This study explores the efficacy of advanced antibiotic compounds against P. aeruginosa, focusing on Antibiotic B, an enhanced derivative of Ceftriaxone. The study measured the intracellular uptake of Antibiotic B and...This study explores the efficacy of advanced antibiotic compounds against P. aeruginosa, focusing on Antibiotic B, an enhanced derivative of Ceftriaxone. The study measured the intracellular uptake of Antibiotic B and introduced a novel adjuvant, Influximax, which augmented its antibacterial activity. Results showed a diminished potential for resistance emergence with Antibiotic B, particularly when used in combination with Influximax. The study suggests that optimizing antibiotic delivery into bacterial cells and leveraging syner-gistic adjuvant combinations can enhance drug resistance combat. .展开更多
To investigate the distribution of the genes of two major metallo-β-1actamases （MBL;i.e.,IMP and VIM） and class 1 integrons （intI） in the clinical imipenem-resistant Pseudomonas aeruginosa, a total of 65 isolates...To investigate the distribution of the genes of two major metallo-β-1actamases （MBL;i.e.,IMP and VIM） and class 1 integrons （intI） in the clinical imipenem-resistant Pseudomonas aeruginosa, a total of 65 isolates, from a university hospital in Sichuan between December 2004 and April 2005 were screened for MBL genes by PCR using primers specific for blaIMP-1, blaVIM and blaVIM-2 genes. The MBL-positive isolates were further assessed for class 1 integrons by PCRusing specific primers. The nucleotide sequences of several PCR products were also determined. The results revealed that the blaVIM gene was found in 81.5% （53/65） of all isolates, blaVIM-2 gene was found in only 1 isolate and the intl gene was observed in 45.3% （24/53） of blaVIM-positive isolates. One isolate carried simultaneously both blaIMP-1 and intl genes, and to the best of our knowledge this is the first report of such isolate in southwest China. These observations highlight that the genes for VIM β-1actamase and class 1 integrons were predominantly present among the imipenem-resistant P. aeruginosa tested, confirming the current widespread threat of imipenem-resistant, integron-borne P.aeruginosa.展开更多
Filamentous bacteria(FB)overgrowth is an important cause of sludge bulking in wastewater treatment plants(WWTPs).However,to date,methods for the cultivation and preservation of isolated FB in the laboratory have not b...Filamentous bacteria(FB)overgrowth is an important cause of sludge bulking in wastewater treatment plants(WWTPs).However,to date,methods for the cultivation and preservation of isolated FB in the laboratory have not been completely described.Furthermore,research on whether FB can function as phosphorus accumulating organisms(PAOs)is limited.In this study,a pure strain,a Pseudomonas putida PAO-1(P.putida PAO-1)isolate with phosphorus removal functions was isolated from the biofilm of an alternating anaerobic/aerobic biofilter(AABF),and its physiological characteristics were studied.Nitrate or nitrite could be used by the strain P.putida PAO-1 as electron acceptors for denitrification during phosphorus anoxic uptake,and 0.63 mg NO-3-N was consumed to reduce 1 mg soluble orthophosphate(SOP)by P.putida PAO-1.The strain P.putida PAO-1 consumed phosphorus within the optimal pH range of 6 to 8 and the temperature range of 25℃to 35℃.Cell deformity was a main morphological trait of the strain P.putida PAO-1,and it could elongate(with an elongation rate of 300%-500%)when it was subjected to oligotrophic or high-salt stress(15 g·L-1 NaCl).The findings in this study provide a microbiological reference for understanding the special characteristics of a denitrifying PAO.展开更多
