Skip header and navigation

Refine By

32 records – page 1 of 4.

Analysis by pulsed-field gel electrophoresis of the genetic diversity among Clostridium perfringens isolates from chickens.

https://arctichealth.org/en/permalink/ahliterature56605
Source
Vet Microbiol. 2003 Jul 17;94(3):257-66
Publication Type
Article
Date
Jul-17-2003
Author
B. Nauerby
K. Pedersen
M. Madsen
Author Affiliation
Department of Poultry, Danish Veterinary Institute, Fish and Fur Animals, Hangøvej 2, DK-8200 Aarhus N, Denmark. bn@vetinst.dk
Source
Vet Microbiol. 2003 Jul 17;94(3):257-66
Date
Jul-17-2003
Language
English
Publication Type
Article
Keywords
Animals
Bacterial Typing Techniques - veterinary
Carrier State - veterinary
Chickens - microbiology
Clostridium perfringens - classification - genetics - isolation & purification
DNA, Bacterial - analysis
Denmark
Electrophoresis, Gel, Pulsed-Field - methods - veterinary
Enteritis - microbiology - veterinary
Enterotoxins - genetics
Phylogeny
Poultry Diseases - microbiology
Research Support, Non-U.S. Gov't
Variation (Genetics)
Abstract
The aim of this study was to analyse the genetic diversity among Clostridium perfringens isolates from Danish broiler chickens since both sick and presumably healthy animals were investigated. Isolates (n=279) collected from chickens from 25 farms were analysed by pulsed-field gel electrophoresis (PFGE) with the restriction enzyme SmaI. A high genetic diversity was found. Isolates with different PFGE types were toxin typed by PCR and all were found to be of type A. The results showed that healthy broiler chickens carried several different C. perfringens clones both within a flock and even within individual birds, whereas flocks suffering from necrotic enteritis (NE) or cholangio-hepatitis carried only one or two clones.
PubMed ID
12814893 View in PubMed
Less detail

Analysis of Swedish Bordetella pertussis isolates with three typing methods: characterization of an epidemic lineage.

https://arctichealth.org/en/permalink/ahliterature149892
Source
J Microbiol Methods. 2009 Sep;78(3):297-301
Publication Type
Article
Date
Sep-2009
Author
A. Advani
H G J Van der Heide
H O Hallander
F R Mooi
Author Affiliation
Department of bacteriology, Swedish Institute for Infectious Disease Control (SMI), S-171 82 Solna, Sweden. reza.advani@smi.se
Source
J Microbiol Methods. 2009 Sep;78(3):297-301
Date
Sep-2009
Language
English
Publication Type
Article
Keywords
Alleles
Bacterial Typing Techniques - methods
Bordetella pertussis - classification - genetics - isolation & purification
Cluster analysis
DNA Fingerprinting - methods
DNA, Bacterial - chemistry - genetics
Electrophoresis, Gel, Pulsed-Field - methods
Humans
Minisatellite Repeats
Molecular Epidemiology - methods
Molecular Sequence Data
Polymerase Chain Reaction - methods
Sensitivity and specificity
Sequence Analysis, DNA - methods
Sweden - epidemiology
Whooping Cough - epidemiology - microbiology
Abstract
Three Bordetella pertussis typing methods, pulsed-field gel electrophoresis (PFGE), multi-locus sequence typing (MLST), and multi-locus variable number tandem repeat analysis (MLVA) were compared using a collection of Swedish strains. Of the three typing methods used, PFGE was found to be the most discriminatory. MLVA and MLST were less discriminatory, but may be valuable for strain discrimination when culture is not possible as they are based on PCR. The combination of MLVA/MLST was found to be equally discriminatory as PFGE and should therefore also be considered. The relationship between predominant lineages in Sweden and The Netherlands, characterized by the PFGE type BpSR11 and the allele for the pertussis toxin promoter ptxP3, respectively, was investigated. Linkage was found between the PFGE type BpSR11 and ptxP3 in that all BpSR11 strains carried ptxP3. On the other hand ptxP3 was found in several other PFGE-types. The presence of the ptxP3 allele in different genetic backgrounds may indicate horizontal gene transfer within B. pertussis or homoplasy. Alternatively, this observation may be due to convergence of PFGE types.
PubMed ID
19577594 View in PubMed
Less detail

Application of molecular genetic methods in diagnostics and epidemiology of food-borne bacterial pathogens.

