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1.
PLoS One ; 15(8): e0237127, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32756602

RESUMO

BACKGROUND: The global pandemic of Severe Acute Respiratory Syndrome-Related Coronavirus 2 (SARS-CoV2) has resulted in unprecedented challenges for healthcare systems. One barrier to widespread testing has been a paucity of traditional respiratory viral swab collection kits relative to the demand. Whether other sample collection kits, such as widely available MRSA nasal swabs can be used to detect SARS-CoV-2 is unknown. METHODS: We compared simultaneous nasal MRSA swabs (COPAN ESwabs ® 480C flocked nasal swab in 1mL of liquid Amies medium) and virals wabs (BD H192(07) flexible mini-tip flocked nasopharyngeal swabs in 3mL Universal Transport Medium) for SARS-CoV-2 PCR testing using Simplexa COVID-19 Direct assay on patients over a 4-day period. When the results were discordant, the viral swab sample was run again on the Cepheid Xpert Xpress ® SARS-CoV-2 assay. RESULTS: Of the 81 included samples, there were 19 positives and 62 negatives in viral media and 18 positives and 63 negative in the MRSA swabs. Amongst all included samples, there was concordance between the COPAN ESwabs ® 480C and the viral swabs in 78 (96.3%). CONCLUSION: We found a high rate of concordance in test results between COPAN ESwabs ® 480C in Amies solution and BD H192(07) nasopharyngeal swabs in in 3 mL of Universal Viral Transport medium viral media. Clinicians and laboratories should feel better informed and assured using COPAN ESwabs ® 480C to help in the diagnosis of COVID-19.


Assuntos
Betacoronavirus/genética , Infecções por Coronavirus/diagnóstico , Staphylococcus aureus Resistente à Meticilina/genética , Pneumonia Viral/diagnóstico , Manejo de Espécimes/métodos , Betacoronavirus/isolamento & purificação , Infecções por Coronavirus/virologia , Humanos , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Nasofaringe/microbiologia , Nasofaringe/virologia , Pandemias , Pneumonia Viral/virologia , Estabilidade de RNA , RNA Bacteriano/análise , RNA Bacteriano/metabolismo , RNA Viral/análise , RNA Viral/metabolismo , Reação em Cadeia da Polimerase em Tempo Real
2.
PLoS Pathog ; 16(7): e1008672, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32706832

RESUMO

Most clinical MRSA (methicillin-resistant S. aureus) isolates exhibit low-level ß-lactam resistance (oxacillin MIC 2-4 µg/ml) due to the acquisition of a novel penicillin binding protein (PBP2A), encoded by mecA. However, strains can evolve high-level resistance (oxacillin MIC ≥256 µg/ml) by an unknown mechanism. Here we have developed a robust system to explore the basis of the evolution of high-level resistance by inserting mecA into the chromosome of the methicillin-sensitive S. aureus SH1000. Low-level mecA-dependent oxacillin resistance was associated with increased expression of anaerobic respiratory and fermentative genes. High-level resistant derivatives had acquired mutations in either rpoB (RNA polymerase subunit ß) or rpoC (RNA polymerase subunit ß') and these mutations were shown to be responsible for the observed resistance phenotype. Analysis of rpoB and rpoC mutants revealed decreased growth rates in the absence of antibiotic, and alterations to, transcription elongation. The rpoB and rpoC mutations resulted in decreased expression to parental levels, of anaerobic respiratory and fermentative genes and specific upregulation of 11 genes including mecA. There was however no direct correlation between resistance and the amount of PBP2A. A mutational analysis of the differentially expressed genes revealed that a member of the S. aureus Type VII secretion system is required for high level resistance. Interestingly, the genomes of two of the high level resistant evolved strains also contained missense mutations in this same locus. Finally, the set of genetically matched strains revealed that high level antibiotic resistance does not incur a significant fitness cost during pathogenesis. Our analysis demonstrates the complex interplay between antibiotic resistance mechanisms and core cell physiology, providing new insight into how such important resistance properties evolve.


Assuntos
Proteínas de Bactérias/genética , RNA Polimerases Dirigidas por DNA/genética , Regulação Bacteriana da Expressão Gênica/genética , Staphylococcus aureus Resistente à Meticilina/genética , Proteínas de Ligação às Penicilinas/genética , Resistência beta-Lactâmica/genética , Antibacterianos/farmacologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos
3.
Niger J Clin Pract ; 23(7): 912-918, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32620719

RESUMO

Background: Investigating genetic relatedness between methicillin-resistant Staphylococcus aureus (MRSA) strains from humans and different animal species may clarify the epidemiological characteristic of MRSA infections together. Aim: The aim of the study was to perform genotypic characterization and type strains of MRSA isolated from different clinical sources, by molecular techniques. Materials and Methods: The molecular characterization of the strains was performed by polymerase chain reaction (PCR), using several specific oligonucleotides. These were as follows: S. aureus species-specific sau gene, mecA gene coding PBP2a responsible for methicillin resistance, femA gene coding for a protein, which influences the level of methicillin resistance of S. aureus, and is universally present in all MRSA strains; spa gene coding for protein A; coa gene coding for coagulase, and blaZ gene coding for the production of beta-lactamase. To determine the genetic diversity of these strains, random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) was performed. Results: Among the 415 S. aureus strains, 61 were phenotypically identified as MRSA, and confirmed as S. aureus by amplification of sau gene. However, 90.16% of the strains were mecA positive, while all were negative for femA gene. The presence and polymorphism of coa and spa genes were investigated and 83.60% and 18.03% strains were positive for coa and spa, respectively. While these strains were grouped into six coa-types by PCR, no polymorphism was found for spa gene among strains having only single 190 bp of the band. bla genes were found in 75.40% of strains. These strains were divided into 12 RAPD types. Conclusions: The results showed the relatively high heterogeneity and variation of coa gene among MRSA strains, while further studies on sequencing of these strains may identify which sequence type is predominant in this region.


