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PubMed2004

Surveillance of antimicrobial use and antimicrobial resistance in intensive care units (SARI): 1. Antimicrobial use in German intensive care units.

OBJECTIVE: To study antimicrobial use for benchmarking and ensuring quality of antimicrobial treatment and to identify risk factors associated with the high use of antimicrobials in German intensive care units (ICUs) through implementation of the SARI (Surveillance of Antimicrobial Use and Antimicrobial Resistance in ICUs) system. DESIGN: Prospective, unit-based surveillance on antimicrobial use from February, 2000, until June, 2002. The data are standardised by use of the defined daily dose (DDD) for each antimicrobial defined by the WHO and by calculating use per 1000 patient days. SETTING: The data were obtained from 35 German ICUs and stratified by type of ICU (medical, surgical, interdisciplinary). RESULTS: To date, the project covers a total of 266,013 patient days in 744 reported ICU months and 354,356 DDDs. Mean antimicrobial use density (AD) was 1,332 DDD/1000 patient days and was correlated with length of stay. Penicillins with beta-lactamase inhibitor (AD 338.3) and quinolones (155.5) were the antimicrobial group with the highest ADs. Comparison with US ICARE (Intensive Care Antimicrobial Resistance Epidemiology)/AUR (Antimicrobial Use and Resistance) data revealed a higher AD for glycopeptides and 3rd generation cephalosporins in ICARE/AUR ICUs, but a higher AD for carbapenems in German SARI ICUs regardless of the type of ICU. In the multivariate analysis, length of stay was an independent risk factor for an AD above the 75% percentile of the total amount of antimicrobials used (OR 1.96 per day); likewise, for the AD above the 75% percentile of carbapenems (OR 1.90 per day) and penicillins with extended spectrum (OR 2.01 per day). High use of glycopeptides and quinolones (AD >75% percentile) correlated with central venous catheter (CVC) rate (OR 1.14 per CVC day per 100 patient days and 1.16, respectively). CONCLUSION: The SARI data on antimicrobials serve ICUs as a benchmark by which to improve the quality of antimicrobial drug administration and for international comparison.

Anti-Bacterial Agents↗

PubMed1994

[An experimental examination of the significance of the peak antimicrobial concentration value in urine and time above MIC on the effect of antimicrobial agents--an examination using a severely complicated in vitro bladder model with an autosimulation system for antimicrobial concentration in urine].

Using a severely complicated in vitro bladder model with a computer-controlled autosimulation system for antimicrobial concentration in urine, we examined the significance of the peak concentration value and time above MIC, and obtained the following results. 1. Regarding the initial bactericidal speed, the higher the peak concentration value was, the more quickly the bacterial concentration decreased. 2. Concerning the minimum value of bacterial concentration in the model bladder, the higher the peak concentration value was, the more the level tended to decrease. 3. Regarding inhibition of regrowth of bacteria (ERT) 1) When a particular antimicrobial agent had no PAE on bacteria, the viable bacterial count curve was similar in cases of peak antimicrobial concentration values of higher than 8 MIC. 2) On the other hand, when an antimicrobial agent had PAE on bacteria, regrowth of bacteria occurred quickly below a certain peak concentration (24 MIC or 64 MIC value), although there was some difference depending on the type of antimicrobial agents. Thus, it was suggested that the peak concentration above that level be attained and maintration above that level be attained and maintained for some time were in order to obtain PAE adequately. 4. It is concluded from the aforementioned facts that two factors, a certain high concentration and a certain continued time are necessary for both antimicrobial agent with metabolic disorder and antimicrobial agent with cell wall synthetic inhibition to obtain proper antimicrobial effect. The condition of their necessity differed slightly according to the two different agents.

Adult↗

PubMed1999

Surveillance of antimicrobial use and antimicrobial resistance in United States hospitals: project ICARE phase 2. Project Intensive Care Antimicrobial Resistance Epidemiology (ICARE) hospitals.

