In vitro susceptibility of nosocomial and community acquired strains of Staphylococcus aureus must be periodically evaluated because of its continuous evolution. Aim: To know the antimicrobial susceptibility of S. aureus isolated in Valdivia, to determine the prevalence of methicillin resistance and global patterns of resistance and to compare the evolution of the susceptibility along the years. Material and Methods: A total of 278 S. aureus strains were evaluated: 136 obtained from hospitalized patients, 50 belonged to outpatients and 92 to healthy carriers. Antimicrobial agents tested were: penicillin, oxacillin, vancomycin, gentamycin, ciprofloxacin, lincomycin and erythromycin. Results: Thirty three, 28 and 1.1% of strains isolated from hospitalized, outpatients and carriers, respectively, were methicillin-resistant. Six resistance patterns were found. No vancomycin resistant strain was isolated. Comment: It is worrisome that 2% of S. aureus strains obtained from hospitalized patients showed intermediate resistance to vancomycin

La susceptibilidad in vitro de Staphylococcus aureus adquirido, tanto en el ambiente hospitalario como en la comunidad, debe ser monitorizada periódicamente por su continua evolución. Objetivos: Conocer la susceptibilidad antimicrobiana de cepas de S. aureus aisladas en Valdivia, determinar la prevalencia de cepas resistentes a meticilina y sus respectivos patrones de resistencia, analizar la evolución de esta susceptibilidad a través de los años. Material y Métodos: Se evaluaron 278 cepas de S. aureus: 136 obtenidas de pacientes hospitalizados, 50 de pacientes ambulatorios y 92 de portadores. Los antimicrobianos ensayados fueron: penicilina, oxacilina, vancomicina, gentamicina, ciprofloxacina, lincomicina y eritromicina

Background: Methicillin resistant strains of Staphylococcus aureus (MRSA) are an important cause of nosocomial infections. Aim: To determine the genotypes of MRSA strains. Material and methods: Fifty five strains of MRSA, isolated from patients hospitalized in Hospital Base Valdivia, were studied. The phenotype was determined through MicroScan® in all strains and by minimum inhibitory concentration (MIC) in 41. The genotype of the strains was analyzed by a duplex polymerase chain reaction (PCR) of the mecA gene, amplifying eight hypervariable DNA regions associated to such gene. Results: According to MIC, 88% of strains had a pattern of resistance against multiple antimicrobial (penicillin, ampicillin, cephradine, gentamycin, ciprofloxacin, ¡incomycin and erythromycin). Vancomicin resistan strains were not detected. Only 53 strains (96%) had at least one of the eight hypervariable regions and were classified as MRSA. Genotypic patterns types 15 were the most commonly detected in 38% and 34% of strains, respectively. MicroScan® erroneously classified five strains in an incorrect phenotype, according to results obtained with duplex PCR. MIC results did not differ from those of duplex PCR. Conclusions: Duplex- PCR is a useful tool to detect hyper variable regions associated to mecA gene

A retrospective study by means of indirect immunofluorescence was carried out to detect IgM antibodies against Chlamydia pneumoniae and Mycoplasma pneumoniae in seronegative patients for Hantavirus, with characteristics symptoms of atypical pneumonia. The final results indicate that the prevalence of C. pneumoniae reaches 8,6% and M. pneumoniae is equivalent to 17,1% of the patients studied. By this we can be aware of the importance of these agents in our media, and the necessity of having rapid laboratory techniques that allow an opportune differential diagnosis in pulmonary syndrome for Hantavirus and other pathologies that cause similar symptoms, mainly atypical pneumonia

Em 82 doentes com uretrite foi pesquisada a presença de Chlamydia trachomatis, utilizando a prova da imunofluorescência direta, e de Neisseria gonorrhoeae, Mycoplasma e Ureaplasma, utilizando os métodos padrões. Ch. trachomatis foi encontrada em 19,5% dos casos, sendo que em 11 deles (68,8%) observou-se associação entre Chlamydia e as outras bactérias pesquisadas. Nesses pacientes observou-se presença de secreção uretral escassa e de aspecto gelatinoso.

The presence of Chlamydia trachomatis was studied by the direct immunofluorescence test, as also was that of Neisseria gonorrhoeae, Mycoplasma and Ureaplasma by the standard methods, in 82 patients with urethral discharge. Ch. trachomatis was found in 19.5% (16) of the cases and in 11 of them (68.8%) there was association with the other bacteria investigated. This eleven patients presented a scanty gelatinous discharge.

Se estudiaron 82 pacientes con uretritis para la búsqueda de Chlamydia trachomatis mediante inmunofluorescencia directa, Neisscria gonorrhoeae, Mycoplastna y Ureaplasma mediante métodos estándar. Se encontró un 19,5% de Chlamydia trachomatis y en 11 de ellos (68,8%) se encontró asociada a otras bacterias y estos pacientes presentó una secreción escasa-gelatinosa.

Em 82 doentes com uretrite foi pesquisada a presença de Chlamydia trachomatis, utilizando a prova da imunofluorescência direta, e de Neisseria gonorrhoeae, Mycoplasma e Ureaplasma, utilizando os métodos padrões. Ch. trachomatis foi encontrada em 19,5% dos casos, sendo que em 11 deles (68,8%) observou-se associação entre Chlamydia e as outras bactérias pesquisadas. Nesses pacientes observou-se presença de secreção uretral escassa e de aspecto gelatinoso.

Se estudiaron 82 pacientes con uretritis para la búsqueda de Chlamydia trachomatis mediante inmunofluorescencia directa, Neisscria gonorrhoeae, Mycoplastna y Ureaplasma mediante métodos estándar. Se encontró un 19,5% de Chlamydia trachomatis y en 11 de ellos (68,8%) se encontró asociada a otras bacterias y estos pacientes presentó una secreción escasa-gelatinosa.

The presence of Chlamydia trachomatis was studied by the direct immunofluorescence test, as also was that of Neisseria gonorrhoeae, Mycoplasma and Ureaplasma by the standard methods, in 82 patients with urethral discharge. Ch. trachomatis was found in 19.5% (16) of the cases and in 11 of them (68.8%) there was association with the other bacteria investigated. This eleven patients presented a scanty gelatinous discharge.