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R N Jones

Publications and source records attributed to R N Jones.

At least 73 records · Page 4Linked to original sources
PubMed2002

Multicentre assessment of linezolid antimicrobial activity and spectrum in Europe: report from the Zyvox antimicrobial potency study (ZAPS-Europe).

OBJECTIVE: To evaluate the in vitro spectrum and activity of linezolid, a recent oxazolidinone, according to well-controlled surveillance data from 42 medical centers in 13 countries throughout Europe. METHODS: Participants tested the susceptibility of 125 clinical strains of enterococcal and staphylococcal species against 13 drugs using reference broth microdilution trays or the standardized disk diffusion method of the National Committee for Clinical Laboratory Standards (NCCLS). Streptococcal species (n = 25 at each center) were tested against six drugs using E test (AB BIODISK, Solna, Sweden). Quality assurance testing was conducted using NCCLS-recommended strains and verification of resistance to linezolid and other selected agents was performed by retesting strains at the regional (Europe) and international (USA) monitor sites. RESULTS: A total of 5598 strains from throughout Europe (91% compliance) were tested. Vancomycin resistance was reported in only 0.6 and 3.0% of Enterococcus faecalis and E. faecium, respectively. Penicillin resistance occurred in 25.1% of Streptococcus pneumoniae; 4.9% at the high-level (> or =2 mg/L). The MIC90 for linezolid was 1 mg/L for streptococci and 2 mg/L for enterococci and staphylococci. Using the US FDA- and EUCAST-recommended susceptible breakpoints for linezolid, there were no confirmed reports of linezolid resistance [minimum inhibitory concentration (MIC), > or =8 mg/L]. The distribution of linezolid MIC values was unimodal and varied between 0.25 and 1 mg/L for streptococci (>90% of isolates), and between 1 and 2 mg/L for staphylococci (>90%) and enterococci (>95%). There were no differences in linezolid susceptibility in the vancomycin-, oxacillin-, or penicillin-resistant subsets of strains when compared to susceptible organism populations. CONCLUSIONS: Compared to the North American component of this study, there was substantially less vancomycin resistance among E. faecium isolates (Europe 3.0% vs. North America 63.4%). While the occurrence of penicillin-resistant S. pneumoniae in Europe and North America was similar (25.1% vs. 29.7%), the recovery of high-level penicillin-resistant strains was nearly three-fold higher in North America (4.9% vs. 13.2%). Only linezolid was universally active against all the tested Gram-positive isolates at </=4 mg/L.

Acetamides↗
PubMed2002

A demonstration of a 1:1 correspondence between chiasma frequency and recombination using a Lolium perenne/Festuca pratensis substitution.

A single chromosome of the grass species Festuca pratensis has been introgressed into Lolium perenne to produce a diploid monosomic substitution line 2n = 2x = 14. The chromatin of F. pratensis and L. perenne can be distinguished by genomic in situ hybridization (GISH), and it is therefore possible to visualize the substituted F. pratensis chromosome in the L. perenne background and to study chiasma formation in a single marked bivalent. Recombination occurs freely in the F. pratensis/L. perenne bivalent, and chiasma frequency counts give a predicted map length for this bivalent of 76 cM. The substituted F. pratensis chromosome was also mapped with 104 EcoRI/Tru91 and HindIII/Tru91 amplified fragment length polymorphisms (AFLPs), generating a marker map of 81 cM. This map length is almost identical to the map length of 76 cM predicted from the chiasma frequency data. The work demonstrates a 1:1 correspondence between chiasma frequency and recombination and, in addition, the absence of chromatid interference across the Festuca and Lolium centromeres.

Chromosome Mapping↗
PubMed2002

Physical and genetic mapping in the grasses Lolium perenne and Festuca pratensis.

