Effects of Streptococcus agalactiae infection and oral florfenicol administration on the hemato-biochemistry, erythrocyte morphology and histopathology of Oreochromis niloticus
Abstract
Streptococcosis is considered one of the most important diseases affecting farmed tilapia, causing severe economic losses. Antimicrobial therapy is the principal control measure applied during outbreaks. This research assessed the efficacy of florfenicol (FFC) when fed at 15 mg kg biomass–1 day–1 for 10 days against Streptococcus agalactiae infection in Oreochromis niloticus in terms of survival, changes in hemato-biochemistry, erythro-morphology, and histoarchitecture of the vital organs. Streptococcus agalactiae was moderately virulent to O. niloticus with a lethal dose (LD50) of 1.26×108 cells fish–1 and sensitive to FFC with a minimal inhibitory concentration of 0.78 μg mL–1. It caused systemic infection in tilapia. FFC therapy reduced bacterium-induced mortality and physiological stress. The histopathological findings indicated significant improvement in the kidney and liver tissues of fish. The erythrocyte morphological alterations noted in the challenged fish were irregularly shaped, elongated, crenated, and teardrop cells, hypochromic erythrocytes, ragged cytoplasmic membranes, hypertrophied nuclei, eccentric nuclei, and vacuolation, all of which were mitigated with FFC therapy. Eventually, FFC therapy improved wound healing, normalized plasma biochemistry, and aided recovery from bacterial infection. This study revealed that the therapeutic dose of FFC was effective against S. agalactiae infection in O. niloticus and lessened the physiological stress.
References
Aboyadak IM, Ali NG, Abdel-Aziz MM, Gado MS, El-Shazly KA (2016) Role of some antibacterial drugs in control Streptococcus iniae infection in Oreochromis niloticus. Asian Journal of Pharmaceutical and Clinical Research 1(5): 555–573.
Abraham TJ, Namdeo MS, Adikesavalu H, Banerjee S (2019) Pathogenicity and pathology of Streptococcus agalactiae in challenged Mozambique tilapia Oreochromis mossambicus (Peters 1852) juveniles. Aquatic Research 2(4): 182–190.
Abuseliana A, Hassan D, Saleha AA, Siti KB, Milud A (2010) Streptococcus agalactiae is the etiological agent of mass mortality in farmed red tilapia (Oreochromis sp.). Journal of Animal and Veterinary Advances 9(20): 2640–2646.
Abu-Zahra NI, Elseify MM, Atia AA, Al-sokary ET (2024). Impacts of florfenicol on immunity, antioxidant activity, and histopathology of Oreochromis niloticus: a potential protective effect of dietary Spirulina platensis. Veterinary Research Communication 48: 125–138.
Adikesavalu H, Banerjee S, Patra A, Abraham TJ (2017) Meningoencephalitis in farmed monosex Nile tilapia (L.) caused by Streptococcus agalactiae. Fisheries and Aquatic Life 25(3): 187–200.
Agius C, Roberts RJ (2003) Melano-macrophage centers and their role in fish pathology. Journal of Fish Diseases 26(9): 499–509.
Agnew W, Barnes AC (2007) Streptococcus iniae an aquatic pathogen of global veterinary significance and a challenging candidate for reliable vaccination. Veterinary Microbiology 122(1–2): 1–15.
Alsaid M, Abuseliana AF, Daud HH, Mustapha NM, Bejo SK, ... Hamdan RH (2014) Hematological, biochemical and clinical signs changes following experimental infection of Streptococcus agalactiae in red hybrid tilapia (Oreochromis sp.). Aquacultura Indonesiana 4(9): 289–295.
Alsaid M, Daud HHM, Mustapha NM, Bejo SK, Abdelhadi YM, ... Hamdan RH (2013) Pathological findings of experimental Streptococcus agalactiae infection in red hybrid tilapia (Oreochromis sp.) (pp. 70–73). In: Proceedings of the International Conference on Chemical, Agricultural and Medical Sciences. CAMS-2013, International Institute of Chemical, Biological & Environmental Engineering, Kuala Lumpur, Malaysia.
