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1.
Environ Res ; 255: 119166, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-38759772

RESUMO

Pseudomonas aeruginosa belong to the special pathogen group capable of causing serious infections, with high mortality rates. The aim of this study was to describe the antibiotic resistance and genomic characteristics of Pseudomonas aeruginosa belonging to international high-risk clone ST235 (GPAE0131 isolate), obtained from hospital wastewater. P. aeruginosa GPAE0131 was isolated from ward tertiary hospital in Brazil and the antibiotic resistance profile was determined by the disc-diffusion method. Genomic characteristics related to antibiotic resistance and virulence factors were evaluated by genomic DNA sequencing on the Illumina MiSeq platform and bioinformatic analysis. GPAE0131 isolate showed resistance to piperacillin-tazobactam, cefepime, ceftazidime, imipenem, meropenem, ciprofloxacin, levofloxacin and tobramycin. Resistome comprehend of resistance genes to ß-lactams (blaVIM-2, blaOXA-4, blaOXA-488, blaPDC-35), aminoglycosides (aph(3')-IIb, aac(6')-IIc, aac(6')-Ib9, aadA1), fosfomycin (fosA), chloramphenicol (catB7) and sulfonamides (sul1). Genome comparisons evidence insertion of blaVIM-2 and blaOXA-4 genes. GPAE0131 isolate was predicted to be pathogenic to humans and several virulence factors were found, including encoding gene for ExoU and exotoxin A. All of these features into a pathogenic international high-risk clone (ST235), classified as critical priority, stands out as public health concern due to the widespread dispersal of human pathogens through wastewater. It is suggested that mitigating measures be implemented, such as the treatment of hospital sewage and the addition of tertiary treatment, to prevent the escape of pathogens at this level into the environment.


Assuntos
Pseudomonas aeruginosa , Águas Residuárias , Águas Residuárias/microbiologia , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/patogenicidade , Humanos , Brasil , Antibacterianos/farmacologia , Hospitais , beta-Lactamases/genética , Fatores de Virulência/genética , Genômica
2.
Environ Res ; 233: 116443, 2023 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-37356524

RESUMO

Among the ESKAPE group pathogens, Enterobacter spp. is an opportunistic Gram-negative bacillus, widely dispersed in the environment, that causes infections. In the present study, samples of hospital wastewater, raw and treated urban wastewater, as well as surface receiving water, were collected to assess the occurrence of multidrug-resistant (MDR) Enterobacter spp. A molecular characterization of ß-lactam antibiotic resistance and metal tolerance genes was performed. According to identification by MALDI-TOF MS, 14 isolates were obtained: 7 E. bugandensis, 5 E. kobei, and 2 E. cloacae. The isolates showed resistance mainly to ß-lactam antibiotics, including those used to treat infections caused by MDR bacteria. Multiple antibiotic resistance index was calculated for all isolates. It allowed verify whether sampling points showed a high risk due to antibiotic resistant Enterobacter spp., as well as to determine if the isolates have been in environments with a frequent antibiotic use. Twelve isolates showed ß-lactam antibiotic resistance gene, being the blaKPC widely detected. Regarding metal tolerance, 13 isolates showed at least two genes that encode metal tolerance mechanisms. Overall, metal tolerance mechanisms to silver, copper, mercury, arsenic and tellurium were found. New data on metal tolerance mechanisms dispersion and antibiotic-resistance characterization of the E. bugandensis and E. kobei species were here provided. The occurrence of MDR Enterobacter spp. in analyzed samples draws attention to an urgent need to put control measures into practice. It also evidences waterborne spread of clinically important antibiotic-resistant bacteria recognized as critical priority pathogens.


