Imidacloprid disrupts larval molting regulation and nutrient energy metabolism, causing developmental delay in honey bee Apis mellifera.

Imidacloprid is a global health threat that severely poisons the economically and ecologically important honeybee pollinator, Apis mellifera. However, its effects on developing bee larvae remain largely unexplored. Our pilot study showed that imidacloprid causes developmental delay in bee larvae, but the underlying toxicological mechanisms remain incompletely understood. In this study, we exposed bee larvae to imidacloprid at environmentally relevant concentrations of 0.7, 1.2, 3.1, and 377 ppb. There was a marked dose-dependent delay in larval development, characterized by reductions in body mass, width, and growth index. However, imidacloprid did not affect on larval survival and food consumption. The primary toxicological effects induced by elevated concentrations of imidacloprid (377 ppb) included inhibition of neural transmission gene expression, induction of oxidative stress, gut structural damage, and apoptosis, inhibition of developmental regulatory hormones and genes, suppression of gene expression levels involved in proteolysis, amino acid transport, protein synthesis, carbohydrate catabolism, oxidative phosphorylation, and glycolysis energy production. In addition, we found that the larvae may use antioxidant defenses and P450 detoxification mechanisms to mitigate the effects of imidacloprid. Ultimately, this study provides the first evidence that environmentally exposed imidacloprid can affect the growth and development of bee larvae by disrupting molting regulation and limiting the metabolism and utilization of dietary nutrients and energy. These findings have broader implications for studies assessing pesticide hazards in other juvenile animals.

Pneumatosis intestinalis and hepatic portal venous gas in patient with Amanita exitialis poisoning: A case report from Shenzhen, China.

A 57-year-old male admitted as an emergency for mushroom poisoning with hypovolemic shock, acute renal injury (Cr 213 µmol/L) and metabolic acidosis (pH 7.1). Twenty-six hours ago, he consumed 4 caps of wild mushrooms and presented with acute gastroenteritis, generalized malaise and lower limbs jerk. On ICU admission, he developed ventricular defibrillation and was resuscitated with intubation and ventilation. In addition to plasma exchange and hemoperfusion therapy, the patient was managed with massive fluid and potassium replacement, vasopressors, activated charcoal, silymarin, penicillin G and piperacillin tazobactam. On ICU Day 2, the patient's general condition improved with vasopressor ceased, renal function normalized except large amount of diarrhea. On ICU Day 3, the patient deteriorated again with worsening abdominal distension leading to intra-abdominal hypertension (IAH). Toxic liver injury by mushroom became significant. Repeated acute renal injury, deranged clotting and compromised hemodynamics were also noted which indicated acute abdominal compartment syndrome. Emergent computed tomography (CT) of abdomen revealed Pneumatosis intestinalis (PI) in the small intestines and hepatic portal venous gas (HPVG) in the left liver lobe. Water assisted colonoscopy decompression was performed emergently for IAH relief. Thereafter, the patient improved rapidly with organ dysfunction recovered next day. Acute liver failure gradually subsided. On ICU Day 8, the patient was discharged to general ward. The mushroom was later morphologically identified as Amanita exitialis (A. exitialis) by at least two specialists from Chinese Centre for Disease Control and Prevention (CDC). A. exitialis is a lethal mushroom that mainly affect liver and gastrointestinal (GI) tract. The current case and literature review suggest that the severity of GI injury caused by lethal A. exitialis may be underestimated.

An outbreak of Amanita exitialis poisoning.

BACKGROUND: The mushroom Amanita exitialis is reported to cause acute liver injury. It is found in Southern China, and has been previously associated with a high incidence of mortality. METHODS: We described a series of 10 patients with Amanita exitialis poisoning admitted to The Second Affiliated Hospital of the Chinese University of Hong Kong (Shenzhen) in April 2022. Patient demographics, clinical features, laboratory results, therapeutic interventions, and outcome data were collected. RESULTS: Among the 10 patients, 9 survived, while 1 died. Gastrointestinal symptoms were the first to appear (average latency period, 11 ± 4.2 h). Diarrhea was the most common clinical symptom (average duration, 4.4 days). Abdominal distention was an important sign, especially in severely-ill patients. Thrombocytopenia occurred on day 2 after mushroom ingestion and persisted for 3-4 days. Alanine aminotransferase and total bilirubin peaked on days 2-3. CONCLUSION: Amanita exitialis poisoning is characterized by gastrointestinal symptoms and liver injury. In the patient who died, acute hepatic failure led to hepatic encephalopathy and cerebral edema. Abdominal distension accompanied by thrombocytopenia was common in critically ill patients in this outbreak.

Study on the association between the polymorphism of MCP-1 rs1024611 and the genetic susceptibility of type 2 diabetes with sepsis.

