RESUMO
This study analysed the mechanisms of quinolone resistance among enterotoxigenic Escherichia coli (ETEC) in a periurban area of Lima, Peru. The susceptibility to nalidixic acid and ciprofloxacin, the role of Phe-Arg-b-Naphtylamyde inhibitable-(PAbN) efflux pumps, the presence of mutations in gyrA and parC as well as the presence of aac(6')Ib-cr, qepA, qnrA, qnrB, qnrC, qnrD, qnrVC and oqxAB were determined in 31 ETEC from previous case/control studies of children's diarrhoea. Discordances between disk diffusion, with all isolates showing intermediate or fully resistance to nalidixic acid, and minimal inhibitory concentration (MIC), with 7 isolates being below considered resistance breakpoint, were observed. Twenty-one isolates possessed gyrA mutations (19 S83L, 2 S83A). AAC(6') Ib-cr, QnrS, QnrB and QepA were found in 7, 6, 2 and 1 isolates respectively, with 3 isolates presenting 2 transferable mechanisms of quinolone resistance (TMQR) concomitantly. TMQR were more frequent among isolates with MIC to nalidixic acid ranging from 2 to 16 mg/L (p=0.03), while gyrA mutations were more frequent among isolates with nalidixic acid MIC >= 128 mg/L (p=0.0002). In summary, the mechanisms of quinolone resistance present in ETEC isolates in Peru have been described. Differences in the prevalence of underlying mechanisms associated with final MIC levels were observed. The results suggest two different evolutive strategies to survive in the presence of quinolones related to specific bacterial genetic background.
Assuntos
Escherichia coli Enterotoxigênica , Quinolonas , Criança , Humanos , Escherichia coli Enterotoxigênica/genética , Ácido Nalidíxico/farmacologia , Quinolonas/farmacologia , Ciprofloxacina , Estudos de Casos e ControlesRESUMO
Salmonella Heidelberg is commonly reported in foodborne outbreaks around the world, and chickens and poultry products are known as important source of these pathogen. Multidrug-resistant S. Heidelberg strains are disseminated into poultry production chair, which can lead to severe clinical infections in humans and of difficult to treat. This study aimed at evaluating the ß-lactam susceptibility and genotypic relatedness of Salmonella Heidelberg at Brazilian poultry production chain. Sixty-two S. Heidelberg strains from poultry production chain (poultry, poultry meat and poultry farm) were used. All strains were evaluated to antimicrobial susceptibility by diffusion disk test, as well as ß-lactam resistance genes. Genotypic relatedness was assessed by Pulsed-Field Gel Eletrophoresis, using Xba1 restriction enzyme. Forty-one strains were characterized as multidrug-resistant according to phenotype characterization. The resistance susceptibility revealed 31 distinct profiles, with higher prevalence of streptomycin (61/62), nalidixic acid (50/62), tetracycline (43/62) and ß-lactam drugs (37/62). blaCMY-2 was the more frequent ß-lactamase gene found (38/62); other resistance genes found were blaCTX-M (2/62), blaSHV (3/62) and blaTEM-1 (38/62). No carbapenemase genes was found. The Pulsed-Field Gel Electrophoresis showed 58 different profiles. Strains with a larger number of antimicrobial resistance were grouped into ten major clusters apart from others. The spread of resistance by ampC continues to rise, thereby turning concern to public health, since the ß-lactam antimicrobials are used as a therapeutic treatment in humans.
Assuntos
Farmacorresistência Bacteriana Múltipla , Doenças das Aves Domésticas/microbiologia , Salmonella/enzimologia , beta-Lactamases/genética , Animais , Antibacterianos/farmacologia , Brasil , Galinhas , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Genótipo , Testes de Sensibilidade Microbiana , Ácido Nalidíxico/farmacologia , Doenças das Aves Domésticas/patologia , Salmonella/efeitos dos fármacos , Salmonella/genética , Salmonella/isolamento & purificação , Estreptomicina/farmacologia , beta-Lactamases/metabolismo , beta-Lactamas/farmacologiaRESUMO
The aim of this study was to evaluate the microbiological quality of 45 samples of corn-based farinaceous foods commercialized in Brazil. The bacteriological analysis performed were: detection of Salmonella and Cronobacter, and enumeration of faecal coliforms and Bacillus cereus. The Cronobacter isolates were phenotypically characterized by Vitek 2.0 and the antibiotic susceptibility profile. Molecular characterization was accomplished by real-time PCR targeting dnaG gene and MLST. No sample presented contamination by Salmonella or B. cereus (<102 UFC/g). Faecal coliforms were detected in two (4.4%) samples but in low concentration (≤23.0 MPN/g), and 20 samples (44.4%) contained Cronobacter. Twenty-nine unique Cronobacter isolates were identified as C. sakazakii (n = 18), C. malonaticus (n = 2); that presented 11 different fusA alleles, including new fusA 183. MLST analysis revealed 17 sequence types (STs), six of which were newly identified (ST687-690, 693, and 694). Resistance or intermediary resistance were found to ceftazidime (15.0%), aztreonam (15.0%), nalidixic acid (15.0%), nitrofurantoin (15.0%), cefepime (10.0%), gentamicin (5.0%), and tetracycline (5.0%). The presence of Cronobacter in corn-based farinaceous foods could be a significant risk to infants as these products are used as alternatives to commercially available infant formula. Strategies to manage the risk of Cronobacter infections due to the consumption of these alternative feeds need to be developed by the regulatory agencies.