A single chromosome of the grass species Festuca pratensis has been introgressed into Lolium perenne to produce a diploid monosomic substitution line 2n = 2x = 14. In this line recombination occurs throughout the length of the F. pratensis/L. perenne bivalent. The F. pratensis chromosome and recombinants between it and its L. perenne homeologue can be visualized using genomic in situ hybridization (GISH). GISH junctions represent the physical locations of sites of recombination, enabling a range of recombinant chromosomes to be used for physical mapping of the introgressed F. pratensis chromosome. The physical map, in conjunction with a genetic map composed of 104 F. pratensis-specific amplified fragment length polymorphisms (AFLPs), demonstrated: (1) the first large-scale analysis of the physical distribution of AFLPs; (2) variation in the relationship between genetic and physical distance from one part of the F. pratensis chromosome to another (e.g., variation was observed between and within chromosome arms); (3) that nucleolar organizer regions (NORs) and centromeres greatly reduce recombination; (4) that coding sequences are present close to the centromere and NORs in areas of low recombination in plant species with large genomes; and (5) apparent complete synteny between the F. pratensis chromosome and rice chromosome 1.

Chromosomes, Plant↗
PubMed2002

Antifungal activities of posaconazole, ravuconazole, and voriconazole compared to those of itraconazole and amphotericin B against 239 clinical isolates of Aspergillus spp. and other filamentous fungi: report from SENTRY Antimicrobial Surveillance Program, 2000.

Posaconazole, ravuconazole, and voriconazole are new triazole derivatives that possess potent, broad-spectrum antifungal activity. We evaluated the in vitro activity of these investigational triazoles compared with that of itraconazole and amphotericin B against 239 clinical isolates of filamentous fungi from the SENTRY Program, including Aspergillus spp. (198 isolates), Fusarium spp. (7 isolates), Penicillium spp. (19 isolates), Rhizopus spp. (4 isolates), Mucor spp. (2 isolates), and miscellaneous species (9 isolates). The isolates were obtained from 16 different medical centers in the United States and Canada between January and December 2000. In vitro susceptibility testing was performed using the microdilution broth method outlined in the National Committee for Clinical Laboratory Standards M38-P document. Overall, posaconazole was the most active compound, inhibiting 94% of isolates at a MIC of < or = 1 microg/ml, followed by voriconazole (91%), amphotericin B (89%), ravuconazole (88%), and itraconazole (70%). All three new triazoles demonstrated excellent activity (MIC, < or = 1 microg/ml) against Aspergillus spp. (114 Aspergillus fumigatus, 22 Aspergillus niger, 13 Aspergillus flavus, 9 Aspergillus versicolor, 8 Aspergillus terreus, and 32 Aspergillus spp.): posaconazole (98%), voriconazole (98%), ravuconazole (92%), amphotericin B (89%), and itraconazole (72%). None of the triazoles were active against Fusarium spp. (MIC at which 50% of the isolates tested were inhibited [MIC(50)], >8 microg/ml) or Mucor spp. (MIC(50), >8 microg/ml). Posaconazole and ravuconazole were more active than voriconazole against Rhizopus spp. (MIC(50), 1 to 2 microg/ml versus >8 microg/ml, respectively). Based on these results, all three new triazoles exhibited promising activity against Aspergillus spp. and other less commonly encountered isolates of filamentous fungi. The clinical value of these in vitro data remains to be seen, and in vitro-in vivo correlation is needed for both new and established antifungal agents. Surveillance efforts should be expanded in order to monitor the spectrum of filamentous fungal pathogens and their in vitro susceptibility as these new antifungal agents are introduced into clinical use.

Amphotericin B↗
PubMed2002

In vitro activities of ravuconazole and voriconazole compared with those of four approved systemic antifungal agents against 6,970 clinical isolates of Candida spp.

The in vitro activities of ravuconazole and voriconazole were compared with those of amphotericin B, flucytosine (5FC), itraconazole, and fluconazole against 6,970 isolates of Candida spp. obtained from over 200 medical centers worldwide. Both ravuconazole and voriconazole were very active against all Candida spp. (MIC at which 90% of the isolates tested are inhibited [MIC(90)], 0.25 microg/ml; 98% of MICs were < or 1 microg/ml); however, a decrease in the activities of both of these agents was noted among isolates that were susceptible-dose dependent (fluconazole MIC, 16 to 32 microg/ml) and resistant (MIC, > or = 64 microg/ml) to fluconazole. Candida albicans was the most susceptible species (MIC(90) of both ravuconazole and voriconazole, 0.03 microg/ml), and C. glabrata was the least susceptible species (MIC(90), 1 to 2 microg/ml). Ravuconazole and voriconazole were each more active in vitro than amphotericin B, 5FC, itraconazole, and fluconazole against all Candida spp. and were the only agents with good in vitro activity against C. krusei. These results provide further evidence for the spectrum and potency of ravuconazole and voriconazole against a large and geographically diverse collection of Candida spp.

