Adgaba Nuru

Effect of Jujube Honey on Candida albicans Growth and Biofilm Formation

BACKGROUND AND AIMS Candida species, especially Candida albicans, are major fungal pathogens of humans that are capable of causing superficial mucosal infections and systemic infections in humans. The aim of this study was to evaluate the jujube (Zizyphus spina-christi) honey for its in vitro inhibitory activity against pre-formed biofilm and its interference with the biofilm formation of C. albicans. METHODS The XTT reduction assay, scanning electron microscopy (SEM) and atomic force microscopy (AFM) were employed to determine the inhibitory effect of Jujube honey on C. albicans biofilm. Changes in the infrared spectrum after treatment with honey were also determined by Fourier transform infrared (FTIR) spectroscopy. RESULTS Jujube honey affects biofilms by decreasing the size of mature biofilms and by disruption of their structure. At a concentration of 40% w/v, it interferes with formation of C. albicans biofilms and disrupts established biofilms. The SEM and AFM results indicated that this type of honey affected the cellular morphology of C. albicans and decreased biofilm thickness. CONCLUSIONS The present findings show that jujube honey has antifungal properties against C. albicans and has the ability to inhibit the formation of C. albicans biofilms and disrupt established biofilms.

Geographical distribution and population variation of Apis mellifera jemenitica Ruttner

Summary The races of Apis mellifera L. have evolved as a result of long periods of geographical isolation and ecological adaptation. Among these subspecies, A. m. jemenitica Ruttner 1976 (Rutter 1976c) is particularly interesting because it is the only race reported to occur naturally in both Africa and Asia. According to the literature, its natural distribution is extremely large, extending for 4,500 km from the Arabian Peninsula to West Africa. However, different populations of A. m. jemenitica exhibit a high degree of morphometric variation. Moreover, published classifications of the subspecies do not agree; different names, including A. m. nubi, A. m. sudanensis, and A. m. bandasiihave been applied to different populations of A. m. jemenitica. Although African and Asian A. m. jemenitica are reported to be morphometrically similar, genetic data have not shown African A. m. jementtica to be genetically closer to the Asian A. m. jementtica than to adjacent, contiguous African subspecies like A. m. litorea, A. m. adansoniiand A. m. scutellata, which exchange genes continuously. Moreover, the African and Asian groups differ in migratory, aggressive, and brood-rearing behaviours. Thus, categorizing the geographically-isolated Asian and the African groups of A. m. jemenitica as one honey bee race is questionable. The other important issue is that the present homelands of A. m. jemenitica (near East Asia and East Africa) have been suggested as the geographic origin of A. mellifera. The existence of close similar population in both continents may support the suggestion that either of these two regions as may be the centre of origin and diversification of Apis mellifera.

Nectar of Ziziphus spina-christi (L.) willd (Rhamnaceae):dynamics of secretion and potential for honey production

Abstract The nectar secretion of Ziziphus flowers was studied by removing and measuring the nectar every four hours, for two consecutive days, from 88 flowers of four trees (‘repeated sampling’). In another 120 flowers from the same trees, the accumulated sugar was measured at the end of the flowering stage. The mass of the nectar sugar was determined following the washing technique. The total amount of sugar per tree was calculated by multiplying the number of flowers per tree by the average mass of nectar sugar secreted per flower. The average mass of sugar produced per flower in repeated sampling was 0.79±0.54 mg/flower (range 0.09 - 2.48 mg). The average mass of sugar per flower for each of the four investigated trees was 1.43±0.53 mg, 0.72±0.27 mg, 0.94±0.39 mg and 0.37±0.26 mg, respectively. The differences among trees was statistically significant. For accumulated nectar, the overall average mass of sugar per flower was 0.55±0.23 mg (range 0.06 - 1.29 mg) and the average values for flowers on the investigated trees of Z. spina-christi were 0.69±0.26 mg, 0.41±0.16 mg, 0.51±0.16 mg and 0.53±0.21 mg; these variations were statistically significant. The average mass of nectar sugar calculated for the flowers with accumulated nectar sampling was significantly lower than the average mass of sugar recorded for repeated nectar sugar samplings (0.79±0.54 mg). According to this study, one Ziziphus tree is estimated to produce 3.6 kg of honey (range 2.2 - 5.2 kg), equivalent to about 900 kg of honey/ha (range 550 - 1300 kg). These figures indicate the high potential value of the plant for honey production. Nectar secretion was positively correlated with temperature, indicating the adaptation of the tree to hot climates.

Characterization and gene mapping of a chlorophyll-deficient mutant clm1 of Triticum monococcum L.

Diploid wheat Triticum monococcum L. is a model plant for wheat functional genomics. Chlorophyll-deficient mutant (clm1) was identified during manual screening of the ethyl methanesulphonate (EMS)-treated M2 progenies of T. monococcum accession pau14087 in the field. The clm1 mutant, due to significantly decreased chlorophyll content compared with the wild-type (WT), exhibited pale yellow leaves which slowly recovered to green before flowering. The clm1 mutant showed early flowering, reduced number of tillers, trichome length and density, and different shape as compared with the WT. At the same time, clm1 mutant culm had more chlorophyll-containing parenchymatous tissues compared to WT, presumably to absorb more sunlight for photosynthesis. Genetic analysis indicated that the clm1 mutation was monogenic recessive. The clm1 mutant was mapped between Xgwm473 and Xwmc96 SSR markers, with genetic distances of 2.1 and 2.6 cM, respectively, on the 7AmL chromosome.

