Biomedical subjects

Philip J Turner

Publications and source records attributed to Philip J Turner.

10 recordsLinked to original sources

PubMed2006

Meropenem and imipenem activity against Pseudomonas aeruginosa isolates from the MYSTIC Program.

This article examines the activity of meropenem and imipenem against Pseudomonas aeruginosa isolates from the Meropenem Yearly Susceptibility Test Information Collection program between 1997 and 2005. In particular, it examines the activity of meropenem against imipenem-resistant strains and vice versa. Meropenem proved to be active against up to a 3rd of imipenem-resistant strains.

Anti-Bacterial Agents↗

PubMed2005

Trends in antimicrobial susceptibility in UK centres: the MYSTIC Programme (1997-2002).

Trends in antimicrobial susceptibilities in three UK centres participating in the MYSTIC Programme were examined from 1997 to 2002. Isolates were tested using standard methodology to determine the susceptibility breakpoints of meropenem and several other antimicrobial agents including imipenem, ceftazidime, piperacillin/tazobactam, ciprofloxacin and gentamicin. Data are grouped in 2-year blocks. The carbapenems were the most active agents tested against the Enterobacteriaceae (99-100% and 98-100% susceptibility to meropenem and imipenem, respectively) and non-fermenters, including Pseudomonas spp. and Acinetobacter spp. With the exception of susceptibility to ciprofloxacin, which decreased among Enterobacteriaceae at the end of the 6-year period, all antibiotics tested retained their levels of activity. The proportion of extended-spectrum beta-lactamase (ESBL)- and AmpC-producing Enterobacteriaceae increased during the study (4.8% and 11.3% in 1997-1998; 7.4% and 16.7% in 2001-2002, respectively). Both meropenem and imipenem retained their potency against these ESBL- and AmpC-producing isolates (100% for all time periods). All the other antimicrobial agents tested had much lower susceptibility against these resistant isolates and this decreased further over the 6-year period, with the exception of tazobactam, which maintained its low levels. Although all antibiotics tested retained acceptable activity, the carbapenems remained the most active antimicrobial agents against Gram-negative bacteria, including ESBL- and AmpC-producing isolates.

Anti-Infective Agents↗

PubMed2005

Extended-spectrum beta-lactamases.

The first beta-lactamase was identified in an isolate of Escherichia coli in 1940. To date, there are >130 TEM-type and >50 sulfhydryl variable (SHV)-type beta-lactamases, mainly in E. coli, Klebsiella pneumoniae, and Proteus mirabilis but also in other members of the Enterobacteriaceae family and in some nonenteric organisms, such as Acinetobacter species. The incidence of expanded-spectrum beta-lactamases (ESBLs) varies, depending on which area of the globe the isolates originate from. ESBLs render the oxyimino-cephalosporins ineffective, and ESBL-producing organisms frequently also possess resistance factors to other classes of antibiotics, such as aminoglycosides and fluoroquinolones, and possibly also piperacillin-tazobactam and cefepime. These results suggest that microbiology laboratories should routinely test for the presence of these strains among their isolates and that the antibiotics of choice for infections believed to be caused by these types of organisms are the carbapenems.

Enterobacteriaceae↗

PubMed2005

Trends in antimicrobial susceptibilities among bacterial pathogens isolated from patients hospitalized in European medical centers: 6-year report of the MYSTIC Surveillance Study (1997-2002).

The Meropenem Yearly Susceptibility Test Information Collection (MYSTIC) Program provides antimicrobial susceptibility data. The activity of meropenem and 7 broad-spectrum antimicrobials have been examined against 12645 bacterial isolates from 14 European centers between 1997 and 2002. Cumulative susceptibility rates against all species of Enterobacteriaceae combined were ranked as follows: meropenem (99.9%) > imipenem (97.7%) > ciprofloxacin (86.0%) > piperacillin-tazobactam (85.6%) > ceftazidime (85.4%) > gentamicin (85.4%) > tobramycin (85.0%) > cefotaxime (83.8%). The carbapenems were also found to be the most active of the classes tested against nonfermentative Gram-negative bacilli. Against methicillin-susceptible Staphylococcus aureus and coagulase-negative staphylococci, all beta-lactams tested (except ceftazidime) had susceptibility rates of > or = 99.0% and > or = 94.3%, respectively. Over the 6-year period, there was no loss of activity or increase in resistance rate for either carbapenem against any of the species tested. These data confirm the continued potency and broad-spectrum activity of meropenem in units where it is actively being prescribed.

