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1.
PLoS One ; 15(8): e0238195, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32845920

RESUMO

Nosocomial infections caused by extensively drug-resistant (XDR) or Pan-Drug resistant (PDR) Acinetobacter (A.) baumannii have recently increased dramatically creating a medical challenge as therapeutic options became very limited. The aim of our study was to investigate the antibiotic-resistance profiles and evaluate the various combinations of ciprofloxacin (CIP) or levofloxacin (LEV) with antimicrobial agents and non-antimicrobial agents to combat antimicrobial resistance of XDR A. baumannii. A total of 100 (6.25%) A. baumannii clinical isolates were recovered from 1600 clinical specimens collected from hospitalized patients of two major university hospitals in Upper Egypt. Antimicrobial susceptibility tests were carried out according to CLSI guidelines. Antimicrobial susceptibility testing of the respective isolates showed a high percentage of bacterial resistance to 19 antimicrobial agents ranging from 76 to99%. However, a lower percentage of resistance was observed for only colistin (5%) and doxycycline (57%). The isolates were categorized as PDR (2; 2%), XDR (68; 68%), and multi-drug resistant (MDR) (30; 30%). Genotypic analysis using ERIC-PCR on 2 PDR and 32 selected XDR isolates showed that they were not clonal. Combinations of CIP or LEV with antibiotics (including, ampicillin, ceftriaxone, amikacin, or doxycycline) were tested on these A. baumannii non-clonal isolates using standard protocols where fractional inhibitory concentrations (-FICs) were calculated. Results of the respective combinations showed synergism in 23.5%, 17.65%, 32.35%, 17.65% and 26.47%, 8.28%, 14.71%, 26.47%, of the tested isolates, respectively. CIP or LEV combinations with either chlorpromazine (CPZ) 200 µg/ml, propranolol (PR) in two concentrations, 0.5 mg/ml and 1.0 mg/ml or diclofenac (DIC) 4 mg/ml were carried out and the MIC decrease factor (MDF) of each isolate was calculated and results showed synergism in 44%, 50%, 100%, 100% and 94%, 85%, 100%, 100%, of the tested isolates, respectively. In conclusion, combinations of CIP or LEV with CPZ, PR, or DIC showed synergism in most of the selected PDR and XDR A. baumannii clinical isolates. However, these combinations have to be re-evaluated in vivo using appropriate animal models infected by XDR- or PDR- A. baumannii.


Assuntos
Acinetobacter baumannii/efeitos dos fármacos , Antibacterianos/farmacologia , Clorpromazina/farmacologia , Diclofenaco/farmacologia , Fluoroquinolonas/farmacologia , Propranolol/farmacologia , Infecções por Acinetobacter/tratamento farmacológico , Acinetobacter baumannii/genética , Acinetobacter baumannii/isolamento & purificação , Ciprofloxacino/farmacologia , Infecção Hospitalar/microbiologia , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Combinação de Medicamentos , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Sinergismo Farmacológico , Egito , Humanos , Levofloxacino/farmacologia
2.
J Mycol Med ; 30(2): 100970, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32334948

RESUMO

A survey of mycology laboratories for antifungal susceptibility testing (AFST) was undertaken in France in 2018, to better understand the difference in practices between the participating centers and to identify the difficulties they may encounter as well as eventual gaps with published standards and guidelines. The survey captured information from 45 mycology laboratories in France on how they perform AFST (number of strains tested, preferred method, technical and quality aspects, interpretation of the MIC values, reading and interpretation difficulties). Results indicated that 86% of respondents used Etest as AFST method, with a combination of one to seven antifungal agents tested. Most of the participating laboratories used similar technical parameters to perform their AFST method and a large majority used, as recommended, internal and external quality assessments. Almost all the participating mycology laboratories (98%) reported difficulties to interpret the MIC values, especially when no clinical breakpoints are available. The survey highlighted that the current AFST practices in France need homogenization, particularly for MIC reading and interpretation.


Assuntos
Antifúngicos/uso terapêutico , Laboratórios , Testes de Sensibilidade Microbiana , Micologia , Prática Profissional/estatística & dados numéricos , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão/métodos , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão/normas , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão/estatística & dados numéricos , Farmacorresistência Fúngica , França , História do Século XXI , Humanos , Laboratórios/normas , Laboratórios/estatística & dados numéricos , Ensaio de Proficiência Laboratorial/métodos , Ensaio de Proficiência Laboratorial/estatística & dados numéricos , Testes de Sensibilidade Microbiana/métodos , Testes de Sensibilidade Microbiana/normas , Testes de Sensibilidade Microbiana/estatística & dados numéricos , Micologia/história , Micologia/métodos , Micologia/normas , Micologia/estatística & dados numéricos , Prática Profissional/normas , Controle de Qualidade , Inquéritos e Questionários
3.
Arch Microbiol ; 202(5): 1173-1179, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32076735

