GENERAL BACTERIOLOGY 1. Bacterial Cell (Morphology, Staining
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Glossary - Cellbiology
1 Glossary - Cellbiology Blotting: (Blot Analysis) Widely used biochemical technique for detecting the presence of specific macromolecules (proteins, mRNAs, or DNA sequences) in a mixture. A sample first is separated on an agarose or polyacrylamide gel usually under denaturing conditions; the separated components are transferred (blotting) to a nitrocellulose sheet, which is exposed to a radiolabeled molecule that specifically binds to the macromolecule of interest, and then subjected to autoradiography. Northern B.: mRNAs are detected with a complementary DNA; Southern B.: DNA restriction fragments are detected with complementary nucleotide sequences; Western B.: Proteins are detected by specific antibodies. Cell: The fundamental unit of living organisms. Cells are bounded by a lipid-containing plasma membrane, containing the central nucleus, and the cytoplasm. Cells are generally capable of independent reproduction. More complex cells like Eukaryotes have various compartments (organelles) where special tasks essential for the survival of the cell take place. Cytoplasm: Viscous contents of a cell that are contained within the plasma membrane but, in eukaryotic cells, outside the nucleus. The part of the cytoplasm not contained in any organelle is called the Cytosol. Cytoskeleton: (Gk. ) Three dimensional network of fibrous elements, allowing precisely regulated movements of cell parts, transport organelles, and help to maintain a cell’s shape. • Actin filament: (Microfilaments) Ubiquitous eukaryotic cytoskeletal proteins (one end is attached to the cell-cortex) of two “twisted“ actin monomers; are important in the structural support and movement of cells. Each actin filament (F-actin) consists of two strands of globular subunits (G-Actin) wrapped around each other to form a polarized unit (high ionic cytoplasm lead to the formation of AF, whereas low ion-concentration disassembles AF). -
Group a Streptococcus Produce Pilus-Like Structures Containing Protective Antigens and Lancefield T Antigens
Group A Streptococcus produce pilus-like structures containing protective antigens and Lancefield T antigens Marirosa Mora*†, Giuliano Bensi*†, Sabrina Capo*, Fabiana Falugi*, Chiara Zingaretti*, Andrea G. O. Manetti*, Tiziana Maggi*, Anna Rita Taddei‡, Guido Grandi*, and John L. Telford*§ *Chiron Vaccines, Via Fiorentina 1, 53100 Siena, Italy; and ‡Centro Interdipartimentale di Microscopia Elettronica, University of Tuscia, 01100 Viterbo, Italy Communicated by Rino Rappuoli, Chiron Corporation, Siena, Italy, September 8, 2005 (received for review July 29, 2005) Although pili have long been recognized in Gram-negative patho- extensively characterized and despite five decades of study, there gens as important virulence factors involved in adhesion and is still very little known about the structure and variability of T invasion, very little is known about extended surface organelles in antigens, although a gene of unknown function has been shown Gram-positive pathogens. Here we report that Group A Strepto- to code for the antigen recognized by T6 sera (9). Here we show coccus (GAS), a Gram-positive human-specific pathogen that that four of the 20 T antigens correspond to trypsin-resistant pili causes pharyngitis, impetigo, invasive disease, necrotizing fasciitis, composed of putative adhesion proteins and that recombinant and autoimmune sequelae has long, surface-exposed, pilus-like pilus proteins confer protection against lethal GAS challenge in structures composed of members of a family of extracellular a mouse model of infection and invasive disease. matrix-binding proteins. We describe four variant pili and show that each is recognized by a specific serum of the Lancefield Materials and Methods T-typing system, which has been used for over five decades to Bacterial Strains, Media, and Growth Conditions. -
The Influence of Probiotics on the Firmicutes/Bacteroidetes Ratio In