Assuntos
Cronobacter sakazakii/isolamento & purificação , Cronobacter/isolamento & purificação , Farmacorresistência Bacteriana Múltipla , Tipagem de Sequências Multilocus , Zea mays/microbiologia , Antibacterianos/farmacologia , Aztreonam/farmacologia , Brasil , Cefepima/farmacologia , Ceftazidima/farmacologia , Cronobacter/crescimento & desenvolvimento , Cronobacter sakazakii/crescimento & desenvolvimento , Contaminação de Alimentos/análise , Manipulação de Alimentos , Microbiologia de Alimentos , Gentamicinas , Fórmulas Infantis/análise , Fórmulas Infantis/microbiologia , Testes de Sensibilidade Microbiana , Ácido Nalidíxico/farmacologia , Nitrofurantoína/farmacologia , Tetraciclina/farmacologiaRESUMO
The objective of this study, for the first time, was to optimize Amazonian cyanobacterial culture conditions for improving cell productivity and lipid content, by analyzing the effect of light intensity and nitrogen concentration, for empirically evaluating biodiesel quality parameters. The strains Synechocystis sp. CACIAM05, Microcystis aeruginosa CACIAM08, Pantanalinema rosaneae CACIAM18, and Limnothrix sp. CACIAM25, were previously identified by morphological and molecular analysis (16S rRNA) and were selected based on their production of chlorophyll a and dry cell weight. Then, factorial planning (22) with central points was applied, with light intensity and NaNO3 concentration as independent variables. As response variables, cell productivity and lipid content were determined. Statistical analysis indicated that for all strains, the independent variables were statistically significant for cell productivity. Analysis of the fatty acid composition demonstrated diversity in the composition of the fatty acid profile from the experimental planning assays of each strain. The Biodiesel Analyzer software predicted the biodiesel quality parameters. CACIAM05 and CACIAM25 obtained better parameters with low levels of light intensity and NaNO3 concentration, whereas CACIAM08 and CACIAM18 obtained better parameters with low NaNO3 concentrations and high luminous intensity.
Assuntos
Biocombustíveis , Cianobactérias/metabolismo , Cianobactérias/efeitos da radiação , Fermentação , Luz , Ácido Nalidíxico/metabolismo , Cianobactérias/efeitos dos fármacos , Ácidos Graxos/metabolismo , Ácido Nalidíxico/farmacologiaRESUMO
Currently, Salmonella enterica serovar Typhimurium (S. Typhimurium), is a major global public health problem, which has caused food-borne illnesses in many countries. Today, with the extensive use of antimicrobials, antimicrobial resistance is increasing at a serious rate in S. Typhimurium isolates. The present study sought the role of cysteine (Cys) auxotrophy on the resistance to quinolones and paraquat in S. Typhimurium. Cys auxotrophy was achieved by deleting either the cysDNC, cysJIH or cysQ loci. Deletion of these loci resulted in loss of susceptibility against nalidixic acid, levofloxacin, ciprofloxacin (CIP) and paraquat. Further studies with cysJIH mutant indicated increased expression of multi-antibiotic resistance genes marA and ramA, and consequently increased expression of efflux-pump systems. The cysJIH mutant presented a smaller increase of reactive oxygen species (ROS) in presence of paraquat or CIP. Expression of katG and sodA (expressing for a catalase and a superoxide dismutase, respectively) genes was increased in presence of paraquat in the cysJIH mutant; while expression of the superoxide dismutase gene sodB was decreased. These results indicate that deletion of cysDNC, cysJIH or cysQ genes of S. Typhimurium renders Cys auxotrophy along with decreased susceptibility in response to quinolone and paraquat. Overexpression of efflux-pump systems AcrB-TolC and SmvA-OmpD and antioxidant enzymes KatG and SodA could explain the mechanisms of antimicrobial resistance in the Cys auxotrophic mutants.
Assuntos
Cisteína/metabolismo , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/metabolismo , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Ciprofloxacina/farmacologia , Cisteína/genética , Farmacorresistência Bacteriana Múltipla/genética , Deleção de Genes , Expressão Gênica/efeitos dos fármacos , Genes Bacterianos , Humanos , Levofloxacino/farmacologia , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo , Mutação , Ácido Nalidíxico/farmacologia , Paraquat/farmacologia , Quinolonas/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Salmonella typhimurium/genética , Enxofre/metabolismoRESUMO
Resistance of Salmonella Dublin strains to quinolones and tetracycline has been increasing worldwide. Studies regarding the genotypic resistance traits of strains of this serovar isolated in Brazil are scarce. This study aims to examine the genetic characteristics of Salmonella Dublin strains isolated in Brazil, which are associated with resistance to quinolone and tetracycline. The minimum inhibitory concentrations (MICs) of nalidixic acid, ciprofloxacin, and tetracycline of the 10 strains sensitive and 21 strains resistant to quinolone and tetracycline were determined using Etest.® The mutation profiles of the gyrA, gyrB, parC, and parE genes were accessed by sequencing, while the presence of plasmid-mediated quinolone resistance and tet genes was analyzed by PCR. Quinolone-resistant strains presented the amino acid substitutions Ser96âTyr, Ser96âPhe, Asp107âAsn, or Asp108âGly on the gyrA gene, and the Ser224âPhe and Glu231âAsp mutations on the gyrB gene. The qnrA, tet(A), and tet(B) genes were detected in 5, 13, and 6 strains, respectively. Analysis of the MIC values revealed that 1 and 3 strains presented intermediate and resistant MIC profiles to nalidixic acid, respectively; 6 strains presented intermediate MIC profile to ciprofloxacin; and 13 strains presented resistant MIC profile to tetracycline. In the Salmonella Dublin strains studied, quinolone resistance was mainly related to mutation points that led to target alteration in the gyrA and gyrB genes, while tetracycline resistance was associated with the presence of tet(A) and/or tet(B) genes, with the highest resistance levels detected in strains bearing the tet(B) gene. The presence of the aforementioned genotypic resistance traits in Salmonella Dublin strains isolated over 33 years in Brazil indicates that ciprofloxacin or tetracycline therapy against such strains may fail.
Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana/genética , Quinolonas/farmacologia , Salmonella enterica/efeitos dos fármacos , Tetraciclina/farmacologia , Animais , Brasil , Bovinos , Ciprofloxacina/farmacologia , Genes Bacterianos/genética , Humanos , Testes de Sensibilidade Microbiana , Mutação/genética , Ácido Nalidíxico/farmacologia , Plasmídeos/genética , Reação em Cadeia da PolimeraseRESUMO
Medical cotton gauzes were modified by grafting poly(methacrylic acid) (PMAA) via free radical polymerization to obtain wound dressings with antimicrobial and drug delivery properties. The effect of several reaction parameters including monomer and initiator concentrations, reaction time, and temperature was studied. The grafting was confirmed by Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), swelling studies, and scanning electron microscopy (SEM). The grafted cotton gauzes (gauze-g-PMAA) samples were loaded with ZnO nanoparticles to endow with antibacterial properties. Also, they were tested as drug eluting systems using nalidixic acid as antimicrobial agent. The antibacterial activity of the ZnO-loaded gauze-g-PMAA samples was evaluated against Escherichia coli (E. coli) and Staphylococcus epidermidis (S. epidermidis). The PMAA-grafted gauzes showed antibacterial activity and inhibited the growth of both microorganisms. These results suggest that the PMAA-grafted cotton gauzes could be used in the biomedical area particularly as antimicrobial and drug-eluting wound dressings.
Assuntos
Antibacterianos/química , Bandagens , Celulose/química , Fibra de Algodão , Sistemas de Liberação de Medicamentos , Ácidos Polimetacrílicos/química , Celulose/síntese química , Liberação Controlada de Fármacos , Escherichia coli/efeitos dos fármacos , Ácido Nalidíxico/química , Ácido Nalidíxico/farmacologia , Nanopartículas/química , Polimerização , Ácidos Polimetacrílicos/síntese química , Staphylococcus epidermidis/efeitos dos fármacos , Óxido de Zinco/química , Óxido de Zinco/farmacologiaRESUMO
OBJECTIVES: The aim of this study was to characterise OXA-258 variants and other features that may contribute to carbapenem resistance in Achromobacter ruhlandii. METHODS: Kinetic parameters for purified OXA-258a and OXA-258b were determined measuring the rate of hydrolysis of a representative group of antimicrobial agents. Whole-genome shotgun sequencing was performed on A. ruhlandii 38 (producing OXA-258a) and A. ruhlandii 319 (producing OXA-258b), and in silico analysis of antimicrobial resistance determinants was conducted. Substrates of the AxyABM efflux pump were investigated by inhibition assays using phenylalanine-arginine ß-naphthylamide (PAßN). Outer membrane protein profiles were resolved by 12% sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). RESULTS: Kinetic measurements of purified OXA-258 variants displayed an overall weak catalytic efficiency toward ß-lactams. A detectable hydrolysis of imipenem was observed. In silico genomic analysis confirmed the presence of 32 and 35 putative efflux pump-encoding genes in A. ruhlandii strains 38 and 319, respectively. Complete sequences for AxyABM and AxyXY efflux pumps, previously described in Achromobacter xylosoxidans, were detected. Decreases in the MICs for chloramphenicol, nalidixic acid and trimethoprim/sulfamethoxazole were observed in the presence of the inhibitor PAßN, suggesting that these antibiotics are substrates of AxyABM. AxyXY-encoding genes of A. ruhlandii 38 and A. ruhlandii 319 displayed 99% identity. No differences were observed in the outer membrane protein profiles. CONCLUSIONS: The contribution of OXA-258 enzymes to the final ß-lactam resistance profile may be secondary. Further studies on other putative resistance markers identified in the whole-genome analysis should be conducted to understand the carbapenem resistance observed in A. ruhlandii.
