Pollen-mimicking, enzyme-loaded microparticles to reduce organophosphate toxicity in managed pollinators

Pollinators support the production of 87 of the leading food crops worldwide and contribute over $15 billion to U.S. farm income. Organophosphates are a heavily used group of insecticides that pollinators can be exposed to, especially during crop pollination. Exposure to lethal or sub-lethal doses can impair fitness of wild and managed bees, risking pollination quality and food security. Here, we report a low-cost, scalable in vivo detoxification strategy for organophosphate insecticides involving encapsulation of phosphotriesterase (OPT) in pollen-mimicking microparticles (PMMs). We developed uniform and consumable PMMs capable of loading OPT at 90% efficiency and protecting OPT from degradation in the pH of a bee gut. Microcolonies of bumble bees (Bombus impatiens) fed malathion-contaminated pollen patties demonstrated 100% survival when fed OPT-PMMs but 0% survival with OPT alone and 0% survival with plain sucrose within 5 and 4 days, respectively. Thus, the detrimental effects of malathion were eliminated when bees consumed OPT-PMMs. This design presents a versatile and scalable treatment for managed pollinators to reduce risk from organophosphate insecticides, which can be integrated into supplemental feeds such as pollen patties or dietary syrup.

Apparent Ixodes tick paralysis in a cat from North America

Case summary A 2-year-old castrated male domestic longhair cat presented for acute, diffuse, flaccid paralysis. Thoracic and abdominal radiographs, biochemistry panel and complete blood count were unremarkable. Titers to Toxoplasma gondii, myasthenia gravis radioimmunoassay testing and creatinine kinase levels were within normal limits. The most likely differentials included acute toxicity (coral snake envenomation, organophosphate toxicity), botulism and, less likely, acute polyradiculoneuritis. A thorough physical examination revealed a single engorged tick attached to the ventral neck of the cat, which was later identified as an adult female Ixodes species. Topical fipronil and (S)-methoprene was administered. Over the next 48 h, the cat recovered full motor function and at 5 days post-tick removal the cat had resumed all normal activities. Relevance and novel information Tick paralysis is considered endemic in Australia by bites from, most commonly, the Ixodes holocyclus tick. However, this phenomenon is rarely reported in the USA. This is the first report of a domestic cat suffering from acute tick paralysis in North America.

The Lower Levels of Serum and RBC Cholinesterase in Acute Opioid Poisoning

Background: Cholinesterase is an enzyme that plays a critical role in regulating neural transmission. Many factors may decrease the cholinesterase levels in serum and Red Blood Cells (RBCs). It is suggested that the use of opium may effectively change the levels of Cholinesterase in serum and RBCs. This study aimed to evaluate the serum and RBC levels of cholinesterase in patients who were acutely poisoned with opium. Methods: This cross-sectional study was conducted in 65 patients suffering from acute opium poisoning. The serum levels of cholinesterase were measured using an automated analyzer. The levels were also measured in RBCs, using a colorimetric method. Simultaneously, 65 patients served as the positive controls from among those poisoned with organophosphates. Results: The serum cholinesterase levels were lower than the normal range in 16.9% of patients poisoned with opium and in 76.9% of those poisoned with organophosphate agents (P<0.001). Similarly, the levels of RBC cholinesterase were lower than the normal range as found in 64.6% and 15.4% of patients poisoned acutely with opium (Group 1) and organophosphate (Group 2), respectively (P<0.001). Conclusion: Acute opium poisoning effectively reduced both the levels and activities of cholinesterase in the patients’ serum and RBCs significantly different from those noted in patients suffering from organophosphate toxicity.

Clinical effects from household insecticide: pyrethroid or organophosphate toxicity?

A 54-year-old man with a history of schizophrenia presented to the emergency room for weakness with associated lacrimosis, drooling, nausea, emesis, diarrhoea, diplopia and burning sensation on his skin that began 6 hours after spraying five cans of Raid on his carpet. He was noted to have miotic pupils and hyperactive bowel sounds. Given the clinical presentation, the patient was diagnosed with organophosphate (OP) toxicity. After being admitted, he developed symptoms associated with his OP toxicity and was successfully treated with atropine and pralidoxime. Most Raid products contain pyrethroids; however, both OPs and pyrethroids are available in commercial pesticides and patients may misidentify ingestions. There are limited data reporting the toxicity of pyrethroid overdose in humans and to guide its subsequent treatment. It is crucial to keep a low threshold for diagnosing and treating patients with acute onset of symptoms suspicious for an OP or pyrethroid toxidrome.