Antifungal Agents↗
PubMed2002

Molecular epidemiology of extended-spectrum beta-lactamase-producing, fluoroquinolone-resistant isolates of Klebsiella pneumoniae in Taiwan.

Strains of extended-spectrum beta-lactamase-producing Klebsiella pneumoniae (ESBL-KP) have emerged worldwide. Concomitant ciprofloxacin resistance with ESBL production in K. pneumoniae isolates would severely restrict treatment options. Among 39 (18.5%) of 211 ESBL-KP isolates resistant to ciprofloxacin (MIC, >/=4 micro g/ml), 37 (95%) were high level resistant (MIC, >/=16 micro g/ml). These isolates were also cross resistant to the newer fluoroquinolones, including levofloxacin, gatifloxacin, gemifloxacin, and garenoxacin (BMS 284756). Sitafloxacin was most active against these ciprofloxacin-resistant ESBL-KP isolates with MICs for 67% of the isolates being </=2 micro g/ml. The molecular epidemiology of these multiresistant isolates was investigated by automated ribotyping and pulsed-field gel electrophoresis (PFGE). Ribotyping identified 18 different strains among the 39 ciprofloxacin-resistant ESBL-KP isolates. The majority (67%) of these isolates were contained in six ribogroups which were further confirmed by PFGE. The distribution of the six major strains of ciprofloxacin-resistant ESBL-KP within Taiwan included one (ribogroup 255.3-PFGE type E) with a nationwide distribution and several institution-specific strains. Interhospital cooperation appears necessary, with strict infection control practices coupled with restriction of fluoroquinolone and extended-spectrum beta-lactam use to control both the major epidemic strain and the more diverse strains observed within individual institutions.

Anti-Infective Agents↗
PubMed2002

Trends in antifungal susceptibility of Candida spp. isolated from pediatric and adult patients with bloodstream infections: SENTRY Antimicrobial Surveillance Program, 1997 to 2000.

From 1 January 1997 through 31 December 2000, 2,047 bloodstream infections (BSIs) due to Candida spp. were reported from hospitals in the United States, Canada, Latin America, and Europe participating in the SENTRY Antifungal Surveillance Program. Among individuals in four age groups (< or =1, 2 to 15, 16 to 64, and > or =65 years) Candida albicans was the most common species, causing 60, 55, 55, and 50% of infections, respectively. C. glabrata caused 17 to 23% of BSIs in those ages 16 to 64 and > or = 65 years, whereas it caused only 3% of BSIs in the individuals in the two younger age groups (P < 0.001). C. parapsilosis (which caused 21 to 24% of BSIs) and C. tropicalis (which caused 7 to 10% of BSIs) were more common than C. glabrata in individuals ages < or =1 year and 2 to 15 years. Isolates of Candida spp. showed a trend of decreasing susceptibility to fluconazole, itraconazole, and amphotericin B with increasing patient age (P < or = 0.01). None of the C. glabrata isolates from individuals < or =1 year old were resistant to fluconazole, whereas they made up 5 to 9% of isolates from individuals ages 16 to 64 and > or =65 years. Isolates of C. tropicalis from patients < or =1 year old were more susceptible to flucytosine (MIC at which 90% of isolates are inhibited [MIC(90)], 0.5 microg/ml; 0% resistant isolates) than those from patients > or =65 years old (MIC(90), 32 microg/ml; 11% resistant isolates). The investigational triazoles posaconazole, ravuconazole, and voriconazole were all highly active against all species of Candida from individuals in all age groups. These data demonstrate differences in the species distributions of pathogens and differences in antifungal resistance among isolates from individuals in the pediatric and adult age groups. Ongoing surveillance will enhance efforts to limit the extent of antifungal resistance in individuals in various age groups.

