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1.
Infect Genet Evol ; 117: 105542, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38122920

RESUMO

Emergence of carbapenem-resistant A. baumannii (CRAB) is a global, ongoing healthcare concern. CRAB is among the topmost priority pathogens, with various studies focusing on its global population structure and resistant allelic profiles. However, carbapenem-susceptible A. baumannii (CSAB) isolates are often overlooked due to their sensitivity to beta-lactams, which can provide important insights into origin of CRAB lineages and isolates. In the present study, we report genomic investigation of CRAB and CSAB coexisting in Indian hospital setting. MLST based population structure and phylogenomics suggest they mainly follow distinct evolutionary routes forming two phylogroups. PG-I exclusively for a successful clone (ST2) of CRAB and PG-II comprises diversified CSAB isolates except PG3373, which is CRAB. Additionally, there are few CRAB isolates not belonging to PG-I and sharing clonal relationship with CSAB isolates indicating role of genome plasticity towards extensive drug resistance in the nosocomial environment. Further, genealogical analysis depicts prominent role of recombination in emergence and evolution of a major CRAB lineage. Further, CRAB isolates are enriched in resistomes as compared to CSAB isolates, which were encoded on the genomic island. Such comparative genomic insights will aid in our understanding and localized management of rapidly evolving pandrug resistant nosocomial pathogens.


Assuntos
Infecções por Acinetobacter , Acinetobacter baumannii , Infecção Hospitalar , Humanos , Carbapenêmicos/farmacologia , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Acinetobacter baumannii/genética , beta-Lactamases/genética , Tipagem de Sequências Multilocus , Atenção Terciária à Saúde , Infecções por Acinetobacter/tratamento farmacológico , Infecções por Acinetobacter/epidemiologia , Suscetibilidade a Doenças , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/tratamento farmacológico , Testes de Sensibilidade Microbiana , Proteínas de Bactérias/genética
2.
Diabetes ; 72(11): 1729-1734, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37639628

RESUMO

ONECUT1 (also known as HNF6) is a transcription factor involved in pancreatic development and ß-cell function. Recently, biallelic variants in ONECUT1 were reported as a cause of neonatal diabetes mellitus (NDM) in two subjects, and missense monoallelic variants were associated with type 2 diabetes and possibly maturity-onset diabetes of the young (MODY). Here we examine the role of ONECUT1 variants in NDM, MODY, and type 2 diabetes in large international cohorts of subjects with monogenic diabetes and >400,000 subjects from UK Biobank. We identified a biallelic frameshift ONECUT1 variant as the cause of NDM in one individual. However, we found no enrichment of missense or null ONECUT1 variants among 484 individuals clinically suspected of MODY, in whom all known genes had been excluded. Finally, using a rare variant burden test in the UK Biobank European cohort, we identified a significant association between heterozygous ONECUT1 null variants and type 2 diabetes (P = 0.006) but did not find an association between missense variants and type 2 diabetes. Our results confirm biallelic ONECUT1 variants as a cause of NDM and highlight monoallelic null variants as a risk factor for type 2 diabetes. These findings confirm the critical role of ONECUT1 in human ß-cell function.

