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The aim of this study was to investigate the genetic diversity of Varroa destructor parasitizing Apis mellifera colonies and to test for possible host-parasite association at the mitochondrial DNA (mtDNA) level. Six A. mellifera haplotypes (including a novel C2aa) and five haplotypes of V. destructor were detected in 29 analyzed colonies from eight sampling sites in Serbia. We revealed the presence of the K and S1 haplotypes as well as KS1 and KP1 heteroplasmic mite individuals in all localities, while the P1 haplotype was only found in four sampling sites. Significant differences in V. destructor genetic diversity were found at both apiary and colony levels, with mite haplotypes coexisting in almost all tested colonies. In addition, a significant correlation between the number of analyzed mites per colony and the number of identified V. destructor haplotypes was observed. However, no significant host-parasite relationship was found, suggesting that mites bearing different haplotypes as well as those heteroplasmic individuals are well adapted to the host, A. mellifera, independently of the identified haplotype present in each colony. Our results will contribute to future population and biogeographic studies concerning V. destructor infesting A. mellifera, as well as to better understanding their host-parasite relationship.
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Abelhas/parasitologia , Variação Genética , Interações Hospedeiro-Parasita , Varroidae/fisiologia , Animais , DNA Mitocondrial/análise , Feminino , Haplótipos , Sérvia , Varroidae/genéticaRESUMO
A recently described trypanosomatid species Lotmaria passim and the microsporidium Nosema ceranae infect the honey bee (Apis mellifera), but the interspecific dynamic of these two common gut parasites is unknown. In this study, a real-time qPCR assay was developed to enable the specific detection and quantification of L. passim. The annual dynamics of N. ceranae and L. passim infections were evaluated in ten A. mellifera colonies naturally infected with both parasites at one apiary in Serbia from March 2016 to March 2017. Ten samples (60 bees abdomens) were taken from each colony on 8 sampling occasions. L. passim infection level was evaluated with qPCR, while N. ceranae infection was measured by spore counts. N. ceranae infection level was significantly higher in comparison with that of L. passim (spore or cell equivalents/bee, respectively). Significant positive correlation between infection levels of the parasite species indicates their similar annual dynamics, whilst the differences in the levels of infection between particular months point to a seasonal pattern in the incidence of both parasites. The assay which has been developed and validated creates opportunity for detailed study of L. passim infection kinetics and the improvement in the management practices in beekeeping related to these two parasites.
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Abelhas/parasitologia , Reação em Cadeia da Polimerase em Tempo Real/métodos , Trypanosomatina/fisiologia , Animais , DNA Fúngico/análise , DNA de Protozoário/análise , NosemaRESUMO
This study was done to discover any beneficial effect of a medicinal mushroom Agaricus brasiliensis extract on the honey bee. Firstly, a laboratory experiment was conducted on 640 bees reared in 32 single-use plastic rearing cups. A. brasiliensis extract proved safe in all doses tested (50, 100 and 150 mg/kg/day) irrespective of feeding mode (sugar syrup or candy). Secondly, a three-year field experiment was conducted on 26 colonies treated with a single dose of A. brasiliensis extract (100 mg/kg/day) added to syrup. Each year the colonies were treated once in autumn and twice in spring. The treatments significantly increased colony strength parameters: brood rearing improvement and adult population growth were noticed more often than the increase in honey production and pollen reserves. These positive effects were mainly observed in April. In conclusion, A. brasiliensis extract is safe for the bees and helps maintaining strong colonies, especially in spring.
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Agaricus/química , Abelhas/efeitos dos fármacos , Mel , Fenômenos Fisiológicos da Nutrição Animal/efeitos dos fármacos , Animais , Abelhas/fisiologia , Pólen/fisiologia , Crescimento Demográfico , Reprodutibilidade dos Testes , Estações do Ano , Estatísticas não Paramétricas , Fatores de TempoRESUMO
In this study, honey bees collected in Serbia over 9 consecutive years (2007-2015) were retrospectively surveyed to determine the prevalence of eukaryotic gut parasites by molecular screening of archival DNA samples. We developed species-specific primers for PCR to detect the two known honey bee trypanosomatid species, Crithidia mellificae and the recently described Lotmaria passim. These primers were validated for target specificity under single and mixed-species conditions as well as against the bumblebee trypanosomatid Crithidia bombi. Infections by Nosema apis and Nosema ceranae (Microsporidia) were also determined using PCR. Samples from 162 colonies (18 from each year) originating from 57 different localities were surveyed. L. passim was detected in every year with an overall frequency of 62.3% and annual frequencies ranging from 38.9% to 83.3%. This provides the earliest confirmed record to date for L. passim and the first report of this species in Serbia. N. ceranae was ubiquitous, occurring in every year and at 95.7% overall frequency, ranging annually from 83.3% to 100%. The majority of colonies (60.5%) were co-infected with L. passim and N. ceranae, but colony infections by each species were statistically independent of one another over the nine years. Although C. mellificae and N. apis have both been reported recently at low frequency in Europe, neither of these species was detected in Serbia. These results support the hypothesis that L. passim has predominated over C. mellificae in A. mellifera during the past decade.
