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1.
Fortschr Neurol Psychiatr ; 87(9): 499-502, 2019 Sep.
Artigo em Alemão | MEDLINE | ID: mdl-31519025

RESUMO

Strains of methicillin-resistant Staphylococcus aureus (MRSA) are of major economic and health-related importance to early neurological and neurosurgical rehabilitation. It is crucial to identify MRSA-carriers as soon as possible upon admission in order to prevent transmissions and to initiate contact precautions and decolonization. The present study focuses on validity of a polymerase chain reaction (PCR) test to identify MRSA genetic material from nasopharyngeal samples (BD MAX MRSA XT, BD Diagnostics, Heidelberg, Germany) of early neurological and neurosurgical rehabilitation patients. PCR-results were compared to gold standard (culture). In 2013, 66 patients were tested using PCR and incubation within one week after admission. Sensitivity of PCR was 84.6 %, specificity 86.6 %. Positive predictive value (PPV) was only 61.1 %, while negative predictive value was as high as 95.8 %. In 39 cases, PCR and subsequent culture were done within one day, leading to a sensitivity of 100 % and a specificity of 90.3 %. In this subgroup, PPV was 72.7 %, NPV 100 %. The results from the study suggest that incubation should quickly follow a positive PCR finding (within 24 hours) in order to verify MRSA colonization. High NPV (95.8 resp. 100 %) indicate that PCR negative patients very likely are not colonized with MRSA. A positive PCR test is less reliable (due to false positive results) and should be followed by incubation in due course in order to avoid unnecessary contact precautions.


Assuntos
Programas de Rastreamento/normas , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Reabilitação Neurológica , Reação em Cadeia da Polimerase/normas , Infecções Estafilocócicas/diagnóstico , Infecções Estafilocócicas/microbiologia , Alemanha , Humanos , Sensibilidade e Especificidade
2.
J Agric Food Chem ; 67(36): 10222-10234, 2019 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-31385700

RESUMO

The emergence and rapid spread of methicillin-resistant Staphylococcus aureus (MRSA) critically requires alternative therapeutic options. New antibacterial drugs and strategies are urgently needed to combat MRSA-associated infections. Here, we investigated the antibacterial activity of flavones from Morus alba and the potential mode of action against MRSA. Kuwanon G, kuwanon H, mulberrin, and morusin displayed high efficiency in killing diverse MRSA isolates. On the basis of structure-activity analysis, the cyclohexene-phenyl ketones and isopentenyl groups were critical to increase the membrane permeability and to dissipate the proton motive force. Meanwhile, mechanistic studies further showed that kuwanon G displayed rapid bactericidal activity in vitrowith difficulty in developing drug resistance. Kuwanon G targeted phosphatidylglycerol and cardiolipin in the cytoplasmic membrane through the formation of hydrogen bonds and electrostatic interactions. Additionally, kuwanon G promoted wound healing in a mouse model of MRSA skin infection. In summary, these results indicate that flavones are promising lead compounds to treat MRSA-associated infections through disrupting the proton motive force and membrane permeability.


Assuntos
Antibacterianos/farmacologia , Flavonas/farmacologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/metabolismo , Morus/química , Extratos Vegetais/farmacologia , Infecções Estafilocócicas/microbiologia , Animais , Antibacterianos/química , Antibacterianos/isolamento & purificação , Permeabilidade da Membrana Celular/efeitos dos fármacos , Feminino , Flavonas/química , Flavonas/isolamento & purificação , Flavonoides/química , Flavonoides/isolamento & purificação , Flavonoides/farmacologia , Humanos , Masculino , Meticilina/farmacologia , Staphylococcus aureus Resistente à Meticilina/genética , Camundongos , Camundongos Endogâmicos BALB C , Testes de Sensibilidade Microbiana , Extratos Vegetais/química , Raízes de Plantas/química , Força Próton-Motriz/efeitos dos fármacos
3.
APMIS ; 127(11): 717-726, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31407405

RESUMO

This study aims to determine the prevalence of Staphylococcus aureus colonizing patients and ICU environment of a teaching hospital, the virulence and antimicrobial susceptibility profile of the isolates, and to evaluate the genetic relationship among them. A total of 536 swabs (134 of patients and 402 of ICU environment) were collected and analyzed to detect S. aureus. The antimicrobial susceptibility of the isolates was determined by disk diffusion test, and the detection of the mecA and virulence factors genes was performed by PCR, in addition to SCCmec typing. The genetic similarity of the isolates was determined by PFGE. Staphylococcus aureus was isolated in 12.7% of the swabs. The prevalence of colonization was 13.4% in patients and 12.4% in the environmental samples. The multidrug resistance was determined in 82.4% of the isolates. The prevalence of methicillin-resistant S. aureus was 20.6%, with 50.0% classified as SCCmec IV. The intermediate resistance to vancomycin was detected in 5.9% and 4.4% of the isolates obtained from patients and environment, respectively. Identical isolates obtained from different patients and sources were grouped into several clusters. The results showed dissemination of multidrug-resistant strains between patients and fomites and the persistence of MRSA and VISA isolates in the ICU environment.


