Salmonella spp. are major foodborne pathogens transmitted through contaminated poultry products. The emergence of antibiotic-resistant strains complicates treatment and increases the risk of multidrug-resistant (MDR). In Morocco, data on antimicrobial resistance (AMR) profiles in poultry-associated Salmonella remain limited. This study aimed to assess the prevalence and AMR patterns of Salmonella spp. isolated from poultry samples collected in Morocco in 2023. A total of 1339 poultry samples (ceca, turkey, and chicken meat) were collected using a representative stratified sampling approach from slaughterhouses, farms, and retail markets across the 10 regional directorates of Morocco. The isolation of Salmonella spp. was performed according to ISO 6579-1:2017, and identification was confirmed via matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. Antimicrobial susceptibility to 15 antibiotics was evaluated using Sensititre EUVSEC3 plates. Minimum inhibitory concentrations (MICs) were interpreted according to epidemiological cutoff values established by the European Committee on Antimicrobial Susceptibility Testing. MDR was defined as resistance to at least one antimicrobial agent in three or more antibiotic classes. Salmonella spp. were detected in 155 out of the 1339 samples, with an overall prevalence of 11.6% and regional variation. The category-specific prevalence was 13.8% (48/348) for chicken meat, 12.3% (45/367) for turkey meat, and 10.0% (62/624) for cecal samples. Resistance to nalidixic acid (94.2%), ciprofloxacin (92.3%), tetracycline (63.9%), ampicillin (36.8%), trimethoprim (27.7%), chloramphenicol (16.1%), gentamicin (10.3%), cefotaxime (4.5%), amikacin (3.9%), and ceftazidime (0.6%) was detected, whereas resistance to meropenem was not detected. Overall, 69.7% of the isolates were classified as multidrug-resistant and were mainly resistant to quinolones, tetracyclines, and beta-lactams. These findings highlight the need for strengthened antimicrobial stewardship, improved surveillance, and stricter regulation of antibiotic use in poultry production to reduce public health risks.

Antimicrobial resistance (AMR) presents an existential One Health threat. The spread of AMR in arid and semi-arid landscapes is modulated by ecological interactions and exacerbated by endemicity of livestock diseases and poor sanitation in shared human-animal systems leading to misuse of antibiotics. This study characterized the prevalence, resistance patterns, and spatiotemporal variations of AMR in surface water sources in the Maasai Mara Ecosystem (MME), a rapidly changing water-stressed socio-ecological landscape. Employing cross-sectional study design, water samples were collected from 28 water points between April 2024 and May 2025. Cultured Escherichia coli isolates were evaluated for resistance to eight antibiotics, following CLSI susceptibility testing protocols. AMR prevalence was calculated as proportions, with associations between sampling sites and seasons assessed using chi-square. Local clustering of resistant isolates was evaluated using spatial multinomial modelling, while cost-distance analysis against water points identified the proportion of the MME population with limited access to potable water. E. coli was detected in 92.9% water sources, with all isolates resistant to at least one antibiotic. High resistance rates were observed for Penicillin (100%), Amoxicillin (92.6%), Nitrofurantoin (78.6%), and Ceftazidime (52.9%). River samples exhibited higher resistance (51.4%) than open water pans (40.4%). AMR peaked during short-wet and short-dry seasons (51.3%; 51.5% respectively), with seasonal variations being significant (p = 0.04). Multi-drug-resistant isolates (MDR: resistant to ≥3 antibiotic classes) were detected across all seasons, peaking in the short-wet season. MDR relationship between water sources was insignificant across all sampling sites and seasons (p > 0.05). Spatial analysis (p > 0.05) identified two exploratory clusters: Cluster 1 near dense human areas (RR = 0.78) while Cluster 2 in human-livestock-wildlife zones (RR = 1.26). Cost-distance analysis (p < 0.05) revealed one-third of the MME population is at risk of AMR due to limited access to potable water. Our findings reveal widespread distribution of AMR isolates in shared waterpoints, necessitating targeted One Health Quadripartite interventions.

