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1.
Int J Antimicrob Agents ; 55(3): 105903, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31954832

RESUMO

This study characterizes four KPC-2-producing Klebsiella pneumoniae isolates from neonates belonging to a single sequence type 147 (ST147) in relation to carbapenem resistance and explores probable mechanisms of differential colistin resistance among the clonal cluster. Whole genome sequencing (WGS) revealed that the isolates were nearly 100% identical and harbored resistance genes (blaKPC-2,OXA-9,CTX-M-15,SHV-11,OXA-1,TEM-1B, oqxA, oqxB, qnrB1, fosA, arr-2, sul1, aacA4, aac(6')Ib-cr, aac(6')Ib), and several virulence genes. blaKPC-2 was the only carbapenem-resistant gene found, bracketed between ISKpn7 and ISKpn6 of Tn4401b on a non-conjugative IncFII plasmid. Remarkably, one of the clonal isolates was resistant to colistin, the mechanistic basis of which was not apparent from comparative genomics. The transmissible colistin resistance gene, mcr, was absent. Efflux pump inhibitor, carbonyl cyanide 3-chlorophenylhydrazone (CCCP) rendered a 32-fold decrease in the minimum inhibitory concentration (MIC) of colistin in the resistant isolate only. acrB, tolC, ramA, and soxS genes of the AcrAB-TolC pump system overexpressed exclusively in the colistin-resistant isolate, although the corresponding homologs of the AcrAB-TolC pump, regulators and promoters were mutually identical. No change was observed in the expression of other efflux genes (kpnE/F and kpnG/H) or two-component system (TCS) genes (phoP/phoQ, pmrA/pmrB). Colistin resistance in one of the clonal KPC-2-producing isolates is postulated to be due to overexpression of the AcrAB-TolC pump. This study is probably the first to report clinical clonal K. pneumoniae isolates with differences in colistin susceptibility. The presence of carbapenem-resistant isolates with differential behavior in the expression of a genomically identical pump system indicates the nuances of the resistance mechanisms and the difficulty of treatment thereof.


Assuntos
Antibacterianos/farmacologia , Colistina/farmacologia , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/genética , beta-Lactamases/biossíntese , Proteínas de Bactérias/biossíntese , Proteínas de Transporte/biossíntese , Farmacorresistência Bacteriana/efeitos dos fármacos , Farmacorresistência Bacteriana/genética , Humanos , Recém-Nascido , Unidades de Terapia Intensiva Neonatal , Infecções por Klebsiella/tratamento farmacológico , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/metabolismo
2.
Int J Antimicrob Agents ; 55(3): 105902, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31954833

RESUMO

OBJECTIVE: Faropenem is an oral penem drug with activity against Gram-positive and Gram-negative bacteria, including CTX-M-15-type extended spectrum beta-lactamase (ESBL)-producing Enterobacteriales and anaerobic bacteria. As there are structural similarities, there is concern for the development of carbapenem cross-resistance; however, there are no studies confirming this. This study examined whether in vitro development of faropenem resistance in Escherichia coli isolates would result in cross-resistance to carbapenems. METHODS: Four well-characterized E. coli isolates from the US Centers for Disease Control and Prevention antibiotic resistance isolate bank were utilized. Three isolates (NSF1, NSF2 and NSF3) are ESBL producers (CTX-M-15) and one (NSF4) is pan-susceptible. Faropenem minimum inhibitory concentrations (MICs) were determined and resistance was induced by serial passaging in increasing concentrations of faropenem. Susceptibility to carbapenems was determined and whole-genome sequencing (WGS) was performed to identify the underlying genetic mechanism leading to carbapenem resistance. RESULTS: Faropenem MIC increased from 1 mg/L to 64 mg/L within 10 days for NSF2 and NSF4 isolates, and from 2 mg/L to 64 mg/L within 7 days for NSF1 and NSF3 isolates. Reduced carbapenem susceptibility (ertapenem MIC ≥8 mg/L, doripenem/meropenem ≥2 mg/L and imipenem ≥1 mg/L) developed among three CTX-M-15-producing isolates that were faropenem-resistant, but not in NSF4 isolate that lacked ESBL enzyme. WGS analysis revealed non-synonymous changes in the ompC gene among three CTX-M-15-producing isolates, and a single nucleotide polymorphism (SNP) in the envZ gene in NSF4 isolate. CONCLUSION: Induced resistance to faropenem causes cross-resistance to carbapenems among E. coli isolates containing CTX-M-15-type ESBL enzymes.


