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1.
Food Funct ; 13(4): 1774-1784, 2022 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-35112684

RESUMO

Antibiotic-resistant strains of Streptococcus uberis (S. uberis) frequently cause clinical mastitis in dairy cows resulting in enormous economic losses. The regulation of immunometabolism is a promising strategy for controlling this bacterial infection. To investigate whether taurine alleviates S. uberis infection by the regulation of host glycolysis via HIF1α, the murine mammary epithelial cell line (EpH4-Ev) and C57BL/6J mice were challenged with S. uberis. Our data indicate that HIF1α-driven glycolysis promotes inflammation and damage in response to the S. uberis challenge. The activation of HIF1α is dependent on mTOR-mediated ROS production. These results were confirmed in vivo. Taurine, an intracellular metabolite present in most animal tissues, has been shown to effectively modulate HIF1α-triggered metabolic reprogramming and contributes to a reduction of inflammation, which reduces mammary tissue damage and prevents mammary gland dysfunction in S. uberis-induced mastitis. These data provide a novel putative prophylactic and therapeutic strategy for amelioration of dairy cow mastitis and bacterial inflammation.


Assuntos
Glicólise/efeitos dos fármacos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Infecções Estreptocócicas/metabolismo , Taurina/farmacologia , Animais , Linhagem Celular , Feminino , Glândulas Mamárias Animais/citologia , Camundongos , Camundongos Endogâmicos C57BL , Transdução de Sinais/efeitos dos fármacos , Streptococcus/efeitos dos fármacos
2.
Lett Appl Microbiol ; 74(6): 901-908, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35218013

RESUMO

In the microbiome, probiotics modulate oral diseases. In this study, Streptococcus strain C17T was isolated from the oropharynx of a 5-year-old healthy child, and its potential probiotic properties were analysed using human bronchial epithelial cells (16-HBE) used as an in vitro oropharyngeal mucosal model. The results demonstrated that the C17T strain showed tolerance to moderate pH ranges of 4-5 and 0·5-1% bile. However, it was more tolerant to 0·5% bile than 1% bile. It also demonstrated an ability to accommodate maladaptive oropharyngeal conditions (i.e. tolerating lysozyme at 200 µg ml-1 ). It was also resistant to hydrogen peroxide at 0·8 mM. In addition, we found out that the strain possesses inhibitory activities against various common pathogenic bacteria. Furthermore, C17T was not cytotoxic to 16-HBE cells at different multiplicities of infection. Scanning electron microscopy disclosed that C17T adhesion to 16-HBE cells. Competition, exclusion and displacement assays showed that it had good anti-adhesive effect against S. aureus. The present study revealed that Streptococcus strain C17T is a potentially efficacious oropharyngeal probiotic.


Assuntos
Saúde Bucal , Probióticos , Streptococcus , Aderência Bacteriana , Pré-Escolar , Humanos , Probióticos/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Streptococcus/efeitos dos fármacos , Streptococcus/genética
3.
Fitoterapia ; 157: 105129, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35051555

RESUMO

Tabernaecorymine A, an 18-normonoterpenoid indole alkaloid with conjugated (E)-3-aminoacrylaldehyde fragment was obtained from the stem bark of Tabernaemontana corymbosa. Its structure was elucidated by extensive spectroscopic data analyses, and further verified by ACD/structure elucidator, electronic circular dichroism (ECD) analyses and density functional theory (DFT) chemical shift predictions. The compound exhibited significant antibacterial bioactivity against Streptococcus dysgalactiae with an MIC value of 3.12 µg/mL, which is better than the plant drug berberine.


Assuntos
Antibacterianos/farmacologia , Extratos Vegetais/farmacologia , Alcaloides de Triptamina e Secologanina/farmacologia , Tabernaemontana/química , Antibacterianos/química , Antibacterianos/isolamento & purificação , Bacillus subtilis/efeitos dos fármacos , Dicroísmo Circular , Escherichia coli/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Casca de Planta/química , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Alcaloides de Triptamina e Secologanina/química , Alcaloides de Triptamina e Secologanina/isolamento & purificação , Staphylococcus aureus/efeitos dos fármacos , Streptococcus/efeitos dos fármacos
4.
J Microbiol ; 60(2): 167-176, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34997538