Assuntos
Antibacterianos/farmacologia , Resistência a Meticilina , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/patogenicidade , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/genética , Staphylococcus aureus/patogenicidade , Proteínas de Bactérias/genética , Farmacorresistência Bacteriana , Feminino , Variação Genética , Humanos , Unidades de Terapia Intensiva/estatística & dados numéricos , Masculino , Meticilina/farmacologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Filogenia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Vancomicina/farmacologia , Virulência , Fatores de Virulência/genética
4.
Vet Microbiol ; 235: 118-126, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31282369

RESUMO

The aim of the present study was to investigate the diversity of methicillin-resistant Staphylococcus aureus (MRSA) that originated from Austrian companion animals during the last five-year period. A total of 90 non-repetitive MRSA isolates were obtained during diagnostic activities from autumn 2013 to autumn 2018. They originated from horses (n = 62), cats (n = 13), dogs (n = 10), rabbits (n = 2), a domestic canary, a zoo-kept hammer-headed bat (Hypsignathus monstrosus) and a semi-captive northern bald ibis (Geronticus eremita). Antimicrobial susceptibility testing was performed. All isolates were mecA-positive and mecC-negative. The isolates were genotyped by SCCmec, spa and dru typing, Multiple-Locus Variable number of tandem repeat Analyses (MLVA), S. aureus DNA microarray, and whole-genome sequencing (WGS). Eight sequence types (STs - ST398, ST5275 (new ST), ST225, ST8, ST22, ST152, ST1, and ST45), three SCCmec types (II, IV, and V), sixteen spa types (t003, t008, t011, t015, t032, t034, t1381, t1928, t1985, t223, t334, t355, t430, t6447, t6867, and t7105), fourteen dru types (dt10a, dt10az, dt10q, dt10r, dt11a, dt5e, dt6j, dt9a, dt9ak, dt9g, and four new types dt8as, dt7ak, dt4j, dt14n), and thirty-five MLVA types were detected. WGS-based core genome MLST (cgMLST) displayed five main clusters. Compared to the time period 2004-2013, the results of the present study show not only a higher diversity among the MRSA isolates within the population of Austrian companion animals, but also the introduction of new clones. Although ST398 isolates remained predominant, mainly due to high presence of this lineage among horses, increasing isolation rates of human-associated MRSA clones were observed in cats and dogs.


Assuntos
Variação Genética , Staphylococcus aureus Resistente à Meticilina/classificação , Staphylococcus aureus Resistente à Meticilina/genética , Animais de Estimação/microbiologia , Infecções Estafilocócicas/veterinária , Animais , Antibacterianos/farmacologia , Técnicas de Tipagem Bacteriana , Gatos/microbiologia , Cães/microbiologia , Genótipo , Humanos , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Análise de Sequência com Séries de Oligonucleotídeos , Sequenciamento Completo do Genoma
5.
J Med Microbiol ; 68(9): 1367-1372, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31329093

RESUMO

Methicillin-resistant Staphylococcus lugdunensis (MRSL) is increasingly recognized in healthcare and community settings. To obtain a better understanding of the emergence of MRSL, this study characterized the structure and content of the SCCmec elements harboured by 36 MRSL isolates obtained from diverse sources in Hong Kong from 2008 to 2017. The isolates were investigated by whole-genome sequencing. SCCmec types and subtypes were assigned according to the guidelines from the International Working Group on the Classification of Staphylococcal Cassette Chromosome Elements. The sequence type (ST)-SCCmec combinations in the 36 MRSL isolates were as follows: ST3-SCCmec IV (n=2), ST3-SCCmec V (n=28), ST27-SCCmec V (n=5) and ST42-SCCmec V (n=1). The two SCCmec IV elements were highly similar to the SCCmec IV element harboured by the community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) strain, JCSC6668. The J3-mec complex-J2 regions in the SCCmec V elements were highly similar to the corresponding regions in the CA-MRSA strains PM1 (n=13) or WIS (n=21). Based on the J1 to J3 sequences, the SCCmec V elements can be categorized into nine different subtypes. Our findings highlight the diversified structures of SCCmec elements among MRSL strains and their close relationship with SCCmec elements harboured by CA-MRSA.


Assuntos
Cromossomos Bacterianos/genética , Infecções Comunitárias Adquiridas/microbiologia , Genes Bacterianos/genética , Staphylococcus aureus Resistente à Meticilina/genética , Infecções Estafilocócicas/microbiologia , Staphylococcus lugdunensis/genética , Antibacterianos/farmacologia , Infecções Comunitárias Adquiridas/epidemiologia , DNA Bacteriano/genética , Genoma Bacteriano/genética , Hong Kong/epidemiologia , Humanos , Staphylococcus aureus Resistente à Meticilina/classificação , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Testes de Sensibilidade Microbiana , Epidemiologia Molecular , Análise de Sequência de DNA , Infecções Estafilocócicas/epidemiologia , Estudantes de Medicina
6.
Rev Soc Bras Med Trop ; 52: e20190095, 2019 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-31340369

RESUMO

INTRODUCTION: Staphylococcus aureus is a major nosocomial pathogen that is associated with high virulence and the rapid development of drug resistance. METHODS: We analyzed and compared the antimicrobial resistance, virulence profiles, and molecular epidemiology of 67 S. aureus strains, including 36 methicillin-sensitive (MSSA) and 31 methicillin-resistant (MRSA) strains recovered from a public hospital located in south-eastern Brazil. RESULTS: The clones circulating in this hospital presented a great diversity, and the majority of the strains were related to clones responsible for causing worldwide epidemics: these included USA100 (New York/Japan clone), USA300, and USA600. The 31 MRSA (22 SCCmecII and 9 SCCmecIV) and 36 MSSA strains exhibited low resistance against gentamicin and trimethoprim/sulfamethoxazole. No MRSA strain showed resistance to tetracycline. Virulence gene carriage was more diverse and abundant in MSSA than in MRSA. Of the evaluated adhesion-related genes, ebpS was the most prevalent in both MSSA and MRSA strains. The genes bbp and cna showed a strong association with MSSA strains. CONCLUSIONS: Our findings reinforce the idea that MSSA and MRSA strains should be carefully monitored, owing to their high pathogenic potential.


