| Abstract: |
ABSTRACTInfection is a dynamic process involving invasion of the body by pathogenic microorganisms and reactions of the tissues to microorganisms and their toxins. Pathogenic microorganisms isolated from clinical samples are of great threat to human health.The outcome of an infection depends on the virulence of the pathogen and the relative degree of resistance or susceptibility to antimicrobial chemotherapy. Antimicrobial agents interfere with specific processes that are essential for growth and division.Development of antibiotic resistance in bacteria is a problem of great concern. The high prevalence of resistant bacteria seems to be related to uncontrolled usage of antibiotics. B-lactamases are the most common cause of bacterial resistance to B-lactam One hundred and seven clinical samples and specimens were collected from public, private hospitals and National Cancer Institute (NCI) in Cairo, Egypt. Out of them 72 cases positive for microbial infection. Twelve cases were showed mixed infection. EightyThe identified strains were exposed to in-vitro gamma irradiation at dose level of 24.4 Gy, which is biologically equivalent to the fractionated multiple therapeutic dose used in the protocol of cancer treatment of some patients.The antimicrobial susceptibility of the nine multi-drug resistant strains were carried out by disk diffusion method before and after irradiation. Determination of B-lactamase and AmpC-B-lactamase enzyme production were carried out by two methods. CefotaxiThe result of the present investigation showed that, 9 multi-drug resistant isolates were identified as; 2 isolates Escherichia coli, 2 isolates Pseudomonas aeruginosa, 1 isolate Citrobacter freundii, 1 isolate Morganella morganii all were isolated from uDouble-disk diffusion synergy test (DDST) and combined disk method revealed that six of the isolates (66.6%) were extended-spectrum B-lactamase producers.Minimum inhibitory concentration (MIC) for single antibiotics before and after irradiation showed an increase in MIC of ampicillin\sulbactam to double its value after irradiation with (Morg.60 and Ent.67), cefoperazone with Ps.47, levofloxacin with (Ps.47The combination between (cefoperazone + levofloxacin) was the best between our tested combined antibiotics. It gave synergistic effect with 6 strains out of nine (66.6%) with FIC index values ranged between (0.5 – 0.25), followed by (ampicillin\sulbactam Plasmids profile analysis of multi-drug resistance (Kleb.52, Morg.60 and Ps.72) tested strains before and after irradiation showed one separated band with molecular weight more than 3147bp, with difference in the molecular weight, optical density and Rf vTotal protein analysis of Pseudomonas aeruginosa (Ps.72) showed two bands with different molecular weight and percentage of total protein before and after exposure to in-vitro gamma radiation and in the presence of single and combined antibioticsABSTRACTInfection is a dynamic process involving invasion of the body by pathogenic microorganisms and reactions of the tissues to microorganisms and their toxins. Pathogenic microorganisms isolated from clinical samples are of great threat to human health.The outcome of an infection depends on the virulence of the pathogen and the relative degree of resistance or susceptibility to antimicrobial chemotherapy. Antimicrobial agents interfere with specific processes that are essential for growth and division.Development of antibiotic resistance in bacteria is a problem of great concern. The high prevalence of resistant bacteria seems to be related to uncontrolled usage of antibiotics. B-lactamases are the most common cause of bacterial resistance to B-lactam One hundred and seven clinical samples and specimens were collected from public, private hospitals and National Cancer Institute (NCI) in Cairo, Egypt. Out of them 72 cases positive for microbial infection. Twelve cases were showed mixed infection. EightyThe identified strains were exposed to in-vitro gamma irradiation at dose level of 24.4 Gy, which is biologically equivalent to the fractionated multiple therapeutic dose used in the protocol of cancer treatment of some patients.The antimicrobial susceptibility of the nine multi-drug resistant strains were carried out by disk diffusion method before and after irradiation. Determination of B-lactamase and AmpC-B-lactamase enzyme production were carried out by two methods. CefotaxiThe result of the present investigation showed that, 9 multi-drug resistant isolates were identified as; 2 isolates Escherichia coli, 2 isolates Pseudomonas aeruginosa, 1 isolate Citrobacter freundii, 1 isolate