Abstract:
:Ampicillin resistance in Enterococcus faecium is a serious concern worldwide, complicating the treatment of E. faecium infections. Penicillin-binding protein 5 (PBP5) is considered the main ampicillin resistance determinant in E. faecium The three known E. faecium clades showed sequence variations in the pbp5 gene that are associated with their ampicillin resistance phenotype; however, these changes alone do not explain the array of resistance levels observed among E. faecium clinical strains. We aimed to determine if the levels of PBP5 are differentially regulated between the E. faecium clades, with the hypothesis that variations in PBP5 levels could help account for the spectrum of ampicillin MICs seen in E. faecium We studied pbp5 mRNA levels and PBP5 protein levels as well as the genetic environment upstream of pbp5 in 16 E. faecium strains that belong to the different E. faecium clades and for which the ampicillin MICs covered a wide range. Our results found that pbp5 and PBP5 levels are increased in subclade A1 and A2 ampicillin-resistant strains compared to those in clade B and subclade A2 ampicillin-susceptible strains. Furthermore, we found evidence of major clade-associated rearrangements in the region upstream of pbp5, including large DNA fragment insertions, deletions, and single nucleotide polymorphisms, that may be associated with the differential regulation of PBP5 levels between the E. faecium clades. Overall, these findings highlight the contribution of the clade background to the regulation of PBP5 abundance and point to differences in the region upstream of pbp5 as likely contributors to the differential expression of ampicillin resistance.
journal_name
Antimicrob Agents Chemotherjournal_title
Antimicrobial agents and chemotherapyauthors
Montealegre MC,Roh JH,Rae M,Davlieva MG,Singh KV,Shamoo Y,Murray BEdoi
10.1128/AAC.02034-16subject
Has Abstractpub_date
2016-12-27 00:00:00issue
1eissn
0066-4804issn
1098-6596pii
AAC.02034-16journal_volume
61pub_type
杂志文章abstract::Salmonella enterica serovar Typhi is an important pathogen exclusively for humans and causes typhoid or enteric fever. It has been shown that type IVB pili, encoded by the S. enterica serovar Typhi pil operon located in Salmonella pathogenicity island 7, are important in the pathogenic process. In this study, by using...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.49.10.4052-4060.2005
更新日期:2005-10-01 00:00:00
abstract::Fluoroquinolone antibiotics are prescribed for the treatment of Salmonella enterica infections, but resistance to this family of antibiotics is growing. Here we report that loss of the global regulatory protein cyclic AMP (cAMP) receptor protein (CRP) or its allosteric effector, cAMP, reduces susceptibility to fluoroq...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.01666-17
更新日期:2017-10-24 00:00:00
abstract::Activity of the new antiviral compound selenazofurin was compared with the known active compounds ribavirin and amantadine against influenza A and B viruses. In experiments with Madin Darby canine kidney cells, selenazofurin inhibited the cytopathic effect and yield of influenza A/NWS/33 virus, with 50% effective dose...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.28.3.375
更新日期:1985-09-01 00:00:00
abstract::Effervescent lozenges containing 10 mg of zinc acetate were evaluated as a treatment of upper respiratory tract infections in a double-blind randomized trial by using a placebo which was indistinguishable to most observers in taste and appearance from the active material. Of the 70 treatment courses used by 55 individ...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1128/aac.31.8.1263
更新日期:1987-08-01 00:00:00
abstract::The activities of trimethoprim (TMP) and sulfamethoxazole (SMZ), alone and in combination (SMZ-TMP), and of the following antibiotics were tested against 115 clinical isolates of nontyphoid Salmonella species: tobramycin, gentamicin, ampicillin, amoxicillin, neomycin, kanamycin, chloramphenicol, and tetracycline. The ...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.4.5.555
更新日期:1973-11-01 00:00:00
abstract::The bla(OXA-51)-like gene with an upstream ISAba1 (ISAba1-bla(OXA-51)-like gene) was originally found on the chromosomes of carbapenem-resistant or -susceptible Acinetobacter baumannii isolates. However, a plasmid-borne ISAba1-bla(OXA-51)-like gene has recently been identified in Acinetobacter genomic species 13TU and...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.00764-10
更新日期:2010-11-01 00:00:00
abstract::The basis of bactericidal versus bacteriostatic action of antibiotics and the mechanism of bacterial cell death are largely unknown. Related to this important issue is the essential invulnerability to killing of persisters: cells forming a small subpopulation largely responsible for the recalcitrance of biofilms to ch...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.48.3.890-896.2004