Pseudomonas aeruginosa is one of the leading nosocomial pathogens worldwide, and their infections are difficult to treat due to acquired resistance to many antibiotics. This study aimed to detect class 1 and 2 integro...Pseudomonas aeruginosa is one of the leading nosocomial pathogens worldwide, and their infections are difficult to treat due to acquired resistance to many antibiotics. This study aimed to detect class 1 and 2 integrons and antibiotic susceptibility of clinical isolates of P. aeruginosa. Two hundred and five P. aeruginosa strains were collected from the seven general state hospitals in Turkey. They were characterized by antimicrobial susceptibility testing, screened for class 1 and class 2 integrons, and evaluated for the association between antibiotic resistance phenotypes and the presence of integrons. intI gene was amplified in 10 isolates (4.87%) by PCR and in seven isolates of them (70%) were found different gene cassettes. The aadA gene integrated into the class 1 integrons was most frequently found and it was followed by aac genes and blaOXA family genes. Sequence analysis of variable regions of the class 1 integrons showed five gene cassette arrays;aadA1(99%), aac(3)-Id(82%)-orf-aac(3”)-Ia(99%), aac(3)-Ie(83%)-blaoxa10(100%)- aadA1 (100%), aadA6(99%, 100%), aac(6’)-I(97%)-orf-aadA2(99%). No class 2 integron was detected. This study is the first multicenter study for class 1 integrons and it indicates the low rate of presence of class 1 gene cassette in P. aeruginosa.展开更多
Objective: Describe resistance to beta lactam antibiotics of Pseudomonas aeruginosa in community infection within HIV-1 infected persons. Methods: We have studied prospectively from June 15th to December 31st 2013 int...Objective: Describe resistance to beta lactam antibiotics of Pseudomonas aeruginosa in community infection within HIV-1 infected persons. Methods: We have studied prospectively from June 15th to December 31st 2013 inthe Clinic Hotel-Dieu and NGO VISA of Lomé, adult HIV-1 infected patients under anti retroviral therapy combining tenofovir, lamivudine and efavirenz for at least one year. The technique of agar diffusion susceptibility using discs of Ticarcillin + clavulanic acid is used to study the β-lactamase production. The diagnosis of species was performed by the chloroform test and the test for sensitivity to kanamycin and colistin. Results: Thirty five strains of Pseudomonas aeruginosa were obtained. The T-lymphocytes CD4 mediane was 575 cells/mm3 of blood. Urine represented 15 cases, skin abscesses 11 cases, externa suppurate otitis 7 cases and vaginal swab for 2 cases. The phenotypes were: wild phenotypes 23 cases (65.7%), resistant phenotypes 12 cases. Among resistant phenotypes, 4 were complex phenotype;5 were ESBL phenotypes;2 were hyper productive cephalosporinases phenotypes and 1 was a specific phenotype with impermeability to imipenem. Conclusion: The acquisition of resistance of Pseudomonas aeruginosa to beta lactam antibiotics in community infections among HIV-1 infected person incentives controls and promotes the rational use of antibiotics.展开更多
黄曲霉毒素B_(1)(Aflatoxin B_(1),AFB_(1))是二氢呋喃氧杂萘邻酮的衍生物,是目前已知最强的化学致癌物之一,对人类和动物健康造成严重威胁。研究以铜绿假单胞菌M4的发酵上清液为对象,利用超滤、凝胶过滤色谱和离子交换色谱对AFB_(1)降...黄曲霉毒素B_(1)(Aflatoxin B_(1),AFB_(1))是二氢呋喃氧杂萘邻酮的衍生物,是目前已知最强的化学致癌物之一,对人类和动物健康造成严重威胁。研究以铜绿假单胞菌M4的发酵上清液为对象,利用超滤、凝胶过滤色谱和离子交换色谱对AFB_(1)降解酶进行分离纯化,通过超高效液相色谱-电喷雾-离子肼串联质谱仪对纯化的活性酶进行鉴定,得到比活性为2298.49 U/mg的小分子多肽。利用薄层色谱法和超高效液相色谱-飞行时间质谱仪对AFB_(1)降解产物进行解析,结果显示硅胶板上出现了不同于AFB_(1)的新荧光斑点,质谱检测到一个主要降解产物,利用Massynlynx V4.1软件推测降解产物的分子式为C 11 H 10 O 4,并对AFB_(1)降解产物的降解途径进行推导。研究纯化的耐高温小分子多肽可有效将降解AFB_(1),从降解破坏位点推测降解产物可能是低毒或无毒物质,这为进一步开发AFB_(1)脱毒剂提供参考。展开更多
文摘This study explores the efficacy of advanced antibiotic compounds against P. aeruginosa, focusing on Antibiotic B, an enhanced derivative of Ceftriaxone. The study measured the intracellular uptake of Antibiotic B and introduced a novel adjuvant, Influximax, which augmented its antibacterial activity. Results showed a diminished potential for resistance emergence with Antibiotic B, particularly when used in combination with Influximax. The study suggests that optimizing antibiotic delivery into bacterial cells and leveraging syner-gistic adjuvant combinations can enhance drug resistance combat. .
