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Journal of Clinical Microbiology Oct 1987Thirty strains of microorganisms previously classified in the CDC group EO-2 were studied to determine the relationship of this group and the recently proposed... (Comparative Study)
Comparative Study
Thirty strains of microorganisms previously classified in the CDC group EO-2 were studied to determine the relationship of this group and the recently proposed Psychrobacter immobilis. Results of transformation studies indicated that 9 of the 30 studied strains should be reclassified as P. immobilis. While transformation studies should be used to identify the Psychrobacter genus definitively, some presumptive characteristics useful in differentiating the CDC group EO-2 and P. immobilis were observed. The Psychrobacter genus, compared with the CDC group EO-2, grew well at 25 degrees C, lightly or not at all at 35 degrees C, and not at all at 42 degrees C, grew in nutrient broth without NaCl and with only one exception grew in 6% NaCl, usually did not produce acid from adonitol, dextrin, fructose, or D-mannitol, did not demonstrate the O-shaped cellular morphology, and usually possessed an odor resembling that noted from a phenylethyl alcohol blood agar plate.
Topics: DNA, Bacterial; Gram-Negative Bacteria; Humans; Transformation, Bacterial
PubMed: 3667912
DOI: 10.1128/jcm.25.10.1907-1910.1987 -
Journal of Clinical Microbiology Mar 1988We determined phenotypic characteristics, cellular fatty acid composition, and isoprenoid quinone content of representative strains of CDC groups EO-2, M-5, and M-6,...
Cultural and chemical characterization of CDC groups EO-2, M-5, and M-6, Moraxella (Moraxella) species, Oligella urethralis, Acinetobacter species, and Psychrobacter immobilis.
We determined phenotypic characteristics, cellular fatty acid composition, and isoprenoid quinone content of representative strains of CDC groups EO-2, M-5, and M-6, Moraxella (Moraxella) species, Oligella urethralis, Acinetobacter species, and Psychrobacter immobilis. All organisms contained ubiquinone with eight isoprene units as the major isoprenolog, but distinct differences were observed in fatty acid composition. Twenty-eight of the original collection of CDC group EO-2 strains were further identified as P. immobilis, EO-2, or EO-3 by distinctive cellular fatty acid profiles, cellular morphology, and pigment production. The cellular fatty acid compositions of M-5 and M-6 were similar but were clearly different from those of other organisms. The genus Acinetobacter was differentiated from other organisms in the study by small amounts of 2-hydroxydodecanoic acid (2-OH-12:0), and P. immobilis was differentiated by small amounts of decanoic acid (10:0) and a branched-chain 17-carbon acid (i-17:0). All Moraxella species were distinguished by small amounts of decanoic acid (10:0) and the absence of i-17:0. M. bovis, M. nonliquefaciens, and some strains of M. lacunata formed a single fatty acid group, while M. osloensis, M. phenylpyruvica, M. atlantae, and other strains of M. lacunata (M. lacunata II) had species-specific fatty acid profiles. O. urethralis differed from Moraxella species by the presence of large amounts (49%) of cis-vaccenic acid (18:1 omega 7c), small amounts (1%) of 3-hydroxyhexadecanoate (3-OH-16:0), and the absence of 10:0 and 3-hydroxydodecanoate (3-OH-12:0). The combined use of chemical data and a small number of conventional tests permitted rapid identification and differentiation of these organisms from each other and from related organisms.
Topics: Acinetobacter; Animals; Chromatography, Gas; Fatty Acids; Gram-Negative Bacteria; Humans; Minicomputers; Moraxella; Software; Transformation, Bacterial
PubMed: 3356788
DOI: 10.1128/jcm.26.3.484-492.1988 -
Journal of Food Protection Mar 2000Three phenotypic identification systems were employed to identify 106 strains of gram-negative, nonmotile, aerobic bacteria obtained during iced storage of wild (Salmo...
