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Journal of Dairy Science Nov 2023Staphylococcus chromogenes and Staphylococcus simulans are commonly found in intramammary infections (IMI) associated with bovine subclinical mastitis, but little is...
Staphylococcus chromogenes and Staphylococcus simulans are commonly found in intramammary infections (IMI) associated with bovine subclinical mastitis, but little is known about genotypic variation and relatedness within species. This includes knowledge about genes encoding antimicrobial resistance (AMR) and potential virulence factors (pVF). The aim of this study was therefore to investigate these aspects by whole-genome sequencing of milk isolates from Swedish dairy cows with subclinical mastitis in an observational study. We also wanted to study if specific genotypes were associated with persistent IMI and the inflammatory response at udder quarter level. In total, 105 and 118 isolates of S. chromogenes and S. simulans, respectively, were included. Isolates were characterized using a 7-locus multilocus sequence typing (7-MLST), core genome analysis and in-silico analysis of AMR and pVF genes. Forty-seven sequence types (ST) and 7 core genome clusters of S. chromogenes were identified, and the most common ST were ST-6 and ST-109, both belonging to cluster VII. A 7-locus MLST scheme for S. simulans was not available, but 3 core genome clusters and 5 subclusters were described. Overall, substantial variation in ST and clusters among cows and herds were found in both species. Some ST of S. chromogenes were found in several herds, indicating spread between herds. Moreover, within-herd spread of the same genotype was observed for both species. Only a few AMR genes [blaZ, strpS194, vga(A)] were detected in a limited number of isolates, with the exception of blaZ coding for β-lactamase, which was identified in 22% of the isolates of S. chromogenes with ST-19, ST-102, and ST-103 more commonly carrying this gene compared with other ST. However, the blaZ gene was not identified in S. simulans. The average total number of pVF detected per isolate was similar in S. chromogenes (n = 30) and S. simulans (n = 33), but some variation in total numbers and presence of specific pVF or functional groups of pVF, was shown between ST/clusters within species. Differences in inflammatory response and potentially in persistent IMI at udder quarter level were found between S. chromogenes subtypes but not between S. simulans subtypes. In conclusion, the results from the present study generates new insight into the epidemiology of bovine S. chromogenes and S. simulans IMI, which can have implications for future prevention and antimicrobial treatment of infections related to these species.
PubMed: 37641317
DOI: 10.3168/jds.2023-23523 -
Probiotics and Antimicrobial Proteins Aug 2023Bacteriocins are antimicrobial peptides produced by bacteria. This study aimed to in silico analyze the presence of bacteriocin gene clusters (BGCs) among the genomes of...
Bacteriocins are antimicrobial peptides produced by bacteria. This study aimed to in silico analyze the presence of bacteriocin gene clusters (BGCs) among the genomes of 22 commensal Staphylococcus isolates from different origins (environment/human/food/pet/wild animals) previously identified as bacteriocin producers. The resistome and plasmidome were studied in all isolates. Five types of BGC were detected in 18 genomes of the 22 bacteriocin-producing staphylococci included in this study: class I (Lanthipeptides), class II, circular bacteriocins, the non-ribosomal-peptide lugdunin and the thiopeptide micrococcin P1 (MP1). A high frequency of lanthipeptides was detected in this collection: BGC variants of BSA, bacCH91, and epilancin15X were identified in two Staphylococcus aureus and one Staphylococcus warneri isolates from food and wild animals. Moreover, two potentially new lanthipeptide-like BGCs with no identity to database entries were found in Staphylococcus epidermidis and Staphylococcus simulans from food and wild animal, respectively. Interestingly, four isolates (one S. aureus and one Staphylococcus hominis, environmental origin; two Staphylococcus sciuri, food) carried the MP1 BGC with differences to those previously described. On the other hand, seven of the 22 genomes (~32%) lacked known genes related with antibiotic or disinfectant-acquired resistance mechanisms. Moreover, the potential carriage of plasmids was evaluated, and several Rep-proteins were identified (~73% of strains). In conclusion, a wide variety of BGCs has been observed among the 22 genomes, and an interesting relationship between related Staphylococcus species and the type of bacteriocin has been revealed. Therefore, bacteriocin-producing Staphylococcus and especially coagulase-negative staphylococci (CoNS) can be considered good candidates as a source of novel bacteriocins.