Assuntos
Enterobacter , Águas Residuárias , Enterobacter/genética , Resistência beta-Lactâmica , Antibacterianos/farmacologia , beta-Lactamas/farmacologia , beta-Lactamases/genética , Testes de Sensibilidade Microbiana
3.
Inflamm Res ; 71(12): 1535-1546, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36280620

RESUMO

OBJECTIVE AND DESIGN: Our research aimed to investigate the role of CD14 in pulmonary infection by Achromobacter xylosoxidans in an experimental murine model. METHODS: C57Bl/6 or CD14-deficient mice were infected intratracheally with non-lethal inoculum of A. xylosoxidans. At times 1, 3 and 7 days after infection, lungs, bronchoalveolar lavage and blood were collected. CD14 gene expression was determined by RT-PCR. The bacterial load in the lungs was assessed by counting colony forming units (CFU). Cytokines, chemokines, lipocalin-2 and sCD14 were quantified by the ELISA method. Inflammatory infiltrate was observed on histological sections stained with HE, and leukocyte subtypes were assessed by flow cytometry. In another set of experiments, C57Bl/6 or CD14-deficient mice were inoculated with lethal inoculum and the survival rate determined. RESULTS: CD14-deficient mice are protected from A. xylosoxidans-induced death, which is unrelated to bacterial load. The lungs of CD14-deficient mice presented a smaller area of tissue damage, less neutrophil and macrophage infiltration, less pulmonary edema, and a lower concentration of IL-6, TNF-α, CXCL1, CCL2 and CCL3 when compared with lungs of C57Bl/6 mice. We also observed that A. xylosoxidans infection increases the number of leukocytes expressing mCD14 and the levels of sCD14 in BALF and serum of C57Bl/6-infected mice. CONCLUSIONS: In summary, our data show that in A. xylosoxidans infection, the activation of CD14 induces intense pulmonary inflammatory response resulting in mice death.


Assuntos
Achromobacter denitrificans , Infecções por Bactérias Gram-Negativas , Receptores de Lipopolissacarídeos , Pneumonia , Animais , Camundongos , Receptores de Lipopolissacarídeos/genética , Receptores de Lipopolissacarídeos/metabolismo , Pulmão/metabolismo , Camundongos Endogâmicos C57BL , Fator de Necrose Tumoral alfa/metabolismo , Infecções por Bactérias Gram-Negativas/metabolismo
4.
Environ Res ; 196: 110352, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33098821

RESUMO

Some heavy metals have antimicrobial activity and are considered as potential alternatives to traditional antibiotic therapy. However, heavy metal tolerance genes (HMTG) have been already detected and coding different tolerance mechanisms. Considering that certain metals are promising for antimicrobial therapy, evaluation of HMTG dissemination in bacteria from sewage is essential to understand the evolution of these bacteria and to predict antimicrobial use and control. The present study aimed to evaluate the occurrence of bacteria carrying HMTG in samples of hospital wastewater and from urban wastewater treatment plant (WWTP). The acquired HMTG were investigated by PCR in bacterial collection previously characterized for antibiotic resistant genes (ARGs). HMTG searched include arsB (arsenic efflux pump), czcA (cadmium, zinc and cobalt efflux pump), merA (mercuric reductase), pcoD (copper efflux pump), silA (silver efflux pump) and terF (tellurite resistance protein). Among 45 isolates, 82% of them carried at last one HMTG, in which the silA and pcoD tolerance genes were the most prevalent. A very strong positive correlation was found between these genes (r = 0.91, p < 0.0001). Tolerance genes merA, arsB, czcA and terF were detected in 47%, 13%, 13% and 7% of the isolates, respectively. It was found that 15 isolates co-harbored ARGs (ß-lactamase encoding genes). HMTG are probably more dispersed than ARGs in bacteria, representing a new concern for heavy metals use as effective antimicrobials. To the best of our knowledge, this is the first study on the HMTG searched in Hafnia alvei, Serratia fonticola and Serratia liquefaciens. Hospital wastewater treatment implementation and additional technologies for treatment in WWTP can reduce the impacts on water resources and HMTG spread, ensureing the environmental and human health safety.