RESUMO

Escherichia coli strains are part of the normal biota of humans and animals; however, several clinical reports have implicated E. coli as the etiological agent of diarrhea in humans and companion animals. Thus, the aim of the present study was to know if companion dogs in the city of San Luis Potosi are colonized with virulent potentially harmful E. coli strains. Rectal swabs from 30 dogs, 13 with and 17 without diarrhea were analyzed. Phylogenetic and virulence genes analysis was performed to the E. coli isolates. Additionally, the Kirby-Bauer test was used to analyze the sensitivity to 32 different antimicrobials from 14 families. Eighty-five isolates were identified as E. coli and detected in 97% of healthy and diarrheic dog samples. E. coli isolates from healthy dogs carried several virulence genes, in contrast with those from diarrheic animals that presented only eaeA. In healthy dogs, phylogenetic analysis showed that 57% and 43% of E. coli isolates belonged to commensal (A and B1) and virulent (B2 and D) groups respectively. Meanwhile, diarrheic dogs showed that 69% of the isolates were identified as virulent B2 and D phylogroups. Moreover, E. coli resistant to ß-lactams, aminoglycosides, tetracycline, quinolones, and folate inhibitors were detected in both groups of dogs. The presence of E. coli with eaeA virulence gene in diarrheic dogs, suggest that these strains are associated with the animal´s condition. Finally, major attention must be drawn to the careful handling of dogs because of their capability to harbor and disseminate virulent E. coli strains.


Assuntos
Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/transmissão , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Animais de Estimação/microbiologia , Animais , Antibacterianos/farmacologia , Diarreia/microbiologia , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Cães , Escherichia coli/classificação , Humanos , Filogenia , Virulência/genética , Fatores de Virulência/genética
4.
BMC Infect Dis ; 20(1): 135, 2020 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-32050928

RESUMO

BACKGROUND: Salmonellosis remains an important public health problem globally. The disease is among the leading causes of morbidity and mortality in developing countries that experience poor hygiene and lack of access to clean and safe water. There was an increase in reported cases of Salmonellosis in Njombe Region, Southern Highland of Tanzania between 2015 and 2016 based on clinical diagnosis. Nevertheless, little is known about the factors contributing to the transmission of this disease in the region. This study was conducted to determine the prevalence, antimicrobial susceptibility, and factors associated with Salmonella infection among patients who report gastrointestinal complaints. METHODS: A cross-sectional study was conducted from December 2017 to February 2018 among patients with gastrointestinal complaints at Kibena Regional Hospital. Stool samples were submitted for isolation of Salmonella spp. Identification was based on conventional biochemical tests and serotyping to differentiate typhoid and non-typhoid Salmonella (NTS). Antimicrobial susceptibility was performed using the Kirby-Bauer disc diffusion method. Multivariable logistic regression analysis was performed to examine the factors independently associated with Salmonella infection. RESULTS: The prevalence of Salmonella infection among participants with gastrointestinal complaints was 16.5% (95% CI: 12.7-21.1) of them, 83.7, 95% CI: 70.9-91.5 were NTS while 16.3, 95% CI: 8.5-29.0 were Typhoid Salmonella species. All isolates were sensitive to ceftriaxone and ciprofloxacin, whereas 27.8 and 100% were resistant to co-trimoxazole and ampicillin respectively. The odd of Salmonella infection was fourfold higher among participants with formal employment (AOR 3.8, 95% CI, 1.53-9.40). Use of water from wells/rivers (AOR 2.2, 95% CI, 1.07-4.45), drinking untreated water (AOR 2.6, 95% CI, 1.21-5.48) and often eating at a restaurant (AOR 3.4, 95% CI, 1.28-8.93) had increased odds of Salmonella infection. Likewise, having abdominal pain (AOR 8.5, 95% CI, 1.81-39.78) and diarrhea (AOR 2.3, 95% CI, 1.12-4.68) were independent symptoms that predict Salmonella infection. CONCLUSION: There is a high prevalence of Salmonella infection among people who report gastrointestinal complaints and it is clinically predicated by diarhoea and abdominal pain. Employed participants and those eating at restaurant and drinking unsafe water had higher risk of infection. Salmonella spp. causing gastroenteritis has developed resistance to commonly used antibiotics.


Assuntos
Gastroenteropatias/microbiologia , Infecções por Salmonella/epidemiologia , Salmonella/efeitos dos fármacos , Adolescente , Adulto , Ampicilina/uso terapêutico , Antibacterianos/uso terapêutico , Ceftriaxona/uso terapêutico , Criança , Pré-Escolar , Ciprofloxacino/uso terapêutico , Estudos Transversais , Diarreia/epidemiologia , Diarreia/microbiologia , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Farmacorresistência Bacteriana/efeitos dos fármacos , Feminino , Gastroenteropatias/epidemiologia , Gastroenteropatias/etiologia , Hospitais/estatística & dados numéricos , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Prevalência , Salmonella/isolamento & purificação , Infecções por Salmonella/tratamento farmacológico , Tanzânia/epidemiologia , Combinação Trimetoprima e Sulfametoxazol/uso terapêutico , Febre Tifoide/epidemiologia , Febre Tifoide/microbiologia , Adulto Jovem
5.
Artigo em Inglês | MEDLINE | ID: mdl-31963695