3.
Front Cell Infect Microbiol ; 13: 1151594, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37153161

RESUMO

Introduction: Burkholderia cepacia complex (Bcc) clonal complex (CC) 31, the predominant lineage causing devastating outbreaks globally, has been a growing concern of infections in non-cystic fibrosis (NCF) patients in India. B. cenocepacia is very challenging to treat owing to its virulence determinants and antibiotic resistance. Improving the management of these infections requires a better knowledge of their resistance patterns and mechanisms. Methods: Whole-genome sequences of 35 CC31 isolates obtained from patient samples, were analyzed against available 210 CC31 genomes in the NCBI database to glean details of resistance, virulence, mobile elements, and phylogenetic markers to study genomic diversity and evolution of CC31 lineage in India. Results: Genomic analysis revealed that 35 isolates belonging to CC31 were categorized into 11 sequence types (ST), of which five STs were reported exclusively from India. Phylogenetic analysis classified 245 CC31 isolates into eight distinct clades (I-VIII) and unveiled that NCF isolates are evolving independently from the global cystic fibrosis (CF) isolates forming a distinct clade. The detection rate of seven classes of antibiotic-related genes in 35 isolates was 35 (100%) for tetracyclines, aminoglycosides, and fluoroquinolones; 26 (74.2%) for sulphonamides and phenicols; 7 (20%) for beta-lactamases; and 1 (2.8%) for trimethoprim resistance genes. Additionally, 3 (8.5%) NCF isolates were resistant to disinfecting agents and antiseptics. Antimicrobial susceptibility testing revealed that majority of NCF isolates were resistant to chloramphenicol (77%) and levofloxacin (34%). NCF isolates have a comparable number of virulence genes to CF isolates. A well-studied pathogenicity island of B. cenocepacia, GI11 is present in ST628 and ST709 isolates from the Indian Bcc population. In contrast, genomic island GI15 (highly similar to the island found in B. pseudomallei strain EY1) is exclusively reported in ST839 and ST824 isolates from two different locations in India. Horizontal acquisition of lytic phage ST79 of pathogenic B. pseudomallei is demonstrated in ST628 isolates Bcc1463, Bcc29163, and BccR4654 amongst CC31 lineage. Discussion: The study reveals a high diversity of CC31 lineages among B. cenocepacia isolates from India. The extensive information from this study will facilitate the development of rapid diagnostic and novel therapeutic approaches to manage B. cenocepacia infections.


Assuntos
Anti-Infecciosos , Infecções por Burkholderia , Burkholderia cenocepacia , Complexo Burkholderia cepacia , Sepse , Humanos , Burkholderia cenocepacia/genética , Filogenia , Infecções por Burkholderia/epidemiologia , Complexo Burkholderia cepacia/genética , Genômica , Fibrose
4.
PLoS Biol ; 20(11): e3001878, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36399436

RESUMO

Hypermutation due to DNA mismatch repair (MMR) deficiencies can accelerate the development of antibiotic resistance in Pseudomonas aeruginosa. Whether hypermutators generate resistance through predominantly similar molecular mechanisms to wild-type (WT) strains is not fully understood. Here, we show that MMR-deficient P. aeruginosa can evolve resistance to important broad-spectrum cephalosporin/beta-lactamase inhibitor combination antibiotics through novel mechanisms not commonly observed in WT lineages. Using whole-genome sequencing (WGS) and transcriptional profiling of isolates that underwent in vitro adaptation to ceftazidime/avibactam (CZA), we characterized the detailed sequence of mutational and transcriptional changes underlying the development of resistance. Surprisingly, MMR-deficient lineages rapidly developed high-level resistance (>256 µg/mL) largely without corresponding fixed mutations or transcriptional changes in well-established resistance genes. Further investigation revealed that these isolates had paradoxically generated an early inactivating mutation in the mexB gene of the MexAB-OprM efflux pump, a primary mediator of CZA resistance in P. aeruginosa, potentially driving an evolutionary search for alternative resistance mechanisms. In addition to alterations in a number of genes not known to be associated with resistance, 2 mutations were observed in the operon encoding the RND efflux pump MexVW. These mutations resulted in a 4- to 6-fold increase in resistance to ceftazidime, CZA, cefepime, and ceftolozane-tazobactam when engineered into a WT strain, demonstrating a potentially important and previously unappreciated mechanism of resistance to these antibiotics in P. aeruginosa. Our results suggest that MMR-deficient isolates may rapidly evolve novel resistance mechanisms, sometimes with complex dynamics that reflect gene inactivation that occurs with hypermutation. The apparent ease with which hypermutators may switch to alternative resistance mechanisms for which antibiotics have not been developed may carry important clinical implications.


Assuntos
Pseudomonas aeruginosa , Inibidores de beta-Lactamases , Inibidores de beta-Lactamases/farmacologia , Pseudomonas aeruginosa/genética , Ceftazidima/farmacologia , Cefalosporinas/farmacologia , Antibacterianos/farmacologia
5.
Data Brief ; 42: 108145, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35515983

RESUMO

Genus Pseudoxanthomonas represents a relatively newly characterized group of gamma-proteobacterium of environmental origin. Species of the genus have very similar morphology to strains belonging to Xanthomonas, Xylella and Stenotrophomonas. However, the genome resource of this genus was largely unexplored. The species belonging to the genus are from a wide range of environmental sites including hydrocarbon polluted fields. Here, we have provided the whole genome sequence of all available type strains of the genus of Pseudoxanthomonas. In order to deduce the differences with closely related genera, we have employed the whole genome-based investigation of the type species of genus Pseudoxanthomonas.

