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1.
Medicine (Baltimore) ; 100(2): e24090, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33466172

RESUMO

OBJECTIVE: To understood the pathogen detection status and clinical characteristics of suspected pertussis in children and to observe the drug sensitivity and drug resistance genes of Bordetella pertussis (B. pertussis). METHODS: Three hundred fifty-one cases were collected and their nasopharyngeal swab samples were analyzed by culture and fluorescent quantitative polymerase chain reaction. The susceptibility to erythromycin, clindamycin, ampicillin, levofloxacin, and sulfamethoxazole-trimethoprim were tested by E-test for the positive strains, and the susceptibility to erythromycin was also tested for the KB disk diffusion method. The 23S rRNA gene of the positive strains was amplified and sequenced, and statistical analysis was performed in conjunction with clinical data. RESULTS: The positive rate of bacterial culture was 16.8% (59/351), and the positive rate of PCR was 62.4% (219/351). Two cases were positive about bacterial culture and negative for PCR. There were 221 confirmed cases of pertussis. The E-test results showed that the rate of the sensitivity of the 55 strains of pertussis to erythromycin and clindamycin was 50.9% (28/55), the minimum antibiotic concentration50 (MIC50) and MIC90 values were 0.094/>256 and 0.75/>256 mg/L, respectively, and the MIC50/MIC90 to ampicillin, levofloxacin, and sulfamethoxazole were 0.125/0.19, 0.38/0.5, and 0.125/0.25 mg/L, respectively. The KB disk diffusion method showed 27 of the 55 strains 49.1% (27/55) was resistant to erythromycin; all of the resistant strains had the 23S rRNA gene A2047G mutation, and their MIC of erythromycin was >256 mg/L. CONCLUSION: The diagnosis of pertussis by a fluorescent quantitative polymerase chain reaction method is more sensitive than that of bacterial culture. The resistance of B. pertussis to erythromycin was prominent. All of the strains of B. pertussis resistant to erythromycin in our center had the A2047G mutation of the 23S rRNA gene.


Assuntos
Bordetella pertussis/efeitos dos fármacos , Bordetella pertussis/genética , Farmacorresistência Bacteriana/genética , Testes de Sensibilidade Microbiana/métodos , Coqueluche/microbiologia , Antibacterianos/farmacologia , Criança , Pré-Escolar , China , Técnicas de Cultura , Eritromicina/farmacologia , Feminino , Humanos , Lactente , Masculino , Tipagem Molecular , Mutação , Reação em Cadeia da Polimerase , RNA Ribossômico 23S/genética , Coqueluche/diagnóstico
2.
Bioresour Technol ; 318: 124048, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32871319

RESUMO

This study explored the fate of Zn- resistance genes (ZRGs), antibiotic- resistance genes (ARGs) and related mechanisms associated with bacterial communities during co-composting of erythromycin manufacturing wastes (EMW) and pig manure (PM) at the ratio of 0% (control), 5% (L) and 20% (H) (PM basis). The relative abundance (RAs) of erm genes in most treatments were decreased by 77.75-99.97% after composting. But total RA of czc genes were increased by 8.34, 15.86 and 12.03 times in control, L and H treatment respectively. The higher EMW in H showed a negative impact on removing of erm genes and aggravated the enrichment of ZRGs compared with control and L. Redundancy analysis showed that Firmicutes accounted for the highest explanation of ARGs and ZRGs variations, and Zn in EMW had significant impact on the succession of bacterial community.


Assuntos
Compostagem , Animais , Antibacterianos/farmacologia , Resistência Microbiana a Medicamentos/genética , Eritromicina/farmacologia , Genes Bacterianos , Esterco , Suínos , Zinco
3.
BMC Infect Dis ; 20(1): 615, 2020 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-32814558

RESUMO

BACKGROUND: The global prevalent ptxP3 strains varies from about 10% to about 50% of circulating B. pertussis population in different areas of China. METHODS: To investigate the difference of vaccination status between different genotypes in the circulating B. pertussis after 10 years of acellular pertussis vaccine (aPV) used in China. The nasopharyngeal swabs and isolates of B. pertussis from these patients were used to perform genotyping of antigen genes. We use antibiotic susceptibility test against erythromycin and sequencing methods for site 2047 of 23S rRNA to determine the resistance status. RESULTS: The ptxP1 allele with erythromycin resistant (ER) B. pertussis infection (total of 449 subjects) consisted of 84.70 to 96.70% from 2012 to 2016 in this study. Vaccinated with co-purified aPV was found in 133(133/403,33.0%), 1(1/9,11.1%) and 2(2/21,9.5%) in ptxP1/fhaB3-ER, ptxP1/fhaB2-ES and ptxP3/fhaB2-ES B. pertussis infected children each, which showed a significant difference (χ2 = 6.87, P = 0.032). CONCLUSIONS: The ptxP3-ES B. pertussis was rare while the ptxP1-ER B. pertussis was steadily increased in Xi'an, China from 2012 to 2016, where co-purified aPV was prevalent used. This pose a hypothesis that the co-purified aPV might protect against ptxP3 strains more efficient, which generated a rare chance for ptxP3 strains to be under the antibiotic pressure and further developed to be erythromycin resistance. A further cohort study and the mechanisms of the additional antigen proteins of co-purified aPV protected against B. pertussis should be consideration.


