Impact Of Antimicrobial Use Research Articles

Understanding stewardship

Calf-raising operations provide a unique microbial niche where immature intestinal flora, dense animal populations, and frequent application of antimicrobials may facilitate the emergence of antimicrobial resistant pathogens. In the US, producers report that 18% of calves receive an antimicrobial for diarrhea prior to weaning, often with antimicrobials designated as "critically important" to human medicine. The overall objective for this research was to understand the decision criteria for antimicrobial use for calf diarrhea. We hypothesized that selective antimicrobial use is associated with herd-level predictors, including the presence of veterinarian-written treatment protocols and producer attitudes about the impact of antimicrobial use in livestock.

CIPARS: A One-Health Approach to Antimicrobial Resistance Surveillance

The objective of the Canadian Integrated Program for Antimicrobial Resistance Surveillance (CIPARS) is to provide a unified approach to monitor national trends in antimicrobial resistance (AMR) and antimicrobial use (AMU) in humans and animals and to facilitate the assessment of the public health impact of antimicrobial use. CIPARS is a combination of passive and active surveillance that is coordinated by the Public Health Agency of Canada (PHAC) but is based on extensive collaborations. Stakeholder engagement has led to action based on surveillance results. This One-Health approach provides a holistic understanding of AMR in Canada and enables the evaluation of interventions.

Impact of Antimicrobial Use in the Veterinary Sector on Prevalence of Resistance in Human Healthcare

Impact of Antimicrobial Use in the Veterinary Sector on Prevalence of Resistance in Human Healthcare

PL03.1 STIs - 2013: Resurgence of Early Syphilis, Persistence of High STI Morbidity and Mortality, and Emergence of Antimicrobial Resistant STIs: Implications and Potential Responses

Recent directions in clinical-epidemiologic research on STIs include (1) population-level estimates of STI prevalence (e.g., WHO’s 2011 publication of global estimates), and formal population-level surveys of STI prevalence and risk...

Burden of illness and factors associated with duration of illness in clinical campylobacteriosis.

A population-based study investigated the burden of illness, including the duration of illness associated with laboratory-confirmed cases of campylobacteriosis in two health unit areas. Questionnaire data were collected for 250 cases. The median duration of illness was 8 days and 66% of cases reported symptoms of moderate severity or greater. A Cox proportional hazards model identified antimicrobial use factors associated with a significantly increased rate of symptom resolution (shorter duration of illness): macrolides for less than the recommended number of days, ciprofloxacin for at least 3 days, and antimicrobials not recommended for campylobacteriosis. The impact of antimicrobial use was consistent regardless of when, during the course of illness, the antimicrobial use began. The effectiveness of ciprofloxacin in these results may be due to the low prevalence of resistance to ciprofloxacin in isolates from this study. The effect of antimicrobials not recommended for campylobacteriosis should be further investigated.

Antimicrobial Resistance: Challenges and Perspectives

AbstractIn 2006, the Institute of Food Technologists (IFT) published an Expert Report entitled “Antimicrobial Resistance: Implications for the Food System” (IFT 2006). That report summarized current scientific knowledge pertaining to the public‐health impact of antimicrobial use in the food system and the development and control of antimicrobial resistance. Since that time, intense interest in this topic has continued within the regulatory and scientific communities as well as the general public. This IFT Scientific Status Summary serves to update that 2006 IFT Expert Report by briefly reviewing new scientific evidence relevant to the goals of the initial report and providing a number of key observations and conclusions.

Effect of Antimicrobial Exposure on AcrAB Expression in Salmonella enterica Subspecies enterica Serovar Choleraesuis

Understanding the impact of antimicrobial use on the emergence of resistant bacteria is imperative to prevent its emergence. For instance, activation of the AcrAB efflux pumps is responsible for the emergence of antimicrobial-resistant Salmonella strains. Here, we examined the expression levels of acrB and its multiple regulator genes (RamA, SoxS, MarA, and Rob) in 17 field isolates of S. Choleraesuis by using quantitative PCR methods. The expression of acrB increased in eight of the field isolates (P < 0.05). The expression of acrB was associated with that of ramA in one isolate, soxS in one isolate, and both these genes in six isolates. Thereafter, to examine the effect of selected antimicrobials (enrofloxacin, ampicillin, oxytetracycline, kanamycin, and spectinomycin) on the expression of acrB and its regulator genes, mutants derived from five isolates of S. Choleraesuis were selected by culture on antimicrobial-containing plates. The expression of acrB and ramA was higher in the mutants selected using enrofloxacin (3.3–6.3- and 24.5–37.7-fold, respectively), ampicillin (1.8–7.7- and 16.1–55.9-fold, respectively), oxytetracycline (1.7–3.3- and 3.2–31.1-fold, respectively), and kanamycin (1.6–2.2- and 5.6–26.4-fold, respectively), which are AcrAB substrates, than in each of the parental strains (P < 0.05). In contrast, in AcrAB substrate-selected mutants, the expression of soxS, marA, and rob remained similar to that in parental strains. Of the four antimicrobials, the level of ramA expression was significantly higher in the enrofloxacin- and ampicillin-selected mutants than in the oxytetracycline- and kanamycin-selected mutants (P < 0.05), whereas the expression levels of acrB and multiple regulator genes in spectinomycin-selected mutants were similar to those in each parental strain. These data suggest that exposure to antimicrobials that are AcrAB substrates enhance the activation of the AcrAB efflux pump via RamA, but not via SoxS, MarA, or Rob in S. Choleraesuis.

