Spider venom neurotoxin based bioinsecticides: A novel bioactive for the control of the Asian citrus psyllid Diaphorina citri (Hemiptera).

The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), is a key vector of the phloem-limited bacteria Candidatus Liberibacter asiaticus (CLas) associated with huanglongbing (HLB), the most serious and currently incurable disease of citrus worldwide. Here we report the first investigation into the potential use of a spider venom-derived recombinant neurotoxin, ω/κ-HxTx-Hv1h (hereafter HxTx-Hv1h) when delivered alone or when fused to snowdrop lectin (Galanthus nivalis agglutinin; GNA) to control D. citri. Proteins, including GNA alone, were purified from fermented transformed yeast Pichia pastoris cultures. Recombinant HxTx-Hv1h, HxTx-Hv1h/GNA and GNA were all orally toxic to D. citri, with Day 5 median lethal concentrations (LC50) derived from dose-response artificial diet assays of 27, 20 and 52 µM, respectively. Western analysis of whole insect protein extracts confirmed that psyllid mortality was attributable to protein ingestion and that the fusion protein was stable to cleavage by D. citri proteases. When applied topically (either via droplet or spray) HxTx-Hv1h/GNA was the most effective of the proteins causing >70 % mortality 5 days post treatment, some 2 to 3-fold higher levels of mortality as compared to the toxin alone. By contrast, no significant mortality or phenotypic effects were observed for bumble bees (Bombus terrestris L.) fed on the recombinant proteins in acute toxicity assays. This suggests that HxTx-Hv1h/GNA has potential as a novel bioinsecticide for the management of D. citri offering both enhanced target specificity as compared to chemical pesticides and compatibility with integrated pest management (IPM) strategies.

Prevalence of bacterial burden on macroscopic contaminants of orthopaedic surgical instruments following sterilization.

BACKGROUND: Macroscopic contamination of orthopaedic instruments with particulates, including cortical bone and polymethyl methacrylate (PMMA) bone cement, that have previously undergone pre-operative sterilization is frequently encountered peri- or intraoperatively, calling into question the sterility of such instruments. AIM: To determine if macroscopic contaminants of orthopaedic surgical instrumentation maintain a bacterial burden following sterile processing, and to determine the most commonly contaminated instruments and the most common contaminants. METHODS: Macroscopic contaminants in orthopaedic instrument trays were collected prospectively at a single tertiary referral centre over a 6-month period from August 2021 to May 2022. When identified, these specimens were swabbed and plated on sheep blood agar. All specimens were incubated at 37 °C for 14 days, and inspected visually for colony formation. When bacterial colony formation was identified, samples were sent for species identification. RESULTS: In total, 33 contaminants were tested, and only one contaminant was found to be growing bacterial colonies (Corynebacterium sp.). The items most commonly found to have macroscopic contamination were surgical trays (N=9) and cannulated drills (N=7). The identifiable contaminants were bone (N=10), PMMA bone cement (N=4) and hair (N=4). Eleven macroscopic contaminants were not identifiable. CONCLUSION: This study found that 97% of macroscopic orthopaedic surgical instrument contaminants that underwent sterile processing did not possess a bacterial burden. Contaminants discovered during a procedure are likely to be sterile, and do not pose a substantially increased risk of infection to a patient.

Operative efficiency: comparison of methods to optimize the use of chlorhexidine gluconate applicators.

BACKGROUND: With the high costs of operating room time, minimizing potential causes of time waste is financially beneficial to surgeons and hospitals. The time needed to activate a chlorhexidine gluconate surgical solution applicator presents an opportunity for optimization. Many techniques are employed to expedite the process, but there have been no studies comparing these techniques. AIM: To determine the most efficient method for utilizing a chlorhexidine gluconate surgical prep applicator. METHODS: Six techniques were tested to determine which caused the sponge of a Chloraprep™ applicator to become saturated quickest. These were a single squeeze (control), up-and-down shaking, side-to-side shaking, pressing the sponge on a surface (dab), pressing with cotton swabs (poke), and continuously squeezing the lever of the applicator. The time between the internal glass breaking in the applicator to the time of sponge saturation with solution was measured for each technique. Times were then compared to determine which technique best expedited the process. FINDINGS: The side-to-side shake, up-and-down shake, and 'dab' techniques were each significantly faster than the control group. Side-to-side shaking had the fastest time to sponge saturation on average. The average difference in time to saturation between the side-to-side shake technique and the 'poke' technique may be as much as 27.5 s. CONCLUSIONS: Utilization of the side-to-side shake technique, as well as the up-and-down shake and 'dab' techniques, significantly expedite the time it takes to use a chlorhexidine gluconate applicator. The time savings from employing these techniques could result in significant financial benefits.

