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1.
J Glob Antimicrob Resist ; 27: 63-66, 2021 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-34482020

RESUMO

OBJECTIVES: The aim of this study was to characterise the co-occurrence of blaKPC and blaNDM in a K64-ST11 carbapenem-resistant Klebsiella pneumoniae strain. METHODS: Antimicrobial susceptibility was determined by the disk diffusion method. Whole-genome sequencing was performed using Illumina MiSeq and PacBio II sequencers. High-quality reads were de novo assembled using the SOAPdenovo package. Genome annotation was performed using the NCBI Prokaryotic Genome Annotation Pipeline (PGAP), and genome characteristics were analysed using bioinformatics methods. RESULTS: Klebsiella pneumoniae strain KPWX136 was resistant to most of the tested antibiotics, being susceptible only to polymyxin B and tigecycline. The genome of strain KPWX136 is composed of a single chromosome (5 473 976 bp) and six plasmids including pA (191 359 bp), pB (134 972 bp), pC (117 844 bp), pD (87 095 bp), pE (11 970 bp) and pF (5596 bp). Complete sequence analysis revealed the resistome of isolate KPWX136, which included blaKPC-2 and blaNDM-5 together with 23 other resistance genes, of which 6 resistance genes were located on the chromosome and 19 on plasmids. Virulome analysis showed that KPWX136 carried a large number of virulence-associated genes. Meanwhile, 26 genomic islands and 6 prophages were predicted within the genome. CONCLUSION: Genetic characterisation of K. pneumoniae KPWX136 co-harbouring blaNDM-5 and blaKPC-2 showed that it carried not only 25 resistance genes and a large number virulence factors but also various mobile genetic elements (MGEs) such as plasmids and genomic islands. Therefore, we must be alert to the transmission of resistance genes and virulence determinants via MGEs.

2.
J Med Microbiol ; 70(8)2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34397349

RESUMO

Introduction. Lactococcus petauri LZys1 (L. petauri LZys1) is a type of lactic acid bacteria (LAB), which was initially isolated from healthy human gut.Hypothesis/Gap Statement. It was previously anticipated that L. petauri LZys1 has potential characteristics of probiotic properties. The genetic structure and the regulation functions of L. petauri LZys1 need to be better revealed.Aim. The aim of this study was to detect the probiotic properties L. petauri LZys1 and to reveal the genome information related to its genetic adaptation and probiotic profiles.Methodology. Multiple in vitro experiments were carried out to evaluate its lactic acid-producing ability, resistance to pathogenic bacterial strains, auto-aggregation and co-aggregation ability, and so on. Additionally, complete genome sequencing, gene annotation, and probiotic associated gene analysis were performed.Results. The complete genome of L. petauri LZys1 comprised of 1 985 765 bp, with a DNA G+C content of 38.07 %, containing 50 tRNA, seven rRNA, and four sRNA. A total of 1931 genes were classified into six functional categories by Kyoto Encyclopaedia of Genes and Genomes (KEGG) database. The neighbour-joining phylogeny tree based on the whole genome of L. petauri LZys1 and other probiotics demonstrated that L. petauri LZys1 has a significant similarity to Lactococcus garvieae. The functional genes were detected to expound the molecular mechanism and biochemical processes of its potential probiotic properties, such as atpB gene.Conclusion. All the results described in this study, together with relevant information previously reported, made L. prtauri LZys1 a very interesting potential strain to be considered as a prominent candidate for probiotic use.


Assuntos
Trato Gastrointestinal/microbiologia , Genoma Bacteriano , Lactococcus , Probióticos , Animais , Bactérias/crescimento & desenvolvimento , Bactérias/patogenicidade , Sequência de Bases , Fezes/microbiologia , Genes Bacterianos , Humanos , Lactococcus/citologia , Lactococcus/genética , Lactococcus/isolamento & purificação , Lactococcus/fisiologia , Masculino , Anotação de Sequência Molecular , Mariposas/microbiologia , Filogenia , Polissacarídeos Bacterianos/biossíntese , Polissacarídeos Bacterianos/genética , Sequenciamento Completo do Genoma , Adulto Jovem
3.
Microb Pathog ; 160: 105162, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34461245

RESUMO

Heteroresistance is a poorly understood mechanism of resistance which refers to a phenomenon where there are different subpopulations of seemingly isogenic bacteria which exhibit a range of susceptibilities to a particular antibiotic. In the current study, we identified a multidrug-resistant, carbapenemase-positive K. pneumoniae strain SWMUF35 which was classified as susceptible to amikacin and resistant to meropenem by clinical diagnostics yet harbored different subpopulations of phenotypically resistant cells, and has the ability to form biofilm. Population analysis profile (PAP) indicated that SWMUF35 showed heteroresistance towards amikacin and meropenem which was considered as co-heteroresistant K. pneumoniae strain. In vitro experiments such as dual PAP, dual Times-killing assays and checkerboard assay showed that antibiotic combination therapy (amikacin combined with meropenem) can effectively combat SWMUF35. Importantly, using an in vivo mouse model of peritonitis, we found that amikacin or meropenem monotherapy was unable to rescue mice infected with SWMUF35. Antibiotic combination therapy could be a rational strategy to use clinically approved antibiotics when monotherapy would fail. Furthermore, our data warn that antibiotic susceptibility testing results may be unreliable due to undetected heteroresistance which can lead to treatment failure and the detection of this phenotype is a prerequisite for a proper choice of antibiotic to support a successful treatment outcome.