The impact of antimicrobial use in broiler chickens on growth performance and on the occurrence of antimicrobial-resistant Escherichia coli

The manipulation of intestinal microflora of food producing animals with antimicrobials has been recognized as an important tool for improving growth performance and feed efficiency. However, worldwide concern about the biological consequences regarding antimicrobial-resistance development and persistence associated with antimicrobial use in animal husbandry, has led to a more accurate examination of the effects of these drugs on commensal flora. The objective of this study was to investigate, under field conditions, the influence of preventive antimicrobial administration on growth performance and resistance in faecal Escherichia coli isolated from growing broilers. The study took place over three consecutive broiler flocks reared in a controlled environment poultry house (1600 m 2) that was previously divided into two equal compartments. In each trial, 32 000 day-old broiler chicks were randomly allocated to each compartment. For a three days period, the birds in the medicated group (n = 16 000) were given therapeutic doses in their drinking water of enrofloxacin, gentamicin and amoxicillin when they were 1, 19 and 26 days old, respectively. The birds in the control group (n = 16 000) shared exactly the same rearing conditions. E. coli strains isolated from medicated group showed higher antimicrobial-resistance rates compared with those recovered from the control group. Multi-resistant strains were transient in control broilers, whereas in medicated broilers they were more prevalent and persisted along the rearing period. Influence of antimicrobial use on broiler chickens performance was also examined. In general, medicated broilers tended to consume more feed ( P < 0.01) and grew faster ( P < 0.001) than those on the control group. Cumulative feed conversion rate was lower for medicated broiler chickens ( P < 0.001). It was also observed that medicated broilers had lower water/feed ratio and cumulative mortality than the non-medicated ones ( P < 0.001). These positive effects on performance and viability of chickens are much more perceptible than the emergence and spreading of antimicrobial-resistant strains.

Stakeholder position paper: Epidemiological perspectives on antibiotic use in animals

Epidemiologists studying antimicrobial resistance are often interested in analyzing the association between antimicrobial resistance and antimicrobial use in animals, and on the impact of antimicrobial use in animals on the occurrence of resistance in bacteria affecting human populations. Given the various potential antimicrobial use data sources, it seems likely there will be some variability in the utility of the data for interpreting trends in antimicrobial resistance and investigating the relationship between antimicrobial use in animals and antimicrobial resistance in bacteria affecting human health. From an epidemiologic perspective, the major issues related to incorporation of antimicrobial use data into antimicrobial resistance monitoring programs are the further development of epidemiologic methods for collecting, quantifying, analyzing and interpreting use data; an open and realistic consideration of the limitations of the data; developing an understanding of scaling, temporal and spatial heterogeneity issues; and the interpretative problems of ecologic and atomistic fallacy. Given the many potential biases in antimicrobial use data, attempts to relate levels of antimicrobial use to levels of antimicrobial resistance should be done with caution until the data are better understood and the aforementioned issues have been addressed.

Impact of Antimicrobial Use in Animals and Regulatory Response

There is accumulating evidence that the use of antimicrobials in food-producing animals has adverse human health consequences. The use of these drugs in food animals selects for resistant pathogens and resistance genes that may be transferred to humans through the consumption or handling of foods of animal origin. Recent studies have demonstrated that antimicrobial resistance among foodborne bacteria may cause excess cases of illness, prolonged duration of illness, and increased rates of bacteremia, hospitalization and death.&#x0D; The US Food and Drug Administration (FDA) is committed to resolving the public health impact arising from the use of antimicrobial drugs in food-producing animals. The FDA's goal is to ensure that significant human antimicrobial therapies are not compromised or lost while providing for the safe use of antimicrobials in food animals. The FDA published a guidance document titled "Evaluating the Safety of Antimicrobial New Animal Drugs with Regard to their Microbiological Effects on Bacteria of Human Health Concern" that outlines a pathway drug sponsors can use to address concerns about antimicrobial resistance prior to approval of their drug. 30 The process uses a qualitative risk assessment approach to assess the potential of the intended use of a product to develop resistance in bacteria that may harm humans. The level of risk determines the level of risk management that is required for the drug to be approved.

