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1.
Eur J Clin Microbiol Infect Dis ; 36(7): 1243-1252, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28160148

RESUMO

High rates of trimethoprim/sulfamethoxazole (SXT) resistance, a combination of two antifolate antibiotics trimethoprim (TMP) and sulfamethoxazole (SMZ), have been reported among Staphylococcus aureus isolates in Portuguese-speaking African countries. Our study aimed to evaluate the occurrence of TMP resistance markers in major SXTR methicillin-resistant S. aureus (MRSA) clones from these countries. We accessed also different fitness traits that could explain the success of these isolates over the Brazilian MRSA (the most successful SXTR MRSA clone worldwide but never identified in these countries). Minimum inhibitory concentrations for SXT, TMP and SMZ were determined, and genes encoding TMP resistance (dfrG, dfrA, dfrK and dfrB) were searched. Representatives of the Brazilian clone and of the major MRSA African clones were evaluated for their fitness by individual growth curves, competition assays, survival under desiccation, autolytic activity, resistance to oxidative stress, and also growth at high osmolarity and in acid and alkaline environments. Although all African isolates showed high-level resistance to TMP, the majority presented hetero-resistance to SXT. TMP resistance was linked to the presence of dfrG (78%), dfrA (19%) or both (3%) genes. Compared to the Brazilian clone, the African isolates showed higher growth rates and autolytic activity, and better survival to desiccation and alkaline conditions. Since isolates exhibiting SXT hetero-resistance are frequent in Africa, the implementation of standardized guidelines to detect this phenomenon is of major interest. The predominant MRSA clones in Portuguese-speaking African countries likely possess significant advantages over other clones, such as the Brazilian MRSA, that may explain their epidemiological success.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Infecções Estafilocócicas/microbiologia , Combinação Trimetoprima e Sulfametoxazol/farmacologia , África , Genes Bacterianos , Aptidão Genética , Humanos , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Testes de Sensibilidade Microbiana , Prevalência
2.
Eur J Clin Microbiol Infect Dis ; 34(3): 593-600, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25359581

RESUMO

The epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) in the community in Portugal is not completely understood. To evaluate S. aureus and MRSA carriage among the elderly, we conducted a large cross-sectional study between April 2010 and December 2012. A total of 3,361 adults over 60 years of age were screened for S. aureus nasopharyngeal and oropharyngeal carriage. MRSA were characterized by staphylococcal cassette chromosome mec (SCCmec) typing, spa typing, multilocus sequence typing (MLST), and tested for the presence of Panton-Valentine leukocidin (PVL). Risk factors for MRSA carriage were identified by multiple logistic regression analysis. The prevalence of S. aureus and MRSA carriage among the elderly was 20.1 % and 1.8 %, respectively. The risk of being an MRSA carrier was higher among the elderly living in retirement homes [odds ratio (OR) = 2.90, 95 % confidence interval (CI): 1.48-5.48] and those that had been hospitalized in the previous year (OR = 2.64, 95 % CI: 1.47-4.58). Among the 62 MRSA isolates, 64.5 % were multidrug-resistant and none carried PVL. Most MRSA (82.3 %) were related to three hospital-associated (HA-MRSA) clones disseminated in Portugal: ST105-II (New York/Japan clone; 43.5 %), ST5-IVc (Pediatric clone; 19.4 %), and ST22-IVh (EMRSA-15 clone; 19.4 %). The New York/Japan and Pediatric clones were significantly associated with carriers living in retirement homes, while the EMRSA-15 clone was associated with carriers that had been hospitalized. We conclude that the elderly population in Portugal is essentially free of MRSA. Given the current European societal challenges for a healthy active aging, these results are of importance to healthcare professionals and public authorities to decide on strategies to promote health in this age group.


Assuntos
Portador Sadio/epidemiologia , Portador Sadio/microbiologia , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/microbiologia , Idoso , Idoso de 80 Anos ou mais , Toxinas Bacterianas/genética , Análise por Conglomerados , Estudos Transversais , Exotoxinas/genética , Genótipo , Humanos , Leucocidinas/genética , Masculino , Pessoa de Meia-Idade , Tipagem Molecular , Nasofaringe/microbiologia , Orofaringe/microbiologia , Portugal/epidemiologia , Prevalência , Fatores de Risco
3.
Eur J Clin Microbiol Infect Dis ; 33(3): 423-32, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24057140

