China 
Africa 
Explore chapters and articles related to this topic
Legionella Ecology
Published in Harriet A. Burge, Bioaerosols, 2020
The disadvantage of the autecological approach is that it requires specialized techniques for the identification and assessment of the bacterium. Few bacteria can be characterized by their morphological structure and then only to the genus level, in part because many are pleomorphic depending on their nutritional status. Specific serological and genetic probes allow identification of bacteria to species and subgroup without culture. Under appropriate conditions the bacterium can be assessed as to its viability, state of physiological health, and ability to transform selected isotopically labeled compounds using microautoradiographic techniques (Fliermans and Schmidt, 1975), cytochrome activity (Fliermans et al., 1981b), and fluorescent probe techniques (Rodriguez et al., 1992). Specific polyvalent and/or monoclonal fluorescent antibody probes have been developed to allow visualization of Legionella and evaluation of the role of Legionella in ecological environments that are microbiologically complex and difficult to sample.
Microbiological Considerations in the Selection and Validation of Filter Sterilization
Published in Maik W. Jornitz, Filtration and Purification in the Biopharmaceutical Industry, 2019
For example, organisms of the family Rickettsiaceae number among them numerous important human pathogens (a pathogen being defined as an organism known to produce disease). Among the diseases produced by members of this family are typhus, Rocky Mountain spotted fever, trench fever, and psittacosis (Coxiella burnetti). Fortunately, the majority of organisms in this family would not be expected to survive in dry powder active ingredients or excipients, nor in the typical compounding environment. However, some Coxiella spp. can survive heat and drying and all of these organisms can survive at −70°C for extended periods of time and in lyophilized materials. These organisms lack rigid cell walls and as a result are pleomorphic, which means they are variable in size and shape. These organisms can be found in nature in the 0.3- to 0.6-mm size range which is to say that they could be at least as difficult to filter as B. diminuta.
Procaryotic Cells
Published in Maria Csuros, Csaba Csuros, Klara Ver, Microbiological Examination of Water and Wastewater, 2018
Maria Csuros, Csaba Csuros, Klara Ver
The shape of bacteria is determined by heredity, called monomorphic bacteria. However, a number of environmental conditions can alter the shape of the organisms, causing a different shape, called pleomorphic bacteria. Unfortunately, if this happens identification becomes even more difficult. Spiral bacteria are shown in Figure 2.3.
Biodegradation of biodiesel-oil by Cellulosimicrobium sp. Isolated from Colombian Caribbean soils
Published in Environmental Technology, 2020
Angela Bertel-Sevilla, Leonor Cervantes-Ceballos, Irina Tirado-Ballestas, Wilson Maldonado-Rojas, Juan Alzate-Restrepo, Jesus Olivero-Verbel
The three isolates of C. funkei showed differences regarding both bacilli size and Gram staining. Some of these particular features have been explained by Stackebrandt et al. [54]; Rowlinson et al. [55]; Chatterjee et al. [29]; Antony et al. [56]. These authors described the morphologic variations of the bacteria due to its pleomorphic presentation. Bacterial morphologic changes depend on environmental conditions at the moment of sampling, laboratory procedures and conservation techniques, among others. Little variations of pH, temperature, photoperiod, submission to colorants, salts, fungal inhibitors, among others, affects morphologic features [56]. Little changes, for instance, in incubation time, can modify even the bacterial response to Gram staining, shifting from Gram positive to Gram negative [57].