RESUMO

Background: Methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus epidermidis (MRSE), the most prevalent causes of hospital-associated and community-associated infections, could exist on frequently touched surfaces. This study aims to determine the contamination prevalence and the characteristics of MRSA and MRSE isolated from secondary school environments. Methods: We collected environmental samples from ten secondary schools in Guangzhou city between October 2016 and January 2017. The samples were confirmed for MRSA and MRSE isolates by using biochemical tests and polymerase chain reactions. Antimicrobial susceptibility testing was performed by the Kirby-Bauer disk diffusion method. Staphylococcal cassette chromosome mec (SCCmec) typing, toxin gene screening, and multilocus sequence typing (MLST) were performed to further characterize the isolates. Data were analyzed by two-sample proportion tests. Results: A total of 1830 environmental samples were collected. The prevalence of MRSA and MRSE contamination were 1.86% (34/1830) and 5.14% (94/1830), respectively. The proportions of multidrug resistance in both MRSA (58.82%) and MRSE (63.83%) isolates were high. Seven clonal complexes (CC) and 12 sequence types (ST) were identified, with the CC5 (35.29%) and ST45 (25.53%) being the most prevalent. We found that 44.12% of the MRSA isolates were community-acquired and the main type was ST45-SCCmec IV. We found that 5.88% and 32.35% of MRSA isolates were positive to Panton-Valentine leukocidin (PVL) and toxic shock syndrome toxin-1 (tst) gene, respectively. No MRSE isolate was positive to the toxin genes. Conclusion: Our findings raise potential public health concerns for environmental contamination of MRSA and MRSE in school environments. Surfaces of school environments may potentially provide a source for cross-contamination with these bacteria into the wider community.


Assuntos
Microbiologia Ambiental , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Infecções Estafilocócicas/microbiologia , Antibacterianos/farmacologia , Toxinas Bacterianas , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Enterotoxinas , Exotoxinas , Humanos , Leucocidinas , Meticilina/farmacologia , Resistência a Meticilina , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Prevalência , Instituições Acadêmicas , Infecções Estafilocócicas/epidemiologia , Staphylococcus epidermidis/efeitos dos fármacos , Superantígenos
6.
Lett Appl Microbiol ; 71(1): 94-101, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31943254

RESUMO

This study aimed to examine incidence, virulence and antimicrobial properties in Aeromonas spp. isolated from cockles (Tegillarca granosa) in Korea. Firstly, genomic DNA was extracted from 32 Aeromonas spp. isolates, and PCR screening for virulence, antimicrobial resistance genes was carried out. The disk diffusion assay was used to examine antimicrobial susceptibility. Aeromonas spp. isolates comprised, A. hydrophila (n = 8), A. veronii (n = 15), A. media (n = 2), A. salmonicida (n = 2), A. allosaccharophila (n = 1), A. bestiarum (n = 1), A. culicicola (n = 1), A. enteropelogenes (n = 1) and A. rivipollensis (n = 1). High prevalence of virulence-related genes reported as; act (69%), alt (47%), ast (41%), aerA (56%), lip (50%), ahyB (47%), ser (28%), fla (66%), gcat (44%), ascV (50%) and hlyA (72%). All isolates were multidrug resistant, while highest resistance level observed for ampicillin (100%), followed by imipenem (81%), rifampicin (78%), cephalothin (72%), piperacillin (47%) and Colistin sulfate (31%). The presence of blaSHV , blaCTX , tetE, aac(6')-Ib, strA-strB, qnrS, qnrB and IntI1 genes were reported in varying combinations. Nevertheless, blaTEM , blaIMP , tetA, tetB, qnrA, qnrB and aphAI-IAB genes and the class1 integron were not detected. The high occurrence of virulence and antimicrobial resistance genes in cockles reveals that it can be a potential health risk source for consumers.


Assuntos
Aeromonas/genética , Antibacterianos/farmacologia , Cardiidae/microbiologia , Alimentos Marinhos/microbiologia , Resistência beta-Lactâmica/genética , Aeromonas/efeitos dos fármacos , Aeromonas/isolamento & purificação , Ampicilina/farmacologia , Animais , Cefalotina/farmacologia , Colistina/farmacologia , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Imipenem/farmacologia , Integrons/genética , Piperacilina/farmacologia , Reação em Cadeia da Polimerase , Prevalência , República da Coreia , Rifampina/farmacologia , Virulência/genética
7.
Sci Rep ; 10(1): 928, 2020 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-31988293

RESUMO

Infections caused by Mycobacterium abscessus are increasing in prevalence in cystic fibrosis patients. This opportunistic pathogen's intrinsic resistance to most antibiotics has perpetuated an urgent demand for new, more effective therapeutic interventions. Here we report a prospective advance in the treatment of M. abscessus infection; increasing the susceptibility of the organism to amoxicillin, by repurposing the ß-lactamase inhibitor, relebactam, in combination with the front line M. abscessus drug imipenem. We establish by multiple in vitro methods that this combination works synergistically to inhibit M. abscessus. We also show the direct competitive inhibition of the M. abscessus ß-lactamase, BlaMab, using a novel assay, which is validated kinetically using the nitrocefin reporter assay and in silico binding studies. Furthermore, we reverse the susceptibility by overexpressing BlaMab in M. abscessus, demonstrating relebactam-BlaMab target engagement. Finally, we highlight the in vitro efficacy of this combination against a panel of M. abscessus clinical isolates, revealing the therapeutic potential of the amoxicillin-imipenem-relebactam combination.


Assuntos
Amoxicilina/farmacologia , Compostos Azabicíclicos/farmacologia , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Imipenem/farmacologia , Mycobacterium abscessus/efeitos dos fármacos , Inibidores de beta-Lactamases/farmacologia , Amoxicilina/uso terapêutico , Compostos Azabicíclicos/metabolismo , Compostos Azabicíclicos/uso terapêutico , Sítios de Ligação , Cefalosporinas/metabolismo , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Sinergismo Farmacológico , Quimioterapia Combinada/métodos , Imipenem/uso terapêutico , Testes de Sensibilidade Microbiana , Simulação de Acoplamento Molecular , Infecções por Mycobacterium não Tuberculosas/tratamento farmacológico , Mycobacterium abscessus/enzimologia , Plasmídeos/genética , Inibidores de beta-Lactamases/metabolismo , beta-Lactamases/genética , beta-Lactamases/metabolismo
8.
J Photochem Photobiol B ; 202: 111702, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31760372

RESUMO

In our recent study, we showed that pulsed blue light (PBL) suppresses the growth of Propionibacterium acnes more than continuous wave (CW) blue light in vitro, but it is not known that other bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA), respond similarly to PBL. The high potency of PBL relative to CW blue light makes it a suitable antimicrobial for suppressing bacterial growth in biofilms as well. Therefore, we determined if MRSA-a deadly bacterium of global concern-is susceptible to 450 nm PBL irradiation in vitro, and ascertained whether the bactericidal effect of PBL on planktonic P. acnes culture can be replicated in biofilms of P. acnes and MRSA. In three series of experiments, we irradiated P. acnes and MRSA respectively, either in planktonic cultures, forming biofilms or formed biofilms. Compared to controls, the results showed 100% bacterial suppression in planktonic cultures of MRSA irradiated with 3 mW/cm2 irradiance and 7.6 J/cm2 radiant exposure three times at 30-minute intervals, and also in P. acnes cultures irradiated with 2 mW/cm2 irradiance 5 J/cm2 radiant exposure thrice daily during each of 3 days. Irradiation of biofilms with the same irradiances and radiant exposures that gave 100% bacterial suppression in planktonic cultures resulted in disruption and disassembly of the architecture of MRSA and P. acnes biofilms, more so in forming biofilms than formed biofilms. The antimicrobial effect on each bacterium was minimal in forming biofilms, and even less in formed biofilms. Increasing radiant exposure slightly from 7.6 J/cm2 to 10.8 J/cm2 without changing any other parameter, yielded more disruption of the biofilm and fewer live MRSA and P. acnes, suggesting that 100% bacterial suppression is possible with further refinement of the protocol. In both planktonic cultures and biofilms, PBL suppressed MRSA more than P. acnes.


Assuntos
Biofilmes/efeitos da radiação , Luz , Staphylococcus aureus Resistente à Meticilina/fisiologia , Staphylococcus aureus Resistente à Meticilina/efeitos da radiação , Propionibacterium acnes/efeitos da radiação , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Microscopia de Fluorescência , Propionibacterium acnes/fisiologia , Termodinâmica
9.
J Photochem Photobiol B ; 202: 111713, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31760373

RESUMO

The field of nanobiotechnology and nanomedicine paves way for the use of several nanoparticles. Especially, in biomedical applications, the silver nanoparticles (AgNPs), gold nanoparticles (AuNPs) and palladium nanoparticles (PdNPs) are found most vital and promising, among other nanoparticles. The biomedical activities of these particles mostly depend on their shape, size and distribution. Preparation of these particles in an eco-friendly method is an immediate need of the society. Herein, AuNPs, AgNPs and PdNPs (MNPS) were synthesized by Solanum nigrum Leaves (SNL) extract. The structural and morphological studies were carried out by using TEM, XRD and EDAX, while the optical and chemical properties were studied using UV-visible spectrum and FTIR spectroscopy. The particles obtained were found to possess a FCC (Face Centered Cubic) structure. TEM images of Ag, Au and PdNPs showed spherical well dispersed nanoparticles with average size of 3.46 nm, 9.39 nm and 21.55 nm respectively. The FTIR spectra confirmed polyphenols and antioxidants in SNL extract act as reducing and capping agents respectively in the synthesis of MNPs. The EDX technique confirmed the presence of silver, gold and palladium nanoparticles. Antimicrobial studies noted that the AgNPs have effective inhibition against E. coli. The complete reduction of 4-Nitrophenol and the formation of 4-Aminophenol with the presence of NaBH4 was chosen for the study of catalytic activities of the prepared MNPs. The reduction time of Au and Pd catalyst were smaller compared to that of Ag. This viable preparation method for producing small spherical shaped nanoparticles expected to the applied to the fields of nanomedicine.


Assuntos
Antibacterianos/química , Ouro/química , Nanopartículas Metálicas/química , Paládio/química , Prata/química , Solanum nigrum/química , Antibacterianos/síntese química , Antibacterianos/farmacologia , Catálise , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Escherichia coli/efeitos dos fármacos , Química Verde , Nanopartículas Metálicas/toxicidade , Nitrofenóis/química , Tamanho da Partícula , Extratos Vegetais/química , Folhas de Planta/química , Folhas de Planta/metabolismo , Solanum nigrum/metabolismo
10.
J Photochem Photobiol B ; 202: 111701, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31759194

RESUMO

Propionibacterium acnes infection is the eighth most prevalent disease, affecting 80% of people worldwide. Resistance to antibiotics has been on the rise; over 40% of acne infections now resist commonly used topical and oral anti-acnes antibiotics, making treatment difficult. In our effort to refine blue light as an alternative safe clinically effective treatment, we determined if 100% bacterial suppression is attainable at ultralow irradiances and radiant energies, and explored the relationship between bacterial suppression and fluorescence during treatment. P. acnes were irradiated in vitro repeatedly three times per day at 3- or 4-hour intervals over three or more days, using 3 or 5 J/cm2 radiant energy of 450 nm pulsed blue light (PBL) at irradiances as low as 2 mW/cm2. In another series of experiments, we measured changes in P. acnes fluorescence as bacteria were repeatedly irradiated at various radiant exposures over three to four days. Our results showed that (1) 33% PBL, applied three times per day at 3-hour intervals each day over a three-day period at 2 mW/cm2 irradiance and 5 J/cm2 radiant exposure, resulted in100% bacterial suppression (7 log10 reduction), (2) the absorbed 450 nm light caused P. acnes to fluoresce predominantly in the red spectrum, with the fluorescence diminishing correlatively as treatment was repeated at 3-hour intervals and rising significantly during long periods of no treatment, and (3) treatment at 3-hour intervals gave better results than treatment at 4-hour intervals.


Assuntos
Luz , Propionibacterium acnes/efeitos da radiação , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Espectrometria de Fluorescência , Termodinâmica
11.
J Photochem Photobiol B ; 202: 111719, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31770705

RESUMO

Infection with Propionibacterium acnes is ubiquitous, and drug resistant strains have been on the rise as the use of pharmaceutical antimicrobials continues to engender the emergence of further resistant strains. In previous studies, we showed that treatment with blue light serves as an alternative to pharmaceutical intervention. As a part of our ongoing effort to improve the antimicrobial efficacy of blue light, we studied the effect of pulsed 450 nm light on P. acnes in vitro and compared two pulsed rates with continuous wave irradiation. We irradiated cultures of P. acnes at various irradiances and radiant energies either singly or repeatedly at various time intervals, using printed micro-LEDs, with the goal of finding the lowest combination of irradiance and radiant energy that would yield 100% bacterial suppression. Our results show that treatment with 33% pulsed light gave the best result compared to 20% pulsed wave or continuous wave. Timing irradiation to coincide with the replication cycle of P. acnes produced a significantly better antimicrobial effect. Furthermore, repeated irradiation at 3-h or 4-h interval enabled significant bacterial suppression even at lower irradiances; thus, making single irradiation at high irradiances unnecessary. Moreover, combining repeated irradiation with appropriate duration of treatment and 33% irradiation pulse rate gave optimal 100% [7 log10] bacterial suppression.


Assuntos
Luz , Propionibacterium acnes/efeitos da radiação , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Impressão Tridimensional , Termodinâmica , Fatores de Tempo
12.
J Photochem Photobiol B ; 202: 111706, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31775112

RESUMO

The noble metal such as Ag and Au doped CeO2 nanoparticles was successfully prepared by ionic liquid assisted hydrothermal method in the presence of Justicia adhatoda leaves extract and were used as an antibacterial and anticancer agent. The FT-IR and Raman spectrum exhibit the peaks at 460 and 464 cm-1 assigned to CeO stretching vibrations of NPs. The electron microscopic micrographs confirmed the spherical shaped morphology of prepared NPs. The insertion of Ag and Au ions into the CeO2 surface creates lattice defects the leads to reduce the band gap energy of Ag-Au/CeO2 at 3.15 eV. The XRD results suggested the average crystalline size of the silver­gold loaded CeO2 was 28 nm. From the elemental mapping images, we have visualized that existence and uniform distribution of Ag, Au, Ce, and O in the prepared nanomaterials. The antibacterial activity of unloaded and bimetal loaded CeO2 NPs was evaluated with Gram-positive and Gram-negative bacteria using disc diffusion assay. The AgAu loaded CeO2 NPs exhibited the highest zone of inhibition against E. coli and S. aureus strains when compared with pristine CeO2, Ag loaded CeO2, and Au loaded CeO2 NPs. In addition, the 100 µg mL-1 of CeO2, Ag/CeO2, Au/CeO2 and Ag-Au/CeO2 NPs exposed the 50, 51, 52 and 56% of anticancer activity against the HeLa cells respectively. Overall, this study concludes that the ionic liquid functionalized green synthesized bimetal loaded cerium oxide NPs showed potent antibacterial and anticancer activities.


Assuntos
Antibacterianos/química , Antineoplásicos/química , Líquidos Iônicos/química , Adhatoda/química , Nanopartículas Metálicas/química , Antibacterianos/síntese química , Antibacterianos/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Cério/química , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Ouro/química , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Química Verde , Células HeLa , Humanos , Adhatoda/metabolismo , Nanopartículas Metálicas/toxicidade , Tamanho da Partícula , Extratos Vegetais/química , Folhas de Planta/química , Folhas de Planta/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Prata/química
13.
J Photochem Photobiol B ; 202: 111729, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31835161

RESUMO

Bacterial pathogenicity is becoming a major cause of morbidity and mortality around the globe. Researchers are tirelessly finding solutions to cure or prevent infections caused by bacterial pathogens. Nanotechnology is a fast-growing area of research, effectively influencing and preventing bacterial growth. Nanoparticles (NPs) of silver, copper and gold are being used to kill bacterial pathogens in the past years but the toxicity of NPs at higher concentrations remains a major problem. Therefore, in the present study, Co3O4@ZrO2 (CoZ) core/shell NPs were synthesized using a simple sol-gel method. The synthesized NPs were characterized using different analytical techniques revealing the absorption bands at 456 and 277 nm with crystalline size of ~600 nm core/shell. The functional groups and oxidation states were characterized using FTIR analysis. Further bactericidal properties of core/shell of Co3O4@ZrO2 NPs were tested against Gram negative (Escherichia coli, Pseudomonas aeruginosa) and Gram positive (Staphylococcus aureus, Bacillus subitilis) pathogens. The core/shell CoZ NPs showed maximum growth inhibitions against S. aureus and P. aeruginosa. At the highest concentration of 200 µg/mL, the maximum zone of inhibition was observed. The synthesized CoZ NPs was also subjected to photocatalytic degradation of rhodamine B in 180 min under visible light irradiation. The present study could be an innovative and efficient research for both biomedical and wastewater treatment applications.


Assuntos
Nanopartículas Metálicas/química , Rodaminas/química , Catálise , Cobalto/química , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Luz , Nanopartículas Metálicas/toxicidade , Óxidos/química , Tamanho da Partícula , Fotólise/efeitos da radiação , Zircônio/química
14.
J Infect Public Health ; 13(4): 598-605, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31564530

RESUMO

INTRODUCTION: Pseudomonas aeruginosa (member of ESKAPE group) is predominantly responsible for emerging nosocomial infections and poses serious health concern due to ever-increasing drug resistance trends. The current study investigates the prevalence of such highly resistant P. aeruginosa in major hospital settings and further characterizes and compares them for genetic heterogeneity. MATERIALS AND METHODS: Samples of patients (n=108) with wound infections, bacteremia and burn injuries from major hospitals of Rawalpindi and Islamabad during 2017 to 2018 were collected for the present study. The samples were processed in the COMSATS Microbiology and Public Health lab and screened for the P. aeruginosa by routinely used biochemical tests, drug susceptibility tests and rapid molecular approaches. RESULTS: The results suggested that most of the isolates (88/108) are indeed P. aeruginosa (81.4%) underpinning the need of its active surveillance in hospital settings. Further analysis suggested that 32 of these 88 microbes are multi-drug resistance (36.3%), 16 (18.1%) are extensively drug resistance and 4 (4.5%) are pan-drug resistance. Moreover, double disc synergistic test suggested that 16 (18.1%) are positive for metallo-ß-lactamase production. Molecular screening confirmed that 2 (12.5%) and 3 (18.75%) of these 16 isolates are positive for VIM and NDM gene respectively while all the studied isolates were positive for AmpC ß-lactamase. PAP17 isolate harbors both VIM and NDM genes. ERIC PCR profiling showed that majority of MDR bacteria fall in cluster II and III similarly XDR bacteria also fall in cluster II and III while PDR bacteria fall in cluster IV. CONCLUSION: This study revealed that majority of the isolates are multi drug resistant MDR and extensively drug resistant (XDR). However, the presence of some pan drug resistant (PDR) isolates among such small sample size screened is of utmost concern. Molecular typing of extremely resistant P. aeruginosa revealed high genetic diversity. Therefore, we suggest that regular monitoring and surveillance of such highly resistant P. aeruginosa in hospital settings will help to control their transmission and hence reduce the disease burden.


Assuntos
Antibacterianos/uso terapêutico , Infecção Hospitalar/microbiologia , Hospitais Públicos/estatística & dados numéricos , Pseudomonas aeruginosa/efeitos dos fármacos , Antibacterianos/farmacologia , Infecção Hospitalar/tratamento farmacológico , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Farmacorresistência Bacteriana Múltipla , Humanos , Testes de Sensibilidade Microbiana , Reação em Cadeia da Polimerase Multiplex , Paquistão/epidemiologia , Filogenia , Infecções por Pseudomonas/tratamento farmacológico , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/enzimologia , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/isolamento & purificação , beta-Lactamases/genética
15.
J Biotechnol ; 309: 34-43, 2020 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-31887325

RESUMO

Recent medical strategies rely on the search for effective antimicrobials as surface coatings to prevent and treat infections in humans and animals. Biosurfactants have recently been shown to have properties as antiadhesive and antibiofilm agents. Sophorolipids in particular are biosurfactant molecules known to act as therapeutic agents. This study aimed to evaluate antimicrobial properties of sophorolipids in medical-grade silicone discs using strains of clinical relevance. Sophorolipids were produced under fed batch conditions, ESI-MS analyses were carried out to confirm the congeners present in each formulation. Three different products were obtained SLA (acidic congeners), SL18 (lactonic congeners) and SLV (mixture of acidic and lactonic congeners) and were tested against Staphylococcus aureus ATCC 6538, Pseudomonas aeruginosa ATCC 10145 and Candida albicans IHEM 2894. All three congener mixtures showed a biofilms disruption effect (> 0.1 % w/v) of 70 %, 75 % and 80 % for S. aureus, P. aeruginosa and C. albicans, respectively. On pre-coated silicone discs, biofilm formation of S. aureus was reduced by 75 % using SLA 0.8 % w/v. After 1.5 h the inhibition of C. albicans attachment was between 45-56 % whilst after 24 h incubation the percentage of inhibition for the cell attachment increased to 68-70 % when using SLA 0.8 % w/v. Finally, in co-incubation experiments SLA 0.05 % w/v significantly reduced the ability of S. aureus and C. albicans to form biofilms and to adhere to surfaces by 90-95 % at concentrations between 0.025-0.1 % w/v. In conclusion sophorolipids significantly reduced the cell attachment of both tested strains which suggests that these molecules could have a potential role as coating agents on medical grade silicone devices for the preventions of Gram positive bacteria and yeast infections.


