scholarly journals Longitudinal Study of Shiga Toxin-ProducingEscherichia coliandCampylobacter jejunion Finnish Dairy Farms and in Raw Milk

2019 ◽  
Vol 85 (7) ◽  
Author(s):  
Anniina Jaakkonen ◽  
Hanna Castro ◽  
Saija Hallanvuo ◽  
Jukka Ranta ◽  
Mirko Rossi ◽  
...  
Keyword(s):  
Shiga Toxin ◽  
Pathogenic Bacteria ◽  
Pathogen Detection ◽  
Dairy Farms ◽  
Raw Milk ◽  
Content Type ◽  
Fecal Shedding ◽  
Hygienic Measures ◽  
Cattle Herds ◽  
On Farm

ABSTRACTShiga toxin-producingEscherichia coli(STEC) andCampylobacter jejuniare notable health hazards associated with the consumption of raw milk. These bacteria may colonize the intestines of asymptomatic cattle and enter bulk tank milk via fecal contamination during milking. We studied the frequency of STEC O157:H7 andC. jejunicontamination in tank milk (n = 785) and the in-line milk filters of milking machines (n = 631) versus the frequency of isolation from cattle feces (n = 257) on three Finnish dairy farms for 1 year. Despite simultaneous isolation of STEC O157:H7 (17%) orC. jejuni(53%) from cattle, these bacteria were rarely isolated from milk filters (2% or <1%, respectively) and milk (0%). As revealed by phylogenomics, one STEC O157:H7 strain at a time was detected on each farm and persisted for ≤12 months despite rigorous hygienic measures.C. jejunistrains of a generalist sequence type (ST-883 and ST-1080) persisted in the herds for ≥11 months, and several otherC. jejunitypes were detected sporadically. Thestxgene carried by STEC was detected more frequently from milk filters (37%) than from milk (7%), suggesting that milk filters are more suitable sampling targets for monitoring than milk. A questionnaire of on-farm practices suggested lowerstxcontamination of milk when major cleansing in the barn, culling, or pasturing of dairy cows was applied, while a higher average outdoor temperature was associated with higherstxcontamination. Because pathogen contamination occurred despite good hygiene and because pathogen detection from milk and milk filters proved challenging, we recommend heat treatment for raw milk before consumption.IMPORTANCEThe increased popularity of raw milk consumption has created demand for relaxing legislation, despite the risk of contamination by pathogenic bacteria, notably STEC andC. jejuni. However, the epidemiology of these milk-borne pathogens on the herd level is still poorly understood, and data are lacking on the frequency of milk contamination on farms with cattle shedding these bacteria in their feces. This study suggests (i) that STEC contamination in milk can be reduced, but not prevented, by on-farm hygienic measures while fecal shedding is observable, (ii) that milk filters are more suitable sampling targets for monitoring than milk although pathogen detection from both sample matrices may be challenging, and (iii) that STEC andC. jejunigenotypes may persist in cattle herds for several months. The results can be utilized in developing and targeting pathogen monitoring and risk management on the farm level and contributed to the revision of Finnish legislation in 2017.

Drug-resistant bacterial pathogens in milk and some milk products

2014 ◽  
Vol 44 (3) ◽  
pp. 241-248 ◽  
Author(s):  
Shajuty Marjan ◽  
Kamal Kanta Das ◽  
Saurab Kishore Munshi ◽  
Rashed Noor
Keyword(s):  
Public Health ◽  
Developing Countries ◽  
Pathogenic Bacteria ◽  
Raw Milk ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Biochemical Tests ◽  
Content Type ◽  
Milk Products ◽  
Milk Samples

