Search

The rise of antimicrobial resistance is a global public health crisis that threatens the effective control and prevention of infections. Due to the emergence of pandrug-resistant bacteria, most antibiotics have lost their efficacy. Meanwhile, the development of new antimicrobials has stagnated, which leads to the creation of new and unconventional treatments. Bacteriophages or their components are known to target bacterial cell walls, cell membranes, and lipopolysaccharides (LPS) and hydrolyze them. Bacteriophages being the natural predators of pathogenic bacteria, are inevitably categorized as 'human friends', thus fulfilling the adage that 'the enemy of my enemy is my friend'. Leveraging on their lethal capabilities against pathogenic bacteria, researchers are searching for more ways to overcome the current antibiotic resistance challenge. Bacteriophages are considered to be one of the most effective alternative therapies for multidrug resistant bacteria. In this study, we expressed and purified epsilon 34 phage tailspike protein (E34 TSP) from the E34 TSP gene which was previously cloned into a pET30a-LIC vector, then assessed the ability of this bacteriophage protein in the killing of two CBD-resistant strains of Salmonella spp. We observed that the combined treatment of CBD-resistant strains of Salmonella with CBD and E34 TSP showed poor killing ability whereas the monotreatment with E34 TSP showed considerably higher killing efficiency.

New generation antibiotics are needed to combat the development of resistance to antimicrobials. One of the most promising new classes of antibiotics is cannabidiol (CBD). It is a non-toxic and low-resistance chemical that can be used to treat bacterial infections. The antibacterial activity of Cannabis sativa L. byproducts, specifically CBD, has been of growing interest in the field of novel therapeutics. As research continues to define and characterize the antibacterial activity that CBD possesses against a wide variety of bacterial species it is important to examine potential interaction between CBD and common therapeutics such as broad-spectrum antibiotics. Here, we show that CBD-antibiotic co-therapy can effectively fight S. typhimurium via membrane integrity disruption. This research serves to examine the potential synergy between CBD and three broad-spectrum antibiotics for potential antibiotic-CBD co-therapy. In this study, we reveal that Salmonella typhimurium (S. typhimurium) growth is inhibited at very low dosages of CBD-antibiotic. This interesting finding demonstrates that CBD and CBD-antibiotic co-therapies are viable novel alternatives to combating Salmonella typhimurium.

Corn earworm, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), has emerged as an injurious insect pest to hemp, Cannabis sativa L., a crop newly reintroduced to the United States. Growing hemp presents a potential alternative economic opportunity for farmers but can be challenging with a market that is unstable and just developing. One of the most notable production challenges is managing corn earworm, an insect pest that is particularly damaging when it feeds on flower buds produced in cannabinoid varieties, creating extensive bud tunneling and wounds that allow entry of pathogens that can aid development and presence of bud rot. Damage to seeds is of lesser concern in hemp cultivars grown for grain and minimal risk is associated with hemp grown for fiber. Our ability to research hemp has only recently been allowed as production was largely suspended following World War II and, as such, there has been limited opportunity to develop information for empirically-based pest management recommendations. Further complicating development of integrated pest management (IPM) strategies are regulatory challenges associated with providing registration support to add hemp to pesticide labels, as it was not formally recognized as a crop by U.S. regulatory agencies until late 2019. Research needs and challenges to develop effective IPM programs for corn earworm on hemp are discussed here.

This is the first report of Macrosteles near severini Hamilton (Auchenorrhyncha: Cicadellidae), an invasive leafhopper, in Florida. The leafhopper was first detected in watercress in Florida in 2014. This leafhopper transmits the phytoplasma watercress aster yellows, which can cause significant yield losses. Insecticide trials were carried out in the spring of 2014 to compare the efficacy of buprofezin, flonicamid, flupyradifurone, sulfoxaflor, and tolfenpyrad, none of which were registered for use on watercress at the time of testing, with the grower standards of imidacloprid and spirotetramat, for management of M. nr. severini. All treatments except flonicamid resulted in statistically lower numbers of leafhopper nymphs than the untreated control after 3 or fewer applications. Efficacy data from this trial was provided in support of the registration of sulfoxaflor for watercress. Buprofezin and tolfenpyrad also demonstrated efficacy, and each possesses a mode of action that is distinct from imi...

