INTRODUCTION

Antibiotic resistance is one of the biggest threats to global health, which critically needs alternative solutions [1, 2]. L’abbé & Beenaerts (1989) reported that 5-Amino-1,2,3-triazoles, having a strong electron-withdrawing N-1 substituent, cannot be converted into the azides using the diazotization methods. Synthesis of 3- (o-nitrophenyl) -5-arylthiazolo [2,3-c] pyridin-2-one (2-octanyl) -6-arylthiazolo [3,2-b] [1,2,4] triazoles and its isomers, - [1,2,4] triazoles have antibacterial and antifungal effects.

Triazoles can also be used to preserve food [3-6]. Increasing heating temperature and pH significantly increase the viscosity of milk concentrates, while the distribution of denatured κ-casein and whey proteins between the micellar phase and serum only marginally affects it.

This work aimed to establish the antibacterial effect of 5-(furan-2-yl-, 5-bromofuran-2-yl)-4H-1,2,4-triazole-3-thiol, 2-(5-(furan-2-yl-,5-bromofuran-2-yl)-4H-1,2,4-triazole-3-ylthio) acetate, 5-R-2-(furan-2-yl-,5-bromofuran-2-yl)thiazolo[3,2-b][1,2,4]triazole-4(5H)-one on cryogenic strains of Enterobacteriaceae, Pseudomonadaceae, Staphylococcaceae, Bacillaceae, Listeriaceae, Corynebacteriaceae, and Saccharomycetaceae families in vitro.

MATERIALS AND METHODS

Extracts were filtered through glass funnels using sterile multi-layer gauze filters (fifty 6-mm sterile discs of filter paper) into sterile glass vials for ten days. The discs were dried in a sterile laminar box (BMB-II Laminar-C 1,2 Cytos) under UV rays for 30 minutes before being placed on the agar with the related culture.

Antibacterial effect of the 11 study preparation (Group I 2-(5-(5-bromofuran-2-yl)-4H-1,2,4-triazole-3-ilto)acetate; II-4-hydroxyphenyl; ІІІ - 3-fluorophenyl; IV-3,4-dimethoxyphenyl; V-3,5-dimethoxyphenyl; VI-4-fluorophenyl; VII-4-nitrophenyl; VIII-2-carboxyphenyl; IX-4-hydroxyphenyl; X -3,4-dimethoxyphenyl and XI groups 3,5-dimethoxyphenyl) was determined by agar disc diffusion method. A 0.5-Mac Farland suspension was prepared from a fresh culture of the reference cryogenic strains of 17 bacteria. The obtained suspension was subcultured on MHA (Himedia), followed by cultivation in a TCO-80/1 thermostat at 37 °C for 24 and 48 hours. Discs soaked in suitable extracts were put on top of the subcultures. Discs with 30.0μg Kanamycin – 0-3-Amino-3-deoxy-alpha-D-glucopyranosyl- (1 "6) -0- [6-amino-6-deoxy-alpha-D-glucopyrinazyl- [1" 4)] - 2-deoxy- D-streptamine were considered positive control. Kanamycin is a crystalline white powder, aminoglycoside antibiotic of the first generation, anti-tuberculosis drug of the second row, produced by radiant fungus Streptomyces kanamyceticus or other related microorganisms. Discs with 15.0 µg Amphotericinin (1R,3S,5R,6R,9R, 11R,15S,16R,17R,18S,19E,21E,23E,25E,27E,29E,31E,33R,35S,36R,37S)-33-[(3-amino-3,6-dideoxy-β-D-mannopyranosyl)oxy]-1,3,5,6,9,11,17,37-octahydroxy-15,16,18-trimethyl-13-oxo-14,39-dioxabicyclo [33.3.1] nonatriaconta-19,21,23,25,27,29,31-heptaene- 36-carboxylic acid) was also used as the second control against Candida albicans.

After 24-hour incubation, the inhibition zone diameter was measured using TpsDig2 program and a template (Antibiotic Zone Scale-C, model РW297, India). The data in tables are shown in the form of x ± 1.96 • SD.

RESULTS AND DISCUSSION

It is known from the literature that the reaction of cyclization and the formation of bicyclic 1,2,4-triazole systems follows exactly the scheme of Figure 1 [1]. The authors also investigated and proved that the reduction of 5-benzylidene-2- (3-fluorophenyl) thiazolo [3,2-b] -1,2,4-triazol-6- (5H) -one in the presence of an excess of sodium borohydride leads to ring opening and formation of 3-aryl-2 - ((3- (3-fluorophenyl) -1,2,4-triazol-5-yl) thio) -prop-2-en-1-ol [1].