Purpose – Current study was carried to detect the presence of pathogenic bacteria including the drug-resistant ones from milk and milk products. The paper aims to discuss these issues. Design/methodology/approach – Twenty-six raw milk samples from ten different areas, 28 pasteurized milk samples from 12 different companies and 26 yogurt samples from ten different sources in Dhaka city were microbiologically analyzed through cultural and biochemical identification of the isolates. Drug resistance trait was also determined by the Kirby-Bauer method on Muller-Hinton agar. Findings – Out of 80 samples studied, 74 were found to harbor pathogens within a range of 102-104 cfu/ml, including Escherichia coli, Salmonella spp., Staphylococcus aureus, and Vibrio spp. The study of antibiogram revealed that most of the isolates were resistant against most of the commonly used antibiotics. Research limitations/implications – Employment of only cultural/ biochemical tests excluding the molecular detection of virulence and/or antibiotic resistance genes might stand as a shortfall of the study. Nevertheless, such basic approach of microbiology can make this type of study replicable in the resource poor settings in the other developing countries. Practical implications – Routine detection of drug-resistant bacteria can further unveil the complications in chemotherapy during the endemic food borne diseases. Social implications – The study outcome/knowledge would aid to a better public health management especially in the developing countries. Originality/value – The presence of drug-resistant pathogenic bacteria in most of the tested milk samples poses a great public health threat, especially to the children. Therefore, the study revealed the necessity of maintaining proper hygienic practice and care in handling and processing of milk and milk products.

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 Complete Annotated Genome Sequences of Two Shiga Toxin-Producing Escherichia coli Strains and One Atypical Enteropathogenic E. coli Strain, Isolated from Naturally Colonized Cattle of German Origin

2017 ◽  
Vol 5 (19) ◽  
Author(s):  
Lutz Geue ◽  
Christian Menge ◽  
Christian Berens ◽  
Stefanie A. Barth
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Coli Strain ◽  
Enteric Pathogens ◽  
Genome Sequences ◽  
Content Type ◽  
E Coli ◽  
German Origin ◽  
Cattle Herds ◽  
German Cattle

ABSTRACT Shiga toxin-producing Escherichia coli (STEC) are important zoonotic enteric pathogens with the main reservoir in cattle. Here, we present the genomes of two STEC strains and one atypical enteropathogenic E. coli strain from cattle origin, obtained during a longitudinal study in German cattle herds.

scholarly journals Development of a Sensitive and Rapid Recombinase Polymerase Amplification Assay for Detection of Anaplasma phagocytophilum

2020 ◽  
Vol 58 (5) ◽  
Author(s):  
Le Jiang ◽  
Philip Ching ◽  
Chien-Chung Chao ◽  
J. Stephen Dumler ◽  
Wei-Mei Ching
Keyword(s):  
Anaplasma Phagocytophilum ◽  
Pathogenic Bacteria ◽  
Pathogen Detection ◽  
Limit Of Detection ◽  
Dna Amplification ◽  
Recombinase Polymerase Amplification ◽  
Detection Methods ◽  
Content Type ◽  
Amplification Assay ◽  
Nonspecific Amplification

ABSTRACT Human granulocytic anaplasmosis (HGA) is a tick-borne disease caused by the obligate intracellular Gram-negative bacterium Anaplasma phagocytophilum. The disease often presents with nonspecific symptoms with negative serology during the acute phase. Direct pathogen detection is the best approach for early confirmatory diagnosis. Over the years, PCR-based molecular detection methods have been developed, but optimal sensitivity is not achieved by conventional PCR while real-time PCR requires expensive and sophisticated instruments. To improve the sensitivity and also develop an assay that can be used in resource-limited areas, an isothermal DNA amplification assay based on recombinase polymerase amplification (RPA) was developed. To do this, we identified a 171-bp DNA sequence within multiple paralogous copies of msp2 within the genome of A. phagocytophilum. Our novel RPA assay targeting this sequence has an analytical limit of detection of one genome equivalent copy of A. phagocytophilum and can reliably detect 125 bacteria/ml in human blood. A high level of specificity was demonstrated by the absence of nonspecific amplification using genomic DNA from human or DNA from other closely-related pathogenic bacteria, such as Anaplasma platys, Ehrlichia chaffeensis, Orientia tsutsugamushi, and Rickettsia rickettsii, etc. When applied to patient DNA extracted from whole blood, this new RPA assay was able to detect 100% of previously diagnosed A. phagocytophilum cases. The sensitivity and rapidness of this assay represents a major improvement for early diagnosis of A. phagocytophilum in human patients and suggest a role for better surveillance in its reservoirs or vectors, especially in remote regions where resources are limited.