Assuntos
Bordetella pertussis/efeitos dos fármacos , Bordetella pertussis/genética , Toxina Pertussis/genética , Vacina contra Coqueluche/uso terapêutico , Coqueluche/epidemiologia , Alelos , Antibacterianos/farmacologia , Bordetella pertussis/isolamento & purificação , Pré-Escolar , China/epidemiologia , Farmacorresistência Bacteriana/efeitos dos fármacos , Farmacorresistência Bacteriana/genética , Eritromicina/farmacologia , Genótipo , Humanos , Testes de Sensibilidade Microbiana , Nasofaringe/microbiologia , Vacina contra Coqueluche/imunologia , Prevalência , RNA Ribossômico 23S/genética , Estudos Retrospectivos , Vacinação , Coqueluche/microbiologia , Coqueluche/prevenção & controle
4.
Lett Appl Microbiol ; 71(4): 359-368, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32713031

RESUMO

Staphylococci from Sheedal of Northeast India was isolated, identified and characterized. All the isolated staphylococci were found to be coagulase negative. Based on the rpoB gene sequences followed by analysis using NCBI-BLAST software, seven species of Staphylococcus namely, S. piscifermentans, S. condimenti, S. arlettae, S. sciuri, S. warneri, S. nepalensis and S. hominis were recognized. Phylogenetic analyses revealed three major cluster groups. All the seven Staphylococcus showed their NaCl tolerance from 2 to 8%. No species was able to grow at 55°C. Except S. arlettae and S. sciuri, all the isolated staphylococcal species exhibited growth at pH 4-8. No isolated species was able to ferment mannitol, sucrose and arabinose. All the species exhibited moderate to maximum proteolytic and lipolytic activities. All the seven species were found to be sensitive to the antibiotics, namely, erythromycin, norfloxacin, ampicillin, streptomycin and vancomycin, whereas all were resistant to co-trimoxazole. Only S. piscifermentans was found antagonist to Salmonella enterica, Escherichia coli and Bacillus subtilis, although the clear zone was minimal. All the staphylococcal species except S. arlettae and S. sciuri exhibited hydrophobicity ranging from 25 to 66%. The observed characteristics of isolated Staphylococci from Sheedal revealed their role in fish fermentation.


Assuntos
Alimentos e Bebidas Fermentados/microbiologia , Produtos Pesqueiros/microbiologia , Staphylococcus/isolamento & purificação , Ampicilina/farmacologia , Animais , Antibacterianos/farmacologia , Eritromicina/farmacologia , Fermentação , Peixes/microbiologia , Contaminação de Alimentos/análise , Índia , Filogenia , Staphylococcus/classificação , Staphylococcus/efeitos dos fármacos , Staphylococcus/genética
5.
Biomed Khim ; 66(3): 241-249, 2020 May.
Artigo em Russo | MEDLINE | ID: mdl-32588830

RESUMO

In the present study the electrochemical system based on recombinant cytochrome P450 3A4 (CYP3A4) was used for the investigation of potential drug-drug interaction between medicinal preparations employed for Helicobacter pylori eradication therapy. Drug interactions were demonstrated in association of omeprazole as a proton pump inhibitor (PPI) and macrolide antibiotic erythromycin during cytochrome P450 3A4-mediated metabolism. It was shown that in the presence of omeprazole the rate of N-demethylase activity of CYP3A4 to erythromycin measured by means of product (formaldehyde) formation decreased. Mass-spectrometry analysis of omeprazole sulfone as a CYP3A4-mediated metabolite demonstrated the absence of erythromycin influence on CYP3A4-dependent omeprazole metabolism. This phenomenon may be explained by lower spectral dissociation constant of CYP3A4-omeprazole complex (Kd = 18±2 µM) than that of CYP3A4-erythromycin complex (Kd = 52 µM). Using the electrochemical model of electrochemically-driven drug metabolism it is possible to register CYP3A4-mediated catalytic conversion of certain drugs. In vitro experiments of potential CYP3A4-mediated drug-drug interactions are in accordance with in silico modeling with program PASS and PoSMNA descriptors in the case of omeprazole/erythromycin combinations.


Assuntos
Antibacterianos , Sistema Enzimático do Citocromo P-450 , Interações Medicamentosas , Eritromicina , Omeprazol , Inibidores da Bomba de Prótons , Antibacterianos/farmacologia , Citocromo P-450 CYP3A , Eritromicina/farmacologia , Omeprazol/farmacologia , Inibidores da Bomba de Prótons/farmacologia
6.
PLoS One ; 15(4): e0230423, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32236115

RESUMO

Campylobacter jejuni is one of the most prevalent causes of bacterial gastroenteritis worldwide, and it is largely associated with consumption of contaminated poultry. Current Campylobacter control measures at the poultry production level remain insufficient, and hence there is the need for alternative control strategies. We evaluated the potential of the monoterpene (-)-α-pinene for control of C. jejuni in poultry. The antibacterial and resistance-modulatory activities of (-)-α-pinene were also determined against 57 C. jejuni strains. In addition, the anti-quorum-sensing activity of (-)-α-pinene against C. jejuni NCTC 11168 was determined for three subinhibitory concentrations (125, 62.5, 31.25 mg/L) over three incubation times using an autoinducer-2 bioassay based on Vibrio harveyi BB170 bioluminescence measurements. The effects of a subinhibitory concentration of (-)-α-pinene (250 mg/L) on survival of C. jejuni, and in combination with enrofloxacin on fluoroquinolone resistance development in C. jejuni, were determined in a broiler chicken model, by addition of (-)-α-pinene to the broiler water supply. The reduction of C. jejuni numbers by (-)-α-pinene was further determined in broiler chickens that were colonized with either fluoroquinolone-susceptible or -resistant strains, by direct gavage treatment. We observed weak in vitro antimicrobial activity for (-)-α-pinene alone (MIC >500 mg/L), but strong potentiating effects on antibiotics erythromycin and ciprofloxacin against different Campylobacter strains (>512 fold change). After 24 h of treatment of C. jejuni with (-)-α-pinene, its quorum-sensing signaling was reduced by >80% compared to the untreated control. When given in the drinking water, (-)-α-pinene did not show any significant inhibitory effects on the level of C. jejuni in the colonized chickens, and did not reduce fluoroquinolone resistance development in combination with enrofloxacin. Conversely, when (-)-α-pinene was administered by direct gavage, it significantly reduced the number of fluoroquinolone susceptible C. jejuni in the colonized broiler chickens. These results demonstrate that (-)-α-pinene modulates quorum-sensing in Campylobacter, potentiates antibiotics against different Campylobacter strains, and reduces Campylobacter colonization in broiler chickens.