RESUMO

"Antibiotic tolerance" promotes the rapid subsequent evolution of "antibiotic resistance," however, it is often overlooked because it is difficult to distinguish between tolerant and susceptible organisms. A commensal bacterium S. anginosus subsp. anginosus strain KHUD_S1, isolated from dental biofilm was found to exhibit a high MBC/MIC ratio of 32 against vancomycin. We observed KHUD_S1 cells exposed to vancomycin did not grow but maintained viability. Transmission electron microscope showed KHUD_S1 cells possessed a dense, thick capsule and maintained the cell wall integrity upon vancomycin exposure. To infer the underlying mechanisms of the vancomycin tolerance in KHUD_S1, we performed whole genome sequencing and RNA sequencing. The KHUD_S1 genome carried three genes encoding branching enzymes that can affect peptidoglycan structure through interpeptide bridge formation. Global gene expression profiling revealed that the vancomycin-induced downregulation of carbohydrate and inorganic ion transport/metabolism as well as translation is less prominent in KHUD_S1 than in the vancomycin susceptible strain KHUD_S3. Based on the transcriptional levels of genes related to peptidoglycan synthesis, KHUD_S1 was determined to have a 3D peptidoglycan architecture distinct from KHUD_S3. It was found that, under vancomycin exposure, the peptidoglycan was remodeled through changes in the interpeptide bridge and transpeptidation reactions. Collectively, these features of S. anginosus KHUD_S1, including a dense capsule and differential gene expression in peptidoglycan synthesis, may contribute to vancomycin tolerance. Our results showing the occurrence of vancomycin tolerance amongst oral commensal bacteria highlight the need for considering future strategies for screening of antibiotic tolerance as an effort to reduce antibiotic resistance.


Assuntos
Farmacorresistência Bacteriana , Tolerância a Medicamentos , Streptococcus/citologia , Streptococcus/efeitos dos fármacos , Streptococcus/genética , Vancomicina/farmacologia , Antibacterianos/farmacologia , Biofilmes , Humanos , Boca/microbiologia , Análise de Sequência de RNA , Transcriptoma , Sequenciamento Completo do Genoma
5.
Chembiochem ; 23(3): e202100423, 2022 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-34580974

RESUMO

Streptococcus agalactiae or Group B Streptococcus (GBS) is a Gram-positive bacterial pathobiont that is the etiological cause of severe perinatal infections. GBS can colonize the vagina of pregnant patients and invade tissues causing ascending infections of the gravid reproductive tract that lead to adverse outcomes including preterm birth, neonatal sepsis, and maternal or fetal demise. Additionally, transmission of GBS during labor or breastfeeding can also cause invasive infections of neonates and infants. However, human milk has also been shown to have protective effects against infection; a characteristic that is likely derived from antimicrobial and immunomodulatory properties of molecules that comprise human milk. Recent evidence suggests that human milk oligosaccharides (HMOs), short-chain sugars that comprise 8-20 % of breast milk, have antimicrobial and anti-biofilm activity against GBS and other bacterial pathogens. Additionally, HMOs have been shown to potentiate the activity of antibiotics against GBS. This review presents the most recent published work that studies the interaction between HMOs and GBS.


Assuntos
Antibacterianos/farmacologia , Leite Humano/química , Oligossacarídeos/farmacologia , Streptococcus/efeitos dos fármacos , Antibacterianos/química , Configuração de Carboidratos , Humanos , Testes de Sensibilidade Microbiana , Oligossacarídeos/química
6.
J Nanosci Nanotechnol ; 21(6): 3539-3546, 2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-34739805

RESUMO

We have developed a simple, robust environment-friendly and efficient method for ZnO nanoparticles biosynthesis using Dalbergia sissoo fresh leaf extract. Before using these nanoparticles for antimicrobial assay, a detailed characterization was performed using techniques like Ultraviolet/Visible (UV/Vis) spectroscopy, Particle size analysis (PSA), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), atomic force microscopy (AFM),Transmission electron microscopy (TEM) etc. The average size of biosynthesized ZnO nanoparticles was around 30 nm and they were pure and crystalline by nature. The effectiveness of these biosynthesized nanoparticles were checked against both pathogenic and non-pathogenic microbes. A total of eight bacterial strains-Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, Klebsilla pneumoniae, Staphylococcus aureus, Streptococcus entericus, Bacillus cereus, Pantoea cypripedii and three fungal strains-Candida albicans, Aspergilus niger and Aspergilus flavus were studied to have a clear view of the spectrum of ZnO nanoparticles anti-microbial activity. The effectiveness of biosynthesized ZnO nanoparticles against the microbes was found to be better than the standard reference antibiotics used (streptomycin, chloramphenicol and rifampicin). The results seem to be very promising and can be used for some practical applications of ZnO nanoparticles in nearfuture.


Assuntos
Antibacterianos , Antifúngicos , Nanopartículas Metálicas , Óxido de Zinco , Antibacterianos/farmacologia , Antifúngicos/farmacologia , Aspergillus/efeitos dos fármacos , Bacillus/efeitos dos fármacos , Candida/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Pantoea/efeitos dos fármacos , Extratos Vegetais/farmacologia , Espectroscopia de Infravermelho com Transformada de Fourier , Streptococcus/efeitos dos fármacos , Difração de Raios X , Óxido de Zinco/farmacologia
7.
Microbiol Spectr ; 9(3): e0175121, 2021 12 22.
Artigo em Inglês | MEDLINE | ID: mdl-34787437

