Salmonella enterica (S. enterica) serovars Enteritidis and Typhimurium are the main causes of bacterial gastroenteritis worldwide. This Gram-negative rods bacterium possesses several virulence factors that enable it to survive the host’s nutritional immunity. Toxins and metallophores are among these factors. Heavy metals, in particular, are essential for the survival of all living organisms including bacteria. During infection, S. enterica competes with the host for the available heavy metals by secreting metallophores, which are secondary metabolites. Once produced in the extracellular medium, metallophores complex heavy metals thus allowing Salmonella to acquire metal ions through importing them via channels embedded in their membranes. This review highlights the biosynthesis, export, import, and genetic regulation of different metallophores synthesized by this germ.

Campylobacter spp. are Gram-negative bacilli that are widely recognized as a primary cause of bacterial gastroenteritis worldwide. Campylobacteriosis is the disease caused by this pathogen. Recently, greater attention has been given to the prevalence of campylobacteriosis in different animals, including pets.

Background: This study aimed to investigate the antibacterial and antibiofilm activities of Trifolium purpureum against Escherichia coli. Methods: T. purpureum Loisel. was collected from the mountains of western Lebanon. The plant parts were then extracted by maceration in 70% ethanol and water. The plant fractions were screened for secondary metabolite classes. The antibacterial activity of the extracts was determined using the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Antibiofilm activity was assessed using a colorimetric method, and the effects of T. purpureum extracts on the expression of genes involved in biofilm formation in E. coli were assessed by real-time quantitative polymerase chain reaction (qPCR). Results: Coumarins, tannins, volatile oils, and phenols were absent in T. purpureum; resins were detected only in the flowers, alkaloids were detected in all plant parts except the stems, and saponins, terpenoids, and flavonoids were found in all plant parts. Regarding antibacterial activity, although all extracts had measurable MIC values, only the whole-plant water extract exhibited a bactericidal effect. Furthermore, the water and ethanol extracts exhibited variable biofilm-prevention activity, with minimum biofilm prevention concentration (MBPC) values ranging from 30 to 68.9 mg/mL. Biofilm eradication activity also varied, with minimum biofilm eradication concentration (MBEC) values ranging from 0.13 to 49.65 mg/mL corresponding to 47.3–66.8% eradication. Finally, the whole-plant water extract suppressed the expression of fimA, fimH, and flu in both planktonic cells and cells within established E. coli biofilms. Conclusions: Our results demonstrate that T. purpureum is rich in secondary metabolites and has notable antibacterial and antibiofilm potential against E. coli, especially at the molecular level. These findings suggest that T. purpureum may be a promising candidate for use as an alternative antibacterial and antibiofilm agent.

Background: Respiratory tract infections (RTIs) and urinary tract infections (UTIs) are among the most common infections in humans. It is estimated that millions of deaths occur each year worldwide due to these infections. Pseudomonas aeruginosa (P. aeruginosa), in particular, represents a public health threat since it has a high ability to acquire resistance to different antibiotic classes. The aim of this study was to determine the prevalence and antimicrobial resistance patterns of P. aeruginosa isolates from patients with RTIs and UTIs in Lebanon. Methods: This retrospective study was performed during 2020–2022 and 2024–2025. Samples were collected from both inpatients and outpatients, where identification and isolation of bacteria were performed along with antibiotic susceptibility testing. Results: The overall prevalence of P. aeruginosa isolates in RTI cases over the study period was 10.9%, and that of UTI cases was 1.3%. The general antimicrobial resistance profile of P. aeruginosa isolates from RTI and UTI cases showed the highest resistance for Piperacillin–Tazobactam and Aztreonam, respectively. For RTIs, antibiotic resistance decreased from 48.1% in 2020 to 36.7% in 2025 and increased from 16.7% to 19.4% for UTIs. Conclusions: According to our research, P. aeruginosa with low antibiotic susceptibility is frequently found in isolated samples, highlighting the significant challenge in treating severe infectious illnesses. To choose focused and efficient antibiotic therapy for RTIs and UTIs and to stop the emergence of multidrug-resistant (MDR) bacteria, it is essential to accurately identify the pathogenic microorganisms and their antibiotic susceptibility patterns.