文摘采用发酵-渗透汽化耦合(fermentation coupling with pervaporation,FCP)系统和分批补料式发酵系统培养Pseudomonas aeruginosa BC1制备生物表面活性剂鼠李糖脂,两轮发酵过程分别持续124 h和107 h。在FCP系统中,最大细胞吸光度OD600为1.06;生物表面活性剂OD600为0.61;鼠李糖脂最终产量为1.3 g/L,相比于分批补料式发酵系统提高38%;对比纯水的表面张力67.52 m N/m,发酵第29 h的发酵上清液表面张力为22.56 m N/m。同时,该菌的发酵上清液对液体石蜡、机油、柴油、正己烷、十六烷均有较好的乳化能力。经GC-MS结合SPME分析发现,FCP系统分离出的渗透蒸汽冷凝液中含有乙醇、戊醇等有机物。实验结果表明,相比分批补料式发酵系统,FCP系统能够分离发酵过程中产生的一部分挥发性代谢产物,减轻这些物质对细胞生长的抑制,使细胞浓度和鼠李糖脂产量都有明显提高。
基金a grant from National Natu-ral Science Foundation of China (No. 30370079)
文摘To investigate the distribution of the genes of two major metallo-β-1actamases （MBL;i.e.,IMP and VIM） and class 1 integrons （intI） in the clinical imipenem-resistant Pseudomonas aeruginosa, a total of 65 isolates, from a university hospital in Sichuan between December 2004 and April 2005 were screened for MBL genes by PCR using primers specific for blaIMP-1, blaVIM and blaVIM-2 genes. The MBL-positive isolates were further assessed for class 1 integrons by PCRusing specific primers. The nucleotide sequences of several PCR products were also determined. The results revealed that the blaVIM gene was found in 81.5% （53/65） of all isolates, blaVIM-2 gene was found in only 1 isolate and the intl gene was observed in 45.3% （24/53） of blaVIM-positive isolates. One isolate carried simultaneously both blaIMP-1 and intl genes, and to the best of our knowledge this is the first report of such isolate in southwest China. These observations highlight that the genes for VIM β-1actamase and class 1 integrons were predominantly present among the imipenem-resistant P. aeruginosa tested, confirming the current widespread threat of imipenem-resistant, integron-borne P.aeruginosa.
基金National Natural Science Foundation of China(No.21777024)National Key Research and Development Project,China(No.2019YFC0408503)。
文摘Filamentous bacteria(FB)overgrowth is an important cause of sludge bulking in wastewater treatment plants(WWTPs).However,to date,methods for the cultivation and preservation of isolated FB in the laboratory have not been completely described.Furthermore,research on whether FB can function as phosphorus accumulating organisms(PAOs)is limited.In this study,a pure strain,a Pseudomonas putida PAO-1(P.putida PAO-1)isolate with phosphorus removal functions was isolated from the biofilm of an alternating anaerobic/aerobic biofilter(AABF),and its physiological characteristics were studied.Nitrate or nitrite could be used by the strain P.putida PAO-1 as electron acceptors for denitrification during phosphorus anoxic uptake,and 0.63 mg NO-3-N was consumed to reduce 1 mg soluble orthophosphate(SOP)by P.putida PAO-1.The strain P.putida PAO-1 consumed phosphorus within the optimal pH range of 6 to 8 and the temperature range of 25℃to 35℃.Cell deformity was a main morphological trait of the strain P.putida PAO-1,and it could elongate(with an elongation rate of 300%-500%)when it was subjected to oligotrophic or high-salt stress(15 g·L-1 NaCl).The findings in this study provide a microbiological reference for understanding the special characteristics of a denitrifying PAO.
