Recent advances in prostate cancer: WNT signaling, chromatin regulation, and transcriptional coregulators / 亚洲男科学杂志(英文版)

Prostate cancer is one of the most common diseases in men worldwide. Surgery, radiation therapy, and hormonal therapy are effective treatments for early-stage prostate cancer. However, the development of castration-resistant prostate cancer has increased the mortality rate of prostate cancer. To develop novel drugs for castration-resistant prostate cancer, the molecular mechanisms of prostate cancer progression must be elucidated. Among the signaling pathways regulating prostate cancer development, recent studies have revealed the importance of noncanonical wingless-type MMTV integration site family (WNT) signaling pathways, mainly that involving WNT5A, in prostate cancer progression and metastasis; however, its role remains controversial. Moreover, chromatin remodelers such as the switch/sucrose nonfermentable (SWI/SNF) complex and chromodomain helicase DNA-binding proteins 1 also play important roles in prostate cancer progression through genome-wide gene expression changes. Here, we review the roles of noncanonical WNT signaling pathways, chromatin remodelers, and epigenetic enzymes in the development and progression of prostate cancer.

Aminoglycoside resistance in domestic sewage and clinical Escherichia coli isolates

SUMMARY Introduction: Escherichia coli, a Gram-negative bacillus, is found in diverse environments and causes several human diseases, such as pneumonia and urinary tract infections. Aminoglycosides are antimicrobials that present high activity against Gram-negative species, including multidrug-resistant pathogens. However, the indiscriminate use of these compounds has selected resistant microorganisms, mainly due to the production of aminoglycoside-modifying enzymes (AME). Material and methods: The minimal inhibitory concentration of the aminoglycosides amikacin, gentamicin, and neomycin against clinical (CI, n = 52, only urinary) and domestic sewage (DS, n = 33) E. coli isolates was determined by the microdilution method, according to the European Committee on Antimicrobial Susceptibility Testing. The presence of AMEs among E. coli isolates was determined based on the susceptibility profile to amikacin, gentamicin, kanamycin, and tobramycin, according to Mancini et al. (2019). Results: Overall, 33.3% of the DS isolates and 100% of the CI isolates presented mechanisms of resistance to amikacin, gentamicin, or neomycin. The extended-spectrum beta-lactamase enzymes-producing isolates (23/27, 85%) showed mechanisms of resistance to gentamicin and/or neomycin and resistance to amikacin was simultaneously observed only in CI isolates. All DS isolates were considered wild-type-no AME, while APH (3') (14/52) and AAC (3') (10/52) enzymes were detected among CI isolates, one of which produces APH (3') and AAC (6')-I simultaneously. Conclusion: Resistance to aminoglycosides is present among E. coli isolates in Brazil, but to a lesser extent in environmental isolates. Besides, AMEs are frequent in CI isolates, and surveillance for antimicrobial resistance should be implemented to monitor aminoglycoside-resistant E. coli infections.

Introducción: Escherichia coli se encuentra en diversos ambientes y causa enfermedades humanas. Los aminoglucósidos son antimicrobianos que presentan actividad contra especies gramnegativas. Sin embargo, el uso indiscriminado de estos compuestos ha seleccionado microorganismos resistentes, principalmente debido a la producción de enzimas modificadoras de aminoglucósidos (AME). Material y métodos: La concentración mínima inhibitoria de aminoglucósidos frente a aislados de E.coli clínicos (CI, n = 52) y de aguas residuales sanitarias (DS, n = 33) se determinó mediante el método de microdilución, según la European Committee on Antimicrobial Susceptibility Testing. La presencia de AME se determinó con base en el perfil de susceptibilidad a amikacina, gentamicina, kanamicina y tobra-micina, según Mancini et al. (2019). Resultados: 33,3% de los aislados de DS y 100% de los CI presentaron resistencia a amikacina, gentamicina o neomicina. Los aislados productores de enzimas betalactamasas de espectro extendido (23/27, 85%) mostraron resistencia a gentamicina y/o neomicina y la resistencia a amikacina se observó simultáneamente solo en CI. Todos los aislados de DS se consideraron wild type sin AME, mientras que las enzimas APH (3') (14/52) y AAC (3') (10/52) se detectaron entre CI, uno de los cuales produce APH (3') y AAC (6')-I simultáneamente. Conclusión: La resistencia a los aminoglucósidos está presente entre los aislados de E. coli en Brasil, pero en menor grado en los aislados ambientales. Se debe implementar la vigilancia de la resistencia a los antimicrobianos para monitorear las infecciones por E. coli resistentes a los aminoglucósidos.