Assuntos
Antibacterianos/farmacologia , Carbapenêmicos/farmacologia , Escherichia coli/efeitos dos fármacos , beta-Lactamas/farmacologia , Farmacorresistência Bacteriana/efeitos dos fármacos , Ertapenem/farmacologia , Escherichia coli/metabolismo , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/microbiologia , Humanos , Porinas/biossíntese , beta-Lactamases/biossíntese
3.
Int J Antimicrob Agents ; 55(3): 105905, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31991221

RESUMO

BACKGROUND: Limited treatment options complicate management of infections with New Delhi metallo-ß-lactamase (NDM)-producing organisms. The efficacy of combination therapy with meropenem (MEM) and cefmetazole (CMZ) was assessed against NDM-producing Enterobacteriaceae. MATERIALS AND METHODS: Twelve Escherichia coli clinical isolates harbouring blaNDM-1 and a positive control E. coli BAA-2469 harbouring blaNDM-1 were studied. Minimum inhibitory concentrations (MICs) of MEM, ertapenem (ERT) and CMZ were determined by broth microdilution. Checkerboard and time-kill assays were performed to confirm the in vitro efficacy of the MEM/CMZ combination. Scanning electron microscopy, kinetic studies and whole-genome sequence analysis were used to determine the antimicrobial resistance mechanisms. RESULTS: MICs of MEM, ERT and CMZ in monotherapy ranged from 8 to 32, 16 to 128, and 32 to 512 µg/mL, respectively. In the checkerboard assay, MEM/ERT resulted in no synergy, whereas MEM/CMZ showed a synergistic effect in all the tested isolates. Furthermore, the MIC of MEM in combination decreased by 2- to 8-fold compared with that of MEM alone. The time-kill study revealed a bactericidal effect in 4 of 13 isolates at 24 h. Scanning electron microscopy showed spheroidisation of the bacterial cell in the MEM/CMZ combination; this was not observed in single antibiotic conditions. Kinetic studies indicated CMZ was a better antagonist for NDM-1 than ERT. Whole-genome sequence analysis did not reveal any explainable differences between isolates susceptible and those non-susceptible to combination therapy. CONCLUSION: In vitro studies showed the potential effectiveness of MEM/CMZ combination therapy against NDM-producing organisms.


Assuntos
Antibacterianos/farmacologia , Cefmetazol/farmacologia , Infecções por Enterobacteriaceae/tratamento farmacológico , Enterobacteriaceae/efeitos dos fármacos , Meropeném/farmacologia , Antibacterianos/uso terapêutico , Cefmetazol/uso terapêutico , Quimioterapia Combinada , Enterobacteriaceae/metabolismo , Infecções por Enterobacteriaceae/microbiologia , Ertapenem/farmacologia , Humanos , Meropeném/uso terapêutico , beta-Lactamases/biossíntese
4.
J Dairy Sci ; 103(1): 852-857, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31733863

RESUMO

We performed a survey aimed at analyzing milk samples collected from cows with mastitis for the presence of extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli. Single-quarter mastitic milk samples obtained from 400 cows in 23 Greek dairy herds with a history of E. coli mastitis were processed for the selective isolation of ESBL-producing E. coli. The antimicrobial susceptibility of the ESBL-producing isolates was analyzed using agar disk diffusion, and minimum inhibitory concentrations of colistin were determined by broth microdilution. We used PCR followed by DNA sequencing to characterize the ß-lactamases and mcr-1 (colistin resistance) genes, and for phylotyping and multilocus sequence typing. We found a total of 89/400 (22.25%) E. coli isolates from 12/23 (52%) farms. Six isolates originating from 6 cows on a single farm were ESBL producers and were resistant to cefquinome, amoxicillin-clavulanic acid, aztreonam, ampicillin, and colistin. Five of these isolates were resistant to trimethoprim-sulfamethoxazole, and 5 to streptomycin. The 6 ESBL producers were mcr-1-positive and carried blaTEM-1 genes; 3 also carried blaCTX-M genes, and 3 carried blaSHV genes. All of the ESBL producers belonged to phylogroup A, multilocus sequence type ST666 (n = 5), or a single locus variant of ST666 (n = 1). To our knowledge, this is the first report of endemic bovine mastitis caused by mcr-1-positive, ESBL-producing E. coli. These results highlight the value of active surveillance of antimicrobial resistance not commonly tested by diagnostic laboratories for the early detection of novel resistant strains.


Assuntos
Colistina/farmacologia , Infecções por Escherichia coli/veterinária , Escherichia coli/isolamento & purificação , Mastite Bovina/microbiologia , Animais , Antibacterianos/farmacologia , Bovinos , Cefalosporinas/farmacologia , Indústria de Laticínios , Farmacorresistência Bacteriana , Escherichia coli/efeitos dos fármacos , Escherichia coli/enzimologia , Escherichia coli/genética , Infecções por Escherichia coli/microbiologia , Proteínas de Escherichia coli/biossíntese , Fazendas , Feminino , Grécia , Testes de Sensibilidade Microbiana , Leite , Tipagem de Sequências Multilocus , beta-Lactamases/biossíntese , beta-Lactamases/genética
5.
J Dairy Sci ; 103(1): 877-883, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31733866

