Spread of infectious chronic bee paralysis virus by honeybee (Apis mellifera L.) feces.

Knowledge of the spreading mechanism of honeybee pathogens within the hive is crucial to our understanding of bee disease dynamics. The aim of this study was to assess the presence of infectious chronic bee paralysis virus (CBPV) in bee excreta and evaluate its possible role as an indirect route of infection. Samples of paralyzed bees were (i) produced by experimental inoculation with purified virus and (ii) collected from hives exhibiting chronic paralysis. CBPV in bee heads or feces (crude or absorbed onto paper) was detected by reverse transcription-PCR. CBPV infectivity was assessed by intrathoracic inoculation of bees with virus extracted from feces and by placement of naive bees in cages previously occupied by contaminated individuals. CBPV RNA was systematically detected in the feces of naturally and experimentally infected bees and on the paper sheets that had been used to cover the floors of units containing bees artificially infected with CBPV or the floor of one naturally infected colony. Both intrathoracic inoculation of bees with virus extracted from feces and placement of bees in contaminated cages provoked overt disease in naive bees, thereby proving that the excreted virus was infectious and that this indirect route of infection could lead to overt chronic paralysis. This is the first experimental confirmation that infectious CBPV particles excreted in the feces of infected bees can infect naive bees and provoke overt disease by mere confinement of naive bees in a soiled environment.

Tetracycline residues in honey after hive treatment.

Tetracyclines are used to control bacterial diseases such as European and American foulbrood, which may cause severe losses in the honey bee population and honey production. By using 24 hives randomly distributed into four groups of six hives, this study was performed to measure the occurrence of tetracycline hydrochloride (TC) residues in honey following two types of TC application. Two groups of colonies were treated three times with 0.5 g TC in 1 litre syrup (group S) or in 10 g powdered sugar (group P). Six hives of a first control group (C) fed with untreated syrup were installed at 20 and 45 m from groups S and P, respectively. A second control group (DC) was set up 3 km away. Honey was sampled at different times from all hives, and honey artificially contaminated with TC was stored in the laboratory at 4, 20 and 35 degrees C; all samples were analysed by ELISA and HPLC methods. One day after the last application, the mean TC concentration in brood chamber honey was ten times higher in group S (40.7 mg kg(-1)) than in group P (4.34 mg kg(-1)). After 8 days, TC residues were detected in all hives of group C. After 146 days, the mean TC concentration in harvested honey was 1.54, 0.35 and 0.15 mg kg(-1) for groups S, P and C, respectively. The control group C had been contaminated with TC by drifting. In all hives of group DC, no residues were detected at any time during the study. The honey collected at day 504 did not contain any detectable TC residues, except in one super from group C (0.026 mg kg(-1)). The half-life of TC in honey from supers was similar in groups C, S and P: 65 days. This duration was twice lower than in honey stored in laboratory in similar conditions: at 35 degrees C in the dark (t(1/2) = 121 days). In honey stored at 20 degrees C, TC was quite stable and its half-life was 242 days. The data from these experiments indicate levels of TC residues in honey after a treatment in hives, their persistence and diffusion into the apiary. These results show that the TC must be used with precaution in honey production.

[Contamination of bee products and risk for human health: situation in France]. / Contamination des produits de la ruche et risques pour la santé humaine: situation en France.

To meet the needs of a colony, bees collect honey, honey-dew, pollen and water from an environment exposed to various bacterial and chemical contaminants, which might be incorporated in products for human consumption. In addition to this environmental pollution, contamination of bee products may also occur during packing. In France, tests for various pollutants are performed more or less systematically, at the request of the Ministry of Agriculture, merchants or producers. Honey and royal jelly contain very little bacterial or chemical contamination, due to both the ability of colonies to eliminate pathogenic and non-pathogenic micro-organisms present in their environment, and to the physico-chemical properties of these products, as well as the role of bees in filtering chemical pollutants. To create the framework for European legislation on the testing of products, bacterial and chemical standards should be created and should be based on standardised techniques. The testing of imported bee products requires greater attention.