An Overview of Molecular Stress Response Mechanisms in Escherichia coli Contributing to Survival of Shiga Toxin–Producing Escherichia coli during Raw Milk Cheese Production

2011 ◽  
Vol 74 (5) ◽  
pp. 849-864 ◽  
Author(s):  
SILVIO PENG ◽  
TAURAI TASARA ◽  
JÖRG HUMMERJOHANN ◽  
ROGER STEPHAN
Keyword(s):  
Escherichia Coli ◽  
Stress Response ◽  
Foodborne Pathogens ◽  
Stress Responses ◽  
Shiga Toxin ◽  
Pathogenic Bacteria ◽  
Raw Milk ◽  
Heat Shock Stress ◽  
Raw Milk Cheese ◽  
Cheese Production

The ability of foodborne pathogens to survive in certain foods mainly depends on stress response mechanisms. Insight into molecular properties enabling pathogenic bacteria to survive in food is valuable for improvement of the control of pathogens during food processing. Raw milk cheeses are a potential source for human infections with Shiga toxin–producing Escherichia coli (STEC). In this review, we focused on the stress response mechanisms important for allowing STEC to survive raw milk cheese production processes. The major components and regulation pathways for general, acid, osmotic, and heat shock stress responses in E. coli and the implications of these responses for the survival of STEC in raw milk cheeses are discussed.

scholarly journals Mycobacterium avium subsp. paratuberculosis Antibody Response, Fecal Shedding, and Antibody Cross-Reactivity to Mycobacterium bovis in M. avium subsp. paratuberculosis-Infected Cattle Herds Vaccinated against Johne's Disease

2014 ◽  
Vol 21 (5) ◽  
pp. 698-703 ◽  
Author(s):  
Deepanker Tewari ◽  
Ernest Hovingh ◽  
Rick Linscott ◽  
Edmond Martel ◽  
John Lawrence ◽  
...  
Keyword(s):  
Mycobacterium Bovis ◽  
Mycobacterium Avium ◽  
Cross Reactivity ◽  
Johne's Disease ◽  
Antibody Responses ◽  
Johne’S Disease ◽  
Serum Samples ◽  
Content Type ◽  
Fecal Shedding ◽  
Cattle Herds

ABSTRACTVaccination for Johne's disease with killed inactivated vaccine in cattle herds has shown variable success. The vaccine delays the onset of disease but does not afford complete protection. Johne's disease vaccination has also been reported to interfere with measurements of cell-mediated immune responses for the detection of bovine tuberculosis. Temporal antibody responses and fecal shedding ofMycobacterium aviumsubsp.paratuberculosis, the causative agent of Johne's disease, were measured in 2 dairy cattle herds using Johne's disease vaccine (Mycopar) over a period of 7 years. Vaccination against Johne's disease resulted in positive serumM. aviumsubsp.paratuberculosisantibody responses in both herds, and the responses persisted in vaccinated cattle up to 7 years of age. Some vaccinated animals (29.4% in herd A and 36.2% in herd B) showed no serological reactivity toM. aviumsubsp.paratuberculosis.M. aviumsubsp.paratuberculosis-specific antibody responses were also detected in milk from Johne's disease-vaccinated animals, but fewer animals (39.3% in herd A and 49.4% in herd B) had positive results with milk than with serum samples. With vaccination againstM. aviumsubsp.paratuberculosis, fecal shedding in both dairy herds was reduced significantly (P< 0.001). In addition, when selected Johne's disease-vaccinated and -infected animals were investigated for serological cross-reactivity toMycobacterium bovis, no cross-reactivity was observed.

scholarly journals Molecular screening of bovine raw milk for the presence of Shiga toxin-producing Escherichia coli (STEC) on dairy farms

2014 ◽  
Vol 34 (3) ◽  
pp. 604-608 ◽  
Author(s):  
Tatiane Vendramin ◽  
Débora Mara Kich ◽  
Rachel Dias Molina ◽  
Claucia Fernanda Volken de Souza ◽  
Rosangela Uhrig Salvatori ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Dairy Farms ◽  
Raw Milk ◽  
Molecular Screening

scholarly journals Draft Genome Sequences of 15 Staphylococcus aureus Isolates Recovered from Raw Milk and Associated Milk Filters from Victoria, Australia

2017 ◽  
Vol 5 (2) ◽  
Author(s):  
Kate McMillan ◽  
Theodore R. Allnutt ◽  
Edward M. Fox
Keyword(s):  
Staphylococcus Aureus ◽  
Draft Genome ◽  
Dairy Farms ◽  
Raw Milk ◽  
Genome Sequences ◽  
Content Type ◽  
Whole Genomes ◽  
Sequence Types