Three phenotypic identification systems were employed to identify 106 strains of gram-negative, nonmotile, aerobic bacteria obtained during iced storage of wild (Salmo trutta and Esox lucius) and farmed (Oncorhynchus mykiss) freshwater fish. Using diagnostic tables and computer-assisted identification, the isolates were Psychrobacter (64 strains), Acinetobacter (24 strains), Moraxella (6 strains), Chryseobacterium (5 strains), Myroides odoratus (2 strains), Flavobacterium (1 strain), Empedobacter (1 strain), and unidentified (3 strains). Overall similarities of all strains were determined for 108 characters by numerical analysis (simple matching coefficient of similarity [S] and clustering by unweighted pair group average linkage [UPGMA]). At the 77% similarity level, 92 strains formed nine major clusters (3 or more strains) and four small clusters (2 strains). Cluster 1 (25 isolates divided into two main subclusters) could be assigned to Psychrobacter phenylpyruvicus, clusters 2 and 3 (26 isolates) were designated as Psychrobacter immobilis, and clusters 4 (3 isolates) and 7 (4 isolates) were identified as Psychrobacter urativorans and Psychrobacter spp., respectively. Clusters 5 (five isolates), 6 (three isolates), and 9 (five isolates) were labeled as Acinetobacter spp., Acinetobacter johnsonii, and Acinetobacter lwoffii, respectively. Cluster 8 (12 isolates), with a high resemblance to Thornley's phenon 4 (a heterogeneous group of bacteria isolated from poultry and related to Acinetobacter), remained unnamed. The restriction pattern was identical for strains grouped into clusters 2 and 3 (P. immobilis) but was different for the remaining Psychrobacter isolates. A large proportion of isolates belonging to the family Moraxellaceae were closely related. Psychrobacters and A. johnsonii were present in freshly caught fish and river water. In the latter stages of storage, P. phenylpyruvicus and acinetobacters tended to decrease, whereas P. immobilis increased.
Topics: Animals; Bacterial Typing Techniques; Cold Temperature; DNA, Ribosomal; Esocidae; Fishes; Food Handling; Fresh Water; Gram-Negative Aerobic Bacteria; Numerical Analysis, Computer-Assisted; Oncorhynchus mykiss; Phenotype; RNA, Ribosomal, 16S; Restriction Mapping; Trout
PubMed: 10716558
DOI: 10.4315/0362-028x-63.3.315 -
Food Research International (Ottawa,... Jun 2024The microbiome of surfaces along the beef processing chain represents a critical nexus where microbial ecosystems play a pivotal role in meat quality and safety of end...
The microbiome of surfaces along the beef processing chain represents a critical nexus where microbial ecosystems play a pivotal role in meat quality and safety of end products. This study offers a comprehensive analysis of the microbiome along beef processing using whole metagenomics with a particular focus on antimicrobial resistance and virulence-associated genes distribution. Our findings highlighted that microbial communities change dynamically in the different steps along beef processing chain, influenced by the specific conditions of each micro-environment. Brochothrix thermosphacta, Carnobacterium maltaromaticum, Pseudomonas fragi, Psychrobacter cryohalolentis and Psychrobacter immobilis were identified as the key species that characterize beef processing environments. Carcass samples and slaughterhouse surfaces exhibited a high abundance of antibiotic resistance genes (ARGs), mainly belonging to aminoglycosides, β-lactams, amphenicols, sulfonamides and tetracyclines antibiotic classes, also localized on mobile elements, suggesting the possibility to be transmitted to human pathogens. We also evaluated how the initial microbial contamination of raw beef changes in response to storage conditions, showing different species prevailing according to the type of packaging employed. We identified several genes leading to the production of spoilage-associated compounds, and highlighted the different genomic potential selected by the storage conditions. Our results suggested that surfaces in beef processing environments represent a hotspot for beef contamination and evidenced that mapping the resident microbiome in these environments may help in reducing meat microbial contamination, increasing shelf-life, and finally contributing to food waste restraint.
Topics: Microbiota; Red Meat; Animals; Cattle; Food Microbiology; Food Handling; Bacteria; Metagenomics; Drug Resistance, Bacterial; Abattoirs; Anti-Bacterial Agents; Food Contamination; Drug Resistance, Microbial; Food Packaging
PubMed: 38729711
DOI: 10.1016/j.foodres.2024.114318 -
Food Research International (Ottawa,... Jan 2024Fresh fish is a highly perishable product and is easily spoiled by microbiological activity and chemical oxidation of lipids. However, microbial spoilage is the main...
