| Abstrakt: |
Bacterial resistance to antibiotics is now widely increasing problem, and consumption of antibiotics is the main contributing factor. One of the sources of antibiotics and antibiotic-resistant bacteria is wastewater treatment plant (WWTP) effluent. Recent studies indicate the release of antibiotic-resistant bacteria to effluent-receiving streams. The purpose of this study was to investigate antibiotic resistance of bacteria isolated from onsite wastewater treatment facilities. The wastewater samples were collected from the three different biological facilities of onsite wastewater treatment. Bacterial strains belong to: Streptococcus, Pseudomonas, Stenotrophomonas, Microbacterium, Lactobacillus, Alcaligenes, Flavobacterium, Mycobacterium, Bacillus, Variovorax, Acinetobacter, Chryseobacterium, Aeromonas, Enterococcus, Paenibacillus, Carnobacterium, Sphingobacterium, CDC, and Serratia were chosen for the analysis. Antibiotic susceptibility was determined by disc diffusion method, E-test strips and phenotypic microarrays (PMs). The multiple antibiotic resistance (MAR) patterns for tested strains were determined. Among the tested strains, Paenibacillus azoreducens was resistant to 37 investigated antibiotics belong to 8 various chemical classes. Pseudomonas fragi, Stenotrophomonas rhizophila and Sphingobacterium multivorum were resistant to 22, 21 and 17 antibiotics, respectively. 20% of tested bacteria were resistant to 2-5 antibiotics, but 47% were resistant to more than 5 antibiotics. The results also demonstrate the applicability of the microarrays (PM11 and PM12) as new additional tool to establish antibiotic susceptibility profile of the environmental bacterial strains. PM analysis showed a gain of phenotype (resistance or growth) of the strains to 41 antibiotics belong to 10 different chemical classes. Based on the results, the small wastewater treatment plants could be regarded as a serious threat to the widespread of antibiotic resistance to the natural environments. [ABSTRACT FROM AUTHOR] |
