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1.
Int J Environ Health Res ; 34(5): 2230-2247, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-37726018

RESUMEN

We studied food fraud detection and the reporting of suspected cases using a questionnaire survey and interviews with Finnish food control officers (FCOs). In total, 95 FCOs responded to the questionnaire, and 17 were interviewed. We found that even though many respondents had either suspected (69.2%) or detected (43.4%) food fraud or other food-related crime during the past five years, 46.8% thought they had no realistic chance of detecting food fraud during inspections. Challenges raised by the FCOs we interviewed included inadequate resources (8/17) and difficulties in inspecting documents or establishing their authenticity (14/17). Moreover, many interviewees highlighted difficulties in assessing whether to inform the police about a suspected case (7/17), and 62% (18/29) of respondents who had detected fraud had not reported it to the police. Training in food fraud detection, increased resources and guidelines on reporting suspected food fraud would improve food fraud detection and harmonize reporting.


Asunto(s)
Alimentos , Fraude , Finlandia , Encuestas y Cuestionarios
2.
Int J Environ Health Res ; 34(2): 885-897, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36842960

RESUMEN

We studied regional food control inspection grades and their relation to regional incidence of domestically acquired foodborne diseases (caused by Campylobacter spp. Salmonella spp. enterohemorrhagic Escherichia coli (EHEC), and Listeria monocytogenes) using food control inspection data of local food business operators and infectious disease data from 2014 to 2019 from Finland. We observed that inferior overall inspection grades were associated with increased incidence of Salmonella infections (p=0.02). Specifically, inferior grades on cleanliness of facilities, surfaces, and equipment were associated with increased incidence of Salmonella infections (p=0.04). For this topical inspection area, a high effect size was also seen for Campylobacter infections (p=0.06). Of the individual inspection items, an association between increased incidence of Campylobacter infections and inferior grades on storage of foodstuffs (p=0.01) and verification of hygiene proficiency (p=0.03) was observed. These results suggest that food control recognizes non-compliances that may predispose to foodborne diseases.


Asunto(s)
Infecciones por Campylobacter , Enfermedades Transmisibles , Enfermedades Transmitidas por los Alimentos , Infecciones por Salmonella , Humanos , Infecciones por Campylobacter/epidemiología , Incidencia , Finlandia/epidemiología , Microbiología de Alimentos , Enfermedades Transmitidas por los Alimentos/epidemiología , Infecciones por Salmonella/epidemiología
3.
Int J Environ Health Res ; 34(3): 1314-1327, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36854659

RESUMEN

This study examines the response of food business operators (FBOs) to the COVID-19 pandemic in relation to food safety and FBOs' experiences of remote inspections performed by official food control. The study was conducted between November and December 2020 with a web-based questionnaire for food processing businesses in Finland. Most of the 60 responded FBOs had made changes to many own-check sectors such as working hygiene (83.4%) and preparedness for special situations (78.0%). Of the FBOs, 47.1-83.0% assessed that the changes in the own-check sectors had a positive impact on food safety and 43.2-100.0% believed that some of the changes would remain after the pandemic. Of the FBOs, 69.8% found on-site inspections at least partially replaceable with video inspection of the production areas. This study shows that, although the pandemic seriously interfered with food production, it also induced FBOs to take measures that promote food safety.


Asunto(s)
COVID-19 , Pandemias , Humanos , Pandemias/prevención & control , Finlandia , COVID-19/prevención & control , Inocuidad de los Alimentos , Industria de Alimentos
4.
Int J Environ Health Res ; 33(6): 588-599, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35262429

RESUMEN

Official food control is intended to ensure food safety in the food business. In Finland, inspections of food service are performed using a 4-point risk-based grading system. This study compared routine inspection results of outbreak and nonoutbreak establishments in restaurants and institutional catering to investigate whether certain inspection results were associated with the occurrence of foodborne outbreaks. Also a more specific sample of outbreak establishments was defined using strength of evidence registered for each outbreak. Grade distributions of specific inspected items were compared separately. No significant differences were seen in restaurants but in institutional catering significantly poorer inspection results (p < 0.05) were detected in items concerning the order and cleanliness of facilities, surfaces and equipment in outbreak establishments. Effective correction of noncompliances in cleanliness of the food handling environment and equipment and constant maintenance of a favourable situation is essential in ensuring a high level of consumer safety in food service.