microorganisms Review The Influence of Probiotics on the Firmicutes/Bacteroidetes Ratio in the Treatment of Obesity and Inflammatory Bowel disease Spase Stojanov 1,2, Aleš Berlec 1,2 and Borut Štrukelj 1,2,* 1 Faculty of Pharmacy, University of Ljubljana, SI-1000 Ljubljana, Slovenia; [email protected] (S.S.); [email protected] (A.B.) 2 Department of Biotechnology, Jožef Stefan Institute, SI-1000 Ljubljana, Slovenia * Correspondence: borut.strukelj@ffa.uni-lj.si Received: 16 September 2020; Accepted: 31 October 2020; Published: 1 November 2020 Abstract: The two most important bacterial phyla in the gastrointestinal tract, Firmicutes and Bacteroidetes, have gained much attention in recent years. The Firmicutes/Bacteroidetes (F/B) ratio is widely accepted to have an important influence in maintaining normal intestinal homeostasis. Increased or decreased F/B ratio is regarded as dysbiosis, whereby the former is usually observed with obesity, and the latter with inflammatory bowel disease (IBD). Probiotics as live microorganisms can confer health benefits to the host when administered in adequate amounts. There is considerable evidence of their nutritional and immunosuppressive properties including reports that elucidate the association of probiotics with the F/B ratio, obesity, and IBD. Orally administered probiotics can contribute to the restoration of dysbiotic microbiota and to the prevention of obesity or IBD. However, as the effects of different probiotics on the F/B ratio differ, selecting the appropriate species or mixture is crucial. The most commonly tested probiotics for modifying the F/B ratio and treating obesity and IBD are from the genus Lactobacillus. In this paper, we review the effects of probiotics on the F/B ratio that lead to weight loss or immunosuppression. -
Bacterial Cell Membrane
BACTERIAL CELL MEMBRANE Dr. Rakesh Sharda Department of Veterinary Microbiology NDVSU College of Veterinary Sc. & A.H., MHOW CYTOPLASMIC MEMBRANE ➢The cytoplasmic membrane, also called a cell membrane or plasma membrane, is about 7 nanometers (nm; 1/1,000,000,000 m) thick. ➢It lies internal to the cell wall and encloses the cytoplasm of the bacterium. ➢It is the most dynamic structure of a prokaryotic cell. Structure of cell membrane ➢The structure of bacterial plasma membrane is that of unit membrane, i.e., a fluid phospholipid bilayer, composed of phospholipids (40%) and peripheral and integral proteins (60%) molecules. ➢The phospholipids of bacterial cell membranes do not contain sterols as in eukaryotes, but instead consist of saturated or monounsaturated fatty acids (rarely, polyunsaturated fatty acids). ➢Many bacteria contain sterol-like molecules called hopanoids. ➢The hopanoids most likely stabilize the bacterial cytoplasmic membrane. ➢The phospholipids are amphoteric molecules with a polar hydrophilic glycerol "head" attached via an ester bond to two non-polar hydrophobic fatty acid tails. ➢The phospholipid bilayer is arranged such that the polar ends of the molecules form the outermost and innermost surface of the membrane while the non-polar ends form the center of the membrane Fluid mosaic model ➢The plasma membrane contains proteins, sugars, and other lipids in addition to the phospholipids. ➢The model that describes the arrangement of these substances in lipid bilayer is called the fluid mosaic model ➢Dispersed within the bilayer are various structural and enzymatic proteins, which carry out most membrane functions. ➢Some membrane proteins are located and function on one side or another of the membrane (peripheral proteins). -
Structural and Functional Characterization of the Fimh Adhesin of Uropathogenic Escherichia Coli and Its Novel Applications
Open Access Journal of Bacteriology and Mycology Research Article Structural and Functional Characterization of the FimH Adhesin of Uropathogenic Escherichia coli and Its Novel Applications Neamati F1, Moniri R2*, Khorshidi A1 and Saffari M1 Abstract 1Department of Microbiology and Immunology, School Type 1 fimbriae are responsible for bacterial pathogenicity and biofilm of Medicine, Kashan University of Medical Sciences, production, which are important virulence factors in uropathogenic Escherichia Kashan, Iran coli strains. Many articles are published on FimH, but each examined a specific 2Department of Microbiology, Faculty of Medicine, aspect of this protein. The current review study aimed at focusing on structure Kashan University of Medical Sciences, Qutb Ravandi and conformational changes and describing efforts to use this protein in novel Boulevard, Kashan, Iran potential treatments for urinary tract infections, typing methods, and expression *Corresponding author: Moniri R, Department of systems. The current study was the first review that briefly and effectively Microbiology, Faculty of Medicine, Kashan University of