Patterns of antibacterial use and impact of age, race/ethnicity, and geographic region on antibacterial use in an outpatient medicaid cohort

Exploring variations in recommended first-choice therapy for complicated urinary tract infections in males: Insights from outpatient settings across age, race, and ethnicity

INTRODUCTION

There are known disparities in the treatment of infectious diseases. However, disparities in treatment of complicated urinary tract infections (UTIs) are largely uninvestigated.

OBJECTIVES

We characterized UTI treatment among males in Veterans Affairs (VA) outpatient settings by age, race, and ethnicity and identified demographic characteristics predictive of recommended first-choice antibiotic therapy.

METHODS

We conducted a national, retrospective cohort study of male VA patients diagnosed with a UTI and dispensed an outpatient antibiotic from January 2010 through December 2020. Recommended first-choice therapy for complicated UTI was defined as use of a recommended first-line antibiotic drug choice regardless of area of involvement (ciprofloxacin, levofloxacin, or sulfamethoxazole/trimethoprim) and a recommended duration of 7 to 10 days of therapy. Multivariable models were used to identify demographic predictors of recommended first-choice therapy (adjusted odds ratio [aOR] > 1).

RESULTS

We identified a total of 157,898 males diagnosed and treated for a UTI in the outpatient setting. The average antibiotic duration was 9.4 days (±standard deviation [SD] 4.6), and 47.6% of patients were treated with ciprofloxacin, 25.1% with sulfamethoxazole/trimethoprim, 7.6% with nitrofurantoin, and 6.6% with levofloxacin. Only half of the male patients (50.6%, n = 79,928) were treated with recommended first-choice therapy (first-line drug choice and appropriate duration); 77.6% (n = 122,590) were treated with a recommended antibiotic choice and 65.9% (n = 104,070) with a recommended duration. Age 18-49 years (aOR 1.07, 95% confidence interval [CI] 1.03-1.11) versus age ≥65 years was the only demographic factor predictive of recommended first-choice therapy.

CONCLUSIONS

Nearly half of the patients included in this study did not receive recommended first-choice therapies; however, racial and ethnic disparities were not identified. Underutilization of recommended first-choice antibiotic therapy in complicated UTIs continues to be an area of focus for antimicrobial stewardship programs.

Demographic and Geographic Inequities in Antimicrobial Use and Prescribing

Little is known about how social determinants of health may impact antimicrobial prescribing among racial and ethnic minority populations, different age groups and genders, and across geographic regions. The factors that influence antimicrobial prescribing are complex, but evidence suggests that demographic and socioeconomic factors do influence prescribing patterns. This review describes the inequities observed in antimicrobial use and prescribing that have been heretofore published, with a focus on differences observed by race and ethnicity, age, gender, and geographic region of the United States.

Factors Associated with Geographical Variability of Antimicrobial Use in Japan

INTRODUCTION

Evidence regarding the factors affecting the geographical variation of antimicrobial use (AMU) is relatively scarce. This study aimed to evaluate factors potentially associated with geographical variability of AMU per day per 1000 habitants in the 47 prefectures of Japan.

METHODS

This is an observational ecological study using the Japanese national database in 2019. The outcome was the defined daily doses per 1000 inhabitants per day by prefecture. Multivariable negative binomial regression analysis was conducted using patient- and physician-level variables.

RESULTS

The study included 605,391,054 defined daily doses of AMU in 2019 from the 47 prefectures. In the multivariable negative binomial regression analyses for the outcome of total AMU, the proportion of female individuals (adjusted rate ratio [aRR] 1.04 [1.01-1.08] per 1% increase, p = 0.021), the proportion of upper secondary graduates going to further education (aRR 1.01 [1.00-1.01] per 1% increase, p = 0.005), and the annual number of diagnoses related to upper respiratory infections (URIs) per 1000 inhabitants per day (aRR 1.21 [1.10-1.34], p < 0.001) were significantly correlated with total AMU.

CONCLUSIONS

In this ecological study, the variability of total AMU by Japanese prefecture was associated with the proportion of female individuals, education level, and the number of URI diagnoses per population. The results suggest the potential need for additional stewardship efforts to reduce unnecessary antimicrobial prescriptions for URI.

