Pathogens isolated during treatment failures in otitis

Géhanno, P.; Nguyen, Laurent; Derriennic, M.; Pichon, François; Goehrs, Jean-Marie; Berche, Patrick

doi:10.1097/00006454-199810000-00007

Cited by 58 publications

(41 citation statements)

References 12 publications

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“…However, nonsusceptibility profiles within specific regions are constantly changing and, therefore, current surveillance data are required (5,11,23,33). Most traditional first-line agents, such as penicillin, trimethoprim-sulfamethoxazole (TMP-SMX), and macrolides, are now associated with significant rates of nonsusceptibility (8,13,27,32). Many practice guidelines are recommending newer antimicrobials with lower rates of nonsusceptibility, such as the respiratory fluoroquinolones, for the empirical treatment of community acquired pneumonia in individuals with comorbidities or those requiring hospitalization (3,15,34,41).…”

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confidence: 99%

In Vitro Antimicrobial Susceptibilities of Streptococcus pneumoniae Clinical Isolates Obtained in Canada in 2002

Powis

McGeer

Green

et al. 2004

Antimicrob Agents Chemother

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Empirical treatment is best guided by current surveillance of local resistance patterns. The goal of this study is to characterize the prevalence of antimicrobial nonsusceptibility within pneumococcal isolates from Canada. The Canadian Bacterial Surveillance Network is comprised of laboratories from across Canada. Laboratories collected a defined number of consecutive clinical and all sterile site isolates of S. pneumoniae in 2002. In vitro susceptibility testing was performed by broth microdilution with NCCLS guidelines. Rates of nonsusceptibility were compared to previously published reports from the same network. A total of 2,539 isolates were tested. Penicillin nonsusceptibility increased to 15% (8.5% intermediate, 6.5% resistant) compared to 12.4% in 2000 (P < 0.025, 2 ). Only 32 (1.3%) isolates had an amoxicillin MIC of >4 g/ml and only 2 of 32 cerebrospinal fluid isolates had an intermediate susceptibility to ceftriaxone by meningeal interpretive criteria (MIC ‫؍‬ 1 g/ml). A total of 354 (13.9%) isolates were macrolide nonsusceptible (46.3% MLS B , 56.7% M phenotype), increasing from 11.4% in 2000 (P < 0.0075, 2 ). Only 13 (<1%) isolates had a telithromycin MIC of >1 g/ml. Ciprofloxacin nonsusceptibility (defined as an MIC of >4 g/ml) increased to 2.7% compared to 1.4% in 2000 (P < 0.0025, 2 ) and was primarily found in persons >18 years old (98.5%). Nonsusceptibility to penicillin, macrolides, and fluoroquinolones is increasing in Canada. Nonsusceptibility to amoxicillin and ceftriaxone remains uncommon. Newer antimicrobials such as telithromycin and respiratory fluoroquinolones have excellent in vitro activity.

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confidence: 99%

In Vitro Antimicrobial Susceptibilities of Streptococcus pneumoniae Clinical Isolates Obtained in Canada in 2002

Powis

McGeer

Green

et al. 2004

Antimicrob Agents Chemother

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“…Despite a possibly competitive situation that might limit bacterial expansion to some extent, a mixed infection in the middle ear appeared to increase the strain on host tissues and defenses. Mixed infections are most common in AOM patients with treatment failure (16). To avoid long-standing mixed infections, measures in the form of tympanocentesis and a change of treatment to an antibiotic with a broader spectrum of activity should probably be taken without delay in suspected cases.…”

Section: Discussionmentioning

confidence: 99%

“…Its pharmacokinetic and pharmacodynamic profiles are attractive, but its utility is sometimes compromised by an increasing proportion of ␤-lactamresistant isolates. About 14 to 65% of the nontypeable (NT) H. influenzae isolates from the middle ear produce ␤-lactamase (16,20,22,24). For M. catarrhalis isolates the frequency is virtually 100% (20,22,24).…”

