Spatial Epidemiologic Analysis and Risk Factors for Nontuberculous Mycobacteria Infections, Missouri, USA, 2008–2019

Nontuberculous mycobacteria (NTM) infections are caused by environmental exposure. We describe spatial distribution of NTM infections and associations with sociodemographic factors and flooding in Missouri, USA. Our retrospective analysis of mycobacterial cultures reported to the Missouri Department of Health and Social Services surveillance system during January 1, 2008–December 31, 2019, detected geographic clusters of infection. Multilevel Poisson regression quantified small-area geographic variations and identified characteristics associated with risk for infection. Median county-level NTM infection rate was 66.33 (interquartile range 51–91)/100,000 persons. Risk of clustering was significantly higher in rural areas (rate ratio 2.82, 95% CI 1.90–4.19) and in counties with >5 floodings per year versus no flooding (rate ratio 1.38, 95% CI 1.26–1.52). Higher risk for NTM infection was associated with older age, rurality, and more flooding. Clinicians and public health professionals should be aware of increased risk for NTM infections, especially in similar environments

Intrinsic Differences between Oral and Skin Keratinocytes

<div><p>Keratinocytes cover both the skin and some oral mucosa, but the morphology of each tissue and the behavior of the keratinocytes from these two sites are different. One significant dissimilarity between the two sites is the response to injury. Oral mucosal wounds heal faster and with less inflammation than equivalent cutaneous wounds. We hypothesized that oral and skin keratinocytes might have intrinsic differences at baseline as well as in the response to injury, and that such differences would be reflected in gene expression profiles.</p></div

Differentially Expressed Molecules Related to Cellular Movement and Proliferation.

<p>*Keratin 13 (KRT13), Keratin 4 (KRT4), Paired-like homeodomain 2 (PITX2), Secretory Leukocyte Peptidase Inhibitor (SLPI), Alpha-2-HSglycoprotein (AHSG), CD36 molecule (thrombospond receptor) (CD36), Activated Leukocyte Cell Adhesion Molecule (ALCAM), Matrix Metallopeptidase 3 (MMP3), Kallikrein-related peptidase 6 (KLK6).</p><p>Differentially Expressed Molecules Related to Cellular Movement and Proliferation.</p

Oral and Skin keratinocyte wound closure after <i>In Vitro</i> wound scratching.

<p>Human primary oral and skin keratinocyte monolayers were wounded by scratches. <b>A</b>) The defined areas were photographed at 0, 6 and 24 hours after wounding. <b>B</b>) The number of cells in the denuded initial area were counted. Number of cells 6 hours post scratch: oral 83.4±10.9 vs skin 23.8±6.4. Number of cells 24 hours post scratch: oral 317.3±24.8 vs skin 118.0±37.6 *P<0.01. Student's t-test was used to compare the difference between oral and skin wounds at each time point and two-way ANOVA was used to evaluate grouped data over time. N = 3.</p

Top Biological Functions at each location.

<p>Fischer's exact test was used to calculate a p-value (<0.01) determining the probability each biological function assigned to data set is due to chance alone. Ingenuity Pathway Analysis software.</p

Comparison of skin and oral keratinocyte migration by Gold-Colloidal Migration Assay.

<p>Photographs are representative examples of the tracks made by single cells. The sum of the track areas in the field was divided by the total area of the field and multiplied by 100 to yield the percentage of each field taken up by tracks. This percentage was called the migration index (MI). <b>A</b>) Representative migration assay slides of paired human skin and oral keratinocytes. <b>B</b>) Skin keratinocyte MI 5.1±1.5 and oral keratinocyte MI 13.0±2.7 respectively. Average migration fold ratio of (2.6 fold) oral/skin of N = 3 independent paired oral and skin keratinocyte migration assays.</p