Karina Antúnez

• PhD in Biological Sciences
• Researcher at Clemente Estable Biological Research Institute

Paenibacillus larvae is the causative agent of American Foulbrood (AFB), the most severe bacterial disease affecting honey bee (Apis mellifera) larvae. It was first reported in Uruguay in 1999. Here, we summarize the monitoring strategy carried out from 2001 to date, based on nationwide surveys sampling honey from colonies (2001/2002, 2011, 2021) o...

Over the last quarter century, increasing honey bee colony losses motivated standardized large-scale surveys of managed honey bees (Apis mellifera), particularly in Europe and the United States. Here we present the first large-scale standardized survey of colony losses of managed honey bees and stingless bees across Latin America. Overall, 1736 bee...

Over the last quarter century, increasing bee colony losses motivated standardized large-scale surveys of managed honey bees ( Apis mellifera ), particularly in Europe and the United States. Here we present the first large-scale standardized survey of colony losses of managed honey bees and stingless bees across Latin America. Overall, 1736 beekeep...

Honey bee colonies form a complex superorganism, with individual and social immune defences that control overall colony health. Sometimes these defences are not enough to overcome infections by parasites and pathogens. For that reason, several studies have been conducted to evaluate different strategies to improve honey bee health. A novel alternat...

Novel transmission routes can allow infectious diseases to spread, often with devastating consequences. Ectoparasitic varroa mites vector a diversity of RNA viruses, having switched hosts from the eastern to western honey bees (Apis cerana to Apis mellifera). They provide an opportunity to explore how novel transmission routes shape disease epidemi...

The small hive beetle (SHB), Aethina tumida, is a parasitic pest and scavenger of social bees native to sub-Saharan Africa. It is a generalist species which can also reproduce in association with nests of stingless bees, fruits, and even rotten meat. Although in its native range, it usually does not cause severe damage to strong colonies and nests;...

Novel transmission routes can allow infectious diseases to spread, often with devastating consequences. Ectoparasitic varroa mites vector a diversity of RNA viruses and, having switched hosts from the eastern to western honey bees (Apis cerana to Apis mellifera). They provide an opportunity to explore how novel transmission routes shape disease epi...

Insect pollinators are threatened worldwide, being the exposure to multiple pesticides one of the most important stressor. The herbicide Glyphosate and the insecticide Imidacloprid are among the most used pesticides worldwide, although different studies evidenced their detrimental effects on non-target organisms. The emergence of glyphosate-resista...

The administration of beneficial microbes or probiotics is a widely used strategy to improve human and animal health. In a previous study, we developed a mixture of Apilactobacillus kunkeei strains that, when administered to honey bees, reduced the infection by pathogens Nosema ceranae or the mortality associated with Paenibacillus larvae. However,...

Invasive parasites are major threats to biodiversity. The honey bee ectoparasite, Varroa destructor, has shifted host and spread almost globally several decades ago. This pest is generally considered to be the main global threat to Western honey bees, Apis mellifera, although the damages it causes are not equivalent in all its new host's population...

In recent years, beekeeping industry in Uruguay faces low honey production yields and annual colony losses that can reach 30%, and health problems are involved in much of this situation. Worldwide, research on the factors that threaten honey bee populations has expanded, encompassing nutritional problems, the immune response, the intestinal microbi...

Large-scale honey bee colony losses reported around the world have been associated with intoxication with pesticides, as with the presence of pests and pathogens. Among pesticides, neonicotinoid insecticides are the biggest threat. Due to their extensive use, they can be found in all agricultural environments, including soil, water, and air, are pe...

Honey bees (Apis mellifera) provide invaluable benefits for food production and maintenance of biodiversity of natural environments through pollination. They are widely spread across the world, being adapted to different climatic conditions. To survive the winter in cold temperate regions, honey bees developed different strategies including storage...

The “River Disease” (RD), a disorder impacting honeybee colonies located close to waterways with abundant riparian vegetation (including Sebastiania schottiana, Euphorbiaceae), kills newly hatched larvae. Forager bees from RD-affected colonies collect honeydew excretions from Epormenis cestri (Hemiptera: Flatidae), a planthopper feeding on trees of...

RNA viruses play a significant role in the current high losses of pollinators. Although many studies have focused on the epidemiology of western honey bee (Apis mellifera) viruses at the colony level, the dynamics of virus infection within colonies remains poorly explored. In this study, the two main variants of the ubiquitous honey bee virus DWV a...

Bumble bees (Bombus spp.) are important pollinators insects involved in the maintenance of natural ecosystems and food production. Bombus pauloensis is a widely distributed species in South America, that recently began to be managed and commercialized in this region. The movement of colonies within or between countries may favor the dissemination o...