https://arctichealth.org/en/permalink/ahliterature176690
Source
APMIS. 2004 Nov-Dec;112(11-12):908-29
Publication Type
Article
Author
Susanna Lukinmaa
Ulla-Maija Nakari
Marjut Eklund
Anja Siitonen
Author Affiliation
Laboratory of Enteric Pathogens, National Public Health Institute (KTL), Helsinki, Finland.
Source
APMIS. 2004 Nov-Dec;112(11-12):908-29
Language
English
Publication Type
Article
Keywords
Bacteria - classification - genetics - isolation & purification - pathogenicity
Bacterial Typing Techniques - methods
Campylobacter jejuni - genetics - isolation & purification - pathogenicity
Clostridium perfringens - genetics - isolation & purification - pathogenicity
Databases, Genetic
Electrophoresis, Gel, Pulsed-Field - methods
Enterobacteriaceae - genetics - isolation & purification - pathogenicity
Finland - epidemiology
Food Microbiology
Foodborne Diseases - diagnosis - epidemiology - microbiology
Genotype
Humans
Listeria monocytogenes - genetics - isolation & purification - pathogenicity
Molecular Biology - methods
Molecular Epidemiology - methods
Phenotype
Polymerase Chain Reaction - methods
Salmonella enterica - genetics - isolation & purification - pathogenicity
Yersinia - genetics - isolation & purification - pathogenicity
Abstract
Salmonella enterica, Campylobacter and Yersinia species, Shiga toxin-producing Escherichia coli (STEC), Listeria monocytogenes and Clostridium perfringens are the bacterial pathogens constituting the greatest burden of food-borne disease in Finland. Several molecular genetic methods have been applied to diagnose, discriminate and survey these bacteria. PCR, PCR-RFLP and PFGE are the most widely and successfully used. However, these methods are unable to replace conventional and internationally standardised phenotyping. Electronic database libraries of the different genomic profiles will enable continuous surveillance of infections and detection of possible infection clusters at an early stage. Furthermore, whole-genome sequence data have opened up new insights into epidemiological surveillance. Laboratory-based surveillance performed in a timely manner and exploiting adequate methods, and co-operation at local, national and international levels are among the key elements in preventing food-borne diseases. This paper reviews different applications of molecular genetic methods for investigating enteric bacterial pathogens and gives examples of the methods successfully used in diagnostics and epidemiological studies in Finland.
PubMed ID
15638843 View in PubMed
Less detail

Arcobacter species and their pulsed-field gel electrophoresis genotypes in Finnish raw milk during summer 2011.

https://arctichealth.org/en/permalink/ahliterature107605
Source
J Food Prot. 2013 Sep;76(9):1630-2
Publication Type
Article
Date
Sep-2013
Author
Joana Revez
Marianne Huuskonen
Marjo Ruusunen
Miia Lindström
Marja-Liisa Hänninen
Author Affiliation
Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, P.O. Box 66, FI-00014, Helsinki, Finland. joana.revez@helsinki.fi
Source
J Food Prot. 2013 Sep;76(9):1630-2
Date
Sep-2013
Language
English
Publication Type
Article
Keywords
Animals
Arcobacter - genetics - isolation & purification
Cattle
Consumer Product Safety
Electrophoresis, Gel, Pulsed-Field - methods
Finland - epidemiology
Food contamination - analysis
Food Microbiology
Genotype
Humans
Milk - microbiology
Polymerase Chain Reaction - methods
Prevalence
Abstract
The aim of this study was to investigate the occurrence of Arcobacter species in raw milk in Finland. A total of 177 raw milk samples, each from a separate farm, were examined from June to August 2011. Arcobacter species were isolated using an enrichment and selective detection procedure. Overall, 26 (15 % ) of the 177 samples yielded Arcobacter spp. Samples from 25 farms were positive for Arcobacter butzleri and from 1 farm for Arcobacter cryaerophilus. Moreover, both Arcobacter butzleri and A. cryaerophilus were recovered from 1 positive sample. To evaluate a possible genetic variability, one strain of A. butzleri from each farm and the A. cryaerophilus sample were analyzed by pulsed-field gel electrophoresis. Genotyping revealed that Arcobacter spp. populations are heterogeneous, and no dominant clone has spread in the investigated samples. Our study is the first report on the isolation of both A. butzleri and A. cryaerophilus in raw milk in Finland. Based on our findings, the presence of Arcobacter species in raw milk may pose a potential hazard for human health, in particular for consumers who prefer drinking unpasteurized milk.
PubMed ID
23992510 View in PubMed
Less detail

