Microbiology Commons^™

Acute Effects Of Whole-Body Proton Irradiation On The Immune System Of The C57bl/6 Mouse, Eric H. Kajioka

Loma Linda University Electronic Theses, Dissertations & Projects

The acute effects of proton whole-body irradiation (WBI) on leukocytes, lymphocytes, and hematological parameters in the spleen and blood of C57BI/6 mice were examined and compared to the effects of photon (gamma) WBI derived from a 60cobalt (60Co) source. Adult, female C57BL/6 mice were exposed to a single dose (3 Gy, 0.4 Gy/min dose rate) of either proton WBI at the Bragg peak, proton WBI at the entry plateau, or Co WBI, and sacrifice intervals were at 1,4, 7, and 10 days post- WBI. Flow cytometry analysis of the spleen and peripheral blood showed depression in cell counts for all …

Dna-Dna Checkerboard Hybridization To Identify Bacteria In Human Plaque Samples, Jasan Lee Zimmerman

Loma Linda University Electronic Theses, Dissertations & Projects

Previous research has shown that using DNA probes to identify the presence of specific bacteria in human plaque samples is superior to the commonly used anaerobic cultural procedures. Some periodontal pathogens are either uncultivable or very difficult to grow, such as Prevotella intermedia, P. nigrescens, and Eubacterium brachy. Digoxygenin probes were prepared for 15 oral bacteria. These probes were used with a checkerboard DNA-DNA hybridization scheme to analyze whether human plaque samples contained any of the 15 bacterial species. Our results have shown that this method is successful in identifying bacterial DNA present in the subgingival patient plaque …

The Timing And Pattern Of Myogenesis In Hymenochirus Boettgeri, Matthew T. Smetanick, Rafael O. De Sá

Biology Faculty Publications

Differences in the relative timing of homologous developmental events among closely related species, known as heterochronies, may provide valuable clues in understanding evolutionary relationships (McKinney, 1988; McNamara, 1995). Examining the timing of myogenic events is a relatively easy and effective method for finding heterochronic events. For example, whether muscle proteins and myofibrils appear before or after multinucleation can be determined through histological techniques (Kielbowna, 1981). Simple observations of live specimens can pinpoint functional landmarks such as first twitch (spontaneous or due to external stimuli) and first heartbeat.

Engineering Secreted Proteins For Gene Transfer And Dna Vaccination, Jingxue Liu

Loma Linda University Electronic Theses, Dissertations & Projects

In recent years gene therapy has become a promising way of alleviating incurable human ailments, its concept emerging as the ultimate therapy for many infectious and genetic diseases. Two important aspects of the development of successful gene therapy protocols are the ability to monitor gene transfer readily, and the establishment of new protocols for treating specific diseases. In this work, Renilla luciferase and human glutamic acid decarboxylase (GAD) 65 were engineered for secretion to address some aspects of these issues.

Secreted reporter proteins are promising tools to study gene transfer and expression in a non-destructive manner, and bioluminescent proteins are …

Control Of Cell Shape And Elongation: The Mreb Protein Of Escherichia Coli., Jason Gioia

Honors Capstones

No abstract provided.

Multicenter Comparison Of Pcr Assays For Detection Of Human Herpesvirus 8 Dna In Semen, Philip E. Pellett, Thomas J. Spira, Omar Bagasra, Chris Boshoff, Lawrence Corey, Laura De Lellis, Meei-Li Huang, Jung-Chung Lin, Steve Matthews, Paolo Monini, Paola Romessi, Carlos Sosa, Charles Wood, John A. Stewart

Nebraska Center for Virology: Faculty Publications

Reported prevalences of human herpesvirus 8 (HHV-8) (Kaposi’s sarcoma-associated herpesvirus) in semen have ranged widely. This is possibly due to differences in assay sensitivity, geographic or population-based differences in the true presence of the virus in semen, and PCR contamination. This study assessed interlaboratory sensitivity and reproducibility in the analysis of blinded experimental panels, each consisting of 48 specimens and being composed of semen specimens from different healthy artificial-insemination donors (n = 30) and human immunodeficiency virus (HIV)-infected patients (n= 7) plus positive (n = 4) and negative (n = 7) controls. The experimental panels analyzed in each laboratory were …

Pyoveridine Production By Pseudomonas Aeruginosa Exposed To Metals Or An Oxidative Stress Agent, Kim-Hien Thi Dao, Katherine E. Hamer, Christine L. Clark, Lawrence G. Harshman

