Community factors in the development of antibiotic resistance

Antibiotics nonadherence and knowledge in a community with the world's leading prevalence of antibiotics resistance: implications for public health intervention

Background

Community determinants of antibiotics nonadherence, an important contributor of antibiotics resistance, remained unclear.

Objectives

Our objective was to investigate whether deficient antibiotics knowledge could contribute to nonadherence in a community with high prevalence of antibiotics resistance.

Methods

We recruited 465 people by random sampling from 5 urban areas in Hong Kong. A structured questionnaire was used to assess antibiotics knowledge and adherence. Adherence was defined as completing the most recent course of antibiotics entirely according to physicians’ instructions. An antibiotics knowledge score ranging from 0 to 3 (highest) was composed based on the number of correctly answered questions.

Results

Of the 465 participants interviewed, 96.3% had heard of the term “antibiotics,” and 80.6% recalled having previously received antibiotics prescription. Among the eligible 369 subjects, 32.9% showed nonadherence. Percentages of participants with antibiotics knowledge scores of 0, 1, 2, and 3 were 11%, 27%, 33%, and 29%, respectively. There was a higher prevalence of nonadherence among people with lower antibiotics knowledge score (P < .001). Furthermore, people with nonadherence had a significantly lower mean antibiotics knowledge score (1.3 ± 1.0 versus 2.0 ± 0.9, P < .001), with no interaction with education (P < .05). Adjusted for potential confounders, antibiotics knowledge scores of 2, 1, and 0 independently predicted increased risk of nonadherence by 1-fold (odds ratio [OR], 2.00; 95% confidence interval [CI]: 1.01-3.94; P = .047), 4-fold (OR, 4.77; 95% CI: 2.30-9.92; P < .001), and 17-fold (OR, 18.41; 95% CI: 6.92-48.97; P < .001) respectively, compared with the maximum score of 3.

Conclusion

Lack of antibiotics knowledge is a critical determinant of nonadherence independent of education in the community.

Ciprofloxacin-resistant Escherichia coli in hospital wastewater of Bangladesh and prediction of its mechanism of resistance

Hospital and agriculture wastewater is mostly responsible for causing environmental pollution by spreading un-metabolized antibiotics and resistant bacteria, especially in Bangladesh. Here, we studied the influence of the most frequently prescribed antibiotic, fluoroquinolone (~72%), on the development of antibiotic resistance in Escherichia coli. Out of 300, 24 ciprofloxacin resistant E. coli isolates were selected for the study that showed the MBC(100) higher than expected (600 μg/mL). Here, we profiled plasmid, sequenced gyr genes, screened mutations and analyzed the effect of mutation on drug-protein interaction through molecular docking approach. We found that (1) out of 10, most of them (n = 7) had large plasmid(s); (2) all ciprofloxacin-resistant isolates had gyrA double mutations (S83L and D87Y); (3) no isolate had qnr gene; and (4) docking of ciprofloxacin with DNA gyrase A subunit suggests that acquisition of double mutation leads to alteration of the ciprofloxacin binding pocket.

Impact of dose de-escalation and escalation on daptomycin's pharmacodynamics against clinical methicillin-resistant Staphylococcus aureus isolates in an in vitro model

De-escalation and escalation therapeutic strategies are commonly employed by clinicians on the basis of susceptibility results and patient response. Since no in vitro or in vivo data are currently available to support one strategy over the other for daptomycin, we attempted to evaluate the effects of dose escalation and de-escalation on daptomycin activity against methicillin-resistant Staphylococcus aureus (MRSA) isolates using an in vitro pharmacokinetic/pharmacodynamic (PK/PD) model with simulated endocardial vegetations. Three clinical MRSA isolates, including one heterogeneous vancomycin-intermediate S. aureus (hVISA) isolate and one vancomycin-intermediate S. aureus (VISA) isolate, were exposed to daptomycin at 10 or 6 mg/kg of body weight/day for 8 days using a starting inoculum of ∼10(9) CFU/g of vegetations, with dose escalation and de-escalation initiated on the fourth day. Daptomycin MIC values ranged from 0.5 to 1 μg/ml. In the PK/PD model, high-dose daptomycin (10 mg/kg/day) and de-escalation simulation (10 to 6 mg/kg/day) appeared to be the most efficient regimens against the three tested isolates, exhibiting the fastest bactericidal activity (4 to 8 h) compared to that of the standard regimen of 6 mg/kg/day and the escalation therapy of 6 to 10 mg/kg/day. The differences in the numbers of CFU/g observed between dose escalation and de-escalation were significant for the hVISA strain, with the de-escalation simulation exhibiting a better killing effect than the escalation simulation (P<0.024). Although our results need to be carefully considered, the use of high-dose daptomycin up front demonstrated the most efficient activity against the tested isolates. Different therapeutic scenarios including isolates with higher MICs and prolonged drug exposures are warranted to better understand the outcomes of escalation and de-escalation strategies.

