The rapid increase of bacterial resistance strains to multiple antibiotics has become a global public health concern. In the present study, actinomycetes from different districts of Libyan soil were isolated and scree...The rapid increase of bacterial resistance strains to multiple antibiotics has become a global public health concern. In the present study, actinomycetes from different districts of Libyan soil were isolated and screened for their inhibitory activity against pathogenic bacteria and fungi. Three hundred soil samples were taken from 77 diverse ecosystems, including deserts, forests, pastureland, and cropland located in different climatic regions in Libya. A total of 164 actinomycetes were obtained. Of 164 isolates, 38 (23.2%) isolates were morphologically and microscopically characterized by spore chain and surface morphology, aerial and substrate mycelia and soluble pigments. The preliminary classification of the isolates illustrates that all isolates belong to the genus Streptomyces. These isolates were further examined for their antagonistic potential against nine pathogenic bacteria and fungi. Out of 38, 11 (28.9%) isolates showed their capability to produce inhibitory substances against at least two tested strains. Among bacterial strains, Staphylococcus aureus was susceptible to almost all eleven isolates (90.9%), while Streptococcus pyogenes was found to be resistant to most selected isolates (18.2%). The isolate, 063 (Wadan soil-desert zone) was the only isolate that exhibited broad spectrum antimicrobial activity against all tested pathogenic microbes, and hence was selected for further study. According to its cultural, morphological, physiological, and biochemical characteristics, the isolate 063 was identified as Streptomyces rochei. The results obtained indicate that the Libyan soil, particularly in extreme environments, could be a potent source of bioactive metabolites with antimicrobial potency against a wide variety of microbial pathogens. Thus, this investigation suggested that exploring new habitats in unexplored and untapped regions of Libya could provide a promising source of biologically active compounds for therapeutic applications.展开更多
The present study sought to assess the rational use of antimicrobial agents in a Brazilian intensive care unit (ICU) and its association with antimicrobial resistance in elderly patients admitted to the unit. Results:...The present study sought to assess the rational use of antimicrobial agents in a Brazilian intensive care unit (ICU) and its association with antimicrobial resistance in elderly patients admitted to the unit. Results: Choice of empiric and sensitivity-guided therapy was inadequate in > 80% and 59% of cases respectively. Inadequate antimicrobial therapy, whether empiric or sensitivity-guided, was positively correlated with bacterial resistance (r = 0.316;p = 0.001). Sensitivity testing revealed a 46.5% resistance rate to eight out of the ten most commonly used antibiotics. Multiple drug-resistant organisms were found in 40.8% of patients. A significant increase was observed in the number of multidrug-resistant samples between 2006/2007 and 2008 (r = 0.41, p = 0.006), (r = 0.598, p = 0.001), (r = 0.688, p = 0.00). Conclusion: We found a high rate of antibiotic misuse in the study sample. Inadequate therapy was correlated with resistance to antimicrobial agents.展开更多
Objective:To explore the antibiotic resistance of Brucella melitensis and instruct rational use of antimicrobial agents in clinical treatment of Brucella infection.Methods:Bacteria were cultured and identified by BACT...Objective:To explore the antibiotic resistance of Brucella melitensis and instruct rational use of antimicrobial agents in clinical treatment of Brucella infection.Methods:Bacteria were cultured and identified by BACTEC9120 and VTTEK Ⅱ automicrobic system.E-test was used to detect the minimal inhibitory concentration(MIC) of antimicrobial agents in the drug susceptivity experiment.Results:A total of 19 brucella strains(all Brucella melitensis) were isolated from 19 patients,who had fever between January 2010 and June 2012,and 17 samples were blood,one was bone marrow,the other sample was cerebrospinal fluid.The MIC range of ceftazidime was 2.0-8.0 mg/L,rifampicin was 0.06-2.0 mg/L,amikacin was 4.0-12.0 mg/L,levofloxacin was 2.0-8.0 mg/ L,doxycycline was 8.0-32.0 mg/L,sulfamethoxazole-trimethoprim was 4.0-16.0 mg/L,ampicillin was 1.5-2.0 mg/L and gentamicin was 0.50-0.75 mg/L.Conclusions:The drugs used in this experiment cover common drugs for treating Brcella.Meanwhile,the results are consistent with clinical efficacy.It is suggested personalized regimen according to patients' status in treatment of Brucella.展开更多
AIM: To understand the pathogen characteristics and its sensitivity against antimicrobial agents in fatal bacterial granuloma after eyelid trauma (FBGT) in vitro , and to provide laboratory evidence for diagnosis. MET...AIM: To understand the pathogen characteristics and its sensitivity against antimicrobial agents in fatal bacterial granuloma after eyelid trauma (FBGT) in vitro , and to provide laboratory evidence for diagnosis. METHODS: The FBGT pathogens were isolaated and cultured with reformed rabbit-brain anaerobic enriched broth (RRAB), and identified by ATB/API 20A system. The minimum inhibiting concentration (MIC) was determined by anaerobic broth dilution method. RESULTS: A total of 22 strains of pathogen were separated from 21 patients with FBGT and identified as Propionibacterium acnes (PA) by ATB/API 20A system. The MIC of ciprofloxacin for 22 PA strains was 0.0625-0.5mg/L, the MIC of penicillin, ampicillin, ampicillin/sulbactam, cefoperazone, lincomycin, and imipenem/cilastatin were 0.125-0.5mg/L, the MIC of ticarcillin/clavulanic acid was 0.250-1.000mg/L, and the MIC of metronidazole was 64-256mg/L. The pathogen of FBGT was strictly anaerobic PA, which growed slowly and better in nutritious RRAB broth. All PA were resistant to metronidazole, but susceptive to other routine antimicrobial agents, such as penicillin, ampicillin and lincomycin. CONCLUSION: FBGT should not be treated with metron- idazole. Clinicians should choose combined use of drugs or operation to treat FBGT according to patients' individual condition and the results of drug sensitivity test.展开更多