Morganella morganii all were isolated from uDouble-disk diffusion synergy test (DDST) and combined disk method revealed that six of the isolates (66.6%) were extended-spectrum B-lactamase producers.Minimum inhibitory concentration (MIC) for single antibiotics before and after irradiation showed an increase in MIC of ampicillin\sulbactam to double its value after irradiation with (Morg.60 and Ent.67), cefoperazone with Ps.47, levofloxacin with (Ps.47The combination between (cefoperazone + levofloxacin) was the best between our tested combined antibiotics. It gave synergistic effect with 6 strains out of nine (66.6%) with FIC index values ranged between (0.5 – 0.25), followed by (ampicillin\sulbactam Plasmids profile analysis of multi-drug resistance (Kleb.52, Morg.60 and Ps.72) tested strains before and after irradiation showed one separated band with molecular weight more than 3147bp, with difference in the molecular weight, optical density and Rf vTotal protein analysis of Pseudomonas aeruginosa (Ps.72) showed two bands with different molecular weight and percentage of total protein before and after exposure to in-vitro gamma radiation and in the presence of single and combined antibioticsWith increasing antimicrobial resistance, it is important to find antibiotics with enhanced activity against resistant organisms. Antibiotic combination are used to enhance antibacterial efficacy and prevent the development of resistance.ABSTRACTInfection is a dynamic process involving invasion of the body by pathogenic microorganisms and reactions of the tissues to microorganisms and their toxins. Pathogenic microorganisms isolated from clinical samples are of great threat to human health.The outcome of an infection depends on the virulence of the pathogen and the relative degree of resistance or susceptibility to antimicrobial chemotherapy. Antimicrobial agents interfere with specific processes that are essential for growth and division.Development of antibiotic resistance in bacteria is a problem of great concern. The high prevalence of resistant bacteria seems to be related to uncontrolled usage of antibiotics. B-lactamases are the most common cause of bacterial resistance to B-lactam One hundred and seven clinical samples and specimens were collected from public, private hospitals and National Cancer Institute (NCI) in Cairo, Egypt. Out of them 72 cases positive for microbial infection. Twelve cases were showed mixed infection. EightyThe identified strains were exposed to in-vitro gamma irradiation at dose level of 24.4 Gy, which is biologically equivalent to the fractionated multiple therapeutic dose used in the protocol of cancer treatment of some patients.The antimicrobial susceptibility of the nine multi-drug resistant strains were carried out by disk diffusion method before and after irradiation. Determination of B-lactamase and AmpC-B-lactamase enzyme production were carried out by two methods. CefotaxiThe result of the present investigation showed that, 9 multi-drug resistant isolates were identified as; 2 isolates Escherichia coli, 2 isolates Pseudomonas aeruginosa, 1 isolate Citrobacter freundii, 1 isolate Morganella morganii all were isolated from uDouble-disk diffusion synergy test (DDST) and combined disk method revealed that six of the isolates (66.6%) were extended-spectrum B-lactamase producers.Minimum inhibitory concentration (MIC) for single antibiotics before and after irradiation showed an increase in MIC of ampicillin\sulbactam to double its value after irradiation with (Morg.60 and Ent.67), cefoperazone with Ps.47, levofloxacin with (Ps.47The combination between (cefoperazone + levofloxacin) was the best between our tested combined antibiotics. It gave synergistic effect with 6 strains out of nine (66.6%) with FIC index values ranged between (0.5 – 0.25), followed by (ampicillin\sulbactam Plasmids profile analysis of multi-drug resistance (Kleb.52, Morg.60 and Ps.72) tested strains before and after irradiation showed one separated band with molecular weight more than 3147bp, with difference in the molecular weight, optical density and Rf vTotal protein analysis of Pseudomonas aeruginosa (Ps.72) showed two bands with different molecular weight and percentage of total protein before and after exposure to in-vitro gamma radiation and in the presence of single and combined antibioticsWith increasing antimicrobial resistance, it is important to find antibiotics with enhanced activity against resistant organisms. Antibiotic combination are used to enhance antibacterial efficacy and prevent the development of resistance.
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