RESUMO

This study was carried out to determine the antimicrobial resistance (AMR) genes and mobile genetic elements of 4 fecal blaCMY-2-producing Escherichia coli isolated from Holstein dairy calves on the same farm using whole-genome sequencing. Genomic analysis revealed that 3 of the 4 isolates shared similar genetic features, including sequence type (ST), serotype, plasmid characteristics, insertion ST, and virulence genes. In addition to genes encoding for complex multidrug resistance efflux systems, all 4 isolates were carriers of genes conferring resistance to ß-lactams (blaCMY-2, blaTEM-1B), tetracyclines (tetA, tetB, tetD), aminoglycosides [aadA1, aph(3")-lb, aph(6)-ld], sulfonamides (sul2), and trimethoprim (dfrA1). We also detected 4 incompatibility plasmid groups: Inc.F, Inc.N, Inc.I, and Inc.Q. A novel ST showing a new purA and mdh allelic combination was found. The 4 isolates were likely enterotoxigenic pathotypes of E. coli, based on serotype and presence of the plasmid Inc.FII(pCoo). This study provides information for comparative genomic analysis of AMR genes and mobile genetic elements. This analysis could give some explanation to the multidrug resistance characteristics of bacteria colonizing the intestinal tract of dairy calves in the first few weeks of life.


Assuntos
Bovinos/microbiologia , Escherichia coli/genética , Animais , Antibacterianos/farmacologia , Indústria de Laticínios , Farmacorresistência Bacteriana Múltipla/genética , Escherichia coli/efeitos dos fármacos , Escherichia coli/isolamento & purificação , Escherichia coli/metabolismo , Fezes/microbiologia , Feminino , Plasmídeos , Virulência/genética , Sequenciamento Completo do Genoma , beta-Lactamases/biossíntese
6.
Rev Chilena Infectol ; 36(4): 433-441, 2019 Aug.
Artigo em Espanhol | MEDLINE | ID: mdl-31859766

RESUMO

BACKGROUND: Infections caused by extended-spectrum beta-lactamases enterobacteria (ESBL-EP) have implications for neonatal morbidity and mortality. AIM: To describe the prevalence of ESBL-EP in neonatal sepsis and associated factors. METHODS: A prospective cohort study was conducted from August 2016 to August 2017; newborn babies (NB) hospitalized in the Hospital Civil de Guadalajara "Dr. Juan I. Menchaca" were included. The ESBL-EP were investigated by double-disk synergy test and its association with clinical and demographic characteristics of the NB. RESULTS: A total of 1,501 hospitalized NB were studied, with an average gestational age of 36.3 weeks. They were diagnosed 196 neonatal sepsis events, the most frequent etiologies were enterobacteria (45.5%). Resistance to ampicilin was found in 88.8% and to broad spectrum cephalosporins in more than 42% of the strains; 22.9% of them were ESBL phenotype. Apgar ≤ 7 at five minutes of life (OR 4.6; 95% CI 1.47-14.6) and gestational age < 37 weeks (OR 5.4; 95% CI 1.04-27.) increase the risk. CONCLUSION: In enterobacteria that cause neonatal sepsis, 22.9% were EP-ESBL; infection was more likely in patients with Apgar ≤ 7 at five minutes of age and in preterm infants.


Assuntos
Antibacterianos/farmacologia , Infecção Hospitalar/microbiologia , Infecções por Enterobacteriaceae/microbiologia , Enterobacteriaceae/efeitos dos fármacos , Sepse Neonatal/microbiologia , beta-Lactamases/biossíntese , Adolescente , Adulto , Criança , Enterobacteriaceae/classificação , Feminino , Humanos , Recém-Nascido , Unidades de Terapia Intensiva Neonatal , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Prevalência , Estudos Prospectivos , Fatores de Risco , Adulto Jovem
7.
J Med Microbiol ; 68(12): 1707-1715, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31661049

RESUMO

Purpose. Carbapenemase-producing Enterobacteriaceae (CPE) have become a global concern and a serious threat to human health due to their resistance to multiple antibiotics. In this study, we identified and characterized CPE for the first time in Malawi, southeastern Africa.Methodology. We investigated the possible presence of carbapenemases among a collection of 200 ceftriaxone-nonsusceptible Gram-negative clinical isolates obtained from five Malawian hospitals between January 2016 and December 2017, using both phenotypic and genotypic tests. Molecular typing of CPE was done by PFGE, multilocus sequence typing (ST) or phylogenetic grouping. Resistant plasmids were characterized by S1 PFGE, Southern blotting and conjugation assays.Results. Out of 200 isolates, we detected 16 (8 %) CPE of which all originated from one referral hospital, Kamuzu Central Hospital, in the Central part of Malawi. Of 16 isolates, seven Klebsiella pneumoniae ST340/CC258 carried bla KPC-2, two Escherichia coli ST636 (phylogroup B2) carried bla NDM-5, six E. coli ST617 (phylogroup A) and one Klebsiella variicola carried bla OXA-48. All carbapenemases were plasmid-encoded, but only bla NDM-5-carrying plasmids could be conjugated. Most isolates co-harboured other ß-lactamases and consequently exhibited a wider spectrum of resistance to commonly used antibiotics. We observed indistinguishable genetic profiles between strain types, despite originating from different wards, suggesting acquisition during admission and intra-hospital spread.Conclusion. This report strongly suggests a probable existence of highly resistant various types of CPE organisms in Malawi including KPC-2-producing K. pneumoniae ST340/CC258, a known high-risk epidemic lineage.