Asunto(s)
Enfermedades Transmitidas por los Alimentos , Restaurantes , Humanos , Finlandia/epidemiología , Inspección de Alimentos/métodos , Brotes de Enfermedades , Inocuidad de los Alimentos , Manipulación de Alimentos/métodos , Enfermedades Transmitidas por los Alimentos/epidemiología
5.
Food Microbiol ; 82: 455-464, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31027805

RESUMEN

Listeria monocytogenes causes the foodborne illness listeriosis, which exhibits high fatality among people in risk groups. The incidence of listeriosis has increased in Europe, which raises concerns about L. monocytogenes occurrence in foodstuffs. Ready-to-eat seafood products are considered particularly risky vehicles. Poor hygiene at processing facilities predisposes them to L. monocytogenes contamination, which can be controlled by stringent self-checking system measures. We examined the association of fish-processing plant operational and hygiene practices with the occurrence of L. monocytogenes in vacuum-packaged gravad (cold-salted) and cold-smoked salmon and rainbow trout products. Product sampling of 21 fish-processing plants was carried out, and operational procedures relating to L. monocytogenes control were surveyed using an in-depth risk assessment questionnaire. L. monocytogenes occurred only in sliced and mainly in gravad products of seven fish-processing plants. Shortages in preventive measures were discovered predominantly among the L. monocytogenes positive fish-processing plants. Using generalized linear modeling, we identified the following features associated with L. monocytogenes product contamination: the number of processing machines, deficiencies in the processing environment and machinery sanitation, and staff movement from areas of low toward high hygiene. Furthermore, performing frequent periodic thorough sanitation alongside everyday sanitation practices associated with a decreased risk of product contamination.


Asunto(s)
Productos Pesqueros/microbiología , Manipulación de Alimentos/métodos , Industria de Procesamiento de Alimentos/estadística & datos numéricos , Higiene , Listeria monocytogenes/aislamiento & purificación , Saneamiento/estadística & datos numéricos , Alimentos Marinos/microbiología , Animales , Microbiología Ambiental , Monitoreo del Ambiente , Contaminación de Equipos , Contaminación de Alimentos/análisis , Contaminación de Alimentos/prevención & control , Manipulación de Alimentos/instrumentación , Microbiología de Alimentos , Industria de Procesamiento de Alimentos/normas , Humanos , Higiene/normas , Oncorhynchus mykiss , Salmón , Saneamiento/normas , Encuestas y Cuestionarios , Vacio
6.
Int J Environ Health Res ; 27(3): 215-229, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28552013

RESUMEN

We surveyed the opinions of Finnish food business operators (FBOs) about the uniformity of local official food control and its importance for dairy, fishery and meat plants. A total of 136 FBOs responded to the questionnaire. Most FBOs considered official food control to be important for food safety and were generally satisfied with its quality. However, they often did not perceive official food control as being uniform, and 23% even considered it arbitrary. Small-sized FBOs were particularly critical of the relevance of control actions. The better the FBOs assessed their cooperation with the inspector, the higher they assessed the quality, uniformity and benefits of official food control. The cooperative approach in control practices should be emphasized to support the positive views of FBOs about official food control, thus promoting food safety. Cross-audits among local food control units are recommended to improve the FBOs' experience of uniformity of food control.


Asunto(s)
Industria de Alimentos/normas , Inocuidad de los Alimentos/métodos , Seguridad de Productos para el Consumidor , Finlandia , Contaminación de Alimentos/análisis , Contaminación de Alimentos/prevención & control , Manipulación de Alimentos/normas , Industria de Alimentos/métodos , Inspección de Alimentos/normas , Abastecimiento de Alimentos/normas , Encuestas y Cuestionarios
7.
Sci Rep ; 12(1): 4230, 2022 03 10.
Artículo en Inglés | MEDLINE | ID: mdl-35273330

