Effect of antibiotic prescribing in primary care on meticillin-resistant Staphylococcus aureus carriage in community-resident adults: a controlled observational study

The Effect of Antibiotic Restriction Programs on Prevalence of Antimicrobial Resistance: A Systematic Review and Meta-Analysis

Background

In hospital settings, restriction of selected classes of antibiotics is usually believed to contribute to containment of resistance development. We performed a systematic review and meta-analysis to assess the effect of restricting the use of specific antibiotic classes on the prevalence of resistant bacterial pathogens.

Methods

We conducted a systematic literature search in Embase and PubMed/OVID MEDLINE. We included studies until June 4, 2020 in which a restrictive antibiotic policy was applied and prevalence of resistance and use of antibiotics were reported. We calculated the overall effect of antimicrobial resistance between postintervention versus preintervention periods using pooled odds ratios (ORs) from a mixed-effects model. We stratified meta-analysis by antibiotic-pathogen combinations. We assessed heterogeneity between studies using the I² statistic and sources of heterogeneity using meta-regression.

Results

We included 15 individual studies with an overall low quality of evidence. In meta-analysis, significant reductions in resistance were only observed with nonfermenters after restricting fluoroquinolones (OR = 0.77, 95% confidence interval [CI] = 0.62–0.97) and piperacillin-tazobactam (OR = 0.81, 95% CI = 0.72–0.92). High degrees of heterogeneity were observed with studies restricting carbapenem (Enterobacterales, I² = 70.8%; nonfermenters, I² = 81.9%), third-generation cephalosporins (nonfermenters, I² = 63.3%), and fluoroquiolones (nonfermenters, I² = 64.0%). Results were comparable when excluding studies with fewer than 50 bacteria. There was no evidence of publication bias for any of the antibiotic-pathogen combinations.

Conclusions

We could not confirm that restricting carbapenems or third-generation cephalosporins leads to decrease in prevalence of antibiotic resistance among Enterobacterales, nonfermenters, or Gram-positive bacteria in hospitalized patients. Nevertheless, reducing fluoroquinolone and piperacilline-tazobactam use may decrease resistance in nonfermenters.

Patient-related factors, antibiotic prescribing and antimicrobial resistance of the commensal Staphylococcus aureus and Streptococcus pneumoniae in a healthy population - Hungarian results of the APRES study

Background

Antimicrobial resistance (AMR) is an increasing public health problem worldwide.

We studied some patient-related factors that might influence the antimicrobial resistance.

and whether the volume of antibiotic prescribing of the primary care physicians correlate with the antibiotic resistance rates of commensal nasal Staphylococcus aureus and Streptococcus pneumoniae.

Methods

The socio-demographic questionnaires, the antibiotic prescription and resistance data of commensal nasal S. aureus and S. pneumoniae were collected in the 20 participating Hungarian practices of the APRES study.

Multivariate logistic regression analyses were performed on the patient-related data and the antimicrobial resistance of the S. aureus and S. pneumoniae on individual, patient level.

Ecological analyses were performed with Spearman’s rank correlations at practice level, the analyses were performed in the whole sample (all practices) and in the cohorts of primary care practices taking care of adults (adult practices) or children (paediatric practices).

Results

According to the multivariate model, age of the patients significantly influenced the antimicrobial resistance of the S. aureus (OR = 0.42, p = 0.004) and S. pneumoniae (OR = 0.89, p < 0.001). Living with children significantly increased the AMR of the S. pneumoniae (OR = 1.23, p = 0.019). In the cohorts of adult or paediatric practices, neither the age nor other variables influenced the AMR of the S. aureus and S. pneumoniae.

At practice level, the prescribed volume of penicillins significantly correlated with the resistance rates of the S. aureus isolates to penicillin (rho = 0.57, p = 0.008). The volume of prescribed macrolides, lincosamides showed positive significant correlations with the S. pneumoniae resistance rates to clarithromycin and/or clindamycin in all practices (rho = 0.76, p = 0.001) and in the adult practices (rho = 0.63, p = 0.021).

Conclusions

The age is an important influencing factor of antimicrobial resistance. The results also suggest that there may be an association between the antibiotic prescribing of the primary care providers and the antibiotic resistance of the commensal S. aureus and S. pneumoniae. The role of the primary care physicians in the appropriate antibiotic prescribing is very important to avoid the antibiotic resistance.