Assuntos
Antibacterianos/farmacologia , Resistência a Meticilina , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/genética , Fatores de Virulência/genética , Brasil/epidemiologia , Hospitais Públicos , Humanos , Testes de Sensibilidade Microbiana , Epidemiologia Molecular , Infecções Estafilocócicas/epidemiologia , Staphylococcus aureus/classificação , Staphylococcus aureus/isolamento & purificação , Centros de Atenção Terciária , Virulência/genética
7.
Int J Food Microbiol ; 305: 108244, 2019 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-31202150

RESUMO

This study examined the prevalence and phenotypic and genotypic antibiotic resistance patterns of Staphylococcus aureus in sushi from 20 Danish outlets. Microbial quality of sushi products and food inspector ranking of outlets were assessed and results for thirteen of the outlets were compared with findings from a previous study in 2012. Inspector rankings were similar in the two studies. The mesophilic aerobic counts were slightly lower (p = 0.0296) in 2017 than in 2012 with average values of the 13 shops of 5.2 log CFU/g and 5.7 log CFU/g, respectively. In both studies E. coli was only found in the products from outlets that did not have consistently superior rankings. On the other hand prevalence and average counts of Staphylococcus spp. were slightly higher in 2017 (p = 0.0286) but no methicillin-resistant S. aureus (MRSA) were observed in the present study. Methicillin-sensitive S. aureus (MSSA) were, however, isolated from 18.7% of sushi products with an average count below 2 log CFU/g. Based on spa and multilocus sequence typing (MLST), isolates belonged to clonal complex CC7 (t2016), CC20 (t7836), CC45 (t065, t127, t362), CC88 (t1998) and CC398 (t164, t331, t1451). The Panton-Valentine leukocidin (PVL)-encoding gene lukF was detected only in isolates of the t065 spa-type whereas the scn gene from the ΦSa3 prophage was detected in 76.5% of the isolates, supporting that the majority of isolates were of likely human origin. Thirty-six isolates (70.6%) were resistant to at least one of the antibiotic compounds tested. Antibiotic resistance genes that confer resistance to ß-lactams (blaZ) and macrolides (ermC) were detected in 33.3% and 9.8% of isolates, respectively. The tet(K) gene that encode tetracycline resistance was only found in a t7836 strain. Overall, this study indicates that S. aureus in sushi products in Denmark do not represent a major food safety hazard due to, firstly, the low temperature and limited time of storage of product may prevent significant growth and production of toxic levels of enterotoxin of this species. Secondly, the S. aureus isolates obtained did not include MRSA variants and none of them encoded PVL that constitute one of the virulence factors in pathogenesis. Several MSSA isolates contained however genes encoding antibiotic resistance, which emphasize the potential role of foods as vehicles for transmission of such variants.


Assuntos
Farmacorresistência Bacteriana , Produtos Pesqueiros/microbiologia , Inspeção de Alimentos/normas , Animais , Antibacterianos/farmacologia , Dinamarca , Escherichia coli/classificação , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Peixes , Humanos , Meticilina/farmacologia , Staphylococcus aureus Resistente à Meticilina/classificação , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/classificação , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/genética , Staphylococcus aureus/isolamento & purificação , Fatores de Virulência/genética , beta-Lactamas/farmacologia
8.
J Dairy Sci ; 102(8): 6876-6884, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31155252

RESUMO

Staphylococcus aureus is one of the leading causes of food-borne illness worldwide. Raw milk and dairy products are often contaminated with enterotoxigenic strains of this bacterium. Some of these strains carry antimicrobial resistance, leading to a potential risk for consumers. The aim of this study was to characterize S. aureus strains circulating in raw milk and traditional dairy products for carriage of staphylococcal enterotoxin (se) genes and antimicrobial resistance. Overall, 62 out of 270 samples (23%) were contaminated with S. aureus, and 69 S. aureus strains were identified. We studied the enterotoxin genes using 2 multiplex PCR targeting 11 se genes. Seventeen (24.6%) isolates carried one or more genes encoding for staphylococcal enterotoxins. The most commonly detected se genes were seb and sep, followed by seh, sea, and see. Using the disk diffusion method, we found that resistance to penicillin G and tetracycline was the most common. Eleven isolates of methicillin-resistant S. aureus (MRSA) carried the mecA gene. All MRSA isolates belonged to the same spa type (t024) and sequence type (ST8), and carried the seb and sep enterotoxin genes. However, none of them carried the Panton Valentine leukocidin gene (lukF/S-PV). The presence of enterotoxigenic S. aureus strains, including MRSA, in raw milk and dairy products, raises a serious public health concern, because these strains may cause food poisoning outbreaks, be disseminated to the population, or both.