RESUMEN

Inspections are an important tool for food control. However, there is a lack of knowledge about how inspection history, interval between inspections, and pre-announcement of the inspection affect compliance with food safety legislation in food production establishments. We used register-based meat, fish, and dairy establishment food control inspection data (5550 inspections from 757 establishments) from Finland in 2016-2019 to study compliance in relation to these factors. Hypothesis was that there is an association between inspection grades and (1) inspection history, (2) interval, and (3) pre-announcement. Results indicate that minor non-compliances that do not impair food safety often precede future more severe non-compliances (5.3% non-compliance rate if full compliance at previous inspection compared to 16.8% non-compliance rate if minor non-compliances at previous inspection [Fisher's exact test, p < 0.0001]), and that longer inspection intervals are associated with a decrease in inspection grades (5.9% difference in inspection intervals for inspection with full compliance compared to inspections with severe non-compliances [Generalized estimating equations, p = 0.02]). In addition, pre-announcement of the inspection affects the inspection grades, severe non-compliances were 2.4 times more common at unannounced inspections compared to pre-announced inspections. To conclude, there is an association between inspection grades and inspection history, inspection interval, and inspection announcement.


Asunto(s)
Inspección de Alimentos , Restaurantes , Finlandia , Inocuidad de los Alimentos
8.
J Food Prot ; 72(2): 408-11, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19350988

RESUMEN

Ultrasonic cleaning of a conveyor belt was studied by building a pilot-scale conveyor with an ultrasonic cleaning bath. A piece of the stainless steel conveyor belt was contaminated with meat-based soil and Listeria monocytogenes strains (V1, V3, and B9) and incubated for 72 h to allow bacteria to attach to the conveyor belt surfaces. The effect of ultrasound with a potassium hydroxide-based cleaning detergent was determined by using the cleaning bath at 45 and 50 degrees C for 30 s with and without ultrasound. The detachment of L. monocytogenes from the conveyor belt caused by the ultrasonic treatment was significantly greater at 45 degrees C (independent samples t test, P < 0.001) and at 50 degrees C (independent samples t test, P = 0.04) than without ultrasound. Ultrasonic cleaning efficiency was tested with different cleaning durations (10, 15, 20, and 30 s) and temperatures (30, 45, and 50 degrees C). The differences in the log reduction between cleaning treatments were analyzed by analysis of variance with Tamhane's T2 posthoc test using SPSS (Chicago, IL). The lengthening of the treatment time from 10 to 30 s did not significantly increase the detachment of L. monocytogenes (ANOVA 0.633). At 30 degrees C and at the longest time tested (30 s), the treatment reduced L. monocytogenes counts by only 2.68 log units. However, an increase in temperature from 30 to 50 degrees C improved the effect of the ultrasonic treatment significantly (P < 0.01). Ultrasonic cleaning for 10 s at 50 degrees C reduced L. monocytogenes counts by more than 5 log units. These results indicate that ultrasonic cleaning of a conveyor belt is effective even with short treatment times.


Asunto(s)
Desinfectantes/farmacología , Contaminación de Equipos , Industria de Procesamiento de Alimentos/normas , Hidróxidos/farmacología , Listeria monocytogenes/crecimiento & desarrollo , Compuestos de Potasio/farmacología , Ultrasonido , Adhesión Bacteriana , Recuento de Colonia Microbiana , Seguridad de Productos para el Consumidor , Contaminación de Equipos/prevención & control , Contaminación de Alimentos/prevención & control , Microbiología de Alimentos , Higiene , Listeria monocytogenes/fisiología , Proyectos Piloto , Acero Inoxidable , Temperatura , Factores de Tiempo
9.
Duodecim ; 125(6): 667-73, 2009.
Artículo en Fi | MEDLINE | ID: mdl-19413172

RESUMEN

The main responsibility of the local food control lies in the local food and environmental health units. The producer is responsible for the safety of the food produced, and applies an in-house control system to achieve this goal. The local food safety authority evaluates the in-house control system and assures that it is targeted to the most critical steps in the production to efficiently minimize the food safety risks. The main challenges in implementing efficient food control system are the variability in the knowledge of the producer about food hygiene, inadequate resources in control units and harmonization of the control measures in national level.