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Abelhas/parasitologia , Animais , Reação em Cadeia da Polimerase , Sérvia , Especificidade da Espécie , TrypanosomatinaRESUMO
In the present study, amplification refractory mutation system (ARMS) and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methods were used for identification of recently described Serbia 1 (S1) and Peshter 1 (P1) mitochondrial haplotypes of Varroa destructor. Based on single nucleotide polymorphisms (SNPs) within cytochrome oxidase 1 (cox1) and cytochrome b (cytb) gene sequences, a total of 64 adult V. destructor females were analyzed from locations where the S1 and P1 haplotypes had been detected previously. Results of haplotype identification obtained by ARMS and PCR-RFLP methods were completely consistent with the sequencing data. Furthermore, in some analyzed samples the occurrence of site heteroplasmy at haplotype-defining sites was detected, as it was confirmed by double peaks in the sequence chromatograms. Neither mites with simultaneous nucleotide variability, nor those with combined SNP and heteroplasmy in cox1 and cytb were found. Given that this is the first occurrence of site heteroplasmy in V. destructor, the origin of this phenomenon and possible specific traits of heteroplasmic mites have yet to be determined.
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DNA Mitocondrial/genética , Haplótipos , Técnicas de Amplificação de Ácido Nucleico , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Varroidae/genética , Animais , Feminino , Técnicas de Amplificação de Ácido Nucleico/economia , Reação em Cadeia da Polimerase/economia , Análise de Sequência de DNA , SérviaRESUMO
Canine babesiosis is a frequent and clinically significant tick-borne disease. Sixty symptomatic dogs with clinical findings compatible with babesiosis were included in this study conducted in Serbia. After clinical examination, blood samples were taken for microscopic examination, complete blood count (CBC), Canine SNAP 4Dx Test, DNA analyses and sequencing. The main clinical signs included apathy, anorexia, fever, brown/red discoloration of urine, pale mucous membranes, icterus, splenomegaly, and vomiting. The main clinicopathological findings in Babesia infections were a slight to severe thrombocytopenia and a mild to very severe normocytic normochromic anaemia. Microscopic evaluation revealed 58 positive samples with the presence of large and small intraerythrocytic piroplasms in 57 and 1 sample(s), respectively. No co-infections were found using SNAP test. Two Babesia species, B. canis (58/60) and B. gibsoni (2/60), were differentiated by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Species identification was further confirmed by sequencing PCR products of B. gibsoni samples and six randomly selected B. canis samples. All dogs were treated with imidocarb dipropionate (6.6 mg/kg of body weight), given intramuscularly twice at an interval of 14 days. This report presents the first molecular evidence of the occurrence of B. gibsoni and B. canis, confirmed by DNA sequencing, in sick dogs from Serbia.
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To improve the genomic evaluation of milk-related traits in Holstein-Friesian (HF) cattle it is essential to identify the associated candidate genes. Novel SNP-based analyses, such as the genetic mapping of inherited diseases, GWAS, and genomic selection, have led to a new era of research. The aim of this study was to analyze the association of each individual SNP in Serbian HF cattle with milk production traits and inbreeding levels. The SNP 60 K chip Axiom Bovine BovMDv3 was deployed for the genotyping of 334 HF cows. The obtained genomic results, together with the collected phenotypic data, were used for a GWAS. Moreover, the identification of ROH segments was performed and served for inbreeding coefficient evaluation and ROH island detection. Using a GWAS, a polymorphism, rs110619097 (located in the intron of the CTNNA3 gene), was detected to be significantly (p < 0.01) associated with the milk protein concentration in the first lactation (adjusted to 305 days). The average genomic inbreeding value (FROH) was 0.079. ROH islands were discovered in proximity to genes associated with milk production traits and genomic regions under selection pressure for other economically important traits of dairy cattle. The findings of this pilot study provide useful information for a better understanding of the genetic architecture of milk production traits in Serbian HF dairy cows and can be used to improve lactation performances in Serbian HF cattle breeding programs.