Glyphosate is the most used pesticide around the world. Although different studies have evidenced its negative effect on honey bees, including detrimental impacts on behavior, cognitive, sensory and developmental abilities, its use continues to grow. Recent studies have shown that it also alters the composition of the honey bee gut microbiota. In t...

The "River Disease” (RD), a disorder impacting honeybee colonies located closed to waterways with abundant riparian vegetation (including Sebastiania schottiana , Euphorbiaceae), kills newly hatched larvae. Forager bees from RD-affected colonies collect honeydew excretions from Epormenis cestri (Hemiptera: Flatidae), a planthopper feeding on trees...

One of the main driving forces of the Apis mellifera colony losses reported worldwide is the nutritional stress associated with monoculture areas. We previously demonstrated under field conditions that nutritional stress that occurred during the fall impacts honey bee colony strength and health in the short and long-term. Pollen supplementation to...

A longitudinal study was carried out in order to evaluate Nosema spp. spore counts in two key moments of the year (late autumn and spring) in honeybee colonies from five eco-regions of Argentina. Three hundred and sixty colonies were randomly selected and the infestation level of Nosema spp. and Varroa destructor was assessed in autumn and spring o...

Honeybees are important pollinators, having an essential role in the ecology of natural and agricultural environments. Honeybee colony losses episodes reported worldwide and have been associated with different pests and pathogens, pesticide exposure, and nutritional stress. This nutritional stress is related to the increase in monoculture areas whi...

The ectoparasite Varroa destructor is the greatest biotic threat of honey bees Apis mellifera in vast regions of the world. Recently, the study of natural mite-resistant populations has gained much interest to understand the action of natural selection on the mechanisms that limit the mite population. In this study, the components of the A. mellife...

Cuba is a tropical island where beekeeping is an important economic activity. Cuban honey bees have a European origin, being hybrids of Apis mellifera mellifera and A. m. ligustica. Although Varroa destructor and Nosema are widely distributed in the country, there is no information regarding Nosema species identity and the presence of honey bee vir...

In the past centuries, viruses have benefited from globalization to spread across the globe, infecting new host species and populations. A growing number of viruses have been documented in the western honey bee, Apis mellifera. Several of these contribute significantly to honey bee colony losses. This review synthetizes the knowledge of the diversi...

Aim of study: To evaluate the potential bactericidal activity of natural molecules against Paenibacillus larvae. Moreover, we investigated if molecules that exhibit antimicrobial activity were able to inhibit the proteolytic activity of the bacterium. Area of study: Isolates S1 and S2 were from Balcarce, Buenos Aires province, strain S3 from Rio C...

Aim of study: To evaluate the potential bactericidal activity of natural molecules against Paenibacillus larvae. Moreover, we investigated if molecules that exhibit antimicrobial activity were able to inhibit the proteolytic activity of the bacterium. Area of study: Isolates S1 and S2 were from Balcarce, Buenos Aires province, strain S3 from Rio Cu...

Honeybees Apis mellifera are important pollinators of wild plants and commercial crops. For more than a decade, high percentages of honeybee colony losses have been reported worldwide. Nutritional stress due to habitat depletion, infection by different pests and pathogens and pesticide exposure has been proposed as the major causes. In this study w...

Uruguay is a world reference in some aquaculture sectors such as caviar production in sturgeons farms. Bacterial outbreaks are usual in fish farming as well as in all intensive animal production and the use of antimicrobials appears as a strategy for their control. Motile aeromonads septicemia is the most prevalent infectious disease in Uruguayan a...

The Editor-in-Chief and the Subject Editors of the Journal of Economic Entomology thank the following scientists for their voluntary commitment of valuable professional time and expertise to peer reviewing manuscripts submitted for publication in our journal. The quality and scientific stature of the journal depends on the conscientious efforts of...

Trypanosomatids affecting honey bees, Crithidia mellificae and Lotmaria passim, have been poorly studied in SouthAmerica. We therefore analyzed their presence in Africanized and European honeybees from Uruguay, Argentina and Chile collected between 1990-2011 and assessed their association with other bee parasites and pathogens. Crithidia mellificae...

Latin America is a region with an important and growing apicultural industry and a high diversity of wild bees. Over the last years, the global decline of wild bees and the numerous reports of high colony losses of managed bees have motivated an increase in research on bees in the region. These studies have contributed to improve our understanding...