Asunto(s)
Contaminación de Alimentos/prevención & control , Manipulación de Alimentos/normas , Seguridad de Productos para el Consumidor , Humanos
10.
Sci Rep ; 8(1): 13105, 2018 08 30.
Artículo en Inglés | MEDLINE | ID: mdl-30166603

RESUMEN

Vacuum-packaged cold-salted and cold-smoked fish products are considered typical vehicles for Listeria monocytogenes, the causative agent of the food-borne disease listeriosis, which is increasingly prevalent in the European Union. Efficacy of both the fish processing plant self-checking system and official food control conducted by authorities are crucial for L. monocytogenes prevention in the processing of these risky products. However, the impact of official control on L. monocytogenes prevention in the processing of fish products has not been extensively studied. We investigated the occurrence, control measures, and correction of non-compliances predisposing to L. monocytogenes in Finnish fish processing plants. The following features were associated with L. monocytogenes occurrence: (a) frequency of non-compliances concerning processing machinery, (b) recurrence of non-compliances, and (c) frequency of non-compliances for which official control measures were requested by inspecting authorities. Official control of fish processing plants had focused on risky areas, but non-compliances were common and their correction exhibited deficiencies. We conclude that L. monocytogenes prevention in fish processing can be enhanced by strengthening official food control measures and processing plant compliance. In particular, timely correction of all food safety violations must be improved.


Asunto(s)
Productos Pesqueros , Manipulación de Alimentos , Listeriosis/prevención & control , Animales , Modelos Lineales , Listeria monocytogenes/aislamiento & purificación
11.
Int J Food Microbiol ; 115(2): 173-9, 2007 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-17174432

RESUMEN

A total of 312 samples of sliced, vacuum packaged, cold-smoked pork from 15 meat processing plants in Latvia and Lithuania, obtained over a 15-month period from 2003 until 2004, were analyzed for the presence of Listeria monocytogenes at the end of their shelf-life. Overall, 120 samples (38%) tested positive for L. monocytogenes. Despite the long storing period, the levels of L. monocytogenes in cold-smoked pork products were low. Manufacturing processes were studied at seven meat processing plants. A new approach with a logistic multivariable regression model was applied to identify the main factors associated with L. monocytogenes contamination during the manufacturing of cold-smoked pork products. Brining by injection was a significant factor (odds ratio 10.66; P<0.05) for contamination of product with L. monocytogenes. Moreover, long cold-smoking times (> or = 12 h) had a significant predictive value (odds ratio 24.38; P<0.014) for a sample to test positive for L. monocytogenes. Pulsed-field gel electrophoresis results indicated that various sources of L. monocytogenes contamination existed over periods of time in several meat processing plants. In two meat processing plants, persistent L. monocytogenes strains belonging to serotypes 1/2a and 1/2c were found.


Asunto(s)
Contaminación de Alimentos/análisis , Conservación de Alimentos/métodos , Industria de Procesamiento de Alimentos/normas , Listeria monocytogenes/aislamiento & purificación , Productos de la Carne/microbiología , Medición de Riesgo , Animales , Seguridad de Productos para el Consumidor , Electroforesis en Gel de Campo Pulsado/métodos , Microbiología de Alimentos , Embalaje de Alimentos/métodos , Humanos , Letonia/epidemiología , Listeria monocytogenes/clasificación , Listeria monocytogenes/crecimiento & desarrollo , Lituania/epidemiología , Oportunidad Relativa , Serotipificación , Porcinos , Factores de Tiempo , Vacio
12.
J Food Prot ; 70(3): 758-61, 2007 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-17388072

RESUMEN

Persistent Listeria monocytogenes contamination of food industry equipment is a difficult problem to solve. Ultrasonic cleaning offers new possibilities for cleaning conveyors and other equipment that are not easy to clean. Ultrasonic cleaning was tested on three conveyor belt materials: polypropylene, acetal, and stainless steel (cold-rolled, AISI 304). Cleaning efficiency was tested at two temperatures (30 and 45 degrees C) and two cleaning times (30 and 60 s) with two cleaning detergents (KOH, and NaOH combined with KOH). Conveyor belt materials were soiled with milk-based soil and L. monocytogenes strains V1, V3, and B9, and then incubated for 72 h to attach bacteria to surfaces. Ultrasonic cleaning treatments reduced L. monocytogenes counts on stainless steel 4.61 to 5.90 log units; on acetal, 3.37 to 5.55 log units; and on polypropylene, 2.31 to 4.40 log units. The logarithmic reduction differences were statistically analyzed by analysis of variance using Statistical Package for the Social Sciences software. The logarithmic reduction was significantly greater in stainless steel than in plastic materials (P < 0.001 for polypropylene, P = 0.023 for acetal). Higher temperatures enhanced the cleaning efficiency in tested materials. No significant difference occurred between cleaning times. The logarithmic reduction was significantly higher (P = 0.013) in cleaning treatments with potassium hydroxide detergent. In this study, ultrasonic cleaning was efficient for cleaning conveyor belt materials.


