Saleh A. Kabli

Co-circulation of three camel coronavirus species and recombination of MERS-CoVs in Saudi Arabia

Coronaviruses in the Middle East Middle East respiratory syndrome coronavirus (MERS-CoV) causes severe acute respiratory illness and kills about a third of people infected. The virus is common in dromedary camels, which can be a source of human infections. In a survey for MERSCoV in over 1300 Saudi Arabian camels, Sabir et al. found that dromedaries share three coronavirus species with humans. Diverse MERS lineages in camels have caused human infections, which suggests that transfer among host species occurs quite easily. Haagmans et al. made a MERS-CoV vaccine for use in camels, using poxvirus as a vehicle. The vaccine significantly reduced virus excretion, which should help reduce the potential for transmission to humans, and conferred cross-immunity to camelpox infections. Science, this issue p. 81, p. 77 Several camel coronaviruses occur in the Middle East, and a recombinant lineage is linked to the recent human outbreaks of MERS. Outbreaks of Middle East respiratory syndrome (MERS) raise questions about the prevalence and evolution of the MERS coronavirus (CoV) in its animal reservoir. Our surveillance in Saudi Arabia in 2014 and 2015 showed that viruses of the MERS-CoV species and a human CoV 229E–related lineage co-circulated at high prevalence, with frequent co-infections in the upper respiratory tract of dromedary camels. viruses of the betacoronavirus 1 species, we found that dromedary camels share three CoV species with humans. Several MERS-CoV lineages were present in camels, including a recombinant lineage that has been dominant since December 2014 and that subsequently led to the human outbreaks in 2015. Camels therefore serve as an important reservoir for the maintenance and diversification of the MERS-CoVs and are the source of human infections with this virus.

Solid state production of polygalacturonase and xylanase by Trichoderma species using cantaloupe and watermelon rinds

Different solid state fermentation (SSF) sources were tested such as cantaloupe and watermelon rinds, orange and banana peels, for the production of polygalacturonase (PG) and xylanase (Xyl) by Trichoderma harzianum and Trichoderma virens. The maximum production of both PG and Xyl were obtained by T. harzianum and T. virnes grown on cantaloupe and watermelon rinds, respectively. Time course, moisture content, temperature, pH, supplementation with carbon and nitrogen sources were optimized to achieve the maximum production of both PG and Xyl of T. harzianum and T. virens using cantaloupe and watermelon rinds, respectively. The maximum production of PG and Xyl of T. harzianum and T. virens was recorded at 4–5 days of incubation, 50–66% moisture, temperature 28–35°C and pH 6–7. The influence of supplementary carbon and nitrogen sources was studied. For T. harzianum, lactose enhanced PG activity from 87 to 120 units/g solid, where starch and maltose enhanced Xyl activity from 40 to 55–60 units/g solid for T. virnes. Among the nitrogen sources, ammonium sulphate, ammonium nitrate, yeast extract and urea increased PG activity from 90 to 110–113 units/g solid for T. harzianum. Similarly, ammonium chloride, ammonium sulphate and yeast extract increased Xyl activity from 45 to 55–70 units/g solid for T. virens.

Metabolomic Profiling of 13 Diatom Cultures and Their Adaptation to Nitrate-Limited Growth Conditions

Diatoms are very efficient in their use of available nutrients. Changes in nutrient availability influence the metabolism and the composition of the cell constituents. Since diatoms are valuable candidates to search for oil producing algae, measurements of diatom-produced compounds can be very useful for biotechnology. In order to explore the diversity of lipophilic compounds produced by diatoms, we describe the results from an analysis of 13 diatom strains. With the help of a lipidomics platform, which combines an UPLC separation with a high resolution/high mass accuracy mass spectrometer, we were able to measure and annotate 142 lipid species. Out of these, 32 were present in all 13 cultures. The annotated lipid features belong to six classes of glycerolipids. The data obtained from the measurements were used to create lipidomic profiles. The metabolomic overview of analysed cultures is amended by the measurement of 96 polar compounds. To further increase the lipid diversity and gain insight into metabolomic adaptation to nitrogen limitation, diatoms were cultured in media with high and low concentrations of nitrate. The growth in nitrogen-deplete or nitrogen-replete conditions affects metabolite accumulation but has no major influence on the species-specific metabolomic profile. Thus, the genetic component is stronger in determining metabolic patterns than nitrogen levels. Therefore, lipid profiling is powerful enough to be used as a molecular fingerprint for diatom cultures. Furthermore, an increase of triacylglycerol (TAG) accumulation was observed in low nitrogen samples, although this trend was not consistent across all 13 diatom strains. Overall, our results expand the current understanding of metabolomics diversity in diatoms and confirm their potential value for producing lipids for either bioenergy or as feed stock.