Assuntos
Proteínas de Bactérias/biossíntese , Enterobacteriaceae/isolamento & purificação , beta-Lactamases/biossíntese , Farmacorresistência Bacteriana Múltipla , Enterobacteriaceae/efeitos dos fármacos , Enterobacteriaceae/enzimologia , Enterobacteriaceae/genética , Genoma Bacteriano , Humanos , Testes de Sensibilidade Microbiana
8.
Rev Soc Bras Med Trop ; 52: e20190243, 2019 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-31508786

RESUMO

INTRODUCTION: In recent decades, the prevalence of carbapenem-resistant Acinetobacter isolates has increased, and the production of oxacillinase (OXA)-type carbapenemases is the main mechanism underlying resistance. We evaluated OXA production from 114 Acinetobacter isolates collected between March and December 2013 from different clinical specimens of patients in two hospitals (Hospital 1 [n = 61] and Hospital 2 [n = 53]) located in Niterói, Rio de Janeiro, Brazil. We also evaluated the genetic diversity of OXA-producing isolates. METHODS: All the isolates were identified through the automated system Vitek II and matrix-assisted laser desorption ionization-time of flight mass spectrometry MALDI-TOF MS as belonging to the A. baumannii-A. calcoaceticuscomplex. Antimicrobial susceptibility profiles were verified through agar diffusion tests. The presence of OXA-encoding genes was confirmed by PCR. The genetic diversity of isolates positive for carbapenemase production was analyzed through pulsed-field gel electrophoresis. RESULTS: There was a high rate of resistance to carbapenems in the isolates (imipenem: 96%; meropenem: 92%) from both hospitals. Moreover, a high percentage (95.6%) of OXA-23-positive isolates was observed for both hospitals, indicating that this was the main mechanism of carbapenem-resistance among the studied population. In addition, most isolates (96.5%) were positive for bla OXA-51. A high genetic diversity and a few major genotypes were found among the OXA-23-positive isolates analyzed. Only intra-hospital dissemination was observed. CONCLUSIONS: The elevated dissemination of bla OXA-23-like observed among Acinetobacter isolates from both the studied hospitals highlights the need for continuous epidemiological surveillance in these institutions.


Assuntos
Infecções por Acinetobacter/microbiologia , Acinetobacter/enzimologia , beta-Lactamases/biossíntese , Acinetobacter/efeitos dos fármacos , Acinetobacter/genética , Antibacterianos/farmacologia , Técnicas de Tipagem Bacteriana , Brasil , DNA Bacteriano/genética , Eletroforese em Gel de Campo Pulsado , Hospitais Gerais , Humanos , Testes de Sensibilidade Microbiana , Reação em Cadeia da Polimerase , beta-Lactamases/efeitos dos fármacos
9.
Diagn Microbiol Infect Dis ; 95(3): 114867, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31402069

RESUMO

MICs of plazomicin were determined by agar dilution and broth microdilution in 187 ESBL-producing Escherichia coli (n = 73), carbapenemase-producing Klebsiella pneumoniae (n = 55) methicillin-resistant Staphylococcus aureus (n = 59) clinical isolates. Inoculum effect was determined by broth microdilution assay using two different inocula; 1-5 × 105 (standard inoculum) and 1-5 × 108 CFU/mL. For all isolates tested >98% categorical agreement and ≥95% of essential agreement (±1elog2) was found. At high inocula, MICs of plazomicin increased ≥ eight-fold for 25% of E. coli, 24% of K. pneumoniae and 7% of S. aureus isolates tested. The results indicate that agar dilution and broth microdilution methods were equally suitable for determining plazomicin MICs. Inoculum effect was observed for plazomicin in Escherichia coli and Klebsiella pneumoniae isolates. Further studies that establish the genetic background of the isolates are required to better understand the reasons behind the inoculum effect.


Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Farmacorresistência Bacteriana/efeitos dos fármacos , Testes de Sensibilidade Microbiana/métodos , Sisomicina/análogos & derivados , Bactérias/enzimologia , Carga Bacteriana , Proteínas de Bactérias/biossíntese , Escherichia coli/efeitos dos fármacos , Escherichia coli/enzimologia , Humanos , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/enzimologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Sisomicina/farmacologia , beta-Lactamases/biossíntese
10.
Diagn Microbiol Infect Dis ; 95(3): 114841, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31422873

RESUMO

OBJECTIVES: To compare the performance and time-to-result (TTR) for antimicrobial susceptibility testing (AST) of positive blood cultures (PBC) using the Accelerate Pheno™ system (AXDX) and both a direct VITEK® 2 card inoculation workflow (DV2) and traditional FDA-approved VITEK® 2 workflow using subcultured isolates (V2). METHODS: Patient samples with monomicrobial Gram-negative rod bacteremia were tested on AXDX and DV2 in tandem and compared to V2 AST results. Categorical agreement (CA) errors were adjudicated using broth microdilution. Instrumentation times and AST TTR were compared. RESULTS: AXDX and DV2 had a CA of 93.4% and 97.4%, respectively, compared to V2. Postadjudication, AXDX, DV2, and V2 had CA of 94.7%, 95.7%, and 96.5%, respectively. Instrument run times were 6.6 h, 9.4 h, and 9.2 h, and AST TTR were 8.9 h, 12.9 h and 35.5 h, respectively. CONCLUSIONS: AXDX and DV2 ASTs are fast and reliable, which may have significant antimicrobial stewardship implications.


