Combating Bovine Mastitis in the Dairy Sector in an Era of Antimicrobial Resistance: Ethno-veterinary Medicinal Option as a Viable Alternative Approach

Dietary anti-inflammatory and anti-bacterial medicinal plants and its compounds in bovine mastitis associated impact on human life

Bovine mastitis (BM) is the most common bacterial mediated inflammatory disease in the dairy cattle that causes huge economic loss to the dairy industry due to decreased milk quality and quantity. Milk is the essential food in the human diet, and rich in crucial nutrients that helps in lowering the risk of diseases like hypertension, cardiovascular diseases and type 2 diabetes. The main causative agents of the disease include various gram negative, and positive bacteria, along with other risk factors such as udder shape, age, genetic, and environmental factors also contributes much for the disease. Currently, antibiotics, immunotherapy, probiotics, dry cow, and lactation therapy are commonly recommended for BM. However, these treatments can only decrease the rise of new cases but can't eliminate the causative agents, and they also exhibit several limitations. Hence, there is an urgent need of a potential source that can generate a typical and ideal treatment to overcome the limitations and eliminate the pathogens. Among the various sources, medicinal plants and its derived products always play a significant role in drug discovery against several diseases. In addition, they are also known for its low toxicity and minimum resistance features. Therefore, plants and its compounds that possess anti-inflammatory and anti-bacterial properties can serve better in bovine mastitis. In addition, the plants that are serving as a food source and possessing pharmacological properties can act even better in bovine mastitis. Hence, in this evidence-based study, we particularly review the dietary medicinal plants and derived products that are proven for anti-inflammatory and anti-bacterial effects. Moreover, the role of each dietary plant and its compounds along with possible role in the management of bovine mastitis are delineated. In this way, this article serves as a standalone source for the researchers working in this area to help in the management of BM.

Slow pyrolysis of Terminalia catappa L. municipal solid waste and the use of the aqueous fraction produced for bovine mastitis control

The Terminalia catappa L. tree is an ornamental and shade tree producter of a large amount of biological waste sent to landfills. Therefore, this plant constitutes so-called municipal solid wood waste (MSWW), which causes undesirable impacts on the environment, such as the generation of methane through the action of microorganisms. Sustainable solutions for the proper use and disposal of MSWW are a topic that has assumed great relevance at present due to the high quantities of MSWW generated worldwide. Pyrolysis constitutes an attractive alternative for the sustainable use of MSWW to produce higher value-added products. This study investigated the slow pyrolysis of Terminalia catappa L. fruit and the use of the aqueous fraction produced for bovine mastitis control. We obtained four fractions from the pyrolysis process, with average yields of the aqueous phase (36.22 ± 2.0 %), bio-oil (5.52 ± 0.4 %), biochar (37.55 ± 2.8 %) and gas (20.71 ± 2.0 %). The aqueous fraction was extracted with organic solvents and analyzed by gas chromatography coupled to mass spectrometry (GC‒MS). The extracts were composed mainly of phenols (50 %), furan derivatives, cyclic ketones, and others with lower contents, such as alcohols and esters. The aqueous fraction had bactericidal activity against Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa and Escherichia coli, which are responsible for bovine mastitis. In addition, the fraction showed low cytotoxicity against a murine melanoma cell line from a C57BL/6J mouse, B16F10 cells and mouse peritoneal cells.

When the solution becomes the problem: a review on antimicrobial resistance in dairy cattle

Antibiotics' action, once a 'magic bullet', is now hindered by widespread microbial resistance, creating a global antimicrobial resistance (AMR) crisis. A primary driver of AMR is the selective pressure from antimicrobial use. Between 2000 and 2015, antibiotic consumption increased by 65%, reaching 34.8 billion tons, 73% of which was used in animals. In the dairy cattle sector, antibiotics are crucial for treating diseases like mastitis, posing risks to humans, animals and potentially leading to environmental contamination. To address AMR, strategies like selective dry cow therapy, alternative treatments (nanoparticles, phages) and waste management innovations are emerging. However, most solutions are in development, emphasizing the urgent need for further research to tackle AMR in dairy farms.

