Antimicrobial susceptibility of Haemophilus influenzae, Haemophilus parainfluenzae and Moraxella catarrhalis isolated from adult patients with respiratory tract infections in four southern European countries. The ARISE project

Over a 7-month period in 2000-2001, 1213 Haemophilus influenzae, 112 Haemophilus parainfluenzae and 142 Moraxella catarrhalis isolates were recovered from adult patients with respiratory tract infections. Patients were from four southern European countries (Spain, Italy, Portugal and Greece). The antimicrobial susceptibility of the isolates to 11 antibiotics was determined in a central laboratory. The most active drugs on the basis of MICs were levofloxacin, cefditoren, cefotaxime, cefpodoxime and amoxicillin/clavulanate. MICs > or = 2 mg/l for amoxicillin were found in 19.5, 28.6, and 75.4% of H. influenzae, H. parainfluenzae and M. catarrhalis isolates, respectively. Isolates of H. influenzae and H. parainfluenzae with reduced susceptibility or that were fully resistant to amoxicillin/clavulanate, cefuroxime and clarithromycin were detected (0.2-1.8%) as well as M. catarrhalis resistant to clarithromycin (0.7%). Regular surveys of resistance patterns for antimicrobial agents are necessary.

Presumed endocarditis caused by BRO beta-lactamase-producing Moraxella lacunata in an infant with Fallot's tetrad

A case of presumed endocarditis caused by Moraxella lacunata in a 15-month-old male infant with Fallot's tetrad is described. This infection may have occurred as the result of transmission of this organism between the father and his son. This is the first report of BRO beta-lactamase-producing M. lacunata causing presumed endocarditis.

Acute bacterial rhinosinusitis in pediatric medicine: current issues in diagnosis and management

In children, acute bacterial rhinosinusitis is a common infection and although rare, carries a potential for serious, life threatening complications. Bacterial rhinosinusitis usually follows a viral infection or allergic rhinitis. Early, effective antibacterial therapy is essential to shorten the duration of infection and illness, to diminish mucosal damage, and to prevent contiguous infectious involvement of the orbit or central nervous system. Because the signs and symptoms of acute bacterial rhinosinusitis are similar to those of viral upper respiratory tract infection, establishing an accurate diagnosis in children poses a clinical challenge. Infection with Streptococcus pneumoniae accounts for 30-66% of episodes of acute bacterial rhinosinusitis in children. Other important pathogens include Haemophilus influenzae (20-30%) and Moraxella catarrhalis (12-28%). In selecting initial antimicrobial therapy, priority should be given to drugs with activity against S. pneumoniae. The oral agents that currently offer the greatest activity against this pathogen include amoxicillin, amoxicillin-clavulanate, cefdinir, cefpodoxime proxetil, and cefuroxime axetil; all are considered appropriate for the initial treatment of acute bacterial rhinosinusitis in children. Amoxicillin is customarily used as first-line therapy for uncomplicated acute bacterial rhinosinusitis. For patients who are allergic to amoxicillin, second- or third-generation oral cephalosporins may be used as first-line therapy. Clarithromycin has been suggested as an alternative to amoxicillin or cephalosporins in beta-lactam allergic patients. Clindamycin may also be indicated as first-line treatment in patients who have culture-proven penicillin-resistant S. pneumoniae. If no clinical response occurs within 72 hours, the choice of a second-line antibiotic is governed by the drug's known antimicrobial efficacy, resistance patterns, dosing schedules, the potential for compliance, and knowledge of the patient's drug allergies. High-dose amoxicillin-clavulanate (90 mg/kg/d of the amoxicillin component) has been recommended for high-risk children (e.g. those in day care, and those who have recently received antibiotics) who show no improvement after treatment with the usual dose of amoxicillin (45 mg/kg/d). Broad-spectrum, third-generation oral cephalosporins, such as cefdinir, should be considered as second-line agents when standard therapy has failed or when patients show hypersensitivity to penicillin. Intramuscular ceftriaxone may be appropriate for patients who fail on a second course of antibiotic treatment.

[Antibacterial therapy of acute sinusitis in outpatient practice: results of a multicenter trial]

Now there is no generally accepted practice of antibacterial therapy of acute sinusitis in outpatient clinics of Russia. Choice of antibacterial drugs is often made without consideration of the most probable causative agents of the infection. Out-of-date antibiotics used in many cases do not satisfy modern requirements. Clinically essential features of pharmacokinetics are in some cases ignored. Parenteral administration is often unjustified, combined antibiotic treatment is not always validated.

Worldwide trends in antimicrobial resistance among common respiratory tract pathogens in children

BACKGROUND

Respiratory tract infections among children are a common reason for health care provider visits and the primary reason for antimicrobial prescribing in this population. The increased prevalence of resistance among Streptococcus pneumoniae and Haemophilus influenzae pathogens poses a serious challenge in the successful treatment of respiratory tract infections caused by these pathogens.

METHODS

This paper reviews worldwide trends in antimicrobial resistance among common respiratory tract pathogens, highlighting data obtained from the pediatric population where available.

RESULTS

S. pneumoniae resistance to beta-lactams is mediated through alterations in the penicillin-binding proteins and macrolide resistance to acquisition of efflux or methylation genes. The mechanisms of resistance to the fluoroquinolones include target enzyme alterations via genetic mutations and transport out of the bacterial cell via an efflux pump. Beta-lactamase production is the primary mechanism of resistance to penicillins among H. influenzae isolates. Although S. pneumoniae with reduced susceptibility to penicillin was first documented > 30 years ago, resistance has increased at an alarming rate worldwide in the past decade. According to recent surveillance data, the worldwide prevalence of S. pneumoniae with reduced susceptibility to penicillin is 18.2%. Beta-lactamase production among H. influenzae ranges from approximately 4% in Russia to 26% in the United States and to 31% in France. The prevalence of beta-lactamase-negative, ampicillin-resistant H. influenzae remains very low (< 1%) worldwide, except in Japan, where the incidence is higher. In general, the highest rates of resistance are observed in isolates obtained from children, and risk factors for infection with a resistant pathogen include young age, the site of infection, day-care center attendance and recent antimicrobial use.

CONCLUSIONS

Increased prevalence of antimicrobial resistance among respiratory tract pathogens isolated from children and adults is evident worldwide. Treatment of infections caused by S. pneumoniae and H. influenzae with older agents or ineffective dosing regimens may not eradicate infections and may contribute to the spread of resistance. These observations confirm the need for appropriate antimicrobial use to halt or at least limit the spread of resistance.