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1.
Clin Infect Dis ; 70(7): 1294-1303, 2020 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-31094423

RESUMO

BACKGROUND: Pneumococcal conjugate vaccines (PCVs) have reduced pneumococcal diseases globally. Pneumococcal genomic surveys elucidate PCV effects on population structure but are rarely conducted in low-income settings despite the high disease burden. METHODS: We undertook whole-genome sequencing (WGS) of 660 pneumococcal isolates collected through surveys from healthy carriers 2 years from 13-valent PCV (PCV13) introduction and 1 year after rollout in northern Malawi. We investigated changes in population structure, within-lineage serotype dynamics, serotype diversity, and frequency of antibiotic resistance (ABR) and accessory genes. RESULTS: In children <5 years of age, frequency and diversity of vaccine serotypes (VTs) decreased significantly post-PCV, but no significant changes occurred in persons ≥5 years of age. Clearance of VT serotypes was consistent across different genetic backgrounds (lineages). There was an increase of nonvaccine serotypes (NVTs)-namely 7C, 15B/C, and 23A-in children <5 years of age, but 28F increased in both age groups. While carriage rates have been recently shown to remain stable post-PCV due to replacement serotypes, there was no change in diversity of NVTs. Additionally, frequency of intermediate-penicillin-resistant lineages decreased post-PCV. Although frequency of ABR genes remained stable, other accessory genes, especially those associated with mobile genetic element and bacteriocins, showed changes in frequency post-PCV. CONCLUSIONS: We demonstrate evidence of significant population restructuring post-PCV driven by decreasing frequency of vaccine serotypes and increasing frequency of few NVTs mainly in children under 5. Continued surveillance with WGS remains crucial to fully understand dynamics of the residual VTs and replacement NVT serotypes post-PCV.


Assuntos
Metagenômica , Infecções Pneumocócicas , Portador Sadio/epidemiologia , Criança , Humanos , Lactente , Malaui/epidemiologia , Nasofaringe , Infecções Pneumocócicas/epidemiologia , Infecções Pneumocócicas/prevenção & controle , Vacinas Pneumocócicas , Sorogrupo , Streptococcus pneumoniae/genética , Vacinas Conjugadas
2.
J Antimicrob Chemother ; 75(3): 512-520, 2020 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-31789384

RESUMO

OBJECTIVES: We reported tet(S/M) in Streptococcus pneumoniae and investigated its temporal spread in relation to nationwide clinical interventions. METHODS: We whole-genome sequenced 12 254 pneumococcal isolates from 29 countries on an Illumina HiSeq sequencer. Serotype, multilocus ST and antibiotic resistance were inferred from genomes. An SNP tree was built using Gubbins. Temporal spread was reconstructed using a birth-death model. RESULTS: We identified tet(S/M) in 131 pneumococcal isolates and none carried other known tet genes. Tetracycline susceptibility testing results were available for 121 tet(S/M)-positive isolates and all were resistant. A majority (74%) of tet(S/M)-positive isolates were from South Africa and caused invasive diseases among young children (59% HIV positive, where HIV status was available). All but two tet(S/M)-positive isolates belonged to clonal complex (CC) 230. A global phylogeny of CC230 (n=389) revealed that tet(S/M)-positive isolates formed a sublineage predicted to exhibit resistance to penicillin, co-trimoxazole, erythromycin and tetracycline. The birth-death model detected an unrecognized outbreak of this sublineage in South Africa between 2000 and 2004 with expected secondary infections (effective reproductive number, R) of ∼2.5. R declined to ∼1.0 in 2005 and <1.0 in 2012. The declining epidemic could be related to improved access to ART in 2004 and introduction of pneumococcal conjugate vaccine (PCV) in 2009. Capsular switching from vaccine serotype 14 to non-vaccine serotype 23A was observed within the sublineage. CONCLUSIONS: The prevalence of tet(S/M) in pneumococci was low and its dissemination was due to an unrecognized outbreak of CC230 in South Africa. Capsular switching in this MDR sublineage highlighted its potential to continue to cause disease in the post-PCV13 era.


Assuntos
Infecções Pneumocócicas , Streptococcus pneumoniae , Antibacterianos/farmacologia , Criança , Pré-Escolar , Farmacorresistência Bacteriana , Humanos , Tipagem de Sequências Multilocus , Infecções Pneumocócicas/epidemiologia , Vacinas Pneumocócicas , Sorogrupo , África do Sul/epidemiologia , Resistência a Tetraciclina/genética
3.
J Antimicrob Chemother ; 74(5): 1223-1232, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30778540

