Isolation and characterization of Streptococcus spp. group B in Nile tilapias (Oreochromis niloticus) reared in hapas nets and earth nurseries in the northern region of Parana State, Brazil

Abstract

Isolation and characterization of Streptococcus spp. group B in Nile tilapias (Oreochromis niloticus)... Ciência Rural, v.35, n.6, nov-dez, 2005. foram identificadas como Streptococcus agalactiae e 20 não foram caracterizadas pelo API 20 Strep, mas apresentaram o mesmo perfil bioquímico descrito para a cepa de referência de Streptococcus difficile ). A ausência de hemólise, classificação no grupo B e o perfil bioquímico sugerem que estes estreptococos podem pertencer à espécie Styreptococcus difficile. Palavras-chave: piscicultura, estreptocococos, infecção, bacteriologia.

Evaluation on the Pathogenesis of Streptococcus agalactiae in Nile Tilapia (Oreochromis niloticus)

“…Similar clinical signs were also observed in tilapia experimentally or naturally infected by S. iniae (Perera et al, 1994;Evans et al, 2000;Shelby et al, 2002). Hemorrhagic injuries in the skin, ascites, hepatomegaly and splenomegaly observed in the fishes inoculated in this experiment were compatible with those reported by Salvador et al (2005) and Figueiredo et al (2006) in the tilapia naturally infected in Brazil.…”

“…Swimming in circles, uncoordinated movements, and dorsal rigidness are indicators of the compromising of central nervous system. Salvador et al (2005) observed a high morbidity and mortality in S. agalactiae when tilapia were cultivated in net-tanks, which presented erratic and circular swimming, appetite decrease, uni-or bilateral exophthalmia and visceral cavity distension as main clinical signs. Main macroscopical alterations reported by Salvador et al (2003) were injuries in the skin, fins, branchiae, opacity of the cornea, liquid in visceral cavity, liver and splenomegaly.…”

“…Kawamura et al (2005) proposed a re-classification of S. difficile in order to unify the terminology, considering S. difficile and S. agalactiae synonyms. In Brazil, Salvador et al (2005) isolated Lancefield´s group B non-hemolytic Streptococcus spp. from tilapia cultivated in nettanks and earthen ponds in the state of Paraná.…”

Isolamento e resistência a antimicrobianos de cepas de Streptococcus spp. provenientes de rãs-touro (Lithobates catesbeianus)

“…de peixes (Shoemaker et al, 2000;Salvador et al, 2005). Todas as cepas isoladas apresentaram resultado negativo para a prova da catalase, da bile esculina, produção de H 2 S, hidrólise da ureia, descarboxilação da lisina, dentre outros (Tab.…”

“…principalmente em tilápias (Salvador et al, 2005). Entretanto, este é o primeiro relato do isolamento dessa bactéria em rãs-touro no estado de São Paulo.…”