Antibacterial, Anti-Biofilm, and Anti-Inflammatory Properties of Gelatin-Chitosan-Moringa-Biopolymer-Based Wound Dressings towards Staphylococcus aureus and Escherichia coli

In contemporary times, the sustained aspiration of bioengineering and biomedical applications is the progressive advancement of materials characterized by biocompatibility and biodegradability. The investigation of the potential applications of polymers as natural and non-hazardous materials has placed significant emphasis on their physicochemical properties. Thus, this study was designed to investigate the potential of gelatin-chitosan-moringa leaf extract (G-CH-M) as a novel biomaterial for biomedical applications. The wound-dressing G-CH-M biopolymer was synthesized and characterized. The blood haemolysis, anti-inflammatory, antioxidant, and antibacterial activities of the biopolymer were investigated against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacterial isolates. Our results showed that S. aureus swarming motility was drastically affected. However, the biopolymer had no significant effect on the swarming motility of E. coli. In addition, the biopolymer showed high antibacterial capacities, especially against S. aureus. Plasmid DNA was observed to be effectively protected from oxidative stresses by the biopolymer. Furthermore, the biopolymer exhibited greatly suppressed haemolysis (lower than 2%), notwithstanding the elevated concentration of 50 mg/mL. These results indicated that this novel biopolymer formulation could be further developed for wound care and contamination prevention.

The mechanistic role of natural antimicrobials in preventing Staphylococcus aureus invasion of MAC-T cells using an in vitro mastitis model

BACKGROUND

Starting primarily as an inflammation of the mammary gland, mastitis is frequently driven by infectious agents such as Staphylococcus aureus. Mastitis has a large economic impact globally, which includes diagnostic, treatment, and the production costs not to mention the potential milk contamination with antimicrobial residues. Currently, mastitis prevention and cure depends on intramammary infusion of antimicrobials, yet, their overuse risks engendering resistant pathogens, posing further threats to livestock.

METHODS

In our study we aimed to investigate, in vitro, using bovine mammary epithelial cells (MAC-T), the efficacy of the AuraShield an antimicrobial mixture (As) in preventing S. aureus attachment, internalisation, and inflammation. The antimicrobial mixture (As) included: 5% maltodextrin, 1% sodium chloride, 42% citric acid, 18% sodium citrate, 10% silica, 12% malic acid, 9% citrus extract and 3% olive extract (w/w).

RESULTS AND DISCUSSION

Herein we show that As can significantly reduce both adherence and invasion of MAC-T cells by S. aureus, with no impact on cell viability at all concentrations tested (0.1, 0.2, 0.5, 1%) compared with untreated controls. The anti-apoptotic effect of As was achieved by significantly reducing cellular caspase 1, 3 and 8 activities in the infected MAC-T cells. All As concentrations were proven to be subinhibitory, suggesting that Ac can reduce S. aureus virulence without bacterial killing and that the effect could be dual including a host modulation effect. In this context, we show that As can reduce the expression of S. aureus clumping factor (ClfB) and block its interaction with the host Annexin A2 (AnxA2), resulting in decreased bacterial adherence in infection of MAC-T cells. Moreover, the ability of As to block AnxA2 had a significant decreasing effect on the levels of pro inflammatory cytokine released upon S. aureus interaction with MAC-T cells.

CONCLUSION

The results presented in this study indicate that mixtures of natural antimicrobials could potentially be considered an efficient alternative to antibiotics in treating S. aureus induced mastitis.

Host DNA depletion methods and genome-centric metagenomics of bovine hindmilk microbiome

Bovine mastitis is a multi-etiological and complex disease, resulting in serious economic consequences for dairy farmers and industry. In recent years, the microbiological evaluation of raw milk has been investigated in-depth using next-generation sequencing approaches such as metataxonomic analysis. Despite this, host DNA is a major concern in the shotgun metagenomic sequencing of microbial communities in milk samples, and it represents a big challenge. In this study, we aimed to evaluate different methods for host DNA depletion and/or microbial DNA enrichment and assess the use of PCR-based whole genome amplification in milk samples with high somatic cell count (SCC) by using short- and long-read sequencing technologies. Our results evidenced that DNA extraction performed differently in terms of host DNA removal, impacting metagenome composition and functional profiles.. Moreover, the ratio of SCC/bacteria ultimately impacts microbial DNA yield, and samples with low SCC (SCC below 100,000 cells/mL) are the most problematic. When milk samples with high SCC (SCC above 200,000 cells/mL) underwent multiple-displacement amplification (MDA), we successfully recovered high-quality metagenome-assembled genomes (MAGs), and long-read sequencing was feasible even for samples with low DNA concentration. By associating MDA and short-read sequencing, we recovered two times more MAGs than in untreated samples, and an ongoing co-infection not reported by traditional methods was detected for mastitis pathogen. Overall, this new approach will improve the detection of mastitis-associated microorganisms and make it possible to examine host-microbiome interactions in bovine mastitis.IMPORTANCENext-generation sequencing technologies have been widely used to gain new insights into the diversity of the microbial community of milk samples and dairy products for different purposes such as microbial safety, profiling of starter cultures, and host-microbiome interactions. Milk is a complex food matrix, and additionally, the presence of host nucleic acid sequences is considered a contaminant in untargeted high-throughput sequencing studies. Therefore, genomic-centric metagenomic studies of milk samples focusing on the health-disease status in dairy cattle are still scarce, which makes it difficult to evaluate the microbial ecophysiology of bovine hindmilk. This study provides an alternative method for genome-centric metagenome studies applied to hindmilk samples with high somatic cell content, which is indispensable to examining host-microbiome interactions in bovine mastitis.