PubMed: 37632676
DOI: 10.1007/s12602-023-10119-w -
Drug Metabolism and Personalized Therapy Dec 2023Antibiotic resistance is rising, prompting innovative strategies for eradicating the epidemic. This study investigated the antibacterial properties of the leaves of a...
OBJECTIVES
Antibiotic resistance is rising, prompting innovative strategies for eradicating the epidemic. This study investigated the antibacterial properties of the leaves of a widely used medicinal plant, .
METHODS
The plant's polar (water, methanol) and non-polar (hexane) extracts were tested against several different bacterial strains using the disc diffusion technique.
RESULTS
In a study, it was found that the water extract had the greatest inhibitory effect on and , with minimum inhibitory concentrations of 16.444 and 19.315 g/mL, respectively. Gram-negative strains were more susceptible to plant extracts than Gram-positive strains. The phytochemical analysis indicated the presence of secondary metabolites such as alkaloids, saponins, flavonoids, tannins, and steroids, where absorbance was recorded at 415 nm. The water extract had the highest amount of phenolics, with a total phenolic content of 53.92 0.47 mg and a total flavonoid content of 7.25 0.08 mg. Results suggest that the extract may have potential therapeutic applications for antimicrobial properties.
CONCLUSIONS
The study concluded that the extract's phenolic group of secondary metabolites were responsible for its antibacterial activity. The study highlights as a promising source for discovering new and effective antibacterial compounds.
Topics: Humans; Plants, Medicinal; Plant Extracts; Justicia; Anti-Infective Agents; Anti-Bacterial Agents; Flavonoids; Water; Phenols; Plant Leaves
PubMed: 37381682
DOI: 10.1515/dmpt-2023-0012 -
Food Chemistry Nov 2023In this study, crude peptides from fermented sausages inoculated with Lactobacillus plantarum CD101 and Staphylococcus simulans NJ201 were initially separated by...
In this study, crude peptides from fermented sausages inoculated with Lactobacillus plantarum CD101 and Staphylococcus simulans NJ201 were initially separated by ultrafiltration and molecular-sieve chromatography. The obtained fractions with high 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and ferric-reducing antioxidant power values (MWCO-1 and fraction A) were used in Caco-2 cells to evaluate their cytoprotective effect on oxidative damage triggered by HO. MWCO-1 and A showed slight cytotoxicity. Increased glutathione peroxidase, catalase, and superoxide dismutase activities and decreased malondialdehyde content were observed in the peptide-treated groups. Fraction A was further purified using reversed high-performance liquid chromatography. Eighty potential antioxidant peptides were identified by liquid chromatography with tandem mass spectrometry, and fourteen antioxidant peptides were synthesized. SDEEVEH and FAGDDAPR showed strong DPPH radical scavenging activity, whereas ALELDSNLYR and QEYDESGPSIVHR presented strong ABTS scavenging activity. These peptides might have great potential for food and pharmacological applications.
Topics: Animals; Humans; Swine; Antioxidants; Caco-2 Cells; Hydrogen Peroxide; Pork Meat; Red Meat; Peptides
PubMed: 37331140
DOI: 10.1016/j.foodchem.2023.136566 -
Probiotics and Antimicrobial Proteins Jun 2024Cholangiocarcinoma (CCA), a bile duct cancer with a high mortality rate, has a poor prognosis due to its highly invasive and drug-resistant phenotypes. More effective...