RESUMO

OBJECTIVES: ESBL-producing Klebsiella pneumoniae (KPN) pose a major threat to human health globally. We carried out a WGS study to understand the genetic background of ESBL-producing KPN in Malawi and place them in the context of other global isolates. METHODS: We sequenced genomes of 72 invasive and carriage KPN isolates collected from patients admitted to Queen Elizabeth Central Hospital, Blantyre, Malawi. We performed phylogenetic and population structure analyses on these and previously published genomes from Kenya (n = 66) and from outside sub-Saharan Africa (n = 67). We screened for presence of antimicrobial resistance (AMR) genetic determinants and carried out association analyses by genomic sequence cluster, AMR phenotype and time. RESULTS: Malawian isolates fit within the global population structure of KPN, clustering into the major lineages of KpI, KpII and KpIII. KpI isolates from Malawi were more related to those from Kenya, with both collections exhibiting more clonality than isolates from the rest of the world. We identified multiple ESBL genes, including blaCTX-M-15, several blaSHV, blaTEM-63 and blaOXA-10, and other AMR genes, across diverse lineages of the KPN isolates from Malawi. No carbapenem resistance genes were detected; however, we detected IncFII and IncFIB plasmids that were similar to the carbapenem resistance-associated plasmid pNDM-mar. CONCLUSIONS: There are multiple ESBL genes across diverse KPN lineages in Malawi and plasmids in circulation that are capable of carrying carbapenem resistance. Unless appropriate interventions are rapidly put in place, these may lead to a high burden of locally untreatable infection in vulnerable populations.


Assuntos
Genoma Bacteriano , Genômica , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/classificação , Klebsiella pneumoniae/genética , beta-Lactamases/genética , Antibacterianos/farmacologia , Biologia Computacional/métodos , Farmacorresistência Bacteriana Múltipla , Variação Genética , Genômica/métodos , Humanos , Klebsiella pneumoniae/isolamento & purificação , Malaui , Testes de Sensibilidade Microbiana , Filogenia
4.
J Clin Microbiol ; 56(7)2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29720431

RESUMO

A newly recognized pneumococcal serotype, 35D, which differs from the 35B polysaccharide in structure and serology by not binding to factor serum 35a, was recently reported. The genetic basis for this distinctive serology is due to the presence of an inactivating mutation in wciG, which encodes an O-acetyltransferase responsible for O-acetylation of a galactofuranose. Here, we assessed the genomic data of a worldwide pneumococcal collection to identify serotype 35D isolates and understand their geographical distribution, genetic background, and invasiveness potential. Of 21,980 pneumococcal isolates, 444 were originally typed as serotype 35B by PneumoCaT. Analysis of the wciG gene revealed 23 isolates from carriage (n = 4) and disease (n = 19) with partial or complete loss-of-function mutations, including mutations resulting in premature stop codons (n = 22) and an in-frame mutation (n = 1). These were selected for further analysis. The putative 35D isolates were geographically widespread, and 65.2% (15/23) of them was recovered after the introduction of pneumococcal conjugate vaccine 13 (PCV13). Compared with serotype 35B isolates, putative serotype 35D isolates have higher invasive disease potentials based on odds ratios (OR) (11.58; 95% confidence interval[CI], 1.42 to 94.19 versus 0.61; 95% CI, 0.40 to 0.92) and a higher prevalence of macrolide resistance mediated by mefA (26.1% versus 7.6%; P = 0.009). Using the Quellung reaction, 50% (10/20) of viable isolates were identified as serotype 35D, 25% (5/20) as serotype 35B, and 25% (5/20) as a mixture of 35B/35D. The discrepancy between phenotype and genotype requires further investigation. These findings illustrated a global distribution of an invasive serotype, 35D, among young children post-PCV13 introduction and underlined the invasive potential conferred by the loss of O-acetylation in the pneumococcal capsule.


Assuntos
Infecções Pneumocócicas/epidemiologia , Infecções Pneumocócicas/microbiologia , Vacinas Pneumocócicas/administração & dosagem , Streptococcus pneumoniae/classificação , Streptococcus pneumoniae/patogenicidade , Portador Sadio/epidemiologia , Portador Sadio/microbiologia , Farmacorresistência Bacteriana/genética , Genes Bacterianos/genética , Variação Genética , Genoma Bacteriano/genética , Genótipo , Mutação , Filogenia , Infecções Pneumocócicas/prevenção & controle , Prevalência , Análise de Sequência de DNA , Sorogrupo , Streptococcus pneumoniae/genética
5.
J Allergy Clin Immunol ; 139(3): 977-986.e2, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27523432

RESUMO

BACKGROUND: The Sahel region of West Africa has the highest bacterial meningitis attack and case fatality rate in the world. The effect of climatic factors on patterns of invasive respiratory bacterial disease is not well documented. OBJECTIVE: We aimed to assess the link between climatic factors and occurrence of invasive respiratory bacterial disease in a Sahel region of Niger. METHODS: We conducted daily disease surveillance and climatic monitoring over an 8-year period between January 1, 2003, and December 31, 2010, in Niamey, Niger, to determine risk factors for bacterial meningitis and invasive bacterial disease. We investigated the mechanistic effects of these factors on Streptococcus pneumoniae infection in mice. RESULTS: High temperatures and low visibility (resulting from high concentrations of airborne dust) were identified as significant risk factors for bacterial meningitis. Dust inhalation or exposure to high temperatures promoted progression of stable asymptomatic pneumococcal nasopharyngeal carriage to pneumonia and invasive disease. Dust exposure significantly reduced phagocyte-mediated bacterial killing, and exposure to high temperatures increased release of the key pneumococcal toxin pneumolysin through increased bacterial autolysis. CONCLUSION: Our findings show that climatic factors can have a substantial influence on infectious disease patterns, altering density of pneumococcal nasopharyngeal carriage, reducing phagocytic killing, and resulting in increased inflammation and tissue damage and consequent invasiveness. Climatic surveillance should be used to forecast invasive bacterial disease epidemics, and simple control measures to reduce particulate inhalation might reduce the incidence of invasive bacterial disease in regions of the world exposed to high temperatures and increased airborne dust.