RESUMO

Despite their clinical relevance, few studies have addressed the epidemiology of methicillin-susceptible S. aureus (MSSA). In particular, it is not clear how MSSA population structure has evolved over time and how it might have been shaped by the emergence of MRSA in the community (CA-MRSA). In the present study we have evaluated the MSSA population structure over time, its geographical distribution and relatedness with MRSA in Portugal. A total of 465 MSSA from infection and colonization, collected over a 19-year period (1992-2011) in the northern, central and southern regions of Portugal were analyzed. Isolates were characterized by spa typing and multilocus-sequence typing (MLST). Isolates with predominant spa types were characterized by pulsed-field gel electrophoresis (PFGE). Isolates relatedness was analyzed by eBURST and BURP. The 172 spa types found among the 465 MSSA were grouped into 18 spa-CC (clonal complexes). Ten clonal types were more prevalent (40 %): one major clone (ST30-t012) was present in the entire study period and all over the country and the other nine were intermittently detected over time (ST5-t002, ST8-t008, ST15-t084, ST34-t166, ST72-t148, ST1-t127, ST7-t091, ST398-t571 and ST34-t136). Interestingly, three MSSA clonal types observed only after 1996 were closely related with CA-MRSA epidemic strains (ST8-t008, ST72-t148 and ST1-t127) found currently in Portugal. The MSSA population in Portugal is genetically diverse; however, some dominant clonal types have been established and widely disseminated for almost two decades. We identified MSSA isolates that were related with emergent CA-MRSA clones found in Portugal.


Assuntos
Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/isolamento & purificação , Adolescente , Adulto , Idoso , Portador Sadio/epidemiologia , Portador Sadio/microbiologia , Distribuição de Qui-Quadrado , Criança , Pré-Escolar , Infecções Comunitárias Adquiridas/epidemiologia , Infecções Comunitárias Adquiridas/microbiologia , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/microbiologia , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Pessoa de Meia-Idade , Epidemiologia Molecular , Portugal/epidemiologia , Staphylococcus aureus/efeitos dos fármacos , Adulto Jovem
4.
J Hosp Infect ; 148: 62-76, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38554808

RESUMO

Carbapenem-resistant Klebsiella pneumoniae (CR-KP) are a public health concern, causing infections with a high mortality rate, limited therapeutic options and challenging infection control strategies. In Portugal, the CR-KP rate has increased sharply, but the factors associated with this increase are poorly explored. In order to address this question, phylogenetic and resistome analysis were used to compare the draft genomes of 200 CR-KP isolates collected in 2017-2019 from five hospitals in the Lisbon region, Portugal. Most CR-KP belonged to sequence type (ST) 13 (29%), ST17 (15%), ST348 (13%), ST231 (12%) and ST147 (7%). Carbapenem resistance was conferred mostly by the presence of KPC-3 (74%) or OXA-181 (18%), which were associated with IncF/IncN and IncX plasmids, respectively. Almost all isolates were multi-drug resistant, harbouring resistance determinants to aminoglycosides, beta-lactams, trimethoprim, fosfomycin, quinolones and sulphonamides. In addition, 11% of isolates were resistant to colistin. Colonizing and infecting isolates were highly related, and most colonized patients (89%) reported a previous hospitalization. Moreover, among the 171 events of cross-dissemination identified by core genome multi-locus sequence typing data analysis (fewer than five allelic differences), 41 occurred between different hospitals and 130 occurred within the same hospital. The results suggest that CR-KP dissemination in the Lisbon region results from acquisition of carbapenemases in mobile genetic elements, influx of CR-KP into the hospitals by colonized ambulatory patients, and transmission of CR-KP within and between hospitals. Prudent use of carbapenems, patient screening at hospital entry, and improvement of infection control are needed to decrease the burden of CR-KP infection in Portugal.


Assuntos
Enterobacteriáceas Resistentes a Carbapenêmicos , Genoma Bacteriano , Hospitais , Infecções por Klebsiella , Klebsiella pneumoniae , Portugal/epidemiologia , Humanos , Infecções por Klebsiella/microbiologia , Infecções por Klebsiella/epidemiologia , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/isolamento & purificação , Klebsiella pneumoniae/classificação , Enterobacteriáceas Resistentes a Carbapenêmicos/genética , Enterobacteriáceas Resistentes a Carbapenêmicos/efeitos dos fármacos , Enterobacteriáceas Resistentes a Carbapenêmicos/isolamento & purificação , Enterobacteriáceas Resistentes a Carbapenêmicos/classificação , Idoso , Pessoa de Meia-Idade , Masculino , Antibacterianos/farmacologia , Feminino , Carbapenêmicos/farmacologia , Idoso de 80 Anos ou mais , Infecção Hospitalar/microbiologia , Infecção Hospitalar/epidemiologia , Adulto , Plasmídeos/genética , Farmacorresistência Bacteriana Múltipla/genética , Filogenia , Adulto Jovem , Testes de Sensibilidade Microbiana , Adolescente
5.
Eur J Clin Microbiol Infect Dis ; 32(10): 1269-83, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23604782

