Acta Microbiologica Bulgarica

12-20

Authors: Galabov, A. S., Gesheva, V., Negoita, T.

The review describes the spreading of viruses in Antarctic ecosystems including terrestrial, marine, and freshwater habitats. The great attention is paid to virus infections in Antarctic animal and plant populations. Observation on viruses in Antarctic ecosystems might contribute for their diversity and systematics, as well as for viral ecology. Comparison of the detected viruses with the well-known viruses, using modern methods, reveals some structural differences in their nucleic acids and proteins. Several new virus species unknown in temperate geographic regions were described. Distribution of viruses in Antarctica may elucidate their migration, potential reservoirs, and hosts. Observations on viruses would explain the processes of virus infections, survival, pathogenicity, and medicine.

32-36

Authors: Baykushev, R., Raykova, V., Mitov, I.

Every obstetrician or microbiologist encounters bacterial vaginosis (BV) in his/her practice. 50% of the cases are asymptomatic. The percentage of affected women varies. The aim of this study is interpretation of microscopic and molecular diagnostic techniques for diagnosing fastidious microorganisms associated with BV. 234 women were tested. Vaginal secretions were collected, after medical history and detailed gynecological status were completed. Smears were prepared and stained by Gram. Identification of fastidious Gardnerella vaginalis, Atopobium vaginae, Megasphaera sp. type 1, and BV associated bacterium type 2 (BVAB2) was performed by PCR. 112 of the 234 tested women had microscopic evidence of some vaginal problem. 65 of them, had anaerobic infection found on the basis of the microscopic data. Materials from women suspected for anaerobic infection were subjected to PCR for proving of specific anaerobes. In 63 patients G. vaginalis was found, in 27– A. vaginae, in 18 - Megasphaera sp. type 1, and in 15 - BVAB2. The detected anaerobe in 25 swabs was single. Combination of several pathogens was demonstrated in 40 women. Gram stain is a fast, easily performed, and specific method for diagnosing BV. Methodology limitation is the inability to distinguish visually the different microorganisms involved in the condition. The PCR method provides possibilities for the sensitive, highly specific, and rapid identification of bacteria-specific markers for BV. Accurate determination of microorganisms involved in this syndrome provides possibilities for an adequate and complete treatment of the women affected.

40-47

Authors: Krumova, E., Miteva-Staleva, J., Kostadinova, N., Korinovska, O., Abrashev, R., Spasova, B., Angelova, M.

The fungal strain Aspergillus fumigatus 32 was isolated from metal polluted soil (around the tailing Vlajkov vrah, Bulgaria). Effect of enhanced concentrations of cadmium ions (redox-inactive metal) on the growth and morphology, as well as the participation of oxidative stress in cadmium-induced toxicity, was reported. A. fumigatus demonstrated a high tolerance to cadmium, exhibiting remarkable growth in liquid and agar media. High metal concentrations affected fungal morphology and caused oxidative stress events such as changes in the level of reserve carbohydrates and oxidative damaged proteins. A sharp increase in trehalose content and accelerated consumption of glycogen in the presence of cadmium ions at concentration above 5 µg/ml were detected. In addition, a decrease in carbonylated proteins was measured, particularly pronounced at high concentrations (70 and 100 µg/ml). Cadmium ions exposure with 5, 20, and 50 µg/ml resulted in enhanced superoxide dismutase (SOD) level, but the higher concentrations (70 and 100 µg/ml) significantly inhibited this activity. Continuous decrease was also observed for catalase (CAT) activity. Probably, at higher concentrations of cadmium ions antioxidant enzymatic defence does not seem to be a major mechanism of cadmium tolerance in the strain A. fumigatus.

54-60

Authors: Tomov, A., Doycheva,, A., Mladenova P., Satchanska, G.

In recent years many antimicrobial agents became ineffective against bacteria. This lead to many studies of the antimicrobial effects among plants. Bulgarian vegetables are ingredients in many traditional Bulgarian foods. The aim of the study was to compare the antibacterial activity of organically grown parsley, tomatoes, cayenne peppers, onions and garlic against referent test bacteria - Bacillus subtilis No8751 and Escherichia coli No8752, supplied by the National Bank for Microorganisms and Cell Cultures. Sixteen vegetable samples were analyzed. Petri dishes were cultivated at 37oC for 24 hours. Our results demonstrated low antibacterial activity of tomato and parsley samples against the Gram(+) B. subtilis and from weak to no activity against the Gram (-) E. coli.Fresh garlic samples showed low antibacterial activity against Gram (+) bacteria with only fresh garlic leaves displaying wider sterile zones. No antibacterial activity was demonstrated by the fresh onion bulbs and leaves. In contrast, the mature garlic bulbs showed pronounced activity against the Gram (-) E. coli (30 mm zone d). Cayenne pepper tissue and seeds possess antibacterial properties against both Escherichia coli and Bacillus subtilis.Strong antimicrobial activity against B. subtilis was shown by the mature onion samples with 25 mm zone diameter for the red onion bulbs and 27 mm zone diameter for the white onion bulbs. Both mature onion samples demonstrated low activity towards E. coli.

71-72

Authors: Onderdonk, A. B., Tropcheva, R., Boleti, H., Petkov, P.

Short Communication