Asunto(s)
Desinfectantes/farmacología , Contaminación de Equipos , Contaminación de Alimentos/prevención & control , Listeria monocytogenes/crecimiento & desarrollo , Ultrasonido , Acetales , Análisis de Varianza , Recuento de Colonia Microbiana , Seguridad de Productos para el Consumidor , Contaminación de Equipos/prevención & control , Microbiología de Alimentos , Industria de Procesamiento de Alimentos/métodos , Industria de Procesamiento de Alimentos/normas , Higiene , Polipropilenos , Acero Inoxidable , Temperatura , Factores de Tiempo
13.
J Food Prot ; 70(8): 1866-73, 2007 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-17803143

RESUMEN

Contamination routes of Listeria monocytogenes were examined in a chilled food processing plant that produced ready-to-eat and ready-to-reheat meals during an 8-year period by amplified fragment length polymorphism (AFLP) analysis. A total of 319 L. monocytogenes isolates were recovered from raw materials (n = 18), the environment (n = 77), equipment (n = 193), and products (n = 31), and 18 different AFLP types were identified, five of which were repeatedly found to be persistent types. The three compartments (I to III) of the plant showed markedly different contamination statuses. Compartment I, which produced cooked meals, was heavily contaminated with three persistent AFLP types. AFLP type A1 dominated, and it comprised 93% of the isolates of the compartment. Compartment II, which produced uncooked chilled food, was contaminated with four persistent and five nonpersistent AFLP types. The equipment of compartment III, which produced cooked ready-to-reheat meals, was free of contamination. In compartments that produced cooked meals, the cleaning routines, product types, and lack of compartmentalization seemed to predispose production lines to persistent contamination. The most contaminated lines harbored L. monocytogenes in coolers, conveyors, and packing machines. Good compartmentalization limited the flow of L. monocytogenes into the postheat-treatment area and prevented the undesired movement of equipment and personnel, thus protecting the production lines from contamination. In compartment II, grated cheese was shown to cause product contamination. Therefore, special attention should be paid to continuous quality control of raw ingredients when uncooked ready-to-eat foods are produced. In compartment II, reconstruction of the production line resulted in reduced prevalence rates of L. monocytogenes and elimination of two persistent AFLP types.


Asunto(s)
Contaminación de Equipos , Contaminación de Alimentos/análisis , Industria de Procesamiento de Alimentos/normas , Listeria monocytogenes/genética , Polimorfismo de Longitud del Fragmento de Restricción , Animales , Queso/microbiología , Frío , Microbiología Ambiental , Microbiología de Alimentos , Amplificación de Genes , Carne/microbiología , Control de Calidad
14.
J Vet Med Educ ; 34(2): 205-11, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17446650

RESUMEN

This article describes the Finnish meat-inspection curriculum and presents an expert-panel evaluation of meat-inspection education. The work tasks of the meat-inspection veterinarian are challenging and include classical meat inspection, meat hygiene, hygiene control, and animal disease and welfare. The meat-inspection veterinarian is not only an inspector, which by itself is very demanding, but also an expert or "consultant" on food safety. The significant role of the meat-inspection veterinarian in society puts high demands on meat-inspection education, which should provide veterinary students with sufficient tools to perform meat inspection and hygiene control in slaughterhouses, cutting premises, and further processing plants. To be of high quality, such education must be evaluated from time to time. An expert panel evaluated Finnish undergraduate meat-inspection education and found that it provides veterinary students with good knowledge of meat inspection. The structure of the curriculum, with theoretical studies followed by four weeks of practice in a slaughterhouse, was considered vital for learning and for creating interest in meat inspection. The evaluation also revealed that certain subjects should receive greater emphasis and some new subjects should be introduced. Hygiene-control tasks, in particular, have increased and should receive more emphasis in education. Personnel management and interaction skills should be introduced into the curriculum as these skills influence all the duties of the meat-inspection veterinarian. This article outlines the subjects to be included in the modern, high-quality meat-inspection curriculum recommended by the expert panel.


