scholarly journals Comparison of multilocus enzyme electrophoresis (MEE), ribotyping, restriction enzyme analysis (REA) and phage typing for typing ofListeria monocytogenes

1993 ◽  
Vol 111 (1) ◽  
pp. 71-79 ◽  
Author(s):  
B. Nørrung ◽  
P. Gerner-Smith
Keyword(s):  
Listeria Monocytogenes ◽  
Molecular Typing ◽  
Phage Typing ◽  
Enzyme Analysis ◽  
Restriction Enzyme Analysis ◽  
Enzyme Electrophoresis ◽  
Typing Method ◽  
Multilocus Enzyme Electrophoresis ◽  
Serotype 1 ◽  
Typing Methods

SummaryThe discriminatory power of four methods for typing ofListeria monocytogeneswas compared. The four methods were multilocus enzyme electrophoresis (MEE), ribotyping, restriction enzyme analysis (REA), and a newly developed Danish phage typing system. Ninety-nine human clinical, food and slaughterhouse isolates ofListeria monocytogeneswere typed by each method. The most discriminatory single typing method was phage typing with an overall discriminatory index (DI) of 0·88 followed by REA, MEE and ribotyping with DI-values at 0·87, 0·83 and 0·79 respectively. Considering strains from each of the two predominant O-serotypes alone, serotype 1 was best discriminated by the molecular typing methods, in particular REA, which showed a DI of 0·92. The serotype 4 strains were best discriminated by phage typing (DI = 0·78). If two or more typing methods were combined, the combination of REA and MEE were found to be the most discriminatory combination. The DI values were 0·96, 0·74 and 0·90 for serotype 1, 4, and both combined, respectively. Phage typing is a rapid and inexpensive typing method but not as reproducible as the molecular typing methods. It is the most suitable method for mass screening. In situations where results are required to be highly reliable, i.e. when studying the relationships between only a few strains, a single or a combination of molecular typing methods should be used, preferable MEE and REA.

Genome Variation among Listeria monocytogenes Isolates Derived from Epidemiologically Related Raw Milk and Other Strains

1996 ◽  
Vol 59 (9) ◽  
pp. 998-1002 ◽  
Author(s):  
AKINOBU SAITO ◽  
RYO HONDO
Keyword(s):  
Listeria Monocytogenes ◽  
Restriction Enzyme ◽  
Restriction Enzymes ◽  
Raw Milk ◽  
Enzyme Analysis ◽  
Restriction Enzyme Analysis ◽  
Chromosomal Dna ◽  
Epidemiological Analysis ◽  
Serotype 1 ◽  
Enzyme Patterns

Listeria monocytogenes strains were examined by restriction-enzyme analysis of chromosomal DNA using a total of 18 restriction enzymes. Ten of the 6-base restriction enzymes and one 8-base restriction enzyme produced distinguishable fragments among these strains. Six strains (serotype 1/2a) recovered from raw milk suspected of the same contaminant were compared with seven epidemiologically unrelated strains (serotype 1/2a) using 10 of the 6-base restriction enzymes. The restriction enzyme patterns of the six raw milk isolates were identical to each other, but differed from those of the other strains. Restriction-enzyme analysis of the chromosomal DNA of L. monocytogenes by using the 6-base restriction enzymes may be a useful method of epidemiological analysis for listeriosis outbreaks.

scholarly journals Molecular Epidemiological Survey of Listeria monocytogenes in Seafoods and Seafood-Processing Plants

2000 ◽  
Vol 66 (11) ◽  
pp. 4779-4784 ◽  
Author(s):  
Liv Marit Rørvik ◽  
Brit Aase ◽  
Torill Alvestad ◽  
Dominique A. Caugant
Keyword(s):  
Listeria Monocytogenes ◽  
Epidemiological Survey ◽  
Enzyme Analysis ◽  
Restriction Enzyme Analysis ◽  
Enzyme Electrophoresis ◽  
Processing Plants ◽  
Seafood Products ◽  
Great Genetic Diversity ◽  
Seafood Processing

ABSTRACT To evaluate the role of seafoods in the epidemiology of human listeriosis and the role of the processing environment as a source ofListeria monocytogenes in seafood products, 305 L. monocytogenes isolates were characterized by multilocus enzyme electrophoresis using 21 genetic loci and restriction enzyme analysis of total DNA. Forty-four isolates were recovered from patients in Norway; 93 were isolated from seafoods, seafood-processing environments, and seawater from 55 different producers; and the remaining 168 isolates originated from six seafood-processing plants and one transport terminal examined in detail for L. monocytogenes. The patient isolates fell into 11 electrophoretic types, with four of them being responsible for 77% of the listeriosis cases in 1992 to 1996. Isolates from Norwegian seafoods and processing environments showed great genetic diversity, indicating that seafoods and seafood-processing environments do not offer a niche for specificL. monocytogenes strains. On the other hand, isolates from individual processing plants were genetically more homogenous, showing that plants are likely to be colonized with specific subclones ofL. monocytogenes. The isolation of identical subclones ofL. monocytogenes from both human patients and seafoods, including ready-to-eat products, suggests that such products may have been possible sources for listeriosis cases in Norway.

