Isolamento de Streptococcus spp de tilápias do nilo (Oreochromis niloticus) e qualidade da água de tanques rede na Região Norte do Estado do Paraná, Brasil

Abstract

Isolamento de Streptococcus spp de tilápias do nilo (Oreochromis niloticus) e qualidade da água de tanques... 35Semina: Ciências Agrárias, Londrina, v. 24, n. 1, p. 35-42, jan./jun. 2003 Isolamento de Streptococcus spp de tilápias do nilo (Oreochromis AbstractThis study evaluated 12 intensive breed of Nile tilapia (Oreochromis niloticus) in four properties localized in the north of Parana State, Brazil. In the period of 13 months, 71 fishes were collected and analyzed of hapas nets that presenting morbidity and mortality of tilapias. Parallel, to evaluate the quality of the water of these hapas nets, there was measured the temperature, dissolved oxygen, pH, alkalinity, nitrite and ammonia. Of the 71 fishes, were collected 220 biological samples. 17 (23.94%) fishes were positive for Streptococcus spp. Of the 53 biological samples from 17 fishes, in 24 (45.28%) were isolated streptococci. Londrina, v. 24, n. 1, p. 35-42, jan./jun. 2003 36The main clinical signs and macroscopic lesions in the fishes with isolation of Streptococcus spp. were hepatomegaly and splenomegaly, skin lesion and base of the fins and exoftalmia with cornea opacity. The higher incidence of infections caused by streptococci happened in the months with higher temperatures, mainly in the transition period winter for spring. The values of dissolved oxygen, pH, alkalinity, nitrite and ammonia of the water were normal.

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

“…However, a low mortality rate (13.33%) was observed when the fishes were experimentally instilled in the gills with 5.0 x 10 5 CFU/fish. Similar clinical signs to those observed in this study were reported by Salvador et al (2003;2005), in the Brazilian state of Parana, and also by Figueiredo et al (2006) in the Brazilian states of Espírito Santo and Minas Gerais, in the tilapia cultivated in the earthen ponds and net-tanks. The authors reported lethargia, anorexia, erratic swimming, uni-or bilateral exophthamia, ascites and high mortality.…”

“…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. The intensity of lesions and clinical signs in tilapia depends on factors related to S. agalactiae strain, infective dose, amount of water, temperature, biomass and also on handling (Chang and Plumb, 1996).…”

Infecção por Streptococcus agalactiae em tilápias do Nilo (Oreochromis niloticus)

“…As lesões internas são caracterizadas por congestão branquial, hepatomegalia e esplenomegalia acompanhada de congestão, ascite e encefalomalácea (Figura 1) (SALVADOR et al 2003, FIGUEIREDO et al 2006, TRABULSI & ALTERTHUM 2008, MARCUSSO et al 2015.…”

Nictemeral variations for pacu Caranha, Piaractus mesopotamicus (Holmberg, 1887) culture in single - phase

“…In general, in all the seasons and points, the highest values of temperature were observed between 12:00 and 16:00h. Large part of the most common noxious effects, resultant from pollution, is related direct or indirectly to the oxygen supply for fish breathing (Branco,1972;Salvador et al, 2003). Henry (1981) and Carvalho et al (2007) suggested that the low levels of dissolved oxygen occurred during the Summer.…”