Assuntos
Antibacterianos/farmacologia , Monoterpenos Bicíclicos/farmacologia , Campylobacter jejuni/efeitos dos fármacos , Percepção de Quorum/efeitos dos fármacos , Animais , Antibacterianos/uso terapêutico , Monoterpenos Bicíclicos/uso terapêutico , Infecções por Campylobacter/patologia , Infecções por Campylobacter/prevenção & controle , Campylobacter jejuni/fisiologia , Ceco/microbiologia , Galinhas , Ciprofloxacino/farmacologia , Farmacorresistência Bacteriana/efeitos dos fármacos , Eritromicina/farmacologia , Fluoroquinolonas/farmacologia , Fluoroquinolonas/uso terapêutico , Testes de Sensibilidade Microbiana , Doenças das Aves Domésticas/patologia , Doenças das Aves Domésticas/prevenção & controle
7.
J Pharmacol Sci ; 143(3): 133-140, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32253104

RESUMO

Endogenous noradrenaline (NA) has multiple bioactive functions and, in the central nervous system (CNS), has been implicated in modulating neuroinflammation via ß-adrenergic receptors (ß-ARs). Microglia, resident macrophages in the CNS, have a central role in the brain immune system and have been reported to be activated by NA. However, intracellular signaling mechanisms of the AR-mediated proinflammatory responses of microglia are not fully understood. Using a rapid and stable in vitro reporter assay system to evaluate IL-1ß production in microglial BV2 cells, we found that NA and the ß-AR agonist isoproterenol upregulated the IL-1ß reporter activity. This effect was suppressed by ß-AR antagonists. We further examined the involvement of EPAC (exchange protein directly activated by cAMP) and TPL2 (tumor progression locus 2, MAP3K8) and found that inhibitors for EPAC and TPL2 reduced AR agonist-induced IL-1ß reporter activity. These inhibitors also suppressed NA-induced endogenous Il1b mRNA expression and IL-1ß protein production. Our results suggest that EPAC and TPL2 are involved in ß-AR-mediated IL-1ß production in microglial cells, and extend our understanding of its intracellular signaling mechanism.


Assuntos
Acetilcisteína/análogos & derivados , Eritromicina/análogos & derivados , Interleucina-1beta/metabolismo , MAP Quinase Quinase Quinases/farmacologia , Microglia/metabolismo , Proteínas Proto-Oncogênicas/farmacologia , Acetilcisteína/farmacologia , Agonistas Adrenérgicos beta/farmacologia , Animais , Células Cultivadas , Eritromicina/farmacologia , Expressão Gênica/efeitos dos fármacos , Interleucina-1beta/genética , Isoproterenol/farmacologia , MAP Quinase Quinase Quinases/fisiologia , Camundongos , Norepinefrina/farmacologia , Norepinefrina/fisiologia , Proteínas Proto-Oncogênicas/fisiologia , Receptores Adrenérgicos beta , Transdução de Sinais , Regulação para Cima/efeitos dos fármacos
8.
PLoS One ; 15(4): e0231274, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32271828

RESUMO

We evaluated the minimum inhibitory concentrations of clindamycin and erythromycin toward 98 Bacillus licheniformis strains isolated from several types of fermented soybean foods manufactured in several districts of Korea. First, based on recent taxonomic standards for bacteria, the 98 strains were separated into 74 B. licheniformis strains and 24 B. paralicheniformis strains. Both species exhibited profiles of erythromycin resistance as an acquired characteristic. B. licheniformis strains exhibited acquired clindamycin resistance, while B. paralicheniformis strains showed unimodal clindamycin resistance, indicating an intrinsic characteristic. Comparative genomic analysis of five strains showing three different patterns of clindamycin and erythromycin resistance identified 23S rRNA (adenine 2058-N6)-dimethyltransferase gene ermC and spermidine acetyltransferase gene speG as candidates potentially involved in clindamycin resistance. Functional analysis of these genes using B. subtilis as a host showed that ermC contributes to cross-resistance to clindamycin and erythromycin, and speG confers resistance to clindamycin. ermC is located in the chromosomes of strains showing clindamycin and erythromycin resistance and no transposable element was identified in its flanking regions. The acquisition of ermC might be attributable to a homologous recombination. speG was identified in not only the five genome-analyzed strains but also eight strains randomly selected from the 98 test strains, and deletions in the structural gene or putative promoter region caused clindamycin sensitivity, which supports the finding that the clindamycin resistance of Bacillus species is an intrinsic property.