School of Biological Sciences: Faculty Publications

Siderophores are low molecular mass compounds used by many microorganisms to scavenge dissolved iron, which is typically rare in environments. Pseudomonas aeruginosa (PAO1) was exposed to metals and methyl viologen in low-iron medium in order to monitor the abundance of a specific siderophore (pyoverdine) and monitor growth over time. In this study it was discovered that cadmium can stimulate pyoverdine abundance. Cadmium may interact with and sequester the Fur regulatory protein, which represses siderophore synthesis under conditions of iron sufficiency. Mercury did not stimulate pyoverdine production at concentrations that strongly inhibited bacterial growth, suggesting that pyoverdine production is not governed …

The Mycobactericidal Efficacy Of Orthophthalaldehyde And The Comparative Resistances Of Mycobacterium Bovis, Mycobacterium Terrae, And Mycobacterium Chelonae, Richard A. Robison, Adam W. Gregory, G. Bruce Schaalje, Jonathan D. Smart

Faculty Publications

Objectives: To assess the mycobactericidal efficacy of an agent relatively new to disinfection, ortho-phthalaldehyde (OPA) and to compare the resistances of three Mycobacterium species. Mycobacterium bovis (strain BCG) was compared with Mycobacterium chelonae and Mycobacterium terrae to investigate the feasibility of using either of the latter two species in tuberculocidal testing. M chelonae (a rapid grower) and M terrae (an intermediate grower) both grow faster and are less virulent than M bovis (a slow grower).

Development Of The Suprarostral Plate Of Pipoid Frogs, Rafael O. De Sá, Charles C. Swart

Biology Faculty Publications

The rostral region of nonpipoid tadpoles has two sets of cartilages, the cornua trabeculae and the suprarostral cartilages, whereas the rostral region in pipoid larvae is occupied by a single and continuous cartilage, the suprarostral plate. The homology of this region in pipoid and nonpipoids tadpoles has been controversial. We examined the early formation and development of the suprarostral plate using serially cross-sectioned specimens of Rhinophrynus, Xenopus, and Hymenochirus. We conclude that the cartilaginous structures present in the rostral area of pipoid and nonpipoid larvae are homologous. Furthermore, we found two different developmental patterns among pipoid larvae. The chondrocranium …

Interferon Regulatory Factor 2 Represses The Epstein-Barr Virus BamHi Q Latency Promoter In Type Iii Latency, Luwen Zhang, Joseph S. Pagano

Nebraska Center for Virology: Faculty Publications

Epstein-Barr virus (EBV) nuclear antigen 1 (EBNA-1) is the essential protein for maintenance of the EBV episome and establishment of latency. The BamHI Q promoter (Qp) is used for the transcription of EBNA-1 mRNA in type I and type II latency, which are EBV infection states exemplified by Burkitt’s lymphoma and nasopharyngeal carcinoma. However, Qp is inactive in type III latency, and other promoters (the BamHI C promoter and/or the BamHI W promoter) are used for EBNA-1. The involvement of interferon regulatory factors (IRFs) in the regulation of Qp is suggested by the presence of an essential interferon-stimulated response element …

Microbiology Of The Oil Fly, Helaeomyia Petrolei, Dana R. Kadavy, Bradley A. Plantz, Christopher A. Shaw, Jill Myatt, Tyler A. Kokjohn, Kenneth Nickerson

Papers in Microbiology

Helaeomyia petrolei larvae isolated from the asphalt seeps of Rancho La Brea in Los Angeles, Calif., were examined for microbial gut contents. Standard counts on Luria-Bertani, MacConkey, and blood agar plates indicated ca. 2 x 10⁵ heterotrophic bacteria per larva. The culturable bacteria represented 15 to 20% of the total population as determined by acridine orange staining. The gut itself contained large amounts of the oil, had no observable ceca, and maintained a slightly acidic pH of 6.3 to 6.5. Despite the ingestion of large amounts of potentially toxic asphalt by the larvae, their guts sustained the growth of …

Nonspecific Interactions Alter Lipopolysaccharide Patterns And Protein Mobility On Sodium Dodecyl Sulfate Polyacrylamide Gels, Aidong Yuan, R L. Pardy, Catherine P. Chia

Papers in Microbiology

In testing whether bacterial lipopolysaccharide (LPS) was a natural substrate for an esterase from the soil amebae Dictyostelium discoideum, we observed altered banding patterns of the LPS and changed protein mobility on sodium dodecyl sulfate (SDS) polyacrylamide gels after incubation of LPS with the enzyme. The initial interpretation of these results was that the enzyme had removed ester-linked acyl chains from the LPS, leading to a change in its migration on gels. However, esterase inactivated by treatment with either dithiothreitol (DTT), heat, or SDS generated the same mobility shifts. Bovine serum albumin (BSA) also induced the same change in …