7.
Genomics ; 112(6): 4171-4178, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32653516

RESUMO

We report first complete genomic investigation of extensive drug resistance (XDR) in a nosocomial Stenotrophomonas maltophilia complex strain that is resistant to mainstream drugs (trimethoprim/sulfamethoxazole and levofloxacin). Comprehensive genomic investigation revealed its exclusive fourteen dynamic regions and highly enriched resistome comprising of two sulfonamide resistance genes on two diverse super-integrons of chromosomal origin. In addition, both these integrons harbour array of antibiotic resistance and commonly used disinfectant's resistance genes linked to ISCR elements. Isolation of a novel XDR strain from Indian tertiary care unit belonging to novel ST with diverse array of resistance genes on ISCR linked super-integrons indicates extent and nature of selection pressure in hospitals. Since, repetitive elements have major role in their spread and due to limitations of draft genomes, there is an urgent need to employ complete genome-based investigation for tracking the emergence of XDR at global level and designing strategies of antimicrobial stewardship and disinfection. IMPORTANCE: Hospital settings in India have one of the highest usages of antimicrobials and a heavy patient load. We hereby report a novel clinical isolate of S. maltophilia complex with two super-integrons that harbour array of antimicrobial resistance genes along with biocide and heavy metal resistance genes. Further, the presence of ISCR type of transposable elements on both the integrons indicates their propensity to transfer resistome while their chromosomal origin suggests possibilities for further genomic/phenotypic complexities according to selection pressure. Such complex mobile cassettes in a novel strain is a potential threat to global health care. Hence, to understand the evolution of opportunistic nosocomial pathogen, there is an urgent need to employ cost-effective long read technologies to keep vigilance on novel and XDR pathogens in populous countries. There is also need for surveillance of the usage of disinfectants and other antimicrobials for environmental hygiene and linked/rapid co-evolution of XDR in nosocomial pathogens. Repositories: Complete genome sequence of Stenotrophomonas maltophilia SM866: CP031058.


Assuntos
Farmacorresistência Bacteriana/genética , Evolução Molecular , Genoma Bacteriano , Stenotrophomonas maltophilia/efeitos dos fármacos , Stenotrophomonas maltophilia/genética , Genômica , Humanos , Integrons , Masculino , Pessoa de Meia-Idade , Filogenia , Stenotrophomonas maltophilia/classificação , Stenotrophomonas maltophilia/isolamento & purificação
8.
Microb Drug Resist ; 26(10): 1144-1152, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32354297

RESUMO

Aim: This study aimed at investigating the association of gene expression of multidrug efflux pumps (MexA, MexC, MexE, and MexX), the outer membrane porin OprD, and the ß-lactamase AmpC with the antimicrobial susceptibility among 44 clinical isolates of Burkholderia cepacia complex (Bcc). Results: Increased expression of ampC gene showed significant association with reduced susceptibility to chloramphenicol. In fact, reduced susceptibility to chloramphenicol was correlated with overexpression of most genes (ampC, mexC, mexE, and mexX) studied here in majority (>95%) of the Bcc isolates. Increased mexA expression showed significant association with reduced susceptibility to ß-lactam antimicrobials (ceftazidime, piperacillin-tazobactam, and meropenem) and co-trimoxazole. Reduced susceptibility to meropenem also showed significant correlation with overexpression of mexC and mexX, whereas reduced susceptibility to ceftazidime was also associated with mexE overexpression. Reduced susceptibility to levofloxacin was significantly associated with overexpression of mexX. The involvement of the efflux pumps in levofloxacin and ceftazidime resistance was further inferred from the finding that the efflux pump inhibitor, carbonyl cyanide m-chlorophenylhydrazone reduced minimum inhibitory concentrations for both the antimicrobials. Conclusions: To conclude, this study explored the high-level expression of mexC, mexE, and mexX efflux pumps genes and ampC in the clinical isolates of Bcc, which can be targeted at treating infections caused by Bcc.


