Kaempferol mitigates reproductive dysfunctions induced by Naja nigricollis venom through antioxidant system and anti-inflammatory response in male rats.

Naja nigricollis Venom (NnV) contains complex toxins that affects various vital systems functions after envenoming. The venom toxins have been reported to induce male reproductive disorders in envenomed rats. This present study explored the ameliorative potential of kaempferol on NnV-induced male reproductive toxicity. Fifty male wistar rats were sorted randomly into five groups (n = 10) for this study. Group 1 were noted as the control, while rats in groups 2 to 5 were injected with LD50 of NnV (1.0 mg/kg bw; i.p.). Group 2 was left untreated post envenomation while group 3 was treated with 0.2 ml of polyvalent antivenom. Groups 4 and 5 were treated with 4 and 8 mg/kg of kaempferol, respectively. NnV caused substantial reduction in concentrations of follicle stimulating hormone, testosterone and luteinizing hormone, while sperm motility, volume and counts significantly (p < 0.05) decreased in envenomed untreated rats. The venom enhanced malondialdehyde levels and substantially decreased glutathione levels, superoxide dismutase and glutathione peroxidase activities in the testes and epididymis of envenomed untreated rats. Additionally, epididymal and testicular myeloperoxidase activity and nitric oxide levels were elevated which substantiated severe morphological defects noticed in the reproductive organs. However, treatment of envenomed rats with kaempferol normalized the reproductive hormones with significant improvement on sperm functional parameters. Elevated inflammatory and oxidative stress biomarkers in testis and epididymis were suppressed post kaempferol treatment. Severe histopathological lesions in the epididymal and testicular tissues were ameliorated in the envenomed treated groups. Results highlights the significance of kaempferol in mitigating reproductive toxicity induced after snakebite envenoming.

The Polycyclic Aromatic Hydrocarbon (PAH) degradation activities and genome analysis of a novel strain Stenotrophomonas sp. Pemsol isolated from Mexico.

BACKGROUND: Stenotrophomonas are ubiquitous gram-negative bacteria, which can survive in a wide range of environments. They can use many substances for their growth and are known to be intrinsically resistant to many antimicrobial agents. They have been tested for biotechnological applications, bioremediation, and production of antimicrobial agents. METHOD: Stenotrophomonas sp. Pemsol was isolated from a crude oil contaminated soil. The capability of this isolate to tolerate and degrade polycyclic aromatic hydrocarbons (PAH) such as anthraquinone, biphenyl, naphthalene, phenanthrene, phenanthridine, and xylene was evaluated in Bushnell Hass medium containing PAHs as the sole carbon sources. The metabolites formed after 30-day degradation of naphthalene by Pemsol were analyzed using Fourier Transform Infra-red Spectroscopic (FTIR), Ultra-Performance Liquid Chromatography-Mass Spectrometry (UPLC-MS) and Gas Chromatography-Mass Spectrometry (GC-MS). The genome of Pemsol was also sequenced and analyzed. RESULTS: Anthraquinone, biphenyl, naphthalene, phenanthrene, and phenanthridine except xylene can be used as sole carbon sources for Pemsol's growth in Bushnell Hass medium. The degradation of naphthalene at a concentration of 1 mg/mL within 30 days was tested. A newly formed catechol peak and the disappearance of naphthalene peak detected on the UPLC-MS, and GC-MS analyses spectra respectively confirmed the complete degradation of naphthalene. Pemsol does not produce biosurfactant and neither bio-emulsify PAHs. The whole genome was sequenced and assembled into one scaffold with a length of 4,373,402 bp. A total of 145 genes involved in the degradation of PAHs were found in its genome, some of which are Pemsol-specific as compared with other 11 Stenotrophomonas genomes. Most specific genes are located on the genomic islands. Stenotrophomonas sp. Pemsol's possession of few genes that are associated with bio-emulsification gives the genetic basis for its inability to bio-emulsify PAH. A possible degradation pathway for naphthalene in Pemsol was proposed following the analysis of Pemsol's genome. ANI and GGDH analysis indicated that Pemsol is likely a new species of Stenotrophomonas. It is the first report on a complete genome sequence analysis of a PAH-degrading Stenotrophomonas. Stenotrophomonas sp. Pemsol possesses features that make it a good bacterium for genetic engineering and will be an excellent tool for the remediation of crude oil or PAH-contaminated soil.

Complete Genome Sequence of Stenotrophomonas maltophilia Strain SVIA2, Isolated from Crude Oil-Contaminated Soil in Tabasco, Mexico.

Stenotrophomonas maltophilia strain SVIA2 was isolated from crude oil-contaminated soil from Tabasco, Mexico, and displayed a good potential for the degradation of polycyclic aromatic hydrocarbons (PAHs), using naphthalene, anthracene, phenanthridine, or biphenyl as the unique source of carbon. The SVIA2 genome contains essential genes involved in the degradation of PAHs.

Whole-Genome Sequencing and Comparative Genome Analysis Provided Insight into the Predatory Features and Genetic Diversity of Two Bdellovibrio Species Isolated from Soil.

Bdellovibrio spp. are predatory bacteria with great potential as antimicrobial agents. Studies have shown that members of the genus Bdellovibrio exhibit peculiar characteristics that influence their ecological adaptations. In this study, whole genomes of two different Bdellovibrio spp. designated SKB1291214 and SSB218315 isolated from soil were sequenced. The core genes shared by all the Bdellovibrio spp. considered for the pangenome analysis including the epibiotic B. exovorus were 795. The number of unique genes identified in Bdellovibrio spp. SKB1291214, SSB218315, W, and B. exovorus JJS was 1343, 113, 857, and 1572, respectively. These unique genes encode hydrolytic, chemotaxis, and transporter proteins which might be useful for predation in the Bdellovibrio strains. Furthermore, the two Bdellovibrio strains exhibited differences based on the % GC content, amino acid identity, and 16S rRNA gene sequence. The 16S rRNA gene sequence of Bdellovibrio sp. SKB1291214 shared 99% identity with that of an uncultured Bdellovibrio sp. clone 12L 106 (a pairwise distance of 0.008) and 95-97% identity (a pairwise distance of 0.043) with that of other culturable terrestrial Bdellovibrio spp., including strain SSB218315. In Bdellovibrio sp. SKB1291214, 174 bp sequence was inserted at the host interaction (hit) locus region usually attributed to prey attachment, invasion, and development of host independent Bdellovibrio phenotypes. Also, a gene equivalent to Bd0108 in B. bacteriovorus HD100 was not conserved in Bdellovibrio sp. SKB1291214. The results of this study provided information on the genetic characteristics and diversity of the genus Bdellovibrio that can contribute to their successful applications as a biocontrol agent.

Isolation of Bdellovibrio sp. from soil samples in Mexico and their potential applications in control of pathogens.

In this study, two strains of Bdellovibrio were isolated from soil samples using the culture-dependent technique and two members of the family Enterobacteriaceae (Klebsiella sp. and Salmonella sp.) as prey. The Bdellovibrio strains were bacteriolytic, plaque-forming, and highly motile gram-negative bacteria. We identified and confirmed the Bdellovibrio strains using microscopy, PCR amplification, and sequencing of the 16S rRNA gene. They were observed to be different strains based on hit locus and prey range analyses. Here, the first report on Bdellovibrio strains isolated from soil in Mexico corroborates earlier report indicating that populations of Bdellovibrio found in soil are heterogeneous thereby the need to identify the various strains.