Incidence and Susceptibility to Antimicrobial Agents of Listeria spp. and Listeria monocytogenes Isolated from Poultry Carcasses in Porto, Portugal

2002 ◽  
Vol 65 (12) ◽  
pp. 1888-1893 ◽  
Author(s):  
PATRÍCIA ANTUNES ◽  
CRISTINA RÉU ◽  
JOÃO CARLOS SOUSA ◽  
NAZARÉ PESTANA ◽  
LUÍSA PEIXE

The occurrence of Listeria spp. and Listeria monocytogenes in 63 samples of Portuguese poultry carcasses obtained from two local butcher shops and one canteen in the city of Porto, Portugal, and the susceptibility of these bacteria to antimicrobial agents allowed for use in human or animal therapeutics were evaluated. All poultry samples were contaminated with Listeria spp., and L. monocytogenes was isolated from 41% (26 of 63) of the samples. Other Listeria species, including L. innocua, L. welshimeri, and L. seeligeri, were also isolated from poultry samples. A multiplex polymerase chain reaction method was used for the identification of all of the Listeria isolates; this method showed total conformity with the conventional method of biochemical identification and proved to be more reliable, faster, and less arduous. In addition, high percentages of Listeria spp. (84%) and L. monocytogenes (73%) isolates were found to be resistant to one or more antimicrobial agents of different groups, and 12 different resistance profiles were recorded. The frequency of the resistance of L. monocytogenes isolates to enrofloxacin and clindamycin is notable. The results of this study suggest a high incidence of L. monocytogenes on Portuguese poultry products available for consumers and indicate that poultry could be a potential vehicle of foodborne infections due to strains of L. monocytogenes that are resistant to antimicrobial agents.

Biomolecules ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 397
Author(s):  
Dimitra Kostoglou ◽  
Parthena Tsaklidou ◽  
Ioannis Iliadis ◽  
Nikoletta Garoufallidou ◽  
Georgia Skarmoutsou ◽  
...  

Fresh vegetables and salads are increasingly implicated in outbreaks of foodborne infections, such as those caused by Listeria monocytogenes, a dangerous pathogen that can attach to the surfaces of the equipment creating robust biofilms withstanding the killing action of disinfectants. In this study, the antimicrobial efficiency of a natural plant terpenoid (thymol) was evaluated against a sessile population of a multi-strain L. monocytogenes cocktail developed on stainless steel surfaces incubated in lettuce broth, under optimized time and temperature conditions (54 h at 30.6 °C) as those were determined following response surface modeling, and in comparison, to that of an industrial disinfectant (benzalkonium chloride). Prior to disinfection, the minimum bactericidal concentrations (MBCs) of each compound were determined against the planktonic cells of each strain. The results revealed the advanced killing potential of thymol, with a concentration of 625 ppm (= 4 × MBC) leading to almost undetectable viable bacteria (more than 4 logs reduction following a 15-min exposure). For the same degree of killing, benzalkonium chloride needed to be used at a concentration of at least 20 times more than its MBC (70 ppm). Discriminative repetitive sequence-based polymerase chain reaction (rep-PCR) also highlighted the strain variability in both biofilm formation and resistance. In sum, thymol was found to present an effective anti-listeria action under environmental conditions mimicking those encountered in the salad industry and deserves to be further explored to improve the safety of fresh produce.


1997 ◽  
Vol 60 (5) ◽  
pp. 548-550 ◽  
Author(s):  
NANCY P. RIJPENS ◽  
GEERT JANNES ◽  
LIEVE M. F. HERMAN

The prevelance of Listeria spp. and Listeria monocytogenes in ready-to-eat poultry products was examined. Following 16 or 48 h of enrichment and selective plating, presumptive Listeria colonies were identified using polymerase chain reaction and reverse hybridization on line probe assay strips. Overall, Listeria spp. and Listeria monocytogenes were found in 35.5% and 15.5% of the poultry samples, respectively. The incidence of Listeria spp. was much higher in unpackaged (41.7%) than in prepackaged (11.1%) poultry products.


2020 ◽  
Vol 83 (3) ◽  
pp. 491-496 ◽  
Author(s):  
MATTHEW BAILEY ◽  
RHONDA TAYLOR ◽  
JAGPINDER BRAR ◽  
SYDNEY CORKRAN ◽  
CARMEN VELÁSQUEZ ◽  
...  

ABSTRACT Salmonella is one of the top causes for bacterial foodborne infections in the United States, emphasizing the importance of controlling this pathogen for protecting public health. Poultry and poultry products are commonly associated with Salmonella, and interventions during production and processing are necessary to manage the risk of infection due to consumption of poultry products. In recent times, the demand for organic and antibiotic-free poultry has increased owing to consumer perceptions and concerns of increasing prevalence of antimicrobial-resistant (AMR) pathogens. However, the microbiological effect of these management practices is not clear. This study was conducted to determine the difference in the AMR of Salmonella isolated from poultry processed conventionally and organically. Fecal samples, carcass rinses, and environmental samples were collected over 1 year and analyzed for the prevalence of Salmonella and AMR. Results of this experiment showed that organic chickens were associated with statistically higher levels of Salmonella during early processing steps. However, no difference in Salmonella prevalence was observed between organic and conventional carcasses postchill. In addition, for most antimicrobial agents tested, prevalence of AMR Salmonella in conventional processing was lower in this study than was reported by the National Antimicrobial Resistance Monitoring System for chickens at slaughter. These observations indicate that organic methods may introduce greater risk of Salmonella contamination; however, proper interventions during processing can abate this risk. In addition, this study supports the assertion that raising chickens without the use of antibiotics may result in lower prevalence of AMR Salmonella. HIGHLIGHTS