Monocyte chemoattractant protein-1 (MCP-1) rs1024611 (-2518 A > G) polymorphism are associated with inflammatory diseases. In this study, we investigate the relationship between MCP-1 rs1024611 polymorphism and genetic susceptibility of type 2 diabetes mellitus (T2DM) with sepsis. Two hundred eighty-five patients with T2DM are divided into the diabetes with sepsis group (combined group, 113 cases) and the diabetes group (172 cases). Blood samples and corresponding clinical data were collected. MCP-1 rs1024611 polymorphism in blood samples was detected by pyrosequencing. Meanwhile, the expressions of MCP-1, tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1ß, and IL-6 in blood samples were detected by real-time quantitative polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. The relationship between different genotypes of MCP-1 rs1024611 polymorphic locus and T2DM with sepsis was analyzed by combining with the clinical data of the patients. The frequencies of rs1024611 AG/GG genotypes and G allele in T2DM with sepsis group were significantly higher than those in T2DM patients without sepsis (P = .004 for AG/GG vs AA genotypes; P = .037 for G allele vs A allele). Subgroup analysis showed that the rs1024611 G allele frequency in the septic shock group was significantly higher than the general sepsis group (P = .02). The expressions of MCP-1 and TNF-α in GG genotypes in T2DM with sepsis group were significantly higher than AA or GA genotypes (P < .05). This study preliminarily showed that the rs1024611 A > G polymorphism within the promoter region of MCP-1 gene can upregulate the expression of MCP-1 gene and proinflammatory cytokine TNF-α, which ultimately contributed to the predisposition and progression of T2DM with sepsis.

Physicochemical properties, molecular structure, antioxidant activity, and biological function of extracellular melanin from Ascosphaera apis.

Ascosphaera apis spores containing a dark-colored pigment infect honeybee larvae, resulting in a large-scale collapse of the bee colony due to chalkbrood disease. However, little is known about the pigment or whether it plays a role in bee infection caused by A. apis. In this study, the pigment was isolated by alkali extraction, acid hydrolysis, and repeated precipitation. Ultraviolet (UV) analysis revealed that the pigment had a color value of 273, a maximum absorption peak at 195 nm, and a high alkaline solubility (7.67%) and acid precipitability. Further chemical structure analysis of the pigment, including elemental composition, Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, mass spectrometry, and nuclear magnetic resonance (NMR), proved that it was a eumelanin with a typical indole structure. The molecular formula of melanin is C10H6O4N2, and its molecular weight is 409 Da. Melanin has hydroxyl, carboxyl, amino, and phenolic groups that can potentially chelate to metal ions. Antioxidant function analyses showed that A. apis melanin had a high scavenging activity against superoxide, hydroxyl, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals, and a high reducing ability to Fe3+. Indirect immunofluorescence assay (IFA), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) analyses showed that A. apis melanin was located on the spore wall. The spore wall localization, antioxidant activity, and metal ion chelating properties of fungal melanin have been suggested to contribute to spore pathogenicity. However, further infection experiments showed that melanin-deficient spores did not reduce the mortality of bee larvae, indicating that melanin does not increase the virulence of A. apis spores. This study is the first report on melanin produced by A. apis, providing an important background reference for further study on its role in A. apis.

Melatonin enhances the antioxidant capacity to rescue the honey bee Apis mellifera from the ecotoxicological effects caused by environmental imidacloprid.

Imidacloprid severely poisons the nontarget insect honey bee Apis mellifera. Few treatments are available to mitigate the adverse effects of imidacloprid. The primary concern is that the molecular understanding of imidacloprid toxicity is not comprehensive enough. Oxidative stress is the primary pathophysiological mechanism by which pesticides cause high mortality. Our pilot study found for the first time that imidacloprid stimulates bee brains to secrete melatonin, a free radical scavenger. However, the molecular basis for imidacloprid toxicity and the role of melatonin in coping with imidacloprid have not been systematically investigated in bees. This study administered an environmental dose of imidacloprid (36 ng/bee) orally to A. mellifera. The detoxification gene cytochrome P450 CYP4G11 was significantly induced. However, potent cytotoxicity of imidacloprid suppressed the expression of the antioxidants catalase (CAT) and thioredoxin reductase (TrxR), and the activity of guaiacol peroxidase (GPX), superoxide dismutase (SOD), and reduced glutathione (GSH) was not induced. The levels of reactive oxygen species (ROS) and the lipid peroxidation marker malondialdehyde (MDA) were increased. The expression of the apoptotic genes cysteinyl aspartate specific proteinase (Caspase-3) and apoptosis inducing factor (AIF) increased, and the apoptotic features of midgut cells were prominently apparent. These results suggest that imidacloprid disrupts the bee antioxidant system, causing severe oxidative stress and tissue damage and ultimately leading to apoptosis. Significantly, however, imidacloprid exposure also stimulated bee brains to continuously secrete melatonin. Further preadministration of exogenous melatonin (200 ng/bee) orally to bees significantly reversed and enhanced the activity of the imidacloprid-suppressed antioxidants CAT, SOD, and GSH, which allowed imidacloprid-induced ROS accumulation to be effectively alleviated. The MDA content, apoptotic genes Caspase-3 and AIF, and detoxification gene CYPG411 expression were restored to normalization; midgut cell damage, apoptosis, and mortality were significantly reduced. These findings strongly suggest that melatonin enhanced bee antioxidant capacity, thus attenuating oxidative stress and apoptosis to confer imidacloprid tolerance to honey bees. Melatonin secretion may be a defense mechanism to mitigate imidacloprid toxicity.