Adolescent↗
PubMed2002

Antimicrobial resistance in gram-negative isolates from European intensive care units: data from the Meropenem Yearly Susceptibility Test Information Collection (MYSTIC) programme.

Susceptibility data were collected for 6243 gram-negative isolates from 29 European ICUs participating in the Meropenem Yearly Susceptibility Test Information Collection (MYSTIC) Programme (1997-2000). The most commonly isolated bacteria were Pseudomonas aeruginosa (22.5%), Escherichia coli (19.8%), Klebsiella pneumoniae (10.4%), and Enterobacter cloacae (7.7%). The incidence of extended-spectrum beta-lactamase-producers was higher in Turkish, Russian and Italian ICUs (27.9-39.6%) than in other countries (2.5-10.8%). The frequency of AmpC-cephalosporin hyper-producers was 16.8-55.4%. Meropenem was more active against Proteus mirabilis than imipenem (99.0% versus 88.8% susceptibility, respectively). Against Acinetobacter baumannii, meropenem (79.6% susceptible) and imipenem (82.2%) were more active than comparators (34.3-51.6%). Meropenem and imipenem exhibited good activity against P. aeruginosa (76.1% and 68.2%, respectively; but with inter-country variation). Ciprofloxacin resistance in E. coli and K. pneumoniae increased and needs close monitoring. Meropenem (98.2-99.8% susceptibility) and imipenem (88.8-99.4%) remained potent against important species of gram-negative bacteria from European ICUs actively using meropenem.

Drug Resistance, Bacterial↗
PubMed2002

Emerging antimicrobial resistances among Proteus mirabilis in Europe: report from the MYSTIC Program (1997-2001). Meropenem Yearly Susceptibility Test Information Collection.

Resistance patterns that are currently problematic in Europe can vary greatly within the same species over time, among various patient populations and among geographic regions on the same continent. The results from the Meropenem Yearly Susceptibility Test Information Collection (MYSTIC) Program, which monitors carbapenem resistance rates in institutions using meropenem, were used to determine resistance differences among Proteus mirabilis. MIC results from 688 P. mirabilis strains were classified into 4 patient care groups: ICU (n=426), neutropenia patients (NP; n=145), general wards (n=97) and cystic fibrosis patients (CF; n=20). A total of 40 centers from 12 European countries have participated since 1997, divided into 3 geographic regions (East, North, South). All testing was performed by NCCLS reference methods and interpretive criteria, including screening of extended-spectrum beta-lactamase (ESBL) phenotypes. Over the monitored interval the resistance rates varied for each agent without a clear trend toward a greater rate. Rank order of susceptibility was: meropenem (99%) > piperacillin/tazobactam (TAZ; 96%) > cefepime (95%) > ceftazidime (CAZ; 94%) > imipenem (IPM; 92%). Ciprofloxacin (CIP) was the least active agent tested (MIC90 4 microg/ml; 86% susceptible). Unexpectedly, 3.6% of P. mirabilis were imipenem-resistant (MIC, > or = 16 microg/ml). Greater rates of resistance were found for strains from NP and CF patients, and from eastern or southern European sites, usually associated with epidemic clusters. Generally susceptible species such as P. mirabilis have recently emerged as therapeutic problems in European medical centers following mutations that compromise CIP, CAZ and aminoglycoside use. Imipenem also showed decreased susceptibility of greater than 7% compared to less than 1% for meropenem. Continued surveillance by the MYSTIC Program appears to be a prudent practice to focus effective empiric treatment regimens.

Anti-Bacterial Agents↗
PubMed2002

Comparative antimicrobial spectrum and activity of BMS284756 (T-3811; a desfluoroquinolone) tested against an international collection of staphylococci and enterococci, including in vitro test development and intermethod comparisons.