更新日期:2004-03-01 00:00:00
abstract::Given that tedizolid exhibits substantial lung penetration, we hypothesize that it could achieve good efficacy against Streptococcus pneumoniae lung infections. We evaluated the pharmacodynamics of tedizolid for treatment of S. pneumoniae lung infections and compared the efficacies of tedizolid human-simulated epithel...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.01957-16
更新日期:2016-12-27 00:00:00
abstract::Analysis of the transport functions of individual Candida albicans plasma membrane drug efflux pumps is hampered by the multitude of endogenous transporters. We have stably expressed C. albicans Cdr1p, the major pump implicated in multiple-drug-resistance phenotypes, from the genomic PDR5 locus in a Saccharomyces cere...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.45.12.3366-3374.2001
更新日期:2001-12-01 00:00:00
abstract::The mechanism of action of the fungicidal peptide auristatin PHE was investigated in Cryptococcus neoformans. Since auristatin PHE causes budding arrest in C. neoformans (T. Woyke, G. R. Pettit, G. Winkelmann, and R. K. Pettit, Antimicrob. Agents Chemother. 45:3580-3584, 2001), microtubule integrity and nuclear locali...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.46.12.3802-3808.2002
更新日期:2002-12-01 00:00:00
abstract::A practical preclinical model for the hyperbilirubinemia produced by human immunodeficiency virus protease inhibitors has been developed. Indinavir and atazanavir produced significant hyperbilirubinemia, whereas amprenavir, the negative control, was indistinguishable from the ritonavir booster dose. This model was use...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.50.2.762-764.2006
更新日期:2006-02-01 00:00:00
abstract::The biosynthetic gene cluster of lankamycin (LM), a 14-member macrolide antibiotic, is encoded on the 210-kb linear plasmid pSLA2-L in Streptomyces rochei 7434AN4. LM contains a 3-hydroxy-2-butyl group at the C-13 position, which is different from an ethyl group in erythromycin. The following two possibilities could b...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.00016-06
更新日期:2006-06-01 00:00:00
abstract::Doravirine (DOR, formerly known as MK-1439) is a human immunodeficiency type 1 virus (HIV-1) nonnucleoside reverse transcriptase inhibitor (NNRTI) that is currently in phase 2b clinical trials. In vitro resistance selection of subtype B virus (MT4-green fluorescent protein [GFP] cells), as well as subtype A and C viru...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.04201-14
更新日期:2015-01-01 00:00:00
abstract::Gatifloxacin pneumococcal, staphylococcal and enterococcal postantibiotic effects (PAEs) were 0.5 to 4.0 h, respectively. For Escherichia coli and Pseudomonas aeruginosa, PAEs were 2.2 to 4.8 h. Pneumococcal, staphylococcal, and enterococcal postantibiotic sub-MIC effects (PA-SMEs) (four times the MICs) were 3.7 to 8....
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.43.10.2574
更新日期:1999-10-01 00:00:00
abstract::Methicillin-resistant Staphylococcus aureus (MRSA) is a common pathogen associated with nosocomial pneumonia and is an increasing threat for severe community-acquired pneumonia. We have now investigated the role of interleukin-12 (IL-12) in protective immunity against lung infection with MRSA. The importance of IL-12 ...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.00968-15
更新日期:2015-10-01 00:00:00
abstract::Community-associated infections due to Escherichia coli producing CTX-M-type extended-spectrum β-lactamases are increasingly recognized in the United States. The bla(CTX-M) genes are frequently carried on IncF group plasmids. In this study, bla(CTX-M-15)-harboring plasmids pCA14 (sequence type 131 [ST131]) and pCA28 (...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.04772-14
更新日期:2015-01-01 00:00:00
abstract::Kingella kingae is the major pathogen causing osteoarticular infections (OAI) in young children in numerous countries. Plasmid-borne TEM-1 penicillinase production has been sporadically detected in a few countries but not in continental Europe, despite a high prevalence of K. kingae infections. We describe here for th...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.03562-14
更新日期:2014-10-01 00:00:00
abstract::Ampicillin and erythromycin were shown to act synergistically in vitro against the majority of strains of Nocardia asteroides tested. With these strains, the minimal inhibiting concentration (MIC) of each drug when combined was reduced 4- to more than 512-fold as compared with the MIC of each antibiotic acting individ...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.5.3.344
更新日期:1974-03-01 00:00:00