Amal MNA, Zamri-Saad M (2011) Streptococcosis in tilapia (Oreochromis niloticus): a review. Pertanika Journal of Tropical Agricultural Science 34(2): 195–206.
Amal MNA, Zamri-Saad M, Siti-Zahrah A, Zulkafli AR (2013) Transmission of Streptococcus agalactiae from a hatchery into a newly established red hybrid tilapia, Oreochromis niloticus (L.) × Oreochromis mossambicus (Peters), farm. Journal of Fish Diseases 36(8): 735–739.
Assane IM, Gozi KS, Valladão GMR, Pilarski F (2019) Combination of antimicrobials as an approach to reduce their application in aquaculture: emphasis on the use of thiamphenicol/florfenicol against Aeromonas hydrophila. Aquaculture 507: 238–245.
Assefa A, Abunna F (2018) Maintenance of fish health in aquaculture: review of epidemiological approaches for prevention and control of infectious disease of fish. Veterinary Medicine International 2018: 5432497.
Bardhan A, Abraham TJ, Singha J, Saha S, Sarker S, Patil PK (2022b) The effects of extended feeding of florfenicol-coated medicated diets on the safety, serum biomarkers and blood cells morphology of Nile tilapia Oreochromis niloticus (L.). Environmental Science and Pollution Research 29: 39914–39927.
Barham WT, Smit GL, Schoonbee HJ (1980) The hematological assessment of bacterial infection in rainbow trout, Salmo gairdneri Richardson. Journal of Fish Biology 17(3): 275–281.
Bereiter-Hahn J, Zylberberg L (1993) Regeneration of teleost fish scale. Comparative Biochemistry and Physiology 105A: 625–641.
Bernet D, Schmidt H, Meier W, Burkhardt‐Holm P, Wahli T (1999) Histopathology in fish: proposal for a protocol to assess aquatic pollution. Journal of Fish Diseases 22(1): 25–34.
Bojarski B, Lutnicka H, Swadźba-Karbowy M, Makulska J, Jakubiak M, ... Witeska M (2018) Effects of herbicides pendimethalin and ethofumesate on common carp (Cyprinus carpio) erythrocyte morphology. Folia Biologica (Kraków) 66(3): 143–149.
Bondad-Reantaso MG, Arthur JR, Subasinghe RP (Eds) (2012) Improving biosecurity through prudent and responsible use of veterinary medicines in aquatic food production. FAO Fisheries and Aquaculture Technical Paper. No. 547. Food and Agriculture Organization of the United Nation, Rome. 207 pp.
Bowker JD, Carty D, Bowman MP (2013) The safety of Aquaflor (50% florfenicol) administered in feed to fingerling yellow perch. North American Journal of Aquaculture 75(4): 517–523.
Bowser PR (1993) Clinical pathology of salmonid fishes (pp. 327–332.). In: Stoskopf M (Ed) Fish medicine, W.B. Saunders, Philadelphia, Pennsylvania.
Bowser PR, Wooster GA, Getchell RG, Timmons MB (1998) Streptococcus iniae infection of tilapia Oreochromis niloticus in a recirculation production facility. Journal of the World Aquaculture Society 29(3): 335–339.
Chen CY, Wooster GA, Bowser PR (2004) Comparative blood chemistry and histopathology of tilapia infected with Vibrio vulnificus or Streptococcus iniae or exposed to carbon tetrachloride, gentamicin or copper sulfate. Aquaculture 239(1–4): 421–443.
Chen D, Wang K, Geng Y, Wang J, Huang L, Li J (2011) Streptococcus iniae isolated from channel catfish (Ictalurus punctatus) in China. Israeli Journal of Aquaculture-Bamidgeh 63(1): 593–600.