Antagonistic Effect of Gut Bacteria in the Hybrid Carniolan Honey Bee, Apis Mellifera Carnica, Against Ascosphaera Apis, the Causal Organism of Chalkbrood Disease

Abstract The objective of this study was to isolate and characterize bacterial strains associated with the gut of the hybrid Carniolan honey bee, Apis mellifera carnica, and to determine their in vitro and in vivo potential against Ascosphaera apis, the causal organism of chalkbrood disease, with the purpose of exploring feasible biological control. Six bacterial strains were isolated from healthy worker honey bees by culture-dependent methods. Six fungal strains (A3, A4, A7, A8, A9, and A15) of A. apis were isolated from larvae suffering from chalkbrood disease on Yeast-Glucose-Starch agar (YGPSA) medium. All bacteria were identified by a combination of morphology, Gram stain, and 16S rRNA sequence analysis, and fungal strains were identified by morphology and 5.8S rRNA. In vitro and in vivo inhibition assays were carried out to determine the ability of bacterial isolates to inhibit A. apis, the causal agent of chalkbrood disease. The analysis of 16S rRNA sequences revealed that four bacterial strains (B2, B4, B10, and B100) belong to Bacillus subtilis species, and two strains (P1 and P5) belong to Pseudomonas fluorescence. Significant differences in antagonistic activity of all bacterial strains were observed. B. subtilis isolate B2 showed the highest antagonistic activity, as measured by the inhibition zone against A. apis, followed by the P1 strain of P. fluorescence. SEM analysis also supports the antagonistic activity of these bacteria against A. apis. This study provides a theoretical basis for biological control of honey bee chalkbrood disease.

In vitro evaluation of the effects of some plant essential oils on Paenibacillus larvae, the causative agent of American foulbrood

ABSTRACT Paenibacillus larvae is one of the major bacterial pathogens of honey bee broods and the causative agent of American foulbrood disease. The factors responsible for the pathogenesis of American foulbrood disease are still not fully understood, and the increasing resistance of P. larvae to commonly used antibiotics necessitates a search for new agents to control this disease. The in vitro antibacterial activities of 28 plant essential oils against P. larvae ATCC 9545 were evaluated. Out of the 28 plant essential oils tested, 20 were found to be effective in killing P. larvae. Based on their minimum bactericidal concentration (MBC) values, the effective oils were grouped into three categories: highly effective, moderately effective and minimally effective. Jamaica pepper oil, mountain pepper oil, ajwain oil, corn mint oil, spearmint oil, star anise oil, nutmeg oil and camphor oil were highly effective, with MBC values between 162.0 and 375.0 µg/mL. Jamaica pepper oil was the most effective essential oil, with an MBC value of 162.0 µg/mL. The results of the time-response effect assays showed that no viable P. larvae cells were observed after 24 h of treatment with Jamaica pepper oil (162.0 µg/mL), 36 h of treatment with mountain pepper oil (186.0 µg/mL), 48 h of treatment with ajwain oil (224.8 µg/mL) or 48 h of treatment with oxytetracycline (5.89 µg/mL). The tested essential oils exhibited significant antimicrobial activities against P. larvae, and they may contain compounds that could play an important role in the treatment or prevention of American foulbrood disease.

Beekeeping in the Kingdom of Saudi Arabia Opportunities and Challenges

In the second, and concluding, part of their article on beekeeping in The Kingdom of Saudi Arabia the authors look in detail at the current apicultural scene in this vast land and assess the strengths, weaknesses, opportunities and possible threats that lie ahead.

Beekeeping in the Kingdom of Saudi Arabia Past and Present Practices

The Kingdom of Saudi Arabia is a very large and interesting country about which many people would like to know more. Certainly not a lot has been written about beekeeping here—a situation that Bee World hopes to remedy with two articles which look in detail at the current apicultural scene in this vast land and what future developments can be expected.

Morphometric diversity of indigenous Honeybees, Apis mellifera (Linnaeus, 1758), in Saudi Arabia

Abstract Twenty four morphological traits of Honeybees (Apis mellifera Linnaeus, 1758) were evaluated in 198 native colonies within Saudi Arabia to differentiate among populations. Principal component analysis based on colony means and k-means clustering proposed a separation of Saudi Honeybees into three clusters. These were confirmed by discriminant analysis, which re-classified colonies with 100% accuracy into clusters two and three and 96% accuracy into cluster one. Results indicate significant morphometric variation and a cline of factor one (characters associated with body size) from the north (cluster one) to the south (cluster three), with the highest dissimilarities between bees from the far north and the far south. The substantial variation detected in this study supported the previous description of Saudi Arabian Honeybees made by Ruttner in 1976, which, based on few samples, was not representative of this large and diverse country.

Investigation of gut microbial communities associated with indigenous honey bee (Apis mellifera jemenitica) from two different eco-regions of Saudi Arabia

The microbial communities associated with the alimentary tract of honey bees are very important as they help with food digestion, provide essential nutrients, protect the host from pathogens, detoxify harmful molecules, and increase host immunity. In this study, the structural diversity of the gut microbial communities of native honey bees, Apis mellifera jemenitica from two different geographical regions (Riyadh and Al-Baha) of Saudi Arabia was analyzed by culture-dependent methods and 16S ribosomal RNA (rRNA) gene sequencing. In this study, 100 bacterial isolates were cultivated and phylogenetic analyses grouped them into three phyla: Proteobacteria, Firmicutes, and Actinobacteria. Bacteria in the phylum Proteobacteria were the most dominant (17 species), followed by Firmicutes (13 species) and Actinobacteria (4 species). Some of the identified bacteria (Citrobacter sp., Providencia vermicola, Exiguobacterium acetylicum, and Planomicrobium okeanokoites) were reported for the first time in the genus Apis, while others identified bacteria belonged to the genera Proteus, Enterobacter, Bacillus, Morganella, Lactobacillus, and Fructobacillus. To the best of our knowledge, this is the first study on the gut microbiota of the local honey bees in Saudi Arabia.