Assuntos
Proteínas de Bactérias/genética , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , Técnica de Amplificação ao Acaso de DNA Polimórfico/métodos , Animais , Antibacterianos/farmacologia , Proteínas de Bactérias/isolamento & purificação , Coagulase/genética , Genótipo , Humanos , Meticilina , Resistência a Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/genética
4.
Rev Chilena Infectol ; 37(1): 37-44, 2020 Feb.
Artigo em Espanhol | MEDLINE | ID: mdl-32730398

RESUMO

BACKGROUND: Staphylococcus aureus is one of most prevalent pathogens in the world associated with a high mortality rate and a rapid development of resistance to antibiotics. Despite its pathogenicity, epidemiological monitoring in Mexico is scarce. AIM: To analyze the local molecular epidemiology and determine the clonal origin of methicillin-resistant (MR) strains isolated from patients admitted to Hospital "Dr. Ignacio Morones Prieto". METHODS: A cross-sectional prospective study was carried out from July to December 2016. The characterization of the strains was carried out by Spa genotyping, frequency of specific virulence genes by PCR and antibiogram. RESULTS: The prevalence of MRSA was 25.7%, highlighting the presence of the Spa type t895 in 76% of the resistant strains and a similar pattern of susceptibility to antibiotics. CONCLUSION: The results of this study indicate that the regional prevalence of MRSA has not changed in the last 10 years and provide valuable information on the clonal origin and the virulence factors of the strains of S. aureus isolated in the region.


Assuntos
Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Antibacterianos/farmacologia , Estudos Transversais , Genótipo , Humanos , Staphylococcus aureus Resistente à Meticilina/classificação , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/genética , México/epidemiologia , Testes de Sensibilidade Microbiana , Prevalência , Estudos Prospectivos , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/microbiologia , Fatores de Virulência/genética
5.
Arch Microbiol ; 202(8): 2083-2092, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32494868

RESUMO

Chloramphenicol (CAP) and cyclo-(L-Val-L-Pro) were previously isolated from Streptomyces sp., SUK 25 which exhibited a high potency against methicillin-resistant Staphylococcus aureus (MRSA). This study aimed to profile gene expression of MRSA treated with CAP and cyclo-(L-Val-L-Pro) compounds using DNA microarray. Treatment of MRSA with CAP resulted in upregulation of genes involved in protein synthesis, suggesting the coping mechanism of MRSA due to the inhibition of protein synthesis effect from CAP. Most upregulated genes in cyclo-(L-Val-L-Pro) were putative genes with unknown functions. Interestingly, genes encoding ribosomal proteins, cell membrane synthesis, DNA metabolism, citric acid cycle and virulence were downregulated in MRSA treated with cyclo-(L-Val-L-Pro) compound, suggesting the efficacy of this compound in targeting multiple biological pathways. Contrary to CAP, with only a single target, cyclo-(L-Val-L-Pro) isolated from this study had multiple antimicrobial targets that can delay antibiotic resistance and hence is a potential antimicrobial agent of MRSA.


Assuntos
Cloranfenicol/farmacologia , Regulação para Baixo/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/genética , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Perfilação da Expressão Gênica , Testes de Sensibilidade Microbiana , Infecções Estafilocócicas/tratamento farmacológico , Streptomyces/química
6.
J Infect Chemother ; 26(8): 862-864, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32482515

RESUMO

Panton-Valentine leukocidin (PVL)-positive USA300 clone is a highly pathogenic and global epidemic community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) clone. Athletes are particularly vulnerable to CA-MRSA infection because of the frequency of skin trauma, close-contact situations, and sharing of equipment that is customary in the athletic setting. We experienced a case of Japanese collegiate football player with septic pulmonary emboli secondary to infectious iliofemoral deep venous thrombosis caused by the USA300 clone. Here, we screened the nasal carriage of USA300 clone colonization among asymptomatic teammate of the patient to elucidate the infection route. Among 69 nasal samples, CA-MRSA strains were found in 5.8% (four samples). Molecular epidemiological analyses showed that three of the CA-MRSA strains were USA300 clone. Furthermore, pulsed-field gel electrophoresis revealed that all nasal USA300 clones showed 100% identity with the USA300 clone isolated from their teammate with critical infection. Our findings indicate that nasal colonization of the PVL-positive CA-MRSA, especially USA300 clone, pose a threat among contact sport athletes in Japan likewise other countries. An immediate infection control strategy for contact sport athletes is necessary to prevent outbreaks of PVL-positive CA-MRSA infections.


