Silver Nanoparticles and Sodium Hypochlorite Inhibitory Effects on Biofilm Produced by Pseudomonas aeruginosa from Poultry Farms

In Egypt, pseudomonas infection is one of the most important problems facing poultry production. Pseudomonas spp. is recognized as a major food spoiler and environmental contaminant. Biofilm formation by P. aeruginosa has an important role in the bacterial pathogenesis as well as persistence in the environment. The antibacterial and antibiofilm activities of AgNPs and NaOCL were evaluated against P. aeruginosa isolated from chicken farms. MIC and MBC of AgNPs against planktonic cells of P. aeruginosa were 15 and 20µg/ml, respectively. While those of NaOCL were 2200 and 2600 µg/ml, respectively. The highest inhibition percentages of biofilm formation (97.9%) was observed when P. aeruginosa treated with AgNPs (25µg/ml). While, 87.5% biofilm removal percentage was achieved after treating the established biofilm with 25 µg/ml AgNPs for 2.5 h. Moreover, NaOCL (2800 µg/ml) was able to cause 96.6% inhibition of biofilm formation and 90.3% biofilm removal after 1.5 h contact. The current study revealed that AgNPs and NaOCL were able to promote a significant reduction and removal of the mature biofilms formed by P. aeruginosa and the antibiofilm efficiency increased with the increase of its contact times with the biofilms

Inhibitory Activity of Silver Nanoparticles and Sodium Hypochlorite against Biofilm Produced by Salmonellae Isolated from Poultry Farms

Salmonella typhimurium and Salmonella enteritidis are among the predominant Salmonella serotypes in the Egyptian poultry farms. Salmonella has the ability to build up biofilms on a variety of surfaces. The antibiofilm activities of silver nanoparticles (AgNPs) and sodium hypochlorite (NaOCL) on prevention and controlling of biofilm by Salmonella spp. was estimated. Silver nanoparticles exhibited bactericidal activity against both S. typhimurium and S. enteritidis with MIC value at 15 µg/ml, while, that of NaOCL was 1600 µg/ml. AgNPs (25 ug/ml) could inhibit biofilm formation at percentages of 84.96% and 78.85% against S. typhimurium and S. enteritidis, respectively. A percentage of 87 % biofilm removal by AgNPS after 3 h contact with the built-up biofilm produced by S. typhimurium and S. enteritidis was recorded. NaOCL (2200 µg/ml) exhibited inhibition percentages of biofilm formation at 83.89% and 75.76% against S. typhimurium and S. enteritidis, respectively. While, biofilm removal percentages after 2 h contact between NaOCL (2200 µg/ml) with the formed biofilm by S. typhimurium and S. enteritidis were 87.42% and 89.37%, respectively. It can be concluded that AgNPs and NaOCl were able to promote a significant reduction of biofilm formation by S. typhimurium and S. enteritidis. Also, AgNPs and NaOCl effectively oppress the mature biofilms formed and the antibiofilm efficiency increased with the increase of contact time with the biofilms

Risk Assessment and Quinolones Plasmid-mediated Resistance Genes in Intensive Broiler Farms

Quinolones are frequently applied in intensive production and their risks are creation of residues and development of bacterial resistance, which is one of the major challenges to human health. Muscle, liver and kidney as well as, intestinal contents were collected from intensive broiler farms in Upper Egypt. Samples were analyzed for quinolones residues (norfloxacin, ciprofloxacin, enrofloxacin and danofloxacin) using HPLC. Intestinal contents were investigated for two plasmid-mediated resistance genes; qnrA, qnrB and one chromosomal gene; gyrA. All liver and kidney samples were contaminated with enrofloxacin and the highest level was found in the liver that exceeded the maximum residue limit, which contribute to health hazards for adult and children. QnrB and gyrA genes could be detected in 25% and 8% of the samples, respectively. This study represents the first record about existence of qnrB and gyrA in broiler intestinal content. These results denoted that some broilers’ edibles sold in Egypt contain high level of quinolones. Litter from intensive farms maybe considered as a critical source of resistant genes giving a chance of horizontal transfer of resistant determinants. Consequently, it is necessary to examine broiler products and by-products for the presence of residual quinolones and resistance genes