Using theory to explore facilitators and barriers to delayed prescribing in Australia: a qualitative study using the Theoretical Domains Framework and the Behaviour Change Wheel

BACKGROUND

Delayed antibiotic prescribing reduces antibiotic use for acute respiratory infections in trials in general practice, but the uptake in clinical practice is low. The aim of the study was to identify facilitators and barriers to general practitioners' (GPs') use of delayed prescribing and to gain pharmacists' and the public's views about delayed prescribing in Australia.

METHODS

This study used the Theoretical Domains Framework and the Behaviour Change Wheel to explore facilitators and barriers to delayed prescribing in Australia. Forty-three semi-structured, face-to-face interviews with general practitioners, pharmacists and patients were conducted. Responses were coded into domains of the Theoretical Domains Framework, and specific criteria from the Behaviour Change Wheel were used to identify which domains were relevant to increasing the use of delayed prescribing by GPs.

RESULTS

The interviews revealed nine key domains that influence GPs' use of delayed prescribing: knowledge; cognitive and interpersonal skills; memory, attention and decision-making processes; optimism; beliefs about consequences; intentions; goals; emotion; and social influences: GPs knew about delayed prescribing; however, they did not use it consistently, preferring to bring patients back for review and only using it with patients in a highly selective way. Pharmacists would support GPs and the public in delayed prescribing but would fill the prescription if people insisted. The public said they would delay taking their antibiotics if asked by their GP and given the right information on managing symptoms and when to take antibiotics.

CONCLUSIONS

Using a theory-driven approach, we identified nine key domains that influence GPs' willingness to provide a delayed prescription to patients with an acute respiratory infection presenting to general practice. These data can be used to develop a structured intervention to change this behaviour and thus reduce antibiotic use for acute respiratory infections in general practice.

Methicillin-resistant Staphylococcus aureus nasal carriage among primary school-aged children from Jordan: prevalence, antibiotic resistance and molecular characteristics

BACKGROUND AND AIM

Colonization with methicillin-resistant Staphylococcus aureus (MRSA) increases the risk for subsequent infections with an increased mortality and morbidity. Children were suggested to be a major asymptomatic reservoir for community-associated (CA) MRSA with an ability to quickly spread the MRSA within community. Therefore, the availability of epidemiological and antibiotic susceptibility data of CA-MRSA will be useful for the infection control and management policies. This study aimed to assess the nasal carriage, molecular characteristics and antibiotic susceptibility of MRSA in primary school-aged children from Jordan.

PATIENTS AND METHODS

A total of 210 nasal swabs were collected from children aged 6-11 years. Isolated MRSA and its SCCmec typing, Spa type and PVL (Panton-Valentine Leukociden) toxin were identified following culture, biochemical and PCR. Antibiogram was determined by the disc diffusion method.

RESULTS

The prevalence of CA-MRSA was 7.1%. Allergic rhinitis and recent antibiotic exposure were the only significant risk factors for MRSA nasal carriage among children. Resistance to erythromycin, trimethoprim-sulfamethoxazole and tetracycline was 33.4, 20 and 13.4%, respectively. All isolates were susceptible to the remaining non-β-lactam antibiotics used in this study, in particular linezolid and mupirocin. All MRSA isolates were SCCmec type IV and PVL toxin negative and the majority were Spa type t223.

CONCLUSION AND RECOMMENDATIONS

This is the first study to assess the MRSA prevalence among children aged 6-11 years in Jordan. The prevalence in community children is within the range compared with other studies in other countries. The antibiogram, SCCmec and Spa types of the isolated MRSA are much similar to what was found previously in Jordan. However, all isolates were PVL toxin negative. The study recommends increasing the public awareness of MRSA and the proper antibiotics dispensing. Future studies to follow-up on the changing epidemiology of the CA-MRSA in Jordan are also recommended.

Methicillin-Resistant Staphylococcus aureus Nasal Colonization in Chinese Children: A Prevalence Meta-Analysis and Review of Influencing Factors

OBJECTIVE

To determine the pooled prevalence and review the influencing factors of methicillin-resistant Staphylococcus aureus (MRSA) nasal colonization in Chinese children.