Clinico-Morphological Pattern Of Intracranial Tumors In Children, Sajid H. Shah, Irshad N. Soomro, Akbar S. Hussainy, S H. Hassan

Department of Pathology and Laboratory Medicine

Objective:
The objective of present study was to observe the histopathological pattern of intracranial tumors in children (< 15 yrs) and to correlate the site of lesion along with the histological diagnosis.
Setting:
The study included consecutive cases of intracranial tumors diagnosed in children (< 15 yrs.) in the section of histopathology at the Aga Khan University Hospital, Karachi during the period of three years.
Methods:
The initial histological evaluation of these lesions was performed on H and E stained section of paraffin embedded tissue. Special stains and immunohistochemical analysis was done whenever indicated.
Results:
During the study period, fifty-four cases of intracranial tumors were diagnosed in children. The age ranged from 1-1/2 years to 4 years with male to female ratio of 1.1:1. Astrocytoma comprised 39% of all intracranial tumors of childhood. Medulloblastoma …

Genetic And Transcriptional Analyses Of The Vibrio Cholerae Mannose-Sensitive Hemagglutinin Type 4 Pilus Gene Locus, Jane W. Marsh, Ronald K. Taylor

Dartmouth Scholarship

The mannose-sensitive hemagglutinin (MSHA) of the Vibrio cholerae O1 El Tor biotype is a member of the family of type 4 pili. Type 4 pili are found on the surface of a variety of gram-negative bacteria and have demonstrated importance as host colonization factors, bacteriophage receptors, and mediators of DNA transfer. The gene locus required for the assembly and secretion of the MSHA pilus has been localized to a 16.7-kb region of the V. cholerae chromosome. Sixteen genes required for hemagglutination, including five that encode prepilin or prepilin-like proteins, have been identified. Examination of MSHA-specific cDNAs has localized two promoters …

Osteological Analysis Of The Killifish Genus Cynolebias (Cyprinodontiformes: Rivulidae), Marcelo Loureiro, Rafael O. De Sá

Biology Faculty Publications

Relationships among the species of the annual fish Cynolebias are unclear. An analysis of the variation and utility of osteological characters for phylogenetic analysis was done using cleared and double-stained specimens representing 21 species of Cynolebias. This analysis showed that some of the characters previously used to diagnose this genus and some of the species are polymorphic. Osteologically, Cynolebias can be diagnosed by the following synapomorphies: (1) triangular-shaped parietal, (2) vomer positioned ventral to the parasphenoid, (3) long ventral process of the dentary, (4) teeth on fourth ceratobranchial, and (5) teeth on first epibranchial. In addition, characters that help …

Relationship Between Udp-Glucose 4-Epimerase Activity And Oligoglucose Glycoforms In Two Strains Of Neisseria Meningitidis, F K. Lee, B W. Gibson, William Melaugh, A Zaleski, M A. Apicella

Chemistry Faculty Publications

Sodium dodecyl sulfate-polyacrylamide gel analysis of lipooligosaccharide (LOS) from Neisseria meningitidis has demonstrated considerable microheterogeneity in the variable region of LOS due to the presence of novel glycoforms. As a step toward understanding the basis for the expression of these novel glycoforms, we have examined the LOS structures and UDP-glucose 4-epimerase (epimerase) activity levels in two strains (NMB and MA-1) and their respective galE mutants. Strain NMB was found to have low epimerase activity and to contain multiple glycoforms, some of which appear to contain only glucose sugars. The galE mutant had only the oligoglucose glycoforms. Strain MA-1 had higher …

Microbial Colonization Of The Cloacae Of Nestling Tree Swallows, Tamara K. Mills, Michael P. Lombardo, Patrick A. Thorpe

Peer Reviewed Publications

Microbes have the potential to be important selective forces in many aspects of avian biology. Microbes can affect fitness as a result of either their pathogenic or beneficial effects on host health. Little is known about the chronology of microbial colonization of nestlings or the effects of microbes on fledgling condition. We set out to (1) characterize the time course of microbial colonization of the cloacae of nestling Tree Swallows (Tachycineta bicolor), (2) examine the relationship between cloacal microbes and fledgling condition, and (3) determine if nest mates had similar assemblages of cloacal microbes. We repeatedly measured nestlings …

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 …

Humboldt Journal Of Microbiology: Volume 2, Number 1- May 1999, Press Humboldt

Humboldt Journal of Microbiology

No abstract provided.

