Long-term effects on the nasopharyngeal flora of children following antimicrobial therapy of acute otitis media with cefdinir or amoxycillin-clavulanate

Treatment Challenges of Group A Beta-hemolytic Streptococcal Pharyngo-Tonsillitis

Introduction  Despite its in vitro efficacy, penicillin often fails to eradicate Group A β-hemolytic streptococci (GABHS) from patients with acute and relapsing pharyngo-tonsillitis (PT). Objective  This review of the literature details the causes of penicillin failure to eradicate GABHS PT and the therapeutic modalities to reduce and overcome antimicrobial failure. Data Synthesis  The causes of penicillin failure in eradicating GABHS PT include the presence of β lactamase producing bacteria (BLPB) that "protect" GABHS from any penicillin; the absence of bacteria that interfere with the growth of GABHS; co-aggregation between GABHS and Moraxella catarrhalis; and the poor penetration of penicillin into the tonsillar tissues and the tonsillo-pharyngeal cells, which allows intracellular GABHS and Staphylococcus aureus to survive. The inadequate intracellular penetration of penicillin can allow intracellular GABHS and S. aureus to persist. In the treatment of acute tonsillitis, the use of cephalosporin can overcome these interactions by eradicating aerobic BLPB (including M. catarrhalis), while preserving the potentially interfering organisms and eliminating GABHS. Conclusion  In treatment of recurrent and chronic PT, the administration of clindamycin, or amoxicillin-clavulanic acid, can eradicate both aerobic and anaerobic BLPB, as well as GABHS. The superior intracellular penetration of cephalosporin and clindamycin also enhances their efficacy against intracellular GABHS and S. aureus.

Nasal saline irrigation with or without systemic antibiotics in treatment of children with acute rhinosinusitis

OBJECTIVES

Acute rhinosinusitis (ARS) is a common pediatric problem. Our aim was to determine the efficacy of normal nasal saline irrigation (NSI) with or without amoxicillin in treatment of acute rhinosinusitis (ARS) in children.

METHODS

It is a prospective randomized, blind placebo-controlled trial. Children with uncomplicated ARS were recruited. One group received (amoxacillin 100mg/kg/day) and 0.9% NSI. The second group received placebo and 0.9% NSI. The primary outcome was the effect of treatment on clinical response. Secondary outcomes included: Rating of Pediatric Rhinoconjunctivitis Quality of Life Questionnaire (PRQLQ), middle meatus (MM) bacteriological and cytological cellular responses and adverse effects.

RESULTS

Sixty two patients with ARS were eligible for the study. In amoxicillin group (31 patients); clinical cure was observed in 26 (83.9%) in comparison to 22 (71%) patients in NSI without antibiotics group (31 patients) (p=0.22). No differences between both groups in the reported nasal symptom scores and total symptoms scores improvements at day 7 (p=0.09 and 0.65) and day 14 (p=0.29 and 0.14), respectively. The mean total PRQLQ values had no differences between both groups after the 2 weeks of treatment (p=0.06). At day 7, MM neutrophils reduced significantly in amoxicillin group in comparison to placebo group (p=0.004). At day 14, the MM cytological content had no differences between both groups (p=0.07). Normal NSI with placebo has less reported adverse effects than amoxicillin and nasal saline irrigations (p=0.005).

CONCLUSIONS

NSI can be used alone with the same clinical, bacteriological and cytological cellular changes efficacy and with higher safety profile than amoxicillin after 14 days of treatment in uncomplicated clinically diagnosed ARS in children.

The effects of antimicrobials and exposure to smoking on bacterial interference in the upper respiratory tract of children

Interactions between micro-organisms that include antagonism (interference) and synergism maintain balance between members of the normal endogenous flora, and play a role in preventing colonization by potential pathogens. Bacteria with interference capability of potential respiratory tract pathogens include alpha-hemolytic streptococci, non-hemolytic streptococci, Prevotella spp. and Peptostreptococcus spp. The role of bacterial interference in the occurrence of upper respiratory tract infections and its effect on their eradication is discussed. The infections include otitis media, sinusitis and pharyngo-tonsillitis. Treatment with antimicrobial agents and direct and indirect exposure to smoking, can affect the balance between the interfering organisms and potential pathogens. Introduction into the indigenous microflora of low virulence bacterial strains that are capable of interfering with colonization and infection with virulent organisms has been used to prevent the failure of antimicrobials in the treatment of pharyngo-tonsillitis and otitis media.