Assuntos
Bacillus licheniformis/genética , Bacillus/genética , Clindamicina/farmacologia , Farmacorresistência Bacteriana/genética , Genes Bacterianos , Genômica , Bacillus/efeitos dos fármacos , Bacillus/crescimento & desenvolvimento , Bacillus licheniformis/classificação , Bacillus licheniformis/efeitos dos fármacos , Bacillus licheniformis/crescimento & desenvolvimento , Bacillus subtilis/efeitos dos fármacos , Bacillus subtilis/genética , Bacillus subtilis/crescimento & desenvolvimento , Sequência de Bases , Farmacorresistência Bacteriana/efeitos dos fármacos , Eritromicina/farmacologia , Testes de Sensibilidade Microbiana
9.
Vet Microbiol ; 242: 108568, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32122582

RESUMO

Mainstay therapy for rhodococcosis in foals is the combination of rifampicin and a macrolide. While emergence of resistance to rifampicin and macrolides has been reported, studies demonstrating the development of resistance to such drugs is limited in necropsied foals with rhodococcosis. In this study, the foal necropsy records between 01/01/2011 and 08/30/2019 were reviewed for culture-positive R. equi with MICs and, whether or not the affected foals received any mainstay dual therapy before their deaths. Resistance to antimicrobials in the R. equi isolates from necropsied foals were then compared between treated foals with dual therapy and untreated foals to determine the association between the administration of antimicrobials and development of the drug resistance. In a total of 256 R. equi isolates from each of the 256 necropsied foals with rhodococcosis, rifampicin, azithromycin, clarithromycin and erythromycin showed high rates of resistance, 22.65 %, 16.01 %, 14.84 % and 15.23 %, respectively. The most active antimicrobials exhibiting MIC50/90 values were imipenem, doxycycline, amikacin and gentamicin including in the rifampicin- and macrolides-resistant R. equi isolates. Based on the treatment histories available for the 114 necropsied foals with rhodococcosis, R. equi isolates resistant to rifampicin, and macrolides were significantly more isolated from treated foals with mainstay dual therapy compared to untreated foals. Despite dual therapy, development of resistance against rifampicin and macrolides warrants evaluation of new treatment protocols in foals.


Assuntos
Infecções por Actinomycetales/veterinária , Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla , Doenças dos Cavalos/microbiologia , Rhodococcus equi/efeitos dos fármacos , Infecções por Actinomycetales/tratamento farmacológico , Infecções por Actinomycetales/microbiologia , Animais , Azitromicina/farmacologia , Claritromicina/farmacologia , Eritromicina/farmacologia , Doenças dos Cavalos/tratamento farmacológico , Cavalos/microbiologia , Testes de Sensibilidade Microbiana
10.
RNA ; 26(6): 715-723, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32144191

RESUMO

Macrolides are one of the most successful and widely used classes of antibacterials, which kill or stop the growth of pathogenic bacteria by binding near the active site of the ribosome and interfering with protein synthesis. Dirithromycin is a derivative of the prototype macrolide erythromycin with additional hydrophobic side chain. In our recent study, we have discovered that the side chain of dirithromycin forms lone pair-π stacking interaction with the aromatic imidazole ring of the His69 residue in ribosomal protein uL4 of the Thermus thermophilus 70S ribosome. In the current work, we found that neither the presence of the side chain, nor the additional contact with the ribosome, improve the binding affinity of dirithromycin to the ribosome. Nevertheless, we found that dirithromycin is a more potent inhibitor of in vitro protein synthesis in comparison with its parent compound, erythromycin. Using high-resolution cryo-electron microscopy, we determined the structure of the dirithromycin bound to the translating Escherichia coli 70S ribosome, which suggests that the better inhibitory properties of the drug could be rationalized by the side chain of dirithromycin pointing into the lumen of the nascent peptide exit tunnel, where it can interfere with the normal passage of the growing polypeptide chain.


Assuntos
Antibacterianos/química , Eritromicina/análogos & derivados , Inibidores da Síntese de Proteínas/química , Ribossomos/química , Antibacterianos/farmacologia , Microscopia Crioeletrônica , Eritromicina/química , Eritromicina/farmacologia , Escherichia coli/genética , Modelos Moleculares , Biossíntese de Proteínas/efeitos dos fármacos , Inibidores da Síntese de Proteínas/farmacologia , RNA Ribossômico 23S/química
11.
J Dairy Sci ; 103(4): 3431-3446, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32008788

RESUMO

Staphylococcus aureus is recognized worldwide as one of the main contagious mastitis agents in cattle and can express a set of antimicrobial resistance genes and virulence-associated genes that explain the wide range of outcomes of intramammary infections. Staphylococcus aureus strains are heterogeneous: their different resistance and virulence patterns, associated with host-level factors and treatment factors, are related to the severity of infection. The aim of this study was to determine phenotypic antibiotic susceptibility, occurrence of selected antimicrobial resistance genes and other virulence genes in 93 S. aureus strains isolated from clinical mastitis in 6 countries: Argentina, Brazil, Germany, Italy, the United States (New York State), and South Africa. These isolates were tested against a total of 16 drugs (amoxicillin-clavulanate, ampicillin, cefazolin, cefoperazone, cefquinome, enrofloxacin, erythromycin, gentamicin, kanamycin, lincomycin, oxacillin, penicillin, rifampin, spiramycin, sulfamethoxazole/trimethoprim, tylosin) by minimum inhibitory concentration (MIC) assay, and examined for the presence of 6 antibiotic-resistance genes (blaZ, mecA, mecC, ermA, ermB, ermC) and 6 virulence-associated genes (scn, chp, sak, hla, hlb, sea) via PCR analysis. The phenotypic results of this study revealed the presence of 19.4% penicillin-resistant strains, whereas 22.6% of the strains were classified as having resistance (5.4%) or intermediate resistance (17.2%) to erythromycin. Most (96.8%) of the isolates were inhibited by cephalosporins, and all were susceptible to amoxicillin-clavulanate. Two strains (1 from Germany, 1 from Italy) were resistant to oxacillin and were positive for mecA. Among the other antimicrobial resistance genes, the most frequently detected was blaZ (46.2%), and 32.3% of the isolates were positive for erm genes: ermC (21.5%) and ermB (10.8%). The most prevalent virulence gene was hla (100%), followed by hlb (84.9%) and sea (65.6%). These results show a low prevalence of antibiotic multidrug resistance in S. aureus isolates, even if the detection of selected antimicrobial resistance genes did not always correspond with the occurrence of phenotypic antibiotic resistance; the immune evasion cluster gene prevalence was quite low in the samples analyzed.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Mastite Bovina/microbiologia , Infecções Estafilocócicas/veterinária , Staphylococcus aureus/efeitos dos fármacos , Animais , Argentina , Brasil , Bovinos , Farmacorresistência Bacteriana/genética , Eritromicina/farmacologia , Feminino , Alemanha , Itália , Testes de Sensibilidade Microbiana , New York , Oxacilina/farmacologia , África do Sul , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/isolamento & purificação , Staphylococcus aureus/patogenicidade , Virulência
12.
Biochim Biophys Acta Gen Subj ; 1864(6): 129546, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32032658