Assuntos
Atletas/estatística & dados numéricos , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Nariz/microbiologia , Infecções Estafilocócicas/epidemiologia , Antibacterianos/uso terapêutico , Infecções Assintomáticas/epidemiologia , Toxinas Bacterianas/metabolismo , Infecções Comunitárias Adquiridas/tratamento farmacológico , Infecções Comunitárias Adquiridas/epidemiologia , Infecções Comunitárias Adquiridas/microbiologia , Eletroforese em Gel de Campo Pulsado , Exotoxinas/metabolismo , Humanos , Japão/epidemiologia , Leucocidinas/metabolismo , Masculino , Epidemiologia Molecular , Futebol , Esportes , Infecções Estafilocócicas/tratamento farmacológico , Universidades , Adulto Jovem
7.
Int J Food Microbiol ; 328: 108669, 2020 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-32497922

RESUMO

Methicillin-resistant Staphylococcus aureus (MRSA) is responsible for several difficult-to-treat infections and staphylococcal food poisoning (SFP). This study was conducted to investigate the prevalence and enterotoxigenicity of MRSA in broiler chicken meat and giblets. A total of 5.5% (8/144) of the examined samples were contaminated with mecA positive/mecC negative MRSA, with staphylococcal counts of approximately 102 colony forming units (CFU)/g in breast, leg and gizzard samples and approximately 3.3 × 103 CFU/g in frozen liver samples. Most MRSA isolates (75%, 6/8) harboured the staphylococcal enterotoxin B (seb) gene. Reverse transcription-PCR (RT-PCR) showed that MRSA isolates initiated SEB production in experimentally contaminated chicken livers within 24 h of storage at temperatures over 8 °C. SEB was maximally produced at 24 °C when the MRSA counts reached 7.3 × 103 ± 1.2 × 103 CFU/g sample homogenate. The current study concludes that the main broiler chicken MRSA isolates in Egypt harbour the seb gene. To mitigate possible SEB production, especially in broiler chicken livers, a maximum "out of refrigeration" time limit should be implemented for cold chain poultry products.


Assuntos
Enterotoxinas/genética , Armazenamento de Alimentos/métodos , Fígado/microbiologia , Carne/microbiologia , Staphylococcus aureus Resistente à Meticilina/genética , Produtos Avícolas/microbiologia , Animais , Galinhas/microbiologia , Egito/epidemiologia , Microbiologia de Alimentos , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Staphylococcus aureus Resistente à Meticilina/metabolismo , Refrigeração , Infecções Estafilocócicas/epidemiologia
8.
BMC Infect Dis ; 20(1): 384, 2020 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-32471442

RESUMO

BACKGROUND: A particular ability of the Staphylococcus aureus clonal complex 398 (CC398) to cause bone and joint infections (BJI) remains questionable, since some studies have described high prevalence of MSSA CC398 in prosthetic joint infection (PJI) and diabetic foot ostemolyelitis (DFO). Here, we described the long-term epidemiology of CC398 among S. aureus isolated from BJI and identified risk factors associated with CC398. METHODS: We included all bone and joint samples with S. aureus-positive culture in our university hospital between January 2010 and December 2017. Logistic regression was used for univariate and multivariate analysis. RESULTS: We identified 124 CC398 isolates among the 958 BJI-associated S. aureus. The proportion of CC398 among S. aureus increased steadily from 4% in 2010 to 26% in 2017. Only 4 isolates of CC398 were resistant to methicillin. The distribution of BJI types due to CC398 and non CC398 isolates was similar. In multivariate analysis, age (p = 0.034, OR = 3.9), McCabe score (p = 0.005, OR = 5) and inoculation mechanism (p = 0.020, OR = 3.7) were associated with PJI-related CC398. The year of infection (p < 0.001, OR = 1.6), Charlson's score (p = 0.001, OR = 1.5) and grade 4 (severe) of the International Working Group of the Diabetic Foot classification (p < 0.001, OR = 8.5) were associated with DFO-related CC398. CONCLUSION: We highlighted here the emergence and spread of CC398-MSSA in BJI. Patients with comorbidities are at high risk of CC398 MSSA PJI and DFO. The spread of CC398 in the community and hospital settings remains unclear and further epidemiological studies are needed to identify the determinants of its success.


Assuntos
Artrite Infecciosa/epidemiologia , Doenças Transmissíveis/epidemiologia , Pé Diabético/epidemiologia , Staphylococcus aureus Resistente à Meticilina/genética , Osteomielite/epidemiologia , Infecções Estafilocócicas/epidemiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Artrite Infecciosa/microbiologia , Doenças Transmissíveis/microbiologia , Comorbidade , Pé Diabético/microbiologia , Feminino , Hospitais Universitários , Humanos , Masculino , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Pessoa de Meia-Idade , Osteomielite/microbiologia , Reação em Cadeia da Polimerase , Prevalência , Estudos Retrospectivos , Fatores de Risco , Infecções Estafilocócicas/microbiologia
9.
APMIS ; 128(6): 451-462, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32358920

RESUMO

Bacteria and viruses were analysed in the upper respiratory tract of symptomatic pig farmers and their domestic pigs. Eighty six human nasal and 495 (50 pools) porcine snout swabs were collected in Schleswig-Holstein, Germany. Staphylococcus (S.) aureus (62.8%, 54/86), human rhino- and coronaviruses (HRV, 29.1%, 25/86; HCoV, 16.3%, 14/86) were frequently detected in humans, while Haemophilus parasuis (90.0%, 45/50), Mycoplasma hyorhinis (78.6%, 11/14), Enterovirus G (EV-G, 56.0%, 28/50) and S. aureus (36.0%, 18/50), respectively, were highly prevalent in pigs. The detection of S. aureus in human follow-up samples indicates a carrier status. The methicillin-resistant phenotype (MRSA) was identified in 33.3% (18/54) of nasal swabs and in one of 18 (5.6%) pooled snout swabs that were tested positive for S. aureus. Strains were indicative of the livestock-associated clonal complex CC398, with t011 being the most common staphylococcal protein A type. Enterobacterales and non-fermenters were frequently isolated from swabs. Their detection in follow-up samples suggests a carrier status. All were classified as being non-multiresistant. There was no example for cross-species transmission of viruses. In contrast, transmission of S. aureus through occupational contact to pigs seems possible. The study contributes to the 'One Health' approach.