RESUMO

Methicillin-resistant Staphylococcus aureus (MRSA) is a leading cause of infection in the community (CA-MRSA), but in spite of its relevance, no data exist concerning its epidemiology in Portugal. In this study, we aimed to evaluate the prevalence, population structure, and origin of MRSA in the Portuguese community. A total of 527 isolates, both methicillin-susceptible S. aureus (MSSA) and MRSA, were collected from individuals with no healthcare-related risk factors attending 16 healthcare institutions in Portugal. Isolates were characterized for the presence of mecA, Panton-Valentine leukocidin (PVL), and arginine catabolic mobile element (ACME), and by staphylococcal cassette chromosome mec (SCCmec) typing, pulsed-field gel electrophoresis (PFGE), spa, and multilocus sequence typing (MLST). Susceptibility to a panel of 13 antibiotics was tested. Isolates relatedness was analyzed by goeBURST and BURP. We found a high frequency (21.6%) of MRSA in the community. However, only 11.4% of the isolates belonged to typical CA-MRSA epidemic clones (USA300, USA400, USA700, Southwest Pacific, European, and ST398). The remaining isolates, which constituted the great majority (88.6%), belonged to hospital-associated MRSA (HA-MRSA) epidemic clones, namely, to the EMRSA-15 clone (77.2%). PVL was rare and carried by 17 isolates only (five MRSA and 12 MSSA). In the whole collection, some MRSA and MSSA were highly related. The high frequency of MRSA in the community in Portugal seems to result mainly from dissemination from the hospital. They might also have emerged from an extant MSSA population, by SCCmec acquisition, or MRSA clonal introduction from abroad.


Assuntos
Infecções Comunitárias Adquiridas/epidemiologia , Infecções Comunitárias Adquiridas/microbiologia , Infecção Hospitalar/microbiologia , Staphylococcus aureus Resistente à Meticilina/classificação , Infecções Estafilocócicas/microbiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Análise por Conglomerados , DNA Bacteriano/genética , Feminino , Genótipo , Humanos , Lactente , Recém-Nascido , Masculino , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Epidemiologia Molecular , Tipagem Molecular , Portugal/epidemiologia , Prevalência , Fatores de Virulência/genética , Adulto Jovem
6.
Eur J Clin Microbiol Infect Dis ; 31(4): 605-14, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21822565

RESUMO

Staphylococcus haemolyticus is one of the most clinically relevant coagulase-negative staphylococci (CoNS), particularly in immunocompromised patients; however, little is known regarding its molecular epidemiology. In this work, we characterized the genetic background and the SCCmec region of 36 methicillin-resistant S. haemolyticus (MRSHae) and 10 methicillin-susceptible S. haemolyticus (MSSHae) collected from neutropenic patients in Tunisia between 2002 and 2004. The molecular characterization of MRSHae by pulsed-field gel electrophoresis (PFGE) showed that the great majority of the isolates (77.8%) belonged to only four types. SCCmec typing by polymerase chain reaction (PCR) and Southern hybridization showed that isolates belonging to each PFGE type could carry either one or two SCCmec types. SCCmec V was the most common, but mec complex C was frequently associated to ccr allotypes other than ccrC. The mec complex class C was predominant in MRSHae (47%) and ccrC was predominant among both methicillin-resistant and -susceptible isolates (31 and 50%, respectively). Interestingly, one half (50%) of the MRSHae isolates analyzed lacked the known ccr complexes (ccrAB and ccrC), although they carried the mecA. Conversely, all MSSHae carrying a ccrC complex were multidrug-resistant, although they lack the mecA. The results suggest that ccrC and mec complex C are frequent and may exist autonomously and independently of SCCmec type V in S. haemolyticus. Moreover, the data obtained suggest that small chromosomal rearrangements promoting the loss or structural variation of mec and ccr complex appear to occur frequently, which probably provide S. haemolyticus with a specialized means for SCCmec trapping and/or diversification.


Assuntos
Resistência a Meticilina , Tipagem Molecular , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/microbiologia , Staphylococcus haemolyticus/classificação , Staphylococcus haemolyticus/genética , Southern Blotting , DNA Bacteriano/genética , Eletroforese em Gel de Campo Pulsado , Genes Bacterianos , Genótipo , Humanos , Hospedeiro Imunocomprometido , Epidemiologia Molecular , Neutropenia/complicações , Reação em Cadeia da Polimerase , Prevalência , Staphylococcus haemolyticus/efeitos dos fármacos , Tunísia/epidemiologia
7.
Eur J Clin Microbiol Infect Dis ; 30(2): 293-7, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21046422

RESUMO

In order to evaluate the incidence of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) in Portugal, we analyzed a collection of 38 S. aureus isolates recovered from 30 children attending the pediatric emergency department of a central hospital in Lisbon due to skin and soft tissue infections. Molecular characterization identified seven clonal lineages among the 35 methicillin-susceptible S. aureus (MSSA) isolates, of which the major lineage PFGE A/t159/ST121 included 63% of the isolates. The three MRSA isolates belonged to the Pediatric clone PFGE D/t535/ST5-IV (n = 2) and to the European CA-MRSA clone PFGE G/t044/ST80-IVc (n = 1). All isolates harbored several virulence factors, namely, leukocidins. Panton-Valentine leukocidin (PVL) was produced by isolates from five MSSA lineages and by the ST80 MRSA. Of interest, this is the first reported isolation of CA-MRSA ST80 in Portugal.