RESUMO

Multidrug efflux is a major contributor to antibiotic resistance in Gram-negative bacterial pathogens. Inhibition of multidrug efflux pumps is a promising approach for reviving the efficacy of existing antibiotics. Previously, inhibitors targeting both the efflux transporter AcrB and the membrane fusion protein AcrA in the Escherichia coli AcrAB-TolC efflux pump were identified. Here we use existing physicochemical property guidelines to generate a filtered library of compounds for computational docking. We then experimentally test the top candidate coumpounds using in vitro binding assays and in vivo potentiation assays in bacterial strains with controllable permeability barriers. We thus identify a new class of inhibitors of E. coli AcrAB-TolC. Six molecules with a shared scaffold were found to potentiate the antimicrobial activity of erythromycin and novobiocin in hyperporinated E. coli cells. Importantly, these six molecules were also active in wild-type strains of both Acinetobacter baumannii and Klebsiella pneumoniae, potentiating the activity of erythromycin and novobiocin up to 8-fold.


Assuntos
Anti-Infecciosos/farmacologia , Proteínas de Transporte/química , Proteínas de Escherichia coli/química , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Lipoproteínas/química , Proteínas de Membrana Transportadoras/química , Proteínas Associadas à Resistência a Múltiplos Medicamentos/química , Acinetobacter baumannii/efeitos dos fármacos , Acinetobacter baumannii/patogenicidade , Antibacterianos/efeitos adversos , Antibacterianos/farmacologia , Anti-Infecciosos/química , Proteínas de Transporte/antagonistas & inibidores , Biologia Computacional/métodos , Farmacorresistência Bacteriana/efeitos dos fármacos , Farmacorresistência Bacteriana/genética , Sinergismo Farmacológico , Eritromicina/química , Eritromicina/farmacologia , Proteínas de Escherichia coli/antagonistas & inibidores , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Negativas/patogenicidade , Infecções por Bactérias Gram-Negativas/microbiologia , Infecções por Bactérias Gram-Negativas/patologia , Humanos , Klebsiella pneumoniae , Lipoproteínas/antagonistas & inibidores , Simulação de Acoplamento Molecular , Proteínas Associadas à Resistência a Múltiplos Medicamentos/antagonistas & inibidores , Novobiocina/química , Novobiocina/farmacologia
13.
Chemosphere ; 249: 126147, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32062559

RESUMO

Here we report a set of experiments in which water blooming cyanobacteria Microcystis aeruginosa was repeatedly exposed to erythromycin. Growth inhibition increased with increasing erythromycin concentration (1-150 µg/L) upon first exposure. Maximum inhibition rate (76.06%), occurred under 150 µg/L erythromycin. Moreover, 96-h 50% effective concentration (EC50) was 22.97 µg/L, indicating that the growth of M. aeruginosa was affected by erythromycin under common environmental concentrations. Photosynthesis was hindered by chlorophyll and photosystem II limitations. Malondialdehyde, reactive oxygen species, and superoxide dismutase contents increased significantly under certain concentrations of erythromycin, but superoxide dismutase was suppressed by 150 µg/L erythromycin. Synthesis of intracellular and extracellular microcystins was promoted by 10-60 and by 20-60 µg/L erythromycin, respectively, but both were inhibited by 100-150 µg/L. Principal component analysis and Pearson's correlation revealed the accumulation of reactive oxygen species as the dominant mechanism of erythromycin toxicity to cells. M. aeruginosa repeatedly subjected to erythromycin exposure showed obvious resistance against the antibiotic, especially when treated twice with 60 µg/L erythromycin. The 96-h EC50 was 81.29 µg/L. As compared to the first exposure to erythromycin, photosynthetic and antioxidant activities increased, while growth inhibition and oxidation stress decreased upon multiple exposures. Production and release of microcystins were enhanced by repeated exposure to the antibiotic. Thus, erythromycin persistence in water should be examined, as repeated exposure may lead to serious environmental and human health hazards.