The study was initiated to determine the in vitro activity and MIC/disk test comparisons of BMS284756, a new des-fluoro(6)-quinolone, against isolates of staphylococci and enterococci from the SENTRY Antimicrobial Surveillance Program, 2000. Isolates were tested by reference broth microdilution and standardized disk diffusion methods. Against 3,789 strains of gram-positive cocci from the SENTRY Program (2000), the BMS284756 MIC90 and percentage susceptible at < or = 2 and < or = 4 microg/ml were: Staphylococcus aureus (4 microg/ml; 89.3 and 97.1%), coagulase-negative staphylococci (CoNS; 4 microg/ml; 86.1 and 96.0%) and enterococci (> 4 microg/ml; 62.0 and 76.2%). Also tested were selected staphylococci (300 strains) and enterococci (102 strains) by two standardized methods. The activity of BMS284756 was highly correlated with oxacillin resistance among staphylococci. Oxacillin-susceptible staphylococci were all inhibited by BMS284756 at < or = 0.5 microg/ml, whereas oxacillin-resistant strains required inhibitory concentrations of > or = 1 microg/ml. Excellent correlation was observed between the MIC and 5-microg disk zone diameter for staphylococci and enterococci (r=0.91 to 0.93). Among vancomycin-susceptible enterococci, 67% of Enterococcus faecalis, 25% of E. faecium, and 76% of other Enterococcus spp. isolates were inhibited by BMS284756 at < or = 2 microg/ml. All vancomycin-resistant enterococci (VRE; 11 E. faecalis and 15 E. faecium) were inhibited by > or = 2 microg/ml of BMS284756. Among the non-VRE, non-faecium enterococcal isolates (n=64), 62% were inhibited by < or = 0.5 microg/ml. BMS284756 showed excellent activity against oxacillin-susceptible staphylococci and moderate activity against enterococci other than VRE and E. faecium. Acceptable correlations were observed between MIC and disk test results for both tested genus groups.

Anti-Infective Agents↗
PubMed2001

Frequency of pathogen occurrence and antimicrobial susceptibility among community-acquired respiratory tract infections in the respiratory surveillance program study: microbiology from the medical office practice environment.

Continuing problems of antimicrobial resistance have prompted the initiation of several surveillance programs. Few, if any, of these programs focus on community-acquired respiratory tract infections seen in routine office-based practices. The Respiratory Surveillance Program (RESP; 1999-2000) in 674 community-based physician office practices in the United States determined the frequency of potential bacterial pathogens including Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis in patients diagnosed clinically with community-acquired pneumonia, acute exacerbations of chronic bronchitis, and sinusitis throughout all 9 US census/geographic regions. Susceptibility to the penicillins (ampicillin, penicillin), oral cephalosporins, fluoroquinolones (gatifloxacin, levofloxacin, ciprofloxacin), macrolides (erythromycin, azithromycin, clarithromycin), tetracycline, and trimethoprim/sulfamethoxazole was determined by reference methods. Patients were required to have a culturable focus of infection, and specimens were immediately sent to a reference laboratory. Among 22,689 total specimens (610 community-acquired pneumonia, 4,779 acute exacerbation of chronic bronchitis, 16,213 sinusitis, 1,087 other), H influenzae was the most commonly isolated organism from patients with community-acquired pneumonia (38%) and acute exacerbation of chronic bronchitis (35%) in all nine geographic regions. S pneumoniae was isolated in 18% of community-acquired pneumonia cases, 13% of acute exacerbation of chronic bronchitis cases, and 11% of sinusitis cases. M catarrhalis was most commonly isolated from the nasopharynx of patients with sinusitis (29%). High-level resistance to penicillin (2 microg/mL or greater; 16% overall) and the macrolides (32% to 35%) among S pneumoniae varied both with site of infection and with geographic region. The greatest resistance was observed among isolates from the nasopharynx of patients with sinusitis and from patients from the East South Central or South Atlantic regions of the United States. Although the susceptibility of H influenzae and M catarrhalis to the tested antimicrobials did not vary with the type of infection, beta-lactamase-mediated resistance to ampicillin among H influenzae ranged from 15% in New England to 32% in the East South Central region. The fluoroquinolones were highly active against these cultured isolates from community-acquired respiratory tract infection patients, with >99% of all S pneumoniae, H influenzae, and M catarrhalis strains susceptible to gatifloxacin (MIC(90), 0.5 microg/mL) and levofloxacin (MIC(90), 2 microg/mL). The extended-spectrum fluoroquinolones appear well suited for community-acquired respiratory tract infection therapy, including pathogens other than pneumococcus, H influenzae, and M catarrhalis.