Antimicrobial drugs of several classes play an important role in the treatment of bone and joint infections. In addition to fighting pathogenic microorganisms, the effects of drugs on local tissues and cells are also ...Antimicrobial drugs of several classes play an important role in the treatment of bone and joint infections. In addition to fighting pathogenic microorganisms, the effects of drugs on local tissues and cells are also related to the course and prognosis of bone and joint infections. The multi-directional differentiation potential of bone marrow-derived mesenchymal stem cells (MSCs) is essential for tissue repair after local injury, which is directly related to the recovery of bone, cartilage, and medullary adipose tissue. Our previous studies and the literature indicate that certain antimicrobial agents can regulate the differentiation potential of bone marrow-derived MSCs. Here, in order to systematically analyze the effects of various antimicrobial drugs on local tissue regeneration, we comprehensively review the studies on the effects of these drugs on MSC differentiation, and classify them according to the three differentiation directions (osteogenesis, chondrogenesis, and adipogenesis). Our review demonstrates the specific effects of different antimicrobial agents on bone marrow-derived MSCs and the range of concentrations at which they work, and provides a basis for drug selection at different sites of infection.展开更多
In recent years, zinc oxide nanoparticles(ZnO NPs) have gained tremendous attention attributed to their unique properties. Notably, evidence has shown that zinc is an important nutrient in living organisms. As such, b...In recent years, zinc oxide nanoparticles(ZnO NPs) have gained tremendous attention attributed to their unique properties. Notably, evidence has shown that zinc is an important nutrient in living organisms. As such, both prokaryotes and eukaryotes including bacteria, fungi and yeast are exploited for the synthesis of ZnO NPs by using microbial cells or enzyme, protein and other biomolecules compounds in either an intracellular or extracellular route. ZnO NPs exhibit antimicrobial properties, however, the properties of nanoparticles(NPs) are depended upon on their size and shape, which make them specific for various applications. Nevertheless, the desired size and shape of NPs can be obtained through the optimization process of microbes mediated synthesis by manipulating their reaction conditions. It should be noted that ZnO NPs are synthesized by various chemical and physical methods.Nonetheless, these methods are expensive and not environmentally friendly. On that account, the microbes mediated synthesis of ZnO NPs have rapidly evolved recently where the microbes are cleaner, eco-friendly, nontoxic and biocompatible as the alternatives to chemical and physical practices. Moreover, zinc in the form of NPs is more effective than their bulk counterparts and thus, they have been explored for many potential applications including in animals industry. Notably, with the advent of multi-drug resistant strains, ZnO NPs have emerged as the potential antimicrobial agents. This is mainly due to their superior properties in combating a broad spectrum of pathogens. Moreover, zinc is known as an essential trace element for most of the biological function in the animal’s body. As such, the applications of ZnO NPs have been reported to significantly enhance the health and production of the farm animals. Thus, this paper reviews the biological synthesis of ZnO NPs by the microbes, the mechanisms of the biological synthesis, parameters for the optimization process and their potential application as an antimicrobial agent and feed supplement in the animal industry as well as their toxicological hazards on animals.展开更多
Antibacterial Ag-agents are intensively applied as broad spectrum, high-stability, high-efficiency and high-safety inorganic antibacterial agents. We have developed a new kind of antibacterial Ag-agent, namely Ag_2-x(...Antibacterial Ag-agents are intensively applied as broad spectrum, high-stability, high-efficiency and high-safety inorganic antibacterial agents. We have developed a new kind of antibacterial Ag-agent, namely Ag_2-x(NH_4)xMo_3O_(10) ·3H_2O nanowires(NWs). Carrying Ag atoms in the lattice and Ag-rich nanoparticles on the surface, the Ag-doped NWs show strong antibacterial effects for a variety of bacteria including E.coli, Staphylococcus aureus, Candida albicans and Aspergil lus niger. By performing systematic comparison experiments, we have proven that the main antibacterial effects are neither resulted from the tiny amount of Ag+ions released from the Ag-doped NWs in aqueous solutions, nor resulted from Ag-rich nanoparticles of fragments of the NWs when they are slowly dissolved in the Martin broth. Instead, the effects are mainly resulted from a contact mechanism, under which, the Ag-doped NWs need to be physically in contact with the bacteria to be eliminated. This is a novel phenomenon observed in the interactions between nanomaterials and live cells, which is worthy of further investigation at the molecular scale. As the Ag-doped NWs are not dissolved in pure water or weak acids, one may find practical antibacterial applications in textile industry and food storage industry for these unique nanomaterials.展开更多
The structure, properties and application to water-soluble coatings of a new complex antimicrobial agent Ag-carboxylmethyl citosan-thiabendazole （Ag-CMCTS-TBZ） prepared from different materiel ratios were reported. ...The structure, properties and application to water-soluble coatings of a new complex antimicrobial agent Ag-carboxylmethyl citosan-thiabendazole （Ag-CMCTS-TBZ） prepared from different materiel ratios were reported. The silver ions were preferably coordinated with the free -NH2 groups and the -OH groups of secondary alcohol and carboxyl in CMCTS. TBZ preferably bonded to carboxyl group in CMCTS by electrostatic force and hydrogen bonding. Increase in silver ions content in the complex agent improved to some limited extent the antibacterial activity, but enhanced coloring and cost of the complex agent. Increase in TBZ content resulted in increase of antifungal activity, but decrease of water solubility of the complex agent. The antimicrobial MICs of the complex agent to Esherichia coli, Staphylococcus aureus, Candida albicans, Aspergillus niger, Mucor sp. were 2080, 1560, 2055, 40250, and 4001700mg/kg, respectively. Addition of 0.1% of this complex agent to acrylic emulsion paint made the paint without substantial change in color, luster, viscosity, odor or pH value, but with an excellent and chronically persisting broad-spectra antimicrobial activity.展开更多