Asunto(s)
Curriculum , Educación en Veterinaria/métodos , Inspección de Alimentos , Veterinarios/psicología , Mataderos , Bienestar del Animal , Animales , Seguridad de Productos para el Consumidor , Finlandia , Humanos , Higiene , Carne
15.
J Food Prot ; 68(6): 1228-31, 2005 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15954713

RESUMEN

A total of 257 raw fish samples at two different sites were examined for the presence of Listeria monocytogenes. The prevalence of L. monocytogenes was 4%. From 11 positive samples, nine different L. monocytogenes pulsed-field gel electrophoresis genotypes were recovered. From nine pulsotypes recovered from raw fish and 32 pulsotypes shown by 101 fish product isolates, two raw fish and fish product pulsotypes were indistinguishable from each other. Although the prevalence of L. monocytogenes in raw fish is low, the range of L. monocytogenes strains entering the processing plant in large amounts of raw material is wide. This indicates that the raw material is an important initial contamination source of L. monocytogenes in fish processing plants. This postulation is supported by the identical pulsotypes recovered from both raw and processed fish. Some L. monocytogenes strains entering a plant may thus contaminate and persist in the processing environment, causing recurrent contamination of the final products via processing machines.


Asunto(s)
Contaminación de Equipos , Contaminación de Alimentos/análisis , Industria de Procesamiento de Alimentos/normas , Listeria monocytogenes/aislamiento & purificación , Alimentos Marinos/microbiología , Animales , Electroforesis en Gel de Campo Pulsado/métodos , Peces/microbiología , Contaminación de Alimentos/prevención & control , Microbiología de Alimentos , Industria de Procesamiento de Alimentos/métodos , Genotipo , Listeria monocytogenes/genética , Prevalencia
16.
Syst Appl Microbiol ; 26(4): 539-45, 2003 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-14666982

RESUMEN

This study was set up to evaluate the genetic similarity or dissimilarity of persistent and sporadic Listeria monocytogenes strains existing in eleven food processing facilities, including fish, dairy, meat and poultry processing plants. In each plant persistent and sporadic strains were selected on the basis of PFGE typing results. A total of 17 strains representing persistent strains and 38 sporadic strains originating from eleven food processing plants were included in the study. PFGE macrorestriction patterns of persistent and sporadic strains from different processing plants were compared and the strains were further studied by amplified fragment length polymorphism (AFLP), being a characterisation method giving more whole genome based information. The 17 persistent and 38 sporadic strains showed 14 and 35 pulsotypes, 14 and 28 AFLP types, respectively. The combination of PFGE and AFLP typing results yielded a total of 48 genotypes. Thirteen of 15 genotypes presented by persistent strains were only associated with persistent strains and similarly 94% (33/35) of genotypes showed by sporadic strains were recovered among sporadic strains only. Our results showed that L. monocytogenes strains causing persistent contamination differ from sporadic strains. In AFLP analysis persistent strains did not, however, form any specific clusters and neither was there any difference between the known two genomic groups. These results indicate that even though persistent strains differ from sporadic strains there seems not to be any specific evolutional lineage of persistent strains.


Asunto(s)
Listeria monocytogenes/genética , Técnicas de Tipificación Bacteriana/métodos , Dermatoglifia del ADN/métodos , ADN Bacteriano/genética , ADN Bacteriano/aislamiento & purificación , Electroforesis en Gel de Campo Pulsado , Evolución Molecular , Microbiología de Alimentos , Genotipo , Listeria monocytogenes/clasificación , Listeria monocytogenes/aislamiento & purificación , Epidemiología Molecular/métodos , Polimorfismo Genético , Polimorfismo de Longitud del Fragmento de Restricción
17.
Int J Food Microbiol ; 82(3): 265-72, 2003 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-12593929

