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Background This study aims to achieve biocontrol of multidrug-resistant Listeria monocytogenes in dairy cattle farm s which poses a severe threat to our socio-economic balance and healthcare systems. Methods Naturally occurring phages from dairy cattle environments were isolated and characterized, and the antimicrobial effect of isolated L. monocytogenes phages (LMPs) against multidrug-resistant L. monocytogenes strains were assessed alone and in conjugation with silver nanoparticles (AgNPs). Results Six different phenotypic LMPs (LMP1–LMP6) were isolated from silage ( n  = 4; one by direct phage isolation and three by enrichment method) and manure ( n  = 2; both by enrichment method) from dairy cattle farms. The isolated phages were categorized into three different families by transmission electron microscopy (TEM): Siphoviridae (LMP1 and LMP5), Myoviridae (LMP2, LMP4, and LMP6), and Podoviridae (LMP3). The host range of the isolated LMPs was determined by the spot method using 22 multidrug-resistant L. monocytogenes strains. All 22 (100%) strains were susceptible to phage infection; 50% (3 out of 6) of the isolated phages showed narrow host ranges, while the other 50% showed moderate host ranges. We found that LMP3 (the phage with the shortest tail) had the ability to infect the widest range of L. monocytogenes strains. Eclipse and latent periods of LMP3 were 5 and 45 min, respectively. The burst size of LMP3 was 25 PFU per infected cell. LMP3 was stable with wide range of pH and temperature. In addition, time-kill curves of LMP3 alone at MOI of 10, 1 and 0.1, AgNPs alone, and LMP3 in combination with AgNPs against the most phage-resistant L. monocytogenes strain (ERIC A) were constructed. Among the five treatments, AgNPs alone had the lowest inhibition activity compared to LMP3 at a multiplicity of infection (MOI) of 0.1, 1, and 10. LMP3 at MOI of 0.1 in conjugation with AgNPs (10 µg/mL) exhibited complete inhibition activity after just 2 h, and the inhibition activity lasted for 24 h treatment. In contrast, the inhibition activity of AgNPs alone and phages alone, even at MOI of 10, stopped. Therefore, the combination of LMP3 and AgNPs enhanced the antimicrobial action and its stability and reduced the required concentrations of LMP3 and AgNPs, which would minimize the development of future resistance. Conclusions The results suggested that the combination of LMP3 and AgNPs could be used as a powerful and ecofriendly antibacterial agent in the dairy cattle farm environment to overcome multidrug-resistant L. monocytogenes .

This study was divided into two parts. The first part involved the isolation, and detection of the prevalence and antimicrobial resistance profile of Aeromonas hydrophila, Pseudomonas aeruginosa , and Vibrio species from Nile tilapia fish and marine aquatic water. One hundred freshly dead Nile tilapia fish were collected from freshwater aquaculture fish farms located in Al-Abbassah district, Sharkia Governorate, and 100 samples of marine aquatic water were collected from fish farms in Port Said. The second part of the study focused on determining the in vitro inhibitory effect of dual-combination of AgNPs-H2O2 on bacterial growth and its down regulatory effect on crucial virulence factors using RT-PCR. The highest levels of A. hydrophila and P. aeruginosa were detected in 43%, and 34% of Nile tilapia fish samples, respectively. Meanwhile, the highest level of Vibrio species was found in 37% of marine water samples. Additionally, most of the isolated A. hydrophila, P. aeruginosa and Vibrio species exhibited a multi-drug resistance profile. The MIC and MBC results indicated a bactericidal effect of AgNPs-H2O2. Furthermore, a transcriptional modulation effect of AgNPs-H2O2 on the virulence-associated genes resulted in a significant down-regulation of aerA, exoU, and trh genes in A. hydrophila, P. aeruginosa, and Vibrio spp ., respectively. The findings of this study suggest the effectiveness of AgNPs-H2O2 against drug resistant pathogens related to aquaculture.