Summary: In order to investigate the susceptibility of mixed infection of Ureaplasma Urealyticum(UU) and Mycoplasma Hominis (MH) to 7 kinds of antimicrobial agents and comparison with thatof UU infection in NGU patien...Summary: In order to investigate the susceptibility of mixed infection of Ureaplasma Urealyticum(UU) and Mycoplasma Hominis (MH) to 7 kinds of antimicrobial agents and comparison with thatof UU infection in NGU patients, the in vitro susceptibility was determined by using microdilutionmethod. The positive results were analyzed. The results showed that the sequence of susceptibility to7 kinds of antimicrobial agents for both UU infection group and UU-MH mixed infection group wasalmost the same from the highest susceptibility to the lowest accordingly: Josamycin, Doxycycline,Minocycline, Sparfloxacin, Roxithromycin, Ofloxacin and Azithromycin. The total drug resistancerate for UU-MH mixed infection group (97.67 % ) was significantly higher than that for UU infec-tion group (44.67 %, P＜0. 01). The highest drug resistance rate in UU group and UU-MH mixedinfection group was 31. 33 % (Ofloxacin) and 90. 48 % (Azithromycin) respectively. UU-MHmixed infection showed an increased drug resistance and changes of drug resistance spectrum.展开更多
Objective: A series of 2-benzylideneaminonaphthothiazoles were designed and synthesized incorporating the lipo- philic naphthalene ring to render them more capable of penetrating various biomembranes. Methods: Schiff ...Objective: A series of 2-benzylideneaminonaphthothiazoles were designed and synthesized incorporating the lipo- philic naphthalene ring to render them more capable of penetrating various biomembranes. Methods: Schiff bases were synthe- sized by the reaction of naphtha[1,2-d]thiazol-2-amine with various substituted aromatic aldehydes. 2-(2'-Hydroxy)ben- zylideneaminonaphthothiazole was converted to its Co(II), Ni(II) and Cu(II) metal complexes upon treatment with metal salts in ethanol. All the compounds were evaluated for their antibacterial activities by paper disc diffusion method with Gram positive Staphylococcus aureus and Staphylococcus epidermidis and Gram negative Escherichia coli and Pseudomonas aeruginosa bac- teria. The minimum inhibitory concentrations of all the Schiff bases and metal complexes were determined by agar streak dilution method. Results: All the compounds moderately inhibited the growth of Gram positive and Gram negative bacteria. In the present study among all Schiff bases 2-(2'-hydroxy)benzylideneaminonaphthothiazole showed maximum inhibitory activity and among metal complexes Cu(II) metal complex was found to be most potent. Conclusion: The results obtained validate the hypothesis that Schiff bases having substitution with halogens, hydroxyl group and nitro group at phenyl ring are required for the antibacterial activity while methoxy group at different positions in the aromatic ring has minimal role in the inhibitory activity. The results also indicated that the metal complexes are better antibacterial agents as compared to the Schiff bases.展开更多
We adopted the response surface methodology using single factor and orthogonal experiments to optimize four types of antimicrobial agents that could inhibit biofilm formation by Streptococcus mutans, which is commonly...We adopted the response surface methodology using single factor and orthogonal experiments to optimize four types of antimicrobial agents that could inhibit biofilm formation by Streptococcus mutans, which is commonly found in the human oral cavity and causes tooth decay. The objective was to improve the function of marine Arthrobacter oxydans KQ11 dextranase mouthwash(designed and developed by our laboratory). The experiment was conducted in a three-level, four-variable central composite design to determine the best combination of Zn SO_4, lysozyme, citric acid and chitosan. The optimized antibacterial agents were 2.16 g/L Zn SO_4, 14 g/L lysozyme, 4.5 g/L citric acid and 5 g/L chitosan. The biofilm formation inhibition reached 84.49%. In addition, microscopic observation of the biofilm was performed using scanning electron microscopy and confocal laser scanning microscopy. The optimized formula was tested in marine dextranase Arthrobacter oxydans KQ11 mouthwash and enhanced the inhibition of S. mutans. This work may be promoted for the design and development of future marine dextranase oral care products.展开更多
Amino - functional silicone oil was used as a raw material to synthesize antimicrobial agent by means of alkyla-tion. Through synthetically judging every possible influential factor, a new method was developed to synt...Amino - functional silicone oil was used as a raw material to synthesize antimicrobial agent by means of alkyla-tion. Through synthetically judging every possible influential factor, a new method was developed to synthesize antimicrobial agent CL under moderate condition. Then, antimicrobial agent CL was emulsified with surfactants AEO - 9 and AEO - 3 in appropriate proportion. Practical properties of antimicrobial fabric were tested.展开更多