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Honey bees play a pivotal role in shaping ecosystems and sustaining human health as both pollinators and producers of health-promoting products. However, honey bee colony mortality is on the rise globally, driven by various factors, including parasites, pesticides, habitat loss, poor nutrition, and climate change. This has far-reaching consequences for the environment, economy, and human welfare. While efforts to address these issues are underway, the current progress in electron paramagnetic resonance (EPR) instrumentation affords using the immense potential of this magnetic resonance technique to study small samples such as honey bees. This paper presents the pioneering 2D in vivo EPR imaging experiment on a honey bee, revealing the ongoing redox-status of bees' intestines. This way, by monitoring the spatio-temporal changes of the redox-active spin-probes' EPR signal, it is possible to gain access to valuable information on the course of ongoing bees' pathologies and the prospect of following-up on the efficiency of applied therapies. Employing a selection of diverse spin-probes could further reveal pH levels and oxygen concentrations in bee tissues, allowing a noninvasive assessment of bee physiology. This approach offers promising strategies for safeguarding pollinators and understanding their biology, fostering their well-being and ecological harmony.
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Nosema ceranae, a microsporidian parasite, as one of the stressors that contribute to honey bee decline, has a significant negative impact on the longevity, productivity, and reproductive capacity of honey bee colonies. There are several different strategies for Nosema infection control, including natural-based and antibiotic-based products. In this study, we tested wormwood and oak bark-based supplement "Medenko forte" on survival, Nosema infection, oxidative stress, and expression of immune-related genes in artificially N. ceranae-infected bees. The results revealed a positive influence on the survival of Nosema-infected bees, irrespectively of the moment of supplement application (day 1, day 3, or day 6 after bee emergence), as well as reduction of Nosema loads and, consequently, Nosema-induced oxidative stress. Supplementation had no negative effects on bee immunity, but better anti-Nosema than immune-stimulating effects were affirmed based on expression levels of abaecin, defensin, hymenoptaecin, apidaecin, and vitellogenin genes. In conclusion, the tested supplement "Medenko forte" has great potential in the health protection of Nosema-infected bees. However, further investigations need to be performed to elucidate its mechanisms of action.
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Only two mitochondrial haplotypes (Korea and Japan) of Varroa destructor, the ectoparasitic honey bee mite, are known to be capable of infesting and successfully reproducing in Apis mellifera colonies worldwide. Varroa destructor (then called Varroa jacobsoni) was observed in Serbia for the first time in 1976. In order to obtain insight into the genetic variability of the mites parasitizing A. mellifera we analyzed 45 adult female mites sampled from nine localities dispersed throughout Serbia. Four fragments within cox1, atp6, cox3 and cytb mtDNA genes were sequenced. The Korea haplotype of V. destructor was found to be present at all localities, but also two new haplotypes (Serbia 1 and Peshter 1) were revealed, based on cox1 and cytb sequence variability. The simultaneous occurrence of Korea and Serbia 1 haplotypes was observed at five localities, whereas Peshter 1 haplotype was identifed at only one place.
Assuntos
Abelhas/parasitologia , Variação Genética , Varroidae/genética , Animais , Sequência de Bases , DNA Mitocondrial/química , Haplótipos , Dados de Sequência Molecular , SérviaRESUMO
The aim of this research was to test the CHD gene (Chromo Helicase DNA-binding gene) as a universal molecular marker for sexing birds of relatively distant species. The CHD gene corresponds to the aim because of its high degree of conservation and different lengths in Z and W chromosomes due to different intron sizes. DNA was isolated from feathers and the amplification of the CHD gene was performed with the following sets of polymerase chain reaction (PCR) primers: 2550F/2718R and P2/P8. Sex determination was attempted in 284 samples of 58 bird species. It was successful in 50 bird species; in 16 of those (Alopochen aegyptiacus, Ara severus, Aratinga acuticaudata, Bucorvus leadbeateri, Cereopsis novaehollandiae, Columba arquatrix, Corvus corax, C. frugilegus, Cyanoliseus patagonus, Guttera plumifera, Lamprotornis superbus, Milvus milvus, Neophron percnopterus, Ocyphaps lophotes, Podiceps cristatus, and Poicephalus senegalus), it was carried out for the first time using molecular markers and PCR. It is reasonable to assume that extensive research is necessary to define the CHD gene as a universal molecular marker for successful sex determination in all bird species (with exception of ratites). The results of this study may largely contribute to the aim.
