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Biological Sciences Faculty Publications

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Articles 61 - 76 of 76

Full-Text Articles in Microbiology

Sensory Genes And Mate Choice: Evidence That Duplications, Mutations, And Adaptive Evolution Alter Variation In Mating Cue Genes And Their Receptors, Lisa Horth Jan 2007

Sensory Genes And Mate Choice: Evidence That Duplications, Mutations, And Adaptive Evolution Alter Variation In Mating Cue Genes And Their Receptors, Lisa Horth

Biological Sciences Faculty Publications

Fascinating new data, revealed through gene sequencing, comparative genomics, and genetic engineering, precisely establish which genes are involved in mate choice and mating activity—behaviors that are surprisingly understudied from a genetic perspective. Discussed here are some of the recently identified visual and chemosensory genes that are involved in mate choice and mating behavior. These genes’ products are involved in the production, transmission, and receipt of crucial sensory mate-choice cues that affect fitness. This review exposes newfound evidence that alternative splicing, gene-expression pattern changes, and molecular genetic variation in sensory genes are crucial for both intra- and interspecific mate choice and …

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Design, Synthesis, And Evaluation Of 10-N-Substituted Acridones As Novel Chemosensitizers In Plasmodium Falciparum, Jane X. Kelly, Martin J. Smilkstein, Roland A. Cooper, Kristin D. Lane, Robert A. Johnson, Aaron Janowsky, Rozalia A. Dodean, David J. Hinrichs, Rolf Winter, Michael Riscoe Jan 2007

Design, Synthesis, And Evaluation Of 10-N-Substituted Acridones As Novel Chemosensitizers In Plasmodium Falciparum, Jane X. Kelly, Martin J. Smilkstein, Roland A. Cooper, Kristin D. Lane, Robert A. Johnson, Aaron Janowsky, Rozalia A. Dodean, David J. Hinrichs, Rolf Winter, Michael Riscoe

Biological Sciences Faculty Publications

A series of novel 10-N-substituted acridones, bearing alkyl side chains with tertiary amine groups at the terminal position, were designed, synthesized, and evaluated for the ability to enhance the potency of quinoline drugs against multidrug-resistant (MDR) Plasmodium falciparum malaria parasites. A number of acridone derivatives, with side chains bridged three or more carbon atoms apart between the ring nitrogen and terminal nitrogen, demonstrated chloroquine (CQ)-chemosensitizing activity against the MDR strain of P. falciparum (Dd2). Isobolograrn analysis revealed that selected candidates demonstrated significant synergy with CQ in the CQ-resistant (CQR) parasite Dd2 but only additive (or indifferent) interaction in the CQ-sensitive …

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Ultrastructure Of Mycobacterium Marinum Granuloma In Striped Bass Morone Saxatilis, D. T. Gauthier, W. K. Vogelbein, C. A. Ottinger Jan 2004

Ultrastructure Of Mycobacterium Marinum Granuloma In Striped Bass Morone Saxatilis, D. T. Gauthier, W. K. Vogelbein, C. A. Ottinger

Biological Sciences Faculty Publications

An emerging epizootic of mycobacteriosis currently threatens striped bass Morone saxatilis populations in Chesapeake Bay, USA. Several species of mycobacteria, including Mycobacterium marinum, species resembling M. avium, M. gordonae, M. peregrinum, M. scrofulaceum and M. terrae, and the new species M. shottsii have been isolated from diseased and healthy bass. In this study, we describe the ultrastructure of developing M. marinum granulomas in experimentally infected bass over a period of 45 wk. The primary host response to injected mycobacteria was formation of large macrophage aggregations containing phagocytosed bacilli. M. marinum were always contained within phagosomes. Close …

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Virulence Factors Of The Group A Streptococci And Genes That Regulate Their Expression, Wayne Hines Jan 2004

Virulence Factors Of The Group A Streptococci And Genes That Regulate Their Expression, Wayne Hines

Biological Sciences Faculty Publications

Group A streptococci produce a wide variety of extracellular (cell-associated and released) virulence factors. The function of these factors varies and includes roles in adhesion, spreading, tissue destruction, immune system evasion, and cell toxicity. How these factors are regulated with regard to one another is important for this organism's ability to bring about the variety of diseases this microbe is capable of causing. Therefore, along with the multitude of virulence factors, there are a number of regulatory systems that regulate, either directly or indirectly, the production of these factors and therefore influence the pathogenesis of group A streptococcal infections.

