In contemporary times, the sustained aspiration of bioengineering and biomedical applications is the progressive advancement of materials characterized by biocompatibility and biodegradability. The investigation of the potential applications of polymers as natural and non-hazardous materials has placed significant emphasis on their physicochemical properties. Thus, this study was designed to investigate the potential of gelatin–chitosan–moringa leaf extract (G–CH–M) as a novel biomaterial for biomedical applications. The wound-dressing G–CH–M biopolymer was synthesized and characterized. The blood haemolysis, anti-inflammatory, antioxidant, and antibacterial activities of the biopolymer were investigated against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacterial isolates. Our results showed that S. aureus swarming motility was drastically affected. However, the biopolymer had no significant effect on the swarming motility of E. coli. In addition, the biopolymer showed high antibacterial capacities, especially against S. aureus. Plasmid DNA was observed to be effectively protected from oxidative stresses by the biopolymer. Furthermore, the biopolymer exhibited greatly suppressed haemolysis (lower than 2%), notwithstanding the elevated concentration of 50 mg/mL. These results indicated that this novel biopolymer formulation could be further developed for wound care and contamination prevention.

Camels (Camelus dromedarius) are known to harbor multidrug resistant Gram-negative bacteria and to be involved in the transmission of various microorganisms to humans. Data on the occurrence of colistin resistant Escherichia coli as well as mobilized colistin resistance (mcr) genes in camels are lacking. We investigated the presence of colistin resistance and mcr (1–2) genes in E. coli from the feces of camels in Tunisia. Presumptive E. coli isolates from camel-calves in southern Tunisia were qualitatively screened for growth on Mueller–Hinton agar supplemented with 2 mg/L of colistin. The minimal inhibitory concentration of colistin was determined for isolates growing on this medium. All isolates were screened for the presence of the mcr-1 and mcr-2 genes by polymerase chain reaction without detecting any of these genes. However, one isolate was confirmed resistant to colistin and further testing of this isolate revealed it to be Enterobacter cloacae. Our study demonstrated absence of colistin resistance and of the mcr-1 and mcr-2 genes in E. coli isolated from camel feces in southern Tunisia. Thus, there is no evidence that camels represent a major source of mcr genes contamination for the local population or for tourists visiting southern Tunisia.

Healthy animals can constitute a reservoir forEscherichia colipotentially dangerous for humans. Our objectives were to investigate virulence genes inE. coliisolated from healthy animals in southern Tunisia and to determine their resistance to antimicrobials of high importance in humans and animals. 126 fecal samples were collected from healthy animals (cattle, sheep, goats, chicken, camel, bustard and rabbit) and assayed by PCR for virulence genes and by disk diffusion for antimicrobial resistance. STEC were isolated most frequently from goats (27.7%), sheep (20%) and cattle (14.2%). ExPEC prevalence ofiucD(41.6%),papC(27.7%),sfa(13.8%),afa8(13.8%) andiron(72.2%) was highest in camels. Prevalence of the ExPEC associated genesissandcnfand the EPEC defining geneeaewas highest in rabbits (53.3, 13.3, and 53.3%, respectively). The genes defining enterotoxigenic, enteroinvasive and enteroaggregativeE. coliwere not detected andfaeGwas found only in camels (5.5%). The most common phylogenetic groups were B1 (54.5%) and B2 (16.6%). Virulence gene profiles varied greatly between animal species. Overall, antimicrobial resistance was not highly prevalent, the highest resistance being observed against tetracycline, 43.9%.

Biological polymers such as tissue-engineered scaffolds and skin grafts with improved properties are very required in the pharmaceutical field. The wound-dressing gelatin/chitosan/moringa leaf extract (G-CH-M biopolymer) was synthesised and characterised. The blood compatibility, anti-inflammatory, antioxidant, and antibacterial activities of the biopolymer were investigated. Our results showed that S. aureus swarming motility was drastically affected. However, the biopolymer had no significant effect on the swarming motility of E. coli compared to the control. In addition, biopolymers showed high antibacterial capacities, especially against S. aureus. The biopolymer was also found to be effective in protecting plasmid DNA against oxidative stress. Furthermore, the biopolymer exhibits greatly suppressed hemolysis (lower than 2%), even at a high concentration of 50 mg/mL. These results indicated that this novel biopolymer formulation could be further developed for wound care and contamination prevention.