examined issues related to FimH adhesin. Medical Sciences, Qutb Ravandi Boulevard, Kashan, Iran Keywords: Uropathogenic E. coli; FimH Adhesion; FimH Typing; Received: June 05, 2020; Accepted: July 03, 2020; Conformation Switch; FimH Antagonists Published: July 10, 2020 Abbreviations FimH proteins play important roles in UPEC pathogenicity and the formation of bacterial biofilms [7]. FimH binds to mannosylated UTIs: Urinary Tract Infections; UPEC: Uropathogenic E. uroplakin proteins in the bladder lumen and invades into the Coli; IBCs: Intracellular Bacterial Communities; QIR: Quiescent superficial umbrella cells [8]. After the invasion, UPEC is expelled out Intracellular Reservoir; LD: Mannose-Binding Lectin; PD: Fimbria- of the cell in a TLR4 dependent process, or escape into the cytoplasm Incorporating Pilin; MBP: Mannose-Binding Pocket; LIBS: Ligand- [9]. -
Anoxygenic Photosynthesis in Photolithotrophic Sulfur Bacteria and Their Role in Detoxication of Hydrogen Sulfide
antioxidants Review Anoxygenic Photosynthesis in Photolithotrophic Sulfur Bacteria and Their Role in Detoxication of Hydrogen Sulfide Ivan Kushkevych 1,* , Veronika Bosáková 1,2 , Monika Vítˇezová 1 and Simon K.-M. R. Rittmann 3,* 1 Department of Experimental Biology, Faculty of Science, Masaryk University, 62500 Brno, Czech Republic; [email protected] (V.B.); [email protected] (M.V.) 2 Department of Biology, Faculty of Medicine, Masaryk University, 62500 Brno, Czech Republic 3 Archaea Physiology & Biotechnology Group, Department of Functional and Evolutionary Ecology, Universität Wien, 1090 Vienna, Austria * Correspondence: [email protected] (I.K.); [email protected] (S.K.-M.R.R.); Tel.: +420-549-495-315 (I.K.); +431-427-776-513 (S.K.-M.R.R.) Abstract: Hydrogen sulfide is a toxic compound that can affect various groups of water microorgan- isms. Photolithotrophic sulfur bacteria including Chromatiaceae and Chlorobiaceae are able to convert inorganic substrate (hydrogen sulfide and carbon dioxide) into organic matter deriving energy from photosynthesis. This process takes place in the absence of molecular oxygen and is referred to as anoxygenic photosynthesis, in which exogenous electron donors are needed. These donors may be reduced sulfur compounds such as hydrogen sulfide. This paper deals with the description of this metabolic process, representatives of the above-mentioned families, and discusses the possibility using anoxygenic phototrophic microorganisms for the detoxification of toxic hydrogen sulfide. Moreover, their general characteristics, morphology, metabolism, and taxonomy are described as Citation: Kushkevych, I.; Bosáková, well as the conditions for isolation and cultivation of these microorganisms will be presented. V.; Vítˇezová,M.; Rittmann, S.K.-M.R. -
Gst Gram Staining Learning Objectives the Student Will Use Aseptic Techniques in the Safe Inoculation of Various Forms of Media
GSt Gram Staining Learning Objectives The student will Use aseptic techniques in the safe inoculation of various forms of media. Follow oral and written instructions and manage time in the lab efficiently. Use the bright field light microscope to view microbes under oil immersion, make accurate observations and appropriate interpretations and store the microscope according to lab procedures. Properly prepare a bacterial smear for accurate staining and describe the chemical basis for simple staining and negative staining. Background/Theory Differential staining distinguishes organisms based on their interactions with multiple stains. In other words, two organisms may appear to be different colors. Differential staining techniques commonly used in clinical settings include Gram staining, acid-fast staining, endospore staining, flagella staining, and capsule staining. This link to the OpenStax Microbiology text provides more detail on these differential staining techniques. (OpenStax CNX, 2018) The Gram stain is a differential staining procedure that involves multiple steps. It was developed by Danish microbiologist Hans Christian Gram in 1884 as an effective method to distinguish between bacteria containing the two most common types of cell walls. (OpenStax CNX, 2018) One type consists of an inner plasma membrane and a thick outer layer of peptidoglycan. The other type consists of a double phospholipid Figure 1 Simplified structures of Gram negative cells (left) and Gram positive bilayer with a thin layer of cells (right) peptidoglycan between the two. The Gram Staining technique remains one of the most frequently used staining techniques. The steps of the Gram stain procedure are listed below and illustrated in Figure. (OpenStax CNX, 2018) 1. -