Assuntos
Metais Pesados , Águas Residuárias , Antibacterianos , Genes Bacterianos , Humanos , Metais Pesados/análise , Metais Pesados/toxicidade , Serratia
5.
Environ Monit Assess ; 192(6): 376, 2020 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-32417981

RESUMO

Multidrug resistance mediated by ß-lactamase in Gram-negative bacilli is a serious public health problem. Sewers are considered reservoirs of multiresistant bacteria due to presence of antibiotics that select them and favor their dissemination. The present study evaluated the antibiotic resistance profile and ß-lactamases production in Gram-negative bacilli isolates from hospital sewage and urban wastewater treatment plants (UWWTP) in Brazil. Bacteria were isolated and identified with biochemical tests. Antibiotic susceptibility testing was performed by the disk-diffusion method and detection of extended-spectrum ß-lactamase and carbapenemases by enzymatic inhibitor and conventional PCR. Differences in resistance to amoxicillin clavulanic, aztreonam, cefepime, and cefotaxime were observed in hospital sewage compared with urban sewage (p < 0.05). The multidrug-resistant phenotype was observed in 33.3% of hospital sewage isolates (p = 0.0025). ß-lactamases genes were found in 35.6% of isolates, with the most frequent being blaKPC and blaTEM (17.8%), and blaSHV and blaCTX-M (13.3% and 8.9%, respectively). The data obtained are relevant, since the bacteria detected are on the priority pathogens list from the World Health Organization and hospital sewage could be released untreated into the municipal collection system, which may favor the spread of resistance. Changes in hospital sewage discharge practices, as well as additional technologies regarding effluent disinfection in the UWWTP, can prevent the spread of these bacteria into the environment and negative impact on water resources.


Assuntos
Monitoramento Ambiental , Bactérias Gram-Negativas , Eliminação de Resíduos de Serviços de Saúde , Águas Residuárias , beta-Lactamases , Antibacterianos , Brasil , Cidades , Bactérias Gram-Negativas/enzimologia , Bactérias Gram-Negativas/genética , Hospitais , Testes de Sensibilidade Microbiana
6.
J Antimicrob Chemother ; 73(12): 3293-3297, 2018 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-30184138

RESUMO

Objectives: Brazil is the greatest exporter of chicken meat (CM) in the world. It is of utmost importance to monitor resistance to extended-spectrum cephalosporins (ESCs) in this sector because resistance to ESCs in Escherichia coli isolated from food-producing animals may contaminate humans through the food chain. Thus, the aim of this study was to characterize and compare ESC-resistant E. coli isolated from chickens and retail CM produced in south-eastern Brazil. Methods: Five CM samples and 117 chicken cloacal swabs (CCSs) were inoculated on MacConkey agar supplemented with cefotaxime. Presumptive E. coli colonies were identified and antimicrobial susceptibility was tested. Virulence and acquired blaESBL and blaAmpC genes were sought and genetic environments characterized. Isolates were typed by phylogenetic grouping, XbaI-PFGE and MLST. Results: All five CM samples and 36 CCSs (30.8%) were positive for the presence of ESC-resistant E. coli, leading to the selection of 58 resistant isolates. ESC resistance was mostly due to the presence of the chromosome-encoded blaCTX-M-2 gene, but plasmid-mediated blaCTX-M-2, blaCTX-M-8, blaCTX-M-15, blaCTX-M-55 and blaCMY-2 were also detected. Multireplicon plasmids were sporadically identified, such as IncHI2/P-blaCTX-M-2 and IncFII/N-blaCTX-M-55. Phylogroup D predominated, while PFGE and MLST revealed a high genetic diversity. Conclusions: Live Brazilian chickens and CM act as reservoirs of ESC-resistant E. coli and resistance genes are located on highly diverse genetic determinants. Potentially pathogenic strains, which may represent a threat to human health and a source of environmental contamination, were also identified. Active surveillance is therefore essential in Brazil's chicken production line.