SUMÁRIO Introdução: Escherichia coli é encontrada em vários ambientes e causa doenças em humanos. Os aminoglicosídeos são antimicrobianos que exibem atividade contra espécies Gram-negativas. No entanto, o uso indiscriminado desses compostos tem selecionado microrganismos resistentes, principalmente devido à produção de enzimas modificadoras de aminoglicosídeos (EMA). Material e métodos: A concentração inibitória mínima de aminoglicosídeos contra isolados de E. coli recuperadas de amostras clínicas (IC, n=52) e de águas residuais sanitárias (AR, n=33) foi determinada pelo método de microdiluição, de acordo com o European Committee on Antimicrobial Susceptibility Testing. A presença de EMA foi determinada com base no perfil de suscetibilidade à amicacina, gentamicina, canamicina e tobramicina, de acordo com Mancini et al. (2019). Resultados: 33,3% dos ARS e 100% dos ICs apresentaram resistência à amicacina, gentamicina ou neomicina. Os isolados produtores de enzima beta-lactamase de espectro estendido (23/27, 85%) mostraram resistência à gentamicina e/ou neomicina e resistência à amicacina foi observada simultaneamente apenas em um IC. Todos os ARs foram considerados de tipo selvagem sem EMA, enquanto as enzimas APH (3') (14/52) e AAC (3') (10/52) foram detectadas entre os ICs, um dos quais produz APH (3') e AAC (6')-I simultaneamente. Conclusão: A resistência aos aminoglicosídeos está presente entre isolados clínicos de E. coli no Brasil, mas em menor grau em isolados ambientais. Assim a vigilância da resistência antimicrobiana deve ser implementada para monitorar infecções por E. coli resistentes aos aminoglicosídeos.

Mechanisms of histone methylation and acetylation modifying enzymes in ovarian cancer and therapeutic advances / 中国临床药理学与治疗学

Ovarian cancer is the most malignant gynecologic malignancy. In recent years, histone modifying enzymes (HMEs) have been widely studied as an important part of epigenetic modifi-cations in ovarian cancer. Histone modifying enzymes, including histone methyltransferases and demethylases, histone acetyltransferases and deacetylases, play an important role in the prolif-eration and migration of ovarian cancer cells by modifying histone and non-histone proteins, and can regulate the development of chemoresistance. Inhibitors of various histone modifying enzymes play good anti-tumor effects in ovarian cancer by promoting cell growth arrest and apoptosis, inhibi¬ting tumor cell invasion, and increasing chemo¬therapy sensitivity, and are expected to be a new strategy for precision treatment of ovarian cancer. Therefore, this paper will review the mechanism of action and therapeutic potential of histone modifying enzymes involved in methylation and acetylation processes in ovarian cancer.

Preface to the special issue: biosynthesis of natural products / 生物工程学报

Natural products, important sources of innovative drugs, food, spices and daily chemicals, are closely related to people's healthy life. With the development and integration of modern biological and chemical technologies of natural products, the researches on biosynthesis of natural products have made great progresses in recent years. The biosynthetic pathways of a number of natural products have been analyzed. Many pathway enzymes and modifying enzymes involved in the biosynthesis of natural products have been mined and functionally characterized. Furthermore, genes encoding pathway enzymes have been introduced into chassis to construct cell factories producing natural products through synthetic biology technologies. Also, other biotechnologies including genome editing and genome mining, have been used in the biosynthesis of natural products. In order to further promote the development of researches on biosynthesis of natural products, we edited a Special Issue on the topic of "biosynthesis of natural products", focusing on the researches progress in three aspects: the analysis of biosynthetic pathways of natural products, genome-wide mining and functional characterization of genes encoding tool enzymes, and the scale preparation of natural products by biosynthetic technology. Also included in this Special Issue was the prospect of the biosynthesis of natural products. This Special Issue can provide reference and guidance for the further development of natural product biosynthesis.