Cholangiocarcinoma (CCA), a bile duct cancer with a high mortality rate, has a poor prognosis due to its highly invasive and drug-resistant phenotypes. More effective and selective therapies are urgently needed. Bacteriocins are broad-spectrum antimicrobial peptides/proteins produced by bacterial strains to compete with other bacteria. Recent studies have reported that bacteriocins exhibit anticancer properties against various cancer cell lines with minimal toxicity toward normal cells. In this study, two types of recombinant bacteriocins, rhamnosin from probiotic Lacticaseibacillus rhamnosus and lysostaphin from Staphylococcus simulans, were highly produced in Escherichia coli and subsequently purified via immobilized-Ni affinity chromatography. When their anticancer activity was investigated against CCA cell lines, both rhamnosin and lysostaphin were found capable of inhibiting the growth of CCA cell lines in a dose-dependent fashion but were less toxic toward a normal cholangiocyte cell line. Rhamnosin and lysostaphin as single treatments could suppress the growth of gemcitabine-resistant cell lines to the same extent as or more than they suppressed the parental counterparts. A combination of both bacteriocins more strongly inhibited growth and enhanced cell apoptosis in both parental and gemcitabine-resistant cells partly through the increased expression of the proapoptotic genes BAX, and caspase-3, -8, and -9. In conclusion, this is the first report to demonstrate an anticancer property of rhamnosin and lysostaphin. Using these bacteriocins as single agents or in combination would be effective against drug-resistant CCA.
Topics: Humans; Gemcitabine; Cell Line, Tumor; Deoxycytidine; Cholangiocarcinoma; Bacteriocins; Lysostaphin; Drug Synergism; Drug Resistance, Neoplasm; Antineoplastic Agents; Lacticaseibacillus rhamnosus; Recombinant Proteins; Bile Duct Neoplasms; Apoptosis
PubMed: 37294416
DOI: 10.1007/s12602-023-10096-0 -
Journal of Dairy Science Nov 2023Subclinical mastitis can be common among freshly calved heifers (FCH), but the prevalence differs between herds, possibly due to variation in risk factors. The aims of...
Subclinical mastitis can be common among freshly calved heifers (FCH), but the prevalence differs between herds, possibly due to variation in risk factors. The aims of this observational study were to identify differences in occurrence of intramammary infection (IMI) in FCH between herds with documented good or poorer first-parity udder health based on cow somatic cell count (CSCC) in early lactation, and to study herd differences in animal factors important for udder health, such as udder and hock skin lesions and animal cleanliness. Three groups of herds were included: those with high proportions of FCH with low CSCC (≤75,000 cells/mL) at the first 2 milk recordings after calving (LL), herds with high proportions of FCH with high CSCC (>100,000 cells/mL) at the first and low CSCC at the second recording (HL), and herds with high proportions of FCH with high CSCC at both recordings (HH). Thirty-nine herds (13 LL, 11 HL, 15 HH) were visited 3 times during a 12-mo period for observation of cleanliness and hock lesions, and sampling of udder and teat skin using swab cloths of milk-fed calves, early-pregnant heifers, and late-pregnant heifers. In 25 (9 LL, 9 HL, 7 HH) udder quarter samples from colostrum and milk on d 3 to 4 after calving were taken by the farmers from FCH during one year. The farmers also provided information on calving (individual or group), use of restraint and oxytocin at milking, and presence of teat and udder skin lesions. Bacterial growth in swab samples and quarter samples was investigated by culturing, and a selection of isolates was genotyped using whole-genome sequencing. Cleanliness, hock and udder skin lesions other than udder-thigh dermatitis, and growth of bacteria in swab samples did not differ between herd groups. It was more common that FCH from LL herds, compared with FCH in HH and HL herds, calved in a group of animals. Use of restraint at milking was more common in LL herds than in HH herds, whereas presence of udder-thigh dermatitis was lowest in LL herds. Specific infection was found in 14% of 5,593 quarter samples from 722 FCH. The most common IMI was Staphylococcus chromogenes. Growth of Staphylococcus simulans was more common in HH than in LL and HL herds. In colostrum samples, Staphylococcus haemolyticus was more common in HL and HH than in LL herds. The proportion of quarters with the same specific infection at both samplings was higher in HH than in LL herds and tended to be higher in HH than in HL herds. The proportion of quarters with Staph. chromogenes IMI at both samplings tended to differ between herd groups and was highest in HH herds. Whole-genome sequencing found the same sequence type of Staph. chromogenes and Staphylococcus aureus in both samples in almost all quarters with the same infection at both samplings. The differences in IMI between herd groups were in line with the higher somatic cell count in HH herds. The reasons for the predominance of Staph. chromogenes IMI in FCH need further studies.
PubMed: 37210369
DOI: 10.3168/jds.2022-22995 -
Biochimica Et Biophysica Acta.... Aug 2023Antimicrobial peptides (AMPs) commonly target bacterial membranes and show broad-spectrum activity against microorganisms. In this research we used three AMPs (nisin,...