Assuntos
Achromobacter/enzimologia , Antibacterianos/farmacologia , Proteínas da Membrana Bacteriana Externa/genética , Sequenciamento Completo do Genoma/métodos , Resistência beta-Lactâmica , beta-Lactamases/genética , Achromobacter/genética , Antibacterianos/química , Proteínas de Bactérias/genética , Cloranfenicol/química , Cloranfenicol/farmacologia , Simulação por Computador , Variação Genética , Hidrólise , Imipenem/química , Imipenem/farmacologia , Testes de Sensibilidade Microbiana , Ácido Nalidíxico/química , Ácido Nalidíxico/farmacologia , Combinação Trimetoprima e Sulfametoxazol/química , Combinação Trimetoprima e Sulfametoxazol/farmacologiaRESUMO
Cow raw milk cheese is widely eaten in Brazil. These products may be contaminated with pathogenic bacteria. In this work, we investigated the presence of Escherichia coli in raw milk cheese from different States in Brazil. From 147 "Minas" cheese samples, 28 cheeses were positive for E. coli. Among 39 E. coli isolates of the cheeses, one was positive for eae and negative for bpfA and efa1/lifA using PCR, and so was classified as atypical Enteropathogenic E. coli (aEPEC). Two other isolates were positive for extraintestinal pathogenic E. coli (ExPEC) genes. The aEPEC isolate belongs to serogroup O127 and was classified in A phylogenetic group, and ExPEC isolates were found in O73:H12 (EC-2 strain) and O64474:H8 (EC-9 strain) serotype. This ExPEC belongs to A and C phylogenetic group, respectively. Most of E. coli strains belonged to Clermont phylogenetic groups A (28.2%), C, and E (23.1%). Six strains (15.4%) of E. coli were positive for group B1 and two (5.1%) for B2. E. coli isolates presented an aggregative (46.0%) and diffuse (12.6%) adherence pattern to HeLa cells, and the other isolates did not show adhesion (41.4%). Four E. coli isolates (10.3%) were shown to produce moderate biofilm. The antimicrobial resistance rate was tetracycline (25.6%), followed by ampicillin (17.9%), cefoxitin (7.7%), nalidixic acid (5.1%), and amoxicillin-clavulanic acid (2.6%). One strain was resistant to three antimicrobials (tetracycline, ampicillin, and nalidixic acid). The presence of these microorganisms, the O127 strain, and a new serogroup in Brazil is a potential risk for public health.
Assuntos
Queijo/microbiologia , Farmacorresistência Bacteriana Múltipla/genética , Escherichia coli Enteropatogênica/genética , Leite/microbiologia , Combinação Amoxicilina e Clavulanato de Potássio/farmacologia , Ampicilina/farmacologia , Animais , Antibacterianos/farmacologia , Aderência Bacteriana , Brasil , Cefoxitina/farmacologia , DNA Bacteriano/genética , DNA Bacteriano/isolamento & purificação , Escherichia coli Enteropatogênica/efeitos dos fármacos , Escherichia coli Enteropatogênica/isolamento & purificação , Contaminação de Alimentos , Microbiologia de Alimentos , Células HeLa , Humanos , Testes de Sensibilidade Microbiana , Ácido Nalidíxico/farmacologia , Pasteurização , Filogenia , Sorogrupo , Sorotipagem , Tetraciclina/farmacologiaRESUMO
Drug-resistant Salmonella is frequently detected in most parts of the world, and its rate of resistance has increased significantly in recent years. However, this study aimed to evaluate the minimum inhibitory concentration (MIC, determined with the Kirby-Bauer method) of quinolones in 86 Salmonella spp. strains isolated from pigs. Both the inside and outside of the QRDR region of strains were sequenced. The DNA sequence of the QRDR region of Salmonella spp. revealed the mutations S83F, D87N and S83Y. The region outside the QRDR showed a mutation in L582G. Forty-five isolates of Salmonella ssp. were categorized as quinolone-resistant; out of these, 16 corresponded to Salmonella enterica and isolates showed intermediate resistance (6.25%) to nalidixic acid. Three isolats (18.6%) were resistant to ampicillin; two (12.5%) were resistant to carbenicillin. Moreover, three (18.7%) isolates were resistant to gentamicin, nitrofurantoin and pefloxacin, and 8 (50%) were resistant to trimethoprim/sulfamethoxazole. Six percent of Salmonella spp. strains showed less resistance to antimicrobial agents compared to S. Thyphimurium (18%). The resistance to individual quinolones varied by serotypes. For S. anatum and S. Reading, it was 12.25%, and for S. choreaeaesuis, S. typhimurium monofasica, 6.25%. In contrast, S. agona, S. bredeney and S. london were sensitive to these antibiotics. In conclusion, quinolones have become the drugs of choice for the treatment of severe Salmonella infections. The study of mutations outside the QRDR region opens up new insights about the resistance of Salmonella to fluoroquinolones.