Role of aminoglycoside-modifying enzymes and 16S rRNA methylase (ArmA) in resistance of Acinetobacter baumannii clinical isolates against aminoglycosides

Abstract INTRODUCTION: This study aimed to determine the role of genes encoding aminoglycoside-modifying enzymes (AMEs) and 16S rRNA methylase (ArmA) in Acinetobacter baumannii clinical isolates. METHODS: We collected 100 clinical isolates of A. baumannii and identified and confirmed them using microbiological tests and assessment of the OXA-51 gene. Antibiotic susceptibility testing was carried out using disk agar diffusion and micro-broth dilution methods. The presence of AME genes and ArmA was detected by PCR and multiplex PCR. RESULTS: The most and least effective antibiotics in this study were netilmicin and ciprofloxacin with 68% and 100% resistance rates, respectively. According to the minimum inhibitory concentration test, 94% of the isolates were resistant to gentamicin, tobramycin, and streptomycin, while the highest susceptibility (20%) was observed against netilmicin. The proportion of strains harboring the aminoglycoside resistance genes was as follows: APH(3′)-VIa (aphA6) (77%), ANT(2")-Ia (aadB) (73%), ANT(3")-Ia (aadA1) (33%), AAC(6′)-Ib (aacA4) (33%), ArmA (22%), and AAC(3)-IIa (aacC2) (19%). Among the 22 gene profiles detected in this study, the most prevalent profiles included APH(3′)-VIa + ANT(2")-Ia (39 isolates, 100% of which were kanamycin-resistant), and AAC(3)-IIa + AAC(6′)-Ib + ANT(3")-Ia + APH(3′)-VIa + ANT(2")-Ia (14 isolates, all of which were resistant to gentamicin, kanamycin, and streptomycin). CONCLUSIONS: High minimum inhibitory concentration of aminoglycosides in isolates with the simultaneous presence of AME- and ArmA-encoding genes indicated the importance of these genes in resistance to aminoglycosides. However, control of their spread could be effective in the treatment of infections caused by A. baumannii.

Investigation of carbapenemases and aminoglycoside modifying enzymes of Acinetobacter baumannii isolates recovered from patients admitted to intensive care units in a tertiary-care hospital in Brazil

Abstract INTRODUCTION: Acinetobacter baumannii are opportunistic bacteria, highly capable of acquiring antimicrobial resistance through the production of carbapenemases and aminoglycoside modifying enzymes (AMEs). METHODS: Carbapenemase and AME genes were investigated in A. baumannii recovered from inpatients of a Brazilian hospital. RESULTS: The key genes found were bla OXA-51-like, the association ISAba1- bla OXA-23-like, and the AME genes aph(3´)-VI, aac(6´)-Ib, aac(3)-Ia, and aph(3´)-Ia. Different clusters spread through the institution wards. CONCLUSIONS: The dissemination of bla OXA-23-like and AME-carrying A. baumannii through the hospital highlights the need for improved preventive measures to reduce the spread of infection.

Emergence of aph(3')-VI and accumulation of aminoglycoside modifying enzyme genes in KPC-2-possessing Enterobacter aerogenes isolates from infections and colonization in patients from Recife-PE, Brazil

Abstract INTRODUCTION: The objective of this study was to characterize genes of aminoglycoside modifying enzymes (AMEs) in colonizing and infecting isolates of E. aerogenes harboring bla KPC from patients at a public hospital in Recife-PE, Brazil. METHODS: We analyzed 29 E. aerogenes clinical isolates resistant to aminoglycosides. AMEs genes were investigated by PCR and sequencing. RESULTS: Colonizing and infecting isolates mainly presented the genetic profiles aac(3)-IIa/aph(3')-VI or ant(2")-IIa/aph(3')-VI. This is the first report of aph(3')-VI in E. aerogenes harboring bla KPC in Brazil. CONCLUSIONS: The results highlight the importance in establishing rigorous methods for the surveillance of resistance genes, especially in colonized patients.