RESUMO

A low initial contamination level of the meat surface is the sine qua non to extend the subsequent shelf life of ground beef for as long as possible. Therefore, the short- and long-term effects of a pregrinding treatment with electrolyzed water (EW) on the microbiological and physicochemical features of Piedmontese steak tartare were here assessed on site, by following two production runs through storage under vacuum packaging conditions at 4°C. The immersion of muscle meat in EW solution at 100 ppm of free active chlorine for 90 s produced an initial surface decontamination with no side effects or compositional modifications, except for an external color change that was subsequently masked by the grinding step. However, the initially measured decontamination was no longer detectable in ground beef, perhaps due to a quick recovery by bacteria during the grinding step from the transient oxidative stress induced by the EW. We observed different RNA-based metataxonomic profiles and metabolomic biomarkers (volatile organic compounds [VOCs], free amino acids [FAA], and biogenic amines [BA]) between production runs. Interestingly, the potentially active microbiota of the meat from each production run, investigated through operational taxonomic unit (OTU)-, oligotyping-, and amplicon sequence variant (ASV)-based bioinformatic pipelines, differed as soon as the early stages of storage, whereas microbial counts and biomarker dynamics were significantly distinguishable only after the expiration date. Higher diversity, richness, and abundance of Streptococcus organisms were identified as the main indicators of the faster spoilage observed in one of the two production runs, while Lactococcus piscium development was the main marker of shelf life end in both production runs. IMPORTANCE Treatment with EW prior to grinding did not result in an effective intervention to prolong the shelf life of Piedmontese steak tartare. Our RNA-based approach clearly highlighted a microbiota that changed markedly between production runs but little during the first shelf life stages. Under these conditions, an early metataxonomic profiling might provide the best prediction of the microbiological fate of each batch of the product.


Assuntos
Contaminação de Alimentos/análise , Lactococcus/crescimento & desenvolvimento , Microbiota/efeitos dos fármacos , Carne Vermelha/microbiologia , Streptococcus/crescimento & desenvolvimento , Água/farmacologia , Animais , Bovinos , Manipulação de Alimentos/métodos , Microbiologia de Alimentos , Armazenamento de Alimentos/métodos , Lactococcus/efeitos dos fármacos , Lactococcus/isolamento & purificação , Streptococcus/efeitos dos fármacos , Streptococcus/isolamento & purificação , Água/química , Microbiologia da Água
8.
Pak J Pharm Sci ; 34(3(Supplementary)): 1149-1156, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-34602445

RESUMO

As part of our continuous research to understand the interaction mechanism of drug and metallo-elements, heavy metal complexes of azithromycin (AZI) were synthesized with arsenic oxide, lead carbonate and silver chloride salts in molar ratio of 2: 1 (L: M). Synthesized heavy metal complexes have shown good percent yield and characterized through spectroscopic parameters including UV-Visible, TLC, FT-IR, NMR and elemental analysis (CHN). Spectroscopic characterization reveals the binding of ligand AZI with heavy metals in bi-dentate manner involving the hydroxide and 9a-NCH3 group of the aglycone ring of AZI. These newly synthesized heavy metal complexes were evaluated for their antimicrobial response against selected gram positive and gram negative organisms and antifungal species. It was noted that all newly synthesized complexes exhibits increased activity against B.subtilus whereas, AZI itself didn't show any activity, while synthesized complexes have low to moderate response against all the studied organisms. Complex A-M12 possess greater enzymatic response against both urease and alpha chymotrypsin among all the studied complexes. Results obtained were then statistically analyzed through one way ANOVA and Dunnett's test by using SPSS version 20.0 suggesting the significant response of complexes against selected organisms.


Assuntos
Antibacterianos/farmacologia , Antifúngicos/farmacologia , Trióxido de Arsênio/farmacologia , Azitromicina/farmacologia , Carbonatos/farmacologia , Complexos de Coordenação/farmacologia , Chumbo/farmacologia , Compostos de Prata/farmacologia , Trióxido de Arsênio/química , Azitromicina/análogos & derivados , Azitromicina/química , Bacillus subtilis/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Carbonatos/química , Quimotripsina/metabolismo , Citrobacter/efeitos dos fármacos , Complexos de Coordenação/química , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Ensaios Enzimáticos , Escherichia coli/efeitos dos fármacos , Klebsiella pneumoniae/efeitos dos fármacos , Chumbo/química , Micrococcus luteus/efeitos dos fármacos , Proteus mirabilis/efeitos dos fármacos , Pseudomonas aeruginosa/efeitos dos fármacos , Salmonella typhi/efeitos dos fármacos , Shigella flexneri/efeitos dos fármacos , Compostos de Prata/química , Staphylococcus aureus/efeitos dos fármacos , Streptococcus/efeitos dos fármacos , Urease/metabolismo
9.
BMC Complement Med Ther ; 21(1): 265, 2021 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-34670535

RESUMO

BACKGROUND: Oils in traditional medicine are important products and used routinely for therapeutic purposes. Rose oil (Rosa damascene Mill), a product of Persian medicine, is advised for the treatment of Infectious diseases related to the female genitourinary tract. In the present study, R. damascena petal oil, aqueous, and hydroalcoholic extracts were evaluated for their in vitro antibacterial and anti-Trichomonas vaginalis effects. METHODS: Anti-trichomonas activity evaluation of extracts and oil were assayed by the Homocytometery method. Their antibacterial effects against Escherichia coli, methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, and clinically isolated Group B Streptococcus were assayed by broth microdilution in 96-well plates. RESULTS: The MIC of hydroalcoholic and aqueous extracts ranged from 25-50 and 25-100 mg/ml, respectively. Rose oil at all administered doses failed to show any antibacterial activity. CONCLUSION: All extracts and oil concentrations showed some degree of growth inhibition activity on T. vaginalis; however, hydroalcoholic extract was more efficient.


