Journal of Dairy Science

Thu, 06/17/2021 - 08:04
This observational study determined the lipidome of cow milk during subclinical intramammary infection (IMI) by non-aureus staphylococci (NAS), also defined as coagulase-negative staphylococci, using an untargeted approach. Among the pathogens causing bovine IMI, NAS have become the most frequently isolated bacteria from milk samples. Although the application of system biology approaches to...
Sat, 06/05/2021 - 08:04
In a return to tradition, the popularity of caprine milk is on the rise. However, particularly in countries with developed dairy industries based on bovine milk, there is the risk of adulteration with bovine milk, which is a cheaper alternative. Thus, a rapid, robust, and simple method for the detection of bovine milk added to caprine milk is necessary, and 1H nuclear magnetic resonance...
Sat, 06/05/2021 - 08:04
Bile salts is one of essential components of bile secreted into the intestine to confer antibacterial protection. Cronobacter species are associated with necrotizing enterocolitis in newborns and show a strong tolerance to bile salts. However, little attempt has been made to focus on the molecular basis of the tolerance to bile salts. In this study, we investigated the roles of tolC on growth,...
Fri, 05/28/2021 - 08:02
Effective testing tools for Escherichia coli O157:H7 can prevent outbreaks of foodborne illness. In this paper, a smartphone-based colorimetric aptasensor was developed using functionalized gold nanoparticles (GNP) and multi-walled carbon nanotubes (MWCNT) for monitoring E. coli O157:H7 in milk. The maximum absorption peak of GNP bonded with aptamer (Apt) generated evident transformation from 518...
Fri, 04/30/2021 - 08:02
The prophylactic use of oral antimicrobials, such as neomycin, in milk replacer (MR) or whole milk is a common practice in calf-rearing that is thought to aid in preventing disease. Heavy reliance on antimicrobials is of concern not only because of the development of antimicrobial resistance, but also because of the potentially negative effects on health. The objective of this study was to...
Fri, 04/30/2021 - 08:02
Mastitis is a prevalent disease in dairy cattle, and staphylococci are among the most common causative pathogens. Staphylococci can express resistance to a range of antimicrobials, of which methicillin resistance is of particular public health concern. Additionally, Staphylococcus aureus carries a variety of virulence factors, although less is understood about the virulence of non-aureus...
Fri, 04/23/2021 - 08:04
This study provides a deep insight into Chinese consumer trust in the Chinese dairy value chain, as a lack of trust due to the 2008 melamine scandal has been widely recognized as a barrier to the development of the domestic dairy industry in China. Based on face-to-face interviews with 954 Chinese consumers in Beijing, Shanghai, and Shijiazhuang, this study measured consumer trust in farmers,...
Fri, 04/23/2021 - 08:04
Escherichia coli O157:H7 (E. coli O157:H7), one of the most widespread foodborne pathogens, can cause a series of diseases and even lead to death. In this study, a highly sensitive method was developed by combining aptamer-exonuclease III (Exo III)–assisted amplification with lateral flow assay (LFA) based on gold nanoparticles (AuNP). The compound of single-stranded (ss) DNA-anti-E. coli O157:H7...
Thu, 04/08/2021 - 08:03
New cases of blue cheese discoloration has led to recent research to identify the causal agent and factors that favor blue pigment appearing. Nonetheless, very few reports have described the source of contamination and the measurements to eradicate the microbiological source on cheese farms by determining the relation between blue discoloration on fresh cheese and the Pseudomonas fluorescens...
Thu, 03/25/2021 - 08:02
In this observational study, phenotypic and genotypic patterns of antimicrobial resistance (AMR) in Klebsiella pneumoniae isolated from intramammary infections, clinical mastitis, fresh feces, rectal swabs, animal hindlimbs, and bulk tank milk samples from Brazilian dairy herds were investigated. In addition, we identified specific genetic variants present among extended-spectrum β-lactamase (...
