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Published in Bethe A. Scalettar, James R. Abney, Cyan Cowap, Introductory Biomedical Imaging, 2022
Bethe A. Scalettar, James R. Abney, Cyan Cowap
In this imaging mode, specimens become visible in the same way that stars become visible at night, by making the background dark (instead of bright). Advantages of darkfield include its low cost, its relatively simple implementation, and its ability to markedly enhance contrast for thin unstained samples. Darkfield is especially useful for studying external details and tiny diffracting objects, such as bacteria and isolated organelles. A “darkfield microscopy examination” is a standard test for syphilis.
Microbiological Hazards
Published in Dag K. Brune, Christer Edling, Occupational Hazards in the Health Professions, 2020
The overwhelming majority of cases of syphilis are transmitted venerally. T. pallidum enters the body by penetrating intact mucous membranes, via minute abrasions of the epithelium or possibly through unbroken skin by way of hair follicles.312 Survival of T. pallidum outside the body is brief, and transmission by fomites is extremely rare. Infection therefore virtually requires direct contact with infected lesions. Both primary and secondary syphilitic lesions contain large numbers of treponemes and the number of organisms sufficient to cause infection has been found very small. In inoculation experiments in volunteers, Magnuson et al. found that a 50% infectious inoculum was about 57 organisms.313 In health care personnel, accidental direct inoculation may occur by needle prick, when touching infectious lesions, or when handling infected clinical material. Occupationally acquired lesions in dentists, physicians, and nurses are usually seen as a chancre on a finger, usually masquerading as a paronychia.314 Indeed, syphilis of the finger is most commonly seen in medical personnel.315
Computational Technology in Nanomedicine
Published in Sarhan M. Musa, ®, 2018
Treponema bacteria are a group of spirochete bacteria. Many members of treponema bacteria can cause important diseases for human beings. Syphilis, a sexually transmitted disease, is a well-known sexually transmitted disease that is caused by treponema bacteria. The motility of the pathogenic bacteria in human beings is an interesting focus when one studies on the pathogenesis. To observe the movement of the causative pathogen, Treponema pallidum can be done based on dark-field microscopic observation. The derived track of the pathogen movement at different time can be recorded and further manipulated based on MATLAB.
Steroidal fraction of Carissa carandas L. inhibits microbial hyaluronidase activity by mixed inhibition mechanism
Published in Preparative Biochemistry and Biotechnology, 2019
Sandip Patil, Bhushan Bhadane, Leena Shirsath, Ravindra Patil, Bhushan Chaudhari
The microorganisms capable of producing enzyme hyase include various species of Streptococcus, Staphylococcus, Peptostreptococcus, Propionibacterium, and Clostridium.[12–15] While it has also been reported in different species of Candida, including C. albicans, C. krusei, C. tropicalis, C. parapsilosis, and C. guillermondii.[16] The fungal strains of Penicillium sp. (P. funiculosum, P. purpurogenum),[17]Streptomyces sp., Pseudozyma aphidis, Cryptococcus laurentii[18] were reported for the production of enzyme hyase. The invertebrates like leeches (Hirudo medicinalis, Nephelopsis obscura, Desserobdella picta and Glossiphonia complanata),[19] spiders (Vitalius dubius, Loxosceles intermedia and Hippasa partita),[20,21] social wasp (Polybia paulista),[22] honey bees (Apis dorsata and Apis mellifera),[23] scorpions (Palamneus gravimanus and Buthus martensi)[24,25] also produce hyase. The causative agent of syphilis - Treponema pallidum and Treponema pertenue are also reported to produce hyase.[26] The veterinary pathogens, Streptococcus uberis and Streptococcus dysgalactiae that cause mastitis have also shown the synthesis of hyaluronidase.[27–29] Recently, hyases were reported as important virulence factors of Group B Streptococcus (GBS) involved in ascending vaginal infections in pregnant women leading to increased fetal injuries, preterm birth defects, and fetal demise.[30,31]