Adolescent↗
PubMed2001

Oxazolidinone antibiotics.

Many common gram-positive pathogens (eg, Staphylococcus aureus, Enterococcus spp, and Streptococcus pneumoniae) have become increasingly resistant to antimicrobial agents, and new drugs with activity against gram-positive bacteria are urgently needed. The oxazolidinones, a new chemical class of synthetic antimicrobial agent, have a unique mechanism of inhibiting bacterial protein synthesis. Linezolid, the first oxazolidinone to be approved for clinical use, displays in-vitro activity (generally bacteriostatic) against many important resistant pathogens, including meticillin-resistant Staph aureus, vancomycin-resistant enterococci, and penicillin-resistant Strep pneumoniae. Linezolid is a parenteral agent that also possesses near-complete oral bioavailability plus favourable pharmacokinetic and toxic effect profiles. Clinical trials confirm the activity of linezolid in the setting of pneumonia, skin and soft-tissue infections, and infections due to vancomycin-resistant enterococci. Linezolid shows promise as an alternative to glycopeptides and streptogramins to treat serious infections due to resistant gram-positive organisms. New agents with greater potency and new spectra of activity could arise from further modification of the oxazolidinone nucleus.

Acetamides↗
PubMed2001

Worldwide prevalence of antimicrobial resistance in Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis in the SENTRY Antimicrobial Surveillance Program, 1997-1999.

The in vitro activities of numerous antimicrobials against clinical isolates of Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis from patients with bloodstream and respiratory tract infections in the United States, Canada, Europe, Latin America, and the Asia-Pacific region were studied in the SENTRY Antimicrobial Surveillance Program. Penicillin resistance (minimum inhibitory concentration, > or =2 microg/mL) was noted in all 5 geographic regions, and a high and increasing rate of macrolide resistance among S. pneumoniae isolates was observed. Elevated rates of resistance to clindamycin, trimethoprim-sulfamethoxazole, chloramphenicol, and tetracycline were seen. beta-Lactamase-mediated resistance in H. influenzae to amoxicillin and variable trimethoprim-sulfamethoxazole resistance by region were documented. Resistance to several drugs continues to emerge among pneumococci worldwide, but more stable resistance patterns have been noted for H. influenzae and M. catarrhalis. Continued surveillance of this pathogen group appears to be prudent.

Anti-Bacterial Agents↗
PubMed2001

Emerging importance of multidrug-resistant Acinetobacter species and Stenotrophomonas maltophilia as pathogens in seriously ill patients: geographic patterns, epidemiological features, and trends in the SENTRY Antimicrobial Surveillance Program (1997-1999).

As part of the SENTRY Antimicrobial Surveillance Program, a total of 1078 Acinetobacter species and 842 Stenotrophomonas maltophilia isolates were collected between January 1997 and December 1999 from 5 geographic regions (Canada, the United States, Latin America, Europe, and the Asia-Pacific). The frequency of infections (by geographic region and body site), including those due to imipenem-resistant Acinetobacter species and trimethoprim-sulfamethoxazole (TMP-SMZ)-resistant S. maltophilia, was evaluated. The possibility of seasonal variations in bloodstream infections caused by Acinetobacter species was studied, as was the activity of several therapeutic antimicrobials against all strains. Acinetobacter species and S. maltophilia were most frequently associated with pulmonary infections, independent of the region evaluated. In contrast, patterns of antimicrobial resistance markedly varied among distinct geographic regions, especially for nosocomial isolates. Although the carbapenems were the most active antimicrobials against Acinetobacter species, nearly 11.0% of the nosocomial isolates were resistant to this drug group in both regions. TMP-SMZ, ticarcillin-clavulanic acid, gatifloxacin, and trovafloxacin were the only agents with consistent therapeutic activity against S. maltophilia isolates. Rates of resistance to TMP-SMZ ranged from 2% in Canada and Latin America to 10% in Europe. The geographic differences in resistance patterns among Acinetobacter species and S. maltophilia isolates observed in this study emphasize the importance of local surveillance in determining the most adequate therapy for acinetobacter and S. maltophilia infections and the possible clonal, epidemic nature of occurrence.