High Dose Antimicrobial Protocols for Canine Urinary Tract Infections
High Dose Antimicrobial Protocols for Canine Urinary Tract Infections Thesis Presented in Partial Fulfillment of the Requirements for the Masters of Science in the Graduate School of The Ohio State University By Sara J. Irom, D.V.M. Graduate Program in Veterinary Clinical Sciences The Ohio State University 2010 Thesis Committee: Joshua Daniels, Advisor Dennis Chew Andrew Hillier Copyright by Sara J. Irom 2010 Abstract Background: Treatment for canine urinary tract infections (UTI) typically consists of 7- 14 days of empirically chosen antimicrobial drugs. Enrofloxacin is a veterinary approved fluoroquinolone (FQ) antimicrobial and is useful for treatment of canine UTI. Ciprofloxacin, the primary metabolite of enrofloxacin, contributes additive antimicrobial activity. Higher doses of FQs may inhibit the emergence of antimicrobial resistance. Objectives: 1) Determine if dogs with naturally occurring uncomplicated UTI have equivalent microbiologic cure with a high dose short duration protocol of enrofloxacin, compared to a standard antimicrobial protocol. 2) Measure urine concentrations of enrofloxacin, and ciprofloxacin, following a 20mg/kg single oral dose in healthy dogs (n=6). Animals: Client-owned dogs with naturally occurring, uncomplicated UTI (n=38), and healthy dogs owned by students and staff of OSU-VMC (n=6). Methods: A multi-center clinical trial was conducted. Dogs were assigned to 1 of 2 groups in a randomized blinded manner. Dogs in group 1 received treatment with 18- 20mg/kg oral enrofloxacin (Baytril®) once daily for 3 consecutive days. Dogs in Group 2 were treated with 13.75-25mg/kg oral amoxicillin-clavulante (Clavamox®) twice daily ii for 14 days. Urine and plasma concentrations of enrofloxacin and ciprofloxacin were measured following a single dose of 20mg/kg oral enrofloxacin in 6 healthy dogs. -
THE CASE AGAINST Marine Mammals in Captivity Authors: Naomi A
s l a m m a y t T i M S N v I i A e G t A n i p E S r a A C a C E H n T M i THE CASE AGAINST Marine Mammals in Captivity The Humane Society of the United State s/ World Society for the Protection of Animals 2009 1 1 1 2 0 A M , n o t s o g B r o . 1 a 0 s 2 u - e a t i p s u S w , t e e r t S h t u o S 9 8 THE CASE AGAINST Marine Mammals in Captivity Authors: Naomi A. Rose, E.C.M. Parsons, and Richard Farinato, 4th edition Editors: Naomi A. Rose and Debra Firmani, 4th edition ©2009 The Humane Society of the United States and the World Society for the Protection of Animals. All rights reserved. ©2008 The HSUS. All rights reserved. Printed on recycled paper, acid free and elemental chlorine free, with soy-based ink. Cover: ©iStockphoto.com/Ying Ying Wong Overview n the debate over marine mammals in captivity, the of the natural environment. The truth is that marine mammals have evolved physically and behaviorally to survive these rigors. public display industry maintains that marine mammal For example, nearly every kind of marine mammal, from sea lion Iexhibits serve a valuable conservation function, people to dolphin, travels large distances daily in a search for food. In learn important information from seeing live animals, and captivity, natural feeding and foraging patterns are completely lost. -
Bacteriological Contamination of Drinking Water Wells
Wisconsin Department of Natural Resources, Bureau of Drinking Water and Groundwater PUB-DG-003-2017 Bacteriological Contamination of Drinking Water Wells ost private wells provide a safe and uncontaminated source of drinking Mwater. Some wells do however become contaminated with bacteria. Fortunately certified labs can easily test water for coliform bacteria, a common indicator of bacterial contamination in wells. To ensure your well is not contaminated, it is a good idea to regularly test your water. You should have your water tested at least annually and whenever you notice a change in the taste, odor or color of the water. Most bacteria entering the ground surface along with rainwater or snowmelt are filtered out as the water seeps through the soil. Several strains of bacteria can survive a long time and find their way into the groundwater by moving through coarse soils, shallow fractured