Widespread exploitation of the honeybee by early Neolithic farmers

The pressures on honeybee (Apis mellifera) populations, resulting from threats by modern pesticides, parasites, predators and diseases, have raised awareness of the economic importance and critical role this insect plays in agricultural societies across the globe. However, the association of humans with A. mellifera predates post-industrial-revolution agriculture, as evidenced by the widespread presence of ancient Egyptian bee iconography dating to the Old Kingdom (approximately 2400 bc)1. There are also indications of Stone Age people harvesting bee products; for example, honey hunting is interpreted from rock art2 in a prehistoric Holocene context and a beeswax find in a pre-agriculturalist site3. However, when and where the regular association of A. mellifera with agriculturalists emerged is unknown4. One of the major products of A. mellifera is beeswax, which is composed of a complex suite of lipids including n-alkanes, n-alkanoic acids and fatty acyl wax esters. The composition is highly constant as it is determined genetically through the insect’s biochemistry. Thus, the chemical ‘fingerprint’ of beeswax provides a reliable basis for detecting this commodity in organic residues preserved at archaeological sites, which we now use to trace the exploitation by humans of A. mellifera temporally and spatially. Here we present secure identifications of beeswax in lipid residues preserved in pottery vessels of Neolithic Old World farmers. The geographical range of bee product exploitation is traced in Neolithic Europe, the Near East and North Africa, providing the palaeoecological range of honeybees during prehistory. Temporally, we demonstrate that bee products were exploited continuously, and probably extensively in some regions, at least from the seventh millennium cal bc, likely fulfilling a variety of technological and cultural functions. The close association of A. mellifera with Neolithic farming communities dates to the early onset of agriculture and may provide evidence for the beginnings of a domestication process.

In vitro study of the effect of wound dressings on planktonic and biofilms from diabetic foot isolates

The management of wound bioburden has previously been evaluated using various antimicrobial wound dressings on bacterial pathogens isolated from various wounds. In this present study, the antimicrobial effect of silver-impregnated dressings (Acticoat and Silvercel) and honey-impregnated dressing (Medihoney™ Apinate) on both planktonic bacteria and quasi-biofilms by Staphylococcus aureus and Proteus mirabilis were assessed using a 6-well plate and standard agar technique. In the 6-well plate assay, a bacterial suspension of 108 colony forming unit (CFU)/mL was inoculated on each dressing in excess Luria-Bertani broth and incubated at 35 – 37°C for 30 and 60 minutes and 24 hours. After each incubation time, bacteria were recovered in sodium thioglycolate solution (STS) and the CFU/mL determined on LB agar. Dressings were cut into circular shapes (2cm diameter and placed on Mueller Hinton agar plates pre-inoculated with bacterial suspensions to determine their zones of inhibition (ZOI) after 24 hours incubation. None of the dressings was effective to significantly inhibit bacterial growth or biofilm formation at all the times tested. Acticoat and Medihoney™ Apinate produced ZOIs between 1.5 – 15 mm against both Staphylococcus aureus and Proteus mirabilis. It is possible that, dressings augmented with antibiotics can significantly reduce quasi-biofilms on standard agar.

The in vitro assessment of the synergistic effects of antibiotics and wound dressings on biofilms from diabetic foot pathogens

The impact of biofilm in the effective control of wound microbiome is an ongoing dilemma which has seen the use of different treatment strategies. The effects of wound dressings and antibiotics on both planktonic bacteria and biofilms have been separately evaluated in previous studies. In this current study, the combined antimicrobial effects of some selected wound dressings (silver-impregnated: Acticoat and Silvercel; and honey-impregnated: Medihoney™ Apinate) and antibiotics (ceftazdime and levofloxacin) on Klebsiella pneumoniae and Proteus mirabilis in their quasi-biofilm state were assessed using zone of inhibition (ZOI) test. Before the addition of the wound dressings, bacterial suspension of 108 colony forming units per mL and different concentrations of ceftazidime and levofloxacin (256, 512, 1024 and 5120µg/mL) of a final volume of 1mL were inoculated on Mueller Hinton agar and allowed to dry. Wound dressings cut into circular shapes (2cm diameter) were aseptically placed on the agar plates and incubated at 35 – 37°C for 24 hours. ZOIs associated with Acticoat, Silvercel and Medihoney™ Apinate dressings were compared with that of Atrauman (non-medicated control) dressing. All three dressings showed significant (p < 0.05) biofilm-inhibiting activity against both bacteria at antibiotic concentrations of 1024 and 5120µg/mL with ZOI between 17.5 and 35mm.