Colonization of a Newly Constructed Commercial Chicken Further Processing Plant with Listeria monocytogenes†

2010 ◽  
Vol 73 (2) ◽  
pp. 286-291 ◽  
Author(s):  
MARK E. BERRANG ◽  
RICHARD J. MEINERSMANN ◽  
JOSEPH F. FRANK ◽  
SCOTT R. LADELY

This study was undertaken to determine potential sources of Listeria monocytogenes in a newly constructed chicken further processing plant and document the eventual colonization of the facility by this pathogen. To ascertain the colonization status of the plant, floor drains were sampled after a production shift and again after a cleanup shift on roughly a monthly basis for 21 months. Potential sources of L. monocytogenes to the plant included incoming raw meat, incoming fresh air, and personnel. Nearby environment and community samples were also examined. All L. monocytogenes detected were subjected to DNA sequence–based subtyping. L. monocytogenes was not detected in the plant before the commencement of processing operations. Within 4 months, several subtypes of L. monocytogenes were detected in floor drains, both before and after cleaning and sanitizing operations. No L. monocytogenes was detected on filters for incoming air, samples associated with plant employees, or a nearby discount shopping center. One subtype of L. monocytogenes was detected in a natural stream near the plant; however, this subtype was never detected inside the plant. Eight subtypes of L. monocytogenes were detected in raw meat staged for further processing; one of the raw meat subtypes was indistinguishable from a persistent drain subtype recovered after cleaning on eight occasions in four different drains. Poultry further processing plants are likely to become colonized with L. monocytogenes; raw product is an important source of the organism to the plant.

2001 ◽  
Vol 64 (7) ◽  
pp. 994-999 ◽  
Author(s):  
MARIA K. MIETTINEN ◽  
LIISA PALMU ◽  
K. JOHANNA BJÖRKROTH ◽  
HANNU KORKEALA

The environment and products from two broiler abattoirs and processing plants and raw broiler pieces at the retail level were sampled for Listeria monocytogenes in order to evaluate the contamination level of the broiler carcasses and products. Sampling started in the slaughtering process and finished with raw broiler meat or ready-to-eat cooked product. Sampling sites positive for L. monocytogenes at the broiler abattoir were the air chiller, the skin-removing machine, and the conveyor belt leading to the packaging area. The L. monocytogenes contamination rate varied from 1 to 19% between the two plants studied. Furthermore, 62% (38 of 61) of the raw broiler pieces, bought from retail stores, were positive for L. monocytogenes. Altogether, 136 L. monocytogenes isolates were obtained for serotyping and pulsed-field gel electrophoresis(PFGE) characterization performed with two rare-cutting enzymes (ApaI and AscI). Altogether three serotypes (1/2a, 1/2c, and 4b) and 14 different PFGE types were obtained using information provided from both ApaI and AscI patterns for discrimination basis. The two broiler abattoirs studied did not share the same PFGE types. However, the same PFGE types found in the raw broiler pieces at the retail level were also found in the broiler abattoirs where the broilers had been slaughtered.


2006 ◽  
Vol 69 (4) ◽  
pp. 815-819 ◽  
Author(s):  
CHUNG-HSI CHOU ◽  
JUAN L. SILVA ◽  
CHINLING WANG

Raw channel catfish fillets collected from three processing plants during four time periods were tested for the presence of Listeria species. Listeria monocytogenes was the predominant Listeria species found in these catfish fillets, with 25 to 47% prevalence. Other Listeria species, such as L. welshimeri, L. innocua, L. ivanovii, L. grayi, and L. seeligeri, were also found. L. monocytogenes isolates were further fingerprinted by a repetitive element PCR. Forty distinctive electrophoretic types (ETs) and three genetic clusters were determined by Dice coefficient analysis and UPGMA (unweighted pair group method using arithmetic averages). Twenty of 40 ETs were represented by a single isolate, and the other 20 ETs were represented by 2 to 11 isolates. Thirty-five ETs, represented by 76 isolates, were found in processing plant A, B, or C and designated plant-specific types. The remaining five ETs, represented by 21 isolates, were found in multiple plants and designated nonplant-specific types. In addition, 10 ETs from 52 isolates were found repeatedly during different seasons. Plant-specific and nonplant-specific L. monocytogenes coexisted in processed catfish fillets. Some isolates were persistently found in processed fillets, suggesting that either the current sanitation procedures used by these plants are inadequate or that these isolates originated from the natural habitats of the catfish. The results also suggest that the repetitive element PCR is a useful tool for differentiating L. monocytogenes subtypes and can be used for tracing the source of a contamination.