Bordetella pertussis strains circulating in Europe in 1999 to 2004 as determined by pulsed-field gel electrophoresis.

https://arctichealth.org/en/permalink/ahliterature84599
Source
J Clin Microbiol. 2007 Oct;45(10):3257-62
Publication Type
Article
Date
Oct-2007
Author
Hallander Hans
Advani Abdolreza
Riffelmann Marion
von König Carl H W
Caro Valerie
Guiso Nicole
Mooi Frits R
Gzyl Anna
Kaltoft Margit S
Fry Norman K
Mertsola Jussi
He Qiushui
Author Affiliation
Department of Immunology Vaccinology, Swedish Institute for Infectious Disease Control, Solna, Sweden.
Source
J Clin Microbiol. 2007 Oct;45(10):3257-62
Date
Oct-2007
Language
English
Publication Type
Article
Keywords
Bordetella pertussis - genetics - isolation & purification
Child, Preschool
Electrophoresis, Gel, Pulsed-Field - methods
Europe
Humans
Infant
Infant, Newborn
Pertussis Vaccine - immunology
Time Factors
Vaccination
Abstract
Clinical isolates of Bordetella pertussis collected during the year 2004 (n = 153) in eight European countries, Denmark, Finland, France, Germany, The Netherlands, Poland, Sweden, and United Kingdom, were analyzed by pulsed-field gel electrophoresis (PFGE), and their PFGE profiles were compared with those of isolates collected in 1999 (n = 102). The 255 isolates produced 59 distinct PFGE profiles. Among the 153 isolates from 2004, 36 profiles were found, while within the 102 isolates from 1999, 33 profiles were detected. One PFGE profile, BpSR11, was dominant (30% to 50%) in all countries except Denmark (10%) and Poland (0%). In comparison with 1999, there was an increase in BpSR11 prevalence in Finland in 2004 from 5% to 40%, coinciding with a major incidence peak. Some other PFGE profiles seemed to be associated with limited dissemination. Poland was the only country in which the most common actual European PFGE profiles were not found. In a dendrogram analysis, all common PFGE profiles were identified within PFGE group IV, and BpSR11 clustered together with PFGE subgroup IVbeta. Compared to the 1999 isolates, PFGE group V representative for pertactin variant prn3 strains had disappeared, and a new cluster was seen. In conclusion, some PFGE profiles, such as BpSR11, evidently have a higher capacity to spread, suggesting increased fitness to the present immunological environment. It is therefore of major interest to continue with surveillance programs of B. pertussis isolates, as both waning vaccine-derived immunity and strain variation may play a role in the persistence of pertussis.
PubMed ID
17699646 View in PubMed
Less detail

Calling all Campy--how routine investigation and molecular characterization impacts the understanding of campylobacteriosis epidemiology--Alaska, United States, 2004-2013.

https://arctichealth.org/en/permalink/ahliterature271308
Source
Epidemiol Infect. 2016 Jan;144(2):265-7
Publication Type
Article
Date
Jan-2016
Author
L J Castrodale
G M Provo
C M Xavier
J B McLaughlin
Source
Epidemiol Infect. 2016 Jan;144(2):265-7
Date
Jan-2016
Language
English
Publication Type
Article
Keywords
Alaska - epidemiology
Campylobacter - isolation & purification
Campylobacter Infections - epidemiology - microbiology
Disease Outbreaks
Electrophoresis, Gel, Pulsed-Field - methods
Humans
Seasons
Abstract
Unlike most jurisdictions in the United States, Alaska performs pulsed-field gel electrophoresis (PFGE) characterization of all Campylobacter sp. isolates at the state public health laboratory--a practice that started in 2002. Moreover, in order to ensure early detection and response to campylobacteriosis outbreaks, the Alaska Section of Epidemiology has investigated all incident Campylobacter sp. case reports since 2004. This report summarizes the public health impact of routine incident case investigations and molecular characterization of all Campylobacter sp. isolates. In sum, we found that these efforts have contributed to better characterization of the epidemiology of campylobacteriosis in Alaska, and facilitated more rapid outbreak detection, more public health investigations, and earlier public health interventions.
PubMed ID
26119636 View in PubMed
Less detail

[Characteristics of Listeria monocytogenes strains isolated in Russia and their typing using pulse electrophoresis].