Purpose: To investigate 1) the development in the incidence of ESBL-producing bacteria in hospitals and primary health care, 2) the contribution of primary health care to the incidence of ESBL-producing bacteria, and ...Purpose: To investigate 1) the development in the incidence of ESBL-producing bacteria in hospitals and primary health care, 2) the contribution of primary health care to the incidence of ESBL-producing bacteria, and 3) the development in resistance patterns for all Escherichia coli and Klebsiella pneumoniae isolates in relation to antimicrobial consumption in hospitals and primary health care. Methods: ESBL-data were retrospectively collected from bacterial isolates from all specimens received at the Department of Clinical Microbiology from 2003 to 2011 together with the corresponding patient data. ESBL-production was detected in isolates from 1067 of 59,373 patients (1.8%) with an E. coli infection and in 263 of 8660 patients (3.0%) with a K. pneumoniae infection. Results: From 2003 to 2009, an increase in patients with an ESBL-producing isolate occurred in both hospitals and primary health care at the same time as an increased consumption of broad-spectrum antimicrobial agents was seen. Interventions to reduce prescription of cephalosporins and ciprofloxacin at the hospitals from 2010 resulted in a remarkable decrease in patients with ESBL-producing K. pneumoniae whereas a continuing increase was seen in patients with ESBL-producing E. coli both at hospitals and in primary health care. The proportion of patients with community-acquired ESBL-producing E. coli was stable with an increase of only 1.4% from 2007 to 2011. Conclusions: Reduction in prescription of broad-spectrum antimicrobial agents at the hospital level had an important impact on the incidence of ESBL-producing K. pneumoniae, but not on ESBL-producing E. coli.展开更多
A simple route to synthesize novel fluorinated fused hetero-polycyclic nitrogen systems containing a pyrazolotriazine moiety (5,8,11) have been deduced from cyclization of 2-aminothiocarbonyl-5-arylidene-3-phenyl-1,2,...A simple route to synthesize novel fluorinated fused hetero-polycyclic nitrogen systems containing a pyrazolotriazine moiety (5,8,11) have been deduced from cyclization of 2-aminothiocarbonyl-5-arylidene-3-phenyl-1,2,4-triazin-6(1H)one (2) with diethoxy-phosphine, diethyl carbonate and/or diethyl oxalate in boil THF followed by cyclo condensation with aryl sulfonic acid hydrazide in EtOH/piperidine and finally fluorination with trifluoroethyl acetate. Structures of the products have been established from their elemental analysis and spectral measurements. The antimicrobial activity of the targets has also been evaluated.展开更多
In burn treatments,microorganisms on pressure garments during pressure therapy can prevent rehabilitation by causing functional,hygienic,and aesthetic difficulties. As bacterium is one of the most trouble-causing orga...In burn treatments,microorganisms on pressure garments during pressure therapy can prevent rehabilitation by causing functional,hygienic,and aesthetic difficulties. As bacterium is one of the most trouble-causing organisms,they can threaten patients causing infection during the long period of use of these garments.Novel burn pressure garments having durable antimicrobial property were developed using polyhexamethylene biguanide( PHMB)antimicrobial agent procedure on highly elastic nylon 66 /spandex fabrics in powernet,flat warp and weft knitted structures using paddry-cure method. Commercial wireless pressure sensors were used to control pressures at an acceptable medical range. Antimicrobial activity,wash durability,Fourier transform infrared spectroscopy(FTIR) and Scanning electron microscopy(SEM) analyses were conducted for the treated samples. Antimicrobial test results following AATCC 100 Test Method showed 99% reduction of bacteria for the fabric samples treated with PHMB. A small but significant decrease in antimicrobial activity was observed even after50 launderings. These treatments also yield good results to prevent odor,decrease infection by preventing and /or blocking microbial growth according to the antimicrobial mechanism and support reducing of scarring by providing a hygienic environment around the scar.展开更多
Some more new fluorine substitutedamino compounds bearing 6-aryl-5-oxo-1,2,4-triazin-3-yl moieties and its derivatives 3 - 7 have been synthesised successfully from aroylation of 6-(2’-aminophenyl)-3-thioxo-1,2,4-tri...Some more new fluorine substitutedamino compounds bearing 6-aryl-5-oxo-1,2,4-triazin-3-yl moieties and its derivatives 3 - 7 have been synthesised successfully from aroylation of 6-(2’-aminophenyl)-3-thioxo-1,2,4-triazin-5-one (1), followed by fluoro amination with 4-fluoroanilinein Abs EtOH and then treated with ammonia/EtOH and finally acylation/aroylation or cyclocondensation reactions with malonic acid in AcOH. Structure of the products has been established upon elemental analysis and their spectral measurements. All the obtained compounds evaluated as antimicrobial agents were the compounds which contained both nitro and fluorine elements and exhibited a highly activity the other derivatives.展开更多
A simple condensation afforded some new 3-thioxo-1,2,4-triazin-5-one derivatives (4, 6 and 8). Utilizing a facile condensation of (E)-4-(4’-bromo styryl)-2-oxo-3-buteneoic acid with thiosemicarbazide, dithioic formic...A simple condensation afforded some new 3-thioxo-1,2,4-triazin-5-one derivatives (4, 6 and 8). Utilizing a facile condensation of (E)-4-(4’-bromo styryl)-2-oxo-3-buteneoic acid with thiosemicarbazide, dithioic formic acid hydrazide, and thiocarbahydrazide in different conditions. Structures of these compounds were confirmed by elemental and spectral analysis. The preliminary biocidal activity of these products were evaluated against some microbial and compared to Mycostatine and piperacillin as antibiotics were most of derivatives exhibited good activity.展开更多
Several quinolino-benzoxaborole derivatives have been prepared to start from aminobenzoxaboroles. These derivatives have been evaluated for their anti-cancer activity on human and murine cancer cell lines and based on...Several quinolino-benzoxaborole derivatives have been prepared to start from aminobenzoxaboroles. These derivatives have been evaluated for their anti-cancer activity on human and murine cancer cell lines and based on their relative non-toxicity, these compounds were further evaluated for their antibacterial activity against E. coli, B. subtilis, and M. smegmatis. The synthesized compounds were also evaluated for antifungal activity in C. albicans and C. neoformans.展开更多