Assuntos
Antibacterianos/farmacologia , Cefalosporinas/farmacologia , Farmacorresistência Bacteriana , Escherichia coli/efeitos dos fármacos , Plasmídeos/genética , Produtos Avícolas/microbiologia , Animais , Técnicas de Tipagem Bacteriana , Brasil/epidemiologia , Galinhas/microbiologia , Cloaca/microbiologia , Escherichia coli/isolamento & purificação , Escherichia coli/patogenicidade , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/veterinária , Variação Genética , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Filogenia , Aves Domésticas/microbiologia , Fatores de Virulência/genética , beta-Lactamases/genética
8.
Antimicrob Agents Chemother ; 60(5): 3211-4, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-26953192

RESUMO

The aim of this study was to characterize the genetic context of blaKPC-2 in Pseudomonas aeruginosa sequence type 244 from Brazil. The blaKPC-2 gene was detected in a new small plasmid, pBH6. Complete sequencing revealed that pBH6 was 3,652 bp long and included the Tn3 resolvase and Tn3 inverted repeat (IR), a partial copy of ISKpn6, and a putative ori region but no rep genes. pBH6 replicated stably into Escherichia coli strain DH10B and P. aeruginosa strain PAO.


Assuntos
Proteínas de Bactérias/genética , Plasmídeos/genética , Pseudomonas aeruginosa/genética , Brasil , DNA Bacteriano/genética
10.
J Clin Microbiol ; 52(7): 2530-5, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24808234

RESUMO

In this study, we report the early expansion, evolution, and characterization of a multiresistant Klebsiella pneumoniae clone that was isolated with increasing frequency from inpatients in a tertiary-care university hospital in Brazil. Seven carbapenem- and quinolone-resistant and polymyxin B-susceptible or -resistant K. pneumoniae isolates isolated between December 2012 and February 2013 were investigated. Beta-lactamase- and plasmid-mediated quinolone resistance (PMQR)-encoding genes and the genetic environment were investigated using PCR, sequencing, and restriction fragment length polymorphism (RFLP). Clonal relatedness was established using XbaI-pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), and phylogenetic group characterization. Plasmid analyses included PCR-based replicon typing (PBRT) and hybridization of the S1-PFGE product, plasmid MLST, and conjugation experiments. Virulence potential was assessed by PCR by searching for 10 virulence factor-encoding genes (ureA, fimH, kfuBC, uge, wabG, magA, mrkD, allS, rmpA, and cf29a) and by phenotypic tests to analyze the hypermucoviscous phenotype. The genetic context of a multidrug-resistant and extensively drug-resistant K. pneumoniae ST11-KpI clone harboring IncFIIk-Tn4401a-blaKPC-2, qnrS1, and blaCTX-M-2 was found. Moreover, three isolates displayed high resistance to polymyxin B (MICs = 32, 32, and 128 mg/liter) as well as mucous and hypermucoviscous phenotypes. These bacteria also harbored ureA, fimH, uge, wabG, and mrkD, which code for virulence factors associated with binding, biofilm formation, and the ability to colonize and escape from phagocytosis. Our study describes the association of important coresistance and virulence factors in the K. pneumoniae ST11 international high-risk clone, which makes this pathogen successful at infections and points to the quick expansion and evolution of this multiresistant and virulent clone, leading to a pandrug-resistant phenotype and persistent bacteria in a Brazilian hospital.


