Proteus mirabilis (P. mirabilis), a common commensal and opportunistic pathogen, circulates freely across interconnected human, animal, and environmental reservoirs, embodying the One Health concept. Its key virulence factors—urease activity, swarming motility, and biofilm formation—drive severe urinary tract infections, particularly catheter-associated ones. These virulence traits concurrently facilitate the acquisition and dissemination of antimicrobial resistance (AMR) via mobile genetic elements, leading to extensively drug-resistant clones. Epidemiological and genomic evidence confirms that identical multidrug-resistant clones and resistance mechanisms (ESBLs, carbapenemases) are shared among human clinical isolates, livestock, food products, and environmental samples. This demonstrates continuous, multi-directional transmission through interconnected zoonotic, foodborne, and environmental pathways. The synergistic convergence of potent virulence and escalating AMR within shared reservoirs heightens public health risks. Effective containment therefore demands integrated One Health strategies: enhanced cross-sectorial surveillance, stringent antimicrobial stewardship, robust infection control, and the creation of novel treatments. A coordinated global response is crucial to curb the spread of resistant P. mirabilis and preserve antibiotic efficacy.

Pathogenic Escherichia coli is one of the world's most important zoonotic foodborne pathogens and poses a serious threat to public health. We examined the prevalence, virulence genes, and antibiotic resistance profile of Shiga toxin (Stx)-producing E. coli (STEC) isolated from broiler chickens in the Kafr El-Sheikh governorate, Egypt. A total of 410 samples (230 cloacal swabs, 180 internal organs) were collected to isolate E. coli. A total of 29 (7.07%) E. coli isolates were recovered and identified, and 18 of them harbored Stx genes (stx). Out of 18 isolates, five (17.24%) carried the stx1 gene, five (17.24%) carried the stx2 gene, four (13.79%) carried both stx1 and stx2 genes, and four (13.79%) carried stx1, stx2, and eaeA genes. Overall, complete anti-biotic resistance was observed against amoxicillin, ampicillin, cefpodoxime, and cefoperazone; high resistance was observed against ampicillin/sulbactam, nalidixic acid, cefuroxime, aztreonam, ciprofloxacin, ceftriaxone, chloramphenicol, sulfamethoxazole/trimethoprim, and ceftazidime; moderate resistance against gentamicin; low resistance against cefoxitin; lower resistance was detected against norfloxacin, cefotetan, and amikacin; and the lowest resistance against imipenem. All E. coli isolates demonstrated multidrug resistance against at least four antibiotic classes. Out of 29 E. coli isolates, STEC accounted for 18 isolates, of which the O78, O26:H11, O128:H2, O1:H7, O119:H6, and O91:H21 serogroups were predominant. All E. coli isolates were multidrug resistant and therefore pose a potential public health concern as these virulent, resistant strains may spread to humans. Thus, high levels of hygiene and biosecurity are required by chicken handlers to decrease the danger of infection spreading to humans.(c) 2023 Urmia University. All rights reserved.

Extended-spectrum beta-lactamase (ESBL) and ampicillin resistance gene type C (ampC) in foodborne Citrobacter freundii (C. freundii) pose a severe public health risk, especially when they combine with other critical resistance genes to produce a reservoir of resistance. Therefore, the current study aimed to estimate the prevalence, phenotypic, and genotypic profiling of antimicrobial resistance in C. freundii isolates obtained from diseased broiler chickens and native Egyptian buffaloes in Kafr El-Sheikh and Dakahlia governorates, Egypt. Also, the investigation of the antibacterial activity of chitosan (CS) 1%, 2%, and chitosan nanoparticles (CSNPs), including the estimation of minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) and their combinations with ciprofloxacin (CIP), were evaluated. C. freundii was detected in 57.58% (19/33) of broiler chickens and 52.63% (20/38) of buffalo. Surprisingly, 26.32% (5/19) and 20% (4/20) of chicken and buffalo samples, respectively were multidrug-resistant (MDR), 42.11% (8/19) and 15% (3/20) were extensively drug-resistant (XDR), and 31.58% (6/19) and 65% (13/20) were pan drug-like-resistant (PDR). High frequencies of resistance genes were observed, including int 1, dfrA 1, sul 2, aad A1, qnr A, and bla _TEM (≥ 80%), while other genes such as erm B, bla _CMY−2 , bla _OXA−10 , tet (M), mcr- 1, bla _CTX−M, and cat A1 were detected at variable rates. Alarmingly, all ESBL/AmpC-producing isolates co-harbored multiple critical resistance genes. CSNPs showed markedly lower MIC and MBC values compared with 1% and 2% CS, indicating significantly stronger bactericidal activity. The concerning prevalence of PDR like- C. freundii in food animals is brought to light by our results, which also provide credence to the use of 2% CS–CIP and CSNPs–CIP combinations as potential substitute treatments for resistant infections.

