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PubMed1992

Identification and susceptibility testing for obligate anaerobic bacteria using a semi-automated API ATB plus system.

We evaluated the reliability of the API systems, Rapid ID 32 A and ATB ANA, for the identification and susceptibility testing of obligate anaerobic bacteria in a clinical laboratory that does not possess either an anaerobic chamber or a chromatograph. Tested were 105 clinical isolates. Identifications were compared with those obtained according to the criteria of the Virginia Polytechnic Institute Manual using the API 20 A system with incubation in an anaerobic chamber and gas chromatography. Identifications were concordant in 86.3% of cases. The Rapid ID 32 A system was inaccurate in distinguishing Bacteroides of the fragilis group. Susceptibility to 10 antibiotics of the ATB ANA system was compared to that obtained by MIC determination on Wilkins Chalgren agar. Overall, concordance was 78.2%. Disagreements were mostly minor (16.4%): resistant strains classified as intermediate or intermediate classified as susceptible. When the ATB ANA strip cannot be inoculated in an anaerobic chamber, it is possible that a denser inoculum would decrease the percentage of minor disagreements.

Anti-Bacterial Agents↗

PubMed1977

[The effect of resuscitation on the results obtained in identification of enterobacteriaceae by the API system (author's transl)].

During studies on the reliability of the API system, the question arose whether the small proportion of adequate results in cultures stored at 4 degrees C could be attributable to this method of storage. Therefore, the reactions of those cultures which had caused most problems were studied following periods of storage ofone day, six weeks and nine weeks at 4 degrees C, and in the freeze-dried state. Storage in particular conditions was found to have a definite effect on the reliability of the API system so that a period of resuscitation of forty-eight hours in a bouillon at 37 degrees C is required to restore the cultures to normal.

Bacteriological Techniques↗

PubMed1979

[Use of the API 20E system for rapid identification of Enterobacteriaceae (six hours) (author's transl)].

The authors propose a modification of the method of use of the API 20E system permitting more rapid identification of Enterobacteriaceae within six hours (3 hours preculture and 3 hours incubation on an API 20E plate) it was possible to identify correctly 67% of 192 strains studied at species level and 75.5% studied at generic level. One may note four mistakes (2.1%) of which 3 were minor, (species within the same genus). The construction of a base of numerical data adapted to the technic within six hours would no doubt permit us to reduce the percentage undetermined.

Enterobacteriaceae↗

PubMed1975

[Effect of dietary proteins on the multiplication of the protozoon Nosema apis Z].

By counting the spores of protozoon Nosema apis Z. in Bürker's chamber the author was able to find, in 1495 caged bees sacrificed one week after the parasite invasion, from altogether 26 samples of various feeds statistically sifnificant differences of influencing the protozoon development only in sallow pollen. The differences between the individual feeds were statistically more significant in bees sacrificed 14 days after the invasion. Examination of 1260 bees 14 days after the invasion demonstrated that, as compared with glycide food, the parasite development was enhanced by a feed consisting of 6, 9, and 12 per cent fresh rape pollen, 3 and 6 per cent of fresh and dried sallow pollen, 6 per cent freeze-dried pollen mixture, pollen deposited in honeycombs, 7.5, 10, and 12.5 per cent yeast dough, "Arnika" and 3 per cent Bacto peptone. Even 14 days after the invasion no statistically sifnificant differences of influencing the schizogony of protozoon Nosema apis Z. could be demonstrated in bees fed pure glycide feed, dough with 3 and 6 per cent casein hydrolyzate, 3 and 6 per cent Hammarsten casein, 3 per cent dried whole eggs, 3 per cent rape pollen and 3 and 6 per cent fresh pollen mixtures. In the study the possibility of an indirect effect of pollen on the parasite schizogony through the secrete of the pharyngeal glands is being discussed.

Animals↗

PubMed2026

Uncovering hidden complexity in the Apis mellifera mitotranscriptome: a polyadenylation-centered perspective.

