Borrelia burgdorferi Lyme Disease

Microbiology Borrelia Burgdorferi

The etiology of an increase in the incidence of acute cases of arthritis among youths in the Lyme area of Connecticut in 1977 was at first unclear. The illness was termed Lyme arthritis. It was not until 1981 that hitherto unknown borreliae were found to be responsible for the disease. They were classified as B. burgdorferi in 1984 after their discoverer. Analysis of the genome of various isolates has recently resulted in a proposal to sub-classify B. burgdorferi sensu lato in...

Basic Principles of Medical Microbiology and Immunology

General Aspects of Medical Microbiology 4 Subcellular Infectious Entities 4 Prokaryotic and Eukaryotic Microorganisms 4 5 7 Basic Terminology of Infectiology 8 Determinants of Bacterial Pathogenicity and Virulence 8 11 Strategies against Nonspecific Immunity 12 Strategies against Specific Immunity 13 Regulation of Bacterial Virulence 18 The Genetics of Bacterial Pathogenicity 20 Nonspecific Defense Mechanisms 21 Specific Defense Mechanisms 23 Defects in Immune Defenses 24 Immune Defects...

Chlamydia psittaci Ornithosis Psittacosis

The natural hosts of C. psittaci are birds. This species causes infections of the respiratory organs, the intestinal tract, the genital tract, and the conjunctiva of parrots and other birds. Humans are infected by inhalation of dust from bird excrements containing the pathogens, more rarely by inhalation of infectious aerosols. After an incubation period of one to three weeks, ornithosis presents with fever, headache, and a pneumonia that often takes an...

Sarcoptes scabiei

Causative agent of scabies the itch, sarcoptic itch Infestation with Sarcoptes scabiei var. hominis causes human scabies, a condition characterized by pronounced pruritus, epidermal mite burrows, nodules, and pustules. Transmission is person to person. Various mite species that parasitize animals may also infest the human skin without reproducing, causing the symptoms of pseudoscabies. Occurrence. Scabies caused by Sarcoptes scabiei var. hominis does not occur frequently in Europe, although...

Pediculus humanus capitis Head Louse

Oval body, length 2.2-4.0 mm, morphology very similar to the body louse. Nits are 0.5-0.8 mm long. Localization is mainly in the hair on the head, occasionally also on other hairy areas of the head or upper body. The nits are glued to the base of the hair near the skin. Duration of development from nit to adult is 17 days. The lifespan of adults on human host about one month, survival off host at room temperature is for up to one week. Occurrence and epidemiology. Occurs...

Primary Immune Response

Primary Immune Response

Fig. 2.11 Regulation of T-cell activation is controlled by multiple signals, including costimulatory signals Signal 2 . Stimulation of the T cell via the T-cell receptor TCR Signal 1 activates a tyrosine kinase, which in turn activates phospholipase C PLC . PLC splits phosphatidylinositol bisphosphate PIP2 into inositol trispho-sphate IP3 and diacyl glycerol DAG . IP3 releases Ca2 from intracellular depots, whilst DAG activates protein kinase C PKC . Together, Ca2 and PKC induce and activate...

Human Herpesvirus HHV

Vaccinia Replication Factories

HHV 8 has recently been identified as a decisive cofactor in induction of Kaposi sarcoma. The classic, sporadic form of this malignancy was described in 1872 in the Mediterranean area. It also occurs following organ transplantations and is a significant cause of death in AIDS patients 12 . The contribution of HHV 8 to the pathogenesis of Kaposi sarcoma appears to lie in dysregulation of cytokine and hormone production. In transplantation-association Kaposi sarcoma...

Wuchereria bancrofti and Brugia species

Wuchereria Bancrofti Life Stages

Causative agents of lymphatic filariosis Parasites and occurrence. About 120 million people in 80 countries suffer from lymphatic filariosis caused by Wuchereria bancrofti or Brugia species one-third each in India and Africa, the rest in southern Asia, the Pacific region, and South America , and 1.1 billion people are at infection risk WHO, 2000 . Table 10.4 . Humans are the only natural final hosts of W. bancrofti and the most widely disseminated Brugia strains. There are, however, other...

Haemophilus influenzae

Porphyrin Test Haemophilus

Hemophilic bacteria are so designated because they require growth factors contained in blood. The most important human pathogen in this genus is H. influenzae. Other Haemophilus species either infect only animals or are found in the normal human mucosal flora. These latter include H. parainfluenzae, H. hemolyticus, H. segnis, H. aphrophilus, and H. paraphrophilus. These species can cause infections on occasion. Morphology and culture. Haemophilus are small length 1.0-1.5 im, width 0.3 im ,...

Immunoprecipitation in Liquids and Gels

Immunodiffusion Mancini

Maximum precipitation results when both reaction partners are present in an approximately equivalent ratio Fig. 2.20 . In antibody excess, or antigen excess, the amount of precipitate is considerably reduced. Double diffusion according to Ouchterlony. This technique allows for a qualitative evaluation of whether certain antibodies or antigens are present or not, plus determination of the degree of relationship between antibodies and antigens. It also provides information on...

Toxoplasma gondii

Toxoplasma Cell Stages

Toxoplasma gondii is the causative agent of a zoonosis that occurs worldwide with high prevalences up to 80 depending on region and age . Humans are infected by ingesting oocysts excreted by the definitive hosts cats or by eating unprocessed meat containing Toxoplasma cysts. If a women contracts toxoplasmosis for the first time during pregnancy, diaplacental transmission of the pathogen to the fetus is possible with potential severe consequences for example malformations, eye damage, clinical...

The Cytoplasmic Membrane

Bacterial Cell Structure Plasmid

This elementary membrane, also known as the plasma membrane, is typical of living cells. It is basically a double layer of phospholipids with numerous proteins integrated into its structure. The most important of these membrane Fig.3.7 All bacteria have the same basic structure not to scale . Fig.3.7 All bacteria have the same basic structure not to scale . proteins are permeases, enzymes for the biosynthesis of the cell wall, transfer proteins for secretion of extracellular proteins, sensor or...

Polio Vaccines Pros and Cons

The dead or inactivated vaccine has the advantage of a long stability period and practically foolproof application safety. The disadvantages of this vaccine form are its high cost, the requirement for three injections and weaker or at least shorter-lived protection than is provided by the attenuated form. Work is ongoing on development of enhanced eIPV vaccines of this type. The advantages of the live vaccine are its oral application route, low price and high level of efficiency. One...

Cutaneous Mycoses

Trichophyton Schoenleinii

Dermatophytes Dermatomycoses or Dermatophytoses Dermatophytes are fungi that infect tissues containing plenty of keratin skin, hair, nails . Classification. Dermatophytes are classified in three genera Trichophyton with the important species T. mentagrophytes, T. rubrum, T. schoenleinii, T. tonsurans Microsporum M. audouinii, M. canis, M. gypseum and Epidermophyton E. floccosum . Some dermatophyte species are anthropophilic, others zoophilic. The natural habitat of the geophilic species M....