The immune response of tilapia Oreochromis mossambicus and its susceptibility to Streptococcus iniae under stress in low and high temperatures

Abstract

Mozambique tilapia Oreochromis mossambicus acclimated to 27 degrees C were then held at 19, 23, 27 (control), 31 and 35 degrees C, and were examined for non-specific cellular and humoral responses after 12-96 h. Total leucocyte count decreased significantly when fish were transferred to 19 and 23 degrees C after 48 and 96 h, and when transferred to 35 degrees C over 12-96 h, respectively. Respiratory burst decreased significantly when fish were transferred to 19, 31 and 35 degrees C over 24-96 h, whereas phagocytic activity and phagocytic index decreased significantly when fish were transferred to low temperatures (19 and 23 degrees C) and high temperatures (31 and 35 degrees C) over 12-96 h. Lysozyme activity decreased significantly when fish were transferred to 19 degrees C after 12-96 h, but increased significantly when transferred to 31 and 35 degrees C over 48-96 h. Alternative complement pathway (ACH(50)) also decreased significantly when transferred to 19 and 23 degrees C after 12h, but increased significantly when transferred to 31 and 35 degrees C after 24h. In another experiment, tilapia reared at 27 degrees C were injected intraperitoneally with Streptococcus iniae at a dose of 1 x 10(7)colony-forming units (cfu)fish(-1), and then reared onward at water temperatures of 19, 23, 27 (control), 31 and 35 degrees C. Over 48-168 h, the cumulative mortality of S. iniae-injected fish held in 19 and 35 degrees C was significantly higher than that of injected-fish held in 23, 27 and 31 degrees C. It is concluded that transfer of tilapia O. mossambicus from 27 degrees C to low temperatures (19 and 23 degrees C) after 12h, and transfer of fish from 27 degrees C to high temperatures (31 and 35 degrees C) reduced their immune capability. Moreover, tilapia under temperature stress at 19 and 35 degrees C from 27 degrees C decreased its resistance against S. iniae.

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“…Cold-stress induces changes in serum levels of IgM, leukocyte count (WBC), phagocytosis, thyroxine (T 4 ) and catecholamines in tilapia . Transferring tilapia from 27°C to lower temperatures (19 and 23°C), or to higher temperatures (31 and 35°C), reduces their immune capability, and involve changes to WBC, lysozyme (LZM) and the phagocytic index (Ndong et al, 2007). Plasma LZM level is not correlated with sex, parental origin, rearing length, weight, condition factor or rearing density (Caruso and Lazard, 1999) but handling, transport and toxic water change the levels of LZM (Möck and Peters, 1990;Wu et al, 2007).…”

Physiological responses of Chinese longsnout catfish to water temperature

“…In gilthead sea bream, Sparus aurata, lysozyme activity decreased significantly when transferred from 18°C to 11°C (Tort et al, 2004). Likewise, Ndong et al (2007) found that lysozyme activity decreased significantly when juvenile tilapia Oreochromis mossambicus were transferred from 27°C to 19°C after 12-96 h, but increased significantly when transferred to 31°C and 35°C over 48-96 h. Conversely, some studies have not found an effect of water temperature on serum lysozyme levels (Olsen et al, 1993). Interestingly, plasma lysozyme activity was significantly lower at 25°C than that at 20°C or 35°C in the current study, suggesting that the fish were under less thermal stress.…”

“…Ainsworth et al (1991) found that phagocyte function was significantly suppressed in channel catfish, Ictalurus punctatus, acclimatized at 10°C, but unchanged at 18°C. Ndong et al (2007) reported that both phagocytic activity and the phagocytic index decreased after 12 and 24 h in tilapia, O. mossambicus, that were transferred from 27°C to low temperatures (19°C and 23°C). However, levels returned to normal after 48 h, suggesting that the fish had the ability to adapt to temperature stress.…”

Prevention of Aeromonas hydrophila on catfish juvenile using garlic and shatterstone herb

“…Tetapi pada saat-saat tertentu, nafsu makan ikan menurun. Hal ini diduga terjadi karena diakibatkan fluktuasi suhu harian yang menyebabkan ikan stress sehingga menurunkan nafsu makan (Ndong et al, 2007).…”