Feeding snails (Archachatina marginata) with leaves: growth performance, carcass characteristics, nutrient digestibility, proximate composition and minerals contents of snail meat.

This study explored the dietary impacts of some plant leaves (Centrosema pubescence leaves, Moringa oleifera leaves and Ipomea batata leaves) on the growth performance and carcass characteristics of Archachatina marginata reared in confinement. A twelve (12) weeks feeding trial on nine hundred and sixty (960) African giant land snails (A. marginata) fed various leaves was evaluated. The snails were allotted randomly on their experimental diets. The experimental diets were kitchen waste (leftover food) designated as the control (T1), C. pubescence leaves (T2), M. oleifera leaves (T3), and I. batata leaves (T4). Each treatment had two hundred and forty snails and was replicated four times with sixty snails each per replicate. The proximate compositions of these leaves were analyzed and showed significant values on the moisture content, crude protein, ether extracts, crude fiber, ash, and Nitrogen free extracts respectively. Data were collected on the performance, carcass characteristics, nutrient digestibility, proximate composition and minerals contents of snail meat. The results on the final weight, weight gain, average weight gain and FCR of snails showed that T4 (121.46, 36.10, 0.52 g and 1.49) were significantly (p < 0.05) different across treatment groups. Results on carcass characteristics showed that T4 had superior live weight, dressed weight, foot and dressing percentage values compared to the other groups. Also, T4 revealed significantly (p < 0.05) different across the diets on nutrient digestibility, proximate compositions of snail meat and the mineral composition of the snail meat compared to the other treatments. The study concluded that T4 (I. batata leaves) significantly influences the performance, carcass characteristic and mineral compositions of the snail meat and should be recommended as snail diet for optimum performance at an affordable cost.

Survival of Escherichia coli in Edible Land Snails: Implications for Heliciculture and Public Health.

BACKGROUND: Land snails are considered a delicacy in many countries in Europe and sub-Saharan Africa. However, the interaction of microbial pathogens with land snails may present a public health threat when handling and/or consuming snails. This study examines the survival of Escherichia coli in edible land snails in a model system. METHODS: Well-studied Shigatoxigenic (STEC) and non-STEC strains were compared. Mature Helix spp. were experimentally fed with E. coli-inoculated oats for 48 h. The snail feces after inoculation were periodically sampled and cultured for a 30-day period and subjected to microbiological analyses. RESULTS: The average rate of decline of the non-STEC strain CSH-62 in the feces of live snails was significantly (p < 0.05) faster than that of STEC ERL 06-2503. In addition, the viable population of E. coli ERL 06-2503 significantly (p < 0.05) persisted for a longer time in the intestine of land snails than E. coli CSH-62. CONCLUSION: The results showed that the viable population of the E. coli strains examined demonstrated first-order kinetics, and their survival (CFU/mL) appeared significantly (p < 0.05) dependent on the E. coli pathotype. In addition, the continuous enumeration of E. coli in snail faeces indicated that land snails could serve as a mode of transmission of microbial pathogens to susceptible hosts, including humans. Further research is recommended to better quantify the direct and indirect health risks of pathogen transmission by edible snails to humans.

First Report of the Presence of Enterotoxin Gene in Coagulase-negative Staphylococci Recovered from Meat of Snails (Achatina Achatina).

Introduction: It has been suggested that coagulase-negative staphylococci can serve as reservoirs of virulence genes for other bacteria. This study assessed the presence of such genes in selected isolates recovered from meat of the giant African snail (Achatina achatina). Material and Methods: Virulence genes were detected using a polymerase chain reaction targeting specific primers. Two representative isolates were identified using 16S rRNA gene sequencing. Results: The results showed that the staphylococcal enterotoxin A gene (sea) was present in five out of the eight isolates studied. The isolates expressed resistance mainly to three antibiotics: chloramphenicol, norfloxacin and cloxacillin in descending order of incidence. Most importantly, the Staphylococcus sciuri isolate NEDU 181, in addition to being resistant to the three aforementioned antibiotics, also harboured the sea gene. Conclusion: Our findings demonstrate, for the first time, the presence of toxigenic and antibiotic-resistant coagulase-negative Staphylococcus spp. in commercially-available fresh snail meat. With staphylococcal enterotoxin A known to survive cooking temperature, this presents a food safety concern.

Concentration levels of cadmium and lead in the raw and processed meat of Helix pomatia snails.

This work reports on cadmium and lead contaminations in the edible snail Helix pomatia harvested in Poland. One hundred and 24 samples of Helix pomatia meat collected from seven provinces (voivodeships) of Poland were analyzed for their trace metal levels by graphite furnace atomic absorption spectrometry (GFAAS). The research was conducted in 2 stages. The 1st stage analyzed snail meat prior to any further technological treatment (raw meat). In the 2nd stage, the trace element levels were measured in meat subjected to technological treatment (processed meat). The trace element contents in raw meat samples ranged from 0.06 mg kg-1 to 0.22 mg kg-1 for Cd and from 0.06 mg kg-1 to 0.18 mg kg-1 for Pb. The analyses revealed an increase in the cad- mium content from 0.12 mg kg-1 to 0.18 mg kg-1 in thermally treated snail meat and no changes in lead concentration during the two-stage heat treatment. Regulation (EC) 1881/2006 does not specify the Cd and Pb residue limits in meat of terrestrial edible snails. The limits are set for in- vertebrate aquatic organisms meat (i.e. shellfish, mollusc, cephalopod) and range from 0.5 mg/kg to 1.5 mg/kg of tissue fresh weight for Pb and from 0.5 mg kg -1 to 1 mg kg-1 for Cd (EU Commis- sion 2006). The results demonstrate that the land snail Helix pomatia has a tendency to bioaccu- mulate trace elements, and the cooking process is likely to affect (increase) the Cd content in the snail meat.

Is the consumption of snail meat actually healthy? An analysis of the osteotropic influence of snail meat as a sole source of protein in growing rats.

The study was aimed at determining the osteotropic effects of diets containing snail meat as a sole protein source. In our experiment, we tested three different diets incorporating snail meat originating from Helix pomatia (HP), Cornu.aspesa maxima (CAM) and Cornu.aspersum aspersum (CAA) and compared these to a control diet (CON) in which casein was the source of protein. In all diets, the protein content amounted to 10%, as calculated on a dry weight basis. In the study, forty male Wistar rats with an initial body mass of 50 ± 2 g were randomly placed within the control and three experimental groups. After 28 days of experimental feeding, the rats were sacrificed, and the body mass, total skeletal density and body composition were recorded. Moreover, blood serum (osteocalcin, CTX) and isolated tibia (pQCT, DXA, 3D micro-CT, 3-point bending test) were stored for further analysis. The results reveal that a diet incorporating snail meat significantly decreased BMC (bone mineral content), as well as area of total skeleton and isolated tibia, and was without influence on BMD (bone mineral density). Furthermore, the 3D micro-CT analysis of trabecular compartment documented a reduced Tb.Th (trabecular thickness), as well as Tb.N (trabecular number), and an increased Tb.Sp (trabecular separation). Beyond the aforementioned, the snail-based diets had an influence upon the architectonical properties of the tibia-decreasing its resistance to mechanical loading. Finally, snail meat, when used as an alone source of protein, negatively influenced the metabolism of the bone tissue in growing animals-making bone smaller and weaker.