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1.
J Med Microbiol ; 70(3)2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33750514

RESUMO

Bacteria of the genus Streptococcus, earlier considered typically animal, currently have also been causing infections in humans. It is necessary to make clinicians aware of the emergence of new species that may cause the development of human diseases. There is an increasing frequency of isolation of streptococci such as S. suis, S. dysgalactiae, S. iniae and S. equi from people. Isolation of Streptococcus bovis/Streptococcus equinus complex bacteria has also been reported. The streptococcal species described in this review are gaining new properties and virulence factors by which they can thrive in new environments. It shows the potential of these bacteria to changes in the genome and the settlement of new hosts. Information is presented on clinical cases that concern streptococcus species belonging to the groups Bovis, Pyogenic and Suis. We also present the antibiotic resistance profiles of these bacteria. The emerging resistance to ß-lactams has been reported. In this review, the classification, clinical characteristics and antibiotic resistance of groups and species of streptococci considered as animal pathogens are summarized.


Assuntos
Farmacorresistência Bacteriana , Infecções Estreptocócicas/microbiologia , Streptococcus/fisiologia , Streptococcus/patogenicidade , Zoonoses/microbiologia , Animais , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Humanos , Infecções Estreptocócicas/tratamento farmacológico , Infecções Estreptocócicas/transmissão , Streptococcus/classificação , Streptococcus/efeitos dos fármacos , Virulência , Zoonoses/tratamento farmacológico , Zoonoses/transmissão
2.
Fish Shellfish Immunol ; 110: 23-34, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33378697

RESUMO

Streptococcus parauberis is a pathogenic gram-positive bacterium that causes streptococcosis infection in fish. Since S. parauberis is becoming resistant to multiple antibiotics, the development of alternatives, such as antimicrobial peptides, has gained great attention. Octominin, derived from the defense protein of Octopus minor, showed a significant antimicrobial activity against multidrug resistance S. parauberis, with a minimum inhibitory concentration (MIC) and a minimum bactericidal concentration (MBC) of 50 and 100 µg/mL, respectively. Furthermore, time-kill kinetics, agar diffusion, and bacterial viability assays confirmed the concentration-dependent antibacterial activity of Octominin against S. parauberis. Field emission scanning electron microscopy analysis showed morphological and ultra-structural changes in S. parauberis upon Octominin treatment. Moreover, Octominin treatment demonstrated changes in membrane permeability, induced reactive oxygen species (ROS), and its binding ability to genomic DNA, suggesting its strong bactericidal activity with multiple modes of action. We confirmed the inhibition of biofilm formation and the eradication of existing biofilms in a concentration-dependent manner. Additionally, Octominin on S. parauberis at transcriptional level exhibited downregulation of membrane formation (pgsA and cds1), DNA repairing (recF), biofilm formation (pgaB and epsF) genes, while upregulation of ROS detoxification (sodA) and DNA protecting (ahpF) related genes. An in vivo study confirmed a significantly (P < 0.05) higher relative percentage survival in Octominin-treated larval zebrafish exposed to S. parauberis (93.3%) compared to the control group (20.0%). Collectively, our results confirm that Octominin could be a potential antibacterial and anti-biofilm agent against S. parauberis.


Assuntos
Antibacterianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Biofilmes/efeitos dos fármacos , Viabilidade Microbiana/efeitos dos fármacos , Fragmentos de Peptídeos/farmacologia , Streptococcus/efeitos dos fármacos , Animais , Farmacorresistência Bacteriana Múltipla , Doenças dos Peixes/prevenção & controle , Testes de Sensibilidade Microbiana/veterinária , Microscopia Eletrônica de Varredura , Infecções Estreptocócicas/prevenção & controle , Infecções Estreptocócicas/veterinária , Streptococcus/fisiologia , Streptococcus/ultraestrutura
3.
Molecules ; 25(24)2020 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-33371321

RESUMO

The formation of bacterial biofilms has increased the resistance of bacteria to various environmental factors and is tightly associated with many persistent and chronic bacterial infections. Herein we design a strategy conjugating florfenicol, an antibiotic commonly used in the treatment of streptococcus, with the antimicrobial biomaterial, chitosan oligosaccharides. The results demonstrated that the florfenicol-COS conjugate (F-COS) efficiently eradicated the mature Streptococcus hyovaginalis biofilm, apparently inhibiting drug resistance to florfenicol. A quantity of 250 µg/mL F-COS showed effective inhibitory activity against planktonic cells and biofilm of the bacteria, and a 4-fold improvement of the F-COS compared to unmodified florfenicol was observed. Furthermore, the conjugate showed a broad-spectrum activity against both Gram-positive and Gram-negative bacteria. It suggested that F-COS might have a potential for application in the treatment of biofilm-related infections.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Quitosana/química , Farmacorresistência Bacteriana/efeitos dos fármacos , Oligossacarídeos/química , Oligossacarídeos/farmacologia , Infecções Bacterianas/tratamento farmacológico , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Plâncton/efeitos dos fármacos , Streptococcus/efeitos dos fármacos , Tianfenicol/análogos & derivados , Tianfenicol/química , Tianfenicol/farmacologia
5.
J Vet Sci ; 21(4): e57, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32735095