Background: Urinary tract infection (UTI), is caused by pathogen bacteria, such as: Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Proteus sp. The emergence of antibiotic r...Background: Urinary tract infection (UTI), is caused by pathogen bacteria, such as: Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Proteus sp. The emergence of antibiotic resistance, leads to treatment failure in some cases. One strategy to overcome this is using alternative therapies, one of them by using herbal plants, namely garlic (Allium sativum) which has antimicrobial effects. Aim: To determine the effectiveness of garlic extract against bacteria that causes UTI. Methods: The study used experimental in vitro method;Using garlic extract with 50%& 80%(5 & 8 gr garlic extract in 10 mL aquades as a solvent) concentration and amoxicillin as positive control which then dripped on the medium growth of bacteria’s culture, then measured diameter of the minimum inhibit zone that formed. Results: The inhibitory zone diameter of 50% garlic extract showed intermediate results in Pseudomonas aeruginosa with a diameter of 13.17 mm, and is not sensitive to other bacteria. Concentration at 80% showed sensitive results in Pseudomonas aeruginosa and Escherichia coli with diameter 17.27 mm & 15.5 mm, the result is almost equivalent compared with amoxicillin, with diameter 20.38 mm & 24.23 mm. Conclusion: Garlic extracted with 80% concentration has antimicrobial effect against Pseudomonas aeruginosa and Escherichia coli.展开更多
4-amino-laurylpyridinium chloride(ALPC) was synthesized and employed in antimicrobial finishing of wool fabrics.The structures of the salt was fully characterized by using FTIR,1H-NMR and 13C-NMR analysis.The effects ...4-amino-laurylpyridinium chloride(ALPC) was synthesized and employed in antimicrobial finishing of wool fabrics.The structures of the salt was fully characterized by using FTIR,1H-NMR and 13C-NMR analysis.The effects of pH conditions of finishing baths,finishing time and temperature,and salt concentrations were investigated.ALPC could form ionic interactions with anionic groups on wool,which contribute to durable antimicrobial functions.The finished wool fabrics exhibited antimicrobial efficacy against Escherichia coli.The washing durability of antimicrobial functions on the finished wool fabrics was also studied.展开更多
文摘The rapid increase of bacterial resistance strains to multiple antibiotics has become a global public health concern. In the present study, actinomycetes from different districts of Libyan soil were isolated and screened for their inhibitory activity against pathogenic bacteria and fungi. Three hundred soil samples were taken from 77 diverse ecosystems, including deserts, forests, pastureland, and cropland located in different climatic regions in Libya. A total of 164 actinomycetes were obtained. Of 164 isolates, 38 (23.2%) isolates were morphologically and microscopically characterized by spore chain and surface morphology, aerial and substrate mycelia and soluble pigments. The preliminary classification of the isolates illustrates that all isolates belong to the genus Streptomyces. These isolates were further examined for their antagonistic potential against nine pathogenic bacteria and fungi. Out of 38, 11 (28.9%) isolates showed their capability to produce inhibitory substances against at least two tested strains. Among bacterial strains, Staphylococcus aureus was susceptible to almost all eleven isolates (90.9%), while Streptococcus pyogenes was found to be resistant to most selected isolates (18.2%). The isolate, 063 (Wadan soil-desert zone) was the only isolate that exhibited broad spectrum antimicrobial activity against all tested pathogenic microbes, and hence was selected for further study. According to its cultural, morphological, physiological, and biochemical characteristics, the isolate 063 was identified as Streptomyces rochei. The results obtained indicate that the Libyan soil, particularly in extreme environments, could be a potent source of bioactive metabolites with antimicrobial potency against a wide variety of microbial pathogens. Thus, this investigation suggested that exploring new habitats in unexplored and untapped regions of Libya could provide a promising source of biologically active compounds for therapeutic applications.
文摘The present study sought to assess the rational use of antimicrobial agents in a Brazilian intensive care unit (ICU) and its association with antimicrobial resistance in elderly patients admitted to the unit. Results: Choice of empiric and sensitivity-guided therapy was inadequate in > 80% and 59% of cases respectively. Inadequate antimicrobial therapy, whether empiric or sensitivity-guided, was positively correlated with bacterial resistance (r = 0.316;p = 0.001). Sensitivity testing revealed a 46.5% resistance rate to eight out of the ten most commonly used antibiotics. Multiple drug-resistant organisms were found in 40.8% of patients. A significant increase was observed in the number of multidrug-resistant samples between 2006/2007 and 2008 (r = 0.41, p = 0.006), (r = 0.598, p = 0.001), (r = 0.688, p = 0.00). Conclusion: We found a high rate of antibiotic misuse in the study sample. Inadequate therapy was correlated with resistance to antimicrobial agents.
基金This project was supported by the scientific Research Foundation of Shaanxi Province.China(Grant No.2009JQ4011)
文摘Objective:To explore the antibiotic resistance of Brucella melitensis and instruct rational use of antimicrobial agents in clinical treatment of Brucella infection.Methods:Bacteria were cultured and identified by BACTEC9120 and VTTEK Ⅱ automicrobic system.E-test was used to detect the minimal inhibitory concentration(MIC) of antimicrobial agents in the drug susceptivity experiment.Results:A total of 19 brucella strains(all Brucella melitensis) were isolated from 19 patients,who had fever between January 2010 and June 2012,and 17 samples were blood,one was bone marrow,the other sample was cerebrospinal fluid.The MIC range of ceftazidime was 2.0-8.0 mg/L,rifampicin was 0.06-2.0 mg/L,amikacin was 4.0-12.0 mg/L,levofloxacin was 2.0-8.0 mg/ L,doxycycline was 8.0-32.0 mg/L,sulfamethoxazole-trimethoprim was 4.0-16.0 mg/L,ampicillin was 1.5-2.0 mg/L and gentamicin was 0.50-0.75 mg/L.Conclusions:The drugs used in this experiment cover common drugs for treating Brcella.Meanwhile,the results are consistent with clinical efficacy.It is suggested personalized regimen according to patients' status in treatment of Brucella.
