Candidemia in cancer patients: features of the taxonomic structure.

The aim of the study was to determine the main Candida species isolated from blood of cancer patients, to compare the taxonomic structure of strains obtained from children and adults with candidemia. In total, during the study period, candidemia was microbiologically proven by blood culture in 81 patients (duplicates were excluded). Patients in the intensive care unit (ICU) accounted for 35,8%. The total number of isolates elaborated was 82 strains of 10 Candida species. In general, in the taxonomic structure of candidemias, C. parapsilosis (61.0%) predominates, C. albicans (20.7%) is in the second place, followed by C. glabrata and C. lusitaniae (3.7% each); C. krusei, C. guilliermondii and C. tropicalis (2.4% each). C. parapsilosis was statistically significantly often isolated from blood compared to C. albicans (61.0% versus 20.7%, respectively, p<0.0001). Candidemia was statistically significantly more often detected in adults than in children (63.0% versus 37.0%, respectively, p<0.002). Moreover, in adults, C. parapsilosis was statistically significantly more often isolated from blood than C. albicans (70.6% versus 15.7%, respectively, p<0.0001). In children, there were no significant differences in the frequency of isolation of C. parapsilosis and C. albicans: the proportion of C. parapsilosis was 45.2%, C. albicans - 29.0%. Rare species were identified in 7.8% of cases in adults, and in 12.9% of cases in children without statistical difference (p>0.05). The proportion of Candida non-albicans during the study period was 79.3%, and C. parapsilosis is the main species in this group (76.9%).

Microbiological and molecular identification of the anaerobic component of the oral microbiota in patients with cancer of the oropharyngeal region.

A research objective - to study tumor tissues of primary and recurrent patients with cancer of the oropharyngeal region for the frequency of occurrence of four types of anaerobic periodontogens and their associations by two methods: real-time PCR and cultural. There is speculation that bacteria can influence the pathogenesis of cancer. A comparative assessment of the content of four anaerobic periodontogens (Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythensis, Treponema denticola) in the tumor tissue and in the healthy tissue of the oral mucosa of patients with oropharyngeal cancer was carried out. It was found that the identification of odontopathogens by the real-time PCR method is much more informative than the traditional culture method, with the exception of P. intermedia, for the identification of which the traditional culture method was more effective. In 33.3% of patients, both primary and secondary, the composition of microorganisms was the same in both healthy and tumor tissue. In 20% of primary patients and in 13.3% of repeat patients, no associations of microorganisms included in the study were found in healthy tissue. Associations of 4 bacteria were recorded only in tumor tissue in both primary and repeated patients, and in repeated patients - statistically significantly more often. In 53.3% of repeat patients, associations of 4 bacteria were recorded in tumor tissue, whereas in primary patients, only in one case. P. gingivalis from tumor tissue in repeat patients was statistically significantly more often than in primary patients. T. forsythensis in primary patients was found statistically significantly more often in healthy tissues than in repeat patients, in which T. forsythensis was found statistically significantly more often from tumor tissue than in healthy tissue). T. denticola in healthy tissue was detected in both primary and repeated patients in isolated cases. T. denticola in tumor tissue was found statistically significantly more frequently in both primary and repeated patients compared to healthy tissue. P. gingivalis, T. forsythensis, and T. denticola should perhaps be considered risk indicators indicating the level of significance of their associations with oropharyngeal cancer.