Streptococcal infections Archives - Revista Brasileira de Ginecologia e Obstetrícia
Summary
Rev Bras Ginecol Obstet. 2012;34(12):544-549
DOI 10.1590/S0100-72032012001200003
PURPOSE: To describe the epidemiological cases and microbiological profile of Streptococcus agalactiae serotypes isolated from infected newborns of a Women's Health Reference Centre of Campinas, São Paulo, Brazil. METHODS: Cross-sectional laboratory survey conducted from January 2007 to December 2011. The newborns' strains, isolated from blood and cerebrospinal fluid samples, were screened by hemolysis on blood ágar plates, Gram stain, catalase test, CAMP test, hippurate hydrolysis or by microbiological automation: Vitek 2 BioMerieux®. They were typed by PCR, successively using specific primers for species and nine serotypes of S. agalactiae. RESULTS: Seven blood samples, one cerebrospinal fluid sample and an ocular sample, were isolated from nine newborns with infections caused by S. agalactiae, including seven cases of early onset and two of late onset. Only one of these cases was positive for paired mother-child samples. Considering that 13,749 deliveries were performed during the study period, the incidence was 0.5 cases of GBS infections of early onset per 1 thousand live births (or 0.6 per 1 thousand, including two cases of late onset) with 1, 3, 2, zero and 3 cases (one early and two late onset cases), respectively, for the years from 2007 to 2011. It was possible to apply PCR to seven of nine samples, two each of serotypes Ia and V and three of serotype III, one from a newborn and the other two from a paired mother-child sample. CONCLUSIONS: Although the sample was limited, the serotypes found are the most prevalent in the literature, but different from the other few Brazilian studies available, except for type Ia.
Summary
Rev Bras Ginecol Obstet. 2012;34(12):544-549
DOI 10.1590/S0100-72032012001200003
PURPOSE: To describe the epidemiological cases and microbiological profile of Streptococcus agalactiae serotypes isolated from infected newborns of a Women's Health Reference Centre of Campinas, São Paulo, Brazil. METHODS: Cross-sectional laboratory survey conducted from January 2007 to December 2011. The newborns' strains, isolated from blood and cerebrospinal fluid samples, were screened by hemolysis on blood ágar plates, Gram stain, catalase test, CAMP test, hippurate hydrolysis or by microbiological automation: Vitek 2 BioMerieux®. They were typed by PCR, successively using specific primers for species and nine serotypes of S. agalactiae. RESULTS: Seven blood samples, one cerebrospinal fluid sample and an ocular sample, were isolated from nine newborns with infections caused by S. agalactiae, including seven cases of early onset and two of late onset. Only one of these cases was positive for paired mother-child samples. Considering that 13,749 deliveries were performed during the study period, the incidence was 0.5 cases of GBS infections of early onset per 1 thousand live births (or 0.6 per 1 thousand, including two cases of late onset) with 1, 3, 2, zero and 3 cases (one early and two late onset cases), respectively, for the years from 2007 to 2011. It was possible to apply PCR to seven of nine samples, two each of serotypes Ia and V and three of serotype III, one from a newborn and the other two from a paired mother-child sample. CONCLUSIONS: Although the sample was limited, the serotypes found are the most prevalent in the literature, but different from the other few Brazilian studies available, except for type Ia.
Summary
Rev Bras Ginecol Obstet. 2011;33(12):395-400
DOI 10.1590/S0100-72032011001200004
PURPOSE: To assess the prevalence of Streptococcus agalactiae, a Group B streptococcus, in pregnant women, and their possible risk factors, as well as the impact of perinatal colonization and antimicrobial susceptibility. METHODS: We evaluated 213 pregnant women from 20 weeks of gestation, regardless of risk factors, attending a tertiary teaching hospital. The technique used was a single sterile swab to collect secretions from the vaginal and perianal regions. The newly obtained samples were stored in Stuart transport medium and taken to the laboratory, where they were inoculated in Todd-Hewitt selective medium supplemented with Gentamicin (8 ug/mL) and nalidixic acid (15 ug/mL), with subsequent cultivation on blood agar plates. The materials were tested with Gram, catalase with hydrogen peroxide and CAMP (Christie, Atkins, Munch-Petersen), and results were serologically confirmed with the Streptococcal Grouping Kit, Oxoid®. The positive samples were tested for antimicrobial susceptibility. We also assessed socioeconomic, reproductive, clinical, and obstetric variables, and newborn care. Statistical analysis was performed with Epi-Info 6.04. RESULTS: The prevalence of colonization obtained by field tests was 9.8% by CAMP test, but only 4.2% by serology. The only protective factor was white skin color (p=0.01, 0.45>OR>0.94, 95%CI). There was no difference in prevalence of Group B streptococcus regarding other reproductive and obstetric variables. Infection occurred in only one of the newborns from colonized mothers; although it was revealed infection with Pseudomonas spp. High resistance to ampicillin (4/9), cephalothin (4/9), penicillin (4/9), erythromycin (3/9), clindamycin (7/9), and cloramphenicol (1/9) was detected. CONCLUSIONS: The infection rate was lower than that found in other studies, although a high rate of resistance to antibiotics commonly used for treatment was detected. Since there are no studies on the prevalence of Group B streptococcus in Ceará, we cannot perform a comparative analysis of the population, and further studies are needed with geographically similar groups to validate these results.
