Antibiotics in Dairy Production: Where Is the Problem?

Antibiotics have long been used for the prevention and treatment of common diseases and for prophylactic purposes in dairy animals. However, in recent decades it has become a matter of concern due to the widespread belief that there has been an abuse or misuse of these drugs in animals and that this misuse has led to the presence of residues in derived foods, such as milk and dairy products. Therefore, this review aims to compile the scientific literature published to date on the presence of antibiotic residues in these products worldwide. The focus is on the reasons that lead to their presence in food, on the potential problems caused by residues in the characteristics of dairy products and in their manufacturing process, on the development and spread of antibiotic-resistant bacteria, and on the effects that both residues and resistant bacteria can cause on human and environmental health.he research group was funded by The University of the Basque Country (UPV/EHU) (grant COLAB20/14) and by the Basque Government, grant to Research Groups number IT944-16. G. Santamarina-García received a predoctoral grant from the University of the Basque Country

Characterization of Microbial Shifts during the Production and Ripening of Raw Ewe Milk-Derived Idiazabal Cheese by High-Throughput Sequencing

first_page settings Open AccessArticle Characterization of Microbial Shifts during the Production and Ripening of Raw Ewe Milk-Derived Idiazabal Cheese by High-Throughput Sequencing by Gorka Santamarina-García * [ORCID] , Igor Hernández [ORCID] , Gustavo Amores [ORCID] and Mailo Virto * [ORCID] Lactiker Research Group, Department of Biochemistry and Molecular Biology, Faculty of Pharmacy, University of the Basque Country (UPV/EHU), Paseo de la Universidad 7, 01006 Vitoria-Gasteiz, Spain * Authors to whom correspondence should be addressed. Academic Editor: Huizhong Chen Biology 2022, 11(5), 769; https://doi.org/10.3390/biology11050769 Received: 13 April 2022 / Revised: 5 May 2022 / Accepted: 11 May 2022 / Published: 18 May 2022 Download PDF Browse Figures Citation Export Simple Summary Idiazabal is a traditional cheese produced from raw ewe milk in the Basque Country (Southwestern Europe). The sensory properties of raw milk cheeses have been attributed, among other factors, to microbial shifts that occur during the production and ripening processes. In this study, we used high-throughput sequencing technologies to investigate the microbiota of Latxa ewe raw milk and the dynamics during cheese production and ripening processes. The microbiota of raw milk was composed of lactic acid bacteria (LAB), environmental bacteria and non-desirable bacteria. Throughout the cheese making and ripening processes, the growth of LAB was promoted, whereas that of non-desirable and environmental bacteria was inhibited. Moreover, some genera not reported previously in raw ewe milk were detected and clear differences were observed in the bacterial composition of raw milk and cheese among producers, in relation to LAB and environmental or non-desirable bacteria, some of which could be attributed to the production of flavour related compounds. Abstract In this study, we used high-throughput sequencing technologies (sequencing of V3–V4 hypervariable regions of 16S rRNA gene) to investigate for the first time the microbiota of Latxa ewe raw milk and the bacterial shifts that occur during the production and ripening of Idiazabal cheese. Results revealed several bacterial genera not reported previously in raw ewe milk and cheese, such as Buttiauxella and Obesumbacterium. Both the cheese making and ripening processes had a significant impact on bacterial communities. Overall, the growth of lactic acid bacteria (LAB) (Lactococcus, Lactobacillus, Leuconostoc, Enterococcus, Streptococcus and Carnobacterium) was promoted, whereas that of non-desirable and environmental bacteria was inhibited (such as Pseudomonas and Clostridium). However, considerable differences were observed among producers. It is noteworthy that the starter LAB (Lactococcus) predominated up to 30 or 60 days of ripening and then, the growth of non-starter LAB (Lactobacillus, Leuconostoc, Enterococcus and Streptococcus) was promoted. Moreover, in some cases, bacteria related to the production of volatile compounds (such as Hafnia, Brevibacterium and Psychrobacter) also showed notable abundance during the first few weeks of ripening. Overall, the results of this study enhance our understanding of microbial shifts that occur during the production and ripening of a raw ewe milk-derived cheese (Idiazabal), and could indicate that the practices adopted by producers have a great impact on the microbiota and final quality of this cheese.This research was funded by the Basque Government, grant to Research Groups number IT944-16. G. Santamarina-García received a predoctoral grant from the University of the Basque Country (UPV/EHU)

Intsektuak, etorkizuneko elikadura?

