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1.
Rev Med Suisse ; 16(710): 1906-1911, 2020 Oct 14.
Artigo em Francês | MEDLINE | ID: mdl-33058575

RESUMO

Cephalosporins belong to the betalactam group and are frequently prescribed in both out and inpatient settings. Their broad spectrum of activity allows a varied use in most medical specialties, ranging from preoperative prophylaxis to treatment of febrile agranulocytosis. There are currently five generations of cephalosporins, mainly differentiated according to their structure, spectrum of activity and side-effect profile. So-called siderophore cephalosporins are active against many multiresistant bacteria, especially in cases of complicated urinary tract infections or ventilator-associated pneumonia. This article intends to review some general clinical principles in prescription and monitoring of patients treated with cephalosporins.


Assuntos
Cefalosporinas/uso terapêutico , Bactérias/efeitos dos fármacos , Cefalosporinas/farmacologia , Humanos , Prescrições , Infecções Urinárias/tratamento farmacológico , Infecções Urinárias/microbiologia
2.
AAPS PharmSciTech ; 21(7): 286, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-33063151

RESUMO

The CoViD-19 pandemic has caused a sudden spike in demand and production of hand sanitisers. Concerns are rising regarding the quality of such products, as the safeguard of consumers is a priority worldwide. We analyse here the ethanolic content of seven off-the-shelf hand sanitiser gels (two biocides and five cosmetics) from the Italian market, using gas chromatography. The WHO recommends that products containing ethanol should have 60-95% (v/v) alcohol. Four of the tested hand gels have ethanolic contents within the recommended range, while three products (all cosmetics) contain < 60% (v/v), i.e. 52.1% (w/w), ethanol. The product with the lowest alcoholic content has 37.1% w/w ethanol. Toxic methanol is not found in any of the hand sanitisers. We show, in addition, that products with the highest ethanolic content have generally greater antibacterial activity. In conclusion, all tested products are complying with the EU regulations, as the three "substandard" products are classified as cosmetics, whose purpose is cleaning and not disinfecting. Nevertheless, if such hand cleaners were inappropriately used as hand disinfectants, they might be ineffective. Thus, consumer safety relays on awareness and ability to distinguish between biocidal and cosmetics hand gels. The obtained results might sensitise the scientific community, health agencies and ultimately consumers towards the risks of using hand sanitisers of substandard alcoholic concentration. If the wrong product is chosen by consumers, public health can be compromised by the inappropriate use of "low-dosed" cosmetic gels as disinfectants, particularly during the period of the CoViD-19 pandemic.


Assuntos
Infecções por Coronavirus , Higienizadores de Mão/análise , Pandemias , Pneumonia Viral , Antibacterianos/análise , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Cromatografia Gasosa , Cosméticos , Escherichia coli/efeitos dos fármacos , Etanol/análise , Europa (Continente) , Géis , Desinfecção das Mãos , Higienizadores de Mão/farmacologia , Higienizadores de Mão/normas , Metanol/análise , Testes de Sensibilidade Microbiana , Staphylococcus aureus/efeitos dos fármacos
3.
Trop Doct ; 50(4): 330-334, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32998655

RESUMO

Acute infectious purpura fulminans is a serious, potentially fatal condition. We present a case series of 11 patients from March 2005 to March 2017, whose clinical symptoms were fever (100%), confusion (63.6%) and headache (55%), and whose common laboratory abnormalities were thrombocytopenia (100%), elevated alkaline phosphatase (70%) and anaemia (63.6%). Three patients (27%) developed gangrene and two presented in shock. Only one grew Neisseria meningitidis in cerebrospinal fluid (CSF) culture and another confirmed by latex agglutination and polymerase chain reaction in CSF. Five others had serology confirmed spotted fever rickettsioses (SFG). All received broad spectrum antibiotics; in 9/11 patients, this included doxycycline or azithromycin. The mean hospital stay was 10.2 days and overall mortality was 18.2%.