Assuntos
Amicacina , Carbapenêmicos , Animais , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Modelos Animais de Doenças , Klebsiella pneumoniae , Meropeném/farmacologia , Camundongos , Testes de Sensibilidade Microbiana , Falha de Tratamento
4.
J Med Microbiol ; 70(3)2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33528353

RESUMO

Introduction. Since mcr-1 was first reported in China, there have been ten variants of MCR appearing nationwide so far. Multidrug-resistant Enterobacteriaceae bacteria carrying both NDM and MCR have become a serious threat to global public health.Hypothesis/Gap Statement. The genetic structure of mcr-9 needs to be better understood in order to better prevent and control the transmission of drug-resistant genes.Aims. The aim of this study was to characterize the presence of two Enterobacter hormaechei isolates, which carries bla NDM-5 CME2 and the coexistence of mcr-9 and bla NDM-1 strain CMD2, which were isolated from a patient with diabetes in Sichuan, China.Methodology. The microbroth dilution method was used for antibiotic susceptibility. Conjugation experiment was used to investigate the transferability of bla NDM-1, bla NDM-5 and mcr-9. Whole-genome sequencing was performed on Illumina HiSeq platform. The ability of biofilm formation was detected by crystal-violet staining, the virulence of the bacteria was measured by Galleria mellonella killing assay.Results. bla NDM-5 carrier CME2 and CMD2 with bla NDM-1 and mcr-9 were resistant to carbapenems, ß-lactam, aminoglycoside, quinolone and tetracycline, while CMD2 was also resistant to colistin. Conjugation assay and plasmid replicon typing further demonstrated that both bla NDM-1 and bla NDM-5 were respectively present on the self-transferrable IncX3 plasmid, mcr-9 was located on the self-transferrable IncHI2 plasmid. Through the analysis of mcr-9 gene context, the structure was DUF4942-rcnR-rcnA-copS-IS903-mcr-9-wbuC-qseC-qseB-IS1R-ΔsilR-IS903, bla NDM-1 context was IS3000-ΔISAba125-IS5-bla NDM-1-ble-trpF-groS-groL-insE-ΔIS26 structure, bla NDM-5 structure was IS3000-bla NDM-5-ble-trpF-dsbC-ΔIS26-umuD-ISKox3-tnpR-parA. Biofilm formation of CME2 was stronger than CMD2. There was no significant difference in virulence between the two strains.Conclusion. This study reveals two multiple drug-resistant E. hormaechei isolates from diabetes patient samples. E. hormaechei carrying two NDM-resistant genes is already a serious threat, where MCR is an important cause of treatment failure in bacterial infections. This study is a reminder not only to prevent infection in patients with diabetes, but also to constantly monitor the epidemic and spread of the drug-resistant gene.


Assuntos
Enterobacteriáceas Resistentes a Carbapenêmicos/isolamento & purificação , Coinfecção/microbiologia , Complicações do Diabetes/microbiologia , Enterobacter/isolamento & purificação , Infecções por Enterobacteriaceae/microbiologia , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Biofilmes/crescimento & desenvolvimento , Enterobacteriáceas Resistentes a Carbapenêmicos/efeitos dos fármacos , Enterobacteriáceas Resistentes a Carbapenêmicos/genética , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Farmacorresistência Bacteriana Múltipla/genética , Enterobacter/efeitos dos fármacos , Enterobacter/genética , Genoma Bacteriano/genética , Humanos , Masculino , Testes de Sensibilidade Microbiana , Plasmídeos/genética , Fatores de Virulência/genética , Adulto Jovem
5.
Diagn Microbiol Infect Dis ; 99(3): 115263, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33248418

RESUMO

This study aimed to characterize molecular mechanism of 3 Salmonella enterica strains and novel mobile genetic elements identified in them. The strains, designated SW1, SW39, and SW109084, were obtained from diarrhea patients. The results of susceptibility testing showed SW39 was nonsusceptible to imipenem and cefotaxime. Whole genome sequencing was performed on Illumina HiSeq platform. Multilocus-sequence typing revealed SW1 belonged to ST2529 which was first confirmed in S. enterica, SW109084 was ST34 which was first reported in Enteritidis and SW39 was ST19. Resistome analysis showed SW1, SW109084, and SW39 carried 14, 19, and 17 antibiotic resistance genes. Seven transposons and 4 integrons were confirmed in these strains. Notably, a novel In6- and In7-like class 1 integron designated InSW39 and a novel transposon Tn5393k were identified in plasmid pSW39. The study of genomics and resistance in S. enterica plays a significant role in prevention and treatment of Salmonella infections.