Prevalence of virulence- and antibiotic resistance-associated genotypes and phenotypes in Staphylococcus aureus strains from the food sector compared to clinical and cow mastitis isolates

Background

Infections by the pathogen Staphylococcus aureus currently represent one of the most serious threats to human health worldwide, especially due to the production of enterotoxins and the ability to form biofilms. These structures and the acquisition of antibiotic resistance limit the action of antibiotics and disinfectants used to combat this microorganism in the industry and the clinic.

Methods

This work reports a comparative phenotypic and genotypic study of 18 S. aureus strains from different origins: clinical samples, milk from mastitic cows and food industry surfaces, most of which were isolated in Northern Spain.

Results

Genetically, the strains were very diverse but, in most cases, a closer proximity was observed for those from the same source. Notably, the average number of virulence genes was not significantly different in strains from the food sector. Of the 18 strains, 10 coded for at least one enterotoxin, and four of them carried 6 or 7 enterotoxin genes. The latter were all veterinary or clinical isolates. Most strains carried prophages, plasmids and/or pathogenicity islands. Regarding antibiotic resistance, although phenotypically all strains showed resistance to at least one antibiotic, resistance genes were only identified in 44.5% of strains, being mastitis isolates those with the lowest prevalence. Virulence-related phenotypic properties such as haemolytic activity, staphyloxanthin production, biofilm-forming capacity and spreading ability were widely distributed amongst the isolates.

Conclusions

Our results indicate that production of virulence factors, antibiotic resistance and biofilm formation can be found in S. aureus isolates from diverse environments, including the food industry, although some of these traits are more prevalent in strains isolated from infections in cows or humans. This emphasizes on the importance of monitoring the spread of these determinants not only in samples from the clinical environment, but also along the food chain, a strategy that falls under the prism of a one-health approach.

Basic concepts, recent advances, and future perspectives in the diagnosis of bovine mastitis

Mastitis is one of the most widespread infectious diseases that adversely affects the profitability of the dairy industry worldwide. Accurate diagnosis and identification of pathogens early to cull infected animals and minimize the spread of infection in herds is critical for improving treatment effects and dairy farm welfare. The major pathogens causing mastitis and pathogenesis are assessed first. The most recent and advanced strategies for detecting mastitis, including genomics and proteomics approaches, are then evaluated . Finally, the advantages and disadvantages of each technique, potential research directions, and future perspectives are reported. This review provides a theoretical basis to help veterinarians select the most sensitive, specific, and cost-effective approach for detecting bovine mastitis early.

Effect of intramammary lipopolysaccharide challenge after repeated intrauterine infusion of lipopolysaccharide on the inflammation status of goat mammary glands

Previous studies have shown that a single infusion of lipopolysaccharide (LPS) into the uterus induces mammary gland inflammation. However, repeated LPS infusions return the mammary glands to their basal state of inflammation. To confirm that this is a state of tolerance to LPS, we examined whether tolerance induced by repeated intrauterine LPS infusions limits mammary gland inflammation following subsequent intramammary LPS infusions. In the first experiment, three goats were treated with repeated intrauterine infusions of LPS dissolved in black ink for 5 consecutive days. Blood and milk samples were collected at 2, 4, 6, 12, 24, 48, 72, 96, and 120 h and smeared on glass slides to confirm the translocation of LPS from the uterus to the mammary gland. Black particles were detected in the blood and milk samples more than 2 h after the first infusion and in the connective tissue of the mammary gland after day 5. In the second experiment, goats were divided into two groups: an intrauterine infusion group (IU; n = 7) and a control group (CON; n = 6). The IU group received an intrauterine infusion of 100 μg of LPS in saline for 5 days. Subsequently, LPS was infused into the mammary glands of both groups to examine the effect of intrauterine treatment on the mammary inflammatory response after intramammary LPS infusion. Blood and milk samples were collected at 6, 12, and 24 h, and then daily until 7 d after the intramammary LPS challenge. Interestingly, a significant increase in the milk somatic cell count (SCC), IL-8, IL-1β, and TNF-α concentrations were observed in the CON group compared to the IU group. This suggests that pretreatment with repeated intrauterine infusions of LPS suppresses the inflammatory responses to subsequent intramammary LPS challenges.