Mitochondrial transcription is gaining increasing attention as researchers seek to better understand the full coding potential of mitochondrial DNA (mtDNA). Emerging evidence suggests that mtDNA may encode additional elements beyond classical oxidative phosphorylation genes, pointing to a more complex transcriptional architecture than previously recognized. In this study, we explored the mitochondrial transcriptome of Apis mellifera (Insecta: Hymenoptera), with a particular focus on polyadenylation-associated features. Our analysis revealed that both sense and antisense transcripts undergo polyadenylation, although transcript abundance and poly(A) tail lengths varied markedly across mitochondrial genes. Several transcripts exhibited alternative isoforms, either extended or truncated, frequently including intergenic regions. These regions may represent functional non-coding elements or structural variants rather than conventional untranslated regions (UTRs). Interestingly, some transcripts also contained non-templated nucleotide additions particularly cytosine residues immediately upstream of the poly(A) tails. Monocistronic units that included portions of downstream intergenic regions were among the most abundantly represented, suggesting a possible regulatory role for these sequences. To experimentally validate our in silico findings, we performed RT-qPCR to assess relative gene expression and applied 3' RACE-PCR to define transcript boundaries. These approaches confirmed the presence of multiple transcript isoforms and supported the involvement of polyadenylation in shaping mitochondrial RNA diversity. Together, our findings reveal a previously underappreciated level of complexity in the A. mellifera mitochondrial transcriptome and highlight the potential regulatory significance of polyadenylation dynamics and intergenic region transcription.

Animals↗

PubMed2026

Simulation of CRISPR/Cas9-mediated gene editing for the Vitellogenin gene in Apis mellifera.

CRISPR/Cas9 genome editing provides a powerful framework for interrogating gene function in Apis mellifera. Yet, empirical application remains challenging due to biological constraints, including haplodiploid genetics, narrow embryonic injection window, and the social rearing requirements that complicate functional validation. These constraints necessitate in silico pre-screening to maximize editing success before resource-intensive wet-lab implementation. Within the omnigenic framework, which distinguishes core regulatory genes from peripheral loci buffered by network effects, vitellogenin (Vg) represents an optimal target which is ancestrally dedicated to yolk provisioning; it has been co-opted to orchestrate diverse non-reproductive functions including longevity, stress resistance, immunity, and social behavior. We developed a computational pipeline to design a list of 57 and 56 candidate guide RNAs (gRNA) for targeted Vg knockout, evaluating candidate sites in both functional exons 2 and 3 based on structural accessibility and frameshift efficiency. Comparative analysis revealed complementary strengths in two top-best candidates from initial target pool of predicted gRNAs. The gRNA targeting exon 2 exhibits weaker secondary structure (ΔG = -0.25 kcal/mol versus -2.10 kcal/mol for exon 3), aligning with empirical evidence that sites with ΔG > -1.0 kcal/mol achieve 2-5 × higher Cas9 binding efficiency. This site yielded moderate frameshift frequency (77.8%; 61.9 percentile). Conversely, the predicted editing outcome for the gRNA targeting exon 3, despite stronger structural constraints, demonstrated superior functional disruption metrics demonstrating very high frameshift frequency (88.3%; 95.2 percentile), high in silico editing precision, minimal microhomology-mediated repair bias, and reproducible outcomes wherein nearly all predicted indels disrupt the coding sequence. Protein structure and domain analyses further predict that frameshift edits will generate a truncated protein missing all downstream functional domains. We recommend parallel empirical validation of both exon 2 and exon 3 targets to resolve the trade-off between structural accessibility (favoring higher editing rates) and frameshift efficacy (favoring complete loss-of-function). This dual-target strategy accommodates uncertainty in in vivo performance while maximizing the probability of generating informative phenotypes. Our in silico framework enables rational CRISPR design in non-model organisms by computationally balancing biophysical accessibility with functional impact, accelerating functional genomics in species where empirical optimization faces substantial biological constraints.