Evidence of Bacterial Biofilms among Infected and Hypertrophied Tonsils in Correlation with the Microbiology, Histopathology, and Clinical Symptoms of Tonsillar Diseases

Diseases of the tonsils are becoming more resistant to antibiotics due to the persistence of bacteria through the formation of biofilms. Therefore, understanding the microbiology and pathophysiology of such diseases represent an important step in the management of biofilm-related infections. We have isolated the microorganisms, evaluated their antimicrobial susceptibility, and detected the presence of bacterial biofilms in tonsillar specimens in correlation with the clinical manifestations of tonsillar diseases. Therefore, a total of 140 palatine tonsils were collected from 70 patients undergoing tonsillectomy at University Malaya Medical Centre. The most recovered isolate was Staphylococcus aureus (39.65%) followed by Haemophilus influenzae (18.53%). There was high susceptibility against all selected antibiotics except for cotrimoxazole. Bacterial biofilms were detected in 60% of patients and a significant percentage of patients demonstrated infection manifestation rather than obstruction. In addition, an association between clinical symptoms like snore, apnea, nasal obstruction, and tonsillar hypertrophy was found to be related to the microbiology of tonsils particularly to the presence of biofilms. In conclusion, evidence of biofilms in tonsils in correlation with the demonstrated clinical symptoms explains the recalcitrant nature of tonsillar diseases and highlights the importance of biofilm's early detection and prevention towards better therapeutic management of biofilm-related infections.

Comparison of clinical efficacy between 3-day combined clavulanate/amoxicillin preparation treatment and 10-day amoxicillin treatment in children with pharyngolaryngitis or tonsillitis

The efficacy of 3-day treatment with a combined clavulanate/amoxicillin preparation (Clavamox combination dry syrup for pediatric cases) and 10-day treatment with amoxicillin against pediatric pharyngolaryngitis and tonsillitis caused by Group A β-hemolytic Streptococcus was compared. Among the patients included in the efficacy evaluation (54 from the clavulanate/amoxicillin group and 43 from the amoxicillin group), the clinical response rate on completion of treatment was 98.1 % in the clavulanate/amoxicillin group and 92.9 % in the amoxicillin group, thus supporting the equivalent efficacy of these two therapies. The Group A β-hemolytic Streptococcus eradication rate at approximately 1-2 weeks after completion/discontinuation of treatment was 65.4 % in the clavulanate/amoxicillin group and 85.4 % in the amoxicillin group. Even in cases from which the pathogen continued to be isolated, relapse/recurrence of clinical symptoms was seldom seen. Urinalysis, conducted to assess the presence or absence of acute glomerulonephritis, revealed no abnormality in any patient. These results suggest that 3-day treatment with this clavulanate/amoxicillin preparation is expected to provide a valid means of treating pediatric pharyngolaryngitis and tonsillitis caused by Group A β-hemolytic Streptococcus.

Bacterial interference in upper respiratory tract infections: a systematic review

BACKGROUND

Published definitions of bacterial interference (BI) differ, some focusing on changes in the normal flora and others on changes in subsequent infection. A need for consensus was identified at a roundtable discussion of BI in upper respiratory tract infections (URTI). We conducted a systematic review of the available data to justify a consensus definition of BI specific to URTI as "a dynamic, antagonistic interaction between at least 2 organisms that affects the life cycle of each, changes the microenvironment, and alters the organisms' colonization, invasiveness, and ability to affect the health of the host."

METHODS

Continued communication among the faculty postroundtable was used to identify and refine the search criteria to (1) in vitro and in vivo studies assessing bacterial URTI, (2) BI evaluated by response to treatment of URTI with antimicrobial agents, and (3) bacterial function in relation to interactions between normal (nonpathogenic) and pathological flora. The criteria were applied to systematic searches of MEDLINE (1950 onward), EMBASE (1974 onward), and the Cochrane Library (2007).