By 2050, a population growth of 2,000 million people is expected. Taking into account the environmental impacts of current food production and the increase in the quantities of food to be obtained, the need for new alternatives increases. In 2018, insects have been accepted in Europe as new foods and although they are little studied resources, it has been suggested that they may be the key to the food of the future. Therefore, the main objective of this work is to identify the different types of insects that can serve as food, analyse them and reflect and delve into the aspects of safety and nutrition. Insects are an interesting source of nutrients, as they are rich in high-quality proteins and polyunsaturated fatty acids. Moreover, they are an attractive source to meet the needs of minerals such as iron, magnesium or zinc, and vitamins such as those of group A or B. Disease prevention and health promotion by bioactive antioxidant, antihypertensive or antimicrobial peptides from insects are also noteworthy. Technologically, they contain compounds with interesting functional characteristics for the food industry, such as gelling proteins. However, food safety requires great control to protect consumer health due to the presence of biological risks, such as pathogenic microorganisms, toxins or heat-resistant spores, and chemicals, such as heavy metals, antinutrients, pesticides or dioxins. In any case, further research is fundamental due to the diversity of non-investigated species, as well as the scarcity of data on nutrition and safety aspects; 2050. urterako 2.000 milioi biztanleko demografia-hazkuntza aurreikusten da. Elikagaien gaur egungo ekoizpenaren ingurumen-inpaktuek eta lortu behar diren elikagaien kantitateen igoerek alternatiba berrien beharrak areagotzen dituzte. 2018. urtean intsektuak elikagai berri gisa onartu dira Europan eta, nahiz eta gutxi ikerturiko baliabidea izan, etorkizuneko elikaduraren giltza izan daitekeela iradoki da. Horrenbestez, lan honen helburu nagusia izango da elikagai gisa onartu diren intsektu motak identifikatzea, aztertzea eta kaltegabetasun eta nutrizio alderdiei buruz hausnartzea eta sakontzea. Intsektuak nutrienteen iturri interesgarria dira, kalitate altuko proteinetan eta gantz-azido poliasegabeetan aberatsak direlako. Gainera, mineralen (esaterako, burdina, magnesioa edo zinka) eta bitaminen (A edo B taldekoak, adibidez) beharrak asetzeko iturri erakargarria dira. Era berean, aipatzekoak dira gaixotasunak ekiditeari eta osasuna sustatzeari begira, intsektuen peptido bioaktibo antioxidatzaileengatik, antihipertentsiboengatik edo antimikrobianoengatik. Teknologikoki, elikagaien industriarako ezaugarri funtzional interesgarriak dituzten konposatuak dituzte; esaterako, proteina gelifikatzaileak. Hala ere, elikagaien kaltegabetasunak kontrol handia eskatzen du kontsumitzailearen osasuna babesteko, intsektuetan aurkitzen direlako, era berean, arrisku biologikoak (mikroorganismo patogenoak, toxinak edo espora termoerresistenteak, adibidez) eta kimikoak (metal astunak, antinutrienteak, plagizidak edo dioxinak, esaterako). Nolanahi ere, funtsezkoa da ikerketan sakontzea, ikertu gabeko espezieen aniztasunagatik, bai eta nutrizioaren eta kaltegabetasunaren arloko datuen urritasunagatik

Relationship between the Dynamics of Gross Composition, Free Fatty Acids and Biogenic Amines, and Microbial Shifts during the Ripening of Raw Ewe Milk-Derived Idiazabal Cheese

This study reports for the first time the relationship between bacterial succession, characterized by high-throughput sequencing (sequencing of V3–V4 16S rRNA regions), and the evolution of gross composition, free fatty acids (FFAs) and biogenic amines (BAs) during cheese ripening. Specifically, Idiazabal PDO cheese, a raw ewe milk-derived semi-hard o hard cheese, was analysed. Altogether, 8 gross parameters were monitored (pH, dry matter, protein, fat, Ca, Mg, P and NaCl) and 21 FFAs and 8 BAs were detected. The ripening time influenced the concentration of most physico-chemical parameters, whereas the producer mainly affected the gross composition and FFAs. Through an O2PLS approach, the non-starter lactic acid bacteria Lactobacillus, Enterococcus and Streptococcus were reported as positively related to the evolution of gross composition and FFAs release, while only Lactobacillus was positively related to BAs production. Several environmental or non-desirable bacteria showed negative correlations, which could indicate the negative impact of gross composition on their growth, the antimicrobial effect of FFAs and/or the metabolic use of FFAs by these genera, and their ability to degrade BAs. Nonetheless, Obesumbacterium and Chromohalobacter were positively associated with the synthesis of FFAs and BAs, respectively. This research work provides novel information that may contribute to the understanding of possible functional relationships between bacterial communities and the evolution of several cheese quality and safety parameters.This research was funded by the Basque Government, grant number IT944-16. G. Santamarina-García received a predoctoral grant from the University of the Basque Country (UPV/EHU)