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Proteínas Aviárias , Aves/fisiologia , Proteínas de Ligação a DNA , Marcadores Genéticos/genética , Análise para Determinação do Sexo/veterinária , Animais , Proteínas Aviárias/genética , Primers do DNA/genética , Proteínas de Ligação a DNA/genética , Plumas/química , Feminino , Íntrons/genética , Masculino , Reação em Cadeia da Polimerase/veterinária , Análise para Determinação do Sexo/métodos , Especificidade da EspécieRESUMO
One of the most important approaches in the prevention and treatment of nosemosis is the use of herbal preparations as food supplements for bees. Therefore, the aim of this study was to investigate the effects of a plant-based supplement branded as "B+" on honeybees in a laboratory experiment. Four experimental groups were established: treated group (T), N. ceranae-infected and treated group (IT), N. ceranae-infected group (I) and non-infected group (NI). Survival, N. ceranae spore load and oxidative stress parameters together with expression levels of antioxidant enzyme genes and vitellogenin gene were monitored. The mortality in the T, IT and NI groups was significantly (p < 0.001) lower than in than in the I group. Within Nosema-infected groups, the IT group had a significantly lower (p < 0.001) number of N. ceranae spores than the I group. In addition, expression levels of genes for antioxidant enzymes were lower (p < 0.001) in the IT group compared to the I group. The concentration of malondialdehyde and the activities of antioxidant enzymes (superoxide dismutase, catalase and glutathione S-transferase) were significantly lower (p < 0.001) in the IT group compared to the I group. No negative effects of the tested supplement were observed. All these findings indicate that the tested supplement exerted beneficial effects manifested in better bee survival, reduced N. ceranae spore number and reduced oxidative stress of bees (lower expression of genes for antioxidant enzymes and oxidative stress parameters).
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Thymol is a natural essential oil derived from the plant Thymus vulgaris L. It is known to be beneficial for human and animal health and has been used in beekeeping practice against Varroa mite for years. In this study, the genotoxic and antigenotoxic potential of thymol were evaluated on the honey bee (Apis mellifera L.) continuous cell line AmE-711 for the first time. Using the Comet assay, three increasing concentrations (10, 100, and 1000 µg/mL) of thymol were tested. Negative control (non-treated cells) and positive control (cells treated with 100 µM H2O2) were also included. The absence of thymol cytotoxicity was confirmed with the Trypan blue exclusion test. Thymol in the concentration of 10 µg/mL did not increase DNA damage in AmE-711 honey bee cells, while 100 and 1000 µg/mL concentrations showed genotoxic effects. For testing the antigenotoxic effect, all concentrations of thymol were mixed and incubated with H2O2. The antigenotoxic effect against was absent at all concentrations (10, 100, 1000 µg/mL) tested. Moreover, thymol enhanced the H2O2-induced DNA migration in the Comet assay. The obtained results indicate genotoxic effects of thymol on cultured honey bee cells suggesting its careful application in beekeeping practice to avoid possible negative effects on honey bees.
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With an almost global distribution, Varroa destuctor is the leading cause of weakening and loss of honey bee colonies. New substances are constantly being tested in order to find those that will exhibit high anti-Varroa efficacy at low doses/concentrations, without unwanted effects on bees. Lithium (Li) salts stood out as candidates based on previous research. The aims of this study were to evaluate Li citrate hydrate (Li-cit) for its contact efficacy against Varroa, but also the effect of Li-cit on honey bees by estimating loads of honey bee viruses, expression levels of immune-related genes and genes for antioxidative enzymes and oxidative stress parameters on two sampling occasions, before the treatment and after the treatment. Our experiment was performed on four groups, each consisting of seven colonies. Two groups were treated with the test compound, one receiving 5 mM and the other 10 mM of Li-cit; the third received oxalic acid treatment (OA group) and served as positive control, and the fourth was negative control (C group), treated with 50% w/v pure sucrose-water syrup. Single trickling treatment was applied in all groups. Both tested concentrations of Li-cit, 5 and 10 mM, expressed high varroacidal efficacy, 96.85% and 96.80%, respectively. Load of Chronic Bee Paralysis Virus significantly decreased (p < 0.01) after the treatment in group treated with 5 mM of Li-cit. In OA group, loads of Acute Bee Paralysis Virus and Deformed Wing Virus significantly (p < 0.05) increased, and in C group, loads of all viruses significantly (p < 0.01 or p < 0.001) increased. Transcript levels of genes for abaecin, apidaecin, defensin and vitellogenin were significantly higher (p < 0.05-p < 0.001), while all oxidative stress parameters were significantly lower (p < 0.05-p < 0.001) after the treatment in both groups treated with Li-cit. All presented results along with easy application indicate benefits of topical Li-cit treatment and complete the mosaic of evidence on the advantages of this salt in the control of Varroa.