Assuntos
Hemocultura , Testes Diagnósticos de Rotina/métodos , Testes de Sensibilidade Microbiana/métodos , Gestão de Antimicrobianos , Bacteriemia/microbiologia , Testes Diagnósticos de Rotina/instrumentação , Testes Diagnósticos de Rotina/normas , Bactérias Gram-Negativas/isolamento & purificação , Bactérias Gram-Negativas/metabolismo , Infecções por Bactérias Gram-Negativas/microbiologia , Humanos , Testes de Sensibilidade Microbiana/instrumentação , Testes de Sensibilidade Microbiana/normas , Estudos Prospectivos , Fatores de Tempo , Fluxo de Trabalho , beta-Lactamases/biossíntese
11.
MMWR Morb Mortal Wkly Rep ; 68(30): 664-666, 2019 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-31369523

RESUMO

Candida auris is an emerging drug-resistant yeast that causes outbreaks in health care facilities; cases have been reported from approximately 30 countries. U.S. cases of C. auris are likely the result of importation from abroad followed by extensive local transmission in health care settings (1). Early detection of Candida auris is key to preventing its spread. C. auris frequently co-occurs with carbapenemase-producing organisms (CPOs), like carbapenem-resistant Enterobacteriaceae (CRE), organisms for which testing and public health response capacity substantially increased beginning in 2017. In September 2018, the Maryland Department of Health (MDH) was notified of a hospitalized resident with CPO infection and colonization and recent hospitalization in Kenya. In light of this history, the patient was screened for C. auris and found to be colonized. Public health responses to CPOs can aid in the early identification of C. auris. As part of CPO investigations, health departments should assess whether the patient has risk factors for C. auris and ensure that patients at risk are tested promptly.


Assuntos
Proteínas de Bactérias/biossíntese , Candida/isolamento & purificação , Candidíase/diagnóstico , Hospitalização/estatística & dados numéricos , beta-Lactamases/biossíntese , Humanos , Quênia , Estados Unidos
12.
J Med Microbiol ; 68(8): 1140-1147, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31274402

RESUMO

INTRODUCTION: Moraxella catarrhalis is an important but insufficiently studied respiratory pathogen. AIM: To determine antibiotic susceptibility and impact of recent antibiotics on M. catarrhalis from children with chronic endobronchial suppuration. METHODOLOGY: We cultured nasopharyngeal (NP) swabs and bronchoalveolar lavage (BAL) fluids collected from children who were prospectively enrolled in studies of chronic cough and had flexible bronchoscopy performed. Recent ß-lactam or macrolide antibiotic use was recorded. M. catarrhalis isolates stored at -80 °C were re-cultured and susceptibility determined to a range of antibiotics including the macrolide antibiotic erythromycin. RESULTS: Data from concurrently collected NP and BAL specimens were available from 547 children (median age 2.4 years) enrolled from 2007 to 2016. M. catarrhalis NP carriage was detected in 149 (27  %) children and lower airway infection (≥104 c.f.u. ml-1 BAL) in 67 (12  %) children. In total, 91  % of 222 M. catarrhalis isolates were ß-lactamase producers, and non-susceptibility was high to benzylpenicillin (98 %), cefaclor (39 %) and cotrimoxazole (38 %). Overall, >97  % isolates were susceptible to cefuroxime, chloramphenicol, erythromycin and tetracycline; three isolates were erythromycin-resistant (MIC >0.5 mg l-1). Recent macrolide antibiotics (n=152 children, 28 %) were associated with significantly reduced M. catarrhalis carriage and lower airway infection episodes compared to children who did not receive macrolides; odds ratios 0.19 (95  % CI 0.10-0.35) and 0.15 (0.04-0.41), respectively. CONCLUSION: Despite the frequent use of macrolides, few macrolide-resistant isolates were detected. This suggests a fitness cost associated with macrolide resistance in M. catarrhalis. Macrolide antibiotics remain an effective choice for treating M. catarrhalis lower airway infection in children with chronic endobronchial suppuration.