The Editor-in-Chief and the Subject Editors of the Journal of Economic Entomology thank the following scientists for their voluntary commitment of valuable professional time and expertise to peer reviewing manuscripts submitted for publication in our journal. The quality and scientific stature of the journal depends on the conscientious efforts of...

Over the past decade, several countries have carried out monitoring programs of managed honey bee colonies, which suggest beekeeping difficulties, with high colony loss rates all over the world. Although Latin America plays a major role in the global honey supply, information about trends in beekeeping activities and honey bee colony losses are lac...

Information about motile aeromonads from aquaculture systems of the Neotropical region is scarce. The aim of this study was to characterize motile Aeromonas isolated from ornamental and consumable fishes cultured in Uruguay. Biochemical and molecular methods were used for species identification. Antimicrobial susceptibility and the presence of viru...

Over the past decade, in some regions of the world, honey bee (Apis mellifera L.) colonies have experienced rates of colony loss that are difficult for beekeepers to sustain. The reasons for losses are complex and interacting, with major drivers including varroa and related viruses, pesticides, nutrition and beekeeper practices. In these endeavors...

For more than 60 years, sporadic cases of massive summer honey bee larvae mortality in colonies located near freshwater systems with abundant riparian vegetation have been reported in Uruguay. This odd phenomenon, known as “River disease” by beekeepers, can lead to colony death by depopulation. The aim of this study was to detect the causes of larv...

Due to their social behaviour, honey bees can be infected by a wide range of pathogens including the microsporidia Nosema ceranae and the bacteria Paenibacillus larvae. The use of probiotics as food additives for the control or prevention of infectious diseases is a widely used approach to improve human and animal health. In this work, we generated...

Over the past decade, several countries have carried out monitoring of managed honey bee colonies suggesting high losses all over the world. Although Latin America plays a major role in the global honey supply, estimates of honey bee colony losses are lacking. Using the FAO dataset we reveal a worrying situation for apiculture in Latin America, whe...

In recent years, large-scale colony losses of honey bees (Apis mellifera) have been reported and the infection with the microsporidia Nosema ceranae has been involved. However, the effect of N. ceranae at the colony level and its role in colony losses vary in different geographic areas. This difference may be related to the presence of multiple N....

An initial survey in 2009 carried out at a site in northwestern Patagonia region, Argentina, revealed for the first time in South America the presence of the flagellate Crithidia bombi and the neogregarine Apicystis bombi, two pathogens associated with the Palaearctic invasive bumble bee Bombus terrestris. In order to determine the long-term persis...

American foulbrood (AFB) is a severe bacterial disease that affects larvae of honey bees (Apis mellifera). The causative agent of AFB is the spore-forming bacteria Paenibacillus larvae. The use of antibiotics for the control of AFB has led to the appearance of resistant bacterial strains and residues in beehive products. Nowadays, antibiotics are l...

Nosema ceranae is an obligate intracellular parasite and the etiologic agent of Nosemosis that affects honeybees. Beside the stress caused by this pathogen, honeybee colonies are exposed to pesticides under beekeeper intervention, such as acaricides to control Varroa mites. These compounds can accumulate at high concentrations in apicultural matric...

High rates of honey bee colony losses have been reported worldwide; however, data about colony loss rates in South America is scarce. This study quantified colony losses experienced in Uruguay during the 2013–2014 season and identifies the self-diagnosed causes for these losses. An estimated 2.6% of all Uruguayan beekeepers, who collectively manage...

Honeybees are essential components to modern agriculture and economy. However, a continuous increase in cases of colony losses and colony depopulation are being reported worldwide. This critical situation has put the fragile equilibrium between bees and plants on the edge. As a consequence, several scientists have begun to focus their lines of rese...

Honeybees are essential components to modern agriculture and economy. However, a continuous increase in cases of colony losses and colony depopulation are being reported worldwide. This critical situation has put the fragile equilibrium between bees and plants on the edge. As a consequence, several scientists have begun to focus their lines of rese...

Here, we present the first honey bee pest and pathogen epidemiological study in Uruguay, as an attempt to increase the information about South American honey bee health status. Varroa destructor appeared to be widely distributed in the country, showing a prevalence of 75.7% in autumn. A third of affected colonies showed infestation levels above irr...

Nosema ceranae is one of the most prevalent pathogens in Apis mellifera and has recently been found in multiple host species including several species of bumblebees. Prevalence and infection intensity of N. ceranae was determined in two species of native bumblebees from Uruguay. N. ceranae was the only microsporidia identified and mean prevalence w...

Honeybees are susceptible to a wide range of pathogens, which have been related to the occurrence of colony loss episodes reported mainly in north hemisphere countries. Their ability to resist those infections is compromised if they are malnourished or exposed to pesticides. The aim of the present study was to carry out an epidemiological study in...