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confidence: 99%

“…There is experimental evidence for such a sheltering effect for Staphylococcus aureus in group A beta-hemolytic streptococcal abscesses (3) and M. catarrhalis in pneumococcal pneumonia (21). S. pneumoniae and NT H. influenzae coexist in up to 10% of the samples of middle ear fluid (16). The activity of amoxicillin against the pneumococcus in a mixed infection could thereby be threatened.…”

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β-Lactamase-Producing Nontypeable Haemophilus influenzae Fails To Protect Streptococcus pneumoniae from Amoxicillin during Experimental Acute Otitis Media

Westman

Lundin

Hermansson

et al. 2004

Antimicrob Agents Chemother

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Acute otitis media (AOM) is the most common reason for outpatient antimicrobial therapy. Mixed infections pose a potential problem, since the first-line drug used for the treatment of AOM, amoxicillin, can be neutralized by ␤-lactamase-producing pathogens of the upper respiratory tract. To study the effects of a 5-day course of amoxicillin on a mixed middle ear infection, rats were challenged with Streptococcus pneumoniae alone or in combination with ␤-lactamase-producing nontypeable Haemophilus influenzae. Amoxicillin was introduced at the clinical peak of the infection. Local and systemic changes were monitored by otomicroscopy, bacterial culture, and analysis of histological changes and the expression of the transforming growth factor beta (TGF-␤) gene. ␤-Lactamase-producing H. influenzae did not demonstrate an ability to protect S. pneumoniae. Amoxicillin eradicated the pneumococci in all treated animals but increased to some degree the ability of H. influenzae to persist at the site of infection. Thus, only an insignificant acceleration of the resolution of the AOM caused by a mixture of pathogens was observed during treatment. Moderate to major morphological changes could not be avoided by treatment of the mixed infections, but a slight downregulation of TGF-␤ expression was observed. In contrast to infections caused by a single pathogen, the mixed infections induced white plaques in the tympanic membrane at a remarkably high frequency independent of treatment. These experimental findings constitute support for further studies of antimicrobial drugs and AOM caused by bacteria with and without mechanisms of antibiotic resistance.Acute otitis media (AOM) is one of the most common bacterial infections in pediatric patients. The predominant pathogens causing AOM are Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis (22). Of these three agents S. pneumoniae has the lowest spontaneous clearance rate, and it is the microorganism most often associated with severe and fatal complications of AOM (1,18,25). As a consequence, the antimicrobial drug used for the treatment of AOM in routine practice must have a spectrum which covers this bacterium to be efficacious.Hitherto, amoxicillin has been the first-line therapeutic choice in several countries (10,14). Its pharmacokinetic and pharmacodynamic profiles are attractive, but its utility is sometimes compromised by an increasing proportion of ␤-lactamresistant isolates. About 14 to 65% of the nontypeable (NT) H. influenzae isolates from the middle ear produce ␤-lactamase (16,20,22,24). For M. catarrhalis isolates the frequency is virtually 100% (20,22,24). Because of the high rate of ␤-lactamase production in these two species, the use of ␤-lactamase-resistant drugs such as macrolides and trimethoprimsulfamethoxazole is often recommended (9). However, many of these antibiotics are not entirely effective as empirical treatment for AOM, especially macrolides for the treatment of infections caused by NT H. influenzae, and they may increase the rat...

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“…Estudos realizados nos anos 80 indicam que a maioria das falhas terapêuticas não eram causadas por patógenos resistentes ao antimicrobiano prescrito 30,34 . Entretanto, avaliações mais recentes, durante a década de 90, tem demonstrado a participação expressiva de cepas de PRP, em casos de OMA refratária (definida como falha clínica com 48 a 72 horas de tratamento, ou como recaída, diante do reaparecimento das manifestações clínicas até o quarto dia após a suspensão do tratamento) , [37][38][39][40] . De fato, o PRP tem sido duas a três vezes mais freqüentemente detectado em crianças com OMA refratária do que naquelas com OMA ainda não submetida ao tratamento 37 .…”