Acinetobacter↗
PubMed2001

Survey of infections due to Staphylococcus species: frequency of occurrence and antimicrobial susceptibility of isolates collected in the United States, Canada, Latin America, Europe, and the Western Pacific region for the SENTRY Antimicrobial Surveillance Program, 1997-1999.

Between January 1997 and December 1999, bloodstream isolates from 15,439 patients infected with Staphylococcus aureus and 6350 patients infected with coagulase-negative Staphylococcus species (CoNS) were referred by SENTRY-participating hospitals in the United States, Canada, Latin America, Europe, and the Western Pacific region. S. aureus was found to be the most prevalent cause of bloodstream infection, skin and soft-tissue infection, and pneumonia in almost all geographic areas. A notable increase in methicillin (oxacillin) resistance among community-onset and hospital-acquired S. aureus strains was observed in the US centers. The prevalence of methicillin (oxacillin)-resistant S. aureus varied greatly by region, site of infection, and whether the infection was nosocomial or community onset. Rates of methicillin resistance were extremely high among S. aureus isolates from centers in Hong Kong and Japan. Uniformly high levels of methicillin resistance were observed among CoNS isolates. Given the increasing multidrug resistance among staphylococci and the possible emergence of vancomycin-resistant strains, global strategies are needed to control emergence and spread of multiply resistant staphylococci.

Anti-Bacterial Agents↗
PubMed2001

Clinical prevalence, antimicrobial susceptibility, and geographic resistance patterns of enterococci: results from the SENTRY Antimicrobial Surveillance Program, 1997-1999.

As part of the SENTRY Antimicrobial Resistance Surveillance Program, a total of 4998 strains of enterococci isolated from 1997 to 1999 were processed. The occurrence of enterococcal infections by species and site of infection was analyzed, as were the occurrence of vancomycin-resistant enterococci (VRE) and their resistance phenotypes and genotypes. Trends in antimicrobial susceptibility to a variety of agents (including experimental compounds) were also reported. Enterococci accounted for >9% of isolates from all bloodstream infections (BSIs) in North America. Ampicillin was active against strains from Latin America and Europe but not against those from the United States and Canada. US isolates were considerably more resistant to vancomycin (17% resistant strains in 1999) than were those from patients in the rest of the world. The highest proportion of VRE was observed among BSI isolates (81.7%). Quinupristin-dalfopristin, chloramphenicol, and doxycycline were the most active agents tested against VRE. The results of this study confirm the worldwide trend in increasing occurrence of enterococci and the emerging pattern of antimicrobial resistance among such isolates.

Anti-Bacterial Agents↗
PubMed2001

Characterization of Pseudomonas aeruginosa isolates: occurrence rates, antimicrobial susceptibility patterns, and molecular typing in the global SENTRY Antimicrobial Surveillance Program, 1997-1999.

During 1997-1999, a total of 70,067 isolates (6631 Pseudomonas aeruginosa isolates) were analyzed in the SENTRY program by geographic region and body site of infection. The respiratory tract was the most common source of P. aeruginosa. P. aeruginosa isolation rates increased during the study interval. Europe was the only region to show a significant decline in beta-lactam and aminoglycoside susceptibility rates. There was a reduction in the rates of susceptibility of Canadian isolates to imipenem and of Latin American isolates to meropenem. A total of 218 multidrug-resistant P. aeruginosa isolates (MDR-PSA; resistant to piperacillin, ceftazidime, imipenem, and gentamicin) were observed; MDR-PSA occurrence rates (percentages of all isolates) ranged from 8.2% (Latin America) to 0.9% (Canada). No antimicrobial inhibited >50% of MDR-PSA strains. Molecular characterization of selected, generally resistant strains was performed. Isolates showing unique ribogroups were found in Europe, Latin America, and the United States, but clonal spread was documented in several medical centers.

Anti-Bacterial Agents↗