Assuntos
DNA Girase/genética , Farmacorresistência Bacteriana/genética , Quinolonas/farmacologia , Salmonella/efeitos dos fármacos , Salmonella/genética , Animais , Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Sequência de Bases , DNA Bacteriano/genética , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Fluoroquinolonas/farmacologia , Genes Bacterianos/genética , Mutação , Ácido Nalidíxico/farmacologia , Salmonella/isolamento & purificação , Infecções por Salmonella/tratamento farmacológico , Salmonella enterica/genética , Salmonella enterica/isolamento & purificação , SuínosRESUMO
The objective of this study was to evaluate the phenotypic and genotypic profile of antimicrobial susceptibility and the possible involvement of extended spectrum beta-lactamases (ESBLs) in the resistance profile of Salmonella Heidelberg (SH) isolated from chicken meat. We used 18 SH isolates from chicken meat produced in 2013 in the state of Paraná, Southern Brazil. The isolates were submitted to disk-diffusion tests and from these results it was possible to determine the number of isolates considered multiresistant and the index of multiple antimicrobial resistance (IRMA) against ten antimicrobials routinely used in human and veterinary medicine. It was considered multidrug resistant the isolate that showed resistance to three or more classes of antibiotics. Another test performed was the disc-approximation in order to investigate interposed zones of inhibition, indicative of ESBLs production. In the isolates that presented multidrug resistance (18/18), a search of resistance genes involved in the production of ESBLs was performed using PCR: blaCMY-2, blaSHV-1, blaTEM-1, blaCTX-M2, blaOXA-1, blaPSE-1 and AmpC. The overall antimicrobial resistance was 80.55%. The highest levels of resistance were observed for nalidixic acid and ceftiofur (100%). The most commonly resistance pattern found (42.1%) was A (penicillin-cephalosporin-quinolone-tetracycline). The results were negative for ghost zone formation, indicative of ESBLs. However, PCR technique was able to detect resistance genes via ESBLs where the blaTEM-1 gene showed the highest amplification (83.33%), and the second most prevalent genes were blaCMY-2 (38.88%) and AmpC gene (38.88%). The blaOXA-1 and blaPSE-1 genes were not detected. These results are certainly of concern since SH is becoming more prevalent in the South of Brazil and able to cause severe disease in immune compromised individuals, showing high antimicrobial resistance to those drugs routinely used in the treatment and control of human and animal salmonellosis.
Assuntos
Farmacorresistência Bacteriana Múltipla/genética , Salmonella/enzimologia , Salmonella/genética , beta-Lactamases/genética , Animais , Antibacterianos/classificação , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Brasil , Cefalosporinas/farmacologia , Galinhas , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Doenças Transmitidas por Alimentos/microbiologia , Genes Bacterianos/genética , Humanos , Carne/microbiologia , Testes de Sensibilidade Microbiana , Ácido Nalidíxico/farmacologia , Reação em Cadeia da Polimerase/métodos , Salmonella/efeitos dos fármacos , Salmonella/isolamento & purificação , Infecções por Salmonella/microbiologia , Salmonelose Animal/microbiologia , beta-Lactamases/classificaçãoRESUMO
Nontyphoidal Salmonella are one of the leading causes of foodborne diseases in the world. As poultry products are recognized as main sources of human salmonellosis, nontyphoidal Salmonella control has become a global issue for the poultry industry. The increasing antimicrobial resistance in poultry-related nontyphoidal Salmonella serovars is a global matter of concern. By monitoring the evolution of antimicrobial resistance, alternative treatments can be identified and possible restrictions in the treatment of systemic human salmonellosis foreseen. A meta-analysis was conducted to assess the profile and temporal evolution of the antimicrobial resistance of nontyphoidal Salmonella of poultry and human origin in Brazil, isolated in the period from 1995 to 2014. Four databases were researched; twenty-nine articles met the eligibility criteria and were included in the meta-analysis. In the nontyphoidal isolates of poultry origin, the highest levels of antimicrobial resistance were verified for sulfonamides (44.3%), nalidixic acid (42.5%), and tetracycline (35.5%). In the human-origin isolates, the resistance occurred mainly for sulfonamides (46.4%), tetracycline (36.9%), and ampicillin (23.6%). Twenty-two articles described results of antimicrobial resistance specifically for Salmonella Enteritidis, also enabling the individual meta-analysis of this serovar. For most antimicrobials, the resistance levels of Salmonella Enteritidis were lower than those found when considering all the nontyphoidal serovars. In the poultry-origin isolates, a quadratic temporal distribution was observed, with reduced resistance to streptomycin in Salmonella Enteritidis and in all nontyphoidal serovars, and a linear increase of resistance to nalidixic acid in Salmonella Enteritidis. In the human-origin isolates, a linear increase was identified in the resistance to nalidixic acid in Salmonella Enteritidis and in all the nontyphoidal isolates, and to gentamicin in Salmonella Enteritidis. Continuous monitoring of the development and spread of antimicrobial resistance could support the measurement of the consequences on poultry and human health.
Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla , Produtos Avícolas/microbiologia , Intoxicação Alimentar por Salmonella/microbiologia , Salmonelose Animal/microbiologia , Ampicilina/farmacologia , Animais , Brasil , Gentamicinas/farmacologia , Humanos , Testes de Sensibilidade Microbiana , Ácido Nalidíxico/farmacologia , Salmonella enteritidis/efeitos dos fármacos , Salmonella enteritidis/isolamento & purificação , Estreptomicina/farmacologia , Tetraciclina/farmacologiaRESUMO
Salmonella Enteritidis strains that are resistant to nalidixic acid and exhibit reduced susceptibility to fluoroquinolones have been increasing worldwide. In Brazil, few studies have been conducted to elucidate the quinolone resistance mechanisms of S. Enteritidis strains. This study analyzed the profile of gyrA, gyrB, parC, and parE mutations and plasmid-mediated quinolone resistance (PMQR) mechanisms in S. Enteritidis NalR strains isolated in Brazil. Moreover, the minimum inhibitory concentrations (MICs) of ciprofloxacin were evaluated in 84 NalR strains and compared with 20 NalS strains. The mutation profiles of the gyrA gene were accessed by high-resolution melting analysis and gyrB, parC, and parE by quinolone resistance-determining region sequencing. The MICs of ciprofloxacin were accessed with Etest®. The strains were divided into five gyrA melting profiles. The NalR strains exhibited the following amino acid substitutions: Ser97âPro, Ser83âPhe, Asp87âAsn, or Asp87âTyr. The average MICs of ciprofloxacin was 0.006 µg/ml in the NalS and 0.09 µg/ml in the NalR strains. No points of mutation were observed in the genes gyrB, parC, and parE. The qnrB gene was found in two strains. In conclusion, the reduced susceptibility to ciprofloxacin observed in NalR strains may cause treatment failures once this drug is commonly used to treat Salmonella infections. Moreover, this reduced susceptibility in these Brazilian strains was provided by target alteration of gene gyrA and not by mobile elements, such as resistance plasmids.
Assuntos
DNA Girase/genética , Farmacorresistência Bacteriana/genética , Mutação , Ácido Nalidíxico/farmacologia , Doenças das Aves Domésticas/epidemiologia , Infecções por Salmonella/epidemiologia , Salmonella enteritidis/genética , Substituição de Aminoácidos , Animais , Antibacterianos/farmacologia , Brasil/epidemiologia , Galinhas , Ciprofloxacina/farmacologia , DNA Girase/metabolismo , DNA Topoisomerase IV/genética , DNA Topoisomerase IV/metabolismo , Fazendas , Expressão Gênica , Humanos , Produtos da Carne/microbiologia , Testes de Sensibilidade Microbiana , Plasmídeos/química , Plasmídeos/metabolismo , Doenças das Aves Domésticas/tratamento farmacológico , Doenças das Aves Domésticas/microbiologia , Prevalência , Infecções por Salmonella/tratamento farmacológico , Infecções por Salmonella/microbiologia , Salmonella enteritidis/efeitos dos fármacos , Salmonella enteritidis/isolamento & purificação , Salmonella enteritidis/metabolismoRESUMO
Campylobacter jejuni is recognized as a leading cause of acute bacterial gastroenteritis in humans. The over-use of antimicrobials in the human population and in animal husbandry has led to an increase in antimicrobial-resistant infections, particularly with fluoroquinolones and macrolides. The aim of the present study was to provide information of the current status of antimicrobial resistance patterns in Campylobacter jejuni from poultry sources. Fifty strains were recovered from broiler slaughterhouses in Rio Grande do Sul state, Brazil, 2012. The strains were investigated for antimicrobial susceptibility against three agents (ciprofloxacin, nalidixic acid and erythromycin) by minimal inhibitory concentrations. The strains were analysed by polymerase chain reaction-restriction fragment length polymorphism for detection of the Thr-86 mutation that confers resistance to ciprofloxacin. In addition, all the strains were tested for the presence of efflux systems (cmeB gene) conferring antimicrobial resistance. The minimum inhibitory concentrations results showed that 98% of isolates were sensitive to erythromycin and most isolates were resistant to ciprofloxacin (94%) and nalidixic acid (90%). A complete correlation was observed between the minimum inhibitory concentrations and PCR-RFLP assay. Finally, the cmeB gene that is responsible for multidrug resistance was detected in 16 isolates out the 50 strains (32%).
Assuntos
Antibacterianos/farmacologia , Infecções por Campylobacter/veterinária , Campylobacter jejuni/genética , Galinhas/microbiologia , Fluoroquinolonas/farmacologia , Macrolídeos/farmacologia , Doenças das Aves Domésticas/microbiologia , Matadouros , Animais , Brasil/epidemiologia , Infecções por Campylobacter/microbiologia , Campylobacter jejuni/efeitos dos fármacos , Campylobacter jejuni/isolamento & purificação , Ciprofloxacina/farmacologia , Farmacorresistência Bacteriana Múltipla , Eritromicina/farmacologia , Humanos , Testes de Sensibilidade Microbiana/veterinária , Ácido Nalidíxico/farmacologia , Polimorfismo de Fragmento de RestriçãoRESUMO
OBJECTIVE: Rheumatoid arthritis (RA) is a costly and crippling autoimmune disease that can lead to the development of depression, contributing to suboptimal clinical outcomes. However, no longitudinal studies have identified an association between rheumatoid arthritis and subsequent depression. This study aimed to investigate the incidence and risk factors of depression among RA patients in Taiwan. METHODS: Using Taiwan's National Health Insurance Research Database, we identified 3,698 newly diagnosed RA patients aged 18 years or older, together with 7,396 subjects without RA matched by sex, age and index date, between 2000 and 2004. The incidence of depression and the risk factors among RA cases were evaluated using Cox proportional-hazard regression. RESULTS: The incidence of depression was 1.74-fold greater in the RA cohort than in the non-RA cohort (11.80 versus 6.89 per 1,000 person-years; p<0.01). Multivariate analysis showed that RA subjects who were female, were older, or had comorbidities such as stroke, chronic kidney disease, or cancer had a significantly greater risk of depression compared with those without these conditions. CONCLUSION: This population-based cohort study showed a strong relationship between RA and a subsequent risk of depression. The findings could be beneficial to healthcare providers for identifying individuals with a higher predisposition for depression, thereby possibly facilitating the provision of an appropriate rehabilitation intervention after RA onset to support the patient's adaptation. .
