NEW Product MAY 2006

1. NEW Product MAY 2006 STREPTO B ID NEW chromogenic media available ! STREPTO B ID NEW PRODUCTin the bMx offer SECOND in theNEW PREVENTION range dedicated to the “Screening of Strepto B for pregnant women”

2. PRESCRIBE CONFIDENCE… …COMPLETE RANGE promoted globally Todd Hewitt Broth+ATBs + STREPTO B ID + Slidex STREPTO B = Greater reliability Validated solution Proof : ECCMID poster P 798 38

3. True positives False negatives PPV [CI at 95%] Incubation period 24 hrs 116 1 99.1% [95.2% - 99.9%] Strepto B ID 48 hrs 143 12 92.3%* [86.8% - 95.6%] Without enrichment 24 hrs 98 0 100% [96.1% - 100%] Granada 48 hrs 133 0 100% [97.1% - 100%] 24 hrs 238 6 97.5% [94.7% - 98.9%] Strepto B ID 48 hrs 252 13 95.1% [91.7% - 97.1%] With enrichment 24 hrs 207 0 100% [98.1% - 100%] Granada 48 hrs 235 1 99.6% [97.6% - 99.9%] Sensitivity of detection [CI at 95%] True positives False negatives Incubation period 24 hrs 116 139 45.5% [39.4% - 51.7%] Strepto B ID 48 hrs 143 112 56.1%* [49.8% - 62.1%] Without enrichment 24 hrs 98 157 38.4% [32.6% - 44.7%] Granada 48 hrs 133 122 52.2% [45.9% - 58.3%] 24 hrs 238 17 93.3% [89.4% - 95.8%] Strepto B ID 48 hrs 252 3 98.8% [96.5% - 99.6%] With enrichment 24 hrs 207 48 81.2% [75.8% - 85.6%] Granada 48 hrs 235 20 92.2% [88.1% - 94.9%] Prevention of perinatal Group B streptococcal infections: Evaluation of a new chromogenic medium Strepto B ID C. Roure, V. Fiaty, Y. Gilles, H. Salord, S. Tigaud, Hôpital de la Croix-Rousse, Laboratoire de Microbiologie, Lyon, France P798 Table 2: Positive predictive values of Strepto B ID and Granada media, with and without enrichment. ABSTRACT Objective: The aim of this prospective study was to compare a method using the new chromogenic agar Strepto B ID (bioMérieux SA, France), Granada agar (Biomedics) and Columbia blood agar with colistin-nalidixic acid (BA-CNA) (bioMérieux), to detect vaginal colonization by group B streptococci (GBS) in pregnant women. Method: Specimens for GBS screening received over a 3 month period from pregnant women (683 vaginal swabs and 41 urine), 13 newborn gastric fluids at two hospitals were included and tested during this study. These specimens were cultured in parallel onto the three media by direct inoculation and after enrichment in Todd-Hewitt + antibiotics broth. Each medium was observed after 24 and 48hrs of incubation. Results: Overall GBS was detected in 255 cases (35%) on at least one medium after enrichment. Before and after enrichment, the sensitivity was 45.8% and 93.3% for Strepto B ID, 39.6% and 82.9% for Granada, 45.4% and 92.5% for BA-CNA respectively at 24hrs. Prolonged incubation (48hrs) enabled to increase the sensitivity: before and after enrichment, the sensitivity was 55.8% and 99.2.% for Strepto B ID, 52.5% and 92.9% for Granada, 52.9% and 96.7% for BA-CNA. Regarding thespecificity, the Granada medium method gave 99.8% versus 97.3% for the Strepto B ID after enrichment and 48 hrs of incubation. Conclusion: These findings show that the Strepto B ID medium, the first chromogenic medium to detect GBS, is more sensitive than the Granada medium. However, the Granada medium method is more specific after enrichment and 48 hrs of incubation. The enrichment phase increases significantly the GBSsensitivity of detection especially with Strepto B ID. This new medium is easy to use due to the incubation under aerobic conditions. Reading at 24 hrs Figure 1: GBS vaginal specimens collection GBS colonies are pale pink to red, round and pearly RESULTS Group B streptococcus is detected in 35% of the samples, whatever the medium. Sensitivity of detection at 48 hours without enrichment on Strepto B ID, Granada and Columbia CNA media are respectively 56.1%, 52.2% and 52.9%. This sensitivity reaches 98.8%, 92.2%, 96.7% after previous enrichment.Whatever the method and the incubation period, the sensitivity of Strepto B ID medium is significantly higher than for the other two media. Negative predictive values (reading at 48 hours) are 80.8 % (Strepto B ID) and 79.8% (Granada) without enrichment, and 99.4 % (Strepto B ID) and 96% (Granada) with previous enrichment. OBJECTIVES * Example of interpretation: without previous enrichment of a Strepto B-positive sample, there are 92.3 possibilities out of 100 that the colonies showing a characteristic coloration (pale pink to red) on Strepto B ID medium, after a period of incubation of 48 hrs, are Group B Streptococcal strains . GBS remains a leading cause of serious neonatal infections despite great progress in perinatal GBS disease prevention. The CDC recommends the use of a screening method for GBS colonization in pregnant women to identify candidates for intra-partum prophylaxis. Strepto B ID is a new, ready-to-use, chromogenic medium, designed for rapid identification of GBS. The aim of the study was to evaluate the biological performance of Strepto B ID on clinical samples. Strepto B ID medium performance was compared to Granada medium and to Columbia CNA + 5% sheep blood, with and without previous selective enrichment, using biological samples. CONCLUSION The systematic screening for Group B Streptococci carriage is recommended at the end of pregnancy, ideally between the 34th and the 38th week of amenorrhea, in order to prevent neonatal Group B streptococcal infections. Culture techniques from vaginal cavity swabbing are currently the best. Strepto B ID appears to be a very effective medium for the screening of Group B Streptococci. As for every chromogenic medium, a trained eye is necessary to pinpoint characteristic colonies. According to the results obtained during this study, Strepto B ID is more sensitive than Granada medium. Table 1: Sensitivity of detection for Strepto B ID and Granada media MATERIAL AND METHODS • A total of 737 samples (683 vaginal swabs, 41 urine collections and 13 gastric fluids) were cultured, both directly and after previous selective enrichment (Todd Hewitt broth + antibiotics, bioMérieux, France) onto: • Strepto B ID agar (bioMérieux, France) • Granada medium (BIOMEDICS, Spain) • Columbia CNA + 5% sheep blood agar (bioMérieux, France) • Culture plates were incubated at 38°C in aerobic (Strepto B ID, Columbia CNA) or anaerobic conditions (Granada) and interpreted after a period of incubation of both 24 and 48 hours. • Suspected colonies (red or pink on Strepto B ID [Fig. 1], red or orange on Granada, beta-hemolytic on Columbia-CNA) were GBS confirmed using a Slidex agglutination test (bioMérieux, France). • Statistical tests: Mac Nemar or binomial. * Example of interpretation: without previous enrichment of a Strepto B-positive sample, there are 56.1 possibilities out of 100 to detect a strain from this micro-organism on Strepto B ID medium, after a 48-hr period of incubation .