2013 ◽  
Vol 76 (8) ◽  
pp. 1366-1376 ◽  
Author(s):  
LINDSEY M. McDONNELL ◽  
KATHLEEN A. GLASS ◽  
JEFFREY J. SINDELAR

The objective of this study was to identify ingredients that inhibit Listeria monocytogenes in natural, organic, or clean-label ready-to-eat meat and poultry products. Fourteen ingredients were screened in uncured (no-nitrate-or-nitrite-added), traditional-cured (156 ppm of purified sodium nitrite), cultured (alternative cured, natural nitrate source, and Staphylococcus carnosus), or preconverted (alternative cured, natural nitrite source) turkey slurries. Slurries were cooked, cooled, inoculated to yield 3 log CFU/ml L. monocytogenes, stored at 4°C, and tested weekly for 4 weeks. Three antimicrobial ingredients, 1.5% vinegar–lemon–cherry powder blend, 2.5% buffered vinegar, and 3.0% cultured sugar–vinegar blend, were incorporated into alternative-cured ham and uncured roast beef and deli-style turkey breast. Controls included all three meat products without antimicrobial ingredients and a traditional-cured ham with 2.8% sodium lactate–diacetate. Cooked, sliced products were inoculated with 3 log CFU/g L. monocytogenes, vacuum packed, and stored at 4 or 7°C, for up to 12 weeks. For control products without antimicrobial agents stored at 4°C, a 2-log L. monocytogenes increase was observed at 2 weeks for ham and turkey and at 4 weeks for roast beef. Growth (>1-log increase) in the sodium lactate–diacetate was delayed until week 6. Compared with the control, the addition of either vinegar–lemon–cherry powder blend or buffered vinegar delayed L. monocytogenes growth for an additional 2 weeks, while the addition of cultured sugar–vinegar blend delayed growth for an additional 4 weeks for both ham and turkey. The greatest L. monocytogenes delay was observed in roast beef containing any of the three antimicrobial ingredients, with no growth detected through 12 weeks at 4°C for all the treatments. As expected, L. monocytogenes grew substantially faster in products stored at 7°C than at 4°C. These data suggest that antimicrobial ingredients from a natural source can enhance the safety of ready-to-eat meat and poultry products, but their efficacy is improved in products containing nitrite and with lower moisture and pH.


2011 ◽  
Vol 39 (No. 1) ◽  
pp. 7-12 ◽  
Author(s):  
R. Fialová ◽  
M. Navrátil ◽  
P. Válová

The presence of phytoplasmas in apple trees with proliferation symptoms, rubbery wood symptoms and no symp­toms was determined by using polymerase chain reaction assays with primers amplifying phytoplasma 16S rRNA gene. Phytoplasmas were detected in all trees with proliferation symptoms. Positive tests for phytoplasma in the group of trees with rubbery wood symptoms and of those without symptoms revealed a relatively high incidence of latent phytoplasma infection. Using restriction fragment length polymorphism analysis, phytoplasma of the same identity – apple proliferation phytoplasma (subgroup 16SrX-A) – was recorded in all positively tested trees.  


2008 ◽  
Vol 1 (1) ◽  
pp. 49
Author(s):  
M. Conter ◽  
D. Paludi ◽  
A. Mureddu ◽  
E. Zanardi ◽  
S. Ghidini ◽  
...  

Author(s):  
Jacob A Miller ◽  
Quynh-Thu Le ◽  
Benjamin A Pinsky ◽  
Hannah Wang

Abstract Background The incidence of endemic Epstein-Barr Virus (EBV)-associated nasopharyngeal carcinoma (NPC) varies considerably worldwide. In high-incidence regions, screening trials have been conducted. We estimated the mortality reduction and cost-effectiveness of EBV-based NPC screening in populations worldwide. Methods We identified 380 populations in 132 countries with incident NPC and developed a decision-analytic model to compare ten unique onetime screening strategies to no screening for men and women at age 50 years. Screening performance and the stage distribution of undiagnosed NPC were derived from a systematic review of prospective screening trials. Results Screening was cost-effective in up to 14.5% of populations, depending on the screening strategy. These populations were limited to East Asia, Southeast Asia, North Africa, or were Asian, Pacific Islander, or Inuit populations in North America. A combination of serology and nasopharyngeal polymerase chain reaction (PCR) was most cost-effective, but other combinations of serologic and/or plasma PCR screening were also cost-effective. The estimated reduction in NPC mortality was similar across screening strategies. For a hypothetical cohort of patients in China, 10-year survival improved from 71.0% (95%CI = 68.8%–73.0%) without screening to a median of 86.3% (range = 83.5%–88.2%) with screening. This corresponded to a median 10-year reduction in NPC mortality of 52.9% (range= 43.1%–59.3%). Screening interval impacted absolute mortality reduction and cost-effectiveness. Conclusions We observed decreased NPC mortality with EBV-based screening. Screening was cost-effective in many high-incidence populations and could be extended to men and women as early as age 40 years in select regions. These findings may be useful when choosing among local public health initiatives.


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