Chitinolytic enzyme production and genetic improvement of a new isolate belonging to Streptomyces anulatus

Thirty bacterial isolates were obtained from different sources and sites at Jeddah, Saudi Arabia, on chitin agar medium; 9 of the 30 isolates were cultured in liquid medium containing chitin as sole carbon and nitrogen sources. Isolate SM21, which was isolated from shrimp shells, showed the best growth and chitinase production in liquid medium. According to its morphological, physiological and biochemical characteristics, SM21 belongs to the genus Streptomyces and was identified as Streptomyces anulatus SM21. Identification was confirmed using 16S rDNA analysis. The chitinase enzyme was precipitated with 80% NH4SO4 and purified using DEAE-cellulose ion exchange chromatography followed by Sephadex G-100 gel filtration. The molecular weight determined using sodium dodecyl sulfate polyacrylamide gel electrophoresis was 28 kDa. Genetic improvement using the protoplast fusion technique was carried out between the identified Streptomyces isolate and Streptomyces coelicolor SM1. These two species, which have different resistance profiles to streptomycin and tetracycline (400 μg/ml and 10 μg/ml, respectively), were used in an intraspecific protoplast fusion using PEG 6000. The percentage of real protoplasts that could regenerate successfully was 71% for S. coelicolor SM1 and 80% for S. anulatus SM21. Out of three recombinant fusants obtained, one (named Fu3) showed higher chitinase production compared to both parents (5 fold increase).

Mycoflora Associated with Some Textiles in Jeddah City

تم عزل الفطريات المصاحبة لثمانية أنواع مختلفة من المنسوجات ( ألياف طبيعية ، وصناعية وخليط) جمعت من مراكز تسويقية في مدينة جدة بالمملكة العربية السعودية. وقد تم استخدام طرق التلامس ، والتخفيف ، والتجانس، والترطيب في عزل وتقدير أعداد وتعريف الفطريات المصاحبة للمنسوجات.وقد تم الحصول على ثلاث وعشرين عزلة فطرية، شكلت أنواع الأسبر جللس نسبة 35% متبوعة بأنواع البنيسيليا والفيوزاريا بنسبة 13% لكل منها. وقد سجلت أعلى أعداد الفطريات على منسوجات القطن ( حتى عندما كانت مخلوطة) حيث بلغت 1932 مستعمرة لكل سم2. جاءت بعدها منسوجات الصوف، بأعداد بلغت 1421 مستعمرة لكل سم2. وفي حين أظهرت منسوجات الحرير قابلية أقل للإصابة بالفطريات، كانت الأعداد الفطرية في منسوجات البوليستر متوسطة الكثافة. كذلك تم اختبار تأثير بعض الظروف البيئية ( مثل الحرارة والوسط الغذائي ودرجة الحموضة والرطوبة النسبية ) على النمو الفطري لعشر من الفطريات المعزولة المعرفوة بإحداث بعض الأضرار للإنسان وهي Alternaria alternata, Aspergillus flavus, A. fumigatus, A. niger, Fusarium oxysporium, Geotrichum sp., Gliocladium atrum, Penicillium chrysogenum, Rhizopus nigricans, Trichoderma viride ولقد أظهرت دراسة الأنشطة الإنزيمية للسليوليز والبروتييز تفوق T.viride و Geotrichm sp. و A. nger و A. alternate و P. chry- sogemum. كما أوضحت دراسة النشاط التضادي لنوعين من المنظفات التباين في درجة التأثير على الفطريات المختبرة حسب نوع وتركيز المنظف.

Molecular and serotyping characterization of shiga toxogenic Escherichia coli associated with food collected from Saudi Arabia.

Shiga toxin-producing Escherichia coli (STEC) strains are considered as one of the major food-borne disease agents in humans worldwide. STEC strains, also called verotoxin-producing E. coli strains. The objectives of the present study were serotyping and molecular characterization of shiga toxigenic E. coli associated with raw meat and milk samples collected from Riyadh, Saudi Arabia. A total of 540 milk samples were collected from 5 dairy farms and 150 raw meat samples were collected from different abattoirs located in Riyadh, Saudi Arabia. E. coli were recovered from 86 milk samples (15.93%), serotyping of E. coli isolates revealed, 26 (4.81%) strains O157: H7, 23 (4.26%) strains O111, 20 (3.70%) strains O113: H21, 10 (1.85%) strains O22: H8 and 7 (1.3%) strains O172: H21. Meanwhile, 17 (11.33%) strains of E. coli were recovered from raw meat samples, serotyping of E. coli isolates revealed, 6 (4%) strains O157: H7, 5 (3.33%) strains O111 and 4 (2.67%) strains O174: H2 and only two (1.33%) strains were identified as O22: H8. Shiga toxin2 was detected in 58 (67.44%) serotypes of E. coli recovered from milk samples and 16 (94.12%) serotypes of E. coli recovered from meat samples, while intimin gene was detected in 38 (44.186%) serotypes of E. coli recovered from milk samples and in 10 (58.82%) serotypes of E. coli recovered from meat samples. The results of this study revealed the efficiency of combination between serotyping and molecular typing of E. coli isolates recovered from food of animal origin for rapid detection and characterization of STEC.