Assuntos
Púrpura Fulminante/diagnóstico , Púrpura Fulminante/terapia , Adulto , Antibacterianos/uso terapêutico , Bactérias/efeitos dos fármacos , Bactérias/isolamento & purificação , Feminino , Hospitalização , Humanos , Índia , Masculino , Pessoa de Meia-Idade , Púrpura Fulminante/mortalidade , Púrpura Fulminante/patologia , Rickettsiose do Grupo da Febre Maculosa/diagnóstico , Rickettsiose do Grupo da Febre Maculosa/tratamento farmacológico , Rickettsiose do Grupo da Febre Maculosa/mortalidade , Rickettsiose do Grupo da Febre Maculosa/patologia , Resultado do Tratamento
4.
Nat Commun ; 11(1): 4365, 2020 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-32868761

RESUMO

Current approaches explore bacterial genes that change transcriptionally upon stress exposure as diagnostics to predict antibiotic sensitivity. However, transcriptional changes are often specific to a species or antibiotic, limiting implementation to known settings only. While a generalizable approach, predicting bacterial fitness independent of strain, species or type of stress, would eliminate such limitations, it is unclear whether a stress-response can be universally captured. By generating a multi-stress and species RNA-Seq and experimental evolution dataset, we highlight the strengths and limitations of existing gene-panel based methods. Subsequently, we build a generalizable method around the observation that global transcriptional disorder seems to be a common, low-fitness, stress response. We quantify this disorder using entropy, which is a specific measure of randomness, and find that in low fitness cases increasing entropy and transcriptional disorder results from a loss of regulatory gene-dependencies. Using entropy as a single feature, we show that fitness and quantitative antibiotic sensitivity predictions can be made that generalize well beyond training data. Furthermore, we validate entropy-based predictions in 7 species under antibiotic and non-antibiotic conditions. By demonstrating the feasibility of universal predictions of bacterial fitness, this work establishes the fundamentals for potentially new approaches in infectious disease diagnostics.


Assuntos
Bactérias/genética , Evolução Molecular Direcionada , Farmacorresistência Bacteriana/genética , Estresse Fisiológico , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Bactérias/metabolismo , Fenômenos Fisiológicos Bacterianos , Doenças Transmissíveis/diagnóstico , Entropia , Regulação Bacteriana da Expressão Gênica , Genes Bacterianos , Genoma Bacteriano , Análise de Sequência de RNA , Streptococcus pneumoniae/efeitos dos fármacos , Streptococcus pneumoniae/genética , Streptococcus pneumoniae/metabolismo , Transcriptoma
5.
Sheng Wu Gong Cheng Xue Bao ; 36(8): 1590-1599, 2020 Aug 25.
Artigo em Chinês | MEDLINE | ID: mdl-32924357

RESUMO

ß-defensin is a primary protein immune factor in channel catfish's (Ietalurus punetaus) resistance to pathogenic microorganisms. Its primary structure contains a signal peptide composed of 24 amino acid residues at the N-terminal and a mature peptide composed of 43 amino acid residues at the C-terminal. The mature peptide region is responsible for the biological activity of ß-defensin. In the present study, a recombinant strain of Pichia pastoris that produces channel catfish ß-defensin, was constructed to realize the biosynthesis of channel catfish ß-defensin based on eukaryotic expression. First, the ß-defensin gene "IPBD" was isolated from the skin of channel catfish by RT-PCR. After linking it with the expression vector pPICZA, pPICZA-IPBD was transferred into competent P. pastoris X-33 cells to obtain recombinant P. pastoris strains. The yeast transformants with multi-copy gene inserts were obtained by using the culture medium containing 1 000 µg/mL zeocin. Using BMM culture medium (without amino nitrogen culture medium) instead of BMMY culture medium (with amino nitrogen culture medium), the fermentation and culture conditions of the recombinant strain were optimized, and the optimal conditions for producing channel catfish ß-defensin were determined as follows: the expression was induced for 96 h with 1.0% methanol at 28 °C , 250 r/min. Purified protein with molecular weight of 5.98 kDa was obtained by nickel affinity chromatography, and MALDI-TOF/TOF mass spectrometry proved that it was the expected recombinant IPBD. The antibacterial test results showed that the inhibitory rates of recombinant IPBD on Gram-positive Staphylococcus aureus and Listeria monocytogenes and Gram-negative Pseudomonas aeruginosa were 69.6%, 71.6% and 65.8%, respectively. This study provides a recombinant DNA technique for the development of small molecule natural antibacterial peptide from fish.


