Apesar das diversas recomendações disponíveis na literatura sobre o diagnóstico laboratorial da resistência à oxacilina em Staphylococcus aureus, a verdade é que ainda não existe consenso absoluto sobre qual ou quais métodos utilizar e quando utilizar cada um deles. Segundo a literatura, a maioria dos métodos disponíveis apresenta um índice não desprezível de erros diagnósticos. Em casos de isolados de processos infecciosos invasivos, ou de infecções persistentes e/ou refratárias aos antimicrobianos, o uso de um método adicional ou confirmatório pode ser importante. Além disso, a contínua reavaliação desses testes é necessária.

Despite guidelines published in the literature, the optimal routine phenotypic method for detecting methicillin resistance in Staphylococcus aureus remains controversial. Most available methods have a considerable rate of errors, according to the literature. When testing invasive isolates or isolates from persistent/refractory infections, using an additional or confirmatory method could be important. In addition, the continual evaluation of these tests is necessary.

OBJETIVO: o Streptococcus pneumoniae habitualmente coloniza a orofaringe de pessoas sadias. O estado de portador assintomático está relacionado à invasão de estruturas adjacentes e ao surgimento de doença invasiva. Foi realizado estudo transversal, descritivo, objetivando verificar a prevalência de colonização de orofaringe pelo S. pneumoniae em crianças que freqüentam creches no município de Taubaté, SP, verificar a freqüência de sorotipos de Streptococcus pneumoniae nas cepas isoladas e relacionar os sorotipos mais freqüentes com os sorotipos presentes na composição da vacina pneumocócica heptavalente conjugada atualmente em uso. MÉTODOS: foram coletados, de 29 de junho a 15 de dezembro de 1998, 987 swabs de orofaringe de crianças entre 8 e 71 meses de idade, matriculadas nas creches municipais de Taubaté, SP. A identificação do S. pneumoniae foi baseada na observação das colônias que apresentassem hemólise parcial nos meios AS e AS-G, e pela observação da inibição do crescimento ao redor do disco de optoquina. A sorotipagem foi realizada pela reação de Quellung, utilizando anti-soros específicos, e adotado o sistema de nomenclatura dinamarquês. RESULTADOS: o Streptococcus pneumoniae foi isolado em 209 das 987 crianças (taxa de colonização= 21,1%). Vinte e oito sorotipos foram identificados. Os sete sorotipos mais freqüentes foram: 6A/6B (21,5%), 19F (14,8%), 18C (7,4%), 23F (7,4%), 9V (6,7%),14 (5,2%) e 10A (4,4%). Com exceção do sorotipo 10A, todos os outros seis estão incluídos na vacina. O único sorotipo vacinal não encontrado foi o sorotipo 4. CONCLUSÃO: estima-se, então, uma concordância de 63% entre os sorotipos colonizadores de orofaringe e os sorotipos presentes na vacina.

OBJECTIVE: Streptococcus pneumoniae usually colonizes the oropharynx of healthy people. Oropharyngeal carriage is related to the invasion of adjacent structures and to the development of invasive disease. A descriptive cross-sectional study was performed aiming at verifying the prevalence of oropharyngeal colonization by S. pneumoniae in children attending day care centers in the city of Taubaté - SP; verifying the frequency of S. pneumoniae serotypes in isolated strains; and relating the most frequent serotypes to the composition of the conjugated heptavalent pneumococcal vaccine currently in use. METHODS: from June 29 to December 15 1998, samples of oropharyngeal material were collected from 987 children, ranging from 8 to 71 months old, enrolled in day care centers in Taubaté - SP. The identification of S. pneumoniae was based on the observation of the colonies that presented partial hemolysis in agar-blood and agar-blood with gentamycin plates and on the observation of inhibited growth around the optochin disc. Serotyping was performed by the Quellung reaction, using specific antiserum, provided by the Centers for Disease Control and Prevention (Atlanta, GA/USA), and the Danish nomenclature system. RESULTS: as a result, S. pneumoniae was isolated from the oropharynx in 209 out of 987 children (colonization rate of 21.2%). Twenty eight serotypes were identified. The seven most frequent serotypes were: 6A/6B (21.5%), 19F (14.8%), 18C (7.4%), 23F (7.4%), 9V (6.7%), 14 (5.2%), 10A (4.4%). Except for serotype 10A, all the other six are included in the vaccine. The only vaccine serotype which was not found was serotype 4. CONCLUSION: agreement of 63% between the oropharynx colonizer serotypes and the serotypes present in the vaccine was found.

This study was conducted to evaluate the activity of azithromycin in comparison to 12 other antibacterial agents against recent isolates obtained consecutively from patients with respiratory tract or skin infections, from January to July, 2000. A total of 717 Gram-positive cocci were analyzed in this study and the following species were studied: Staphylococcus aureus (n=576), beta-hemolytic streptococci ( n=115), and Streptococcus pneumoniae (n=26). Susceptibility testing was carried out by the disk diffusion method and interpreted according to NCCLS breakpoints. The activity of azithromycin was compared to erythromycin, clindamycin, chloramphenicol, ciprofloxacin, ofloxacin, oxacillin, penicillin, ceftriaxone, tetracycline, trimethoprim/sulfamethoxazole, teicoplanin, and vancomycin. Of the 26 S. pneumoniae isolates recovered from the respiratory tract, 5 (19.2%) were intermediate resistant to penicillin. All of these strains were susceptible to chloramphenicol, ofloxacin, and vancomycin, and 24 (92%) were also susceptible to azithromycin, clindamycin, and erythromycin. Among the 67 beta-hemolytic streptococci strains isolated from the respiratory tract, 66 (99%) were susceptible to azithromycin, erythromycin, clindamycin, and ofloxacin. All 48 beta-hemolytic streptococci strains isolated from skin were susceptible to azithromycin and clindamycin, 47 (98%) were susceptible to erythromycin, and 46 (96%) were susceptible to ofloxacin. Of the 576 strains of S. aureus, 253 (43.9%) were isolated from the respiratory tract and 323 (56.1%) from skin. Among S. aureus isolates from the respiratory tract and skin, 46 (18%) and 78 (24%), respectively were resistant to oxacillin. Isolates from the respiratory tract and skin showed the same percentage of resistance (36%) to azithromycin. These in vitro results suggest that azithromycin can be a therapeutic option for treatment of infections caused by these bacteria since the newer macrolides have several distinct advantages over erytromycin including improved oral bioavailability, longer half-life allowing once or twice daily administration, higher tissue concentrations and less gastrointestinal adverse effects.