Assuntos
Antibacterianos/farmacologia , Infecções por Burkholderia/tratamento farmacológico , Complexo Burkholderia cepacia/efeitos dos fármacos , Farmacorresistência Bacteriana/genética , Proteínas de Bactérias/genética , Infecções por Burkholderia/microbiologia , Complexo Burkholderia cepacia/genética , Regulação Bacteriana da Expressão Gênica , Humanos , Testes de Sensibilidade Microbiana , Porinas/genética , beta-Lactamases/genética
9.
Infect Genet Evol ; 75: 103986, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31362071

RESUMO

Acinetobacter baumannii is a nosocomial pathogen increasingly affecting the critically ill patients and represents a major public health challenge. Carbapenem-resistant A. baumannii (CRAB) is found to be associated with International Clones (ICs) and different classes of carbapenemases. The objective of the present study was to investigate the prevalence of carbapenem resistance genes, clonal relationship and genetic structure of clinical isolates of A. baumannii. In the present study, multi-locus sequence typing (MLSTOX) and analysis were carried out using Oxford scheme for 86 clinical isolates of CRAB along with 11 carbapenem sensitive A. baumannii (CSAB) collected over a period of two years (2014-2016) from two tertiary care hospitals of North India. We observed a high prevalence of the blaOXA-23-like (97.7%) among the CRAB followed by blaNDM-1 (29.1%) and blaOXA58-like (3.5%). Forty-seven Sequence Types (STs) were represented by all 97 isolates, out of which, 28 (59.6%) were novel STs that were assigned to 41 isolates. STs 451 (13%), 447 (7%), 195 (6%) and 848 (5%) were the most common STs. The majority of CRAB isolates (44.3%) belonged to the CC92, followed by the CC447 (15.1%), CC109 (9.3%) and CC110 (3.4%), which corresponds to the IC2, 8, 1 and 7 respectively. Phylogenetic and recombination analysis suggested two major and one minor lineage in the population. Further linkage disequilibrium analysis suggested clonal nature of the population as recombination was noticed at a low frequency, which was not enough to split the clonal relationship. The knowledge of genetic structure of CRAB from this study will be invaluable to illustrate epidemiology, surveillance and understanding its global diversity.


Assuntos
Infecções por Acinetobacter/epidemiologia , Acinetobacter baumannii/classificação , Proteínas de Bactérias/genética , Farmacorresistência Bacteriana , Tipagem de Sequências Multilocus/métodos , beta-Lactamases/genética , Acinetobacter baumannii/genética , Acinetobacter baumannii/isolamento & purificação , Técnicas de Tipagem Bacteriana , Carbapenêmicos , Evolução Molecular , Humanos , Índia/epidemiologia , Epidemiologia Molecular , Filogenia , Prevalência , Centros de Atenção Terciária
10.
Access Microbiol ; 1(2): e000015, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-32974511

RESUMO

Order Lysobacterales (earlier known Xanthomonadales ) is a taxonomically complex group of a large number of gamma-proteobacteria classified in two different families, namely Lysobacteraceae and Rhodanobacteraceae . Current taxonomy is largely based on classical approaches and is devoid of whole-genome information-based analysis. In the present study, we have taken all classified and poorly described species belonging to the order Lysobacterales to perform a phylogenetic analysis based on the 16 S rRNA sequence. Moreover, to obtain robust phylogeny, we have generated whole-genome sequencing data of six type species namely Metallibacterium scheffleri , Panacagrimonas perspica , Thermomonas haemolytica , Fulvimonas soli , Pseudofulvimonas gallinarii and Rhodanobacter lindaniclasticus of the families Lysobacteraceae and Rhodanobacteraceae . Interestingly, whole-genome-based phylogenetic analysis revealed unusual positioning of the type species Pseudofulvimonas , Panacagrimonas , Metallibacterium and Aquimonas at family level. Whole-genome-based phylogeny involving 92 type strains resolved the taxonomic positioning by reshuffling the genus across families Lysobacteraceae and Rhodanobacteraceae . The present study reveals the need and scope for genome-based phylogenetic and comparative studies in order to address relationships of genera and species of order Lysobacterales .