METHODS

Articles published between January 2005 and October 2015 that studied prevalence or influencing factors of MRSA nasal colonization in Chinese children were retrieved from Chinese Biomedical Literature database (CBM), China National Knowledge Infrastructure (CNKI) database, Chinese VIP database, Chinese Wanfang database, Medline database and Ovid database. Prevalence and influencing factors were analyzed by STATA 13.1.

RESULTS

Thirteen articles were included. The overall prevalence of MRSA nasal colonization was 4.4% (95% confidence interval [CI]: 0.027-0.062). With an MRSA prevalence of 3.9% (95% CI: 0.018-0.061) in healthy children and 5.8% (95% CI: 0.025-0.092) in children with underlying medical conditions. Children recruited in the hospitals presented MRSA prevalence of 6.4% (95% CI: 0.037-0.091), which was higher than those recruited in the communities [2.7% (95% CI: 0.012-0.043)]. A number of influencing factors for MRSA nasal colonization were noted in three eligible studies: gender (male vs female; OR: 0.67; 95% CI: 0.55-0.82), younger age (OR: 2.98; 95% CI: 1.31-6.96 and OR: 1.56; 95% CI: 1.21-2.00), attending day care centers (OR: 2.97; 95% CI: 1.28-6.76), having infectious diseases (OR: 2.31; 95% CI: 1.10-4.52), using antibiotics (OR: 2.77; 95% CI: 1.45-5.05), residing in northern Taiwan (OR: 1.41; 95% CI: 1.15-1.71), passive smoking (OR: 1.30; 95% CI: 1.02-1.63), and pneumococcal vaccination (OR: 1.22; 95% CI: 1.01-1.48).

CONCLUSIONS

Children could act as reservoirs of MRSA transmissions. Hospitals remained the most frequent microorganism-circulated settings. More MRSA infection control strategies are required to prevent the dissemination among children.

Tobacco Smoking as a Risk Factor for Increased Antibiotic Prescription

INTRODUCTION

Antibiotic resistance is rapidly spreading, affecting millions of people and costing billions of dollars. Potential factors affecting antibiotic prescription, such as tobacco use, could dramatically influence this public health crisis. The study determined the magnitude of impact that tobacco use has on antibiotic prescribing patterns.

METHODS

Pooled data were analyzed in 2015 from the 2006-2010 National Ambulatory Medical Care Survey, a cross-sectional survey describing use of ambulatory medical services in the U.S. via healthcare provider-patient encounters. Patients aged >18 years with documented tobacco use status diagnosed with an infection were included (i.e., all encounters in the analysis included an infectious diagnosis of interest). The analytic sample included 8,307 visits, representing 294 million visits nationally.

RESULTS

Half (49.9%) of encounters that included any infection had an antibiotic prescribed. Adjusted odds of receiving antibiotics among current tobacco users was 1.20 (95% CI=1.02, 1.42), and even higher for encounters of respiratory infections (AOR=1.31, 95% CI=1.05, 1.62). Antibiotic prescription rates were lower among patients aged >65 years, those with comorbid asthma or cancer, non-whites, and those covered by Medicaid and higher for primary care physicians.

CONCLUSIONS

Despite lack of evidence-based rationale, among a national sample of patients with an infectious diagnosis, tobacco users had 20%-30% higher odds of receiving antibiotics than non-tobacco users. This is the first U.S. study to quantify the magnitude of this unsubstantiated practice. Prescribers should understand that tobacco use could be associated with higher antibiotic prescription, which may subsequently increase antimicrobial resistance in the community.

Prevalence and resistance patterns of commensal S. aureus in community-dwelling GP patients and socio-demographic associations. A cross-sectional study in the framework of the APRES-project in Austria

BACKGROUND

The aim of the present study was to assess the prevalence and resistance of commensal S. aureus in the nasal microbiota of community-dwelling persons in Austria, as well as to identify possible associations with socio-demographic factors. Multi-drug resistance in this population was additionally studied.

METHOD

This cross-sectional study was conducted within the context of the European APRES project. In nine European countries, nasal swabs were collected from 32,206 general practice patients who received care for non-infectious reasons. In Austria, 20 GPs attempted to recruit 200 consecutive patients without infectious diseases, with each patient completing demographic questionnaires as well as providing a nose swab sample. Isolation, identification, and resistance testing of S. aureus were performed. Statistical analyses included subgroup analyses and logistic regression models.