Academic Medical Centers↗

PubMed2005

In vitro synergy test of meropenem and sulbactam against clinical isolates of Acinetobacter baumannii.

Meropenem and imipenem are often the drugs of choice for the treatment of infections due to multidrug-resistant Acinetobacter baumannii. The present study aimed at evaluating the interaction between meropenem and sulbactam through microdilution and checkerboard methods against 48 clinical isolates of A. baumannii collected from Brazilian hospitals. All the isolates presented elevated minimum inhibitory concentration (>or=2 microg/mL) to either meropenem or sulbactam. The checkerboard method with the combination of meropenem and sulbactam demonstrated 29.2% (14/48) synergism, 47.9% (23/48) partial synergism, 10.5% (5/48) additive, 6.2% (3/48) indifference, and 6.2% (3/48) antagonism (SigmaFIC(min)=0.09 and SigmaFIC(max)=8). Thus, combinations of meropenem and sulbactam may show synergism or partial synergism for most A. baumannii isolates. Further studies may help identify treatment options for patients with infections caused by these organisms, particularly with this combination, where both drugs have time-dependent activities and might be suitable for therapy optimization studies.

Acinetobacter baumannii↗

PubMed2005

Use of a program-specific website to disseminate surveillance data obtained from the Meropenem Yearly Susceptibility Test Information Collection (MYSTIC) Study.

The Meropenem Yearly Susceptibility Test Information Collection (MYSTIC) Program is a multicenter, longitudinal surveillance study initiated in 1997 that compares the activity of meropenem and comparator antimicrobials in centers that are actively prescribing meropenem. Antimicrobial surveillance programs, such as MYSTIC, provide important information on the emergence of bacterial resistance and the nature of the underlying mechanisms in different geographical regions. Data concerning these mechanisms and patterns of antimicrobial resistance allow the implementation of changes in antimicrobial prescribing practices and infection control interventions. Therefore, it is important that data from surveillance programs be analyzed and accessible to clinicians within reasonable, clinically useful, intervals. In this article, the use of a website designed to disseminate data collected from the MYSTIC program is described. This web-based program allows specific surveillance data to be examined in a timely manner and can assist the clinician when choosing the most appropriate antibiotic for the situation encountered and hopefully maximize successful clinical outcomes.

Anti-Bacterial Agents↗

PubMed2005

An overview of the Meropenem Yearly Susceptibility Test Information Collection (MYSTIC) Program: 1997-2004.

This overview provides a summary of the Meropenem Yearly Susceptibility Test Information Collection (MYSTIC) Program over an 8-year period from 1997 to 2004. The evolution of the MYSTIC Program is described, as well as its design compared with other surveillance programs. In addition, the global MYSTIC Program data, published to date, are summarized, and the empiric use of carbapenems, their current indications, and meropenem usage versus resistance was discussed. From 1997 to 2004, 120 medical centers that were actively prescribing meropenem in 32 countries worldwide participated in the program. The MYSTIC Program results demonstrate the sustained potency and continued effectiveness of meropenem globally against clinically relevant Gram-negative and Gram-positive pathogens including extended spectrum beta-lactamase- and AmpC beta-lactamase-producing organisms, which may also display resistance to the fluoroquinolones and/or aminoglycosides. Furthermore, in centers actively prescribing meropenem, resistance to meropenem is not increasing despite greater resistance among the comparator antimicrobial agents. Thus, antipseudomonal carbapenems such as meropenem and imipenem remain an effective treatment option.

