In Vitro Efficacy of Chitosan Nanoparticles Against Staphylococcus aureus and Klebsiella Spp. Isolates From Bovine Mastitis Milk: Addressing Antibiotic Resistance and Exploring Alternative Treatments

Abd El-Mongy, Mahmoud; Khalefa, Hanan Saad; Arafa, Nadia S.; A. Mosleh, Amani I.; Nada, Shaimaa M

doi:10.21608/ejvs.2025.419155.3097

In Vitro Efficacy of Chitosan Nanoparticles Against Staphylococcus aureus and Klebsiella Spp. Isolates From Bovine Mastitis Milk: Addressing Antibiotic Resistance and Exploring Alternative Treatments

Document Type : Original Article

Authors

¹ Microbial Biotechnology Department, Genetic Engineering and Biotechnology Research Institute, University of Sadat City, Egypt.

² department of veterinary hygiene and management, faculty of veterinary medicine, Cairo university.

³ Animal health research institute -Shibin El-Kom branch, ARC, E-Menufia city, Egypt

⁴ Department of Microbiology, Animal Health Research Institute, Shebin El–Kom Branch ARC, Egypt

10.21608/ejvs.2025.419155.3097

Abstract

This study evaluates the potential antimicrobial properties of chitosan nanoparticles (CNPs) against extended-spectrum beta-lactamases (ESBLs)-producing bacteria (S. aureus and K. pneumoniae) isolated from mastitic milk samples taken from bovine livestock within the El-Menoufia government. One hundred milk samples were tested using the California Mastitis Test, and the isolated bacteria were identified using traditional and molecular techniques. A scanning electron microscope, a Fourier transform infrared spectrometer (FTIR), and X-ray diffraction were utilized to characterize CNPs. The results show that Klebsiella spp. were found in 48% of clinical mastitis cows and 24% of buffaloes, and in 36% and 20% of subclinical cases, respectively. Staphylococcus spp. were found in 56% of clinical mastitis cows and 32% of buffaloes, and in 44% and 24% of subclinical cases. Antibiogram analysis showed Klebsiella spp. were most sensitive to quinolones (53%) and least to tetracycline (34%),while Staphylococcus spp. showed the highest sensitivity to ofloxacin (43.5%) and ampicillin/sulbactam (41.1%). The distribution of bla_TEM gene was observed at 41.8%, followed by bla_SHV gene and bla_CTX-Mgene were 34.8% and 32.5% respectively. K. pneumoniae and S. aureus showed the highest multidrug resistance against the tested antibiotic discs. The CNPs were tested in vitro against isolated bacteria and exhibited inhibition zones ranging from 6 to 12 mm. Transfer electron microscopy (TEM) images showed that CNPs significantly altered cell morphology, leading to bacterial death. Therefore, nanoparticles could be a promising solution for controlling, preventing, and treating bovine mastitis.

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