6.
Front Microbiol ; 11: 598478, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33250886

RESUMO

Pseudomonas aeruginosa is the most relevant pathogen to the severe exacerbations of patients with chronic obstructive pulmonary disease (COPD). However, the genetic and functional characteristics of P. aeruginosa isolates from COPD airways still remain less understood. In this study, the genetic, phylogenetic, phenotypic, and transcriptional features of P. aeruginosa isolates from COPD sputa were comprehensively explored by susceptibility testing, comparative-genomic analysis, phylogenetic analysis, phenotypic profiling, and comparative-transcriptomic analysis. We found that P. aeruginosa was prevalent in elder COPD patients and highly resisted to many commonly used antibiotics. P. aeruginosa COPD isolates harbored a substantial number of variant sites that might influence the primary metabolism and substance transport system. These isolates were discretely distributed in the phylogenetic tree and clustered with internationally collected P. aeruginosa in two major groups, and could be classified into three groups according to their differences in virulence-related phenotypes. Furthermore, the transcriptional patterns of COPD isolates could be classified into PAO1-like group with reduced protein secretion and motility and PAO1-distinct group with decreased substance transport but enhanced primary metabolism. In conclusion, this study demonstrates that P. aeruginosa isolates from COPD patients have abundant genetic and phenotypic diversity, and provides an important reference for further exploring the survival strategy of P. aeruginosa in COPD airways and the development of anti-pseudomonal therapy.

7.
Microb Pathog ; 149: 104536, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32980472

RESUMO

Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) and resistant bacterial co-infection is a serious threat to pig farms. This study was aimed to determine the characteristics of the co-infection of PRRSV with resistant bacterial strains in pig farms. The presence of the PRRSV orf5 gene was confirmed by RT-PCR from 395 samples. Bacterial strains were isolated from PRRSV positive samples. Antimicrobial drug susceptibility was determined by the Kirby-Bauer method. Resistant genes were determined by PCR amplification and sequencing. The whole genome of carbapenems resistant E.coli was sequenced and analyse. A total of 75 samples were PRRSV positive, and 45 different orf5 sequences were finally determined. Phylogenetic analysis showed that 45 sequences are clustered into four groups, including JXA1-like, NADC30-like, GD-QY2-like, and CH-1a-like viruses. Twenty-one samples were identified with PRRSV and amoxicillin resistance bacterial co-infection, and 23 were found with amoxicillin resistance (including 15 Escherichia coli, 3 Klebsiella pneumoniae, 2 Haemophilus parasuis, 1 Actinobacillus pleuropneumoniae, 1 Pasteurella multocida, and 1 Proteus mirabilis). All bacterial strains were resistant to the most commonantibiotics and were carriers of a large number of resistance genes. Whole-genome sequencing of E. coli ScEc7 yielded 113 scaffolds of genome DNA, one IncX3 plasmid pScEc7-NDM-5 (46,161 bp) and one IncF plasmid pScEc7-CTX-M (129,978 bp). It carries19 resistance genes, 8 virulence factors, and several mobile genetic elements. The results obtained let us to concluded that: (1) Co-infection is common in pig farms. (2) The orf5 gene continues to undergo its sequences divergence. (3) The bacterial carrying diverse resistance genes were resistant to most of the commonly used antibiotics. (4) Carbapenems resistant isolate has a large number of resistance genes, virulence factors, and MGEs. Therefore, continuous study of the characteristic of PRRSV and resistant bacterial co-infection is necessary for healthy pig aquaculture.


Assuntos
Coinfecção , Síndrome Respiratória e Reprodutiva Suína , Vírus da Síndrome Respiratória e Reprodutiva Suína , Animais , China/epidemiologia , Coinfecção/epidemiologia , Coinfecção/veterinária , Escherichia coli/genética , Variação Genética , Incidência , Filogenia , Síndrome Respiratória e Reprodutiva Suína/epidemiologia , Vírus da Síndrome Respiratória e Reprodutiva Suína/genética , Suínos
8.
Infect Drug Resist ; 13: 1527-1536, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32547122

