SummaryIn this study, phenotypic and genotypic features of 10 L. garvieae strains isolated from rainbow trout farms were examined with 3 reference strains (Spain, England and ATCC 43921) comperativly. Rapid 32 STREP and conventional microbiologic tests were used for determining phenotipic features of L. garvieae strains. Altough there are diff erences, in Rapid 32 STREP system, between strains in terms of β-Glucuronidase, D-ribose, sorbitol, lactose, raffinose, alanyl-phenylalanyl-proline arylamidase, pyrrolidonyl arylamidase, hippurate hydrolysis, urease tests, all strains have been confirmed as L. garvieae by API web. In RAPD PCR analysis, in which ERIC 2 primer is used, L. garvieae isolates were genotyped within 3 separate clusters according to similarity coefficient index of 70%, and it was detected that a vast majority of isolates with Turkey-origin (8 isolates) belongs to predominant type LG1 genotype. In addition to this, antimicrobial tests of L. garvieae strains shows that there are resistance against gentamycin, neomycin, lincomycin, sulfamethoxazole-trimethoprim, oxytetracycline, erythromycin, amoxicillin, fl orfenicol and doxycycline, which are frequently used on fish in our country. Keywords: Oncorhynchus mykiss, Lactococcus garvieae, Rapid32 STREP, RAPD PCR, Antimicrobial sensitivity Lactococcus garvieae Suşlarının Fenotipik, Genotipik Karakterizasyonu ve Antimikrobiyal Duyarlılıklarının Belirlenmesi ÖzetAraştırmada, gökkuşağı alabalığı işletmelerinden izole edilmiş olan 10 adet Lactococcus garvieae suşunun 3 adet referans suşla (İspanya, İngiltere ve ATCC 43921) karşılaştırmalı olarak fenotipik ve genotipik özellikleri incelenmiştir. L. garvieae suşlarının fenotipik özelliklerinin belirlenmesinde konvansiyonel mikrobiyolojik ve Rapid 32 STREP testleri kullanılmıştır. Rapid 32 STREP sistemde suşlar arasında β-Glucuronidase, D-ribose, sorbitol, lactose, raffinose, alanyl-phenylalanyl-proline arylamidase, pyrrolidonyl arylamidase, hippurate hydrolysis, urease testleri yönüyle farklıklar olmasına rağmen API Web'de tüm suşlar L. garvieae olarak doğrulanmıştır. ERIC2 primerinin kullanıldığı RAPD PCR analizinde L. garveae izolatları %70 benzerlik katsayısına göre 3 farklı genotipe ayrılmış ve Türkiye kökenli izolatların büyük bir bölümü (8 izolat) predominant tip olan LG1 genotipine dahil olduğu belirlenmiştir. Ayrıca bu çalışmada L. garvieae suşlarının antibiyotik duyarlılık testlerinde ülkemizde balıklarda sıklıkla kullanılan gentamisin, neomycin, lincomycin, sulphamethoxazoletrimetoprim, oksitetrasiklin, eritromycin, amoxycillin, fl orfenikol ve doksisiklin'e karşı direnç geliştirmiş oldukları belirlenmiştir.

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In this study, we compared 142 Yersinia ruckeri isolates collected between 2013 and 2016 from 6 different regions in Turkey. A total of 18 different genogroups were found, though most of the isolates clustered into the same genogroup as serotype O1. As immunization of fish with inactivated Y. ruckeri by injection, immersion, or feeding provide minimal protection against Y. ruckeri infection in Turkey, many fish producers use antimicrobials unrestrictedly, resulting in antimicrobial resistance in aquatic pathogens. Accordingly, we investigated resistance to the antimicrobials most commonly used to treat yersiniosis. More than 80% of the Y. ruckeri isolates were susceptible to sulfamethoxazole-trimethoprim (SXT), florfenicol (FFC), and tetracycline, whereas none were susceptible to sulfamethoxazole. The most commonly used antimicrobials (SXT and FFC) can be effectively administered because the resistance levels to these drugs are the lowest among those reported for agents used to control enteric red mouth disease (12.6 and 14.7%, respectively). In conclusion, to the best of our knowledge, this study is the first characterization of the antimicrobial resistance genes floR, sulI, tetC, tetD, and tetE in Y. ruckeri isolates from aquaculture. Additionally, we detected the sulII gene but not the tetA, tetB, tetM, tetS, or sulIII genes.

