Therapeutic effect of biosynthetic gold nanoparticles on multidrug-resistant Escherichia coli and Salmonella species isolated from ruminants

Abstract

Background and Aim: Multidrug-resistant (MDR) pathogenic microorganisms have become a global problem in ruminants as a result of the intensive use of antibiotics, causing the development of resistance among gut microbiota. The antibiotic-resistant microorganisms can be transferred from diseased animals to humans. This study aimed to determine the prevalence of MDR Escherichia coli and Salmonella spp. isolated from cattle, buffaloes, sheep, and goats suffering from respiratory signs, diarrhea, and mastitis and to screen the antibiotic sensitivity of selected isolated bacteria. It also detected antibiotic-resistance genes by polymerase chain reaction (PCR), produced green gold nanoparticles (AuNPs) using plant extracts (Artemisia herba-alba and Morus alba), and evaluated the antimicrobial activities of these biosynthesized nanoparticles on selected pathogens (E. coli and Salmonella spp.). Materials and Methods: MDR E. coli and Salmonella spp. were investigated using fecal samples (n=408), nasal swabs (n=358), and milk samples (n=227) of cattle, buffaloes, sheep, and goats with or without clinical signs, including respiratory manifestations, pneumonia, diarrhea, and mastitis, from different governorates in Egypt. E. coli and Salmonella spp. were isolated and identified on selective media, which were confirmed by biochemical reactions and PCR. Antimicrobial susceptibility testing against 10 commonly used antibiotics was performed using the Kirby-Bauer disk diffusion method. Antibiotic resistance genes blaTEM, blaSHV, blaOXA, and blaCTX-M were detected by PCR. The antibacterial effect of the biosynthesized AuNPs was evaluated by MIC and well diffusion assay. The biosynthesized AuNPs were also characterized by ultraviolet-visible spectrophotometry and transmission electron microscopy (TEM). Results: Among all fecal samples, the prevalence of E. coli was 18.4% (183/993) and that of Salmonella spp. was 16.7% (66/408), as determined by cultural and molecular tests. All isolates of E. coli and Salmonella spp. were 100% resistant to ampicillin (AM) and amoxicillin and highly resistant to cefoxitin and AM-sulbactam. The total rate of resistance genes in E. coli was 61.2% (112/183), while that in Salmonella was 63.6% (42/66) for pathogens isolated from ruminants with respiratory manifestations, pneumonia, diarrhea, and mastitis. Among the resistance genes, blaTEM had the highest prevalence rate in E. coli (25.9%, 21/81) while blaSHV had the lowest (9.8%, 8/81) in fecal swabs. AuNPs were successfully synthesized using aqueous leaf extract of A. herba-alba and M. alba as bioreducing agents. TEM analysis showed particle size of 10-42 nm for A. herba-alba and M. alba AuNPs. The biosynthesized AuNPs showed antibacterial activity against MDR E. coli and Salmonella spp. Conclusion: Rapid and accurate diagnostic methods are the cornerstone for effective treatment to reduce the risk of antimicrobial-resistant pathogenic microorganisms. This is particularly important for overcoming the increasing rate of MDR in ruminants with respiratory manifestations, pneumonia, diarrhea, and mastitis. This can be complemented by the development of AuNPs synthesized in an environmentally friendly manner AuNPs using natural plant extracts for the treatment of antibiotic-resistant microorganisms.

Antibacterial activity of metallic-core gold and silver nanoparticles against some animal pathogens

“…Moreover, the SEM displayed that the AgNPs have a spherical shape, while the AuNPs are rod-shaped, as reported in this research. Abdalhamed et al (2021a) examined AuNPs produced using phytochemicals for the green production of metallic NPs and found similar results to ours.. According to Nagar et al (2016), while bio-surfactants used to synthesize AgNPs alter the pH value and decrease their size (60 nm), nanoparticles are uniform at pH 9.…”

“…Additionally, using NPs (nanoparticles) offers a solid policy to cope with infections and diseases triggered by MDR bacteria in animals (Farouk et al, 2020;Salah et al, 2020;Abdalhamed et al, 2021a;Masimen et al, 2022). Salah et al (2020) reported AgNPs exhibited a robust bactericidal influence against S. aureus isolated from mastitic ewes and goats.…”

Selective detection of diethanolamine utilizing an LMR/LSPR-based optical fiber sensor

“…A methanol extract of the fruit mesocarp of Balanites aegyptiaca was used to synthesize gold (Au) nanoparticles with slight modifications to the method described earlier. 43,44 Freshly collected Balanites aegyptiaca fruits were thoroughly washed under tap water followed by double-distilled water. For the preparation of the extract, the washed fruits were peeled, and the mesocarp was separated from the fruits.…”

Development of gold nanoparticles-lateral flow test as a novel field diagnostic assay for detecting foot-and-mouth disease and lumpy skin disease viruses

“…The size of gold-nanoparticles ranged from 5 to 30 nm. They were prepared by adding 1% disodium citrate solution (w/v) added to 0.01% aqueous chloroauric acid solution (w/v) at 100°C for 5 min according to the protocol described by Abdalhamed et al ( 18 ), then gradually cooled, the pH of the solution was adjusted to 8.4, and then the solution was stored at 4°C in a dark bottle. Monoclonal antibody (Ab) (100 mg/ml) was added drop wise into a 10 ml solution.…”

“…The lateral flow test (LFT) is rapid diagnostic technique based on specific immune responses involving antigens and antibodies that does not necessitate any special. An antibody labeled with gold nanoparticles (GNP) placed in a dried state on fiber glass with the great sensitivity ( 18 ).…”