The diversity and beneficial characteristics of endophytic microorganisms have been studied in Plectranthus tenuiflorus medicinal plant. However, information regarding naturally occurring P. tenuiflorus plant associated endophytes among different organs of host is limited. Endophytic bacteria were isolated from root, stem, and leaves of P. tenuiflorus plant. Among 28 endophytic bacterial isolates from different organs of P. tenuiflorus plant, 8 isolates were identified by partial sequencing of their 16S rRNA gene. The isolated endophytic bacteria were Bacillus sp., Bacillus megaterium, Bacillus pumilus, Bacillus licheniformis, Micrococcus luteus, Paenibacillus sp., Pseudomonas sp., and Acinetobacter calcoaceticus. The most isolates that exhibited extracellular enzymatic activity were belonged to the genus Bacillus. Furthermore, Bacillus sp. (HE613660) exhibited the stronger activities in extracellular enzymes such as amylase, esterase, lipase, protease, pectinase, xylanase, and cellulase than other strains. Considerable antimicrobial activities against a panel of human pathogenic microorganisms (Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Streptococcus agalactiae, Proteus mirabilis, and Candida albicans) were recorded using crude extracts of the collected endophytic strains.

We investigated the occurrence and genetic diversity of Trichoderma in the river Danube national park, a primeval, riparian forest area located south-east of Vienna (Austria) which represents one of the last cases of an original European river-floodplain landscape. Forty-six strains were isolated and identified at the species level by analysis of morphological characters, by sequence analysis of their internal transcribed spacer regions 1 and 2 (ITS 1 and 2) of the rDNA cluster and--in some cases--a fragment of the translation elongation factor 1alpha (tef1) gene, and RAPD-analysis. Twenty-one strains were positively identified as T. harzianum, thirteen as T. rossicum, four as T. cerinum, two as T. hamatum, and one each as T. atroviride and T. koningii: four strains yielded two different ITS1 and 2 as well as tef1 sequence types, which were not alignable with any known species. Our studies show that they represent two new taxa of Trichoderma.

This study was carried out to describe the bacterial load and the occurrence of some disease-causing enteric bacteria on raw vegetables sold in Saudi markets. The study further aimed to analyze antibiotic resistance rates, production of extended-spectrum beta lactamase, and plasmid carriage among bacterial population of raw vegetables. Results revealed that none of them contained Bacillus cereus, Salmonella, and Escherichia coli O157:H7. However, Staphylococcus aureus and Shigella were detected in 11.8% and 4.4% of the samples, respectively. The bacterial loads ranged from 3 to 8 log(10) CFUg(-1) for aerobic bacteria and 1 to 4 log(10) CFUg(-1) for coliforms as well as Enterobacteriaceae. The isolates exhibited resistance in decreasing order for ampicillin (76.5%), cephalothin (69.5%), trimethoprime-sulfamethoxazole (36.7%), aminoglycosides (21.9%), tetracycline (17.2%), fluoroquinolones (17.2%), amoxycillin-clavulanic acid (13.3%), and chloramphenicol (7.8%). Maximum resistance to extended-spectrum beta-lactam antibiotics occurred in 14.8% of isolates and the production of extended-spectrum beta-lactamase was achieved by 2.3% of isolates. Multiple resistances to four or more antimicrobial agents along with plasmid with varied sizes were documented. These investigations indicate the occurrence of antibiotic resistance and plasmid carriage among bacterial isolates populating raw vegetables.

The present study was carried out to screen and analyze the genetic characteristics of antibiotic resistance in Escherichia coli strains isolated from chicken meat marketed in the local markets of the Taif region in Saudi Arabia. A total of 119 samples were purchased from various supermarkets and examined for bacterial contamination with resistant E. coli. Thirty-seven E. coli isolates were evaluated for their antibiotic susceptibilities and the presence of class 1 integrons and antibiotic resistance genes. Results of antibiograms revealed that E. coli isolates were resistant to one or more of the antibiotics tested. Resistance was most frequently observed against sulphafurazole (89.2%), ampicillin (78.4%), nalidixic acid (70.3%), streptomycin (48.6%), chloramphenicol (32.4%), and gentamicin (24.3%). Fifteen E. coli strains have multidrug resistance phenotypes and harbored at least three antibiotic resistance genes. The bla(TEM) (beta-lactamase) and sul (sulfonamide) resistance encoding genes were detected in all the tested isolates. Polymerase chain reaction screening detected class 1 integrons in all multiresistant E. coli isolates. The present study provides an assessment of the occurrence of multidrug resistance of E. coli from raw chicken meat collected from local markets.

This study aimed to determine the mycological profile of the retail date fruits distributed in different markets at Taif, Saudi Arabia. The presence of aflatoxins and ochratoxin A was also measured. Twenty-two fungal species belonging to 12 genera were isolated from 50 different date samples. Aspergillus flavus, A. niger, Penicillium chrysogenum, and Rhizopus stolonifer were the most prevalent species among isolated fungi. Eighty isolates of A. flavus and 36 of A. niger were detected for their aflatoxins and ochratoxin production potentials using thin layer chromatography. Toxicity test using Artimia larvae indicated that seven out of 18 A. flavus isolates had aflatoxins potentials, while nine out of 36 isolates of A. niger were ochratoxigenic. The quadruplex polymerase chain reaction using specific primers demonstrated the presence of four genes: nor A, ver 1, omt A, and avf A in seven A. flavus toxigenic isolates. Nine A. niger toxigenic isolates showed positive results for the presence of the PKS gene. In conclusion, the present study highlighted the potential hazards of mycotoxins on human health from consuming raw dates. Rapid molecular detection methods described here might help the food authorities to assure the safety of raw dates distributed in local markets.

Onion bulbs can become contaminated with various molds during the storage period, the most important causal agents being black aspergilli (Aspergillus section Nigri). Taxonomic studies have revealed that this group of Aspergillus contains many species that cannot be reliably identified using standard morphological methods. Therefore, it is necessary to define the fungus causing this problem in the onion exactly, especially since some species assigned to section Nigri are well known as ochratoxin and/or fumonisin producers. Sixty fungal isolates belonging to 10 fungal genera were isolated from 40 onion samples originated from the Taif region in Saudi Arabia. Black aspergilli were detected in 37 onion samples. Using primer pairs (awaspec and Cmd6) designed based on partial calmodulin gene sequence data, 37 isolates were identified as A. welwitschiae. The ochratoxin A and fumonisin B2 contents of the onion samples were examined. No ochratoxins were detected in the collected samples, while fumonisin B2 was detected in 37.5% of the onion samples. Eighteen of 37 isolates of Aspergillus welwitschiae were recognized as potential producers for fumonisin B2. Multiplex polymerase chain reactions designed to detect biosynthetic genes of fumonisins confirmed these results.

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Little is known about the bacterial communities associated with the rose plants inhabiting dry desert ecosystems. The aim of this study was to isolate and characterize endophytic bacteria from different organs of rose plant. Endophytic bacteria were observed in healthy roots, stems, leaves, and flowers of rose plant, with a significantly higher density in roots, followed by stems, leaves, and petals. A total of 38 bacterial endophytes were isolated and are closely related phylogenetically to Acetobacter, Acinetobacter, Methylococcus, Bacillus, Micrococcus, Planococcus by 16S rRNA sequence analysis. Six endophytic bacteria were found to produce IAA, solubilize Ca 3 (PO 4 ) 2 and produce siderophore. The six endophytic bacteria all had the capacity to produce hydrolytic enzyme such as cellulase, xylanase, pectinase, amylase, protease, lipase, and chitinase, but difference existed among these isolates.