Proteus mirabilis (P. mirabilis) serves as a multi-host–pathogen regarded as an alarming foodborne infectious disease, causing illnesses of variable severity in both livestock and human beings. The present study aimed to estimate the prevalence, antibiotic susceptibility profiles, and associated antimicrobial resistance genes (ARGs) of P. mirabilis isolates obtained from diseased broiler chickens and native Egyptian buffaloes in Kafr El-Sheikh and Dakahlia governorates, Egypt. In addition, this study investigated the antibacterial activity of chitosan (CS) and chitosan nanoparticles (CSNPs), including the estimation of the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of CS at concentrations of 1% and 2%, as well as CSNPs. Furthermore, the sub-MIC values were utilized to assess the inhibitory effects of CS and CSNPs on swarming motility. P. mirabilis was detected in 68% (34/50) of broiler chickens and 40.74% (11/27) of buffaloes. Interestingly, all P. mirabilis isolates were tested against 21 antimicrobial drugs and showed high resistance against either critical, highly important, or important antimicrobial drugs. For chicken-originated P. mirabilis, 50% (17/34) of isolates were revealed to be extensively drug-resistant (XDR) and 50% (17/34) of isolates were revealed to be pan-drug-resistant (PDR). Meanwhile, 9.09% (1/11) of buffalo-originated P. mirabilis isolates were revealed to be XDR and 90.91% (10/11) of the isolates were revealed to be PDR. Among P. mirabilis isolates from broiler chickens, the prevalence of resistance genes was as follows: int1 (97.06%), dfrA1 (100%), sul2 (97.06%), catA1 (44.12%), aadA1 (97.06%), tet(M) (81.82%), ermB (23.53%), msrA (0%), qnrA (47.06%), qnrS (0%), gyrA (0%), mcr-1 (11.76%), bla_TEM (97.06%), bla_CTX-M (26.47%), bla_OXA-10 (2.94%), bla_CMY-2 (41.18%), and bla_SHV (0%). The corresponding detection rates in buffalo-derived isolates were 100%, 100%, 90.91%, 63.64%, 100%, 70.59%, 18.18%, 0%, 9.09%, 0%, 0%, 18.18%, 81.82%, 18.18%, 18.18%, 63.64%, and 0%, respectively. Carbapenemase genes were found in none of the isolates from either species. CSNPs demonstrated superior antibacterial and anti-virulence activity against resistant P. mirabilis. CSNPs exhibited significantly lower MIC (0.067–0.081 mg/mL) and MBC (0.167–0.177 mg/mL) values compared with conventional CS formulations (MIC: 3.25–4.5 mg/mL; MBC: 6.67–9.08 mg/mL) in both broiler and buffalo isolates. In inhibition zone assays, the CSNPs + ciprofloxacin (CIP) combination showed the highest efficacy with a 50–58% increase in the inhibition area. Both CSNPs and CS 2% substantially reduced swarming motility by 45–52%, with CSNPs showing the strongest inhibitory effect. These outcomes highlight how P. mirabilis carries and disseminates antibiotic resistance, presenting serious threats to health policy and livestock. Also, CS or CSNPs, either alone or enhanced with CIP, are effective in vitro against resistant P. mirabilis, which promotes the treatment of Proteus infections to guarantee a bactericidal impact.