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Candida infections and related mortality have become a challenge to global health. Nontoxic and natural bioactive compounds from plants are regarded as promising candidates to inhibit these multidrug resistant strains. In the present study, in vitro assays and in silico molecular docking approach was combined to evaluate the inhibitory effect of crude extracts from Allium ampeloprasum and its variety A. porrum on Candida pathogens. Phytochemical screening revealed the presence of phenolic acids and flavonoids in higher quantity. Spectral studies of the extracts support the presence of phenols, flavonoids and organosulfur compounds. Aqueous extract of A. ampeloprasum showed a total antioxidant capacity of 68 ± 1.7 mg AAE/ g and an IC 50 value of 0.88 ± 2.1 mg/ml was obtained for DPPH radicals scavenging assay. C. albicans were highly susceptible (19.9 ± 1.1 mm) when treated with aqueous A. ampeloprasum extract. Minimum inhibitory concentrations were within the range of 19–40 μg/ml and the results were significant (p ≤ 0.05). In silico molecular docking studies demonstrated that bioactive phytocompounds of A. ampeloprasum and A. porrum efficiently interacted with the active site of Secreted aspartyl proteinase 2 enzyme that is responsible for the virulence of pathogenic yeasts. Rosmarinic acid and Myricetin exhibited low binding energies and higher number of hydrogen bond interactions with the protein target. Thus the study concludes that A. ampeloprasum and A. porrum that remain as underutilized vegetables in the Allium genus are potential anti-candida agents and their pharmacologically active compounds must be considered as competent candidates for drug discovery.

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Using 16S rDNA gene sequencing technique, three different species of non-symbiotic bacteria of entomopathogenic nematodes (EPNs) (Steinernema sp. and Heterorhabditis sp.) were isolated and identified from infected insect cadavers (Galleria mellonella larvae) after 48-hour post infections. Sequence similarity analysis revealed that the strains SRK3, SRK4 and SRK5 belong to Ochrobactrum cytisi, Schineria larvae and Ochrobactrum anthropi, respectively. The isolates O. anthropi and S. larvae were found to be associated with Heterorhabditis indica strains BDU-17 and Yer-136, respectively, whereas O. cytisi was associated with Steinernema siamkayai strain BDU-87. Phenotypically, temporal EPN bacteria were fairly related to symbiotic EPN bacteria (Photorhabdus and Xenorhabdus genera). The strains SRK3 and SRK5 were phylogeographically similar to several non-symbionts and contaminated EPN bacteria isolated in Germany (LMG3311T) and China (X-14), while the strain SRK4 was identical to the isolates of S. larvae (L1/57, L1/58, L1/68 and L2/11) from Wohlfahrtia magnifica in Hungary. The result was further confirmed by RNA secondary structure and minimum energy calculations of aligned sequences. This study suggested that the non-symbionts of these nematodes are phylogeographically diverged in some extent due to phase variation. Therefore, these strains are not host-dependent, but environment-specific isolates.