2014 ◽  
Vol 77 (12) ◽  
pp. 2129-2132 ◽  
Author(s):  
MARK E. BERRANG ◽  
CHARLES L. HOFACRE ◽  
JOSEPH F. FRANK

Listeria monocytogenes can colonize a poultry processing plant as a resident in floor drains. Limiting growth and attachment to drain surfaces may help lessen the potential for cross-contamination of product. The objective of this study was to compare a hydrogen peroxide-peroxyacetic acid–based chemical to chitosan-arginine or heat to prevent attachment of or destroy existing L. monocytogenes on the inner surface of model floor drains. L. monocytogenes was introduced to result in about 109 planktonic and attached cells within untreated polyvinyl chloride model drain pipes. Treatments (0.13% peroxide-based sanitizer, 0.1% chitosan-arginine, or 15 s of hot water at 95 to 100°C) were applied immediately after inoculation or after 24 h of incubation. Following treatment, all pipes were incubated for an additional 24 h; planktonic and attached cells were enumerated by plate count. All treatments significantly (P < 0.05) lowered numbers of planktonic and attached cells recovered. Chitosan-arginine resulted in approximately a 6-log reduction in planktonic cells when applied prior to incubation and a 3-log reduction after the inoculum had a chance to grow. Both heat and peroxide significantly outperformed chitosan-arginine (8- to 9-log reduction) and were equally effective before and after incubation. Heat was the only treatment that eliminated planktonic L. monocytogenes. All treatments were less effective against attached cells. Chitosan-arginine provided about a 4.5-log decrease in attached cells when applied before incubation and no significant decrease when applied after growth. Like with planktonic cells, peroxide–peroxyacetic acid and heat were equally effective before or after incubation, causing decreases ranging from 7 to 8.5 log for attached L. monocytogenes. Applied at the most efficacious time, any of these techniques may lessen the potential for L. monocytogenes to remain as a long-term resident in processing plant floor drains.


2021 ◽  
Vol 12 ◽  
Author(s):  
Hongzhi Zhang ◽  
Fengxia Que ◽  
Biyao Xu ◽  
Linjun Sun ◽  
Yanqi Zhu ◽  
...  

Listeria monocytogenes is the etiologic agent of listeriosis, which remains a significant public health concern in many countries due to its high case-fatality rate. The constant risk of L. monocytogenes transmission to consumers remains a central challenge in the food production industry. At present, there is very little known about L. monocytogenes contamination in ready-to-eat (RTE) processing plants in China. In this study, L. monocytogenes in an RTE meat processing plant in Shanghai municipality was characterized using pulsed-field gel electrophoresis (PFGE) and whole genome sequencing (WGS). Furthermore, the biofilm formation ability of the pathogen was also tested. Results revealed that L. monocytogenes isolates were present in 12 samples out of the 48 samples investigated. Most of them (66.7%, 8/12) were identified from the processing facilities irrespective of observed hygiene levels of aerobic plate count (APC) and coliforms. Coliforms were present in only one processing area. ST5 (1/2b) isolates were predominant (83.3%, 10/12) and were identified in two dominant pulsotypes (PTs) (three in PT3 and seven in PT4, respectively). Results of the core-genome multi-locus sequence typing (cgMLST) showed that ST5 in three PTs (PT1, PT3, and PT4) had 0–8 alleles, which confirmed that clonal transmission occurred in the RTE meat processing facilities. In addition, the biofilm formation test confirmed that the isolates from the processing facilities could form biofilms, which helped them colonize and facilitate persistence in the environment. These results indicated that common sanitation procedures regularly applied in the processing environment were efficient but not sufficient to remove L. monocytogenes isolates, especially biofilm of L. monocytogenes. Furthermore, the ST5 isolates in this study exhibited 12 alleles with one ST5 clinical isolate, which contributes to the understanding of the potential pathogenic risk that L. monocytogenes in RTE meat processing equipment posed to consumers. Therefore, strong hygienic measures, especially sanitation procedures for biofilms eradication, should be implemented to ensure the safety of raw materials. Meanwhile, continuous surveillance might be vital for the prevention and control of listeriosis caused by L. monocytogenes.