文摘AIM: To understand the pathogen characteristics and its sensitivity against antimicrobial agents in fatal bacterial granuloma after eyelid trauma (FBGT) in vitro , and to provide laboratory evidence for diagnosis. METHODS: The FBGT pathogens were isolaated and cultured with reformed rabbit-brain anaerobic enriched broth (RRAB), and identified by ATB/API 20A system. The minimum inhibiting concentration (MIC) was determined by anaerobic broth dilution method. RESULTS: A total of 22 strains of pathogen were separated from 21 patients with FBGT and identified as Propionibacterium acnes (PA) by ATB/API 20A system. The MIC of ciprofloxacin for 22 PA strains was 0.0625-0.5mg/L, the MIC of penicillin, ampicillin, ampicillin/sulbactam, cefoperazone, lincomycin, and imipenem/cilastatin were 0.125-0.5mg/L, the MIC of ticarcillin/clavulanic acid was 0.250-1.000mg/L, and the MIC of metronidazole was 64-256mg/L. The pathogen of FBGT was strictly anaerobic PA, which growed slowly and better in nutritious RRAB broth. All PA were resistant to metronidazole, but susceptive to other routine antimicrobial agents, such as penicillin, ampicillin and lincomycin. CONCLUSION: FBGT should not be treated with metron- idazole. Clinicians should choose combined use of drugs or operation to treat FBGT according to patients' individual condition and the results of drug sensitivity test.
基金National Natural Science Foundation of China,Nos.81472119 and 81672196Shanghai Municipal Education Commission-Gaofeng Clinical Medicine Grant Support,No.20161423
文摘Antimicrobial drugs of several classes play an important role in the treatment of bone and joint infections. In addition to fighting pathogenic microorganisms, the effects of drugs on local tissues and cells are also related to the course and prognosis of bone and joint infections. The multi-directional differentiation potential of bone marrow-derived mesenchymal stem cells (MSCs) is essential for tissue repair after local injury, which is directly related to the recovery of bone, cartilage, and medullary adipose tissue. Our previous studies and the literature indicate that certain antimicrobial agents can regulate the differentiation potential of bone marrow-derived MSCs. Here, in order to systematically analyze the effects of various antimicrobial drugs on local tissue regeneration, we comprehensively review the studies on the effects of these drugs on MSC differentiation, and classify them according to the three differentiation directions (osteogenesis, chondrogenesis, and adipogenesis). Our review demonstrates the specific effects of different antimicrobial agents on bone marrow-derived MSCs and the range of concentrations at which they work, and provides a basis for drug selection at different sites of infection.
基金Universiti Putra Malaysia(UPM)for financing this work through Putra Graduate Initiative(IPS)
文摘In recent years, zinc oxide nanoparticles(ZnO NPs) have gained tremendous attention attributed to their unique properties. Notably, evidence has shown that zinc is an important nutrient in living organisms. As such, both prokaryotes and eukaryotes including bacteria, fungi and yeast are exploited for the synthesis of ZnO NPs by using microbial cells or enzyme, protein and other biomolecules compounds in either an intracellular or extracellular route. ZnO NPs exhibit antimicrobial properties, however, the properties of nanoparticles(NPs) are depended upon on their size and shape, which make them specific for various applications. Nevertheless, the desired size and shape of NPs can be obtained through the optimization process of microbes mediated synthesis by manipulating their reaction conditions. It should be noted that ZnO NPs are synthesized by various chemical and physical methods.Nonetheless, these methods are expensive and not environmentally friendly. On that account, the microbes mediated synthesis of ZnO NPs have rapidly evolved recently where the microbes are cleaner, eco-friendly, nontoxic and biocompatible as the alternatives to chemical and physical practices. Moreover, zinc in the form of NPs is more effective than their bulk counterparts and thus, they have been explored for many potential applications including in animals industry. Notably, with the advent of multi-drug resistant strains, ZnO NPs have emerged as the potential antimicrobial agents. This is mainly due to their superior properties in combating a broad spectrum of pathogens. Moreover, zinc is known as an essential trace element for most of the biological function in the animal’s body. As such, the applications of ZnO NPs have been reported to significantly enhance the health and production of the farm animals. Thus, this paper reviews the biological synthesis of ZnO NPs by the microbes, the mechanisms of the biological synthesis, parameters for the optimization process and their potential application as an antimicrobial agent and feed supplement in the animal industry as well as their toxicological hazards on animals.
基金the NSF of China(Grant No.11074010)the MOST of China(Grant No.2011DFA51450)for financial support
文摘Antibacterial Ag-agents are intensively applied as broad spectrum, high-stability, high-efficiency and high-safety inorganic antibacterial agents. We have developed a new kind of antibacterial Ag-agent, namely Ag_2-x(NH_4)xMo_3O_(10) ·3H_2O nanowires(NWs). Carrying Ag atoms in the lattice and Ag-rich nanoparticles on the surface, the Ag-doped NWs show strong antibacterial effects for a variety of bacteria including E.coli, Staphylococcus aureus, Candida albicans and Aspergil lus niger. By performing systematic comparison experiments, we have proven that the main antibacterial effects are neither resulted from the tiny amount of Ag+ions released from the Ag-doped NWs in aqueous solutions, nor resulted from Ag-rich nanoparticles of fragments of the NWs when they are slowly dissolved in the Martin broth. Instead, the effects are mainly resulted from a contact mechanism, under which, the Ag-doped NWs need to be physically in contact with the bacteria to be eliminated. This is a novel phenomenon observed in the interactions between nanomaterials and live cells, which is worthy of further investigation at the molecular scale. As the Ag-doped NWs are not dissolved in pure water or weak acids, one may find practical antibacterial applications in textile industry and food storage industry for these unique nanomaterials.
