Hookworm infection is a major public health problem that threatens about 500 million people throughout tropical areas of the world. Adult hookworms survive for many years in the host intestine, where they suck blood, causing iron deficiency anemia and malnutrition. Numerous molecules, named excretory/secretory (ES) products, are secreted by hookworm adults and/or larvae to aid in parasite survival and pathobiology. Although the molecular cloning and characterization of hookworm ES products began 25 years ago, the biological role and molecular nature of many of them are still unclear. Hookworm ES products, with distinct structures and functions, have been linked to many essential events in the disease pathogenesis. These events include host invasion and tissue migration, parasite nourishment and reproduction, and immune modulation. Several of these products represent promising vaccine targets for controlling hookworm disease and therapeutic targets for many inflammatory diseases. This review aims to summarize our present knowledge about hookworm ES products, including their role in parasite biology, host-parasite interactions, and as vaccine and pharmaceutical targets and to identify research gaps and future research directions in this field.

To determine the effect of astragalus and ginseng polysaccharides (APS, GPS) on immune response and improvement of H5N1 vaccine, 360-day-old broilers were randomly divided into 8 groups of 45 chicks, comprising APS groups (1–3); GPS groups (4–6); vaccine group (7); and blank control (8) (without polysaccharide and vaccine). From day 12 after hatch groups 1–3 were given APS and groups 4–6 with GPS both at 100, 200, and 400 (mg/kg), respectively. At day 15 after hatch, groups 1–7 were vaccinated with 0.3 mL H5N1 vaccine subcutaneously; daily weight gain (DWG) and serum Ig antibody (by HI-test) were measured on 3, 7, 14, and 28 days after vaccination. Serum antibody titers and expression of cytokines (IL-2, IL-10, I FN-γ, and TNF) were determined by ELISA and RT-PCR. Results revealed that all the polysaccharide groups were numerically increased in antibody levels and the expression of cytokines was significant (P<0.05) in the APS and GPS groups compared to corresponding vaccine group and blank control. DWG was higher (P<0.05) in 400 mg/kg APS groups than control groups. Thus oral supplements of GPS and APS have shown their potential in the improvement of immune response and could be used as adjuvant in a formulation of H5N1 vaccine.

Ancylostoma caninumis a blood-feeding parasitic intestinal nematode which infects dogs, cats, and other mammals throughout the world. A highly sensitive and species-specific PCR-RFLP technique was utilised to detect the prevalence ofA. caninumin cats in Guangzhou, southern China. Of the 102 fecal samples examined, the prevalence ofA. caninumin cats was 95.1% and 83.3% using PCR-RFLP and microscopy, respectively. Among them, the prevalence of single hookworm infection withA. caninumwas 54.90%, while mixed infections with bothA. caninumandA. ceylanicumwere 40.20%. Comparative analysis of three complete ITS sequences obtained from cat-derivedA. caninumshowed the same length (738 bp) as that of dog-derivedA. caninum. However, the sequence variation range was 98.6%–100%, where only one cat isolate (M63) showed 100% sequence similarity in comparison with two dog-derivedA. caninumisolates (AM850106, EU159416) in the same studied area. The phylogenetic tree revealedA. caninumderived from both cats and dogs in single cluster. Results suggest that cats could be the main host ofA. caninumin China, which may cause cross-infection between dogs and cats in the same area.

Zheng G, et al. Korean J Parasitol. 2014 Jun;52(3):299-304. http://dx.doi.org/10.3347/kjp.2014.52.3.299