Biology subjects

Ibrahim, I.

Publications and source records attributed to Ibrahim, I..

4 recordsLinked to original sources

bioRxiv2023

Understanding the Mechanisms of Salmonella Typhimurium resistance to Cannabidiol

The emergence of multidrug resistance poses a huge risk to public health globally. Yet these recalcitrant pathogens continue to rise in incidence rate with resistance rates significantly outpacing the speed of antibiotic development. This therefore presents an aura of related health issues such as untreatable nosocomial infections arising from organ transplants, surgeries, as well as community acquired infections that are related to people with compromised immunity e.g., diabetic and HIV patients etc. There is a global effort to fight multidrug resistant pathogens spearheaded by the World Health Organization, thus calling for research into novel antimicrobials agents to fight multiple drug resistance. Previously, our laboratory demonstrated that Cannabidiol (CBD) was an effective antimicrobial against Salmonella Typhimurium (S. Typhimurium). However, we observed resistance development over time. To understand the mechanisms S. Typhimurium uses to develop resistance to Cannabidiol (CBD), we studied the abundance of bacteria lipopolysaccharide (LPS) and membrane sterols of both susceptible and resistant S. Typhimurium. Using real-time quantitative polymerase chain reaction (rt qPCR), we also analyzed the expression of selected genes known for aiding resistance development in S. Typhimurium. We discovered that there was a significantly higher expression of blaTEM, fimA, fimZ, and integrons in the CBD-resistant bacteria, and these were also accompanied by a shift in abundance in cell surface molecules such as lipopolysaccharide (LPS) and sterols.

microbiology↗

bioRxiv2023

Erythropoietic, hematinic and leucocytic activities of the aqueous extracts of the fruits and leaves of Solanum torvum

The Turkey berry (Solanum torvum) plant is globally exploited for its medicinal and pharmacological benefits. This study was conducted to investigate the erythropoietic, hemanitic and leucocytic activities of the aqueous extracts of the fruits and leaves of Solanum torvum. Three groups of rabbits with five replicates each (aged 6-8 weeks) where either given the aqueous extracts of fresh turkey berry fruits, fresh turkey berry leafs, or distilled water at a dose of 0.5ml and a concentration of 100g of leaf or fruit against 100ml of distilled water (1g per 1ml of distilled water) per day over a six-week period. The rabbits were fed ad libitum with concentrate and water throughout the experimental period. A full blood count (FBC) using a BC 2600 hematology analyzer was conducted on the collected blood samples of the experimental animals at the end of the sixth week of extract administration. The blood samples of the rabbits given the aqueous extracts of the fruit and leaf of turkey berry at the end of the six weeks of treatment administration showed a significant (p<0.05) increase in red blood cell count, hemoglobin level, white blood cell count and hematocrit. The results indicated that Solanum torvum had a positive erythropoietic, hemanitic and leucocytic properties. This implies that Solanum torvum is effective in improving the quality of blood and hence can prevent some hematological disorders.

developmental biology↗

bioRxiv2022

CBD resistant Salmonella strains are susceptible to Epsilon 34 phage tailspike protein

The rise of antimicrobial resistance is a global public health crisis that threatens the effective control and prevention of infections. Due to the emergence of pandrug-resistant bacteria, most antibiotics have lost their efficacy. Meanwhile, the development of new antimicrobials has stagnated, which leads to the creation of new and unconventional treatments. Bacteriophages or their components are known to target bacterial cell walls, cell membranes, and lipopolysaccharides (LPS) and hydrolyze them. Bacteriophages being the natural predators of pathogenic bacteria, are inevitably categorized as "human friends", thus fulfilling the adage that "the enemy of my enemy is my friend". Leveraging on their lethal capabilities against pathogenic bacteria, researchers are searching for more ways to overcome the current antibiotic resistance challenge. Bacteriophages are considered to be one of the most effective alternative therapies for multidrug resistant bacteria. In this study, we expressed and purified epsilon 34 phage tailspike protein (E34 TSP) from the E34 TSP gene which was previously cloned into a pET30a-LIC vector, then assessed the ability of this bacteriophage protein in the killing of two CBD-resistant strains of Salmonella spp. We observed that the combined treatment of CBD-resistant strains of Salmonella with CBD and E34 TSP showed poor killing ability whereas the monotreatment with E34 TSP showed considerably higher killing efficiency.

microbiology↗

bioRxiv2022

An ERAD-independent role for rhomboid pseudoprotease Dfm1 in mediating sphingolipid homeostasis

Nearly one-third of nascent proteins are initially targeted to the endoplasmic reticulum (ER) where they are correctly folded and assembled before being delivered to their final cellular destinations. To prevent the accumulation of misfolded membrane proteins, ER-associated-degradation (ERAD) removes these clients from the ER membrane to the cytosol in a process known as retrotranslocation. Our recent work demonstrates that rhomboid pseudoprotease, Dfm1, is involved in the retrotranslocation of ubiquitinated integral membrane ERAD substrates. To survey for potential interaction partners of Dfm1, we performed protein-proximity labeling by BioID (proximity-dependent biotin identification) followed by mass spectrometry and identified several interacting proteins known to play a role in the sphingolipid biosynthesis pathway. Specifically, we found that Dfm1 physically interacts with the SPOTS complex, which is composed of serine palmitoyltransferase (SPT) enzymes and accessory components and is critical for catalyzing the first rate-limiting step of the sphingolipid biosynthesis pathway. We demonstrate for the first time that Dfm1 has a role in ER export, a function that is independent of Dfm1s canonical ERAD retrotranslocation function. Specifically, we show that loss of Dfm1 results in the accumulation of phosphorylated Orm2 at the ER, suggesting a novel role for Dfm1 in controlling Orm2 export from the ER and its subsequent degradation by EGAD. Moreover, recruitment of Cdc48 by Dfm1, which is critical for its role in ERAD retrotranslocation, is dispensable for Dfm1s role in ER export. Given that the accumulation of human Orm2 homologs, ORMDLs, are associated with many maladies, our study serves as a molecular foothold for understanding how dysregulation of sphingolipid metabolism leads to various diseases.

cell biology↗