Assuntos
Eritromicina/toxicidade , Microcystis/efeitos dos fármacos , Antibacterianos/farmacologia , Clorofila/metabolismo , Cianobactérias/metabolismo , Eritromicina/farmacologia , Malondialdeído , Microcistinas , Estresse Oxidativo/efeitos dos fármacos , Fotossíntese/efeitos dos fármacos , Espécies Reativas de Oxigênio/farmacologia , Superóxido Dismutase/metabolismo
14.
J Biol Chem ; 295(7): 2057-2067, 2020 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-31915244

RESUMO

Macrolide antibiotics, such as erythromycin and josamycin, are natural polyketide products harboring 14- to 16-membered macrocyclic lactone rings to which various sugars are attached. These antibiotics are used extensively in the clinic because of their ability to inhibit bacterial protein synthesis. More recently, some macrolides have been shown to also possess anti-inflammatory and other therapeutic activities in mammalian cells. To better understand the targets and effects of this drug class in mammalian cells, we used a genome-wide shRNA screen in K562 cancer cells to identify genes that modulate cellular sensitivity to josamycin. Among the most sensitizing hits were proteins involved in mitochondrial translation and the mitochondrial unfolded protein response, glycolysis, and the mitogen-activated protein kinase signaling cascade. Further analysis revealed that cells treated with josamycin or other antibacterial agents exhibited impaired oxidative phosphorylation and metabolic shifts to glycolysis. Interestingly, we observed that knockdown of the mitogen-activated protein kinase kinase kinase 4 (MAP3K4) gene, which contributes to p38 mitogen-activated protein kinase signaling, sensitized cells only to josamycin but not to other antibacterial agents. There is a growing interest in better characterizing the therapeutic effects and toxicities of antibiotics in mammalian cells to guide new applications in both cellular and clinical studies. To our knowledge, this is the first report of an unbiased genome-wide screen to investigate the effects of a clinically used antibiotic on human cells.


Assuntos
Antibacterianos/farmacologia , MAP Quinase Quinase Quinase 4/genética , Biossíntese de Proteínas/efeitos dos fármacos , Proteínas Quinases p38 Ativadas por Mitógeno/genética , Animais , Antibacterianos/efeitos adversos , Resistência Microbiana a Medicamentos/efeitos dos fármacos , Eritromicina/efeitos adversos , Eritromicina/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Glicólise/efeitos dos fármacos , Humanos , Josamicina/efeitos adversos , Josamicina/farmacologia , Células K562 , MAP Quinase Quinase Quinase 4/antagonistas & inibidores , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Macrolídeos/efeitos adversos , Macrolídeos/farmacologia , Proteínas Quinases Ativadas por Mitógeno/genética , Fosforilação Oxidativa/efeitos dos fármacos , Inibidores da Síntese de Proteínas/efeitos adversos , Inibidores da Síntese de Proteínas/farmacologia , Resposta a Proteínas não Dobradas/efeitos dos fármacos , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidores
15.
Appl Microbiol Biotechnol ; 104(5): 2193-2203, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31925486

RESUMO

Mutations in rrn encoding ribosomal RNA (rRNA) and rRNA modification often confer resistance to ribosome-targeting antibiotics by altering the site of their interaction with the small (30S) and large (50S) subunits of the bacterial ribosome. The highly conserved central loop of domain V of 23S rRNA (nucleotides 2042-2628 in Escherichia coli; the exact position varies by species) of the 50S subunit, which is implicated in peptidyl transferase activity, is known to be important in macrolide interactions and resistance. In this study, we identified an A2302T mutation in the rrnA-23S rRNA gene and an A2281G mutation in the rrnC-23S rRNA gene that were responsible for resistance to erythromycin in the model actinomycete Streptomyces coelicolor A3(2) and its close relative Streptomyces lividans 66, respectively. Interestingly, genetic and phenotypic characterization of the erythromycin-resistant mutants indicated a possibility that under coexistence of the 23S rRNA mutation and mutations in other genes, S. coelicolor A3(2) and S. lividans 66 can produce abundant amounts of the pigmented antibiotics actinorhodin and undecylprodigiosin depending on the combinations of mutations. Herein, we report the unique phenomenon occurring by unexpected characteristics of the 23S rRNA mutations that can affect the emergence of additional mutations probably with an upswing in spontaneous mutations and enrichment in their variations in Streptomyces strains. Further, we discuss a putative mechanism underlying secondary metabolite overproduction by Streptomyces strains with a 23S rRNA mutation conferring erythromycin resistance.


Assuntos
Antibacterianos/farmacologia , Eritromicina/farmacologia , RNA Bacteriano/genética , RNA Ribossômico 23S/genética , Streptomyces coelicolor/genética , Streptomyces lividans/genética , Farmacorresistência Bacteriana , Testes de Sensibilidade Microbiana , Mutação , RNA Bacteriano/metabolismo , RNA Ribossômico 23S/metabolismo , Metabolismo Secundário , Streptomyces coelicolor/efeitos dos fármacos , Streptomyces coelicolor/metabolismo , Streptomyces lividans/efeitos dos fármacos , Streptomyces lividans/metabolismo
16.
Curr Pharm Biotechnol ; 21(10): 948-954, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31994459

RESUMO

BACKGROUND: Staphylococcus aureus (S. aureus) is the most common infectious agent in the community and hospitals. Infections with S. aureus are now becoming difficult to be treated by using conventional antibiotics due to its emerging methicillin-resistant S. aureus (MRSA) strain. OBJECTIVE: In the present study, MRSA was isolated from clinical samples and evaluated for resistance against different antibiotics, TiO2 nanoparticles, and their combinations. METHODS: Clinical samples were collected from Ayub Medical Complex (AMC), Abbottabad, Pakistan, and identified by different biochemical tests and polymerase chain reactions (PCR). Kirby-Bauer disk diffusion method was performed to evaluate antimicrobial susceptibility. Minimum Inhibitory Concentration (MIC) of ampicillin, ciprofloxacin, erythromycin, and vancomycin was found out by agar dilution method while the broth dilution method was used for the MIC of TiO2 nanoparticles and their combinations with erythromycin. RESULTS: All 13/100 (13%) MRSA were successfully identified. All isolates were susceptible to quinupristin/ dalfopristin, teicoplanin, and vancomycin, while the highest resistance was seen with erythromycin, penicillin, and tetracycline. MIC showed high resistance against ampicillin (0.25-512 mg/L) and erythromycin (0.25-1024 mg/L). CONCLUSION: The MIC value of 2 mM TiO2 nanoparticles was found to be the most effective concentration after 12 h of incubation, while the combination of erythromycin with 3 mM TiO2 nanoparticles was found to be more potent which significantly lowered down the MIC of erythromycin to 2-16 mg/L.