Determination Of The Microbiological Load Of The Principal Meat Products Sold In The Markets Of Riobamba, Miguel Angel Castillo Palacios

Theses and Dissertations

This investigation was done with the objective to determine the microbiological load of the main meat products such as: beef, chicken meat, sausage, and viena sausage which are sold in the Riobamba city markets. This investigation was carried out in the Microbiological Laboratory Livestock Science faculty of the Polytechnical Superior school. Specific chemical products were used to determine mesofilas (37 degrees C), xicrofilas (5 degrees C), and termofilas bacteria which did not develop at 45 degrees C, however exicrofilas and mesofilas bacteria were found in every market and meat product in this study. The meat product hygiene is the same …

Characterization Of The Jembrana Disease Virus Tat Gene And The Cis- And Trans-Regulatory Elements In Its Long Terminal Repeats, Hexin Chen, Graham Wilcox, Gde Kertayadnya, Charles Wood

Nebraska Center for Virology: Faculty Publications

Jembrana disease virus (JDV) is a newly identified bovine lentivirus that is closely related to the bovine immunodeficiency virus (BIV). JDV contains a tat gene, encoded by two exons, which has potent transactivation activity. Cotransfection of the JDV tat expression plasmid with the JDV promoter chloramphenicol acetyltransferase (CAT) construct pJDV-U3R resulted in a substantial increase in the level of CAT mRNA transcribed from the JDV long terminal repeat (LTR) and a dramatic increase in the CAT protein level. Deletion analysis of the LTR sequences showed that sequences spanning nucleotides 268 to 153, including the TATA box and the predicted first …

Chlorella Virus Pbcv-1 Encodes A Functional Homospermidine Synthase, Annette Kaiser, Michael Vollmert, Dorothea Tholl, Michael V. Graves, James Gurnon, Weimei Xing, Amber D. Lisec, Kenneth Nickerson, James L. Van Etten

Kenneth Nickerson Papers

Sequence analysis of the 330-kb genome of chlorella virus Paramecium bursaria chlorella virus 1 (PBCV-1) revealed an open reading frame, A237R, that encodes a protein with 34% amino acid identity to homospermidine synthase from Rhodopseudomonas viridis. Expression of the a237r gene product in Escherichia coli established that the recombinant enzyme catalyzes the NAD⁺-dependent formation of homospermidine from two molecules of putrescine. The a237r gene is expressed late in PBCV-1 infection. Both uninfected and PBCV-1-infected chlorella, as well as PBCV-1 virions, contain homospermidine, along with the more common polyamines putrescine, spermidine, and cadaverine. The total number of polyamine …

Carmoviruses (Tombusviridae), Feng Qu, Thomas Jack Morris

School of Biological Sciences: Faculty Publications

Carmovirus is one of two officially recognized genera of Tombusviridae. Members of Tombusviridae all have icosahedral virions of about 30 nm in diameter with T = 3 symmetry that consists of 180 coat protein (CP) subunits of about 38- 43 kDa and a single-stranded (ss) RNA genome ranging in size from 4.0 to 4.7 kb. Carmoviruses share recognizable sequence similarity in both the polymerase and structural genes with members of the other genus, Tombusvirus. Sequence comparisons and phylogenetic analysis of these genes support the view that the genera are distinct but closely related. In addition, the genome organization of the …

Construction Of An Escherichia Coli Lac Repressor-Based System To Study Human Cytomegalovirus Gene Expression, Laura Fernanda Cageao-Luchetti

Theses and Dissertations in Biomedical Sciences

An Escherichia coli lac repressor-based system was developed to study the roles of human cytomegalovirus (HCMV) genes during viral replication. To this end, a recombinant HCMV expressing the lac repressor was generated (RVlac), and an HCMV-specific promoter was targeted for conditional expression by inserting the lac operator sequence. The promoter of a nonessential gene was chosen in order to be able to assess parameters of repression and derepression of the operator-containing promoter in the endogenous locus, without having virus growth dependent on the specific inducer isopropylthiogalactoside (IPTG). The feasibility of this approach to conditionally express an HCMV promoter …

The Leukemic Protein Core Binding Factor Beta (Cbfbeta)-Smooth-Muscle Myosin Heavy Chain Sequesters Cbfalpha2 Into Cytoskeletal Filaments And Aggregates, Neeraj Adya, Terryl Stacy, Nancy A. Speck, Pu Paul Liu

