Numerical taxonomy of psychrotrophic bacteria isolated from raw ewes' milk

1993 ◽  
Vol 60 (3) ◽  
pp. 371-383 ◽  
Author(s):  
María-Rosario García-Armesto ◽  
Miguel Prieto ◽  
Carlos Alonso ◽  
María-Luisa GarcíLópez ◽  
María-Camino García-Fernández ◽  
...  
Keyword(s):  
Low Temperature ◽  
Aeromonas Hydrophila ◽  
Numerical Taxonomy ◽  
Taxonomic Study ◽  
Coagulase Negative Staphylococci ◽  
Gram Negative ◽  
Identification Schemes ◽  
Psychrotrophic Bacteria ◽  
Numerical Taxonomic Study ◽  
Reference Strains

SummaryA total of 204 psychrotrophic isolates from raw ewes' milk (hand and machine milked) were identified by conventional methods. In addition, a numerical taxonomic study was conducted on 180 of these isolates and 19 reference strains. Three of the isolates were yeasts. Using identification schemes, 54 isolates were assigned to genera of Gram-negative aerobic rods (Pseudomonas, Acinetobacter, Flavobacterium, MoraxellaandPsychrobacter), 48 were Enterobacteriaceae (Entero-bacter, Hafnia, Klebsiella, CitrobacterandSerratia) and one was identified asAeromonas hydrophila. The 98 Gram-positive isolates were identified asEnterococcus, Streptococcus, Leuconostoc, Lactococcus, Bacillus, Staphylococcus, Micrococcus, Aureobacterium, KurthiaandMicrobacterium. At the 82% similarity level (SSM), 18 clusters were formed. Cluster I included 34 strainsof Lactococcus, StreptococcusandLeuconostoc. Most of the 35 strains in cluster II wereEnterococcus. Clusters III and IV were identified asKurthiaandMicrobacteriumrespectively. Cluster V was identified asAureobacteriumand cluster VI consisted of coagulase-negative staphylococci. Gram-negative isolates formed 12 clusters:Aeromonas(one cluster), Enterobacteriaceae (two clusters),Flavobacterium(two clusters),PseudomonasandPsychrobacter immobilis(three clusters) andAcinetobacter(four clusters). Non-motile variants ofPs. fragiwere found.Enterococcusand Enterobacteriaceae did not have significant spoilage properties. As expected, Gram-negative aerobic rods were proteolytic and/or lipolytic even at low temperature. Contamination with certain types of psychrotrophs (Gram-negative aerobic rods and enterococci) seemed to be associated with the milking method. The isolate ofAes. hydrophilahad properties associated with virulence.

scholarly journals A Numerical Taxonomic Study of Anaerobic Gram-negative Bacilli Classified as Bacteroides ureolyticus Isolated from Patients with Non-gonococcal Urethritis

Microbiology ◽  
1986 ◽  
Vol 132 (11) ◽  
pp. 3137-3146 ◽  
Author(s):  
E. A. R. Fontaine ◽  
T. N. Bryant ◽  
D. Taylor-Robinson ◽  
S. P. Borriello ◽  
H. A. Davies
Keyword(s):  
Taxonomic Study ◽  
Gram Negative ◽  
Gonococcal Urethritis ◽  
Numerical Taxonomic Study

Numerical taxonomic study of three N2-fixing yellow-pigmented bacteria related to Pseudomonas paucimobilis

1990 ◽  
Vol 36 (12) ◽  
pp. 850-855 ◽  
Author(s):  
René Bally ◽  
Alain Givaudan ◽  
Jacques Bernillon ◽  
Thierry Heulin ◽  
Jacques Balandreau ◽  
...  
Keyword(s):  
Taxonomic Study ◽  
Protein Patterns ◽  
Phenotypic Characteristics ◽  
Serological Tests ◽  
Phenotypic Properties ◽  
Yellow Pigmentation ◽  
Numerical Taxonomic Study ◽  
Pseudomonas Paucimobilis ◽  
Pigmented Bacteria ◽  
Reference Strains

Three N2-fixing yellow bacteria (5AJ, 5ATR, and 29AJ) isolated from the rhizosphere of rice, previously found to be related to Flavobacterium capsulatum by DNA–rRNA hybridization, were compared on the basis of 115 morphological, physiological, biochemical, and nutritional characters. The bacteria were nonfermentative, irregular motile rods with polar flagella. They exhibited a gram-negative reaction and yellow pigmentation. A numerical analysis using these phenotypic characteristics showed that the bacteria were more closely related to Pseudomonas paucimobilis than to F. capsulatum. A relationship to the P. paucimobilis cluster was also supported by the presence of the pigment nostoxanthin. This pigment was also found in F. capsulatum and could be used as a distinctive marker for this group of yellow bacteria. Their phenotypic properties, protein patterns, and serological tests (ELISA) showed that two of the isolates (5AJ and 5ATR) were identical and had originated from the same parental strain. On the other hand, the serological tests indicated that both N2-fixing yellow bacteria (5AJ or 5ATR and 29AJ) differed from the reference strains, F. capsulatum and P. paucimobilis. Key words: N2-fixing bacteria, taxonomic study, nostoxanthin, Pseudomonas.

