Foodborne bacteria in raw drone brood of Apis mellifera – a preliminary survey

2020 ◽  
pp. 1-6
Author(s):  
P. Herren ◽  
L. Fieseler ◽  
D. Ambuehl ◽  
J. Grunder
Keyword(s):  
Apis Mellifera ◽  
Varroa Destructor ◽  
Food Source ◽  
Viable Cell ◽  
Preliminary Survey ◽  
Edible Insects ◽  
Foodborne Bacteria ◽  
Cell Counts ◽  
Drone Brood ◽  
Coagulase Positive Staphylococci

Drone brood of Apis mellifera is often removed from the beehive to control the honeybee parasite Varroa destructor. Instead of discarding the drone brood, it could rather be used as a new food source for human nutrition. However, studies on microbiological hazards caused by edible insects are rare, especially in the case of drone brood. In this survey, microbial total viable cell counts and the most common foodborne bacteria were assessed in raw drone brood. Samples were taken from 24 beehives from four apiaries in Switzerland. The drone brood combs were harvested either by the beekeepers with their personal equipment or by the researchers with sterile equipment. No difference in the total viable cell counts was found between these two methods. All samples were free of Salmonella. Viable counts of Bacillus cereus, coagulase-positive staphylococci, Enterobacteriaceae and Escherichia coli were all below the detection limits of the recommended ISO reference methods. However, Listeria monocytogenes was detected in eight samples (all <10 cfu/g), which has not been reported in edible insects until now.

Varroa destructor (Acari: Varroidae) infestation in queen, worker, and drone brood of Apis mellifera (Hymenoptera: Apidae)

2002 ◽  
Vol 134 (3) ◽  
pp. 381-390 ◽  
Author(s):  
M.T. Santillán-Galicia ◽  
G. Otero-Colina ◽  
C. Romero-Vera ◽  
J. Cibrián-Tovar
Keyword(s):  
Apis Mellifera ◽  
Varroa Destructor ◽  
Egg Laying ◽  
Choice Test ◽  
Simultaneous Test ◽  
Adult Females ◽  
Drone Brood ◽  
Worker Brood

AbstractVarroa destructor Anderson and Trueman females were placed in contact with queen, worker, and drone brood cells of Apis mellifera L. that were soon to be sealed. In a non-choice test, V. destructor adult females were introduced into a comb containing either queen or worker brood cells; 0.62 and 18.28% of the mites entered the queen and worker brood cells, respectively. Only 1 of the 11 mites that entered queen brood cells oviposited, laying a single egg. In another test, brood cells were combined in the same comb in a 1:25:3 queen:worker:drone ratio. The percentages of egg-laying mites in queen, worker, and drone brood cells were 16.66, 61.86, and 79.06%, respectively. When queen, worker, and drone brood cells were combined in equal proportions (33.3:33.3:33.3), percent infestation was significantly different among queen (3.25%), worker (49.12%), and drone (90.07%) brood. Multiple infestation was found in drone brood cells but not in others. Also, mites were inoculated into sealed queen cells. These cells contained either one or two mites (either at the egg or protonymph stage). Conversely, in a simultaneous test with worker brood cells, the offspring per foundress mite included a mean of three individuals (either at the egg, protonymph, or deutonymph stage). It is concluded that V. destructor can infest queen, worker, and drone brood cells, but drone brood cells are preferred; in addition, queen brood cells do not provide an optimal environment for reproduction because it causes a delay in mite oviposition and (or) progeny development.

УГРОЗЫ РАСПРОСТРАНЕНИЯ ВИРУСНЫХ ИНФЕКЦИЙ У ПЧЕЛ (Apis mellifera L.) И РОЛЬ КЛЕЩА Varroa destructor В РАЗВИТИИ ПАТОЛОГИЙ

2016 ◽  
Vol 51 (2) ◽  
pp. 156-171
Author(s):  
А.В. СПРЫГИН ◽  
◽  
Ю.Ю. БАБИН ◽  
Е.М. ХАНБЕКОВА ◽  
Л.Е. РУБЦОВА ◽  
...  
Keyword(s):  
Apis Mellifera ◽  
Varroa Destructor

Eficacia del humo de frutos de Guazuma ulmifolia (Sterculiaceae) y vapores de timol para el control de Varroa destructor infestando abejas africanizadas

2019 ◽  
Vol 10 (3) ◽  
pp. 778-788
Author(s):  
William De Jesús May-Itzá ◽  
Luis Abdelmir Abdelmir Medina Medina
Keyword(s):  
Apis Mellifera ◽  
Varroa Destructor ◽  
Guazuma Ulmifolia

