-
Veterinary Microbiology Jul 2024Non-aureus staphylococci (NAS) are an essential group of bacteria causing antimicrobial resistant intramammary infections in livestock, particularly dairy cows....
Non-aureus staphylococci (NAS) are an essential group of bacteria causing antimicrobial resistant intramammary infections in livestock, particularly dairy cows. Therefore, bacteriophages emerge as a potent bactericidal agent for NAS mastitis. This study aimed to obtain NAS-specific bacteriophages using bacterial strains isolated from cows with mastitis, subsequently evaluating their morphological, genomic, and lytic characteristics. Four distinct NAS bacteriophages were recovered from sewage or the environment of Chinese dairy farms; PT1-1, PT94, and PT1-9 were isolated using Staphylococcus chromogenes and PT1-4 using Staphylococcus gallinarum. Both PT1-1 (24/54, 44 %) and PT94 (28/54, 52 %) had broader lysis than PT1-4 (3/54, 6 %) and PT1-9 (10/54, 19 %), but PT1-4 and PT1-9 achieved cross-species lysis. All bacteriophages had a short latency period and good environmental tolerance, including surviving at pH=4-10 and at 30-60℃. Except for PT1-9, all bacteriophages had excellent bactericidal efficacy within 5 h of co-culture with host bacteria in vitro at various multiplicity of infection (MOIs). Based on whole genome sequencing, average nucleotide identity (ANI) analysis of PT1-1 and PT94 can be classified as the same species, consistent with whole-genome synteny analysis. Although motifs shared by the 4 bacteriophages differed little from those of other bacteriophages, a phylogenetic tree based on functional proteins indicated their novelty. Moreover, based on whole genome comparisons, we inferred that cross-species lysis of bacteriophage may be related to the presence of "phage tail fiber." In conclusion 4 novel NAS bacteriophages were isolated; they had good biological properties and unique genomes, with potential for NAS mastitis therapy.
Topics: Sewage; Animals; Staphylococcus; Cattle; Female; Mastitis, Bovine; Genome, Viral; Staphylococcus Phages; Bacteriophages; Staphylococcal Infections; Phylogeny; Genomics; Whole Genome Sequencing
PubMed: 38820726
DOI: 10.1016/j.vetmic.2024.110133 -
PloS One 2024Retrospective evaluation of udder recovery following treatment of the inflamed quarter with acoustic pulse technology (APT) of cows with subclinical mastitis was done on...
Retrospective evaluation of udder recovery of cows with subclinical mastitis following treatment with acoustic pulse technology (APT) on commercial dairy farms and its economic impact.
Retrospective evaluation of udder recovery following treatment of the inflamed quarter with acoustic pulse technology (APT) of cows with subclinical mastitis was done on 4 Israeli commercial dairy farms. Here, we evaluated the APT treatment as a tool to manage subclinical mastitis and its economic consequences in commercial farms. Recovery of the infected glands following APT treatment was compared to the customary no-treatment (NT) for cows with subclinical mastitis. Over 2 years, 467 cows with subclinical mastitis were identified. Subclinical mastitis was defined by elevated somatic cell count (SCC; >1 × 106 cells/mL) in the monthly test-day milk sample; 222 cows were treated with APT and 245 cows were not treated and served as control. Differences between treatment groups in culling, milk quality, milk yield and bacterial elimination were analyzed. After treatment, cure from bacteria was calculated only for cows with pre-isolated bacteria. The percentage of sampled cows determined as cured (no bacterial finding) in the NT group was 32.7% (35/107) (30.9% Gram negative; 32.4% Gram positive) and in the APT-treated group, 83.9% (42/55) (89.4% Gram negative; 80.6% Gram positive). Culling rate due to mastitis was significantly lower (>90%) in the APT-treated vs. NT group. Recovery was 66.0% in the APT group compared to 11.5% in the NT group at 90 d post-treatment. Average milk volume per cow in the APT-treated group was 16.1% higher compared to NT cows. Based on the study, savings incurred by using APT to treat only subclinical cows per 100-cow herd can total $15,106/y, or $309 per treated subclinically infected cow.
Topics: Animals; Cattle; Mastitis, Bovine; Female; Retrospective Studies; Dairying; Mammary Glands, Animal; Milk; Farms; Israel
PubMed: 38820257
DOI: 10.1371/journal.pone.0303947 -
BMC Genomics May 2024Maedi-visna virus (MVV) is a lentivirus that infects monocyte/macrophage lineage cells in sheep, goats, and wild ruminants and causes pneumonia, mastitis, arthritis, and...