RESULTS

3309 nose swabs and corresponding questionnaires from Austrian subjects were analyzed. S. aureus was identified in 16.6 % (n = 549) of nose swabs, of which 70.1 % were resistant against one or more antibiotics, mainly penicillin. S. aureus carrier status was significantly associated with male sex (OR 1.6; 1.3-2.0), younger age (OR 1.3; 1.0-1.8), living in a rural area (OR 1.4; 1.1-1.7) and working in the healthcare sector (OR 1.5; 1.0-2.1). Multi-drug resistances were identified in 13.7 % (n = 75) of the S. aureus carriers and 1.5 % (n = 8) tested positive for MRSA. The highest resistance rate was observed against penicillin (64.8 %), followed by azithromycin (13.5 %) and erythromycin with 13.3 %.

CONCLUSION

This study describes the prevalence and resistance patterns of commensal S. aureus in community-dwelling persons in Austria and shows that differences exist between socio-demographic groups. Demographic associations have been found for S. aureus carriers but not for carriers of resistant S. aureus strains. Only two thirds of S. aureus strains were found to be resistant against small spectrum penicillin. As it is recognized that one of the corner stones for the containment of antibiotic resistance is the appropriate prescription of antibiotics in the outpatient sector, this finding lends support to the avoidance of prescription of broad-spectrum antibiotics to treat S. aureus infections in the community.

[Prevalence of nasal carriage of Staphylococcus aureus and Streptococcus pneumoniae in Primary Care and factors associated with colonization]

OBJECTIVE

To determine (i) the prevalence of Staphylococcus aureus (S.aureus) and Streptococcus pneumoniae (S.pneumoniae) nasal carriage in Primary Health Care patients in area of Barcelona, and (ii) the factors associated with S.aureus and S.pneumoniae colonization.

METHODS

Multi-center cross-sectional study conducted in 2010-2011 with the participation of 27 Primary Health Care professionals. Nasopharyngeal swabs were obtained from 3,969 patients over 4 years of age who did not present with any sign of infection.

DEPENDENT VARIABLES

S.aureus and/or S.pneumoniae carrier state.

INDEPENDENT VARIABLES

socio-demographic characteristics, health status, vaccination status, occupation, and living with children. A descriptive analysis was performed. The prevalence of carriers of S.aureus and/or S.pneumoniae was calculated and logistic regression models were adjusted by age.

RESULTS

In children from 4 to 14 years old, the prevalence of S.aureus carriers was 35.7%, of S.pneumoniae 27.1%, and 5.8% were co-colonized. In adults older than 14 years old, the prevalence was 17.8%, 3.5%, and 0.5%, respectively. In children, S.aureus carrier state was inversely associated with S.pneumoniae carrier state; S.pneumoniae was associated with younger age, and inversely associated with S.aureus carrier state. In adults, being a carrier of S.aureus was associated with male gender, younger age, and a health-related occupation, whereas S.pneumoniae carrier state was associated with living with children under 6 years of age. The proportion of co-colonized carriers was low (1.0%).

CONCLUSIONS

The proportion of S.aureus and S.pneumoniae carriers was higher in children than in adults. Age was the only factor associated with healthy carrier status for S.aureus and for S.pneumoniae.

Molecular epidemiology of nasal isolates of methicillin-resistant Staphylococcus aureus from Jordan