Se evaluó la eficacia del humo de los frutos secos de Guazuma ulmifolia y los vapores de timol en el control del ácaro Varroa destructor infestando colonias de abejas africanizadas (Apis mellifera) de Yucatán. Se utilizaron tres tratamientos: Grupo 1 (G1), las colonias de abejas recibieron 5 a 8 bocanadas de humo de los frutos secos de G. ulmifolia dos veces por semana, durante un período de tres semanas; Grupo 2 (G2), las colonias recibieron 4-8 g de cristales de timol con tres aplicaciones cada siete días, y Grupo 3 (G3 o grupo control) las colonias no recibieron ningún tratamiento durante las tres semanas del experimento. Se colectaron 200 a 300 abejas adultas de cada colonia previo a la aplicación de los tratamientos (día 0) y a los 7, 14 y 21 días después de las aplicaciones, con la finalidad de determinar los niveles de infestación y eficacia de los tratamientos. Los resultados indican que los niveles de infestación de V. destructor en las abejas adultas disminuyeron al final del experimento (21 días) y fueron estadísticamente diferentes para los tres tratamientos, siendo menor para G2. La eficacia al final de los tratamientos fue de 41 y 69 %, para G1 y G2, respectivamente. Estos resultados corroboran que la aplicación de cristales de timol es una alternativa para el control del ácaro V. destructor en Yucatán, y que la aplicación del humo de los frutos secos de G. ulmifolia reduce los niveles de infestación de este parásito en comparación con las colonias que no recibieron ningún tipo de tratamiento (G3).

scholarly journals 1250. Novel Boronic Acid Transition State Analogs (BATSI) with in vitro inhibitory activity against class A, B and C β-lactamases

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S643-S643
Author(s):  
Maria F Mojica ◽  
Christopher Bethel ◽  
Emilia Caselli ◽  
Magdalena A Taracila ◽  
Fabio Prati ◽  
...  
Keyword(s):  
Active Site ◽  
Inhibitory Activity ◽  
Covalent Bond ◽  
Thiol Group ◽  
Viable Cell ◽  
Free Thiol ◽  
Transition State Analogs ◽  
Cell Counts ◽  
Free Thiol Group

Abstract Background Catalytic mechanisms of serine β-lactamases (SBL; classes A, C and D) and metallo-β-lactamases (MBLs) have directed divergent strategies towards inhibitor design. SBL inhibitors act as high affinity substrates that -as in BATSIs- form a reversible, dative covalent bond with the conserved active site Ser. MBL inhibitors bind the active-site Zn2+ ions and displace the nucleophilic OH-. Herein, we explore the efficacy of a series of BATSI compounds with a free-thiol group at inhibiting both SBL and MBL. Methods Exploratory compounds were synthesized using stereoselective homologation of (+) pinandiol boronates to introduce the amino group on the boron-bearing carbon atom, which was subsequently acylated with mercaptopropanoic acid. Representative SBL (KPC-2, ADC-7, PDC-3 and OXA-23) and MBL (IMP-1, NDM-1 and VIM-2) were purified and used for the kinetic characterization of the BATSIs. In vitro activity was evaluated by a modified time-kill curve assay, using SBL and MBL-producing strains. Results Kinetic assays revealed that IC50 values ranged from 1.3 µM to &gt;100 µM for this series. The best compound, s08033, demonstrated inhibitory activity against KPC-2, VIM-2, ADC-7 and PDC-3, with IC50 in the low μM range. Reduction of at least 1.5 log10-fold of viable cell counts upon exposure to sub-lethal concentrations of antibiotics (AB) + s08033, compared to the cells exposed to AB alone, demonstrated the microbiological activity of this novel compound against SBL- and MBL-producing E. coli (Table 1). Table 1 Conclusion Addition of a free-thiol group to the BATSI scaffold increases the range of these compounds resulting in a broad-spectrum inhibitor toward clinically important carbapenemases and cephalosporinases. Disclosures Robert A. Bonomo, MD, Entasis, Merck, Venatorx (Research Grant or Support)

scholarly journals Exploring Two Honey Bee Traits for Improving Resistance Against Varroa destructor: Development and Genetic Evaluation

Insects ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 216
Author(s):  
Matthieu Guichard ◽  
Benoît Droz ◽  
Evert W. Brascamp ◽  
Adrien von Virag ◽  
Markus Neuditschko ◽  
...  
Keyword(s):  
Apis Mellifera ◽  
Honey Bee ◽  
Honey Bees ◽  
Varroa Destructor ◽  
Field Trial ◽  
Genetic Evaluation ◽  
Phenotypic Correlation ◽  
Apis Mellifera Mellifera ◽  
Novel Traits ◽  
Resistance Traits

