Antimicrobial activity of sophorolipids against Eimeria maxima and Clostridium perfringens, and their effect on growth performance and gut health in necrotic enteritis

Authors: PARK, INKYUNG - US Department Of Agriculture (USDA); OH, SUNGTAEK - Johns Hopkins University; NAM, HYOYOUN - US Department Of Agriculture (USDA); CELI, PIETRO - University Of Melbourne; Lillehoj, Hyun

Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/10/2022
Publication Date: 4/2/2022
Citation: Park, I., Oh, S., Nam, H., Celi, P., Lillehoj, H.S. 2022. Antimicrobial activity of sophorolipids against Eimeria maxima and Clostridium perfringens, and their effect on growth performance and gut health in necrotic enteritis. Poultry Science. 101:101731. https://doi.org/10.1016/j.psj.2022.101731.
DOI: https://doi.org/10.1016/j.psj.2022.101731

Interpretive Summary: There is a timely need to develop antibiotic alternative strategies due to increasing consumers’ awareness of antimicrobial resistance and food safety concerns. In this paper, ARS scientists and collaborators explore natural compounds from bacterial cell wall as safe feed additives for poultry production to reduce the negative impact of intestinal infections. In this work, the authors studied sopholipids (SLs) which are glycolipid membrane component isolated from common yeast cell wall since there are much information concerning the antimicrobial activity of SLs. This report shows that SLs can reduce gut damage in coccidiosis and necrotic enteritis that are caused by several distinct species of Eimeria parasites and pathogenic Clostridium perfringens and are responsible for an estimated annual economic loss of more than $ 19 billion worldwide. In vivo dietary supplementation of young chickens with SLs undergoing coccidiosis and necrotic enteritis showed much beneficial effects including enhanced growth performance, decreasing parasite fecundity and decreased gut inflammation. Overall, dietary SL supplementation improved poultry growth and gastrointestinal functionality in young broiler chickens, demonstrating significant potential as an antibiotic alternative. Further research on the mode of action of SLs will be needed to apply this information to develop a commercially applicable feed additive product.

Technical Abstract: In vitro antimicrobial activity of sopholipids (SLs) against Eimeria maxima and Clostridium perfringens and their in vivo effects on growth performance and gut health in necrotic enteritis (NE)-afflicted broiler chickens were studied. For testing direct killing effects of SLs on enteric pathogens, freshly prepared sporozoite of Eimeria acervulina, E. maxima, and E. tenella were adjusted to 2.5 × 105 into each well of 96 well plate, and vegetative stage of Clostridium perfringens was prepared as 1 × 109 cfu/well. Four different SLs [C18:1 lactonic diacetyled SL (SL1), C18:1 deacetyled SL (SL2), C18:1 monoacetyled SL (SL3), and C18:1 diacetyled SL (SL4)], and two anti-coccidial chemical controls, decoquinate and monensin, were evaluated at three dose levels (125 µg/mL, 250 µg/mL and 500 µg /mL). Samples were incubated at 41°C for 3 hr and microbial survival ratios were measured by counting the number of live microbes stained by fluorescent dye using Cellometer. For assessing the effects of SLs in vivo, 2, 336 (0 day-old) male commercial broiler chickens were used. Birds were randomly allocated to six treatment groups (7 chickens/cage, 8 cages/treatment) as follows: control group which received a basal diet (CON), negative control group (NC) which received a basal diet and NE challenge, four SL treatment groups with NE, NC+SL1, NC+SL2, NC+SL3, and NC+SL4 with the inclusion rates of SLs in each group 200 mg/kg feed. For NE-induced chicken, all chickens except the CON group were orally infected with E. maxima (10,000 oocysts/chicken) at d 14 followed by C. perfringens (1 ×109 cfu/chicken) at d 19. Disease parameters measured included gut lesion scoring, intestinal cytokine production and tight junction protein expression. Data were analyzed using Mixed Model (PROC MIXED) in SAS. In vitro (Experiment 1), all SLs dose–dependently decreased (P < 0.001) the viability of three different species of Eimeria sporozoites and C. perfringens. In vivo (Experiment 2), dietary SLs decreased disease parameters of NE (P < 0.001), BW, ADG, and ADFI, and increased (P < 0.001) FCR compared to CON whereas SL1 and SL4 increased (P < 0.05) them compared to NC. Furthermore, SL1 and SL4 decreased (P <0.05) gut lesion scores with increased gene expression of IL1, IL8, TNFSF15, and IL10 in NE-afflicted chickens. Overall, dietary SLs promoted growth performances, intestinal immune responses, and intestinal barrier integrity of NE-afflicted young broiler chickens.