Veterinary Research Communications最新文献

This study investigated the concurrent infection of Pseudomonas aeruginosa and Saprolegnia parasitica in Oreochromis niloticus from Lake Manzala during the period from October to December 2023, employing phenotypic and genotypic characterizations of the isolated pathogens. Naturally infected fish displayed septicemic picture, fin rot, and the presence of cotton wool-like masses on the skin and fins. Water quality analysis revealed elevated salinity, unionized ammonia and nitrite levels, alongside with suboptimal water temperature. P. aeruginosa and S. parasitica were isolated from 30% and 31.8% of the clinically affected and moribund examined fish, respectively. Molecular analysis of P. aeruginosa 16 S-rDNA and S. parasitica ITS-rDNA genes demonstrated a genetic similarity with their ancestral strains from the families Pseudomonadaceae and Saprolegniaceae, respectively. The pathogenicity of P. aeruginosa was confirmed through β-hemolysis and biofilm production. Antimicrobial susceptibility testing of P. aeruginosa indicated high susceptibility to colistin sulfate (100%) and meropenem (87.95%), with notable resistance to tetracycline (100%) and ampicillin (93.9%). Virulence gene analysis identified several key genes, including toxA (93.9%), exoS (66.7%), lasB (45.45%), phzM (33.3%), pslA (33.3%), and fliC (42.4%). Resistance profiling revealed the presence of multiple antibiotic resistance genes, including tetA (100%), bla_TEM (93.9%), bla_CTX-M-1 (81.8%), bla_OXA-1 (54.4%), qnrA (30.3%), and bla_NDM-1 (12.1%). Extensive drug resistance (XDR) and multiple drug resistance (MDR) phenotypes were observed in 12.1% and 27.3% of P. aeruginosa isolates, respectively, with high multiple antibiotic resistance (MAR) indices. Scanning electron microscopy (SEM) of skin lesions revealed extensive mycelial networks of S. parasitica on ulcerated skin surfaces. The co-occurrence of highly virulent, multidrug-resistant P. aeruginosa and S. parasitica underscores the complexity of treatment and highlights the need for targeted intervention strategies in aquaculture systems for disease prevention and control.

Background: The emergence of bacteria producing extended-spectrum β-lactamases (ESBLs) has presented a substantial challenge to veterinary and human medicine. ESBL-producing Escherichia coli exhibits biofilm-forming capabilities that enhance its persistence in domestic animals, contribute to chronic infectious diarrhea, and increase the risk of treatment failure. This study investigated ESBL-producing E. coli in dogs and evaluated the antimicrobial and antibiofilm activities of NHK-EO, an innovative essential oil formulation derived from Coleus amboinicus (N), Ocimum basilicum (H), and Ocimum tenuiflorum (K).

Methods: The chemical composition of NHK-EO was analyzed using gas chromatography-mass spectrometry (GC-MS). Fifty-six rectal swab samples were randomly collected from dogs aged 3 months to 10 years, including 30 clinically healthy and 26 diarrheic animals of both sexes. Bacterial isolation and identification were conducted using conventional biochemical tests and the VITEK automated system. ESBL production was confirmed through genotypic detection of bla_CTX-M using polymerase chain reaction, and antimicrobial susceptibility was evaluated to determine multidrug resistance profiles. Twenty isolates (10 from healthy and 10 from diarrheic dogs) were selected for further analyses. The antimicrobial activity of NHK-EO was assessed using the broth microdilution method, and biofilm formation and inhibition were evaluated using crystal violet staining. Data are presented as mean ± standard deviation from three independent experiments.

Results: GC-MS analysis of NHK-EO revealed three major constituents: carvacrol (16.37%), eugenol (15.04%), and linalool (13.97%). In total, 78 Gram-negative bacterial isolates were identified, with E. coli being the predominant species (56 isolates, 71.79%). Among these, four bla_CTX-M-positive E. coli isolates (three from healthy dogs and one from a diarrheic dog) exhibited strong biofilm-forming ability. The minimum inhibitory concentration (MIC) of NHK-EO against the isolates was 1024-2048 µg/mL. The MIC of NHK-EO against the four bla_CTX-M-positive E. coli isolates was 1024 µg/mL. NHK-EO at 1/4× MIC (256 µg/mL) exerted significant inhibitory effects on both prebiofilm and postbiofilm formation, as confirmed using scanning electron microscopy. Treated samples exhibited notably reduced biofilm mass and decreased bacterial density compared with untreated controls.

