Evaluation of the Antimicrobial Activity of Phytochemicals from Tea and Agarwood Leaf Extracts against Isolated Bacteria from Poultry and Curd.

Antibiotic-resistant bacteria are becoming increasingly common, leading to a global health crisis. The effects of abusing antibiotics not only increase pathogenic resistance but also cause various diseases and syndromes. Gut microbiota contains many beneficial roles for health, while antibiotics kill both pathogens and gut microbiota which is considered one of the major side effects of antibiotics. In fact, new antibiotic compounds are needed in this urgent scenario; phytoremediation is the oldest but most effective method, and research on the antibacterial properties of several types of medicinal plants has already been conducted. Tea and agarwood plants are well known for their economic contribution in both beverage and cosmetic production, as well as for their medicinal value. In this study, tea and agarwood leaf extracts were analyzed for their antimicrobial activity against both pathogenic and beneficial bacteria. Fresh tea (Camellia sinensis) leaves were collected in three varieties, namely, BT-6 from Sylhet, BT-7 from Moulvibazar, and BT-8 from Habiganj; also, green tea (nonfermented tea), black tea (fully fermented tea), and agarwood (Aquilaria malaccensis) were collected from Sylhet region of Bangladesh. Unlike commercial antibiotics, which have side effects on probiotics (beneficiary bacteria), leaf extract activities were analyzed to check if they had positive effects on probiotics that can be found in the gastrointestinal tract as well as dairy products. Potential beneficiary bacteria, Lysinibacillus macroides strain SRU-001 (NCBI accession no. MW665108), and pathogenic bacteria, Aeromonas caviae strain YPLS-62 (NCBI accession no. MW666783), were isolated from the small intestine of poultry and curd, respectively. Tea and agarwood leaves (5 g powder/80 mL methanol) with solvents were kept for seven days at room temperature, and extracts were applied for antimicrobial assays by the disc diffusion assay against the isolated bacteria. 50 µL of each leaf extract was examined against 50 µL of each bacterial culture, where gentamicin was a control. After 24 hours of incubation, tea and agarwood leaf extracts showed an 11-15 mm zone of inhibition against pathogenic A. caviae, while only BT-8 showed 7 mm (disc diameter 6 mm) against probiotic L. macroides. However, compared to leaf extracts, gentamicin showed a 27 mm zone of inhibition against both L. macroides strain SRU-001 and A. caviae strain YPLS-62 bacteria. This research clearly indicates that gentamicin kills both pathogenic and beneficiary bacteria, while leaf extracts from tea and agarwood plants contain antimicrobial activity against only pathogenic A. caviae but no effects on probiotic L. macroides. This outcome indicates not only the potential therapeutic values of tea and agarwood leaves as antibiotics over commercial antibiotics but also the chance of having pathogens in curd and potential beneficial bacteria from the poultry small intestine.

Effect of heat-treated green tea waste feeding on fermentation kinetics, in vitro degradability, in vivo apparent digestibility, nitrogen balance, and blood metabolites in Black Bengal goat.

The study was conducted to examine the effect of heat treatment of green tea waste (GTW) on rumen degradability, apparent digestibility, and plasma metabolites in Black Bengal goat based on in vitro and in vivo studies. The in vitro incubation was performed with autoclaved, oven, and freeze-dried GTW, whereas animal study was conducted using 12 Black-Bengal goats in a 3 × 3 Latin-square design. Goats were fed a total-mixed-ration without (control) or with the partial replacement of soybean meal and barley with 50 g/kg dry matter (DM) of either oven-dried or autoclaved GTW. Heat treatments reduced ether extract and tannins concentration but increased the effective DM and crude protein (CP) degradability of GTW. The highest values of in vitro volatile fatty acid concentration, molar proportion of propionate, ammonia-nitrogen concentration, and cumulative gas production were observed for oven-dried GTW among the tested GTW. Dietary treatment did not alter the DM intake, but apparent CP digestibility and retained nitrogen (N) were increased in goats fed control or oven-dried GTW incorporated diets. Feeding autoclaved GTW diet increased the urinary and fecal N excretion in goats. In contrast, plasma glucose concentration was highest in goats fed control or oven-dried GTW diet. In conclusion, oven drying could be a practical approach to increase protein digestibility and retained N in goats.

Effects of supplementation of probiotics instead of antibiotics to broiler diet on growth performance, nutrient retention, and cecal microbiology.

OBJECTIVES: The research was carried out on broilers to determine the efficacy of probiotics (Bacillus subtilis and Saccharomyces boulardii combined) supplementation on growth performances, nutrient retention (metabolizable energy, dry matter, and crude protein), and cecal microbiology (Bifidobacteria spp., Clostridium spp., and coliforms). MATERIALS AND METHODS: A total of 160 broiler chicks (day-old) were selected and differentiated randomly into 4 groups (T0, T1, T2, and T3) (40 × 4) comprising 40 birds in every single group. The control group (T0) was fed commercial broiler feed only and the other three groups, referred to as treatment groups (T1, T2, and T3), were treated with 1 gm ciprofloxacin, 1 gm probiotic, and 1 gm probiotic plus 0.5 gm enzyme, respectively, in per liter of fresh dietary water 8 h daily for 7 days in each phase. Experimental trials were divided into 2 phases, the starter phase from day 0 to 21 and the finisher phase from day 22 to 35. RESULTS: Bodyweight gain and nutrient retention in experimental broiler birds in treatment groups were significantly (p < 0.05) higher than the control group. Overall body weight gain and nutrient retention of broiler chicks in treatment groups T2 and T3 were better than T1. From day 22 to 35, cecal Clostridium and coliform bacterial load counts were significantly lower p < 0.01, p < 0.05, and p < 0.01, respectively, in T1, T2, and T3 treatments than T0. Overall, Clostridium and coliform bacterial counts in the birds of treatment group T2 were significantly lower (p < 0.05) than T0. CONCLUSION: The probiotics, in addition to enzyme supplementation, had suitable influence effects on growth performance of broilers, birds retention of nutrient, and microfloral count in birds' cecum.