A numerical taxonomic study of the British Phaeophyta

1975 ◽  
Vol 55 (4) ◽  
pp. 763-784 ◽  
Author(s):  
G. Russell ◽  
R. L. Fletcher
Keyword(s):  
Numerical Taxonomy ◽  
Taxonomic Study ◽  
Numerical Techniques ◽  
Marine Algal ◽  
Numerical Taxonomic Study

The principles and aims of numerical taxonomy were clearly stated by Sokal & Sneath (1963) and their procedures have since been adopted by many botanists working with numerous different groups of plants. Marine algal taxonomists, however, seem largely to have ignored these developments although Whitton (1969) has recommended that numerical techniques should be employed to help solve outstanding problems in the taxonomy of the Cyanophyta.

A numerical taxonomic study of variation in populations of Typhlodromus caudiglans Schuster (Acarina: Phytoseiidae)

1978 ◽  
Vol 56 (1) ◽  
pp. 55-65 ◽  
Author(s):  
D. A. Chant ◽  
R. I. C. Hansell ◽  
H. Rowell
Keyword(s):  
Host Plants ◽  
Numerical Taxonomy ◽  
Morphological Characters ◽  
The Other ◽  
Climatic Variables ◽  
Taxonomic Study ◽  
Multivariate Tests ◽  
Morphological Variations ◽  
Numerical Taxonomic Study ◽  
Typhlodromus Caudiglans

Variation in morphological characters between Canadian populations of Typhlodromus caudiglans Schuster (Acarina: Phytoseiidae) was examined by the methods of numerical taxonomy. Western populations are separated from the other populations when multivariate tests are used. Two subspecies are proposed, and Typhlodromella nodosus De Leon is synonymized with Typhlodromus caudiglans. Morphological variations between northern and eastern populations are correlated with climatic variables and with host plants.

scholarly journals Numerical taxonomic study of the genus Crotalaria L. (Crotalarieae, Fabaceae) in Nigeria

2018 ◽  
Vol 50 (1) ◽  
pp. 25-32
Author(s):  
Samaila Samaila Yaradua ◽  
Dhafer Ahmed Alzahrani ◽  
Abubakar Bello
Keyword(s):  
Cluster Analysis ◽  
Multivariate Analysis ◽  
Numerical Taxonomy ◽  
Field Work ◽  
Taxonomic Study ◽  
Cophenetic Correlation ◽  
Euclidian Distance ◽  
Ordination Analysis ◽  
Qualitative Characters ◽  
Numerical Taxonomic Study

Abstract Numerical taxonomic study of the genus Crotalaria L. in Nigeria was conducted to identify and differentiate some of the species of the genus Crotalaria using numerical taxonomy based on quantitative and qualitative characters. Field work was conducted, where different species were collected and analyzed using multivariate analysis. The results showed that all the collected species are distinct at Euclidian distance of 0.41 in the cluster analysis with Cophenetic correlation (r)=0.964. The ordination analysis based on the results of the PCA, separated the specimens into 7 groups corresponding to the result of cluster analysis. The first two components of the PCA account for 81.5%. The length of petiole, width of leaflet and length of fruit contributed more to showing delimitation among the species.

scholarly journals National Temporal Trend Analysis of Infective Endocarditis among Patients Infected with HIV in Spain (1997–2014): A Retrospective Study

2019 ◽  
Vol 8 (8) ◽  
pp. 1167 ◽  
Author(s):  
Maria Fe Muñoz-Moreno ◽  
Pablo Ryan ◽  
Alejandro Alvaro-Meca ◽  
Jorge Valencia ◽  
Eduardo Tamayo ◽  
...  
Keyword(s):  
Retrospective Study ◽  
Infective Endocarditis ◽  
Hospital Admissions ◽  
Downward Trend ◽  
Coagulase Negative Staphylococci ◽  
Data Set ◽  
Gram Negative ◽  
Epidemiological Trend ◽  
Incidence And Mortality ◽  
Significant Downward Trend

Background: People living with human immunodeficiency virus (HIV) (PLWH) form a vulnerable population for the onset of infective endocarditis (IE). We aimed to analyze the epidemiological trend of IE, as well as its microbiological characteristics, in PLWH during the combined antiretroviral therapy era in Spain. Methods: We performed a retrospective study (1997–2014) in PLWH with data obtained from the Spanish Minimum Basic Data Set. We selected 1800 hospital admissions with an IE diagnosis, which corresponded to 1439 patients. Results: We found significant downward trends in the periods 1997–1999 and 2008–2014 in the rate of hospital admissions with an IE diagnosis (from 21.8 to 3.8 events per 10,000 patients/year; p < 0.001), IE incidence (from 18.2 to 2.9 events per 10,000 patients/year; p < 0.001), and IE mortality (from 23.9 to 5.5 deaths per 100,000 patient-years; p < 0.001). The most frequent microorganisms involved were staphylococci (50%; 42.7% Staphylococcus aureus and 7.3% coagulase-negative staphylococci (CoNS)), followed by streptococci (9.3%), Gram-negative bacilli (8.3%), enterococci (3%), and fungus (1.4%). During the study period, we found a downward trend in the rates of CoNS (p < 0.001) and an upward trends in streptococci (p = 0.001), Gram-negative bacilli (p < 0.001), enterococci (p = 0.003), and fungus (p < 0.001) related to IE, mainly in 2008–2014. The rate of community-acquired IE showed a significant upward trend (p = 0.001), while the rate of health care-associated IE showed a significant downward trend (p < 0.001). Conclusions: The rates of hospital admissions, incidence, and mortality related to IE diagnosis in PLWH in Spain decreased from 1997 to 2014, while other changes in clinical characteristics, mode of acquisition, and pathogens occurred over this time.