The search for the means to understand and control the emergence and spread of antimicrobial resistance has become a public health priority. Project ICARE (Intensive Care Antimicrobial Resistance Epidemiology) has established laboratory-based surveillance for antimicrobial resistance and antimicrobial use at a subset of hospitals participating in the National Nosocomial Infection Surveillance system. These data illustrate that for most antimicrobial-resistant organisms studied, rates of resistance were highest in the intensive care unit (ICU) areas and lowest in the outpatient areas. A notable exception was ciprofloxacin- or ofloxacin-resistant Pseudomonas aeruginosa, for which resistance rates were highest in the outpatient areas. For most of the antimicrobial agents associated with this resistance, the rate of use was highest in the ICU areas, in parallel to the pattern seen for resistance. These comparative data on use and resistance among similar areas (i.e., ICU or other inpatient areas) can be used as a benchmark by participating hospitals to focus their efforts at addressing antimicrobial resistance.

Anti-Bacterial Agents↗

PubMed1993

A survey of undergraduate and continuing medical education about antimicrobial chemotherapy in the United Kingdom. British Society of Antimicrobial Chemotherapy Working Party on Antimicrobial Use.

1 A questionnaire about undergraduate teaching on antimicrobial chemotherapy was sent to academic Departments of Clinical Pharmacology, Pharmacology and Medical Microbiology throughout the UK. 2 Questionnaires about postgraduate lectures and information circulated to doctors about antimicrobial chemotherapy were sent to Drug Information Centres and Postgraduate Tutors throughout the UK. Review articles and editorials in general medical journals were assessed. 3 The median amount of core undergraduate teaching on antimicrobial chemotherapy was 13.5 h but the range was from 9.0 h to 102.0 h. Content was predominantly oriented towards drugs rather than diseases and towards prescribing in hospital rather than in the community. Most teaching was by formal lecture as part of a core programme. On a scale from 0 to 5 the median emphasis given to individual topics ranged from 2.50 to 3.75 but the range of emphasis given by individual medical schools was wide, for example from 1.00 to 4.50 for teaching on pharmacokinetics. 4 Postgraduate tutors identified advice from local specialists and requests from local practitioners as the most important determinants of content of continuing medical education. Material from drug information centres was predominantly oriented towards discussion of individual drugs rather than management of specific diseases and even this limited survey found evidence of duplication. The UK general medical literature contained a total of 112 reviews or editorials on antimicrobial chemotherapy covering a wide range of topics but these were not, and should not be assumed to be comprehensive. 5 Almost all doctors regularly prescribe antimicrobials and require education about the subject. Wide variations in current medical practice should be addressed explicitly through more extensive use of problem solving. The literature suggests that knowledge is most effectively disseminated through local networks of practitioners. There should be more national co-ordination of the content of information to be disseminated through the existing drug information networks.

Anti-Bacterial Agents↗

PubMed2002

Emergence, spread, and environmental effect of antimicrobial resistance: how use of an antimicrobial anywhere can increase resistance to any antimicrobial anywhere else.

Use of an antimicrobial agent selects for overgrowth of a bacterial strain that has a gene expressing resistance to the agent. It also selects for the assembly and evolution of complex genetic vectors encoding, expressing, linking, and spreading that and other resistance genes. Once evolved, a competitive construct of such genetic elements may spread widely through the world's bacterial populations. A bacterial isolate at any place may thus be resistant-not only because nearby use of antimicrobials had amplified such a genetic construct locally, but also because distant use had caused the construct or its components to evolve in the first place and spread there. The levels of resistance at any time and place may therefore reflect in part the total number of bacteria in the world exposed to antimicrobials up until then. Tracing the evolution and spread of such genetic elements through bacterial populations far from one another, such as those of animals and humans, can be facilitated by newer genetic methods.

Animals↗

PubMed1979

Antimicrobial spectrum of triclosan, a broad-spectrum antimicrobial agent for topical application. II. Comparison with some other antimicrobial agents.

The antimicrobial activity of 5-chloro-2(2,4-dichlorophenoxy) phenol (triclosan, one of the active ingredients of Logamel, Ciba-Geigy) was compared in vitro with that of other antimicrobials exclusively or occasionally used as topical agents in dermatology: hexachlorophene, clioquinol, chlorquinaldol. gentamicin, neomycin, nystatin, econazole, clotrimazole and salicylic acid. Upon determination of the MICs for 53 strains of aerobic and anaerobic bacteria, yeasts and fungi, triclosan was found to display a high degree of activity against most of the test organisms and to have the broadest spectrum of chemotherapeutically significant antimicrobial activity of the substances tested.