Assuntos
Infecções Respiratórias/microbiologia , Infecções Respiratórias/virologia , Infecções Estafilocócicas/veterinária , Sus scrofa/microbiologia , Sus scrofa/virologia , Doenças dos Suínos/epidemiologia , Animais , Portador Sadio , Humanos , Gado , Staphylococcus aureus Resistente à Meticilina/genética , Testes de Sensibilidade Microbiana , Mucosa Nasal/microbiologia , Mucosa Nasal/virologia , Doenças Profissionais/microbiologia , Prevalência , Infecções Respiratórias/epidemiologia , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/transmissão , Suínos , Doenças dos Suínos/microbiologia , Doenças dos Suínos/transmissão , Doenças dos Suínos/virologia , Viroses/epidemiologia , Viroses/transmissão , Viroses/veterinária
10.
J Med Microbiol ; 69(4): 600-604, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32427561

RESUMO

Introduction. Nasal and skin colonization by methicillin-resistant Staphylococcus aureus (MRSA) are linked to a higher incidence of infection after total joint replacement. The prevalence of colonization is poorly defined in Latin American countries.Aim. The aim of the present study was to determine the prevalence of MRSA colonization in the nostrils and groin using real-time polymerase chain reaction (RT-PCR) in patients undergoing total hip arthroplasty (THA).Methodology. In this cross-sectional study, 146 patients undergoing THA between December 2015 and March 2017 in a tertiary-care university-affiliated hospital in Chile were screened for MRSA colonization before the procedure using RT-PCR independently in the nostrils and groin. Risk factors for colonization were documented.Results. Seven of the 146 (5 %) patients undergoing THA were carriers of MRSA in the nostrils and/or the groin. Recent antibiotic use was identified as a risk factor for colonization, OR=4.86 [95 % confidence interval (CI): 1.56-13.96]. Patients reporting at least one of the seven surveyed risk factors had an OR of 2.39 (95 % CI: 0.37-25.77) for colonization. MRSA colonization frequency was twofold higher in the groin as opposed to the nostrils (P=0.014).Conclusion. Five percent of the patients undergoing THA were identified as carriers of MRSA. Recent antibiotic use is a relevant risk factor for MRSA colonization in patients undergoing primary total hip arthroplasty.


Assuntos
Artroplastia de Quadril/efeitos adversos , Staphylococcus aureus Resistente à Meticilina/crescimento & desenvolvimento , Infecções Estafilocócicas/microbiologia , Infecção da Ferida Cirúrgica/microbiologia , Adulto , Antibacterianos/administração & dosagem , Portador Sadio/tratamento farmacológico , Portador Sadio/microbiologia , Estudos Transversais , Feminino , Humanos , Masculino , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Infecções Estafilocócicas/tratamento farmacológico , Infecção da Ferida Cirúrgica/tratamento farmacológico , Adulto Jovem
11.
PLoS One ; 15(4): e0232456, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32353071

RESUMO

Since its emergence in the early 2000s, livestock-associated methicillin-resistant Staphylococcus aureus clonal complex 398 (LA-MRSA CC398) has led to an increasing number of human infections in Denmark and other European countries with industrial pig production. LA-MRSA CC398 is primarily associated with skin infections among pig farm workers but is also increasingly recognized as a cause of life-threatening disease among elderly and immunocompromised people. Pig farm workers may serve as vehicles for the spread of LA-MRSA CC398 and other farm-origin bacteria between farms and into the general population. Yet, little is known about the bacterial community dynamics in pig farm workers and other persons with long- and short-term exposure to the pig farm environment. To gain insight into this, we investigated the nasal microbiomes in pig farm workers during a workweek on four LA-MRSA CC398-positive pig farms, as well as in short-term visitors two hours before, immediately after, and 48 hours after a 1-hour visit to another LA-MRSA CC398-positive pig farm. S. aureus and LA-MRSA CC398 carriage was quantified by means of culture, and the composition of the bacterial communities was investigated through sequencing of the 16S rRNA gene. Pig farm workers often carried LA-MRSA CC398 and other bacteria from the pig farm environment, both at work and at home, although at lower levels at home. In contrast, short-term visitors were subject to a less dramatic and rapidly reversible change in the nasal bacterial community composition. These results suggest that pig farm workers may be an important source of LA-MRSA CC398 and perhaps other pathogens of human and veterinary relevance.