Fresh fish is a highly perishable product and is easily spoiled by microbiological activity and chemical oxidation of lipids. However, microbial spoilage is the main factor linked with the rapid fish sensorial degradation due to the action of specific spoilage organisms (SSOs) that have the ability to dominate over other microorganisms and produce metabolites responsible for off-flavours. We explored the microbial dynamics in fresh anchovies stored in different packaging (air, modified atmosphere, under vacuum) and temperatures (0, 4 and 10 °C) using shotgun metagenomics, highlighting the selection of different microbial species according to the packaging type. Indeed, Pseudoalteromonas nigrifaciens, Psychrobacter cryohalolentis and Ps. immobilis, Pseudomonas deceptionensis and Vibrio splendidus have been identified as the main SSOs in aerobically stored anchovies, while Shewanella baltica, Photobacterium iliopiscarium, Ps. cryohalolentis and Ps. immobilis prevailed in VP and MAP. In addition, we identified the presence of spoilage-associated genes, leading to the potential production of biogenic amines and different off-flavors (HS, TMA). In particular, the abundance of microbial genes leading to BA biosynthesis increased at higher storage temperature, while those related to HS and TMA production were enriched in aerobically and VP packed anchovies, suggesting that MAP could be an effective strategy in delaying the production of these compounds. Finally, we provided evidence of the presence of a wide range of antibiotic resistance genes conferring resistance to different classes of antibiotic (β-lactams, tetracyclines, polymyxins, trimethoprims and phenicols) and highlighted that storage at higher temperature (4 and 10 °C) boosted the abundance of ARG-carrying taxa, especially in aerobically and MAP packed fish.
Topics: Animals; Food Packaging; Anti-Bacterial Agents; Food Microbiology; Food Preservation; Genomics; Microbiota
PubMed: 38129066
DOI: 10.1016/j.foodres.2023.113788 -
Journal of Clinical Microbiology Sep 1991Psychrobacter immobilis was isolated from the cerebrospinal fluid (CSF) and blood of a 2-day-old infant who appeared well except for a fever and a full anterior...
Psychrobacter immobilis was isolated from the cerebrospinal fluid (CSF) and blood of a 2-day-old infant who appeared well except for a fever and a full anterior fontanelle. The infant was treated with antibiotics intravenously. After 48 h, he became afebrile and CSF and blood cultures were negative; he was then discharged. After 96 h of incubation, CSF and blood cultures yielded a gram-negative organism, P. immobilis. The child was readmitted to the hospital, and the same organism was again isolated from his blood and CSF.
Topics: Humans; Infant, Newborn; Male; Meningitis, Bacterial; Neisseriaceae; Neisseriaceae Infections
PubMed: 1774332
DOI: 10.1128/jcm.29.9.2041-2042.1991 -
European Journal of Biochemistry Feb 1997A heat-labile beta-lactamase has been purified from culture supernatants of Psychrobacter immobilis A5 grown at 4 degrees C and the corresponding chromosomal ampC gene...
A heat-labile beta-lactamase has been purified from culture supernatants of Psychrobacter immobilis A5 grown at 4 degrees C and the corresponding chromosomal ampC gene has been cloned and sequenced. All structural and kinetic properties clearly relate this enzyme to class C beta-lactamases. The kinetic parameters of P. immobilis beta-lactamase for the hydrolysis of some beta-lactam antibiotics are in the same range as the values recorded for the highly specialized cephalosporinases from pathogenic mesophilic bacteria. By contrast, the enzyme displays a low apparent optimum temperature of activity and a reduced thermal stability. Structural factors responsible for the latter property were analysed from the three-dimensional structure built by homology modelling. The deletion of proline residues in loops, the low number of arginine-mediated H-bonds and aromatic-aromatic interactions, the lower global hydrophobicity and the improved solvent interactions through additional surface acidic residues appear to be the main determinants of the enzyme flexibility.