Administration, Topical↗

PubMed1998

Antimicrobial use and resistance in eight US hospitals: complexities of analysis and modeling. Intensive Care Antimicrobial Resistance Epidemiology Project and National Nosocomial Infections Surveillance System Hospitals.

OBJECTIVE: To evaluate the relation between antimicrobial use and resistance in intensive-care unit (ICU) and non-ICU inpatient areas in eight US hospitals. METHODS: We determined antimicrobial use in terms of defined daily doses, antimicrobial-use density (defined daily doses/1,000 patient days), and percentage resistance for five antimicrobial-organism combinations in the ICU and non-ICU inpatient areas of eight US hospitals participating in project Intensive Care Antimicrobial Resistance Epidemiology. RESULTS: Antimicrobial resistance and use varied tremendously among the eight hospitals. Antimicrobial resistance among these five nosocomial pathogens was significantly higher within the inpatient setting of these hospitals, compared with the outpatient setting. One hospital consistently ranked highest for use of all classes of antimicrobials examined. High antimicrobial use was not associated necessarily with high resistance for a particular antimicrobial-organism pair. CONCLUSION: Antimicrobial use varied significantly across these hospitals, but generally was higher in ICUs. These results suggest that concomitant surveillance of both antimicrobial resistance and antimicrobial use is helpful in interpreting antimicrobial resistance in a hospital or ICU and that further analysis is required to determine the role of variables other than antimicrobial use in a statistical model for predicting antimicrobial resistance.

Anti-Bacterial Agents↗

PubMed2006

Comparison of prevalence, antimicrobial resistance, and occurrence of multidrug-resistant Salmonella in antimicrobial-free and conventional pig production.

Conventional swine production evolved to routinely use antimicrobials, and common occurrence of antimicrobial-resistant Salmonella has been reported. There is a paucity of information on the antimicrobial resistance of Salmonella in swine production in the absence of antimicrobial selective pressure. Therefore, we compared the prevalence and antimicrobial resistance of Salmonella isolated from antimicrobial-free and conventional production systems. A total of 889 pigs and 743 carcasses were sampled in the study. Salmonella prevalence was significantly higher among the antimicrobial-free systems (15.2%) than the conventional systems (4.2%) (odds ratio [OR] = 4.23; P < 0.05). Antimicrobial resistance was detected against 10 of the 12 antimicrobials tested. The highest frequency of resistance was found against tetracycline (80%), followed by streptomycin (43.4%) and sulfamethoxazole (36%). Frequency of resistance to most classes of antimicrobials (except tetracycline) was significantly higher among conventional farms than antimicrobial-free farms, with ORs ranging from 2.84 for chloramphenicol to 23.22 for kanamycin at the on-farm level. A total of 28 antimicrobial resistance patterns were detected. A resistance pattern with streptomycin, sulfamethoxazole, and tetracycline (n = 130) was the most common multidrug resistance pattern. There was no significant difference in the proportion of isolates with this pattern between the conventional (19.5%) and the antimicrobial-free systems (18%) (OR = 1.8; P > 0.05). A pentaresistance pattern with ampicillin, chloramphenicol, streptomycin, sulfamethoxazole, and tetracycline was strongly associated with antimicrobial-free groups (OR = 5.4; P = 0.01). While showing the higher likelihood of finding antimicrobial resistance among conventional herds, this study also implies that specific multidrug-resistant strains may occur on antimicrobial-free farms. A longitudinal study with a representative sample size is needed to reach more conclusive results of the associations detected in this study.

Animal Husbandry↗

PubMed1999

Antimicrobial prescribing in long-term care facilities: prospective evaluation of potential antimicrobial use and cost indicators.