RESUMO

Purpose: To characterize the genetic feature of a multi-drug-resistant Aeromonas caviae strain isolated from the diarrhea sample of a 45-year-old male patient with acute diarrhea. Materials and Methods: Whole-genome of the A. caviae strain SCAc2001 was sequenced via the Illumina system, followed by a series of bioinformatic analyses to describe the genetic feature. Results: The genome sequence of A. caviae SCAc2001 was assembled into 340 scaffolds (305 of them were > 1000 bp in length and 4,487,370 bp in total) with an average G+C content of 61.09%. Phylogenetic analysis showed that the A. caviae SCAc2001 strain was highly similar to the A. caviae strain R25-2 and T25-39. Resistome analysis identified that A. caviae SCAc2001 carried 13 antimicrobial resistance genes, including ß-lactams (bla KPC, bla CTX-M-14, bla TEM-1, bla OXA-10, bla OXA-427, bla VEB-3 and bla MOX-6), aminoglycosides (aadA1), fluoroquinolones (aac(6')-Ib-cr), phenicol resistance (catB3), sulfonamide (sul1), trimethoprim (dfrA5) and colistin resistance (mcr-3.3).And also, A. caviae ScAc2001 carried 54 putative virulence genes including the type IV pilus, fimbria, flagellarthe, and hemolysin A encoding genes, and 12 pathogen-host interactions (PHI) genes. There were also four genomic islands and eight prophages in the genome of A. caviae ScAc2001. In addition, A. caviae SCAc2001 also carried three secondary metabolism products coding clusters including nonribosomal peptide synthetases (nrps), hserlactone and bacteriocin. Conclusion: A. caviae ScAc2001 carries many resistance genes, a variety of virulence factors, PHI genes and four genomic islands and eight prophages, which poses a severe threat to infectious diseases control strategies, diagnosis methods and clinical treatment.

9.
Infect Drug Resist ; 13: 855-865, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32273730

RESUMO

Purpose: To characterize the genetic feature of the carbapenems resistant Acinetobacter johnsonii strain Acsw19 isolated from municipal sludge. This strain was found to carry two copies of bla NDM-1, cmlB1-like gene, and bla OXA-211-like gene along with other 8 antimicrobial resistance genes, 3 plasmids, 15 genomic islands and 8 prophages. Methods: A carbapenem-resistant Acinetobacter johnsonii strain Acsw19 isolated from municipal sludge was subjected to whole-genome sequencing (WGS) via the PacBio and Illumina MiSeq platforms. Thereafter, the characteristic was analyzed by a series of bioinformatics software. Results: The results showed that the genome of Acsw19 was consisted of a 3,433,749 bp circular chromosome and 3 circular plasmids, pAcsw19-1 (11,161 bp), pAcsw19-2 (351,885 bp) and pAcsw19-3 (38,391bp), respectively. Resistome analysis showed that Acsw19 carried 12 antimicrobial resistance genes, including 6 [cmlB1-like, bla NDM-1, bla OXA-58, aph (3')-VIa, msr(E) and mph(E)] in the plasmid pAcsw19-2 and 6 (bla OXA-211-like, bla NDM-1, aph(3")-Ib, aph(6)-Id, sul2, and floR) in the chromosome genome. Specifically, the cmlB1-like gene shared 86.33%, 71.7% and 71.9% similarities with the cmlB1, cmlA4 and cmlA8 gene, and the bla OXA-211-like gene shared 94.4%, 95.39% and 96.36% similarities with bla OXA-211, bla OXA-643 and bla OXA-652, at the nucleotide level, respectively. Phylogenetic analysis showed that the bla OXA-211-like gene and cmlB1-like gene had the closest evolutionary relationship with bla OXA-643 and cmlB1, respectively. These results indicated that the bla OXA-211-like and cmlB1-like genes identified in the current study should be the novel variant resistance genes. Conclusion: Carrying of two copies of bla NDM-1, cmlB1-like, bla OXA-211-like and along with other 8 antimicrobial resistance genes, 3 plasmids, 15 genomic islands and 8 prophages Acinetobacter johnsonii strain might increase the possibility of spreading of resistance genes.

10.
J Glob Antimicrob Resist ; 20: 272-274, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32007616

RESUMO

OBJECTIVES: The aim of this study was to characterise a high biofilm-forming capacity, hypermucoviscous, blaKPC and blaNDM co-producing Klebsiella pneumoniae strain (KSH203). METHODS: Antimicrobial susceptibility, biofilm formation and hypermucoviscous phenotype were determined by the disk diffusion method, crystal violet staining and positive string test, respectively. Whole-genome sequencing was performed using a PacBio RS II Sequencer. High-quality reads were de novo assembled using Celera Assembler v.8.0. Genome annotation was performed using the NCBI Prokaryotic Genome Annotation Pipeline (PGAP), and the genome characteristics were analysed by bioinformatics methods. RESULTS: Klebsiella pneumoniae strain KSH203 was resistant to all antibiotics tested but was only intermediate-resistant to polymyxin B. This strain showed high biofilm-forming ability and a hypermucoviscous phenotype with serotype K25 belonging to the ST11 clone. KSH203 consists of a 5 464 059-bp single chromosome and four plasmids including pKSH203-NDM (53 144 bp), pKSH203-KPC (159 467 bp), pKSH203-CTX-M-3 (156 910 bp) and pKSH203-qnrS (253 705 bp). A total of 44 antimicrobial resistance genes and a large number virulence-associated genes were identified in the genome of strain KSH203. CONCLUSION: In this study, we illustrate the whole genome sequence of high biofilm-forming capacity, hypermucoviscous K. pneumoniae isolate KSH203 with capsular serotype K25 belonging to ST11 isolated from a patient in China, which carried a large number of antimicrobial resistance genes and virulence-associated genes. Future studies are needed to be aware of dissemination of this type of strain among environmental, animal and human isolates.