Emergence of Zika Virus Epidemic and the National Response in Jamaica.

BACKGROUND: Jamaica, along with the Americas, experienced major epidemics of arboviral diseases transmitted by the Aedes aegypti mosquito in recent years. These include dengue fever in 2012, Chikungunya fever in 2014 and Zika virus infection (ZIKV) in 2016. We present the emergence of the ZIKV epidemic in Jamaica and outline the national response. METHODS: The Ministry of Health's preparedness included: heightened surveillance, clinical management guidance, vector control and management, laboratory capacity strengthening, training and staffing, risk communication and public education, social mobilization, inter-sectoral collaboration, resource mobilization and international cooperation. RESULTS: The first case of ZIKV was confirmed on January 29, 2016 with date of onset of January 17, 2016. From January 3 to July 30, 2016 (Epidemiological Week (EW) 1-30), 4648 cases of ZIKV were recorded (4576 suspected, 72 laboratory-confirmed). Leading symptoms were similar among suspected and confirmed cases: rash (71% and 88%), fever (65% and 53%) and joint pains (47% and 38%). There were 17 suspected cases of Guillain Barre syndrome; 383 were reported in pregnant women, with no reports of microcephaly to date. Zika and dengue viruses were circulating predominantly in 2016. At EW30, 1744 cases of dengue were recorded (1661 suspected and 83 confirmed). Dengue serotypes 3 and 4 were circulating with 121 reports of dengue haemorrhagic fever. CONCLUSION: The possibility exists for endemicity of ZIKV similar to dengue and chikungunya in Jamaica. A ZIKV vaccine, similar to the dengue and chikungunya vaccines, is needed to be fast-tracked into clinical trials to mitigate the effects of this disease.

Emergence of zika virus epidemic and the national response in Jamaica

BACKGROUND: Jamaica, along with the Americas, experienced major epidemics of arboviral diseases transmitted by the Aedes aegypti mosquito in recent years. These include dengue fever in 2012, Chikungunya fever in 2014 and Zika virus infection (ZIKV) in 2016. We present the emergence of the ZIKV epidemic in Jamaica and outline the national response. METHODS: The Ministry of Health's preparedness included: heightened surveillance, clinical management guidance, vector control and management, laboratory capacity strengthening, training and staffing, risk communication and public education, social mobilization, inter-sectoral collaboration, resource mobilization and international cooperation. RESULTS: The first case of ZIKV was confirmed on January 29, 2016 with date of onset of January 17, 2016. From January 3 to July 30, 2016 (Epidemiological Week (EW) 1-30), 4648 cases of ZIKV were recorded (4576 suspected, 72 laboratory-confirmed). Leading symptoms were similar among suspected and confirmed cases: rash (71% and 88%), fever (65% and 53%) and joint pains (47% and 38%). There were 17 suspected cases of Guillain Barre syndrome; 383 were reported in pregnant women, with no reports of microcephaly to date. Zika and dengue viruses were circulating predominantly in 2016. At EW30, 1744 cases of dengue were recorded (1661 suspected and 83 confirmed). Dengue serotypes 3 and 4 were circulating with 121 reports of dengue haemorrhagic fever...(AU) CONCLUSION:The possibility exists for endemicity of ZIKV similar to dengue and chikungunya in Jamaica. A ZIKV vaccine, similar to the dengue and chikungunya vaccines, is needed to be fast-tracked into clinical trials to mitigate the effects of this disease.

Direct ultraviolet writing of channel waveguides in congruent lithium niobate single crystals.

We report the fabrication of optical channel waveguides in congruent lithium niobate single crystals by direct writing with continuous-wave ultraviolet frequency-doubled Ar+ laser radiation (244 nm). The properties and performance of such waveguides are investigated, and first results are presented.