Increasing antimicrobial resistance （AR） has become a severe problem of public health in the world, whereas control of the AR of bacteria will be based on investigation of the AR mechanism. Furthermore, understandin...Increasing antimicrobial resistance （AR） has become a severe problem of public health in the world, whereas control of the AR of bacteria will be based on investigation of the AR mechanism. Furthermore, understanding the existent selectivity of AR organisms from animals can prevent the emergence and diffusion of AR effectively. PCR amplifications of gyrA and parC genes have been performed for detecting fluoroquinolones-resistance （FR） genes. A conjugational transfer test has been carried out using a donor which is resistant to tetracycline （TE）, ampicillin （AMP）, sulfamethoxazole-trimethoprim （SXT）, and a recipient which is sensitive to TE, AMP, and SXT. The AR strains have been passed 20 passages. Two groups of chicken inoculated multi-AR Escherichia coli （E. coli） and multi-AR Salmonella, respectively, are mix-fed. The result shows that amino acid codons of Ser-83 and Asp-87 are mutations from gyrA and there are no mutations from parC genes in all the FR strains. Resistance to TE, AM, and SXT can transfer among E. coli and the conjugal transfer frequency of TE is 3×10^-7. AR can inherit in 20 passages at least. The multi-AR E. coli and Salmonella can be isolated from all chickens three days after inoculation but CIP-resistant strains decrease during the time run out and disappear at 23 days after inoculation. The results indicate that the mutations of gene gyrA are correlative with the FR phenotype. AR genes that are not connected to the chromosome can transfer horizontally and vertically. AR bacteria can diffuse quickly and eliminate naturally from the host if the chicken is not under the pressure of this antibiotic.展开更多
The coagulase-negative staphylococci (CoNS) group was considered saprophytic or rarely pathogenic for many years. Since the first case of septicemia caused by CoNS, there has been a progressive increase in the prevale...The coagulase-negative staphylococci (CoNS) group was considered saprophytic or rarely pathogenic for many years. Since the first case of septicemia caused by CoNS, there has been a progressive increase in the prevalence of healthcare-associated infections caused by CoNS. The CoNS group has emerged as one of the main causes of nosocomial infections related to vascular catheters and prostheses, especially among immunocompromised patients. This gradual increase in infections is due to the change in the relationship between patients and procedures since CoNS are closely related to devices implanted in the human body. CoNS are successful in colonizing the host because they have several virulence mechanisms, such as biofilm formation and production of enzymes and toxins, in addition to several mechanisms of resistance to antimicrobials. Despite their great clinical relevance, few studies have focused on CoNS’s pathogenicity and resistance to antimicrobials, which reveals the current need to better understand the factors by which this group became pathogenic to humans and other animals. This review aims to synthesize the aspects related to the pathogenicity and antimicrobial resistance in CoNS.展开更多
A total of 241 Escherichia coli （E. coli） isolates from 349 avian samples （292 from cloacae, 29 from feed and water, 28 from dust and padding） were collected from Northeast, South, North, and Central China in rece...A total of 241 Escherichia coli （E. coli） isolates from 349 avian samples （292 from cloacae, 29 from feed and water, 28 from dust and padding） were collected from Northeast, South, North, and Central China in recent years. The percentage of isolation was 69.1%. There are 67 serogroups each with 1-2 isolates distributed in different regions, and some of these regions had the preponderant serogroups. Antimicrobial-resistance （AR） of E. coli was so severe that the majority were multi-AR. Fifty percent strains were resistant to 10-19 antimicrobial drugs. Overall, the isolates represented resistance to nalidixic acid （88.1%）, tetracycline （85.7%）, sulfamethoxazole （81.0%）, trimethoprim-sulfamethpxazole （77.1%）, ampicillin （76.2%）, amoxilline （74.3%）, streplomycin （66.2%）, fluoroquinolones （57.1-66.7%）, chloramphenicol （52.9%）, gentamicin （39.0%）, and kanamycin （36.2%）. The isolates were sensitive to cefalexin, amoxilline-clavulanic acid, amikacin, and florfenicol with an AR rate of 0-19,5% only, The results showed that the AR was more severe in chicken farms in which the antibiotics were used broadly and repeatedly. This study indicated the AR characterization of E, coli in different areas of China. It will be a foundation for studying AR mechanism and regulating the usage of antimicrobial in the poultry industry.展开更多