Asymptomatic carriage of methicillin-resistant Staphylococcus aureus (MRSA) can predispose the host to a wide range of infections. To inform public health strategies, this study sought to determine the prevalence and the phenotypic and genotypic characteristics of MRSA from nasal swabs of health care workers (HCWs) and other healthy individuals in Jordan. Overall, 716 nasal swabs were collected from 297 HCWs, 141 adults and 278 children in the community. MRSA was recovered from 56 (7.8%) nasal swabs, which represented carriage rates of 10.1%, 4.3% and 7.2% among HCWs, adults and children, respectively. The MRSA isolates were resistant to oxacillin (100%), erythromycin (42.8%), tetracycline (37.5%), clindamycin (5.3%), fucidin (5.3%), and ciprofloxacin (3.5%). A total of 17 different spa types belonging to eight different clonal complexes (CCs) were identified. All isolates were mecA positive, and mecC-MRSA was not detected. Analysis of the staphylococcal cassette chromosome mec (SCCmec) elements revealed that the majority (54; 96.4%) of the samples harbored the smaller type IV and V elements (the most common were SCCmec IVa or IVc, and there were two each of the IVg and V elements), and two were nontypable. The genes for Panton-Valentine leukocidin (luk-PV) were detected in 5.4% of the study isolates. A tst-positive, CC22-MRSA-SCCmecIVa clone (spa type t223) was identified as the dominant MRSA lineage among the nasal carriage isolates from both HCWs and other individuals (adults and children) in the community. These findings provide important information for public health personnel for the formulation of effective infection prevention and control strategies. Studies to further our understanding of the distribution, pathogenicity, transmissibility and fitness of this lineage would be prudent.

Risk factors for methicillin resistant Staphylococcus aureus: a multi-laboratory study

Background

The present study aimed to investigate the dose response relationship between the prescriptions of antimicrobial agents and infection/colonization with methicillin resistant Staphylococcus aureus (MRSA) taking additional factors like stay in a health care facility into account.

Methods

Multi-centre retrospective study on a cohort of patients that underwent microbiological diagnostics in Belgium during 2005. The bacteriological results retrieved from 17 voluntary participating clinical laboratories were coupled with the individual antimicrobial consumption patterns (July 2004-December 2005) and other variables as provided by pooled data of health insurance funds. Multivariate analysis was used to identify risk factors for MRSA colonization/infection.

Results

A total of 6844 patients of which 17.5% died in the year 2005, were included in a logistic regression model. More than 97% of MRSA was associated with infection (clinical samples), and only a minority with screening/colonization (1.59%). Factors (95% CI) significantly (p≤<0.01) associated with MRSA in the final multivariate model were: admission to a long term care settings (2.79–4.46); prescription of antibiotics via a hospital pharmacy (1.30–2.01); age 55+ years (3.32–5.63); age 15–54 years (1.23–2.16); and consumption of antimicrobial agent per DDD (defined daily dose) (1.25–1.40).

Conclusions

The data demonstrated a direct dose-response relationship between MRSA and consumption of antimicrobial agents at the individual patient level of 25–40% increased risk per every single day. In addition the study indicated an involvement of specific healthcare settings and age in MRSA status.

Antibiotic Prescribing in Primary Care and Antimicrobial Resistance in Patients Admitted to Hospital with Urinary Tract Infection: A Controlled Observational Pilot Study

There is growing evidence that primary care prescribed antibiotics lead to antibiotic resistance in bacteria causing minor infections or being carried by asymptomatic adults, but little research to date has investigated links between primary care prescribed antibiotics and resistance among more serious infections requiring hospital care. Knowledge of these effects is likely to have a major influence on public expectations for, and primary care use of, antibiotics. This study aimed to assess the feasibility of recruiting symptomatic adult patients admitted to hospital with urinary infections and to link primary and secondary data information to investigate the relationship between primary care prescribed antibiotics and antimicrobial resistance in these patients. A microbiology database search of in patients who had submitted a urine sample identified 740 patients who were potentially eligible to take part in the study. Of these, 262 patients did not meet the eligibility criteria, mainly due to use of a urinary catheter (40%). Two-hundred and forty three patients could not be recruited as the nurse was unable to visit the patients prior to discharge, as they were too unwell. Eighty patients provided complete information. Results indicate that there is evidence that prior antibiotic use is associated with resistant infections in hospital patients. A fully powered study, conducted using routinely collected data is proposed to fully clarify the precision of the association.

Detection and clinical relevance of Staphylococcus aureus nasal carriage: an update

Staphylococcus aureus nasal carriage is a well-defined risk factor of infection with this bacterium. The increased risk of S. aureus infection in nasal carriers is supported by the fact that the strains isolated from both colonization and infection sites are indistinguishable in most of the cases. Persistent nasal carriage seems to be associated with an increased risk of infection and this status could be defined now in clinical routine by using one or two quantitative nasal samples. There is evidence for supporting the detection of nasal carriage of S. aureus in patients undergoing cardiac surgery and in those undergoing hemodialysis in order to implement decolonization measures. More studies are needed to determine which carriers have the highest risk of infection and why decolonization strategies failed to reduce S. aureus infection in some other groups of patients.