Table 1 shows the antibacterial effect of the extracts of studied preparation on cryogenic strains of Enterobacteriaceae and Pseudomonadaceae families in vitro. We determined the moderate sensitivity of E. coli  055 K 59 No. 3912/41 to 1.0% of the preparation of the second experimental group, which is 13.3% (1.9 mm) above the control. Other experimental preparation appeared to be resistant to this strain, although the growth retardation zone ranged from 0.1% of the drugs ranging from 0 (group IV) to 11.2 mm (group I) and at 1% from 10.4 (groups V and X) to 11.2 mm (group I).

Analyzing the effectiveness of the experimental preparation on Enterococcus faecalis ATCC No. 19433, we found fluctuations in the growth retardation zone of more than 10 mm in all groups, and in groups I, V, VI, VI, and XI, this indicator is slightly below the control by 7.4-8.9%. A similar trend was observed when studying the effect of drugs on Klebsiella pneumoniae K-56 No. 3534/51, Salmonella typhimurium 144, and Salmonella adobraco 1: found moderately sensitive growth inhibition of Klebsiella pneumoniae under the influence of 1% concentration of drugs in groups I, II, VII, VII, and IX (growth retardation range 13.1-14.4 mm), as well as Salmonella typhimurium only in group XI (1.0% of the preparation - the growth retardation zone was 14.2 mm). In addition to experimental groups V and VI, when the dilution of drugs was 0.1% (growth retardation zone on Salmonella typhimurium was from 8 mm to absence) in other groups, this figure was higher than 10 mm and ranged within: for 0.1% concentration of drugs from 10.2mm (group II) to 12.6mm (group III), for 1% - from 10.4mm (group IV) to 12.7mm (group III). The effect of drugs on Salmonella adobraco in Groups II, VIII, and VIII was significantly lower than the control (17.9%); (16.6 and 17.2%, respectively).

We found a moderately sensitive antibacterial effect on the strain Pseudomonas aeruginosa ATCC No. 2853 (F) under the action of 1.0% concentration of drugs in groups III, VI, and XI (growth inhibition zone was 13.4, 12.1, and 12.3 mm, respectively).

^* Discs with 30.0μg kanamycin were utilized as the positive control (n=12) 

At the same time, growth inhibition of microorganisms affected by drugs on ATSC Staphylococcus aureus 25923 was detected. (Table 2). Using of the test compounds at a concentration of 0.1% causes the sensitivity of microorganisms and growth retardation in groups V, VI, and VIII (13.1; 15.3 and 11.2 mm), in turn, the use of test compounds at a concentration of 1.0% causes the sensitivity of microorganisms and growth retardation already in III-IX and XI samples within 11.2-15.8 mm. A moderate sensitivity of Staphylococcus epidermidis ATSC No. 14990 was also detected. Using 1.0% of drugs in groups II, V, VIII, IX, and XI, the growth retardation zone was 11.7, 11.7, 11.4, 13.3, and 13.5 mm, respectively.

We found moderate antibacterial efficacy in the use of experimental drugs on Bacillus subtilis ATSC No. 6633. Thus, using 0.1% drug, the growth inhibition of microorganisms was detected only in groups VII and VII, then in 1.0% of the drug, the growth retardation zone in groups II, III, IV, VIII, VII, and XI, was 11.4, 14.6, 11.9, 11.6, 12.3, and 11.5 mm, respectively).

Antibacterial effect under the influence of experimental drugs was also found on the microorganisms of the family Listeriaceae. It has been experimentally proven that the use of samples on Listeria monocytogenes ATCC No. 19112 moderate inhibition zone in the III and IV groups of 1.0% of the drug (12.4 and 12.7 mm); Listeria ivanovi - in I, II, III, IV, and IX groups (within 14.3-16.3 mm), and Listeria innocua ATCC No. 33090 already in the I, III, IV, VII, IX and X groups (from 14.2 to 16.7 mm). Also when using 1.0% drug in groups I, III, and IX, the growth retardation zone of the Listeria ivanovi was below control by only 13.8, 9.9, and 7.7%, respectively.

^* Discs with 30.0 μg kanamycin were used as a positive control (n=12) 

The antibacterial effects of studied preparation on cryogenic strains of Actinobacteria type microorganisms, Actinomycetales series, Corynebacteriaceae family and Ascomycota department, Saccharomycetes class, Saccharomycetaceae family are presented in Table 3.

^* Discs with 30.0μg kanamycin were considered as the positive control (n=12)  ^** P>0,95; ^*** P>0,99

^**** Discs with 15.0μg amphotericin were considered as a positive control for Candida albicans