Assessment of antibiotic use patterns in bovine mastitis treatment in the dairy sector in Serbia

The dairy sector is essential for the world's food systems, playing a vital role in agricultural production. Yet, mastitis, an inflammation of the mammary gland, affects a considerable portion of the dairy cow population annually, leading to reduced productivity and sustainability. Insight into therapeutic protocols is essential for a better understanding of the situation on farms with the aim of developing new or harmonizing existing protocols in the mastitis treatment. This study conducted on dairy farm in Serbia aimed to explore the most commonly used antibiotics during bovine mastitis treatment and their association with daily milk yield. Data from 100 lactating cows, including therapeutic protocols, lactation numbers, mastitis episodes, milk yield, and antibiotic usage, were obtained from a computerized database and statistically analysed. The results demonstrated a high prevalence of narrow-spectrum antibiotics usage, with the majority of cows treated with combination therapy. The route of antibiotic application did not significantly impact daily milk yield, while treatment duration had no discernible effect. Nonetheless, specific antibiotics were associated with milk yield variations, suggesting the need for careful antibiotic selection and management in mastitis therapy. These findings emphasize the importance of prudent antibiotic use to safeguard animal health and long-term milk production sustainability.

The use of a homeopathic preparation in the treatment of subclinical form of mastitis in cows

Background

Mastitis is a disease of productive cows, widespread throughout the world, and characterized by significant economic damage to the dairy industry. The subclinical form of this disease is aggravated by additional difficulties with its diagnosis and the lack of clear treatment protocols.

Aim

Therefore, the study of the effectiveness of diagnostic studies and the search for new methods of treatment of latent forms of mastitis is an important direction in scientific research in countries with developed dairy cattle breeding.

Methods

Studies conducted on the number of dairy cows of the production cooperative "Izhevsky" of the Akmola region of the Republic of Kazakhstan showed that when using rapid tests Kenotest, Somatest, Mastidine test, and Wideside test, the same results were obtained when the disease was detected in cows. The effectiveness of the tests was at the level of 60%-62% when using the settling sample as a control. Medical procedures were carried out using the Aquaton-2 microwave radiation apparatus and a homeopathic preparation. When using physiotherapy with microwave radiation, a decrease in the level of microbial contamination of milk from the treated part of the udder by 1.5-5 times was observed.

Results

Biologically active substances of plant origin in the homeopathic preparation, due to the immunostimulating effect, made it possible to increase the level of γ-globulins in the blood serum of sick animals during the application.

Conclusion

The complex use of both methods in the treatment of animals with a subclinical form of mastitis made it possible to reduce the level of somatic cells in the milk of the affected udder lobe to a level that cannot be determined using Kenotest in 4-6 days, which is 2-4 days faster than using these methods separately.

The Impact of Low-Level Benzalkonium Chloride Exposure on Staphylococcus spp. Strains and Control by Photoinactivation

Exposure of bacteria to low concentrations of biocides can facilitate horizontal gene transfer, which may lead to bacterial adaptive responses and resistance to antimicrobial agents. The emergence of antibacterial resistance not only poses a significant concern to the dairy industry but also adds to the complexity and cost of mastitis treatment. This study was aimed to evaluate how selective stress induced by benzalkonium chloride (BC) promotes antibiotic non-susceptibility in Staphylococcus spp. In addition, we investigated the efficacy of photodynamic inactivation (PDI) in both resistant and susceptible strains. The study determined the minimum inhibitory concentration (MIC) of BC using the broth microdilution method for different Staphylococcus strains. The experiments involved pairing strains carrying the qacA/qacC resistance genes with susceptible strains and exposing them to subinhibitory concentrations of BC for 72 h. The recovered isolates were tested for MIC BC and subjected to disc diffusion tests to assess changes in susceptibility patterns. The results demonstrated that subinhibitory concentrations of BC could select strains with reduced susceptibility and antibiotic resistance, particularly in the presence of S. pasteuri. The results of PDI mediated by toluidine blue (100 µM) followed by 60 min irradiation (total light dose of 2.5 J/cm2) were highly effective, showing complete inactivation for some bacterial strains and a reduction of up to 5 logs in others.