Assuntos
Antibacterianos/farmacologia , Óleos Voláteis/farmacologia , Extratos Vegetais/farmacologia , Trichomonas vaginalis/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Humanos , Irã (Geográfico) , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Pseudomonas aeruginosa/efeitos dos fármacos , Rosa , Streptococcus/efeitos dos fármacos
10.
Sci Rep ; 11(1): 18461, 2021 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-34531515

RESUMO

Antibiotic resistance is a serious threat that occurs globally in the health sector due to increased consumption of inappropriate antibiotics. Guidelines for prescribing antibiotics for ARTIs have been issued in general practice to promote rational antibiotic prescribing. This study was conducted to compare the effectiveness of cefixime and tetracycline as a solution to improve monitoring of appropriate antibiotic use in the treatment of ARTIs. All stock isolates were rejuvenated first, and cultured on standard media and Kirby-Bauer disc diffusion method was used for susceptibility testing in accordance with the Clinical and Laboratory Standard Institute's (CLSI) recommendations. Identification of bacteria from a single isolate was carried out to determine which bacteria were resistant to cefixime and tetracycline. A total of 466 single isolates of bacteria were analyzed, which showed a percentage of resistance to cefixime 38.0%, and tetracycline 92.86%. Bacterial isolates were resistant to cefixime and tetracycilne was a genus of Haemophilus, Streptococcus, Corynebacterium, Staphylococcus, and bordetella. Cefixime compared to tetracycline was proven to be superior in terms of the effectiveness of ARIs treatment.


Assuntos
Antibacterianos/toxicidade , Cefixima/toxicidade , Farmacorresistência Bacteriana , Infecções Respiratórias/tratamento farmacológico , Tetraciclina/toxicidade , Antibacterianos/administração & dosagem , Antibacterianos/uso terapêutico , Bordetella/efeitos dos fármacos , Cefixima/administração & dosagem , Cefixima/uso terapêutico , Corynebacterium/efeitos dos fármacos , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Cálculos da Dosagem de Medicamento , Haemophilus/efeitos dos fármacos , Humanos , Infecções Respiratórias/epidemiologia , Infecções Respiratórias/microbiologia , Staphylococcus/efeitos dos fármacos , Streptococcus/efeitos dos fármacos , Tetraciclina/administração & dosagem , Tetraciclina/uso terapêutico
11.
Int J Biol Macromol ; 188: 473-481, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34352320

RESUMO

ß-defensin family plays a critical role in host defense against infections. In this study, we found that pBD129 are widely expressed in porcine tissues such as the intestine, liver, and spleen. Interestingly, the expression level of pBD129 in most tissues was higher in Tibetan pigs than in DLY (Duroc × Landrace × Yorkshire) pigs (P < 0.05), and was significantly upregulated upon E. coli K88 infection (P < 0.05). The pBD129 protein was successfully expressed in E. coli and the molecule weight was estimated by SDS-PAGE to be 37.2 kDa. Mass spectrometry verified the protein as a pBD129. The protein showed antibacterial activities against Streptococcus and E. coli DH5α with a minimal inhibitory concentration (MIC) of 32 µg/mL. Hemolytic and cytotoxicity assays indicated that pBD129 had no detrimental effect on cell viability. Importantly, pBD129 significantly reduced the apoptosis of porcine intestinal epithelial cells exposure to bacterial endotoxins, which was associated with down-regulation of inflammatory cytokines such as the IL-1ß, IL-6 and TNFα (P < 0.05), and down-regulation of apoptosis-related genes such as the caspase-3, caspase-8, and caspase-9 (P < 0.05). These results suggested that pBD129 is a novel modulator of innate immunity involved in mammalian inflammatory responses.


Assuntos
Infecções por Escherichia coli/terapia , Fatores Imunológicos/genética , Inflamação/genética , beta-Defensinas/genética , Animais , Apoptose/efeitos dos fármacos , Células Epiteliais/efeitos dos fármacos , Infecções por Escherichia coli/genética , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/veterinária , Regulação da Expressão Gênica/efeitos dos fármacos , Fatores Imunológicos/farmacologia , Inflamação/induzido quimicamente , Inflamação/patologia , Inflamação/terapia , Mucosa Intestinal/metabolismo , Mucosa Intestinal/microbiologia , Lipopolissacarídeos/toxicidade , Testes de Sensibilidade Microbiana , Streptococcus/efeitos dos fármacos , Streptococcus/patogenicidade , Suínos , beta-Defensinas/farmacologia
12.
Prev Vet Med ; 194: 105451, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34364060

