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Over the last 15 years, microbially induced calcite precipitation (MICP) has emerged as a possible solution to mitigate coastal erosion. To date, most MICP soil treatments that have been studied involve column injection using a pump. In recent years, MICP application through surface percolation has gained traction as an alternative technique, but data using this technique are limited. More recently, a new treatment recipe/technique was developed, and this technique was termed bioslurry. Like most MICP studies, research with bioslurry has concentrated on the column injection method, and surface percolation has received very limited attention. This paper discusses the treatment of Florida beach sand by surface percolating bioslurry. Researchers experimented with variations of the bioslurry recipe to optimize erosion resistance, which was assessed using a pocket erodometer combined with physical measurements. In addition, treated specimen morphology was preliminarily examined using X-ray diffraction and scanning electron microscopy. Results showed that erosion resistance was maximized when 15% to 25% of the specimens' pore volumes were filled with bioslurry and that this erosion resistance may be sufficient to withstand worst-case storm events after only one treatment. In addition, previous researchers always used a relatively long (i.e., ∼12 h) stir time when preparing bioslurry. Results presented here show that it may be possible to produce comparable data with much shorter stir times (i.e., 1 to 2 h). [ABSTRACT FROM AUTHOR]

Previous studies have demonstrated that fruiting body-derived Myxococcus xanthus myxospores contain two fully replicated copies of its genome, implying developmental control of chromosome replication and septation.In this study, we employ DNA replication inhibitors to determine if chromosome replication is essential to development and the exact time frame in which chromosome replication occurs within the developmental cycle. Our results show that DNA replication during the aggregation phase is essential for developmental progression, implying the existence of a checkpoint that monitors chromosome integrity at the end of the aggregation phase.

Previous studies have demonstrated that fruiting body-derived Myxococcus xanthus myxospores contain two fully replicated copies of its genome, implying developmental control of chromosome replication and septation. In this study, we employ DNA replication inhibitors to determine if chromosome replication is essential to development and the exact time frame in which chromosome replication occurs within the developmental cycle. Our results show that DNA replication during the aggregation phase is essential for developmental progression, implying the existence of a checkpoint that monitors chromosome integrity at the end of the aggregation phase. [ABSTRACT FROM AUTHOR]

Antibiotic-resistant strains of Klebsiella pneumoniae often exhibit porin loss. In this study, we investigated how porin loss impacted the composition of secreted outer membrane vesicles as well as their ability to trigger proinflammatory cytokine secretion by macrophages. We hypothesize that porin loss associated with antibiotic resistance will directly impact both the composition of outer membrane vesicles and their interactions with phagocytic cells. Using clonally related clinical isolates of extended-spectrum beta-lactamase (ESBL)-positive Klebsiella pneumoniae with different patterns of porin expression, we demonstrated that altered expression of OmpK35 and OmpK36 results in broad alterations to the protein profile of secreted vesicles. Additionally, the level of OmpA incorporation was elevated in strains lacking a single porin. Porin loss significantly impacted macrophage inflammatory responses to purified vesicles. Outer membrane vesicles lacking both OmpK35 and OmpK36 elicited significantly lower levels of proinflammatory cytokine secretion than vesicles from strains expressing one or both porins. These data demonstrate that antibiotic resistance-associated porin loss has a broad and significant effect on both the composition of outer membrane vesicles and their interactions with phagocytic cells, which may impact bacterial survival and inflammatory reactions in the host., (Copyright © 2016, American Society for Microbiology. All Rights Reserved.)

Nocardia asteroides causes an acute, necrotizing pneumonia characterized by extensive infiltration of polymorphonuclear neutrophils (PMNs) into the lungs. Although PMNs have historically been classified as end-point cells, recent investigations have indicated that PMNs have the ability to secrete cytokines such as interleukin (IL)-4 and IL-12. This study investigated the ability of PMNs to produce cytokines in a murine model of N. asteroides pulmonary infection. Flow cytometric analysis demonstrated the production of interferon-gamma (IFN-gamma), but not IL-4, by PMNs in response to this infection. IFN-gamma production correlated with peak infiltration of PMNs into the lungs. Cell sorting and enzyme-linked immunosorbent assay were used to confirm cytokine production by cells with nuclear morphology characteristic of PMNs. This is the first report of IFN-gamma production by neutrophils in response to an infection in vivo. These results suggest that PMNs play an important role in directing the host toward a T helper cell type 1 phenotypic response in the lungs.