Wed, 03/17/2021 - 08:02
Listeria monocytogenes is a major foodborne pathogen that adversely affects the food industry. In this study, 6 anti-listerial lactic acid bacteria (LAB) isolates were screened. These anti-listerial LAB isolates were identified via 16S rRNA gene sequencing and analyzed via repetitive extragenic palindromic-PCR. Probiotic assessment of these isolates, comprising an evaluation of the antibiotic...
Wed, 03/17/2021 - 08:02
The presence of pathogenic Shiga toxin–producing Escherichia coli (STEC) in dairy products represents a public health concern because of its ability to produce the toxins Stx1 and Stx2, which cause intestinal diseases. Monitoring the stages of milk production and checking dairy products for contamination are crucial steps to ensure dairy safety. This study aimed to report the occurrence of...
Wed, 03/17/2021 - 08:02
Bacillus cereus is one of the most important spoilage microorganisms in milk. The heat-resistant protease produced is the main factor that causes rotten, bitter off-flavors and age gelation during the shelf-life of milk. In this study, 55 strains of B. cereus were evaluated, of which 25 strains with protease production ability were used to investigate proteolytic activity and protease heat...
Fri, 03/12/2021 - 08:02
In this study, we established a rapid and sensitive method for the detection of viable Salmonella Typhimurium, Staphylococcus aureus, and Listeria monocytogenes in milk using biotin-exposure-based immunomagnetic separation (IMS) combined with sodium dodecyl sulfate (SDS), propidium monoazide (PMA), and multiplex real-time PCR (mRT-PCR). We used IMS to lessen the assay time for isolation of target...
Thu, 03/11/2021 - 08:04
The objective of the study was to evaluate the effect of hygiene measures in automatic milking units on the transmission of 3 mastitis pathogens considered to be mainly or partly transmitted from cow to cow during milking events. Two studies were conducted as within-herd experimental trials in 2 Danish commercial dairy herds (A and B) with automatic milking systems. Interventions to enhance...
Sat, 03/06/2021 - 08:04
The objective of this prospective cohort study was to explore associations between intramammary infection (IMI) in late-lactation cows and postcalving udder health and productivity. Cows (n = 2,763) from 74 US dairy herds were recruited as part of a previously published cross-sectional study of bedding management and IMI in late-lactation cows. Each herd was visited twice for sampling. At each...
Sat, 03/06/2021 - 08:04
Bisphenol A (BPA) as a chemical hazard may enter the milk chain during primary production at the farm and, successively, during milk processing at a dairy company. To identify the potential pathways that play a role in the occurrence of BPA, a monitoring model for risk assessment based on the identification of the hazards at each stage of milk processing was investigated. Milk samples were...
Sat, 03/06/2021 - 08:04
This study aimed to determine the occurrence of methicillin-resistant (MR) non-aureus staphylococci (NAS) on 20 preselected German dairy farms. Farms were selected based on the detection of methicillin-resistant Staphylococcus aureus (MRSA) during previous diagnostic investigations. Bacterial culture of presumptive MR-NAS was based on a 2-step enrichment method that has been recommended for MRSA...
Sat, 03/06/2021 - 08:04
Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is a major etiologic agent that causes bloody diarrhea, hemorrhagic colitis, and hemolytic uremic syndrome (HUS). Shiga toxin (Stx) is the main virulence factor of EHEC responsible for the progression to HUS. Although many laboratories have made efforts to develop an effective treatment for Stx-mediated HUS, a specific therapy has not been found...
Sat, 03/06/2021 - 08:04
The objective was to describe and compare antimicrobial resistance patters of esculin-hydrolyzing streptococci and streptococcal-like organisms (Streptococcus uberis, Enterococcus faecium, Enterococcus faecalis, Lactococcus garvieae, Lactococcus lactis) from routine diagnostic samples of the udder health laboratory of the Bavarian Animal Health Services between 2015 and 2019. All routine...