scholarly journals A molecular characterization ofClostridium difficileisolates from humans, animals and their environments

1993 ◽  
Vol 111 (2) ◽  
pp. 257-264 ◽  
Author(s):  
G. O'Neill ◽  
J. E. Adams ◽  
R. A. Bowman ◽  
T. V. Riley
Keyword(s):  
Fragment Length Polymorphism ◽  
Hospital Environment ◽  
Enzyme Analysis ◽  
Restriction Enzyme Analysis ◽  
Direct Transmission ◽  
Chromosomal Dna ◽  
Veterinary Clinic ◽  
Enhanced Chemiluminescence ◽  
Typing Methods ◽  
Rflp Typing

SummaryIt is generally accepted that most patients withClostridium difficile-associated diarrhoea acquire the organism from the environment. Recently we demonstrated that household pets may constitute a significant reservoir ofC. difficilethrough gastrointestinal carriage in up to 39% of cats and dogs. These findings suggested that direct transmission from household pets, or contamination of the environment by them, may be a factor in the pathogenesis ofC. difficile-associated diarrhoea. To investigate this possibility, we examined isolates ofC. difficilefrom humans, pets and the environment by restriction enzyme analysis (REA) and restriction fragment length polymorphism (RFLP) typing using enhanced chemiluminescence. Both REA and RFLP typing methods usedHindIII digests of chromosomal DNA. A total of 116 isolates ofC. difficilefrom pets (26), veterinary clinic environmental sites (33), humans (37) and hospital environmental sites (20) was examined. REA was far more discriminatory than RFLP typing and for all isolates there were 34 REA types versus 6 RFLP types. There was good correlation between the REA types found in isolates from pets and from the veterinary clinic environment, and between isolates from humans and from those found in the hospital environment. There was, however, no correlation between REA type ofC. difficilefound in pets and isolates of human origin. We conclude that there may still be a risk of humans acquiringC. difficilefrom domestic pets as these findings may be the result of geographical variation.

Comparison of Restriction Enzyme Analysis, Arbitrarily Primed PCR, and Protein Profile Analysis Typing for Epidemiologic Investigation of an Ongoing Clostridium difficileOutbreak

1998 ◽  
Vol 36 (10) ◽  
pp. 2957-2963 ◽  
Author(s):  
Mary Ellen Rafferty ◽  
Aldona L. Baltch ◽  
Raymond P. Smith ◽  
Lawrence H. Bopp ◽  
Carol Rheal ◽  
...  
Keyword(s):  
Clostridium Difficile ◽  
General Hospital ◽  
Restriction Enzyme ◽  
Profile Analysis ◽  
Protein Profile ◽  
Enzyme Analysis ◽  
Restriction Enzyme Analysis ◽  
Typing Methods ◽  
Arbitrarily Primed Pcr ◽  
Predominant Strain

During an outbreak of diarrhea in a general hospital in 1992, 166Clostridium difficile isolates from 102 patients were typed by restriction enzyme analysis (REA), arbitrarily primed PCR (AP-PCR), and protein profile analysis (PP) techniques. A total of 18 types and 5 subtypes were identified by REA, 32 types were identified by AP-PCR, and 9 types were identified by PP. Analysis of the data indicated the presence of a predominant strain among 76, 75, and 84% of the isolates by REA, AP-PCR, and PP, respectively. Subsequently, 45C. difficile isolates which had been collected in 1990 from 33 patients in the same hospital following a significant increase in the number of cases of diarrhea caused by C. difficile were studied by REA, AP-PCR, and PP typing techniques. Thirteen types and one subtype were identified by REA, 12 types were identified by AP-PCR, and 5 types were identified by PP. As with the isolates from 1992, a dominant strain was identified. This strain was represented by 53, 64, and 70% of the total number of isolates when the strains were typed by REA, AP-PCR, and PP, respectively. Every isolate (210 of 211) from both 1990 and 1992 that was available for typing was typeable by all three methods. Furthermore, the same dominant strain was identified in both 1990 and 1992 by each method. This study demonstrates that each of the three typing methods can be useful in epidemiologic investigations of C. difficileoutbreaks and that one strain can be dominant in an institution over a number of years.