Assuntos
Técnicas de Tipagem Bacteriana , Infecções Comunitárias Adquiridas/epidemiologia , Tipagem Molecular , Infecções dos Tecidos Moles/epidemiologia , Infecções Cutâneas Estafilocócicas/epidemiologia , Staphylococcus aureus/classificação , Criança , Pré-Escolar , Infecções Comunitárias Adquiridas/microbiologia , Eletroforese em Gel de Campo Pulsado , Genótipo , Humanos , Leucocidinas/biossíntese , Portugal/epidemiologia , Prevalência , Infecções dos Tecidos Moles/microbiologia , Infecções Cutâneas Estafilocócicas/microbiologia , Staphylococcus aureus/isolamento & purificação , Fatores de Virulência/biossíntese
8.
Eur J Clin Microbiol Infect Dis ; 29(5): 543-50, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20229224

RESUMO

In order to obtain insights into the methicillin-resistant Staphylococcus aureus (MRSA) population structure in the Azores archipelago, 106 MRSA isolates were collected from patients attending an Azorean central hospital between January 2007 and February 2008. Antimicrobial resistance was determined for all isolates. Molecular typing was performed by pulsed-field gel electrophoresis (PFGE), spa typing, multilocus sequence typing (MLST), staphylococcal chromosome cassette mec (SCCmec) typing and the presence of Panton-Valentine leukocidin (PVL). The majority of the isolates (87%, n = 92) belonged to the EMRSA-15 clone (ST22, SCCmec-IVh), followed by the Pediatric clone (ST5-VI/IVc) (11%, n = 12). The Berlin clone (ST45-IVa) and a new clone (spa type t1839, ST1339 and SCCmec V variant) were represented by single isolates. All of the isolates carried SCCmec types IV, V or VI and a non-multiresistant antibiotic profile, resembling the currently emerging community MRSA. Moreover, PVL was described for the first time to be associated with the Pediatric clone carrying SCCmec type VI. We provided the first description of the population structure of MRSA in the Azores islands, which seems to be shaped by genetic events occurring locally, as well as by the regular population exchange between the islands, continental Portugal, the United Kingdom and the United States.


Assuntos
Proteínas de Bactérias/genética , Técnicas de Tipagem Bacteriana/métodos , Resistência a Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Técnicas de Diagnóstico Molecular/métodos , Infecções Estafilocócicas/microbiologia , Antibacterianos/farmacologia , Açores/epidemiologia , Toxinas Bacterianas/genética , Eletroforese em Gel de Campo Pulsado , Exotoxinas/genética , Transferência Genética Horizontal , Humanos , Leucocidinas/genética , Staphylococcus aureus Resistente à Meticilina/classificação , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/genética , Testes de Sensibilidade Microbiana , Prevalência , Infecções Estafilocócicas/epidemiologia
9.
J Clin Microbiol ; 46(1): 118-29, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17989196

RESUMO

In the present study we give some direction on the selection of the most appropriate typing method(s) to be used for the characterization of Staphylococcus epidermidis, in view of the most recent findings on the evolution, population structure, and epidemiology of this species. In order to achieve this aim, quantitative assessment of the correlation of the results of three typing methods--pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), and staphylococcal chromosomal cassette mec (SCCmec) typing, which target different regions of the chromosome that evolve at different rates--was performed. In order to evaluate the discriminatory ability and the strength and direction of the correlation of the different typing methods, Simpson's index of diversity (SID), the adjusted Rand coefficient (AR), and the Wallace coefficient (W) were calculated. PFGE was the most discriminatory method (SID = 99%), followed by MLST (SID = 90%) and SCCmec typing (SID = 75%). The values of AR and W (0.10 < AR < 0.30; 0.50 < W < 0.75) indicated that the partition of the same isolate collection by PFGE, MLST, and SCCmec typing provided results that had only a poor correlation with each other. However, the information provided by the combination of PFGE and SCCmec enabled the prediction of the results obtained by MLST at the level of the clonal complex with a high degree of precision (W > 0.90). We propose that clones of S. epidermidis be defined by the combination of the PFGE type followed by the SCCmec type, which provides reliable information on the short-term epidemiology and the ability to predict with consistency long-term clonal evolution.