Conclusions: NHK-EO possesses significant antimicrobial and antibiofilm activities against E. coli, including ESBL-producing strains, indicating its potential as an alternative therapeutic agent to mitigate antimicrobial resistance. Further research is warranted to explore its clinical applications in veterinary and human medicine.

This study evaluated renal health in non-azotemic geriatric dogs using routine biomarkers, including the urinary protein-to-creatinine ratio (UPC), urinalysis, fractional excretion of chloride, urinary gamma-glutamyl transferase (uGGT), and urinary alkaline phosphatase (uALP), aiming to identify early indicators of renal injury. These biomarkers were compared with structural changes observed via renal ultrasonography. A total of 84 dogs were enrolled and divided into two groups: young (n = 10; 1-4 years) and geriatric (n = 74; 7-17 years). All dogs underwent complete blood counts, serum biochemistry (creatinine, urea, alkaline phosphatase, alanine aminotransferase, sodium, potassium), and urinary analyses (urinary creatinine, chloride, UPC, uGGT, uALP), along with urinalysis. Renal ultrasonography was performed in dogs with abnormal UPC values. Statistically significant differences were found in UPC and the uGGT/urinary creatinine ratio (p < 0.05). A notable proportion of non-azotemic geriatric dogs showed proteinuria (UPC > 0.5). In these cases, ultrasonography revealed alterations in renal echogenicity-ranging from preserved to mild or marked changes-as well as varying degrees of corticomedullary differentiation and loss of renal architecture. The integration of accessible, low-cost laboratory tests with ultrasonographic assessment offers a more comprehensive evaluation of renal function and morphology, highlighting the importance of early detection for effective management and improved quality of life in aging dogs. As this was a cross-sectional study, evaluation was limited to a single time point; longitudinal follow-up would be valuable to clarify disease progression, especially in borderline or mildly proteinuric dogs.

Coccidiosis is a significant disease impacting livestock, induced by parasites of the Genus Eimeria. This study examined the in silico molecular docking and pharmacokinetic characteristics of bioactive constituents from Roweothuria polii methanolic extract (RME) against the Mus musculus catalase enzyme, along with its in vivo effectiveness in recovering the host's nutritional status affected by Eimeria papillata. RME was formulated and assessed for its antioxidant potential, protein concentration, and amino acid profile. Fourier transform-infrared spectroscopy analysis was conducted to identify the functional groups present. Twenty-five male Swiss albino mice were divided into five groups: Control, RME administration, infected with 1000 sporulated E. papillata oocysts, infected-treated with RME, and infected-treated with amprolium. Following five days of therapy, growth performance metrics, intracellular parasite stages and jejunal protein content were assessed. The oxidative state and cytokines gene expression were assessed. Results indicated that RME exhibited a scavenging efficacy of 46.61%, with a total protein content of 8.13% and the presence of 17 amino acids. The bioactive components of RME, namely squalene, methyl arachidonate and linoleic acid demonstrated the highest binding affinity in molecular docking assays targeting the catalase enzyme. In silico ADMET profiling indicated advantageous pharmacokinetic characteristics, exhibiting reduced toxicity concerns. In vivo showed that RME therapy significantly enhanced body weight loss and feed intake in infected mice. RME treatment diminished parasite stages and enhanced antioxidant status. Furthermore, RME therapy restored jejunal protein levels and downregulated cytokine gene expression. These findings underscored the bioactivity of RME and its potential usefulness against E. papillata.