2013 ◽  
Vol 76 (11) ◽  
pp. 1969-1971 ◽  
Author(s):  
M. E. BERRANG ◽  
R. J. MEINERSMANN ◽  
J. F. FRANK

Listeria monocytogenes is a common constituent of the microbiological community in poultry processing plants and can be found in low numbers on raw poultry. Raw meat is the most important source of this pathogen in commercial cooking facilities. Germicidal UV light was tested as a means to kill L. monocytogenes inoculated onto broiler breast fillets. Treatments at 800 μW/cm2 for 5 s to 5 min of exposure were tested against inocula of 35 to 60 cells per fillet. All fillets were sampled by rinsing in enrichment broth, and surviving pathogens were quantified using most-probable-number (MPN) analysis. Five replications each with 5 fillets per treatment were analyzed to achieve 25 sample fillets per treatment. All treatment times resulted in a significant decrease in L. monocytogenes numbers compared with paired untreated controls. Treated samples retained 0.2 to 1.5 MPN L. monocytogenes per fillet, and exposure time had no significant effect on the number of surviving cells. A 5-s treatment with germicidal UV light has potential as an intervention method to limit the transfer of L. monocytogenes on raw skinless breast fillets from a slaughter plant to a cooking plant.


2005 ◽  
Vol 68 (5) ◽  
pp. 980-985 ◽  
Author(s):  
M. E. BERRANG ◽  
R. J. MEINERSMANN ◽  
J. F. FRANK ◽  
D. P. SMITH ◽  
L. L. GENZLINGER

Samples from environmental sites and raw product in a chicken further processing plant were collected every 6 weeks for 12 months. Each sample site was examined before and after a complete production shift. All samples were examined for the presence of Listeria monocytogenes, which was detected in floor drains on the raw product side of the plant preoperation and in drains on both raw and cooked sides following 8 h of processing operation. L. monocytogenes also was detected in raw product and once in fully cooked product but never on cooked product contact surfaces. One hundred sixty-one isolates were collected from 75 positive samples. All isolates were subtyped using a sequence-based method, and 14 unique subtypes were detected through the course of the study. Four of these types were found repeatedly and appeared to be resident in the plant. Three of the four resident strains were detected on raw product at some point during the year-long study, suggesting that raw product may be one source of L. monocytogenes in the processing plant environment. These data highlight the need for research to investigate why some types of L. monocytogenes persist in a processing plant environment but others do not.


2008 ◽  
Vol 71 (5) ◽  
pp. 1028-1034 ◽  
Author(s):  
ANNE JENSEN ◽  
DENITA WILLIAMS ◽  
ELIZABETH A. IRVIN ◽  
LONE GRAM ◽  
MARY ALICE SMITH

