| 1. |
- Danielsson-Tham, Marie-Louise, 1947-, et al.
(författare)
-
Causes behind a human cheese-borne outbreak of gastrointestinal listeriosis
- 2004
-
Ingår i: Foodborne pathogens and disease. - New York, USA : Mary Ann Liebert. - 1535-3141 .- 1556-7125. ; 1:3, s. 153-159
-
Tidskriftsartikel (refereegranskat)abstract
- In a previous paper, we reported an outbreak of gastrointestinal listeriosis due to consumption of fresh cheese made from raw milk and manufactured on a summer farm. The aim of the present study was to investigate why the cheese harbored Listeria monocytogenes. To our knowledge, this is the first documented outbreak of listeriosis caused by raw milk cheese where the human epidemic strain has been cultured from a dairy animal, whose milk has been used for cheese production. The conditions on a summer farm can hardly fulfil the requirements for hygienic and strictly controlled conditions necessary for safe processing of fresh cheese.
|
|
| 2. |
- Ellström, Patrik, et al.
(författare)
-
A Prospective Follow-Up Study on Transmission of Campylobacter from Poultry to Abattoir Workers
- 2014
-
Ingår i: Foodborne Pathogens and Disease. - : Mary Ann Liebert Inc. - 1535-3141 .- 1556-7125. ; 11:9, s. 684-688
-
Tidskriftsartikel (refereegranskat)abstract
- Contact with poultry or poultry meat is a well-known risk factor for campylobacteriosis, but prospective studies on transmission of Campylobacter from chickens to humans during slaughter are scarce. In this study, we monitored transmission of Campylobacter from slaughtered chicken to originally culture-negative abattoir workers during the peak season of colonized chicken and human Campylobacter infection. Stool samples were obtained from 28 abattoir workers together with data on health status once a month between June and September 2010, with a follow-up sample collected in February 2011. Campylobacter-positive individuals and chicken flocks were identified by culture, and isolates were further characterized using molecular techniques. Campylobacter was isolated from seven asymptomatic individuals. Four of them had been newly employed and had not reported any previous Campylobacter infection. Four human isolates had matching genetic fingerprints with isolates from recently slaughtered chickens. Our results further support the role of chicken as the source of human Campylobacter infection but suggest that asymptomatic Campylobacter infection may occur even in individuals with only limited earlier exposure to Campylobacter.
|
|
| 3. |
- Gustafsson, Camilla, et al.
(författare)
-
"Meat Juice" Is Not a Homogeneous Serological Matrix
- 2015
-
Ingår i: Foodborne Pathogens and Disease. - : Mary Ann Liebert Inc. - 1535-3141 .- 1556-7125. ; 12, s. 280-288
-
Tidskriftsartikel (refereegranskat)abstract
- Meat juice samples are used in serological assays to monitor infectious diseases within the food chain. However, evidence of inferior sensitivity, presumably due to low levels of antibodies in the meat juice compared to serum, has been presented, and it has been suggested that adjusting the dilution factor of meat juice in proportion to its blood content could improve sensitivity. In the present study, the agreement between Toxoplasma gondii-specific immunoglobulin G (IgG) levels in meat juice and serum was evaluated, and whether the level of immunoglobulins in meat juice was dependent on its blood content. Serum and meat juice from diaphragm, heart, tongue, Musculus triceps brachii and M. semitendinosus were collected from 20 pigs experimentally infected with T. gondii. Analysis of total IgG, heme-containing proteins (hematin), and hemoglobin (Hb) revealed significant differences between samples from different muscles, with the highest levels in samples from heart and tongue, and the lowest in samples from leg muscles. Comparison of T. gondii-specific antibody titers in meat juice and serum revealed a strong positive correlation for meat juice from heart (r(s)=0.87; p<0.001), while it was lower for M. semitendinosus (r(s)=0.71; p<0.001) and diaphragm (r(s)=0.54; p=0.02). Meanwhile, the correlation between total IgG and T. gondii titer ratio (meat juice/serum) was highest in diaphragm (r(s)=0.77; p<0.001) followed by M. semitendinosus (r(s)=0.64; p=0.005) and heart (r(s)=0.50; p=0.051). The correlation between Hb and T. gondii titer ratio was only significant for diaphragm (r(s)=0.65; p=0.008), and for hematin no significant correlation was recorded. In conclusion, the specific IgG titers in meat juice appeared to depend on the total IgG level, but the correlation to blood (Hb or hematin) was poor. Importantly, large significant differences in total IgG levels as well as in specific antibody titers were recorded, depending on the muscle the meat juice had been extracted from.
|
|
| 4. |
- Lopez-Valladares, Gloria, 1963-, et al.