Assuntos
Bronquiectasia/tratamento farmacológico , Bronquiectasia/microbiologia , Macrolídeos/farmacologia , Macrolídeos/uso terapêutico , Infecções por Moraxellaceae/tratamento farmacológico , Infecções por Moraxellaceae/microbiologia , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Bronquiectasia/patologia , Líquido da Lavagem Broncoalveolar/microbiologia , Pré-Escolar , Doença Crônica , Farmacorresistência Bacteriana , Feminino , Humanos , Lactente , Masculino , Testes de Sensibilidade Microbiana , Infecções por Moraxellaceae/patologia , Nasofaringe/microbiologia , Supuração , beta-Lactamases/biossíntese
13.
Microb Pathog ; 135: 103620, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31310833

RESUMO

NDM-1-producing Enterobacteriaceae are multidrug-resistant bacteria, also called superbacteria, that have become important global human health threats in recent years. However, data about NDM-1-producing bacteria in animals are rare. In this study, an NDM-1-producing Escherichia coli isolate (designated E120413) was obtained from pigs in Henan province, China in 2012. The susceptibility of E. coli E120413 to antimicrobial agents was determined using Kirby-Bauer disk diffusion and micro-dilution methods. Susceptibility tests indicated that E. coli E120413 was resistant to almost all common antibiotics with high MIC values obtained for most antibiotics tested. E. coli E120413 was detected in the heart, liver, spleen, lung, kidney, brain, stomach, duodenum, mesenteric lymph nodes, and fecal samples of piglets in both cohabitation and experimental groups and the bacteria persisted for more than 2 weeks. However, no obvious clinical symptoms or serious pathological lesions were observed. This is the first investigation of NDM-1-producing E. coli isolate from pigs in China. Although no significant pathological lesions were observed, NDM-1-producing E. coli was found to be highly transmissible and to cause persistent infection in pigs.


Assuntos
Infecções por Enterobacteriaceae/microbiologia , Escherichia coli/enzimologia , Escherichia coli/isolamento & purificação , Suínos/microbiologia , beta-Lactamases/biossíntese , Animais , Antibacterianos/farmacologia , China , Modelos Animais de Doenças , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Infecções por Enterobacteriaceae/patologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Fezes/microbiologia , Testes de Sensibilidade Microbiana , Virulência , beta-Lactamases/genética
14.
Vet Microbiol ; 233: 52-60, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31176413

RESUMO

The spread of extended-spectrum ß-lactamases (ESBLs) in Escherichia coli is a major public health issue and ESBL-producing bacteria are frequently reported in livestock. For the assessment of the role of the foodborne transmission pathway in Germany, detailed data on the prevalence and characteristics of isolates of food origin are necessary. The objective of this study was to describe the prevalence of cefotaxime resistant E. coli as well as ESBL/pAmpC-producing E. coli and their characteristics in foods in Germany. Out of 2256 food samples, the highest prevalence of cefotaxime resistant E. coli was observed in chicken meat (74.9%), followed by turkey meat (40.1%). Prevalence in beef, pork and minced meat was considerably lower (4.2-15.3%). Whereas 18.0% of the raw milk samples, collected at farm level were positive, this was true only for few cheese samples (1.3%). In one out of 399 vegetable samples a cefotaxime-resistant E. coli was isolated. ESBL resistance genes of the CTX-M-group (10.1% of all samples) were most frequently detected, followed by genes of the pAmpC (2.6%), SHV (2.0%) and TEM (0.8%) families. Distribution of ESBL/AmpC-encoding E. coli resistance genes and E. coli phylogroups was significantly different between the chicken related food samples and all other food items. Our study results reflect that consumers might get exposed to ESBL/pAmpC-producing E. coli through several food chains. These results together with those collected at primary production and in the human population in other studies will allow more detailed analysis of the foodborne pathways, considering transmission from livestock populations to food at retail and to consumers in Germany.


Assuntos
Proteínas de Bactérias/genética , Escherichia coli/genética , Microbiologia de Alimentos , Carne/microbiologia , beta-Lactamases/genética , Animais , Antibacterianos/farmacologia , Proteínas de Bactérias/biossíntese , Cefotaxima/farmacologia , Farmacorresistência Bacteriana , Escherichia coli/enzimologia , Infecções por Escherichia coli/transmissão , Infecções por Escherichia coli/veterinária , Proteínas de Escherichia coli/biossíntese , Proteínas de Escherichia coli/genética , Alemanha , Gado/microbiologia , Aves Domésticas/microbiologia , Prevalência , Carne Vermelha/microbiologia , Verduras/microbiologia , beta-Lactamases/biossíntese
15.
Vet Microbiol ; 233: 61-67, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31176414

RESUMO

The incidence of infections with extended spectrum ß-lactamase producing Escherichia coli (ESBL-E) is increasing both in humans and animals. There is a paucity of data about the rate of faecal carriage of ESBL-E in pets. In this study, faecal swabs collected from 586 pets (225 cats; 361 dogs) in Auckland, New Zealand, were analysed for the presence of ESBL-E by culture, and a questionnaire was delivered to the owners. The ESBL-E were characterised and data elicited by the questionnaires were used for a multivariable analysis, to investigate the factors associated with faecal ESBL-E carriage. The prevalence of ESBL-E in faecal swabs was 6.4%. The ß-lactamase genes detected in the ESBL-E were the blaCTX-M-14 (n = 2) and blaCMY-2 (n = 34). Several isolates displayed multilocus sequence types (ST) associated with human and animal infections. Multiple isolates sharing the same ST displayed different antibiograms and ß-lactamase genes, reflecting horizontal gene transfer between and within ST. Variables independently associated with increased odds of ESBL-E carriage were: animal received systemic antimicrobial treatment in the six months before the sampling; presence of household members working in veterinary clinics; presence of household members travelling overseas in the six months before the sampling. We conclude that pets are colonised by ESBL-E which are genotypically similar to the bacteria found to infect humans and animals. The statistical analysis suggested a number of eco-epidemiological factors associated with ESBL-E carriage. In particular, they suggest veterinary clinics may represent hot-spots of antimicrobial resistance.