Antibiotics administration without prescription in Bangladesh

Background

Antibiotic resistance is a global challenge. Therefore, adhering to proper antibiotic administration protocols is essential to mitigating the problem. This study investigated the prevalence, and factors associated with, antibiotics administration without prescription by registered doctors in Bangladesh.

Method

This cross-sectional survey was carried out among 1102 adults. The outcome variable was antibiotics administration without prescription. The exploratory variables included the those relating to sociodemographics, attitudes, and knowledge (antibiotic-treatable diseases, types of disease specification, and antimicrobial drugs specifications). Descriptive and inferential statistics were performed, with a p-value of 0.05 considered significant with a 95% confidence interval.

Results

The prevalence of antibiotics administration without prescription was found to be 37.02%. Age was significantly associated with the administration of antibiotics without prescription. Those who had taken antibiotics in the previous 2 months reported a significantly higher prevalence of antibiotics administration without prescription. The participants' attitudes toward antibiotics and knowledge of antibiotic-treatable diseases, types of disease, and antimicrobial drugs were significantly associated with antibiotics administration without prescription.

Conclusion

These findings may assist in facilitating relevant initiatives to improve the magnitude of antibiotics utilization without prescription, and mitigate the emergence of antibiotic resistance in Bangladesh.

Clinical Characteristics of Idiopathic Intracranial Hypertension in Patients Over 50 Years of Age: A multicenter clinical cohort study

PURPOSE

To characterize the clinical features of idiopathic intracranial hypertension (IIH) in patients >50 years of age compared to the typical IIH population and existing data for this older cohort.

DESIGN

Retrospective, clinical cohort study.

METHODS

Medical records of 65 patients >50 years of age at first diagnosis of IIH were reviewed based on the Modified Dandy Criteria from 4 academic centers. Each center provided randomly selected controls from IIH patients <50 years of age for each study patient at their location. Data recorded included patient demographics, presenting symptoms, medications, coexisting medical conditions, cerebrospinal fluid (CSF) opening pressure, treatments, and neuro-ophthalmic data from initial and final visits.

RESULTS

Compared to controls, the older cohort showed the following characteristics: fewer females (n = 51 [78.5%] vs. controls: n = 60 [92.3%]; P = .045), fewer headaches (n = 33 [50.8%] vs. controls: 52 [80.0%]; P = .001), more frequent incidental discoveries of papilledema (n = 19 [29.2%] vs. controls: 7 [10.8%]; P = .015), and lower CSF opening pressure [median: 33 cm H₂O [range: 21-58 cm H₂O] vs. the median for controls: 34 cm H₂O [range: 24-67 cm H₂O; P = .029).

CONCLUSIONS

Patients with IIH diagnosed at >50 years of age were less often female and had lower CSF opening pressure, fewer headaches, a higher chance of incidentally identified papilledema, and body mass index similar to that of younger IIH patients. Older IIH onset was not associated with worse visual outcome.

Hospital-acquired Clostridioides difficile infection among patients at an urban safety-net hospital in Philadelphia: Demographics, neighborhood deprivation, and the transferability of national statistics

OBJECTIVE

To investigate associations between healthcare-associated Clostridioides difficile infection and patient demographics at an urban safety-net hospital and compare findings with national surveillance statistics.

METHODS

Study participants were selected using a case-control design using medical records collected between August 2014 and May 2018 at Hahnemann University Hospital in Philadelphia. Controls were frequency matched to cases by age and length of stay. Final sample included 170 cases and 324 controls. Neighborhood-level factors were measured using American Community Survey data. Multilevel models were used to examine infection by census tract, deprivation index, race/ethnicity, insurance type, referral location, antibiotic use, and proton-pump inhibitor use.

RESULTS

Patients on Medicare compared to private insurance had 2.04 times (95% CI, 1.31-3.20) the odds of infection after adjusting for all covariables. Prior antibiotic use (2.70; 95% CI, 1.64-4.46) was also associated with infection, but race or ethnicity and referral location were not. A smaller proportion of hospital cases occurred among white patients (25% vs 44%) and patients over the age of 65 (39% vs 56%) than expected based on national surveillance statistics.