Assuntos
Laticínios/microbiologia , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Leite/microbiologia , Argélia , Animais , Toxinas Bacterianas/genética , Bovinos , Farmacorresistência Bacteriana/genética , Enterotoxinas/genética , Exotoxinas/genética , Leucocidinas/genética , Staphylococcus aureus Resistente à Meticilina/genética , Testes de Sensibilidade Microbiana , Penicilina G , Resistência às Penicilinas/genética , Infecções Estafilocócicas/epidemiologia , Resistência a Tetraciclina/genética
9.
Vet Microbiol ; 233: 5-10, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31176412

RESUMO

This work aimed to determine the prevalence, diversity, antibiotic-resistance phenotype/genotype and virulence factors in staphylococci of farm-animals. Nasal samples of 117 farm-animals (calve: 72; lamb: 37; goat: 8) were collected from one slaughterhouse in La Rioja/Spain and cultured for staphylococci and methicillin-resistant Staphylococcus (MRS) recovery. Identification was performed by MALDI-TOF. Antimicrobial resistance phenotype/genotype was determined by susceptibility testing and specific PCRs. Molecular typing (spa-typing, multilocus-sequence-typing, agr-typing, SCCmec), and detection of 12 virulence genes and human Immune-evasive-cluster (IEC) genes were performed by PCR/sequencing in S. aureus. Two marker genes of arginine catabolic mobile element (ACME) were determined by PCR (USA300-MRSA detection). Staphylococci were identified in 50%, 54% and 21% of goat, lamb and calve samples, respectively. Among the 13 S. aureus isolates recovered, 11 were susceptible to all antimicrobials tested, and two were multidrug-resistant-MRSA [beta-lactams (blaZ, mecA), macrolides [(msr(A)/msr(B)] and fluoroquinolones]. The MSSA harboured either tst or enterotoxin genes, while the MRSA harboured the lukF/lukS-PV genes. Five sequence-types were detected. The two MRSA strains (from lamb and goat) were typed as t5173/ST8/agr-I/SCCmec-IVa/ACME-positive, corresponding to USA300 clone, and were IEC-B-positive. Among the 47 coagulase-negative staphylococci (CoNS), six species were identified, predominating S. simulans (n = 25) and S. sciuri (n = 11). Fifty-three percent of CoNS showed resistance to at least one antimicrobial agent (six multidrug-resistant strains), and the following resistance phenotypes/genotypes were detected: streptomycin [27.6%; ant(6)-Ia, str], tetracycline [23.4%; tet(M), tet(L), tet(K)], clindamycin [19.1%; lnu(A), vgaA], erythromycin [10.6%; erm(C), msr(A)/msr(B)], chloramphenicol (8.5%; fexA), tobramycin (6.4%), penicillin-cefoxitin (4.3%; blaZ, mecA), and SXT (2.1%). The detection of the MRSA-USA300 lineage in food animals is worrisome and should be further monitored.


Assuntos
Portador Sadio/veterinária , Reservatórios de Doenças/veterinária , Variação Genética , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus/classificação , Fatores de Virulência/genética , Animais , Antibacterianos/farmacologia , Portador Sadio/microbiologia , Reservatórios de Doenças/microbiologia , Farmacorresistência Bacteriana Múltipla/genética , Genes Bacterianos , Genótipo , Cabras/microbiologia , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Testes de Sensibilidade Microbiana , Nariz/microbiologia , Reação em Cadeia da Polimerase , Prevalência , Carne Vermelha/microbiologia , Ovinos/microbiologia , Espanha/epidemiologia , Infecções Estafilocócicas/epidemiologia , Staphylococcus/efeitos dos fármacos , Tetraciclina/farmacologia
10.
Int J Food Microbiol ; 304: 119-126, 2019 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-31195259

RESUMO

Staphylococcus aureus encodes numerous toxins that are known or strongly suspected to cause specific diseases or symptoms. Panton-Valentine leukocidin (PVL) is one of these important toxins that is associated with high mortality rates. In our previous study, 1581 S. aureus strains were isolated from 4300 samples of retail foods obtained from most of the provincial capitals in China from 2011 to 2016. This study aimed to investigate the prevalence of PVL-positive S. aureus isolates from retail foods in China and characterize these isolates by antibiotic resistance testing, spa typing, multilocus sequence typing (MLST) and enterotoxin gene analyses. In total, seventy-two isolates (72/1581, 4.6%) possessed pvl genes, including 24.1% MRSA isolates (26/108) and 3.1% MSSA isolates (46/1473), covering different types of food. The strains were divided into seventeen sequence types (STs) and twenty-seven spa types, and 43.1% (31/72) of the PVL-positive S. aureus isolates belonged to CC59-t437. These isolates contained at least one of the following enterotoxin genes: sei (97.2%), sem (86.1%), seq (80.6%), seg (68.1%), sek (68.1%), seb (62.5%), sel (52.8%), sej (50.0%), seh (48.6%), sep (45.8%), sea (38.9%), ser (37.5%), sen (27.8%), sec (16.7%), see (16.7%), sed (6.9%), seo (6.9%) and seu (6.7%). A total of 87.5% of the S. aureus isolates (63/72) harboured the classic SE genes (sea, seb, sec, sed, and see), whereas all the S. aureus isolates harboured the genes of the egc cluster (seg, sei, sem, sen, seo, and seu). In antimicrobial susceptibility tests, 98.6% of the isolates (71/72) exhibited resistance to at least one antibiotic, including 47 multi-drug-resistant isolates. Resistance to penicillin (94.4%), erythromycin (83.4%), clindamycin (63.9%), kanamycin (61.1%), telithromycin (58.3%), streptomycin (51.4%), tetracycline (47.2%), chloramphenicol (27.8%), fusidic acid (27.8%) and other antibiotics (<20%) was observed. All the PVL-positive MRSA isolates belonged to CC59-t437, which is the predominant type of community-associated (CA)-MRSA in China. The presence of these isolates in food represents a potential health risk for consumers and warrants further attention.