RESUMO

BACKGROUND: Streptococcus dysgalactiae subspecies equisimilis (SDSE) acts as an etiological agent for lameness, neurological signs, and high mortality in pigs. Despite its importance in pig industries and zoonotic potential, little is known about the effects of this pathogen. OBJECTIVES: This study aimed to determine the molecular characteristics and antimicrobial resistance of SDSE strains isolated from diseased pigs. METHODS: A total 11 SDSE isolates were obtained from diseased pigs. Bacterial identification, PCR for virulence genes, emm typing, and antimicrobial resistance genes, multilocus sequence typing, and antimicrobial susceptibility test were performed. RESULTS: Nine isolates were from piglets, and 8 showed lameness, sudden death, or neurological signs. The isolates were PCR-positive for sla (100%), sagA (100%), and scpA (45.5%), and only 1 isolate amplified the emm gene (stL2764). Eight different sequence types were detected, categorized into 2 clonal complexes and 4 singletons. All the isolates in this study were included in a small cluster, which also contained other strains derived from humans and horses. The minimum inhibitory concentrations for the tested beta-lactams were low, while those for macrolides, tetracyclines, and fluoroquinolones were relatively high. PCR analysis of the macrolide and tetracycline resistance genes demonstrated that the isolates carried erm(B) (18.2%, n = 2), mef(A/E) (9.1%, n = 1), tet(M) (18.2%, n = 2), and tet(O) (90.2%, n = 10). Two isolates presented a mutation in parC, which is associated with fluoroquinolone resistance. CONCLUSION: This study provided insight into swine-derived SDSE, as it is related to veterinary medicine, and elucidated its zoonotic potential, in the context of molecular epidemiology and antimicrobial resistance in public health.


Assuntos
Farmacorresistência Bacteriana/genética , Infecções Estreptocócicas/veterinária , Streptococcus/efeitos dos fármacos , Doenças dos Suínos/diagnóstico , Animais , Antibacterianos/farmacologia , Testes de Sensibilidade Microbiana/veterinária , Tipagem de Sequências Multilocus/veterinária , República da Coreia , Infecções Estreptocócicas/diagnóstico , Infecções Estreptocócicas/microbiologia , Streptococcus/genética , Suínos , Doenças dos Suínos/microbiologia
6.
PLoS One ; 15(7): e0235560, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32614907

RESUMO

The present study investigated the effects of four woody forages (Moringa oleifera Lam (MOL), fermented MOL, Folium mori (FM) and fermented FM) on biodiversity and bioactivity of aerobic culturable gut bacteria of tilapia (Oreochromis niloticus) by a traditional culture-dependent method. A total of 133 aerobic culturable isolates were recovered and identified from the gut of tilapia, belonging to 35 species of 12 genera in three bacterial phyla (Firmicutes, Actinobacteria and Proteobacteria). Among them, 6 bacterial isolates of Bacillus baekryungensis, Bacillus marisflavi, Bacillus pumilus, Bacillus methylotrophicus, Proteus mirabilis and Pseudomonas taiwanensis were isolated from all the five experimental groups. The Bray-Curtis analysis showed that the bacterial communities among the five groups displayed obvious differences. In addition, this result of bioactivity showed that approximate 43% of the aerobic culturable gut bacteria of tilapia displayed a distinct anti-bacterial activity against at least one of four fish pathogens Streptococcus agalactiae, Streptococcus iniae, Micrococcus luteus and Vibrio parahemolyticus. Furthermore, Bacillus amyloliquefaciens and Streptomyces rutgersensis displayed strong activity against all four indicator bacteria. These results contribute to our understanding of the intestinal bacterial diversity of tilapia when fed with woody forages and how certain antimicrobial bacteria flourished under such diets. This can aid in the further exploitation of new diets and probiotic sources in aquaculture.


