Efficacy of Nisin-Coated Polymer Films To Inactivate Salmonella Typhimurium on Fresh Broiler Skin†

2000 ◽  
Vol 63 (9) ◽  
pp. 1189-1196 ◽  
Author(s):  
NANDINI NATRAJAN ◽  
BRIAN W. SHELDON

Nisin is an antimicrobial peptide produced by the food-grade microorganism Lactococcus lactis subsp. lactis. This peptide inhibits many gram-positive bacteria, and when combined with chelating agents it inhibits gram-negative bacteria such as Salmonella sp. The efficacy of packaging films treated with nisin-containing formulations to reduce Salmonella contamination of fresh broiler drumstick skin and increase the refrigerated shelf life was investigated. Three films (5.1 cm2) of varying hydrophobicities (polyvinyl chloride [PVC], linear low density polyethylene, nylon) were coated with one of three liquid formulations (pH 3.5 to 3.8) composed of 100 μg/ml nisin and varying concentrations of citric acid, EDTA, and Tween 80. The treated films were applied either wet or dry to 5.1-cm2 broiler drumstick skin samples inoculated with a nalidixic acid-resistant (NAr) strain of Salmonella Typhimurium. After incubation at 4°C for 24 h the populations of surviving Salmonella TyphimuriumNAr organisms were recovered from the skin and film samples using a rinse procedure and enumerated on brain heart infusion agar containing 800 ppm NA. Log reductions (untreated versus treated skin) in Salmonella TyphimuriumNAr populations ranged from 0.4 to 2.1. Treatment formulation compositions and wet versus dry treatment application also influenced the extent of kill. The shelf life of refrigerated broiler drumsticks was extended by 0.6 to 2.2 days following a 3-min immersion in a nisin-containing treatment solution and subsequent storage in a foam tray pack containing a nisin-treated PVC overwrap and a nisin-treated absorbent tray pad. These findings demonstrated that Salmonella Typhimurium and spoilage microorganism populations on the surface of fresh broiler skin and drumsticks can be significantly reduced using immersion treatments, absorbent tray pads, and packaging films treated with nisin-containing formulations.

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 414-415
Author(s):  
Yamicela Castillo-Castillo ◽  
Marina Ontiveros ◽  
Eric J Scholljegerdes ◽  
Robin Anderson ◽  
Claudio Arzola-Alvarez ◽  
...  

Abstract Silages can harbor pathogenic and antimicrobial resistant microbes which risk infection of food-producing animals. Livestock producers need effective yet environmentally friendly interventions to preserve the feed value of these fermented materials. Medium chain fatty acids such as laurate and its glycerol monoester, monolaurin, are potent inhibitors of many Gram-positive bacteria and when tested at 5 mg/mL in anaerobic cultures (n = 3/treatment) inoculated with 105 colony forming units (CFU) of Listeria monocytogenes and grown at 37oC in ½ strength Brain Heart infusion broth achieved near complete elimination of viable cells after 6 h compared to a 2.2 ± 0.1 log10 CFU/mL increase observed in controls. Culture of a tetracycline-resistant Enterococcus faecalis with 5 mg laurate/mL likewise achieved near complete elimination of viable cells (5 log10 CFU/mL) by 6 h incubation. The bactericidal effect of 5 mg monolaurin was less against E. faecalis, achieving a decrease of 1.8 ± 0.2 log10 CFU/mL and not decreased further after 24 h. When tested against air-exposed silage, pH 7.53 (4 g), mixed with 4 mL water, 5 mg laurate or monolaurin decreased viability of experimentally-inoculated L. monocytogenes (105 CFU/g silage) more (P < 0.05) than untreated controls after 24 h aerobic incubation (22oC), with viable counts being decreased 6.3 ± 0.1, 5.9 ± 0.8 and 4.5 ± 0.1 log10 CFU/g, respectively. In contrast, viable recovery of the experimentally-inoculated (105 CFU/g) tetracycline-resistant E. faecalis was reduced more (P < 0.05) than controls (decreased 0.7 ± 0.1 log10 CFU/g) after 6 h incubation when similarly tested with laurate and monolaurin (1.7 ± 0.5 and 3.0 ± 0.9 log10 CFU/g, respectively) but counts after 24 h were similar, decreasing on average 2.0 ± 0.5 log10 CFU/g). Results indicate laurate and monolaurin may be useful in killing L. monocytogenes and tetracycline-resistant E. faecalis during silage feed-out.