Thu, 03/04/2021 - 08:04
The presence of Cronobacter sakazakii must be controlled in infant powder plants, because it may cause infectious disease in infants, with high mortality. Testing for C. sakazakii in powdered infant formula should be performed before delivery, and it requires rapid and specific detection methods. In this study, we established a surface-enhanced Raman scattering (SERS) immunochromatographic test...
Thu, 03/04/2021 - 08:04
Biopreservation is defined as using microbes, their constituents, or both to control spoilage while satisfying consumer demand for clean-label products. The study objective was to investigate the efficacy of bacterial cultures in biopreserving cottage cheese against postprocessing fungal contamination. Cottage cheese curd and dressing were sourced from a manufacturer in New York State. Dressing...
Thu, 03/04/2021 - 08:04
This study aimed to investigate the survival of the foodborne pathogen Escherichia coli O157:H7 in white-brined cheeses as influenced by the presence of Lactobacillus reuteri. The white cheeses were made from pasteurized bovine milk inoculated with E. coli O157:H7 (cocktail of 3 strains) to achieve ∼5 log10 cfu/g with absence or presence of Lb. reuteri (∼6 log10 cfu/g). Cheese samples were brined...
Thu, 03/04/2021 - 08:04
This study was designed to determine antimicrobial resistance phenotypes and genotypes and virulence factors in Staphylococcus aureus and coagulase-negative staphylococci (CNS) in unpasteurized milk sold in Djelfa, Algeria. Eighty-two unpasteurized cow milk samples were randomly obtained from 82 retail stores in Djelfa and tested to detect staphylococci. Species were identified by biochemical...
Tue, 03/02/2021 - 08:04
Due to the lack of specific genes for rapid detection methods of Cronobacter sakazakii in food samples, whole genome sequence analysis was performed in this investigation using the basic local alignment search tool. Forty-two DNA fragments unique to C. sakazakii were mined, then primers were designed and screened by PCR and loop-mediated isothermal amplification (LAMP). Two primer sets, CS1 and...
Tue, 03/02/2021 - 08:04
Bulk tank milk samples from 392 Northern Ireland dairy farms and individual milk from animals (n = 293) on 4 of these farms were tested by a novel phagomagnetic separation (PhMS)-quantitative (q)PCR assay able to detect and quantify viable Mycobacterium avium ssp. paratuberculosis (MAP), to demonstrate its potential utility as a milk surveillance tool. Viable MAP were detected in 26.5% of the...
Tue, 03/02/2021 - 08:04
Heat-stable endopeptidases in raw milk, especially the alkaline metallopeptidase AprX secreted by Pseudomonas spp., are a well-known challenge for the dairy industry. They can withstand UHT treatment and may cause quality defects over the shelf life of milk products. Therefore, we established an indirect ELISA for the detection of Pseudomonas AprX in milk. We developed a 2-step sample treatment...
Fri, 02/19/2021 - 08:02
The primary objective of this study was to evaluate the protective efficacy of a novel recombinant subunit vaccine containing the protein YidR (rYidR) against clinical mastitis (CM) caused by Klebsiella spp. and Escherichia coli. Given that E. coli infection is known to cause metritis, we also evaluated the effect of rYidR vaccination on the incidence of metritis and conception at the first...
Sat, 02/13/2021 - 08:04
Bacillus cereus is an important food-borne pathogenic bacteria and a putrid microorganism in the dairy industry. Raw and pasteurized buffalo milk play important roles in the dairy market in southwestern China. However, the reports on the prevalence and characterization of B. cereus strains isolated from the above sources are lacking. In this study, 150 raw buffalo milk samples and 300 pasteurized...
Fri, 02/05/2021 - 08:02
Streptococcus agalactiae is a contagious pathogen that causes bovine mastitis worldwide, resulting in considerable economic losses. In this study, we isolated 42 S. agalactiae strains in 379 milk samples from cows with subclinical mastitis on 15 dairy farms in 12 Chinese provinces. Analysis based on capsular typing and multilocus sequence typing, combined with patterns of virulence gene scanning...