Assuntos
Anti-Infecciosos/farmacologia , Biofilmes/efeitos dos fármacos , Ácidos Oleicos/farmacologia , Silicones/química , Antibacterianos/farmacologia , Candida albicans/efeitos dos fármacos , Candida glabrata/metabolismo , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Fermentação , Humanos , Ácidos Oleicos/química , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos
16.
Ann Lab Med ; 40(1): 21-26, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31432635

RESUMO

BACKGROUND: The existing modified carbapenem inactivation methods (mCIMs) recommended by the CLSI for detecting carbapenemase production have not been applicable for Acinetobacter baumannii. We evaluated the influence of matrices used in mCIMs and CIMTris on the stability of the disks for detecting carbapenemase producers and suggested optimal mCIM conditions for detecting carbapenemase-producing A. baumannii. METHODS: Seventy-three A. baumannii isolates characterized for antimicrobial susceptibility and carbapenemase encoding genes were tested for carbapenemase production using mCIM and CIMTris. The influence of the matrices (Tryptic soy broth [TSB] and Tris-HCl) used in these methods on the stability of the meropenem (MEM) disk was also evaluated. The mCIM conditions were adjusted to enhance screening sensitivity and specificity for detecting carbapenemase-producing A. baumannii. RESULTS: The matrices had an impact on the stability of the MEM disk after the incubation period (two or four hrs). TSB nutrient broth is an appropriate matrix for mCIM compared with Tris-HCl pH 7.6, which leads to the loss of MEM activity in CIMTris. The sensitivity and the specificity of the optimal mCIM were both 100%. CONCLUSIONS: We established optimal mCIM conditions for simple, accurate, and reproducible detection of carbapenemase-producing A. baumannii.


Assuntos
Acinetobacter baumannii/metabolismo , Antibacterianos/metabolismo , Proteínas de Bactérias/metabolismo , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão/métodos , Meropeném/metabolismo , beta-Lactamases/metabolismo , Acinetobacter baumannii/efeitos dos fármacos , Acinetobacter baumannii/isolamento & purificação , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Farmacorresistência Bacteriana/efeitos dos fármacos , Meropeném/farmacologia , beta-Lactamases/genética
17.
J Photochem Photobiol B ; 203: 111743, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31864091

RESUMO

The designing of new antibacterial agents with high and long-lasting activities are urgently needed in order to cope with the fast-emerging bacterial resistance. Zinc oxide nanoparticles (ZnO) have shown a significant promise as broad-spectrum antibacterial agents, and are efficient material in compromising bacterial membrane stability that leads to an increased cell permeability to nano-products. However, further engineering is required to improve their biological activities and to minimize their toxicity to healthy cells. In an attempt to resolve this issue, two semiconductor materials, ZnO and selenium (Se), were fabricated into a unique structural composite by a newly developed facile green method, and the designed composite was applied as an antibacterial nanomedicine. The developed methodology involves the initial preparation of ZnO, followed by its fabrication with Se at different temperatures (70 °C to 95 °C). Our experimental data showed that well defined interpenetrated crystalline Se network on ZnO (ZnO-Se) can be obtained at 80 °C for 180 min. The as-prepared ZnO-Se showed promising results in inhibiting the challenged bacterial strains under light irradiation (visible light) as compared to free ZnO. The enhanced biocidal property of ZnO-Se could be ascribed to its improved light-harvesting ability for sustainable induction of reactive oxygen species (ROS) and an active contact killing mechanism. Thus, ZnO-Se composite with a novel architecture could be a promising material in the treatment of bacterial infections by a mutual antibacterial synergy from the incorporated elements. Interestingly, the ZnO-Se has the ability to scavenge the overproduction of hydroxyl radicals, thus protecting the healthy cells from oxidative damage.


Assuntos
Antibacterianos/síntese química , Luz , Nanocompostos/química , Selênio/química , Óxido de Zinco/química , Antibacterianos/farmacologia , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Nanocompostos/toxicidade , Nanomedicina , Espécies Reativas de Oxigênio/metabolismo , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/efeitos da radiação , Temperatura
18.
Mater Sci Eng C Mater Biol Appl ; 107: 110193, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31761189

RESUMO

In this study, natural waste of marine corals was calcined to prepare an antimicrobial agent. Energy-dispersive X-ray fluorescence spectroscopy showed that the major element and compound of calcined corals were Ca and CaO, respectively, while X-ray photoelectron spectroscopy revealed the occurrence of more than one oxygen species (O1s) on the surface of calcined corals, which was ascribed to the presence of MgO. Scanning electron microscopy imaging showed that calcined corals had a rough surface and an irregular shape, and the particle size distribution indicated that the average particle size of the calcined corals was 7.3 µm. The calcined corals exhibited large zones of inhibition against gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) bacteria as well as a fungus (Penicillium sp.), in the antimicrobial tests using well diffusion method. Notably, as a membrane-active and species-specific agent, pronounced antimicrobial activity for calcined corals was observed against S. aureus. Our newly developed bioactive calcined corals could be the potential antimicrobial agents in medical, biological, and food packaging applications.