Assuntos
Portador Sadio/veterinária , Farmacorresistência Bacteriana Múltipla/genética , Infecções por Escherichia coli/veterinária , Escherichia coli/genética , Animais de Estimação/microbiologia , beta-Lactamases/genética , Animais , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Portador Sadio/epidemiologia , Gatos/microbiologia , Cães/microbiologia , Escherichia coli/enzimologia , Infecções por Escherichia coli/epidemiologia , Fezes/microbiologia , Feminino , Transferência Genética Horizontal , Genética Populacional , Genótipo , Hospitais Veterinários , Humanos , Masculino , Tipagem de Sequências Multilocus , Nova Zelândia/epidemiologia , Prevalência , beta-Lactamases/biossíntese
16.
Diagn Microbiol Infect Dis ; 95(2): 131-133, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31208819

RESUMO

The KPC K-SeT immunochromatographic test (Coris BioConcept®, Gembloux, Belgium) has been widely used for detection of KPC in Enterobacteriaceae with reported sensitivities and specificities of 100%. However, to our knowledge, there are no reports of its use in KPC-positive Pseudomonas species. We evaluated the KPC K-SeT test in 36 clinical isolates of Enterobacteriaceae (21 KPC-positive and 15 KPC-negative) and 20 Pseudomonas species (5 KPC-positive and 15 KPC-negative) using conventional PCR for carbapenemase genes as the reference method. The KPC K-SeT test detected 25 out of 26 KPC-positive isolates (96.1%). The undetected isolate was 1 P. aeruginosa bearing the mutation D179Y in the omega loop region of KPC-2 carbapenemase. This mutation was already reported in Enterobacteriaceae as conferring resistance to ceftazidime-avibactam. To our knowledge, this is the first report of evaluation of KPC K-SeT test in KPC-positive P. aeruginosa isolates.


Assuntos
Proteínas de Bactérias/análise , Cromatografia de Afinidade , Enterobacteriaceae/enzimologia , Ensaios Enzimáticos/métodos , Pseudomonas/enzimologia , beta-Lactamases/análise , Proteínas de Bactérias/biossíntese , Proteínas de Bactérias/genética , Enterobacteriaceae/genética , Enterobacteriaceae/isolamento & purificação , Infecções por Enterobacteriaceae/microbiologia , Reações Falso-Negativas , Humanos , Reação em Cadeia da Polimerase , Pseudomonas/genética , Pseudomonas/isolamento & purificação , Infecções por Pseudomonas/microbiologia , Sensibilidade e Especificidade , beta-Lactamases/biossíntese , beta-Lactamases/genética
17.
Future Microbiol ; 14: 691-704, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31148474

RESUMO

Aim: To determine the prevalence of New Delhi metallo-ß-lactamase (NDM)-producing Gram-negative pathogens isolated from children's samples. Materials & methods: Carbapenem-resistant clinical isolates (n = 117) were confirmed by VITEK® 2 compact system, matrix-assisted laser desorption ionization-time of flight and multilocus sequence typing. MIC (µg/ml) of various antibiotics was determined by VITEK 2 compact system. Molecular characterization of the isolates was performed by PCR, DNA sequencing, PFGE and DNA hybridization. Results: Out of 117 carbapenemase producers, 37 (31.6%) and 29 (24.7%) were Klebsiella pneumoniae and Acinetobacter baumannii, respectively. 72 (61.5%) isolates were NDM positive and among these 60, 9 and 3 were NDM-1, -5 and -7, respectively. Majority of the NDM-producing K. pneumoniae belonged to ST11 and ST273 while most of the Escherichia coli belonged to ST405 and ST101. blaNDM were mainly located on 150kb plasmids. MIC displayed high resistance against ß-lactams drugs including carbapenems, and the most sensitive drugs were tigecycline and colistin. Conclusion: Dissemination of blaNDM-producing pathogens, particularly in children clinical settings, is a matter of great public health concern.