(författare)
-
Division of Human Listeria monocytogenes Pulsed-Field Gel Electrophoresis (PFGE) Types Belonging to Lineage I (Serovar 4b, 1/2b, and 3b) into PFGE Groups
- 2015
-
Ingår i: Foodborne pathogens and disease. - : Mary Ann Liebert. - 1535-3141 .- 1556-7125. ; 12:5, s. 447-453
-
Tidskriftsartikel (refereegranskat)abstract
- The 63 pulsed-field gel electrophoresis (PFGE) types identified among 427 clinical isolates of Listeria monocytogenes that were characterized in a previous study by serotyping and PFGE (AscI) could be further divided into 17 PFGE groups. While the 63 PFGE types, all part of lineage I, were established based on the number and distribution of all bands in each DNA profile, the 17 PFGE groups were based on the configuration of small bands with sizes L. monocytogenes serovar 4b isolates (n=334) were divided into 8 PFGE groups; the 32 PFGE types of serovar 1/2b isolates (n=90) and the serovar 3b isolates (n=3, 1 PFGE type) were divided into 9 PFGE groups. An association was observed between PFGE groups and serovars. L. monocytogenes isolates belonging to PFGE groups I, J, Q, R, X, Z, o-4, and o-5 all shared serovar 4b, whereas isolates from PFGE groups D, G, O, P, T, U, o-1, o-2, and o-3 shared serovar 1/2b. Small fragments L. monocytogenes isolates. From the results of the present study, a procedure for accelerating the identification of PFGE types when analyzing new PFGE profiles can be suggested. Therefore, we propose a stepwise procedure to PFGE profiling by first identifying the PFGE group using the smaller band patterns <145.5 kb, and then determining PFGE types based on the band patterns >145.5 kb.
|
|
| 5. |
- Lopez-Valladares, Gloria, 1963-, et al.
(författare)
-
Implicated food products for listeriosis and changes in serovars of Listeria monocytogenes affecting humans in recent decades
- 2018
-
Ingår i: Foodborne pathogens and disease. - : Mary Ann Liebert. - 1535-3141 .- 1556-7125. ; 15:7, s. 387-397
-
Tidskriftsartikel (refereegranskat)abstract
- Listeriosis is a foodborne disease with a high fatality rate, and infection is mostly transmitted through ready-toeat(RTE) foods contaminated with Listeria monocytogenes, such as gravad/smoked fish, soft cheeses, andsliced processed delicatessen (deli) meat. Food products/dishes stored in vacuum or in modified atmospheresand with extended refrigerator shelf lives provide an opportunity for L. monocytogenes to multiply to largenumbers toward the end of the shelf life. Elderly, pregnant women, neonates, and immunocompromisedindividuals are particularly susceptible to L. monocytogenes. Listeriosis in humans manifests primarily assepticemia, meningitis, encephalitis, gastrointestinal infection, and abortion. In the mid 1990s and early 2000s ashift from L. monocytogenes serovar 4b to serovar 1/2a causing human listeriosis occurred, and serovar 1/2a isbecoming more frequently linked to outbreaks of listeriosis, particularly in Europe and Northern America.Consumer lifestyle has changed, and less time is available for food preparation. Modern lifestyle has markedlychanged eating habits worldwide, with a consequent increased demand for RTE foods; therefore, more RTE andtake away foods are consumed. There is a concern that many Listeria outbreaks are reported from hospitals.Therefore, it is vitally important that foods (especially cooked and chilled) delivered to hospitals and residentialhomes for senior citizens and elderly people are reheated to at least 72C: cold food, such as turkey deli meatand cold-smoked and gravad salmon should be free from L. monocytogenes. Several countries have zerotolerance for RTE foods that support the growth of Listeria.
|
|
| 6. |
- Lopez-Valladares, Gloria, 1963-, et al.