The foodborne pathogen Listeria monocytogenes can cause infection in immunocompromised humans and in the fetuses of pregnant women. We have demonstrated that one group of genetically similar L. monocytogenes strains (random amplified polymorphic DNA [RAPD] type 9) dominate and persist in several independent fish processing plants. The purpose of the present study was to determine the virulence potential of one RAPD type 9 strain (La111), one human clinical strain (Scott A), and one monkey clinical strain (12443) in a pregnant guinea pig model. Animals were orally exposed to 108 CFU of L. monocytogenes in whipping cream on gestation day (GD) 36 and euthanized on GD 42, 45, or 56. Strains 12443 and Scott A were shed from treated animals for 20 days, whereas La111 was shed only in the first 10 days. Strains 12443 and Scott A were recovered from maternal liver, spleen, and gallbladder on all 3 days of euthanization, whereas La111 was recovered only at GD 45 and 56. Scott A was not isolated from any placentas or fetuses. For dams treated with 12443, 22% of the fetuses were positive for L. monocytogenes, and surprisingly, treatment of dams with La111 resulted in 56% infected fetuses. L. monocytogenes was isolated from 16 and 20% of placentas for 12443 and La111, respectively. The study demonstrates that a food processing plant persistent strain of L. monocytogenes is able to cross the fetoplacental barrier in pregnant guinea pigs. Furthermore, we demonstrate that although information can be gained from model virulence assays, assessment of the virulence potential of a strain may require more complex hosts.


2009 ◽  
Vol 72 (6) ◽  
pp. 1283-1287 ◽  
Author(s):  
AIVARS BĒRZIŅŠ ◽  
MARGARITA TERENTJEVA ◽  
HANNU KORKEALA

Nine groups of different retail ready-to-eat vacuum-packaged meat products from 10 Baltic meat processing plants were analyzed for presence and numbers of Listeria monocytogenes at the end of shelf life. A total of 38 (18%) of 211 samples tested positive for L. monocytogenes serotype 1/2a (88%) or 1/2c (12%). The prevalence of L. monocytogenes in cold-smoked, sliced, vacuum-packaged beef and pork products (42%) was significantly higher than in cooked, sliced, vacuum-packaged meat products (0.8%) (P < 0.001). Enumeration of L. monocytogenes showed that 84% of the positive samples contained <100 CFU/g upon expiry of product shelf life. The numbers of L. monocytogenes exceeded 100 CFU/g only in cold-smoked, sliced, vacuum-packaged beef products. Identical pulsed-field gel electrophoresis types were recovered from different production lots of cold-smoked vacuum-packaged beef and pork products produced by the same meat processing plant, demonstrating L. monocytogenes contamination as a recurrent problem within one meat processing plant.


2015 ◽  
Vol 82 (1) ◽  
pp. 308-317 ◽  
Author(s):  
Sagrario Ortiz ◽  
Victoria López-Alonso ◽  
Pablo Rodríguez ◽  
Joaquín V. Martínez-Suárez

ABSTRACTThe aim of this study was to investigate the basis of the putative persistence ofListeria monocytogenesin a new industrial facility dedicated to the processing of ready-to-eat (RTE) Iberian pork products. Quaternary ammonium compounds, which included benzalkonium chloride (BAC), were repeatedly used as surface disinfectants in the processing plant. Clean and disinfected surfaces were sampled to evaluate if resistance to disinfectants was associated with persistence. Of the 14 isolates obtained from product contact and non-product contact surfaces, only five different pulsed-field gel electrophoresis (PFGE) types were identified during the 27-month study period. Two of these PFGE types (S1 and S10-1) were previously identified to be persistent and BAC-resistant (BACr) strains in a geographically separate slaughterhouse belonging to the same company. The remaining three PFGE types, which were first identified in this study, were also BACr. Whole-genome sequencing andin silicomultilocus sequence typing (MLST) analysis of five BACrisolates of the different PFGE types identified in this study showed that the isolate of the S1 PFGE type belonged to MLST sequence type 31 (ST31), a low-virulence type characterized by mutations in theinlAandprfAgenes. The isolates of the remaining four PFGE types were found to belong to MLST ST121, a persistent type that has been isolated in several countries. The ST121 strains contained the BAC resistance transposon Tn6188. The disinfection-resistantL. monocytogenespopulation in this RTE pork product plant comprised two distinct genotypes with different multidrug resistance phenotypes. This work offers insight into theL. monocytogenessubtypes associated with persistence in food processing environments.


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