Dartmouth Scholarship

The fusion gene CBFB-MYH11 is generated by the chromosome 16 inversion associated with acute myeloid leukemias. This gene encodes a chimeric protein involving the core binding factor β (CBFβ) and the smooth-muscle myosin heavy chain (SMMHC). Mouse model studies suggest that this chimeric protein CBFβ-SMMHC dominantly suppresses the function of CBF, a heterodimeric transcription factor composed of DNA binding subunits (CBFα1 to 3) and a non-DNA binding subunit (CBFβ). This dominant suppression results in the blockage of hematopoiesis in mice and presumably contributes to leukemogenesis. We used transient-transfection assays, in combination with immunofluorescence and green fluorescent protein-tagged proteins, to monitor …

Identification And Characterization Of Spcu, A Chaperone Required For Efficient Secretion Of The Exou Cytotoxin, Viviane Finck-Barbançon, Timothy L. Yahr, Dara W. Frank

Dartmouth Scholarship

In recent studies, we have shown that Pseudomonas aeruginosa strains that are acutely cytotoxic in vitro damage the lung epithelium in vivo. Genetic analysis indicated that the factor responsible for acute cytotoxicity was controlled by ExsA and therefore was part of the exoenzyme S regulon. The specific virulence determinant responsible for epithelial damage in vivo and cytotoxicity in vitro was subsequently mapped to the exoU locus. The present studies are focused on a genetic characterization of the exoU locus. Northern blot analyses and complementation experiments indicated that a region downstream of exoU was expressed and that the expression of this …

Analysis Of Protein And Rna Interactions Of The Hiv-1 Rev Protein, John Francis

Loma Linda University Electronic Theses, Dissertations & Projects

The HIV-1 Rev protein enters the nucleus via it’s nuclear localization sequence/RNA binding domain and interacts with a ≈234 nt region of viral RNA, termed the Rev Response Element (RRE), which is located in the env region of unspliced and singly-spliced HIV-1 mRNA. The Rev nuclear export sequence (NES) then mediates translocation of the viral transcript to the cytoplasm, allowing for translation of viral structural genes and active virion formation. We report identification of two yeast nucleopore proteins, NUP49 and NUP100, that have been found to interact with Rev in vivo using the yeast two-hybrid system. NUP49 and NUP100 contain …

Fecal Bacteria Survival And Infiltration Through A Shallow Agricultural Soil: Timing And Tillage Effects, C. S. Stoddard, Mark S. Coyne, John H. Grove

Plant and Soil Sciences Faculty Publications

Human and livestock exposure to fecal pathogens via contaminated surface or groundwater is an important water quality concern for soils receiving animal wastes. The effects of manure application timing (spring or fall application) and soil management (no-tillage or conservation tillage) on fecal bacteria infiltration through shallow karst soils in central Kentucky (the Bluegrass region) have not been evaluated. We performed a field experiment to measure fecal coliforms and fecal streptococci in leachate from dairy manure-amended no-tillage and conservation tillage soils. Manure significantly increased fecal bacteria in leachate compared with unmanured treatments. After manure application, the leachate that collected in zero-tension …

Expression Of Chromosomally Insertedbacillus Thuringiensis Israelensistoxin Genes Inbacillus Sphaericus, E. Bar, N. Sandler, M. Makayoto, A. Keynan

All Peer-Reviewed Publications

Bacillus thuringiensis israelensisδ-endotoxin genes were inserted into transposon Tn917in plasmid pTV51Ts and cloned into the chromosome ofBacillus sphaericus2362. Many of the transformants reacted with antibody to the 135-, 128-, 65-, and 28-kDaB.t.israelensistoxin proteins and were approximately 10 times more toxic toA. aegyptilarvae than the untransformed host. Some of the transformants differed physiologically and morphologically from the wild-typeB. sphaericus.The toxicity of the transformed phenotype was maintained through many transfers in the absence of selective pressure. © 1998 Academic Press.

The Seca Subunit Of Escherichia Coli Preprotein Translocase Is Exposed To The Periplasm, Jerry Eichler, William Wickner

Dartmouth Scholarship

SecA undergoes conformational changes during translocation, inserting domains into and across the membrane or enhancing the protease resistance of these domains. We now show that some SecA bound at SecYEG is accessible from the periplasm to a membrane-impermeant probe in cells with a permeabilized outer membrane but an intact plasma membrane.