Assuntos
Poluentes Atmosféricos , Poeira , Meningites Bacterianas/epidemiologia , Adolescente , Animais , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Camundongos , Níger/epidemiologia , Infecções Pneumocócicas/imunologia , Fatores de Risco , Streptococcus pneumoniae , Temperatura
6.
J Clin Microbiol ; 55(6): 1837-1846, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28356413

RESUMO

An emm32.2 invasive group A streptococcus (iGAS) outbreak occurred in Liverpool from January 2010 to September 2012. This genotype had not previously been identified in Liverpool, but was responsible for 32% (14/44) of all iGAS cases reported during this time period. We performed a case-case comparison of emm32.2 iGAS cases with non-emm32.2 control iGAS cases identified in the Liverpool population over the same time period to assess patient risk factors for emm32.2 iGAS infection. The emm32.2 iGAS cases were confined to the adult population. We show that homelessness, intravenous drug use, and alcohol abuse predisposed patients to emm32.2 iGAS disease; however, no obvious epidemiological linkage between the patients with emm32.2 iGAS could be identified. Comparative whole-genome sequencing analysis of emm32.2 iGAS and non-emm32.2 control isolates was also performed to identify pathogen factors which might have driven the outbreak. We identified 19 genes, five of which had previously been implicated in virulence, which were present in all of the emm32.2 iGAS isolates but not present in any of the non-emm32.2 control isolates. We report that a novel emm32.2 genotype emerged in Liverpool in 2010 and identified a specific subset of genes, which could have allowed this novel emm32.2 genotype to persist in a disadvantaged population in the region over a 3-year period.


Assuntos
Antígenos de Bactérias/genética , Proteínas da Membrana Bacteriana Externa/genética , Proteínas de Transporte/genética , Surtos de Doenças , Genótipo , Infecções Estreptocócicas/epidemiologia , Infecções Estreptocócicas/microbiologia , Streptococcus pyogenes/classificação , Streptococcus pyogenes/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Epidemiologia Molecular , Streptococcus pyogenes/isolamento & purificação , Reino Unido/epidemiologia , Sequenciamento Completo do Genoma , Adulto Jovem
7.
J Antimicrob Chemother ; 72(6): 1602-1609, 2017 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-28333330

RESUMO

Objectives: Efforts to treat Escherichia coli infections are increasingly being compromised by the rapid, global spread of antimicrobial resistance (AMR). Whilst AMR in E. coli has been extensively investigated in resource-rich settings, in sub-Saharan Africa molecular patterns of AMR are not well described. In this study, we have begun to explore the population structure and molecular determinants of AMR amongst E. coli isolates from Malawi. Methods: Ninety-four E. coli isolates from patients admitted to Queen's Hospital, Malawi, were whole-genome sequenced. The isolates were selected on the basis of diversity of phenotypic resistance profiles and clinical source of isolation (blood, CSF and rectal swab). Sequence data were analysed using comparative genomics and phylogenetics. Results: Our results revealed the presence of five clades, which were strongly associated with E. coli phylogroups A, B1, B2, D and F. We identified 43 multilocus STs, of which ST131 (14.9%) and ST12 (9.6%) were the most common. We identified 25 AMR genes. The most common ESBL gene was bla CTX-M-15 and it was present in all five phylogroups and 11 STs, and most commonly detected in ST391 (4/4 isolates), ST648 (3/3 isolates) and ST131 [3/14 (21.4%) isolates]. Conclusions: This study has revealed a high diversity of lineages associated with AMR, including ESBL and fluoroquinolone resistance, in Malawi. The data highlight the value of longitudinal bacteraemia surveillance coupled with detailed molecular epidemiology in all settings, including low-income settings, in describing the global epidemiology of ESBL resistance.


Assuntos
Farmacorresistência Bacteriana Múltipla/genética , Infecções por Escherichia coli/microbiologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Resistência beta-Lactâmica/genética , beta-Lactamases/genética , Adolescente , Adulto , Criança , Pré-Escolar , Cloranfenicol/farmacologia , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/epidemiologia , Feminino , Genes Bacterianos , Variação Genética , Genômica , Humanos , Malaui/epidemiologia , Masculino , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Filogenia , População Urbana/estatística & dados numéricos , Adulto Jovem
8.
J Clin Microbiol ; 54(5): 1326-34, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-26962082