Assuntos
Toxinas Bacterianas/genética , Farmacorresistência Bacteriana Múltipla/genética , Enterotoxinas/genética , Exotoxinas/genética , Leucocidinas/genética , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/genética , Infecções Estafilocócicas/epidemiologia , Antibacterianos/farmacologia , China/epidemiologia , Contaminação de Alimentos/análise , Microbiologia de Alimentos/métodos , Doenças Transmitidas por Alimentos/microbiologia , Genótipo , Humanos , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Staphylococcus aureus Resistente à Meticilina/patogenicidade , Tipagem de Sequências Multilocus , Prevalência , Infecções Estafilocócicas/microbiologia
11.
Pol J Microbiol ; 68(1): 93-104, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31050257

RESUMO

Staphylococcus aureus is a common human and livestock opportunistic pathogen, and there is evidence of animal to human transmission. This paper aimed to recognize properties of the isolates from collections of human and livestock S. aureus strains and to estimate compatibility of results based on phenotypic tests, microarrays and the spa typing methods. The second goal was to study differences between human and animal isolates in terms of specificity of their hosts and the strain transmission among various hosts. Most strains showed multi-susceptible profiles and produced enzymes on a high level, and they were phenotypically and genetically similar. However, in contrast to the Polish bovine mastitis strains, the Slovakian strains were multi-resistant. In this research, the strains showed significant differences in terms of their phenotypic manifestations and the presence of hemolysins genes; however, other enzyme-encoding genes correlated to a higher extent with the microarrays results. Interestingly, there was a lack of enterotoxin genes in human Poultry-like protein A+ strains in comparison to other human strains. Our study showed that differences between virulence profiles of the human and animal strains correlated with their origin rather than their hosts, and any trait allowed clearly distinguishing between them based on the microarray results.Staphylococcus aureus is a common human and livestock opportunistic pathogen, and there is evidence of animal to human transmission. This paper aimed to recognize properties of the isolates from collections of human and livestock S. aureus strains and to estimate compatibility of results based on phenotypic tests, microarrays and the spa typing methods. The second goal was to study differences between human and animal isolates in terms of specificity of their hosts and the strain transmission among various hosts. Most strains showed multi-susceptible profiles and produced enzymes on a high level, and they were phenotypically and genetically similar. However, in contrast to the Polish bovine mastitis strains, the Slovakian strains were multi-resistant. In this research, the strains showed significant differences in terms of their phenotypic manifestations and the presence of hemolysins genes; however, other enzyme-encoding genes correlated to a higher extent with the microarrays results. Interestingly, there was a lack of enterotoxin genes in human Poultry-like protein A+ strains in comparison to other human strains. Our study showed that differences between virulence profiles of the human and animal strains correlated with their origin rather than their hosts, and any trait allowed clearly distinguishing between them based on the microarray results.


Assuntos
Reservatórios de Doenças/microbiologia , Mastite Bovina/microbiologia , Staphylococcus aureus Resistente à Meticilina/classificação , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Infecções Estafilocócicas/microbiologia , Animais , Antibacterianos/farmacologia , Bovinos , Farmacorresistência Bacteriana Múltipla/genética , Proteínas Hemolisinas/genética , Humanos , Gado/microbiologia , Staphylococcus aureus Resistente à Meticilina/genética , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Infecções Oportunistas/microbiologia
12.
J Med Microbiol ; 68(6): 957-960, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31050633

RESUMO

The qacA/B gene is one of the major determinants of resistance to antiseptics in methicillin-resistant Staphylococcus aureus (MRSA). Here, we compared the fast-acting bactericidal activity of skin antiseptics, including olanexidine gluconate (OLG), a new biguanide antiseptic agent introduced in Japan, against clinical qacA/B-positive MRSA strains by determination of minimum bactericidal concentration and time-kill assay. Our findings provide, for the first time, data indicating that the fast-acting bactericidal activity of OLG against qacA/B-positive MRSA is higher than that of chlorhexidine gluconate, even though both are biguanide antiseptics.


Assuntos
Anti-Infecciosos Locais/farmacologia , Proteínas de Bactérias/genética , Biguanidas/farmacologia , Glucuronatos/farmacologia , Proteínas de Membrana Transportadoras/genética , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Infecções Estafilocócicas/microbiologia , Clorexidina/análogos & derivados , Clorexidina/farmacologia , Meticilina/farmacologia , Staphylococcus aureus Resistente à Meticilina/enzimologia , Staphylococcus aureus Resistente à Meticilina/genética , Infecções Estafilocócicas/tratamento farmacológico
13.
BMC Infect Dis ; 19(1): 402, 2019 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-31077140

RESUMO

BACKGROUND: There have been no reports regarding clinical features and molecular characteristics of childhood methicillin-susceptible Staphylococcus aureus (MSSA) infections in Taiwan. METHODS: We prospectively collected clinical S. aureus isolates from patients aged < 18 years in a university-affiliated hospital in 2015. Only the first isolate from each patient was included. Medical records were retrospectively reviewed. Patients were classified as community-associated (CA) or healthcare-associated (HA) by the epidemiologic criteria. All MSSA isolates were molecularly characterized. RESULTS: A total of 495 S. aureus isolates were identified, and 178 (36.0%) were MSSA. Among the 131 MSSA-infected patients enrolled, 94 (71.8%) were community-associated and 60 (45.8%) were inpatients. Patients with HA infections was significantly younger than those with CA infections (median, 15 vs. 67.5 months). The most common specimen of MSSA identified was pus or wound (73.3%). Compared to HA-MSSA, CA-MSSA isolates were significantly less frequently from sputum (6.4% vs. 27%, p = 0.001). Nineteen pulsotypes were identified. Four pulsotypes accounted for 60% of the isolates. Isolates of ST15/pulsotype F were more frequently seen in CA than in HA (p = 0.064) while isolates of ST188/pulsotype AX frequently seen in HA (p = 0.049). PVL genes were identified in 11 isolates (8.4%), nine of which were characterized as ST59/pulsotype D, same as the local endemic CA-MRSA clone. CONCLUSIONS: MSSA accounted for around one-third of childhood S. aureus infections in northern Taiwan. SSTI was the most common manifestation. The molecular characteristics of these clinical MSSA isolates were relatively diverse and had certain significant differences between CA and HA isolates.