Comprehensive Approaches for the Search and Characterization of Staphylococcins

Novel and sustainable approaches are required to curb the increasing threat of antimicrobial resistance (AMR). Within the last decades, antimicrobial peptides, especially bacteriocins, have received increased attention and are being explored as suitable alternatives to antibiotics. Bacteriocins are ribosomally synthesized antimicrobial peptides produced by bacteria as a self-preservation method against competitors. Bacteriocins produced by Staphylococcus, also referred to as staphylococcins, have steadily shown great antimicrobial potential and are currently being considered promising candidates to mitigate the AMR menace. Moreover, several bacteriocin-producing Staphylococcus isolates of different species, especially coagulase-negative staphylococci (CoNS), have been described and are being targeted as a good alternative. This revision aims to help researchers in the search and characterization of staphylococcins, so we provide an up-to-date list of bacteriocin produced by Staphylococcus. Moreover, a universal nucleotide and amino acid-based phylogeny system of the well-characterized staphylococcins is proposed that could be of interest in the classification and search for these promising antimicrobials. Finally, we discuss the state of art of the staphylococcin applications and an overview of the emerging concerns.

Molecular epidemiology and characterization of antimicrobial-resistant Staphylococcus haemolyticus strains isolated from dairy cattle milk in Northwest, China

Introduction

Non-aureus Staphylococcus (NAS) species are currently the most commonly identified microbial agents causing sub-clinical infections of the udder and are also deemed as opportunistic pathogens of clinical mastitis in dairy cattle. More than 10 NAS species have been identified and studied but little is known about S. haemolyticus in accordance with dairy mastitis. The present study focused on the molecular epidemiology and genotypic characterization of S. haemolyticus isolated from dairy cattle milk in Northwest, China.

Methods

In this study, a total of 356 milk samples were collected from large dairy farms in three provinces in Northwest, China. The bacterial isolation and presumptive identification were done by microbiological and biochemical methods following the molecular confirmation by 16S rRNA gene sequencing. The antimicrobial susceptibility testing (AST) was done by Kirby-Bauer disk diffusion assay and antibiotic-resistance genes (ARGs) were identified by PCR. The phylogenetic grouping and sequence typing was done by Pulsed Field Gel Electrophoresis (PFGE) and Multi-Locus Sequence Typing (MLST) respectively.

Results

In total, 39/356 (11.0%) were identified as positive for S. haemolyticus. The overall prevalence of other Staphylococcus species was noted to be 39.6% (141/356), while the species distribution was as follows: S. aureus 14.9%, S. sciuri 10.4%, S. saprophyticus 7.6%, S. chromogenes 4.2%, S. simulans 1.4%, and S. epidermidis 1.1%. The antimicrobial susceptibility of 39 S. haemolyticus strains exhibited higher resistance to erythromycin (92.3%) followed by trimethoprim-sulfamethoxazole (51.3%), ciprofloxacin (43.6%), florfenicol (30.8%), cefoxitin (28.2%), and gentamicin (23.1%). All of the S. haemolyticus strains were susceptible to tetracycline, vancomycin, and linezolid. The overall percentage of multi-drug resistant (MDR) S. haemolyticus strains was noted to be 46.15% (18/39). Among ARGs, mphC was identified as predominant (82.05%), followed by ermB (33.33%), floR (30.77%), gyrA (30.77%), sul1 (28.21%), ermA (23.08%), aadD (12.82%), grlA (12.82%), aacA-aphD (10.26%), sul2 (10.26%), dfrA (7.69%), and dfrG (5.13%). The PFGE categorized 39 S. haemolyticus strains into A-H phylogenetic groups while the MLST categorized strains into eight STs with ST8 being the most predominant while other STs identified were ST3, ST11, ST22, ST32, ST19, ST16, and ST7.

Conclusion

These findings provided new insights into our understanding of the epidemiology and genetic characteristics of S. haemolyticus in dairy farms to inform interventions limiting the spread of AMR in dairy production.

Evaluation of Virulence, Antimicrobial Resistance and Biofilm Forming Potential of Methicillin-Resistant Staphylococcus aureus (MRSA) Isolates from Bovine Suspected with Mastitis