RESUMO

Serotype 1 is an important cause of invasive pneumococcal disease in South Africa and has declined following the introduction of the 13-valent pneumococcal conjugate vaccine in 2011. We genetically characterized 912 invasive serotype 1 isolates from 1989 to 2013. Simpson's diversity index (D) and recombination ratios were calculated. Factors associated with sequence types (STs) were assessed. Clonal complex 217 represented 96% (872/912) of the sampled isolates. Following the introduction of the 13-valent pneumococcal conjugate vaccine (PCV13), ST diversity increased in children <5 years (D, 0.39 to 0.63, P = 0.002) and individuals >14 years (D, 0.35 to 0.54, P < 0.001): ST-217 declined proportionately in children <5 years (153/203 [75%] versus 21/37 [57%], P = 0.027) and individuals >14 years (242/305 [79%] versus 96/148 [65%], P = 0.001), whereas ST-9067 increased (4/684 [0.6%] versus 24/228 [11%], P < 0.001). Three subclades were identified within ST-217: ST-217C1 (353/382 [92%]), ST-217C2 (15/382 [4%]), and ST-217C3 (14/382 [4%]). ST-217C2, ST-217C3, and single-locus variant (SLV) ST-8314 (20/912 [2%]) were associated with nonsusceptibility to chloramphenicol, tetracycline, and co-trimoxazole. ST-8314 (20/912 [2%]) was also associated with increased nonsusceptibility to penicillin (P < 0.001). ST-217C3 and newly reported ST-9067 had higher recombination ratios than those of ST-217C1 (4.344 versus 0.091, P < 0.001; and 0.086 versus 0.013, P < 0.001, respectively). Increases in genetic diversity were noted post-PCV13, and lineages associated with antimicrobial nonsusceptibility were identified.


Assuntos
Variação Genética , Filogenia , Infecções Pneumocócicas/epidemiologia , Infecções Pneumocócicas/microbiologia , Sorogrupo , Streptococcus pneumoniae/classificação , Streptococcus pneumoniae/isolamento & purificação , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Epidemiologia Molecular , África do Sul/epidemiologia , Streptococcus pneumoniae/genética , Adulto Jovem
9.
BMC Infect Dis ; 16(1): 649, 2016 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-27821148

RESUMO

BACKGROUND: Pneumococcus kills over one million children annually and over 90 % of these deaths occur in low-income countries especially in Sub-Saharan Africa (SSA) where HIV exacerbates the disease burden. In SSA, serotype 1 pneumococci particularly the endemic ST217 clone, causes majority of the pneumococcal disease burden. To understand the evolution of the virulent ST217 clone, we analysed ST217 whole genomes from isolates sampled from African and Asian countries. METHODS: We analysed 226 whole genome sequences from the ST217 lineage sampled from 9 African and 4 Asian countries. We constructed a whole genome alignment and used it for phylogenetic and coalescent analyses. We also screened the genomes to determine presence of antibiotic resistance conferring genes. RESULTS: Population structure analysis grouped the ST217 isolates into five sequence clusters (SCs), which were highly associated with different geographical regions and showed limited intracontinental and intercontinental spread. The SCs showed lower than expected genomic sequence, which suggested strong purifying selection and small population sizes caused by bottlenecks. Recombination rates varied between the SCs but were lower than in other successful clones such as PMEN1. African isolates showed higher prevalence of antibiotic resistance genes than Asian isolates. Interestingly, certain West African isolates harbored a defective chloramphenicol and tetracycline resistance-conferring element (Tn5253) with a deletion in the loci encoding the chloramphenicol resistance gene (cat pC194), which caused lower chloramphenicol than tetracycline resistance. Furthermore, certain genes that promote colonisation were absent in the isolates, which may contribute to serotype 1's rarity in carriage and consequently its lower recombination rates. CONCLUSIONS: The high phylogeographic diversity of the ST217 clone shows that this clone has been in circulation globally for a long time, which allowed its diversification and adaptation in different geographical regions. Such geographic adaptation reflects local variations in selection pressures in different locales. Further studies will be required to fully understand the biological mechanisms which makes the ST217 clone highly invasive but unable to successfully colonise the human nasopharynx for long durations which results in lower recombination rates.


Assuntos
Infecções Pneumocócicas/microbiologia , Streptococcus pneumoniae/genética , África , Ásia , Farmacorresistência Bacteriana/genética , Variação Genética , Humanos , Nasofaringe/microbiologia , Filogenia , Infecções Pneumocócicas/epidemiologia , Recombinação Genética , Seleção Genética , Sorogrupo , Streptococcus pneumoniae/efeitos dos fármacos , Streptococcus pneumoniae/isolamento & purificação , Resistência a Tetraciclina/genética
10.
Infect Immun ; 83(10): 4165-73, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26259813

RESUMO

Streptococcus pneumoniae is a nasopharyngeal commensal that occasionally invades normally sterile sites to cause bloodstream infection and meningitis. Although the pneumococcal population structure and evolutionary genetics are well defined, it is not clear whether pneumococci that cause meningitis are genetically distinct from those that do not. Here, we used whole-genome sequencing of 140 isolates of S. pneumoniae recovered from bloodstream infection (n = 70) and meningitis (n = 70) to compare their genetic contents. By fitting a double-exponential decaying-function model, we show that these isolates share a core of 1,427 genes (95% confidence interval [CI], 1,425 to 1,435 genes) and that there is no difference in the core genome or accessory gene content from these disease manifestations. Gene presence/absence alone therefore does not explain the virulence behavior of pneumococci that reach the meninges. Our analysis, however, supports the requirement of a range of previously described virulence factors and vaccine candidates for both meningitis- and bacteremia-causing pneumococci. This high-resolution view suggests that, despite considerable competency for genetic exchange, all pneumococci are under considerable pressure to retain key components advantageous for colonization and transmission and that these components are essential for access to and survival in sterile sites.