ABSTRACT This study describes draft whole genomes of 15 Staphylococcus aureus isolates from dairy farms located in Victoria, Australia. Two novel sequence types (ST3183 and ST3184) were identified among these isolates.

scholarly journals Application of Metagenomic Sequencing to Food Safety: Detection of Shiga Toxin-Producing Escherichia coli on Fresh Bagged Spinach

2015 ◽  
Vol 81 (23) ◽  
pp. 8183-8191 ◽  
Author(s):  
Susan R. Leonard ◽  
Mark K. Mammel ◽  
David W. Lacher ◽  
Christopher A. Elkins
Keyword(s):  
Escherichia Coli ◽  
Food Safety ◽  
Shiga Toxin ◽  
Rational Design ◽  
Pathogen Detection ◽  
Antimicrobial Agents ◽  
Detection Sensitivity ◽  
Metagenomic Sequencing ◽  
Virulence Determinants ◽  
Content Type

ABSTRACTCulture-independent diagnostics reduce the reliance on traditional (and slower) culture-based methodologies. Here we capitalize on advances in next-generation sequencing (NGS) to apply this approach to food pathogen detection utilizing NGS as an analytical tool. In this study, spiking spinach with Shiga toxin-producingEscherichia coli(STEC) following an established FDA culture-based protocol was used in conjunction with shotgun metagenomic sequencing to determine the limits of detection, sensitivity, and specificity levels and to obtain information on the microbiology of the protocol. We show that an expected level of contamination (∼10 CFU/100 g) could be adequately detected (including key virulence determinants and strain-level specificity) within 8 h of enrichment at a sequencing depth of 10,000,000 reads. We also rationalize the relative benefit of static versus shaking culture conditions and the addition of selected antimicrobial agents, thereby validating the long-standing culture-based parameters behind such protocols. Moreover, the shotgun metagenomic approach was informative regarding the dynamics of microbial communities during the enrichment process, including initial surveys of the microbial loads associated with bagged spinach; the microbes found included key genera such asPseudomonas,Pantoea, andExiguobacterium. Collectively, our metagenomic study highlights and considers various parameters required for transitioning to such sequencing-based diagnostics for food safety and the potential to develop better enrichment processes in a high-throughput manner not previously possible. Future studies will investigate new species-specific DNA signature target regimens, rational design of medium components in concert with judicious use of additives, such as antibiotics, and alterations in the sample processing protocol to enhance detection.

scholarly journals Bacterial Quality, Prevalence of Pathogens, and Molecular Characterization of Biofilm-Producing Staphylococcus aureus from Korean Dairy Farm Environments

Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1306
Author(s):  
Sangdon Ryu ◽  
Minhye Shin ◽  
Bohyun Yun ◽  
Woongji Lee ◽  
Hyejin Choi ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Foodborne Pathogens ◽  
Biofilm Formation ◽  
Bacterial Infections ◽  
Pathogenic Bacteria ◽  
Dairy Farm ◽  
Dairy Farms ◽  
Raw Milk ◽  
Processing Plant ◽  
Microbiological Analysis

Raw milk acts as a mediator of major foodborne pathogenic bacterial infections. However, the sources of pathogens that contaminate milk are often unclear. This study assessed the prevalence of sanitary quality-indicating bacteria (total aerobic bacteria, psychrotrophic bacteria, coliform, and yeast/molds), including seven foodborne pathogens, in a dairy farm environment and processing plant in Korea. The microbiological analysis showed that a few sites, such as vat bottoms, room floors, drain holes, and niches, showed high microbial loads in most dairy farms. Based on quantitative microbial tests, Bacillus cereus was detected in three farms and Staphylococcus aureus was detected in only one farm. Among them, S. aureus JDFM SA01 isolated from a milk filter showed strong biofilm formation and toxicity to the host Caenorhabditis elegans. Subsequently, RNA-seq was performed to characterize the biofilm formation ability of S. aureus JDFM SA01. In biofilms, the significant upregulation of genes encoding microbial surface components and recognizing adhesive matrix molecules promotes adhesion might explain the increased viability and biomass of biofilms. This study provided insight into the prevalence of pathogenic bacteria and microbial contamination levels across dairy farms.

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