Assuntos
Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Infecções Estafilocócicas/microbiologia , Adolescente , Criança , Pré-Escolar , Infecções Comunitárias Adquiridas/microbiologia , Infecção Hospitalar/microbiologia , Feminino , Hospitais Universitários , Humanos , Masculino , Staphylococcus aureus Resistente à Meticilina/genética , Estudos Prospectivos , Estudos Retrospectivos , Infecções Estafilocócicas/epidemiologia , Taiwan/epidemiologia
14.
BMC Infect Dis ; 19(1): 478, 2019 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-31142269

RESUMO

BACKGROUND: Staphylococcus aureus and beta-hemolytic streptococci (BHS) diseases disproportionately affect populations in middle/low-income countries. To assess if this disparity is reflected in colonization by these organisms, we compared their colonization frequency among children from different socioeconomic status (SES) communities in a city with high income inequality. METHODS: Between May-August 2014, we collected nasal and throat swabs to investigate S. aureus and BHS colonization among children who attended private and public pediatric clinics. Patients were classified as high SES, middle/low SES, and slum residents. We investigated the antimicrobial resistance profile, the SCCmec types and the presence of PVL genes among methicillin-resistant S. aureus (MRSA). We also examined the antimicrobial resistance profile and serogroups of BHS. RESULTS: Of 598 children, 221 (37%) were colonized with S. aureus, of which 49 (22%) were MRSA. MRSA colonization was higher in middle/low SES (n = 18; 14%) compared with high SES (n = 17; 6%) and slum (n = 14; 8%) residents (p = 0.01). All MRSA strains were susceptible to clindamycin, nitrofurantoin, and rifampin. The highest non-susceptibility frequency (42.9%) was observed to erythromycin. SCCmec type V was only found in isolates from high SES children; types I and II were found only in middle/low SES children. Ten (20%) MRSA isolates carried PVL genes. Twenty-four (4%) children were BHS carriers. All BHS (n = 8) found in high SES children and six (67%) isolates from slum patients belonged to group A. All group B streptococci were from middle/low SES children, corresponding to five (71%) of the seven BHS isolated in this group. BHS isolates were susceptible to all drugs tested. CONCLUSIONS: Children from different SES communities had distinct bacterial colonization profiles, including MRSA carriage. Public health officials/researchers should consider SES when assessing disease transmission and control measures.


Assuntos
Farmacorresistência Bacteriana , Infecções por Bactérias Gram-Positivas/diagnóstico , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Criança , Pré-Escolar , Estudos Transversais , Farmacorresistência Bacteriana/efeitos dos fármacos , Feminino , Infecções por Bactérias Gram-Positivas/microbiologia , Humanos , Masculino , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Testes de Sensibilidade Microbiana , Cavidade Nasal/microbiologia , Fatores de Risco , Fatores Socioeconômicos , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/genética , Staphylococcus aureus/isolamento & purificação , Streptococcus/efeitos dos fármacos , Streptococcus/genética , Streptococcus/isolamento & purificação
15.
Braz J Infect Dis ; 23(2): 134-138, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31103436

RESUMO

This study characterized 30 MRSA isolates from intensive care unit (ICU) environment and equipment surfaces and healthy children. The SCCmec types I, IVa and V were detected in HA-MRSA isolates while CA-MRSA showed the SCCmec type IVa and V. Most isolates were classified as agr group II. All isolates presented the sei gene, and only HA-MRSA were positive for etb e tst genes. Three genotypes were related to Pediatric (ST5/SCCmecIV) and Berlin (ST45/SCCmecIV) clones. The present study showed molecular similarity between CA- and HA-MRSA isolates in hospital and community settings in a Brazilian region.


Assuntos
Infecções Comunitárias Adquiridas/microbiologia , Infecção Hospitalar/microbiologia , Unidades de Terapia Intensiva/estatística & dados numéricos , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Brasil , Equipamentos e Provisões Hospitalares/microbiologia , Genótipo , Humanos , Staphylococcus aureus Resistente à Meticilina/patogenicidade , Infecções Estafilocócicas/genética , Infecções Estafilocócicas/microbiologia , Fatores de Virulência/genética , Fatores de Virulência/isolamento & purificação
16.
Analyst ; 144(12): 3878-3885, 2019 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-31114822