Differential expression of histone demethylase KDM3B and JMJD1C in acute myeloid leukemia / 中国生化药物杂志

Objective To investigate the synergistic regulation of KDM3B and JMJD1C in leukemia. Methods The expression level of JMJD1C and KDM3B were analyzed in multiple acute myeloid leukemia (AML) cell lines. AML cell lines NB4 and HL-60 were treated with Daminozide, followed by determination of H3K9 mono-methylation and di-methylation. AML cell lines NB4 and HL-60 were treated with Daminozide, ATRA (retinoid acid All-trans), C Vitamin and the expression of KDM3B and JMJD1C were detected by real-time quantitative PCR. Results The expression level of KDM3B and JMJD1C in the AML cell lines was negatively correlated. In NB4 and HL-60 cells treated by daminozide, H3K9 mono-methylation and di- methylation level showed a rising trend in these two cell groups. After treatment of NB4 cells with the 3 reagents, the level of mRNA of KDM3B was down-regulated while the level of mRNA of JMJD1C was up-regulated. In HL-60 cells treated by daminozide, the mRNA level of KDM3B was up-regulated and the mRNA level of JMJD1C was down-regulated. Conclusion The expression of KDM3B and JMJD1C is negatively correlated in patients with AML.

Prevalence of resistance to aminoglycosides and fluoroquinolones among Pseudomonas aeruginosa strains in a University Hospital in Northeastern Poland

The present study was conducted to investigate the prevalence of genes encoding resistance to aminoglycosides and fluoroquinolones among twenty-five Pseudomonas aeruginosa isolated between 2002 and 2009. In PCR, following genes were detected: ant(2")-Ia in 9 (36.0%), aac(6')-Ib in 7 (28.0%), qnrB in 5 (20.0%), aph(3")-Ib in 2 (8.0%) of isolates.

Caracterización de actinobacterias raras, degradadoras de lignocelulosa: demostración de actividad lacasa en dos aislados de Tsukamurella sp y Cellulosimicrobium sp / Characterization of lignocellulose-degrading rare actinobacteria: demostration of laccase activity in two isolates of Tsukamurella sp and Cellulosimicrobium sp

Las características fisicoquímicas de la lignina y su compactación con la celulosa han dificultado la explotación biotecnológica de enormes cantidades de biomasa vegetal. Las lacasas constituyen una subfamilia de oxidasas multicobre que intervienen en la despolimerización de la lignina. Si bien han sido ampliamente caracterizadas en los hongos, los estudios de la diversidad y las funcionalidades de las lacasas en los procariotas se han centrado especialmente en isoformas enzimáticas de Streptomyces sp. En este trabajo se aislaron 20 cepas de actinobacterias del suelo. La actividad lacasa de 17 de ellas fue evidenciada en ensayos cualitativos con guayacol y dos cepas seleccionadas fueron caracterizadas en detalle. Las pruebas morfológicas y el análisis de las secuencias del gen 16S rRNA apuntan a que estos dos aislados pertenecen a los géneros Tsukamurella y Cellulosimicrobium. En cultivo sumergido con agitación, AC01 (Tsukamurella sp.) expresó una máxima actividad de oxidación de ABTS (2,2’-azino-bis-(3-etilbenzotiazolin-6-sulfonato) de 108 U/L. Por otra parte, AC18 (Cellulosimicrobium sp.) que había exhibido una actividad oxidativa de guayacol superior a las 16 cepas restantes y demostró ser resistente a niveles tóxicos de cobre, logró un valor máximo de oxidación del ABTS de 0,56 U/L. Estos resultados sugieren que en el aislado AC18 operaría un fenómeno de especificidad de sustrato o de inductor, regulador de la expresión y de la actividad lacasa cuantificable. La caracterización genómica y funcional de las lacasas de nuevas actinobacterias lignocelulósicas ampliará la gama de centros redox con aplicaciones biotecnológicas específicas, además de facilitar el establecimiento de sus relaciones evolutivas con las eucariotas.