For the development of novel selection traits in honey bees, applicability under field conditions is crucial. We thus evaluated two novel traits intended to provide resistance against the ectoparasitic mite Varroa destructor and to allow for their straightforward implementation in honey bee selection. These traits are new field estimates of already-described colony traits: brood recapping rate (‘Recapping’) and solidness (‘Solidness’). ‘Recapping’ refers to a specific worker characteristic wherein they reseal a capped and partly opened cell containing a pupa, whilst ‘Solidness’ assesses the percentage of capped brood in a predefined area. According to the literature and beekeepers’ experiences, a higher recapping rate and higher solidness could be related to resistance to V. destructor. During a four-year field trial in Switzerland, the two resistance traits were assessed in a total of 121 colonies of Apis mellifera mellifera. We estimated the repeatability and the heritability of the two traits and determined their phenotypic correlations with commonly applied selection traits, including other putative resistance traits. Both traits showed low repeatability between different measurements within each year. ‘Recapping’ had a low heritability (h2 = 0.04 to 0.05, depending on the selected model) and a negative phenotypic correlation to non-removal of pin-killed brood (r = −0.23). The heritability of ‘Solidness’ was moderate (h2 = 0.24 to 0.25) and did not significantly correlate with resistance traits. The two traits did not show an association with V. destructor infestation levels. Further research is needed to confirm the results, as only a small number of colonies was evaluated.

scholarly journals Genomic survey of the ectoparasitic mite Varroa destructor, a major pest of the honey bee Apis mellifera

BMC Genomics ◽  
2010 ◽  
Vol 11 (1) ◽  
Author(s):  
R Scott Cornman ◽  
Michael C Schatz ◽  
J Spencer Johnston ◽  
Yan-Ping Chen ◽  
Jeff Pettis ◽  
...  
Keyword(s):  
Apis Mellifera ◽  
Honey Bee ◽  
Varroa Destructor ◽  
Major Pest

Trophallaxis in honeybees, Apis mellifera (L.), as related to their past experience at the food source

2003 ◽  
Vol 66 (4) ◽  
pp. 791-795 ◽  
Author(s):  
Alejandro J Wainselboim ◽  
Walter M Farina
Keyword(s):  
Apis Mellifera ◽  
Food Source ◽  
Past Experience

scholarly journals Survival Strategy of Erwinia amylovora against Copper: Induction of the Viable-but-Nonculturable State

2006 ◽  
Vol 72 (5) ◽  
pp. 3482-3488 ◽  
Author(s):  
M�nica Ordax ◽  
Ester Marco-Noales ◽  
Mar�a M. L�pez ◽  
Elena G. Biosca
Keyword(s):  
Pathogenic Bacteria ◽  
Erwinia Amylovora ◽  
Control Plant ◽  
Viable Cell ◽  
Epifluorescence Microscopy ◽  
Survival Strategy ◽  
Vbnc State ◽  
Tetrazolium Chloride ◽  
Viable But Nonculturable ◽  
Cell Counts

ABSTRACT Copper compounds, widely used to control plant-pathogenic bacteria, have traditionally been employed against fire blight, caused by Erwinia amylovora. However, recent studies have shown that some phytopathogenic bacteria enter into the viable-but-nonculturable (VBNC) state in the presence of copper. To determine whether copper kills E. amylovora or induces the VBNC state, a mineral medium without copper or supplemented with 0.005, 0.01, or 0.05 mM Cu2+ was inoculated with 107 CFU/ml of this bacterium and monitored over 9 months. Total and viable cell counts were determined by epifluorescence microscopy using the LIVE/DEAD kit and by flow cytometry with 5-cyano-2,3-ditolyl tetrazolium chloride and SYTO 13. Culturable cells were counted on King's B nonselective solid medium. Changes in the bacterial morphology in the presence of copper were observed by scanning electron microscopy. E. amylovora entered into the VBNC state at all three copper concentrations assayed, much faster when the copper concentration increased. The addition of different agents which complex copper allowed the resuscitation (restoration of culturability) of copper-induced VBNC cells. Finally, copper-induced VBNC cells were virulent only for the first 5 days, while resuscitated cells always regained their pathogenicity on immature fruits over 9 months. These results have shown, for the first time, the induction of the VBNC state in E. amylovora as a survival strategy against copper.

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