Assuntos
Bactérias/isolamento & purificação , Ciclídeos/microbiologia , Microbioma Gastrointestinal , Aerobiose , Animais , Antibacterianos/farmacologia , Bacillus/efeitos dos fármacos , Bacillus/genética , Bacillus/isolamento & purificação , Bactérias/classificação , Bactérias/efeitos dos fármacos , Bactérias/genética , Biodiversidade , Dieta/veterinária , Microbioma Gastrointestinal/efeitos dos fármacos , Intestinos/microbiologia , Testes de Sensibilidade Microbiana , Filogenia , RNA Ribossômico 16S/química , RNA Ribossômico 16S/metabolismo , Streptococcus/efeitos dos fármacos , Streptococcus/genética , Streptococcus/isolamento & purificação
7.
Niger J Clin Pract ; 23(7): 900-905, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32620717

RESUMO

Objectives: This study aims to investigate the effects of various mouthwashes on bacteremia development following a debonding process, which is performed after orthodontic treatment. Subjects and Methods: The study included patients who received fixed orthodontic treatment and were indicated for debonding. A total of 40 patients in four groups were selected for the study; no mouthwash (Group 1), mouthwash containing 0.12% chlorhexidine-gluconate (Group 2), mouthwash containing essential-oils (Group 3), and mouthwash containing 7.5% povidone-iodine (Group 4). Before (T0) and following (T1) the debonding procedure, blood samples were obtained from the patients. Then, the blood samples were placed in blood culture bottles to investigate bacterial growth. Results: Based on the results of the study, it was determined that the blood samples obtained at T0did not indicate any bacterial growth. Furthermore, it was observed that the blood samples obtained at T1included Streptococcus viridans, Streptococcus oralis, Streptococcus mutans, and Staphylococcus aereus growth, respectively, in 4 patients from Group 1 while Streptococcus salivarius growth was observed in 1 patient from Group 3 in addition to Streptococcus mitis growth in 1 patient from Group 4. No bacterial growth was observed in Group 2. While the results obtained between Group 1 and Group 2 were statistically significant, no statistically significant difference was observed between other groups. Conclusions: Finally, it was determined that the mouthwash 0.12% chlorhexidine-gluconate was statistically significant in comparison to the control group. It can be concluded that this mouthwash can be used to decrease bacterial density in oral flora before debonding procedures.


Assuntos
Anti-Infecciosos Locais/farmacologia , Bacteriemia/tratamento farmacológico , Clorexidina/análogos & derivados , Antissépticos Bucais/farmacologia , Staphylococcus/efeitos dos fármacos , Streptococcus/efeitos dos fármacos , Adulto , Clorexidina/farmacologia , Descolagem Dentária , Feminino , Humanos , Masculino , Staphylococcus/classificação , Staphylococcus/isolamento & purificação , Streptococcus/classificação , Streptococcus/isolamento & purificação , Resultado do Tratamento
8.
J Dairy Sci ; 103(8): 7249-7259, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32475664

RESUMO

The mode of action of bismuth subnitrate in teat sealant formulations as a preventative for intramammary infections during the dry period is unknown. Although previous studies proposed an action mechanism-creating a physical barrier in the teat canal to prevent bacterial invasion-it has not been proven experimentally. We hypothesized that bismuth subnitrate has an inhibitory effect on bacterial growth, in addition to its barrier effect. The objective of this study was to assess the effect of bismuth subnitrate on bacterial growth of major mastitis-causing agents. A strain of Streptococcus uberis (SR115), 2 strains of Staphylococcus aureus (SA3971/59 and SA1), and a strain of Escherichia coli (P17.14291) were tested in vitro for their ability to grow in the presence or absence of bismuth subnitrate. Disk diffusion testing, impedance measurement, and evaluation of bacterial growth in shaking conditions were the methods used to test this hypothesis. A reduction of growth in the presence of bismuth subnitrate occurred for all the strains tested. However, we observed strain and species variations in the extent of growth inhibition. These results suggest that an inhibitory effect on bacterial growth by bismuth subnitrate could partially explain the efficacy of bismuth-based formulations for preventing intramammary infections over the dry period. Further research is required to test the effect of teat sealant formulations on bacterial growth.


Assuntos
Bismuto/farmacologia , Escherichia coli/efeitos dos fármacos , Mastite Bovina/prevenção & controle , Leite/microbiologia , Staphylococcus aureus/efeitos dos fármacos , Streptococcus/efeitos dos fármacos , Animais , Bovinos , Escherichia coli/crescimento & desenvolvimento , Feminino , Glândulas Mamárias Animais/microbiologia , Mastite Bovina/microbiologia , Staphylococcus aureus/crescimento & desenvolvimento , Streptococcus/crescimento & desenvolvimento
9.
PLoS One ; 15(4): e0231887, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32320455