Assuntos
Bacteriemia/microbiologia , Proteínas de Bactérias/genética , Meningite/microbiologia , Infecções Estreptocócicas/microbiologia , Streptococcus pneumoniae/genética , Proteínas de Bactérias/metabolismo , Genoma Bacteriano , Genômica , Humanos , Streptococcus pneumoniae/classificação , Streptococcus pneumoniae/isolamento & purificação , Streptococcus pneumoniae/metabolismo
11.
BMC Infect Dis ; 15: 234, 2015 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-26088623

RESUMO

BACKGROUND: Carriage of either single or multiple pneumococcal serotypes (multiple carriage) is a prerequisite for developing invasive pneumococcal disease. However, despite the reported high rates of pneumococcal carriage in Malawi, no data on carriage of multiple serotypes has been reported previously. Our study provides the first description of the prevalence of multiple pneumococcal carriage in Malawi. METHODS: The study was conducted in Blantyre and Karonga districts in Malawi, from 2008 to 2012. We recruited 116 children aged 0-13 years. These children were either HIV-infected (N = 44) or uninfected (N = 72). Nasopharyngeal samples were collected using sterile swabs. Pneumococcal serotypes in the samples were identified by microarray. Strains that could not be typed by microarray were sequenced to characterise possible genetic alterations within the capsular polysaccharide (CPS) locus. RESULTS: The microarray identified 179 pneumococcal strains (from 116 subjects), encompassing 43 distinct serotypes and non-typeable (NT) strains. Forty per cent (46/116) of children carried multiple serotypes. Carriage of vaccine type (VT) strains was higher (p = 0.028) in younger (0-2 years) children (71 %, 40/56) compared to older (3-13 years) children (50 %, 30/60). Genetic variations within the CPS locus of known serotypes were observed in 19 % (34/179) of the strains identified. The variants included 13-valent pneumococcal conjugate vaccine (PCV13) serotypes 6B and 19A, and the polysaccharide vaccine serotype 20. Serotype 6B variants were the most frequently isolated (47 %, 16/34). Unlike the wild type, the CPS locus of the 6B variants contained an insertion of the licD-family phosphotransferase gene. The CPS locus of 19A- and 20-variants contained an inversion in the sugar-biosynthesis (rmlD) gene and a 717 bp deletion within the transferase (whaF) gene, respectively. CONCLUSIONS: The high multiple carriage in Malawian children provides opportunities for genetic exchange through horizontal gene transfer. This may potentially lead to CPS locus variants and vaccine escape. Variants reported here occurred naturally, however, PCV13 introduction could exacerbate the CPS genetic variations. Further studies are therefore recommended to assess the invasive potential of these variants and establish whether PCV13 would offer cross-protection. We have shown that younger children (0-2 years) are a reservoir of VT serotypes, which makes them an ideal target for vaccination.


Assuntos
Infecções Pneumocócicas/microbiologia , Streptococcus pneumoniae/genética , Adolescente , Cápsulas Bacterianas/genética , Técnicas Bacteriológicas , Criança , Pré-Escolar , Proteção Cruzada/imunologia , DNA Bacteriano/análise , DNA Bacteriano/isolamento & purificação , Feminino , Variação Genética , Infecções por HIV/complicações , Infecções por HIV/diagnóstico , Humanos , Lactente , Recém-Nascido , Malaui , Masculino , Nasofaringe/microbiologia , Análise de Sequência com Séries de Oligonucleotídeos , Filogenia , Infecções Pneumocócicas/complicações , Infecções Pneumocócicas/prevenção & controle , Vacinas Pneumocócicas/imunologia , Análise de Sequência de DNA , Sorogrupo , Streptococcus pneumoniae/classificação , Streptococcus pneumoniae/isolamento & purificação
12.
Clin Infect Dis ; 58(10): e137-45, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24496208

RESUMO

BACKGROUND: We documented bacterial meningitis trends among adults and children presenting to a large teaching hospital in Malawi during introduction of Haemophilus influenzae type b (Hib) vaccination and the rollout of antiretroviral therapy (ART). METHODS: We analyzed data from 51 000 consecutive cerebrospinal fluid (CSF) samples obtained from adults, adolescents, and children with suspected meningitis admitted to the Queen Elizabeth Central Hospital, Blantyre, Malawi, between 2000 and 2012. RESULTS: There was a significant decline in the total number of CSF isolates over 12 years (incident rate ratio [IRR], 0.93; 95% CI, .92-.94; P < .001). This decline was entirely in children aged <5 years (IRR, 0.87; 95% CI, .85-.88; P < .001) and coincided with the introduction of Hib vaccination. The number of adult isolates has remained unchanged (IRR, 0.99; 95% CI, .97-1.0; P = .135) despite rapid scale-up of ART provision. In children aged <5 years, Streptococcus pneumoniae, nontyphoidal salmonellae (NTS), and Hib were the most frequently isolated pathogens, and have declined over this time period. Streptococcus pneumoniae was the most frequently isolated pathogen in older children and adults. Estimated incidence of bacterial meningitis in 2012 was 20 per 100,000 cases in children aged <14 years, 6 per 100,000 adolescents, and 10 per 100,000 adults. CONCLUSIONS: Rates of bacterial meningitis have declined in children, but not adults, coinciding with the introduction of Hib vaccination. The highly successful rollout of ART has not yet resulted in a reduction in the incidence in adults where the burden remains high. Long-term surveillance of bacterial meningitis outside of the epidemic "meningitis belt" in Africa is essential.