https://arctichealth.org/en/permalink/ahliterature212008
Source
Zh Mikrobiol Epidemiol Immunobiol. 1996 May-Jun;(3):60-4
Publication Type
Article
Author
B I Marakusha
K. Darwich
I S Tartakovskii
Source
Zh Mikrobiol Epidemiol Immunobiol. 1996 May-Jun;(3):60-4
Language
Russian
Publication Type
Article
Keywords
Animals
Bacterial Typing Techniques - statistics & numerical data
Chromosomes, Bacterial - genetics
DNA, Bacterial - genetics
Electrophoresis, Gel, Pulsed-Field - methods - statistics & numerical data
Food Microbiology
Guinea Pigs
Humans
Listeria monocytogenes - classification - genetics - isolation & purification - pathogenicity
Mice
Restriction Mapping
Russia
Sewage - microbiology
Virulence
Abstract
On the basis of specially developed scheme for the isolation of Listeria strains comprising 2 enrichment stages and the use of growth inhibitors, 128 L. monocytogenes cultures were isolated from clinical material, foodstuffs and sewage water. Highly virulent L.monocytogenes strains isolated from clinical material belonged to serovar 4b (54%) and 1/2a (38%), while those isolated from foodstuffs and sewage water belonged to 4b (74%). The restriction analysis of the chromosomal DNA of the isolated cultures with the use of restrictase EcoR1 on the basis of pulsed-field gel electrophoresis (PFGE) made it possible to distinguish Listeria strains in accordance with 5 types of restrictograms. The restrictograms of highly virulent L. monocytogenes strains, serovar 4b, belonged to types 1 and 2, while those of L. monocytogenes strains, serovar 1/2a, belonged to types 2 and 3. The comparative use of different methods for typing L. monocytogenes (sero-, phago-, bio- and resistotyping, the analysis of plasmid composition and restriction analysis) revealed that the combination of serotyping and restriction analysis on the basis of PFGE proved to be most promising for the characterization of the isolated L. monocytogenes strains and the assessment of their epidemic importance.
PubMed ID
8771733 View in PubMed
Less detail

Comparative analysis of amplified fragment length polymorphism and pulsed field gel electrophoresis in a hospital outbreak and subsequent endemicity of ampicillin-resistant Enterococcus faecium.

https://arctichealth.org/en/permalink/ahliterature181921
Source
FEMS Immunol Med Microbiol. 2004 Jan 15;40(1):33-9
Publication Type
Article
Date
Jan-15-2004
Author
Roland Jureen
Stig Harthug
Steinar Sørnes
Asbjørn Digranes
Rob J L Willems
Nina Langeland
Author Affiliation
Institute of Medicine, University of Bergen, 5021 Bergen, Norway. roland.jurren@med.uib.no
Source
FEMS Immunol Med Microbiol. 2004 Jan 15;40(1):33-9
Date
Jan-15-2004
Language
English
Publication Type
Article
Keywords
Ampicillin - pharmacology
Ampicillin Resistance
Bacterial Proteins - genetics
Bacterial Typing Techniques
Cross Infection - epidemiology - microbiology
Data Interpretation, Statistical
Disease Outbreaks - prevention & control
Electrophoresis, Gel, Pulsed-Field - methods
Endemic Diseases
Enterococcus faecium - classification - genetics - isolation & purification
Gram-Positive Bacterial Infections - epidemiology - microbiology
Humans
Microbial Sensitivity Tests
Norway - epidemiology
Polymorphism, Restriction Fragment Length
Abstract
Reliable molecular methods for determination of relatedness between bacterial isolates have become increasingly important to evaluate outbreaks and endemic situations with nosocomial pathogens. In the present study Simpson's index of diversity with calculated confidence intervals was used to compare amplified fragment length polymorphism (AFLP) and pulsed field gel electrophoresis (PFGE) analysis of a hospital outbreak of ampicillin-resistant Enterococcus faecium and subsequent endemicity. The outbreak, in a Norwegian tertiary hospital, of infections caused by these enterococci started in 1995 and increased in 1996 after which the situation turned endemic. The purpose of this study was to compare the two methods in this setting and to determine the length of time during an outbreak that these methods are sufficiently valid to be of value for hospital infection control efforts. One hundred and sixty clinical isolates from urine specimens collected during the period 1995-1999 were included. The findings indicate that PFGE and AFLP are equally discriminative and could in this setting be used for typing purposes over the whole 5-year period.
PubMed ID
14734184 View in PubMed
Less detail