BACKGROUND: Few studies exist regarding methods of monitoring antimicrobial prescribing in the long-term care setting. METHODS: Data were collected monthly in 4 long-term care facilities (LTCFs) for 20 to 26 months. The data included incidence (No. of antimicrobial courses started per 1000 resident care days) of antimicrobial use, antimicrobial utilization ratio (ratio of the number of antimicrobial-days to the number of resident care days), cost of antimicrobial-day, and cost of therapy per resident care day. In one facility, physician-specific data were also collected. RESULTS: Seasonal variation in the incidence of antimicrobial use was identified, with the highest rates occurring in the winter months. Significant differences in the mean incidence of antimicrobial use, mean antimicrobial utilization ratio, mean cost per antimicrobial-day, and mean cost per resident care day were identified among the 4 LTCFs during the study period. A significant correlation existed between incidence of antimicrobial use or antimicrobial utilization ratio and the overall infection rate or site-specific rates when the data from all 4 LTCFs were aggregated for analysis. Monthly variation in cost per antimicrobial-day was best explained by the monthly variation in prescribing of high-cost (>$15 per day) agents. With these same parameters for use and cost, considerable variation in prescribing and cost of therapy was noted among 7 physicians in the same facility. CONCLUSIONS: The parameters evaluated detected significant differences in prescribing and cost of antimicrobials among 4 LTCFs. If these findings are verified in larger studies, these parameters may be useful for monitoring trends in prescribing and for interfacility comparisons after adjustment for case-mix differences.

Analysis of Variance↗

PubMed2006

Optimising antimicrobial prescription in hospitals by introducing an antimicrobial stewardship programme in Hong Kong: consensus statement.

OBJECTIVE: To discuss the implementation of an 'antimicrobial stewardship programme' as a means to improve the quality of antimicrobial use in a hospital setting in Hong Kong. PARTICIPANTS: Consensus working group on 'antimicrobial stewardship programme', The Scientific Committee on Infection Control, Centre for Health Protection, Department of Health, comprised 11 experts. The remit of the working group was to discuss the rationale and requirement for optimising antimicrobial prescriptions in hospitals by the introduction of an 'antimicrobial stewardship programme'. EVIDENCE: PubMed articles, national and international guidelines, and abstracts of international meetings published between January 2000 and December 2004 on programmes for improving the use of antimicrobials in hospitals. Only English medical literature was reviewed. CONSENSUS PROCESS: Data search was performed independently by three members of the working group. They met on three occasions before the meeting to discuss all collected articles. A final draft was circulated to the working group before a meeting on 3 January 2005. Five commonly asked questions about an 'antimicrobial stewardship programme' were selected for discussion by the participants. Published information on the rationale, components, outcome measures, advantages, and disadvantages of the programme was reviewed. Recent unpublished data from local studies of an 'antimicrobial stewardship programme' were also discussed. The timing, potential problems, and practical issues involved in the implementation of an 'antimicrobial stewardship programme' in Hong Kong were then considered. The consensus statement was circulated to and approved by all participants. CONCLUSION: The continuous indiscriminate and excessive use of antimicrobial agents promotes the emergence of antibiotic-resistant organisms. Antimicrobial resistance substantially raises already-rising health care costs and increases patient morbidity and mortality. Pattern of prescriptions in hospitals can be improved through the implementation of an 'antimicrobial stewardship programme'. A 'universal' and 'continuous' 'antimicrobial stewardship programme' should now be established in Hong Kong hospitals.

Anti-Infective Agents↗

PubMed2006

Investigation of antimicrobial use and the impact of antimicrobial use guidelines in a small animal veterinary teaching hospital: 1995-2004.

OBJECTIVE: To evaluate patterns of antimicrobial use and the impact of antimicrobial use guidelines at a small animal veterinary teaching hospital. DESIGN: Retrospective study. SAMPLE POPULATION: All antimicrobial prescriptions for dogs and cats admitted to the hospital in 1995 through 2004. PROCEDURE: Pharmacy records were reviewed, and antimicrobial prescriptions for all dogs and cats admitted during the study period were recorded. Amounts of individual drugs dispensed directly to the intensive care and surgical units were determined. Changes in antimicrobial use during the study period were assessed; changes in antimicrobial use patterns in 2000 through 2004 were evaluated to assess the impact of implementation of antimicrobial use guidelines in 2001. RESULTS: There was a significant decrease in prescriptions/1,000 admissions during the study period. From 1995 to 2004, the use of first-generation cephalosporins, fluoroquinolones, penicillins, and trimethoprim-sulfonamides decreased, whereas the use of metronidazole increased. The use of first-generation cephalosporins, fluoroquinolones, and penicillins decreased from 2000 to 2004. First-line drugs accounted for 90.7% of prescriptions during the study period. The use of third-line drugs decreased from 2000 to 2004. CONCLUSIONS AND CLINICAL RELEVANCE: Characterization of antimicrobial use is an important step in defining and evaluating the prudent use of antimicrobials. Whereas the true effect of antimicrobial use guidelines is unclear, these results suggest that the guidelines may have had an effect on antimicrobial prescription patterns in this small animal veterinary teaching hospital. Analysis of objective data regarding antimicrobial use and changes in antimicrobial use patterns over time is important in veterinary practices.