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Dissecting The Loci Of Low-Level Quinine Resistance In Malaria Parasites, Michael T. Ferdig, Roland A. Cooper, Jianbing Mu, Bingbing Deng, Deirdre A. Joy, Xin-Zhuan Su, Thomas E. Wellems Jan 2004

Dissecting The Loci Of Low-Level Quinine Resistance In Malaria Parasites, Michael T. Ferdig, Roland A. Cooper, Jianbing Mu, Bingbing Deng, Deirdre A. Joy, Xin-Zhuan Su, Thomas E. Wellems

Biological Sciences Faculty Publications

Quinine (QN) remains effective against Plasmodium falciparum, but its decreasing efficacy is documented from different continents. Multiple genes are likely to contribute to the evolution of QN resistance. To locate genes contributing to QN response variation, we have searched a P. falciparum genetic cross for quantitative trait loci (QTL). Results identify additive QTL in segments of chromosomes (Chrs) 13, 7 and 5, and pairwise effects from two additional loci of Chrs 9 and 6 that interact, respectively, with the QTL of Chrs 13 and 7. The mapped segments of Chrs 7 and 5 contain pfcrt, the determinant of …

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Identification And Characterization Of A Nontypeable Haemophilus Influenzae Putative Toxin-Antitoxin Locus, Dayle A. Daines, Justin Jarisch, Arnold L. Smith Jan 2004

Identification And Characterization Of A Nontypeable Haemophilus Influenzae Putative Toxin-Antitoxin Locus, Dayle A. Daines, Justin Jarisch, Arnold L. Smith

Biological Sciences Faculty Publications

Background: Certain strains of an obligate parasite of the human upper respiratory tract, nontypeable Haemophilus influenzae (NTHi), can cause invasive diseases such as septicemia and meningitis, as well as chronic mucosal infections such as otitis media. To do this, the organism must invade and survive within both epithelial and endothelial cells. We have identified a facilitator of NT(Hi) survival inside human cells, virulence-associated protein D (vapDHi, encoded by gene H10450). Both vapDHi and a flanking gene, H10451, exhibit the genetic and physical characteristics of a toxin/antitoxin ( TA) locus, with VapDHi serving as the …

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Isolation And Characterization Of Mycobacteria From Striped Bass Morone Saxatilis From The Chesapeake Bay, Martha W. Rhodes, Howard Kator, Ilsa Kaattari, David Gauthier, Wolfgang Vogelbein, Christopher A. Ottinger Jan 2004

Isolation And Characterization Of Mycobacteria From Striped Bass Morone Saxatilis From The Chesapeake Bay, Martha W. Rhodes, Howard Kator, Ilsa Kaattari, David Gauthier, Wolfgang Vogelbein, Christopher A. Ottinger

Biological Sciences Faculty Publications

Mycobacteriosis in striped bass Morone saxatilisof Chesapeake Bay, USA, was first diagnosed in 1997 based on the presence of granulomatous inflammation and acid-fast bacteria in skin and spleen. To confirm histopathology, bacteriological detection and identification of mycobacteria were begun using splenic tissue from fish with and without skin ulcerations. On the basis of initial studies using a variety of selective and nonselective media, decontamination, homogenization and incubation conditions, a simple and quantitative recovery method using aseptic necropsy of splenic tissue was developed. Optimal recovery was obtained by spread-plating homogenates on Middlebrook 7H10 agar with incubation for 3 mo at …

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Experimental Mycobacteriosis In Striped Bass Morone Saxatilis, D. T. Gauthier, M. W. Rhodes, W. K. Vogelbein, H. Kator, C. A. Ottinger Jan 2003

Experimental Mycobacteriosis In Striped Bass Morone Saxatilis, D. T. Gauthier, M. W. Rhodes, W. K. Vogelbein, H. Kator, C. A. Ottinger

Biological Sciences Faculty Publications

Striped bass Morone saxatilis were infected intraperitoneally with approximately 105 Mycobacterium marinum, M. shottsii sp. nov., or M. gordonae. Infected fish were maintained in a flow-through freshwater system at 18 to 21°C, and were examined histologically and bacteriologically at 2, 4, 6, 8, 17, 26, 36 and 45 wk post-infection (p.i.). M. marinum caused acute peritonitis, followed by extensive granuloma development in the mesenteries, spleen and anterior kidney. Granulomas in these tissues underwent a temporal progression of distinct morphological stages, culminating in well-circumscribed lesions surrounded by normal or healing tissue. Mycobacteria were cultured in high numbers from …

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Multiple Transporters Associated With Malaria Parasite Responses To Chloroquine And Quinine, Jianbing Mu, Michael T. Ferdig, Xiaorong Feng, Deirdre A. Joy, Junhui Duan, Tetsuya Furuya, G. Subramanian, L. Aravind, Roland A. Cooper, John C. Wootton, Momia Xiong, Xin-Zhuan Su Jan 2003

