Detection of human papillomavirus DNA in genital lesions by using a modified commercially available in situ hybridization assay.

A modified, commercially available DNA-DNA in situ hybridization test that uses biotinylated probes for the identification of human papillomavirus (HPV) DNA types 6/11, 16/18, and 31/33/35 was evaluated. HPV DNA was detected in 314 of 787 (40%) histologically abnormal genital biopsy specimens by using the ViraType in situ assay (Life Technologies, Gaithersburg, Md.), in which the hybridization time was increased from 2 to 16 h. Ninety percent of positive condyloma acuminata specimens contained HPV type 6/11 DNA. The prevalences of HPV DNA for cervical intraepithelial neoplasia I, II, and III lesions by this in situ hybridization test were 42, 54, and 55%, respectively. The combined prevalence of HPV type 16/18 and 31/33/35 DNAs increased with the severity of the lesion, while the prevalence of type 6/11 DNA decreased. HPV type 6/11 DNA was found only in 1 of 16 (6%) positive cervical intraepithelial neoplasia III specimens. HPV type 16/18 and 31/33/35 DNA was detected in 11 of 16 (69%) and 4 of 16 (25%) in situ hybridization-positive cervical intraepithelial neoplasia III specimens, respectively. Thus, the observation that certain "higher-risk" HPV genotypes are associated with upper-grade cervical precancer lesions was confirmed by this commercial hybridization system. In general, the assay was found to be well suited for use in the clinical laboratory. The ViraType in situ procedure modified for a longer hybridization time may be helpful in identifying lesions containing higher-risk HPV strains.

Selective pigment medium for Streptococcus agalactiae.

Increased awareness of the importance of Streptococcus agalactiae (Group B streptococcus) in neonatal morbidity and mortality has demonstrated the need for a selective and differential primary plating medium. In this report we describe a selective pigment medium containing colistin and nalidixic acid that allows presumptive identification of S. agalactiae from the primary plate, even when specimens are polymicrobic. A preliminary study compared the value of three media for pigment production by 137 known S. agalactiae strains. This was followed by a clinical laboratory trial using the best of these pigment media at an obstetric hospital in which 581 specimens from neonates, female reproductive tracts, and urinary tracts were screened. Subsequent to the clinical laboratory trial, an epidemiological investigation using the selective pigment medium was conducted on a mother/infant population. Of the 1,331 specimens screened for S. agalactiae, 75 (5.6%) were positive on 5% sheep blood agar and 79 (5.9%) were positive on the selective pigment medium.

Criteria, purposes, and methods for evaluating the clinical competence of students in the allied health professions.

A review is presented of the methods related to the development of criteria and methods for evaluating the clinical competence of students in the allied health professions. The evaluation instrument should reflect the competencies expected of the student at the entry level of the profession and should be objective, valid, reliable, and practical. Since strengths and limitations are inherent in all types of evaluative techniques, a combination of techniques is desirable. The evaluation process should serve as a means of assessing student performance, improving instruction, evaluating program goals and objectives, and encouraging student development.

Bromcresol green dextrose broth for the presumptive identification of group B streptococci.

A 1 percent dextrose broth using bromcresol green as a pH indicator is described for the presumptive identification of group B streptococci. The results in the medium are read after 24 hr incubation at 36C as a color change. This medium was tested using 550 strains of streptococci belonging to groups A, B, C, D, and G. All of the group A strains were negative whereas all of the group B and Group D strains were positive. Thus, by using bacitracin susceptibility, esculin hydrolysis, and BCG dextrose broth, the presumptive identification of the frequently encountered streptococci can be accomplished.

Slide method for detection of antibody-coated bacteria in urine sediments.

An immunofluorescent slide method incorporating 0.1% (wt/vol) Evans blue as a counterstain was developed and compared with a recently described tube method. Seventy-one urine specimens were tested concurrently by both methods. Results of the two methods agreed in 70 specimens and disagreed in only 1. We found the slide method to be less costly and time consuming than the tube method.