Animals↗

PubMed1991

Common projection areas of antennal and visual pathways in the honeybee brain, Apis mellifera.

The convergence of primary sensory neurons of the antennae, higher order visual interneurons, and antennal motoneurons was analysed with neuroanatomical techniques in the honeybee, Apis mellifera. The different modalities evoke specific antennal responses in this insect. Three different fluorescent dyes were applied successively in the same preparation in order to visualise the various fiber projections from the antennae and the lobula in the brain of the honeybee. Three neuropile areas where sensory fibers of the antennae overlap with visual projection neurons from the lobula were found. Within the posterior-median protocerebrum the antennal tract T6-1 comes in close vicinity to the lobula tract LoT-9 and to some other lobula fibers that cannot be assigned to a special tract. Antennal T6-3 fibers overlap with lobula LoT-7 neurons within the posterior protocerebrum more laterally. Antennal T5 fibers arborise in the dorsal lobe and show common projection sites with lobula LoT-3 neurons. The multimodal convergence in the three common neuropiles demonstrates that these areas are important centers for multimodal information processing between sensory, motor, and descending neurons in insects.

Animals↗

PubMed1977

Ocellar projections within the central nervous system of the worker honey bee, Apis mellifera.

The projections of ocellar fibres within the brain and thorax of the honey bee, Apis mellifera, were established using a modified cobalt sulphide technique, supplemented by serial sectioning of the brain for the light microscope. The results are: 5 large fibres in each lateral nerve and 12 in the median nerve have wide-field terminal arborisations in ocellar association areas on either side of the posterior slope area. 9 medium-sized fibres in each lateral nerve and 12 in the median nerve form a second ocellar association area on each side of the perioesophageal foramen. A group of fine fibres , stained via the ocellar nerves, arborise just below and anterior to the protocerebral bridge. 10 medium-sized fibres run from the level of the ocellar nerve tracts to the first and second thoracic ganglia, branching in a number of discrete areas within each ganglion. These fibres also form a restricted ocellar association area within the suboesophageal ganglion. A few fibres run between the higher-order optic centres and the ocellar tract. The large- and medium-sized fibres give off short, stout spines from their axons within the ocellar tracts.

Animals↗

PubMed1976

Contrasting patterns of DNA sequence arrangement in Apis mellifera (honeybee) and Musca domestica (housefly).

We have examined the organization of the repeated and single copy DNA sequences in the genomes of two insects, the honeybee (Apis mellifera) and the housefly (Musca domestica). Analysis of the reassociation kinetics of honeybee DNA fragments 330 and 2,200 nucleotides long shows that approximately 90% of both size fragments is composed entirely of non-repeated sequences. Thus honeybee DNA contains few or no repeated sequences interspersed with nonrepeated sequences at a distance of less than a few thousand nucleotides. On the other hand, the reassociation kinetics of housefly DNA fragments 250 and 2,000 nucleotides long indicates that less than 15% of the longer fragments are composed entirely of single copy sequences. A large fraction of the housefly DNA therefore contains repeated sequences spaced less than a few thousand nucleotides apart. Reassociated repetitive DNA from the housefly was treated with S1 nuclease and sized on agarose A-50. The S1 resistant sequences have a bimodal distribution of lengths. Thirty-three percent is greater than 1,500 nucleotide pairs, and 67% has an average size about 300 nucleotide pairs. The genome of the housefly appears to have at least 70% of its DNA arranged as short repeats interspersed with single copy sequences in a pattern qualitatively similar to that of most eukaryotic genomes.

Animals↗

PubMed1977

Genetic control and development expression of malate dehydrogenase in Apis mellifera.

