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The Journal of Veterinary Medical... Jun 2024Phytochemicals isolated from essential oils are effective alternatives for inhibiting microbial pathogens. Bovine protothecal mastitis is the cause of a reduction in...
Phytochemicals isolated from essential oils are effective alternatives for inhibiting microbial pathogens. Bovine protothecal mastitis is the cause of a reduction in milk production and the secretion of thin, watery milk with white flakes. In the present study, we performed in vitro susceptibility testing of the phytochemicals carvacrol, citral, and thymol in Prototheca strains isolated from cases of protothecosis in small animals and cow feces. The susceptibility of the algae to carvacrol, citral, and thymol was assessed using the modified CLSI M27-A3 broth microdilution method. The ranges of the minimum inhibitory concentrations (MIC%) of the phytochemicals in all isolates were 0.03% to 0.125% for carvacrol, 0.03% to 0.25% for citral, and 0.06% to 0.25% for thymol. Based on these results, carvacrol, citral, and thymol appear effective against Prototheca species at the tested concentrations, and may thus be useful for environmental disinfection in barns.
PubMed: 38925982
DOI: 10.1292/jvms.24-0032 -
Animal Science Journal = Nihon Chikusan... 2024We hypothesized that teats with a teat apex score (TAS) of 4 on a 4-point scale would exhibit elevated levels of denatured collagen compared with teats with lower TAS....
We hypothesized that teats with a teat apex score (TAS) of 4 on a 4-point scale would exhibit elevated levels of denatured collagen compared with teats with lower TAS. We procured keratin layer and smooth muscle samples from Holsteins with TAS ranging from 1 to 4, as well as from crossbred heifers (Japanese Black male and Holstein female) with TAS of 1. Teats with a TAS of 4 demonstrated increased total collagen content, higher amounts of type I collagen (the harder, thicker variant), and reduced amounts of type III collagen (the softer, thinner variant) compared with teats with lower TAS. Teats with TAS of 3 and 4 exhibited evidence of damaged collagen in smooth muscle layers compared with teats with TAS of 1. Additionally, we identified 47-kDa heat shock protein-positive fibroblasts in the smooth muscles of teats with TAS of 3 and 4. Therefore, the smooth muscle of teats with a TAS of 4 exhibited increased amounts of denatured collagen in comparison to teats with lower TAS.
Topics: Animals; Cattle; Female; Muscle, Smooth; Collagen; Keratins; Mammary Glands, Animal; Protein Denaturation; Male; Collagen Type I; Fibroblasts; Collagen Type III
PubMed: 38923230
DOI: 10.1111/asj.13969 -
Veterinary Sciences Jun 2024Traditionally, non- staphylococci and mammaliicocci (NASM) were not considered significant players in bovine mastitis. This study investigated the involvement of NASM (...
Traditionally, non- staphylococci and mammaliicocci (NASM) were not considered significant players in bovine mastitis. This study investigated the involvement of NASM ( and ) and lactic acid bacteria (LAB) strains () through bovine neutrophil responses. Bovine neutrophils displayed minimal apoptosis upon NASM and LAB challenge. Neutrophils expressed high TLR2 after challenge, but TLR6 expression varied and remained low in NASM pathogen recognition. Bovine neutrophils effectively engulfed and killed LAB, but their activity was significantly impaired against NASM. This was evident in , where reduced TLR6 recognition and a weakened phagocytic response likely contributed to a lower bactericidal effect. Regardless of the bacteria encountered, intracellular ROS production remained high. -challenged neutrophils displayed upregulation in genes for pathogen recognition (TLRs), ROS production, and both pro- and anti-apoptotic pathways. This response mirrored that of . except for and , suggesting these bacteria have divergent roles in triggering cell death. Our findings suggest that manipulates bovine neutrophil defenses through coordinated changes in functional responses and gene expression, while LAB strains have a weaker influence on apoptosis.