Chen J, Sun R, Pan C, Sun Y, Mai B, Li QX (2020) Antibiotics and food safety in aquaculture. Journal of Agricultural and Food Chemistry 68(43): 11908–11919.
Clauss TM, Dove AD, Arnold JE (2008) Hematologic disorders of fish. Veterinary Clinics of North America: Exotic Animal Practice 11(3): 445–462.
Darwish AM (2007) Laboratory efficacy of florfenicol against Streptococcus iniae infection in sunshine bass. Journal of Aquatic Animal Health 19(1): 1–7.
Eldar A, Perl S, Frelier PF, Bercovier H (1999) Red drum Sciaenops ocellatus mortalities associated with Streptococcus iniae infection. Diseases of Aquatic Organisms 36(2): 121–127.
El-Sayed AFM (2019) Tilapia culture, 2nd edition. Academic Press, London.
Engle CR, van Senten J, Clark C, Boldt N (2023) Has the regulatory compliance burden reduced the competitiveness of the US tilapia industry? Fishes 8(3): 151.
Esmaeili M (2021) Blood performance: a new formula for fish growth and health. Biology 10(12): 1236.
FAO (2022) The state of world fisheries and aquaculture 2022, towards blue transformation. Food and Agriculture Organization of the United Nation, Rome.
FAO (2023) OECD-FAO Agricultural outlook 2023-2032. OECD Publishing, Paris.
Faria FC, Leal CAG, Carvalho-Castro GA, Leite RC, Figueiredo HCP (2013) Carrier state induced by oxytetracycline therapy against streptococcosis in Nile tilapia, Oreochromis niloticus (L.). Journal of Fish Diseases 37(9): 853–857.
Feng JB, Jia XP (2009) Single dose pharmacokinetic study of florfenicol in tilapia (Oreochromis niloticus × O. aureus) held in freshwater at 22°C. Aquaculture 289(1–2): 129–133.
Haenen OLM, Dong HT, Hoai TD, Crumlish M, Karunasagar I, ... Bondad-Reantaso MG (2023) Bacterial diseases of tilapia, their zoonotic potential and risk of antimicrobial resistance. Reviews in Aquaculture 15: 154–185.
Isiaku AI, Sabri MY, Ina-Salwany MY, JHassan MD, Tanko PN, Bello MB (2017) Biofilm is associated with chronic streptococcal meningoencephalitis in fish. Microbial Pathogenesis 102: 59–68.
Junge W, Wilke B, Halabi A, Klein G (2004) Determination of reference intervals for serum creatinine, creatinine excretion and creatinine clearance with an enzymatic and a modified Jaffe method. International Journal of Clinical Chemistry 344(1–2): 137–148.
Limbu SM, Zhou L, Sun SX, Zhang ML, Du ZY (2018) Chronic exposure to low environmental concentrations and legal aquaculture doses of antibiotics cause systemic adverse effects in Nile tilapia and provoke differential human health risk. Environment International 115: 205-219.
Martins ML, Shoemaker CA, Xu D, Klesius PH (2011) Effect of parasitism on vaccine efficacy against Streptococcus iniae in Nile tilapia. Aquaculture 314(1–4): 18–23.
Martins ML, Vieira FN, Jeronimo GT, Mourino JL, Dotta G, ... Pereira G (2009) Leukocyte response and phagocytic activity in Nile tilapia experimentally infected with Enterococcus sp. Fish Physiology and Biochemistry 35: 219–222.
Michaylova V, Ilkova P (1971) Photometric determination of micro amounts of calcium with arsenazo III. Analytica Chimica Acta 53(1): 194–198.
Mishra A, Nam GH, Gim JA, Lee HE, Jo A, Kim HS (2018) Current challenges of Streptococcus infection and effective molecular, cellular, and environmental control methods in aquaculture. Molecules and Cells 41(6): 495–505.