RESUMO

INTRODUCTION: Nasopharyngeal (NP) colonization with antimicrobial-resistant bacteria is a global public health concern. Antimicrobial-resistance (AMR) genes carried by the resident NP microbiota may serve as a reservoir for transfer of resistance elements to opportunistic pathogens. Little is known about the NP antibiotic resistome. This study longitudinally investigated the composition of the NP antibiotic resistome in Streptococcus-enriched samples in a South African birth cohort. METHODS: As a proof of concept study, 196 longitudinal NP samples were retrieved from a subset of 23 infants enrolled as part of broader birth cohort study. These were selected on the basis of changes in serotype and antibiogram over time. NP samples underwent short-term enrichment for streptococci prior to total nucleic acid extraction and whole metagenome shotgun sequencing (WMGS). Reads were assembled and aligned to pneumococcal reference genomes for the extraction of streptococcal and non-streptococcal bacterial reads. Contigs were aligned to the Antibiotic Resistance Gene-ANNOTation database of acquired AMR genes. RESULTS: AMR genes were detected in 64% (125/196) of the samples. A total of 329 AMR genes were detected, including 36 non-redundant genes, ranging from 1 to 14 genes per sample. The predominant AMR genes detected encoded resistance mechanisms to beta-lactam (52%, 172/329), macrolide-lincosamide-streptogramin (17%, 56/329), and tetracycline antibiotics (12%, 38/329). MsrD, ermB, and mefA genes were only detected from streptococcal reads. The predominant genes detected from non- streptococcal reads included blaOXA-60, blaOXA-22, and blaBRO-1. Different patterns of carriage of AMR genes were observed, with only one infant having a stable carriage of mefA, msrD and tetM over a long period. CONCLUSION: This study demonstrates that WMGS can provide a broad snapshot of the NP resistome and has the potential to provide a comprehensive assessment of resistance elements present in this niche.


Assuntos
Metagenômica , Nasofaringe/microbiologia , Análise de Sequência de DNA , Antibacterianos/farmacologia , Estudos de Coortes , Feminino , Humanos , Lactente , Estudos Longitudinais , Masculino , Nasofaringe/efeitos dos fármacos , África do Sul , Streptococcus/efeitos dos fármacos , Streptococcus/genética , Streptococcus/fisiologia
10.
Food Microbiol ; 90: 103458, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32336375

RESUMO

Pozol is a beverage prepared with maize dough made after boiling the kernels in limewater. This pretreatment could act as a selective force that shapes the starter microbiota, with microorganisms able to survive the fermentation. Since Streptococcus infantarius subsp. infantarius (Sii) dominates in pozol, we evaluated the effect of acid and alkali stresses on strain Sii-25124 in commercial APT broth as a first attempt to assess its adaptation capacity. Results suggest that Sii-25124 has adaptative advantages to pH changes that possibly contribute to its persistence even after the acidification of the dough. Its cardinal pH values were 4.0 and 11.0, with an optimum between 6.6 and 8.0. It showed alkali tolerance unlike other pozol Sii strains. Adaptation at pH 4.0, 10.0 and 11.0, compared with non-adapted cells, induced acid tolerance enhancing survival at pH 3.6 (P < 0.05); a 2 min heat shock at 62 °C induced alkali tolerance response enhancing survival at pH 10.5 (P < 0.05). The up-regulation of dnaK, groEL, ptsG and atpB was observed during 5 h of exposition at pH 3.6, 4.0 and 10.0, showing similar expression rates after induction by acid shock or alkaline stress. Changes of atpB were more evident having almost five-fold induction during long-term stress.


Assuntos
Ácidos/farmacologia , Adaptação Fisiológica , Álcalis/farmacologia , Alimentos e Bebidas Fermentados/microbiologia , Streptococcus/efeitos dos fármacos , Streptococcus/metabolismo , Proteínas de Bactérias/genética , Chaperonina 60/genética , Microbiologia de Alimentos , Concentração de Íons de Hidrogênio , Streptococcus/isolamento & purificação
11.
Carbohydr Polym ; 235: 115951, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32122488

RESUMO

Fabrication of nanocomposite biofilms with enhanced mechanical and antibacterial properties was successfully achieved from hyaluronan (HA) and partially deacetylated chitin nanowhiskers (ChNWs) by a casting-evaporation method. The hydrolysis process of chitin showed an important role in the dimensions, stability, and the crystallinity of extracted ChNWs in a time-dependent manner. The volume fraction of ChNWs nanofiller varying from (0.001 to 0.5) exhibited a great influence on the mechanical properties of the biofilms (young modulus, strength) was enhanced by the high load-bearing capacity of NWs compared with net HA film. The antibacterial activity of the nanocomposite biofilms exhibited significant bactericidal activity against different types of bacteria (-/+ gram). HA/ChNWs Nanocomposite biofilms did not show any toxicity against normal human dermal fibroblasts (NHDF) and human primary osteogenic sarcoma (Saos-2) cell lines. The new biofilms with unique properties like edibleness, environmental friendliness, high mechanical properties, antibacterial performance, and non-cytotoxicity that could be used in skin tissue regenerations, and drug delivery applications.