CONCLUSIONS

Medicare and antibiotics were associated with Clostridioides difficile infection, but evidence did not indicate association with race or ethnicity. This finding diverges from national data in that infection is higher among white people compared to nonwhite people. Furthermore, a greater proportion of hospital cases were aged <65 years than expected based on national data. National surveillance statistics on CDI may not be transportable to safety-net hospitals, which often disproportionately serve low-income, nonwhite patients.

Clinician Practice Patterns That Result in the Diagnosis of Coccidioidomycosis Before or During Hospitalization

BACKGROUND

Coccidioidomycosis (CM) is common and important within endemic regions, requiring specific testing for diagnosis. Long delays in diagnosis have been ascribed to ambulatory clinicians. However, how their testing practices have impacted patient care has not been systematically unexplored.

METHODS

We analyzed practice patterns for CM diagnoses over 3 years within a large Arizona healthcare system, including diagnosis location, patient characteristics, and care-seeking patterns associated with missed diagnosis.

RESULTS

For 2043 CM diagnoses, 72.9% were made during hospital admission, 21.7% in ambulatory clinics, 3.2% in emergency units, and only 0.5% in urgent care units. A 40.6% subgroup of hospitalized patients required neither intensive care unit or hospital-requiring procedures, had a median length of stay of only 3 days, but still incurred both substantial costs ($27.0 million) and unnecessary antibiotic administrations. Prior to hospital diagnosis (median of 32 days), 45.1% of patients had 1 or more visits with symptoms consistent with CM. During those visits, 71.3% were not tested for CM. Diagnoses were delayed a median of 27 days.

CONCLUSIONS

Lack of testing for CM in ambulatory care settings within a region endemic for CM resulted in a large number of hospital admissions, attendant costs, and unneeded antibacterial drug use, much of which would otherwise be unnecessary. Improving this practice is challenging since many clinicians did not train where CM is common, resulting in significant inertia to change. Determining the best way to retrain clinicians to diagnose CM earlier is an opportunity to explore which strategies might be the most effective.

Differences in US antibiotic prescription use by facility and patient characteristics: evidence from the National Ambulatory Medical Care Survey

BACKGROUND

Antibiotic resistance is increasing, largely due to the overuse of antibiotics. Patient demographic characteristics can influence rates of antibiotic prescription, but less research has assessed the role of facility-level characteristics.

OBJECTIVE

The objective of this study was to examine the prevalence of antibiotic prescriptions for viral-like illness, as well as patient and provider factors that influence antibiotic prescription practices.

METHODS

We conducted an observational cohort study using data from the 2012 National Ambulatory Medical Care Survey. We compared the prevalence of antibiotic prescription for all aetiologies and for viral-like illnesses between community health centres, non-community health centre clinics and emergency departments. Then, we used logistic regression models to compare the odds of antibiotic prescription use by facility and patient characteristics.

RESULTS

Data came from 630 community health centre visits, 857 non-community health centre outpatient clinic visits and 627 emergency department visits. Compared to patients visiting non-community health centre clinics, patients visiting community health centres and emergency departments for any aetiology were more likely to receive antibiotic prescriptions. Patients with viral-like illnesses were less likely to receive antibiotics at community health centres and exhibited similar odds of receiving antibiotics at emergency departments. Certain patient demographics (age, race/ethnicity and payment source) were associated with variation in overall antibiotic prescription, but these factors were mostly unassociated with antibiotic prescription for viral-like illnesses.

CONCLUSIONS

The care setting that patients visit may influence their odds of receiving antibiotics. Initiatives addressing overuse of antibiotics should be mindful of facility- and patient-based characteristics when designing interventions.

Rise in mortality involving poisoning by medicaments other than narcotics, including poisoning by psychotropic drugs in different age/racial groups in the US

BACKGROUND

Increase in mortality involving poisoning, particularly by narcotics, is known to have been one of the factors that affected life expectancy in the US during the last two decades, especially for white Americans and Native Americans. However, the contribution of medicaments other than narcotics to mortality in different racial/age groups is less studied.