Thu, 01/28/2021 - 08:05
Listeria monocytogenes is an invasive foodborne pathogen that is ubiquitously present in the dairy farm environment. Although cattle are a reservoir of L. monocytogenes, most adult animals do not exhibit clinical symptoms, suggesting a homeostasis between this pathogen and the bovine gastrointestinal ecosystem. Nevertheless, substantial prevalence of L. monocytogenes fecal shedding by dairy...
Thu, 01/28/2021 - 08:05
The genus Staphylococcus is recognized worldwide as a cause of bacterial infections in humans and animals. Antibiotics used in dairy cattle combined with ineffective control can increase antimicrobial resistance. The objective of this study was to characterize 95 Staphylococcus strains isolated from organic and conventional Minas Frescal cheese production regarding antibiotic resistance (...
Thu, 12/24/2020 - 08:03
Staphylococcus aureus is one of the most common mastitis-causing bacteria in dairy cows. It is associated with reduced production performance in animals and with huge financial losses for the dairy industry worldwide. An accurate and sensitive method for the early diagnosis and identification of Staph. aureus in milk samples is essential. The present study aimed to establish a closed-tube...
Thu, 12/24/2020 - 08:03
Staphylococcus aureus is one of the most frequent pathogens causing intramammary infections in dairy herds. Consequently, virulence factors, pathobiology, and epidemiology of Staphylococcus aureus strains have been widely assessed through the years. Nevertheless, not much has been described about the epidemiology of Staph. aureus strains from bulk tank milk (BTM) and adherences on milking...
Thu, 12/24/2020 - 08:03
Staphylococcus aureus can elicit mild to more severe degrees of mastitis in cattle, depending on the response of the host's immune system and the virulence factors of the specific isolate. Several virulence factors are controlled by a global regulatory system, designated accessory gene regulator (agr). Thus, the objective was to examine associations between different capsular and agr types and...
Thu, 12/24/2020 - 08:03
Staphylococcus aureus is a widespread foodborne pathogen that threatens human health. In particular, multidrug-resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA) are emerging problems in modern health care, food safety, and animal health, which require the development of new antimicrobials to replace overused conventional antibiotics. Dairy products can potentially act...
Fri, 12/11/2020 - 08:01
Fresh unripened curd cheese has long been a well-known Eastern European artisanal dairy product; however, due to possible cross-contamination from manual production steps, high moisture content (50–60%), and metabolic activity of present lactic acid bacteria, the shelf life of curd cheese is short (10–20 d). Therefore, the aim of this study was to improve the shelf life of Eastern European acid-...
Fri, 12/11/2020 - 08:01
The objective of this prospective cohort study was to investigate the effect of bovine coronavirus (BCoV), bovine rotavirus (BRoV), and Cryptosporidium parvum on dairy calf health and performance and to determine the prevalence of these pathogens. A total of 198 male dairy calves housed at a grain-fed veal facility were examined from June 11, 2018, to October 9, 2018. Calves were fed milk...
Fri, 12/11/2020 - 08:01
Food loss and waste is a major concern in the United States and globally, with dairy foods representing one of the top categories of food lost and wasted. Estimates indicate that in the United States, approximately a quarter of dairy products are lost at the production level or wasted at the retail or consumer level annually. Premature microbial spoilage of dairy products, including fluid milk,...
Tue, 12/01/2020 - 08:02
In this study, a new vancomycin (Van)-modified poly-l-lysine (PLL) magnetic bead (MB) technique was developed for isolation of gram-positive bacteria. The method combines magnetic separation with a multiplex PCR (mPCR) assay and gel electrophoresis for easy and rapid detection of Bacillus cereus. Vancomycin was used as a molecular ligand between the MB and the d-alanyl-d-alanine moieties on the...
