New papers on microbiology of the built environment, February 20, 2016

Set in stone

Commentary: Making microbiology of the built environment relevant to design – G. Z. Brown,
Jeff Kline, Gwynne Mhuireach, Dale Northcutt and Jason Stenson – Microbiome (OA)

Architects are enthusiastic about “bioinformed design” as occupant well-being is a primary measure of architectural success. However, architects are also under mounting pressure to create more sustainable buildings. Scientists have a critical opportunity to make the emerging field of microbiology of the built environment more relevant and applicable to real-world design problems by addressing health and sustainability in tandem. Practice-based research, which complements evidence-based design, represents a promising approach to advancing knowledge of the indoor microbiome and translating it to architectural practice.

News article: Researchers outline progress in turning bacteria into mini construction workers – The Construction Index (OA)

Setting bacteria to work as mini construction workers to repair concrete was one of the research topics covered at a major science conference in the USA last week. (…) Certain bacteria produce calcium carbonate as a metabolic product. The scientists soak balls of clay with the spores of these bacteria and mix the balls into concrete. Once water penetrates the concrete, the microorganisms become active and release calcium carbonate, one of the main components of concrete. “The bacteria can close cracks of up to a few millimeters in width in a matter of a few days,” said Grosse.

Call in sick

Discovery of cahuitamycins as biofilm inhibitors derived from a convergent biosynthetic pathway – Sung Ryeol Park – Nature Communications (OA). Also see the press release by the University of Michigan.

Pathogenic microorganisms often have the ability to attach to a surface, building a complex matrix where they colonize to form a biofilm. This cellular superstructure can display increased resistance to antibiotics and cause serious, persistent health problems in humans. Here we describe a high-throughput in vitro screen to identify inhibitors of Acinetobacter baumannii biofilms using a library of natural product extracts derived from marine microbes. Analysis of extracts derived from Streptomyces gandocaensis results in the discovery of three peptidic metabolites.

Air dispersed essential oils combined with standard sanitization procedures for environmental microbiota control in nosocomial hospitalization rooms – Fabrizio Gelmini – Complementary Therapies in Medicine ($$)

Aim of this study was to evaluate the efficacy of nebulized selected essential oils (EO) in reducing the microbial contamination in residential health care house rooms. (…) Reductions in both bacterial and fungal contamination were observed between rooms cleaned using standard sanitization alone or in combination with essential oils nebulization.

Note: not sure if it is a good idea to use Bacillus spores next to immunocompromised patients. I am also concerned about their Ethics approval.  Impact of a Probiotic-Based Cleaning Intervention on the Microbiota Ecosystem of the Hospital Surfaces: Focus on the Resistome Remodulation – Elisabetta Caselli – PLOS ONE (OA)

Recently we observed that an innovative approach, based on a cleanser added with spores of non-pathogenic probiotic Bacilli, was effective in stably counteracting the growth of several pathogens contaminating hospital surfaces. Here, we wanted to study the impact of the Bacillus-based cleanser on the drug-resistance features of the healthcare pathogens population. In parallel, the ability of cleanser-derived Bacilli to infect hospitalized patients was also investigated. (…) These results indicate that this probiotic-based procedure is active not only in controlling surface microbial contamination but also in lowering drug-resistant species, suggesting that it may have relevant clinical and therapeutical implications for the management of HAIs.

Poop and the City

Lower Neighborhood Socioeconomic Status Associated with Reduced Diversity of the Colonic Microbiota in Healthy Adults – Gregory E. Miller – PLOS ONE (OA)

This study examined whether socioeconomic-status was associated with alpha-diversity of the colonic microbiota. Forty-four healthy adults underwent un-prepped sigmoidoscopy, during which mucosal biopsies and fecal samples were collected. Subjects’ zip codes were geocoded, and census data was used to form a composite indicator of neighborhood socioeconomic-status, reflecting household income, educational attainment, employment status, and home value.(…) In these models neighborhood socioeconomic-status continued to explain 11—22 percent of the variability in diversity indicators.