The physicochemical characteristics of lignin and its compaction with cellulose have restricted the biotechnological exploitation of enormous amounts of plant biomass. Laccases are a subfamily of multicopper oxidases involved in lignin depolymerization. Although they have been extensively characterized in fungi, studies of the diversity and functions of laccases in prokaryotes are mainly on enzyme isoforms of Streptomyces sp. In this work we isolated 20 strains of soil actinomycetes. The laccase activity of 17 of them was evidenced in qualitative assays with guaiacol, and two selected strains were characterized in detail. The morphological evidence and the analysis of the 16S rRNA gene sequences suggest that these two isolates belong to the genera Tsukamurella and Cellulosimicrobium. In submerged cultures with shaking, AC01 (Tsukamurella sp.) exhibited a maximal oxidation activity of ABTS (2,2 '-azino-bis-(3-ethylbenzthiazoline-6-sulfonate) of 108 U/L. On the other hand, AC18 (Cellulosimicrobium sp.) that exhibited a higher oxidative activity of guaiacol than the other 16 isolated strains and showed resistance to toxic levels of copper, reached a maximum ABTS oxidation rate of 0.56 U/L. These results suggest that in AC18 operates a mechanism of substrate or inducer specificity, regulating the measurable laccase activity and laccase gene expression. Genomic and functional characterization of laccases of new ligninolytic actinomycetes may help to extend the range of redox centers with specific biotechnological applications, as well as establishing their evolutionary relationships with eukaryotes.

Aminoglycoside-resistant genes in Klebsiella pneumoniae / 中华临床感染病杂志

ObjectiveTo investigate the prevalence of 16S rRNA methylase genes, aminoglycoside modifying enzymes (AMEs) genes and small multidrug resistance efflux pump gene smr-2 in Klebsiella pneumoniae. MethodsTotally 138 Klebsiella pneumoniae isolates were collected in the First Affiliated Hospital, college of medicine, Zhejiang University from January 2007 to December 2009. Polymerase chain reaction (PCR) and DNA sequencing were performed to screen the presence of six 16S rRNA methylase genes ( rmtA, rmtB, rmtC, rmtD, armA and npmA), seven AMEs genes[aac ( 3 )- Ⅰ , aac ( 3 )- Ⅱ,aac(6′)- Ⅰ b, aac(6′)-Ⅱ, ant(2″)- Ⅰ , ant(3″)- Ⅰ , aph(3′)-Ⅵa]and small multidrug resistance efflux pumps gene (smr-2).Results Thirteen (9. 4％) isolates were found to carry rmtB gene, whereas 87 (63.0％) isolates were found to carry at least one kind of AMEs genes but no smr-2 was detected. The positive rates of aac(3)-Ⅱ, aac(6′)- Ⅰ b, ant (3″)- Ⅰ and ant(2″)- Ⅰ were 40.6％ (56/138), 31.9％ (44/138), 28.3％ (39/138) and 2.2％ (3/138), respectively. All strains harboring rmtB gene carried one to three AMEs genes. Among 44 aac(6′)- Ⅰ b positive strains, 37 (84. 1％ ) were confirmed to carryaac(6′)- Ⅰ b-cr. ConclusionFor Klebsiella pneumoniae, rmtB is the predominant subtype in 16S rRNA methylase genes, accompanying with several AMEs genes.

Expressions of aminoglycoside modifying enzymes genes in extended-spectrum β-lactamase-producing Klebsiella pneumoniae isolates / 中华临床营养杂志

Objective To investigate the expressions of aminoglycoside modifying enzymes (AMEs)genes of extended-spectrum β-lactamase-producing Klebsiella pneumoniae (ESBL-KP) isolates in our hospital, with an attempt to provide evidence for rational clinical antibiotics use. Mothods A total of 42 strains of ESBL-KP were isolated from January 2007 to January 2008 in our hospital The expressions of 9 AMEs including aac (3)-Ⅰ , aac (3)-Ⅱ , aac (3)-l, aac (3)-Ⅳ, aac (6')- Ⅰ , aac (6')-Ⅰ, apb (3')-Ⅵ, ant (3")-Ⅰ, and ant (2") -Ⅰ were identified by polymerase chain reaction. Results The positive rates of aac (3) - Ⅱ, ant (3") - Ⅰ ,aac (6') - Ⅰ , apb (3') -Ⅵ, and aac (3) - Ⅰ were 85. 7%, 59. 5%, 21.4% , 9. 5%, and 7. 1% , respectively. All the other genotypes were negative. The positive rate of AMEs reached 90. 5% (38 of 42). Conclusions The expression rates of AMEs genes are high among ESBL-KP isolates in our hospital. The aminoglycoside resistance may be relevant with AMEs.