Organic zucchini squash is a high-value vegetable crop in Florida and potential exists to expand its production throughout the state. A lack of knowledge on the effectiveness of organic products and their integration with natural enemies is an important constraint to the regulation of pest populations in organic squash production in Florida. The objectives of this study were to evaluate the effect of insecticides labeled for organic production that can be used for management of Bemisia tabaci (Gennadius) biotype B, on organically grown squash; and to determine the effects of the most efficient insecticides on a key natural enemy, Delphastus catalinae (Horn). Experiments were conducted in the greenhouse in exclusion cages. The first experiment compared the effects of four bioinsecticides on whitefly densities. Insecticides include 1) AzaSol (azadirachtin), 2) PyGanic EC 1.4 (pyrethrin), 3) M-Pede (insecticidal soap), and 4) Entrust (spinosad). The second experiment investigated the effects of bioinsecticides on D. catalinae Treatment effectiveness was evaluated 1, 3, and 5 d posttreatment. PyGanic and M-Pede were highly effective in controlling whitefly populations on organic squash, while moderate control was provided by AzaSol and there was no control provided by Entrust. PyGanic and M-Pede treatments reduced D. catalinae populations when adults were released 1 d post pesticide application. However, when adults were released 5 d post application, there was no reduction. The importance of using bioinsecticides in combination with natural enemies to regulate pest populations in organic cropping systems is discussed.

Three experiments were conducted to evaluate early POST control of yellow woodsorrel using PRE-applied herbicides. In experiment 1, yellow woodsorrel was seeded at two dates in a commercial pine-bark substrate and grown until reaching either the cotyledon–one-leaf (C-1L) or two- to four-leaf (2-4L) growth stage. The herbicides isoxaben, indaziflam, and dimethenamid-p were applied at these growth stages. Two rates of isoxaben and indaziflam provided yellow woodsorrel control (≥ 80% reduction in fresh weight [FW]) when applied at the C-1L stage; however, once yellow woodsorrel reached the 2-4L stage, indaziflam was the only herbicide that provided effective control at both rates tested. Experiments 2 and 3 were similar to experiment 1, except two labeled rates of dithiopyr were also evaluated. In experiment 2, all herbicides evaluated provided ≥ 90% reduction in FW of yellow woodsorrel at the C-1L stage. Although no differences in FW were observed among any of the herbicide treatments when yellow woodsorrel were treated at the 2-4L stage, control ratings indicated that indaziflam provided the most effective yellow woodsorrel control. Experiment 3 results also indicated that isoxaben, indaziflam, and dithiopyr controlled yellow woodsorrel (≥ 95% reduction in FW) when treatments were applied at the C-1L stage, whereas dimethenamid-p reduced shoot FW 70%. When yellow woodsorrel was treated after reaching the 2-4L stage, indaziflam provided the greatest control of any herbicide evaluated.

Crop enhancement with value added traits may affect vulnerability to insects, and evaluating the susceptibility levels of the various value added traits in elite germplasm would aid in developing integrated pest management strategies. During 2007-2008, five 'Benning' soybean (Glycine max (L.) Merr) lines with different value added nutritional traits and four insect resistant quantitative trait loci (QTL) lines were evaluated in an effort to determine their pest vulnerability under artificial and natural insect pest populations. The lines showed variable susceptibility to lepidopterous insect pests classified as defoliators and stem feeders in replicated greenhouse and field tests. The study was carried out in Athens and Midville, GA. The green cloverworm (Hypena scabra (F.)) was the most common lepidopteran defoliator occurring in the fields. Other caterpillar pests found included the soybean looper (Pseudoplusia includens (Walker)), the bollworm (Helicoverpa zea (Boddie)), and the velvetbean caterpillar (Anticarsia gemmatalis (Hübner)). Data indicated that there was no significantly increased pest susceptibility among the value added cultivars with improved nutritional qualities, with the insect resistant quantitative trait loci lines Benning M and Benning MGH consistently being less susceptible to lepidopterous (Noctuidae) leaf injury.