2015 ◽  
Vol 52 (11) ◽  
pp. 7245-7253 ◽  
Author(s):  
Inam u Nisa ◽  
Bilal Ahmad Ashwar ◽  
Asima Shah ◽  
Adil Gani ◽  
Asir Gani ◽  
...  

2019 ◽  
Vol 48 ◽  
Author(s):  
Thayse Caroline de Abreu BRANDI ◽  
Amanda Nunes MONTEIRO ◽  
Hugo Leandro Azevedo da SILVA ◽  
Adriano Gomes da CRUZ ◽  
Lucianne Cople MAIA ◽  
...  

Resumo Introdução A presença de aparelho ortodôntico fixo dificulta a higienização e potencializa o acúmulo de biofilme bacteriano nas superfícies dentárias. O desenvolvimento de produtos que minimize isso é desejo de pesquisadores em todo o mundo. Objetivo Verificar a ação bacterapêutica de produtos lácteos contendo ou não probióticos sob pool de Streptococcus mutans (SM) (ATCC 25175) e S salivarius (SS) (ATCC 7073), além da adesão desses produtos à superfície de bráquetes ortodônticos. Material e método Pool de cepas ATCC de SM e SS foi formado e plaqueado sobre placa de Petri contendo meio de cultura brain heart infusion ágar (BHI). Após formação do meio, um orifício foi feito no centro da placa seguido do seu preenchimento com 150 µL dos produtos a serem testados, formando os seguintes grupos: GL - Leite bovino; GLP - Leite bovino com probiótico; GLF - Leite fermentado; e GLFP - Leite fermentado com probiótico. Na sequência, as placas foram incubadas por 48h, em estufa a 37ºC. A seguir, foi feita a medição do halo formado entre o produto e o meio com régua milimetrada. Já no disco de membrana, foi formado biofilme com o mesmo pool de cepas, sob discos de membrana. Em seguida, foi feita a diluição seriada contendo o produto de acordo com o grupo: P1 (água); P2 (L); P3 (LP); P4 (LFP), seguida do plaqueamento e a contagem total de micro-organismos. Para a adesividade dos produtos lácteos, bráquetes ortodônticos foram submergidos em cada solução (GL, GLP, GLF e GLFP) e foram incubadas a 37°C/24h. Posteriormente, cada bráquete foi transferido para um ependorf contendo solução salina estéril, que foi submetida a diluições seriadas, posteriormente incubadas a 37°C/48h sob microaerofilia para contagem das UFC/mL. Para análise dos dados, utilizaram-se os testes Levene, Shapiro-Wilk e Kruskal-Wallis. O nível de significância adotado foi de 5% (α = 0,05). Resultado Não houve formação de halo de inibição entre os produtos e o meio de cultura (p<0,05); no disco de membrana, não foram observadas diferenças estatísticas entre os grupos (p=0,679); os grupos tratados com leite bovino com probiótico e leite fermentado com probiótico apresentaram adesividade aos bráquetes ortodônticos (p=0,056). Conclusão Os achados do presente estudo permitem concluir que, em estudos in vitro, não foi possível verificar a bacterioterapia a partir de produtos lácteos contendo ou não probióticos em cepas de SM e SS.


2013 ◽  
Vol 65 (5) ◽  
pp. 1537-1544 ◽  
Author(s):  
S.A. Carvalho ◽  
L.S. Carmo ◽  
E.F. Abreu ◽  
R.S. Dias ◽  
A.C.M. Apolônio ◽  
...  