Assuntos
Farmacorresistência Bacteriana Múltipla , Evolução Molecular , Infecções por Klebsiella/epidemiologia , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/classificação , Klebsiella pneumoniae/genética , beta-Lactamases/metabolismo , Adulto , Idoso , Brasil/epidemiologia , Análise por Conglomerados , Feminino , Genes Bacterianos , Genótipo , Hospitais Universitários , Humanos , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/isolamento & purificação , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Epidemiologia Molecular , Tipagem Molecular , Filogenia , Plasmídeos , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Análise de Sequência de DNA , Adulto Jovem , beta-Lactamases/genética
12.
Braz J Microbiol ; 54(1): 469-474, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36607526

RESUMO

Salmonella spp. is an important global issue in food-producing animals. The present study evaluated antimicrobial resistance and virulence profiles in Salmonella spp. isolates from chickens in Brazil. Identification of serotypes, virulence and antimicrobial resistance genes, and plasmid profiles were performed. Three different serovars were found, S. Schwarzengrund, S. Newport and S. Kentucky. All isolates were considered Multidrug- resistance (MDR). Among the 32 Salmonella spp. isolates analysed, 29 isolates carried blaCTX-M-2 gene and showed the insertion sequence ISCR1 and a class 1 integron structure upstream from blaCTX-M-2. This gene was harboured in large IncHI2A plasmids with approximately 280kb. Furthermore, 30 isolates harboured tetA and tetB genes and 25 also harboured qnrB. The virulence genes invA, misL, orfL, spiC and pipD were detected in all isolates. The study shows a high prevalence of MDR Salmonella isolates disseminated in poultry farms. The association of the replicon IncHI2A with the resistance genes found, elevate the risk of foodborne disease outbreaks.


Assuntos
Antibacterianos , Galinhas , Animais , Antibacterianos/farmacologia , Galinhas/microbiologia , Brasil/epidemiologia , Farmacorresistência Bacteriana Múltipla/genética , Salmonella/genética , Plasmídeos
13.
Environ Pollut ; 316(Pt 2): 120645, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36375580

RESUMO

Klebsiella quasipneumoniae subsp. similipneumoniae has emerged as a human pathogen and sporadic isolates from non-clinical sources were reported. Here, we described the phenotypic- and genomic-characteristics of a multidrug-resistant (MDR) and potentially hypervirulent (MDR-hv) Klebsiella quasipneumoniae subsp. similipneumoniae (KqA1) isolated from hospital wastewater. The antibiotic susceptibility profile of KqA1 was investigated using disk-diffusion method, broth microdilution method, and agar dilution method, and the genetic characteristics of antimicrobial resistance, mobile genetics elements, and virulence were evaluated by genomic DNA sequencing on the Illumina® NovaSeq6000 platform as well as by bioinformatic analysis. Resistome analyses revealed the presence of genes related to resistance to ß-lactams, aminoglycosides, quinolones, tetracyclines, sulfonamides, trimethoprim, chloramphenicol, macrolides, and fosfomycin. New genetic contexts to blaGES-16 (carbapenemase gene) and to fosA (fosfomycin resistance gene) were described. A set of mechanisms that can contribute to antibiotic resistance, commonly detected in Klebsiella spp., was also found including chromosomal mutations, efflux systems, proteins, and regulators. Moreover, KqA1 presented genes related to tolerance to metals (arsenic, copper, nickel, cobalt, magnesium, cadmium, zinc, tellurium, selenium) and to biocides (quaternary-ammonium compounds). The isolate was classified as potentially hypervirulent due to a wide range of virulence factors found associated to regulation, motility, biofilm, effector delivery systems, immune modulation, nutritional/metabolic factors, adherence, invasion, and competitive advantage. The occurrence of MDR-hv KqA1 in hospital wastewater points out how this environment matrix plays a crucial role in the maintenance and selection of critical bacterial pathogens. Regarding One Health perspective, it is evident the need for multidisciplinary implementation of control measures for antibiotic-resistant bacteria, not only in hospital settings but also in a general environmental context to mitigate the dissemination of MDR and hv bacteria.