All purulence is local - epidemiology and management of skin and soft tissue infections in three urban emergency departments

BACKGROUND

Skin and soft tissue infection (SSTIs) are commonly treated in emergency departments (EDs). While the precise role of antibiotics in treating SSTIs remains unclear, most SSTI patients receive empiric antibiotics, often targeted toward methicillin-resistant Staphylococcus aureus (MRSA). The goal of this study was to assess the efficiency with which ED clinicians targeted empiric therapy against MRSA, and to identify factors that may allow ED clinicians to safely target antibiotic use.

METHODS

We performed a retrospective analysis of patient visits for community-acquired SSTIs to three urban, academic EDs in one northeastern US city during the first quarter of 2010. We examined microbiologic patterns among cultured SSTIs, and relationships between clinical and demographic factors and management of SSTIs.

RESULTS

Antibiotics were prescribed to 86.1% of all patients. Though S. aureus (60% MRSA) was the most common pathogen cultured, antibiotic susceptibility differed between adult and pediatric patients. Susceptibility of S. aureus from ED SSTIs differed from published local antibiograms, with greater trimethoprim resistance and less fluoroquinolone resistance than seen in S. aureus from all hospital sources. Empiric antibiotics covered the resultant pathogen in 85.3% of cases, though coverage was frequently broader than necessary.

CONCLUSIONS

Though S. aureus remained the predominant pathogen in community-acquired SSTIs, ED clinicians did not accurately target therapy toward the causative pathogen. Incomplete local epidemiologic data may contribute to this degree of discordance. Future efforts should seek to identify when antibiotic use can be narrowed or withheld. Local, disease-specific antibiotic resistance patterns should be publicized with the goal of improving antibiotic stewardship.

Impact of an enhanced antibiotic stewardship on reducing methicillin-resistant Staphylococcus aureus in primary and secondary healthcare settings

The objective of this study was to evaluate the impact of restricting high-risk antibiotics on methicillin-resistant Staphylococcus aureus (MRSA) incidence rates in a hospital setting. A secondary objective was to assess the impact of reducing fluoroquinolone use in the primary-care setting on MRSA incidence in the community. This was an interventional, retrospective, ecological investigation in both hospital and community (January 2006 to June 2010). Segmented regression analysis of interrupted time-series was employed to evaluate the intervention. The restriction of high-risk antibiotics was associated with a significant change in hospital MRSA incidence trend (coefficient=-0·00561, P=0·0057). Analysis showed that the intervention relating to reducing fluoroquinolone use in the community was associated with a significant trend change in MRSA incidence in community (coefficient=-0·00004, P=0·0299). The reduction in high-risk antibiotic use and fluoroquinolone use contributed to both a reduction in incidence rates of MRSA in hospital and community (primary-care) settings.

MRSA nasal colonization in children: prevalence meta-analysis, review of risk factors and molecular genetics

BACKGROUND

We report a meta-analysis of methicillin-resistant Staphylococcus aureus (MRSA) nasal colonization prevalence in children and a review of the risk factors as well as molecular genetic characterization.

METHODS

All relevant studies reporting prevalence data on MRSA nasal colonization in children published between January 2000 and August 2010 were retrieved from the MEDLINE database and analyzed.

RESULTS

After screening 544 studies, 50 studies were included. We obtained an estimate of MRSA prevalence of 2.7% (95% confidence interval [CI]: 2.2-3.1); of 5.2% (95% CI: 3.1-7.3) in children with underlying conditions and of 2.3% (95% CI: 1.8-2.7) in healthy children; 5.4% (95% CI: 3.1-7.7) in children recruited in hospitals and 3% (95% CI: 2.4-3.6) in children recruited in the community. Staphylococcal cassette chromosome mec type IV is the most diffused cassette globally.

CONCLUSION

The hospital remains the environment where the microorganism circulates most. Children with underlying conditions could act as vectors of microorganisms between the hospital and the community. MRSA prevention strategies should be tailored to each specific institution, taking into account the nosocomial prevalence of MRSA nasal colonization and infections, and the prevalence of nasal colonization in the community that refers to the specific health care center.