Assuntos
Portador Sadio/epidemiologia , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Exposição Ocupacional/efeitos adversos , Infecções Estafilocócicas/epidemiologia , Suínos/microbiologia , Adulto , Animais , Portador Sadio/microbiologia , Portador Sadio/transmissão , DNA Bacteriano/isolamento & purificação , Fazendas/estatística & dados numéricos , Feminino , Humanos , Masculino , Staphylococcus aureus Resistente à Meticilina/genética , Microbiota/genética , Pessoa de Meia-Idade , Nariz/microbiologia , RNA Ribossômico 16S/genética , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/transmissão , Fatores de Tempo , Adulto Jovem
12.
J Med Microbiol ; 69(6): 850-853, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32430095

RESUMO

Atopic dermatitis (AD) is a chronic skin disease that affects up to 20 % of the paediatric population worldwide. Staphylococcus aureus colonizes anterior nares and can be transmitted in the home environment, aggravating AD. This study aimed to detect S. aureus from nares of AD patients and their family contacts, as well as to evaluate the antimicrobial resistance, virulence and clonality of these isolates. Among the 48 family groups investigated, 30 groups were selected, as both the child and his/her respective contact had methicillin-sensitive S. aureus (MSSA) (24 cases; 54 MSSA isolates) or methicillin-resistant S. aureus (MRSA) isolates (6 cases; 13 MRSA isolates). All MRSA isolates carried SCCmec IV. S. aureus carrying PVL genes were detected in 60 % of patients. Pulsed-field gel electrophoresis (PFGE) analysis was performed for 31 isolates from 15 family groups: all 6 with MRSA and 9 with MSSA isolates. Similar genotypic profiles between isolates from patients and their family contacts were noted in 10 (66.6 %) family groups, 5 (83.3 %) of the MRSA family groups and 5 (55.5 %) of the MSSA family groups, indicating that the pathogen was transmitted through family contacts.


Assuntos
Dermatite Atópica/microbiologia , Mucosa Nasal/microbiologia , Staphylococcus aureus/genética , Adolescente , Criança , Pré-Escolar , Eletroforese em Gel de Campo Pulsado , Humanos , Lactente , Recém-Nascido , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus/efeitos dos fármacos
13.
Nucleic Acids Res ; 48(10): 5540-5554, 2020 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-32347931

RESUMO

In the fight against antimicrobial resistance, the bacterial DNA sliding clamp, ß-clamp, is a promising drug target for inhibition of DNA replication and translesion synthesis. The ß-clamp and its eukaryotic homolog, PCNA, share a C-terminal hydrophobic pocket where all the DNA polymerases bind. Here we report that cell penetrating peptides containing the PCNA-interacting motif APIM (APIM-peptides) inhibit bacterial growth at low concentrations in vitro, and in vivo in a bacterial skin infection model in mice. Surface plasmon resonance analysis and computer modeling suggest that APIM bind to the hydrophobic pocket on the ß-clamp, and accordingly, we find that APIM-peptides inhibit bacterial DNA replication. Interestingly, at sub-lethal concentrations, APIM-peptides have anti-mutagenic activities, and this activity is increased after SOS induction. Our results show that although the sequence homology between the ß-clamp and PCNA are modest, the presence of similar polymerase binding pockets in the DNA clamps allows for binding of the eukaryotic binding motif APIM to the bacterial ß-clamp. Importantly, because APIM-peptides display both anti-mutagenic and growth inhibitory properties, they may have clinical potential both in combination with other antibiotics and as single agents.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , DNA Polimerase III/antagonistas & inibidores , Peptídeos/química , Peptídeos/farmacologia , Animais , Antibacterianos/metabolismo , Antibacterianos/uso terapêutico , DNA Polimerase III/química , Replicação do DNA/efeitos dos fármacos , DNA Polimerase Dirigida por DNA , Feminino , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/crescimento & desenvolvimento , Camundongos Endogâmicos BALB C , Mutagênese/efeitos dos fármacos , Inibidores da Síntese de Ácido Nucleico/química , Inibidores da Síntese de Ácido Nucleico/farmacologia , Inibidores da Síntese de Ácido Nucleico/uso terapêutico , Peptídeos/metabolismo , Peptídeos/uso terapêutico , Antígeno Nuclear de Célula em Proliferação/metabolismo , Domínios e Motivos de Interação entre Proteínas , Infecções Cutâneas Estafilocócicas/tratamento farmacológico , Staphylococcus epidermidis/efeitos dos fármacos , Staphylococcus epidermidis/genética , Staphylococcus epidermidis/crescimento & desenvolvimento
14.
Wei Sheng Yan Jiu ; 49(1): 56-62, 2020 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-32290915