Comparison of DNA fingerprinting methods for use in investigation of type E botulism outbreaks in the Canadian Arctic.

https://arctichealth.org/en/permalink/ahliterature169440
Source
J Clin Microbiol. 2006 May;44(5):1635-44
Publication Type
Article
Date
May-2006
Author
Daniel Leclair
Franco Pagotto
Jeffrey M Farber
Brigitte Cadieux
John W Austin
Author Affiliation
Bureau of Microbial Hazards, Health Products and Food Branch, Food Directorate, Health Canada, Tunney's Pasture, PL 2204A2, Ottawa, Ontario, Canada K1A 0L2.
Source
J Clin Microbiol. 2006 May;44(5):1635-44
Date
May-2006
Language
English
Publication Type
Article
Keywords
Arctic Regions - epidemiology
Bacterial Typing Techniques
Base Sequence
Botulism - epidemiology - microbiology
Canada - epidemiology
Clostridium botulinum type E - classification - genetics - isolation & purification
DNA Fingerprinting - methods
DNA, Bacterial - genetics
Disease Outbreaks
Electrophoresis, Gel, Pulsed-Field - methods
Environmental Microbiology
Food Microbiology
Humans
Random Amplified Polymorphic DNA Technique
Reproducibility of Results
Ribotyping
Abstract
Pulsed-field gel electrophoresis (PFGE), randomly amplified polymorphic DNA (RAPD) analysis, and automated ribotyping were compared for epidemiological typing of Clostridium botulinum type E using clinical and food isolates associated with four botulism outbreaks occurring in the Canadian Arctic. All type E strains previously untypeable by PFGE, even with the use of a formaldehyde fixation step, could be typed by the addition of 50 microM thiourea to the electrophoresis running buffer. Digestion with SmaI or XhoI followed by PFGE was used to link food and clinical isolates from four different type E botulism outbreaks and differentiate them from among 39 group II strains. Strain differentiation was unsuccessful with the automated ribotyping system, producing a single characteristic EcoRI fingerprint common to all group II strains. RAPD analysis of C. botulinum group II strains was not consistently reproducible with primer OPJ-6 or OPJ-13, apparently discriminating between epidemiologically related strains. A modified PFGE protocol was judged to be the most useful method for typing epidemiologically related C. botulinum type E strains, based on its ability to type all strains reproducibly and with an adequate level of discrimination.
Notes
Cites: J Clin Microbiol. 2000 Jan;38(1):464-510618146
Cites: J Clin Microbiol. 1994 Dec;32(12):3013-77883892
Cites: J Clin Microbiol. 2000 Jul;38(7):2484-710878030
Cites: J Clin Microbiol. 2000 Jul;38(7):2791-210878091
Cites: J Food Prot. 2000 Oct;63(10):1347-5211041133
Cites: J Food Prot. 2001 Nov;64(11):1653-411726139
Cites: J Clin Microbiol. 2002 Jan;40(1):101-411773100
Cites: J Clin Microbiol. 2002 Sep;40(9):3198-20312202553
Cites: J Clin Microbiol. 2002 Sep;40(9):3546-7; author reply 354712202619
Cites: J Clin Microbiol. 2003 Jul;41(7):3181-612843061
Cites: Diagn Microbiol Infect Dis. 2003 Dec;47(4):619-2114711485
Cites: J Appl Microbiol. 1998 Jan;84(1):5-1715244052
Cites: Emerg Infect Dis. 2004 Sep;10(9):1606-1115498163
Cites: Appl Microbiol. 1972 Feb;23(2):427-84552895
Cites: Appl Environ Microbiol. 1998 Nov;64(11):4161-79797260
Cites: Lett Appl Microbiol. 1999 Apr;28(4):327-3310212447
Cites: Proc Natl Acad Sci U S A. 1995 May 23;92(11):5229-337539145
Cites: Appl Environ Microbiol. 1995 Dec;61(12):4441-78534108
Cites: Electrophoresis. 1995 Jun;16(6):888-947498131
Cites: J Clin Microbiol. 1995 Dec;33(12):3169-738586695
Cites: J Clin Microbiol. 1997 Feb;35(2):339-469003592
Cites: Appl Environ Microbiol. 1998 Feb;64(2):703-89464411
Cites: Int J Food Microbiol. 1998 Aug 18;43(1-2):1-59761332
Cites: Appl Environ Microbiol. 1999 May;65(5):2057-6410224001
Cites: Int J Food Microbiol. 1999 Mar 1;47(1-2):121-3110357280
Cites: J Clin Microbiol. 1999 Jul;37(7):2209-1410364587
Cites: FEMS Immunol Med Microbiol. 1999 Jul;24(3):287-9210397313
Cites: Int J Food Microbiol. 1999 Jun 1;48(3):179-8910443537
Cites: Can Commun Dis Rep. 1999 Jul 15;25(14):121-210458064
Cites: Appl Environ Microbiol. 2004 Dec;70(12):7192-915574917
Cites: J Med Microbiol. 2005 Feb;54(Pt 2):155-715673509
Cites: Appl Environ Microbiol. 2005 Mar;71(3):1148-5415746312
Cites: Can J Microbiol. 1975 Jun;21(6):920-61097074
Cites: Can Med Assoc J. 1977 Sep 3;117(5):483-9332309
Cites: MMWR Morb Mortal Wkly Rep. 1985 Sep 6;34(35):546-73927146
Cites: J Infect Dis. 1988 Jun;157(6):1158-623373020
Cites: Nucleic Acids Res. 1988 May 25;16(10):4341-522837731
Cites: J Clin Microbiol. 1988 Nov;26(11):2465-63069867
Cites: J Clin Microbiol. 1990 Sep;28(9):1903-52229371
Cites: FEMS Microbiol Lett. 1992 Sep 15;75(2-3):247-521398041
Cites: FEMS Microbiol Lett. 1993 Mar 15;108(1):103-107682527
Cites: Res Microbiol. 1993 Jun;144(5):373-98248630
Cites: Microbiology. 1994 Jun;140 ( Pt 6):1367-718081502
Cites: J Clin Microbiol. 1994 Aug;32(8):1963-97989550
Cites: J Clin Microbiol. 2000 Jun;38(6):2403-610835016
PubMed ID
16672387 View in PubMed
Less detail

