Prevalencia de infección cervical por Chlamydia trachomatis en mujeres de la Región Metropolitana / Prevalence of cervical infection by Chlamydia trachomatis among Chilean women living in the Metropolitan Región

Background: Chlamydia trachomatis is the most common bacterial sexually transmitted infection (STI) worídwide. In women, chlamydia infections are 75 percent asymptomatic and can lead to pelvic inflammatory disease, infertility, and ectopic pregnancy. Infants exposed to the microorganism at birth also have a high risk to develop conjunctivitis and pneumonía. Aim: To determine the prevalence of C trachomatis in women in the Metropolitan área of Santiago (Chile). Patients and methods: Cervical specimens were collected from 403 women attending three gynecological outpatient settings from Apríl 2003 to June 2005. These included one public hospital (n =100), a prívate medical center (n =268), and a clinic for adolescents (n =35). Mean ages ofeach group of patients were 35.6±8,2, 33.4±8.1 and 16.9±4.2 years, respectively. The diagnosis of C trachomatis was performed by the amplification byPCRofa 517-base pair segment of the cryptic plasmid on specimens extracted by a commercial procedure. Positive specimens were conñrmed by nested PCRs targeting the ompl gene. The presence of vaginal infections and its association with C trachomatis was investigated in a subset of 223 women ofthe prívate center. Residís: C trachomatis was detected in the cervix of 19 out of 403 women, resulting in a prevalence of 4.7 percent. The distribution of positive cases among different age groups was not significantly different. Women presenting with bacterial vaginosis had a significantly higher prevalence of C trachomatis infection (p <0.01). Conclusions: This study found a high prevalence of C trachomatis among gynecologic patients that should prompt preventive strategies.

Serotipos y susceptibilidad antimicrobiana de Streptococcus agalactiae / Serotypes and antimicrobial susceptibility of Streptococcus agalactiae

Background : Streptococcus agalactiae or group B streptococcus, GBS, is the leading cause of neonatal and maternal infections and an opportunistic pathogen in adults with underlying disease. In the last decade, a dramatic increase in the resistance of this microorganism to erythromycin and clindamycin has been observed. Aim: To determine the serotype distribution and antimicrobial susceptibility of isolates of S agalactiae collected from infections and colonization and to assess the genetic mechanisms of macrolide and clindamycin resistance. Material and methods: A total of 100 GBS isolates were collected between 1998 and 2002, in Santiago, Chile. They were isolated from the amniotic fluid from patients with premature rupture of membranes (7 isolates), blood from neonatal sepsis (10 isolates), neonate colonizations (2 strains), skin and soft tissue infections (7 isolates), urinary tract infections (5 isolates), genital infections (3 isolates), articular fluid (one isolate), and 65 strains were recovered from vaginal colonization55. Results: Serotypes Ia, II and III were the predominant serotypes identified in our study, accounting for 90 (90 percent) of the strains. Five isolates belonged to serotypes Ib (5 percent) and two (2 percent) to serotype V respectively; no strains belonging to serotype IV were found. All strains were susceptible to penicillin G, ampicillin and cefotaxime, and four isolates (4 percent) were resistant to both erythromycin (MIC >64 µg/ml) and clindamycin (MIC >64 µg/ml). The strains had a constitutive macrolide-lincosamide-streptogramin (cMLSB) resistance phenotype and the erm(A) gene was present in the four isolates. Conclusions: Serotypes Ia, II and III were the predominant serotypes in this study. All strains were susceptible to penicillin G, ampicillin and cefotaxime, and four (4 percent) strains were resistant to both erythromycin and clindamycin. The cMLSB resistance phenotype, and the erm(A) gene was detected in resistant strains (Rev MÚd Chile 2004; 132: 549-55).

Biotipos y susceptibilidad antimicrobiana de Gardnerella vaginalis / Biotypes and antimicrobial susceptibility of Gardnerella vaginalis

Se determinaron los biotipos y susceptibilidad a ampicilina, clindamicina, eritromicina, ciprofloxacina y tetraciclina de 63 cepas de Gardnerella vaginalis aisladas de pacientes con vaginosis bacteriana. Las cepas se distribuyeron en los 8 biotipos del esquema de clasificación de Piot, siendo los biotipos 1 y 2 los más frecuentes (44,4 por ciento). Todas las cepas fueron susceptibles a ampicilina y resistentes a ciprofloxacina. Cuatro cepas (6,4 por ciento) presentaron resistencia a clindamicina y dos (3,2 por ciento) a eritromicina. Treinta y una cepas (49,2 por ciento) fueron resistentes a tetraciclina. Se estudió la base genética de la resistencia a tetraciclina en ocho cepas resistentes, demostrándose la presencia del determinante tet (M) en todas ellas.

Streptococcus Beta hemolítico grupo B: colonización materna y neonatal / Beta-hemolytic Streptococcus group B: maternal and neonatal colonization

Streptococcus B hemolítico grupo B (SBHGB) es agente causal importante en infección del R.N. El reservorio principal es el tracto gastrointestinal de la madre originando colonización vaginal. El R.N. adquiere este microorganismo durante el parto o por vía ascendente en pacientes con ruptura de membranas. El objetivo de este estudio fue precisar tasa de colonización por SBHGB rectal y vaginal de embarazadas previo al parto así como de sus R.N. Se estudiaron, 102 embarazadas y 50 no embarazadas (grupo control) en las cuales se tomó muestra rectal y vaginal y a sus R.N. secreción nasal y umbilical. Se inocularon estas muestras en medio Todd Hewitt con antimicrobianos y en agar Columbia CNA. En 18 (17,6%) de las pacientes se aisló SBHGB correspondiendo a 10 muestras vaginales (9,8%), 7 vaginales y rectales (6,8%) y 1 solo rectal. El 38,9% (7/18) de los R.N. presentaron colonización y de ellos (42,9%) se asoció a infección grave