BACKGROUND
Maedi-visna virus (MVV) is a lentivirus that infects monocyte/macrophage lineage cells in sheep, goats, and wild ruminants and causes pneumonia, mastitis, arthritis, and encephalitis. The immune response to MVV infection is complex, and a complete understanding of its infection and pathogenesis is lacking. This study investigated the in vivo transcriptomic patterns of lung tissues in sheep exposed to MVV using the RNA sequencing technology.
RESULT
The results indicated that 2,739 genes were significantly differentially expressed, with 1,643 downregulated genes and 1,096 upregulated genes. Many variables that could be unique to MVV infections were discovered. Gene Ontology analysis revealed that a significant proportion of genes was enriched in terms directly related to the immune system and biological responses to viral infections. Kyoto Encyclopedia of Genes and Genomes analysis revealed that the most enriched pathways were related to virus-host cell interactions and inflammatory responses. Numerous immune-related genes, including those encoding several cytokines and interferon regulatory factors, were identified in the protein-protein interaction network of differentially expressed genes (DEGs). The expression of DEGs was evaluated using real-time polymerase chain reaction and western blot analysis. CXCL13, CXCL6, CXCL11, CCR1, CXCL8, CXCL9, CXCL10, TNFSF8, TNFRSF8, IL7R, IFN-γ, CCL2, and MMP9 were upregulated. Immunohistochemical analysis was performed to identify the types of immune cells that infiltrated MVV-infected tissues. B cells, CD4 and CD8 T cells, and macrophages were the most prevalent immune cells correlated with MVV infection in the lungs.
CONCLUSION
Overall, the findings of this study provide a comprehensive understanding of the in vivo host response to MVV infection and offer new perspectives on the gene regulatory networks that underlie pathogenesis in natural hosts.
Topics: Animals; Visna-maedi virus; Lung; Sheep; Gene Expression Profiling; Transcriptome; Pneumonia, Progressive Interstitial, of Sheep; Protein Interaction Maps; Gene Expression Regulation; Gene Ontology
PubMed: 38816794
DOI: 10.1186/s12864-024-10448-2 -
Italian Journal of Food Safety May 2024Cost-effective methods are crucial in small-scale operations to assess the physicochemical properties of milk, identify potential clinical or subclinical mastitis, and...
Cost-effective methods are crucial in small-scale operations to assess the physicochemical properties of milk, identify potential clinical or subclinical mastitis, and test β-lactams in small ruminants. The aim was to evaluate the importance of physicochemical characteristics, somatic cells, and antibacterial substances as factors for monitoring the quality and safety of bulk tank milk from sheep and goats. Furthermore, we aimed to elucidate the influence of grazing capacity on the composition of sheep milk. The fat content of sheep milk (n=119) was found to be 7.7%, with a range of 5.3% to 9.9%. The average fat content of dairy goats (n=33) was found to be 4.9%, with a range of 2.8-6.7%. The results indicate that 2.8% of sheep milk samples and 7.8% of goat milk samples exhibited clear positive reactions when assessed using the California mastitis test. β-lactam antibiotics were present in 0.7% of sheep milk samples, but not in any of the goat milk samples using lateral flow strips. This measurement method can be useful to detect adulterated milk and better understand the quality and safety of small ruminant milk before processing.
PubMed: 38807741
DOI: 10.4081/ijfs.2024.12122 -
Animal Nutrition (Zhongguo Xu Mu Shou... Jun 2024Mastitis affects almost all mammals including humans and dairy cows. In the dairy industry, bovine mastitis is a disease with a persistently high incidence, causing... (Review)
Review
Mastitis affects almost all mammals including humans and dairy cows. In the dairy industry, bovine mastitis is a disease with a persistently high incidence, causing serious losses to the health of cows, the quality of dairy products, and the economy of dairy farms. Although local udder infection caused by the invasion of exogenous pathogens into the mammary gland was considered the main cause of mastitis, evidence has been established and continues to grow, showing that nutrition factors and gastrointestinal microbiome (GM) as well as their metabolites are also involved in the development of mammary inflammatory response. Suboptimal nutrition is recognized as a risk factor for increased susceptibility to mastitis in cattle, in particular the negative energy balance. The majority of data regarding nutrition and bovine mastitis involves micronutrients. In addition, the dysbiotic GM can directly trigger or aggravate mastitis through entero-mammary gland pathway. The decreased beneficial commensal bacteria, lowered bacterial diversity, and increased pathogens as well as proinflammatory metabolites are found in both the milk and gastrointestinal tract of mastitic dairy cows. This review discussed the relationship between the nutrition (energy and micronutrient levels) and mastitis, summarized the role of GM and metabolites in regulating mastitis. Meanwhile, several non-antibiotics strategies were provided for the prevention and alleviation of mastitis, including micronutrients, probiotics, short-chain fatty acids, high-fiber diet, inulin, and aryl hydrocarbon receptor.