(författare)
-
Lineage II (Serovar 1/2a and 1/2c) Human Listeria monocytogenes Pulsed-Field Gel Electrophoresis Types Divided into PFGE Groups Using the Band Patterns Below 145.5 kb
- 2017
-
Ingår i: Foodborne pathogens and disease. - New Rochelle, USA : Mary Ann Liebert. - 1535-3141 .- 1556-7125. ; 14:1, s. 8-16
-
Tidskriftsartikel (refereegranskat)abstract
- Among 504 clinical lineage II isolates of Listeria monocytogenes isolated during 1958-2010 in Sweden, 119 pulsed-field gel electrophoresis (PFGE) types (AscI) have been identified based on the number and distribution of all banding patterns in each DNA profile. In this study, these types were further divided into PFGE groups based on the configuration of small bands with sizes <145.5 kb. The 504 isolates included 483 serovar 1/2a isolates distributed into 114 PFGE types and 21 serovar 1/2c isolates distributed into 9 PFGE types; these were further divided into 21 PFGE groups. PFGE group, that is, configuration of small bands below 145.5 kb, and serovars were correlated. L. monocytogenes isolates belonging to PFGE groups A, B, C, E, F, H, K, L, M, S, V, W, Y, and Ö-6 to Ö-12 shared serovar 1/2a, with one exception. PFGE group E also included two PFGE types sharing serovar 1/2c and four PFGE types belonging to either serovar 1/2a or 1/2c. Isolates belonging to PFGE group N shared serovar 1/2c. In contrast to lineage I isolates, small fragments <33.3 kb were visible in all L. monocytogenes isolates belonging to lineage II. In the results from both the present and previous studies, the genomic region of small bands was genetically more conservative than in large bands. The distribution of these small bands established the relatedness of strains and defined a genetic marker for both lineages I and II, while also establishing their serogroup. The division of L. monocytogenes PFGE types into PFGE groups is advantageous as the profile of every new isolate can be identified easily and quickly through first studying the PFGE group affiliation of the isolate based on the smaller band patterns <145.5 kb, and then identifying the PFGE type based on the band patterns >145.5 kb.
|
|
| 7. |
- Parihar, Vishal Singh, et al.
(författare)
-
Characterization of human invasive isolates of Listeria monocytogenes in Sweden 1986-2007
- 2008
-
Ingår i: Foodborne pathogens and disease. - : Mary Ann Liebert. - 1535-3141 .- 1556-7125. ; 5:6, s. 755-761
-
Tidskriftsartikel (refereegranskat)abstract
- Since 1986, 68% of the Listeria monocytogenes isolates from human cases of invasive listeriosis in Sweden are available for retrospective studies. The aim of the present study was to characterize 601 human invasive isolates of L. monocytogenes in Sweden from 1986 to 2007 by using serotyping and pulsed-field gel electrophoresis. Since 1996, serovar 4b was permanently reduced to the second or third most common serovar in human cases in Sweden. During the latter period, 2000-2007, only 13% belonged to serovar 4b and 71% to 1/2a. The dendrogram, based on pulsovars, reveals two clusters with different serovars. Cluster 1 exhibits serovars 4b and 1/2b, whereas cluster 2 consists of serovar 1/2a. Serovar 1/2a seems to be more heterogeneous than serovar 4b.
|
|
| 8. |
- Söderström, A, et al.
(författare)
-
A large Escherichia coli O157 outbreak in Sweden associated with locally produced lettuce.
- 2008
-
Ingår i: Foodborne pathogens and disease. - : Mary Ann Liebert Inc. - 1556-7125 .- 1535-3141. ; 5:3, s. 339-49
-
Tidskriftsartikel (refereegranskat)abstract
- In 2005 a large outbreak of verotoxin-producing Escherichia coli (VTEC) occurred in Sweden. Cases were interviewed and cohort and case-control studies were conducted. Microbiological investigations were performed using polymerase chain reaction (PCR) to detect the Shiga-like toxin (Stx) genes followed by cultivation and pulsed-field gel electrophoresis. A total of 135 cases were recorded, including 11 cases of hemolytic uremic syndrome. The epidemiological investigations implicated lettuce as the most likely source of the outbreak, with an OR of 13.0 (CI 2.94-57.5) in the case-control study. The lettuce was irrigated by water from a small stream, and water samples were positive for Stx 2 by PCR. The identical VTEC O157 Stx 2 positive strain was isolated from the cases and in cattle at a farm upstream from the irrigation point. An active surveillance and reporting system was crucial and cooperation between all involved parties was essential for quickly identifying the cause of this outbreak. Handling of fresh greens from farm to table must be improved to minimize the risk of contamination.
|
|
| 9. |
- Tham, Wilhem, 1951-, et al.
(författare)
-
Occurrence of Genetic Variants of Listeria monocytogenes Strains
- 2013
-
Ingår i: Foodborne pathogens and disease. - : Mary Ann Liebert. - 1535-3141 .- 1556-7125. ; 10:9, s. 825-826
-
Tidskriftsartikel (refereegranskat)abstract
- Isolates of Listeria monocytogenes saved from outbreaks of listeriosis, cases of sporadic listeriosis, and similar events do not always belong to a solitary genetic variant. Variants of the same strain may have evolved from a unique clone, and plasmid loss or gain and phage-mediated genetic changes are suggested as the main mechanism. Some of these reports are summarized in this short communication.
|
|
| 10. |
|
|