RESUMO

Livestock has been recognized as a reservoir of antibiotic-resistant bacteria. Prevalence of resistance has been associated with herd size and intensification of animal production systems. Brazil is one of the emergent hotspots of bacterial resistance, which is also associated with animal husbandry. This study aimed to evaluate the resistance profile of pathogens that cause subclinical mastitis and the relationship between resistance status at farm level and different production systems. Milk samples from cows diagnosed with subclinical mastitis were collected from farms that adopt different husbandry systems with different production intensities, i.e., agroecological, low input, high input, Free-Stall and Compost-bedded pack barn. Etiological agents were isolated and microbiologically identified, and antibiotic susceptibility testing was conducted, using the disk diffusion method. The main isolated agents were Streptococcus spp. (n = 54, 30.5 %) and coagulase-positive Staphylococcus (CPS) (n = 54; 30.5 %). The recovered isolates displayed high antibiotic resistance against Sulfamethazine (80.2 %), Gentamicin (29.37 %), Penicillin (29.37 %), Oxacillin (28.82 %) and Ampicillin (26 %). Multidrug resistance was found for all agents and in all farming systems (39.54 %). Neither production systems (p = 0.26) nor farming systems (p = 0.24) significantly affected the resistance rates of samples. Therefore, intensive production systems may not be a root cause of increased rates of antimicrobial resistance in the milk production chain, suggesting that other environmental factors should be investigated. It is noteworthy that high levels of multidrug resistance were even found in bacteria earlier considered as minor pathogens. This development can be taken as a warning that environmental bacteria are potential transmitters of resistance genes to the environment.


Assuntos
Doenças dos Bovinos , Farmacorresistência Bacteriana , Mastite Bovina , Infecções Estafilocócicas , Animais , Antibacterianos/farmacologia , Bovinos , Doenças dos Bovinos/microbiologia , Indústria de Laticínios , Feminino , Mastite Bovina/epidemiologia , Testes de Sensibilidade Microbiana/veterinária , Leite , Infecções Estafilocócicas/veterinária , Staphylococcus/efeitos dos fármacos , Staphylococcus/isolamento & purificação , Streptococcus/efeitos dos fármacos , Streptococcus/isolamento & purificação
13.
Vet Ital ; 57(1): 41-47, 2021 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-34313097

RESUMO

Streptococcal species are known to be responsible for bovine mastitis. The aim of the present study was to determine antimicrobial drug resistance patterns of hemolytic streptococci distributed according to Lancefield serogrouping. Streptococcus sp. strains were isolated from 124 bovine milk samples from 31 cows with subclinical or clinical mastitis submitted to Mehmet Akif Ersoy University Faculty of Veterinary Medicine, Department of Microbiology Laboratory in Burdur province, Turkey from January 2015 to January 2017. A total of 63 Streptococcus sp. were isolated and the most frequently obtained isolates were classified as Lancefield's serogroup B (84.13%), the remaining isolates as serogroup F (15.87%). Out of 63 isolates, 53 (84.13%) showed beta­hemolytic activity whereas 10 (15.87%) alpha­hemolytic activity. Antimicrobial resistance was assessed by disk diffusion test against the most common antibiotics used in the field. Among the 63 Streptococcus sp. tested, the highest antimicrobial resistance patterns were observed for neomycin (95.24%), trimethoprim sulphamethoxazole (87.30%) and gentamicin (69.84%). None of the isolates showed resistance to amoxicillin­clavulanic acid, except for one serogroup F isolate. The resistance rates for the other antimicrobials ranged from 1.59% to 38.04%. A total of 50 isolates exibited multi­drug resistance to ≥ 3 antimicrobial agents tested. Overall, our results suggested that there is an urgent need to enhance awareness among the dairy farmers in choosing the appropriate drug for treating mastitis.


Assuntos
Antibacterianos/uso terapêutico , Gestão de Antimicrobianos , Farmacorresistência Bacteriana , Mastite Bovina/tratamento farmacológico , Streptococcus/isolamento & purificação , Animais , Antibacterianos/farmacologia , Bovinos , Indústria de Laticínios , Feminino , Mastite Bovina/microbiologia , Streptococcus/efeitos dos fármacos , Turquia/epidemiologia
14.
Appl Environ Microbiol ; 87(16): e0039121, 2021 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-34105992