Assuntos
Farmacorresistência Bacteriana Múltipla , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/classificação , Sequenciamento Completo do Genoma/métodos , China , Tamanho do Genoma , Genoma Bacteriano , Humanos , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/isolamento & purificação , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Plasmídeos/genética , Polimixina B/farmacologia , Sorogrupo
11.
Chemosphere ; 246: 125735, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31911327

RESUMO

Phosphorus and heavy metals are discarded to the domestic sewage in our daily life, it is necessary to find easy methods for phosphorus and heavy metals accumulation. Here, a group of short peptides (ChBpHs) were found to react with hydrogen phosphate forming insoluble substances. ChBpHs are composed by a choline binding peptides (ChBp) and a C-terminal histidine rich tail. The reaction region to hydrogen phosphate was determined at 1-18th amino acid in ChBp. The affinities of ChBpHs are different, with minimum react concentrations of Na2HPO4 ranging from 2 to 12 mM. In addition, the C-terminal histidine tail enables ChBpHs with affinities to metal ions in vitro. Prokaryotic expression of ChBpH1 in Escherichia coli resulted in the reduction of soluble hydrogen phosphate in the culture medium. The accumulation of phosphate is time and concentration dependent, maximum reduction was detected at 24 h post induction (23% in phosphate rich medium and 14% in normal medium). The reduction of nickel ions (about 20%) was only detected after cells were broken. In conclusion, this preliminary investigation of ChBpHs indicates the potential applications for bioconcentration of soluble phosphate in the future.


Assuntos
Metais Pesados/química , Peptídeos/química , Fosfatos/química , Eliminação de Resíduos Líquidos/métodos , Escherichia coli , Histidina , Hidrogênio , Íons , Níquel , Fósforo , Esgotos/química
12.
Infect Drug Resist ; 12: 2819-2826, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31571938

RESUMO

Background: Emergence of bla KPC and bla NDM co-producing Klebsiella pneumoniae strains have led to the limited therapeutic options for clinical treatment. Understanding the diversity and frequency of resistance and virulence genes of these isolates is of great significance. Purpose: The aim of this study is to research the diversity and frequency of resistance and virulence genes in the bla KPC and bla NDM co-producing Klebsiella pneumoniae strains. Methods and Results: In this study, 117 K. pneumonia strains were isolated from China, and among of which, 24 were found to be bla KPC and bla NDM co-producing with significant resistance against almost all the commonly used antibiotics. Additionally, 4 strains were hypermucoviscous and 8 showed high serum resistance. Overall, bla SHV, bla CTX-M, tetA and sul1 resistance genes found in 100% of the isolates, followed by bla TEM (95.8%), oqxA/B (91.7%), qnrB (87.5%), aac(6')Ib-cr (83.3%), bla DHA (79.2%), rmtB (66.7%), qnrS (54.2%), cat(54.2%), floR (50.0%), sul2 (45.8%) cmlA (20.8%)andbla CMY (8.33%), respectively. What' more, seven bla CTX-M subtypes [bla CTX-M-14 (n=18), bla CTX-M-3(n=11), bla CTX-M-65 (n=4), bla CTX-M-15 (n=3), bla CTX-M-28 (n=2), bla CTX-M-55 (n=2), bla CTX-M-22 (n=1)] and six bla SHV subtypes [bla SHV-12(n=16), bla SHV-11 (n=4), bla SHV-2a(n=1), bla SHV-1(n=1), bla SHV-38(n=1) and bla SHV-28(n=1)] were detected. The frequency of virulence genes was as follows: 100% for entB, ybtS and irp, 95.8% for mrkD, 91.66% for fimH, 79.2% for iutA, 62.5% for iroBCDE, aerobactin and kfu, 66.7% for allS, 45.8% for wcaG, 37.5% for rmpA, 20.8% for pagO and 16.7% for magA. Conclusion: From this study, we concluded that the bla KPC and bla NDM co-producing Klebsiella pneumoniae strains have a high diversity and frequency of resistance and virulence genes. This study may offer hospitals important information about the control of infections caused by bla KPC and bla NDM co-producing Klebsiella pneumoniae.