Assuntos
Antibacterianos/farmacologia , Biofilmes , Quitina/farmacologia , Ácido Hialurônico/farmacologia , Nanocompostos/química , Antibacterianos/química , Antibacterianos/isolamento & purificação , Bacillus subtilis/efeitos dos fármacos , Configuração de Carboidratos , Linhagem Celular , Quitina/química , Quitina/isolamento & purificação , Escherichia coli/efeitos dos fármacos , Humanos , Ácido Hialurônico/química , Ácido Hialurônico/isolamento & purificação , Klebsiella pneumoniae/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Tamanho da Partícula , Streptococcus/efeitos dos fármacos , Propriedades de Superfície
12.
Vet Microbiol ; 242: 108592, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32122596

RESUMO

A number of veterinary clinical pathology laboratories in New Zealand have been reporting emergence of increased minimum in inhibitory concentrations for ß-lactams in the common clinical bovine mastitis pathogen Streptococcus uberis. The objective of this study was to determine the genetic basis of this increase in MIC for ß-lactams amongst S. uberis. Illumina sequencing and determination of oxacillin MIC was performed on 265 clinical isolates. Published sequences of the five penicillin binding proteins pbp1a, pbp1b, pbp2a, pbp2b, and pbp2x were used to identify, extract and align these sequences from the study isolates. Amino acid substitutions resulting from single nucleotide polymorphisms (SNP) within these genes were analysed for associations with elevated (≥ 0.5 mg/L) oxacillin MIC together with a genome wide association study. The population structure of the study isolates was approximated using a phylogenetic tree generated from an alignment of the core genome. A total of 53 % of isolates had MIC ≥ 0.5 mg/L for oxacillin. A total of 101 substitutions within the five pbp were identified, of which 11 were statistically associated with an MIC ≥ 0.5 mg/L. All 140 isolates which exhibited an increased ß-lactam MIC had SNPs leading to pbp2x E381K and Q554E substitutions. The phylogenetic tree indicated that the genotype and phenotype associated with the increased MIC for oxacillin were present in several different lineages suggesting that acquisition of this increased ß-lactam MIC had occurred in multiple geographically distinct regions. Reanalysis of the data from the intervention studies from which the isolates were originally drawn found a tendency for the pbp2x E381K substitution to be associated with lower cure rates. It is concluded that there is geographically and genetically widespread presence of pbp substitutions associated with reduced susceptibility to ß-lactam antimicrobials. Additionally, presence of pbp substitutions tended to be associated with poorer cure rate outcomes following antimicrobial therapy for clinical mastitis.


Assuntos
Antibacterianos/farmacologia , Mastite Bovina/microbiologia , Streptococcus/efeitos dos fármacos , Streptococcus/genética , Resistência beta-Lactâmica/genética , Substituição de Aminoácidos , Animais , Proteínas de Bactérias/genética , Bovinos , Feminino , Estudo de Associação Genômica Ampla , Testes de Sensibilidade Microbiana , Nova Zelândia , Oxacilina/farmacologia , Proteínas de Ligação às Penicilinas/genética , Filogenia , Polimorfismo de Nucleotídeo Único
13.
Int J Mol Sci ; 21(6)2020 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-32183193

RESUMO

Saliva plays a crucial role in oral cavity. In addition to its buffering and moisturizing properties, saliva fulfills many biofunctional requirements, including antibacterial activity that is essential to assure proper oral microbiota growth. Due to numerous extra- and intra-systemic factors, there are many disorders of its secretion, leading to oral dryness. Saliva substitutes used in such situations must meet many demands. This study was design to evaluate the effect of core-shell magnetic nanoparticles (MNPs) adding (gold-coated and aminosilane-coated nanoparticles NPs) on antimicrobial (microorganism adhesion, biofilm formation), rheological (viscosity, viscoelasticity) and physicochemical (pH, surface tension, conductivity) properties of three commercially available saliva formulations. Upon the addition of NPs (20 µg/mL), antibacterial activity of artificial saliva was found to increase against tested microorganisms by 20% to 50%. NPs, especially gold-coated ones, decrease the adhesion of Gram-positive and fungal cells by 65% and Gram-negative bacteria cells by 45%. Moreover, the addition of NPs strengthened the antimicrobial properties of tested artificial saliva, without influencing their rheological and physicochemical properties, which stay within the range characterizing the natural saliva collected from healthy subjects.


Assuntos
Anti-Infecciosos/química , Nanopartículas de Magnetita/química , Saliva Artificial/química , Anti-Infecciosos/farmacologia , Aderência Bacteriana/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Candida/efeitos dos fármacos , Elasticidade , Condutividade Elétrica , Ouro/química , Pseudomonas/efeitos dos fármacos , Saliva Artificial/farmacologia , Silanos/química , Streptococcus/efeitos dos fármacos , Tensão Superficial , Viscosidade
14.
Transfusion ; 60(5): 1050-1059, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32187695