Potential of Three-Way Randomly Amplified Polymorphic DNA Analysis as a Typing Method for TwelveSalmonella Serotypes

1999 ◽  
Vol 65 (11) ◽  
pp. 4830-4836 ◽  
Author(s):  
S. M. Soto ◽  
B. Guerra ◽  
M. A. González-Hevia ◽  
M. C. Mendoza
Keyword(s):  
Dna Analysis ◽  
Phage Typing ◽  
Clinical Samples ◽  
Randomly Amplified Polymorphic Dna ◽  
Typing Method ◽  
Phage Types ◽  
Typing Methods ◽  
In Vitro Stability ◽  
Reference Strains

ABSTRACT The potential of a three-way randomly amplified polymorphic DNA (RAPD) procedure (RAPD typing) for typing Salmonella enterica strains assigned to 12 serotypes was analyzed. The series of organisms used included 235 strains (326 isolates) collected mainly from clinical samples in the Principality of Asturias and 9 reference strains. RAPD typing was performed directly with broth cultures of bacteria by using three selected primers and optimized PCR conditions. The profiles obtained with the three primers were used to define RAPD types and to evaluate the procedure as a typing method at the species and serotype levels. The typeability was 100%; the reproducibility and in vitro stability could be considered good. The concordance of RAPD typing methods with serotyping methods was 100%, but some profiles obtained with two of the three primers were obtained with strains assigned to different serotypes. The discrimination index (DI) within the series of organisms was 0.94, and the DI within serotypes Typhimurium, Enteritidis, and Virchow were 0.72, 0.52, and 0.66, respectively. Within these serotypes the most common RAPD types were differentiated into phage types and vice versa; combining the types identified by the two procedures (RAPD typing and phage typing) resulted in further discrimination (DI, 0.96, 0.74, and 0.87, respectively). The efficiency, rapidity, and flexibility of the RAPD typing method support the conclusion that it can be used as a tool for identifying Salmonella organisms and as a typing method that is complementary to serotyping and phage typing methods.

Application of Multilocus Enzyme Electrophoresis to Epidemiologic Investigations ofXanthomonas Maltophilia

1991 ◽  
Vol 12 (3) ◽  
pp. 163-167 ◽  
Author(s):  
Barbara Schable ◽  
Margarita E. Villarino ◽  
Martin S. Favero ◽  
J. Michael Miller
Keyword(s):  
Intensive Care Unit ◽  
Intensive Care ◽  
Epidemiological Data ◽  
Case Definition ◽  
Enzyme Electrophoresis ◽  
Typing Method ◽  
Multilocus Enzyme Electrophoresis ◽  
General Community ◽  
Suspected Outbreak

AbstractObjective:To test the utility of a newly developed multilocus enzyme electrophoresis typing method for Xanthomonas maltophilia.Design:Isolates were first screened by slide agglutination, which served as the standard to characterize the outbreak strains. All isolates were then subjected to multilocus enzyme elec-trophoresis and the results analyzed based on epidemiological data.Setting:This outbreak occurred in a shock-trauma intensive care unit of a large general community hospital.Patients:Patients admitted to the shock-trauma intensive care unit who had X maltophilia isolated from any site > 24 hours after admission met the case definition. Specimens from patients who fit the case definition were characterized, as were specimens from other patients that were used as controls for nonoutbreak isolates. Environmental samples were also evaluated for X maltophilia.Results:Most of the 64 isolates received during this outbreak were serotype 10, and when they were subjected to multilocus enzyme electro-phoresis, one electrophoretic type predominated and correlated to most outbreak isolates. Unrelated isolates of serotype 10 from other institutions all exhibited unique electrophoretic types.Conclusion:Application of multilocus enzyme electrophoresis to X maltophilia outbreaks is a valuable addition to the characterization of suspected outbreak strains.

Division of Listeria monocytogenesSerovar 1/2a Strains into Two Groups by PCR and Restriction Enzyme Analysis

1999 ◽  
Vol 65 (5) ◽  
pp. 2054-2056 ◽  
Author(s):  
Helle Unnerstad ◽  
Inger Nilsson ◽  
Henrik Ericsson ◽  
Marie-Louise Danielsson-Tham ◽  
Jacques Bille ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Restriction Enzyme ◽  
Gel Electrophoresis ◽  
Enzyme Analysis ◽  
Restriction Enzyme Analysis ◽  
Restriction Profile ◽  
Pcr Product

ABSTRACT Altogether, 100 strains of Listeria monocytogenesserovar 1/2a isolated from humans, animals, food, and the environment were typed by a combination of PCR and restriction enzyme analysis (REA). A PCR product of 2,916 bp, containing the downstream end of the gene inlA (955 bp), the space between inlA andinlB (85 bp), and 1,876 bp of the gene inlB, was cleaved with the enzyme AluI, and the fragments generated were separated by gel electrophoresis. By this method two different cleavage patterns were obtained. Seventy of the 100 strains shared one restriction profile, and the remaining 30 strains shared the second one. No relation was found between the types differentiated by PCR-REA and the origins of the strains.

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