![]() ![]() Quorum quenching (QQ) is the process of interrupting quorum sensing through three mechanisms: (1) interference with the synthesis of signal molecules, (2) enzyme-mediated degradation of signal molecules, and (3) blocking of signal molecule receptors (Geske et al. Since quorum sensing regulates different biological functions associated with virulence, and as the emergence of multi-drug resistant bacterial strains is on the rise, there is increasing pressure to discover new antimicrobial agents targeting virulence, including bacterial adhesion, toxin function, regulation of virulence expression (D'Angelo et al. The increasing incidence of multidrug-resistant bacteria poses a significant challenge for physicians and veterinarians, limiting treatment choices and raising concerns about transmission to humans through the food chain and the emergence of super-resistant bacteria (Li et al. pneumoniae resistance to broad-spectrum β-lactams has become an alarming and growing public health challenge based on the recent reports on antimicrobial resistance from the US Centers for Disease Control and Prevention (CDC) and the European Centre for Disease Prevention Control (CDC 2019 ECDC 2020). It has worldwide approval for respiratory diseases in chicks and turkey poults (Hornish and Katarski 2002). Ceftiofur is a third-generation cephalosporin antibiotic with a wide spectrum of activity against Gram-negative and Gram-positive pathogens, that exerts its bactericidal action by inhibition of the bacterial cell wall synthesis (El-Sayed et al. pneumoniae isolated from poultry samples were C4-HSL, C6-HSL, and C12-HSL (Hosny and Fadel 2021).īeta-lactams are the most commonly used antibiotics for treating infections caused by Enterobacteriaceae in the veterinary sector (Rubin and Pitout 2014). It was reported that the most quantifiable AHLs produced by K. ![]() pneumoniae has the typical LuxR/LuxI quorum sensing system and the most commonly produced signal molecules is N-acyl-homoserine lactones (AHLs) (Chan 2013). The expression of virulence factors such as capsular polysaccharides, lipopolysaccharides, adherence factors, siderophore production, and biofilm formation have been reported to be under the regulation of quorum sensing in Klebsiella species (Clegg and Murphy 2017 Santajit et al. 2016 Hosny and Fadel 2021 Khelfa and Morsy 2015 Zhai et al. The general isolation rates of the bacteria in poultry are 10% to 35% (Aly et al 2014 Hamza et al. ![]() pneumoniae have been isolated from chickens suffered from omphalitis, dermatitis, cellulitis, and inflamed respiratory mucosa (Kowalczyk et al 2022). pneumoniae is one of the most common causes of yolk sac infections in chicks (Khan et al. pneumoniae is also found in livestock and poultry causing respiratory symptoms, production loss, and even deaths if untreated or immunosuppressed (Hamza et al. It causes a wide variety of community-acquired infections in human, including urinary tract infections, pneumonia, septicemia, and liver abscesses (Hayati et al. Klebsiella pneumoniae is an opportunistic Gram-negative bacterial pathogen that normally inhabits the mucosal surfaces of humans and animals, and is also commonly found in different environmental sources such as water and soil (Struve and Krogfelt 2004 Hosny and Fadel 2021). This is the first report of the administration of N-acyl homoserine lactonase for the control of multi-resistant K. The elimination half-life in niosome-treated groups was longer than that reported in ceftiofur-treated groups. The maximum ceftiofur serum concentrations in treated groups were observed 2 h following administration. The niosome-treated challenged group showed mild signs and lesions with lower mortality and colony count than the positive control group. The viability of Vero cells was unaffected up to 5 × MIC (2.4 gml −1). The niosome was spherical and 56.5 ± 4.41 nm in size. Pharmacokinetic parameters were evaluated in four treated groups at nine-time points. Tracheal swabs were collected from groups П, V, and VI for counting K. Signs, mortality, and gross lesions were recorded. In groups Ш and IV, ceftiofur and niosome were administrated intramuscularly at a dose of 10 mg/kg body weight for five consecutive days, while groups V and VI received the injections following the K. Fourteen-day-old chicks were assigned to six groups: groups Ӏ and П served as negative and positive controls, receiving saline and K. The niosome was formulated, characterized, and tested for minimal inhibitory concentration (MIC) and cytotoxicity. The lactonase enzyme was extracted from eight quorum-quenching isolates. ![]() pneumoniae isolates previously recovered from different poultry and environmental samples were screened for the ahlK gene. In this study, the efficiency of the ceftiofur N-acyl homoserine lactonase niosome against multi-resistant Klebsiella pneumoniae in broilers was evaluated. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |