scholarly journals Microbial Profile of Fresh Beef Sold in the Markets of Ngaoundéré, Cameroon, and Antiadhesive Activity of a Biosurfactant against Selected Bacterial Pathogens

2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Hippolyte T. Mouafo ◽  
Annick M. B. Baomog ◽  
Jorelle J. B. Adjele ◽  
Alphonse T. Sokamte ◽  
Augustin Mbawala ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Microbial Diversity ◽  
Salmonella Enteritidis ◽  
Meat Industry ◽  
Microbial Profile ◽  
Meat Spoilage ◽  
Food Borne ◽  
Food Borne Illness ◽  
Microbiological Criteria ◽  
Potential Use

Owing to its composition, meat is recognized as one of the best media for microbial growth leading to meat spoilage and food-borne illness. The ability of microorganisms to adhere to surfaces where meat is deposited during selling is a nonnegligible cause of meat contamination. This work was performed to assess the microbial profile of fresh beef sold in the markets of Ngaoundéré town and evaluate the antiadhesive activity of a biosurfactant derived from Lactobacillus paracasei subsp. tolerans N2 against selected pathogenic strains isolated in fresh beef. All fresh beef samples analysed were contaminated with both pathogenic and spoilage microorganisms at levels higher than the microbiological criteria set by the European Commission. A total of 151 strains belonging to 12 species (Pseudomonas putida, Pseudomonas aeruginosa, Pseudomonas sp., Escherichia coli 1, Escherichia coli, Salmonella enteritidis, Salmonella sp., Staphylococcus epidermidis, Staphylococcus xylosus, Staphylococcus aureus, Candida albicans, and Candida sp.) were isolated and identified. A specific relationship between the microbial diversity of fresh beef and the sampling sites was observed. Biosurfactant displayed antiadhesive activity against all the tested strains and the complete inhibition (100%) of Bacillus sp. BC1, S. aureus STP1, and S. xylosus STP2 was noticed at biosurfactant concentration of 10 mg/mL. This study indicates the microbial diversity of fresh beef sold in Ngaoundéré markets and suggests the potential use of biosurfactant as an antiadhesive agent in the meat industry.

scholarly journals Pathogens Contamination Level Reduction on Beef Using Organic Acids Decontamination Methods

2017 ◽  
Vol 74 (2) ◽  
pp. 212 ◽  
Author(s):  
Sorin Daniel DAN ◽  
Marian MIHAIU ◽  
Oana REGET ◽  
Delia OLTEAN ◽  
Alexandra TĂBĂRAN
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Citric Acid ◽  
Organic Acids ◽  
Salmonella Enteritidis ◽  
Contamination Level ◽  
Bacterial Strains ◽  
Food Borne ◽  
Food Borne Illness ◽  
Level Reduction

In this study we aimed to assess the efficiency of organic acids in different concentrations regarding pathogens as Salmonella, Listeria and Escherichia on beef, which can cause food borne illness in humans. The samples were sterilized using UV radiation for 30 minutes, afterwards being contaminated with 1 ml of microbial suspension (0.5 MacFarland). We used reference bacterial strains for Salmonella Enteritidis, Escherichia coli and Listeria monocytogenes. The samples were subjected to decontamination procedure by introducing 25mL of solution of lactic, acetic or citric acid in concentration of 1%, 2% and 3%. The results showed a reduction of initial pathogen load, ranging from 0.32 to 7.78 log CFU/g, depending on the type of acid, concentration and pathogen sensitivity. After decontamination, standardized methods have been used for the isolation of pathogenic germs. Based on statistical analysis we conclude that pathogens have a different sensitivity to the action of acid solutions, their sensitivity in ascending order being: Listeria monocytogenes, Salmonella Enteritidis and Escherichia coli. Among the organic acids, the most efficient was lactic acid, followed by acetic acid and less efficient citric acid. The greatest reduction of germs was determined by the concentration of 3%.

scholarly journals Behavior of Different Shiga Toxin-Producing Escherichia coli Serotypes in Various Experimentally Contaminated Raw-Milk Cheeses

2012 ◽  
Vol 79 (1) ◽  
pp. 150-158 ◽  
Author(s):  
Stéphane D. Miszczycha ◽  
Frédérique Perrin ◽  
Sarah Ganet ◽  
Emmanuel Jamet ◽  
Fanny Tenenhaus-Aziza ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Human Health Risk ◽  
Raw Milk ◽  
Public Health Implication ◽  
Content Type ◽  
Growth And Survival ◽  
The Public ◽  
Food Borne ◽  
Food Borne Illness

ABSTRACTShiga toxin-producingEscherichia coli(STEC) is an important cause of food-borne illness. The public health implication of the presence of STEC in dairy products remains unclear. Knowledge of STEC behavior in cheeses would help to evaluate the human health risk. The aim of our study was to observe the growth and survival of experimentally inoculated STEC strains in raw-milk cheeses manufactured and ripened according to five technological schemes: blue-type cheese, uncooked pressed cheese with long ripening and with short ripening steps, cooked cheese, and lactic cheese. Cheeses were contaminated with different STEC serotypes (O157:H7, O26:H11, O103:H2, and O145:H28) at the milk preparation stage. STEC growth and survival were monitored on selective media during the entire manufacturing process. STEC grew (2 to 3 log10CFU · g−1) in blue-type cheese and the two uncooked pressed cheeses during the first 24 h of cheese making. Then, STEC levels progressively decreased in cheeses that were ripened for more than 6 months. In cooked cheese and in lactic cheese with a long acidic coagulation step (pH < 4.5), STEC did not grow. Their levels decreased after the cooking step in the cooked cheese and after the coagulation step in the lactic cheese, but STEC was still detectable at the end of ripening and storage. A serotype effect was found: in all cheeses studied, serotype O157:H7 grew less strongly and was less persistent than the others serotypes. This study improves knowledge of the behavior of different STEC serotypes in various raw-milk cheeses.

scholarly journals ​Incidence and Pathology of Paratyphoid Infection in Poultry

2021 ◽  
Author(s):  
Anushri Tiwari ◽  
Madhu Swamy ◽  
Yamini Verma ◽  
Amita Dubey
Keyword(s):  
Salmonella Typhimurium ◽  
Whole Blood ◽  
Salmonella Enteritidis ◽  
Biochemical Characterization ◽  
Agglutination Test ◽  
Fecal Samples ◽  
Food Borne ◽  
Poultry Farms ◽  
Food Borne Illness ◽  
Histopathological Studies

Background: Paratyphoid infection of poultry is caused by non-host adapted motile salmonellae and are responsible for numerous cases of food borne illness worldwide. The present study was carried out from July 2019 to February 2020 in Jabalpur to know the occurrence and pathology of paratyphoid bacteria in poultry. Methods: Whole blood agglutination test was performed to know the prevalence of salmonellosis in and areas surrounding Jabalpur region and pooled fecal samples were collected from poultry farms to perform microbe culture and biochemical characterization. Serotyping of Salmonella isolates was done using polyvalent antisera. Necropsy examination was conducted to observe gross and histopathological lesions. Conclusion: Rapid whole blood agglutination test determined the percent prevalence of Salmonella as 28.0% from 25 private poultry outlets. The percent prevalence of salmonellosis by collecting pooled fecal samples from 15 broiler and 11 layer farms was recorded as 20.0% and 45.4% respectively. Salmonellosis was recorded in 1.58% of total necropsy cases of birds examined for gross and histopathological studies. Polyvalent antisera diagnosed 27.27% motile paratyphoid salmonellae, out of which 18.18% tested positive for Salmonella Enteritidis while 9.09% tested positive for Salmonella Typhimurium. Birds with paratyphoid infection showed hepatomegaly, discoloration, hemorrhagic and necrotic foci in liver and various grades of hemorrhagic to catarrhal enteritis were recorded.

scholarly journals An Improved Cloning Vector for Construction of Gene Replacements in Listeria monocytogenes

2003 ◽  
Vol 69 (5) ◽  
pp. 3020-3023 ◽  
Author(s):  
Guojie Li ◽  
S. Kathariou
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Plasmid Vector ◽  
Gene Replacement ◽  
Direct Selection ◽  
Genetic Studies ◽  
Food Borne ◽  
Food Borne Illness ◽  
Selection For ◽  
Selection Of

ABSTRACT Listeria monocytogenes is a gram-positive, facultative intracellular bacterium implicated in severe food-borne illness (listeriosis) in humans. The construction of well-defined gene replacements in the genome of L. monocytogenes has been instrumental to several genetic studies of the virulence and other attributes of the organism. Construction of such mutations by currently available procedures, however, tends to be labor intensive, and gene replacement mutants are sometimes difficult to recover due to lack of direct selection for the construct. In this study we describe the construction and use of plasmid vector pGF-EM, which can be conjugatively transferred from Escherichia coli S17-1 to L. monocytogenes and which provides the genetic means for direct selection of gene replacements.

scholarly journals TheEscherichia coliO157:H7 Carbon Starvation-Inducible Lipoprotein Slp Contributes to Initial AdherenceIn Vitrovia the Human Polymeric Immunoglobulin Receptor

2018 ◽  
Author(s):  
Christine Fedorchuk ◽  
Indira T. Kudva ◽  
Subhashinie Kariyawasam
Keyword(s):  
Escherichia Coli ◽  
Immunofluorescence Microscopy ◽  
Polymeric Immunoglobulin Receptor ◽  
Wild Type ◽  
Immunoglobulin Receptor ◽  
E Coli ◽  
Data Support ◽  
Food Borne ◽  
Food Borne Illness ◽  
Adherence Mechanism

AbstractEscherichia coliO157:H7 is the most well-studied serotype of enterohemorrhagicE. coli(EHEC) class ofE. coliintestinal pathogens, and is responsible for many outbreaks of serious food-borne illness worldwide each year. Adherence mechanisms are a critical component of its pathogenesis, persistence in natural reservoirs, and environmental contamination.E. coliO157:H7 has a highly effective virulence operon, the Locus of Enterocyte Effacement (LEE), and its encoded intimate adherence mechanism is well characterized. However, factors involved in the preceding initial attachment are not well understood. In this study, we propose a mechanism of initial adherence used byE. coliO157:H7in vitro. We describe a bacterial protein not previously reported to be involved in adherence, Slp, and its interactions with the human host protein polymeric immunoglobulin receptor (pIgR). The human pIgR has previously been shown to act as an adherence receptor for some mucosal pathogens, and is highly expressed in the intestine. Following observation of significant colocalization betweenE. coliO157:H7 and pIgR location on Caco-2 cells, a co-immunoprecipitation (Co-IP) assay using a human recombinant Fc-tagged pIgR protein led to the identification of this protein. Disruption of Slp expression inE. coliO157:H7, through deletion of its encoding geneslp, produced a significant adherence deficiency to Caco-2 cells at early time points associated with initial adherence. Plasmid complementation ofslpfully restored the wild-type phenotype. Furthermore, immunofluorescence microscopy revealed evidence that this interaction is specific to the pathogenic strains ofE. colitested, and not the nonpathogenic strain E. coli K12. Additionally, deletion ofslpresulted in the absence of the corresponding protein band in further Co-IP assays, while the plasmid-encodedslpcomplementation of the deletion mutant strain restored the wild-type pattern. These data support the proposal that Slp directly contributes to initial adherence, with the pIgR protein as its proposed receptor.Author summaryEscherichia coliO157:H7 and other enterohemorrhagicE. coli(EHEC) are responsible for tens of thousands of cases of food-borne illness in the United States each year.E. coliO157:H7 has a particularly effective intimate adherence mechanism. However, the mechanisms of initial adherence, which facilitate attachment and virulence prior to the engagement of intimate adherence, are not well understood. In this study, we describe an initial adherence interaction between theE. coliO157:H7 Slp and the human polymeric immunoglobulin receptor (pIgR) expressed by the human colonic epithelial cell line Caco-2. The relationship was first demonstrated as a significant colocalization between the locations ofE. coliO157:H7 bacterial cells and pIgR protein using immunofluorescence microscopy. TheE. coliO157:H7 Slp protein was identified, and disruption of theslpgene resulted in a severe adherence deficiency to Caco-2 cells during initial adherence. This effect was reversed upon complementation of the Δslpstrain with a plasmid-encodedslpgene, and the constitutive over-expression ofslpresulted in hyper-adherence exceeding that of the wild-typeE. coliO157:H7. These data support the proposition that Slp directly contributes to initial adherence, with the pIgR protein as its proposed receptor.

scholarly journals Persistent Colonization of Sheep byEscherichia coli O157:H7 and Other E. coliPathotypes

2000 ◽  
Vol 66 (11) ◽  
pp. 4926-4934 ◽  
Author(s):  
N. A. Cornick ◽  
S. L. Booher ◽  
T. A. Casey ◽  
H. W. Moon
Keyword(s):  
Escherichia Coli ◽  
Young Adult ◽  
Shiga Toxin ◽  
The Other ◽  
E Coli ◽  
Adult Sheep ◽  
Food Borne ◽  
Food Borne Illness ◽  
Byescherichia Coli ◽  
Frequency Magnitude

ABSTRACT Shiga toxin-producing Escherichia coli (STEC) is an important cause of food-borne illness in humans. Ruminants appear to be more frequently colonized by STEC than are other animals, but the reason(s) for this is unknown. We compared the frequency, magnitude, duration, and transmissibility of colonization of sheep by E. coli O157:H7 to that by other pathotypes of E. coli. Young adult sheep were simultaneously inoculated with a cocktail consisting of two strains of E. coli O157:H7, two strains of enterotoxigenic E. coli (ETEC), and one strain of enteropathogenic E. coli. Both STEC strains and ETEC 2041 were given at either 107 or 1010CFU/strain/animal. The other strains were given only at 1010 CFU/strain. We found no consistent differences among pathotypes in the frequency, magnitude, and transmissibility of colonization. However, the STEC strains tended to persist to 2 weeks and 2 months postinoculation more frequently than did the other pathotypes. The tendency for persistence of the STEC strains was apparent following an inoculation dose of either 107 or 1010 CFU. One of the ETEC strains also persisted when inoculated at 1010 CFU. However, in contrast to the STEC strains, it did not persist when inoculated at 107 CFU. These results support the hypothesis that STEC is better adapted to persist in the alimentary tracts of sheep than are other pathotypes ofE. coli.

scholarly journals Multiple contaminations of chickens with Campylobacter, Escherichia coli and Salmonella in Yaounde (Cameroon)

2010 ◽  
Vol 4 (09) ◽  
pp. 583-686 ◽  
Author(s):  
Ariane Nzouankeu ◽  
Antoinette Ngandjio ◽  
Guy Ejenguele ◽  
Thomas Njine ◽  
Marguerite Ndayo Wouafo
Keyword(s):  
Escherichia Coli ◽  
Food Safety ◽  
Salmonella Enteritidis ◽  
Public Awareness ◽  
Poultry Meat ◽  
Risk Of Infection ◽  
Retail Markets ◽  
E Coli ◽  
Food Borne ◽  
Salmonella Hadar

Introduction: Food-borne diseases associated with Campylobacter, Escherichia coli, and Salmonella are mainly caused by the consumption of raw or undercooked poultry meat. The objective of this study was to evaluate the prevalence of Campylobacter, Escherichia coli, and Salmonella in chickens. Methodology: One hundred and fifty chickens collected from eight retail markets in Yaounde were examined for the presence of Campylobacter, Escherichia coli, and Salmonella using standard bacteriological procedures. Results: Of the 150 chickens collected, 135 (90%) were contaminated with Campylobacter (68.9% C. coli and 31.1% C. jejuni). All the chickens were positive for E. coli. Among the 150 isolates, 17 (11.3%) were enteropathogenic E. coli (EPEC). Additionally, 103 Salmonella strains were recovered from 90 chickens. Salmonella Enteritidis (45.6%) and Salmonella Hadar (28.1%) were the most frequent serotypes. Multiple contamination was found in 142 chickens (94.6%), of which 83 (55.3%) were concurrently contaminated with Campylobacter, Escherichia coli, and Salmonella. Conclusion: These results show that chickens in Cameroon are highly contaminated with Campylobacter, Escherichia coli, and Salmonella. The multiple contaminations of chickens is a potential risk of infection for consumers and highlights the necessity of public awareness for food safety. 

Adherence of enterohemorrhagic Escherichia coli in a beef system

1995 ◽  
Vol 53 ◽  
pp. 1022-1023
Author(s):  
T. S. Schwach ◽  
E. A. Zottola
Keyword(s):  
Escherichia Coli ◽  
Food System ◽  
Enterohemorrhagic Escherichia Coli ◽  
Frozen Ground ◽  
Internal Organs ◽  
Growth Environment ◽  
E Coli ◽  
Food Borne ◽  
Food Borne Illness ◽  
Pure Cultures

Microbiologists have traditionally studied pure cultures growing in laboratory media. Food microbiologists, interested in interactions between the food system, pathogen, and host have tried to extrapolate information in the same manner. However, clinical isolates readily lose virulence characteristics when repeatedly subcultured into laboratory media. Expression of many virulence factors, such as fimbriae, extracellular polymers and outer membrane adhesins are affected by growth environment; an environment which encompasses not only nutrient availability and growth temperature, but also physical surroundings, moisture, oxygen and pH levels, and the presence of competitive flora. The ability of an organism to adhere to a surface is a major virulence factor.Enterohemorrhagic Escherichia coli (EHEC) are one of five groups of enteropathic E. coli which cause intestinal disease world-wide. The most well known of this group, serotype O157:H7, has been implicated in major food-borne illness outbreaks primarily due to the consumption of undercooked hamburgers. They are found in the intestinal tracts of cattle, feces, hanging carcasses, and frozen ground beef. E. coli O157:H7 adheres to large intestinal epithelium with characteristic lesions and produces verocytoxins which damage internal organs, such as the kidney.

Destruction of Escherichia coli O157:H7 and Salmonella typhimurium in Lebanon Bologna by Interaction of Fermentaron pH, Heating Temperature, and Time

1998 ◽  
Vol 61 (2) ◽  
pp. 152-157 ◽  
Author(s):  
KAMESWAR R. ELLAJOSYULA ◽  
STEPHANIE DOORES ◽  
EDWARD W. MILLS ◽  
RICHARD A. WILSON ◽  
RAMASWAMY C. ANANTHESWARAN ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Salmonella Typhimurium ◽  
Heating Temperature ◽  
Enterohemorrhagic Escherichia Coli ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Food Borne ◽  
Recent Outbreak ◽  
Food Borne Illness ◽  
Effects Of Ph

Fermented meats have caused food-borne illness due to enterohemorrhagic Escherichia coli. Consumption of Lebanon bologna was epidemiologically associated with a recent outbreak of salmonellosis. The present study was conducted to determine the effects of pH (after the fermentation step), final heating temperature, and time on destruction of E. coli O157:H7 and Salmonella typhimurium in Lebanon bologna. Raw Lebanon bologna mix was inoculated with either of the pathogens (ca. 108 CFU/g) and fermented for 12 h at 80°F (26.7°C) and then at 100°F (37.8°C) until the pH reached either 5.2 or 4.7. The mix was then heated to 110,115, or 120°F (43.3, 46.1, or 48.9°C). The bologna was sampled at various times, decimally diluted, and plated on either McConkey sorbitol agar or XLD agar to enumerate E. coli O157:H7 and S. typhimurium, respectively. Fermentation alone reduced populations of both pathogens by &lt;2 log units and heating alone reduced populations of E. coli O157:H7 by &lt; 3 log units. A combination of fermenting to either pH 5.2 or 4.7, followed by heating at 110°F (43.3°C) for 20 h, 115°F (46.1°C) for 10 h, or 120°F (48.9°C) for 3 h reduced populations of both pathogens by &gt;7 log units. Overall, S. typhimurium cells were either equally or significantly less resistant (P &lt; 0.01) than cells of E. coli O157:H7. Significant interactions (P &lt; 0.01) among the three factors for the destruction of E. coli O157:H7 were observed. A process-specific regression equation was developed to predict the destruction of E. coli O157:H7 in Lebanon bologna.

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