Assuntos
Fosfomicina , Águas Residuárias , Humanos , Fatores de Virulência/genética , Testes de Sensibilidade Microbiana , Klebsiella/genética , Klebsiella/metabolismo , beta-Lactamases/genética , beta-Lactamases/metabolismo , Farmacorresistência Bacteriana Múltipla/genética , Antibacterianos/farmacologia , Hospitais
14.
Braz J Microbiol ; 43(4): 1309-14, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24031957

RESUMO

Mutations in the quinolone resistance-determining regions (QRDR) in chromosomal gyrA and parC genes and fluoroquinolone susceptibility profiles were investigated in quinolone-resistant Enterobacteriaceae isolated from community and hospitalized patients in the Brazilian Southeast region. A total of 112 nalidixic acid-resistant enterobacterial isolates collected from 2000 to 2005 were investigated for mutations in the topoisomerases genes gyrA and parC by amplifying and sequencing the QRDR regions. Susceptibility to fluoroquinolones was tested by the agar dilution method. Amongst the 112 enterobacterial isolates, 81 (72.3%) were resistant to ciprofloxacin and 5 (4.5%) showed reduced susceptibility. Twenty-six (23.2%) were susceptible to ciprofloxacin. Several alterations were detected in gyrA and parC genes. Escherichia coli isolates (47.7%) showed double mutations in the gyrA gene and a single one in the parC gene. Two unusual aminoacid substitutions are reported, an Asp87-Asn in a Citrobacter freundii isolate with reduced susceptibility to fluoroquinolones and a Glu84-Ala in one E. coli isolate. Only a parC gene mutation was found in fluoroquinolone-susceptible Enterobacter aerogenes. None of the isolates susceptible to ciprofloxacin presented mutations in topoisomerase genes. This comprehensive analysis of QRDRs in gyrA and parC genes, covering commonly isolated Enterobacteriaceae in Brazil is the largest reported up to now.

15.
Braz J Microbiol ; 53(4): 1799-1806, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35984599

RESUMO

Salmonella enterica serovar Choleraesuis (S. Choleraesuis) is a swine-adapted serovar associated to invasive infections in humans. In Brazil, data of strains of this serovar are scarce. In the present study, six S. Choleraesuis strains of animal (n = 5) and human (n = 1) origin from Brazil were screened for phenotypic antimicrobial resistance using disk-diffusion assay and using whole-genome sequencing data to search for antimicrobial resistance genes, plasmids, prophages, and Salmonella pathogenicity islands (SPIs). Its genetic relatedness was evaluated by MLST and SNP analysis. A single isolate from swine gallbladder harbored the colistin resistance gene mcr-1.1 into a IncX4 plasmid. In the six strains analyzed, resistance was found to tetracycline, nalidixic acid, ciprofloxacin, ampicillin, piperacillin, streptomycin, cefazoline, gentamycin, sulfamethoxazole-trimethoprim, and choloramphenicol, along with resistance genes aac(6')-Iaa, aac(3)-IV, aph(3'')-Ib, aph(6)-Id, aph(4)-Ia, aadA1, aph(3')-IIa, blaTEM-1A, floR, sul1, sul2, tet(B), drfA1, erm(B), mph(B), lnu(G), qacE, and gyrA point mutation Serine83 → Tyrosine and parC Threonine57 → Serine. Furthermore, IncF and IncH plasmids, ten SPIs, and seven prophage types were detected. All strains were assigned to ST145 and five belonged to a common SNP cluster of S. Choleraesuis strains from Brazil. The presence of S. Choleraesuis isolated from animals harboring relevant antimicrobial resistance profiles and virulence determinants reinforced the urge for enhanced surveillance to avoid its transmission to humans through food items.


Assuntos
Colistina , Salmonella enterica , Animais , Antibacterianos/farmacologia , Brasil , Farmacorresistência Bacteriana Múltipla/genética , Vesícula Biliar/microbiologia , Genômica , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Plasmídeos/genética , Salmonella enterica/genética , Sorogrupo , Suínos/microbiologia
16.
Diagn Microbiol Infect Dis ; 104(3): 115784, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35994834