This study was divided into two parts. The first part, the determination of methicillin-resistant Staphylococcus aureus (MRSA) prevalence in 25 broiler chicken farms, with the detection of multidrug resistant MRSA strains. The prevalence of MRSA was 31.8% (159 out of 500 samples) at the level of birds and it was 27% (27 out of 100) in the environmental samples. The highest antimicrobial resistance of the recovered MRSA strains was recorded to streptomycin (96%). All isolates (100%) had multidrug resistance (MDR) to four or more antibiotics with 16 distinct antibiotic resistant patterns, and multiple antibiotic resistance index (MARI) of 0.4–1. The second part, implementing novel biocontrol method for the isolated multidrug resistant MRSA strains through the isolation of its specific phage and detection of its survival rate at different pH and temperature degrees and lytic activity with and without encapsulation by chitosan nanoparticles (CS-NPs). Encapsulated and non-encapsulated MRSA phages were characterized using transmission electron microscope (TEM). Encapsulation of MRSA phage with CS-NPs increasing its lytic activity and its resistance to adverse conditions from pH and temperature. The findings of this study suggested that CS-NPs act as a protective barrier for MRSA phage for the control of multidrug resistant MRSA in broiler chicken farms.

This study was conducted during the period of August 2021 to April 2022 and divided into two parts. The first part involved the isolation and characterization of Salmonella from 200 diseased broiler chickens collected from farms in Dakahlia Governorate, Egypt, with the detection of its antimicrobial susceptibility. The second experimental part involved in ovo inoculation of probiotics and florfenicol to evaluate their effects on hatchability, embryonic viability, growth performance traits and the control of multidrug-resistant Salmonella Enteritidis infections post hatching. The point prevalence of Salmonella in the internal organs of diseased chickens was 13% (26/200), including 6 serotypes: S. Enteritidis , S. Typhimurium , S. Santiago , S. Colindale , S. Takoradi and S. Daula. Multidrug resistance was found in 92% (24/26) of the isolated strains with a multiantibiotic resistance index of 0.33–0.88 and 24 antibiotic resistance patterns. The in ovo inoculation of probiotic with florfenicol showed significant improvement in the growth performance parameters compared with other groups and had the ability to prevent colonization of multidrug resistant S. Enteritidis in the majority of the experimental chicks, and the remaining chicks showed very low colonization, as detected by RT‒PCR. These findings suggested the application of in ovo inoculation techniques with both probiotics and florfenicol as a promising tool to control multidrug-resistant S. Enteritidis in poultry farms.

Background Campylobacter species (spp.) are one of the most important zoonotic bacteria possessing potential hazards for animal and human health worldwide. Migratory birds are implicated as significant carriers for microbes and a play very important role in the dissemination of Campylobacter to broiler chickens and their environment. The purpose of this investigation was to detect the prevalence, antibiotic resistant patterns, virulence and diversity of pathogenic Campylobacter spp. in 7 migratory bird species (Northern shoveler, Common pochard, Common teal, Northern pintail, Eared Grebe, Great Crested Grebe and Garganey) and broiler chickens that were collected from broiler poultry farms and live bird markets. Results The prevalence of Campylobacter was 12.5% (25/200), of which 15% (15/100) was recovered from 5 migratory bird species only and 10% (10/100) from broiler chickens. At the level of migratory birds, eight isolates (53.3%) were Campylobacter jejuni ( C. jejuni ) and 7 isolates (46.7%) were Campylobacter coli ( C. coli ) meanwhile, in broiler chickens C. jejuni and C. coli were 50% (5/10) for each. All isolated strains had phenotypic resistance to doxycycline, while all of the isolates were susceptible to amikacin. The multidrug resistance to three, four or five antimicrobial classes was found in 72% (18/25) of the isolated strains. The multiantibiotic resistance index between the examined isolates was 0.22–0.77, with 10 antibiotic resistance patterns. The virulence of isolated Campylobacter strains (from both migratory birds and broiler chicken birds) was detected by targeting the Vir B11, cia B and iam genes which were recorded at 16%, 52% and 100%, respectively. Additionally, 100% and 84% of the antibiotic resistance genes were identified as tetA and BlaOXA-61, respectively. Conclusions The results of this study revealed the diversity between all the isolated strains from migratory birds and their similarity to broiler chicken isolates. The findings of the present study highlight the impact of migratory birds visiting Egypt and other countries on pathogenic Campylobacter spp. carrying pathogenic virulence and resistance genes, necessitating the application of biosecurity measures to prevent migratory birds from entering farms during their migration period.