Analysis of risk factors for a high prevalence of extended-spectrum {beta}-lactamase-producing Enterobacteriaceae in asymptomatic individuals in rural Thailand

The prevalence of and risk factors associated with extended-spectrum β-lactamase (ESBL)-producing micro-organisms have not been well studied in healthy individuals. The aim of this study was to determine this in healthy individuals in Thailand. Stool samples and questionnaires obtained from 445 participants from three provinces in Thailand were analysed. The antimicrobial susceptibility of the isolates was assessed using phenotypic and genotypic methods. PCR analysis was performed to detect and group the bla(CTX-M) genes. The prevalence of CTX-M-type ESBL-producing Enterobacteriaceae in the three provinces was as follows: 29.3 % in Nan (43/147), 29.9 % in Nakhon Si Thammarat (43/144) and 50.6 % in Kanchanaburi (78/154) (P<0.001). Of the 445 samples, 33 (7.4 %), 1 (0.2 %) and 127 (28.5 %) isolates belonged to the bla(CTX-M) gene groups I, III and IV, respectively. Escherichia coli was the predominant member of the Enterobacteriaceae producing CTX-M-type ESBLs (40/43, 39/43 and 70/78 isolates in Nan, Nakhon Si Thammarat and Kanchanaburi, respectively). No statistically significant association was observed between the presence of ESBL-producing bacteria and gender, age, education, food habits or antibiotic usage. However, the provinces that had the highest prevalence of ESBL-producing Enterobacteriaceae also had the highest prevalence of use and purchase of antibiotics without a prescription. Thus, this study revealed that faecal carriage of ESBL-producing Enterobacteriaceae is very high in asymptomatic individuals in Thailand, with some variations among the provinces. This high prevalence may be linked to antibiotic abuse.

Use of procalcitonin (PCT) to guide discontinuation of antibiotic use in an unspecified sepsis is an antimicrobial stewardship program (ASP)

Clinicians have used procalcitonin (PCT) (biomarker to differentiate bacterial from non-bacterial sepsis) to guide use of antibiotics in patients. As the data for utility of PCT to discontinue antibiotics in an antimicrobial stewardship program (ASP) are lacking, we aim to describe the outcomes of patients in whom PCT was used to discontinue antibiotics under our ASP. An antimicrobial stewardship (AS) team intervened to discontinue antibiotics in patients with persistent fever or leucocytosis, source of sepsis unknown or negative bacteriological cultures, who had completed an adequate course of antibiotic therapy and had a PCT of <0.5 μg/L. Main outcomes evaluated were 14-day re-infection, 30-day mortality and readmission. Antibiotic therapy was discontinued in 42 patients in 1 year. Unknown source of sepsis was found in 38% of the patients (including possible malignant fever) and culture-negative pneumonia was found in 21%. Two patients died of advanced cancer. One patient decided for comfort care and died one week later. One patient died due to a second episode of pneumonia 37 days after first PCT test. Six patients were readmitted within 30 days due to non-infectious causes. Three patients were readmitted due to culture-negative pneumonia. None had a 14-day re-infection. PCT used to discontinue antibiotics under our ASP did not compromise patients' outcome.

Gram-Negative and Gram-Positive Antibacterial Properties of the Whole Plant Extract of Willow Herb (Epilobium angustifolium)

The emergence of new pathogens and the increase in the number of multidrug-resistant strains in well-established pathogens during the past decade represent a growing public health concern globally. With the current lack of research and development of new antibiotics by large pharmaceutical companies due to poor financial returns, new alternatives need to be explored including natural herbal or plant-based extracts with reported antibacterial properties. Willow herb ( Epilobium angustifolium) preparations have been used in traditional aboriginal and folk medicine preparations externally as an antiphlogistic to treat prostate and gastrointestinal disorders and as an antiseptic to treat infected wounds. The authors hypothesized that a whole plant extract of willow herb would exhibit antimicrobial properties on a variety of both Gram-positive and gram-negative bacteria in culture. The authors found that, in comparison to growth controls, willow herb extract significantly inhibited the growth of Micrococcus luteus ( p < .01), Staphylococcus aureus ( p < .05), Escherichia coli ( p < .001), and Pseudomonas aeruginosa ( p < .001). They also found that willow herb extract inhibited the growth of bacteria in culture more effectively than vancomycin ( p < .05) or tetracycline ( p < .004). These results provide preliminary support for the traditional folkloric claim that the plant willow herb possesses antibacterial properties against a variety of gram-positive and gram-negative bacteria. Given that whole plant extract was utilized for this study, further investigations are warranted to determine which specific part of the plant (i.e., leaves, stem, roots, and flowers) possess the antibacterial properties.