RESUMO

Antimicrobial peptides are evolving as novel therapeutic options against the increasing problem of multidrug-resistant microorganisms, and nisin is one such avenue. However, some bacteria possess a specific nisin resistance system (NSR), which cleaves the peptide reducing its bactericidal efficacy. NSR-based resistance was identified in strains of Streptococcus uberis, a ubiquitous pathogen that causes mastitis in dairy cattle. Previous studies have demonstrated that a nisin A derivative termed nisin PV, featuring S29P and I30V, exhibits enhanced resistance to proteolytic cleavage by NSR. Our objective was to investigate the ability of this nisin derivative to eradicate and inhibit biofilms of S. uberis DPC 5344 and S. uberis ATCC 700407 (nsr+) using crystal violet (biomass), 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) (viability) assays, and confocal microscopy (viability and architecture). When preestablished biofilms were assessed, both peptides reduced biofilm biomass by over 60% compared to that of the untreated controls. However, a 42% higher reduction in viability was observed following treatment with nisin PV compared to that of nisin A. Accordingly, confocal microscopy analysis revealed significantly more dead cells on the biofilm upper surface and a reduced thickness following treatment with nisin PV. When biofilm inhibition was assessed, nisin PV inhibited biofilm formation and decreased viability up to 56% and 85% more than nisin A, respectively. Confocal microscopy analysis revealed a lack of biofilm for S. uberis ATCC 700407 and only dead cells for S. uberis DPC 5344. These results suggest that nisin PV is a promising alternative to effectively reduce the biofilm formation of S. uberis strains carrying NSR. IMPORTANCE One of the four most prevalent species of bovine mastitis-causing pathogens is S. uberis. Its ability to form biofilms confers on the bacteria greater resistance to antibiotics, requiring higher doses to be more effective. In a bid to limit antibiotic resistance development, the need for alternative antimicrobials is paramount. Bacteriocins such as nisin represent one such alternative that could alleviate the impact of mastitis caused by S. uberis. However, many strains of S. uberis have been shown to possess nisin resistance determinants, such as the nisin resistance protein (NSR). In this study, we demonstrate the ability of nisin and a nisin derivative termed PV that is insensitive to NSR to prevent and remove biofilms of NSR-producing S. uberis strains. These findings will add new information to the antimicrobial bacteriocins and control of S. uberis research fields specifically in relation to biofilms and nsr+ mastitis-associated strains.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Nisina/química , Nisina/farmacologia , Streptococcus/efeitos dos fármacos , Bioengenharia , Farmacorresistência Bacteriana , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Nisina/genética , Streptococcus/crescimento & desenvolvimento , Streptococcus/fisiologia
15.
Bioorg Chem ; 114: 105078, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34161878

RESUMO

This study was focused on the synthesis of new pyrimidines 4a,b, 5a,b and pyrazoles 6a, b as ATP mimicking tyrosine kinase inhibitors of the epidermal growth factor receptor (EGFR). The new compounds were assessed as cytotoxic candidates against human breast cancer cells (MCF-7) and hepatocellular carcinoma cells (HepG-2). All the new compounds appeared as more potent cytotoxic agents than erlotinib, while only compound 4a exhibited more potency than 5-flourouracil and 4b analogue was equipotent to it. Accordingly, the kinase suppression effect of 4a and 4b was further evaluated against EGFRWT, EGFRL858R and EGFRT790M. Both pyrimidine analogues 4a and 4b displayed outstanding inhibitory activity against EGFRWT and its two mutated isoforms EGFRL858R and EGFRT790M in comparing to erlotinib and osimertinib as reference drugs. Additionally, all the new analogues were subjected to antimicrobial assay. Interestingly, both 4a and 4b represented the most promising activity of wide spectrum antimicrobial effect against the examined microbes in comparison to gentamycin and ketoconazole as standard drugs. Moreover, docking results proved the good binding interactions of the compounds 4a and 4b with EGFRWT and EGFRT790M which were in accordance with the results of the in vitro enzyme assay. Additional in silico ADMET studies were performed for the new derivatives which represented their good oral absorption, good drug-likeness properties and low toxicity risks in human.


Assuntos
Antibacterianos/farmacologia , Antifúngicos/farmacologia , Antineoplásicos/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Pirazóis/farmacologia , Pirimidinas/farmacologia , Antibacterianos/síntese química , Antibacterianos/química , Antifúngicos/síntese química , Antifúngicos/química , Antineoplásicos/síntese química , Antineoplásicos/química , Aspergillus fumigatus/efeitos dos fármacos , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/metabolismo , Humanos , Testes de Sensibilidade Microbiana , Modelos Moleculares , Estrutura Molecular , Mucorales/efeitos dos fármacos , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Proteus vulgaris/efeitos dos fármacos , Pirazóis/síntese química , Pirazóis/química , Pirimidinas/síntese química , Pirimidinas/química , Streptococcus/efeitos dos fármacos , Relação Estrutura-Atividade
16.
J Infect Dev Ctries ; 15(5): 672-677, 2021 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-34106891

RESUMO

INTRODUCTION: Streptococcus pneumoniae can be responsible for severe human infections. Optochin resistance has been a potential cause of misidentification of pneumococcus and other members of the mitis group. Hence, rapid and easy optochin resistant (Optr) S. pneumoniae identification is essential. METHODOLOGY: Atypical pneumococci were characterized using optochin susceptibility, bile solubility based on spectrophotometric reading, serotyping, pulsed field gel electrophoresis (PFGE), 16S rRNA sequencing and PCR-based assays targeting pneumococcal genes lytA, ply, pspA, cpsA, Spn9802 and Spn9828. RESULTS: Optical density values for the bile solubility test suggest the identification of four Optr S. pneumoniae and one Streptococcus pseudopneumoniae. All Optr pneumococci harbored cpsA, lytA, ply, Spn9802, Spn9828 and pspA genes. Only ply, spn9802 and Spn9828 genes were detected in S. pseudopneumoniae. The 16S rRNA sequencing differentiates between these two species. Optr S. pneumoniae strains belonged to different genotypes and serotypes (14, 19A, 3 and 9V). Three Optr S. pneumoniae isolates were typed as pspA family 2, while one belonged to pspA family 1. Sequencing of the atpA and atpC gene of the Optr variants revealed three mutations in the ATPase a-subunit (L99I, M23V and V52I) and one mutation in ATPase c-subunit (V48I). CONCLUSIONS: Our data indicate that bile OD-values provides an accurate, fast and easy method to discriminate between Optr S. pneumoniae and other Streptococcus mitis group. Moreover molecular techniques, confirming the bile test, can be used in order to prevent these atypical pneumococci and alert clinical microbiologists of the presence of these strains in the community.