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Nosema ceranae is the most widespread microsporidian species which infects the honey bees of Apis mellifera by causing the weakening of their colonies and a decline in their productive and reproductive capacities. The only registered product for its control is the antibiotic fumagillin; however, in the European Union, there is no formulation registered for use in beekeeping. Thymol (3-hydroxy-p-cymene) is a natural essential-oil ingredient derived from Thymus vulgaris, which has been used in Varroa control for decades. The aim of this study was to investigate the effect of thymol supplementation on the expression of immune-related genes and the parameters of oxidative stress and bee survival, as well as spore loads in bees infected with the microsporidian parasite N. ceranae. The results reveal mostly positive effects of thymol on health (increasing levels of immune-related genes and values of oxidative stress parameters, and decreasing Nosema spore loads) when applied to Nosema-infected bees. Moreover, supplementation with thymol did not induce negative effects in Nosema-infected bees. However, our results indicate that in Nosema-free bees, thymol itself could cause certain disorders (affecting bee survival, decreasing oxidative capacity, and downregulation of some immune-related gene expressions), showing that one should be careful with preventive, uncontrolled, and excessive use of thymol. Thus, further research is needed to reveal the effect of this phytogenic supplement on the immunity of uninfected bees.
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Agaricus bisporus water crude extract was tested on honey bees for the first time. The first part of the cage experiment was set for selecting one concentration of the A. bisporus extract. Concentration of 200 µg/g was further tested in the second part of the experiment where bee survival and food consumption were monitored together with Nosema infection level and expression of five genes (abaecin, hymenoptaecin, defensin, apidaecin, and vitellogenin) that were evaluated in bees sampled on days 7 and 15. Survival rate of Nosema-infected bees was significantly greater in groups fed with A. bisporus-enriched syrup compared to those fed with a pure sucrose syrup. Besides, the anti-Nosema effect of A. bisporus extract was greatest when applied from the third day which coincides with the time of infection with N. ceranae. Daily food consumption did not differ between the groups indicating good acceptability and palatability of the extract. A. bisporus extract showed a stimulative effect on four out of five monitored genes. Both anti-Nosema and nutrigenomic effects of A. bisporus extract were observed when supplementation started at the moment of N. ceranae infection or preventively (before or simultaneously with the infection).
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Depending on the infection level and colony strength, Nosema ceranae, a microsporidian endoparasite of the honey bee may have significant consequences on the health, reproduction and productivity of bee colonies. Despite exerting some side effects, fumagillin is most often used for Nosema control. In this study, in a cage experiment, N. ceranae infected bees were treated with fumagillin or the extract of Agaricus blazei mushroom, a possible alternative for Nosema control. Bee survival, Nosema spore loads, the expression levels of immune-related genes and parameters of oxidative stress were observed. Fumagillin treatment showed a negative effect on monitored parameters when applied preventively to non-infected bees, while a noticeable anti-Nosema effect and protection from Nosema-induced immunosuppression and oxidative stress were proven in Nosema-infected bees. However, a protective effect of the natural A. blazei extract was detected, without any side effects but with immunostimulatory activity in the preventive application. The results of this research suggest the potential of A. blazei extract for Nosema control, which needs to be further investigated.