This two-phase study evaluated biosecurity vulnerabilities across 100 commercial poultry farms via a field survey and an in vitro assessment of hydrogen peroxide (H 2 O 2 ) versus a silver nanoparticle–hydrogen peroxide (AgNPs– H 2 O 2 ) composite. Survey metrics revealed critical baseline deficiencies: 80% of farmers lacked antimicrobial resistance (AMR) awareness, 90% practiced no litter treatment, and 70% of untreated waste was sold directly to aquaculture. Molecular analysis of 192 litter samples verified a 72.4% E. coli prevalence, with Multiple Antibiotic Resistance (MAR) indices peaking at 0.90. Phenotypic profiling showed high resistance to ampicillin (89.9%) and amoxicillin-clavulanic acid (61.2%), whereas colistin demonstrated 100% susceptibility. A significant co-resistance was identified between imipenem and tetracycline (φ = 0.65, p_adj < 0.001) and between cefotaxime and ceftazidime (φ = 0.58, p_adj < 0.001), P  < 0.01) after Benjamini-Hochberg FDR correction. Concurrently, the AgNPs– H 2 O 2 composite exhibited superior efficacy with a Minimum Inhibitory Concentration (MIC) of 3.125 µg/mL, proving four-fold more potent than standalone H 2 O 2 . Time-kill kinetics demonstrated complete bacterial reduction within 24 h ( P  < 0.001), successfully suppressing the post-6-hour regrowth observed with H 2 O 2 alone. While this study is limited by its regional geographical scope and the lack of molecular characterization for specific resistance genes, it conclusively identifies veterinary supervision deficits ( P  < 0.0001) as a driver of extensively drug-resistant (XDR) transmission. Ultimately, the AgNPs– H 2 O 2 composite offers a promising in vitro One Health biosecurity strategy, achieving complete bacterial reduction under controlled conditions at a 75% lower concentration than standalone H 2 O 2 , pending field validation.

Multidrug resistance (MDR) considered as global crisis facing poultry industry. Migratory birds play very important role in the dissemination of antimicrobial resistant pathogen during their fly way specially to poultry farms. Therefore, 750 samples from migratory birds and 300 samples from broiler chicken farms and its environment were collected during the winter seasons of five years (2019 to 2023). The samples were subjected to the isolation of Salmonella enterica and Escherichia coli with the detection of antimicrobial resistance (phenotypic and genotypic) with insight to the genetic similarity between the isolates from migratory birds and broiler chickens’ farms. Different members of Enterobacteriaceae were isolated; Salmonella enterica , Escherichia coli , Citrobacter , Enterobacter , Klebsiella , Proteus , Providencia , Serratia , Hafnia. 298 (28.4%) of S. enterica strains belonging to 27 serovars. S. Typhimurium, S . Kentucky, S . Enteritidis and S . Shangani were the common 4 serotypes between migratory birds and farms. Meanwhile, we found 489 (46.6%) isolates of E. coli belonging to 24 serogroups and O91, O128, O26, O125, O55, O103 and O159 were the common 7serogroups between migratory birds and farms samples. The majority of Salmonella (91.6%; 274 out of 298) and E. coli (92%; 450 out of 489) were MDR. The MDRI range of Salmonella and E. coli was 0.08- 1.The genetic similarity between the isolates of migratory birds and broiler chicken farms were detected by ERICPCR and hot map. This study suggests the continuous applications of surveillance programs for migratory birds and biosecurity measures in poultry farms.

Pseudomonas aeruginosa is an opportunistic pathogen causing severe infection in animals and humans. This study aimed to determine the ecological distribution and prevalence of multidrug-resistant (MDR) P. aeruginosa isolated from dairy cattle, the environment, and workers’ hand swabs. Samples (n = 440) were collected from farms and households (n = 3, each). Rectal swabs, udder skin swabs, milk, workers’ hand swabs, feed, water, water sources, and beddings were collected. Samples were subjected to the bacterial identification of P. aeruginosa via 16S rRNA. Antimicrobial resistance (AMR) was detected either phenotypically using an antibiotic susceptibility test or genotypically with AMR resistance genes (ARGs) such as drfA, sul1, and ermB. P. aeruginosa was detected on dairy farms and households (10.3–57.5%, respectively), with an average of 23.2%. The resistance of dairy farm strains was observed against sulfamethoxazole, imipenem, cefepime, piperacillin–tazobactam, and gentamycin (100%, 72.7%, 72.7%, 68.8%, and 63.3%, respectively). Meanwhile, the resistance of household strains was observed against sulfamethoxazole, imipenem, amoxicillin, gentamicin, cefepime, and erythromycin by 91.3%, 82.6%, 75.4%, 75.4%, 68.1%, and 63.8%, respectively. The susceptibility of farm strains was detected against norfloxacin, ciprofloxacin, and levofloxacin (90.9%, 84.8%, and 72.7%, respectively). Meanwhile, the susceptibility of household strains was detected against ciprofloxacin, amikacin, and norfloxacin (100%, 84.1%, and 72.5%, respectively). About 81.4% of P. aeruginosa strains were MDR. ARGs (drfA, sul1, and ermB) were detected in farm strains (48.5%, 72.7%, and 24.4%, respectively) and household strains (50.7%, 72.5%, and 47.8%, respectively). Almost all P. aeruginosa had MAR over 0.2, indicating repeated application of antibiotics. P. aeruginosa prevalence was fivefold higher in households than on farms. MDR strains were higher amongst household strains than farm strains.