Assuntos
Antibacterianos/farmacologia , Eritromicina/farmacologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Nanopartículas/química , Titânio/farmacologia , Antibacterianos/química , Sinergismo Farmacológico , Eritromicina/química , Humanos , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Testes de Sensibilidade Microbiana , Infecções Estafilocócicas/microbiologia , Titânio/química
17.
Int J Infect Dis ; 90: 219-222, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31682962

RESUMO

The emergence of non-vaccine multidrug-resistant Streptococcus pneumoniae serotypes is on rise. This study was performed to investigate a highly resistant serotype 15A S. pneumoniae isolated from the blood specimen of a 20-month-old patient who died of her infection. The SS40_16 isolate was resistant to erythromycin, co-trimoxazole, tetracycline, and chloramphenicol, as well as to penicillin, ceftriaxone, and cefotaxime (using meningitis cut-off points, Clinical and Laboratory Standards Institute). The isolate belonged to sequence type 1591 (ST1591) and was related to CC81 clonal complex, suggesting the possibility of horizontal gene transfer. Scanning electron microscopy comparison between resistant and sensitive pneumococcal isolates also indicated similar phenotypic characteristics that confer high resistance. The emergence of highly resistant non-vaccine pneumococci is of great concern to public health and in the clinical setting. Pneumococcal surveillance programs represent a crucial tool, not only for determining the impact of pneumococcal conjugate vaccines, but also for monitoring the selective pressure of serotype replacement with regard to the treatment of invasive pneumococcal disease.


Assuntos
Farmacorresistência Bacteriana Múltipla , Infecções Pneumocócicas/microbiologia , Streptococcus pneumoniae/fisiologia , Antibacterianos/farmacologia , Cefotaxima/farmacologia , Ceftriaxona/farmacologia , Eritromicina/farmacologia , Feminino , Transferência Genética Horizontal , Humanos , Lactente , Penicilinas/farmacologia , Infecções Pneumocócicas/epidemiologia , Sorogrupo , Sorotipagem , Streptococcus pneumoniae/classificação , Streptococcus pneumoniae/efeitos dos fármacos , Streptococcus pneumoniae/genética
18.
Inflamm Res ; 69(1): 139-151, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31820024

RESUMO

OBJECTIVE: Macrolides have been reported to reduce the exacerbation of severe asthma. The aim of this study was to clarify the effects and mechanisms of EM900, a non-antibiotic macrolide, on allergic airway inflammation. METHODS: Mice were sensitized and challenged by house dust mite (HDM), then exposed to polyinosinic-polycytidylic acid (poly(I:C)) as a model of asthma complicated with viral infection. Mice were administered with EM900. Airway inflammation was assessed from inflammatory cells in bronchoalveolar lavage fluid (BALF) and cytokines in lung tissues. Lung interstitial macrophages were counted by flow cytometry. Cytokine production, phosphorylation of NF-κB, and p38 in macrophages were examined by ELISA and western blotting. RESULTS: Counts of cells in BALF and concentrations of IL-13, IL-5, RANTES, IL-17A, and MIP-2 were significantly decreased by EM900 compared to those without EM900. Percentages of lung interstitial macrophages were significantly decreased with EM900. Concentrations of IL-6, RANTES, and MIP-2 induced by HDM and poly(I:C) were significantly suppressed by EM900 through the suppression of NF-κB and p38 phosphorylation in macrophages. CONCLUSIONS: HDM and poly(I:C)-induced airway inflammation is attenuated by EM900 with the inhibition of lung interstitial macrophages. Clinical use of EM900 is expected, because EM900 has inhibitory effects against airway inflammation without inducing bacterial drug resistance.


Assuntos
Anti-Inflamatórios/uso terapêutico , Asma/tratamento farmacológico , Eritromicina/análogos & derivados , Macrófagos Alveolares/efeitos dos fármacos , Viroses/tratamento farmacológico , Animais , Anti-Inflamatórios/farmacologia , Asma/imunologia , Asma/patologia , Líquido da Lavagem Broncoalveolar/citologia , Líquido da Lavagem Broncoalveolar/imunologia , Citocinas/imunologia , Modelos Animais de Doenças , Eritromicina/farmacologia , Eritromicina/uso terapêutico , Feminino , Pulmão/efeitos dos fármacos , Pulmão/imunologia , Pulmão/patologia , Macrófagos Alveolares/imunologia , Camundongos Endogâmicos BALB C , Poli I-C , Pyroglyphidae/imunologia , Viroses/imunologia , Viroses/patologia
19.
Int J Chron Obstruct Pulmon Dis ; 14: 2697-2709, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31819402