Methicillin-resistant Staphylococcus aureus (MRSA) is a pathogen that poses a significant threat in cases of chronic mastitis in dairy animals. The ability of MRSA to persist in the host is attributed to various virulence factors, genes encoding surface adhesins, and determinants of antibiotic resistance, which provide it a survival advantage. This investigation focused to determine the virulence factors, antimicrobial resistance (AMR) profile and biofilm production potential of 46 MRSA isolates from 300 bovine mastitis milk samples. The AMR profile revealed a high level of resistance, with 46 and 42 isolates resistant to cefoxitin and oxacillin, respectively, followed by 24 and 12 isolates resistant to lomefloxacin and erythromycin, respectively. Only 2 isolates resistant to tetracycline and none were resistant to chloramphenicol. The study also evaluated various virulence factors such as coa (n = 46), nuc (n = 35) hlg (n = 36), pvl (n = 14), tsst-1(n = 28) spa (n = 39) and enterotoxin genes sea (n = 12) and seg (n = 28) and identified antibiotic resistance determinants mecA and blaZ in 46 and 27 isolates, respectively. Intercellular adhesion genes icaA and icaD were present in 40 and 43 isolates, respectively and surface adhesion genes ebps, fnbpA, eno, sasG, cna, and bap were found in 43, 40, 38, 26, 21 and 1 isolates, respectively. Microtiter plate (MTP) assay revealed that 29 MRSA isolates were capable of producing biofilms, whereas 17 were not. Biofilms producing MRSA isolates possessed adhesion genes, virulence factors, toxin genes and AMR genes that may act synergistically towards a chronic disease progression, illness and severe damage to the udder, which generally last for several months and very challenging to cure.

Intramammary Ethno-Veterinary Formulation in Bovine Mastitis Treatment for Optimization of Antibiotic Use

Increasing pressure on animal and human health as well as food security, due to antimicrobial resistance, is leading to increased demand for natural-product-derived antibiotics worldwide. Considering the importance of bovine mastitis as well as the huge challenge posed by mastitis therapy in cattle production, the main goal of this research was to evaluate the effectiveness of the essential oil-based pharmaceutical (Phyto-Bomat), as an alternative to the existing treatment with antibiotics. The therapeutic response of the cows was monitored using clinical and bacteriological cure of the proposed formulation. Among 550 dairy cows, 75 were diagnosed with a clinical or subclinical form of mastitis and divided into three experimental groups: treated with antibiotic; Phyto-Bomat; antibiotic and Phyto-Bomat. Indicators of bacteriological cure were somatic cell count (SCC), total bacterial count, and causative agent isolation, while the clinical cure was accessed by observing physical udder conditions. All mentioned indicators were assessed before and after the treatment (1st and 7th day post-treatment), with all of the three therapeutic protocols. After Phyto-Bomat treatment, no visible signs of irritation were noticed, while no significant effect in reducing SCC and total bacterial count was observed. Phyto-Bomat has shown promising results in the treatment of mastitis, without the risk of udder irritation, alone or in combination with antibiotics as part of a mastitis control program during lactation.

Plant-derived nanoparticles as alternative therapy against Diarrheal pathogens in the era of antimicrobial resistance: A review

Diarrhea is a condition in which feces is discharged from the bowels frequently and in a liquid form. It is one of the frequent causes of morbidity and mortality in developing countries. The impact of Diarrhea is worsened by the increasing incidence of antimicrobial resistance among the causative agents, and this is now categorized as a global healthcare challenge. Antimicrobial resistance among Diarrheal pathogens also contributes to extended infection durations, and huge economic loss even in countries with advanced public health policies. The ever-increasing incidence of antimicrobial resistance including the contraindications arising from the administration of antibiotics in some Diarrheal cases highlights a crucial need for the development of novel non-antibiotic alternative agents for therapeutic and biocontrol applications. One such intervention includes the application of plant-derived nanoparticles (PDNPs) with novel antimicrobial properties. Given their small size and large surface area to volume ratio, PDNPs can attack target bacterial cell walls to generate reactive oxygen species that may simultaneously disrupt bacteria cell components such as DNA and proteins leading to cell damage or death. This potential can make it very difficult for pathogenic organisms to develop resistance against these antibacterial agents. In this review, we provide a critical overview on the antimicrobial resistance crisis among Diarrheagenic bacteria. We also discuss the evidence from the existing literature to support the potential associated with the use of PDNPs as alternative therapeutic agents for multidrug resistant and antibiotics administer contraindicated bacteria that are associated with Diarrhea.

Chemical Composition, Antimicrobial Activity, and Withdrawal Period of Essential Oil-Based Pharmaceutical Formulation in Bovine Mastitis Treatment