RESUMO

Information regarding resistance and virulence traits of meningitis-causing enterobacteria in hospital environment remains scarce. The aim of this study was to characterize virulence and acquired resistance genes of carbapenem-resistant and/or 3rd to 4th generation cephalosporin-resistant Klebsiella pneumoniae isolated from the cerebrospinal fluid of inpatients. Antimicrobial susceptibility testing was performed by disk diffusion. The string test was performed to identify hypermucoviscous phenotype. Galleria mellonella infection model was used to evaluate the virulence profile of the isolates. Screening for virulence determinants and acquired resistance genes were performed by PCR. The blaCTX-M and/or blaKPC and/or rmtG were detected in all the isolates. Genetic virulence determinants, including mrkD, entB, iroD, fecIRA, uge, wabG, fimH, ureA, ybtS, and clb were detected in the majority of multidrug-resistant K. pneumoniae isolates. One isolate presented hypermucoviscous phenotype, and several isolates showed enhanced virulence in G. mellonella infection model. The combination of the virulence genes found here seems to support not only the known virulence genetic context among nosocomial infections-causing K. pneumoniae but also the role that clb and ybtS may play in K. pneumoniae virulence.


Assuntos
Infecções por Klebsiella , Klebsiella pneumoniae , Antibacterianos/farmacologia , Carbapenêmicos , Cefalosporinas , Humanos , Infecções por Klebsiella/microbiologia , Testes de Sensibilidade Microbiana , Ureia , Virulência/genética , Fatores de Virulência/genética , beta-Lactamases/genética
17.
Sci Rep ; 12(1): 6454, 2022 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-35440801

RESUMO

This study aimed to assess the ultrapure cannabidiol (CBD) antibacterial activity and to investigate the antibacterial activity of the combination CBD + polymyxin B (PB) against Gram-negative (GN) bacteria, including PB-resistant Gram-negative bacilli (GNB). We used the standard broth microdilution method, checkerboard assay, and time-kill assay. CBD exhibited antibacterial activity against Gram-positive bacteria, lipooligosaccharide (LOS)-expressing GN diplococcus (GND) (Neisseria gonorrhoeae, Neisseria meningitidis, Moraxella catarrhalis), and Mycobacterium tuberculosis, but not against GNB. For most of the GNB studied, our results showed that low concentrations of PB (≤ 2 µg/mL) allow CBD (≤ 4 µg/mL) to exert antibacterial activity against GNB (e.g., Klebsiella pneumoniae, Escherichia coli, Acinetobacter baumannii), including PB-resistant GNB. CBD + PB also showed additive and/or synergistic effect against LOS-expressing GND. Time-kill assays results showed that the combination CBD + PB leads to a greater reduction in the number of colony forming units per milliliter compared to CBD and PB alone, at the same concentration used in combination, and the combination CBD + PB was synergistic for all four PB-resistant K. pneumoniae isolates evaluated. Our results show that CBD has translational potential and should be further explored as a repurposed antibacterial agent in clinical trials. The antibacterial efficacy of the combination CBD + PB against multidrug-resistant and extensively drug-resistant GNB, especially PB-resistant K. pneumoniae, is particularly promising.


Assuntos
Canabidiol , Polimixina B , Antibacterianos/farmacologia , Canabidiol/farmacologia , Reposicionamento de Medicamentos , Farmacorresistência Bacteriana Múltipla , Sinergismo Farmacológico , Bactérias Gram-Negativas , Klebsiella pneumoniae , Testes de Sensibilidade Microbiana , Polimixina B/farmacologia
18.
Antimicrob Agents Chemother ; 55(7): 3579-83, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21576442

RESUMO

This article reports the spread of bla(KPC-2) in the Sao Paulo and Rio de Janeiro states, facilitated by globally spread K. pneumoniae clonal complex 258 (CC258) clones (ST258, ST11, and ST437) and a diversity of plasmids (IncFII, IncN, and IncL/M, two untypeable plasmids carrying Tn4401a or Tn4401b) successfully disseminated among species of the Enterobacteriaceae (Enterobacter cloacae, Serratia marcescens, and Citrobacter freundii). It also constitutes the first description of sequence type 258 (ST258) in Brazil, which was associated with a nosocomial hospital outbreak in Ribeirao Preto city.


