The Experts below are selected from a list of 279 Experts worldwide ranked by ideXlab platform
Henrik Caspar Wegener - One of the best experts on this subject based on the ideXlab platform.
-
Phage Typing of salmonella typhimurium is it still a useful tool for surveillance and outbreak investigation
Eurosurveillance, 2010Co-Authors: Dorte Lau Baggesen, Gitte Sorensen, Eva Moller Nielsen, Henrik Caspar WegenerAbstract:Phage Typing has for decades been useful as a phenotypical, definitive method for epidemiological characterisation of Salmonella Typhimurium. The system recommended by the World Health Organization (WHO) Collaborative Centre for Phage Typing of Salmonella has, however, become rather complex, and the present study illustrates the challenges of sufficient standardisation of the interpretation of lysis results to make sure that the same strain is assigned to the same Phage type in different laboratories. Even though molecular Typing methods will replace phenotypic characterisation methods in the future, it is our opinion that Phage Typing will remain for some time a useful tool to strengthen global Salmonella surveillance. Therefore, improved standardisation and quality assurance is essential to obtain a robust and harmonized method that allows comparison of results between laboratories.
-
listeria monocytogenes in poultry and poultry products epidemiological investigations in seven danish abattoirs
Journal of Applied Microbiology, 1996Co-Authors: B Ojeniyi, Henrik Caspar Wegener, N E Jensen, Magne BisgaardAbstract:Listeria monocytogenes was isolated from 11/236 (4 x 7%) caecal samples from parent flocks, providing broilers to the abattoirs investigated. Caecal samples from 2078 broilers representing 90 randomly selected broiler flocks were negative for L. monocytogenes. A total of 3080 samples from seven abattoirs including poultry processing line samples, and final products were also examined for L. monocytogenes. Listeria monocytogenes was isolated in 0 x 3% to 18 x 7% of the samples collected in the different abattoirs. Epidemiological Typing of 247 L. monocytogenes isolates, including seroTyping, Phage Typing, pulsed-field gel electrophoresis and riboTyping revealed 62 different clones. Based upon typability and discriminatory power, DNA Typing methods used were found equally suitable as epidemiological markers. SeroTyping and Phage Typing were not found useful as epidemiological markers for poultry isolates of L. monocytogenes since only 120/247 (48 x 6%) isolates were typable by Phage Typing and 230/247 (93 x 1%) L. monocytogenes belonged to serotype 01 while 6/247 (2 x 4%) belonged to 04. The discovery of a few dominating clones in each abattoir might indicate an endemic occurrence of L. monocytogenes. It is concluded that L. monocytogenes in the broiler production is primarily localized to the abattoirs. The incidence of L. monocytogenes may be reduced by improving the hygiene.
-
Phage types of salmonella enterica ssp enterica serovar typhimurium isolated from production animals and humans in denmark
Acta Veterinaria Scandinavica, 1994Co-Authors: Dorte Lau Baggesen, Henrik Caspar WegenerAbstract:S. Typhimurium is one of the 2 most common salmonella serotypes causing human salmonellosis in Denmark. In order to illustrate the significance of different production animals as a source of infection, 1461 isolates were characterized by Phage Typing. The isolates originated from human patients and from cattle, pigs and poultry. By Phage Typing the isolates could be separated in 35 different Phage types. Five types (10, 12, 66, 110 and 135) predominated and comprised 78.8% of the isolates. In humans, 57.3% of the isolates were Phage type 12. This Phage type was also predominant in pig herds and, to a lesser degree, in cattle. Phage types 110, 120, 135 and 193 constituted 86.5% of the poultry isolates while these Phage types only made up 12.9% of the human isolates. The investigation showed that pigs are probably a major source of S. Typhimurium infection in humans in Denmark today.
-
Development of a Phage Typing system for Staphylococcus hyicus
Research in microbiology, 1993Co-Authors: Henrik Caspar WegenerAbstract:Abstract BacterioPhages were released by 98% of 100 Staphylococcus hyicus strains studied after treatment with mitomycin C. Twenty-three Phages with different lytic specta were included in a Phage Typing system and used for Typing S. hyicus . On a test-set of 100 epidemiologically unrelated S. hyicus strains isolated from Danish pig herds, the Phages were able to type 92% of the strains, producing 16 different Phage types. Reproducibility of the Phage Typing system after subculture of the strains and using fresh Phage stock was 96%. Typability ranged from 52 to 80% when Typing porcine strains originating from other countries. Although Phages were isolated from porcine skin strains exclusively, the system produced Phage type in S. hyicus strains of bovine origin. Ten strains of S. aureus and S. chromogenes were not typable by these Phages. Strains belonging to one Phage type (A/B/C/W) were isolated significantly more often from piglets with exudative epidermitis than from healthy piglets. The Phage Typing system described appears to be a valuable tool in diagnosis of exudative epidermitis in pigs, and furthermore, might be of value in epidemiological studies of S. hyicus .