Animals↗

PubMed1997

Effect of antimicrobial use and other risk factors on antimicrobial resistance in pneumococci.

Penicillin-resistant and multi-resistant pneumococci have spread globally and reached high prevalence in many countries. Antimicrobial use is considered a major driving force for resistance, although the influence in the community has not been as clearly demonstrated. Other risk factors may be important, and only with a clear understanding of the risk factors can effective control measures be introduced. The main habitat of the pneumococcus is the nasopharynx of children. Carriage increases from birth and is maximal at pre-school age. Antimicrobial use in children is likely to have a significant influence on the susceptibility of pneumococci. Most studies looking for risk factors for resistance in pneumococci have identified antimicrobial use as a risk factor, especially the following aspects: ongoing, recent, repeated, frequent, and prophylactic antibiotic use. The effect of individual classes of antimicrobials has not been studied in detail but use of beta-lactam antibiotics and trimethoprim-sulpha has been associated with increased risk. Other risk factors are young age, nosocomial acquisition, prior hospitalization, and HIV infection. Day-care centers can facilitate the spread of resistant pneumococci and an Icelandic study showed that carriage of resistant pneumococci was associated with young age, domicile in an area with high antimicrobial consumption, recent antimicrobial use, frequent antimicrobial use, and use of trimethoprim-sulpha. The rapid increase of penicillin-resistant pneumococci in Iceland was met with propaganda against overuse of antimicrobials, which lead to reduction of antimicrobial use and subsequently a reduced incidence of penicillin-resistant pneumococci. This reduction may be related to reduced antimicrobial use. Reducing antimicrobial use should be considered important for programs aimed at reducing antimicrobial resistance.

Child↗

PubMed2004

Defined daily doses of antimicrobials reflect antimicrobial prescriptions in ambulatory care.

BACKGROUND: Data on actual antimicrobial prescriptions are rarely made available and the World Health Organization (WHO) recommends using the number of defined daily doses (DDDs) as a measurement unit for inter-country comparisons of antimicrobial use in outpatients. However, because antimicrobials are given for limited periods of time and the DDDs may not represent the doses used in practice, this measurement unit has been blamed for poorly reflecting the number of antimicrobial prescriptions in outpatients. METHODS: For 11 out of 15 European countries, data on national outpatient sales of antimicrobials and on antimicrobial prescriptions to outpatients in 1997 were purchased from the Institute for Medical Statistics (IMS) Health. For two additional countries, i.e. Sweden and Denmark, similar data were obtained from the National Corporation of Swedish Pharmacies and the Danish Medicines Agency, respectively. The relationships between the number of DDDs and the number of prescriptions, on the one hand, and the antimicrobial use density (DDD per 1000 inhabitant-days) and the prescription rate (prescriptions per 1000 inhabitants), on the other hand, were assessed with the two-tailed Spearman coefficient for non-parametric correlations. RESULTS: The number of DDDs, as defined by the WHO, and the number of prescriptions of antimicrobials to outpatients in European countries in 1997 were strongly correlated. Similarly, the antimicrobial use density and the prescription rate in these countries were strongly correlated. These relationships were found for total systemic antimicrobials and for all major antimicrobial classes. CONCLUSION: Our results confirm the relevance of the number of DDDs per 1000 inhabitant-days as a measurement unit to compare outpatient antimicrobial use among countries or regions.

Ambulatory Care↗

PubMed2006

Usage of veterinary therapeutic antimicrobials in Denmark, Norway and Sweden following termination of antimicrobial growth promoter use.