Starch gel electrophoresis of extracts of Apis mellifera indicates that genetic variability exists for the enzyme cytoplasmic malate dehydrogenase (E.C. 1.1.1.37). Analysis of individuals throughout development indicates that the isozyme patterns are identical for larvae and adults and suggests a dimeric structure for the molecule. The isozyme pattern observed in pupae is more complex than that of larvae and adults may be due to an additional pupal-specific MDH gene being expressed or to an epigenetic modification of the isozymes. Forty-three colonies with artificially inseminated queens were used to study the Mendelian pattern of inheritance. The data revealed that the MDH isozymes are encoded by three alleles, Mdh-1A, Mdh-1B, and Mdh-1C. The frequency of the Mdh-1 alleles is different in two analyzed subspecies, A. m. adansonii (African bees) and A. m. ligustica (Italian bees), with Mdh-1A and Mdh-1B in the African bees being 0-768 and 0.202, respectively. For the Italian bees, these frequencies are 0.136 and 0:154, respectively.

Alleles↗

PubMed1977

Evaluation of two test-kits--API and Oxi Ferm tube--for identification of oxidative-fermentative Gram-negative rods.

Two test-kits--API and Oxi Ferm tube--have been compared for accuracy in individual tests and for identification on the genus or species level with conventional biochemical tests on 154 oxidative-fermentative gram-negative rods. The two test systems were found to be reliable and permit identification of the clinically most significant oxidative-fermentative strains.

Bacteriological Techniques↗

PubMed1977

Fertile diploid drones in africanized honeybees, Apis mellifera adansonii.

59 diploid drones of Apis mellifera adansonii, 12-37 days old, were tested for the presence of semen after provoked ejaculation; 13 drones ejaculated semen enough to be used in an instrumental insemination, but only three on them (5%) furnished 1 mm3 of semen. The problems referring to the attainment of descendants from the 2n drones are briefly discussed.

Animals↗

PubMed1975

Ultrastructural analysis of the freeze-etched spore envelope of the microsporidian, Nosema apis Zander.

The outer limiting layer of the spore coat of Nosema apis is relatively smooth. The inner limiting layer shows two fractured faces, the concave face carrying many stud-like projections, 120 nm long and 50 nm high, while the convex face carries numerous depressions which are complementary to the projections. In addition, the convex face bears 7 nm particles. In between the outer and inner limiting layers lies the thick homogeneous portion of spore coat which is comprised of numerous microfibres, each 9 nm in diameter. These microfibres resemble those in the freeze-etched host endocuticle. Next to the inner limiting layer of the spore coat are double spore membranes. The convex faces of these spore membranes have a dense population of particles, each 7 nm in diameter.

Animals↗

PubMed1992

Phylogenetic relationships in the honeybee (genus Apis) as determined by the sequence of the cytochrome oxidase II region of mitochondrial DNA.

The complete nucleotide sequence of the mitochondrial cytochrome oxidase II (COII) gene was determined for five species of the honeybee (Genus: Apis): A. andreniformis, A. cerana, A. dorsata, A. florea, and A. koschevnikovi; these were then compared to the known sequence of the A. millifera gene from Crozier et al. (1989, Mol. Biol. Evol., 6: 399-411) and the wasp Excristes roborator (Liu and Beckenbach, 1992, Mol. Phylogenet. Evol., 1:41-52). Phylogenetic relationships were derived using the parasimony methods DNAPARS and PROTPARS of Felsenstein ("PHYLIP Manual Version 3.4, "University Herbarium, Univ. of California, Berkeley). The results suggest that A. dorsata is the most ancestral species, followed by the branching of A. florea/A. andreniformis and A. koschevnikovi, and then A. mellifera and A. cerana. This inference differs from the currently accepted view that considers the A. florea/A. andreniformis line to be the most ancestral.

Amino Acid Sequence↗

PubMed2026

Comparative in silico analysis of Apis mellifera immune responses to Varroa destructor and Tropilaelaps mercedesae: Common and mite-specific molecular signatures.

