Investigation of the effects of some phytochemicals on Yersinia ruckeri and antimicrobial resistance / Investigação dos efeitos de alguns fitoquímicos em Yersinia ruckeri e resistência antimicrobiana

Abstract In this study, it is aimed to investigate the effects of Moringa oleifera and Sorbus domestica plant extracts on bacterial disease agents Yersinia ruckeri in aquaculture. Morphological and biochemical properties of 2 different Y. ruckeri isolates were determined. Then, Real-Time PCR analysis and gene sequencing of the isolates were identified. Phytochemicals (M. oleifera and S. domestica) and antibiotics (Oxytetracycline (OX) and Enrofloxacin (ENR)) were used together in the antibiogram test of antibiotics compared to the effect status of antibiotics. Also, the effects of phytochemicals on Y. ruckeri growth was examined comparatively by spectrophotometrically measuring at 600 nm wavelength every 2 hours according to bacterial growth densities with 10 different groups formed on TSB medium. As a result of the study, it was observed that the isolates formed Gram negative, catalase positive, oxidase negative, mobile and typical Y. ruckeri colonies. After the biochemical tests performed with Microgen ID panel, 99.85% similarity was determined. The isolates overlap with the 16S rRNA gene region after sequence analysis, and 99% of the isolates were similar in phylogenetic analysis. After the antibiogram test, Oxytetracycline and Enrofloxacin antibiotics were resistant to Y. ruckeri but the effects of phytochemicals were less on solid medium (MHA). As a result of the measurements carried out in liquid medium (TSB), it was observed that phytochemicals such as M. oliefera and S. domestica inhibit the growth of bacteria by 40-50%. As the importance of antibiotic resistance is increasing day by day, we believe that these phytochemicals will give positive results in treatment instead of using antibiotics.

Resumo Neste estudo, objetiva-se investigar os efeitos dos extratos de plantas de Moringa oleifera e Sorbus domestica sobre agentes bacterianos Yersinia ruckeri na aquicultura. Foram determinadas as propriedades morfológicas e bioquímicas de 2 isolados diferentes de Y. ruckeri. Em seguida, a análise de PCR em tempo real e o seqüenciamento genético dos isolados foram identificados. Fitoquímicos (M. oleifera e S. domestica) e antibióticos (Oxitetraciclina e Enrofloxacina) foram usados ​​juntos no teste de antibiograma dos antibióticos em comparação com o status de efeito dos antibióticos. Além disso, os efeitos dos fitoquímicos no crescimento de Y. ruckeri foram examinados comparativamente por medição espectrofotométrica no comprimento de onda de 600 nm a cada 2 horas de acordo com as densidades de crescimento bacteriano com 10 grupos diferentes formados no meio TSB. Como resultado do estudo, observou-se que os isolados formaram colônias Gram-negativas, catalase-positivas, oxidase-negativas, móveis e típicas de Y. ruckeri. Após os testes bioquímicos realizados com o painel Microgen ID, foi determinada uma similaridade de 99,85%. Os isolados se sobrepõem à região do gene 16S rRNA após a análise da sequência e 99% dos isolados foram semelhantes na análise filogenética. Após o teste do antibiograma, os antibióticos Oxitetraciclina e Enrofloxacina foram resistentes a Y. ruckeri, mas os efeitos dos fitoquímicos foram menores no meio sólido (MHA). Como resultado das medições realizadas em meio líquido (TSB), observou-se que os fitoquímicos inibem o crescimento de bactérias em 40-50%. Como a importância da resistência aos antibióticos está aumentando dia a dia, acreditamos que as plantas que são mais alternativas e mais adequadas para o uso de antibióticos hoje em dia darão resultados positivos no tratamento.

Development and evaluation of a multiplex PCR assay for simultaneous detection of Flavobacterium psychrophilum, Yersinia ruckeri and Aeromonas salmonicida subsp. salmonicida in culture fisheries

Bacterial cold water disease, enteric red mouth disease and frunculosis are the common bacterial diseases of fish worldwide. The etiologic agents of these diseases are Flavobacterium (F.) psychrophilum, Yersinia (Y.) ruckeri and Aeromonas (A.) salmonicida subsp. salmonicida, respectively. In this study, a multiplex polymerase chain reaction (m-PCR) method with YER8/10-Fer3/4-FP1/3 primer pairs which can identify these fish pathogens simultaneously was developed and optimized. In optimized conditions, neither false specific nor nonspecific amplification occurred. The detection limits of the m-PCR method using DNA extracts from dilutions of pure cultures of bacteria were 35 pg for Y. ruckeri and F. psychrophilum and 70 pg for A. salmonicida subsp. salmonicida. It was determined that 15 CFU Y. ruckeri and F. psychrophilum and 30 CFU A. salmonicida subsp. salmonicida could be detected by m-PCR developed using genomic DNA extracted from dilutions of the suspensions. The detection limits in the presence of tissue debris were 125 CFU for Y. ruckeri and F. psychrophilum and 250 CFU for A. salmonicida subsp. salmonicida. In conclusion, we submit that the m-PCR method developed and optimized in this study can be used for accurate and rapid identification of these bacteria.