Thiry-nine Types of Resistant-related Genes in a Pan-resistant Alcaligenes xylosoxidans subsp xylosoxidans in Sputum from a Severe Chronic Hepatitis Patient / 中华医院感染学杂志

OBJECTIVE To study 39 kinds of resistant-related genes in a pan-resistant Alcaligenes xylosoxidans subsp xylosoxidans(AXXxx) in the sputum isolated from a severe hepatitis B patient.METHODS The susceptibility to antimicrobial agents were detected by MIC.16S rRNA and 39 resistant-related genes including 29 ?-lactamases genes,6 aminoglycoside-modifying enzymes(AMEs)genes,1 chlorhexidine-sulfadiazine resistant gene(qacE△1-sul1)and 3 intergron genes separated(intⅠ1,2,3) an AXXxx strain in the sputum of a severe hepatitis B patient were measured by PCR,and verified by DNA sequencing.RESULTS Among the strains,7 kinds of resistant-related genes(blaTEM-116,blaCARB-8,aac(6′)-Ⅱ,aac(3)-Ⅱ,ant(3″)-Ⅰ,qacE△1-sul1,and intI1)detected out.But other 27 kinds of ?-lactamases genes,3 kinds of AMEs(aac(6′)-Ⅰb,aac(3)-Ⅰ,ant(2″)-Ⅰ) genes,and 2 kinds of intⅠ(intⅠ2 and intⅠ3) genes were negative.CONCLUSIONS The pan-resistant A.xylosoxidans,mainly relates to 7 kinds of resistant-related genes(blaTEM-116,blaCARB-8,aac(6′)-Ⅱ,aac(3)-Ⅱ,ant(3″)-Ⅰ,qacE△1-sul1,and intⅠ1).

Forty Types of Resistant-related Genes in a Pan-resistant Pseudomonas aeruginosa / 中华医院感染学杂志

OBJECTIVE To study 40 kinds of resistant-related genes in a pan-resistant Pseudomonas aeruginosa.METHODS To detect the susceptibility of antimicrobial agents by MIC,40 resistant-related genes including 29 ?-lactamases genes,porin oprD2 genes,6 aminoglycoside-modifying enzymes(AMEs)genes,chlorhexidine/sulfadiazine resistant gene(qacE△1-sul1)and intergron(intⅠ1,2,3),etc,form 1 strain of P.aeruginosa were measured by PCR,and verified by DNA sequencing.RESULTS In the strain,there were positive of 6 kinds of resistant-related genes(blaTEM,blaOXA10,aac(6′)-Ⅱ,aac(3)-Ⅱ,qacE△1-sul1 and intⅠ1),but without oprD2 genes.Twenty-seven kinds of ?-lactamases genes,4 kinds of AMEs(aac(6′)-Ⅰb,aac(3)-Ⅰ,ant(3″)-Ⅰ and ant(2″)-Ⅰ),and 2 kinds of intⅠ(intⅠ2 and intⅠ3) were negative.CONCLUSIONS The multi-resistant mechanisms of pan-resistant P.aeruginosa are mainly related to 7 kinds of resistant-related genes(blaTEM,blaOXA10,oprD2,aac(6′)-Ⅱ,aac(3)-Ⅱ,qacE△1-sul1 and intⅠ1).

A Pan-resistant Burkholderia cenocepacia Strain in Sputum from a Severe Chronic Hepatitis Patient:Study of 39 types of Its Resistant-related Genes / 中华医院感染学杂志