Section: Manuseiounclassified

Penicillin-resistant pneumococcus: practical implications

Mantese¹

1999

J Pediatr (Rio J)

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ResumoObjetivo: Rever aspectos epidemiológicos, laboratoriais e clínicos do pneumococo resistente à penicilina e considerar o impacto, no manuseio atual das principais infecções, frente ao crescente aumento da resistência desse patógeno às drogas.Métodos: Revisão bibliográfica dos últimos dez anos, pelo sistema MEDLINE e busca direta. Foram citados apenas os artigos considerados relevantes para o objetivo atual.Resultados e conclusões: O Streptococcus pneumoniae é um agente importante em otite média, pneumonia e meningite, em crianças. A evolução clínica da infecção pneumocócica é influenciada por diversos fatores, tais como a idade e o estado de saúde de base do paciente, a topografia e a severidade da infecção e a adequação do tratamento instituído. A penicilina G foi uniformemente eficaz contra o pneumococo até há três décadas, quando surgiram os primeiros relatos de cepas invasivas resistentes à penicilina. Nos últimos dez anos, ocorreu uma ampla disseminação dessas cepas, que têm demonstrado, paralelamente ao aumento gradativo do nível de resistência à penicilina, um aumento da resistência a outros ß lactâmicos e demais antimicrobianos.Este artigo apresenta uma revisão suscinta dos mecanismos genéticos e fenotípicos da resistência do pneumococo aos antibió-ticos ß lactâmicos, dos testes bacteriológicos disponíveis para a determinação do padrão de sensibilidade in vitro do pneumococo aos antimicrobianos e, por fim, da participação do patógeno na otite média aguda, na pneumonia comunitária/bacteremia e na meningite. Novas orientações no tratamento empírico da meningite têm sido recomendadas, referentes a taxas de ocorrência e nível de resistên-cia do pneumococo aos ß lactâmicos e presença nos hospedeiros de fatores de "risco", tais como indivíduos com doenças imunodepressoras ou que freqüentemente consumam antibióticos. O rápido aumento na prevalência de cepas resistentes às drogas enfatiza a importância do emprego criterioso de antibióticos e o desenvolvimento de vacinas conjugadas, capazes de prevenir as infecções invasivas e reduzir as taxas de portador, mesmo em crianças abaixo dos dois anos.J. pediatr. (Rio J.). 1999; 75 (Supl.1): S74-S90: pneumococo, Streptococcus pneumoniae, penicilina, otite média aguda, pneumonia, bacteremia, meningite. AbstractObjective: To review epidemiological, laboratorial and clinical aspects of the penicillin-resistant pneumococcus, and to consider the impact of the rapidly increasing drug-resistance on the management of the main infections caused by these pathogens.Methods: Bibliographic review covering the last ten years, using both Medline system and direct research.Results and conclusions: The Streptococcus pneumoniae is an important agent in acute otitis media, pneumonia and meningitis in children. The clinical evaluation of the pneumococcal infections depends on the age and health condition of the patient, site and severity of the infection and the adequacy of the treatment. Penicillin was uniformly effective against pneumococcus until three decades ago, when the first r...

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Pathogens isolated during treatment failures in otitis

Abstract: Penicillin-resistant S. pneumoniae isolates are frequently responsible for therapeutic failure in cases of acute otitis media in the Paris region.

Cited by 58 publications

References 12 publications

In Vitro Antimicrobial Susceptibilities of Streptococcus pneumoniae Clinical Isolates Obtained in Canada in 2002

In Vitro Antimicrobial Susceptibilities of Streptococcus pneumoniae Clinical Isolates Obtained in Canada in 2002

β-Lactamase-Producing Nontypeable Haemophilus influenzae Fails To Protect Streptococcus pneumoniae from Amoxicillin during Experimental Acute Otitis Media

Penicillin-resistant pneumococcus: practical implications

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