RESUMEN

Persistent and non-persistent Listeria monocytogenes strains were tested for initial resistance and adaptive and cross-adaptive responses towards two quaternary ammonium compounds, alkyl-benzyl-dimethyl ammonium chloride and n-alkyldimethyl ethylbenzyl ammonium chloride, one tertiary alkylamine, 1,3-propanediamine-N-(3-aminopropyl)N-dodecyl, sodium hypochlorite and potassium persulphate. The initial resistance of two persistent and two non-persistent L. monocytogenes strains was observed to differ. Both types of strains adapted after a 2-h sublethal exposure to the quaternary ammonium compounds and the tertiary alkylamine, the highest increase in the minimum inhibitory concentration (MIC) being 3-fold. Progressively increasing disinfecting concentrations at 10 and 37 degrees C resulted in adaptation of L. monocytogenes to all disinfectants except potassium sulphate. The highest observed increase in MIC was over 15-fold, from 0.63 to 10 microg/ml of n-alkyldimethyl ethylbenzyl ammonium chloride. All strains reached approximately similar MICs. Stability of the increased resistance was tested by measuring MICs every seventh day for 28 days. The increased resistance to sodium hypochlorite disappeared in 1 week, but the quaternary ammonium compounds and the tertiary alkylamine showed increased resistance for 28 days. These results suggest that cellular changes due to adaptive responses continue to have an effect on the resistance some time after the exposure. All disinfectants were shown to cause cross-adaptation of L. monocytogenes, the highest increase in MIC being almost 8-fold. The only agent that L. monocytogenes could not be shown to cross-adapt to was potassium persulphate which did, however, cause cross-adaptation to the other disinfectants. The mechanism behind these adaptive responses seemed to be non-specific as cross-adaptation was observed not only between related but also unrelated disinfectants. These findings suggest that sustaining high disinfectant effectiveness may be unsuccessful by rotation, even when using agents with different mechanisms of action.


Asunto(s)
Adaptación Fisiológica , Desinfectantes/farmacología , Microbiología de Alimentos , Listeria monocytogenes/fisiología , Compuestos de Amonio Cuaternario/farmacología , Recuento de Colonia Microbiana , Farmacorresistencia Bacteriana , Listeria monocytogenes/efectos de los fármacos , Listeria monocytogenes/genética , Listeria monocytogenes/crecimiento & desarrollo , Pruebas de Sensibilidad Microbiana , Hipoclorito de Sodio/farmacología , Temperatura
18.
Int J Food Microbiol ; 77(1-2): 83-90, 2002 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-12076041

RESUMEN

The purpose of the study was to obtain fingerprinting data of Listeria monocytogenes strains isolated in various foods to determine possible associations of strains with product type, producer, country or isolation time. Two hundred and ninety-five L. monocytogenes strains originating from food items of 41 producers of 10 countries were characterized by pulsed-field gel electrophoresis (PFGE) typing. Combination of AscI and ApaI macrorestriction patterns (MRP) yielded 66 different pulsotypes. Ten pulsotypes were common to two or more product types and 17 pulsotypes were detected in foods of more than one producer having no apparent association with each other. Similar pulsotypes of L. monocytogenes were recovered in products of different countries over several years. Some of the pulsotypes were recurrently recovered from the same product of the same producer, suggesting a possible persistence of these strains in the processing plant. However, some of the recurrently isolated L. monocytogenes pulsotypes were repeatedly found in products of several producers, which may indicate that persistent houseflora strains are not always producer-specific. Furthermore, the similarity of macrorestriction patterns expressed as clusters, based on the numerical analysis of macrorestriction patterns, was not found to correlate with product type, country, producer or year of isolation. Our data suggest a wide geographical and temporal distribution of a number of L. monocytogenes strains isolated in food products. The existence of similar L. monocytogenes strains in various food products of several producers should be considered if food strain fingerprint results are used to help trace the vehicles for infections.