Assuntos
Terapia Antirretroviral de Alta Atividade , Cápsulas Bacterianas , Vacinas Anti-Haemophilus , Meningites Bacterianas/epidemiologia , Adolescente , Adulto , Líquido Cefalorraquidiano/microbiologia , Criança , Pré-Escolar , Uso de Medicamentos , Infecções por HIV/complicações , Infecções por HIV/epidemiologia , Haemophilus influenzae tipo b/isolamento & purificação , Humanos , Incidência , Lactente , Malaui/epidemiologia , Meningites Bacterianas/líquido cefalorraquidiano , Meningites Bacterianas/complicações , Meningites Bacterianas/microbiologia , Meningite por Haemophilus/complicações , Meningite por Haemophilus/epidemiologia , Meningite por Haemophilus/microbiologia , Meningite Meningocócica/complicações , Meningite Meningocócica/epidemiologia , Meningite Pneumocócica/complicações , Meningite Pneumocócica/epidemiologia , Meningite Pneumocócica/microbiologia , Streptococcus pneumoniae/isolamento & purificação
13.
J Antimicrob Chemother ; 69(2): 368-74, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24080503

RESUMO

OBJECTIVES: This study aimed to define the molecular basis of co-trimoxazole resistance in Malawian pneumococci under the dual selective pressure of widespread co-trimoxazole and sulfadoxine/pyrimethamine use. METHODS: We measured the trimethoprim and sulfamethoxazole MICs and analysed folA and folP nucleotide and translated amino acid sequences for 143 pneumococci isolated from carriage and invasive disease in Malawi (2002-08). RESULTS: Pneumococci were highly resistant to both trimethoprim and sulfamethoxazole (96%, 137/143). Sulfamethoxazole-resistant isolates showed a 3 or 6 bp insertion in the sulphonamide-binding site of folP. The trimethoprim-resistant isolates fell into three genotypic groups based on dihydrofolate reductase (encoded by folA) mutations: Ile-100-Leu (10%), the Ile-100-Leu substitution together with a residue 92 substitution (56%) and those with a novel uncharacterized resistance genotype (34%). The nucleotide sequence divergence and dN/dS of folA and folP remained stable from 2004 onwards. CONCLUSIONS: S. pneumoniae exhibit almost universal co-trimoxazole resistance in vitro and in silico that we believe is driven by extensive co-trimoxazole and sulfadoxine/pyrimethamine use. More than one-third of pneumococci employ a novel mechanism of co-trimoxazole resistance. Resistance has now reached a point of stabilizing evolution. The use of co-trimoxazole to prevent pneumococcal infection in HIV/AIDS patients in sub-Saharan Africa should be re-evaluated.


Assuntos
Genótipo , Infecções Pneumocócicas/epidemiologia , Infecções Pneumocócicas/genética , Streptococcus pneumoniae/genética , Streptococcus pneumoniae/isolamento & purificação , Combinação Trimetoprima e Sulfametoxazol/administração & dosagem , Sequência de Aminoácidos , Humanos , Malaui/epidemiologia , Testes de Sensibilidade Microbiana , Dados de Sequência Molecular , Infecções Pneumocócicas/tratamento farmacológico , Prevalência
14.
PLoS One ; 19(4): e0298325, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38578803

RESUMO

Surveillance methods of circulating antibiotic resistance genes (ARGs) are of utmost importance in order to tackle what has been described as one of the greatest threats to humanity in the 21st century. In order to be effective, these methods have to be accurate, quickly deployable, and scalable. In this study, we compare metagenomic shotgun sequencing (TruSeq DNA sequencing) of wastewater samples with a state-of-the-art PCR-based method (Resistomap HT-qPCR) on four wastewater samples that were taken from hospital, industrial, urban and rural areas. ARGs that confer resistance to 11 antibiotic classes have been identified in these wastewater samples using both methods, with the most abundant observed classes of ARGs conferring resistance to aminoglycoside, multidrug-resistance (MDR), macrolide-lincosamide-streptogramin B (MLSB), tetracycline and beta-lactams. In comparing the methods, we observed a strong correlation of relative abundance of ARGs obtained by the two tested methods for the majority of antibiotic classes. Finally, we investigated the source of discrepancies in the results obtained by the two methods. This analysis revealed that false negatives were more likely to occur in qPCR due to mutated primer target sites, whereas ARGs with incomplete or low coverage were not detected by the sequencing method due to the parameters set in the bioinformatics pipeline. Indeed, despite the good correlation between the methods, each has its advantages and disadvantages which are also discussed here. By using both methods together, a more robust ARG surveillance program can be established. Overall, the work described here can aid wastewater treatment plants that plan on implementing an ARG surveillance program.