Determinants of carriage of resistant Staphylococcus aureus among S. aureus carriers in the Indonesian population inside and outside hospitals

SUMMARY OBJECTIVES

To identify determinants of carriage of resistant Staphylococcus aureus in both hospitalized patients and individuals from the community in two urban centres in Indonesia.

METHODS

Staphylococcus aureus cultures and data on recent antibiotic use, demographic, socioeconomic, disease-related and healthcare-related variables were collected from 3995 community dwellers and hospitalized persons. Nasal S. aureus carriage was found in 362 persons (9.1%). Logistic regression analysis was performed to identify which variables were independently associated with carriage of resistant S. aureus.

RESULTS

The penicillins were the most frequently used antibiotics both in the community and in hospitalized patients. In the community, admission to a hospital was associated with carriage of S. aureus resistant to any of the tested antibiotics [odds ratio (OR) 2.5, 95% confidence interval (95% CI) 1.3-4.9] and any tetracycline resistance (OR 2.4, 95% CI 1.1-5.1). Having no symptoms was associated with less carriage of S. aureus with resistance to any of the tested antibiotics (OR 0.5, 95% CI 0.3-0.9) and any tetracycline resistance (OR 0.5, 95% CI 0.3-0.9). Crowding (OR 4.5, 95% CI 1.2-4.9) and low income (OR 8.9, 95% CI 1.8-43.9) were associated with multidrug resistance. In hospitalized patients, the use of penicillins was associated with resistance to any of the tested antibiotics (OR 3.9, 95% CI 1.4-11.6) and any tetracycline resistance (OR 3.7, 95% CI 1.1-12.0).

CONCLUSIONS

Antibiotic policies including proper diagnosis, treatment and drug delivery process should be made by healthcare providers in Indonesia to help limit the emergence of antibiotic resistance.

Antibiotic identification, use, and self-medication for respiratory illnesses among urban Latinos

PURPOSE

The purpose of this study was to describe the extent to which antibiotic and nonantibiotic medications commonly used for upper respiratory infections (URIs) were correctly identified by a sample of urban dwelling Latinas and the association of medication identification with antibiotic use and self-medication.

DATA SOURCES

One hundred women completed an interview and were asked to identify whether a list of 39 medications (17 antibiotics, 22 nonantibiotics) were antibiotics or not, whether anyone in the household had used the medication, their ages, and the source of the medication.

RESULTS

Overall, participants correctly identified 62% of nonantibiotics and 34% of antibiotics. Seventy three (73%) women in the study reported antibiotic use by at least one member of the household in the past year. Among users, self-medication was reported in 67.2% of antibiotics for adults, but in only 2.4% of children. There was no difference in antibiotic recognition between those who self-medicated and those who did not, but antibiotic self-medication was associated with a significantly lower recognition of nonantibiotics (p= .01).

IMPLICATIONS FOR PRACTICE

Measures to improve antibiotic utilization should address self-medication and consider the cultural and social context in which antibiotic use occurs.

Promises and pitfalls of recent advances in chemical means of preventing the spread of nosocomial infections by environmental surfaces

Hard, nonporous environmental surfaces in health care settings are now receiving due recognition for their role in the spread of several types of nosocomial pathogens. The corresponding increase in the means to decontaminate such surfaces to interrupt the spread of infections is leading to the marketing of a plethora of products and procedures, including the "green" variety, with varying claims of microbicidal activity, human and environmental safety, and materials compatibility. Limitations of the existing methods to assess environmental surface disinfectants and the regulations that govern their premarket registration make objective evaluations difficult. Label claims of many such products also do not reflect the realities of field use along with a strong tendency to focus on the "bug de jour." Furthermore, whereas wiping is often an integral part of environmental surface decontamination, products meant for the purpose are rarely assessed with the physical effect of wiping incorporated. Many "green" products possess neither the spectrum of microbicidal activity nor the speed of action essential for use in health care settings. In general, "self-sanitizing" surfaces being marketed actively these days require greater scrutiny for field-relevant microbicidal activity as well as the potential to enhance microbicide resistance. The widening use of environmental surface disinfectants is also raising concerns on their human and environmental safety at many levels along with the realization that routine surface disinfection procedures in health care settings are frequently inadequate and possibly counterproductive. All this points to an urgent review of the basic procedures for assessing existing and new environmental surface disinfectants for their microbicidal activity, label claims, registration requirements, overall safety, and routine practices of environmental surface decontamination.