Assuntos
Técnicas de Tipagem Bacteriana/métodos , Epidemiologia Molecular/métodos , Staphylococcus epidermidis/classificação , Staphylococcus epidermidis/genética , Cromossomos Bacterianos/genética , Infecção Hospitalar/microbiologia , Impressões Digitais de DNA , DNA Bacteriano/química , DNA Bacteriano/genética , Genótipo , Humanos , Análise de Sequência de DNA , Infecções Estafilocócicas/microbiologia , Estatística como Assunto
10.
Microb Drug Resist ; 14(1): 1-6, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18346009

RESUMO

A clinical isolate of methicillin-resistant Staphylococcus aureus (MRSA) with intermediate resistance to vancomycin (minimal inhibitory concentration [MIC] of 4 mug/ml) was isolated in 2006 from a surgical wound of a patient hospitalized at the orthopedics ward of Hospital de São Marcos--Braga, in the town of Braga. A combination of molecular typing methods, including pulsed-field gel electrophoresis (PFGE), spa typing, multilocus sequence typing, and staphylococcal chromosomal cassette mec typing, identified the vancomycin intermediate-resistant S. aureus VISA-BRAGA as a derivative of the epidemic MRSA (EMRSA)-15 clone, which has been isolated with increasing frequency from several Portuguese hospitals recently. Compared to another EMRSA-15 isolate with the same genetic background (including PFGE subtype) the VISA-BRAGA isolate exhibited relatively high oxacillin MIC, slow growth, loss of hemolytic activity, and increased resistance to vancomycin and to daptomycin although neither of these two antibiotics was used in therapy. The VISA-BRAGA isolate described here appears to represent the first S. aureus with decreased susceptibility to vancomycin identified in a Portuguese hospital.


Assuntos
Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/efeitos dos fármacos , Infecção da Ferida Cirúrgica/microbiologia , Resistência a Vancomicina , Contagem de Colônia Microbiana , Infecção Hospitalar/microbiologia , DNA Bacteriano/análise , Farmacorresistência Bacteriana Múltipla , Eletroforese em Gel de Campo Pulsado , Feminino , Humanos , Testes de Sensibilidade Microbiana , Portugal , Staphylococcus aureus/genética , Staphylococcus aureus/isolamento & purificação
11.
Clin Microbiol Infect ; 14(1): 82-4, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17986268

RESUMO

Serotype 1 pneumococci are rarely isolated from carriers, but are an important cause of pneumococcal invasive disease in many regions of the world. This report describes the emergence and expansion of a single serotype 1 lineage (characterised by multilocus sequence type 306) among healthy carriers attending day-care centres in Portugal. The prevalence of serotype 1 strains among all pneumococci increased from 0% in 2001 and 2002, to 0.4% in 2003, and 3.1% in 2006. These observations paralleled the introduction and increased use of the seven-valent pneumococcal conjugate vaccine in the study group, suggesting a direct relationship between these events.


Assuntos
Portador Sadio/microbiologia , Vacinas Meningocócicas/imunologia , Infecções Pneumocócicas/microbiologia , Vacinas Pneumocócicas/imunologia , Streptococcus pneumoniae/classificação , Streptococcus pneumoniae/isolamento & purificação , Técnicas de Tipagem Bacteriana , Criança , Pré-Escolar , Genótipo , Vacina Pneumocócica Conjugada Heptavalente , Humanos , Lactente , Portugal , Análise de Sequência de DNA , Sorotipagem , Streptococcus pneumoniae/genética , Streptococcus pneumoniae/imunologia
12.
J Hosp Infect ; 100(3): 344-349, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29807064

RESUMO

BACKGROUND: The prevalence of nosocomial meticillin-resistant Staphylococcus aureus (MRSA) was previously estimated as 23% in a paediatric hospital in Luanda, Angola and 18% in a general hospital in São Tomé and Príncipe. AIM: To evaluate the prevalence of S. aureus/MRSA colonization among hospitalized children and their parents at two hospitals in Angola and São Tomé and Príncipe. METHODS: In 2017, 127 hospitalized children and 129 of their parents had nasal swabs for S. aureus/MRSA carriage in the two countries. The isolates were tested for the presence of the mecA and Panton-Valentine leukocidin (PVL) genes, and characterized by pulsed-field gel electrophoresis (PFGE), spa typing, multi-locus sequence typing and SCCmec typing. FINDINGS: Twenty of 127 children (15.7%) and 13 of 129 parents (10.1%) were MRSA nasal carriers. Three lineages comprised 88% of the MRSA isolates: (i) PFGE A-ST5-SCCmec IVa (N=15; 45%), associated with spa type t105, recovered in Angola alone; (ii) PFGE N-ST8-IV/V (N=7; 21%), associated with spa types t008/t121, recovered in São Tomé and Príncipe alone; and (iii) PFGE B-ST88-IVa (N=7; 21%), associated with spa types t325/t786, present in both countries. Fifteen child/guardian pairs were colonized with identical MRSA (N=8) or meticillin-susceptible S. aureus (N=7) strains. PVL was detected in 25% of isolates, including two MRSA (ST30-V and ST8-IVa). CONCLUSION: Hospitalized children and their parents are important reservoirs of MRSA. Infection control measures should focus on parents in order to minimize the spread of MRSA to the community.