RESUMO

BACKGROUND: Our previous study showed that ultraviolet C (UVC) from xenon (Xe) flash without any photoreactive compounds inactivated bacteria in platelet concentrates (PCs) with less damage to platelets (PLTs) as compared with Xe flash containing ultraviolet A, ultraviolet B, and visible light. Here, we report a UVC irradiation system for PCs under flow conditions consisting of a flow path-irradiation sheet, a peristaltic pump, and a collection bag. STUDY DESIGN AND METHODS: Platelet concentrates containing Ringer's solution (R-PCs) inoculated with bacteria were injected into a flow path sheet using a peristaltic pump, being irradiated with UVC from Xe flash. The quality of the irradiated PCs containing platelet additive solution (PAS-PCs) was assessed based on PC variables, PLT surface markers, and aggregation ability. RESULTS: Streptococcus dysgalactiae (12 tests) and Escherichia coli (11) were all negative on bacterial culture, while Staphylococcus aureus (12) and Klebsiella pneumoniae (14) grew in one and two R-PCs, respectively. Bacillus cereus spores were inactivated in 7 of 12 R-PCs. PC variables became significantly different between irradiated and nonirradiated PAS-PCs. P-selectin, first procaspase-activating compound (PAC-1) binding, and phosphatidylserine increased by irradiation. Aggregability stimulated by adenosine diphosphate, collagen, or thromboxane A2 increased in the irradiated PAS-PCs, while that by thrombin became smaller compared with nonirradiated controls. CONCLUSION: This newly developed system inactivated bacteria including spores in R-PCs. PAS-PCs irradiated by this system retained acceptable in vitro quality and aggregability. Usage of a peristaltic pump instead of agitator during irradiation may enable this system to be directly combined with an apheresis blood cell separator.


Assuntos
Plaquetas/citologia , Preservação de Sangue , Desinfecção/instrumentação , Viabilidade Microbiana , Raios Ultravioleta , Xenônio/farmacologia , Bacillus cereus/efeitos dos fármacos , Bacillus cereus/fisiologia , Bacillus cereus/efeitos da radiação , Bactérias/efeitos dos fármacos , Bactérias/efeitos da radiação , Remoção de Componentes Sanguíneos , Plaquetas/efeitos dos fármacos , Plaquetas/efeitos da radiação , Preservação de Sangue/instrumentação , Preservação de Sangue/métodos , Segurança do Sangue/instrumentação , Segurança do Sangue/métodos , Desinfecção/métodos , Contaminação de Medicamentos/prevenção & controle , Escherichia coli/efeitos dos fármacos , Escherichia coli/fisiologia , Escherichia coli/efeitos da radiação , Humanos , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/fisiologia , Klebsiella pneumoniae/efeitos da radiação , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Viabilidade Microbiana/efeitos da radiação , Soluções para Preservação de Órgãos/farmacologia , Agregação Plaquetária/efeitos dos fármacos , Agregação Plaquetária/fisiologia , Agregação Plaquetária/efeitos da radiação , Controle de Qualidade , Solução de Ringer/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/fisiologia , Staphylococcus aureus/efeitos da radiação , Streptococcus/efeitos dos fármacos , Streptococcus/fisiologia , Streptococcus/efeitos da radiação
15.
PLoS One ; 15(3): e0229417, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32134941

RESUMO

Streptococcus pneumoniae infections are one of the major causes of morbility and mortality worldwide. Although vaccination and antibiotherapy constitute fundamental and complementary strategies against pneumococcal infections, they present some limitations including the increase in non-vaccine serotypes and the emergence of multidrug-resistances, respectively. Ribosomally-synthesized antimicrobial peptides (i.e. bacteriocins) produced by Lactic Acid Bacteria (LAB) may represent an alternative or complementary strategy to antibiotics for the control of pneumococal infections. We tested the antimicrobial activity of 37 bacteriocinogenic LAB, isolated from food and other sources, against clinical S. pneumoniae strains. Streptococcus infantarius subsp. infantarius LP90, isolated from Venezuelan water-buffalo milk, was selected because of its broad and strong anti-pneumococcal spectrum. The in vitro safety assessment of S. infantarius LP90 revealed that it may be considered avirulent. The analysis of a 19,539-bp cluster showed the presence of 29 putative open reading frames (ORFs), including the genes encoding 8 new class II-bacteriocins, as well as the proteins involved in their secretion, immunity and regulation. Transcriptional analyses evidenced that the induction factor (IF) structural gene, the bacteriocin/IF transporter genes, the bacteriocin structural genes and most of the bacteriocin immunity genes were transcribed. MALDI-TOF analyses of peptides purified using different multichromatographic procedures revealed that the dairy strain S. infantarius LP90 produces at least 6 bacteriocins, including infantaricin A1, a novel anti-pneumococcal two-peptide bacteriocin.


