Abstract:
:We report here on a quantitative real-time reverse transcription-PCR (qRT-PCR) assay for assessing drug efficacy against the intracellular pathogen Cryptosporidium parvum. The qRT-PCR assay detects 18S rRNA transcripts from both parasites, that is, the cycle threshold for 18S rRNA from parasites (C(T)([P18S])) and host cells (C(T)([H18S])), and evaluates the relative expression between parasite and host rRNA levels (i.e., deltaC(T) = C(T)([P18S]) - C(T)([H18S])) to minimize experimental and operational errors. The choice of qRT-PCR over quantitative PCR (qPCR) in this study is based on the observations that (i) the relationship between the logarithm of infected parasites (log[P]) and the normalized relative level of rRNA (deltadeltaC(T)) is linear, with a fourfold dynamic range, by qRT-PCR but sigmoidal (nonlinear) by qPCR; and (ii) the level of RNA represents that of live parasites better than that of DNA, because the decay of RNA (99% in approximately 3 h) in dead parasites is faster than that of DNA (99% in approximately 24 to 48 h) under in vitro conditions. The reliability of the qRT-PCR method was validated by testing the efficacies of nitazoxanide and paromomycin on the development of two strains of C. parvum (IOWA and KSU-1) in HCT-8 cells in vitro. Both compounds displayed dose-dependent inhibitions. The observed MIC50 values for nitazoxanide and paromomycin were 0.30 to 0.45 micro/ml and 89.7 to 119.0 microg/ml, respectively, comparable to the values reported previously. Using the qRT-PCR assay, we have also observed that pyrazole could inhibit C. parvum development in vitro (MIC50 = 15.8 mM), suggesting that the recently discovered Cryptosporidium alcohol dehydrogenases may be explored as new drug targets.
journal_name
Antimicrob Agents Chemotherjournal_title
Antimicrobial agents and chemotherapyauthors
Cai X,Woods KM,Upton SJ,Zhu Gdoi
10.1128/AAC.49.11.4437-4442.2005subject
Has Abstractpub_date
2005-11-01 00:00:00pages
4437-42issue
11eissn
0066-4804issn
1098-6596pii
49/11/4437journal_volume
49pub_type
杂志文章abstract::Isoxyl (ISO), a thiourea derivative that was successfully used for the clinical treatment of tuberculosis during the 1960s, is an inhibitor of the synthesis of oleic and mycolic acids in Mycobacterium tuberculosis. Its effect on oleic acid synthesis has been shown to be attributable to its inhibitory activity on the s...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.00433-07
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abstract::The in vitro activity of WY-49605 (SUN5555) (WY) was compared with those of cefaclor, cefixime, and amoxicillin-clavulanic acid against 2,958 consecutive clinical isolates from five medical centers and 402 respiratory pathogens from 18 other facilities. Most members of the family Enterobacteriaceae were inhibited by W...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章,多中心研究
doi:10.1128/aac.39.7.1591
更新日期:1995-07-01 00:00:00
abstract::Thirty-five strains of Pasteurella multocida from humans and animals were tested for susceptibility to five cephalosporins by a broth dilution method. Cefcanel showed high activity against all isolates (MIC and MBC, less than or equal to 0.64 micrograms/ml). The corresponding figure for cefaclor and cefuroxime was 2.5...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.33.12.2142
更新日期:1989-12-01 00:00:00
abstract::The occurrence of resistance to last-resort antibiotics was evaluated among Enterobacteriaceae isolates recovered from hospitalized children in a remote African archipelago, São Tomé and Príncipe, where there is limited access to those antibiotics. Fifty patients were screened for colonization by carbapenem-, pan-amin...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.01021-18
更新日期:2018-08-27 00:00:00
abstract::Saccharomicins A and B, two new heptadecaglycoside antibiotics, were isolated from the fermentation broth of the rare actinomycete Saccharothrix espanaensis. They represent a novel class of bactericidal antibiotics that are active both in vitro and in vivo against bacteria and yeast (MICs: Staphylococcus aureus, <0.12...
