Antimicrobial activity of camphor tree silver nano-particles against foulbrood diseases and finding out new strain of Serratia marcescens via DGGE-PCR, as a secondary infection on honeybee larvae.

American foulbrood (AFB) and European foulbrood (EFB) are the two major bacterial diseases affecting honeybees, leading to a decrease in viability of the hive, decreasing honey production, and resulting in significant economic losses to beekeepers. Due to the inefficiency and/or low efficacy of some antibiotics, researches with nanotechnology represent, possibly, new therapeutic strategies. Nanostructure drugs have presented some advantagesover the conventional medicines, such as slow, gradual and controlled release, increased bioavailability, and reduced side-effects. In this study, different infected larvae were collected from two apiaries; the combs that had symptoms of American and European foulbrood were isolated. In vitro antimicrobial activity of camphor tree silver nano-particles against foulbrood diseases were characterized using UV-Vis spectrophotometry and scanning electron microscope (SEM) that proves the formation of silver nanoparticles with size range 160-660 nm. The antimicrobial activity of the silver nanoparticles was tested using agar diffusion assay and proved their ability to effectively cease the pathogenic bacterial growth in both AFB and EFB. DGGE-PCR technique has been applied for the identification of un-common bacterial infections honeybees depending on 16S rRNA amplification from their total extracted DNA and has been identified as Serratia marcescens (TES), deposited in GenBank with a new accession number (MT240613). The results were confirmed strain has been detected by DGGE-PCR analysis causing uniquely infected brood that was attacked by the American Foulbrood It could be concluded that greenly synthesized silver nanoparticles is projected to be used as effective treatment for honeybee bacterial diseases. These material need more investigations under field conditions and study the possibility of its residues in honeybee products such as honey, and beeswax.

Efficacy of Pluchea dioscoridis leaf extract against pathogenic Candida albicans.

INTRODUCTION: This study aimed to evaluate the efficacy of Pluchea dioscoridis leaf extract on growth, survival, morphogenesis, and virulence gene expression of Candida albicans. METHODOLOGY: Anticandidal activity was studied using the hole-plate method against four pathogenic C. albicans strains from clinical isolates. The effect of the extract on the growth profile of the yeast was also examined via a time-kill assay. Microscopic observations using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were made to determine the major alterations in the microstructure of C. albicans. Quantitative changes in phospholipase, hemolysin, and secreted aspartyl proteinase (SAP1 and SAP10) genes expression as virulence factors were analyzed using real-time polymerase chain reaction (RT-PCR). RESULTS: The extract exhibited high anticandidal activity, with the zones of inhibition between 0.5 and 6 cm, and recorded a minimum inhibitory concentration (MIC) value of 30 mg/mL. The time-kill study suggested that the extract possessed yeasticidal properties at higher concentrations and eradicated the growth of yeast cells. The SEM and TEM micrographs exhibited major abnormalities that occurred on the yeast cells after being exposed to the extract, resulting in complete alterations in their morphology and collapse of the cells beyond repair. At MIC concentration, phospholipase, proteinase, and hemolysin gene expression was reduced to 90%, 70%, 90% for SAP1, and 40% for SAP10, respectively, compared to that obtained from untreated C. albicans, as demonstrated by quantitative reverse transcription (RT)-PCR analysis. CONCLUSIONS: The P. dioscoridis leaf extract may be an effective anticandidal agent to treat pathogenic yeast infections.

New Paenibacillus larvae bacterial isolates from honey bee colonies infected with American foulbrood disease in Egypt.

The American foulbrood disease is widely distributed all over the world and causes a serious problem for the honeybee industry. Different infected larvae were collected from different apiaries, ground in phosphate saline buffer (PSB) and bacterial isolation was carried out on nutrient agar medium. Different colonies were observed and were characterized biologically. Two bacterial isolates (SH11 and SH33) were subjected to molecular identification using 16S rRNA gene and the sequence analysis revealed that the two isolates are Paenibacillus larvae with identity not exceeding 83%. The DNA sequence alignment between the other P. larvae bacterial strains and the two identified bacterial isolates showed that all the examined bacterial strains have the same ancestor, i.e. they have the same origin. The SH33 isolate was closely related to the P. larvae isolated from Germany, whereas the isolate SH11 was close to the P. larvae isolated from India. The phylogenetic tree constructed for 20 different Bacillus sp. and the two isolates SH11 and SH33 demonstrated that the two isolates are Bacillus sp. and they are new isolates. The bacterial isolates will be subjected to more tests for more confirmations.

Detection of BRCA1 and BRCA2 gene mutation in Egyptian females with breast cancer and their relatives by PCR-SSCP method.

Germline mutations in the BRCA1 or BRCA2 genes predispose their carriers to breast or/and ovarian cancers during their lifetime. This study was performed to identify germline mutations in BRCA1 and BRCA2 genes for the early detection of pre-symptomatic mutation carriers in Egyptian healthy females who were first-degree relatives of affected women from families with and without family history of breast cancer. Sixty-two patients (index cases) with invasive breast cancer belonging to sixty families and their asymptomatic female first-degree relatives (300 cases) were studied for germline mutations of BRCA1 and BRCA2 genes. Five mutations were detected in 52 families (86.7%) with inherited mutations in either BRCA1 or BRCA2. Sixty percent of these families had BRCA1 mutation and 26.7% had BRCA2 mutations. They were identified by using the combination of SSCP and heteroduplex analysis. All but one of the mutations were detected within the BRCA1 gene in addition to one mutation in the BRCA2 gene.