Topics: Adaptation, Physiological; Amino Acid Sequence; Antarctic Regions; Base Sequence; Chromosomes, Bacterial; Cold Temperature; Enzyme Stability; Genes, Bacterial; Gram-Negative Aerobic Bacteria; Hot Temperature; Molecular Sequence Data; beta-Lactamases
PubMed: 9063463
DOI: 10.1111/j.1432-1033.1997.00186.x -
Applied and Environmental Microbiology Dec 1995A class C beta-lactamase has been purified from the culture supernatant of the antarctic psychrophile Psychrobacter immobilis A8. This psychrophilic beta-lactamase...
A class C beta-lactamase has been purified from the culture supernatant of the antarctic psychrophile Psychrobacter immobilis A8. This psychrophilic beta-lactamase displays a low level of thermal stability and a low optimal temperature of activity. In contrast to other cold-adapted enzymes, its level of specific activity is not higher than that of mesophilic class C beta-lactamases.
Topics: Acinetobacter; Amino Acid Sequence; Molecular Sequence Data; Temperature; beta-Lactamases
PubMed: 8534113
DOI: 10.1128/aem.61.12.4474-4476.1995 -
BMC Genomics Dec 2014Microbial communities of traditional cheeses are complex and insufficiently characterized. The origin, safety and functional role in cheese making of these microbial...
BACKGROUND
Microbial communities of traditional cheeses are complex and insufficiently characterized. The origin, safety and functional role in cheese making of these microbial communities are still not well understood. Metagenomic analysis of these communities by high throughput shotgun sequencing is a promising approach to characterize their genomic and functional profiles. Such analyses, however, critically depend on the availability of appropriate reference genome databases against which the sequencing reads can be aligned.
RESULTS
We built a reference genome catalog suitable for short read metagenomic analysis using a low-cost sequencing strategy. We selected 142 bacteria isolated from dairy products belonging to 137 different species and 67 genera, and succeeded to reconstruct the draft genome of 117 of them at a standard or high quality level, including isolates from the genera Kluyvera, Luteococcus and Marinilactibacillus, still missing from public database. To demonstrate the potential of this catalog, we analysed the microbial composition of the surface of two smear cheeses and one blue-veined cheese, and showed that a significant part of the microbiota of these traditional cheeses was composed of microorganisms newly sequenced in our study.
CONCLUSIONS
Our study provides data, which combined with publicly available genome references, represents the most expansive catalog to date of cheese-associated bacteria. Using this extended dairy catalog, we revealed the presence in traditional cheese of dominant microorganisms not deliberately inoculated, mainly Gram-negative genera such as Pseudoalteromonas haloplanktis or Psychrobacter immobilis, that may contribute to the characteristics of cheese produced through traditional methods.
Topics: Bacteria; Cheese; Dairy Products; Databases, Genetic; Fermentation; Genome, Bacterial; Metagenomics; Microbiota; Sequence Analysis
PubMed: 25496341
DOI: 10.1186/1471-2164-15-1101 -
Journal of Clinical Microbiology Feb 1990The name Psychrobacter immobilis recently has been proposed for a group of chiefly psychrotrophic, aerobic, gram-negative, nonmotile, oxidase-positive coccobacilli...
The name Psychrobacter immobilis recently has been proposed for a group of chiefly psychrotrophic, aerobic, gram-negative, nonmotile, oxidase-positive coccobacilli commonly found associated with fish, processed meat, and poultry products. This article reports an ocular infection in a 12-day-old newborn who acquired the infection in the hospital, probably because of frequent manipulations in a closed aerated incubator. Also, this report intends to alert microbiologists to opportunistic infections that might be confused with infections caused by unusual oxidase-positive, gram-negative diplococci and to the isolation of P. immobilis from a human infection.
Topics: Cross Infection; Eye Infections, Bacterial; Gram-Negative Aerobic Bacteria; Humans; Infant, Newborn; Male; Water Microbiology
PubMed: 2312690
DOI: 10.1128/jcm.28.2.400-401.1990