Prevalence and resistance of commensal Staphylococcus aureus, including meticillin-resistant S aureus, in nine European countries: a cross-sectional study

BACKGROUND

Information about the prevalence of Staphylococcus aureus resistance to antimicrobial drugs has mainly been obtained from invasive strains, although the commensal microbiota is thought to be an important reservoir of resistance. We aimed to compare the prevalence of nasal S aureus carriage and antibiotic resistance, including meticillin-resistant S aureus (MRSA), in healthy patients across nine European countries.

METHODS

In this cross-sectional study, nasal swabs were obtained from 32,206 patients recruited by family doctors participating in existing nationwide family doctor networks in Austria, Belgium, Croatia, France, Hungary, Spain, Sweden, the Netherlands, and the UK. Eligible patients were aged 4 years or older (≥ 18 years in the UK) and presented with a non-infectious disorder. Swabs were sent to national microbiological laboratories for identification and isolation of S aureus. Antibiotic resistance testing was done at one central microbiological laboratory. We established the genotypic structure of the isolated MRSA strains with the spa typing method.

FINDINGS

S aureus was isolated from 6956 (21 · 6%) of 32,206 patients swabbed. The adjusted S aureus prevalence for patients older than 18 years ranged from 12 · 1% (Hungary) to 29 · 4% (Sweden). Except for penicillin, the highest recorded resistance rate was to azithromycin (from 1 · 6% in Sweden to 16 · 9% in France). In total, 91 MRSA strains were isolated, and the highest MRSA prevalence was reported in Belgium (2 · 1%). 53 different spa types were detected-the most prevalent were t002 (n = 9) and t008 (n = 8).

INTERPRETATION

The prevalence of S aureus nasal carriage differed across the nine European countries assessed, even after correction for age, sex, and family doctor. Generally, the prevalence of resistance, including that of MRSA, was low. The MRSA strains recorded showed genotypic heterogeneity, both within and between countries.

FUNDING

European Commission, 7th Framework Programme(grant agreement 223083).

Relationship and susceptibility profile of Staphylococcus aureus infection diabetic foot ulcers with Staphylococcus aureus nasal carriage

BACKGROUND

Staphylococcus aureus is the main cause of diabetic foot infection with the patient's endogenous flora as the principal source. Nasal carriage of S. aureus has been identified as an important risk factor for the acquisition of diabetic foot infections.

OBJECTIVES

The study assessment the associations of S. aureus with methicillin resistant S. aureus were isolation from diabetic foot infection and nasal carriage of the same patients and their antibiotic susceptibility profile.

METHODS

Diagnosis of S. aureus and methicillin resistant S. aureus were carried out by using standard procedures. Antibiotic sensitivity profiles were determent by breakpoint dilution method.

RESULTS

Out of 222 S. aureus isolation, 139 (62.61%) were isolated from the diabetic foot and 83 (37.39%) from the nasal carriage. Seventy one (30.87%) of the patients were S. aureus infection diabetic foot with nasal carriage. Among diabetic foot infection and nasal carriage patients, 40.85% of S. aureus were considered as methicillin resistant S. aureus. Rifampicin (96.40%) and Levofloxacin (91.44%) were active against S. aureus.

CONCLUSION

Patients at strong risk for methicillin resistant S. aureus nasal carriage and subsequent diabetic foot infection with high resistance to antibiotics.

Antimicrobial agent exposure and the emergence and spread of resistant microorganisms: issues associated with study design

Antibiotics are essential agents that have greatly reduced human mortality due to infectious diseases. Their use, and sometimes overuse, have increased over the past several decades in humans, veterinary medicine and agriculture. However, the emergence of resistant pathogens is becoming an increasing problem that could result in the re-emergence of infectious diseases. Antibiotic prescription in human medicine plays a key role in this phenomenon. Under selection pressure, resistance can emerge in the commensal flora of treated individuals and disseminate to others. However, even if the effects of antimicrobial use on resistance is intuitively accepted, scientific rationales are required to convince physicians, legislators and public opinion to adopt appropriate behaviours and policies. With this review, we aim to provide an overview of different epidemiological study designs that are used to study the relationship between antibiotic use and the emergence and spread of resistance, as well as highlight their main strengths and weaknesses.