The Africanization process of the honeybee Apis mellifera in America is considered one of the most spectacular biological invasions documented so far. It started in São Paulo (Brazil) in 1956 and the process has extended to almost all the continent (from the United States, to Argentina and Uruguay). The aim of this study was to evaluate the present...

Adequate protein nutrition supports healthy honey bees and reduces the susceptibility to disease. However little is known concerning the effect of the diet on Nosema ceranae development, an obligate intracellular parasite, which disturbs the protein metabolism of honey bees (Apis mellifera). Here we tested the effect of natural (bee bread) and non-...

Different episodes of mortalities of honey bee (Apis mellifera L.) colonies have been associated with the presence of honey bee pathogens. Since the Biobio Region has among the highest number of apiaries in Chile, the aim of the present study was to identify viruses in the Region affecting honey bees, evaluate their relation to other pathogens, and...

Nosema apis and Nosema ceranae are causative agents of Nosemosis in the honey bee Apis mellifera, although N. ceranae may cause a more virulent disease. Selection of colonies with high tolerance to N. ceranae could be important for reducing problems caused by this pathogen. The aim of the present work was to evaluate the existence of honey bee colo...

Sacbrood virus (SBV) is the causal agent of a disease of honey bee larvae, resulting in failure to pupate and causing death. The typical clinical symptom of SBV is an accumulation of SBV-rich fluid in swollen sub-cuticular pouches, forming the characteristic fluid-filled sac that gives its name to the disease. Outbreaks of the disease have been rep...

The microorganisms Ascosphaera apis, Paenibacillus larvae and Melissococcus plutonius are the three most important pathogens that affect honeybee brood. The aim of the present study was to evaluate the prevalence of these pathogens in honeybee colonies and to elucidate their role in the honeybee colony losses in Spain. In order to get it, a multipl...

Nosema ceranae is one of the causative agents of Nosemosis, a severe disease that affects the honeybee Apis mellifera. The aim of the present work was to compare N. ceranae and RNA virus infections in Africanized bees (hybrid of Apis mellifera scutellata and A. m. mellifera) and European (Italian) bees (A. m. ligustica) under field conditions. Afri...

American foulbrood is one of the most devastating diseases of the honey bee. It is caused by the spore-forming, Gram-positive rod-shaped bacterium Paenibacillus larvae. The recent updated genome assembly and annotation for this pathogen now permits in-depth molecular studies. In this paper, selected techniques and protocols for American foulbrood r...

##Assembly-Data-START## Assembly Method :: Clustal X v. 1.83 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##

##Assembly-Data-START## Assembly Method :: Clustal X v. 1.83 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##

##Assembly-Data-START## Assembly Method :: Clustal X v. 1.83 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##

##Assembly-Data-START## Assembly Method :: Clustal X v. 1.83 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##

##Assembly-Data-START## Assembly Method :: Clustal X v. 1.83 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##

##Assembly-Data-START## Assembly Method :: Clustal X v. 1.83 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##

##Assembly-Data-START## Assembly Method :: Clustal X v. 1.83 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##

##Assembly-Data-START## Assembly Method :: Clustal X v. 1.83 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##

##Assembly-Data-START## Assembly Method :: Clustal X v. 1.83 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##

##Assembly-Data-START## Assembly Method :: Clustal X v. 1.83 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##

##Assembly-Data-START## Assembly Method :: Clustal X v. 1.83 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##

The mite Varroa destructor is an ectoparasite affecting honey bees worldwide. Synthetic acaricides have been among the principal tools available to beekeepers for its control, although several studies have shown its negative effects on honey bee physiology. Recent research suggests that those molecules strongly impact on immune signaling cascades a...

RNA viruses that affect honeybees have been involved in colony losses reported around the world. The aim of the present work was to evaluate the prevalence and distribution of honeybee viruses during 2006-2007 in Spanish professional apiaries, and their association with colony losses. Four hundred and fifty-six samples from apiaries located in diff...

Paenibacillus larvae is the causative agent of American Foulbrood (AFB), a deleterious disease that affects honeybees. In Uruguay it was first reported in 1999. In 2001 the bacterium was spread all over the country, and its prevalence in honey was estimated in 51%. Two P. larvae genotypes were found; ERIC I - BOX A, worldwide distributed and ERIC I...

American foulbrood is a bacterial disease of worldwide distribution that affects larvae of the honeybee Apis mellifera. The causative agent is the Gram-positive, spore-forming bacterium Paenibacillus larvae. Several authors have proposed that P. larvae secretes metalloproteases that are involved in the larval degradation that occurs after infection...