RESUMO

Purpose: Elastin peptides (EP) can induce lung inflammation and emphysema. Erythromycin has been shown to decrease acute exacerbation frequency and delay lung function decline in chronic obstructive pulmonary disease patients and ameliorate emphysema in murine models; however, the mechanism remains unclear. We aimed to observe the preventive and immunomodulatory effects of erythromycin in a mouse model of EP-induced emphysema. Methods: In the in vivo study, Balb/c mice were treated with EP intranasally on day 0, and then administered erythromycin (100 mg/kg) or vehicle orally on day 1, which was continued every other day. Mice exposed to cigarette smoke were used as an emphysema positive control. The severity of emphysema and inflammation in the lungs of EP-exposed mice with or without erythromycin treatment were observed on day 40 after EP administration. In the in vitro study, naïve CD4+T cells were isolated from healthy mice spleens and stimulated by EP with or without erythromycin incubation. Flow cytometry was used to measure the proportions of Th1, Th17, and Treg cells. ELISA was used to detect cytokine levels of IFN-γ, IL-17, IL-6, and TGF-ß. Transcript levels of Ifnγ, IL17a, and Foxp3 were evaluated by qRT-PCR. Results: After exposure to EP, Th1 and Th17 cell percentages and the levels of inflammatory cytokines increased in vivo and in vitro, while Treg cells decreased in vivo. Erythromycin reduced IFN-γ, IL-17, IL-6 inflammatory cytokines, MLI, and the inflammation score in the lungs of EP-exposed mice. In vitro, erythromycin also limited Th17 and Th1 cell differentiation and downregulated transcript levels of Ifnγ and IL17a in the EP-stimulated CD4+T cells. Conclusion: The Th1 and Th17 cell responses were increased in EP-induced emphysema. Prophylactic use of erythromycin effectively ameliorated emphysema and modulated CD4+T cells responses in EP-induced lung inflammation in mice.


Assuntos
Anti-Inflamatórios/farmacologia , Linfócitos T CD4-Positivos/efeitos dos fármacos , Citocinas/metabolismo , Elastina , Eritromicina/farmacologia , Mediadores da Inflamação/metabolismo , Pulmão/efeitos dos fármacos , Fragmentos de Peptídeos , Pneumonia/tratamento farmacológico , Enfisema Pulmonar/tratamento farmacológico , Animais , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Células Cultivadas , Citocinas/genética , Modelos Animais de Doenças , Pulmão/imunologia , Pulmão/metabolismo , Masculino , Camundongos Endogâmicos BALB C , Pneumonia/induzido quimicamente , Pneumonia/imunologia , Pneumonia/metabolismo , Enfisema Pulmonar/induzido quimicamente , Enfisema Pulmonar/imunologia , Enfisema Pulmonar/metabolismo , Transdução de Sinais , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismo , Células Th1/efeitos dos fármacos , Células Th1/imunologia , Células Th1/metabolismo , Células Th17/efeitos dos fármacos , Células Th17/imunologia , Células Th17/metabolismo
20.
Int J Food Microbiol ; 311: 108356, 2019 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-31670141

RESUMO

Different samples of three products including Bikalga and Soumbala from Burkina Faso (West Africa) and Ntoba Mbodi from Congo-Brazzaville (Central Africa) were evaluated. The bacteria (400) were phenotyped and genotypically characterized by Rep-PCR, PFGE, 16S rRNA and rpoB gene sequencing and spa typing. Their PFGE profiles were compared with those of 12,000 isolates in the Center for Disease Control (CDC, USA) database. They were screened for the production of enterotoxins, susceptibility to 19 antimicrobials, presence of 12 staphylococcal toxin and 38 AMR genes and the ability to transfer erythromycin and tetracycline resistance genes to Enterococcus faecalis JH2-2. Fifteen coagulase negative (CoNS) and positive (CoPS) species characterized by 25 Rep-PCR/PFGE clusters were identified: Staphylococcus arlettae, S. aureus, S. cohnii, S. epidermidis, S. gallinarum, S. haemolyticus, S. hominis, S. pasteuri, S. condimenti, S. piscifermentans, S. saprophyticus, S. sciuri, S. simulans, S. warneri and Macrococcus caseolyticus. Five species were specific to Soumbala, four to Bikalga and four to Ntoba Mbodi. Two clusters of S. gallinarum and three of S. sciuri were particular to Burkina Faso. The S. aureus isolates exhibited a spa type t355 and their PFGE profiles did not match any in the CDC database. Bacteria from the same cluster displayed similar AMR and toxin phenotypes and genotypes, whereas clusters peculiar to a product or a location generated distinct profiles. The toxin genes screened were not detected and the bacteria did not produce the staphylococcal enterotoxins A, B, C and D. AMR genes including blazA, cat501, dfr(A), dfr(G), mecA, mecA1, msr(A) and tet(K) were identified in CoNS and CoPS. Conjugation experiments produced JH2-2 isolates that acquired resistance to erythromycin and tetracycline, but no gene transfer was revealed by PCR. The investigation of the heterogeneity of Staphylococcus species from alkaline fermented foods, their relationship with clinical and environmental isolates and their safety in relation to antimicrobial resistance (AMR) and toxin production is anticipated to contribute to determining the importance of staphylococci in alkaline fermented foods, especially in relation to the safety of the consumers.


Assuntos
Enterotoxinas/genética , Alimentos e Bebidas Fermentados/microbiologia , Staphylococcus , Antibacterianos/farmacologia , Burkina Faso , Coagulase/genética , Congo , RNA Polimerases Dirigidas por DNA/genética , Farmacorresistência Bacteriana/genética , Eritromicina/farmacologia , Genótipo , Testes de Sensibilidade Microbiana , Fenótipo , Reação em Cadeia da Polimerase , RNA Ribossômico 16S/genética , Staphylococcus/classificação , Staphylococcus/efeitos dos fármacos , Staphylococcus/genética , Staphylococcus/isolamento & purificação , Tetraciclina/farmacologia
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