Assuntos
Expressão Gênica , Pichia , beta-Defensinas , Animais , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Ictaluridae/genética , Pichia/genética , beta-Defensinas/genética , beta-Defensinas/isolamento & purificação , beta-Defensinas/metabolismo , beta-Defensinas/farmacologia
6.
Sheng Wu Gong Cheng Xue Bao ; 36(8): 1650-1658, 2020 Aug 25.
Artigo em Chinês | MEDLINE | ID: mdl-32924363

RESUMO

Endophytic fungus is an important treasure trove for discovery of structurally unusual and biologically diverse compounds. A phytochemical investigation on a fungus Clonostachys rosea inhabits inner tissue of Blumea balsamifera (L.) DC. was initiatedrecently in our lab. Six pure compounds were isolated through silica gel column chromatography, sephadex LH-20, and semi-preparative HPLC techniques, with bio-guided strategy. Their structures were characterized as verticillin A (1), (S)-(+)-fusarinolic acid (2), 8-hydroxyfusaric acid (3), cerebroside C (4), 3-Maleimide-5-oxime (5), and bionectriol A (6) by analyses of NMR and MS data. All compounds were tested in vitro antibacterial activities against four strains of bacteria, Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Pseudomonas aeruginosa, and results revealed that 1, 4 and 6 display notableinhibition againstthree bacteria, with MIC values ranging from 2 to 16 µg/mL. Our findings provide references for mining novel antibiotics from endophytes originated from Li Minority medicinal plant B. balsamifera (L.) DC.


Assuntos
Antibacterianos , Asteraceae , Hypocreales , Antibacterianos/química , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Asteraceae/microbiologia , Bactérias/efeitos dos fármacos , Endófitos , Hypocreales/química , Hypocreales/metabolismo , Testes de Sensibilidade Microbiana
7.
Adv Exp Med Biol ; 1267: 117-133, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32894480

RESUMO

Antibiotic resistance is a global epidemic, becoming increasingly pressing due to its rapid spread. There is thus a critical need to develop new therapeutic approaches. In addition to searching for new antibiotics, looking into existing mechanisms of natural host defense may enable researchers to improve existing defense mechanisms, and to develop effective, synthetic drugs guided by natural principles. Histones, primarily known for their role in condensing mammalian DNA, are antimicrobial and share biochemical similarities with antimicrobial peptides (AMPs); however, the mechanism by which histones kill bacteria is largely unknown. Both AMPs and histones are similar in size, cationic, contain a high proportion of hydrophobic amino acids, and possess the ability to form alpha helices. AMPs, which mostly kill bacteria through permeabilization or disruption of the biological membrane, have recently garnered significant attention for playing a key role in host defenses. This chapter outlines the structure and function of histone proteins as they compare to AMPs and provides an overview of their role in innate immune responses, especially regarding the action of specific histones against microorganisms and their potential mechanism of action against microbial pathogens.


Assuntos
Antibacterianos/química , Antibacterianos/imunologia , Bactérias/imunologia , Histonas/química , Histonas/imunologia , Animais , Antibacterianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/química , Peptídeos Catiônicos Antimicrobianos/farmacologia , Bactérias/efeitos dos fármacos , Histonas/farmacologia , Imunidade Inata
8.
Anticancer Res ; 40(9): 4807-4818, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32878769

RESUMO

The microbiome is extremely important for human health; more recently its role in the context of cancer became clear. Microbial effects range from enhancing cancer immunity and cancer therapy efficacy, to promoting cancer progression and inhibiting treatment efficacy. These broad implications led researchers to investigate these specific interactions, as well as how modification of the microbiome can improve cancer survival and treatment efficacy. While these interactions are better established for cancers such as gastric cancer, they are far less understood in others. As non-small cell lung cancer (NSCLC) makes up the majority of lung cancer cases, and is among the top causes of cancer deaths worldwide, understanding the mechanisms by which the microbiome may impact progression and treatment is crucial to improve patient survival and treatment response. A literature review was conducted to reveal the crosslink between human microbiome and lung cancer. This includes immune priming, induction of pro- or anti-tumor response, and the local effects of intra-tumoral microbiota. Overall, this is a complex multifactorial relationship, and there are broad implications as to how this knowledge can improve cancer treatment. Solutions include manipulation of the microbiome using probiotics, bacterial vaccines and antibiotics. Bacteria biomarkers may also be used as a diagnostic tool.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/microbiologia , Carcinoma Pulmonar de Células não Pequenas/terapia , Neoplasias Pulmonares/microbiologia , Neoplasias Pulmonares/terapia , Microbiota/fisiologia , Antibacterianos/uso terapêutico , Antineoplásicos/uso terapêutico , Bactérias/efeitos dos fármacos , Bactérias/isolamento & purificação , Carcinoma Pulmonar de Células não Pequenas/imunologia , Carcinoma Pulmonar de Células não Pequenas/patologia , Humanos , Imunomodulação , Neoplasias Pulmonares/imunologia , Neoplasias Pulmonares/patologia , Microbiota/efeitos dos fármacos , Resultado do Tratamento
10.
Chemosphere ; 258: 127392, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32947654

RESUMO

Discharge of urban stormwater containing organic matter, heavy metals and sometime human feces, to the natural aquatic reservoirs without any treatment is not only an environmental problem. It can lead to prevalence of antibiotic resistant bacteria in stormwater systems and transmission of antibiotic resistance genes to the environment. We performed antibiotic resistome identification and virus detection in stormwater samples from Stockholm, using publicly available metagenomic sequencing MinION data. A MinION platform offers low-cost, precise environmental metagenomics analysis. 37 groups of antibiotic resistant bacteria (ARB), 11 resistance types with 26 resistance mechanisms - antibiotic resistance genes (ARGs) giving tolerance to the aminoglycoside, beta-lactams, fosmidomycin, MLS, multidrug and vancomycin were identified using ARGpore pipeline. The majority of the identified bacteria species were related to the natural environment such as soil and were not dangerous to human. Alarmingly, human pathogenic bacteria carrying resistance to antibiotics currently used against them (Bordetella resistant to macrolides and multidrug resistant Propionibacterium avidum) were also found in the samples. Most abundant viruses identified belonged to Caudovirales and Herpesvirales and they were not carrying ARGs. Unlike the virome, resistome and ARB were not unique for stormwater sampling points. This results underline the need for extensive monitoring of the microbial community structure in the urban stormwater systems to assess antimicrobial resistance spread.


Assuntos
Farmacorresistência Bacteriana/genética , Metagenoma , Bactérias/efeitos dos fármacos , Monitoramento Ambiental , Fezes/microbiologia , Genes Bacterianos/efeitos dos fármacos , Humanos , Macrolídeos , Metagenômica/métodos , Microbiota/efeitos dos fármacos , Águas Residuárias/microbiologia , beta-Lactamas
11.
PLoS One ; 15(9): e0237948, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32877437

RESUMO

The lack of new antibiotics necessitates the improvement of existing ones, many of which are limited by toxic side effects. Aminoglycosides, antibiotics with excellent activity and low bacterial resistance, are hampered by dose-dependent toxic effects in patients (nephrotoxicity, ototoxicity). High antibiotic concentrations are often required to treat dormant, non-dividing bacteria, though previous studies show that aminoglycosides can be activated against such bacteria by specific metabolites. Here, we employed this mechanism to greatly boost the activity of low concentrations of aminoglycosides against prevalent Gram-negative pathogens (Escherichia coli, Salmonella enterica, and Klebsiella pneumoniae), suggesting that less toxic drug concentrations might be used effectively in patients. We go on to show that this effect improved treatment of biofilms, did not increase aminoglycoside resistance, and was due to the generation of proton-motive force (PMF). By single-cell microscopy, we demonstrate that stationary-phase cells, while non-dividing, actively maintain a growth-arrested state that is not reversed by metabolite addition. Surprisingly, within starved populations, we observed rare cells (3%) that divided without added nutrients. Additionally, we discovered that mannitol could directly protect human kidney cells from aminoglycoside cytotoxicity, independent of the metabolite's effect on bacteria. This work forwards a mechanism-based strategy to improve existing antibiotics by mitigating their toxic side effects.


Assuntos
Aminoglicosídeos/química , Aminoglicosídeos/farmacologia , Antibacterianos/farmacologia , Bactérias/crescimento & desenvolvimento , Infecções Bacterianas/tratamento farmacológico , Biofilmes/crescimento & desenvolvimento , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/prevenção & controle , Antibacterianos/química , Bactérias/efeitos dos fármacos , Infecções Bacterianas/microbiologia , Infecções Bacterianas/patologia , Biofilmes/efeitos dos fármacos , Farmacorresistência Bacteriana/efeitos dos fármacos , Humanos , Testes de Sensibilidade Microbiana
12.
BMC Microbiol ; 20(1): 265, 2020 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-32847510

RESUMO

BACKGROUND: Acetic acid has been used to clean and disinfect surfaces in the household for many decades. The antimicrobial efficacy of cleaning procedures can be considered particularly important for young, old, pregnant, immunocompromised people, but may also concern other groups, particularly with regards to the COVID-19 pandemics. This study aimed to show that acetic acid exhibit an antibacterial and antifungal activity when used for cleaning purposes and is able to destroy certain viruses. Furthermore, a disinfecting effect of laundry in a simulated washing cycle has been investigated. RESULTS: At a concentration of 10% and in presence of 1.5% citric acid, acetic acid showed a reduction of > 5-log steps according to the specifications of DIN EN 1040 and DIN EN 1275 for the following microorganisms: P. aeruginosa, E. coli, S. aureus, L. monocytogenes, K. pneumoniae, E. hirae and A. brasiliensis. For MRSA a logarithmic reduction of 3.19 was obtained. Tests on surfaces according to DIN EN 13697 showed a complete reduction (> 5-log steps) for P. aeruginosa, E. coli, S. aureus, E. hirae, A. brasiliensis and C. albicans at an acetic acid concentration of already 5%. Virucidal efficacy tests according to DIN EN 14476 and DIN EN 16777 showed a reduction of ≥4-log-steps against the Modified Vaccinia virus Ankara (MVA) for acetic acid concentrations of 5% or higher. The results suggest that acetic acid does not have a disinfecting effect on microorganisms in a dosage that is commonly used for cleaning. However, this can be achieved by increasing the concentration of acetic acid used, especially when combined with citric acid. CONCLUSIONS: Our results show a disinfecting effect of acetic acid in a concentration of 10% and in presence of 1.5% citric acid against a variety of microorganisms. A virucidal effect against enveloped viruses could also be proven. Furthermore, the results showed a considerable antimicrobial effect of acetic acid when used in domestic laundry procedures.


Assuntos
Ácido Acético/farmacologia , Anti-Infecciosos/farmacologia , Betacoronavirus/efeitos dos fármacos , Ácido Cítrico/farmacologia , Infecções por Coronavirus/prevenção & controle , Desinfetantes/farmacologia , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Bactérias/efeitos dos fármacos , Desinfecção/métodos , Fungos/efeitos dos fármacos , Humanos , Norovirus/efeitos dos fármacos
13.
Sheng Wu Gong Cheng Xue Bao ; 36(7): 1356-1364, 2020 Jul 25.
Artigo em Chinês | MEDLINE | ID: mdl-32748593

RESUMO

Salinity is the most important factor for the growth of crops. It is an effective method to alleviate the toxic effect caused by salt stress using saline-alkali-tolerant and growth-promoting bacteria in agriculture. Seven salt-tolerant bacteria were screened from saline-alkali soil, and the abilities of EPS production, alkalinity reduction and IAA production of the selected strains were investigated. A dominant strain DB01 was evaluated. The abilities of EPS production, alkalinity reduction and IAA production of strain DB01 were 0.21 g/g, 8.7% and 8.97 mg/L, respectively. The isolate was identified as Halomonas aquamarina by partial sequencing analysis of its 16S rRNA genes, and had the ability to inhibit the growth of Fusarium oxysporum f. sp., Alternaria solani, Phytophthora sojae and Rhizoctonia cerealis. It also could promote root length and germination rate of wheat seedlings under salt stress. Halomonas aquamarina can provide theoretical basis for the development of soil microbial resources and the application in saline-alkali soil improvement.


Assuntos
Álcalis , Raízes de Plantas , Tolerância ao Sal , Microbiologia do Solo , Álcalis/metabolismo , Bactérias/efeitos dos fármacos , Bactérias/genética , Halomonas/genética , Raízes de Plantas/microbiologia , RNA Ribossômico 16S/genética , Tolerância ao Sal/genética , Plântula/crescimento & desenvolvimento , Plântula/microbiologia , Solo/química , Triticum/microbiologia
14.
PLoS One ; 15(8): e0237603, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32841261

RESUMO

BACKGROUND/PURPOSE: To date, studies examining polymicrobial infections in ocular disease have mostly been limited to keratitis or endophthalmitis. We characterized polybacterial infections compared to monobacterial infections in prior clinical studies evaluating besifloxacin ophthalmic suspension 0.6% for the treatment of bacterial conjunctivitis and report on associated microbiological outcomes. METHODS: In this post-hoc analysis, microbiological data for subjects with conjunctivitis due to one or more than one bacterial species in three previous studies (two vehicle-, one active-controlled) of besifloxacin were extracted. Bacterial species identified at baseline were deemed causative if their colony count equaled or exceeded species-specific prespecified threshold criteria. In subjects with polybacterial infections, the fold-increase over threshold was used to rank order the contribution of individual species. Baseline pathogens and their minimum inhibitory concentrations (MICs) for common ophthalmic antibiotics were compared by infection type, as were microbial eradication rates following treatment with besifloxacin. RESULTS: Of 1041 subjects with culture-confirmed conjunctivitis, 17% had polybacterial and 83% had monobacterial conjunctivitis at baseline. In polybacterial compared to monobacterial infections, Haemophilus influenzae and Streptococcus pneumoniae were identified less frequently as the dominant infecting species (P = 0.042 and P<0.001, respectively), whereas Streptococcus mitis/S. mitis group was identified more frequently as dominant (P<0.001). Viral coinfection was also identified more frequently in polybacterial infections (P<0.001). Staphylococcus aureus was the most common coinfecting species in polybacterial infections and the second most common dominant species in such infections. With few exceptions, MICs for individual species were comparable regardless of infection type. Clinical microbial eradication rates with besifloxacin were high regardless of infection type (P≤0.016 vs vehicle at follow-up visits). CONCLUSIONS: Approximately one in five subjects with bacterial conjunctivitis are infected with more than one bacterial species underscoring the need for a broad-spectrum antibiotic for such infections. Besifloxacin treatment resulted in robust eradication rates of these infections comparable to monobacterial infections. TRIAL REGISTRATION: NCT000622908, NCT00347932, NCT00348348.


Assuntos
Antibacterianos/uso terapêutico , Azepinas/uso terapêutico , Bactérias/classificação , Bactérias/efeitos dos fármacos , Conjuntivite Bacteriana/tratamento farmacológico , Fluoroquinolonas/uso terapêutico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Conjuntivite Bacteriana/microbiologia , Conjuntivite Bacteriana/patologia , Método Duplo-Cego , Feminino , Seguimentos , Humanos , Lactente , Recém-Nascido , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Prognóstico , Estudos Prospectivos , Adulto Jovem
15.
PLoS One ; 15(8): e0237258, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32756605

RESUMO

Aquatic weeds such as muskgrass (Chara spp.), water hyacinth (Eichhornia crassipes), water lettuce (Pistia stratiotes), hydrilla (Hydrilla verticillate), filamentous algae (Lyngbya wollei), and duckweed (Lemna minor) thrive in farm canals within the Everglades Agricultural Area of South Florida. Their presence, particularly during the summer months is an environmental concern with regards to water quality, in addition to being a nuisance because of their ability to multiply and spread rapidly in open waters causing restricted drainage/irrigation flow and low dissolved oxygen levels. Chemical control is effective but can have undesirable off-target effects, so reduced herbicide use is desirable. Hence, need exists to discover ways in which these weeds could be best managed or utilized. The objective of this research was to evaluate the allelopathic effect of these weeds to determine their use as potential biopesticides. Six aqueous extracts were tested against 100 bacterial strains isolated from plants and soil to evaluate their antimicrobial activity. These extracts were also used to determine their insecticidal and antifeedant effects on fall armyworm (FAW, Spodoptera frugiperda). Both extracts and powder form of the aquatic weeds were tested for their herbicidal activity towards seed germination and growth of three common terrestrial weed species. At a dilution of 1:100 and 1:1,000, none of the aquatic weeds inhibited in-vitro growth of the bacterial strains, with one exception (filamentous algae extract at 1:100 reduced growth of one bacterial isolate by 54%). Water lettuce reduced the survival rate of FAW by 14% while hydrilla and duckweed caused 11% and 9% reduction of FAW growth, respectively. Powdered duckweed inhibited the growth of nutsedge by 41%, whereas filamentous algae powder and extract reduced germination of amaranth by 20% and 28%, respectively. Harvesting these weeds and converting them into useable compounds could not only eliminate the in situ farm canal and water quality problems but also result in development of new soil amendments or biopesticides.


Assuntos
Antibacterianos/toxicidade , Agentes de Controle Biológico/toxicidade , Plantas Daninhas/química , Agricultura , Animais , Antibacterianos/química , Bactérias/efeitos dos fármacos , Agentes de Controle Biológico/química , Cianobactérias/química , Eichhornia/química , Hydrocharitaceae/química , Inseticidas/química , Inseticidas/toxicidade , Plantas/microbiologia , Microbiologia do Solo , Spodoptera/efeitos dos fármacos
16.
Sci Total Environ ; 746: 140894, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32763594

RESUMO

Multidrug-resistant bacteria cause difficult-to-treat infections and pose a risk for modern medicine. Sources of multidrug-resistant bacteria include hospital, municipal and slaughterhouse wastewaters. In this study, bacteria with resistance to 3rd generation cephalosporins were isolated from all three wastewater biotopes, including a maximum care hospital, municipal wastewaters collected separately from a city and small rural towns and the wastewaters of two pig and two poultry slaughterhouses. The resistance profiles of all isolates against clinically relevant antibiotics (including ß-lactams like carbapenems, the quinolone ciprofloxacin, colistin, and trimethoprim/sulfamethoxazole) were determined at the same laboratory. The bacteria were classified according to their risk to human health using clinical criteria, with an emphasis on producers of carbapenemases, since carbapenems are prescribed for hospitalized patients with infections with multi-drug resistant bacteria. The results showed that bacteria that pose the highest risk, i. e., bacteria resistant to all ß-lactams including carbapenems and ciprofloxacin, were mainly disseminated by hospitals and were present only in low amounts in municipal wastewater. The isolates from hospital wastewater also showed the highest rates of resistance against antibiotics used for treatment of carbapenemase producers and some isolates were susceptible to only one antibiotic substance. In accordance with these results, qPCR of resistance genes showed that 90% of the daily load of carbapenemase genes entering the municipal wastewater treatment plant was supplied by the clinically influenced wastewater, which constituted approximately 6% of the wastewater at this sampling point. Likewise, the signature of the clinical wastewater was still visible in the resistance profiles of the bacteria isolated at the entry into the wastewater treatment plant. Carbapenemase producers were not detected in slaughterhouse wastewater, but strains harboring the colistin resistance gene mcr-1 could be isolated. Resistances against orally available antibiotics like ciprofloxacin and trimethoprim/sulfamethoxazole were widespread in strains from all three wastewaters.


Assuntos
Matadouros , Águas Residuárias , Animais , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Bactérias/genética , Carbapenêmicos , Farmacorresistência Bacteriana/efeitos dos fármacos , Farmacorresistência Bacteriana/genética , Hospitais Municipais , Humanos , Testes de Sensibilidade Microbiana , Suínos , beta-Lactamases/genética
17.
Ecotoxicol Environ Saf ; 204: 111114, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32798752

RESUMO

The widely distributed seaweed Ulva fasciata has nutrient absorption abilities and can be used in the bioremediation of polluted maricultural environments. This study explored microbial community and antibiotic resistance gene (ARG) variation in mariculture sediments in response to different trace levels (10, 100, and 500 µg L-1) of oxytetracycline (OTC) and the presence of Ulva fasciata. The increase in OTC level promoted nutrient (NO3_-N and PO43--P) removal mainly due to Ulva fasciata adsorption. The abundances of the Euryarchaeota and Planctomycetes phyla in sediments were positively related to the increase in OTC stress, while a negative correlation occurred for the Proteobacteria phylum via metagenomic analysis. Compared with the control system, the increase rates of total ARGs were 3.90%, 7.36% and 13.42% at the OTC levels of 10, 100 and 500 µg L-1, respectively. OTC stress mainly favoured the collateral enrichment of non-corresponding polypeptide and MLS ARGs, mainly due to the enrichment of the phyla Planctomycetes and Euryarchaeota by the synergistic effect of OTC and nutrients. The results of quantitative PCR with tetracycline resistance genes (TRGs) (tetO, tetT, tetPB, tetW and otrA) and a horizontal transfer gene (intl1) demonstrated that all of genes had much higher gene numbers in sediments after 3 months of OTC stress than in those without OTC stress, which was strongly related to the variation in the phyla Bacteroidetes, Gemmatimonadetes and Acidobacteria. The significant correlation between intl1 and the target TRGs is indicative of the important role of the horizontal transfer of integron-resistant genes in the spread of TRGs.