RESUMO

OBJECTIVE: To understand the antimicrobial resistance, virulence factors, and molecular characterization of MRSA isolates cultured from ready-to-eat(RTE) foods from several provinces in China. METHODS: Totally, 397 S. aureus isolates were collected from RTE foods from several provinces in China, in 2017. The mecA gene was amplified to detect the MRSA strains among all 397 isolates by a polymerase chain reaction(PCR) method. Furthermore, the antimicrobial susceptibility and virulence factors of the MRSA isolates were detected by broth microdilution method and PCR, respectively, while the molecular characterization of all MRSA isolates were analyzed by pulsed-field gel electrophoresis(PFGE). RESULTS: In total, 32 MRSA isolates were identified from 397 isolates. All 32 MRSA isolates were resistant to penicillin, oxacillin and cefoxitin. Meanwhile, 78. 1%, 65. 6%, 53. 1, 28. 1% and 12. 5% of the 32 MRSA isolates showed resistant to erythromycin, clindamycin, tetracycline, chloramphenicol, and ciprofloxacin, respectively. Resistance rates to gentamicin and trimethoprim-sulfamethoxazole of all MRSA isolates were less than 10%. Eleven drug resistant spectrums were identified and 29 out of 32 MRSA isolates were identified as multi-drug resistant(MDR) isolates and two isolates were found to resistant to 9 antimicrobial agents tested in this study. Of all, 27 MRSA isolates were detected to harboring 13 virulence genes with sel-q(56. 3%), sel-k(43. 8%), seb(28. 1%) and sec(18. 8%) genes being the top four frequently detected. Besides, the result also showed that two or more virulence genes could be detected in one MRSA isolate. Finally, all 32 MRSA were identified to have 26 PFGE patterns and no dominant PFGE patterns were found in this study. CONCLUSION: An overall high level antimicrobial resistance was found among RTE associated MRSA in China in 2017, so was the MDR condition. Virulence genes could be frequently detected in RTE associated MRSA isolates. The PFGE patterns of RTE associated MRSA showed wide distribution characteristics.


Assuntos
Farmacorresistência Bacteriana Múltipla , Contaminação de Alimentos , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Fatores de Virulência/genética , Antibacterianos/farmacologia , China , Eletroforese em Gel de Campo Pulsado , Microbiologia de Alimentos , Testes de Sensibilidade Microbiana
15.
Ann Clin Microbiol Antimicrob ; 19(1): 10, 2020 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-32220258

RESUMO

BACKGROUND: Staphylococcus aureus is a primary pathogen of orthopedic infections. By mediating antimicrobial resistance, S. aureus biofilm plays an important role in the recalcitrance of orthopedic infections, especially for the intractable osteomyelitis (OM). This study investigated the relationship between biofilm production and various genetic or phenotypic characteristics among orthopedic S. aureus strains. METHODS: A total of 137 orthopedic S. aureus isolates were enrolled and divided into OM and non-OM groups. Biofilm production was evaluated using the crystal violet assay. Genetic and phenotypic characteristics including MRSA identification, MLST and spa typing, carriage of virulence genes, drug resistance, and patients' inflammatory responses indicators were characterized. The relationship between biofilm production and above-mentioned features was respectively analyzed among all isolates and compared between OM and non-OM isolates. RESULTS: Biofilm production presented no significant difference between OM (including 9 MRSA isolates) and non-OM (including 21 MRSA isolates) strains. We found that ST88, t377 and ST630-MSSA-t377 strains produced very strong biofilms, while MLST types of ST15, ST25, ST398, ST5, ST59 and spa types of t002, t2325, t437 tended to produce weaker biofilms. Strains with the following profiles produced stronger biofilms: fib(+)-hlgv(+)-lukED(+)-sei(-)-sem(-)-seo(-) for all isolates, sei(-)-sem(-)-seo(-) for OM isolates, and cna (+)-fib (+)-hlgv (+)-lukED (+)-seb(-)-sed(-) for non-OM isolates. In addition, not any single drug resistance was found to be related to biofilm production. We also observed that, among OM patients, strains with stronger biofilms caused weaker inflammatory responses. CONCLUSION: Some genetic or phenotypic characteristics of orthopedic strains were associated with biofilm production, and this association could be different among OM and non-OM strains. The results are of great significance for better understanding, evaluating and managing different kinds of biofilm-associated orthopedic infections, and provide potential targets for biofilm clearance.


Assuntos
Biofilmes , Doenças Musculoesqueléticas/microbiologia , Infecções Estafilocócicas , Staphylococcus aureus , Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Farmacorresistência Bacteriana Múltipla/genética , Genótipo , Humanos , Staphylococcus aureus Resistente à Meticilina/genética , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Doenças Musculoesqueléticas/tratamento farmacológico , Osteomielite/tratamento farmacológico , Osteomielite/microbiologia , Fenótipo , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/genética , Staphylococcus aureus/isolamento & purificação , Fatores de Virulência/genética
16.
PLoS One ; 15(3): e0230031, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32163464

RESUMO

We characterised 80 Staphylococcus aureus strains isolated from human patients with SSTIs at a rural hospital in Ethiopia. Susceptibility to antibiotic of all strains was tested. The MLST method was used to type and a phylogenetic analysis was conducted employing the sequences of 7 housekeeping genes. PCR amplification was used to investigate the presence of the following virulence genes in all strains: hla (α-haemolysin), tstH (toxic shock syndrome toxin), luk PV (Panton-Valentine leukocidin), fnbA (fibronectin binding protein A) and mecA (methicillin resistance). Most of the strains were resistant to penicillin and ampicillin, but only 3 strains were resistant to oxacillin, and 1 of them was a true MRSA. The MLST results showed a high diversity of sequence types (ST), 55% of which were new, and ST152 was the most prevalent. A phylogeny study showed that many of the new STs were phylogenetically related to other previously described STs, but bore little relationship to the only ST from Ethiopia described in the database. Virulence gene detection showed a high prevalence of strains encoding the hla, fnbA and pvl genes (98.77%, 96.3% and 72.84%, respectively), a low prevalence of the tst gene (13.58%) and a markedly low prevalence of MRSA (1.25%). S. aureus strains isolated from patients in a rural area in Ethiopia showed low levels of antibiotic resistance, except to penicillin. Moreover, this study reveals new STs in Eastern Africa that are phylogenetically related to other previously described STs, and confirm the high prevalence of the pvl gene and the low prevalence of MRSA on the continent.