Summary
Rev Bras Ginecol Obstet. 2011;33(12):395-400
DOI 10.1590/S0100-72032011001200004
PURPOSE: To assess the prevalence of Streptococcus agalactiae, a Group B streptococcus, in pregnant women, and their possible risk factors, as well as the impact of perinatal colonization and antimicrobial susceptibility. METHODS: We evaluated 213 pregnant women from 20 weeks of gestation, regardless of risk factors, attending a tertiary teaching hospital. The technique used was a single sterile swab to collect secretions from the vaginal and perianal regions. The newly obtained samples were stored in Stuart transport medium and taken to the laboratory, where they were inoculated in Todd-Hewitt selective medium supplemented with Gentamicin (8 ug/mL) and nalidixic acid (15 ug/mL), with subsequent cultivation on blood agar plates. The materials were tested with Gram, catalase with hydrogen peroxide and CAMP (Christie, Atkins, Munch-Petersen), and results were serologically confirmed with the Streptococcal Grouping Kit, Oxoid®. The positive samples were tested for antimicrobial susceptibility. We also assessed socioeconomic, reproductive, clinical, and obstetric variables, and newborn care. Statistical analysis was performed with Epi-Info 6.04. RESULTS: The prevalence of colonization obtained by field tests was 9.8% by CAMP test, but only 4.2% by serology. The only protective factor was white skin color (p=0.01, 0.45>OR>0.94, 95%CI). There was no difference in prevalence of Group B streptococcus regarding other reproductive and obstetric variables. Infection occurred in only one of the newborns from colonized mothers; although it was revealed infection with Pseudomonas spp. High resistance to ampicillin (4/9), cephalothin (4/9), penicillin (4/9), erythromycin (3/9), clindamycin (7/9), and cloramphenicol (1/9) was detected. CONCLUSIONS: The infection rate was lower than that found in other studies, although a high rate of resistance to antibiotics commonly used for treatment was detected. Since there are no studies on the prevalence of Group B streptococcus in Ceará, we cannot perform a comparative analysis of the population, and further studies are needed with geographically similar groups to validate these results.
Summary
Rev Bras Ginecol Obstet. 2005;27(11):672-676
DOI 10.1590/S0100-72032005001100007
PURPOSE: to evaluate the influence of vaginal environment of pregnant women on group B streptococcus (GBS) survival after 8, 24 e 48 h in Amies and Stuart transport media. METHODS: Three vaginal samples were collected from 30 pregnant women attending the Prenatal Care Outpatient Clinic of the Centro de Atenção Integral à Saúde da Mulher (CAISM), Universidade Estadual de Campinas (UNICAMP). The first sample was placed directly onto Todd-Hewitt selective medium; the second was used to perform a gram-stained microscopy, and the third swab was placed in 2 mL physiological saline to which 200 µL of a suspension with 1-2 x 10(8) colony-forming units of GBS was added. After homogenization, six swabs were collected from this suspension (3 from Amie medium and 3 from Stuart medium). These six swabs were kept at room temperature for 8, 24 and 48 h and then incubated on blood agar. Bacterial growth at 37ºC was observed after a 24-h incubation period and it was semiquantitatively graded (0-3+) according to the number of colonies. Statistical analysis was performed by the exact Fisher test and the level of significance was set at 0.05. RESULTS: the recovery of GBS after 48-h storage in Amie and Stuart media was 97 e 87%, respectively. In one of the four cases where no GBS recovery was possible after 48 h of storage, vaginal pH was higher than 4.5, and in two of those cases cytolytic vaginosis was found. CONCLUSIONS: both transport media showed to be appropriate for GBS recovery up to 48 h after sampling. Characteristics of the vaginal enviroment did not influence GBS recovery as observed in this study.
Summary
Rev Bras Ginecol Obstet. 2005;27(11):672-676
DOI 10.1590/S0100-72032005001100007
PURPOSE: to evaluate the influence of vaginal environment of pregnant women on group B streptococcus (GBS) survival after 8, 24 e 48 h in Amies and Stuart transport media. METHODS: Three vaginal samples were collected from 30 pregnant women attending the Prenatal Care Outpatient Clinic of the Centro de Atenção Integral à Saúde da Mulher (CAISM), Universidade Estadual de Campinas (UNICAMP). The first sample was placed directly onto Todd-Hewitt selective medium; the second was used to perform a gram-stained microscopy, and the third swab was placed in 2 mL physiological saline to which 200 µL of a suspension with 1-2 x 10(8) colony-forming units of GBS was added. After homogenization, six swabs were collected from this suspension (3 from Amie medium and 3 from Stuart medium). These six swabs were kept at room temperature for 8, 24 and 48 h and then incubated on blood agar. Bacterial growth at 37ºC was observed after a 24-h incubation period and it was semiquantitatively graded (0-3+) according to the number of colonies. Statistical analysis was performed by the exact Fisher test and the level of significance was set at 0.05. RESULTS: the recovery of GBS after 48-h storage in Amie and Stuart media was 97 e 87%, respectively. In one of the four cases where no GBS recovery was possible after 48 h of storage, vaginal pH was higher than 4.5, and in two of those cases cytolytic vaginosis was found. CONCLUSIONS: both transport media showed to be appropriate for GBS recovery up to 48 h after sampling. Characteristics of the vaginal enviroment did not influence GBS recovery as observed in this study.