13.
Antibiotics (Basel) ; 8(3)2019 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-31527387

RESUMO

Carbapenem-resistant Enterobacteriaceae have been a global public health issue in recent years. Here, a carbapenem-resistant Kluyvera cryocrescens strain SCW13 was isolated from hospital sewage, and was then subjected to whole-genome sequencing (WGS). Based on WGS data, antimicrobial resistance genes were identified. Resistance plasmids were completely circularized and further bioinformatics analyses of plasmids were performed. A conjugation assay was performed to identify a self-transmissible plasmid mediating carbapenem resistance. A phylogenetic tree was constructed based on the core genome of publicly available Kluyvera strains. The isolate SCW13 exhibited resistance to cephalosporin and carbapenem. blaNDM-1 was found to be located on a ~53-kb self-transmissible IncX3 plasmid, which exhibited high similarity to the previously reported pNDM-HN380, which is an epidemic blaNDM-1-carrying IncX3 plasmid. Further, we found that SCW13 contained a chromosomal blaKLUC-2 gene, which was the probable origin of the plasmid-born blaKLUC-2 found in Enterobacter cloacae. Phylogenetic analysis showed that K. cryocrescens SCW13 exhibited a close relationship with K. cryocrescens NCTC10483. These findings highlight the further dissemination of blaNDM through clonal IncX3 plasmids related to pNDM-HN380 among uncommon Enterobacteriaceae strains, including Kluyvera in this case.

14.
Pathog Dis ; 77(4)2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-31348491

RESUMO

Pseudomonas aeruginosa is an important opportunistic pathogen normally associated with increasing morbidity and mortality of immunocompromised hosts with respiratory infections. The phenotypic and genetic features of P. aeruginosa from patients with chronic obstructive pulmonary disease (COPD) remain poorly understood. By using the sputum samples of 25 hospitalized COPD patients from the affiliated hospital of Southwest Medical University (China), we identified a P. aeruginosa isolate, COP2, which showed multiple antibiotic resistance and enhanced Pseudomonas quinolone signal (PQS) production but decreased motility, biofilm formation and virulence compared with the model strain PAO1. Importantly, COP2 harbored a substantial amount of mutations that might influence the functions of 1771 genes in the genome and the evolutionary status of this isolate was clearly distinct from the PAO1 lineage. Accordingly, COP2 had a discrepant transcriptional pattern relating to flagellar assembly, antibiotic resistance, biofilm and PQS production, and can increase the capacities of compound degradation in response to resource/space stresses. Therefore, the identification of COP2 in this study provides preliminary information regarding the genetic features and survival strategy of P. aeruginosa in colonizing COPD lungs and lays the foundations for further understanding of the pathogenic mechanisms of pseudomonal infections.


Assuntos
Pulmão/microbiologia , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/fisiologia , Doença Pulmonar Obstrutiva Crônica/complicações , Biofilmes/crescimento & desenvolvimento , China , Farmacorresistência Bacteriana , Humanos , Locomoção , Mutação , Pseudomonas aeruginosa/isolamento & purificação , Quinolonas , Escarro , Transcriptoma , Virulência , Sequenciamento Completo do Genoma
15.
BMC Biol ; 17(1): 20, 2019 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-30841874

RESUMO

BACKGROUND: Microbial communities are susceptible to the public goods dilemma, whereby individuals can gain an advantage within a group by utilizing, but not sharing the cost of producing, public goods. In bacteria, the development of quorum sensing (QS) can establish a cooperation system in a population by coordinating the production of costly and sharable extracellular products (public goods). Cooperators with intact QS system and robust ability in producing public goods are vulnerable to being undermined by QS-deficient defectors that escape from QS but benefit from the cooperation of others. Although microorganisms have evolved several mechanisms to resist cheating invasion in the public goods game, it is not clear why cooperators frequently coexist with defectors and how they form a relatively stable equilibrium during evolution. RESULTS: We show that in Pseudomonas aeruginosa, QS-directed social cooperation can select a conditional defection strategy prior to the emergence of QS-mutant defectors, depending on resource availability. Conditional defectors represent a QS-inactive state of wild type (cooperator) individual and can invade QS-activated cooperators by adopting a cheating strategy, and then revert to cooperating when there are abundant nutrient supplies irrespective of the exploitation of QS-mutant defector. Our mathematical modeling further demonstrates that the incorporation of conditional defection strategy into the framework of iterated public goods game with sound punishment mechanism can lead to the coexistence of cooperator, conditional defector, and defector in a rock-paper-scissors dynamics. CONCLUSIONS: These findings highlight the importance of behavioral heterogeneity in stabilizing the population structure and provide a potential reasonable explanation for the maintenance and evolution of cooperation in microbial communities.