基金supported by Recep Tayyip Erdogan University Research Fund Grants BAP-2013.102.03.12 and BAP-2013.102.03.13.
文摘Pseudomonas aeruginosa is one of the leading nosocomial pathogens worldwide, and their infections are difficult to treat due to acquired resistance to many antibiotics. This study aimed to detect class 1 and 2 integrons and antibiotic susceptibility of clinical isolates of P. aeruginosa. Two hundred and five P. aeruginosa strains were collected from the seven general state hospitals in Turkey. They were characterized by antimicrobial susceptibility testing, screened for class 1 and class 2 integrons, and evaluated for the association between antibiotic resistance phenotypes and the presence of integrons. intI gene was amplified in 10 isolates (4.87%) by PCR and in seven isolates of them (70%) were found different gene cassettes. The aadA gene integrated into the class 1 integrons was most frequently found and it was followed by aac genes and blaOXA family genes. Sequence analysis of variable regions of the class 1 integrons showed five gene cassette arrays;aadA1(99%), aac(3)-Id(82%)-orf-aac(3”)-Ia(99%), aac(3)-Ie(83%)-blaoxa10(100%)- aadA1 (100%), aadA6(99%, 100%), aac(6’)-I(97%)-orf-aadA2(99%). No class 2 integron was detected. This study is the first multicenter study for class 1 integrons and it indicates the low rate of presence of class 1 gene cassette in P. aeruginosa.
文摘Objective: Describe resistance to beta lactam antibiotics of Pseudomonas aeruginosa in community infection within HIV-1 infected persons. Methods: We have studied prospectively from June 15th to December 31st 2013 inthe Clinic Hotel-Dieu and NGO VISA of Lomé, adult HIV-1 infected patients under anti retroviral therapy combining tenofovir, lamivudine and efavirenz for at least one year. The technique of agar diffusion susceptibility using discs of Ticarcillin + clavulanic acid is used to study the β-lactamase production. The diagnosis of species was performed by the chloroform test and the test for sensitivity to kanamycin and colistin. Results: Thirty five strains of Pseudomonas aeruginosa were obtained. The T-lymphocytes CD4 mediane was 575 cells/mm3 of blood. Urine represented 15 cases, skin abscesses 11 cases, externa suppurate otitis 7 cases and vaginal swab for 2 cases. The phenotypes were: wild phenotypes 23 cases (65.7%), resistant phenotypes 12 cases. Among resistant phenotypes, 4 were complex phenotype;5 were ESBL phenotypes;2 were hyper productive cephalosporinases phenotypes and 1 was a specific phenotype with impermeability to imipenem. Conclusion: The acquisition of resistance of Pseudomonas aeruginosa to beta lactam antibiotics in community infections among HIV-1 infected person incentives controls and promotes the rational use of antibiotics.
文摘黄曲霉毒素B_(1)(Aflatoxin B_(1),AFB_(1))是二氢呋喃氧杂萘邻酮的衍生物,是目前已知最强的化学致癌物之一,对人类和动物健康造成严重威胁。研究以铜绿假单胞菌M4的发酵上清液为对象,利用超滤、凝胶过滤色谱和离子交换色谱对AFB_(1)降解酶进行分离纯化,通过超高效液相色谱-电喷雾-离子肼串联质谱仪对纯化的活性酶进行鉴定,得到比活性为2298.49 U/mg的小分子多肽。利用薄层色谱法和超高效液相色谱-飞行时间质谱仪对AFB_(1)降解产物进行解析,结果显示硅胶板上出现了不同于AFB_(1)的新荧光斑点,质谱检测到一个主要降解产物,利用Massynlynx V4.1软件推测降解产物的分子式为C 11 H 10 O 4,并对AFB_(1)降解产物的降解途径进行推导。研究纯化的耐高温小分子多肽可有效将降解AFB_(1),从降解破坏位点推测降解产物可能是低毒或无毒物质,这为进一步开发AFB_(1)脱毒剂提供参考。