Assuntos
Antibacterianos/metabolismo , Bacteriocinas/genética , Bacteriocinas/metabolismo , Infecções Pneumocócicas/metabolismo , Streptococcus/efeitos dos fármacos , Streptococcus/isolamento & purificação , Sequência de Aminoácidos , Antibacterianos/administração & dosagem , Antibacterianos/isolamento & purificação , Bacteriocinas/administração & dosagem , Bacteriocinas/isolamento & purificação , Humanos , Infecções Pneumocócicas/genética , Infecções Pneumocócicas/microbiologia , Streptococcus/classificação
16.
Int J Antimicrob Agents ; 55(2): 105859, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31794868

RESUMO

Many enterococcal strains produce bacteriocins, which could be useful as natural food preservatives through inhibition of pathogenic and spoilage microorganisms. There is little knowledge of the distribution and spectrum of bacteriocin activity and the distribution of bacteriocin-encoding genes in enterococci isolated from dogs. Therefore, we subjected 160 enterococcal isolates (E. faecium n=92, E. faecalis n=35, E. hirae n=28, E. casseliflavus n=3, E. mundtii n=2) from 105 samples of dog faeces to polymerase chain reaction (PCR) detection of genes for enterocin A, P, B, L50A, L50B, AS-48, and bac31 and to screening for bacteriocin activity. The results showed the presence of at least one of the tested genes in 54/160 isolates, with E. faecium the most common gene-possessing species. The most frequently occurring gene for production of enterocin A was observed in combination with enterocin P and B. Bacteriocin activity was observed in 76/160 isolates against at least one of 5 indicator bacteria from the genus Listeria, Enterococcus, Streptococcus and Staphylococcus. Four selected strains (IK25, Bri, I/Dz, P10) were active mostly against different species of Enterococcus (in the range 400-25 600 AU/mL) and Listeria sp. (800-12 800 AU/mL) but no Gram-negative bacteria were inhibited. Protein character, thermostability (up to 121°C) and stability at different pH values (3.0-10.0) were confirmed for crude bacteriocins of these four strains. The antimicrobial substance of E. faecium IK25 strain was identified as enterocin B using molecular weight detection and the presence of genes.


Assuntos
Antibacterianos/metabolismo , Bacteriocinas/metabolismo , Enterococcus/metabolismo , Animais , Antibacterianos/farmacologia , Bacteriocinas/genética , Bacteriocinas/farmacologia , Cães , Enterococcus/genética , Enterococcus/isolamento & purificação , Microbioma Gastrointestinal , Listeria/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Reação em Cadeia da Polimerase , Staphylococcus/efeitos dos fármacos , Streptococcus/efeitos dos fármacos
17.
Fish Shellfish Immunol ; 98: 899-907, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31765793

RESUMO

Streptococcus dysgalactiae is an important pathogenic bacterium that has caused economic loss for the cobia industry in Taiwan, ROC. This study presents a highly effective subunit vaccine composed of a moonlight protein, α-enolase, for the prevention of S. dysgalactiae infection. First, α-enolase was cloned, transformed, and expressed in E. coli for production of recombinant protein. Then, the protective efficacies of α-enolase recombinant protein were evaluated in combination with either a pro-inflammatory cytokine, TNF-α, or an oil adjuvant, ISA 763 AVG. The results showed that the combination of α-enolase and ISA 763 AVG was highly protective (RPS = 88.89%), while a negative effect was found in the group immunised with α-enolase adjuvanted with TNF-α (RPS = 22.22%). A further study was conducted with double dose of ISA 763 AVG, which led to an increased RPS value of 97.37%. Moreover, immunised cobia exhibited significantly greater lysozyme activity, antibody responses, and expression of certain immune-related genes post-challenge. Altogether, our results demonstrated that a combination of α-enolase recombinant protein with ISA 763 AVG adjuvant is a promising vaccine that can be employed for protection of cobia against S. dysgalactiae infection.


Assuntos
Vacinas Bacterianas/farmacologia , Doenças dos Peixes/prevenção & controle , Peixes/imunologia , Fosfopiruvato Hidratase/farmacologia , Infecções Estreptocócicas/veterinária , Streptococcus/efeitos dos fármacos , Animais , Vacinas Bacterianas/administração & dosagem , Doenças dos Peixes/imunologia , Doenças dos Peixes/microbiologia , Fosfopiruvato Hidratase/administração & dosagem , Infecções Estreptocócicas/imunologia , Infecções Estreptocócicas/prevenção & controle
18.
Microbiol Immunol ; 64(2): 113-122, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31750556

RESUMO

Streptococcus dysgalactiae subsp. equisimilis (SDSE) causes severe invasive streptococcal infections, especially in elderly people. Between 2013 and 2018, 88 streptococci were isolated from clinical blood culture in a hospital in Toyama prefecture, Japan. The collection included six Group A SDSE (ASD) strains, which are rarely isolated. Multilocus sequence typing categorized five of the six strains into ST128 and the remaining strain into a new type. Maximum-likelihood phylogenetic analysis revealed that the six ASD strains had highly similar genome sequences. Bayesian analysis indicated that the most recent common ancestor of the strains appeared 39 years ago. The ASD strains possessed carbohydrate synthase genes that are conserved in Streptococcus pyogenes strains, whereas one strain featured a different arrangement of the gene cluster. The carbohydrate synthase genes varied by Lancefield type (A, C, and G).