Assuntos
Evolução Biológica , Modelos Biológicos , Pseudomonas aeruginosa/fisiologia , Percepção de Quorum
16.
Nat Microbiol ; 4(3): 459-469, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30617346

RESUMO

Pseudomonas aeruginosa is a versatile Gram-negative pathogen with intricate intracellular regulatory networks that enable it to adapt to and flourish in a variety of biotic and abiotic habitats. However, the mechanism permitting the persistent survival of P. aeruginosa within host tissues and causing chronic symptoms still remains largely elusive. By using in situ RNA sequencing, here we show that P. aeruginosa adopts different metabolic pathways and virulence repertoires to dominate the progression of acute and chronic lung infections. Notably, a virulence factor named TesG, which is controlled by the vital quorum-sensing system and secreted by the downstream type I secretion system, can suppress the host inflammatory response and facilitate the development of chronic lung infection. Mechanically, TesG can enter the intracellular compartment of macrophages through clathrin-mediated endocytosis, competitively inhibit the activity of eukaryotic small GTPase and thus suppress subsequent neutrophil influx, cell cytoskeletal rearrangement of macrophages and the secretion of cytokines and chemokines. Therefore, the identification of TesG in this study reveals a type I secretion apparatus of P. aeruginosa that functions during the host-pathogen interaction, and may open an avenue for the further mechanistic study of chronic respiratory diseases and the development of antibacterial therapy.


Assuntos
Interações Hospedeiro-Patógeno , Infecções por Pseudomonas/imunologia , Pseudomonas aeruginosa/metabolismo , Sistemas de Secreção Tipo I/metabolismo , Fatores de Virulência/metabolismo , Animais , Doença Crônica , Feminino , Humanos , Inflamação , Pulmão/microbiologia , Redes e Vias Metabólicas , Camundongos , Camundongos Endogâmicos C57BL , Infecções por Pseudomonas/patologia , Percepção de Quorum , Análise de Sequência de RNA , Sistemas de Secreção Tipo I/genética , Virulência , Fatores de Virulência/genética
17.
J Glob Antimicrob Resist ; 16: 4-5, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30472400

RESUMO

OBJECTIVES: Acinetobacter spp. isolates carrying the blaNDM-1 gene are frequently reported. However, most reported blaNDM-1 genes are carried by clinical strains. Here we report a carbapenem-resistant Acinetobacter towneri isolate from hospital sewage in China co-harbouring blaNDM-1 and blaOXA-58 in the genome. METHODS: Whole-genome sequencing was performed using a single molecule, real-time (SMRT) sequencing platform with a Pacific Biosciences RS II Sequencer and MiSeq system. Reads were de novo assembled using Celera Assembler v.8.0. Genome annotation was performed using the NCBI Prokaryotic Genome Annotation Pipeline (PGAP), and the genome sequence was analysed by bioinformatics methods. RESULTS: The 2963729-bp genome with a G+C content of 41.30% displayed 11 antimicrobial resistance genes, including blaNDM-1 and blaOXA-58. Meanwhile, 2 plasmids and 19 genomic islands were predicted within the genome. CONCLUSION: The whole-genome sequence reported here can be compared with other genomes of NDM-1-producing Acinetobacter spp. These data could facilitate further understanding of the specific genomic features of carbapenem-resistant Acinetobacter spp. in China.


Assuntos
Acinetobacter/genética , Farmacorresistência Bacteriana Múltipla/genética , Genoma Bacteriano , Hospitais , Esgotos/microbiologia , Acinetobacter/enzimologia , China , Testes de Sensibilidade Microbiana , Plasmídeos/genética , Sequenciamento Completo do Genoma , beta-Lactamases/genética
18.
Microb Pathog ; 128: 1-6, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30576714

RESUMO

Carbapenem-resistant Enterobacteriaceae strains as a new serious threat for the public health have been increasingly reported worldwide. In this study, one multi-resistant Escherichia coli strain ZSH6 which co-carried blaKPC-2, blaNDM-5 and blaCTX-M, was isolated from human blood sample. By using plasmid conjugation experiments, ZSH6 was found to harbor three plasmids carrying the blaNDM-5 gene, the blaKPC-2 and blaCTX-M gene, respectively. Whole-genome sequencing of ZSH6 yielded 122 scaffolds of chromosomal DNA and three circular plasmids including pZSH6-blaKPC-2 (46,319 bp), pZSH6-blaNDM-5 (46,161bp) and pZSH6-blaCTX-M (184,723). The isolate was classified to Sequence Type 2 and to the O89: H10 serotype. The results of genome analyses revealed that ZSH6 carried three virulence factors (capU, gad and iss) and twenty resistance genes [blaKPC-2blaNDM-5, blaCTX-M-3, blaCTX-M-65, blaTEM-1, floR, tet(A), tet(B), dfrA17, aadA5, sul1, mdf(A), mph(A), erm(B), aph(3')-Ia, aph(3')-Ib, aph(4)-Ia, aph(6)-Id, aac(3)-Iva, aac(3)-IId]. Therefore, the co-existence of such a large number of resistance genes in multiple plasmids making ZSH6 highly resistant to almost all kinds of commonly used antibiotics, and brings a serious challenge for resistance control and clinical treatment of infections caused by this bacterium.