journal_title:Antimicrobial agents and chemotherapy
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doi:10.1128/aac.44.8.2154-2159.2000
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abstract::An efficient and reproducible procedure was developed for extracting aminoglycosides from renal cortical tissue. It involves a double homogenization and two rinsings with trichloroacetic acid. A higher recovery is obtained compared with that of other previously reported methods. ...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.25.6.783
更新日期:1984-06-01 00:00:00
abstract::Early studies of immobilized peptides mainly focused upon the relationship between structural properties and the activity of soluble and surface-tethered sequences. The intention of this study was to analyze the influence of immobilization parameters upon the activity profile of peptides. Resin beads (TentaGel S NH(2)...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.01254-08
更新日期:2009-03-01 00:00:00
abstract::The in vitro and in vivo activities of Sm-1652 were compared with those of other cephalosporins. SM-1652 possessed a wide antibacterial spectrum which included activity against Pseudomonas aeruginosa. It also exhibited potent antibacterial activities against gram-positive cocci and clinical isolates of glucose nonferm...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.22.5.721
更新日期:1982-11-01 00:00:00
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journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.38.12.2838
更新日期:1994-12-01 00:00:00
abstract::The effects of probenecid on the pharmacokinetics and renal clearance of acyclovir were studied in humans. Acyclovir (5 mg/kg) was given as a 1-h infusion to three volunteers with normal renal function both before and after oral administration of probenecid (1 g). The kinetics were well described by a two-compartment ...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.21.5.804
更新日期:1982-05-01 00:00:00
abstract::We encountered three clinical isolates of methicillin-resistant Staphylococcus aureus which were susceptible to netilmicin and arbekacin in the absence of beta-lactam antibiotics but which were resistant to them in the presence of beta-lactam antibiotics. One of these strains, KU5801, was used to further investigate t...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.46.5.1516-1521.2002
更新日期:2002-05-01 00:00:00
abstract::Heteroresistant (methicillin-resistant) and nonheteroresistant strains of Staphylococcus aureus were tested for their susceptibility to penicillinase-resistant penicillins at incubation temperatures of 37, 35, and 30 C. Susceptibilities were determined by agar dilution and by the standard Kirby-Bauer agar diffusion te...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.4.3.263
更新日期:1973-09-01 00:00:00
abstract::Ovotransferrin immobilized by covalent linkage to Sepharose 4B showed a bacteriostatic effect towards Escherichia coli similar to that of free ovotransferrin. The growth of the bacteria, after exposure to the gel-bound ovotransferrin and its removal, depended on the length of exposure. The results suggest that the ant...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.21.5.840
更新日期:1982-05-01 00:00:00
abstract::The experimental model of infected fibrin clots in rabbits was used to study the penetration and in vivo activity of cefixime against Klebsiella pneumoniae, Escherichia coli, and Staphylococcus aureus. The respective MICs of cefixime against these strains were 0.25, 2, and 8 micrograms/ml. The clots were infected with...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.30.6.913
更新日期:1986-12-01 00:00:00
abstract::Mutations in the kelch propeller domain (K13 propeller) of Plasmodium falciparum parasites from Southeast Asia are associated with reduced susceptibility to artemisinin. We exposed in vitro-cultured stage V gametocytes from Cambodian K13 propeller mutant parasites to dihydroartemisinin and evaluated the inhibition of ...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.01426-18
更新日期:2018-11-26 00:00:00
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journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章,评审
doi:10.1128/AAC.01814-20
更新日期:2020-12-16 00:00:00
abstract::Standard antituberculosis (anti-TB) therapy requires the use of multiple drugs for a minimum of 6 months, with variable outcomes that are influenced by a number of microbiological, pathological, and clinical factors. This is despite the availability of antibiotics that have good activity against Mycobacterium tubercul...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.05208-11
更新日期:2012-01-01 00:00:00
abstract::The mutations in the quinolone resistance-determining region of the gyrA gene from clinical isolates of Pseudomonas aeruginosa were determined by DNA sequencing. The strains were isolated in 1989 and 1993. No mutations were detected in the clinical isolates in 1989, while five types of mutations were identified in the...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.39.9.1970
更新日期:1995-09-01 00:00:00
abstract::Mutations in the Plasmodium falciparum genes pfcrt and pfmdr1 are selected by amodiaquine treatment in Africa. To examine the importance of these mutations in amodiaquine-treated Asian parasites, we determined pre- and posttreatment genotypes for amodiaquine treatment failures from a clinical trial in Afghanistan. The...