Infectious pancreatic necrosis virus (IPNV) is a common pathogen of rainbow trout (Oncorhynchus mykiss) in Turkey. We found that 455 of 1,676 sample pools tested were IPNV positive. Positive samples were found in all geographical regions where sampling was conducted. Sequence and phylogenetic analyses of VP2 from 30 isolates representing all regions showed that the viruses were highly similar in sequence and grouped within Genogroup 5 (serotype Sp-A2). No correlations between sequences, sampling sites or geographical origins were identified. Although clinical disease was evident in several farms, analyses of the amino acid sequence of VP2 showed that all virus strains harboured the P 217 T 221 motif, assumed to be associated with low virulence. We conclude that IPNV is prevalent in Turkish rainbow trout farms and that the viruses are very homogenous and likely to be of European origin. Frequent exchange of eggs and live fish within the farming industry may explain the homogeneity of the IPNV.

SummaryIn this study, 15 Yersinia ruckeri isolates that had been isolated from rainbow trout farms and 2 reference strains (serotype 1 and serotype 2) were examined in terms of phenotypic, serotypic and genotypic characteristics. Conventional microbiological and API 20 E tests were used to determine phenotypic characteristics of Y. ruckeri isolates and it was determined that the Y. ruckeri showed significantly homogenous profile by microagglutination test performed by using serotype 1 and serotype 2 immunsera, and 11 of 15 isolates were serotyped as serogroup 1 while the rest 4 were serotyped as serogroup 2. In Random Amplified Polymorphic DNA (RAPD) analysis, Y. ruckeri isolates were genotyped within 2 separate clusters according to 70% similarity coefficient index and it was detected that first cluster includes 2 genotypes (YR1 and YR2) and second cluster includes 3 genotypes (YR3, YR4 and YR5). Furthermore, antibiotic resistance profiles of Y. ruckeri strains were determined and it was found that they were resistance to florfenicol, erythromycin, oxytetracycline and trimethoprim-sulphamethoxazole which have been licensed for fish health in Turkey. It is considered that findings obtained will form a basis to develop diagnosis kit and/or vaccination for Y. ruckeri. Keywords: Oncorhynchus mykiss, Yersinia ruckeri, API 20 E, Microagglutination, RAPD-PCR Gökkuşağı Alabalıklarından İzole Edilen Yersinia ruckeri Suşlarının Fenotipik, Serotipik ve Genetik Farklılıklarının Belirlenmesi ve Antibioyotiplendirilmesi ÖzetBu çalışmada gökkuşağı alabalığı işletmelerinden izole edilmiş olan 15 adet Yersinia ruckeri izolatının 2 adet referans suşla (serotip 1 ve serotip 2) karşılaştırmalı olarak fenotipik, serotipik ve genotipik özellikleri bakımından incelenmesi amaçlanmıştır. Y. ruckeri izolatlarının fenotipik özelliklerinin belirlenmesinde klasik mikrobiyolojik ve API 20 E testleri kullanılmış ve bu testlerde bakterinin oldukça homojen bir yapı gösterdiği belirlenmiştir. Serotip 1 ve serotip 2 immunserumlar kullanılarak yapılan mikroaglütinasyon testinde ülkemizden izole edilmiş olan 15 suştan 11'nin serotip 1, 4'ünün ise serotip 2 özellikte olduğu belirlenmiştir. Rastgele Çoğaltılmış Polimorfik DNA (RAPD) analizinde Y. ruckeri izolatları %70 benzerlik katsayısına göre 2 ayrı küme içerisinde gruplanmış, kümelerden birincisinin 2 (YR1 ve YR2), ikincisinin ise 3 genotip (YR3, YR4 ve YR5) içerdiği saptanmıştır. Ayrıca bu çalışmada Y. ruckeri izolatlarının antibiyotik duyarlılıkları belirlemiş ve bu izolatların ülkemizde balıklarda ruhsatlı olan florfenikol, eritromisin, oksitetrasiklin ve trimetoprimsulfamethoxazole karşı direnç geliştirmiş oldukları saptanmıştır. Çalışma sonucunda elde edilen bulguların Y. ruckeri için teşhis kiti ve/veya aşı geliştirme çalışmalarına temel teşkil edeceği düşünülmektedir. Anahtar sözcükler: Oncorhynchus mykiss, Yersinia ruckeri, API 20 E, Mikroaglütinasyon, RAPD PCR Determination of Phenotypic, Serotypic and Genetic Diversity and Antibiotyping of Yersinia ruckeri INTRODUCTIONYersinia ruckeri...