Penicillium expansum strain isolated from indoor building material was able to grow on gypsum board and emitted guttation droplets containing chaetoglobosins and communesins A, B and D.

AIMS: Emission of toxic metabolites in guttation droplets of common indoor fungi is not well documented. The aims of this study were (i) to compare mycotoxins in biomass and guttation droplets from indoor fungi from a building following health complaints among occupants, (ii) to identify the most toxic strain and to test if mycotoxins in guttation liquids migrated trough air and (iii) to test if toxigenic Penicillium expansum strains grew on gypsum board. METHODS AND RESULTS: Biomass suspensions and guttation droplets from individual fungal colonies representing Aspergillus, Chaetomium, Penicillium, Stachybotrys and Paecilomyces were screened toxic to mammalian cells. The most toxic strain, RcP61 (CBS 145620), was identified as Pen. expansum Link by sequence analysis of the ITS region and a calmodulin gene fragment, and confirmed by the Westerdijk Institute based on ITS and beta-tubulin sequences. The strain was isolated from a cork liner, was able to grow on gypsum board and to produce toxic substances in biomass extracts and guttation droplets inhibiting proliferation of somatic cells (PK-15, MNA, FL) in up to 20 000-fold dilutions. Toxic compounds in biomass extracts and/or guttation droplets were determined by HPLC and LC-MS. Strain RcP61 produced communesins A, B and D, and chaetoglobosins in guttation droplets (the liquid emitted from them) and biomass extracts. The toxins of the guttation droplets migrated c. 1 cm through air and condensed on a cool surface. CONCLUSIONS: The mycotoxin-containing guttation liquids emitted by Pen. expansum grown on laboratory medium exhibited airborne migration and were >100 times more toxic in bioassays than guttation droplets produced by indoor isolates of the genera Aspergillus, Chaetomium, Stachybotrys and Paecilomyces. SIGNIFICANCE AND IMPACT OF THE STUDY: Toxic exudates produced by Pen. expansum containing communesins A, B and D, and chaetoglobosins were transferable by air. This may represent a novel mechanism of mycotoxin dispersal in indoor environment.

Indoor Trichoderma strains emitting peptaibols in guttation droplets.

AIMS: The production of peptaibols, toxic secondary metabolites of Trichoderma, in the indoor environment is not well-documented. Here, we investigated the toxicity of peptaibols in the guttation droplets and biomass of Trichoderma strains isolated from problematic buildings. METHODS AND RESULTS: Seven indoor-isolated strains of T. atroviride, T. trixiae, T. paraviridescens and T. citrinoviride were cultivated on malt extract agar, gypsum boards and paperboards. Their biomass extracts and guttation droplets were highly cytotoxic in resting and motile boar sperm cell assays and in inhibition of somatic cell proliferation assays. The toxins were identified with HPLC/ESI-MS/MS as trichorzianines, trilongins, trichostrigocins and trichostrigocin-like peptaibols. They exhibited toxicity profiles similar to the reference peptaibols alamethicin, trilongins, and trichorzianine TA IIIc purified from T. atroviride H1/226. Particular Trichoderma strains emitted the same peptaibols in both their biomasses and exudate droplets. The trilongin-producing T. citrinoviride SJ40 strain grew at 37°C. CONCLUSIONS: To our knowledge, this is the first report of indoor-isolated Trichoderma strains producing toxic peptaibols in their guttation droplets. SIGNIFICANCE AND IMPACT OF THE STUDY: This report proves that indoor isolates of Trichoderma release peptaibols in their guttation droplets. The presence of toxins in these types of exudates may serve as a mechanism of aerosol formation for nonvolatile toxins in the indoor air.

Bacterial community changes in copper and PEX drinking water pipeline biofilms under extra disinfection and magnetic water treatment.

AIMS: To study the stability of biofilms and water quality in pilot scale drinking water copper and PEX pipes in changing conditions (extra disinfection, magnetic water treatment, MWT). METHODS AND RESULTS: Next-generation sequencing (NGS) of 16S ribosomal RNA genes (rDNA) to describe total bacterial community and ribosomal RNA (rRNA) to describe active bacterial members in addition to traditional microbiological methods were applied. Biofilms from control copper and PEX pipes shared same most abundant bacteria (Methylobacterium spp., Sphingomonas spp., Zymomonas spp.) and average species diversities (Shannon 3·8-4·2) in rDNA and rRNA libraries, whereas few of the taxa differed by their abundance such as lower total Mycobacterium spp. occurrence in copper (<0·02%) to PEX (<0·2%) pipes. Extra disinfection (total chlorine increase from c. 0·5 to 1 mg l-1 ) affected total and active population in biofilms seen as decrease in many bacterial species and diversity (Shannon 2·7, P < 0·01, rRNA) and increase in Sphingomonas spp. as compared to control samples. Furthermore, extra-disinfected copper and PEX samples formed separate clusters in unweighted non-metric multidimensional scaling plot (rRNA) similarly to MWT-treated biofilms of copper (but not PEX) pipes that instead showed higher species diversity (Shannon 4·8, P < 0·05 interaction). CONCLUSIONS: Minor chlorine dose addition increased selection pressure and many species were sensitive to chlorination. Pipe material seemed to affect mycobacteria occurrence, and bacterial communities with MWT in copper but not in PEX pipes. SIGNIFICANCE AND IMPACT OF THE STUDY: This study using rRNA showed that chlorination affects especially active fraction of bacterial communities. Copper and PEX differed by the occurrence of some bacterial members despite similar community profiles.

Microbial growth in building material samples and occupants' health in severely moisture-damaged homes.

