Association of milk microbiome with bovine mastitis before and after antibiotic therapy.

Background and Aim: Mastitis is recognized as the most common disease in cattle and causes economic losses in the dairy industry. A number of opportunistic bacterial taxa have been identified as causative agents for this disease. Conventionally, antibiotics are used to treat mastitis; however, most bacteria are resistant to the majority of antibiotics. This study aimed to use molecular methods to identify milk microbiome patterns characteristic of mastitis that can help in the early diagnosis of this disease and in the development of new treatment strategies. Materials and Methods: To evaluate the microbiome composition, we performed NGS sequencing of the 16S rRNA gene of the V3 region. Results: An increase in the abundance of the bacterial genera Hymenobacter and Lachnospiraceae NK4A136 group is associated with the development of subclinical and clinical mastitis in dairy cows. These bacteria can be added to the list of markers used to detect mastitis in cows. Furthermore, a decrease in the abundance of Ralstonia, Lachnospiraceae NK3A20 group, Acetitomaculum, Massilia, and Atopostipes in cows with mastitis may indicate their role in maintaining a healthy milk microbiome. Antibiotics reduced the levels of Streptococcus in milk compared to those in the healthy group and cows before antibiotic treatment. Antibiotic therapy also contributed to an increase in the abundance of beneficial bacteria of the genus Asticcacaulis. Conclusion: This study expands our understanding of the association between milk microbiota and mastitis.

Changes in the Microbiome Profile in Different Parts of the Intestine in Piglets with Diarrhea.

Determining the taxonomic composition of microbial consortia of the piglet intestine is of great importance for pig production. However, knowledge on the variety of the intestinal microbiome in newborn piglets is limited. Piglet diarrhea is a serious gastrointestinal disease with a high morbidity and mortality that causes great economic damage to the pig industry. In this study, we investigated the microbiome of various sections of the piglet intestine and compared the microbiome composition of healthy and diarrheal piglets using high-throughput sequencing of the 16S rRNA gene. The results showed that bacteria of the Lactobacillus genus were the most common in the ileum, while Fusobacterium and Bacteroides dominated in the rectum. Comparing the microbiome composition of healthy and diarrheal piglets revealed a reduced number of Lactobacillus bacteria as a hallmark of diarrhea, as did an increased content of representatives of the Escherichia-Shigella genus and a reduced number of Bacteroides, which indicates the contribution of these bacteria to the development of diarrhea in piglets. The relative abundance of Enterococcus bacteria was higher in the diarrhea group. Although some bacteria of this genus are commensals, a small number of species may be associated with the development of diarrhea in piglets. Therefore, our results indicate that the gut microbiome may be an important factor in the development of diarrhea in piglets.

Action of Extracellular Proteases of Aspergillus flavus and Aspergillus ochraceus Micromycetes on Plasma Hemostasis Proteins.

In this study, we investigated the properties of proteolytic enzymes of two species of Aspergillus, Aspergillus flavus 1 (with a high degree of pathogenicity) and Aspergillus ochraceus L-1 (a conditional pathogen), and their effects on various components of the hemostasis system (in vitro) in the case of their penetration into the bloodstream. We showed that micromycete proteases were highly active in cleaving both globular (albuminolysis) and fibrillar (fibrin) proteins, and, to varying degrees, they could coagulate the plasma of humans and animals (due to proteolysis of factors of the blood coagulation cascade) but were not able to coagulate fibrinogen. The proteases of both Aspergillus fully hydrolyzed thrombi in 120-180 min. Micromycetes did not show hemolytic activity but were able to break down hemoglobin.

Role of microorganisms isolated from cows with mastitis in Moscow region in biofilm formation.

