ABSTRACT:
Bacterial pathogens such as Edwardsiella ictaluri, Flavobacterium columnare, and virulent Aeromonas hydrophila have a significant economic impact on farm-raised catfish in the United States. Due to the limited number of licensed vaccines, and regulations with antimicrobials usage, there is need to find alternative therapeutics for sustainable aquaculture. Therefore, the antibacterial activities of trans-cinnamaldehyde (TC), caprylic acid (CA), and β-resorcylic acid (BA) were assessed against E. ictaluri 93–146, F. columnare 94–081, and A. hydrophila ML09–119 using broth microdilutions, and the capacity of TC to prevent E. ictaluri infection was evaluated during a challenge trial. Results demonstrated that TC inhibited growth of E. ictaluri, F. columnare, and A. hydrophila at 40, 20, and 80 µg/ml. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) of E. ictaluri, F. columnare, and A. hydrophila after incubation with TC revealed cell wall lysis, leakage of cytoplasmic contents, and pleomorphism in the bacterial shape with rupture of outer membranes. By the histological analysis, no abnormal changes were observed in the catfish intestines as a result of supplementation of TC. Moreover, an increasing number of goblet cells was observed in catfish received TC compared to control. In the E. ictaluri challenge trial, significantly higher survival was found in catfish that received TC at the levels of 15 and 20 mg/kg compared to control group (49.12% and 65.52% survival vs 11.11% survival). Bacterial concentrations in spleen and anterior kidney were significantly (P <.05) lower in fish fed with TC (20 mg/kg diet) compared to control at 5-day post-infection. Results indicate that supplementation of catfish feed with TC reduces E. ictaluri infection. A safe and efficacious alternative to antimicrobials will reduce the emergence and spread of antimicrobial resistant strains.

ABSTRACT:
Best management practices (BMPs) are conservation efforts implemented to address environmental challenges associated with agricultural production. One such BMP, a tailwater recovery (TWR) system, has a dual purpose aimed at mitigating solids and nutrient losses from agricultural landscapes and creating an additional surface water source for irrigation. This study analyzes the costs of using five TWR systems to reduce solids, nutrients, and retain water. All systems were located in the Lower Mississippi Alluvial Valley and were used to irrigate crops including rice (Oryza sativa), corn (Zea mays), and soybeans (Glycine max). Costs to reduce solids and nutrients were calculated using annual payments and revenue losses due to lost tillable area from implementation of TWR systems. Similarly, cost to save and irrigate a mega-liter (ML) of water was determined as the annual payment for TWR systems, revenue losses and measured pumping cost. The range of mean total cost to reduce solids using TWR systems was $0 to $0.77 per kg; P was $0.61 to $3315.72 per kg; and N was $0.13 to $396.44 per kg. The range of mean total cost to retain water using TWR systems was $189.73 to $628.23 per ML, compared to a range of mean cost of groundwater of $13.99 to $36.17 per ML. Compared to other BMPs, TWR systems are one of the least expensive ways to reduce solid losses but remain an expensive way to reduce nutrient losses. The costs of using TWR systems to provide an additional irrigation water source range from less expensive than common conservation practices used to improve water use efficiency to more expensive and comparable to practices such as desalination. Therefore, TWR systems may be a prohibitively more expensive BMP to retain nutrients and water on some agricultural landscapes than other solutions.

ABSTRACT:
Natural preservatives for wood protection have gained increasing attention due to their intrinsic antimicrobial properties, renewability, and lower impact on the environment. We report a study on the use of β-cyclodextrin (βCD) derivatives as sustained-release carriers of allyl isothiocyanate (AITC), as a model natural preservative compound. The formation of AITC inclusion complex in βCDs is qualitatively confirmed by FT-IR and the maximum inclusion yield is estimated to be 39%. Impregnation of wood with the water-borne βCD-AITC complexes allows penetration and even distribution of the preservative in the lumen and possibly in the cell walls. The efficacy of the βCD-AITC complexes as wood preservatives of southern yellow pine is examined by the AWPA E10-16 standard. Compared with the water-treated and AITC-treated wood, βCD-AITC-treated wood exhibits decrease in mass loss from 45% to 25% and no visible cell wall damage after exposure to brown and white rot fungi. The results indicate that βCD suppresses the premature leaching of otherwise volatile AITC and suggests a novel approach of application of volatile or water-immiscible natural preservatives for wood protection.

ABSTRACT:
Aeromonas are Gram-negative, non-spore forming rods belonging to the family Aeromonadaceae within the class Gammaproteobacteria. These facultative anaerobic bacteria are ubiquitous in aquatic environments and have a broad host range. We present here the complete genome sequence of multidrug-resistant A. veronii strain MS-18-37 isolated from diseased catfish. The genome size of this strain is 4,683,931, with a G+C content of 58.60%. Annotation reveals multiple genes that encode antibiotic resistance. The complete genome sequence of A. veronii strain MS-18-37 will provide a genetic basis for understanding molecular mechanisms of antimicrobial resistance and exchange in Aeromonas.

ABSTRACT:
Preservation of cellular integrity and its mechanisms after ovarian tissue cryopreservation (OTC) and in vitro culture (IVC) procedures are crucial aspects for the success of preservation and recovery of female fertility. This study aimed to evaluate the effects of two cryopreservation methods (slow-freezing, SF, and vitrification, VIT) on the equine ovarian tissue after 1, 3, and 7 days of IVC by assessing: (i) preantral follicle morphology and distribution of follicle classes; (ii) protein expression of markers of cell proliferation for EGFR and Ki-67; (iii) markers of apoptosis for Bax and Bcl-2; and (iv) DNA fragmentation. Percentages of normal primordial follicles were similar (P > 0.05) among SF-control, VIT-control, and fresh control groups. After 7 days of culture, VIT-IVC7 had a greater (P < 0.05) total percentage of normal preantral follicles when compared with SF-IVC7, but both had a lower (P < 0.05) percentage than fresh IVC7 group. Prior to and after 7 days of culture, expression of EGFR and Ki-67 were similar (P > 0.05) among fresh, SF, and VIT groups. After 7 days of culture, VIT had higher (P < 0.05) Bax expression than the fresh and SF tissues, but Bcl-2 was similar (P > 0.05) among groups. Prior to IVC, TUNEL signals were similar (P > 0.05) among groups; however, VIT-IVC7 had greater (P < 0.05) TUNEL signals when compared with the fresh IVC7 group. In conclusion, findings demonstrated: (i) similar efficiency between SF and VIT compared with fresh control to preserve morphologically normal follicles; and (ii) similar tissue functionality and cell proliferation capability after equine OTC by either SF and VIT methods following IVC for 7 days. The results herein presented shed light on equine fertility preservation programs using OTC techniques.