Due to the emergence of antibiotic-resistant bacteria, the risk it represents to public health, and the possible consequences for animal health and welfare, there is an increasing focus on reducing antimicrobial usage (AMU) in animal husbandry. Therefore, a great interest in developing alternatives to AMU in livestock production is present worldwide. Recently, essential oils (EOs) have gained great attention as promising possibilities for the replacement of antibiotics. The current study aimed to test the potential of using a novel EO-based pharmaceutical formulation (Phyto-Bomat) in bovine mastitis treatment. The antibacterial activity was performed using the microdilution technique. Lactating dairy cows were treated with 15 mL of Phyto-Bomat in the inflamed quarter for 5 consecutive days in order to analyze blood and milk samples for thymol and carvacrol residues using gas chromatography and mass spectrometry (GC-MS). Antimicrobial activity expressed as the minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) indicates that this formulation has the highest activity against Gram-positive strains. The dominant compounds in Phyto-Bomat were thymol and carvacrol, at 12.58 ± 1.23 mg/mL and 23.11 ± 2.31 mg/mL, respectively. The quantification of these two compounds in evaluated biological samples showed that 24 h after administration the concentration of thymol and carvacrol in milk samples was at the same level as before application. On the other hand, thymol and carvacrol were detectable in plasma samples even after 24 h post-treatment, with values ranging from 0.15-0.38 and 0.21-0.66 µg/mL, respectively. The tested formulation showed encouraging results of antibacterial activity against bovine mastitis pathogens, as well as the withdrawal period of dominant compounds, which implies that further testing regarding the bacteriological and clinical cure rates in clinical settings is needed.

Determination of antibiotic resistance and biofilm formation in Klebsiella strains isolated from bovine mastitis cases

Mastitis is diseases of dairy cows with a high economic impact. Bovine mastitis is caused by a wide range of bacterial pathogens. As one of the major environmental pathogens Klebsiella ssp. was investigated in this study by some phenotypic characteristics like antibiotic resistance patterns and biofilm formation properties. A number of 483 cows by dairy farms around the Konya were examined by California Mastitis Test (CMT) producing 36 positive in terms of subclinical mastitis. A further 19 samples from clinical mastitic udders were also collected. Samples were inoculated onto Trypticase Soy Agar medium enriched with sheep blood and incubated aerobicaly for 24-48 hours at 37 °C. By morphological, biochemical and cultural charcateristics 14 isolates out of 37 coliform were identified as Klebsiella ssp. The double disc synergy method and Congo Red Agar test were used to perform antibiotic susceptibility and in vitro slime forming properties, respectively. Resistances to the antibiotics Ampicillin, Carbenicillin, Cephotaxime, Chloramphenicol, Erythromycin, Gentamicin, Neomycin, Oxytetracycline, Sulphamethoxazole/Trimpethoprim, Amoxicillin-Clavulanate and Imipenem were 78.5%, 78.5%, 35.7%, 42.8%, 100%, 7%, 7%, 50%, 14%, 21% and 7%, respectively. Three of the total isolets produced biofilm only. This appears to the first report on ESBL producing Klebsiella ssp from subclinical cases of bovine mastitis in Konya, Türkiye. Presently, two numbers of antimicrobial combinations to treat bovine cases are recommended by this work. In conclusion, because of costly challange nature of Klebsiella caused bovine mastitis implemantation of an effective mastitis control program should be used in local farms from Konya.

Research progress on the association between mastitis and gastrointestinal microbes in dairy cows and the effect of probiotics

Mastitis in dairy cows affects milk quality and thereby constrains the development of the dairy industry. A clear understanding of the pathogenesis of mastitis can help its treatment. Mastitis is caused by the invasion of pathogenic bacteria into the mammary gland through the mammary ducts. However, recent studies suggested that an endogenous entero-mammary pathway in dairy cattle might also be playing an important role in regulating mastitis. Also, probiotic intervention regulating host gut microbes has become an interesting tool to control mastitis. This review discusses the association of gastrointestinal microbes with mastitis and the mechanism of action of probiotics in dairy cows to provide new ideas for the management of mastitis in large-scale dairy farms.

Application of Plant-Derived Nanoparticles (PDNP) in Food-Producing Animals as a Bio-Control Agent against Antimicrobial-Resistant Pathogens

Antibiotics are regularly used in animal husbandry to treat diseases. This practice is beneficial to animals’ health and helps ensure food security. However, the misuse of antibiotics, especially in food-producing animals, has resulted in the advent of antimicrobial resistance (AMR) and its dissemination among foodborne pathogens. The occurrence of AMR in bacteria pathogens that cause infections in animals and those associated with food spoilage is now considered a global health concern affecting humans, animals and the environment. The search for alternative antimicrobial agents has kindled the interest of many researchers. Among the alternatives, using plant-derived nanoparticles (PDNPs) for treating microbial dysfunctions in food-producing animals has gained significant attention. In traditional medicine, plant extracts are considered as safe, efficient and natural antibacterial agents for various animal diseases. Given the complexity of the AMR and concerns about issues at the interface of human health, animal health and the environment, it is important to emphasize the role of a One Health approach in addressing this problem. This review examines the potential of PDNPs as bio-control agents in food-producing animals, intending to provide consumers with microbiologically safe food while ensuring food safety and security, better health for animals and humans and a safe environment.