Multiple Transporters Associated With Malaria Parasite Responses To Chloroquine And Quinine, Jianbing Mu, Michael T. Ferdig, Xiaorong Feng, Deirdre A. Joy, Junhui Duan, Tetsuya Furuya, G. Subramanian, L. Aravind, Roland A. Cooper, John C. Wootton, Momia Xiong, Xin-Zhuan Su

Biological Sciences Faculty Publications

Mutations and/or overexpression of various transporters are known to confer drug resistance in a variety of organisms. In the malaria parasite Plasmodium falciparum, a homologue of P-glycoprotein, PfMDR1, has been implicated in responses to chloroquine (CO), quinine (ON) and other drugs, and a putative transporter, PfCRT, was recently demonstrated to be the key molecule in CO resistance. However, other unknown molecules are probably involved, as different parasite clones carrying the same pfcrt and pfmdr1 alleles show a wide range of quantitative responses to CO and ON. Such molecules may contribute to increasing incidences of ON treatment failure, the molecular basis …

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Rickettsial Infection In Dermacentor Variabilis (Acari : Ixodidae) Inhibits Transovarial Transmission Of A Second Rickettsia, Kevin R. Macaluso, Daniel E. Sonenshine, Shane M. Ceraul, Abdu F. Azad Jan 2002

Rickettsial Infection In Dermacentor Variabilis (Acari : Ixodidae) Inhibits Transovarial Transmission Of A Second Rickettsia, Kevin R. Macaluso, Daniel E. Sonenshine, Shane M. Ceraul, Abdu F. Azad

Biological Sciences Faculty Publications

This study examined the ability of ticks to maintain multiple species of spotted fever group rickettsiae via transovarial transmission. Using a capillary feeding method, previously established Rickettsia montana- and Rickettsia rhipicephali-infected cohorts of Dermacentor variabilis (Say) were exposed to R. rhipicephali and R. montana, respectively, in two reciprocal challenge experiments. Eggs collected from individual females, for two successive generations, of each cohort were assessed for rickettsial infection by polymerase chain reaction for each challenge experiment. Assessment of the eggs from challenged ticks identified that both R. montana- and R. rhipicephali-infected ticks were refractory to their …

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Hyaluronidases Of Gram-Positive Bacteria, Wayne L. Hynes, Sheryl Lynne Walton Jan 2000

Hyaluronidases Of Gram-Positive Bacteria, Wayne L. Hynes, Sheryl Lynne Walton

Biological Sciences Faculty Publications

Bacterial hyaluronidases, enzymes capable of breaking down hyaluronate, are produced by a number of pathogenic Gram-positive bacteria that initiate infections at the skin or mucosal surfaces. Since reports of the hyaluronidases first appeared, there have been numerous suggestions as to the role of the enzyme in the disease process. Unlike some of the other more well studied virulence factors, much of the information on the role of hyaluronidase is speculative, with little or no data to substantiate proposed roles. Over the last 5 years, a number of these enzymes from Gram-positive organisms have been cloned, and the nucleotide sequence determined. …

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Response Of The Tick Dermacentor Variabilis (Acari: Ixodidae) To Hemocoelic Inoculation Of Borrelia Burgdorferi (Spirochetales), Robert Johns, Daniel E. Sonenshine, Wayne L. Hynes Jan 2000

Response Of The Tick Dermacentor Variabilis (Acari: Ixodidae) To Hemocoelic Inoculation Of Borrelia Burgdorferi (Spirochetales), Robert Johns, Daniel E. Sonenshine, Wayne L. Hynes

Biological Sciences Faculty Publications

When Borrelia burgdorferi B31 low passage strain spirochetes were directly injected into the hemocoel of Dermacentor variabilis(Say) females, the bacteria were cleared from the hemocoel within < 24 h. Viable spirochetes were not found in hemolymph, salivary gland, or ovary tissues by subculturing or by IFA. The hemocyte population increased ≈6 times within the first 6 h after inoculation compared with the uninoculated controls. In contrast, the soluble total hemolymph protein content decreased inversely with the increase in hemocytes. Borreliacidal activity was demonstrated with cell-free hemolymph from D. variabilis. In vitro antimicrobial assays using hemolymph from borrelia-challenged and nonchallenged ticks resulted in 72% spirochete reductions compared with only 11.5%, respectively, within 1 h. Additional evidence of induced antimicrobial hemolymph protein activity was demonstrated by SDS-PAGE, which revealed upregulation of a lysozyme-like peptide (≈ 15 kDa) (22% increase) and the induction of a ≈ 5.8 kDa peptide in the B. burgdorferi-challenged ticks. In contrast with the nonvector borne Bacillus subtilis …

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Nucleotide Sequence Of The Streptococcin A-Ff22 Lantibiotic Regulon: Model For Production Of The Lantibiotic Sa-Ff22 By Strains Of Streptococcus Pyogenes, Robert E. Mclaughlin, Joseph J. Ferretti, Wayne L. Hynes Jan 1999