Antimicrobial growth promoters (AGPs) were phased out in Denmark, Norway and Sweden in 1998-1999, 1995 and 1986, respectively. The annual usage of therapeutic antimicrobials in animals in Denmark almost doubled during the period when AGPs were phased out (1988-1999) and in the subsequent 2 years. The increase was mainly due to an increased consumption of therapeutic antimicrobials in weaning pigs. The annual increase in usage of therapeutic antimicrobials and the annual increase in numbers of slaughter-swine produced in Denmark correlates well, except for 1999 when AGP use was discontinued in weaning pigs, and the following year. In Norway, the usage of therapeutic antimicrobials in animals decreased by 39% from 1995 to 2000. During 2001-2003 the annual usage remained at the 2000-level. The annual numbers of slaughter-swine produced in Norway increased gradually by 10% after the AGP discontinuation (from 1995 to 2003). In Sweden, the usage of therapeutic antimicrobials in animals increased by 21% the first 2 years subsequent to the AGP ban (1986-1988), remained then constant until 1994; from 1994 to 2003 this usage declined by 47%. The initial increase was caused by increased use in broilers and in weaning piglets. The amounts used in animals in Sweden in 2003 were half of the amounts used in 1994. The annual numbers of slaughter-swine produced in Sweden declined gradually by 16% in the study period, although fluctuating. In Denmark, Norway and Sweden the number of dairy cattle and beef cattle declined only slightly in the various study periods while numbers of broilers produced increased notably, especially in Norway and Sweden. Following the termination of AGPs the total usage of antimicrobials (AGPs and therapeutic antimicrobials) in animals in Denmark declined 36% (from 1996 to 2003): in Norway this figure was 45% (from 1995 to 2003). In Sweden, the total usage of antimicrobials in animals in 2003 amounted to only one third of the amounts used in 1984 (decreased from 51 to 16 tonnes). Termination of AGPs was only a temporary risk factor for increased usage of therapeutic antimicrobials in food-animals in Sweden and Denmark; however, an exception might be usage in weaning piglets in Denmark. Furthermore, the discontinuation of AGP use has decreased the overall annual usage of antimicrobials in animals in Denmark, Norway and Sweden considerably.

Animal Diseases↗

PubMed1998

Associations among antimicrobial drug treatments and antimicrobial resistance of fecal Escherichia coli of swine on 34 farrow-to-finish farms in Ontario, Canada.

Logistic regression was used to model associations between antimicrobial treatment and resistance among fecal Escherichia coli of finisher pigs at the farm level. Four sets of potential risk factors representing different levels of refinement of antimicrobial use on farms were modelled on resistance to antimicrobials. Final models for each antimicrobial were constructed from treatment and management variables significant on initial screening, and corrections for overdispersion were made. In general, in-feed antimicrobial treatment of pigs was more consistently associated with an increased risk of resistance than individual-animal treatment. Antimicrobial treatment in starter rations was significant in final models of resistance to ampicillin, carbadox, nitrofurantoin, sulfisoxizole, and tetracycline. Treatment in grower-finisher rations was significantly associated with resistance to ampicillin, spectinomycin, sulfisoxizole, and tetracycline. There was little evidence that in-feed antimicrobials increased the risk of resistance to gentamicin, which is a drug used only for individual-pig treatment in this study population. These results suggest that antimicrobial medication of rations of post-weaning pigs selects for and maintains antimicrobial resistance among E. coli of finisher pigs. Although resistance was common on farms that did not medicate rations of post-weaning pigs, the results indicate that antimicrobial use does increase the risk of resistance to the antimicrobials studied.

Animal Husbandry↗

PubMed1990

Epidemiologic evidence that prior antimicrobial exposure decreases resistance to infection by antimicrobial-sensitive Salmonella.

Exposure to antimicrobials is known to increase the risk of infection with antimicrobial-resistant strains of Salmonella, but this effect has not been previously demonstrated with antimicrobial-sensitive strains. The effect of prior antimicrobial exposure was studied during a multistate outbreak of salmonellosis caused by an antimicrobial-sensitive strain of Salmonella havana: 19 (26%) of 72 persons infected had taken an antimicrobial within 30 days before onset of symptoms. Antimicrobial therapy was begun a mean of 15.9 days before and stopped a mean of 7.9 days before onset. In a case-control study, 11 (31%) of 35 case-patients had taken antimicrobials within 30 days of onset compared with 9 (13%) of 70 age- and neighborhood-matched controls (matched odds ratio, 4.3; 95% confidence interval, 1.3, 13.5). The association remained when controlled for the presence of underlying illness or immunosuppression. Prior antimicrobial exposure appears to increase the risk of infection with antimicrobial-sensitive and resistant strains of Salmonella. The delay between antimicrobial use and onset of symptoms suggests that the effect may be due to prolonged alteration of the colonic bacterial flora, resulting in decreased resistance to colonization.

