Gamal Younis

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.

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.

This study aimed to determine the prevalence, serovars, virulence gene profiles, antimicrobial resistance patterns, and extended-spectrum β-lactamase (ESBL) genes in Salmonella isolated from broiler chickens in Egypt. In this study, 200 samples were obtained from broiler chickens. Samples were processed using standard bacteriological techniques, and suspected isolates were biochemically identified and molecularly confirmed by PCR targeting the inv A gene. Serotyping was performed according to the Kauffmann–White scheme. Virulence genes ( hil A, stn , spv C, and spi C) and ESBL genes ( bla _TEM , bla _SHV , and bla _{CTX −M} ) were detected by PCR. Antimicrobial susceptibility testing was carried out following CLSI guidelines. Nineteen isolates (9.5%) were confirmed as Salmonella . Serotyping revealed four serovars: S . Kentucky (52.63%), S . Typhimurium (21.05%), S . Salamae (15.79%), and S . Infantis (10.53%). All isolates carried inv A and hil A, while stn and spi C were present in 84.21% and 73.68% of isolates, respectively, spv C was detected in only one isolate (5.26%). All isolates were resistant to ceftazidime, cefepime, and erythromycin. High resistance rates were also observed against amoxicillin, amoxicillin-clavulanic acid, ciprofloxacin, and doxycycline. Detection of ESBL genes revealed that bla _TEM was present in 16 isolates (84.2%), bla _CTX−M in 6 isolates (31.6%), and bla _SHV in 2 isolates (10.5%). Statistical analyses (Chi-square and Spearman’s correlation tests) further confirmed significant associations between ESBL genes and both phenotypic resistance and virulence determinants, strengthening the validity of our findings. The high prevalence of virulence factors and antimicrobial resistance traits, particularly extensively drug-resistant (XDR) phenotypes and ESBL-encoding genes among Salmonella isolates from poultry, represents a critical public health concern. These findings emphasize the need for continuous molecular surveillance, improved antimicrobial stewardship, and enhanced biosecurity strategies in poultry production in Egypt.

The current study describes the presence of Bacillus cereus (B. cereus) in contaminated foods of animal source and ready for human consumption with highlighting on their virulence contributing factors by detection of its virulence genes in addition to identification of their sequencing.

Pseudomonas fluorescens is one of the main causes of septicemic diseases among freshwater fish, causing severe economic losses and decreasing farm efficiency. Thus, this research was aimed to investigate the occurrence of P. fluorescens in Nile Tilapia (O. niloticus) fish in Egypt, gene sequencing of 16SrDNA gene, and antimicrobial susceptibility. P. fluorescens strains were detected in 32% (128\400) of apparently healthy (9%; 36\400) and diseased (23%; 92\400) Nile tilapia fish. The highest prevalence was observed in gills of fish, 31.3% followed by intestine 26.9%, liver 24.2%, and kidneys 17.6%. The PCR results for the 16SrDNA gene of P. fluorescens showed 16SrDNA gene in 30% of examined isolates. Moreover, Homogeny and a strong relationship between strains of P. fluorescens was confirmed using 16SrDNA sequences. Beside the responsibility of 16SrDNA gene on the virulence of P. fluorescens. The results of antimicrobial susceptibility tests revealed that all strains were resistant to piperacillin (100%), followed by ceftazidime (29.7%), and cefepime (25.8%). The strains of P. fluorescence were highly sensitive to cefotaxime (74.2%), followed by ceftriaxone and levofloxacin (70.3% each). Interestingly, 29.7% of strains of P. fluorescens were multiple antimicrobial-resistant (MAR).

This research has revealed the presence and prevalence of carbapenam-resistance and virulence genes among APEC isolates from broiler chickens in Egypt.

Prevalence of dermatophytosis in companion animals and how it can be treated, finding of cats and dogs tested positive for Microsporum and Trichophyton species.