PubMed: 38800734
DOI: 10.1016/j.aninu.2024.01.010 -
Infection and Drug Resistance 2024The present study was designed to investigate the resistance determinants and virulence factors of 45 isolates from clinical bovine mastitis in Hexi Corridor of Gansu,...
PURPOSE
The present study was designed to investigate the resistance determinants and virulence factors of 45 isolates from clinical bovine mastitis in Hexi Corridor of Gansu, China.
METHODS
Minimum inhibitory concentrations (MICs) was tested by E-test method. Gene of antimicrobial resistance, virulence integrase and integron gene cassettes were determined by PCR and DNA sequencing.
RESULTS
The T. pyogenes isolates exhibited high resistance to streptomycin (88.9%) and tetracycline (64.4%), followed by erythromycin (15.6%) and gentamicin (13.3%). Resistance to streptomycin was most commonly encoded by (88.9%); and to tetracycline, by (64.4%). Importantly, all streptomycin-resistant isolates carried alone or in combination with and . Similarly, all tetracycline-resistant isolates harbored alone or in combination with . Meanwhile, was detected in 13.3% isolates, only one erythromycin-resistant isolate was not identified for this gene. Moreover, all isolates carried class 1 integrons, and 17.8% of them contained gene cassettes, including arrays (4.4%), aad (2.2%) and (2.2%). Furthermore, all tested isolates harbored virulent genes and , followed by (88.9%), (86.6%) (75.6%), (40.0%), (35.6%) and (6.7%).
CONCLUSION
To our knowledge, this is the first report of integron gene cassettes of T. pyogenes isolates from bovine mastitis cases in China. These findings are useful for developing the prevention and the virulence factors of could be promising candidates for vaccine antigens for bovine mastitis caused by in China.
PubMed: 38800580
DOI: 10.2147/IDR.S433578 -
Veterinary World Apr 2024Milk, a nutritious food, is widely consumed in human diets; however, contamination by micro-organisms can negatively impact its quality and consumer health....
BACKGROUND AND AIM
Milk, a nutritious food, is widely consumed in human diets; however, contamination by micro-organisms can negatively impact its quality and consumer health. Contamination by micro-organisms affects the quality of milk, which can affect the quality of the milk production chain. This study aimed to determine the changes in milk composition and antibiotic susceptibility related to bacteria isolated from dairy cow milk.
MATERIALS AND METHODS
Raw milk samples were collected from 72 dairy cows. All milk samples were subjected to the California Mastitis Test (CMT) for CMT score determination. We also investigated milk composition, bacterial culture (BC), and antibiotic susceptibility.
RESULTS
About 47.22% and 30.56% of dairy cattle were positive for CMT + BC and automatic somatic cell count (ASCC) + BC, respectively. Fecal appearance and animal age were found to be risk factors for ASCC + BC positivity in dairy cattle. Bacteria were found in approximately 76% of milk samples, with the most common isolated species being α-hemolytic spp., coagulase-negative spp., and . Of these, 70% are resistant to at least one antibiotic. Variation in the multidrug resistance pattern was high in spp.
CONCLUSIONS
Fecal appearance and animal age are risk factors for ASCC + BC positivity in dairy cattle. This study identified antibiotic and multidrug resistance patterns, which require comprehensive studies and effective surveillance systems. Remarkably, the use of antibiotic therapy in dairy cattle should be monitored.
PubMed: 38798280
DOI: 10.14202/vetworld.2024.735-743 -
Animal : An International Journal of... Jun 2024Health traits have high economic values in dairy cattle breeding, which can cause considerable financial loss through involuntary culling. In this study, fourteen health...
Health traits have high economic values in dairy cattle breeding, which can cause considerable financial loss through involuntary culling. In this study, fourteen health traits were analysed, including five composite health traits: reproductive disorders, udder health (UH), digestive disorders, metabolic disorders, locomotory diseases (LD), and nine independent health traits: gestation disorders and peripartum disorders, irregular estrus cycle and sterility, metritis (ME), mastitis (MA), abomasal displacement (AD), enteritis (EN), and ketosis, claw diseases (CD), laminitis complex. This study analysed variance components for health traits through both single and bivariate repeatability animal models. All health traits showed low heritability, ranging from 0.001 to 0.025. Most of the health traits in five categories showed negative genetic correlations, ranging from -0.012 (CD and EN) to -0.634 (ME and EN). Strong positive genetic correlations appeared within the same category, ranging from 0.469 (EN and AD) to 0.994 (UH and MA, LD and CD). Furthermore, approximate genetic correlations were evaluated between health traits and routinely collected traits (longevity, fertility, production, and conformation). In general, the low to moderate approximate genetic correlations were estimated between health traits and routinely collected traits. The estimated correlations between health traits and longevity, fertility, production, and conformation traits could provide an indirect reference for disease-resistance breeding in Holstein cattle.