Assuntos
Portador Sadio/epidemiologia , Pacientes Internados , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Pais , Infecções Estafilocócicas/epidemiologia , Angola/epidemiologia , Portador Sadio/microbiologia , Criança , Pré-Escolar , Eletroforese em Gel de Campo Pulsado , Feminino , Genótipo , Hospitais , Humanos , Masculino , Staphylococcus aureus Resistente à Meticilina/classificação , Staphylococcus aureus Resistente à Meticilina/genética , Tipagem de Sequências Multilocus , Prevalência , São Tomé e Príncipe/epidemiologia , Infecções Estafilocócicas/microbiologia , Fatores de Virulência/genética
13.
J Med Microbiol ; 67(8): 1042-1046, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29939129

RESUMO

Multidrug-resistant bacteria pose a major threat to effective antibiotics and alternatives to fight multidrug-resistant pathogens are needed. We synthetized molybdenum oxide (MoO3) nanoparticles (NP) and determined their antibacterial activity against 39 isolates: (i) eight Staphylococcus aureus, including representatives of methicillin-resistant S. aureus epidemic clones; (ii) six enterococci, including vancomycin-resistant isolates; and (iii) 25 Gram-negative isolates (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii, Enterobacter cloacae), including extended spectrum beta-lactamases and carbapenemases producers. All isolates showed a MoO3 NP MIC of 700-800 mg l-1. MoO3 NP produced a clear inhibition zone for S. aureus and all Gram-negative isolates at concentrations ≥25 mg ml-1 and ≥50 mg ml-1 for enterococci. When the NP solutions were adjusted to pH ~7, the biocidal activity was completely abolished. MoO3 NP create an acidic pH and show a universal antimicrobial activity against susceptible and resistant isolates belonging to the most relevant bacterial species responsible for hospital-acquired infections.


Assuntos
Antibacterianos/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Molibdênio/farmacologia , Nanopartículas , Óxidos/farmacologia , Antibacterianos/química , Infecções Bacterianas/microbiologia , Bactérias Gram-Negativas/isolamento & purificação , Bactérias Gram-Positivas/isolamento & purificação , Humanos , Concentração de Íons de Hidrogênio , Testes de Sensibilidade Microbiana , Molibdênio/química , Óxidos/química
14.
Clin Microbiol Infect ; 13(10): 971-9, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17697003

RESUMO

The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in Hungary has been increasing and is now close to 20% among invasive isolates of S. aureus. In order to understand the evolution of MRSA in Hungary, two collections of isolates were studied: 22 representatives of a collection of 238 MRSA isolates recovered between 1994 and 1998, and a collection of 299 MRSA isolates recovered between 2001 and 2004. The isolates were first characterised by pulsed-field gel electrophoresis (PFGE) and were distributed into 19 different PFGE patterns. Representatives of each pattern were further characterised by spa typing, multilocus sequence typing (MLST) and staphylococcal cassette chromosome mec (SCCmec) typing. The Hungarian clone that was predominant in 1994-1998 (PFGE E, ST239-III) had almost disappeared in 2003-2004, being replaced by the Southern German clone (PFGE B, ST228-I) and the New York/Japan epidemic clone (PFGE A, ST5-II), which represented c. 85% of the 2001-2004 isolates. Thus, this study describes, for the first time, the co-dominance and extensive spread of the New York/Japan clone in a European country.


Assuntos
Resistência a Meticilina/genética , Infecções Estafilocócicas/epidemiologia , Staphylococcus aureus/efeitos dos fármacos , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Técnicas de Tipagem Bacteriana , DNA Bacteriano/análise , DNA Bacteriano/isolamento & purificação , Eletroforese em Gel de Campo Pulsado , Evolução Molecular , Humanos , Hungria/epidemiologia , Meticilina/farmacologia , Testes de Sensibilidade Microbiana , Vigilância da População , Análise de Sequência de DNA , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/classificação , Staphylococcus aureus/genética , Staphylococcus aureus/isolamento & purificação
15.
Clin Microbiol Infect ; 12(1): 22-8, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16460542

RESUMO

Methicillin-resistant Staphylococcus aureus (MRSA) isolates (n = 216), collected between January 1999 and May 2003 in a tertiary-care university hospital in Guadalajara, Mexico, were characterised by antibiotype, pulsed-field gel electrophoresis (PFGE) of SmaI macrorestriction fragments, and hybridisation of ClaI digests with mecA- and Tn554-specific DNA probes. Representatives of the single clonal type found were analysed by spa typing, multilocus sequence typing and staphylococcal chromosomal cassette mec (SCCmec) typing, and were tested for the presence of 22 virulence determinants and agr type. A single PFGE pattern was identified, with minor variations over time, with spa type 2, sequence type 5, SCCmec type II, agr type 2 and the presence of the enterotoxin genes seg and sei, the gamma-haemolysin variant gene hlg-v and the leukocidin lukE-lukD genes. In addition, the isolates showed antimicrobial resistance to beta-lactams, macrolides, chloramphenicol and imipenem, and susceptibility to gentamicin, rifampicin, trimethoprim-sulphamethoxazole and vancomycin. Following its appearance in 1997, this clone spread within the hospital, and is now present in most of the hospital units and wards.