Assuntos
Antozoários/química , Anti-Infecciosos/química , Compostos de Cálcio/química , Óxidos/química , Animais , Antozoários/metabolismo , Anti-Infecciosos/farmacologia , Cálcio/química , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Escherichia coli/efeitos dos fármacos , Tamanho da Partícula , Penicillium/efeitos dos fármacos , Pós/química , Staphylococcus aureus/efeitos dos fármacos
19.
APMIS ; 128(1): 41-47, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31692136

RESUMO

Campylobacteriosis is one of the most frequently reported zoonoses worldwide. The well-documented increase in the ciprofloxacin resistance has increased the importance of rapid detection of the resistance. The incidence of ciprofloxacin resistance was investigated using real-time PCR. Identification of one hundred and fifty-eight strains was performed by PCR. Minimum inhibitory concentration (MIC) of ciprofloxacin was determined by Epsilometer test. Following the confirmation of the efficiencies of singleplex real-time PCR methods using two different probes, a cytosine to thymine point mutation at codon 86 was detected by allelic discrimination. Of the 158 strains, 114 (72.2%) were determined to be resistant to ciprofloxacin. The MIC50 and the MIC90 of ciprofloxacin were found to be 8 and ≥32 mg/L, respectively. By real-time PCR, the presence of the mutation was confirmed in all, but one, resistant strains and the absence of the mutation was demonstrated in all, but one, susceptible strains. The rate of resistance is high among C. jejuni strains and ciprofloxacin should not be used in the treatment of such infections in Turkey. A cytosine to thymine mutation is the most frequently detected mechanism for the resistance. Real-time PCR can be used for the quick screening of the resistance.


Assuntos
Antibacterianos/farmacologia , Campylobacter jejuni/efeitos dos fármacos , Campylobacter jejuni/genética , Ciprofloxacino/farmacologia , Farmacorresistência Bacteriana/genética , Mutação Puntual , Alelos , Infecções por Campylobacter/epidemiologia , Infecções por Campylobacter/microbiologia , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Eletroforese em Gel de Campo Pulsado , Humanos , Concentração Inibidora 50 , Testes de Sensibilidade Microbiana , Fenótipo , Prevalência , Turquia
20.
Braz. J. Vet. Res. Anim. Sci. (Online) ; 57(1): e160956, 2020. ilus, mapas, tab
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1122160

RESUMO

Antimicrobial resistance is a current and important issue to public health, and it is usually associated with the indiscriminate use of antimicrobials in animal production. This study aimed to evaluate the antimicrobial susceptibility profile in bacterial isolates from pigs with clinical respiratory signs in Brazil. One hundred sixty bacterial strains isolated from pigs from 51 pig farms in Brazil were studied. In vitro disk-diffusion method was employed using 14 antimicrobial agents: amoxicillin, penicillin, ceftiofur, ciprofloxacin, enrofloxacin, chlortetracycline, doxycycline, oxytetracycline, tetracycline, erythromycin, tilmicosin, florfenicol, lincomycin, and sulfadiazine/trimethoprim. The majority of isolates were resistant to at least one antimicrobial agent (98.75%; 158/160), while 31.25% (50/160) of the strains were multidrug resistant. Streptococcus suis and Bordetella bronchiseptica were the pathogens that showed higher resistance levels. Haemophilus parasuis showed high resistance levels to sulfadiazine/trimethoprim (9/18=50%). We observed that isolates from the midwestern and southern regions exhibited four times greater chance of being multidrug resistant than the isolates from the southeastern region studied. Overall, the results of the present study showed a great level of resistance to lincomycin, erythromycin, sulfadiazine/trimethoprim, and tetracycline among bacterial respiratory pathogens isolated from pigs in Brazil. The high levels of antimicrobial resistance in swine respiratory bacterial pathogens highlight the need for the proper use of antimicrobials in Brazilian pig farms.(AU)


A resistência antimicrobiana é uma questão atual e muito importante para a saúde pública, geralmente associada ao uso indiscriminado de antimicrobianos na produção animal. Diante disso, foi investigado o perfil de sensibilidade-antimicrobiana em isolados bacterianos de suínos com sinais clínicos respiratórios no Brasil. Foram estudadas 96 isolados provenientes de 51 granjas de suínos do Brasil. O método de disco-difusão foi empregado usando 14 antimicrobianos: amoxicilina, penicilina, ceftiofur, ciprofloxacina, enrofloxacina, clortetraciclina, doxiciclina, oxitetraciclina, tetraciclina, eritromicina, tilmicosina, florfenicol, lincomicina e sulfadiazina/trimetoprim. Streptococcus suis e Bordetella bronchiseptica foram os patógenos que apresentaram maiores níveis de resistência. Haemophilus parasuis apresentou altos níveis de resistência à sulfadiazina/trimetoprim (9/18=50%). Observou-se que isolados das regiões Centro-Oeste e Sul apresentaram quatro vezes mais chance de serem multirresistentes do que os isolados da região Sudeste. A maioria foi resistente a pelo menos um agente antimicrobiano (98,75%; 158/160) e 31,25% (50/160) das estirpes isoladas eram multirresistentes. No geral, os resultados do presente estudo mostraram grande nível de resistência à lincomicina, eritromicina, sulfadiazina/trimetoprim e tetraciclina entre patógenos respiratórios bacterianos isolados de suínos no Brasil. Os altos níveis de resistência antimicrobiana em patógenos bacterianos respiratórios em suínos reforçam a necessidade do uso criterioso de antimicrobianos na suinocultura brasileira.(AU)


Assuntos
Animais , Suínos , Bordetella bronchiseptica , Farmacorresistência Bacteriana Múltipla , Streptococcus , Brasil/epidemiologia , Pasteurella multocida , Actinobacillus pleuropneumoniae , Haemophilus parasuis , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão/veterinária
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