Department of Biology

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https://hdl.handle.net/20.500.14291/8356

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Now showing 1 - 5 of 12
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    Detection of Cronobacter sakazakii in powdered infant milk formula using real-time PCR
    (2010-11-30) Kim, Myoung-Su; Ball State University
    Cronobacter sakazakii is a neonatal pathogen that has been found commonly in contaminated dried infant milk formula and milk powder. The fluorogenic selective marker, 4-Methylumbelliferyl-α-D-glucoside and secondary selective markers, sodium thiosulfate & ferric citrate have been used in differential media to indicate the presence of C. sakazakii based on α-D-glucosidase enzymes unique to this pathogen. This research will compare four enrichment broths for maximum recovery from powdered infant milk formula: C. sakazakii – Enterobacter sakazakii enrichment (ESE) broth, Tryptic Soy Broth (TSB), Enterobacteriaceae enrichment (EE) broth, and M-Coliform broth. Differential selective and nonselective agars including Trypticase Soy Agar (TSA), Violet red bile agar (VRBA), Violet red bile D-glucose agar (VRBDGA), and a newly developed KJ medium will be compared for the efficacy of isolation for the species and for optimal α-D-glucosidase activity with the fluorogenic selective marker, 4-Methylumbelliferyl- α-D-glucoside and secondary selective markers. C. sakazakii strains ATCC 29544, ATCC 29004, ATCC 12868, and ATCC 51329 will be utilized as positive controls to run in artificially contaminated powder infant milk formula (PIMF) with each enrichment broth. DNA will be extracted from enrichments, which will be examined using real-time TaqMan PCR in order to compare to culture-based detection to determine relative sensitivities between the two approaches. The fluorogenic selective marker, secondary selective markers, and using a TaqMan probe PCR protocol will prove to be a rapid and specific powerful tool for the detection of Cronobacter sakazakii in powdered infant milk formula.
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    Yellow Perch Length-Fecundity and Length-Egg Size Relationships in Indiana Waters of Lake Michigan
    (2006) Lauer, Thomas S.; Shroyer, Steven M.; Kilpatrick, John M.; McComish, Thomas S.; Allen, Paul J.; Ball State University, Department of Biology, Aquatic Biology and Fisheries Center
    This study was undertaken to quantify the length-fecundity and length-egg size relationships for yellow perch Perca flavescens in the Indiana waters of Lake Michigan. Data were pooled from gill net collections made in 1985-86 and 1999, resulting in a wide length range of mature female yellow perch (172-332 mm TL). The length - fecundity relationship was: log10F = -3.220 + 3.223 log10TL (r2 = 0.89), where F = fecundity and TL = total length in mm. The mean preserved egg volume increased with yellow perch TL and was represented by the equation: log10V = - 2.06 + 1.10 log10TL (r2 = 0.48), where V = preserved egg volume (mL), and TL = total length. These results reveal that larger females produced both more and larger eggs than smaller females. Therefore, intense harvest targeting large yellow perch (primarily females) in the 1980s and 1990s may have had an effect on the quantity and quality of eggs spawned by the population, possibly resulting in reduced recruitment.
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    Changes in Mottled Sculpin and Johnny Darter Trawl Catches after the Appearance of Round Gobies in the Indiana Waters of Lake Michigan
    (2004) Lauer, Thomas E.; Allen, Paul J.; McComish, Thomas S.; Ball State University, Department of Biology, Aquatic Biology and Fisheries Center
    We investigated the response of the mottled sculpin Cottus bairdi and the johnny darter Etheostoma nigrum to the invasion and proliferation of the round goby Neogobius melanostomus at three near-shore locations in southern Lake Michigan. Fish were collected by trawling from June through August, 1984 to 2002. Mean annual catches of mottled sculpins in trawl samples ranged from 0 to 4.4/h from 1984 to 1998, while mean annual johnny darter catches ranged from 0 to 29/h in the same period. Round gobies were first sampled in 1998, with relative population abundance building in the following years, ranging up to 371/h at site K by 2001. From 1999 to 2002, only a single mottled sculpin and only 12 johnny darters were collected in 72 hrs of trawling. This study documents the rapid decline of the mottled sculpin and johnny darter following the round goby invasion to this portion of the lake.
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    Preliminary Results of 2007 Ball State University Yellow Perch Research in Indiana Waters of Lake Michigan
    (2007-10) Lauer, Thomas E.; Doll, Jason C.; Ball State University, Department of Biology, Aquatic Biology and Fisheries Center
    This is a brief update on yellow perch population dynamics in Indiana waters of Lake Michigan and near-shore fish community characteristics based on results of 2007 sampling by the Aquatic Biology and Fisheries Center at Ball State University. Data should be considered provisional, as revisions may be made before publication of our progress report due June 30, 2008.
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    Final Project Report: Dynamics and Models of the Yellow Perch in Indiana Waters of Lake Michigan and Near-Shore Fish Community Characteristics
    (2007-06) Lauer, Thomas E.; Doll, Jason C.; Ball State University, Department of Biology, Aquatic Biology and Fisheries Center
    This document is a final project report report from the period July 1, 2000 – June 30, 2007 conducted by the Aquatic Biology and Fisheries Center, Department of Biology at Ball State University to the Indiana Department of Natural Resources Division of Fish and Wildlife and funded by the Sport Fish Restoration Program and Ball State University.