PubMed: 38922009
DOI: 10.3390/vetsci11060262 -
Veterinary Sciences May 2024Bovine mastitis is an important and costly disease to dairy cattle. Diagnostic methods usually performed in Brazil are somatic cell counts (SCC) and milk microbiology....
Bovine mastitis is an important and costly disease to dairy cattle. Diagnostic methods usually performed in Brazil are somatic cell counts (SCC) and milk microbiology. Low bacteria shedding in milk implies no colony growth in microbiological tests and false negative results. and are principal pathogens of mixed mastitis. However, has a higher bacterial release from the mammary gland than , affecting microbiological sensitivity to diagnose . This study aimed to estimate the SCC and total bacterial count (TBC) from cows according to pathogen isolated in milk and to evaluate variation in diagnosis by a microbiological test during treatment, which is called blitz therapy. Both and presented high SCC means, although showed shedding of bacteria 2.3 times greater than . Microbiological sensitivity to increased for 5 months during treatment. The prevalence of fell after 5 months of therapeutic procedures. The prevalence of increased to 39.0. The results showed that due to high sensitivity, the polymerase chain reaction (PCR) could be used at the beginning of blitz therapy with the goal of eradication from the dairy herd.
PubMed: 38921980
DOI: 10.3390/vetsci11060233 -
Pathogens (Basel, Switzerland) Jun 2024is an important zoonotic pathogen capable of causing foodborne illness and bovine mastitis. Bacteriophages have been increasingly considered a promising tool to control...
is an important zoonotic pathogen capable of causing foodborne illness and bovine mastitis. Bacteriophages have been increasingly considered a promising tool to control unwanted bacteria. The aim of this study is to determine the antibiotic resistance profile of isolated from raw milk and the efficacy of phage in controlling multidrug-resistant in raw milk. Antibiotic susceptibility testing showed the highest resistance rates of isolates to co-trime (27.34%) and ampicillin (27.34%), followed by streptomycin (25.18%), tetracycline (23.02%), and the lowest resistance rates to ciprofloxacin, gentamycin, and ceftazidime, all at a rate of 2.16%. All isolates were susceptible to meropenem. Of the 139 isolates, 57 (41.01%) were resistant to at least one antibiotic, and 35 (25.18%) were classified as MDR strains. Molecular characterization indicated that 5 (3.6%) out of the 139 isolates were STEC strains carrying gene. Seven (5.04%) isolates were phenotypically identified as ESBLEC, and four isolates (2.88%) were resistant to colistin. The results of the genotypic test revealed that four out of seven ESBLEC strains carried both and , two harbored , and one possessed , while was detected in all four colistin-resistant isolates. In particular, one isolated strain (EM148) was determined to be a multidrug-resistant strain simultaneously carrying , , and . A total of eight phages were successfully recovered from raw milk. The application of phage PEM3 significantly reduced viable counts of multidrug-resistant host EM148 in raw milk by at least 2.31 log CFU/mL at both 24 °C and 4 °C.
PubMed: 38921792
DOI: 10.3390/pathogens13060494 -
Pathogens (Basel, Switzerland) May 2024() is a major human pathogen and can cause a wide range of diseases, including pneumonia, osteomyelitis, skin and soft tissue infections (SSTIs), endocarditis,... (Review)
Review
() is a major human pathogen and can cause a wide range of diseases, including pneumonia, osteomyelitis, skin and soft tissue infections (SSTIs), endocarditis, mastitis, bacteremia, and so forth. Rats have been widely used in the field of infectious diseases due to their unique advantages, and the models of infections have played a pivotal role in elucidating their pathogenic mechanisms and the effectiveness of therapeutic agents. This review outlined the current application of rat models in infections and future prospects for rat models in infectious diseases caused by .
PubMed: 38921732
DOI: 10.3390/pathogens13060434 -
MSphere Jun 2024Hematophagous (stable) fly populations in dairy barns are sustained by a constant availability of cattle hosts and manure, which serve as major reservoirs of both...
