Background In the early 1990s there was an increase in erythromycin resistance among group A streptococci in Finland. In response, policies regarding outpatient antibiotic therapy were changed, and nationwide recommendations were issued that called for reductions in the use of macrolide antibiotics for respiratory and skin infections in outpatients. We studied the effect of this policy on the pattern of erythromycin resistance throughout Finland. Methods From 1991 through 1996, a total of 39,247 group A streptococcal isolates from throat swabs (82 percent of the isolates) and pus samples (18 percent) and 290 isolates from blood cultures were studied in regional microbiology laboratories. The susceptibility of the isolates to erythromycin was tested by the disk-diffusion or the screening-plate method. Results Consumption of macrolide antibiotics decreased from 2.40 defined daily doses per 1000 inhabitants per day in 1991 to 1.38 in 1992 (P = 0.007) and remained near the lower level during the study period....

The Effect of Changes in the Consumption of Macrolide Antibiotics on Erythromycin Resistance in Group A Streptococci in Finland

Background Penicillin-resistant strains of Streptococcus pneumoniae are now found worldwide, and strains with resistance to cephalosporin are being reported. The appropriate antibiotic therapy for pneumococcal pneumonia due to resistant strains remains controversial. Methods To examine the effect of resistance to penicillin and cephalosporin on mortality, we conducted a 10-year, prospective study in Barcelona of 504 adults with culture-proved pneumococcal pneumonia. Results Among the 504 patients, 145 (29 percent) had penicillin-resistant strains of S. pneumoniae (minimal inhibitory concentration [MIC] of penicillin G, 0.12 to 4.0 μg per milliliter), and 31 patients (6 percent) had cephalosporin-resistant strains (MIC of ceftriaxone or cefotaxime, 1.0 to 4.0 μg per milliliter). Mortality was 38 percent in patients with penicillin-resistant strains, as compared with 24 percent in patients with penicillin-sensitive strains (P = 0.001). However, after the exclusion of patients with polymicrobial pneumonia an...

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Resistance to penicillin and cephalosporin and mortality from severe pneumococcal pneumonia in Barcelona, Spain.

From 1995 to 2000, a total of 673 Enterococcus faecium and 1,088 Enterococcus faecalis isolates from pigs together with 856 E. faecium isolates from broilers were isolated and tested for susceptibility to four classes of antimicrobial agents used for growth promotion as part of the Danish program of monitoring for antimicrobial resistance. The four antimicrobials were avilamycin, erythromycin, vancomycin, and virginiamycin. Major changes in the use of antimicrobial agents for growth promotion have occurred during the last 6 years in Denmark. The government banned the use of avoparcin in 1995 and of virginiamycin in 1998. Furthermore, the producers have voluntarily stopped all use beginning in 1999. The avoparcin ban in 1995 was followed by a decrease in the occurrence of glycopeptide-resistant E. faecium (GRE) in broilers, from 72.7% in 1995 to 5.8% in 2000. The occurrence of glycopeptide resistance among isolates from pigs remained constant at around 20% from 1995 to 1997. It was shown that, in GRE from pigs, the genes encoding macrolide and glycopeptide resistance were genetically linked and that, following the decrease in the use of tylosin during 1998 and 1999, the occurrence of GRE in pigs decreased to 6.0% in 2000. From 1995 to 1997 the occurrence of erythromycin resistance among E. faecium and E. faecalis isolates from pigs was almost 90%. Use of tylosin decreased considerably during 1998 and 1999, and this decrease was followed by decreases in the occurrence of resistance to 46.7 and 28.1% among E. faecium and E. faecalis isolates from pigs, respectively. Erythromycin resistance among E. faecium isolates from broilers reached a maximum of 76.3% in 1997 but decreased to 12.7% in 2000 concomitantly with more limited use of virginiamycin. Use of virginiamycin increased from 1995 to 1997 and was followed by an increased occurrence of virginiamycin resistance among E. faecium isolates in broilers, from 27.3% in 1995 to 66.2% in 1997. In January 1998 the use of virginiamycin was banned in Denmark, and the occurrence of virginiamycin resistance decreased to 33.9% in 2000. Use of avilamycin increased from 1995 to 1996 and was followed by an increase in avilamycin resistance among E. faecium isolates from broilers, from 63.6% in 1995 to 77.4% in 1996. Since 1996 avilamycin usage has decreased, followed by a decrease in resistance to 4.8% in 2000. Our observations show that it is possible to reduce the occurrence of antimicrobial resistance in a national population of food animals when the selective pressure is removed. Cases in which resistance to vancomycin was linked to resistance to erythromycin were exceptions. In such cases resistance did not decrease until the use of both avoparcin and tylosin was limited.