Klebsiella pneumoniae is a leading cause of hospital-acquired infections, particularly in intensive care units (ICUs), where multidrug-resistant (MDR) and hypervirulent strains represent major therapeutic challenges. This study investigated the phenotypic and molecular features of isolates recovered from ICU patients and the hospital environment in Benghazi, Libya. Antimicrobial susceptibility was determined using disk diffusion and the colistin broth disk elution method. Extended-spectrum-β-lactamase (ESBL) and carbapenemase production were assessed phenotypically and confirmed by PCR and sequencing, whereas clonal relatedness was analyzed through OmpK36 typing. Hypervirulence was evaluated using the string test, PCR detection of virulence genes, and biofilm formation assays. A total of 56 isolates (46 clinical and 10 environmental) were included. All isolates were resistant to ceftriaxone, with high resistance rates to ceftazidime, cefotaxime, carbapenems, ciprofloxacin, and gentamicin. ESBL production was observed in 76% of clinical and 80% of environmental isolates, and 95% of all isolates were classified as MDR. A significant proportion of K. pneumoniae isolates (n = 15) exhibited resistance to colistin in the absence of detectable mcr genes. Strong and moderate biofilm production was detected in 30.4% and 17.9% of isolates, respectively. The bla NDM-5 was prevalent among clinical (45/46; 97.8%) and environmental (9/10; 90%) isolates. Similarly, bla CTX-M-15 was detected in 35/46 (76%) clinical isolates and 8/10 (80%) environmental isolates, whereas bla OXA-48 was detected in 26/46 (56.5%) clinical and 10/10 (100%) environmental isolates. A potentially hypervirulent phenotype was observed in 17.8% of the isolates, associated with the virulence genes iucA, iutA, and peg-344. OmpK36 Groups C and D predominated. These results highlight the alarming spread of MDR and hypervirulent strains in ICUs and underscore the need for reinforced infection control strategies.

Multidrug-resistant (MDR) Klebsiella infections represent an increasing therapeutic challenge, underscoring the need for complementary antimicrobial strategies. Essential oils (EOs) are complex mixtures of bioactive compounds, and their antibacterial effects may not be fully explained by their predominant constituents. We compared the antibacterial activity of isolated carvacrol with that of oregano (Origanum vulgare), summer savory (Satureja hortensis), and thyme (Thymus vulgaris) essential oils against MDR Klebsiella isolates and evaluated their ability to enhance conventional antibiotics. Essential oils were chemically characterized by gas chromatography-mass spectrometry (GC-MS). Antibacterial activity was evaluated by agar diffusion, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) assays. Interactions with ceftazidime, gentamicin, and ciprofloxacin were assessed using full checkerboard assays and fractional inhibitory concentration indices (FICIs). Toxicity was evaluated in Galleria mellonella and Tenebrio molitor larvae. GC-MS identified carvacrol as the predominant constituent of oregano (71.47%) and summer savory (48.83%) oils, whereas thyme oil contained low levels of carvacrol (1.83%). Whole oregano and summer savory oils exhibited greater bactericidal activity than isolated carvacrol in several comparisons, despite the high carvacrol content of these oils. Thyme oil also showed substantial antibacterial activity despite its low carvacrol concentration, indicating that activity was not determined solely by carvacrol abundance. Toxicity assays indicated low toxicity for carvacrol, oregano, and thyme oils under the tested conditions, whereas summer savory showed moderate, species-dependent toxicity. Overall, whole essential oils exhibited antibacterial activities that could not be explained solely by their carvacrol content, supporting a contribution of their multicomponent phytochemical composition. Their ability to potentiate conventional antibiotics further supports their potential as complementary antimicrobial agents against MDR Klebsiella. Further studies using purified constituents and defined combinations are warranted to determine the specific mechanisms underlying these effects.