11.
Front Microbiol ; 9: 2864, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30532748

RESUMO

Nosocomial infections caused by antibiotic-resistant Gram-negative pathogens are of grave concern today. Polymyxins are considered as the last resorts of therapy to treat these multi-drug resistant (MDR) bacteria. But their associated nephrotoxicity and neurotoxicity calls for the development of safer polymyxin therapy until novel and less toxic antibiotics are discovered. No other polymyxin molecule except polymyxin B and E (colistin) is explored thoroughly in literature to demonstrate its clinical relevance. In the present study, we have isolated two antimicrobial compounds named P1 and P2 from the soil isolate Paenibacillus dendritiformis strain PV3-16, which we later identified as polymyxin A2 and A1 respectively. We tested their minimum inhibitory concentrations (MICs) against MDR clinical isolates, performed membrane permeabilization assays and determined their interaction with lipopolysaccharide (LPS). Finally, we studied their toxicity against human Leukemic monocyte cell line (THP-1) and embryonic kidney cell line (HEK 293). Both compounds displayed equal efficacy when compared with standard polymyxins. P1 was 2-4 fold more active in most of the clinical strains tested. Moreover, P1 showed higher affinity toward LPS. In cytotoxicity studies, P1 had IC50 value (>1000 µg/ml) similar to colistin against HEK cells but immune cells, i.e., THP-1 cell lines were more sensitive to polymyxins. P1 showed less toxicity in THP-1 cell line than all other polymyxins checked. To sum up, P1 (polymyxin A2) possessed better efficacy than polymyxin B and E and had least toxicity to immune cells. Since polymyxin A was not investigated thoroughly, we performed the comprehensive in vitro assessment of this molecule. Moreover, this is the first report of isolation and characterization of polymyxin A from P. dendritiformis. This compound should be further investigated for its in vivo efficacy and toxicity to develop it as a drug candidate.

12.
Int J Syst Evol Microbiol ; 68(10): 3190-3196, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30129919

RESUMO

A Gram-stain-positive, motile, endospore-producing, facultative anaerobic bacterial strain, designated ATCC 27380T, was isolated from heat-stressed soil of Cape Canaveral, Florida, USA. Growth was observed at 20-42 °C (optimum, 37 °C), at pH 6.0-10.0 (optimum pH 7.0) and in the presence of 0.5-3 % NaCl (optimum 0.5 %). The cell wall contained meso-diaminopimelic acid as the diagnostic amino acid and the isoprenoid quinone was MK-7. The polar lipids present were phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol and one unknown phospholipid. The main fatty acids were iso-C15 : 0 and anteiso-C15 : 0. Phylogenetic analysis based on 16S rRNA gene sequencing affiliated strain ATCC 27380T to the genus Paenibacillus, and showed the highest sequence similarity to Paenibacillus rigui JCM 16352T (97.0 %). The other closely related type strains exhibited 16S rRNA gene sequence similarity values below 95.9 %. The draft genome of ATCC 27380T had a size of 4,361,187 bases, with a G+C content of 51.0 %. The average nucleotide identity and in silico DNA-DNA hybridization values between strain ATCC 27380T and P. rigui JCM 16352T were 72.5% and 18.5 %, respectively, which were below the threshold suggested for species differentiation (96% and 70 %, respectively). The average amino acid identity between strain ATCC 27380T and P. rigui JCM 16352T was 68.72 %, which was above the suggested genus level demarcation of 65 %. Based on phenotypic, genotypic and chemotaxonomic data, strain ATCC 27380T represents a novel species in the genus Paenibacillus, for which the name Paenibacillusxerothermodurans sp. nov. (=DSM 520T=NRRL NRS-1629T=ATCC 27380T) is proposed.


Assuntos
Temperatura Alta , Paenibacillus/classificação , Filogenia , Microbiologia do Solo , Técnicas de Tipagem Bacteriana , Composição de Bases , Parede Celular/química , DNA Bacteriano/genética , Ácido Diaminopimélico/química , Ácidos Graxos/química , Florida , Hibridização de Ácido Nucleico , Paenibacillus/genética , Paenibacillus/isolamento & purificação , Peptidoglicano/química , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Esporos Bacterianos , Vitamina K 2/análogos & derivados , Vitamina K 2/química
13.
Microb Genom ; 4(8)2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-30084764