Assuntos
Humanos , Anti-Infecciosos/farmacologia , Salmonella typhi/efeitos dos fármacos , Antibacterianos/farmacologia , Cloranfenicol/farmacologia , Ciprofloxacina/farmacologia , Farmacorresistência Bacteriana , Índia , Testes de Sensibilidade Microbiana , Ácido Nalidíxico/farmacologia , Estudos Retrospectivos , Febre Tifoide/microbiologiaRESUMO
INTRODUCTION: Previous studies have identified Salmonella as the main causative agent of foodborne diseases in the state of Rio Grande do Sul (RS), southern Brazil, between 1997 and 2006. This study aimed to describe the Salmonella serotypes, antimicrobial patterns, and food vehicles of salmonellosis that occurred in RS between 2007 and 2012. METHODOLOGY: Information about Salmonella isolates and salmonellosis outbreaks registered in the official records of the Central Laboratory of RS (FEEPS/IPB-LACEN/RS) was analyzed. RESULTS: Among the 163 isolates investigated, 138 (84.7%) were identified as S. Enteritidis. The second and third most frequent serovars identified were S. Schwarzengrund (5.5%) and S. Typhimurium (3.7%). Homemade mayonnaise was the food vehicle most frequently identified (17.39%), followed by pastry products (15.94%) and beef (12.32%). Antimicrobial resistance was analyzed; 12 drugs were tested. Higher percentages of resistance were observed to nitrofurantoin (94.2%) and nalidixic acid (89.1%). The resistance to these two drugs was verified in 80.43% of the isolates. Multi-resistance to three and five drugs was verified in four and two isolates, respectively. CONCLUSIONS: Comparing the results of the present study with results of previous reports, it was possible to conclude that S. Enteritidis and homemade mayonnaise are still the main serotype and food vehicle of salmonellosis in RS and that antimicrobial resistance has been increasing among S. Enteritidis responsible for foodborne outbreaks in southern Brazil.
Assuntos
Farmacorresistência Bacteriana Múltipla , Microbiologia de Alimentos , Doenças Transmitidas por Alimentos/microbiologia , Infecções por Salmonella/microbiologia , Salmonella/isolamento & purificação , Animais , Antibacterianos/farmacologia , Brasil/epidemiologia , Bovinos , Surtos de Doenças , Doenças Transmitidas por Alimentos/epidemiologia , Humanos , Produtos da Carne/microbiologia , Ácido Nalidíxico/farmacologia , Nitrofurantoína/farmacologia , Salmonella/efeitos dos fármacos , Salmonella/patogenicidade , Infecções por Salmonella/epidemiologia , Salmonella enteritidis/isolamento & purificação , Salmonella enteritidis/patogenicidade , SorogrupoRESUMO
BACKGROUND: Antibiotic resistance is an increasing problem, particularly in countries where antibiotic use is frequently not controlled. The aim of this study was to analyse the prevalence of the molecular mechanisms of quinolone-resistance in E. coli isolated from faeces of healthy Peruvian children or those presenting diarrhoea. METHODS: The presence of target mutations, transferable quinolone-resistance mechanisms and the role of Phe-Arg-ß-Naphtylamyde inhibitible efflux pumps were studied in 96 Escherichia coli (46 diarrheogenic and 50 non-diarrheogenic) isolates exhibiting resistance or diminished susceptibility to quinolones. RESULTS: The most resistant phenotype, Nal(R) and Cip(R), was most frequently present in isolates of healthy children. The distribution of quinolone resistance mechanisms between diarrheogenic (DEC) and commensal (non DEC) isolates was equitable, although the aac(6')Ib-cr gene was mainly detected in DEC isolates: 17 (34%) vs non DEC isolates nine (20%). QnrB was present in five (10%) DEC vs three (6%) non DEC isolates. CONCLUSIONS: Point mutations in gyrA and parC genes play a relevant role in quinolone resistance acquisition and highlight the role of efflux pumps also. This study provides knowledge about the molecular mechanisms involved in quinolone resistance in isolates in a non exposed population under high community antibiotic pressure.
Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla , Infecções por Escherichia coli/microbiologia , Escherichia coli/efeitos dos fármacos , Quinolonas/farmacologia , Proteínas de Bactérias/genética , Ciprofloxacina/farmacologia , Dipeptídeos/farmacologia , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Farmacorresistência Bacteriana Múltipla/genética , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/epidemiologia , Proteínas de Escherichia coli/genética , Fezes/microbiologia , Feminino , Humanos , Lactente , Masculino , Testes de Sensibilidade Microbiana , Ácido Nalidíxico/farmacologia , Peru/epidemiologia , PrevalênciaRESUMO
One hundred and six nalidixic acid-resistant Enterobacteriaceae isolates from two Brazilian hospitals isolated from June to October 2010 were evaluated to characterize the co-existence of plasmid-mediated quinolone resistant (PMQR) and extended-spectrum ß-lactamase (ESBL) determinants. The qnr genetic environment was determined by PCR and sequencing. Conjugation and hybridization experiments determined whether qnr-carrying plasmids were self-transferable. The aac(6')-Ib-cr and qepA genes were also screened. Thirteen qnr-like genes (12.3 %) were identified, with qnrB1 the most common, followed by qnrS1, qnrB2 and qnrB19. No qnrA, qnrC, qnrD or qepA determinant was detected. All qnr-positive strains possessed chromosomal substitutions in gyrase- and topoisomerase-encoding genes and four harboured a aac(6')-Ib-cr gene. The co-production of blaCTX-M was observed in ten qnr-positive strains. These results indicate the dissemination of PMQR genes shown in clinical isolates from Brazil, and their co-existence with ESBL genes emphasizes the complexity of plasmid-mediated resistance determinants among Enterobacteriaceae.
Assuntos
Farmacorresistência Bacteriana , Enterobacteriaceae/enzimologia , Ácido Nalidíxico/farmacologia , Plasmídeos/genética , beta-Lactamases/metabolismo , Antibacterianos/farmacologia , Brasil , Cefotaxima/farmacologia , Cromossomos Bacterianos/genética , Cromossomos Bacterianos/metabolismo , Enterobacteriaceae/efeitos dos fármacos , Enterobacteriaceae/isolamento & purificação , Genes Bacterianos , Testes de Sensibilidade Microbiana , Mutação , Plasmídeos/metabolismo , Infecção da Ferida Cirúrgica/microbiologia , Urina/microbiologia , beta-Lactamases/genéticaRESUMO
INTRODUCTION: Salmonella Enteritidis is recognized worldwide as one of the main agents of human gastrointestinal infection. Several reports indicate the presence of isolates with decreased sensitivity to ciprofloxacin that can lead to a delayed response or the development of resistance during treatment. OBJECTIVE: To describe and characterize isolates of Salmonella Enteritidis associated to an outbreak of food-borne diseases in Popayán, Cauca. MATERIALS AND METHODS: Ten Salmonella Enteritidis isolates from nine patients and one food sample (chicken sandwich) were analyzed by biochemical tests, serotyping and antimicrobial sensitivity. The minimum inhibitory concentration to ciprofloxacin was determined by E-test and the genetic profile of the isolates was tested by pulsed field gel electrophoresis (PFGE) with XbaI and Blnl enzymes. RESULTS: Salmonella Enteritidis was identified in all isolates. They were resistant to nalidixic acid and had a decreased sensitivity to ciprofloxaxin between 0.25 and 0.5 µg/ml; all isolates were sensitive to all the other antimicrobials we tested. Ten isolates were grouped by PFGE with the XbaI enzyme in the COIN11.JEG.X01.0038 pattern, and seven isolates were confirmed with the BlnI enzyme using the COIN11.JEG.A26.0009 pattern. CONCLUSION: We report for the first time an outbreak of nalidixic acid-resistant Salmonella Enteritidis in Colombia and confirmed by phenotypic and genotypic analysis the association between the isolates from patients and the chicken sandwich as the source of infection.
Assuntos
Antibacterianos/farmacologia , Surtos de Doenças , Farmacorresistência Bacteriana Múltipla , Microbiologia de Alimentos , Ácido Nalidíxico/farmacologia , Intoxicação Alimentar por Salmonella/epidemiologia , Salmonella enteritidis/efeitos dos fármacos , Adolescente , Adulto , Idoso , Animais , Técnicas de Tipagem Bacteriana/métodos , Galinhas/microbiologia , Criança , Pré-Escolar , Ciprofloxacina/farmacologia , Colômbia/epidemiologia , DNA Bacteriano/genética , Feminino , Manipulação de Alimentos/normas , Humanos , Higiene , Lactente , Masculino , Carne/microbiologia , Pessoa de Meia-Idade , Refrigeração , Restaurantes/normas , Intoxicação Alimentar por Salmonella/tratamento farmacológico , Intoxicação Alimentar por Salmonella/microbiologia , Salmonella enteritidis/classificação , Salmonella enteritidis/genética , Salmonella enteritidis/isolamento & purificaçãoRESUMO
INTRODUCTION: The frequency of aac(6')-Ib-cr gene in ESBL-producing strains of Klebsiella pneumoniae and Escherichia coli is unknown, in Chile. METHODOLOGY: The aac(6')-Ib and aac(6')-Ib-cr genes were investigated using polymerase chain reaction (PCR), restriction fragment length polymorphism (RFLP), and sequencing, in strains isolated from 10 Chilean hospitals between 2008-2009. RESULTS: The aac(6')-Ib-cr gene was detected in 54% of K. pneumoniae and 74% of E. coli strains. The CIM(50) of CIP was higher among strains harboring aac(6')-Ib-cr, 8 times higher in K. pneumoniae and 4 times higher in E. coli. Moreover, both aac(6')-Ib and aac(6')-Ib-cr were simultaneously found in 13 K. pneumoniae and 3 E. coli isolates. CONCLUSION: This is the first report of aac(6')-Ib-cr in ESBL-producing strains of K. pneumoniae and E. coli isolated from in-patients in Chilean hospitals located along an area of more than 2,800 Km.