文摘The structure, properties and application to water-soluble coatings of a new complex antimicrobial agent Ag-carboxylmethyl citosan-thiabendazole （Ag-CMCTS-TBZ） prepared from different materiel ratios were reported. The silver ions were preferably coordinated with the free -NH2 groups and the -OH groups of secondary alcohol and carboxyl in CMCTS. TBZ preferably bonded to carboxyl group in CMCTS by electrostatic force and hydrogen bonding. Increase in silver ions content in the complex agent improved to some limited extent the antibacterial activity, but enhanced coloring and cost of the complex agent. Increase in TBZ content resulted in increase of antifungal activity, but decrease of water solubility of the complex agent. The antimicrobial MICs of the complex agent to Esherichia coli, Staphylococcus aureus, Candida albicans, Aspergillus niger, Mucor sp. were 2080, 1560, 2055, 40250, and 4001700mg/kg, respectively. Addition of 0.1% of this complex agent to acrylic emulsion paint made the paint without substantial change in color, luster, viscosity, odor or pH value, but with an excellent and chronically persisting broad-spectra antimicrobial activity.
文摘Summary: In order to investigate the susceptibility of mixed infection of Ureaplasma Urealyticum(UU) and Mycoplasma Hominis (MH) to 7 kinds of antimicrobial agents and comparison with thatof UU infection in NGU patients, the in vitro susceptibility was determined by using microdilutionmethod. The positive results were analyzed. The results showed that the sequence of susceptibility to7 kinds of antimicrobial agents for both UU infection group and UU-MH mixed infection group wasalmost the same from the highest susceptibility to the lowest accordingly: Josamycin, Doxycycline,Minocycline, Sparfloxacin, Roxithromycin, Ofloxacin and Azithromycin. The total drug resistancerate for UU-MH mixed infection group (97.67 % ) was significantly higher than that for UU infec-tion group (44.67 %, P＜0. 01). The highest drug resistance rate in UU group and UU-MH mixedinfection group was 31. 33 % (Ofloxacin) and 90. 48 % (Azithromycin) respectively. UU-MHmixed infection showed an increased drug resistance and changes of drug resistance spectrum.
文摘Objective: A series of 2-benzylideneaminonaphthothiazoles were designed and synthesized incorporating the lipo- philic naphthalene ring to render them more capable of penetrating various biomembranes. Methods: Schiff bases were synthe- sized by the reaction of naphtha[1,2-d]thiazol-2-amine with various substituted aromatic aldehydes. 2-(2'-Hydroxy)ben- zylideneaminonaphthothiazole was converted to its Co(II), Ni(II) and Cu(II) metal complexes upon treatment with metal salts in ethanol. All the compounds were evaluated for their antibacterial activities by paper disc diffusion method with Gram positive Staphylococcus aureus and Staphylococcus epidermidis and Gram negative Escherichia coli and Pseudomonas aeruginosa bac- teria. The minimum inhibitory concentrations of all the Schiff bases and metal complexes were determined by agar streak dilution method. Results: All the compounds moderately inhibited the growth of Gram positive and Gram negative bacteria. In the present study among all Schiff bases 2-(2'-hydroxy)benzylideneaminonaphthothiazole showed maximum inhibitory activity and among metal complexes Cu(II) metal complex was found to be most potent. Conclusion: The results obtained validate the hypothesis that Schiff bases having substitution with halogens, hydroxyl group and nitro group at phenyl ring are required for the antibacterial activity while methoxy group at different positions in the aromatic ring has minimal role in the inhibitory activity. The results also indicated that the metal complexes are better antibacterial agents as compared to the Schiff bases.
基金Supported by the National Natural Science Foundation of China(Nos.3147171931271929)+2 种基金the Jiangsu Province and Technology Support Program(No.BE2013662)the Lianyungang Fifth“521 High-Level Talent Training Project”the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘We adopted the response surface methodology using single factor and orthogonal experiments to optimize four types of antimicrobial agents that could inhibit biofilm formation by Streptococcus mutans, which is commonly found in the human oral cavity and causes tooth decay. The objective was to improve the function of marine Arthrobacter oxydans KQ11 dextranase mouthwash(designed and developed by our laboratory). The experiment was conducted in a three-level, four-variable central composite design to determine the best combination of Zn SO_4, lysozyme, citric acid and chitosan. The optimized antibacterial agents were 2.16 g/L Zn SO_4, 14 g/L lysozyme, 4.5 g/L citric acid and 5 g/L chitosan. The biofilm formation inhibition reached 84.49%. In addition, microscopic observation of the biofilm was performed using scanning electron microscopy and confocal laser scanning microscopy. The optimized formula was tested in marine dextranase Arthrobacter oxydans KQ11 mouthwash and enhanced the inhibition of S. mutans. This work may be promoted for the design and development of future marine dextranase oral care products.
文摘Amino - functional silicone oil was used as a raw material to synthesize antimicrobial agent by means of alkyla-tion. Through synthetically judging every possible influential factor, a new method was developed to synthesize antimicrobial agent CL under moderate condition. Then, antimicrobial agent CL was emulsified with surfactants AEO - 9 and AEO - 3 in appropriate proportion. Practical properties of antimicrobial fabric were tested.
文摘Purpose: To investigate 1) the development in the incidence of ESBL-producing bacteria in hospitals and primary health care, 2) the contribution of primary health care to the incidence of ESBL-producing bacteria, and 3) the development in resistance patterns for all Escherichia coli and Klebsiella pneumoniae isolates in relation to antimicrobial consumption in hospitals and primary health care. Methods: ESBL-data were retrospectively collected from bacterial isolates from all specimens received at the Department of Clinical Microbiology from 2003 to 2011 together with the corresponding patient data. ESBL-production was detected in isolates from 1067 of 59,373 patients (1.8%) with an E. coli infection and in 263 of 8660 patients (3.0%) with a K. pneumoniae infection. Results: From 2003 to 2009, an increase in patients with an ESBL-producing isolate occurred in both hospitals and primary health care at the same time as an increased consumption of broad-spectrum antimicrobial agents was seen. Interventions to reduce prescription of cephalosporins and ciprofloxacin at the hospitals from 2010 resulted in a remarkable decrease in patients with ESBL-producing K. pneumoniae whereas a continuing increase was seen in patients with ESBL-producing E. coli both at hospitals and in primary health care. The proportion of patients with community-acquired ESBL-producing E. coli was stable with an increase of only 1.4% from 2007 to 2011. Conclusions: Reduction in prescription of broad-spectrum antimicrobial agents at the hospital level had an important impact on the incidence of ESBL-producing K. pneumoniae, but not on ESBL-producing E. coli.