RESUMO

As molecular diagnostics move away from polymerase chain reaction (PCR) in order to target point-of-care testing applications, loop-mediated isothermal amplification (LAMP) is gaining popularity due its rapid, sensitive and specific detection with simpler instrumentation. However, while Taqman PCR enables real-time quantitative readout and multiplexed gene detection in single samples, analogous methods in LAMP are not yet broadly developed. To date, the real-time detection methods applied to LAMP involve turbidimetry or measuring fluorescence of an intercalator; however, both of these methods are nonspecific to the target of interest and do not allow for multiple gene detection in a single sample. Probe-based methods have been developed to address the need for specific target detection and multiplexed, one-pot reactions, but most of these methods have strict assay conditions and require the design of loop primers, which is not always possible. DARQ LAMP is a probe-based method that offers the most promise for quantitative and real-time multiplexed detection, as it has a relatively simple design and can be used in either a four-primer or six-primer system. However, previous work has only shown the assay to function well in a narrow range of reaction conditions, which is restrictive given that various LAMP assays require a broad range of conditions. In this work we investigate the use of the newest-generation strand-displacing polymerase and demonstrate that it has higher tolerance to reaction conditions than previous polymerases. Using the results from these studies, we demonstrate a single-reaction triplex assay for the detection of methicillin-resistant S. aureus (MRSA), which would not be possible with any of the previously reported LAMP systems.


Assuntos
DNA Bacteriano/química , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Técnicas de Amplificação de Ácido Nucleico/métodos , Sequência de Bases , DNA Bacteriano/genética , DNA Polimerase Dirigida por DNA/química , Fluorescência , Corantes Fluorescentes/química , Limite de Detecção , Staphylococcus aureus Resistente à Meticilina/genética
17.
Zoonoses Public Health ; 66(5): 512-525, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31124311

RESUMO

Food animals are considered reservoirs of methicillin-resistant Staphylococcus aureus (MRSA) and are implicated in their zoonotic transmission in the farm-to-plate continuum. LA-MRSA has been reported as a zoonotic agent that has the potential to spread to humans and may cause infections in at-risk groups. In this study, whole genome sequencing was used to describe the genetic environment (resistance mechanisms, virulence factors and mobile genetic elements) and investigate the genetic lineages of MRSA isolates from pigs in Cameroonian and South African abattoirs. During March-October 2016, 288 nasal and rectal pooled samples from 432 pigs as well as nasal and hand swabs from 82 humans were collected. Genomic DNA was sequenced using an Illumina MiSeq platform. Generated reads were de novo-assembled using the Qiagen CLC Genomics Workbench and SPAdes. The assembled contigs were annotated, and antibiotic resistance genes, virulence factors, plasmids, SCCmec and phage elements were identified with ResFinder, Virulence Finder, PlasmidFinder, SCCmec Finder and PHAST, respectively. Core genome single nucleotide analysis was undertaken to assess clonal relatedness among isolates. A lower MRSA prevalence was observed in pigs in Cameroon (n = 1/13; 0.07%) compared with South Africa (n = 4/22; 18.18%), and none of the workers were colonized by MRSA. Genome analysis identified various antibiotic resistance genes along with six virulence factors in all isolates. All MRSA isolates belonged to the clonal lineage ST398 (spa-type t011) and harboured the type Vc SCCmec and several plasmids. Our study shows that the livestock-associated MRSA clonal lineage ST398 is already present in both Cameroon and South Africa and is probably underestimated in the absence of molecular epidemiological studies. It reveals the serious food safety and public health threat associated with this animal strain and underscores the need for interventions to contain this resistant clone.


Assuntos
Genoma Bacteriano , Staphylococcus aureus Resistente à Meticilina/genética , Infecções Estafilocócicas/veterinária , Doenças dos Suínos/microbiologia , Zoonoses/microbiologia , Animais , Camarões/epidemiologia , Tipagem de Sequências Multilocus , Filogenia , África do Sul/epidemiologia , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/microbiologia , Suínos , Doenças dos Suínos/epidemiologia , Zoonoses/epidemiologia
18.
J Appl Microbiol ; 127(1): 284-291, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31063623

RESUMO

AIMS: To determine the Staphylococcus aureus carriage rate in wild mammals in Aragon, northern Spain, to analyse their antimicrobial resistance phenotype/genotype and to characterize the recovered isolates. METHODS AND RESULTS: Nasal and rectal swabs of 103 mammals were collected in Aragón during the period 2012-2015. Antimicrobial susceptibility, the presence of antimicrobial resistance genes and virulence factors were investigated. Molecular characterization was carried out by spa, MLST, agr and SCCmec. Staphylococcus aureus were recovered from 23 animals (22%). Four of the 23 S. aureus were methicillin-resistant S. aureus (MRSA). Three MRSA were mecC-positive and were isolated from European rabbits and were typed as t843 (ascribed to CC130). The remaining MRSA was a mecA-carrying isolate from European hedgehog, typed as ST1-t386-SCCmecIVa-agrIII and it harboured the blaZ, erm(C), ant(6)-Ia and aph(3´)-IIIa resistance genes. A high diversity of spa-types was detected among the 19 methicillin-susceptible S. aureus isolates, which showed high susceptibility to the antimicrobials tested. The tst gene and different combinations of staphylococcal enterotoxins were found. CONCLUSIONS: Staphylococcus aureus were detected in nasal and rectal samples of wild mammals. Wild rabbits could be a reservoir of mecC-MRSA. SIGNIFICANCE AND IMPACT OF THE STUDY: This work provides information on the presence and characteristics of S. aureus from mammals in a defined geographic region in Spain.