Comparison of genotyping methods by application to Salmonella livingstone strains associated with an outbreak of human salmonellosis.

https://arctichealth.org/en/permalink/ahliterature75468
Source
Int J Food Microbiol. 2005 Sep 25;104(1):93-103
Publication Type
Article
Date
Sep-25-2005
Author
John Eriksson
Charlotta Löfström
Anna Aspán
Anders Gunnarsson
Ingela Karlsson
Elisabeth Borch
Birgitta de Jong
Peter Rådström
Author Affiliation
Applied Microbiology, Lund Institute of Technology, Lund University, P.O. Box 124, SE-221 00 Lund, Sweden.
Source
Int J Food Microbiol. 2005 Sep 25;104(1):93-103
Date
Sep-25-2005
Language
English
Publication Type
Article
Keywords
Animal Feed - microbiology
Animals
Cluster analysis
Disease Outbreaks
Electrophoresis, Gel, Pulsed-Field - methods
Food contamination - analysis
Genotype
Humans
Norway - epidemiology
Random Amplified Polymorphic DNA Technique - methods
Reproducibility of Results
Research Support, Non-U.S. Gov't
Ribotyping - methods
Salmonella - genetics - isolation & purification
Salmonella Food Poisoning - epidemiology
Sensitivity and specificity
Sweden - epidemiology
Abstract
During 2000 and 2001, an outbreak of human salmonellosis occurred in Sweden and Norway, caused by Salmonella livingstone. In this study, the genotypic differences between three strains obtained from food sources during the outbreak, two human strains and 27 more or less unrelated strains were analysed, using the three methods; automated ribotyping, pulsed field gel electrophoresis (PFGE) and randomly amplified polymorphic DNA (RAPD). Each method was evaluated regarding its discriminatory ability, reproducibility and typeability. Simpson's discriminatory index calculated for each method was 0.556 for automated ribotyping, 0.766 for PFGE and 0.236 for RAPD. The reproducibility, defined as the minimum similarity between individual replicates in a cluster analysis, was 96% for automated ribotyping and PFGE, and 90% for RAPD. All the strains were typeable with each method. When combining results for the three genotyping methods, it was found that RAPD did not increase the discriminatory index and was therefore excluded from further analysis. Using a combination of the results obtained from ribotyping and PFGE (D=0.855), two strains that had been isolated from feed factories during 1998 were shown to be identical to the outbreak strain, indicating a possible route of contamination due to a clone of Salmonella livingstone persisting in feed producing facilities. No connection to poultry was established.
PubMed ID
15978689 View in PubMed
Less detail

32 records – page 1 of 4.