Synergistic Action of Biosynthesized Silver Nanoparticles and Culture Supernatant of Bacillus amyloliquefacience against the Soft Rot Pathogen Dickeya dadantii.

Nanomaterials are increasingly being used for crop growth, especially as a new paradigm for plant disease management. Among the other nanomaterials, silver nanoparticles (AgNPs) draw a great deal of attention because of their unique features and multiple usages. Rapid expansion in nanotechnology and utilization of AgNPs in a large range of areas resulted in the substantial release of these nanoparticles into the soil and water environment, causing concern for the safety of ecosystems and phytosanitary. In an attempt to find an effective control measure for sweet potato soft rot disease, the pathogen Dickeya dadantii was exposed to AgNPs, the cell-free culture supernatant (CFCS) of Bacillus amyloliquefaciens alone, and both in combination. AgNPs were synthesized using CFCS of Bacillus amyloliquefaciens strain A3. The green synthesized AgNPs exhibited a characteristic surface plasmon resonance peak at 410-420 nm. Electron microscopy and X-ray diffraction spectroscopy determined the nanocrystalline nature and 20-100 nm diameters of AgNPs. Release of metal Ag+ ion from biosynthesized AgNPs increases with time. AgNPs and CFCS of B. amyloliquefaciens alone exhibited antibacterial activity against the growth, biofilm formation, swimming motility, and virulence of strain A3. The antibacterial activities elevated with the elevation in AgNPs and CFCS concentration. Similar antibacterial activities against D. dadantii were obtained with AgNPs at 50 µg·mL-1, 50% CFCS alone, and the combination of AgNPs at 12 µg·mL-1 and 12% CFCS of B. amyloliquefaciens. In planta experiments indicated that all the treatments reduced D. dadantii infection and increased plant growth. These findings suggest that AgNPs along with CFCS of B. amyloliquefaciens can be applied to minimize this bacterial disease by controlling pathogen-contaminated sweet potato tuber with minimum Ag nano-pollutant in the environment.

Molecular Screening of PAX2 Gene Polymorphism in Primary Vesicoureteral Reflux Patients in Taif Governorate, KSA.

<b>Background and Objective:</b> Primary Nonsyndromic Vesicoureteral Reflux (PVUR) is a widespread genetic malformation and considered a prevalent Congenital Abnormality of the Kidney and Urinary Tract (CAKUT). Mutations in the <i>PAX2 </i>gene have been associated with abnormalities in the kidney extending from CAKUT to oncogenic processes. The present study analyzes the <i>PAX2</i> polymorphisms and their association with primary VUR in Saudi children patients from the Taif governorate. <b>Materials and Methods:</b> Fifteen children with primary VUR were identified and screened for gene mutations in the <i>PAX2</i> gene by direct sequencing method of purified Polymerase Chain Reaction (PCR) products of all exons to elucidate the correlation between <i>PAX2</i> gene and VUR. <b>Results:</b> Seven new variants have been defined. Three polymorphic missense variants in homozygous genotype form were found in intron 8 and detected in eight patients, One missense mutation was found in exon 10 in the site of transactivation domain and detected in ten patients and <i>in-silico</i> analysis predicted it as a pathogenic one, Three mutations were found in exon 11 and detected in all patients as a compound homozygous. <b>Conclusion:</b> <i>PAX2</i>is important for normal kidney development and mutations in the gene possibly lead to disturbance in the protein structure and could be non-functional thus mutations in <i>PAX2</i> may be one of the causes of PVUR in Saudi Arabia. Further investigation is necessary to understand the aetiology of disease and maybe other genes implicated in VUR.

Molecular Investigation of Multidrug-Resistant Escherichia coli Clinical Isolates from Patients with Urinary Tract Infections.

<b>Background and Objective:</b> Urinary tract infections believe to be one of the main acquainted infections by <i>Escherichia coli</i> in hospitals with an excessive incidence of illness. This study aimed to analyze the antibiotic resistance profile and molecular characteristics of <i>E. coli</i> isolates recovered from patients with urinary tract infection at different hospitals in Taif Governorate, Saudi Arabia. <b>Materials and Methods:</b> Out of 143 isolates collected for 11 months, from February-December 2019, 24 isolates were identified as <i>E. coli</i> by API system and 16S rRNA sequences techniques. An antibiotic sensitivity test was performed using the disk diffusion method. Besides, the repetitive sequence repeat-PCR (Rep-PCR) technique was used for genotyping the 24 isolates. <b>Results:</b> Almost all isolates were resistant to most tested antibiotics such as ampicillin, ceftazidime, cefepime, trimethoprim/sulfamethoxazole, amox/clavulanic. The PCR results show that virulence genes <i>kpsII</i> and <i>yaiO</i> were detected in all <i>E. coli</i> isolates. <i>Stx1</i>, <i>fimH</i>, <i>hly</i> and <i>uidA</i> were moderate detected in all isolates. <b>Conclusion:</b> The high frequencies of antibiotic-resistant <i>E. coli</i> isolates in patients with urinary tract infections in the current study suggest that continuous surveillance of the use of appropriate antibiotics is required and that control of infections is necessary.

Molecular Diagnosis of Mycoplasma Species Infection in Camels Using Semi-nested PCR.

BACKGROUND AND OBJECTIVE: Bacteriological isolation and identification of Mycoplasma species is difficult and time-consuming, therefore, molecular identification of Mycoplasma using PCR targeting specific genes is considered a specific and sensitive method for identification. The aim of current study was to isolate, characterize Mycoplasma infection in dromedary camels in Saudi Arabia. MATERIALS AND METHODS: Nasal swabs were randomly collected from 93 camels and tested for Mycoplasma by sequencing of their 16S rRNA genes using universal primers. RESULTS: The 93 samples, 24 were positive for Mycoplasma. However, no positive results were obtained using species-specific primers for Mycoplasma arginine, M. bovis or M. mycoides subsp. mycoides, thus, 16S rDNA sequencing methods and semi-nested PCR were employed. Sequences were matched to those in GenBank and phylogenetic analysis was performed. Mycoplasma edwardii (77-84% similarity with Mycoplasma edwardii ATCC 23462) and one isolate of Mycoplasma yeastsii (100% similarity with M. yeastsii GM274B) were identified. Further, some Mycoplasma species were identified as previously uncultured. The incidence of Mycoplasma infection in camels in Taif city, Saudi Arabia, was approximately 26%. CONCLUSION: This study provides insights into the accuracy and efficiency of PCR and universal primers for the detection and identification of Mycoplasma, thereby circumventing conventional culturing methods that require several days to complete and exhibit low accuracy.