Nucleotide Sequence Of The Streptococcin A-Ff22 Lantibiotic Regulon: Model For Production Of The Lantibiotic Sa-Ff22 By Strains Of Streptococcus Pyogenes, Robert E. Mclaughlin, Joseph J. Ferretti, Wayne L. Hynes

Biological Sciences Faculty Publications

Streptococcin A-FF22 (SA-FF22) is a type AII linear lantibiotic produced by Streptococcus pyogenes strain FF22. Sequence analysis of an approximate 10 kb region of DNA showed it to contain nine open reading frames arranged in three operons responsible for regulation, biosynthesis and immunity of SA-FF22. This region is organized similarly to the Lactococcus lactis lacticin 481 region, however, unlike lacticin 481, a two-component regulatory system is essential for SA-FF22 production. located immediately downstream of the scn region is a putative transposase gene, the presence of which supports earlier data that indicated a mobile nature to this region. (©) 1999 Published …

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Cascading Disturbances In Florida Bay, Usa: Cyanobacteria Blooms, Sponge Mortality, And Implications For Juvenile Spiny Lobsters Panulirus Argus, Mark J. Butler Iv, John H. Hunt, William F. Herrnkind, Michael J. Childress, Rodney Bertelsen, William Sharp, Thomas Matthews, Jennifer M. Field, Harold G. Marshall Dec 1995

Cascading Disturbances In Florida Bay, Usa: Cyanobacteria Blooms, Sponge Mortality, And Implications For Juvenile Spiny Lobsters Panulirus Argus, Mark J. Butler Iv, John H. Hunt, William F. Herrnkind, Michael J. Childress, Rodney Bertelsen, William Sharp, Thomas Matthews, Jennifer M. Field, Harold G. Marshall

Biological Sciences Faculty Publications

Florida Bay, the shallow lagoon separating mainland Florida and the Florida Keys, USA, is experiencing an unprecedented series of ecological disturbances. In 1991, following reports of other ecosystem perturbations, we observed widespread and persistent blooms of cyanobacteria that coincided with the decimation of sponge communities over hundreds of square kilometers. Juvenile Caribbean spiny lobsters Panulirus argus, among other animals, rely on sponges for shelter; the impact of sponge loss on the abundance of lobsters and their use of shelter, in particular, has been dramatic. The loss of sponges on 27 experimental sites in hard bottom habitat in central Florida Bay …

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Identification Of A Protein In Several Borrelia Species Which Is Related To Ospc Of The Lyme Disease Spirochetes., Richard T. Marconi, D. Scott Samuels, Tom G. Schwan, Claude F. Garon Oct 1993

Identification Of A Protein In Several Borrelia Species Which Is Related To Ospc Of The Lyme Disease Spirochetes., Richard T. Marconi, D. Scott Samuels, Tom G. Schwan, Claude F. Garon

Biological Sciences Faculty Publications

Using oligonucleotide probes which have previously been shown to be specific for the ospC gene found in the Lyme disease spirochete species Borrelia burgdorferi, B. garinii, and group VS461, we detected an ospC homolog in other Borrelia species including B. coriaceae, B. hermsii, B. anserina, B. turicatae, and B. parkeri. In contrast to the Lyme disease spirochetes, which carry the ospC gene on a 26-kb circular plasmid, we mapped the gene in other Borrelia species to linear plasmids which varied in size among the isolates tested. Some isolates carry multiple copies of the gene residing on linear plasmids of different …

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Coumermycin A1 Inhibits Growth And Induces Relaxation Of Supercoiled Plasmids In Borrelia Burgdorferi, The Lyme Disease Agent, D. Scott Samuels, Claude F. Garon Jan 1993

Coumermycin A1 Inhibits Growth And Induces Relaxation Of Supercoiled Plasmids In Borrelia Burgdorferi, The Lyme Disease Agent, D. Scott Samuels, Claude F. Garon

Biological Sciences Faculty Publications

Coumermycin A1 is an inhibitor of DNA gyrase, an enzyme that catalyzes supercoiling of DNA and is required for bacterial DNA replication. We have investigated the activity of this coumarin antibiotic on Borrelia burgdorferi, a spirochete and the causative agent of Lyme disease. B. burgdorferi was more susceptible than many other eubacteria to coumermycin as well as novobiocin, another coumarin antibiotic; this contrasted with its relative resistance to the DNA gyrase inhibitors nalidixic acid, oxolinic acid, and ciprofloxacin. Coumermycin at 0.2 micrograms/ml inhibited the growth of B. burgdorferi B31 in BSK II medium. A 100-fold-lower concentration induced the relaxation of …

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