OBJECTIVE To study 39 kinds of resistant-related genes in a pan-resistant Burkholderia cenocepacia(BCE) strain,in the sputum from a severe hepatitis B patient.METHODS To detect the susceptibility to antimicrobial agents by MIC,16S rRNA,39 resistant-related genes including 29 ?-lactamases genes,6 aminoglycoside-modifying enzymes(AMEs) genes,chlorhexidine/sulfadiazine resistant gene(qacE△1-sul1),integron(intⅠ1,2,3),et al,of 1 strain of BCE in the sputum from a severe hepatitis B patient,were measured by PCR,and verified by DNA sequencing.RESULTS The strain was BCE conformed by 16S rRNA-PCR-DNA sequencing.It was susceptible to ceftazidime,cefepime,ciprofloxacin,levofloxacin,and trimethoprim/sulfamethoxazole,but resistant to piperacillin,aztreonam,cefotaxime,cefoxitin,meropenem,imipenem,nitrofurantoin,gentamicin and amikacin.There were positive of 6 kinds of resistant-related genes(blaTEM-116,aac(6′)-Ⅰb,aac(3)-Ⅰ,ant(2″)-Ⅰ,ant(3″)-Ⅰ,and intⅠ1),28 kinds of ?-lactamases genes,2 kinds of AMEs genes(aac(6′)-Ⅱ and aac(3)-Ⅱ),2 kinds genes of intⅠ(intⅠ2 and intⅠ3) were negative.CONCLUSIONS The multi-resistant BCE is with its multiple resistant mechanisms,and mainly relates to 6 kinds of resistant-related genes(blaTEM-116,aac(6′)-Ⅰb,aac(3)-Ⅰ,ant(2″)-Ⅰ,ant(3″)-Ⅰ and intⅠ1.

Detection of Two Types of Aminoglycoside-modifying Enzymes Genes in Chryseobacterium spp / 中华医院感染学杂志

OBJECTIVE To study 6 kinds of aminoglycoside-modifying enzymes (AMEs) genes in Chryseobacterium spp isolates. METHODS The isolates were identified by API20NE Gram-negative identification cards,and the susceptibility of antimicrobial agents was detected by MIC kits ( bioM?rieux ) 6 AMEs genes of 2 strains of Chryseobacterium spp were measured by PCR,and verified by DNA sequencing and sequence analysis. RESULTS In the 2 strains,2 kinds of resistant genes [aac(6′)-Ⅱ and ant(2″)-Ⅰ] were positive,and 4 kinds genes of AMEs [aac (6′)-Ⅰb,aac(3)-Ⅱ,ant(3″)-Ⅰ and aac(3)-Ⅰ] were negative.The amplicons were purified,sequenced and analyzed with BLAST 2.0 and found to be identical to aac(6′)-Ⅱ and ant(2″)-Ⅰ. CONCLUSIONS There are AMEs in Chryseobacterium spp isolates. This is the first report on AMEs genes [coexistance of aac(6′)-Ⅱ and ant(2″)-Ⅰ] in Chryseobacterium spp.

Genotypes of Aminoglycoside-modifying Enzymes of Acinetobacter baumannii / 中华医院感染学杂志

OBJECTIVE To investigate the genotypes of aminoglycoside-modifying enzymes(AMEs)genes of Acinetobacter baumannii.METHODS Clinical isolates of A.baumannii were collected from 2003 to 2006,and their resistance to gentamicin,amikacin and tobramycin were tested by K-B method.Twenty-three isolates were chosen because of their resistance to aminoglycoside antibiotics(at least resistant to one kind of the drugs).Nine types of the AMEs were detected by PCR.RESULTS Drug resistant rates of 23 isolates of A.baumannii to gentamicin,amikacin and tobramycin,were 86.96%,56.5% and 69.56%,respectively.The detection rates of the 9 AMEs,including ant(3')-Ⅰ,aac(3)-Ⅰ、aac(6')-Ⅰ,aph(3')-Ⅵ,aac(3)-Ⅱ,aac(6')-Ⅱ and ant(2″)-Ⅰ were 69.56%,60.87%,56.52%,47.82%,30.4%,26.09% and 21.73%,respectively.CONCLUSIONS The resistance to aminoglycoside antibiotics of A.baumannii is mainly caused by AMEs.

Drug-resistant Genes Associated with Aminoglycosides in Acinetobacter baumannii Isolated from ICU / 中华医院感染学杂志