Parasitic mites Varroa destructor and Tropilaelaps mercedesae represent major threats to global honey bee (Apis mellifera) health and productivity, yet comparative molecular insights into host responses remain limited. To address this, we systematically compiled published studies (2015-2025) reporting genes associated with honey bee interactions with V. destructor (11 studies, 87 genes), T. mercedesae (4 studies, 35 genes), and hygienic behavior (6 studies, 44 genes). Gene identifiers were harmonized to the Amel_HAv3.1 genome assembly, yielding three non-redundant sets: 64 Varroa-associated, 34 Tropilaelaps-associated, and 44 hygienic behavior-associated genes. Venn analysis identified 10 overlapping genes (including A0A088A8D5, A0A088ADL8, ABAE_APIME, Def1, Def2, Gapdh, HYTA_APIME, Imd, LOC726783, and Vg), suggesting conserved defense mechanisms, while 41 and 24 genes were uniquely associated with Varroa and Tropilaelaps, respectively. Enrichment analyses revealed Varroa-responsive genes were enriched in immune processes, chitin catabolism, and signaling pathways (Toll/Imd, MAPK, Wnt). Tropilaelaps-associated genes were enriched for antibacterial defense and stress response, with Toll/Imd signaling as the sole significantly enriched pathway. Overlapping genes reinforced core innate immunity activation. Protein-protein interaction network centrality analysis identified key hub genes: Def1, HYTA_APIME, ABAE_APIME, PPO, Imd, PGRP-LC, Vg for Varroa; and ACPH1_APIME, MRJP1, Vg, LOC726783 for Tropilaelaps. Results demonstrate that, despite differences in mite biology, honey bees show a conserved immune response against both parasites, centered on antibacterial defense, humoral immunity, and activation of the Toll/Imd pathway. Although limited by the in-silico nature and research asymmetries reflecting Tropilaelaps' emergence, this curated resource establishes a comprehensive framework for elucidating shared and distinct molecular defense mechanisms. Ultimately, this approach prioritizes diagnostic markers and candidate genes for functional validation and breeding strategies to enhance colony resilience against mite‑driven disease globally.

Animals↗

PubMed1975

Transfer of the methyl group of methionine to choline and to tRNA in the honeybee Apis mellifica L.

Contrary to some previous reports on the absence of biological transmethylation reactions in some insect species, the transfer of the methyl group of methionine-methyl 14C leading to choline and to methylated bases in tRNA was shown in the honeybee Apis mellifica. The addition of antibiotics to the food of the insect does not diminish the incorporation of radioactivity, proving that intestinal bacteria are not responsible for the methylation reactions observed.

Animals↗

PubMed1991

Learning by honeybees (Apis mellifera) on arrival at and departure from a feeding place.

The question of when in the course of a visit to a feeding place foraging honeybees (Apis mellifera) learn about its location was studied in Experiment 1 by moving the animals a short distance after they arrived and began to feed. A preference for the arrival place developed, although less rapidly than in control animals for which the arrival and departure places were the same. In Experiments 2-5, a distinctive object was used to define the location of the feeding place. When the object was removed after arrival or introduced only after arrival, the animals learned less about its color and shape than did control animals for which it was present throughout each visit. The results contradict the claim that honeybees learn about certain characteristics of a feeding place only on arrival and about others only on departure.

Animals↗

PubMed1992

Learning in honeybees (Apis mellifera) as a function of sucrose concentration.

Foraging honeybees (Apis mellifera) were trained with 2 successively presented targets differing in color or odor, one of which always contained a 5-microliters drop of 50% sucrose solution and the other, a 5-microliters drop of 20% sucrose solution. Latency of response to each target was measured during the training, and at the conclusion, preference was measured in an unrewarded choice test. Analysis of the latencies showed both a prospective effect (faster response to the 50% target than to the 20% target) and a nonassociative retrospective effect (faster response after leaving the 20% target than after leaving the 50% target) reminiscent of the frustration effect in rats. The results both for prospective latency and for choice can be understood on the simple theory that the attractiveness of a target depends on the strength of its association with sucrose and that the effect of concentration is on asymptotic strength.

Animals↗