Anti-Bacterial Agents↗

PubMed2005

Integrating Escherichia coli antimicrobial susceptibility data from multiple surveillance programs.

Collaboration between networks presents opportunities to increase analytical power and cross-validate findings. Multivariate analyses of 2 large, international datasets (MYSTIC and SENTRY) from the Global Advisory on Antibiotic Resistance Data program explored temporal, geographic, and demographic trends in Escherichia coli resistance from 1997 to 2001. Elevated rates of nonsusceptibility were seen in Latin America, southern Europe, and the western Pacific, and lower rates were seen in North America. For most antimicrobial drugs considered, nonsusceptibility was higher in isolates from men, older patients, and intensive care unit patients. Nonsusceptibility to ciprofloxacin was higher in younger patients, rose with time, and was not associated with intensive care unit status. In univariate analyses, estimates of nonsusceptibility from MYSTIC were consistently higher than those from SENTRY, but these differences disappeared in multivariate analyses, which supports the epidemiologic relevance of findings from the 2 programs, despite differences in surveillance strategies.

Anti-Bacterial Agents↗

PubMed2004

The OPTAMA programme: utilizing MYSTIC (2002) to predict critical pharmacodynamic target attainment against nosocomial pathogens in Europe.

OBJECTIVES: The Optimising Pharmacodynamic Target Attainment using the MYSTIC (Meropenem Yearly Susceptibility Test Information Collection) Antibiogram (OPTAMA) programme identifies antibiotic regimens with the highest probability of attaining critical pharmacodynamic targets, accounting for the inherent variability in pharmacokinetics, dosages and MIC distributions. METHODS: European MIC data were obtained from the MYSTIC programme. Pharmacodynamic target attainment was calculated by Monte Carlo simulation for meropenem, imipenem, ceftazidime, cefepime, piperacillin/tazobactam and ciprofloxacin against Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii and Pseudomonas aeruginosa. RESULTS: Significant differences in probability of target attainment were found, with Northern Europe demonstrating the highest probabilities of target attainment and Eastern Europe the lowest. The carbapenems had the highest target attainments and susceptibility levels across all regions and pathogens. The cephalosporins demonstrated high target attainments and susceptibility results against E. coli and K. pneumoniae in Northern and Southern Europe. Piperacillin/tazobactam and ciprofloxacin had the lowest levels for both parameters in all regions. Desirable target attainment was not achieved (except for carbapenems in Northern Europe) for A. baumannii and P. aeruginosa; thus, combination therapy may be appropriate empirical therapy for these pathogens in Southern and Eastern Europe. The closest correlations between target attainment and susceptibility were for meropenem 1 g every 8 h, imipenem 0.5 g every 6 h and ceftazidime 1 g every 8 h. CONCLUSIONS: The study highlighted significant overestimations between the probability of target attainment and the reported percentage susceptibility, particularly for piperacillin/tazobactam and ciprofloxacin. The approach of the OPTAMA programme provides a novel tool which complements susceptibility data to help in the selection of appropriate empirical antibiotic therapy.

Acinetobacter baumannii↗

PubMed2004

Susceptibility of meropenem and comparators tested against 30,634 Enterobacteriaceae isolated in the MYSTIC Programme (1997-2003).

A total of 30,634 global Enterobacteriaceae isolates collected from the MYSTIC (Meropenem Yearly Surveillance Test Information Collection) Programme were tested using a reference methodology against meropenem and seven other broad-spectrum agents commonly used in the hospital setting (1997-2003). The most active compound was meropenem (99.6% susceptible), followed by imipenem (98.4%), cefepime (94.0%), gentamicin (86.8%), piperacillin/tazobactam (85.8%), ceftazidime (85.0%), ciprofloxacin (84.6%), and tobramycin (84.5%). Continued surveillance of antimicrobial compounds' in vitro activity is necessary to recommend regimens that are likely to be effective in clinical practice.

Anti-Bacterial Agents↗