Assuntos
Farmacorresistência Bacteriana Múltipla/genética , Proteínas de Escherichia coli/genética , Escherichia coli/genética , Plasmídeos/genética , Sorogrupo , beta-Lactamases/genética , Idoso de 80 Anos ou mais , Antibacterianos/farmacologia , Enterobacteriáceas Resistentes a Carbapenêmicos , China , Escherichia coli/classificação , Escherichia coli/efeitos dos fármacos , Escherichia coli/patogenicidade , Infecções por Escherichia coli/sangue , Infecções por Escherichia coli/microbiologia , Genes Bacterianos/genética , Genoma Bacteriano , Genótipo , Humanos , Masculino , Filogenia , Pneumonia/microbiologia , Fatores de Virulência/genética , Sequenciamento Completo do Genoma
19.
Diagn Microbiol Infect Dis ; 93(4): 355-361, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30552032

RESUMO

Carbapenem-resistant Klebsiella pneumoniae (CRKP) has become a major cause of nosocomial infections and posed challenges on clinical treatments. The main objective of this study was to determinate the genetic characteristics of the NDM-19-producing CRKP strain SCM96. From 2015 to 2017, 18 CRKP strains were recovered from sputum samples of patients in respiratory medicine in 6 hospitals from 5 provinces and cities in China. Polymerase chain reaction results for carbapenem resistance genes detection showed strain SCM96 carried blaNDM-19. Three types of transconjugants harboring different plasmids were selected by conjugation experiment. The Whole Genome Sequencing (WGS) was performed using the PacBio RS platform. The genome size of SCM96 was 5,579,775 bp and composed of chromosomal DNA (5,398,745 bp) and 2 plasmids, IncFII type plasmid pSCM96-1 (134,869 bp) and IncX3 type plasmid pSCM96-2 (46,161 bp). SCM96 belonged to ST15 and K28. In addition to the 4 antibiotic resistance genes located in the chromosome, pSCM96-1 carried a complex resistance region containing 17 resistance genes and several mobile genetic elements (MGEs) like △Tn6029, In4-like integron, and Tn3, and pSCM96-2 had only 1 blaNDM-19 gene. As far as we know, this was the first description of blaNDM-19 in K. pneumoniae. Up to 22 antibiotic resistance genes, several important MGEs, and transferable plasmids might increase the possibility of co-spreading of blaNDM-19 with other resistance genes.


Assuntos
Enterobacteriáceas Resistentes a Carbapenêmicos/enzimologia , Enterobacteriáceas Resistentes a Carbapenêmicos/genética , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/enzimologia , Klebsiella pneumoniae/genética , Plasmídeos/análise , beta-Lactamases/genética , Enterobacteriáceas Resistentes a Carbapenêmicos/isolamento & purificação , China , Cidades , Conjugação Genética , Transferência Genética Horizontal , Genes Bacterianos , Hospitais , Humanos , Sequências Repetitivas Dispersas , Klebsiella pneumoniae/isolamento & purificação , Reação em Cadeia da Polimerase , Infecções Respiratórias/microbiologia , Escarro/microbiologia , Sequenciamento Completo do Genoma
20.
Front Microbiol ; 9: 2287, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30364310

RESUMO

It is reported that a wide range of bacterial infections are polymicrobial, and the members in a local microcommunity can influence the growth of neighbors through physical and chemical interactions. Pseudomonas aeruginosa is an important opportunistic pathogen that normally causes a variety of acute and chronic infections, and clinical evidences suggest that P. aeruginosa can be frequently coisolated with other pathogens from the patients with chronic infections. However, the interspecific interaction and the coexisting mechanism of P. aeruginosa with coinfecting bacterial species during evolution still remain largely unclear. In this study, the relationships of P. aeruginosa with other Gram-positive (Staphylococcus aureus) and Gram-negative (Klebsiella pneumoniae) are investigated by using a series of on-plate proximity assay, in vitro coevolution assay, and RNA-sequencing. We find that although the development of a quorum-sensing system contributes P. aeruginosa a significant growth advantage to compete with S. aureus and K. pneumoniae, the quorum-sensing regulation of P. aeruginosa will be decreased during evolution and thus provides a basis for the formation of interspecific coexistence. The results of comparative transcriptomic analyses suggest that the persistent survival of S. aureus in the microcommunity has no significant effect on the intracellular transcriptional pattern of P. aeruginosa, while a more detailed competition happens between P. aeruginosa and K. pneumoniae. Specifically, the population of P. aeruginosa with decreased quorum-sensing regulation can still restrict the proportion increase of K. pneumoniae by enhancing the type VI secretion system-elicited cell aggressivity during further coevolution. These findings provide a general explanation for the formation of a dynamic stable microcommunity consisting of more than two bacterial species, and may contribute to the development of population biology and clinical therapy.

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