Background:Secondary antimicrobial resistance bacterial(AMR)pneumonia could lead to an increase in mortality in COVID-19 patients,particularly of geriatric patients with underlying diseases.The comedication of current...Background:Secondary antimicrobial resistance bacterial(AMR)pneumonia could lead to an increase in mortality in COVID-19 patients,particularly of geriatric patients with underlying diseases.The comedication of current medicines for AMR pneumonia with corticosteroids may lead to suboptimal treatment or toxicities due to drug-drug interactions(DDIs).Objective:This study aimed to propose new promising dosage regimens of photoactivated curcumin when co-administered with corticosteroids for the treatment of antimicrobial resistance(AMR)pneumonia in COVID-19 patients.Methods:A whole-body physiologically-based pharmacokinetic(PBPK)with the simplified lung compartments model was built and verified following standard model verification(absolute average-folding error or AAFEs).The pharmacokinetic properties of photo-activated were assumed to be similar to curcumin due to minor changes in physiochemical properties of compound by photoactivation.The acceptable AAFEs values were within 2-fold.The verified model was used to simulate new regimens for different formulations of photoactivated curcumin.Results:The AAFEs was 1.12-fold.Original formulation(120 mg once-daily dose)or new intramuscular nano-formulation(100 mg with a release rate of 10/h given every 7 days)is suitable for outpatients with MRSA pneumonia to improve patient adherence.New intravenous formulation(2000 mg twice-daily doses)is for hospitalized patients with both MRSA and VRSA pneumonia.Conclusion:The PBPK models,in conjunction with MIC and applied physiological changes in COVID-19 patients,is a potential tool to predict optimal dosage regimens of photo-activated curcumin for the treatment of co-infected AMR pneumonia in COVID-19 patients.Each formulation is appropriate for different patient conditions and pathogens.展开更多
文摘Increasing antimicrobial resistance （AR） has become a severe problem of public health in the world, whereas control of the AR of bacteria will be based on investigation of the AR mechanism. Furthermore, understanding the existent selectivity of AR organisms from animals can prevent the emergence and diffusion of AR effectively. PCR amplifications of gyrA and parC genes have been performed for detecting fluoroquinolones-resistance （FR） genes. A conjugational transfer test has been carried out using a donor which is resistant to tetracycline （TE）, ampicillin （AMP）, sulfamethoxazole-trimethoprim （SXT）, and a recipient which is sensitive to TE, AMP, and SXT. The AR strains have been passed 20 passages. Two groups of chicken inoculated multi-AR Escherichia coli （E. coli） and multi-AR Salmonella, respectively, are mix-fed. The result shows that amino acid codons of Ser-83 and Asp-87 are mutations from gyrA and there are no mutations from parC genes in all the FR strains. Resistance to TE, AM, and SXT can transfer among E. coli and the conjugal transfer frequency of TE is 3×10^-7. AR can inherit in 20 passages at least. The multi-AR E. coli and Salmonella can be isolated from all chickens three days after inoculation but CIP-resistant strains decrease during the time run out and disappear at 23 days after inoculation. The results indicate that the mutations of gene gyrA are correlative with the FR phenotype. AR genes that are not connected to the chromosome can transfer horizontally and vertically. AR bacteria can diffuse quickly and eliminate naturally from the host if the chicken is not under the pressure of this antibiotic.