Model or meal? Farm animal populations as models for infectious diseases of humans

In recent decades, theory addressing the processes that underlie the dynamics of infectious diseases has progressed considerably. Unfortunately, the availability of empirical data to evaluate these theories has not grown at the same pace. Although laboratory animals have been widely used as models at the organism level, they have been less appropriate for addressing issues at the population level. However, farm animal populations can provide empirical models to study infectious diseases at the population level.

Curbing the menace of antimicrobial resistance in developing countries

Several reports suggest that antimicrobial resistance is an increasing global problem; but like most pandemics, the greatest toll is in the less developed countries. The dismally low rate of discovery of antimicrobials compared to the rate of development of antimicrobial resistance places humanity on a very dangerous precipice. Since antimicrobial resistance is part of an organism's natural survival instinct, total eradication might be unachievable; however, it can be reduced to a level that it no longer poses a threat to humanity. While inappropriate antimicrobial consumption contributes to the development of antimicrobial resistance, other complex political, social, economic and biomedical factors are equally important. Tackling the menace therefore should go beyond the conventional sensitization of members of the public and occasional press releases to include a multi-sectoral intervention involving the formation of various alliances and partnerships. Involving civil society organisations like the media could greatly enhance the success of the interventions

Effect of intensive education on knowledge, attitudes, and practices regarding upper respiratory infections among urban Latinos

BACKGROUND

Although upper respiratory infections (URIs) take a major social and economic toll, little research has been conducted to assess the impact of educational interventions on knowledge, attitudes, and practices of community members regarding prevention and treatment of URIs, particularly among recently immigrated urban Latinos who may not be reached by the mainstream healthcare system.

OBJECTIVES

The objective of this study was to assess the impact of a culturally appropriate, home-based educational intervention on the knowledge, attitudes, and practices regarding prevention and treatment of URIs among urban Latinos.

METHODS

Using a pretest-posttest design, Spanish-language educational materials available from sources such as the Centers for Disease Control and Prevention were adapted based on feedback from community focus groups and provided to households during an in-person home visit every 2 months (generally three to four visits). Outcome data regarding knowledge, attitudes, and practices were collected in home-based interviews using an 85-item instrument adapted and pilot tested from three other validated instruments. Nonparametric and multiple linear regression analyses were used to summarize data and identify predictors of knowledge scores.

RESULTS

Four hundred twenty-two households had complete data at baseline and 6 months. Knowledge and attitude scores were improved significantly, and use of alcohol hand sanitizer and rates of influenza vaccine were increased significantly (all p <.01).

DISCUSSION

Although this home-based educational intervention was successful in improving knowledge, attitudes, and self-reported practices among urban Latinos regarding prevention and treatment of URIs, further research is needed to determine the cost-effectiveness of such a person-intensive intervention, the long-term outcomes, and whether less intensive interventions might be equally effective.

Antimicrobial resistance: international control strategies, with a focus on limited-resource settings

Microorganisms resistant to multiple anti-infective agents have increased worldwide. These organisms threaten both optimal care of patients with infection as well as the viability of current healthcare systems. In addition, antimicrobials are valuable resources that enhance both prevention and treatment of infections. As resistance diminishes this resource, it is a societal goal to minimise resistance and therefore to reduce forces that produce resistance. This review considers strategies for minimising resistance that are needed at several different levels of responsibility, ranging from the patient care provider to international agencies. It then describes responses that might be appropriate according to the resources available for control, focusing on limited-resource settings. Antimicrobial resistance represents an international concern. Response to this problem demands concerted efforts from multiple sectors both in developed and developing countries, as well as the strengthening of multinational/international partnerships and regulations. Both medical and public health agencies should be in the forefront of these efforts.

Characterization of the branched antimicrobial peptide M6 by analyzing its mechanism of action and in vivo toxicity

We analyzed functional activity of the antimicrobial peptide M6 in vitro and in vivo. The peptide was identified by our group by phage library selection, rational modification and synthesis in a tetrabranched form (Pini et al., Antimicrob. Agents Chemother. 2005; 49: 2665-72). We found that it binds lipopolysaccharide, causes perforation of cell membranes without destroying external cell morphology and strongly binds DNA. The latter feature suggests that it could inhibit metabolic pathways, blocking DNA replication and/or transcription. We also observed that M6 does not stimulate humoral immune response when repeatedly administered to animals. We also analyzed M6 toxicity when administered to animals by intraperitoneal or by intravenous injection, determining a preliminary LD50 (125 and 37.5 mg/kg, respectively), which suggested that M6 could be used in vivo. These features make the antimicrobial branched peptide M6 a promising candidate for the development of a new antibacterial drug.