Home About us Contact
|
Home About us Contact | ||
|
|
||
Microbial Agents (microbial + agent)
Selected AbstractsThe association between non-biting midges and Vibrio choleraeENVIRONMENTAL MICROBIOLOGY, Issue 12 2008Meir Broza Summary Vibrio cholerae is a natural inhabitant of aquatic ecosystems, yet its interactions within this habitat are poorly understood. Here we describe the current knowledge on the interaction of V. cholerae with one group of co-inhabitants, the chironomids. Chironomids, non-biting midges (Chironomidae, Diptera), are an abundant macroinvertebrate group encountered in freshwater aquatic habitats. As holometabolous insects, chironomids start life when their larvae hatch from eggs laid at the water/air interface; through various feeding strategies, the larvae grow and pupate to become short-lived, non-feeding, adult flying insects. The discovery of the connection between V. cholerae and chironomids was accidental. While working with Chironomus transavaalensis, we observed the disintegration of its egg masses and searched for a possible microbial agent. We identified V. cholerae as the primary cause of this phenomenon. Haemagglutinin/protease, a secreted extracellular enzyme, degraded the gelatinous matrix surrounding the eggs, enabling bacterial growth. Observation of chironomids in relation to V. cholerae continuously for 7 years in various types of water bodies in Israel, India, and Africa revealed that environmental V. cholerae adhere to egg-mass surfaces of various Chironomini (,bloodworms'). The flying adults' potential to serve as mechanical vectors of V. cholerae from one water body to another was established. This, in turn, suggested that these insects play a role in the ecology of V. cholerae and possibly take part in the dissemination of the pathogenic serogroups during, and especially between, epidemics. [source] POST-PASTEURIAN CULTURES: The Microbiopolitics of Raw-Milk Cheese in the United StatesCULTURAL ANTHROPOLOGY, Issue 1 2008HEATHER PAXSON ABSTRACT Out of concern for public health, the U.S. government bans the sale of cheese made from unpasteurized milk if it is aged fewer than 60 days. But while the FDA views raw-milk cheese as a potential biohazard, riddled with pathogenic microbes, aficionados see it as the reverse: as a traditional food processed for safety by the action of good microbes. This article offers a theoretical frame for understanding the recent rise in American artisan raw-milk cheese production, as well as wider debates over food localism, nutrition, and safety. Drawing on ethnographic interviews with cheese makers and purveyors and on participant-labor conducted on a Vermont sheep dairy farm, I develop the concept of microbiopolitics to analyze how farmer,cheese makers, industry consultants, retailers, and consumers negotiate Pasteurian (hygienic) and post-Pasteurian (probiotic) attitudes about the microbial agents at the heart of raw-milk cheese and controversies about this nature,culture hybrid. [source] Prevention of cancer through immunization: Prospects and challenges for the 21st centuryEUROPEAN JOURNAL OF IMMUNOLOGY, Issue S1 2007Abstract Persistent infection by several microbial agents is responsible for at least 15% of cancer globally, including most cancers of the liver, stomach, and cervix. The recent development of vaccines that can prevent infection and premalignant disease caused by human papillomaviruses (HPV), which cause virtually all cases of cervical cancer as well as some other cancers, has focused renewed attention on infection control as a means of reducing the global cancer burden. For vaccines to prevent cancer-causing infection with hepatitis C virus, Helicobacter pylori, or Epstein Barr virus, new vaccine technologies to induce more effective protective responses are required. For the two available cancer control vaccines, designed to prevent infection with HPV and hepatitis B virus, the major challenge is to promote effective vaccine deployment through education programs and increased affordability/accessibility for underserved populations, particularly in the developing world, where the cancer burden attributable to infection by these two viruses is greatest. [source] An epidemiological study on the occurrence of Staphylococcus aureus in superficial abscesses of patients presenting for surgery in a teaching hospital in Khartoum, SudanFEMS IMMUNOLOGY & MEDICAL MICROBIOLOGY, Issue 2 2000Seif Eldin Ibrahim Mahdi Abstract A group of patients (n=86) suffering from superficial abscesses was recruited in the Khartoum Teaching Hospital, Sudan. Detailed clinical and socio-economic data were collected. It appeared that 83% of all patients were younger than 40. Labourers were most prevalent (28%), followed by students (23%) and housewives (16%). The head and neck were most often affected (22%), with hands being second (19%). In 92% of all pus cultures a microbial agents was identified, the large majority being Staphylococcus aureus (69%). Among patients, 47% were nasal carriers of S. aureus, similar to the carriage rate measured among controls, suggesting that nasal carriage is no risk factor for abscess development. Multivariate logistic regression analysis revealed that a history of abscess, recent traditional medical treatment, poor hygiene and low socio-economic status were significantly and independently associated with the occurrence of superficial abscesses. [source] Lymphocutaneous nocardiosis and cutaneous pheohyphomycosis in a liver transplant recipientINTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 6 2008Isabel Hidalgo Parra Background, Infections are the leading cause of morbidity and mortality in transplanted patients. The increasing number of immunocompromised patients has not only augmented infections by specific pathogens, but also by opportunistic microbial agents. Methods, A mixed cutaneous infection caused by Nocardia brasiliensis and Exophiala jeanselmei is reported in a liver transplant patient. Results, The cutaneous lesions were painful nodules which drained purulent material. They were located on the right lower limb, with lymphadenopathies in the groin. Conclusions, The patient was treated with itraconazole (600 mg/day) plus trimethoprim (1600 mg/day),sulfamethoxazole (320 mg/day) for 8 weeks, with complete remission of the lesions. [source] Impact of donor infections on outcome of orthotopic liver transplantationLIVER TRANSPLANTATION, Issue 5 2003Michael Angelis Infection occurs when microbial agents enter the host, either through airborne transmission or by direct contact of a substance carrying the infectious agent with the host. Human body fluids, solid organs, or other tissues often are ideal vectors to support microbial agents and can transmit infections efficiently from donor to recipient. In the case of blood transfusion and tissue transplantation, the main consequence of such a transmission is infection of the recipient. However, in the case of solid-organ transplantation, and particularly for liver transplantation, donor infections are not only transmitted to the recipient, the donor infection also may affect the donated liver's preservability and subsequent function in the recipient irrespective of the systemic consequences of the infection. In addition, solid organ recipients of infected organs are less able to respond to the infectious agent because of their immunosuppressive treatment. Thus, transmission of infections from organ donor to liver recipient represents serious potential risks that must be weighed against a candidate's mortality risk without the transplant. However, the ever-increasing gap between the number of donors and those waiting for liver grafts makes consideration of every potential donor, regardless of the infection status, essential to minimize waiting list mortality. In this review, we will focus on assessing the risk of transmission of bacterial, fungal, viral, and parasitic infectious agents from cadaveric liver donors to recipients and the effect such a transmission has on liver function, morbidity, and mortality. We will also discuss risk-benefit deliberations for using organs from infected donors for certain types of recipients. These issues are critically important to maximize the use of donated organs but also minimize recipient morbidity and graft dysfunction. [source] Bacterial risk and sperm cryopreservationANDROLOGIA, Issue 5 2004R. Levy Summary. Prior to sperm cryopreservation, French guidelines only recommend viral screening for serological status towards human immunodeficiency virus, hepatitis B and C viruses and Treponema palidum. The probability of semen infection by other bacterial pathogens is not taken into consideration by the current recommendations. The objective of the present study was to evaluate this risk and a strategy to reduce it prospectively. Ninety-six patients consulting for sperm cryopreservation underwent a semen culture simultaneously to cryopreservation. The patients were classified into three groups following semen culture results: negative culture (group 1, 77/96, 80.2%), positive culture with saprophytic agents (group 2, 9/96, 9.4%) and positive culture with pathogen agents (group 3, 10/96, 10.4%). For six patients of the latter group showing a genital infection with Ureaplasma urealyticum, a discontinuous gradient selection performed on the cryopreserved sample was efficient to discard bacteria. These data emphasize the usefulness to cultivate semen simultaneously to cryopreservation and demonstrate the ability to remove some microbial agents from semen before its use in assisted reproductive techniques. [source] | ||||||||||