Wed, 11/25/2020 - 08:02
Klebsiella pneumoniae is an opportunistic and environmental mastitis-causing pathogen, with potential for contagious transmission. Repetitive element sequence-based PCR was used to determine genetic diversity and explore potential transmission and reservoirs for mastitis caused by K. pneumoniae on 2 large Chinese dairy farms. A total of 1,354 samples was collected from the 2 dairy farms,...
Wed, 11/25/2020 - 08:02
Rapid and sensitive detection technology is the key to preventing food-borne disease outbreaks. In this study, a low-field nuclear magnetic resonance (NMR) biosensor based on polyamidoamine dendrimers was prepared for the rapid detection of Salmonella in milk. The polyamidoamine dendrimer was biotinylated by amide reaction and chelated to diethylene triamine pentacetate acid and gadolinium to...
Thu, 11/12/2020 - 08:02
We conducted a longitudinal study to evaluate the effect of non-aureus staphylococci (NAS) causing subclinical intramammary infections (IMI) on quarter milk somatic cell count (qSCC) and quarter milk yield (qMY). In total, 324 quarters of 82 Holstein Friesian heifers were followed from calving to 130 d in milk (DIM) and were sampled 10 times each at 14-d intervals. The IMI status of each quarter...
Thu, 11/12/2020 - 08:02
Digital dermatitis is a bacterial infection that causes lesions above the heel bulbs on cattle hooves, and several bacterial species from the genus Treponema are suspected to be causative agents of this polymicrobial condition. Transmission of the bacteria to healthy cows is understudied, particularly with regard to potential insect vectors. Therefore, the objective of this research was to...
Thu, 11/12/2020 - 08:02
Our aim was to investigate the associations between management factors, compliance with current legislation, and herd-level calf mortality. In a national calf welfare audit, veterinary inspectors from the Norwegian Food Safety Authority assessed compliance with current legislation on calf welfare (n = 912 herds). Nine criteria were assessed and rated as satisfactory (1) or not satisfactory (0):...
Thu, 11/12/2020 - 08:02
While the increase in thermal resistance of microorganisms at reduced water activity is demonstrated for low-moisture food products, the effect of storage time on the thermal resistance of microorganisms in low-moisture foods is not well established. As low-moisture foods are stored for long periods and are used as ingredients, cross-contamination can occur at any time period before the lethality...
Fri, 11/06/2020 - 08:02
Nontuberculous mycobacteria (NTM) compose a group of mycobacteria that do not belong to the Mycobacterium tuberculosis complex group. They are frequently isolated from environmental samples such as water, soil, and, to a lesser extent, food samples. Isolates of NTM represent a major health threat to humans worldwide, especially those who have asthma or are immunocompromised. Human disease is...
Fri, 11/06/2020 - 08:02
We identified 199 Staphylococcus aureus isolates from quarter milk samples of 1,289 dairy cattle between 2014 and 2018. About 66% of the isolates were resistant to at least 1 antimicrobial agent; the highest rate of resistance was to penicillin, followed by resistance to ampicillin, erythromycin, and sulfadimethoxine. We obtained 30 methicillin-resistant S. aureus (MRSA) strains from 6 farms in 3...
Fri, 10/30/2020 - 08:01
Cheeses are able to serve as suitable matrices for supplying probiotics to consumers, enabling appropriate conditions for bacteria to survive gastric transit and reach the gut, where they are assumed to promote beneficial processes. The present study aimed to evaluate the microbiological, immunological, and histological changes in the gut of Salmonella Enteritidis-challenged rats fed goat cheese...
Fri, 10/23/2020 - 08:02
Little is known about the effects of commonly found levels of Fusarium mycotoxins on the performance, metabolism, and immunity of dairy cattle. We investigated the effects of regular contamination levels, meaning contamination levels that can be commonly detected in dairy feeds, of deoxynivalenol (DON) and fumonisins (FB) in total mixed ration (TMR) on the performance, diet digestibility, milk...

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