Paenibacillus larvae is a gram-positive spore-forming bacteria, causative agent of American Foulbrood (AFB), a severe disease affecting larvae of the honeybee Apis mellifera. In an attempt to detect potential virulence factors secreted by P. larvae, we identified an enolase among different secreted proteins. Although this protein is a cytosolic enz...

In this work we describe the protective effects of quercetin against H(2)O(2) in 24-h-pretreated neuronal cultures. We explored quercetin availability and subcellular fate through the use of HPLC-Diode Array Detection (DAD), epifluorescence, and confocal microscopy. We focused on quercetin modulation of thiol-redox systems by evaluating changes in...

American Foulbrood is a severe disease affecting larvae of honeybee Apis mellifera, causing significant decrease in the honeybee population, beekeeping industries and agricultural production. In spite of its importance, little is known about the virulence factors secreted by Paenibacillus larvae during larval infection. The aim of the present work...

Two microsporidia species have been shown to infect Apis mellifera, Nosema apis and Nosema ceranae. This work presents evidence that N. ceranae infection significantly suppresses the honey bee immune response, although this effect was not observed following infection with N. apis. Immune suppression would also increase susceptibility to other bee p...

Paenibacillus larvae is the causative agent of American Foulbrood (AFB), the most severe bacterial disease that affects honeybee larvae. AFB causes a significant decrease in the honeybee population affecting the beekeeping industry and agricultural production. After infection of larvae, P. larvae secretes proteases that could be involved in the pat...

Chronic bee paralysis virus (CBPV) is responsible for chronic paralysis, an infectious and contagious disease of adult honey bees (Apis mellifera L.). The full-length nucleotide sequences of the two major RNAs of CBPV have previously been characterized. The Orf3 of RNA1 has shown significant similarities to the RNA-dependent RNA polymerase (RdRp) o...

More than 18 RNA viruses that affect honeybees have been reported. Most of themcause unapparent infections or persist in a latent form in healthy colonies, while only afew viruses produce clinical symptoms easily recognizable by beekeepers. The presenceof these viruses has been associated with honeybee mortality episodes that have beentaking place...

Paenibacillus larvae is the causative agent of American Foulbrood (AFB), a severe disease that affects larvae of the honeybees. Due to the serious effects associated with AFB and the problems related to the use of antibiotics, it is necessary to develop alternative strategies for the control of the disease. The aim of the present work was to evalua...

Paenibacillus larvae is the causative agent of American Foulbrood (AFB), a severe disease of honeybees (Apis melifera). The aim of this work was to develop a strategy for the subtyping and the epidemiological analysis of P. larvae. Phenotypic characterisation, susceptibility to several antibiotics, electrophoresis of whole bacterial proteins, rep-P...

Paenibacillus larvae causes American foulbrood (AFB), a severe disease that affects the brood of honey bee Apis mellifera. AFB is worldwide distributed and causes great economic losses to beekeepers, but in many cases early diagnosis could help in its prevention and control. The aim of the present work was to design a reliable protocol for DNA extr...

Mortality of honeybees is a serious problem that beekeepers have to face periodically in Uruguay and worldwide. The presence of RNA viruses, in addition to other pathogens may be one of its possible causes. In this work, we detected Chronic bee paralysis virus, Acute bee paralysis virus, Black queen cell virus, Sacbrood virus and Deformed wing viru...

Chronic bee paralysis virus (CBPV) causes a disease characterized by trembling, flightless, and crawling bees, while Acute bee paralysis virus (ABPV) is commonly detected in apparently healthy colonies, usually associated to Varroa destructor. Both viruses had been detected in most regions of the world, except in South America. In this work, we det...

American foulbrood is a severe bacterial disease affecting larvae of the honeybee Apis mellifera and it is caused by Paenibacillus larvae larvae. The disease is present worldwide and cases have been reported in almost all the beekeeping regions of the five con- tinents. During 2001 and 2002 we carried out a nationwide study to assess the presence a...

American foulbrood is a severe bacterial disease affecting larvae of the honeybee Apis mellifera and it is caused by Paenibacillus larvae larvae. The disease is present worldwide and cases have been reported in almost all the beekeeping regions of the five continents. During 2001 and 2002 we carried out a nationwide study to assess the presence and...

In this study we describe an approach to the characterization of the cultivable heterotrophic bacterial flora of honey bee hives. We assessed the bacterial abundance in brood combs and on hive floors at different times of the year, and identified several isolated bacteria. The number of bacteria recovered from brood combs was notably lower than the...