Genetic features of Streptococcus agalactiae strains causing severe neonatal infections, as revealed by pulsed-field gel electrophoresis and hylB gene analysis

A collection of 114 independent Streptococcus agalactiae strains, including 54 strains isolated from the cerebrospinal fluid (CSF) samples of neonates and 60 strains from asymptomatic patients, was characterized by pulsed-field gel electrophoresis (PFGE) of DNA restricted with SmaI and by PCR analysis of the hylB gene. All strains were previously studied by multilocus enzyme electrophoresis (MLEE) (R. Quentin, H. Huet, F.-S. Wang, P. Geslin, A. Goudeau, and R. K. Selander, J. Clin. Microbiol. 33:2576-2581, 1995). Among these 114 strains, there were 92 PFGE patterns. Eleven genetic groups (A to K) were identified with 38% divergence. A more homogeneous group (PFGE group A) was defined, consisting of 73% of the strains previously identified as belonging to a particular MLEE phylogenetic group. A 162-kb fragment was identified as a marker of strains that invaded the central nervous system of neonates. It was detected in 69% of the PFGE patterns obtained with CSF isolates and in only 1.8% of the PFGE patterns obtained with carrier strains. The hylB gene encoding hyaluronate lyase was amplified for all strains in our collection. Ten of 15 isolates belonging to an MLEE subgroup, previously described as being likely to cause invasive infection, had an insertion in the hylB gene (IS1548).

Characterization of Streptococcus agalactiae strains by randomly amplified polymorphic DNA analysis

A collection of 54 unrelated Streptococcus agalactiae strains isolated from cerebrospinal fluid samples from neonates and 60 unrelated strains isolated from carriers that had been previously studied by multilocus enzyme electrophoresis (R. Quentin, H. Huet, F.-S. Wang, P. Geslin, A. Goudeau, and R. K. Selander, J. Clin. Microbiol. 33:2576-2581, 1995) were characterized by randomly amplified polymorphic DNA (RAPD) assay. Four primers, 5'AGGGGGTTCC3', 5'AACGCGCAAC3', 5'GCATCAATCT3', and 5'AGTCGGGTGG3', named OPS16, AP42, A4, and OPS11, respectively, were selected from 29 primers tested. This investigation identified 71 RAPD types. The three families of strains defined by multilocus enzyme electrophoresis analysis, which contain most of the cerebrospinal fluid isolates, were also identified by clustering analysis of RAPD data. Each of these three groups exhibits specific RAPD patterns or fragments. The discriminatory power of the RAPD typing method was also evaluated. The simplest typing scheme was obtained by the combination of RAPD typing done with primers AP42 and OPS11 and serotyping (index of discrimination, 0.97).

Body figure perceptions and eating attitudes among Australian schoolchildren aged 8 to 12 years

OBJECTIVE

How widespread is the desire for thinness among preadolescent Australian children and are there gender differences?

METHOD

Two hundred forty-four children from Grades 3 to 6 completed the children's version of the Eating Attitudes Test (ChEAT), reported whether they had ever wanted to be thinner or tried to lose weight, and selected pictures ranging from thin to fat to depict their current and ideal body images.

RESULTS

Fifty percent of girls and 33% of boys have wanted to be thinner, and 40% and 24%, respectively, have attempted to lose weight. Percentages of girls and boys scoring above the ChEAT screening threshold for anorexia risk were 14% and 8%, respectively. ChEAT scores, attitudes and behaviors, and current and ideal figure perceptions were significantly related to body mass index (BMI).

DISCUSSION

Attitudes and behaviors were consistent with recent U.S. and Israeli findings that concerns about being overweight are prevalent among 8- to 12-year-olds. High ChEAT scores among Grade 3 children raised the question of whether very young children adequately understand this questionnaire.

Children's perceptions of their current and ideal body sizes and body mass index

244 Australian schoolchildren aged between 8 and 12 years indicated their current and ideal body sizes by means of Collins' pictorial figures. Children's height and weight were also measured. Body-mass indices were calculated from these data, and percentile ranks estimated according to international reference data. Consistent with Collins' findings, 39% of girls and 26% of boys wanted to be thinner than they perceived themselves to be; however, this desire was strongly related to actual body size so the percentages were very different for weight categories established on the basis of Body Mass Index. In the overweight quartile, 76% of girls and 56% of boys wanted to be thinner, whereas in the underweight quartile only 10% of girls and no boys wanted to be thinner. The response of overweight children may be sensible, but the desire of some underweight girls to be even thinner is of concern. Some recent literature suggests that underweight individuals tend to overestimate their body sizes. About a half of our underweight children slightly overestimated their body sizes but only one child overestimated grossly.