Assuntos
Hospitais Universitários , Resistência a Meticilina , Infecções Estafilocócicas/epidemiologia , Staphylococcus aureus/classificação , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/farmacologia , Técnicas de Tipagem Bacteriana , Criança , Pré-Escolar , DNA Bacteriano/análise , Eletroforese em Gel de Campo Pulsado , Genótipo , Humanos , Lactente , México/epidemiologia , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Fenótipo , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/genética , Staphylococcus aureus/patogenicidade , Virulência/genética
16.
J Mol Biol ; 225(1): 81-92, 1992 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-1583695

RESUMO

The virulent Bacillus subtilis bacteriophage SPP1 encapsidates its DNA by a headful mechanism. Analyzing phage missense mutants, which package less DNA than SPP1 wild-type but show no other affected properties, we have identified a gene whose product is involved in the sizing of phage DNA during maturation. Characterization of this gene and its product provides an experimental access to the poorly understood mechanism of DNA sizing in packaging. The gene (gene 6 or siz) was cloned and sequenced. An open reading frame (ORF) coding for a 57.3 kDa polypeptide was identified. All the single nucleotide substitutions present in different siz mutants affect the net charge of that protein. The gene was further characterized by assignment of several nonsense mutations (sus) to the ORF. Phages carrying the latter type of mutations could be complemented in trans when gene 6 is provided by a plasmid.


Assuntos
Bacteriófagos/genética , DNA Viral/genética , Genes Virais , Sequência de Aminoácidos , Bacillus subtilis , Bacteriófagos/ultraestrutura , Sequência de Bases , Clonagem Molecular , DNA Viral/metabolismo , Teste de Complementação Genética , Microscopia Eletrônica , Dados de Sequência Molecular , Mutação , Mapeamento por Restrição , Proteínas Virais/genética
17.
Microb Drug Resist ; 11(2): 83-93, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-15910220

RESUMO

We selected 106 methicillin-resistant Staphylococcus epidermidis (MRSE) and 22 methicillin-susceptible S. epidermidis (MSSE) hospital isolates--each with a different PFGE pattern--for more detailed documentation of genetic diversity. The 106 MRSE isolates showed extensive variation in the SmaI DNA fragments hybridizing with the DNA probe for mecA, the molecular size of which varied from as low as 20 kb up to over 500 kb. Parallel variation was also observed in the size of DNA fragments hybridizing with the chromosomal genes orfX and gyrA, and this was also observed in MSSE isolates. In contrast, SmaI fragments associated with the housekeeping genes murE and aroE, both located distantly from orfX, showed little size variation. Typing for the mec complex and ccr identified 10 different SCCmec structures and a large number of strains (21 isolates) that were non-typeable. The majority of strains studied (36%) carried a SCCmec type IV-like structure, including strains with non-related PFGE profiles. On the other hand, closely related strains often carried different types of SCCmec. The findings indicate that the acquisition and/or loss of mobile genetic elements, including various structural types of SCCmec, may occur frequently in the vicinity of the orfX gene on the S. epidermidis chromosome.


Assuntos
Resistência a Meticilina , Staphylococcus aureus/genética , Proteínas de Bactérias/genética , Cromossomos Bacterianos , Elementos de DNA Transponíveis , Eletroforese em Gel de Campo Pulsado , Variação Genética , Proteínas de Ligação às Penicilinas , Staphylococcus aureus/efeitos dos fármacos
18.
Microb Drug Resist ; 11(4): 309-22, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16359190

RESUMO

A total of 3,539 Streptococcus pneumoniae (Pn) were recovered from 4,969 nasopharyngeal samples of children attending 13 day-care centers (DCCs) located in Lisbon, Portugal, during a surveillance study from January, 2001, through March, 2003, integrated in the European intervention project (EURIS, European Resistance Intervention Study). All Pn isolates were tested for anti-biotyping and drug-resistant pneumococci (DRPn) were further tested by serotyping and pulsed-field gel electrophoresis (PFGE). Overall carriage of Pn was very high (71.2%) and 39.9% of the isolates were resistant to antimicrobials (22.5% with decreased susceptibility to penicillin and 17.4% susceptible to penicillin and resistant to other antimicrobials). Serotypes 6B, 14, 23 F, 19F, and 19 A were prevalent among the 1,287 DRPn and 5.8% of the isolates were non-typeable. Eighty PFGE patterns were identified among 1,285 DRPn, and 93.1% of the DRPn belonged to 26 major clonal types that comprised: Pneumococcal Molecular Epidemiology Network (PMEN) clones (76.3%), Portuguese (PT)-DCC clones, previously detected in 1996-1999 (14.3%), and EURIS PT-DCC new clones, identified for the first time in the EURIS study, during 2001-2003 (9.4%). Comparing with previous Portuguese surveillance studies carried out since 1996, we observed that carriage increased from 47% to 71%, but no major changes were detected on the prevalence of pneumococcal serotypes. Moreover, although PMEN clones were predominant in all DCCs, in the present study the majority of them were gradually decreasing in time whereas several PT-DCC and new clones seemed to be increasing.