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The dominant donkey breed in the Balkans is the mid-sized Balkan donkey with a grey to chocolate coat color. Local breeders from Serbia, however, still maintain a few larger individuals of a lighter coat color, named Banat donkey, and speculate that they are descendants of a Spanish donkey heard that had been transferred to the Banat region by the Hapsburg Queen Maria Theresa in the XVIII century for a specific purpose, to work in local vineyards. We have previously found a unique nuclear gene-pool and a prevalence of mitochondrial Clade 2 haplotypes in several such animals. In this study, we: (i) perform a comparative analysis of 18 morphological traits of the Banat donkey (seven individuals), Balkan donkey (53 individuals from two sub-populations of this breed) and the potential hybrids (eight individuals), and demonstrate the morphological distinctiveness of the Banat donkey, highlighting the diagnostic traits for distinguishing the breed: hip height, croup width, body length and chest depth; (ii) re-analyse published nuclear microsatellite data for these groups, and reveal that, although severely depopulated, the genetically distinct Banat donkey is not severely affected by the loss of genetic diversity and inbreeding; (iii) demonstrate that previously published Banat donkey mitochondrial haplotypes, analyzed genealogically together with those reported in ancient and modern individuals from Spain, Italy, Turkey, Cyprus and Africa, are shared with three Spanish breeds and individuals belonging to Amiata and some other Italian breeds. A unique morphological feature present in Banat and Somali wild donkeys, but also in Amiata donkeys, black stripes on legs, suggests that the origin of Clade 2 donkeys may be much more complex than previously thought. Actions to preserve the Banat donkey, a valuable but critically endangered genetic resource (<100 individuals), are urgent.
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During their lifetime honey bees (Apis mellifera) rarely experience optimal conditions. Sometimes, a simultaneous action of multiple stressors, natural and chemical, results in even greater effect than of any stressor alone. Therefore, integrative investigations of different factors affecting honey bees have to be carried out. In this study, adult honey bees exposed to thiamethoxam in larval and/or adult stage and infected with Nosema ceranae were examined. Newly emerged bees from colonies, non-treated or treated with thiamethoxam, were organized in six groups and kept in cages. Thiamethoxam treated bees were further exposed to either thiamethoxam or Nosema (groups TT and TN), or simultaneously to both (group TTN). Newly emerged bees from non-treated colonies were exposed to Nosema (group CN). From both, treated and non-treated colonies two groups were organized and further fed only with sugar solution (groups C and TC). Here, we present the expression profile of 19 genes in adult worker honey bees comprising those involved in immune, detoxification, development and apoptosis response. Results showed that gene expression patterns changed with time and depended on the treatment. In group TC at the time of emergence the majority of tested genes were downregulated, among which nine were significantly altered. The same gene pattern was observed on day six, where the only significantly upregulated gene was defensin-1. On day nine most of analyzed genes in all experimental groups showed upregulation compared to control group, where upregulation of antimicrobial peptide genes abaecin, defensin-1 and defensin-2 was significant in groups TT and TTN. On day 15 we observed a similar pattern of expression in groups TC and TT exposed to thiamethoxam only, where most of the detoxification genes were downregulated. Additionally RNA loads of Nosema and honey bee viruses were recorded. We detected a synergistic interaction of thiamethoxam and Nosema, reflected in lowest honey bee survival.
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Abelhas/fisiologia , Inseticidas/toxicidade , Nosema , Tiametoxam/toxicidade , Animais , Peptídeos Catiônicos Antimicrobianos , Abelhas/efeitos dos fármacos , Abelhas/microbiologia , Expressão Gênica , Infecções , Proteínas de Insetos , Larva/efeitos dos fármacos , Larva/microbiologia , Larva/fisiologia , Microsporidiose/veterináriaRESUMO
Among numerous factors that contribute to honey bee colony losses and problems in beekeeping, pesticides and Nosema ceranae have been often reported. In contrast to insecticides, whose effects on bees have been widely studied, fungicides did not attract considerable attention. Prochloraz, an imidazole fungicide widely used in agriculture, was detected in honey and pollen stored inside hives and has been already proven to alter immune gene expression of honey bees at different developmental stages. The aim of this study was to simulate the realistic conditions of migratory beekeeping, where colonies, both uninfected and infected with N. ceranae, are frequently transported to the vicinity of crop fields treated with prochloraz. We investigated the combined effect of prochloraz and N. ceranae on honey bees that faced fungicide during the larval stage through food consumption and microsporidium infection afterwards. The most pronounced changes in gene expression were observed in newly emerged Nosema-free bees originating from colonies previously contaminated with prochloraz. As exclusively upregulation was registered, prochloraz alone most likely acts as a challenge that induces activation of immune pathways in newly emerged bees. The combination of both stressors (prochloraz and Nosema infection) exerted the greatest effect on six-day-old honey bees. Among ten genes with significantly altered expression, half were upregulated and half downregulated. N. ceranae as a sole stressor had the weakest effects on immune gene expression modulation with only three genes significantly dysregulated. In conclusion, food contaminated with prochloraz consumed in larval stage could present a threat to the development of immunity and detoxification mechanisms in honey bees.