Wolfgang Rabsch - One of the best experts on this subject based on the ideXlab platform.
-
Typing of salmonella enterica serovar infantis isolates from 51 outbreaks in germany between 1974 and 2009 by a novel Phage Typing scheme
Epidemiology and Infection, 2013Co-Authors: Tatjana Miller, Peggy G Braun, Karsten Fehlhaber, Rita Prager, Yvonne Pfeifer, Wolfgang RabschAbstract:SUMMARY We developed a new Phage-Typing method and evaluated its application in combination with XbaI macrorestriction analysis by pulsed-field gel electrophoresis (PFGE) as a useful tool for the long-term epidemiology of Salmonella enterica serovar Infantis. In this study, we investigated 1008 S. Infantis isolates recovered from humans, various animal species and food products from 1973 to 2009. The Typing scheme is based on 17 Typing Phages, defining 61 different patterns within the strain collection. The experiments showed that Phage Typing is a reliable method for differentiation of outbreaks and sporadic clinical cases as well as for elucidation of chains of transmission. The combined analysis of Phage Typing and PFGE revealed the existence of epidemic clones with a high stability over time like PT29/XB27 which was identified in nosocomial salmonellosis, community outbreaks as well as in broiler chickens from 2002 to 2009.
-
salmonella typhimurium Phage Typing for pathogens
Methods of Molecular Biology, 2007Co-Authors: Wolfgang RabschAbstract:Phage Typing provides a rapid, accurate, and cheap method of investigating Salmonella strains for epidemiological use. Salmonella strains within a particular serovar may be differentiated into a number of Phage types by their pattern of susceptibility to lysis by a set of Phages with different specificity. Characterization based on the pattern of Phage lysis of wild strains isolated from different patients, carriers, or other sources is valuable in epidemiological study. The Phages must have well-defined propagation strains that allow reproducible discrimination between different Salmonella Typhimurium strains. Different schemes have been developed for this serovar in different countries. The Felix/Callow (England) and Lilleengen Typing systems (Sweden) used for laboratory-based epidemiological analysis were helpful for control of salmonellosis. More recently, the extended Phage-Typing system of Anderson (England) that distinguishes more than 300 definitive Phage types (DTs) has been used worldwide in Europe, the United States, and Australia. The use of this method for decades show us that some Phage types (DT204 in the 1970s and DT104 in the 1990s) have a broad host range and are distributed worldwide, other Phage types such as DT2 or DT99 are frequently associated with disease in pigeons, indicative of a narrow host range.
-
molecular epidemiology of salmonella enterica serovar agona characterization of a diffuse outbreak caused by aniseed fennel caraway infusion
Epidemiology and Infection, 2005Co-Authors: Wolfgang Rabsch, Rita Prager, Judith Koch, Klaus Stark, Peter Roggentin, Jochen Bockemuhl, Gero Beckmann, R Stark, W Siegl, A AmmonAbstract:During 2002-2003 increased numbers of notified salmonellosis due to S. enterica serovar Agona were observed in Germany. In order to understand the recent spread of this serovar and to trace the route of infection to its source, a new Phage-Typing scheme and pulsed field gel electrophoresis (PFGE) were used to analyse these isolates. By using 14 bacterioPhages, 52 Phage types were distinguished among the S. Agona strains. PFGE also differentiated 52 different patterns. A combination of both methods generated 94 clonal types among 165 S. Agona strains originating from Germany and other countries including the United States, United Arab Emirates, Turkey, India, Austria and Finland, indicating a great biological diversity within this serovar. However, 36 recent S. Agona isolates from infantile gastroenteritis in Germany, from an untreated batch of aniseed imported from Turkey and from fennel-aniseed-caraway infusion (packed in tea bags) revealed clonal identity indicating their epidemiological relatedness as a new source of infection. It is suggested that strains of S. Agona will continue to be of public health concern, and that Phage Typing together with PFGE Typing should be applied as reliable and rapid tools for epidemiological subTyping and future monitoring.