Assuntos
Antibacterianos , Águas Residuárias , Antibacterianos/farmacologia , Antibacterianos/análise , Genes Bacterianos , Tetraciclina/análise , Resistência Microbiana a Medicamentos/genética
15.
Front Public Health ; 12: 1244353, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38947352

RESUMO

Introduction: The Eastern Mediterranean Regional Office (EMRO) region accounts for almost 8% of all global Mycobacterium tuberculosis (TB) cases, with TB incidence rates ranging from 1 per 100,000 per year in the United Arab Emirates (UAE) to 204 per 100,000 in Djibouti. The national surveillance data from the Middle East and North Africa (MENA) region on the epidemiology and antimicrobial resistance trends of TB, including MDR-TB remains scarce. Methods: A retrospective 12-year analysis of N = 8,086 non-duplicate diagnostic Mycobacterium tuberculosis complex (MTB complex) isolates from the UAE was conducted. Data were generated through routine patient care during the 2010-2021 years, collected by trained personnel and reported by participating surveillance sites to the UAE National Antimicrobial Resistance (AMR) Surveillance program. Data analysis was conducted with WHONET, a windows-based microbiology laboratory database management software developed by the World Health Organization Collaborating Center for Surveillance of Antimicrobial Resistance, Boston, United States (https://whonet.org/). Results: A total of 8,086 MTB-complex isolates were analyzed. MTB-complex was primarily isolated from respiratory samples (sputum 80.1%, broncho-alveolar lavage 4.6%, pleural fluid 4.1%). Inpatients accounted for 63.2%, including 1.3% from ICU. Nationality was known for 84.3% of patients, including 3.8% Emiratis. Of UAE non-nationals, 80.5% were from 110 countries, most of which were Asian countries. India accounted for 20.8%, Pakistan 13.6%, Philippines 12.7%, and Bangladesh 7.8%. Rifampicin-resistant MTB-complex isolates (RR-TB) were found in 2.8% of the isolates, resistance to isoniazid, streptomycin, pyrazinamide, and ethambutol, was 8.9, 6.9, 3.4 and 0.4%, respectively. A slightly increasing trend of resistance among MTB-complex was observed for rifampicin from 2.5% (2010) to 2.8% (2021). Conclusion: Infections due to MTB-complex are relatively uncommon in the United Arab Emirates compared to other countries in the MENA region. Most TB patients in the UAE are of Asian origin, mainly from countries with a high prevalence of TB. Resistance to first line anti-tuberculous drugs is generally low, however increasing trends for MDR-TB mainly rifampicin linked resistance is a major concern. MDR-TB was not associated with a higher mortality, admission to ICU, or increased length of hospitalization as compared to non-MDR-TB.


Assuntos
Tuberculose Resistente a Múltiplos Medicamentos , Emirados Árabes Unidos/epidemiologia , Humanos , Estudos Retrospectivos , Tuberculose Resistente a Múltiplos Medicamentos/epidemiologia , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Masculino , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/isolamento & purificação , Feminino , Adulto , Antituberculosos/farmacologia , Antituberculosos/uso terapêutico , Pessoa de Meia-Idade , Farmacorresistência Bacteriana , Adolescente , Testes de Sensibilidade Microbiana , Adulto Jovem , Vigilância da População
18.
Front Public Health ; 11: 1244351, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38145065

RESUMO

Introduction: Methicillin resistant Staphylococcus aureus (MRSA) is a major contributor to the global burden of antimicrobial resistance (AMR). As MRSA continues to evolve, the need for continued surveillance to evaluate trends remains crucial. This study was carried out to assess MRSA trends in the United Arab Emirates (UAE) based on analysis of data from the national AMR surveillance program. Methods: We carried out a 12-year (2010-2021) retrospective analysis of MRSA demographic and microbiological data collected as part of the UAE national AMR surveillance program. Participating centers from across the country routinely submit AMR surveillance data collected by trained personnel to the National AMR Surveillance Committee, where data is analyzed using a unified WHONET platform. Data on non-duplicate isolates associated with clinical infections were obtained and included in the analysis. Results: A total of 29,414 non-duplicate MRSA isolates associated with clinical infections were reported between 2010 and 2021 (2010: n = 259; 2021: n = 4,996). MRSA represented 26.4% of all S. aureus (n = 111,623) isolates identified during the study period. In 2010, among the S. aureus isolates with reported oxacillin testing, 21.9% (n/N = 259/1,181) were identified as MRSA and this showed an increase to 33.5% (n/N = 4,996/14,925) in 2021. Although there was variation in the distribution of MRSA across the seven emirates of the country, most had an upward trend. Patient demographics reflected a male preponderance, with most being adults and from the outpatient setting. Isolates were mostly from skin and soft tissue infection specimens (72.5%; n/N = 21,335/29,414). Among the inpatients (N = 8,282), a total of 3,313 MRSA isolates were from specimens obtained ≤ 48 h after admission indicative of community acquired infection. Increasing resistance trends were observed for most antibiotics including ciprofloxacin, levofloxacin, moxifloxacin, erythromycin, gentamicin, trimethoprim-sulfamethoxazole, and quinupristin/dalfopristin. Low levels of resistance (0.0-0.8%) were sustained for linezolid except for 2015, 2016, and 2017 with 2.5, 2.6, and 2.9%, respectively. No confirmed vancomycin resistance was reported. Conclusion: The increasing trend of MRSA isolates associated with clinical infections in the hospital and community settings is a concern. Continued monitoring including incorporation of genomic surveillance and infection control measures are recommended to stem the dissemination.