Assuntos
Infecções Estreptocócicas , Streptococcus/genética , Idoso , Teorema de Bayes , Sangue/microbiologia , Metabolismo dos Carboidratos/genética , DNA Bacteriano , Resistência Microbiana a Medicamentos/genética , Genoma Bacteriano , Humanos , Japão/epidemiologia , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Filogenia , Infecções Estreptocócicas/epidemiologia , Infecções Estreptocócicas/microbiologia , Streptococcus/classificação , Streptococcus/efeitos dos fármacos , Streptococcus/isolamento & purificação , Fatores de Virulência/genética , Sequenciamento Completo do Genoma
19.
J Fish Dis ; 43(2): 239-252, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31820468

RESUMO

Pure bacterial cultures were isolated from different tissues of moribund Megalobrama terminalis from a high mortality event that occurred at a farm in Foshan, China. Two isolates (F2 and F3) were identified as Streptococcus dysgalactiae subsp. dysgalactiae based on morphological and biochemical detection as well as molecular analysis. In brain heart infusion broth, the best growth conditions of isolate F3 were 35ºC, salinity 5‰ and pH 7. Furthermore, infection with isolate F3 (1.2 × 106  CFU/fish) led to the death of M. terminalis and zebrafish (Danio rerio). However, isolate F3 had no obvious pathogenicity to tilapia (GIFT, Oreochromis niloticus). When the water temperature was 29ºC, the corresponding mortality rates for zebrafish infected by isolate F3 were higher than those at 23ºC. Culture for 24 and 72 hr with isolate F3 resulted in the same mortality rates for zebrafish. The antimicrobial susceptibility assay revealed that isolate F3 was susceptible to ampicillin, florfenicol and several other antibiotics but resistant to nalidixic acid, streptomycin, sulfamethoxazole/trimethoprim, neomycin and amikacin. To our knowledge, this is the first report that S. dysgalactiae infected the subtropical freshwater fish M. terminalis, which indicates that this bacterium is a potential threat to subtropical freshwater fish.


Assuntos
Cyprinidae , Doenças dos Peixes/microbiologia , Infecções Estreptocócicas/veterinária , Streptococcus/fisiologia , Streptococcus/patogenicidade , Animais , Antibacterianos/farmacologia , China , Ciclídeos , Farmacorresistência Bacteriana , Filogenia , Infecções Estreptocócicas/microbiologia , Streptococcus/classificação , Streptococcus/efeitos dos fármacos , Peixe-Zebra
20.
Arch Oral Biol ; 109: 104554, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31563709

RESUMO

OBJECTIVE: Psidium sp., Mangifera sp. and Mentha sp. and its mixture (PEM) are known to have antimicrobial and anti-adherence effects. DESIGN: Here, we have investigated these individual plant extracts and its synergistic mixture (PEM) for its anti-cariogenic effect to reduce populations of single and mixed-species of Streptococcus sanguinis and Streptococcus mutans in a planktonic or/and biofilm and their others reduced virulence. Bacterial populations in the biofilm after 24 h, hydrophobic cell surface activity to n-hexadecane and pH changes at 5 min' intervals until 90 min of incubation were recorded. Total phenolic content and bioactive compounds in the crude aqueous plant extracts were analysed. Regulatory gene expressions of S. mutans adhesins genes (gtfB, gtfC, gbpB and spaP) upon treatment with PEM were investigated in planktonic and biofilm conditions. RESULTS: All plant extracts strongly reduced S. mutans in the biofilm compared to S. sanguinis in single and mixed-species. PEM reduced S. mutans by 84% with S. sanguinis 87% in the mixed population. Psidium sp. and PEM highly reduced cell-surface hydrophobicity of the two bacteria thus reducing adherence and biofilm formation. PEM and Mangifera sp. lowered initial pH change in the mixed populations of S. sanguinis and S. mutans. PEM downregulated the S. mutans gtfB gene expression in the single species planktonic and mixed-species biofilms. CONCLUSIONS: The effectiveness of PEM in reducing S. mutans within the biofilm, cell-surface hydrophobicity, acid production and adhesin gene (gtfB) expression in mixed-species with S. sanguinis indicates its potential as an antibacterial agent against dental caries. This is attributed to the phenolic content in the PEM.


Assuntos
Biofilmes/efeitos dos fármacos , Mangifera/química , Mentha/química , Extratos Vegetais/farmacologia , Psidium/química , Ácidos/análise , Aderência Bacteriana/efeitos dos fármacos , Genes Bacterianos , Concentração de Íons de Hidrogênio , Streptococcus/efeitos dos fármacos , Streptococcus mutans/efeitos dos fármacos , Streptococcus sanguis
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