Prevalence of Bovine Mastitis and Its Associated Risk Factors among Dairy Cows in Ethiopia during 2005–2022: A Systematic Review and Meta-Analysis

Bovine mastitis remains a major prevalent disease in cattle and places a significant economic burden on the global dairy industry. The goal of this systematic review and meta-analysis was to examine the overall prevalence of mastitis and its associated risk factors among dairy cows. Scientific articles written in English were recovered from PubMed, ScienceDirect, Web of Science, Google Scholar, Cochrane Library, and other sources from Google Engine and University Library Databases. “Prevalence,” “bovine mastitis,” “clinical mastitis,” “subclinical mastitis,” “associated factors,” “dairy cows,” and “Ethiopia” were search terms used for this study. For critical appraisal, PRISMA 2009 was applied. Heterogeneity and publication bias were evaluated using Cochran's Q, inverse variance (I²), and funnel plot asymmetry tests. A random-effects model was used to calculate the pooled burden of mastitis and its associated factors among dairy cows, along with the parallel odds ratio (OR) and 95% confidence interval (CI). A total of 6438 dairy cows were included in the 17 eligible studies for this meta-analysis. The overall pooled prevalence of mastitis among dairy cows in Ethiopia was 43.60% (95% CI: 34.71, 52.49), of which 12.59% (95% CI: 7.18, 18.00) and 32.21% (95% CI: 24.68, 39.74) were clinical and subclinical cases, respectively. Of the regions, the highest and lowest pooled prevalence estimates of mastitis among dairy cows were 49.90% (95% CI: 31.77, 68.03) and 25.09% (95% CI: 3.86, 46.32) in the Oromia and Amhara regions, respectively. The highest pooled prevalence estimate in the study period was recorded between 2017 and 2022, with a pooled prevalence estimate of 46.83% (95% CI: 35.68, 57.97), followed by the study period from 2005 to 2016, with a pooled prevalence estimate of 39.97% (95% CI: 25.50, 54.44). Gram-positive bacteria (84.70%) were the most prevalent mastitis-causing agents compared with Gram-negative bacteria (15.30%). Breed (AOR: 2.17, 95% CI: 1.44, 2.90), lactation stage (AOR: 1.59, 95% CI: 1.04, 2.15), parity (AOR: 3.31, 95% CI: 1.69, 4.94), history of mastitis (AOR: 3.56, 95% CI: 2.40, 4.71), floor type (AOR: 1.59, 95% CI: −0.16, 3.34), and teat injury (AOR: 6.98, 95% CI: 0.33, 13.64) were factors significantly associated with mastitis among dairy cows in Ethiopia. Early diagnosis and proper medication, as well as implementing appropriate prevention and control measures, are necessary for the management of mastitis in dairy cows.

Environmental Bovine Mastitis Pathogens: Prevalence, Antimicrobial Susceptibility, and Sensitivity to Thymus vulgaris L., Thymus serpyllum L., and Origanum vulgare L. Essential Oils

Mastitis is considered to be one of the most important diseases of dairy cows in terms of health, production, and economy. Being the most common cause of antibiotic consumption in dairy cows, treatment of this disease is one of the biggest challenges in the veterinary profession as an increasing number of pathogens develop resistance to antibiotics used in the treatment. Therefore, new alternative approaches for limiting the use of antibiotics in livestock are required. For this reason, our study aimed to investigate prevalence of environmental mastitis associated bacterial strains, as well as the sensitivity of isolated strains to different antibiotics. Additionally, the therapeutic potential of three essential oils (EOs) was tested against bovine Serratia spp. and Proteus spp. mastitis pathogens, based on their chemical composition, as well as antibacterial potential. The study was carried out on 81 milk samples collected from dairy cows with mastitis. In order to determine prevalence of S. marcescens and P. mirabilis, microbiological isolation and identification were performed. Antimicrobial susceptibility testing was performed by disk diffusion method and the microdilution method was used to determine the antibacterial activity of selected EOs. In the oregano EO, a total of 23 compounds were detected, with carvacrol as a dominant component (78.94%). A total of 26 components were present in the EO of common thyme, where thymol was the most abundant compound (46.37%). Thymol also dominated (55.11%) the wild thyme EO. All tested EOs displayed antibacterial activity against all strains to different extents, while wild and common thyme EOs were the most effective. It could be concluded that the tested EOs represent promising therapeutic candidates for effective non-antibiotic treatment of mastitis.