Persistence of antimicrobial resistance in respiratory streptococci

Abstract

A B S T R A C TObjectives: To assess whether persistence of antimicrobial resistance (i.e. non-susceptible resistance status) after treatment with penicillins or cephalosporins versus macrolides or tetracyclines differs and to compare the results obtained using routinely collected data with findings reported in prospective studies. Methods: Routinely collected microbiological data from 14 voluntary participating laboratories (2005) containing information on resistance status and individual antimicrobial consumption patterns (mid 2004-2005) were analysed using a generalised estimating equation (GEE) approach. The link function was adjusted to acknowledge that the proportion of resistant isolates in the population not treated with antibiotics [baseline resistance (BR)] is not necessarily zero. To optimise the comparability of this study with prospective studies, the analysis was repeated after removal of 14 isolates from patients who did not survive 2005. Results: BR estimates were unstable and their confidence intervals were wide, which called for a sensitivity analysis using an adjusted GEE model with three different BR estimates. All models indicated that the proportion of susceptible isolates differed by treatment group and increased significantly over time, with this increase being independent of treatment group. Persistence of resistance after exposure to macrolides or tetracyclines was approximately three times as long as after exposure to penicillins or cephalosporins. Conclusions: Resistance following treatment with macrolides or tetracyclines persists longer than following treatment with penicillins or cephalosporins, which confirms the findings from prospective studies and suggests the use of routinely collected data as a valuable alternative to determine such differences in persistence of resistance.

Characteristics of the antibiotic regimen that affect antimicrobial resistance in urinary pathogens

“…This is in line with similar observations in other bacteria [ 8 ]. The effect of number of days between the sample and the last prescription (log(time)) was significant and negative; indicating that probability of resistance is higher in the days after the treatment and decreases over time, confirming earlier findings in bacteria retrieved from the respiratory tract [ 28 ]. We further observed a high variability in ARI across participating laboratories and this demands further research in terms of validation of antimicrobial resistance surveillance.…”

“…Also patients not receiving antibiotics were excluded in the current study design. The latter information could be used to assess a baseline level of resistance as our study group earlier explored for the respiratory tract system [ 28 ]. Since also antimicrobial agents prescribed for indications other that urinary tract infections were included in the analysis it seems reasonable to conclude that resistance selection pressures are not restricted to one organ system, given the potential effect of antimicrobial agents on the digestive tract [ 14 ] and thereby indirectly on organisms shed by stool that can cause urinary tract infections.…”

Disease-Specific Quality Indicators for Outpatient Antibiotic Prescribing for Respiratory Infections (ESAC Quality Indicators) Applied to Point Prevalence Audit Surveys in General Practices in 13 European Countries

“…Macrolides remain commonly prescribed for the treatment of RTIs, but the development of widespread macrolide resistance has limited their use [ 19 ]. In addition, macrolide resistance persists much longer compared to amoxicillin resistance, which is another reason to encourage amoxicillin prescribing, if prescribing is indicated [ 20 , 21 ]. Similarly, even though amoxicillin-clavulanic acid is commonly prescribed for RTI, due to its popularity and rising resistance, many countries now discourage the use of amoxicillin-clavulanic acid [ 22 , 23 , 24 ].…”