Assuntos
Quinina/análogos & derivados , Infecções Estreptocócicas/diagnóstico , Streptococcus pneumoniae/isolamento & purificação , Streptococcus/isolamento & purificação , Farmacorresistência Bacteriana , Genes Bacterianos , Genótipo , Humanos , Testes de Sensibilidade Microbiana , Técnicas de Diagnóstico Molecular , Quinina/farmacologia , Quinina/uso terapêutico , RNA Ribossômico 16S , Infecções Estreptocócicas/tratamento farmacológico , Infecções Estreptocócicas/epidemiologia , Infecções Estreptocócicas/microbiologia , Streptococcus/efeitos dos fármacos , Streptococcus/genética , Streptococcus pneumoniae/efeitos dos fármacos , Streptococcus pneumoniae/genética , Tunísia/epidemiologia
17.
Pediatr Infect Dis J ; 40(8): e316-e318, 2021 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-33941742

RESUMO

Streptococcus pseudoporcinus is a newly recognized ß-hemolytic streptococcus, that is considered a rare pathogen in adults. Infections in children have not been reported. We describe a child with Klippel-Trenaunay syndrome that developed of S. pseudoporcinus cellulitis and bacteremia, which was difficult-to-treat, relapsed and required prolonged antibiotic courses. S. pseudoporcinus can cause invasive infection in children, especially in the presence of predisposing conditions.


Assuntos
Bacteriemia/etiologia , Celulite (Flegmão)/etiologia , Síndrome de Klippel-Trenaunay-Weber/complicações , Infecções Estreptocócicas/complicações , Streptococcus/isolamento & purificação , Antibacterianos/uso terapêutico , Bacteriemia/tratamento farmacológico , Celulite (Flegmão)/tratamento farmacológico , Criança , Humanos , Masculino , Infecções Estreptocócicas/tratamento farmacológico , Streptococcus/efeitos dos fármacos , Resultado do Tratamento
18.
Daru ; 29(1): 133-145, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33966255

RESUMO

BACKGROUND: Punica granatum L. (pomegranate) with astringent activities and Matricaria chamomilla L. (chamomile) with anti-inflammatory and antioxidant properties are natural remedies used for various skin disorders, including wound healing. OBJECTIVES: This study was conducted to evaluate the individual and combined wound healing activity of the methanol extracts of pomegranate and chamomile flowers. METHODS: After preparing the menthol fraction of pomegranate and chamomile flowers, the content of total phenols, total tannins, and total flavonoids of fractions was measured. For standardization of pomegranate and chamomile fractions, Gallic acid and apigenin-7-O-glucoside contents of them were determined using high-performance liquid chromatography (HPLC). Moreover, their antioxidant activities were examined using DPPH and FRAP tests. The antimicrobial assay was performed against Staphylococcus aureus, Staphylococcus epidermidis, and Pseudomonas aeruginosa. Three different concentrations of methanol fraction of each plant and one combination dose of fractions were investigated for their wound healing activities in an excision wound model on the rats' dorsum. Finally, histopathological studies were done at the end of the experiment. RESULTS: Phytochemical examinations showed high amounts of phenolic compounds in pomegranate flowers, while chamomile flower fractions contained a high amount of total flavonoids. Both fractions, especially pomegranate, had potent antioxidant activity. The best results for wound closure were observed 7 days after wound induction. All treated groups exhibited superior wound contraction compared to their placebo at all measurement times. The combined form of pomegranate and chamomile had better wound healing properties compared to a single therapy, especially on time earlier to wound induction. CONCLUSION: This study represented high antioxidant and wound healing activities for methanol fraction of pomegranate and chamomile flowers, which could be related to their high content of phytochemicals. In comparison with single herb treatment, the combined form of these two fractions in lower concentrations accelerated wound closure.