METHODS

We regressed annual rates of mortality involving poisoning by medicaments but not narcotics/psychodysleptics (ICD-10 codes T36-39.xx or T41-50.8 but not T40.xx present as either underlying or contributing causes of death), as well as annual rates of mortality for certain subcategories of the above, including mortality involving poisoning by psychotropic drugs but not narcotics/psychodysleptics (ICD-10 codes T43.xx but not T40.xx present as either underlying or contributing causes of death) in different age/racial groups for both the 2000-2011 period and the 2011-2017 period against calendar year.

RESULTS

Annual numbers of deaths involving poisoning by medicaments but not narcotics/psychodysleptics grew from 4,332 between 2000-2001 to 11,401 between 2016-2017, with the growth in the rates of those deaths being higher for the 2011-2017 period compared to the 2000-2011 period. The largest increases in the rates of mortality involving poisoning by medicaments but not narcotics/psychodysleptics were in non-elderly Non-Hispanic Native Americans, followed by Non-Hispanic whites. Most of those increases came from increases in the rates of mortality involving poisoning by psychotropic medications; the latter rates grew for the period of 2015-2017 vs. 2000-2002 by factors ranging from 2.75 for ages 35-44y to 5.37 for ages 55-64y.

CONCLUSIONS

There were major increases in mortality involving poisoning by non-narcotic, particularly psychotropic medicaments, especially in non-elderly non-Hispanic whites and Native Americans. Our results support the need for a comprehensive evaluation of the effect of psychotropic medications on health-related outcomes, including mortality for causes other than poisoning, and the impact of medication misuse.

Changes in Outpatient Use of Antibiotics by Adults in the United States, 2006-2015

INTRODUCTION

Numerous initiatives over the past decade have targeted the problem of antibiotic overuse in the US; however, the cumulative impact of such initiatives upon recent patterns of use is not known.

OBJECTIVES

The aims of this study were to (1) describe general trends in outpatient antibiotic use among adults over the period 2006-2015; and (2) identify rapid shifts in use during this time period as potential indicators for key events.

METHODS

This was an observational study set in the ambulatory setting. Patients ≥ 18 years of age were selected from the Optum Clinformatics Datamart™, a commercial insurance claims database. The outcome measures of interest were prescriptions filled/1000 enrolled individuals, by year or quarter. We used linear regression to identify trends in use over multiple years, and change-point regression to identify rapid shifts in use within individual years.

RESULTS

From 2006 to 2015, antibiotic use declined significantly, decreasing by 12% for adults younger than 65 years of age (913-807 prescriptions/1000 individuals, p = 0.0001) and by 5% for adults ≥ 65 years of age (991-943 prescriptions/1000 individuals, p = 0.018). With change-point regression, we identified a number of rapid shifts in the use of specific antibiotic classes, such as downward shifts in the use of quinolones and macrolides during the second quarter of 2008 and 2013, respectively.

CONCLUSIONS

Over the period 2006-2015 outpatient use of antibiotics decreased substantially among adults. Rapid shifts in use occurring in 2008 and 2013 may reflect the presence of key drivers of change, such as abrupt changes in access to care or perceived antibiotic safety.

Patient, Provider, and Practice Characteristics Associated with Inappropriate Antimicrobial Prescribing in Ambulatory Practices

OBJECTIVE

To reduce inappropriate antimicrobial prescribing across ambulatory care, understanding the patient-, provider-, and practice-level characteristics associated with antibiotic prescribing is essential. In this study, we aimed to elucidate factors associated with inappropriate antimicrobial prescribing across urgent care, family medicine, and pediatric and internal medicine ambulatory practices.

DESIGN, SETTING, AND PARTICIPANTS

Data for this retrospective cohort study were collected from outpatient visits for common upper respiratory conditions that should not require antibiotics. The cohort included 448,990 visits between January 2014 and May 2016. Carolinas HealthCare System urgent care, family medicine, internal medicine and pediatric practices were included across 898 providers and 246 practices.

