China
Africa
Explore chapters and articles related to this topic
Biotransformation of Monoterpenoids by Microorganisms, Insects, and Mammals
Published in K. Hüsnü Can Başer, Gerhard Buchbauer, Handbook of Essential Oils, 2020
Yoshiaki Noma, Yoshinori Asakawa
The microbial transformation of citronellal (261) and citral (275 and 276) was reported by way of Pseudomonas aeruginosa (Joglekar and Dhavlikar, 1969). This bacterium, capable of utilizing citronellal (261) or citral (275 and 276) as the sole carbon and energy source, has been isolated from soil by the enrichment culture technique. It metabolized citronellal (261) to citronellic acid (262) (65%), citronellol (258) (0.6%), dihydrocitronellol (259) (0.6%), 3,7-dimethyl-1,7-octanediol (260) (1.7%), and menthol (137) (0.75%) (Figure 22.5). The metabolites of citral (275 and 276) were geranic acid (278) (62%), 1-hydroxy-3,7-dimethyl-6-octen-2-one (279) (0.75%), 6-methyl-5- heptenoic acid (280) (0.5%), and 3-methyl-2-butenoic acid (286) (1%) (Figure 22.5). In a similar way, Pseudomonas convexa converted citral (275 and 276) to geranic acid (278) (Hayashi et al., 1967). The biotransformation of citronellol (258) and geraniol (271) by P. aeruginosa, P. citronellolis, and Pseudomonas mendocina was also reported by another group (Cantwell et al., 1978).
Taxonomy and Grouping
Published in Paul Pumpens, Single-Stranded RNA Phages, 2020
Meanwhile, a CLAT (FRNA culture, latex agglutination, and typing) method, i.e., an antibody-coated polymeric bead agglutination assay, was proposed as a simple and rapid 180-min procedure to detect the FRNA coliphage groups with antibody-coated particles (Love and Sobsey 2007). The CLAT assay was performed on a cardboard card by mixing a drop of coliphage enrichment culture with a drop of antibody-coated polymeric beads as the detection reagent and visual agglutination or clumping of positive samples occurred in <60 seconds. The CLAT method successfully classified FRNA coliphages into four serogroups, in similar proportions to those obtained with a nucleic acid hybridization assay (Love and Sobsey 2007).
Arcobacter
Published in Dongyou Liu, Handbook of Foodborne Diseases, 2018
Nuria Salas-Massó, Alba Perez-Cataluña, Luis Collado, Arturo Levican, Maria José Figueras
The majority of Arcobacter species can be classified as fastidious bacteria, because they grow and replicate slowly (plates should be incubated between 48 and 72 hours), with the only exception of A. butzleri that is the most common species of the genus [1]. This is the least fastidious species able to growth in the presence of 1.5% NaCl, lactose, glucose, and citrate, with some strains showing the ability to reduce nitrate and to be thermotolerant to 42°C [14,18,26]. The fast-growing characteristics of A. butzleri in the enrichment culture mask the abundance of other species like Arcobacter cryaerophilus [1,23,27]. In the study of Salas-Massó et al. [26], A. cryaerophilus was not recovered using medium supplemented with salt (2.5% NaCl), but it was the second most abundant species recovered from sewage-contaminated water using the Arcobacter-CAT medium without salt. The dominance of A. cryaerophilus is in agreement with its high abundance in the metagenome of wastewater [28].
Recent updates in the development of molecular assays for the rapid identification and susceptibility testing of MRSA
Published in Expert Review of Molecular Diagnostics, 2023
Masako Mizusawa, Karen C Carroll
The Panther Fusion MRSA assay (Hologic, San Diego, CA, U.S.A.) is a CE-marked automated multiplex PCR assay using Invader Plus® chemistry that includes targets for orfX-SCCmec, mecA/mecC gene, and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) to detect MRSA from nasal E-swab specimens [71]. In a prospective study conducted in teaching hospitals in France, 434 nasal E-swab specimens were tested with both standard culture and the Panther Fusion MRSA assay [72]. The overall agreement rate was 97.9% for MRSA detection [72]. Four out of 30 MRSA-positive samples were not detected due to an atypical SCCmec cassette and two samples were falsely detected as MRSA due to co-colonization with a MSSA drop-out strain and a methicillin-resistant coagulase-negative staphylococcal strain [72]. In a single-center study in Denmark that tested 1097 E-swab samples from nose, pharynx, and perineum with Panther Fusion MRSA assay, the invalid rate was 0.5% [73]. The analysis of 1091 samples with valid results demonstrated the sensitivity of 78.0% and the specificity of 97.7% across sample types compared to enrichment culture as a reference method [73].
The rumen microbiome: a crucial consideration when optimising milk and meat production and nitrogen utilisation efficiency
Published in Gut Microbes, 2019
Chloe Matthews, Fiona Crispie, Eva Lewis, Michael Reid, Paul W. O’Toole, Paul D. Cotter
The gastrointestinal tract of ruminant animals has a wide range of extremities, making it difficult to replicate conditions for optimal growth. While specific microbes can grow and can be characterised, a large percentage are unculturable in vitro and cannot be grown on laboratory media. Culture-dependant techniques rely on various selective and enrichment culture conditions in order to replicate the microbes’ natural environment. Culturing anaerobes is quite difficult due to the need to exclude oxygen, the slow growth of the microbes and the complexity of other growth requirements (Rufener et al.).65 used a continuous culture system in order to replicate the rumen environment. This technique, along with similar techniques, was used for the enumeration and identification of rumen microbes.
Topical lotions utilized in outpatient rehabilitation clinics as a potential source of bacterial contamination
Published in Physiotherapy Theory and Practice, 2019
Henry G. Spratt, David Levine, Julie Bage, David K. Giles, A. Grace Collier
To determine if bacteria could possibly utilize some component of the lotions as sole carbon source in support of growth, enrichment culture mediums were produced (Madsen, 2008) using three of the lotions studied here (FU, PCB, and PB). The idea of an enrichment medium is to add one carbon source (a “sole” source) to a mixture of additional nutrients that includes all other major nutrients required for bacterial growth. Our enrichment mediums consisted of minimal basal salts (“medium B”) (Gerhardt, Murray, Wood, and Krieg, 1994) to which one of the lotions was added at 1 g/liter. To ensure proper emulsion of the lotion into the aqueous phase of the basal salts mixture, a surfactant, Tween 80, was added (at 1 ml/l). The different enrichment media were transferred into test tubes, which were then sterilized by autoclaving. Using sterile tubes of the enrichment media, four species of skin-associated bacteria, or potentially skin-associated bacteria (S. aureus, E. coli, P. aeruginosa, and M. luteus), were used to inoculate the three different enrichment mediums in replicated (triplicate) fashion. After inoculation, the enrichment culture tubes were incubated at 37°C for 1 week, after which growth was determined based on the presence of turbidity in the tubes compared with sterile controls.