-
Phage Typing and pfge pattern analysis as tools for epidemiological surveillance of salmonella enterica serovar bovismorbificans infections
Epidemiology and Infection, 2002Co-Authors: Almut Liesegang, Wolfgang Rabsch, Rita Prager, Dianne Davos, Anja Siitonen, J C Balzer, Diane Lightfoot, Hermann Claus, Helmut TschapeAbstract:Some years ago, an increase in the number of sporadic cases and outbreaks of salmonellosis due to S. enterica serovar Bovismorbificans was observed in several European countries including Finland, Sweden, England/Wales, Austria, and Germany. In order to understand the recent spread of this serovar and to trace the route of infection back to its source, it was considered necessary to subtype S. Bovismorbificans isolates. Using Phage Typing (newly described here) and molecular fingerprinting (PFGE-pattern, plasmid profiles and ribotype) the isolates of European origin could be subtyped and compared to S. Bovismorbificans isolates that originated in overseas countries such as Australia, Thailand, India, etc. where this serovar was isolated more frequently. Significant clonal diversity was identified but some of the clonal types of S. Bovismorbificans dominated the epidemics and single cases in Europe as well as in overseas countries. The clonal identity among these isolates indicates an international distribution, new sources of infection, and highlights the urgent requirement for standardized laboratory based surveillance networks (e.g. Enter-Net). Moreover, it is suggested that strains of S. Bovismorbificans will continue to be of concern in public health and that Phage Typing together with PFGE Typing can be applied as reliable and rapid tools for their future monitoring.
Magne Bisgaard - One of the best experts on this subject based on the ideXlab platform.
-
listeria monocytogenes in poultry and poultry products epidemiological investigations in seven danish abattoirs
Journal of Applied Microbiology, 1996Co-Authors: B Ojeniyi, Henrik Caspar Wegener, N E Jensen, Magne BisgaardAbstract:Listeria monocytogenes was isolated from 11/236 (4 x 7%) caecal samples from parent flocks, providing broilers to the abattoirs investigated. Caecal samples from 2078 broilers representing 90 randomly selected broiler flocks were negative for L. monocytogenes. A total of 3080 samples from seven abattoirs including poultry processing line samples, and final products were also examined for L. monocytogenes. Listeria monocytogenes was isolated in 0 x 3% to 18 x 7% of the samples collected in the different abattoirs. Epidemiological Typing of 247 L. monocytogenes isolates, including seroTyping, Phage Typing, pulsed-field gel electrophoresis and riboTyping revealed 62 different clones. Based upon typability and discriminatory power, DNA Typing methods used were found equally suitable as epidemiological markers. SeroTyping and Phage Typing were not found useful as epidemiological markers for poultry isolates of L. monocytogenes since only 120/247 (48 x 6%) isolates were typable by Phage Typing and 230/247 (93 x 1%) L. monocytogenes belonged to serotype 01 while 6/247 (2 x 4%) belonged to 04. The discovery of a few dominating clones in each abattoir might indicate an endemic occurrence of L. monocytogenes. It is concluded that L. monocytogenes in the broiler production is primarily localized to the abattoirs. The incidence of L. monocytogenes may be reduced by improving the hygiene.
-
the characterization of danish isolates of salmonella enterica serovar enteritidis by Phage Typing and plasmid profiling 1980 1990
Apmis, 1994Co-Authors: D J Brown, Dorte Lau Baggesen, H B Hansen, H C Hansen, Magne BisgaardAbstract:Plasmid profiling, Phage Typing and antimicrobial resistance Typing have been carried out on 736 isolates of Salmonella enterica serovar Enteritidis collected in Denmark during the period 1980 to 1990. Strains originated from cases of human salmonellosis, broiler poultry flocks, layer poultry flocks, quarantined imported poultry, environmental samples from hatchery units, and from bovines. Phage type (PT) 1 was found to be the most common type among isolates of poultry origin (57.6%) followed by PT4 (28.8%). Isolates belonging to PT8 were found exclusively in imported birds. Phage Typing of a representative sample of human isolates revealed the predominance, as in most other Western European countries, of PT4 (61.8%). PT1, however, was found in 17.0% of human strains, a much higher incidence than expected. Antibiotic resistance was observed in 4 out of 107 human isolates (3.7%) and 2 out of 205 non-human isolates (1%) tested.
Usman Chatib Warsa - One of the best experts on this subject based on the ideXlab platform.