METHODS

Prescribing rates were reported per 1,000 visits. Indications were defined using the International Classification of Disease, Ninth and Tenth Revisions, Clinical Modification (ICD-9/10-CM) criteria. In multivariable models, the risk of receiving an antibiotic prescription was reported with adjustment for practice, provider, and patient characteristics.

RESULTS

The overall prescribing rate in the study cohort was 407 per 1,000 visits (95% confidence interval [CI], 405–408). After adjustment, adult patients seen by an advanced practice practitioner were 15% more likely to receive an antimicrobial than those seen by a physician provider (incident risk ratio [IRR], 1.15; 95% CI, 1.03–1.29). In the pediatric sample, older providers were 4 times more likely to prescribe an antimicrobial than providers aged ≤30 years (IRR, 4.21; 95% CI, 2.96–5.97).

CONCLUSIONS

Our results suggest that patient, practice, and provider characteristics are associated with inappropriate antimicrobial prescribing. Future research should target antibiotic stewardship programs to specific patient and provider populations to reduce inappropriate prescribing compared to a “one size fits all” approach.

Infect Control Hosp Epidemiol 2018;39:307–315

Antimicrobial utilization in an Iraqi province: a comprehensive evaluation of antibiotic source and cost

PURPOSE

The aims were to calculate total systemic antibiotic consumption and cost in both public and private sectors in all care settings in Al-Najaf province, Iraq, during 2012, recognize the percentage of each pharmacological class for the dispensed antibiotics and identify oral and parenteral antibiotic percentages dispensed and the portions manufactured nationally and imported.

METHODS

Cross-sectional study was conducted in Al-Najaf to calculate the total cost and quantities of antibiotics consumed during 2012 using World Health Organization Guidelines for Defined Daily Dose (DDD).

KEY FINDINGS

The results showed more than 21 million DDDs were dispensed in Al-Najaf in one year, and more than half (54.2%) were dispensed by governmental healthcare institutions. A thousand inhabitants in the province consumed 45.26 DDDs per day. Extended-spectrum (34.49%) and combined penicillins (26.08%) were the most frequently consumed while meropenem was the least frequently consumed (0.02%). Ninety-five per cent of the consumed antibiotics were oral dosage forms, and five per cent were parenteral dosage forms. The total cost of antibiotic consumed was more than nine million U.S dollars.

CONCLUSIONS

The antibiotic consumption ratio in this province was comparable to neighbouring countries, but far higher compared to European countries. Penicillins, cephalosporins and quinolones were the most popular antibiotics. Around half of the antibiotics consumed were made by national pharmaceutical companies that mainly produce oral antibiotics. The public sector consumed a higher portion, but spent a lower amount compared to private sectors. This is the first time report of antibiotic consumption in Iraq. More studies evaluating antibiotic consumption can improve utilization.

Consumption of antibiotics for community-acquired infections by adults in Greece: A cross-sectional study

We studied the rates and characteristics of antibiotics consumption for community-acquired infections in 309 adult patients. Of them, 293 (94.8%) had received at least 1 course of antibiotics during the past year. In total, 419 courses of antibiotics were consumed during the past year, including 285 (68%) following medical examination, 72 (17.2%) following telephone consultation, 30 (7.2%) following suggestion by a pharmacist, and in 16 (3.8%) the antibiotic was available at home. Older age and asthma were significantly associated with a higher risk for antibiotics consumption.

Antibiotic prescriptions in the community by type of provider in the United States, 2005-2010

OBJECTIVES

Although antibiotic prescriptions are decreasing in the United States, broad-spectrum prescribing is increasing. It is unknown if decreases observed in national antibiotic prescribing differ by provider group. Understanding prescribing trends over time by provider group can be helpful for customizing antimicrobial stewardship efforts. Therefore, the purposes of this study were to describe outpatient antibiotic prescribing by provider group overall and adjusted for population and number of providers. In addition, trends in prescribing by class and seasonal variation are described by provider group over 6 years.