Klebsiella spp. is identified as a zoonotic pathogen with a growing concern for poultry. To address this pathogen, 125 chicken samples were collected. Klebsiella variicola (K. variicola) was first detected in Egypt. The findings revealed an isolation of (30.4%) of Klebsiella spp (K. pneumoniae (94.7%) and Klebsiella variicola (K.variicola) (5.3%). The capsular typing of K. pneumoniae isolates revealed that 15.8%, 36.8%, 10.5%, 26.3%, and 5.3% belonged to phylogenetic groups K1, K2, K5, K54, and K57, respectively. The Klebsiella isolates exhibited remarkable resistance against ampicillin (94.7%), cefotaxime (89.5%), and ceftazidime (86.9%). Notably, 91.6% of the isolates were susceptible to imipenem, making it a drug of choice. 50% of Klebsiella isolates were XDR, while 47.4% were MDR with MAR indices ≥ 0.5, indicating they originated from high-risk contamination sources. 97.4% of isolates harbored at least one β-lactams resistance gene, of which bla_TEM (92.1%), bla_SHV (89.5%), bla_CTXM-1 (84.2%), and bla_DHA (50%). 7.9% of the investigated isolates possessed all carbapenemase genes (bla_NDM-1, bla_IMP-1, bla_KPC). Considering non-ESBLs, 84.2% of isolates harbored the tetA gene, while 63.2%, 52.6%, and 50% were positive for sul1, aadA, and qnrA genes. ureA, mrkD, entB genes were the most prevalent ones (100%), followed by fimH, mrkA, uge (94.7%), iutA (84.2%), iroN (73.9%), rmpA (39.5%), and magA (13.2%), with no detection of clbA and clbB genes. Our strains are genetically identical to human isolates. Our data indicated multiple health risks linked to phenotypic and genotypic resistance, as well as zoonotic importance. The Apple Cider Vinegar (ACV) possesses significant antibacterial properties.

The use of probiotics and natural nutraceuticals with demonstrated therapeutic effects for companion animals is becoming increasingly popular in the veterinary community. Probiotics are alternative to antibiotics, which produce adverse effects, such as promoting bacterial resistance and altering the intestinal microbial ecology and in turn affecting the animal's health. In this study, the in vitro safety and technological characteristics of previously isolated beneficial canine strains were evaluated for the design of a probiotic formulation for dogs. The screening of inhibitory substances production was performed in 100 isolates by plate diffusion technique. 30 strains were pre-selected to evaluate their in vitro safety and innocuity by phenotypic and genotypic antibiotic resistance and expression of pathogenicity enzymes related to virulence factors. Finally, 10 were selected to assay their tolerance to gastrointestinal conditions and stress situations such as high temperatures and solute concentrations by microplate assays. Compatibility between the selected strains was also determined in order to include them in a probiotic multi-strain formulation for canines. According to the results obtained, some strains showed inhibitory activity against common pathogens, and 38% were able to produce H₂O₂. Antibiotic resistance genes were detected in only one of the selected strains, none evidenced gelatinase or lecithinase activity and most isolates showed alpha and gamma hemolysis. Resistance to gastrointestinal tract and stress conditions was strain dependent. The compatible strains with complementary beneficial characteristics were: Lactobacillus johnsonii 67, Lactiplantibacillus plantarum 74, Ligilactobacillus salivarius 84 and Pediococcus acidilactici 81 and are being included in the design of a probiotic formulas to be evaluated in small dogs.

Varicellovirus bovinealpha-5 (BoAHV-5) is a neurotropic virus that causes necrotizing meningoencephalitis in calves. This report describes two outbreaks of BoAHV-5-associated meningoencephalitis in beef cattle. The incidence was 6.2% and 12.93% for each outbreak, respectively. Lethality was 100% in both outbreaks. Neurological signs included dullness, ataxia, and circling. The main gross finding was focal malacia in the parietal and frontal cerebral cortex of five calves autopsied. Microscopically, severe necrotizing meningoencephalitis with intranuclear eosinophilic to amphophilic inclusion bodies within astrocytes was observed in the five animals. BoAHV-5 was detected by PCR in the central nervous system of two animals (one from each outbreak). Although this disease has been reported before in South America, the most recent reports date back to the 1980s. The findings of this study suggest that BoAHV-5 should be considered a differential diagnosis for neurological disease in calves.

Amyloid A (AA) amyloidosis is a progressive disease caused by the deposition of AA, an abnormally folded protein derived from serum amyloid A (SAA), in organs throughout the body. AA amyloidosis occurs in various mammals and birds but is extremely rare in commercial pigs. A possible reason for this is that a variant SAA is crucial for the onset of AA amyloidosis in pigs. However, AA amyloidosis with wild-type SAA was recently reported in microminipigs, which are the smallest laboratory pigs, leaving the importance of this variant unclear. This is a report of the involvement of wild-type SAA in AA amyloidosis in 4-month-old three-way crossed pigs (Landrace, Large White, and Duroc: LWD). Using immunohistochemistry, transmission electron microscopy, mass spectrometry, and DNA sequencing, we determined that the amyloid fibrils were derived from wild-type SAA without detectable variant, which is a rare finding in commercial pigs. This finding suggests that AA amyloidosis can occur in commercial pigs regardless of the presence of the SAA variant.