Salmonella Antimicrobial Resistance Patterns on Midwest and Northeast Dairy Farms

Potential impact of antimicrobial use in livestock on the development of antimicrobial-resistant zoonotic pathogens is an ongoing and controversial public health issue. Our objective was to determine the prevalence of antimicrobial resistance among Salmonella isolates collected from dairy farms.

Computerized antimicrobial decision support: an offline evaluation of a database-driven empiric antimicrobial guidance program in hospitalized patients with a bloodstream infection

Introduction: We developed a computerized antimicrobial guidance program based on the last 5 years of our laboratory culture data augmented by expert infectious disease logic. The program is designed to assist physicians with the targeting of empiric antimicrobials for hospitalized patients by tracking pathogenic bacteria and their evolving antimicrobial resistance profiles. Costs, toxicities, and environmental impact of antimicrobial use also influence the final recommendations. We undertook the following analysis to verify its potential safety and efficacy in hospitalized patients with a bloodstream infection. Methods: We retrospectively enrolled all inpatients with a positive blood culture for a previously undetermined pathogen during the first 6 months of 2002 and determined the empiric therapy initiated within the 12 h before and after the time of culture. Antimicrobial recommendations from the microbiologic decision support tool were then determined by matching specimen (blood), hospital unit, community- versus hospital-acquired category, age category, and gender. Generated antimicrobial recommendations were tailored to patient allergies, age category, and presence of pregnancy, lactation, or hepatic impairment. Results: The microbiology laboratory recorded 226 unique patient/pathogen blood cultures during the study period. Physicians initiated effective empiric therapy in 150 of the 226 cases, for an effectiveness rate of 66%. The computer-guided therapy was effective in 195 of the 226 cases for a rate of 86%. A contingency table analysis showed 55 cases where the computer recommendation was effective but the physicians’ selection was not, and eight cases where the physicians’ antimicrobials were effective but the computer’s were not ( P<0.0001). Discussion: For patients with a bloodstream infection, we found that our computer-guided statistically-derived antimicrobial therapy would potentially improve the rate of effectiveness of empirically chosen antimicrobials.

Computerized antimicrobial decision support: an offline evaluation of a database-driven empiric antimicrobial guidance program in hospitalized patients with a bloodstream infection

Introduction: We developed a computerized antimicrobial guidance program based on the last 5 years of our laboratory culture data augmented by expert infectious disease logic. The program is designed to assist physicians with the targeting of empiric antimicrobials for hospitalized patients by tracking pathogenic bacteria and their evolving antimicrobial resistance profiles. Costs, toxicities, and environmental impact of antimicrobial use also influence the final recommendations. We undertook the following analysis to verify its potential safety and efficacy in hospitalized patients with a bloodstream infection. Methods: We retrospectively enrolled all inpatients with a positive blood culture for a previously undetermined pathogen during the first 6 months of 2002 and determined the empiric therapy initiated within the 12 h before and after the time of culture. Antimicrobial recommendations from the microbiologic decision support tool were then determined by matching specimen (blood), hospital unit, community- versus hospital-acquired category, age category, and gender. Generated antimicrobial recommendations were tailored to patient allergies, age category, and presence of pregnancy, lactation, or hepatic impairment. Results: The microbiology laboratory recorded 226 unique patient/pathogen blood cultures during the study period. Physicians initiated effective empiric therapy in 150 of the 226 cases, for an effectiveness rate of 66%. The computer-guided therapy was effective in 195 of the 226 cases for a rate of 86%. A contingency table analysis showed 55 cases where the computer recommendation was effective but the physicians’ selection was not, and eight cases where the physicians’ antimicrobials were effective but the computer’s were not (P<0.0001). Discussion: For patients with a bloodstream infection, we found that our computer-guided statistically-derived antimicrobial therapy would potentially improve the rate of effectiveness of empirically chosen antimicrobials.

From the Farm to the Kitchen Table: the Negative Impact of Antimicrobial Use in Animals on Humans

Antimicrobials used as growth promotion agents in the livestock and poultry industries appear to result in the spread of drug-resistant pathogens to humans such as vancomycin-resistant enterococci, fluoroquinolone-resistant Campylobacter jejuni, and multidrug-resistant strains of Salmonella enterica. We present some epidemiologic evidence supporting this link and suggest that the use of antimicrobial agents for nontherapeutic purposes in food animals should be severely limited, if not banned altogether.

Making sense of antimicrobial use and resistance surveillance data: application of ARIMA and transfer function models

Making sense of antimicrobial use and resistance surveillance data: application of ARIMA and transfer function models

Impact of Antimicrobial Use on the Epidemiology of Nosocomial Infections on the Oncology Ward: Implications for Infection Control

Impact of Antimicrobial Use on the Epidemiology of Nosocomial Infections on the Oncology Ward: Implications for Infection Control