Assuntos
Antibacterianos/toxicidade , Aquicultura , Resistência Microbiana a Medicamentos/genética , Genes Bacterianos , Ulva/fisiologia , Bactérias/efeitos dos fármacos , Biodegradação Ambiental , Integrons , Microbiota/efeitos dos fármacos , Oxitetraciclina/análise , Alga Marinha/efeitos dos fármacos , Resistência a Tetraciclina/efeitos dos fármacos , Ulva/efeitos dos fármacos
18.
Ecotoxicol Environ Saf ; 204: 111124, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32805504

RESUMO

Dechlorane Plus (DP) is a typical polychlorinated flame retardant that has been emerged in chemical products. Due to its accumulation and amplification effect, the toxicity of DP has become a widespread environmental safety issue. However, whether DP can affect the intestinal tract of teleost fish remains largely unclear. To understand its effects on the intestinal barrier, morphological characteristics and intestinal microbiome of common carp, different concentrations (30, 60 and 120 µg/L) of DP were exposed to common carps for 4 weeks. The results indicated that DP evidently shortened the intestinal folds and damaged the intestinal epithelium layer. In addition, the mRNA expression levels of occludin, claudin-2 and zonula occludens-1 (ZO-1) were significantly decreased with increasing DP concentrations. Furthermore, the relative abundance of some microbiota species were also changed significantly. Our study first demonstrated that DP could cause damage to the intestinal epithelium and destroy the intestinal barrier and increase the relative abundance of pathogenic bacteria, thereby increasing the probability of contact between intestinal epithelium and pathogenic bacteria, which in turn lead to an increased susceptibility to various diseases and poor health. In summary, our findings reveal that chronic DP exposure can have a harmful effect on the intestinal flora balance and is potentially linked to human disease.


Assuntos
Carpas/microbiologia , Retardadores de Chama/toxicidade , Microbioma Gastrointestinal/efeitos dos fármacos , Hidrocarbonetos Clorados/toxicidade , Compostos Policíclicos/toxicidade , Animais , Bactérias/efeitos dos fármacos , Mucosa Intestinal , Intestinos/efeitos dos fármacos , Microbiota
19.
PLoS One ; 15(8): e0237263, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32764812

RESUMO

BACKGROUND: Chronic infected wounds are generally difficult to manage and treatment can be particularly challenging in resource-limited settings where diagnostic testing is not readily available. In this study, the epidemiology of microbial pathogens in chronically infected wounds in rural Ghana was assessed to support therapeutic choices for physicians. METHODS: Culture-based bacterial diagnostics including antimicrobial resistance testing were performed on samples collected from patients with chronic wounds at a hospital in Asante Akim North Municipality, Ghana. Fungal detection was performed by broad-range fungal PCR and sequencing of amplicons. RESULTS: In total, 105 patients were enrolled in the study, from which 207 potential bacterial pathogens were isolated. Enterobacteriaceae (n = 84, 41%) constituted the most frequently isolated group of pathogens. On species level, Pseudomonas aeruginosa (n = 50, 24%) and Staphylococcus aureus (n = 28, 14%) were predominant. High resistance rates were documented, comprising 29% methicillin resistance in S. aureus as well as resistance to 3rd generation cephalosporins and fluoroquinolones in 33% and 58% of Enterobacteriaceae, respectively. One P. aeruginosa strain with carbapenem resistance was identified. The most frequently detected fungi were Candida tropicalis. CONCLUSIONS: The pathogen distribution in chronic wounds in rural Ghana matched the internationally observed patterns with a predominance of P. aeruginosa and S. aureus. Very high resistance rates discourage antibiotic therapy but suggest an urgent need for microbiological diagnostic approaches, including antimicrobial resistance testing to guide the management of patients with chronic wounds in Ghana.


Assuntos
Antibacterianos/farmacologia , Bactérias/isolamento & purificação , Fungos/isolamento & purificação , Infecção dos Ferimentos/tratamento farmacológico , Infecção dos Ferimentos/microbiologia , Adulto , Idoso , Animais , Antibacterianos/uso terapêutico , Bactérias/efeitos dos fármacos , Candida tropicalis/efeitos dos fármacos , Candida tropicalis/isolamento & purificação , Farmacorresistência Bacteriana , Farmacorresistência Fúngica , Feminino , Fungos/efeitos dos fármacos , Gana/epidemiologia , Hospitais de Distrito , Humanos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/isolamento & purificação , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/isolamento & purificação , Infecção dos Ferimentos/epidemiologia , Adulto Jovem
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