Oda SS, Tohamy HG, Massoud RG (2016) Pathological alterations in Nile tilapia experimentally infected with Streptococcus iniae and Candida albicans. Turkish Journal of Fisheries and Aquatic Sciences 16(4): 779–788.
Ohira Y, Shimizu M, Ura K, Takagi Y (2007) Scale regeneration and calcification in goldfish Carassius auratus: quantitative and morphological processes. Fisheries Science 73(1): 46–54.
Patel JB, Abraham TJ, Bardhan A, Das R, Sen A, ... Patil PK (2024) Efficacy of oxolinic acid against Aeromonas hydrophila infection in Nile tilapia Oreochromis niloticus juveniles. Aquaculture Studies 24(3): AQUAST1653.
Patil PK, Mishra SS, Pradhan PK, Manna SK, Abraham TJ, ... Jena J (2022) Usage pattern of chemicals, biologicals and veterinary medicinal products in Indian aquaculture. Reviews in Aquaculture 14(4): 2038–2063.
Reda RM, Ibrahim RE, Ahmed EG, El-Bouhy ZM (2013) Effect of oxytetracycline and florfenicol as growth promoters on the health status of cultured Oreochromis niloticus. Egyptian Journal of Aquatic Research 39(4): 241–248.
Reed LJ, Muench H (1938) A simple method of estimating fifty per cent endpoints. American Journal of Epidemiology 27(3): 493–497.
Roberts RJ (2012) Fish Pathology, 4th edition. John Wiley and Sons, USA.
Schmidt H, Goetz K, Hallmann I, Holt CV (1961) The course of resynthesis of blood glucose. Biochemical Journal 334: 534–544.
Schoenfeld RG, Lewellan CJ (1964) A colorimetric method for determination of serum chloride. Clinical Chemistry 10(6): 533–539.
Sherif AH, Abdellatif JI, Elsiefy MM, Gouda MY, Mahmoud AE (2022) Occurrence of infectious Streptococcus agalactiae in the farmed Nile tilapia. Egyptian Journal Aquatic Biology Fisheries 26(3): 403–432.
Straus DL, Bowker JD, Bowman MP, Carty D, Mitchell AJ, Farmer BD (2012) Safety of aquaflor-medicated feed to sunshine bass. North American Journal of Aquaculture 74(1): 1–7.
Thuong HN, Tran TLN, Le TNT, Vo VT (2022) Hematological parameters of red tilapia (Oreochromis sp.) fed lemongrass essential oil (Cymbopogon citratus) after challenge with Streptococcus agalactiae. Israeli Journal of Aquaculture 55(3): 1123–1130.
Tietz NW (1994) Accuracy in clinical chemistry--does anybody care? Clinical Chemistry 40(6): 859–861.
USFDA (2023) Approved aquaculture drugs. U.S. Food and Drug Administration. https://www.fda.gov/animal-veterinary/aquaculture/approved-aquaculture-drugs. Accessed on 13 October 2023.
Vo VT, Tran TH, Nguyen TTT, Truong VT, Pham CT, ... Thuong HNT (2022) Hematological parameters of red tilapia (Oreochromis sp.) fed essential oils of Mentha piperita after challenge with Streptococcus agalactiae. Pakistan Journal of Zoology 2022: 1–8.
Wardani WW, Alimuddin A, Junior MZ, Setiawati M, Nuryati S, Suprayudi MA (2021) Growth performance, fillet quality and immunity after challenge with Streptococcus agalactiae of red tilapia (Oreochromis sp.) fed diet containing cysteamine and creatine. Aquaculture Research 52(9): 4237–4248.
Wolf PL, Williams D, Coplon N, Coulson AS (1972) Low aspartate transaminase activity in serum of patients undergoing chronic hemodialysis. Clinical Chemistry 18(6): 567–568.
Copyright (c) 2025 The Author(s)
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