Assessment of the influence of intrinsic environmental and geographical factors on the bacterial ecology of pit latrines – Belen Torondel – Microbial Biotechnology (OA)

(…) bacterial diversity and composition was studied in 30 latrines in Tanzania and Vietnam using pyrosequencing of 16S rRNA genes, and correlated with a number of intrinsic environmental factors such as pH, temperature, organic matter content/composition and geographical factors. Clear differences were observed at the operational taxonomic unit, family and phylum level in terms of richness and community composition between latrines in Tanzania and Vietnam. The results also clearly show that environmental variables, particularly substrate type and availability, can exert a strong structuring influence on bacterial communities in latrines from both countries.

Water and waste

Pathogens in Ornamental Waters: A Pilot Study – Maria Nascimento – MDPI Int. J. Environ. Res. Public Health (OA)

In parks, ornamental waters of easy access and populated with animals are quite attractive to children and yet might hide threats to human health. The present work focuses on the microbiota of the ornamental waters of a Lisboa park, characterized during 2015. The results show a dynamic microbiota integrating human pathogens such as Klebsiella pneumoniae, Aeromonas spp. and Enterobacter spp., and also antibiotic resistant bacteria.

Efficacy of dental unit waterlines disinfectants on a polymicrobial biofilm – Damien Costa – Water Research ($$)

Due to their high surface-volume ratio, their laminar flow and frequent stagnation periods, dental unit waterlines (DUWL) foster the attachment of microorganisms and the development of biofilm, resulting in the continuous contamination of the outlet water from dental units; this contamination may be responsible for a potential risk of infection due to the exposure of patients and medical staff to droplet inhalation or splashed water. In this study, the anti-biofilm activity of three disinfectants recommended by dental unit manufacturers —Calbenium©, Oxygenal 6© and Sterispray© — was evaluated.

Characterization of bacterial communities in wetland mesocosms receiving pharmaceutical-enriched wastewater – Dongqing Zhang – Ecological Engineering ($$)

A 16S rRNA gene multiplex 454 pyrosequencing approach was used to characterize the structure of the bacterial community in subsurface flow constructed wetlands planted with Typha angustifolia and unplanted wetland mesocosms receiving ibuprofen-enriched wastewater at a concentration of 250 μg L−1. (…) The efficient ibuprofen removal observed in this study suggested that the IBP-enriched wetland systems may have selected a restricted group of bacteria that was able to survive best in the disturbed condition and participate in the IBP biodegradation.

Spoiler alerts

Screening for Viral Pathogens in African Simian Bushmeat Seized at A French Airport – Sarah Temmam – Transboundary and Emerging Diseases ($$)

The hunting, manipulation and consumption of wildlife-based products, especially those of primate origin, may be a threat to human health; however, few studies have investigated the role of bushmeat trade and consumption as a potential source of human infections to date. In this study, we report the screening of viral pathogens in African simian game seized by French customs at Toulouse Blagnac Airport. (…) A large-scale inventory of bacteria, viruses and parasites is urgently needed to globally assess the risk for human health of the trade, manipulation and consumption of wildlife-related bushmeat.

Not much microbiology here: Changes of microbial spoilage, lipid-protein oxidation and physicochemical properties during post mortem refrigerated storage of goat meat – Azad Behnan Sabow – Animal Science Journal ($$)

Examined was the effect of post mortem refrigerated storage on microbial spoilage, lipid-protein oxidation and physicochemical traits of goat meat. Seven Boer bucks were slaughtered, eviscerated and aged for 24 h. The Longissimus lumborum (LL) and Semitendinosus (ST) muscles were excised and subjected to 13 days post mortem refrigerated storage. The pH, lipid and protein oxidation, tenderness, color and drip loss were determined in LL while microbiological analysis was performed on ST.