journal_title:Antimicrobial agents and chemotherapy
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更新日期:2010-09-01 00:00:00
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journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.39.1.107
更新日期:1995-01-01 00:00:00
abstract::Burkholderia pseudomallei, the causative agent of melioidosis, is inherently resistant to a variety of antibiotics including aminoglycosides, macrolides, polymyxins, and beta-lactam antibiotics. Despite resistance to many beta-lactams, ceftazidime and beta-lactamase inhibitor-beta-lactam combinations are commonly used...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
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abstract::Alalevonadifloxacin (WCK 2349) is a novel l-alanine ester prodrug of levonadifloxacin that is being developed as an oral fluoroquinolone antibiotic. The primary objective of this study was to determine and compare plasma, epithelial lining fluid (ELF), and alveolar macrophage (AM) concentrations of levonadifloxacin fo...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.02297-17
更新日期:2018-02-23 00:00:00
abstract::Acyclovir reduced mortality and organ virus titers in mice inoculated intraperitoneally with 10 50% lethal doses of mouse cytomegalovirus. This susceptibility to acyclovir of a herpesvirus which lacks thymidine kinase is surprising. Alternative phosphorylating enzymes may account for this susceptibility. ...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.20.2.275
更新日期:1981-08-01 00:00:00
abstract::Approximately 39% of methicillin-resistant Staphylococcus aureus (MRSA) sequence type 239 (ST239)-like bloodstream isolates from Liverpool Hospital (obtained between 1997 and 2008) carry an arginine catabolic mobile element (ACME). Whole-genome sequencing revealed that an ACME II variant is located between orfX and SC...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.00013-12
更新日期:2012-06-01 00:00:00
abstract::An oligonucleoside methylphosphonate (ONMP) complementary to the splice acceptor site of immediate-early (IE) pre-mRNAs 4 and 5 (IE4,5SA) inhibits herpes simplex virus type 1 (HSV-1) growth in vitro and in infected animals. The antiviral effect appears to be due to inhibition of IE pre-mRNA 4 and 5 splicing and/or IE4...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.38.4.675
更新日期:1994-04-01 00:00:00
abstract::Quinolones, in addition to their antibacterial activities, act as immunomodulators. Osteopontin (OPN), a member of the extracellular matrix proteins, was found to play a role in the immune and inflammatory response. We found that quinolones significantly enhanced OPN secretion, namely, garenoxacin (220%), moxifloxacin...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
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更新日期:2012-06-01 00:00:00
abstract::When strains harboring R factor and showing ampicillin (APC) resistance were inoculated on plates containing various concentrations of APC, mutants carrying various levels of APC resistance occurred at high frequencies. Increases in the level of APC resistance were due to a quantitative increase in the formation of pe...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.3.3.315
更新日期:1973-03-01 00:00:00
abstract::N(2)-(3,4-Dichlorobenzyl)-7-(2-[1-morpholinyl]ethyl)guanine (MorE-DCBG, 362E) is a synthetic purine that selectively inhibits the replication-specific DNA polymerase of Clostridium difficile. MorE-DCBG and its analogs strongly inhibited the growth of a wide variety of C. difficile strains. When administered orally in ...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.06097-11
更新日期:2012-03-01 00:00:00
abstract::A unique group of viridans streptococci has been found in South Africa. These organisms were isolated in close temporal and physical proximity to the isolation of penicillin-resistant pneumococci. The strains were resistant to penicillin, oxacillin, the cephalosporins (all generations), piperacillin, azlocillin, and m...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.24.5.702
更新日期:1983-11-01 00:00:00
abstract::Efavirenz-based antiretroviral regimen is preferred during rifampin-containing tuberculosis therapy. However, current pharmacokinetic data are insufficient to guide optimized concurrent dosing. This study aimed to better characterize the effects of rifampin on efavirenz pharmacokinetics. Subjects were randomized to re...
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.00980-10
更新日期:2011-07-01 00:00:00