Vaccination against Corynebacterium pseudotuberculosis infections controlling caseous lymphadenitis (CLA) and oedematousskin disease

Corynebacterium pseudotuberculosis (C. pseudotuberculosis) is a causative organism of caseous lymphadenitis (CLA) in sheep and acute disease in buffaloes known as oedematous skin disease (OSD). Human affected with the disease show liver abscess and abscess in the internal lymph nodes. The vaccination against CLA up till now occurs by using formalin inactivated whole cells of biovar 1 (sheep strain). Combined vaccine composed of formalin inactivated whole cells of sheep strain and recombinant phospholipase D (rPLD) and another vaccine composed of formalin inactivated whole cells (buffalo origin) and rPLD were prepared in Biotechnology center for services and Researches laboratory at Cairo university and applied for protection against CLA. Both vaccines induced complete protection (100%) against challenge with virulent biovar 1 or biovar 2. Also vaccination against OSD was performed by two types of vaccines. Vaccine-1 was composed of formalin inactivated whole cell biovar 1 combined with rPLD and the second vaccine was composed of formalin inactivated whole cells of biovar 2 combined with rPLD. No lesions developed in vaccinated and non vaccinated buffaloes challenged with C. pseudotuberculosis biovar revealing that biovar 1 C. pseudotuberculosis is not infective for buffaloes. Buffaloes vaccinated with the second vaccine and control non vaccinated animals challenged with biovar 2 (buffalo origin) resulted in development of OSD in all animals. This indicates that OSD results due to production of toxin (s) other than PLD. Discovering this toxin (s) is of value in formulation of a future vaccine against OSD.

Recent approaches for control of E. coli and respiratory complex in Middle East

This study was conducted on 100 one-day-old broiler chicks to evaluate the effect of Poulvac E. coli vaccine in reduction of clinical signs and complications after concurrent infectious bronchitis virus (variant 02) and virulent E. coli O78 challenges. The birds were evaluated for clinical signs, mortality for 7 days post-infection, PM lesion score, average body weight and serological evaluation. Re-isolation and RT-PCR for the challenging infectious bronchitis virus (IBV) variant 02 were conducted thereafter. The results showed that the Poulvac E. coli at one-day old chicks in the presence of co-infection with virulent E. coli and IBV variant 02 provides better body weight gain at 35 days than the other groups. The challenge with IBV variant 02 alone in non-vaccinated birds doesn’t give any mortality; this indicated that the severity of IBV variant 02 increased by the presence of co-infection with Avian Pathogenic E. coli (APEc). The mortality percentage associated with both E. coli and IBV variant 02 infections in the none vaccinated group by Poulvac E. coli was 25% while this percentage was 10% of the vaccinated group. The Poulvac E. coli is not negatively affecting the immune response against different concurrent viral vaccines like Infectious bursal disease (IBD), and moreover, it improves the immune response against some others like Newcastle disease virus (NDV), Avian Influenza (AI) H5 and IBV.

Isolation of antimicrobial producing Actinobacteria from soil samples

Emergence of multidrug resistant bacteria has made the search for novel bioactive compounds from natural and unexplored habitats a necessity. Actinobacteria have important bioactive substances. The present study investigated antimicrobial activity of Actinobacteria isolated from soil samples of Egypt. One hundred samples were collected from agricultural farming soil of different governorates. Twelve isolates have produced activity against the tested microorganisms (S. aureus, Bacillus cereus, E. coli, K. pneumoniae, P. aeruginosa, S. Typhi, C. albicans, A. niger and A. flavus). By VITEK 2 system version: 07.01 the 12 isolates were identified as Kocuria kristinae, Kocuria rosea, Streptomyces griseus, Streptomyces flaveolus and Actinobacteria. Using ethyl acetate extraction method the isolates culture’s supernatants were tested by diffusion method against indicator microorganisms. These results indicate that Actinobacteria isolated from Egypt farms could be sources of antimicrobial bioactive substances.

Solid-state fermentation by Trichoderma viride for enhancing phenolic content, antioxidant and antimicrobial activities in ginger

The phenolic content of methanol and water extracts of ginger fermented by Trichoderma spp. using solid‐state fermentation (SSF) was evaluated and was compared with unfermented ginger. The total phenolic content in fermented ginger increased several times. The highest phenolic content in ginger was detected after SSF by T. viride. The optimal physiological conditions for the maximum production of phenolic compounds and β‐glucosidase activity of fermented ginger by T. viride were detected at day 7 incubation, pH 6·0, 30°C and 30% moisture. The SSF of ginger by T. viride greatly enhanced the antioxidant potency of phenolic compounds and was evaluated using DPPH and ABTS assays. A potent antibacterial activity of the phenolic compounds of fermented ginger was observed against all the tested human‐pathogenic bacteria.