Assuntos
Antibacterianos/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Virulência/genética , Proteínas de Bactérias/classificação , Proteínas de Bactérias/genética , Toxinas Bacterianas/classificação , Toxinas Bacterianas/genética , Cefalosporinas/farmacologia , Farmacorresistência Bacteriana/genética , Etiópia , Exotoxinas/classificação , Exotoxinas/genética , Hospitais Rurais , Humanos , Leucocidinas/classificação , Leucocidinas/genética , 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 , Penicilinas/farmacologia , Filogenia , Infecções Estafilocócicas/diagnóstico , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/classificação , Staphylococcus aureus/isolamento & purificação , Staphylococcus aureus/patogenicidade
17.
PLoS One ; 15(2): e0228676, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32040487

RESUMO

Production of the Panton-Valentine leukocidin (PVL) by Staphylococcus aureus is mediated via the genes lukS-PV and lukF-PV which are carried on bacteriophage ϕSa2. PVL is associated with S. aureus strains that cause serious infections and clones of community-associated methicillin-resistant S. aureus (CA-MRSA) that have additionally disseminated widely. In Western Australia (WA) the original CA-MRSA were PVL negative however, between 2005 and 2008, following the introduction of eight international PVL-positive CA-MRSA, PVL-positive WA CA-MRSA were found. There was concern that PVL bacteriophages from the international clones were transferring into the local clones, therefore a comparative study of PVL-carrying ϕSa2 prophage genomes from historic WA PVL-positive S. aureus and representatives of all PVL-positive CA-MRSA isolated in WA between 2005 and 2008 was performed. The prophages were classified into two genera and three PVL bacteriophage groups and had undergone many recombination events during their evolution. Comparative analysis of mosaic regions of selected bacteriophages using the Alignments of bacteriophage genomes (Alpha) aligner revealed novel recombinations and modules. There was heterogeneity in the chromosomal integration sites, the lysogeny regulation regions, the defence and DNA processing modules, the structural and packaging modules and the lukSF-PV genes. One WA CA-MRSA (WA518751) and one international clone (Korean Clone) have probably acquired PVL-carrying ϕSa2 in WA, however these clones did not disseminate in the community. Genetic heterogeneity made it impossible to trace the source of the PVL prophages in the other WA clones. Against this background of PVL prophage diversity, the sequence of one group, the ϕSa2USA/ϕSa2wa-st93 group, was remarkably stable over at least 20 years and associated with the highly virulent USA300 and ST93-IVa CA-MRSA lineages that have disseminated globally.


Assuntos
Toxinas Bacterianas/genética , Bacteriófagos/genética , Exotoxinas/genética , Leucocidinas/genética , Staphylococcus aureus Resistente à Meticilina/virologia , Linhagem da Célula , DNA Bacteriano/genética , Genótipo , Geografia , Lisogenia , Staphylococcus aureus Resistente à Meticilina/genética , Epidemiologia Molecular , Tipagem de Sequências Multilocus , Fases de Leitura Aberta , Prófagos/genética , Fatores de Virulência/genética , Austrália Ocidental
18.
BMC Infect Dis ; 20(1): 137, 2020 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-32054452

RESUMO

BACKGROUND: Currently, Staphylococcus aureus is one of the most important pathogens worldwide, especially for methicillin-resistant S. aureus (MRSA) infection. However, few reports referred to patients' MRSA infections in Yunnan province, southwest China. METHODS: In this study, we selected representative MRSA strains from patients' systemic surveillance in Yunnan province of China, performed the genomic sequencing and compared their features, together with some food derived strains. RESULTS: Among sixty selective isolates, forty strains were isolated from patients, and twenty isolated from food. Among the patients' strains, sixteen were recognized as community-acquired (CA), compared with 24 for hospital-acquired (HA). ST6-t701, ST59-t437 and ST239-t030 were the three major genotype profiles. ST6-t701 was predominated in food strains, while ST59-t437 and ST239-t030 were the primary clones in patients. The clinical features between CA and HA-MRSA of patients were statistical different. Compared the antibiotic resistant results between patients and food indicated that higher antibiotic resistant rates were found in patients' strains. Totally, the average genome sizes of 60 isolates were 2.79 ± 0.05 Mbp, with GC content 33% and 84.50 ± 0.20% of coding rate. The core genomes of these isolates were 1593 genes. Phylogenetic analysis based on pan-genome and SNP of strains showed that five clustering groups were generated. Clustering ST239-t030 contained all the HA-MRSA cases in this study; clustering ST6-t701 referred to food and CA-MRSA infections in community; clustering ST59-t437 showed the heterogeneity for provoking different clinical diseases in both community and hospital. Phylogenetic tree, incorporating 24 isolates from different regions, indicated ST239-t030 strains in this study were more closely related to T0131 isolate from Tianjin, China, belonged to 'Turkish clade' from Eastern Europe; two groups of ST59-t437 clones of MRSA in Yunnan province were generated, belonged to the 'Asian-Pacific' clone (AP) and 'Taiwan' clone (TW) respectively. CONCLUSIONS: ST239-t030, ST59-t437 and ST6-t701 were the three major MRSA clones in Yunnan province of China. ST239-t030 clonal Yunnan isolates demonstrated the local endemic of clone establishment for a number of years, whereas ST59-t437 strains revealed the multi-origins of this clone. In general, genomic study on epidemic clones of MRSA in southwest China provided the features and evolution of this pathogen.


