Phenotypic and genotypic characterization of resistance and virulence in Pseudomonas aeruginosa isolated from poultry farms in Egypt using whole genome sequencing.

Pseudomonas aeruginosa (P. aeruginosa) is an ESKAPE pathogen that can quickly develop resistance to most antibiotics. This bacterium is a zoonotic pathogen that can be found in humans, animals, foods, and environmental samples, making it a One-Health concern. P. aeruginosa threatens the poultry industry in Egypt, leading to significant economic losses. However, the investigation of this bacterium using NGS technology is nearly non-existent in Egypt. In this study, 38 isolates obtained from broiler farms of the Delta region were phenotypically investigated, and their genomes were characterized using whole genome sequencing (WGS). The study found that 100% of the isolates were resistant to fosfomycin and harbored the fosA gene. They were also resistant to trimethoprim/sulfamethoxazole, although only one isolate harbored the sul1 gene. Non-susceptibility (resistant, susceptible with increased dose) of colistin was observed in all isolates. WGS analysis revealed a high level of diversity between isolates, and MLST analysis allocated the 38 P. aeruginosa isolates into 11 distinct sequence types. The most predominant sequence type was ST267, found in 13 isolates, followed by ST1395 in 8 isolates. The isolates were susceptible to almost all tested antibiotics carrying only few different antimicrobial resistance (AMR) genes. Various AMR genes that confer resistance mainly to ß-lactam, aminoglycoside, sulfonamide, and phenicol compounds were identified. Additionally, several virulence associated genes were found without any significant differences in number and distribution among isolates. The majority of the virulence genes was identified in almost all isolates. The fact that P. aeruginosa, which harbors several AMR and virulence-associated factors, is present in poultry farms is alarming and threatens public health. The misuse of antimicrobial compounds in poultry farms plays a significant role in resistance development. Thus, increasing awareness and implementing strict veterinary regulations to guide the use of veterinary antibiotics is required to reduce health and environmental risks. Further studies from a One-Health perspective using WGS are necessary to trace the potential transmission routes of resistance between animals and humans and clarify resistance mechanisms.

The Prevalence and Molecular Biology of Staphylococcus aureus Isolated from Healthy and Diseased Equine Eyes in Egypt.

This work aimed to characterize S. aureus isolates from the eyes of healthy and clinically affected equines in the Kafrelsheikh Governorate, Egypt. A total of 110 animals were examined for the presence of S. aureus, which was isolated from 33 animals with ophthalmic lesions and 77 healthy animals. We also investigated the antimicrobial resistance profile, oxacillin resistance mechanism, and the major virulence factors implicated in many studies of the ocular pathology of pathogenic S. aureus. The association between S. aureus eye infections and potential risk factors was also investigated. The frequency of S. aureus isolates from clinically affected equine eyes was significantly higher than in clinically healthy equids. A significant association was found between the frequency of S. aureus isolation from clinically affected equine eyes and risk factors including age and season but not with sex or breed factors. Antimicrobial resistance to common antibiotics used to treat equine eyes was also tested. Overall, the isolates showed the highest sensitivity to sulfamethoxazole (100%) and the highest resistance to cephalosporin (90.67%) and oxacillin (90.48%). PCR was used to demonstrate that mecA was present in 100% of oxacillin- and ß-lactam-resistant S. aureus strains. The virulence factor genes Spa (x region), nuc, and hlg were identified in 62.5%, 100%, and 56%, of isolates, respectively, from clinically affected equines eyes. The severity of the eye lesions increased in the presence of γ-toxin-positive S. aureus. The phylogenetic tree of the Spa (x region) gene indicated a relationship with human reference strains isolated from Egypt as well as isolates from equines in Iran and Japan. This study provides insight into the prevalence, potential risk factors, clinical pictures, zoonotic potential, antimicrobial resistance, and ß-lactam resistance mechanism of S. aureus strains that cause eye infection in equines from Egypt.

Molecular Diagnosis of Mycoplasma Species Infection in Camels Using Semi-nested PCR.

BACKGROUND AND OBJECTIVE: Bacteriological isolation and identification of Mycoplasma species is difficult and time-consuming, therefore, molecular identification of Mycoplasma using PCR targeting specific genes is considered a specific and sensitive method for identification. The aim of current study was to isolate, characterize Mycoplasma infection in dromedary camels in Saudi Arabia. MATERIALS AND METHODS: Nasal swabs were randomly collected from 93 camels and tested for Mycoplasma by sequencing of their 16S rRNA genes using universal primers. RESULTS: The 93 samples, 24 were positive for Mycoplasma. However, no positive results were obtained using species-specific primers for Mycoplasma arginine, M. bovis or M. mycoides subsp. mycoides, thus, 16S rDNA sequencing methods and semi-nested PCR were employed. Sequences were matched to those in GenBank and phylogenetic analysis was performed. Mycoplasma edwardii (77-84% similarity with Mycoplasma edwardii ATCC 23462) and one isolate of Mycoplasma yeastsii (100% similarity with M. yeastsii GM274B) were identified. Further, some Mycoplasma species were identified as previously uncultured. The incidence of Mycoplasma infection in camels in Taif city, Saudi Arabia, was approximately 26%. CONCLUSION: This study provides insights into the accuracy and efficiency of PCR and universal primers for the detection and identification of Mycoplasma, thereby circumventing conventional culturing methods that require several days to complete and exhibit low accuracy.

Epidemiological and Molecular Investigation of Ocular Fungal Infection in Equine from Egypt.