UNLABELLED
Hematophagous (stable) fly populations in dairy barns are sustained by a constant availability of cattle hosts and manure, which serve as major reservoirs of both zoonotic and opportunistic bacterial pathogens. However, the composition of the fly microbiota, the mechanisms by which flies acquire their microbiome, and the ability of potentially pathogenic bacteria to colonize and persist in fly hosts remain to be investigated. Here, we longitudinally collected fly and manure samples from two connected dairy facilities. High throughput 16S rRNA gene amplicon sequencing was then used to characterize and compare bacterial communities present on or within flies and in manure collected from the same facility, while culture-dependent methods were used to verify the viability of clinically relevant bacteria. Bacterial alpha diversity was overall higher in manure samples as compared to fly samples, with manure-associated bacterial communities being dominated by members of the Bacteroidales, Eubacteriales, and Oscillospirales. In contrast, flies harbored relatively low-complexity communities dominated by members of the Enterobacterales, Staphylococcales, and Lactobacillales. Clinically relevant bacterial strains, including spp. and other taxa associated with mastitic cows housed in the same facilities, were detected in paired fly and manure samples but exhibited dramatically elevated abundances in fly samples as compared to manure samples. Viable colonies of , , and spp. were also readily isolated from fly samples, confirming that flies harbor culturable mastitis-associated bacteria. This study identifies biting flies as bona fide carriers of opportunistically pathogenic bacterial taxa on dairy farms.
IMPORTANCE
Disease prevention on dairy farms has significant implications for cattle health, food security, and zoonosis. Of particular importance is the control of bovine mastitis, which can be caused by diverse bacteria, including , , , and spp. Despite being one of the most significant and costly cattle diseases worldwide, the epidemiology of bovine mastitis is not well understood. This study provides parallel culture-independent and culture-dependent evidence to support the carriage of opportunistically pathogenic bacteria by flies on dairy farms. We further show that the fly microbiota is enriched in clinically relevant taxa-the vast majority of which can be traced to the manure habitats in which flies breed. Altogether, our results identify biting flies as underrecognized carriers of bacterial taxa associated with environmental bovine mastitis and other opportunistic infections in vertebrates and offer important insights into mechanisms of microbial acquisition by these and other medically important insects.
PubMed: 38920390
DOI: 10.1128/msphere.00336-24 -
BMC Veterinary Research Jun 2024Acinetobacter lwoffii (A. lwoffii) is a Gram-negative bacteria common in the environment, and it is the normal flora in human respiratory and digestive tracts. The...
BACKGROUND
Acinetobacter lwoffii (A. lwoffii) is a Gram-negative bacteria common in the environment, and it is the normal flora in human respiratory and digestive tracts. The bacteria is a zoonotic and opportunistic pathogen that causes various infections, including nosocomial infections. The aim of this study was to identify A. lwoffii strains isolated from bovine milk with subclinical mastitis in China and get a better understanding of its antimicrobial susceptibility and resistance profile. This is the first study to analyze the drug resistance spectrum and corresponding mechanisms of A. lwoffii isolated in raw milk.
RESULTS
Four A. lwoffii strains were isolated by PCR method. Genetic evolution analysis using the neighbor-joining method showed that the four strains had a high homology with Acinetobacter lwoffii. The strains were resistant to several antibiotics and carried 17 drug-resistance genes across them. Specifically, among 23 antibiotics, the strains were completely susceptible to 6 antibiotics, including doxycycline, erythromycin, polymyxin, clindamycin, imipenem, and meropenem. In addition, the strains showed variable resistance patterns. A total of 17 resistance genes, including plasmid-mediated resistance genes, were detected across the four strains. These genes mediated resistance to 5 classes of antimicrobials, including beta-lactam, aminoglycosides, fluoroquinolones, tetracycline, sulfonamides, and chloramphenicol.
CONCLUSION
These findings indicated that multi-drug resistant Acinetobacter lwoffii strains exist in raw milk of bovine with subclinical mastitis. Acinetobacter lwoffii are widespread in natural environmental samples, including water, soil, bathtub, soap box, skin, pharynx, conjunctiva, saliva, gastrointestinal tract, and vaginal secretions. The strains carry resistance genes in mobile genetic elements to enhance the spread of these genes. Therefore, more attention should be paid to epidemiological surveillance and drug resistant A. lwoffii.