-
antimicrobial susceptibilities and Phage Typing of staphylococcus aureus clinical isolates in indonesia
Journal of Infection and Chemotherapy, 1996Co-Authors: Usman Chatib Warsa, Toyoji Okubo, Ryoichi OkamotoAbstract:A total of 814 strains ofStaphylococcus aureus isolated from clinical specimens in Jakarta from 1986 through 1993 were examined for their susceptibility to 18 antimicrobial agents. Strains with multiple resistance against sulfanilamide, penicillin, tetracycline, and chloramphenicol predominated. Strains resistant against new broad-spectrum antimicrobial agents, such as β-lactams, macrolides, aminoglycosides, and quinolones, increased rapidly after 1990. The incidence of methicillin-resistantS. aureus (MRSA), which increased from 2.5% in 1986 to 9.6% in 1990, partly accounted for the increased frequency of strains inS. aureus resistant to multiple drugs. All MRSA strains were coagulase type IV. On Phage Typing, 58.6% of methicillin-susceptible strains (MSSA) and 66.7% of MRSA strains were nontypable by routine test dilution (RTD). The predominant Phage groups in MSSA and MRSA were group II (21.5%) and group III (19.0%), respectively.
Dorte Lau Baggesen - One of the best experts on this subject based on the ideXlab platform.
-
Phage Typing of salmonella typhimurium is it still a useful tool for surveillance and outbreak investigation
Eurosurveillance, 2010Co-Authors: Dorte Lau Baggesen, Gitte Sorensen, Eva Moller Nielsen, Henrik Caspar WegenerAbstract:Phage Typing has for decades been useful as a phenotypical, definitive method for epidemiological characterisation of Salmonella Typhimurium. The system recommended by the World Health Organization (WHO) Collaborative Centre for Phage Typing of Salmonella has, however, become rather complex, and the present study illustrates the challenges of sufficient standardisation of the interpretation of lysis results to make sure that the same strain is assigned to the same Phage type in different laboratories. Even though molecular Typing methods will replace phenotypic characterisation methods in the future, it is our opinion that Phage Typing will remain for some time a useful tool to strengthen global Salmonella surveillance. Therefore, improved standardisation and quality assurance is essential to obtain a robust and harmonized method that allows comparison of results between laboratories.
-
the characterization of danish isolates of salmonella enterica serovar enteritidis by Phage Typing and plasmid profiling 1980 1990
Apmis, 1994Co-Authors: D J Brown, Dorte Lau Baggesen, H B Hansen, H C Hansen, Magne BisgaardAbstract:Plasmid profiling, Phage Typing and antimicrobial resistance Typing have been carried out on 736 isolates of Salmonella enterica serovar Enteritidis collected in Denmark during the period 1980 to 1990. Strains originated from cases of human salmonellosis, broiler poultry flocks, layer poultry flocks, quarantined imported poultry, environmental samples from hatchery units, and from bovines. Phage type (PT) 1 was found to be the most common type among isolates of poultry origin (57.6%) followed by PT4 (28.8%). Isolates belonging to PT8 were found exclusively in imported birds. Phage Typing of a representative sample of human isolates revealed the predominance, as in most other Western European countries, of PT4 (61.8%). PT1, however, was found in 17.0% of human strains, a much higher incidence than expected. Antibiotic resistance was observed in 4 out of 107 human isolates (3.7%) and 2 out of 205 non-human isolates (1%) tested.
-
Phage types of salmonella enterica ssp enterica serovar typhimurium isolated from production animals and humans in denmark
Acta Veterinaria Scandinavica, 1994Co-Authors: Dorte Lau Baggesen, Henrik Caspar WegenerAbstract:S. Typhimurium is one of the 2 most common salmonella serotypes causing human salmonellosis in Denmark. In order to illustrate the significance of different production animals as a source of infection, 1461 isolates were characterized by Phage Typing. The isolates originated from human patients and from cattle, pigs and poultry. By Phage Typing the isolates could be separated in 35 different Phage types. Five types (10, 12, 66, 110 and 135) predominated and comprised 78.8% of the isolates. In humans, 57.3% of the isolates were Phage type 12. This Phage type was also predominant in pig herds and, to a lesser degree, in cattle. Phage types 110, 120, 135 and 193 constituted 86.5% of the poultry isolates while these Phage types only made up 12.9% of the human isolates. The investigation showed that pigs are probably a major source of S. Typhimurium infection in humans in Denmark today.