Assuntos
Enterobacteriaceae/enzimologia , Klebsiella pneumoniae/enzimologia , beta-Lactamases/genética , Brasil , Enterobacteriaceae/genética , Geografia , Klebsiella pneumoniae/genética , Plasmídeos
19.
Infect Genet Evol ; 89: 104716, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33429069

RESUMO

The rapid emergence of resistant bacteria is occurring worldwide. The understanding of the dissemination of antimicrobial resistance using high-throughput sequencing and bioinformatics approaches is providing valuable insights into the genetic basis of the horizontal gene transfer and the emergence of the antibiotic resistance threat. This ultimately can offer vital clues to the development of coordinated efforts to implement new policies to continue fighting against bacterial infections. The poultry microbiota is characterized as a potential reservoir of resistance genes, mostly derived from the Enterobacteriaceae which have become increasingly important in human and animal infections. In this work, complete genome sequences were achieved for four multidrug-resistant Salmonella spp. isolated from poultry from different farms in Brazil. We identified highly similar IncHI2-ST2 megaplasmids (larger than 275.000 bp) in all Salmonella isolates studied. These megaplasmids carry a resistome comprised of eleven different resistance genes (aac(6')-Iaa, aadA1b, aph(4)-Ia, aph(6)-Id, aph(3″)-Ib, aph(3')-Ia, aac(3)-Iva, sul1, tetA, tetB and dfrA1b) and four heavy metal tolerance operons (telluride, mercury, silver and copper). In conclusion, the multidrug-resistant plasmids identified in S. enterica serovar Schwarzengrund and Newport isolated from poultry show a variety of antibiotic resistance and heavy metal tolerance genes, providing advantages for the bacteria to survive under extremely unfavorable conditions.


Assuntos
Farmacorresistência Bacteriana/genética , Plasmídeos , Aves Domésticas/microbiologia , Salmonella/efeitos dos fármacos , Salmonella/genética , Animais , Antibacterianos/farmacologia , Genes Bacterianos
20.
Infect Genet Evol ; 87: 104658, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33271337

RESUMO

IMP-1-producing Pseudomonas aeruginosa was first reported in Japan and since then, bacteria with this metallo-ß-lactamase have been detected worldwide. Pseudomonas monteilii (part of P. putida group) were considered an environmental pathogen with low virulence potential; however, multidrug-resistant and carbapenem-resistant P. monteilii have emerged. The present study reports the draft sequence of an extensively drug-resistant IMP-16-producing P. monteilii 597/14 isolated from cerebrospinal fluid in 2014. The sequencing data revealed blaIMP-16 as a gene cassette on class 1 integron, In1738 characterized in this study. Furthermore, the resistome of Pm597/14 consisted of 7 resistance genes (aadA1b, strA, strB, aacA4, blaIMP-16, blaOXA-2, sul1) and diverse virulence determinants involved in the adherence, LPS, antiphagocytosis, iron uptake and mercuric resistance. Although different virulence determinants were found in this study, using Galleria mellonella infection model, Pm597/14 did not kill any larvae between 7 days post-infection. P. monteilii isolates have been reported from clinical and environmental sources, carrying different MBL genes showing its potential role as their reservoir.


Assuntos
Antibacterianos , Líquido Cefalorraquidiano , Farmacorresistência Bacteriana Múltipla , Infecções por Pseudomonas , Pseudomonas , Virulência , Humanos , Antibacterianos/uso terapêutico , Líquido Cefalorraquidiano/microbiologia , DNA Bacteriano , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Japão , Testes de Sensibilidade Microbiana , Pseudomonas/genética , Pseudomonas/isolamento & purificação , Infecções por Pseudomonas/tratamento farmacológico , Análise de Sequência de DNA , Virulência/efeitos dos fármacos , Virulência/genética
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