Assuntos
Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Adulto , Masculino , Humanos , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus/genética , Estudos Retrospectivos , Emirados Árabes Unidos/epidemiologia , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/microbiologia
19.
Front Public Health ; 11: 1243973, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38106909

RESUMO

Introduction: Pseudomonas is a group of ubiquitous non-fermenting Gram-negative bacteria (NFGNB). Of the several species associated with humans, Pseudomonas aeruginosa (PA) can acclimate to diverse environments. The global frequency of PA infections is rising and is complicated by this organism's high intrinsic and acquired resistance to several clinically relevant antibiotics. Data on the epidemiology, levels, and trends of antimicrobial resistance of PA in clinical settings in the MENA/GCC region is scarce. Methods: A retrospective 12-year analysis of 56,618 non-duplicate diagnostic Pseudomonas spp. from the United Arab Emirates (UAE) was conducted. Data was generated at 317 surveillance sites by routine patient care during 2010-2021, collected by trained personnel and reported by participating surveillance sites to the UAE National antimicrobial resistance (AMR) Surveillance program. Data analysis was conducted with WHONET (https://whonet.org/). Results: Among the total isolates (N = 56,618), the majority were PA (95.6%). Data on nationality revealed 44.1% were UAE nationals. Most isolates were from soft tissue (55.7%), followed by respiratory tract (26.7%). PA was more commonly found among inpatients than among outpatients, followed by ICUs. PA showed a horizontal trend for resistance to fluoroquinolones, 3rd- and 4th-generation cephalosporins, and decreasing trends of resistance for aminoglycosides and meropenem. The highest percentage of multidrug resistant (MDR) isolates was reported in 2011 at 35.6%. As an overall trend, the percentage of MDR, extensively drug-resistant (XDR), and possible pandrug-resistant (PDR) isolates generally declined over the study period. Carbapenem-resistant PA (CRPA) were associated with a higher mortality (RR: 2.7), increased admission to ICU (RR: 2.3), and increased length of stay (LOS) (12 excess inpatient days per case), as compared to carbapenem-susceptible PA (CSPA). Conclusion: The resistance trends in Pseudomonas species in the UAE indicated a decline in AMR and in percentages of Pseudomonas isolates with MDR and XDR profiles. The sustained Pseudomonas spp. circulation particularly in the hospital settings highlights the importance of surveillance techniques, infection control strategies, and stewardship to limit the continued dissemination. This data also shows that CRPA are associated with higher mortality, increased ICU admission rates, and a longer hospitalization, thus higher costs due to increased number of in-hospital and ICU days.


Assuntos
Infecções por Pseudomonas , Pseudomonas aeruginosa , Humanos , Estudos Retrospectivos , Emirados Árabes Unidos/epidemiologia , Farmacorresistência Bacteriana Múltipla , Infecções por Pseudomonas/epidemiologia , Infecções por Pseudomonas/microbiologia , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Carbapenêmicos
20.
Front Public Health ; 11: 1244482, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38145078

RESUMO

Background: Carbapenem-resistant Enterobacterales (CRE) are spreading in the United Arab Emirates (UAE) where their dissemination is facilitated by international travel, trade, and tourism. The objective of this study is to describe the longitudinal changes of CRE as reported by the national AMR surveillance system of the UAE. Methods: In this study, we retrospectively describe CRE isolated from 317 surveillance sites, including 87 hospitals and 230 centers/clinics from 2010 to 2021. The associated clinical, demographic, and microbiological characteristics are presented by relying on the UAE national AMR surveillance program. Data was analyzed using WHONET microbiology laboratory database software (http://www.whonet.org). Results: A total of 14,593 carbapenem resistant Enterobacterales were analyzed, of which 48.1% were carbapenem resistant Klebsiella pneumoniae (CRKp), 25.1% carbapenem resistant Escherichia coli (CREc), and 26.8% represented 72 other carbapenem resistant species. Carbapenem resistant strains were mostly associated with adults and isolated from urine samples (36.9% of CRKp and 66.6% of CREc) followed by respiratory samples (26.95% for CRKp) and soft tissue samples (19.5% for CRKp). Over the studied period carbapenem resistance rates remained high, especially in K. pneumoniae, and in 2021 were equivalent to 67.6% for imipenem, 76.2% for meropenem, and 91.6% for ertapenem. Nevertheless, there was a statistically significant decreasing trend for imipenem and meropenem resistance in Klebsiella species (p < 0.01) while the decrease in ertapenem resistance was non-significant. Concerning E. coli, there was a statistically significant decreasing trend for meropenem and imipenem resistance over the 12 years, while ertapenem resistance increased significantly with 83.8% of E. coli exhibiting ertapenem resistance in 2021. Resistance rates to ceftazidime and cefotaxime remained higher than 90% (in 2021) for CRKp and cefotaxime rates increased to 90.5% in 2021 for CREc. Starting 2014, resistance to colistin and tigecycline was observed in carbapenem resistant Enterobacterales. CRE were associated with a higher mortality (RR: 6.3), admission to ICU (RR 3.9), and increased length of stay (LOS; 10 excess inpatient days per CRE case). Conclusion: This study supports the need to monitor CRE in the UAE and draws attention to the significant increase of ertapenem resistance in E. coli. Future surveillance analysis should include a genetic description of carbapenem resistance to provide new strategies.


Assuntos
Antibacterianos , Escherichia coli , Humanos , Adulto , Antibacterianos/farmacologia , Meropeném , Ertapenem , Estudos Retrospectivos , Escherichia coli/genética , Emirados Árabes Unidos/epidemiologia , Carbapenêmicos/farmacologia , Imipenem , Klebsiella pneumoniae/genética , Cefotaxima
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