Assuntos
Antibacterianos/uso terapêutico , Anti-Inflamatórios/uso terapêutico , Antioxidantes/uso terapêutico , Matricaria , Extratos Vegetais/uso terapêutico , Punica granatum , Cicatrização/efeitos dos fármacos , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Anti-Inflamatórios/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Compostos de Bifenilo/química , Flavonoides/análise , Flores , Masculino , Fenóis/análise , Compostos Fitoquímicos/análise , Compostos Fitoquímicos/farmacologia , Compostos Fitoquímicos/uso terapêutico , Picratos/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Ratos Wistar , Pele/efeitos dos fármacos , Pele/patologia , Staphylococcus aureus/efeitos dos fármacos , Streptococcus/efeitos dos fármacos , Taninos/análise
19.
Korean J Parasitol ; 59(2): 173-178, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33951774

RESUMO

The DM9 domain is a protein unit of 60-75 amino acids that has been first detected in the fruit fly Drosophila as a repeated motif of unknown function. Recent research on proteins carrying DM9 domains in the mosquito Anopheles gambiae and the oyster Crassostrea gigas indicated an association with the uptake of microbial organisms. Likewise, in the trematode Fasciola gigantica DM9-1 showed intracellular relocalization following microbial, heat and drug stress. In the present research, we show that FgDM9-1 is a lectin with a novel mannose-binding site that has been recently described for the protein CGL1 of Crassostrea gigas. This property allowed FgDM9-1 to agglutinate gram-positive and -negative bacteria with appropriate cell surface glycosylation patterns. Furthermore, FgDM9-1 caused hemagglutination across all ABO blood group phenotypes. It is speculated that the parenchymal located FgDM9-1 has a role in cellular processes that involve the transport of mannose-carrying molecules in the parenchymal cells of the parasite.


Assuntos
Proteínas de Helminto/farmacologia , Lectina de Ligação a Manose/farmacologia , Aglutinação , Sequência de Aminoácidos , Animais , Bactérias/citologia , Bactérias/efeitos dos fármacos , Eritrócitos/citologia , Eritrócitos/efeitos dos fármacos , Fasciola/química , Fasciola/genética , Proteínas de Helminto/química , Proteínas de Helminto/genética , Proteínas de Helminto/metabolismo , Hemaglutinação/efeitos dos fármacos , Humanos , Lectina de Ligação a Manose/química , Lectina de Ligação a Manose/genética , Lectina de Ligação a Manose/metabolismo , Alinhamento de Sequência , Streptococcus/citologia , Streptococcus/efeitos dos fármacos
20.
Vet Ophthalmol ; 24(3): 265-278, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33794048

RESUMO

OBJECTIVES: To identify bacterial microorganisms associated with canine keratomalacia, review their antimicrobial sensitivity, and evaluate clinical outcomes compared to results of microbial culture. METHODS: Retrospective analysis of clinical records of dogs diagnosed with a melting corneal ulcer presented to a referral hospital in Hertfordshire, UK between 2014 and 2018. RESULTS: One hundred and ten melting corneal ulcers were sampled in 106 dogs. The most common pure bacterial isolate was Pseudomonas aeruginosa (n = 26) followed by ß-hemolytic Streptococcus (n = 12). Melting corneal ulcers that cultured coagulase-positive Staphylococcus, coliform bacteria, Pasteurella multocida, Enterococcus, and Streptococcus viridans presented in smaller numbers and were analyzed together (n = 16). Multiple cultures were identified in nine cases (n = 9). Forty-seven cultures yielded no bacterial growth (n = 47). The susceptibility to fluoroquinolones remained high with the exception of ß-hemolytic Streptococci. There was no significant difference in the ulcer severity at presentation in regard to the cultured bacteria. Overall, 63 eyes (57%) received surgical grafting in addition to medical treatment. In 14 cases (13%), the progression of corneal melting despite medical ± surgical treatment resulted in enucleation. Fifty-seven percent (8/14) of the enucleated eyes cultured pure Pseudomonas aeruginosa isolates. In contrast, all ß-hemolytic Streptococcus-associated ulcers healed. CONCLUSIONS: The most common bacterial species associated with canine keratomalacia were Pseudomonas aeruginosa and ß-hemolytic Streptococcus. Because of the variation in antibacterial sensitivity between these two species, bacterial culture and sensitivity testing should be performed in all dogs presenting with keratomalacia. Melting corneal ulcers associated with pure Pseudomonas infection were significantly more likely to result in globe loss than melting corneal ulcers associated with other cultures.


Assuntos
Doenças do Cão/epidemiologia , Infecções Oculares Bacterianas/veterinária , Deficiência de Vitamina A/veterinária , Animais , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Cães , Inglaterra/epidemiologia , Infecções Oculares Bacterianas/tratamento farmacológico , Infecções Oculares Bacterianas/epidemiologia , Infecções Oculares Bacterianas/microbiologia , Feminino , Masculino , Linhagem , Infecções por Pseudomonas/tratamento farmacológico , Infecções por Pseudomonas/epidemiologia , Infecções por Pseudomonas/microbiologia , Infecções por Pseudomonas/veterinária , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/isolamento & purificação , Registros/veterinária , Estudos Retrospectivos , Infecções Estreptocócicas/tratamento farmacológico , Infecções Estreptocócicas/epidemiologia , Infecções Estreptocócicas/microbiologia , Infecções Estreptocócicas/veterinária , Streptococcus/efeitos dos fármacos , Streptococcus/isolamento & purificação , Deficiência de Vitamina A/tratamento farmacológico , Deficiência de Vitamina A/epidemiologia , Deficiência de Vitamina A/microbiologia
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