Topics: Animals; Cattle; Mastitis, Bovine; Female; Acinetobacter; Milk; China; Anti-Bacterial Agents; Microbial Sensitivity Tests; Acinetobacter Infections; Drug Resistance, Bacterial; Drug Resistance, Multiple, Bacterial
PubMed: 38918815
DOI: 10.1186/s12917-024-04119-3 -
Critical Reviews in Microbiology Jun 2024Bovine mastitis is a mammary gland inflammation that can occur due to infectious pathogens, and , which are, respectively, the most prevalent Gram-positive and... (Review)
Review
Bovine mastitis is a mammary gland inflammation that can occur due to infectious pathogens, and , which are, respectively, the most prevalent Gram-positive and Gram-negative bacteria associated with this disease. Currently, antibiotic treatment has become more complicated due to the presence of resistant pathogens. This review, therefore, aims to identify the most common resistance genes reported for these strains in the last four years. During the review, it was noted that , , and are the most reported genes for and associated with drug inactivation, mainly β-lactamases. They are characterized by generating bacterial resistance to β-lactam antibiotics, the most common treatment in animal and human bacterial treatments (penicillins and cephalosporins, among others). Genes associated with efflux systems were also present in the two strains and included , and , which generate resistance to macrolide and tetracycline antibiotics. Additionally, the effects of spreading resistance between animals and humans through direct contact (such as consumption of contaminated milk) or indirect contact (through environmental contamination) has been deeply discussed, emphasizing the importance of having adequate sanitation and antibiotic control and administration protocols.
PubMed: 38916977
DOI: 10.1080/1040841X.2024.2369140 -
Scientific Reports Jun 2024Mastitis is considered one of the most widespread infectious disease of cattle and buffaloes, affecting dairy herds. The current study aimed to characterize the...
Mastitis is considered one of the most widespread infectious disease of cattle and buffaloes, affecting dairy herds. The current study aimed to characterize the Staphylococcus aureus isolates recovered from subclinical mastitis animals in Pothohar region of the country. A total of 278 milk samples from 17 different dairy farms around two districts of the Pothohar region, Islamabad and Rawalpindi, were collected and screened for sub clinical mastitis using California Mastitis Test. Positive milk samples were processed for isolation of Staphylococcus aureus using mannitol salt agar. The recovered isolates were analyzed for their antimicrobial susceptibility and virulence genes using disc diffusion and PCR respectively. 62.2% samples were positive for subclinical mastitis and in total 70 Staphylococcus aureus isolates were recovered. 21% of these isolates were determined to be methicillin resistant, carrying the mecA gene. S. aureus isolates recovered during the study were resistant to all first line therapeutic antibiotics and in total 52% isolates were multidrug resistant. SCCmec typing revealed MRSA SCCmec types IV and V, indicating potential community-acquired MRSA (CA-MRSA) transmission. Virulence profiling revealed high prevalence of key genes associated with adhesion, toxin production, and immune evasion, such as hla, hlb, clfA, clfB and cap5. Furthermore, the Panton-Valentine leukocidin (PVL) toxin, that is often associated with recurrent skin and soft tissue infections, was present in 5.7% of isolates. In conclusion, the increased prevalence of MRSA in bovine mastitis is highlighted by this study, which also reveals a variety of virulence factors in S. aureus and emphasizes the significance of appropriate antibiotic therapy in combating this economically burdensome disease.
Topics: Animals; Cattle; Mastitis, Bovine; Female; Staphylococcal Infections; Pakistan; Virulence; Anti-Bacterial Agents; Staphylococcus aureus; Methicillin-Resistant Staphylococcus aureus; Virulence Factors; Microbial Sensitivity Tests; Milk; Bacterial Proteins
PubMed: 38914650
DOI: 10.1038/s41598-024-65448-9