Assuntos
Bactérias Gram-Negativas/enzimologia , Bactérias Gram-Negativas/genética , beta-Lactamases/biossíntese , beta-Lactamases/genética , Acinetobacter baumannii/efeitos dos fármacos , Acinetobacter baumannii/enzimologia , Acinetobacter baumannii/genética , Acinetobacter baumannii/isolamento & purificação , Antibacterianos/farmacologia , Proteínas de Bactérias/biossíntese , Proteínas de Bactérias/genética , Criança , DNA Bacteriano/análise , Farmacorresistência Bacteriana Múltipla/genética , Escherichia coli/efeitos dos fármacos , Escherichia coli/enzimologia , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Feminino , Perfilação da Expressão Gênica , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Negativas/isolamento & purificação , Infecções por Bactérias Gram-Negativas/epidemiologia , Infecções por Bactérias Gram-Negativas/microbiologia , Humanos , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/enzimologia , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/isolamento & purificação , Masculino , Testes de Sensibilidade Microbiana , Epidemiologia Molecular , Tipagem de Sequências Multilocus , Paquistão/epidemiologia , Plasmídeos , Análise de Sequência de DNA
19.
Mater Sci Eng C Mater Biol Appl ; 102: 829-843, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31147055

RESUMO

The synthesis of nickel oxide nanoparticles (NiO NPs) and graphene/nickel oxide nanocomposites (Gr/NiO NCs) was performed using a simple chemical reduction method. Powder X-ray diffraction (XRD) and thermogravimetric analysis (TGA) were used to examine the crystalline nature and thermal stability of the synthesized NiO NPs and Gr/NiO NCs, respectively. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were utilized to observe the morphology of NiO NPs and Gr/NiO NCs and estimate their size range. TEM suggested that the NiO NPs were speared onto the surface of Gr nanosheet. The efficiency of NiO NPs and Gr/NiO NCs against extended spectrum ß-lacamase (ESBL) producing bacteria, which was confirmed by specific HEXA disc Hexa G-minus 24 (HX-096) and MIC strip methods (CLSI); namely Escherichia coli (E. coli) and Pseudomonas aeruginosa (P. aeruginosa) was investigated using the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) methods. MIC results suggested that the NiO NPs and Gr/NiO NCs possess maximum growth inhibition of 86%, 82% and 94%, 92% at 50 and 30 µg/mL concentrations, respectively. Similarly, both nanomaterials were found to inhibit the ß-lacamase enzyme at concentrations of 60 µg/mL and 40 µg/mL, respectively. The cytotoxicity of NiO NPs and Gr/NiO NCs was quantified against A549 human lung cancer cells. Cell death percentage values of 52% at 50 µg/mL against NiO NPs and 54% at 20 µg/mL against Gr/NiO NCs were obtained, respectively. The NCs were found to reduce cell viability, increase the level of reactive oxygen species (ROS) and modify both the mitochondrial membrane permeability and cell cycle arrest.


Assuntos
Escherichia coli/enzimologia , Grafite/farmacologia , Nanocompostos/química , Níquel/farmacologia , Pseudomonas aeruginosa/enzimologia , beta-Lactamases/biossíntese , Células A549 , Antibacterianos/farmacologia , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/patologia , Forma Celular/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Humanos , Concentração Inibidora 50 , Klebsiella pneumoniae/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Nanocompostos/ultraestrutura , Pseudomonas aeruginosa/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo
20.
Int J Biol Macromol ; 135: 931-939, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31170488

RESUMO

The sarcotesta of Punica granatum fruit contains an antimicrobial lectin called PgTeL. In this work, we evaluated the antibacterial activity of PgTeL against five drug-resistant Escherichia coli isolates able to produce ß-lactamases. Minimum inhibitory (MIC) and bactericidal (MBC) concentrations were determined by broth dilution. Morphometric and viability analyses were performed by flow cytometry, and ultrastructural changes were evaluated by scanning electron microscopy. Potential synergistic effects of PgTeL with antibiotics and anti-biofilm effect were also evaluated. PgTeL showed antibacterial activity against all isolates with MIC and MBC values ranging from 12.5 to 50.0 µg/mL and from 25.0 to 100.0 µg/mL, respectively. For most isolates, PgTeL postponed the growth start by at least ten hours. At the MIC, the lectin caused alterations in size, shape and structure of bacterial cells. The combination PgTeL-ceftazidime showed a synergistic effect for all isolates. Synergy was also detected with ampicillin (one isolate), carbenicillin (one isolate), cefotaxime (one isolate), cephalexin (four isolates) and cefuroxime (three isolates). PgTeL exhibited anti-biofilm activity against all isolates, causing ≥50% inhibition of biofilms at or above 6.25 µg/mL. The antibacterial effect of PgTeL and its synergy with antibiotics indicate that this fruit-derived molecule may have potential for future treatment of multidrug-resistant infections.


Assuntos
Antibacterianos/farmacologia , Escherichia coli/efeitos dos fármacos , Lythraceae/química , Lectinas de Plantas/farmacologia , Antibacterianos/química , Antibacterianos/isolamento & purificação , Biofilmes/efeitos dos fármacos , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Escherichia coli/metabolismo , Escherichia coli/ultraestrutura , Frutas/química , Testes de Sensibilidade Microbiana , Lectinas de Plantas/química , Lectinas de Plantas/isolamento & purificação , Resistência beta-Lactâmica , beta-Lactamases/biossíntese
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