DESIGN

Cross-sectional observation of outpatient antibiotic prescriptions.

SETTING AND PARTICIPANTS

A population-level analysis of U.S. prescribing from 2005 to 2010 with the use of the IMS Health Xponent dataset.

MAIN OUTCOME MEASURES

Number and rates of prescriptions dispensed overall and by provider group.

RESULTS

The majority (81.0%) of antibiotics were prescribed by physicians, followed by dentists (10.4%), nurse practitioners (NPs; 4.5%), and physician assistants (PAs; 4.2%). The percentage of antibiotic prescriptions decreased for physicians, but increased significantly for NPs and PAs. Provider-based and population-based prescribing rates decreased for physicians and dentists and increased for NPs and PAs. Penicillins were prescribed most frequently by all provider groups, decreasing for physicians and dentists. Increased prescribing of broad-spectrum agents was observed for NPs and PAs. With the exception of dentists, antibiotic prescriptions were higher in winter than in summer, with the largest seasonal increase by NPs.

CONCLUSION

Over 6 years, antibiotic prescriptions overall and for broad-spectrum agents decreased for physicians and increased for NPs and PAs. Thus, increasing trends in the US of broad-spectrum antibiotic prescriptions can be attributed to midlevel providers. Interventions should be designed to reverse increasing prescribing trends, especially of broad-spectrum agents prescribed by NPs and PAs. Stewardship efforts should also be targeted towards dentists, since this group prescribes a higher proportion of antibiotics compared with midlevel providers.

Clostridium difficile infection health disparities by race among hospitalized adults in the United States, 2001 to 2010

BACKGROUND

Recognition of health disparities in Clostridium difficile infection (CDI) is an initial step toward improved resource utilization and patient health. The purpose of this study was to identify health disparities by black vs. white race among hospitalized adults with CDI in the United States (U.S.) over 10 years.

METHODS

This was a retrospective analysis of the U.S. National Hospital Discharge Surveys from 2001 to 2010. Eligible cases included adults with an ICD-9-CM code for CDI (008.45). Patients with missing race or "other race" were excluded. The primary outcome, CDI incidence, was calculated as CDI discharges per 1,000 total discharges. Data weights were used to determine national estimates. Secondary outcomes included in-hospital mortality, hospital length of stay (LOS), and severe CDI. Comparisons were made using bivariable analyses. Race was assessed as an independent risk factor for CDI outcomes using logistic regression or proportional hazards models.

RESULTS

These data represent 1.7 million CDI discharges, where 90 % of patients were identified as white and 10 % black. Blacks differed from whites with respect to all baseline characteristics (p <0.0001). CDI incidence was significantly higher in whites compared to blacks (7.7/1,000 discharges vs. 4.9/1,000 discharges, p < 0.0001). Blacks had higher mortality (7.4 % vs. 7.2 %, p < 0.0001), LOS >7 days (57 % vs. 52 %, p < 0.0001), and severe CDI (24 % vs. 19 %, p < 0.0001). In multivariable analyses, black race was a positive predictor of mortality (OR 1.12, 95 % CI 1.09-1.15) and severe CDI (OR 1.09, 95 % CI 1.07-1.11), and negative predictor for hospital LOS (OR 0.93, 95 % CI 0.93-0.94).

CONCLUSIONS

CDI incidence was higher for white patients; however, black race was independently associated with mortality and severe CDI.

Individuals hospitalized with acute mania have increased exposure to antimicrobial medications

OBJECTIVES

We have preciously documented that many individuals with acute mania have immune activation. However, the sources of immune activation have not been identified. We investigated whether individuals hospitalized with acute mania have evidence of bacterial infections as determined by the prescription of systemic antimicrobial agents.

METHODS

We assessed the recent prescription of systemic antimicrobial medications and the site of presumed bacterial infection in 234 individuals hospitalized for acute mania in either an inpatient unit or a day hospital. We also assessed individuals hospitalized for other psychiatric disorders (n=368) and controls (n=555). We employed logistic regression models to compare the rates of antibiotic prescription in individuals with the different diagnoses, employing demographic variables as covariates.