BACKGROUND AND AIM: Mastitis is one of the most important diseases of cows and the most expensive pathology for the dairy industry. Therefore, this study was conducted to explore the role of microorganisms isolated from cows with mastitis in the formation of biofilms under the conditions of farm biogeocenosis in the Moscow region. MATERIALS AND METHODS: Periodic visits to 12 farms in the Moscow region were conducted to explore the microbial profile of the udder of cows with mastitis. During the visits, 103 milk samples from sick animals were collected and examined. Through microbiological analyses, 486 cultures of microorganisms were identified, which are assigned to 11 genera. Mastitis in cows is caused not only by a single pathogen but also by microbial associations, which included two to seven microbial isolates. RESULTS: It was observed that 309 isolates (63.6%) from the total number of isolated microorganisms could form a biofilm. The ability to form biofilms was most frequently observed in Staphylococcus aureus (18.8%), Escherichia coli (11.9%), and Staphylococcus uberis (11.7%) cultures from the total number of biofilm-forming microbial cultures. Low biofilm-forming ability among the isolated microorganisms was found in lactobacilli, wherein only 20 (22.5%) Lactobacillus strains had the ability to form biofilms. The isolated microorganisms exhibited different sensitivities to antimicrobial agents, which cause difficulty in selecting an antimicrobial agent that would act on all aspects of the parasitocenosis. CONCLUSION: A high proportion of microorganisms isolated from cows with mastitis have the ability to form biofilms. The isolated microorganisms exhibited different and highly heterogeneous sensitivity to the action of antimicrobial drugs. This causes difficulty in using these tools for the effective control of mastitis in cows, which is frequently caused by pathogenic associations of microbial biofilms. Therefore, it is important to explore novel and more effective methods to combat this disease.

Use of nanoscale metals in poultry diet as a mineral feed additive.

The research was aimed at studying the efficiency of a nanoscale alloy of copper (Cu) and zinc (Zn) to be used as a mineral additive for feeding broiler chickens, compared to inorganic and organic forms of these elements. Biochemical studies of the blood serum were performed using an automated analyzer. The mineral composition was determined by atomic emission and mass spectrometry (MS-ISP). The study was performed on broiler chickens of cross Smena 7 (n = 72) in the conditions of a vivarium. There were 3 treatment groups with 24 chickens in each. Replacing the inorganic form of mineral supplements with the nanosized alloy resulted in a positive productive effect, with a tendency to increasing the content of serum protein. The nanoscale form of metals improved (P ≤ 0.05) the activity of aminotransferases. At the same time, the liver microstructure of experimental groups is similar to that of the control. There was a moderate plethora and poor polymorphoncellular infiltration around the interlobular triads with a clear morphological organization of the stromal and parenchymal components of the liver. However, the lack of oxidative stress was confirmed by the dynamics of catalase (CT), total superoxide dismutase (T-SOD) and malondialdehyde (MDA) levels, and the concentrations of which did not exceed the reference level. Replacing Cu and Zn sulfates with the nanoscale alloy (group 1) and organic form (group 2) of these elements in the diet of broiler chickens was accompanied by the increasing pool of these elements in the organisms at the end of the experiment. Copper was accumulated throughout the experiment in experimental group 1, compared to the reference, with the maximum difference in the liver of 36.5% (P ≤ 0.05), in the feathers 2.5 times (P ≤ 0.01). Assessment of the Zn level dynamics in the feathers revealed a well noticeable tendency to reducing its concentrations during the experiment in all groups. Against the background of feeding a nanoscale alloy, Zn concentration in the liver exceeded the reference by 66.8% (P ≤ 0.01) only at the end of the experiment. Thus, nanoscale forms of Cu and Zn have a cumulative effect, and may become an alternative to inorganic and organic forms of these elements in poultry nutrition.

Occurrence of BVDV Infection and the Presence of Potential Risk Factors in Dairy Cattle Herds in Poland.

The aim of the study was to analyze the risk factors of BVDV infection, in different regions of Poland, with respect to certain parameters of animal health, including productivity, herd management practices, the presence of BVDV, and the effect of non-vaccination. A total of 354 cattle herds were estimated and linked to the analysis of the different factors that might be correlated with productive results. The presence of antibodies against BVDV was found in 33.3% of examined herds, and the heterogenous distribution of BVDV-positive herds in all regions of Poland (p = 0.001) was confirmed. We found statistical correlations between BVDV infection and pasture (p = 0.004) and the number of grazing animals (p < 0.001), and also the purchase of animals for replacement (p = 0.004) was observed. Production or clear clinical outcomes potentially linked to BVDV infection in the herd have not been observed. The results of this study indicate that the rate of BVDV infection was most strongly correlated with the geographical location of the examined cattle populations in Poland. The second most significant factors were the grazing of animals and the purchasing of new animals to be introduced to herds. The strengthened procedures of management, as well as the implementation of eradication programs, should be considered in the examined herds.