Background and Aim: Escherichia coli is the cause of avian colibacillosis, a significant threat to the poultry industry and public health. Thus, this study investigated the prevalence of E. coli in diseased chicken broilers, pathological effects of these bacteria, and interleukin (IL) gene expression of different serotypes of E. coli (O78, O26, O44, and O55) on experimentally infected chickens. Materials and Methods: A total of 295 organ samples (liver, lungs, heart, and spleen) from 59 diseased broiler chickens were used for conventional identification of E. coli. Chickens were orally infected with one of the following E. coli serotypes (O78, O26, O44, or O55) and examined for clinical signs, mortality, macroscopic and microscopic lesions, and IL gene expression using real-time quantitative polymerase chain reaction. Results: E. coli was isolated from 53.2% of broiler chicken organs with a high prevalence in lungs (26.1%). The most prevalent serotypes were O78, O26, O44, O55, O157, and O127 prevalence of 27.8, 22.2, 16.7, 16.7, 5.6, and 5.6%, respectively. In the experimental design, five groups (G1-G5) of birds were established. G1 served as the negative control group, while G2-G5 were challenged orally with E. coli O78, O26, O55, or O44, respectively. Chickens infected with E. coli O78 or O26 showed significant clinical signs in comparison to the other infected birds. Mortality (13.3%) was only observed in birds infected with E. coli O78. Necropsy of dead birds after E. coli O78 infection showed pericarditis, enteritis, airsacculitis, and liver and lung congestion. More severe histopathological changes were observed in intestines, spleen, liver, and lung from chickens infected with either E. coli O78 or O26 than for birds infected with other serotypes. On the 2nd day post-infection, E. coli challenge, particularly with E. coli O78, displayed significantly upregulated levels of ileal IL-6 and IL-8, but ileal IL-10 level tended to be downregulated in comparison to the control group. Conclusion: This study assessed the application of cytokines as therapeutic agents against infectious diseases, particularly colibacillosis.

Pathogenic Yersinia enterocolitica (Y. enterocolitica) is one of the food-borne entero-pathogen responsible for yersiniosis in humans. The purpose of this research was to survey the prevalence, virulence-associated genes, and antimicrobial resistance of Y. enterocolitica isolated from meat and meat product samples in Egypt. Forty-one (5.9%) out of 700- samples of chicken meat, beef, ground beef, and sausage were positive Y. enterocolitica with a high prevalence in chicken meat (12%). Five virulence genes (ail, inv, ystA, ystB, and yadA) were characterized among 41 Y. enterocolitica isolates with variable frequencies. Among the strains tested, the ystB gene was detected with a high percentage (78.1%), followed by inv gene (70.7%), ail gene (14.6%), ystA gene (12.2%), and yadA gene (2.4%). A high resistance rate was estimated to amoxicillin-clavulanic acid (100%), followed by cefazolin (95%), ampicillin (65.9%), and doxycycline (51.2%), whilst a high sensitivity rate was observed to gentamicin and ciprofloxacin (97.6% each). Interestingly, the multidrug resistance was specified in the 70.7% of strains and showing 13 resistance patterns. Based on nucleotide sequence analysis of the 16s rRNA gene, the phylogenetic tree showed the genetic relatedness amongst Y. enterocolitica isolates. These findings highlighted the emergence of virulent and multidrug-resistant pathogenic Y. entrocolitica in retailed meat and meat products in Egypt.

This pilot study aimed to characterize Riemerella anatipestifer from ducklings, testing their susceptibility to antimicrobial agents and to detect their virulence markers. Seven R. anatipestifer isolates with 11.67% infection rate were identified out of sixty freshly dead ducklings and confirmed by PCR assay targeting gyrB gene. The gyrB gene sequences of R. anatipestifer isolates were 100% identical to each other and also showed 100% sequence similarity to the published gyrB genes. Four virulence genes namely ompA, prtC, hagA, and sspA were identified in all isolates except sspA was detected in 5 isolates. The antibiogram revealed higher sensitive to imipenem, amikacin, and rifampin, while, a remarkably high resistance was displayed against ampicillin, penicillin, cefipime, trimethoprim/sulfamethoxazole, gentamicin, ceftazidime, streptomycin and cefoperazone. Proper and rapid identification of R. anatipestifer with detection of their antimicrobial susceptibility and its virulence potential is essential for understanding the epidemiology of R. anatipestifer and to apply the effective control strategies.