abstract::Thein vitroantibacterial activities of ceftazidime-avibactam and comparator agents were evaluated using reference broth microdilution methods against 1,743Pseudomonas aeruginosaisolates collected in 2014 from 69 U.S. medical centers, representing each of the nine census regions. Ceftazidime-avibactam demonstrated pote...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.03056-15
更新日期:2016-03-25 00:00:00
abstract::We evaluated the in vitro activity of polymyxin B plus imipenem, meropenem, or tigecycline against six KPC-2-producing Enterobacteriaceae strains with high MICs for these antimicrobial agents. Polymyxin B with carbapenems, especially meropenem, were the most active combinations for Klebsiella pneumoniae and Enterobact...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.00365-15
更新日期:2015-01-01 00:00:00
abstract::Ethambutol (EMB) plays a pivotal role in the chemotherapy of drug-resistant tuberculosis (TB), including multidrug-resistant tuberculosis (MDR-TB). Resistance to EMB is considered to be caused by mutations in the embCAB operon (embC, embA, and embB). In this study, we analyzed the embCAB mutations among 139 MDR-TB iso...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.04933-14
更新日期:2015-04-01 00:00:00
abstract::In order to establish a screening system for xenosiderophores which can be utilized by mycobacteria, we generated a set of mutants of Mycobacterium smegmatis that are blocked in different steps of the well-known iron acquisition system. One mutant with a block in mycobactin biosynthesis was generated from strain mc(2)...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.45.5.1317-1322.2001
更新日期:2001-05-01 00:00:00
abstract::A total of 4,226 Spanish clinical isolates of Candida spp. were analyzed to assess resistance to voriconazole according to breakpoints established by the European Committee for Antimicrobial Susceptibility Testing (where susceptibility [S] to voriconazole corresponds to a MIC of ≤ 0.12 mg/liter). Resistance was uncomm...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.01757-10
更新日期:2011-04-01 00:00:00
abstract::Shiga toxin (Stx)-producing Escherichia coli (STEC) causes hemorrhagic colitis and hemolytic-uremic syndrome (HUS). The rates of STEC infection and complications, including death, are highest among young children and elderly individuals. There are no causal therapies. Because Stx is the primary pathological agent lead...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.01661-08
更新日期:2009-07-01 00:00:00
abstract::The need for daily parenteral administration is an important limitation in the clinical use of pentavalent antimonial drugs against leishmaniasis. In this study, amphiphilic antimony(V) complexes were prepared from alkylmethylglucamides (L8 and L10, with carbon chain lengths of 8 and 10, respectively), and their poten...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.00639-13
更新日期:2013-09-01 00:00:00
abstract::We studied the influences of antimicrobial agents on the colonization of the respiratory tract and infection with Enterococcus faecalis in intensive care unit (ICU) patients receiving mechanical respiration for at least 3 days. In a matched-cohort analysis, patients receiving topical antimicrobial prophylaxis (TAP) of...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.39.12.2783
更新日期:1995-12-01 00:00:00
abstract::Seventy-two A. fumigatus clinical isolates from China were investigated for azole resistance based on mutations of cyp51A. We identified four azole-resistant strains, among which we found three strains highly resistant to itraconazole, two of which exhibit the TR34/L98H/S297T/F495I mutation, while one carries only the...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.00003-15
更新日期:2015-07-01 00:00:00
abstract::When developing novel microbicide products for the prevention of HIV infection, the preclinical safety program must evaluate not only the active pharmaceutical ingredient but also the product itself. To that end, we applied several relatively standard toxicology study methodologies to female sheep, incorporating an as...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.04954-14
更新日期:2015-07-01 00:00:00
abstract::The Carba NP test was evaluated against a panel of 244 carbapenemase- and non-carbapenemase-producing Enterobacteriaceae and Pseudomonas aeruginosa isolates. We confirmed the 100% specificity and positive predictive value of the test, but the sensitivity and negative predictive value were 72.5% and 69.2%, respectively...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.00878-13
更新日期:2013-09-01 00:00:00
abstract::As a relationship between nelfinavir antiretroviral efficacy and plasma concentrations has been previously established, nelfinavir pharmacokinetics was investigated in order to optimize the individual treatment schedule in a pediatric population. A population pharmacokinetic model was developed to describe the concent...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.50.3.910-916.2006
更新日期:2006-03-01 00:00:00