ASSESSMENT OF ANTIMICROBIAL RESISTANCE OF Salmonella spp. ISOLATED FROM FARMED ASIAN CLAM Corbicula fluminea

U ovom istraživanju, Salmonella spp. je uspješno izolirana iz azijskog školjkaša Corbicula fluminea primjenom Ksiloza Lizin Deoksiolata (XLD) selektivnog agara. Ukupno je izolirano 200 bakterijskih kolonija iz živih azijskih školjkaša i podvrgnuto ispitivanju osjetljivosti na antimikrobne tvari primjenom disk difuzije. U istraživanju je primijenjeno ukupno 18 antibiotika, i to: oksolinska kiselina, nalidiksična kiselina, eritromicin, tetraciklin, doksiciklin, oleandomicin, oksitetraciklin, spiramicin, ampicillin, kanamicin, fosfomicin, florfenikol, linkomicin, novobiocin, kloramfenikol, amoksicilin, flumekvin i sulfametoksazol. Rezultati ove studije ukazali su da je ukupni uzorak osjetljivih na antibiotike za Salmonella spp. izolirane iz uzorka C. fluminea bilo 50% ili 1800 slučajeva. Potom su uslijedili slučajevi rezistencije na antibiotike od 45% ili 1620 slučajeva i posredno osjetljivih na antibiotike (5% ili 180 slučajeva). Na temelju rezultata, tetraciklin, doksiciklin, oksitetraciklin i flumekvin pokazali su najveću inhibiciju izolirane Salmonella spp. Indeks višestruke rezistencije na antibiotike (MAR) bio je 0,36, što ukazuje da su uzorci školjkaša bili visoko izloženi testiranim antibioticima.In the present study, Salmonella spp. was successfully isolated from Asian clam Corbicula fluminea by using Xylose Lysine Deoxycholate (XLD) selective agar. A total of 200 bacterial colonies from live Asian clams were isolated and subjected to antimicrobial sensitivity test by using disc diffusion method. A total of 18 antibiotics was applied in the present study, namely oxolinic acid, nalidixic acid, erythromycin, tetracycline, doxycycline, oleandomycin, oxytetracycline, spiramycin, ampicillin, kanamycin, fosfomycin, florfenicol, lincomycin, novobiocin, chloramphenicol, amoxycillin, flumequine and sulphamethoxazole. The findings of the present study showed that total antibiotic sensitive case for Salmonella spp. isolated from C. fluminea sample was 50% or 1800 cases. This was followed by antibiotic resistance case 45% or 1620 cases and intermediary antibiotic sensitive case (5% or 180 cases). Based on the results of the present study, tetracycline, doxycycline, oxytetracycline and flumequine showed the highest inhibition of isolated Salmonella spp. The multiple antibiotic resistance (MAR) index was 0.36, indicating the sampled clams were highly exposed to the tested antibiotics

In vitro analysis of mushroom proteases that may tenderize beef

Meat tenderness is an important characteristic that influences consumer purchasing decisions. Protease extracts from natural plant sources such as pineapple have exhibited broad proteolytic activity that can over-tenderize the meat and negatively affect texture and quality. Therefore, identification and evaluation of other proteases capable of tenderizing beef is necessary. Previously, mushrooms have been shown to enhance flavor and nutritional composition of meat dishes, as well as having beneficial antioxidant and health effects. Mushrooms also contain a variety of proteases that were analyzed in this study for their ability to proteolyze beef proteins using an in vitro model system. Eight mushroom varieties were tested including white button (white immature Agaricus bisporus), crimini (brown immature Agaricus bisporus), portobello (mature Agaricus bisporus), shitakke (Lentinula edodes), enoki (Flammulina velutipes), oyster (Pleurotus ostreatus), king trumpet (Pleurotus eryngii), and brown beech (Hypsizygus tessellatus). Mushrooms were homogenized in a 20 mM Tris buffer (pH 8.0), filtered, centrifuged, and combined with purified bovine myofibrils for incubation at 25°C. Samples were collected at 0, 30, 60, 240, and 1440 min. Myofibrillar proteins of each sample were solubilized and separated using SDS-PAGE. Densities of protein bands were compared between the time-points to determine which of the eight mushroom varieties proteolyzed myofibrillar proteins including actin and myosin. Mushroom proteolytic activity was also quantified with a standard casein assay. Pleurotus ostreatus, mature Agaricus bisporus, and Pleurotus eryngii had the greatest caseinolytic activity at 1.06 U/mL, 0.70 U/mL, and 0.68 U/mL respectively, while Flammulina velutipes had the least at 0.03 U/mL. These results support the possibility that mushroom proteases may be able to tenderize beef, forming the basis for future research trials.OSU Department of Animal Sciences Undergraduate Research Experience (ASURE)OSU Second-Year Transformational Experience Program (STEP)No embargoAcademic Major: Food Science and Technolog

In vitro analysis of mushroom proteases that may tenderize beef

Food Science, Safety, & Security (The Ohio State University Denman Undergraduate Research Forum)Meat tenderness is an important characteristic that influences consumer purchasing decisions. Protease extracts from pineapple, ginger, papaya and kiwi have exhibited proteolytic activity to tenderize meat products. Unfortunately, many of these proteases have broad activity that can overtenderize the meat and negatively affect texture and quality. Therefore, identification and evaluation of other proteases capable of tenderizing beef is necessary. Previously, mushrooms have been shown to enhance flavor and nutritional composition of meat dishes, as well as having beneficial antioxidant and health effects. Mushrooms also contain a variety of proteases that were analyzed in this study for their ability to denature beef proteins using an in vitro model system. Eight mushroom varieties were tested including white button (white immature Agaricus bisporus), crimini (brown immature Agaricus bisporus), portobello (mature Agaricus bisporus), shitakke (Lentinula edodes), enoki (Flammulina velutipes), oyster (Pleurotus ostreatus), king trumpet (Pleurotus eryngii), and brown beech (Hypsizygus tessellatus). Mushrooms were homogenized in a 20 mM Tris buffer (pH 8.0), filtered, then centrifuged. Afterward, purified bovine myofibrils were combined with the crude mushroom protease extracts and incubated at 25°C. Samples were collected at 0, 30, 60, 240, and 1440 min. After, myofibrillar proteins were solubilized and separated using SDS-PAGE. Density of protein bands were quantified and compared between the time-points. The data indicated that all eight mushroom varieties proteolyzed myofibrillar proteins including actin and myosin. Therefore, these results support the possibility that mushroom proteases may be able to tenderize beef, forming the basis for future research trials.OSU Department of Animal Sciences Undergraduate Research Experience (ASURE)OSU Second-Year Transformational Experience Program (STEP)No embargoAcademic Major: Food Science and Technolog