bedrock, quarries, sinkholes, inadequately grouted wells or cracks in the well casing. Insects or small rodents can also carry bacteria into wells with inadequate caps or seals. Coliform bacteria are naturally occurring in soil and are found on vegetation and in surface waters. Water from a well properly located and constructed should be free of coliform bacteria. While coliform bacteria do not cause illness in healthy individuals, their presence in well water indicates the water system is at risk to more serious forms of contamination. The presence of another type of bacteria, Escherichia coli (E. coli), indicates fecal contamination of the water. Fecal coliform bacteria inhabit the intestines of warm-blooded animals and are typically found in their fecal matter. -
Micromasters of the Earth
Micromasters of the Earth Anna WĘGRZYN – the Department of Environmental Biotechnology at the Faculty of Energy and Environmental Engineering at the Silesian University of Technology, Gliwice Please cite as: CHEMIK 2011, 65, 11, 1182-1189 Introduction membrane constitutes about 25% of the whole bacterium mass. It is estimated that our planet was formed about 4.6 billion Peptidoglycan (murein) is a fundamental substance of the bacterial cell years ago. At the very beginning, it was just a lifeless ball of melted wall. In their cell walls, bacteria can contain different quantities of murein magma. The Earth surface was gradually getting cool until reaching which is connected with a diversified sensitivity to dyes. Depending the temperature at which water and other chemical compounds on the number of peptidoglycan layers, the applied dyes (e.g. crystal could have been created. First traces of life are being discovered in violet) are retained inside the cell wall or leached from it. This is the rocks formed about 3.85 billion years ago. Stromatolites - biogenic basis for classifying bacteria into a group of Gram-positive or Gram- rocks dated at about 3.4 billion years which formation was connected negative bacteria (originating from the name of the Danish scientist with activities of cyanobacteria – autotrophic organisms being able to Gram who was the first person to perform the complex staining with XII Conference Environmental produce oxygen in the process of photosynthesis, constitute the fossil crystal violet in 1884). The cells of Gram-negative bacteria contain trace of the prokaryotic structure1 of primitive forms. The creation of lower quantities of murein than in case of Gram-positive bacteria. -
Identification of Type 3 Fimbriae in Uropathogenic Escherichia Coli
JOURNAL OF BACTERIOLOGY, Feb. 2008, p. 1054–1063 Vol. 190, No. 3 0021-9193/08/$08.00ϩ0 doi:10.1128/JB.01523-07 Copyright © 2008, American Society for Microbiology. All Rights Reserved. Identification of Type 3 Fimbriae in Uropathogenic Escherichia coli Reveals a Role in Biofilm Formationᰔ Cheryl-Lynn Y. Ong,1 Glen C. Ulett,1 Amanda N. Mabbett,1 Scott A. Beatson,1 Richard I. Webb,2 Wayne Monaghan,3 Graeme R. Nimmo,3 David F. Looke,4 1 1 Alastair G. McEwan, and Mark A. Schembri * Downloaded from School of Molecular and Microbial Sciences1 and Centre for Microscopy and Microanalysis,2 University of Queensland, Brisbane, Australia, and Queensland Health Pathology Service3 and Infection Management Services, Princess Alexandra Hospital, Brisbane, Australia4 Received 21 September 2007/Accepted 17 November 2007 Catheter-associated urinary tract infection (CAUTI) is the most common nosocomial infection in the United States. Uropathogenic Escherichia coli (UPEC), the most common cause of CAUTI, can form biofilms on indwelling catheters. Here, we identify and characterize novel factors that affect biofilm formation by UPEC http://jb.asm.org/ strains that cause CAUTI. Sixty-five CAUTI UPEC isolates were characterized for phenotypic markers of urovirulence, including agglutination and biofilm formation. One isolate, E. coli MS2027, was uniquely proficient at biofilm growth despite the absence of adhesins known to promote this phenotype. Mini-Tn5 mutagenesis of E. coli MS2027 identified several mutants with altered biofilm growth. Mutants containing insertions in genes involved in O antigen synthesis (rmlC and manB) and capsule synthesis (kpsM) possessed enhanced biofilm phenotypes. Three independent mutants deficient in biofilm growth contained an insertion in a gene locus homologous to the type 3 chaperone-usher class fimbrial genes of Klebsiella pneumoniae.