Group B streptococcus (GBS) is a major cause of serious infections in neonates. The 2002 revised guidelines of the Centers for Disease Control and Prevention (CDC) for the prevention of perinatal GBSdisease recommend that all pregnant women be screened for GBS carriage at between 35 and 37 weeks of gestation and that intrapartum antibiotic prophylaxis be given to carriers. We studied the performances of four different GBS detection assays in the context of antenatal screening. Between May and August 2004, the 605 vaginorectal swab specimens received at our bacteriology laboratory for GBS antenatal detection were tested by the four assays. The standard culture method was done according to the CDC recommendations. The three experimental assays performed with the growth from the selective enrichment (LIM) broth (Todd-Hewitt broth with 15 g/ml nalidixic acid and 10 g/ml colistin) after overnight incubation were a GBS antigen detection assay (PathoDx) and two PCR assays (for cfb and scpB). The most accurate assay was the scpB PCR (sensitivity, 99.6%; specificity, 100%), followed by the cfb PCR (sensitivity, 75.3%; specificity, 100%), GBS antigen detection (sensitivity, 57.3%; specificity, 99.5%), and standard culture (sensitivity, 42.3%; specificity, 100%). The GBS antigen detection assay was found to be more sensitive than the standard culture method, and moreover, the assay has a low cost and is easy to perform in all obstetrical centers which have access to the most basic of diagnostic microbiology services. We believe that antigen detection on incubated LIM broth should replace the standard culture method for screening for GBS carriage at 35 to 37 weeks of gestation. The impact of the greater sensitivities of PCR assays on the diminution of neonatal GBS infections remains to be demonstrated.Group B streptococcus (GBS) has been the leading cause of early-onset neonatal sepsis in industrialized countries for more than 30 years. Infection occurs through vertical transmission from a GBS-colonized mother to the newborn during labor and birth. Intrapartum antibiotic prophylaxis (IAP) has been shown not only to interrupt the transmission of GBS from mother to infant (28) but also to reduce the incidence of early-onset GBS disease (23). Guidelines from professional organizations issued in 1996 recommended two different strategies for the selection of candidates for IAP: either screening for GBS vaginorectal carriers or identification of maternal clinical risk factors for early-onset neonatal GBS disease (5).Results from a large prospective study showed the superiority of the screening approach in preventing early-onset GBS neonatal disease (22). This finding was confirmed in a retrospective review of GBS disease in infants (26). In 2002, the Centers for Disease Control and Prevention (CDC) recommended that all pregnant women be screened for carriage of GBS at between 35 and 37 weeks of gestation and that IAP be offered to the carriers (20). The culture method has a slow turnaround time requiring 36 to 72 h before results...
Legionella pneumophila is frequently detected in hot water distribution systems and thermal control is a common measure implemented by health care facilities. A risk assessment based on water temperature profiling and temperature distribution within the network is proposed, to guide effective monitoring strategies and allow the identification of high risk areas. Temperature and heat loss at control points (water heater, recirculation, representative points-of-use) were monitored in various sections of five health care facilities hot water distribution systems and results used to develop a temperature-based risk assessment tool. Detailed investigations show that defective return valves in faucets can cause widespread temperature losses because of hot and cold water mixing. Systems in which water temperature coming out of the water heaters was kept consistently above 60 °C and maintained above 55 °C across the network were negative for Legionella by culture or qPCR. For systems not meeting these temperature criteria, risk areas for L. pneumophila were identified using temperature profiling and system's characterization; higher risk was confirmed by more frequent microbiological detection by culture and qPCR. Results confirmed that maintaining sufficiently high temperatures within hot water distribution systems suppressed L. pneumophila culturability. However, the risk remains as shown by the persistence of L. pneumophila by qPCR.
first aligned the genome sequences of the 250 isolates against the NRCS-A reference genome CR01, resulting in a total of 22,621 single nucleotide polymorphisms (SNPs). To quantify recombination, we used ClonalFrameML 12 , which is specifically aimed at analysing whole-genome sequence data (see Supplementary Information). The results indicated that the impact of recombination (r) on the genome-wide substitution rate in S. capitis overall is almost equal to the impact of mutation (m), with r/m = 0.85. ClonalFrameML identified 190 recombination events in the global genealogy (Extended Data Fig. 1). The largest detected events (up to 26 kb) are probably products of horizontal gene transfer, some of which correspond to the insertion of pathogenicity islands. Clonal specialization and geographical dispersion of NRCS-A.The reconstructed maximum-likelihood tree (Fig. 1a) enabled us to draw a clear distinction between NRCS-A isolates that harbour the previously described specific NRCS-A pulsed-field gel electrophoresis pattern 8 (n = 197) and all the other strains found in basal positions (n = 53; hereafter 'basal'). These reconstructions revealed that this NRCS-A population is composed of at least three sublineages, which we named in chronological order of divergence on the basis of the observed branching order in the tree: 'proto-outbreak 1' (n = 18), 'proto-outbreak 2' (n = 17) and 'outbreak' (n = 162) (Fig. 1a,b). These three clades are supported both by bootstrap values greater than 95% and by the trimodal distribution of the
Microbial drinking water quality can be altered in large buildings, especially after stagnation. In this study, bacterial profiles were generated according to the stagnation time and the volume of water collected at the tap. Successive volumes of cold and hot water were sampled after controlled stagnation periods. Bacterial profiles revealed an important decline (> 2 log) in culturable cells in the first 500 mL sampled from the hot and cold water systems, with a steep decline in the first 15 mL. The strong exponential correlation (R2 ≥ 0.97) between the culturable cell counts in water and the pipe surface-to-volume ratio suggests the biofilm as the main contributor to the rapid increase in suspended culturable cells measured after a short stagnation of one-hour. Results evidence the contribution of the high surface-to-volume ratio at the point of use and the impact of short stagnation times on the increased bacterial load observed. Simple faucets with minimal internal surface area should be preferred to minimize surface area. Sampling protocol, including sampling volume and prior stagnation, was also shown to impact the resulting culturable cell concentration by more than 1000-fold. Sampling a smaller volume on first draw after stagnation will help maximize recovery of bacteria.
From 1997 to 2006, in the province of Quebec, Canada, 15 isolates of Streptococcus pseudoporcinus from 1 urine and 14 vaginorectal cultures were recovered from the genitourinary tract of pregnant women. All these women originated from the Caribbean or sub-Saharan Africa (P=0.00045 compared with a suitable control group). The S. pseudoporcinus isolates were compared to eight isolates of Streptococcus porcinus identified in Quebec from 1995 to 2006, all from animals, of which five were swine. 16S rRNA gene sequencing was required to differentiate between S. pseudoporcinus and S. porcinus animal isolates.
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