There is no commonly approved approach to detect and quantify the health-relevant microbial exposure in moisture-damaged buildings. In 39 single-family homes with severe moisture damage, we studied whether concentrations of viable microbes in building material samples are associated with health among 71 adults and 68 children, and assessed with symptoms questionnaires, exhaled NO, and peak expiratory flow (PEF) variability. Symptoms were grouped into three scores: upper respiratory symptoms, lower respiratory symptoms, and general symptoms. The homes were divided into three groups based on viable counts of fungi, actinomycetes, and total bacteria cultivated from building material samples. Highest group of actinomycete counts was associated with more general symptoms, worse perceived health, and higher daily PEF variability (aOR 12.51; 1.10-141.90 as compared to the lowest group) among adults, and with an increase in lower respiratory symptoms in children, but the confidence intervals were wide. We observed significant associations of fungal counts and total microbial score with worse perceived health in adults. No associations with exhaled NO were observed.

Volatile organic compounds and formaldehyde as explaining factors for sensory irritation in office environments.

This study's database comprised results of volatile organic compound (VOC) measurements from 176 office buildings. In 23 of the 176 buildings, formaldehyde measurements were also conducted. It was suspected that the buildings had indoor air problems, but a walk-through inspection did not reveal any clear, abnormal contaminant sources. The 50 most abundant VOCs and their concentrations in 520 air samples were analyzed. The irritation potency was estimated for 33 out of the 50 common VOCs and their mixtures, as well as for formaldehyde. This information was used to calculate the recommended indoor air levels (RILs) for the VOCs. The RILs were considerably higher than the measured mean indoor air concentrations in the buildings. However, the RIL for formaldehyde was exceeded in most of the 23 buildings studied. According to the evaluation of irritation potency, formaldehyde was a more likely cause of sensory irritation than the mixture of common nonreactive VOCs at the concentrations that occurred in the buildings without abnormal indoor sources. Furthermore, environmental symptoms of office workers were characterized in 20 office buildings (including the database of 176 office buildings) with the aid of an indoor air questionnaire. The most frequent symptoms related to the indoor environment were involved the upper respiratory tract. However, no relationship could be shown between the reported symptoms and the occurrence of VOC and formaldehyde concentrations in these buildings. Generally, the study results indicated that formaldehyde was the more likely agent causing sensory irritation than the mixture of the common nonreactive VOCs at the concentrations occurring in the buildings without abnormal indoor sources.

A critical analysis of postoperative complications of antebrachium TEN-nailing in 35 children.

BACKGROUND: Unstable antebrachium diaphyseal fractures in children are nowadays increasingly treated operatively by elastic intramedullary nailing. AIM: Aim of the study was to critically assess both radiological and functional outcome of antebrachium fractures treated by titanium elastic nail (TEN) in a pediatric cohort. MATERIAL AND METHODS: This retrospective study investigated 75 consecutive children, who were treated for antebrachium shaft fractures at Tampere University Hospital during the time period from January 2001 to December 2005. All the fractures were classified according to OTA. Thirty-five children (mean age 12.3 years) were treated by TEN-nailing. Twenty four of the forearm fractures were instable, five were open, five were re-fractures and one had ulnar nerve deficit. In all but one patient both forearm bones were fractured. Twelve (34%) operations were managed by closed reduction, open reduction was needed in 23 (66%) patients. In 29 cases both bones were fixed with TEN-nail. In the four patients with re-fracture in both ulna and radius only the radius was TEN-nailed. In one case radius was fixed with TEN-nail and ulna with K-wire and in another case radius was fixed with TEN-nail and ulna with plate. Fracture pattern, mode of reduction, surgical approach, short- and long-term complications and outcome were recorded. RESULTS: Twenty three (66%) patients achieved healing of the fractures without any limitation in range of motion. Twelve patients with postoperative complication were followed up 31-74 (median of 54) months. Eleven (31%) patients had minor postoperative complications and one (0,3%) patient had a Volkmann's ischemic contracture. Five of complicated patients had more than one problem. Immediate post-operative problems were noted in these five patients. At follow-up visits four patients complained of ulnar nail discomfort, two had neural symptoms. Additionally, three children suffered from re-fractures. DISCUSSION: Despite various minor complications, TEN-nailing is considered suitable treatment for unstable forearm shaft fractures. Most of the problems were related to poor technical performance in nailing.

The paradoxical effect of smoking in preeclamptic pregnancies: smoking reduces the incidence but increases the rates of perinatal mortality, abruptio placentae, and intrauterine growth restriction.

OBJECTIVES: Smoking is associated with a reduced risk of preeclampsia, but what is the outcome of pregnancy when preeclampsia develops in women who smoke? STUDY DESIGN: Single births in Sweden from 1987 through 1993 to nulliparous women aged 15 to 34 years (N = 317,652) were included. Poisson regression analyses were used to calculate adjusted relative risks and rates of adverse pregnancy outcomes. RESULTS: Maternal smoking was associated with significantly reduced risks of mild and severe preeclampsia (relative risks = 0.6 and 0.5, respectively). In pregnancies with severe preeclampsia, smoking at least 10 cigarettes per day was associated with increased rates of perinatal mortality (from 24 to 36 per 1000), abruptio placentae (from 31 to 67 per 1000), and being small for gestational age (from 28% to 68%), whereas the corresponding smoking-related increases in rates in nonhypertensive pregnancies were considerably less. CONCLUSIONS: Smokers in whom preeclampsia develops have very high risks of perinatal mortality, abruptio placentae, and small-for-gestational-age infants.