OBJECTIVE To investigate the antibiotic resistance of multi-resistant Acinetobacter baumannii(ABA) and distribution of aminoglycoside-modifying enzymes and 16S rRNA methylase genes in ICU in Yinzhou People′s Hospital in Ningbo. METHODS The samples of 20 ABA isolates were collected from Oct 2007 to Jul 2008 in ICU.K-B method was used to determine the sensitivity to 32 antibacterials and the aminoglycoside-modifying enzymes and 16S rRNA methylase genes were analyzed by polymerase chain reaction(PCR). RESULTS From 20 ABA isolates,8 strains carried aminoglycoside-modifying enzymes genes aac(3)-Ⅰ,aac(3)-Ⅱ,aac(6′)-Ⅰb,and ant(3″)-Ⅰ,their positive rate was 10%,15%,30% and 25%,respectively;no strain carried 16S rRNA methylase genes. CONCLUSIONS The antibiotics resistance of A.baumannii is very serious in Yinzhou People′s Hospital in Ningbo.Aminoglycoside-modifying enzymes genes aac(3)-Ⅰ,aac(3)-Ⅱ,aac(6′)-Ⅰb and ant(3″)-Ⅰ exist in multi-resistant A.baumannii widely.They would be the main causes of high drug-resistantce to aminoglycosides.

Analysis on 16S rRNA methylase genes and aminoglycoside modifying enzymes genes in Enterobacter cloacae in China / 中华流行病学杂志

Objective To investigate the 16S rRNA methylase genes and Aminoglycoside modifying enzymes(AMEs)genes in Enterobacter cloacae isolated from the People's Liberation Army 98th Hospital,Huzhou district,Zhejiang province,China.Methods 40 strains of Enterobacter cloacae were isolated from the inpatients between September,2003 and November,2004.5 kinds of 16S rRNA methylase gene (including armA,rmtA,rmtB,rmtC and rmtD)and 9 kinds of AMEs gene[including aac(3)-Ⅰ,aac(3)-Ⅱ,aac(3)-Ⅲ,aac(3)-Ⅳ,aac(6')-Ⅰ b,aac(6')-Ⅱ,ant(3'')-Ⅰ,ant(2'')-Ⅰ and aph(3')-Ⅵ]were analyzed by PCR and verificated by DNA sequencing.Results In 40 strains of Enterobacter cloacae,the positive rates of genes of rmtB,aac(3)-Ⅱ,aac(6')-Ⅰ b,ant(3'')-Ⅰ,ant(2'')-Ⅰ and aph(3')-Ⅵ were 12.5%(5/40),27.5%(11/40),72.5%(29/40),32.5%(13/40),5.0%(2/40)and 5.0%(2/40),respectively.8 kinds of the rest of genes were all tested negative.The total positive rate of AMEs gene was 85.0%(34/40).Among 29 strains of Enterobacter cloacae that the aac(6')-Ⅰ b gene was positive,through PCR and verification by DNA sequencing,7 strains(24.1%)were confirmed to take the aac(6')-Ⅰ b-cr(the GenBank register number:EF375620,EU159121)alone,18 strains(62.1%)were confirmed to take the aac(6')-Ⅰ b-Suzhou(EU085533)alone,3 strains(10.3%)were confirmed to take both aac (6')-Ⅰ b-Suzhou and aac(6')-Ⅰ b-cr while only 1(3.4%)was aac(6')-Ⅰ b(the classical type).Conclusion There was lower positive rate of 16S rRNA methylase gene but very high AMEs genotypes in Enterobacter cloacae isolated from inpatients and the finding of rmtB gene was reported for the first time in the world.At least 5 kinds of AMEs gene existed in Enterobacter cloacae were isolated and they were the new host of both gene of aac(6')-Ⅰ b-cr and aac(6')-Ⅰ b-Suzhou,with aac(6')-Ⅰ b-Suzhou gene was the predominance subtype in aac(6')-Ⅰ b.

Study on the Genotyping of Aminoglycoside Modifying Enzymes Genes from Pan-drug Resistant Acinetobacter Baumannii / 医学研究杂志

Objective To investigate the genotyping of aminoglycoside modifying enzymes on Pan-drug resistant A..baumannii(PDRA)isolated.Methods The antibiotic susceptibility of 16 different antibiotics of A.baumannii were tested by K-B method,aminoglycoside modifying enzymes coding genes of A.baumannii were detected by PCR.Results The detection rates of OXA-23group were 41.8%and aminoglycoside modifying enzymes coding genes of aac(3)-Ⅰ,aac(6')-Ⅰand ant(3″)-Ⅰ were 64.1%,64.1% and 74.4%.Conclusions The study showed that it is more serious for PDRA carrying aminoglycoside modifying enzymes coding genes.