Assuntos
Antibacterianos/farmacologia , Portador Sadio/microbiologia , Farmacorresistência Bacteriana Múltipla , Streptococcus pneumoniae/efeitos dos fármacos , Streptococcus pneumoniae/isolamento & purificação , Anticorpos Antibacterianos/sangue , Criança , Creches , Pré-Escolar , Eletroforese em Gel de Campo Pulsado , Humanos , Lactente , Testes de Sensibilidade Microbiana , Nasofaringe/microbiologia , Vigilância da População , Portugal , Streptococcus pneumoniae/genética
19.
Clin Microbiol Infect ; 11(3): 177-84, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15715714

RESUMO

As routine identification of coagulase-negative staphylococci is problematic, the performance of automated ribotyping was evaluated for identification of coagulase-negative staphylococci other than Staphylococcus epidermidis. In total, 177 isolates were tested, comprising 149 isolates from blood samples, 15 isolates that were not identified by internal transcribed spacer (ITS)-PCR in a previous study, and 13 reference strains. The identification results were compared with those obtained by the API 20 Staph system, with standard phenotypic and molecular methods as reference. Most (n = 166; 93.8%) isolates were identified correctly by automated ribotyping. For 61 isolates, API 20 Staph and ribotyping were in agreement, but for 105 isolates, ribotyping provided correct identification and API 20 Staph did not. Four isolates not identified by automated ribotyping were recognised correctly by API 20 Staph. The remaining seven isolates could not be identified by either of the two methods. Automated ribotyping was able to distinguish Staphylococcus capitis reliably from Staphylococcus caprae. The results demonstrate the value of automated ribotyping for identification of coagulase-negative Staphylococcus (CoNS) isolates from human sources and may help to clarify the clinical relevance of CoNS species. In addition, automated ribotyping was able to detect polymorphisms that may be useful for epidemiological purposes within S. capitis, Staphylococcus hominis, Staphylococcus haemolyticus, Staphylococcus simulans, S. caprae, Staphylococcus warneri, Staphylococcus lugdunensis, Staphylococcus schleiferi, Staphylococcus sciuri, Staphylococcus pasteuri and Staphylococcus xylosus.


Assuntos
Ribotipagem/métodos , Staphylococcus/classificação , Staphylococcus/isolamento & purificação , Fenótipo , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Especificidade da Espécie
20.
Clin Microbiol Infect ; 21(9): 842.e1-842.e10, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26003281

RESUMO

The aim of the present study was to determine the prevalence and risk factors for methicillin-resistant Staphylococcus aureus (MRSA) nasal carriage among patients and healthcare workers in Angola (ANG), São Tomé and Príncipe (STP), Cape Verde (CV) and East Timor (ET), and to characterize the antimicrobial susceptibility, virulence content and population structure of all S. aureus. Despite the importance of MRSA as a major human pathogen, data from these former Portuguese colonies in Africa and Asia are scarce. A total of 2065 nasal swabs recovered between 2010-14 were included in the study. Antimicrobial susceptibility testing and molecular characterization of S. aureus showed: (i) a very high MRSA prevalence in ANG (61.6%), moderate in STP (25.5%), low in CV (5.6%) and null in ET; (ii) a high prevalence of Panton-Valentine leukocidin in STP (36.8%), ET (29.2%) and CV (28.3%) contrasting with ANG (7.9%); (iii) ST5-SCCmecIVa, ST8-IV/V and ST5-VI were the major MRSA clones in ANG (65.2%), STP (44.8%) and CV (50%), respectively; (iv) a high resistance to trimethoprim-sulfamethoxazole in ANG (66.5%) and STP (50.9%), to rifampin in ANG (77.3%), and to tetracycline in STP (26.3%) and ET (20.8%); (v) three major methicillin-susceptible S. aureus clones (ST15, ST508, ST152) were present in all four countries. Age <18 years (OR 2.03, 95% CI 1.24-3.31), previous surgery (OR 2.45, 95% CI 1.24-4.83), no smoking (OR 4.04, 95% CI 1.05-15.50), and longer hospitalization (OR 2.53, 95% CI 1.49-4.28) were risk factors for MRSA carriage. This study provided the first comprehensive overview on MRSA in former Portuguese colonies in Africa and Asia, missing data in the world map.


Assuntos
Portador Sadio/epidemiologia , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Mucosa Nasal/microbiologia , Infecções Estafilocócicas/epidemiologia , Adolescente , Adulto , África/epidemiologia , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/farmacologia , Portador Sadio/microbiologia , Criança , Pré-Escolar , Ásia Oriental/epidemiologia , Feminino , Genótipo , Humanos , Lactente , Recém-Nascido , Masculino , Staphylococcus aureus Resistente à Meticilina/classificação , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/genética , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Tipagem Molecular , Fenótipo , Infecções Estafilocócicas/microbiologia , Fatores de Virulência/genética , Adulto Jovem
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