RESULTS

We found that individuals hospitalized with acute mania had a substantially increased rate of recent antimicrobial prescription, defined as exposure within three days of ascertainment (adjusted odds ratio=5.5, 95% confidence interval: 2.2-14.1, P<.0002). Overall, a total of 18 of the 234 (7.7%) individuals hospitalized for acute mania were prescribed antibiotics as opposed to seven of 555 (1.3%) controls. The prescription of antibiotics was associated with being on an inpatient unit as opposed to being in the day hospital, and having increased mania symptom severity but not with other clinical ratings, demographic variables, or psychiatric medications. Hospitalization for other psychiatric disorders was not associated with the recent prescription of antimicrobial medications. The urinary tract was the most common site of infection in women, while the respiratory tract and mucosal surfaces were the most common sites in men.

CONCLUSIONS

Individuals hospitalized with acute mania have a markedly increased rate of bacterial infections, as evidenced by the recent prescription of antimicrobial agents. The prevention and effective treatment of bacterial infections may be important interventions for the management of individuals with mania.

Evaluation of Clarithromycin Resistance Among Iranian Helicobacter pylori Isolates by E-Test and Real-Time Polymerase Chain Reaction Methods

Background

Helicobacter pylori is an important pathogen of human gastric mucosa. Antibiotic resistance, especially resistance to clarithromycin is a major factor for treatment failure of H. pylori infections. The main mechanism of clarithromycin resistance in these bacteria is related to point mutations in three different locations of 23S rRNA gene.

Objectives

The aims of this study were to evaluate the resistance rate to clarithromycin among local H. pylori isolates by the E-test method and to determine the profile of point mutation in 23S rRNA by real-time polymerase chain reaction (PCR) method.

Patients and Methods

Eighty biopsy samples were collected from dyspeptic patients by endoscopy during 2011 - 2012. All samples were homogenized immediately and cultured on supplemented brucella blood agar and incubated under microaerophilic conditions. Further biochemical tests and ureC gene PCR was done for H. pylori confirmation. The H. pylori OC1096 strain was used as the control strain, simultaneously. Frequency of clarithromycin resistance was determined by the E-test method based on the clinical and laboratory standard institute (CLSI) standards. Point mutation profile was determined by real-time PCR and further analysis of melting curve, amplicon sequencing was done continuously.

Results

From 80 biopsy samples, 20 positive H. pylori isolates were detected and confirmed by biochemical tests and PCR method. Overall, 21.7% of the H. pylori isolates, showed clarithromycin resistance phenotype by use of the E-test. Also, the minimal inhibitory concentration of clarithromycin was determined as ≥ 0.5 mg/L by the E-test method. Only point mutation in the location of A2143G with melting temperature of 54.7°C was observed in all resistant isolates.

Conclusions

This study showed that the frequency of H. pylori clarithromycin resistance in Iran is relatively high. Since clarithromycin is not commonly used in Iran for H. pylori eradication, the high rate of resistance could be related to cross-reactivity between other macrolides. Therefore, macrolide antibiotics must be prescribed with precaution in any case of treatment other than H. pylori infections. All resistant isolates showed A2143G mutation in 23S rRNA as the dominant pattern of point mutation at least in Tehran H. pylori isolates.

Antibiotic resistance: a primer and call to action

During the past century, discoveries of microorganisms as causes of infections and antibiotics as effective therapeutic agents have contributed to significant gains in public health in many parts of the world. Health agencies worldwide are galvanizing attention toward antibiotic resistance, which is a major threat to public health (Centers for Disease Control and Prevention, 2013; World Health Organization, 2014). Some life scientists believe that we are approaching the post-antibiotic age (Davies & Davies, 2010). The growing threat of antimicrobial resistance is fueled by complex factors with biological, behavioral, and societal aspects. This primer provides an overview of antibiotic resistance and its growing burden on public health, the biological and behavioral mechanisms that increase antibiotic resistance, and examples of where health communication scholars can contribute to efforts to make our current antibiotic drugs last as long as possible. In addition, we identify compelling challenges for current communication theories and practices.