The production of Toxic Shock Syndrome Toxin-1 (TSST-1), enterotoxins and bacteriocin-like substances was evaluated in 95 strains of Staphylococcus aureus recovered from raw bovine milk (n=31) and from food samples involved in staphylococcal food poisoning (n=64). Enterotoxigenicity tests with the membrane over agar associated to optimal sensibility plate assays were performed and showed that 96.77% of strains recovered from milk and 95.31% from food samples produced enterotoxins A, B, C, D or TSST-1. Reference strains S. epidermidis, Bacillus cereus, Listeria monocytogenes, Lactobacillus casei, Pseudomonas aeruginosa, S. aureus, Salmonella Typhimurium, Escherichia coli, Enterococcus faecalis and Bacteroides fragilis were used as indicator bacteria in the antagonistic assays, the first five being sensitive to antagonistic substances. Brain heart infusion agar, in pH values ranging from 5.0 to 7.0 in aerobic atmosphere showed to be the optimum condition for antagonistic activity as evaluated with the best producer strains against the most sensitive indicator bacterium, L. monocytogenes. Sensitivity to enzymes confirmed the proteinaceous nature of these substances. Neither bacteriophage activity nor fatty acids were detected and the antagonistic activity was not due to residual chloroform. Results did not establish a positive correlation between the bacteriocinogenic profile and toxigenicity in the tested S. aureus strains.


2004 ◽  
Vol 67 (5) ◽  
pp. 1014-1016 ◽  
Author(s):  
M. J. CHO ◽  
R. W. BUESCHER ◽  
M. JOHNSON ◽  
M. JANES

The effects of (E,Z)-2,6-nonadienal (NDE) and (E)-2-nonenal (NE) on Bacillus cereus, Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella Typhimurium were investigated. A suspension of each organism of 6 to 9 log CFU/ml was incubated for 1 h at 37° C in brain heart infusion solution that contained 0 to 500 or 1,000 ppm of NDE or NE. Depending on concentration, exposure to either NDE or NE caused a reduction in CFU of each organism. Treatment with 250 and 500 ppm NDE completely eliminated viable B. cereus and Salmonella Typhimurium cells, respectively. L. monocytogenes was the most resistant to NDE, showing only about a 2-log reduction from exposure to 500 ppm for 1 h. Conversely, this concentration of NDE caused a 5.8-log reduction in E. coli O157:H7 cells. NE was also effective in inactivating organisms listed above. A higher concentration of NE, 1,000 ppm, was required to kill E. coli O157:H7, L. monocytogenes, or Salmonella Typhimurium compared with NDE. In conclusion, both NDE and NE demonstrated an apparent bactericidal activity against these pathogens.


2010 ◽  
Vol 79 (4) ◽  
pp. 581-586 ◽  
Author(s):  
Süheyla Türkyılmaz ◽  
Seyhan Kaynarca

The aim of this study was to isolate yeasts from subclinical mastitic cows and to investigate the slime production by the isolated yeasts. The material used in this study included 339 milk samples from 152 dairy cattle with subclinical mastitis.Milk wasplated onto blood agar, MacConkey agar and Sabouraud dextrose agar. Forty-onesamples (12.1% of total milk samples) were found positive for the yeast by API 20 C AUX identification system. The isolated yeasts were classified into four genera ofCandida, Trichosporon, CryptococcusandSaccharomyces.TheCandidaspecies were following:C. krusei,C. kefyr,C. guilliermondii,C. famata,C. rugosaandC. utulis. Other yeasts were identified asTrichosporon mucoides,T. asahii,Cryptococcus laurentii,C.  neoformansandSaccharomyces cerevisiae. Slime production was tested on Congo red brain heart infusion agar and evaluated according to Congo red phenomenon. Fifteen (36.6%) strains were slime factor positive: seven wereC. krusei, fourC. kefyr, oneC. guilliermondii, oneC. famata, oneT. asahii, and oneC. laurentii. The results of the present study indicate that yeast mastitis is significant for causing economic losses and slime production is mostly found in non-albicans Candidaspecies. Therefore, non-albicans Candidaspecies should be examined for slime production.


2016 ◽  
Vol 73 (1) ◽  
pp. 114
Author(s):  
B.V.C. Mahajan ◽  
W.S. Dhillon ◽  
M.K. Sidhu ◽  
S.K. Jindal ◽  
Mahesh Kumar ◽  
...  

Food Control ◽  
2015 ◽  
Vol 47 ◽  
pp. 306-311 ◽  
Author(s):  
Elena Dalzini ◽  
Elena Cosciani-Cunico ◽  
Valentina Bernini ◽  
Barbara Bertasi ◽  
Marina-Nadia Losio ◽  
...  

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