An armored scale, Melanaspis deklei Dietz & Davidson (Hemiptera: Sternorrhyncha: Diaspididae), is recorded for the first time in South Carolina. While not known to be a serious pest of agricultural crops or ornamental plants in its recorded distribution (Mexico, Florida, Georgia, and the West Indies), M. deklei has become a pest of wax myrtle, Myrica cerifera (L.) Small (Myricaceae), grown as ornamental plants in the urban landscape of coastal South Carolina. Infestations have been identified in Horry, Georgetown, and Beaufort Counties, SC. A study was conducted to evaluate the efficacy of neonicotinoids (acetamiprid, clothianidin, dinotefuran, imidacloprid, and thiamethoxam), insect growth regulators (buprofezin and pyriproxyfen), paraffinic oil, and acephate against this armored scale species in 2008 and 2009. None of the tested insecticides achieved significant reduction of scale insect density when compared to the untreated control. There was, however, a trend for plants treated with two appl...

Impatiens (Impatiens wallerana) cultivars ‘Super Elfin Red’ and ‘Dazzler Violet’, resistant or susceptible, respectively, to western flower thrips (Frankliniella occidentalis) were grown under 112 or 336 mg?L-1 N in combination with 10, 20, or 40 mg?L-1 P to investigate the effect of fertilization and host plant resistance on thrips population level and plant quality. Half of the plants were inoculated with thrips at two weeks after fertigation treatments began (WAT) and sampled at 4 and 8 WAT. For thrips-free plants, both N rates and the two higher P rates resulted in marketquality plants with various tissue N and P concentrations. Plant quality was lower in thrips-infested plants due to thrips damage to foliage as distortion on expending leaves and browning on edges of fully expended leaves. Higher numbers of adult and immature thrips were found in ‘Dazzler Violet’ than ‘Super Elfin Red’. However, distortion index, which represented degree of distortion on young leaves, was higher in the resistant cultivar, and the two cultivars had similar quality ratings at 8 WAT. For both cultivars, N had no effect on thrips population, and plants fertilized with 20 or 40 mg?L-1 had higher number of thrips than the low rate. However, percentage of damaged leaf area, which represented the severity of browning, was found higher in plants fertilized at the low P rate. As a result, both cultivars fertilized with higher P rates had better plant quality although these plants had more thrips. Therefore, when infestation level is moderately low, i.e. 10 thrips per plant, plant nutrient status favoring thrips development may not necessarily result in lower plant quality. The final outcome of plant marketability is a combination of plant growth, thrips damage, and the ability of plants to compensate for pest damage.

This test was conducted at the Southeastern Research and Education Center, Midville, GA. The test was set up in a RCB design with 4 replications and one untreated check per replication. The plots were 4 rows by 50 ft with an untreated border row on each side. The rows were planted on beds spaced 38 inches apart using a 4-row Max Emerge II John Deere planter. Temik 15G at 3.0 lb product/acre was placed in-furrow at planting for early season thrips control. Treatment applications began on 14 Jul when square damage was approaching a threshold of 5%. Treatments were applied with a CO2 spraying system mounted on a Powell high cycle sprayer. The sprayer traveled at a speed of 3.0 mph. Treatments were applied at a volume rate of 10 gpa, at 50 psi, with 3 nozzles per row using TX-3 hollow cone nozzles. Treatments were applied on 14, 20, 27 Jul, and 4 Aug. Weekly efficacy evaluations were done by randomly selecting 5 plants from the middle two rows of each plot and counting all the fruiting structures (squares and bolls) on the upper third of each plant. Fruiting structures were examined for feeding damage and the presence of larvae. The efficacy surveys were done on 20, 27 Jul, 4, and 11 Aug. On 5 Oct, yield was taken by mechanically harvesting the two middle rows of each plot. Means for percent square damage and yield were analyzed using ANOVA with means separation using LSD (P ≤ 0.05).