The effect of screening-to-labor interval on the sensitivity of late-pregnancy culture in the prediction of group B streptococcus colonization at labor: A prospective multicenter cohort study.

INTRODUCTION: The aim of this study was to evaluate the effect of increasing screening-to-labor interval on the performance of group B streptococcus (GBS) screening by late-pregnancy enriched culture compared with intrapartum real-time polymerase chain reaction (RT-PCR). MATERIAL AND METHODS: Group B streptococcus colonization was determined in 2624 women with singleton pregnancies by culture at 35-37 weeks of gestation and at the beginning of labor by culture and RT-PCR from recto-vaginal swab samples. RESULTS: Group B streptococcus colonization rates were 29.0% in late-pregnancy culture, 29.7% in intrapartum culture and 28.2% in intrapartum PCR. Intrapartum culture was used as a reference, the late-pregnancy culture had an overall sensitivity of 89.2% (95% CI 88.0%-90.4%) and specificity of 96.5% (95% CI 95.8%-97.2%), and intrapartum PCR had sensitivity of 91.5% (95% CI 90.4%-92.6%) and specificity of 98.5% (95% CI 98.0%-99.0%). However, up to 4 weeks after screening, the sensitivity of late-pregnancy culture was equivalent to or higher than that of RT-PCR. The RT-PCR was invalid in 0.9% of the women. Between late-pregnancy screening and labor, GBS colonization changed from negative to positive in 3.2% and from positive to negative in 2.5% of the women. CONCLUSIONS: The late-pregnancy enriched culture and intrapartum RT-PCR have comparable sensitivities in the detection of GBS when culture screening is conducted no more than 4 weeks before labor. Late-pregnancy culture sampling should be postponed to at least 37 weeks of gestation.

Presence of viral and bacterial pathogens in the nasopharynx of otitis-prone children. A prospective study.

OBJECTIVE: The purpose of the present study was to examine and follow up the presence of respiratory viral and bacterial pathogens in the nasopharynx of otitis-prone children during the cold season and compare the findings with the child's respiratory symptoms. METHODS: We enrolled 121 otitis-prone children, aged 10 months to 4 years for a prospective study. The nasopharyngeal swab (NPS) were studied at the baseline and after 12 and 24 weeks for respiratory viruses and at the baseline and after 24 weeks for bacteria. Presence of picorna(rhino-entero-parecho)-, influenza-, adenoviruses and Mycoplasma pneumoniae was detected by PCR. NPS specimens were cultured for Haemophilus influenzae, Streptococcus pneumoniae and Moraxella catarrhalis. Clinical data (the rate of respiratory symptom days, otitis media, tympanometry findings, day-care attendance and the number of siblings) were compared with microbiological data. RESULTS: Rhinovirus was found in 30% of the samples at the baseline, in 8% and in 19% of the samples after 12 and 24 weeks, respectively. Enterovirus was detected in 19% of the samples, in 21% and in 12% of samples after 12 and 24 weeks, respectively. Picornavirus positivity correlated with the respiratory symptoms but not with the number of otitis media or with abnormal tympanometry. Two samples were adeno- and three samples influenzavirus positive. Parechovirus and M. pneumoniae were negative in all samples. Rhinovirus positivity correlated with that of M. catarrhalis and S. pneumonia but not with H. influenzae. Microbiological positivity was not significantly associated with the type of day-care. CONCLUSIONS: Picornaviruses as well as bacteria were commonly found in the nasopharynx of otitis-prone children during the cold season, even in the absence of clinical symptoms.

Simplified phenotypic scheme evaluated by 16S rRNA sequencing for differentiation between Yersinia enterocolitica and Y. enterocolitica-like species.

Many clinical laboratories are familiar with a sizeable group of "unserotypeable Yersinia enterocolitica" strains. Due to identification problems, this group may hide Y. bercovieri, Y. mollaretii, and Y. rohdei strains. We present a simple scheme to distinguish between pathogenic Y. enterocolitica and potentially nonpathogenic Y. enterocolitica-like strains.

Biological effects of Trichoderma harzianum peptaibols on mammalian cells.

Trichoderma species isolated from water-damaged buildings were screened for toxicity by using boar sperm cells as indicator cells. The crude methanolic cell extract from Trichoderma harzianum strain ES39 inhibited the boar sperm cell motility at a low exposure concentration (50% effective concentration, 1 to 5 microg [dry weight] ml of extended boar semen(-1)). The same exposure concentration depleted the boar sperm cells of NADH(2). Inspection of the exposed boar sperm cells by transmission electron microscopy revealed damage to the plasma membrane. By using the black lipid membrane technique, it was shown that the semipurified metabolites (eluted from a SepPak C(18) cartridge) of T. harzianum strain ES39 induced voltage-dependent conductivity. The high-performance liquid chromatography-purified metabolites of T. harzianum strain ES39 dissipated the mitochondrial membrane potential (Deltapsi(m)) of human lung epithelial carcinoma cells (cell line A549). The semipurified metabolites (eluted from a SepPak C(18) cartridge) of T. harzianum strain ES39 were analyzed by mass spectrometry (MS). Matrix-assisted laser desorption ionization and nanoflow electrospray ionization MS revealed five major peptaibols, each of which contained 18 residues and had a mass ranging from 1,719 to 1,775 Da. Their partial amino acid sequences were determined by collision-induced dissociation tandem MS.