RESUMO

Stenotrophomonas maltophilia has evolved as one of the leading multidrug-resistant pathogens responsible for a variety of nosocomial infections especially in highly debilitated patients. As information on the genomic and intraspecies diversity of this clinically important pathogen is limited, we sequenced the whole genome of 27 clinical isolates from hospitalized patients. Phylogenomic analysis along with the genomes of type strains suggested that the clinical isolates are distributed over the Stenotrophomonas maltophilia complex (Smc) within the genus Stenotrophomonas. Further genome-based taxonomy coupled with the genomes of type strains of the genus Stenotrophomonas allowed us to identify five cryptic genomospecies, which are associated with the clinical isolates of S. maltophilia and are potentially novel species. These isolates share a very small core genome that implies a high level of genetic diversity within the isolates. Recombination analysis of core genomes revealed that the impact of recombination is more than mutation in the diversification of clinical S. maltophilia isolates. Distribution analysis of well-characterized antibiotic-resistance and efflux pump genes of S. maltophilia across multiple novel genomospecies provided insights into its antibiotic-resistant ability. This study supports the existence of multiple cryptic species within the Smc besides S. maltophilia, which are associated with human infections, and highlights the importance of genome-based approaches to delineate bacterial species. This data will aid in improving clinical diagnosis and for understanding species-specific clinical manifestations of infection due to Stenotrophomonas species.


Assuntos
Infecção Hospitalar/genética , Farmacorresistência Bacteriana/genética , Infecções por Bactérias Gram-Negativas/genética , Filogenia , Stenotrophomonas maltophilia/genética , Humanos , Stenotrophomonas maltophilia/isolamento & purificação
14.
J Clin Diagn Res ; 11(9): SD01-SD02, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29207800

RESUMO

Recurrent unilateral pneumonia poses a diagnostic dilemma for all paediatricians. Isolated pulmonary venous atresia is an uncommon entity, which presents with recurrent unilateral pulmonary infections, dyspnoea on exertion and haemoptysis. It is associated with significant mortality and morbidity. Owing to rarity of condition, there may be some difficulties in the diagnosis and therapy. Pulmonary angiography is the investigation of choice. However, the current multislice CT scanners may obviate the need for pulmonary angiography. We report a two-year-old child with this rare congenital malformation and discuss diagnostic modalities and management options.

15.
Front Microbiol ; 8: 590, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28428775

RESUMO

Burkholderia cenocepacia is a clinically dominant form among the other virulent species of Burkholderia cepacia complex (Bcc). In the present study, we sequenced and analyzed the genomes of seven nosocomial Bcc isolates, five of which were isolated from the bloodstream infections and two isolates were recovered from the hospital setting during the surveillance. Genome-based species identification of the Bcc isolates using a type strain explicitly identified the species as B. cenocepacia. Moreover, single nucleotide polymorphism analysis revealed that the six isolates were clonal and phylogenetically distinct from the other B. cenocepacia. Comparative genomics distinctly revealed the larger genome size of six clonal isolates as well as the presence of a novel 107 kb genomic island named as BcenGI15, which encodes putative pathogenicity-associated genes. We have shown that the BcenGI15 has an ability to actively excise from the genome and forming an extrachromosomal circular form suggesting its mobile nature. Surprisingly, a homolog of BcenGI15 was also present in the genome of a clinical isolate named Burkholderia pseudomallei strain EY1. This novel genetic element is present only in the variants of B. cenocepacia and B. pseudomallei isolates suggesting its interspecies existence in the main pathogenic species of the genus Burkholderia. In conclusion, the whole genome analysis of the genomically distinct B. cenocepacia clinical isolates has advanced our understanding of the epidemiology and evolution of this important nosocomial pathogen as well as its relatives.

16.
Sci Rep ; 6: 35769, 2016 10 21.
Artigo em Inglês | MEDLINE | ID: mdl-27767197

RESUMO

Burkholderia cepacia complex (Bcc) is a complex group of bacteria causing opportunistic infections in immunocompromised and cystic fibrosis (CF) patients. Herein, we report multilocus sequence typing and analysis of the 57 clinical isolates of Bcc collected over the period of seven years (2005-2012) from several hospitals across India. A total of 21 sequence types (ST) including two STs from cystic fibrosis patient's isolates and twelve novel STs were identified in the population reflecting the extent of genetic diversity. Multilocus sequence analysis revealed two lineages in population, a major lineage belonging to B. cenocepacia and a minor lineage belonging to B. cepacia. Split-decomposition analysis suggests absence of interspecies recombination and intraspecies recombination contributed in generating genotypic diversity amongst isolates. Further linkage disequilibrium analysis indicates that recombination takes place at a low frequency, which is not sufficient to break down the clonal relationship. This knowledge of the genetic structure of Bcc population from a rapidly developing country will be invaluable in the epidemiology, surveillance and understanding global diversity of this group of a pathogen.