Assuntos
Variação Genética , Infecções Estafilocócicas/veterinária , Staphylococcus aureus/genética , Animais , Animais Selvagens/microbiologia , Antibacterianos/farmacologia , Farmacorresistência Bacteriana/genética , Mamíferos/microbiologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Coelhos/microbiologia , Espanha/epidemiologia , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/isolamento & purificação , Fatores de Virulência/genética
19.
Microb Pathog ; 133: 103543, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31102653

RESUMO

PURPOSE: Whole genome sequencing (WGS) analysis of Staphylococcus aureus is increasingly used in clinical practice. Although bioinformatics tools used in WGS analysis readily define the S. aureus virulome, the clinical value of this type of analysis is unclear. Here, virulence genes in S. aureus bacteremia (SAB) isolates were evaluated by WGS, with superantigens (SAgs) further evaluated by conventional PCR and functional assays, and results correlated with mortality. METHODS: 152 SAB isolates collected throughout 2015 at a large Minnesota medical center were studied and associated clinical data analyzed. Virulence genes were identified from previously-reported WGS data (https://doi.org/10.1371/journal.pone.0179003). SAg genes sea, seb, sec, sed, see, seg, seh, sei, sej, and tst were also assessed by individual PCR assays. Mitogenicity of SAgs was assessed using an in vitro proliferation assay with splenocytes from HLA-DR3 transgenic mice. RESULTS: Of the 152 SAB isolates studied, 106 (69%) were methicillin-susceptible S. aureus (MSSA). The number of deaths attributed and not attributed to SAB, and 30-day survivors were 24 (16%), 2 (1%), and 128 (83%), respectively. From WGS data, both MSSA and MRSA had high proportions of adhesion (>80%) and immune-evasion (>70%) genes. There was no difference in virulomes between survivor- and non-survivor-associated isolates. Although over 60% of SAB isolates produced functional SAgs, there were no differences in the distribution or prevalence of SAg genes between survivor- and non-survivor-associated isolates. CONCLUSION: In this study of one year of SAB isolates from a large medical center, the S. aureus virulome, as assessed by WGS, and also for SAgs using individual PCRs and phenotypic characterization, did not impact mortality.


Assuntos
Bacteriemia/microbiologia , Bacteriemia/mortalidade , Farmacorresistência Bacteriana/genética , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/mortalidade , Staphylococcus aureus/genética , Staphylococcus aureus/patogenicidade , Idoso , Idoso de 80 Anos ou mais , Animais , Bacteriemia/imunologia , Aderência Bacteriana/genética , Sequência de Bases , Proliferação de Células , Feminino , Antígeno HLA-DR3 , Humanos , Evasão da Resposta Imune/genética , Masculino , Staphylococcus aureus Resistente à Meticilina/genética , Camundongos , Camundongos Transgênicos , Pessoa de Meia-Idade , Minnesota , Reação em Cadeia da Polimerase , Infecções Estafilocócicas/imunologia , Superantígenos/genética , Superantígenos/imunologia , Virulência/genética , Fatores de Virulência/genética
20.
BMC Res Notes ; 12(1): 244, 2019 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-31036061

RESUMO

OBJECTIVES: Diabetic foot ulcers (DFUs) often lead to hospital admissions, amputations and deaths; however, there is no up-to-date information on microbial isolates from DFUs and no mention of utilization of molecular techniques in Sub-Saharan Africa. We conducted a cross-sectional study among 83 adult patients at a tertiary hospital in Kenya over 12 months. The study aimed to isolate, identify bacteria, their antibiotic susceptibility patterns in active DFUs, and to compare standard microbiological methods versus a real-time PCR commercial kit in the detection of Staphylococcus aureus DNA and methicillin-resistant S. aureus (MRSA) DNA. RESULTS: Eighty swabs (94%) were culture-positive; 29% were Gram-positive and 65% were Gram-negative. The main organisms isolated were S. aureus (16%), Escherichia coli (15%), Proteus mirabilis (11%), Klebsiella pneumoniae (7%) and Pseudomonas aeruginosa (7%). The bacterial isolates showed resistance to commonly used antibiotics such as ampicillin, amoxicillin, cefepime, ceftazidime, cefuroxime, clindamycin, erythromycin, piperacillin-tazobactam, tetracycline and trimethoprim-sulphamethoxazole (TMPSMX). Thirty-one percent of the S. aureus isolated and 40% of the Gram-negatives were multi-drug resistant organisms (MDROs). There was a high prevalence of nosocomial bacteria. MRSA were not identified using culture methods but were identified using PCR. PCR was more sensitive but less specific than culture-based methods to identify S. aureus.


Assuntos
Antibacterianos/uso terapêutico , Infecções Bacterianas/diagnóstico , Pé Diabético/diagnóstico , Farmacorresistência Bacteriana Múltipla , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Infecções Bacterianas/tratamento farmacológico , Infecções Bacterianas/epidemiologia , Infecções Bacterianas/microbiologia , Técnicas de Tipagem Bacteriana , Cefalosporinas/uso terapêutico , Clindamicina/uso terapêutico , Estudos Transversais , Pé Diabético/tratamento farmacológico , Pé Diabético/epidemiologia , Pé Diabético/microbiologia , Escherichia coli/classificação , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Humanos , Quênia/epidemiologia , Klebsiella pneumoniae/classificação , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/isolamento & purificação , Macrolídeos/uso terapêutico , Staphylococcus aureus Resistente à Meticilina/classificação , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Testes de Sensibilidade Microbiana , Penicilinas/uso terapêutico , Proteus mirabilis/classificação , Proteus mirabilis/efeitos dos fármacos , Proteus mirabilis/genética , Proteus mirabilis/isolamento & purificação , Pseudomonas aeruginosa/classificação , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo Real , Staphylococcus aureus/classificação , Staphylococcus aureus/genética , Staphylococcus aureus/isolamento & purificação , Sulfanilamidas/uso terapêutico
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