Normal-Fat vs. High-Fat Diets and Olive Oil vs. CLA-Rich Dairy Fat: A Comparative Study of Their Effects on Atherosclerosis in Male Golden Syrian Hamsters

The relationship between milk fat intake (because of its high saturated fatty acid content) and the risk of suffering from cardiovascular diseases remains controversial. Thus, Golden Syrian hamsters were fed two types of fat—sheep milk fat that was rich in rumenic (cis9,trans11-18:2) and vaccenic (trans11-18:1) acids and olive oil—and two doses (a high- or normal-fat diet) for 14 weeks, and markers of lipid metabolism and atherosclerosis evolution were analyzed. The results revealed that the type and percentage of fat affected most plasma biochemical parameters related to lipid metabolism, while only the expression of five (CD36, SR-B1, ACAT, LDLR, and HMG-CoAR) of the studied lipid-metabolism-related genes was affected by these factors. According to aortic histology, when ingested in excess, both fats caused a similar increase in the thickness of fatty streaks, but the high-milk-fat-based diet caused a more atherogenic plasma profile. The compositions of the fats that were used, the results that were obtained, and the scientific literature indicated that the rumenic acid present in milk fat would regulate the expression of genes involved in ROS generation and, thus, protect against LDL oxidation, causing an effect similar to that of olive oil.This research was funded by the Basque Government (Grant to Research Groups IT944-16). A.B. and G.S.-G. received a research grant from the University of the Basque Country (calls 2009 and 2019, respectively)

Relationship between the dynamics of volatile aroma compounds and microbial succession during the ripening of raw ewe milk-derived Idiazabal cheese

Cheese microbiota contributes to various biochemical processes that lead to the formation of volatile compounds and the development of flavour during ripening. Nonetheless, the role of these microorganisms in volatile aroma compounds production is little understood. This work reports for the first time the dynamics and odour impact of volatile compounds, and their relationship to microbial shifts during the ripening of a raw ewe milk-derived cheese (Idiazabal). By means of SPME-GC-MS, 81 volatile compounds were identified, among which acids predominated, followed by esters, ketones and alcohols. The ripening time influenced the abundance of most volatile compounds, thus the moments of greatest abundance were determined (such as 30–60 days for acids). Through Odour Impact Ratio (OIR) values, esters and acids were reported as the predominant odour-active chemical families, while individually, ethyl hexanoate, ethyl 3-methyl butanoate, ethyl butanoate, butanoic acid or 3-methyl butanal were notable odorants, which would provide fruity, rancid, cheesy or malt odour notes. Using a bidirectional orthogonal partial least squares (O2PLS) approach with Spearman's correlations, 12 bacterial genera were reported as key bacteria for the volatile and aromatic composition of Idiazabal cheese, namely Psychrobacter, Enterococcus, Brevibacterium, Streptococcus, Leuconostoc, Chromohalobacter, Chryseobacterium, Carnobacterium, Lactococcus, Obesumbacterium, Stenotrophomonas and Flavobacterium. Non-starter lactic acid bacteria (NSLAB) were highly related to the formation of certain acids, esters and alcohols, such as 3-hexenoic acid, ethyl butanoate or 1-butanol. On the other hand, the starter LAB (SLAB) was related to particular ketones production, specifically 3-hydroxy-2-butanone; and environmental and/or non-desirable bacteria to certain ketones, hydrocarbons and sulphur compounds formation, such as 2-propanone, t-3-octene and dimethyl sulphone. Additionally, the SLAB Lactococcus and Psychrobacter, Brevibacterium and Chromohalobacter were described as having a negative effect on aroma development caused by NSLAB and vice versa. These results provide novel knowledge to help understand the aroma formation in a raw ewe milk-derived cheese

Cross-sectional, commercial testing, and chromatographic study of the occurrence of antibiotic residues throughout an artisanal raw milk cheese production chain