文摘A simple route to synthesize novel fluorinated fused hetero-polycyclic nitrogen systems containing a pyrazolotriazine moiety (5,8,11) have been deduced from cyclization of 2-aminothiocarbonyl-5-arylidene-3-phenyl-1,2,4-triazin-6(1H)one (2) with diethoxy-phosphine, diethyl carbonate and/or diethyl oxalate in boil THF followed by cyclo condensation with aryl sulfonic acid hydrazide in EtOH/piperidine and finally fluorination with trifluoroethyl acetate. Structures of the products have been established from their elemental analysis and spectral measurements. The antimicrobial activity of the targets has also been evaluated.
基金Financial support of this research was provided by NC State University College of Textilesthe Scientific and Technological Research Council of Turkey
文摘In burn treatments,microorganisms on pressure garments during pressure therapy can prevent rehabilitation by causing functional,hygienic,and aesthetic difficulties. As bacterium is one of the most trouble-causing organisms,they can threaten patients causing infection during the long period of use of these garments.Novel burn pressure garments having durable antimicrobial property were developed using polyhexamethylene biguanide( PHMB)antimicrobial agent procedure on highly elastic nylon 66 /spandex fabrics in powernet,flat warp and weft knitted structures using paddry-cure method. Commercial wireless pressure sensors were used to control pressures at an acceptable medical range. Antimicrobial activity,wash durability,Fourier transform infrared spectroscopy(FTIR) and Scanning electron microscopy(SEM) analyses were conducted for the treated samples. Antimicrobial test results following AATCC 100 Test Method showed 99% reduction of bacteria for the fabric samples treated with PHMB. A small but significant decrease in antimicrobial activity was observed even after50 launderings. These treatments also yield good results to prevent odor,decrease infection by preventing and /or blocking microbial growth according to the antimicrobial mechanism and support reducing of scarring by providing a hygienic environment around the scar.
文摘Some more new fluorine substitutedamino compounds bearing 6-aryl-5-oxo-1,2,4-triazin-3-yl moieties and its derivatives 3 - 7 have been synthesised successfully from aroylation of 6-(2’-aminophenyl)-3-thioxo-1,2,4-triazin-5-one (1), followed by fluoro amination with 4-fluoroanilinein Abs EtOH and then treated with ammonia/EtOH and finally acylation/aroylation or cyclocondensation reactions with malonic acid in AcOH. Structure of the products has been established upon elemental analysis and their spectral measurements. All the obtained compounds evaluated as antimicrobial agents were the compounds which contained both nitro and fluorine elements and exhibited a highly activity the other derivatives.
文摘A simple condensation afforded some new 3-thioxo-1,2,4-triazin-5-one derivatives (4, 6 and 8). Utilizing a facile condensation of (E)-4-(4’-bromo styryl)-2-oxo-3-buteneoic acid with thiosemicarbazide, dithioic formic acid hydrazide, and thiocarbahydrazide in different conditions. Structures of these compounds were confirmed by elemental and spectral analysis. The preliminary biocidal activity of these products were evaluated against some microbial and compared to Mycostatine and piperacillin as antibiotics were most of derivatives exhibited good activity.
文摘Several quinolino-benzoxaborole derivatives have been prepared to start from aminobenzoxaboroles. These derivatives have been evaluated for their anti-cancer activity on human and murine cancer cell lines and based on their relative non-toxicity, these compounds were further evaluated for their antibacterial activity against E. coli, B. subtilis, and M. smegmatis. The synthesized compounds were also evaluated for antifungal activity in C. albicans and C. neoformans.
文摘Background: Urinary tract infection (UTI), is caused by pathogen bacteria, such as: Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Proteus sp. The emergence of antibiotic resistance, leads to treatment failure in some cases. One strategy to overcome this is using alternative therapies, one of them by using herbal plants, namely garlic (Allium sativum) which has antimicrobial effects. Aim: To determine the effectiveness of garlic extract against bacteria that causes UTI. Methods: The study used experimental in vitro method;Using garlic extract with 50%& 80%(5 & 8 gr garlic extract in 10 mL aquades as a solvent) concentration and amoxicillin as positive control which then dripped on the medium growth of bacteria’s culture, then measured diameter of the minimum inhibit zone that formed. Results: The inhibitory zone diameter of 50% garlic extract showed intermediate results in Pseudomonas aeruginosa with a diameter of 13.17 mm, and is not sensitive to other bacteria. Concentration at 80% showed sensitive results in Pseudomonas aeruginosa and Escherichia coli with diameter 17.27 mm & 15.5 mm, the result is almost equivalent compared with amoxicillin, with diameter 20.38 mm & 24.23 mm. Conclusion: Garlic extracted with 80% concentration has antimicrobial effect against Pseudomonas aeruginosa and Escherichia coli.
文摘4-amino-laurylpyridinium chloride(ALPC) was synthesized and employed in antimicrobial finishing of wool fabrics.The structures of the salt was fully characterized by using FTIR,1H-NMR and 13C-NMR analysis.The effects of pH conditions of finishing baths,finishing time and temperature,and salt concentrations were investigated.ALPC could form ionic interactions with anionic groups on wool,which contribute to durable antimicrobial functions.The finished wool fabrics exhibited antimicrobial efficacy against Escherichia coli.The washing durability of antimicrobial functions on the finished wool fabrics was also studied.