RESULTS

Twenty-nine studies met the inclusion criteria, most focused on children with recurrent infections. Qualitative analysis supports the consensus definition. Interfering organisms affected the life cycle of test pathogens and inhibited their colonization, invasiveness, and health outcomes. Data were insufficient for statistical analysis.

CONCLUSION

Interactions between interfering organisms and potential pathogens isolated from the same host can alter response to infection and treatment. More studies are needed, particularly in adults, to understand the role of interfering organisms, the influence of antibiotics, and the potential for recolonization posttreatment.

Treatment failure, recurrence, and antibiotic prescription rates for different acute otitis media treatment methods

In an era of increasing antibiotic resistance, reliance on empirical antibiotic therapy for management of acute otitis media (AOM) will eventually become an untenable strategy. New research efforts are needed to identify effective treatment alternatives. In this retrospective analysis, we assessed AOM treatment failure (AOMTF), recurrent AOM (RAOM), and antibiotic prescription rates for groups of AOM episodes managed with either immediate antibiotics (ABX), tympanocentesis + observation (Tap + OBS), or tympanocentesis + immediate antibiotics (Tap + ABX). No significant differences in rates of AOMTF or RAOM were observed between any of the treatment groups. The 30-day rate of antibiotic prescriptions written for AOM was significantly lower in the TAP + OBS group (1 prescription per 3.8 episodes) than in the immediate antibiotic therapy groups (1.2 prescriptions per episode), P < .001. The comparative risk of AOMTF was slightly higher among AOM episodes caused by Streptococcus pneumoniae (OR 2.523; CI 1.070-5.944; P = 0.056). Neither the presence of other particular otopathogens, nor the presence of drug-resistant otopathogens, nor the choice of any particular AOM antibiotic therapy correlated with increased risk of either AOMTF or RAOM. The observed absence of significant differences in clinical outcomes between the various treatment groups in this study is consistent with findings published by other authors: alternative AOM therapies can help reduce reliance on antibiotics without inviting significant increases in rates of clinical failure.

Otitis Media: A Review, with a Focus on Alternative Treatments

Otitis media (OM) is the accumulation of fluids in the middle ear, with or without symptoms of inflammation. The infection is caused by dysfunction or obstruction of the eustachian tube and is most commonly diagnosed in children under the age of two. The microbiology of OM differs, with Streptococcus pneumoniae, non-typeable Haemophilus influenzae and Moraxella catarrhalis the most commonly isolated pathogens. The emergence of penicillin-resistant Strep. pneumoniae, β-lactamase-producing strains, Haem. influenzae and Mor. catarrhalis is a major concern and health care costs associated with treatment are substantial, especially in cases of unresponsive treatment as a result of incorrect diagnosis. Alternative treatments such as vaccines and a nasal spray containing α-haemolytic streptococci with antimicrobial activity against OM pathogens, have been developed. The rationale behind such treatments is to induce an appropriate immune response against the pathogens and decrease bacterial colonisation in the nasopharynx. Another approach may be treatment with bacteriocins (natural antimicrobial peptides) or bacteriocin-like inhibitory substances (BLIS) produced by lactic acid bacteria. We have recently described an antibacterial peptide produced by Enterococcus mundtii ST4SA and have published on bacteriocins (enterocins) with antibacterial and antiviral activity. This review discusses the condition OM, summarises current methods used to treat the infection, and suggests alternative safe and natural treatments that need to be explored.

Cephalosporins in overcoming beta-lactamase-producing bacteria and preservation of the interfering bacteria in the treatment of otitis, sinusitis and tonsillitis