Assuntos
Complexo Burkholderia cepacia/genética , Variação Genética , Técnicas de Tipagem Bacteriana , Infecções por Burkholderia/microbiologia , Burkholderia cenocepacia/genética , Burkholderia cenocepacia/isolamento & purificação , Burkholderia cepacia/genética , Burkholderia cepacia/isolamento & purificação , Complexo Burkholderia cepacia/classificação , Complexo Burkholderia cepacia/isolamento & purificação , Fibrose Cística/microbiologia , DNA Bacteriano/genética , Humanos , Índia , Desequilíbrio de Ligação , Tipagem de Sequências Multilocus , Infecções Oportunistas/microbiologia , Filogenia , Recombinação Genética , Análise de Sequência de DNA
17.
Sci Rep ; 6: 33665, 2016 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-27651180

RESUMO

Much of the work in periodontal microbiology in recent years has focused on identifying and understanding periodontal pathogens. As the majority of oral microbes have not yet been isolated in pure form, it is essential to understand the phenotypic characteristics of microbes to decipher their role in oral environment. In this study, strain DISK18 was isolated from gingival sulcus and identified as a Megasphaera species. Although metagenomics studies revealed Megasphaera species as a major group within the oral habitat, they have never been isolated in cultivable form to date. Therefore, we have characterized the DISK18 strain to better understand its role in the periodontal ecosystem. Strain Megasphaera sp. DISK18 displayed the ability to adhere and self-aggregate, which are essential requisite features for inhabiting and persisting in oral cavity. It also coaggregated with other pioneer oral colonizers like Streptococcus and Lactobacillus species but not with Veillonella. This behaviour points towards its role in the ecologic succession of a multispecies biofilm as an early colonizer. The absence of virulence determining genes as observed in whole genome sequence analysis coupled with an inability to degrade collagen reveals that Megasphaera sp. strain DISK18 is likely not a pathogenic species and emphasizes its commensal lifestyle.


Assuntos
Placa Dentária/microbiologia , Megasphaera/química , Megasphaera/genética , Metagenoma , Metagenômica , Algoritmos , Aderência Bacteriana , Biofilmes , Feminino , Humanos , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Megasphaera/classificação , Megasphaera/isolamento & purificação , Metagenômica/métodos , Filogenia , Açúcares/metabolismo , Enxofre/química , Temperatura , Compostos Orgânicos Voláteis/química , Sequenciamento Completo do Genoma , Adulto Jovem
18.
Front Microbiol ; 7: 309, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27014232

RESUMO

Genomic resource of type strains and historically important strains of genus Stenotrophomonas allowed us to reveal the existence of 18 distinct species by applying modern phylogenomic criterions. Apart from Stenotrophomonas maltophilia, S. africana represents another species of clinical importance. Interestingly, Pseudomonas hibsicola, P. beteli, and S. pavani that are of plant origin are closer to S. maltophilia than the majority of the environmental isolates. The genus has an open pan-genome. By providing the case study on genes encoding metallo-ß-lactamase and Clustered Regularly Interspaced Short Palindrome Repeats (CRISPR) regions, we have tried to show the importance of this genomic dataset in understanding its ecology.

19.
Genome Announc ; 3(6)2015 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-26543133

RESUMO

Acinetobacter baumannii resistance to carbapenems is of global concern. Here, we report the 3.9 Mb draft genome of a cerebrospinal fluid isolate of A. baumannii strain 10441_14 which is carbapenem resistant and belongs to ST451. This genome will further help in the understanding of the drug resistance mechanism, epidemiology, and pathology of this bacterium.

20.
Genome Announc ; 3(5)2015 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-26472849

RESUMO

We report here the 4.1-Mb draft genome sequence of Acinetobacter baumannii strain 5021_13, a cerebrospinal fluid isolate from northern India. This genome information will help studies toward understanding the epidemiology and pathogenicity of this important nosocomial pathogen.

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