This study investigated antibiotic utilization in artisanal dairies and residue occurrence throughout the raw milk cheese production chain using commercial testing (Charm KIS and Eclipse Farm3G) and UHPLC-QqQ-MS/MS and LC-QqQ-MS/MS. The cross-sectional survey results revealed gaps in the producers’ knowledge of antibiotic use. Commercial testing detected antibiotic levels close to the LOD in 12.5 % of the samples, mainly in raw milk and whey, with 10.0 % testing positive, specifically in fresh and ripened cheeses, indicating that antibiotics are concentrated during cheese-making. Chromatographically, several antibiotics were identified in the faeces of healthy animals, with chlortetracycline (15.7 ± 34.5 µg/kg) and sulfamethazine (7.69 ± 16.5 µg/kg) predominating. However, only tylosin was identified in raw milk (3.28 ± 7.44 µg/kg) and whey (2.91 ± 6.55 µg/kg), and none were found in fresh or ripened cheeses. The discrepancy between commercial and analytical approaches is attributed to compounds or metabolites not covered chromatographically.G. Santamarina-García thanks the University of the Basque Country (UPV/EHU) for a predoctoral fellowship. The authors are grateful for the collaboration of Idiazabal PDO producers and the technical support provided by the Instituto Lactológico de Lekunberri (Lekunberri, Navarre), the Department of Analytical Chemistry, and the Research Centre for Experimental Marine Biology and Biotechnology (PIE) of the University of the Basque Country (Plentzia, Biscay)

Phenotypic and genotypic characterization of antimicrobial resistances reveals the effect of the production chain in reducing resistant lactic acid bacteria in an artisanal raw ewe milk PDO cheese

Antimicrobial resistance (AMR) is a significant public health threat, with the food production chain, and, specifically, fermented products, as a potential vehicle for dissemination. However, information about dairy products, especially raw ewe milk cheeses, is limited. The present study analysed, for the first time, the occurrence of AMRs related to lactic acid bacteria (LAB) along a raw ewe milk cheese production chain for the most common antimicrobial agents used on farms (dihydrostreptomycin, benzylpenicillin, amoxicillin and polymyxin B). More than 200 LAB isolates were obtained and identified by Sanger sequencing (V1-V3 16S rRNA regions); these isolates included 8 LAB genera and 21 species. Significant differences in LAB composition were observed throughout the production chain (P ≤ 0.001), with Enterococcus (e.g., E. hirae and E. faecalis) and Bacillus (e.g., B. thuringiensis and B. cereus) predominating in ovine faeces and raw ewe milk, respectively, along with Lactococcus (L. lactis) in whey and fresh cheeses, while Lactobacillus and Lacticaseibacillus species (e.g., Lactobacillus sp. and L. paracasei) prevailed in ripened cheeses. Phenotypically, by broth microdilution, Lactococcus, Enterococcus and Bacillus species presented the greatest resistance rates (on average, 78.2 %, 56.8 % and 53.4 %, respectively), specifically against polymyxin B, and were more susceptible to dihydrostreptomycin. Conversely, Lacticaseibacillus and Lactobacillus were more susceptible to all antimicrobials tested (31.4 % and 39.1 %, respectively). Thus, resistance patterns and multidrug resistance were reduced along the production chain (P ≤ 0.05). Genotypically, through HT-qPCR, 31 antimicrobial resistance genes (ARGs) and 6 mobile genetic elements (MGEs) were detected, predominating Str, StrB and aadA-01, related to aminoglycoside resistance, and the transposons tnpA-02 and tnpA-01. In general, a significant reduction in ARGs and MGEs abundances was also observed throughout the production chain (P ≤ 0.001). The current findings indicate that LAB dynamics throughout the raw ewe milk cheese production chain facilitated a reduction in AMRs, which has not been reported to date.This work was supported by the University of the Basque Country [grant number COLAB20/14], the Basque Government [grant number IT1568-22] and the MCIN/AEI/10.13039/501100011033 [grant number PID2020-113395RB-C21]. G. Santamarina-García thanks the University of the Basque Country (UPV/EHU) for a predoctoral fellowship. The authors are grateful for the collaboration of Idiazabal PDO producers, the technical and human support provided by SGIker (UPV/EHU/ERDF, EU) and the assistance of L. Azcona during sample preparation and analysis. Open Access funding provided by University of Basque Country