The treatment of upper respiratory tract infections (URTIs) is complicated by the resurgence of beta-lactamase-producing bacteria (BLPB) and the absence of interfering bacteria. BLPB can have a direct pathogenic impact in causing the infection as well as an indirect impact through their ability to produce the enzyme beta-lactamase. BLPB may not only survive penicillin therapy but can also protect other penicillin-susceptible bacteria from penicillin. In this review, the clinical in vitro and in vivo evidence supporting the role of these organisms in the increased failure rate of penicillin in eradication of otitis, sinusitis and pharyngo-tonsillitis is outlined and the implication of that increased rate on the management of infections is discussed. Bacteria with interference capability of potential respiratory pathogens can prevent colonization and subsequent invasion by these organisms. These include alpha-hemolytic streptococci, nonhemolytic streptococci and Prevotella and Peptostreptococcus spp. Treatment with antimicrobials can affect the balance between the interfering organisms and potential pathogens. The role of bacterial interference in URTIs and its effect on their treatment is discussed. The use of some of the cephalosporins that are able to overcome the effect of BLPB and preserve the beneficial interfering bacteria can overcome and modulate these phenomena and achieve better cure of URTIs.

Current issues in the management of acute bacterial sinusitis in children

OBJECTIVE

To review and summarize recent challenges in the microbiology and treatment of acute bacterial sinusitis (ABS), one of the most common infectious diseases in the pediatric community.

METHODS

A review of recent medical literature from 1990 to 2006 was acquired using the National Library of Medicine's PUBMED database.

RESULTS

Multiple mechanisms of penicillin resistance have been identified: porin channel blockage, beta-lactamase production, and changes in penicillin-binding proteins (PBPs). Other factors affecting treatment efficacy include the role of normal nasopharyngeal flora, such as alpha-streptococci. The more widely documented shift in the causative pathogens of acute otitis media (AOM) following the release of the heptavalent pneumococcal conjugate vaccine (PCV7) has also been documented in two studies of ABS in children.

CONCLUSIONS

Treatment of ABS in children is complicated by a number of emerging changes in pathogen resistance patterns. These include beta-lactamase-negative ampicillin resistance (BLNAR) and multi-drug resistance, bacterial interference, and geographic data. These phenomena are likely to impact the treatment of URIs. Appropriate diagnosis and differentiation from viral sinusitis is essential prior to initiating therapy. Clinician education about these emerging issues remains an important strategy in diagnosing and treating ABS in children. This includes an understanding of known patient adherence to antibiotic therapy, such as taste, tolerability, dosing schedule, therapy duration, and patient preference. Clinicians should review judicious ABS treatment approaches that employ agents with documented efficacy against implicated pathogens.

Overcoming penicillin failures in the treatment of Group A streptococcal pharyngo-tonsillitis

The causes of penicillin failure in eradicating Group A beta-hemolytic streptococcal pharyngo-tonsillitis (GABHS PT) are described. These include the presence of beta-lactamase producing bacteria that "protect" Group A beta-hemolytic streptococci (GABHS) from penicillins; the absence of bacteria that interfere with the growth of GABHS; co-aggregation between GABHS and Moraxella catarrhalis; and the poor penetration of penicillin into the tonsillar tissues and the tonsillo-pharyngeal cells. The use of antimicrobials that can overcome and modulate these phenomena and achieve better cure of the infection is described.

The efficacy of cefdinir in acute bacterial rhinosinusitis

Acute bacterial rhinosinusitis is a common infection resulting in substantial morbidity. Cefdinir, an oral cephalosporin, has extended-spectrum, bactericidal activity against common acute bacterial rhinosinusitis pathogens, including Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis. Cefdinir shows rapid oral absorption and good respiratory tissue penetration, and may be administered once daily. In randomised clinical trials, cefdinir showed efficacy similar to that of other recommended regimens in the treatment of acute bacterial rhinosinusitis, namely amoxicillin/clavulanate and levofloxacin. Cefdinir is well tolerated and has shown a low propensity to suppress the normal commensal flora. Cefdinir oral suspension is rated highly by children in terms of its taste and smell. As the only once-daily beta-lactam currently recommended by acute bacterial rhinosinusitis guidelines (for first-line use in patients with mild acute bacterial rhinosinusitis and no recent antibacterial use), cefdinir offers a convenient and attractive treatment option.

The role of bacteria in chronic rhinosinusitis

Sinusitis generally develops as a complication of viral or allergic inflammation of the upper respiratory tract. The bacterial pathogens in acute sinusitis are S. pneumoniae, H. influenzae, and M. catarrhalis, while anaerobic bacteria and S. aureus predominant in CRS.