Topics: Animals; Cattle; Female; Longevity; Fertility; Cattle Diseases; Breeding; Phenotype; Quantitative Trait, Heritable; Dairying
PubMed: 38797058
DOI: 10.1016/j.animal.2024.101177 -
Journal of Global Antimicrobial... May 2024The emergence of antimicrobial-resistant and mastitis-associated Enterococcus faecalis and Enterococcus faecium is of great concern due to the huge economic losses...
Draft genome sequences of clinical mastitis-associated Enterococcus faecalis and Enterococcus faecium carrying multiple antimicrobial resistance genes isolated from dairy cows.
OBJECTIVES
The emergence of antimicrobial-resistant and mastitis-associated Enterococcus faecalis and Enterococcus faecium is of great concern due to the huge economic losses associated with enterococcal infections. Here we report the draft genome sequences of E. faecalis and E. faecium strains that were isolated from raw milk samples obtained from mastitis-infected cows in Bangladesh.
METHODS
The two strains were isolated, identified, and genomic DNA was sequenced using the Illumina NextSeq 550 platform. The assembled contigs were analysed for virulence, antimicrobial resistance genes, and multilocus sequence type. The genomes were compared to previously reported E. faecalis and E. faecium genomes to generate core genome phylogenetic trees.
RESULTS
E. faecalis strain BR-MHR218Efa and E. faecium strain BR-MHR268Efe belonged to multilocus sequence types ST-190 and ST-22, respectively, both of which appear to represent relatively rare sequence types. BR-MHR268Efe harboured only one antibiotic resistance gene encoding resistance towards macrolides (lsa(A)), while BR-MHR218Efa harboured ten different antibiotic resistance genes encoding resistance to aminoglycosides (ant[6]-Ia, aph(3')-III), sulphonamides (aac(6')-II), lincosamides (lnu(B)), macrolides (erm(B)), MLSB antibiotics (msr(C)), tetracyclines (tet(M), tet(L)), trimethoprim (dfrG), and pleuromutilin-lincosamide-streptogramin A (lsa(E)). Virulence gene composition was different between the two isolates. BR-MHR218Efa harboured only two virulence genes involved in adherence (acm and scm). BR-MHR268Efe harboured eight complete virulence operons including three operons involved in adherence (Ace, Ebp pili, and EfaA), two operons involved in biofilm formation (BopD and Fsr), and three exoenzymes (gelatinase, hyaluronidase, SprE).
CONCLUSIONS
The genome sequences of the strains BR-MHR268Efe and BR-MHR218Efa will serve as a reference point for molecular epidemiological studies of mastitis-associated E. faecalis and E. faecium. Additionally, the findings will help understand the complex antimicrobial-resistance in livestock-assoiated Enterococci.
PubMed: 38795772
DOI: 10.1016/j.jgar.2024.05.011 -
Animals : An Open Access Journal From... May 2024We evaluated the relationship between decreased pregnancy-associated glycoprotein (PAG) levels, inflammatory parameters (serum amyloid A [SAA] and milk amyloid A [MAA]),...
We evaluated the relationship between decreased pregnancy-associated glycoprotein (PAG) levels, inflammatory parameters (serum amyloid A [SAA] and milk amyloid A [MAA]), postpartum inflammatory conditions (mastitis, ketosis, and follicular cysts), and the gene. Nineteen Holstein-Friesian cows were included in this study. Up to approximately eight weeks after delivery, weekly health examinations were performed for mastitis and ketosis, and reproductive organ ultrasonography was performed. The decreasing PAG rate was negatively correlated with SAA concentration ( = -0.493, = 0.032). Cows with mastitis exhibited a slower trend of PAG decrease ( = 0.095), and a greater percentage of these cows had MAA concentrations above 12 µg/mL ( = 0.074) compared with those without mastitis. A negative correlation, although nonsignificant ( = -0.263, = 0.385), was observed between the day-open period and decreased PAG rate. The day-open period was correlated with the presence or absence of follicular cysts ( = 0.046). Four cows that developed follicular cysts were homozygous for the G allele of the gene related to repeat breeders. These results indicate a relationship between a decreased PAG rate and inflammatory status during the postpartum period. Thus, suppressing inflammation during the perinatal period may improve reproductive efficiency in the dairy industry.
PubMed: 38791678
DOI: 10.3390/ani14101459