scholarly journals Healthcare-Associated Laboratory-Confirmed Bloodstream Infections—Species Diversity and Resistance Mechanisms, a Four-Year Retrospective Laboratory-Based Study in the South of Poland

2021 ◽  
Vol 18 (5) ◽  
pp. 2785
Author(s):  
Agnieszka Chmielarczyk ◽  
Monika Pomorska-Wesołowska ◽  
Dorota Romaniszyn ◽  
Jadwiga Wójkowska-Mach
Keyword(s):  
Bloodstream Infections ◽  
Diagnostic Techniques ◽  
Resistance Mechanisms ◽  
Infection Prevention And Control ◽  
The South ◽  
Coagulase Negative Staphylococci ◽  
Aminoglycoside Resistance ◽  
Gram Negative ◽  
Maldi Tof ◽  
Carbapenem Resistant

Introduction: Regardless of the country, advancements in medical care and infection prevention and control of bloodstream infections (BSIs) are an enormous burden of modern medicine. Objectives: The aim of our study was to describe the epidemiology and drug-resistance of laboratory-confirmed BSI (LC-BSIs) among adult patients of 16 hospitals in the south of Poland. Patients and methods: Data on 4218 LC-BSIs were collected between 2016–2019. The identification of the strains was performed using MALDI-TOF. Resistance mechanisms were investigated according to European Committee on Antimicrobial Susceptibility Testing, EUCAST recommendations. Results: Blood cultures were collected from 8899 patients, and LC-BSIs were confirmed in 47.4%. The prevalence of Gram-positive bacteria was 70.9%, Gram-negative 27.8% and yeast 1.4%. The most frequently isolated genus was Staphylococcus (50% of all LC-BSIs), with a domination of coagulase-negative staphylococci, while Escherichia coli (13.7%) was the most frequent Gram-negative bacterium. Over 4 years, 108 (2.6%) bacteria were isolated only once, including species from the human microbiota as well as environmental and zoonotic microorganisms. The highest methicillin resistant Staphylococcus aureus (MRSA) prevalence was in intensive care units (ICUs) (55.6%) but S. aureus with resistance to macrolides, lincosamides and streptogramins B (MLSB) in surgery was 66.7%. The highest prevalence of E. faecalis with a high-level aminoglycoside resistance (HLAR) mechanism was in ICUs, (84.6%), while E. faecium-HLAR in surgery was 83.3%. All cocci were fully glycopeptide-sensitive. Carbapenem-resistant Gram-negative bacilli were detected only in non-fermentative bacilli group, with prevalence 70% and more. Conclusions: The BSI microbiology in Polish hospitals was similar to those reported in other studies, but the prevalence of MRSA and enterococci-HLAR was higher than expected, as was the prevalence of carbapenem-resistant non-fermentative bacilli. Modern diagnostic techniques, such as MALDI-TOF, guarantee reliable diagnosis.

Implications of phenotypic plasticity for numerical taxonomy of Ornithogalum montanum (Liliaceae)

1991 ◽  
Vol 69 (1) ◽  
pp. 34-38 ◽  
Author(s):  
M. Pigliucci ◽  
M. G. Politi ◽  
D. Bellincampi
Keyword(s):  
Principal Component Analysis ◽  
Phenotypic Plasticity ◽  
Numerical Taxonomy ◽  
Natural Populations ◽  
Principal Component ◽  
Reaction Norm ◽  
Component Analysis ◽  
Morphological Response ◽  
Numerical Taxonomic Study ◽  
High Degree

Implications of phenotypic plasticity in a subspecific numerical taxonomic study of Ornithogalum montanum Cyr. (Liliaceae) are discussed. Clones belonging to six natural populations were grown in a glasshouse, and their morphological response to three water dosages was analyzed by means of principal component analysis. PC-1 ranks the three groups of replicated populations, suggesting a high degree of phenotypic plasticity; on the other hand, PC-3 is almost environmentally independent. Proximities in the phenetic space are shown to be at least partially environmentally dependent, suggesting a reaction norm for the character correlation matrix. The results do not corroborate a previous recognition of six subspecies of O. montanum. Key words: phenotypic plasticity, numerical taxonomy, Ornithogalum, reaction norm, principal component analysis.

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