Antimicrobial peptides (AMPs) commonly target bacterial membranes and show broad-spectrum activity against microorganisms. In this research we used three AMPs (nisin, epilancin 15×, [R4L10]-teixobactin) and tested their membrane effects towards three strains (Staphylococcus simulans, Micrococcus flavus, Bacillus megaterium) in relation with their antibacterial activity. We describe fluorescence and luminescence-based assays to measure effects on membrane potential, intracellular pH, membrane permeabilization and intracellular ATP levels. The results show that our control peptide, nisin, performed mostly as expected in view of its targeted pore-forming activity, with fast killing kinetics that coincided with severe membrane permeabilization in all three strains. However, the mechanisms of action of both Epilancin 15× as well as [R4L10]-teixobactin appeared to depend strongly on the bacterium tested. In certain specific combinations of assay, peptide and bacterium, deviations from the general picture were observed. This was even the case for nisin, indicating the importance of using multiple assays and bacteria for mode of action studies to be able to draw proper conclusions on the mode of action of AMPs.
Topics: Nisin; Antimicrobial Peptides; Antimicrobial Cationic Peptides; Bacteria; Anti-Bacterial Agents
PubMed: 37100361
DOI: 10.1016/j.bbamem.2023.184160 -
Journal of Biomolecular Structure &... Dec 2023Cold-adapted and organic solvent tolerant lipases have significant potential in a wide range of synthetic reactions in industry. But there are no sufficient studies on...
Cold-adapted and organic solvent tolerant lipases have significant potential in a wide range of synthetic reactions in industry. But there are no sufficient studies on how these enzymes interacts with their substrates. Herein, the predicted structure and function of the lipase (SCL) are studied. Given the high amino acid sequence homology with the lipase (SSL), 3D structure models of closed and open forms of the lipase were built using the structure of SSL as template. The models suggested the presence of a main lid and a second lid that may act with the former as a double door to control the access to the active site. The SCL models also allowed us to identify key residues involved in binding substrates, calcium or zinc ions. By following this model and utilizing molecular dynamics (MD) simulations, the stability of the lipase at low temperatures could be explained in the presence and in the absence of calcium and zinc. Due to its thermolability, the SCL is extremely valuable for different biotechnological applications in a wide variety of industries from molecular biology to detergency to food and beverage preparation.Communicated by Ramaswamy H. Sarma.
Topics: Calcium; Staphylococcus capitis; Molecular Dynamics Simulation; Lipase; Zinc; Ions
PubMed: 36546696
DOI: 10.1080/07391102.2022.2159528 -
Animal Biotechnology Dec 2023This study aimed to investigate the presence of and genes in coagulase negative (CNS) species isolated from bovine mastitis in smallholder dairy farms by using PCR. A...
This study aimed to investigate the presence of and genes in coagulase negative (CNS) species isolated from bovine mastitis in smallholder dairy farms by using PCR. A total of 602 mammary quarter milk samples belong to 170 cows with mastitis were used. Identification of species was achieved by using the commercial Gram-positive identification kit and a total of 52 (8.6%) CNS species were isolated. The most frequently isolated species was (n = 15, 28.8%), followed by (n = 12, 23.1%), (n = 8, 15.4%), (n = 5, 9.6%), (n = 4, 7.7%), (n = 4, 7.7%), (n = 2, 3.8%) and (n = 2, 3.8%). The gene positivity was found in the 13 (25%) of strains. Of the strains carrying gene, eight also harbored the gene. A total of gene positivity was found as 30.8% (n = 16) in 52 CNS species. In conclusion, the present study showed that CNS isolated from cows with mastitis may be reservoir of and genes. To our knowledge, this is the first study showing the presence of and genes in CNS species isolated from bovine with mastitis in the smallholder dairy farms in Turkey.
Topics: Female; Animals; Cattle; Coagulase; Mastitis, Bovine; Staphylococcal Infections; Prevalence; Farms; Turkey; Staphylococcus; Milk; Cattle Diseases
PubMed: 35792781
DOI: 10.1080/10495398.2022.2094802