Background Environmental hygiene is an important factor in poultry production to keep broiler chickens’ health and welfare. This study aimed to evaluate biochar-amended poultry litter to enhance environmental hygiene and broiler chickens’ health and immunity by reducing bacterial load and improving environmental quality. Method For 5 consecutive weeks, a total of 60 one-day-old Cobb broiler chickens were divided into three groups: a control group (CN) reared on sawdust litter, and two treated groups where sawdust litter was amended with 10% biochar (10%BC) and 20% biochar (20%BC) groups. BC was produced from poultry litter of the CN group through pyrolysis at 450 °C. Results Total bacterial count, as well as Escherichia coli and Salmonella count in the air and litter environments, were weekly increased in the CN group. Biochar treatment, especially with the 10%BC group, significantly reduced bacterial counts. Hematological analysis revealed an elevated white blood cell (WBCs) count and a reduced heterophils/lymphocytes (H/L) ratio in the biochar-treated groups, indicating enhanced immune status and reduced stress compared to the CN group. Flow cytometry indicated significant increases in peripheral blood CD4 and CD8 T-lymphocytes, particularly with the 10%BC group. Serum immunoglobulins (IgA, IgY, IgM) were also released significantly with BC groups, especially 10% BC, compared to the CN group. Histopathological alterations in the spleen and thymus gland of broiler chicken biochar groups revealed structural improvements compared with the CN group. Conclusion These findings suggested that biochar addition to poultry litter optimally enhances environmental hygiene, immune function, and overall broiler health, especially with 10%BC concentration. Thus, biochar represents a promising litter management strategy to mitigate bacterial load and improve poultry welfare.

Background Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to an infection. Objective To assess the prevalence and outcome of sepsis in RICU Patients and methods The study was conducted upon 403 patients admitted at RICU of the Abbassia Chest Hospital, Cairo, Egypt; 100 of them had sepsis either on admission or acquired in the RICU during the period from May 2019 to November 2019. Severity of illness was assessed by Acute Physiology and Chronic Health Evaluation II (APACHE II score), which was recorded within 24 h from patient admission. Quick sepsis-related organ failure assessment (qSOFA) score was recorded in emergency room, and sepsis-related organ failure assessment (SOFA) score was recorded on ICU admission and on the 3rd and 7th day of ICU stay. Type of infection (community or hospital acquired), infection site, and pathogenic organisms, all were recorded. Assessment was done also regarding mechanical ventilation, length of RICU stay, the presence of comorbidities, survived patients, and dead ones, as regards causes of death and risk factors. Results The study included 100 cases with sepsis out of 403 admitted cases in the same duration with frequency 24%. Among sepsis patients, 72% were males and 28%were females, with mean age 51.62 ± 18.62 years. The main diagnosis was pneumonia (62%), and the main comorbidity was diabetes mellitus (23%). There was significant increase in age among non-survivors when compared with survivors. There was significant increase in number of mechanically ventilated patients and a highly significant incidence of complications and need for vasoactive drugs among non-survivors when compared with survivors. There was a highly significant higher APACHE II score on the 1st day of admission among non-survivor patients. The SOFA score was significantly higher on the 1st day of admission and significantly higher on the 3rd and 7th day of admission among non-survivor patients when compared to survived patients. Conclusion The current study showed that sepsis affects nearly one quarter of cases admitted at RICU, and it is usually associated with higher mortality rate in those patients. Trial registration ClinicalTrials.gov NCT05240157 . Registered February 15, 2022. Retrospectively registered.