文摘The coagulase-negative staphylococci (CoNS) group was considered saprophytic or rarely pathogenic for many years. Since the first case of septicemia caused by CoNS, there has been a progressive increase in the prevalence of healthcare-associated infections caused by CoNS. The CoNS group has emerged as one of the main causes of nosocomial infections related to vascular catheters and prostheses, especially among immunocompromised patients. This gradual increase in infections is due to the change in the relationship between patients and procedures since CoNS are closely related to devices implanted in the human body. CoNS are successful in colonizing the host because they have several virulence mechanisms, such as biofilm formation and production of enzymes and toxins, in addition to several mechanisms of resistance to antimicrobials. Despite their great clinical relevance, few studies have focused on CoNS’s pathogenicity and resistance to antimicrobials, which reveals the current need to better understand the factors by which this group became pathogenic to humans and other animals. This review aims to synthesize the aspects related to the pathogenicity and antimicrobial resistance in CoNS.
文摘A total of 241 Escherichia coli （E. coli） isolates from 349 avian samples （292 from cloacae, 29 from feed and water, 28 from dust and padding） were collected from Northeast, South, North, and Central China in recent years. The percentage of isolation was 69.1%. There are 67 serogroups each with 1-2 isolates distributed in different regions, and some of these regions had the preponderant serogroups. Antimicrobial-resistance （AR） of E. coli was so severe that the majority were multi-AR. Fifty percent strains were resistant to 10-19 antimicrobial drugs. Overall, the isolates represented resistance to nalidixic acid （88.1%）, tetracycline （85.7%）, sulfamethoxazole （81.0%）, trimethoprim-sulfamethpxazole （77.1%）, ampicillin （76.2%）, amoxilline （74.3%）, streplomycin （66.2%）, fluoroquinolones （57.1-66.7%）, chloramphenicol （52.9%）, gentamicin （39.0%）, and kanamycin （36.2%）. The isolates were sensitive to cefalexin, amoxilline-clavulanic acid, amikacin, and florfenicol with an AR rate of 0-19,5% only, The results showed that the AR was more severe in chicken farms in which the antibiotics were used broadly and repeatedly. This study indicated the AR characterization of E, coli in different areas of China. It will be a foundation for studying AR mechanism and regulating the usage of antimicrobial in the poultry industry.
基金supported by postdoctoral fellowship,Thammasat University(Rangsit Campus),ThailandKesara Na-Bangchang was received funding from Thammasat University under the project Center of Excellence in Pharmacology and Molecular Biology of Malaria and Cholangiocarcinoma(No.1/2556,dated October 12,2013)+1 种基金the National Research Council of Thailand(No.45/2561,dated September 10,2018)Kesara Na-Bangchang is supported by the National Research Council of Thailand under the Research Team Promotion grant(grant number NRCT 820/2563,dated November 12,2020).
文摘Background:Secondary antimicrobial resistance bacterial(AMR)pneumonia could lead to an increase in mortality in COVID-19 patients,particularly of geriatric patients with underlying diseases.The comedication of current medicines for AMR pneumonia with corticosteroids may lead to suboptimal treatment or toxicities due to drug-drug interactions(DDIs).Objective:This study aimed to propose new promising dosage regimens of photoactivated curcumin when co-administered with corticosteroids for the treatment of antimicrobial resistance(AMR)pneumonia in COVID-19 patients.Methods:A whole-body physiologically-based pharmacokinetic(PBPK)with the simplified lung compartments model was built and verified following standard model verification(absolute average-folding error or AAFEs).The pharmacokinetic properties of photo-activated were assumed to be similar to curcumin due to minor changes in physiochemical properties of compound by photoactivation.The acceptable AAFEs values were within 2-fold.The verified model was used to simulate new regimens for different formulations of photoactivated curcumin.Results:The AAFEs was 1.12-fold.Original formulation(120 mg once-daily dose)or new intramuscular nano-formulation(100 mg with a release rate of 10/h given every 7 days)is suitable for outpatients with MRSA pneumonia to improve patient adherence.New intravenous formulation(2000 mg twice-daily doses)is for hospitalized patients with both MRSA and VRSA pneumonia.Conclusion:The PBPK models,in conjunction with MIC and applied physiological changes in COVID-19 patients,is a potential tool to predict optimal dosage regimens of photo-activated curcumin for the treatment of co-infected AMR pneumonia in COVID-19 patients.Each formulation is appropriate for different patient conditions and pathogens.