http://www.ouvertures.net/wp-content/uploads/AAC_01_45_2054.pdf

Effect of Abolishment of the Use of Antimicrobial Agents for Growth Promotion on Occurrence of Antimicrobial Resistance in Fecal Enterococci from Food Animals in Denmark

Context.—The spread of drug-resistant Streptococcus pneumoniae in the community is a public health problem in developed and developing
nations, but whether antibiotic use is responsible for the increase in drug
resistance is not known.Objective.—To analyze the relationship between penicillin-resistant S pneumoniae (PR Sp) pharyngeal carriage and
characteristics of β-lactam use.Design.—Observational study of children attending 20 randomly sampled schools.Setting.—The Loiret, in the center of France.Participants.—A total of 941 children, 3 to 6 years old.Main Outcome Measure(s).—Pharyngeal carriage of S pneumoniae, antibiotic
use, and medical events during the preceding 30 days. Pneumococcal penicillin
G sodium minimal inhibitory concentrations and serotyping were performed.Results.—Medical illnesses and the use of antibiotics were not associated with
PR Sp carriage. However, oral β-lactam use was
associated with an increased risk of PR Sp carriage
(odds ratio [OR], 3.0; 95% confidence interval [CI], 1.1-8.3; P=.03). Children treated by low daily doses of an oral β-lactam
(defined as lower than clinical recommendations) had an increased risk of
PR Sp carriage, as compared with children who did
not (OR, 5.9; 95% CI, 2.1-16.7; P =.002). A treatment
of long duration (>5 days) with a β-lactam was associated with an increased
risk of PR Sp carriage (OR, 3.5; 95% CI, 1.3-9.8; P=.02).Conclusions.—Our results suggest that a low daily dose and a long duration of treatment
with an oral β-lactam contribute to the selective pressure in promoting
pharyngeal carriage of PR Sp.

https://jamanetwork.com/journals/jama/articlepdf/187207/joc6b29.pdf

Low Dosage and Long Treatment Duration of β-Lactam: Risk Factors for Carriage of Penicillin-Resistant Streptococcus pneumoniae

The resistance of Streptococcus pneumoniae to penicillin and other antimicrobial agents is increasing in many parts of the world. The frequency of erythromycin resistance in parts of Europe1 and, to a lesser extent, in the United States2 limits the usefulness of macrolide antibiotics for the treatment of pneumonia, and resistance to trimethoprim-sulfamethoxazole, chloramphenicol, and tetracycline is an important problem in some other countries3,4. Recently, resistance to and clinical failure of the extended-spectrum cephalosporins ceftriaxone and cefotaxime in the treatment of pneumococcal meningitis have been noted in Spain5,6 and the United States7,8. In addition, there have . . .

Management of infections caused by antibiotic-resistant streptococcus pneumoniae

Streptococcus pneumoniae no longer has predictable antibiotic susceptibility There are two areas of high prevalence of resistance (over 25%) to beta-lactam antibiotics in the South-West and North-East of Europe In Spain, a close relationship has been found between the yearly rate of aminopenicillin consumption and penicillin resistance High level resistance (MIC greater than or equal to 1 mg/L) has developed against a previous background of low level resistance The serotypes involved in penicillin resistance in Spain are widespread in other countries Macrolide resistance is high in France (over 15%) and is also increasing in other countries All these resistant isolates remain susceptible to the most recent fluoroquinolones, such as temafloxacin Prospective surveillance, more rational use of antibiotics and a diversification of antibiotic use in respiratory tract infections may serve to limit the threat of antibiotic resistance in S pneumoniae

F. Baquero

Papers

A review of antibiotic resistance patterns of Streptococcus pneumoniae in Europe.