Assuntos
Infecção Hospitalar/microbiologia , Genômica/métodos , Staphylococcus aureus Resistente à Meticilina/genética , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/genética , Adolescente , Adulto , Antibacterianos/efeitos adversos , Antibacterianos/uso terapêutico , Criança , Pré-Escolar , China/epidemiologia , Infecções Comunitárias Adquiridas/microbiologia , Feminino , Microbiologia de Alimentos , Genoma Bacteriano/genética , Genótipo , Humanos , Masculino , Meticilina/efeitos adversos , Meticilina/uso terapêutico , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Testes de Sensibilidade Microbiana , Filogenia , Polimorfismo de Nucleotídeo Único/genética , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/microbiologia , Sequenciamento Completo do Genoma , Adulto Jovem
19.
Open Vet J ; 9(4): 339-348, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-32042657

RESUMO

Background: The mecA gene is a key factor that allows bacterial cells to resist several antibiotics. Aim: This study was conducted to detect the mecA gene polymorphism in ovine wounds and its possible association with the structure and function of penicillin binding protein A2 (PBP2A). Methods: One genetic locus of 1,967 bp that covered the majority of the coding regions of the mecA gene within methicillin-resistant Staphylococcus aureus (MRSA) DNA sequences was designed. Results: In addition to standard microbiological tests, PCR-sequencing reactions and phylogenetic analyses confirmed the identity of the targeted MRSA bacteria. Seven novel missense SNPs, including N57T, N115Y, D120N, D139N, G152V, E189K, and F211V, were observed in the mecA amplicons. Multiple state-of-the-art in silico tools were utilized to assess the consequences of each observed SNP in terms of its effect on the corresponding PBP2A protein structure and function. It was shown that some MRSA isolates exhibited a highly PBP2A-damaging SNP, G152V, which showed an entirely deleterious effect on the PBP2A. Furthermore, G152V induced an alteration in the PBP2A interaction with its receptor, which presumably reduced its affinity to bind with the beta-lactams. Conclusion: The present report indicated a possible role for the observed deleterious G152V SNP in the reduction of PBP2A binding with beta-lactams, which has led to a remarkable increase in MRSA's resistance to antibiotics.


Assuntos
Proteínas de Bactérias/genética , Farmacorresistência Bacteriana/genética , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Mutação , Proteínas de Ligação às Penicilinas/genética , Doenças dos Ovinos/tratamento farmacológico , Infecções Estafilocócicas/veterinária , Animais , Proteínas de Bactérias/metabolismo , Staphylococcus aureus Resistente à Meticilina/genética , Proteínas de Ligação às Penicilinas/metabolismo , Polimorfismo Genético , Ovinos , Doenças dos Ovinos/microbiologia , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/microbiologia
20.
J Med Microbiol ; 69(4): 548-551, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32101159

RESUMO

Introduction. The nuc gene encodes a thermonuclease which is present in Staphylococcus aureus but not in coagulase-negative staphylococci (CoNS) and is the target of the rapid phenotypic thermonuclease test. The effect of nuc gene variation in methicillin-resistant S. aureus (MRSA) on the performance of PCR testing has been noted, although there are no reports about the effect of MRSA on the activity of the thermonuclease enzyme.Aim. Our goals were to examine the sensitivity and specificity of the thermonuclease test used to distinguish S. aureus from CoNS cultured from blood. In addition, we aimed to assess differences in the sensitivity, specificity and accuracy of the thermonuclease test between methicillin-sensitive S. aureus (MSSA) and MRSA isolates.Methodology. We performed a retrospective analysis of 1404 isolates. Each isolate from a positive blood culture was identified as a Gram-positive coccus by microscopy then analysed with the thermonuclease test (Southern Group Laboratory) prior to confirmatory identification using VITEK microbial identification platforms (bioMérieux) and cefoxitin disc diffusion testing.Results. Of 1331 samples included in the final analysis, 189 were thermonuclease-positive, of which 176 were identified as S. aureus. Of the 1142 thermonuclease-negative samples, 13 were finally identified as S. aureus, giving a sensitivity of 93.1 % (95 % confidence interval [CI] 88.5-96.3) and specificity of 98.9 % (95 % CI 98.1-99.4). Of the nine proven MRSA samples, eight were thermonuclease-positive, giving a sensitivity of 88.9 % (95 % CI 51.8-99.7). Thermonuclease test accuracy for MSSA and MRSA isolates was 98.1 % (95 % CI 97.2-98.8) versus 98.8 % (95 % CI 98.0-99.3), respectively.Conclusions. In the era of increasing use of molecular-based microbiology assays, the thermonuclease test remains a simple, inexpensive and robust test for the presumptive identification of S. aureus cultured from blood, irrespective of methicillin sensitivity.


Assuntos
Proteínas de Bactérias/análise , Proteínas de Bactérias/metabolismo , Staphylococcus aureus Resistente à Meticilina/enzimologia , Nuclease do Micrococo/análise , Infecções Estafilocócicas/microbiologia , Proteínas de Bactérias/genética , Ensaios Enzimáticos , Humanos , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Nuclease do Micrococo/genética , Nuclease do Micrococo/metabolismo , Estudos Retrospectivos
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