Adolescent↗

PubMed2006

Field trial evaluating the influence of prophylactic and therapeutic antimicrobial administration on antimicrobial resistance of fecal Escherichia coli in dairy calves.

The objective of this study was to describe the influence of in-feed and therapeutic antimicrobials on resistance in commensal fecal Escherichia coli isolated from preweaned calves. Four groups of 30, day-old calf-ranch calves were enrolled and raised until 4 weeks of age. Groups 1 to 3 were raised without antimicrobials in the feed. Group 1 was isolated from the other groups and received no antimicrobial therapy. Group 2 was housed on the calf ranch and did not receive antimicrobial therapy, whereas groups 3 and 4 could be treated with antimicrobials. Group 4 was fed neomycin and tetracycline HCl in the milk replacer. Fecal samples were collected from calves on days 1, 14, and 28. Three E. coli isolates per sample were evaluated for susceptibility to 12 antimicrobials. Cluster analysis was used to group isolates having similar susceptibility patterns. Cumulative logistic regression was used to evaluate factors associated with increasing levels of multiple antimicrobial resistance. In-feed antimicrobials were associated with higher levels of multiple antimicrobial resistance in fecal E. coli.f In calves not receiving in-feed antimicrobials, older calves had higher levels of resistance compared to day-old calves. Individual antimicrobial therapy increased resistance in these calves but appeared to be transient. There was no environmental influence on resistance in E. coli populations among study groups.

Animals↗

PubMed2006

Antimicrobial use control measures to prevent and control antimicrobial resistance in US hospitals.

OBJECTIVE: Clinical practice guidelines and recommended practices to control use of antibiotics have been published, but the effect of these practices on antimicrobial resistance (AMR) rates in hospitals is unknown. The objective of this study was to examine relationships between antimicrobial use control strategies and AMR rates in a national sample of US hospitals. DESIGN: Cross-sectional, stratified study of a nationally representative sample of US hospitals. METHODS: A survey instrument was sent to the person responsible for infection control at a sample of 670 US hospitals. The outcome was current prevalences of 4 epidemiologically important, drug-resistant pathogens, considered concurrently: methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci, ceftazidime-resistant Klebsiella species, and quinolone (ciprofloxacin)-resistant Escherichia coli. Five independent variables regarding hospital practices were selected from the survey: the extent to which hospitals (1) implement practices recommended in clinical practice guidelines and ensure best practices for antimicrobial use, (2) disseminate information on clinical practice guidelines for antimicrobial use, (3) use antimicrobial-related information technology, (4) use decision support tools, and (5) communicate to prescribers about antimicrobial use. Control variables included the hospitals' number of beds, teaching status, Veterans Affairs status, geographic region, and number of long-term care beds; and the presence of an intensive care unit, a burn unit, or transplant services. A generalized estimating equation modeled all resistance rates simultaneously to identify overall predictors of AMR levels at the facility. RESULTS: Completed survey instruments were returned by 448 hospitals (67%). Four antimicrobial control measures were associated with higher prevalence of AMR. Implementation of recommended practices for antimicrobial use (P < .01) and optimization of the duration of empirical antibiotic prophylaxis (P < .01) were associated with a lower prevalence of AMR. Use of restrictive formularies (P = .05) and dissemination of clinical practice guideline information (P < .01) were associated with higher prevalence of AMR. Number of beds and Veterans Affairs status were also associated with higher AMR rates overall. CONCLUSIONS: Implementation of guideline-recommended practices to control antimicrobial use and optimize the duration of empirical therapy appears to help control AMR rates in US hospitals. A longitudinal study would confirm the results of this cross-sectional study. These results highlight the need for systems interventions and reengineering to ensure more-consistent application of guideline-recommended measures for antimicrobial use.

Anti-Bacterial Agents↗