In Vivo Activity of Repurposed Amodiaquine as a Host-Targeting Therapy for the Treatment of Anthrax

Electrochemical immunosensor for Bacillus anthracis PA toxin using a polypyrrole-gold nanoparticle/multiwall carbon nanotube sensing platform and cadmium sulphide nanocrystal signal tag

A sandwich electrochemical immunosensor was proposed for the sensitive detection of Bacillus anthracis protective antigen (B. anthracis PA) toxin based on cadmium sulphide nanocrystals (CdS NCs) and polypyrrole-gold nanoparticle-modified multiwalled carbon nanotubes (PPy-AuNPs/MWCNTs). Herein, PPy-AuNPs/MWCNTs were used as a biocompatible and conducting matrix for immobilization of rabbit anti-PA antibody [RαPA antibody, i.e. capturing antibody (Ab1)] and to facilitate excellent electrical conductivity. PPy-AuNPs/MWCNTs were synthesized through a one-step chemical reaction of pyrrole and Au3+ on the surface of MWCNTs. CdS NCs were employed as a label for covalent binding of monoclonal mice anti-PA antibody [MαPA antibody, i.e. secondary antibody (Ab2)]. When B. anthracis PA toxin was present in an analytical sample, the sandwich immunoassay was formed, and an electrochemical potentiometric stripping analysis (PSA) signal was generated. The PSA response produced during the detection was caused by Cd2+ ions released from CdS NCs upon acid dissolution. The synergistic action of PPy, AuNPs and MWCNTs was responsible for the electrochemical signal amplification in the immunosensor. Under optimal conditions, the developed immunosensor showed a linear range from 100 pg mL-1 to 10 ng mL-1 (R2 = 0.992) with a detection limit of 10 pg mL-1 (S/N = 3) for B. anthracis PA toxin. The developed electrochemical immunosensor also exhibited excellent stability, reproducibility and good specificity. The immunosensor was applied for the analysis of human serum spiked with B. anthracis PA toxin with satisfactory results.

Anthrax: Transmission, Pathogenesis, Prevention and Treatment

Bacillus anthracis is a deadly pathogen that under unfavourable conditions forms highly resistant spores which enable them to survive for a long period of time. Spores of B. anthracis are transmitted through the contaminated soil or animal products and enter to the host through the skin, lungs or oral route and can cause cutaneous, injection, inhalation and gastrointestinal anthrax, respectively. The disease is caused by the toxin which is produced by them once they germinate within the host cell. Anthrax toxin is the major virulence factor which has the ability to kill the host cell. The role of protein kinases and phosphatases of B. anthracis in toxin production and other virulence related properties have also been reported. There are two vaccines, BioThrax and CYFENDUSTM, which are approved by the FDA-USA to prevent anthrax disease. Recently, anthrax toxin has also been shown to be a potential candidate for cancer therapeutics. Through present review, we aim to provide insights into sporulation, transmission and pathogenesis of B. anthracis as well as the current state of its prevention, treatment, vaccines and possible therapeutic uses in cancer.

Anthrax meningoencephalitis: A case report

The present study describes the case of a patient with anthrax meningoencephalitis with the aim of providing a scientific basis for the control of this disease. The cerebrospinal fluid and blood of the patient were tested for genes and Bacillus anthracis was detected. The patient's meningitis was cured following treatment. Tracing the route of infection, anthrax was detected on the chopping board of the rural cattle and sheep butcher shop where the patient had purchased meat. In 2018, the patient complained of intermittent nasal discharge for 11 days after brain injury and came to the Second People's Hospital of Liaocheng (Linqing, China). Considering the existence of cerebrospinal fluid rhinorrhea, the patient's cerebrospinal fluid biochemistry was assessed and showed low sugar and high protein levels, resulting in a diagnosis of bacterial encephalitis. This encephalitis was considered to be related to bacterial retrograde infection after cerebrospinal fluid rhinorrhea. It is required to strengthen the training of medical personnel according to guidelines and laws and improve the level of early detection, reporting and diagnosis, as well as timely treatment at medical institutions. There is an urgent need to intensify the education of the population regarding the awareness and prevention of the disease. For individuals involved in the breeding, slaughtering and processing of livestock, multiple measures need to be taken to comprehensively intervene and to enhance occupational protection awareness and disease prevention capabilities.

A nanochitosan-D-galactose formulation increases the accumulation of primaquine in the liver

Primaquine is the mainstream antimalarial drug to prevent Plasmodium vivax relapses. However, this drug can induce hemolysis in patients with glucose-6-phosphate dehydrogenase deficiency. Nanostructure formulations of primaquine loaded with D-galactose were used as a strategy to target the drug to the liver and decrease the hemolytic risks. Nanoemulsion (NE-Pq) and nanochitosan (NQ-Pq) formulations of primaquine diphosphate containing D-galactose were prepared and characterized by their physicochemistry properties. Pharmacokinetic and biodistribution studies were conducted using Swiss Webster mice. A single dose of 10 mg/kg of each nanoformulation or free primaquine solution was administered by gavage to the animals, which were killed at 0.5, 1, 2, 4, 8, and 24 hours. Blood samples and tissues were collected, processed, and analyzed by high-performance liquid chromatography. The nanoformulation showed sizes around 200 nm (NE-Pq) and 400 nm (NQ-Pq) and physicochemical stability for over 30 days. Free primaquine solution achieved higher primaquine Cmax in the liver than NE-Pq or NQ-Pq at 0.5 hours. However, the half-life and mean residence time (MRT) of primaquine in the liver were three times higher with the NQ-Pq formulation than with free primaquine, and the volume distribution was four times higher. Conversely, primaquine's half-life, MRT, and volume distribution in the plasma were lower for NQ-Pq than for free primaquine. NE-Pq, on the other hand, accumulated more in the lungs but not in the liver. Galactose-coated primaquine nanochitosan formulation showed increased drug targeting to the liver compared to free primaquine and may represent a promising strategy for a more efficient and safer radical cure for vivax malaria.