Diagnosis and treatment of ocular fungal infection in equine seems very challenging for owners and clinicians. The present study aimed to identify and characterize fungal species isolated from the eyes of clinically healthy and diseased equines (N = 100) from Dakahlia Governorate, Egypt. The work also involved morphological and molecular characterization of the major fungal species. In addition, correlations between the occurrence of isolated fungi and some of the potential risk factors were also investigated. Interestingly, the prevalence rate of ocular mycosis in all examined equines in the study was 28% and there were major clinical signs associated with ocular fungal infection. Moreover, the identified fungal species included Aspergillus flavus, A. fumigatus, A. niger, Penicillium spp., Mucor spp., and Alternari spp. with a corresponding prevalence rate of 63.9%, 27.8%, 15.3%, 18.1%, 13.9%, and 4.2%, respectively, in healthy equine eyes, while their prevalence in diseased equine eyes was 57.1%, 32.1%, 21.4%, 7.1%, 3.6%, and 0%. Furthermore, a statistical significant association (p < 0.05) was found between the frequency of isolation of A. fumigatus and Penicillium and several risk factors (breed, sex, and ground type), while the remaining risk factors and occurrence of fungi were not statistically correlated. A subset of the Aspergillus species samples positive by polymerase chain reaction (PCR) were sequenced and their phylogenetic analysis identified three species of Aspergillus. Taken together, our study provides novel data related to the occurrence of ocular mycosis in equine in Egypt. Given the zoonotic potential of some identified fungi, our data may be helpful for implementation of novel diagnostic and therapeutic strategies for combating this sight-threatening infection in equine.

Evaluation of Bifidobacteria and Lactobacillus Probiotics as Alternative Therapy for Salmonella typhimurium Infection in Broiler Chickens.

Chicken Salmonella enterica serovars are enteric bacteria associated with massive public health risks and economic losses. There is a widespread antimicrobial resistance among S. enterica serotypes, and innovative solutions to antibiotic resistance are needed. We aimed to use probiotics to reduce antibiotic resistance and identify the major probiotic players that modify the early interactions between S. enterica and host cells. One-day-old cobb broiler chicks were challenged with S. typhimurium after oral inoculation with different probiotic strains for 3 days. The adherence of different probiotic strains to Caco-2 intestinal epithelial cells was studied in vitro. Lactobacillus (Lacticaseibacillus) casei ATTC334 and Bifidobacterium breve JCM1192 strains attached to Caco-2 cells stronger than B. infantis BL2416. L. casei ATTC334 and B. breve JCM1192 reduced S. typhimurium recovery from the cecal tonsils by competitive exclusion mechanism. Although B. infantis BL2416 bound poorly to Caco-2 epithelial cells, it reduced S. typhimurium recovery and increased IFN-γ and TNF-α production. L. casei ATTC334, B. breve JCM1192 and B. infantis BL2416 improved body weight gain and the food conversion rate in S. typhimurium-infected broilers. B. longum Ncc2785 neither attached to epithelial cells nor induced IFN-γ and TNF-α release and consequently did not prevent S. typhimurium colonization in broiler chickens. In conclusion, probiotics prevented the intestinal colonization of S. typhimurium in infected chickens by competitive exclusion or cytokine production mechanisms.

Inflammasome Activation in Bovine Peripheral Blood-Derived Macrophages Is Associated with Actin Rearrangement.

Inflammation is critical for infection control and acts as an arsenal defense mechanism against invading microbes through activation of the host immune system. It works via its inflammasome components to sense the dangerous invading microorganism and send messages to the immune system to destroy them. To date, the function of bovine macrophage inflammasome and its relationship with actin has not been identified. This study aimed to investigate the activation of bovine inflammasome by phase one flagellin from Salmonella typhimurium and its interaction with actin. Bovine monocyte-derived macrophages were prepared and challenged with S. typhimurium SL1344 phase one flagellin. The results demonstrated the relationship between the flagellin-based activation of inflammasome and actin rearrangement. The flagellin-based activation of inflammasome promoted the activation and co-localization of F-actin and the inflammasome complex. Actin was remodeled to different degrees according to the stage of inflammasome activation. The actin redistribution varied from polymerization to filopodia, while at the stage of pyroptotic cell death, actin was broken down and interacted with activated inflammasome complexes. In conclusion, flagellin-dependent inflammasome activation and actin localization to the inflammasome at the stage of pyroptotic cell death may be of importance for appropriate immune responses, pending further studies to explore the exact cross-linking between the inflammasome complex and actin.

Development of a transformation system for Aspergillus sojae based on the Agrobacterium tumefaciens-mediated approach.

BACKGROUND: Aspergillus sojae has been an important filamentous fungus in Biotechnology due to its use in diverse fermentative processes for the production of various food products. Furthermore, this fungus is a common expression system for the production of enzymes and other metabolites. The availability of molecular genetic tools to explore its biology is thus of big interest. In this study, an Agrobacterium tumefaciens-mediated transformation (ATMT) system for A. sojae was developed and its applicability evaluated. RESULTS: The donor plasmid named pRM-eGFP was constructed for ATMT of A. sojae. This plasmid contains the ble and egfp genes in its transfer DNA element (T-DNA) to confer phleomycin resistance and express the enhanced green fluorescent protein (EGFP) in A. sojae, respectively. Agrobacterium tumefaciens (LBA4404) harboring the donor plasmid and A. sojae (ATCC 20235) were co-cultured under diverse conditions to achieve ATMT. The maximum number of transformed fungi was obtained after three days of co-culturing at 28°C, and selection with 50 µg/ml phleomycin. Polymerase chain reaction (PCR), fluorescence microscopy and Western Blot analysis for EGFP expression confirmed successful genomic integration of the T-DNA element in A. sojae. The T-DNA was mitotically stable in approximately 40% of the fungal transformants after four generations of sub-culturing under phleomycin pressure. CONCLUSION: We successfully established a new ATMT protocol for A. sojae. This transformation system should enable further protein expression studies on this filamentous fungus.