respectively. When the tests were combined, the sen- sitivity for mannan and anti-mannan improved to 94%, and for mannan and  -D -glucan to 97%. In patients with clinically sus- pected invasive candidiasis, the sensitivity and NPV were as fol- lows: Platelia mannan 50 and 57%, anti-mannan antibody 39 and 49%,  -D -glucan 50 and 57%, and Candida snPCR 53 and 56%, respectively. However, when the tests were combined, the sensi- tivity for mannan and anti-mannan improved to 76%, for man- nan and  -D -glucan to 63%, and for mannan,  -D -glucan and Candida snPCR to 79%. These observations are particularly note- worthy in the absence of positive blood culture results. The per- formance of snPCR offered an advantage over mannan and glu- can tests, since it identified 8 patients (12%) who were infected with more than one Candida species. This observation has thera- peutic implications, since Candida species differ in their antifun- © 2006 S. Karger AG, Basel 1011–7571/06/0155–0401$23.50/0 Accessible online at: www.karger.com/mpp