Asunto(s)
ADN Bacteriano/análisis , Microbiología de Alimentos , Listeria monocytogenes/genética , Técnicas de Tipificación Bacteriana , Dermatoglifia del ADN , Desoxirribonucleasas de Localización Especificada Tipo II , Electroforesis en Gel de Campo Pulsado/métodos , Industria de Procesamiento de Alimentos , Genoma Bacteriano , Listeria monocytogenes/clasificación , Listeria monocytogenes/aislamiento & purificación , Filogenia , Mapeo Restrictivo
19.
J Food Prot ; 65(7): 1129-33, 2002 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-12117246

RESUMEN

The possibility of the transfer of persistent Listeria monocytogenes contamination from one plant to another with a dicing machine was evaluated, and possible reasons for persistent contamination were analyzed. A dicing machine that diced cooked meat products was transferred from plant A to plant B and then to plant C. After the transfer of the dicing machine, L. monocytogenes PFGE type I, originally found in plant A, was soon also found in plants B and C. This L. monocytogenes PFGE type I caused persistent contamination of the dicing lines in plants B and C. The persistent L. monocytogenes strain and three nonpersistent L. monocytogenes strains found in the dicing line of plant C were tested for adherence to stainless steel surfaces and minimal inhibitory concentrations of a quaternary ammonium compound and sodium hypochlorite, disinfectants widely used in the dicing lines. The persistent strain showed significantly higher adherence to stainless steel surfaces than did the nonpersistent strains. The minimal inhibitory concentrations of sodium hypochlorite were similar for all strains, and the minimal inhibitory concentrations of the quaternary ammonium compound for three of the L. monocytogenes PFGE types, including the persistent PFGE type, were high. All persistent L. monocytogenes PFGE type I isolates were found in an area with high hygienic standards, with the dicing machine being the first point of contamination. These observations show that the dicing machine sustained the contamination and suggest that the dicing machine transferred the persistent L. monocytogenes PFGE type from one plant to another.


Asunto(s)
Desinfectantes/farmacología , Contaminación de Equipos , Industria de Procesamiento de Alimentos/instrumentación , Listeria monocytogenes/aislamiento & purificación , Productos de la Carne/microbiología , Animales , Recuento de Colonia Microbiana , Contaminación de Alimentos , Microbiología de Alimentos , Listeria monocytogenes/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Acero Inoxidable , Propiedades de Superficie
20.
J Food Prot ; 66(2): 249-55, 2003 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-12597485

RESUMEN

A total of 486 Listeria monocytogenes isolates originating from 17 Finnish food processing plants (representing meat, poultry, fish, and dairy production) were collected and typed by automated ribotyping using EcoRI as the restriction enzyme. The isolates were divided into 16 different ribotypes (RTs). Some of these isolates (121), representing all EcoRI types and 16 food plants, were subjected to ribotyping with the PvuII enzyme, to pulsed-field gel electrophoresis (PFGE) typing with AscI and SmaI restriction enzymes, and to serotyping with O-antigen antisera. Nineteen ribotypes were generated with PvuII, 42 macrorestriction patterns were generated with AscI and 24 with SmaI, and three serotypes were generated with antisera. When the results were combined, the overall number of RTs was 23, and that of the PFGE types was 46. Thus, the overall discrimination power of PFGE was higher (discrimination index [DI] 0.966) than that of ribotyping (DI 0.906). The most common serotype (90.1% of the isolates) was 1/2, and isolates of serotype 4 (3.3%) were rare. There was no connection between food sectors and RTs or PFGE types, but PFGE indicated the single plants (78.3% of the types) better than ribotyping (56.5%). On the basis of its automation and on the availability of identification databases, automated ribotyping had some advantages over PFGE. Overall, automated ribotyping can be considered a practical and rapid tool when Listeria contamination is suspected and when screening a large number of isolates is necessary, e.g., when tracing contamination sources. However, in cases of outbreaks, the identical patterns must be confirmed by PFGE, which is a more discriminatory method.


Asunto(s)
Electroforesis en Gel de Campo Pulsado/métodos , Microbiología de Alimentos , Listeria monocytogenes/clasificación , Ribotipificación/métodos , Animales , Productos Lácteos/microbiología , Industria de Procesamiento de Alimentos , Listeria monocytogenes/genética , Listeria monocytogenes/aislamiento & purificación , Productos de la Carne/microbiología , Mapeo Restrictivo , Sensibilidad y Especificidad , Serotipificación , Factores de Tiempo
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