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1.
Int J Food Microbiol ; 340: 109055, 2021 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-33485100

RESUMO

This study was undertaken to investigate the prevalence, serotype distribution and antimicrobial resistance in Salmonella isolated from retail meat in Southern China, and to characterize the major mechanisms that mediate the ciprofloxacin resistance of isolates. High levels of Salmonella contamination were detected in pork (67.0%), duck (50.5%) and chicken (46.2%). Thirty different serotypes were identified among 500 detected Salmonella isolates, as well as significant differences in serotypes between different retail meat samples. Notably, 405 (80.1%) isolates exhibited multidrug resistance (MDR). Meanwhile, we also found that 74 (14.8%) Salmonella isolates were resistant to ciprofloxacin and the major mechanisms underlying this resistance were investigated. The commonest mutations in gyrA S83F (40.5%) and D87N (35.1%), and in parC was T57S (71.6%) and S80I (35.1%). Multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE) analysis revealed that the S. Kentucky isolates that were resistant to ciprofloxacin mostly belonged to ST198 (21/23, 91.3%) and PFGE revealed the presence of various genotypes. This study identified a diversity of Salmonella serotypes and a high prevalence of multidrug resistance (MDR) among Salmonella isolated from retail meat in Southern China, which indicates that foodborne Salmonella potentially constitutes a potential food safety risk.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Carne/microbiologia , Mutação , Carne de Porco/microbiologia , Salmonella/genética , Animais , Galinhas , China , Ciprofloxacino/farmacologia , Patos , Eletroforese em Gel de Campo Pulsado , Microbiologia de Alimentos , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Salmonella/efeitos dos fármacos , Salmonella/isolamento & purificação , Sorogrupo , Suínos
2.
Zhonghua Yu Fang Yi Xue Za Zhi ; 55(1): 78-83, 2021 Jan 06.
Artigo em Chinês | MEDLINE | ID: mdl-33455136

RESUMO

Objective: To analyze the etiological characteristics and molecular epidemiological correlation of five cases of typhoid fever during the same period in yantai city. Methods: Six S. Typhis strains were isolated from 5 typhoid patients and epidemiological samples in Yantai city in 2018. The onset time of the cases were from May 26, 2018 to July 24, 2018, distributed in Shuidao Town of Muping District, Dengzhou Street of Penglai District, Donglai Street of Longkou District, Wenhua Street of Muping District and Fulaishan Street of zhifu District. S. Typhis strains were analyzed by conventional bacterial isolation method and XbaⅠ/BlnⅠ double-enzyme digestion pulse-field gel electrophoresis (PFGE). Meanwhile, ViaB virulence gene detection and 27 common antibiotics sensitivity tests were conducted to study the etiology of S. Typhis. Results: Six strains of S. Typhi were isolated from 5 patients and the domestic egg of one patient, which were divided into 4 PFGE patterns by PFGE-XbaⅠ and PFGE-BlnⅠ and among which 3 strains had the same PFGE patterns.One multi-drug resistant strain (foreign patient), one single-drug resistant strain (patient with a history of provincial retention), and one completely sensitive strain were detected. The three strains of the same PFGE pattern exhibit the same drug-sensitive phenotype which were intermediate against aminoglycosides and quinolones and susceptibility against the other antibiotics.All of the strains carried the ViaB virulence factor except the strain from the foreign patient. Conclusion: Local S. Typhi is susceptibility or intermediate against antibiotics commonly used in clinic.Sporadic cases of typhoid fever and typhoid imported infections still need attention.


Assuntos
Febre Tifoide , Antibacterianos/uso terapêutico , Eletroforese em Gel de Campo Pulsado , Humanos , Testes de Sensibilidade Microbiana , Epidemiologia Molecular , Salmonella typhi/genética , Febre Tifoide/tratamento farmacológico , Febre Tifoide/epidemiologia
3.
Methods Mol Biol ; 2153: 403-425, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32840795

RESUMO

The ribosomal RNA (rDNA) sequence is the most abundant repetitive element in the budding yeast genome and forms a tandem cluster of ~100-200 copies. Cells frequently change their rDNA copy number, making rDNA the most unstable region in the budding yeast genome. The rDNA region experiences programmed replication fork arrest and subsequent formation of DNA double-strand breaks (DSBs), which are the main drivers of rDNA instability. The rDNA region offers a unique system to understand the mechanisms that respond to replication fork arrest as well as the mechanisms that regulate repeat instability. This chapter describes three methods to assess rDNA instability.


Assuntos
DNA Ribossômico/metabolismo , Eletroforese em Gel de Campo Pulsado/métodos , Saccharomyces cerevisiae/genética , Southern Blotting , Cromossomos Fúngicos/genética , Quebras de DNA de Cadeia Dupla , Replicação do DNA , DNA Circular/química , DNA Circular/metabolismo , DNA Fúngico/química , DNA Fúngico/metabolismo , DNA Ribossômico/química
4.
Methods Mol Biol ; 2182: 187-196, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32894497

RESUMO

Salmonella is recognized as a major human foodborne pathogen and threat to public health world widely. It is important to carry out epidemiological investigations to determine the primary sources of bacterial contamination. Pulsed-field gel electrophoresis (PFGE) is an important method of the molecular typing, and play an important role in tracking the sources of infection and epidemic control. The PFGE is currently considered as "gold standard" of molecular typing methods for bacterial foodborne pathogen. Here, we describe the PFGE protocol to type the Salmonella from pork.


Assuntos
Técnicas de Tipagem Bacteriana/métodos , Eletroforese em Gel de Campo Pulsado/métodos , Tipagem Molecular/métodos , Salmonella/genética , DNA Bacteriano/genética , Carne de Porco/microbiologia
5.
Methods Mol Biol ; 2220: 79-88, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32975767

RESUMO

PFGE is a valuable tool for assessing L. monocytogenes strain interrelatedness. It is based on the study of total bacterial DNA restriction patterns. Cells are embedded in agarose plugs before being lysed. The released DNA is then digested into large fragments by restriction enzymes. As DNA fragments are too large to be separated by traditional electrophoresis in an agarose gel, changes in the direction of the electrical current are periodically applied in order to allow the proper migration of large DNA fragments. Strains are characterized by the obtained DNA fragment patterns or pulsotypes which vary depending on the number and size of bands.


Assuntos
DNA Bacteriano/análise , Eletroforese em Gel de Campo Pulsado/métodos , Listeria monocytogenes/isolamento & purificação , Enzimas de Restrição do DNA/química , DNA Bacteriano/genética , Microbiologia de Alimentos , Humanos , Listeria monocytogenes/genética , Listeriose/microbiologia , Sefarose/química
6.
Mem Inst Oswaldo Cruz ; 115: e200371, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33174904

RESUMO

BACKGROUND: Acinetobacter baumannii outbreaks have been associated with pandemic International Clones (ICs), but the virulence factors involved with their pathogenicity are sparsely understood. Pigment production has been linked with bacterial pathogenicity, however, this phenotype is rarely observed in A. baumannii. OBJECTIVES: This study aimed to characterise the reddish-brown pigment produced by A. baumannii strains, and to determine its biosynthetic pathway by genomic approaches. METHODS: Pigment characterisation and antimicrobial susceptibility were conducted by phenotypic tests. The clonal relationship was obtained by pulsed field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST). The genome of an A. baumannii was obtained for characterisation of genes involved with pigment production. FINDINGS: The pyomelanin was the pigment produced by A. baumannii. Strains were extensively drug resistant and belonged to the IC-5/ST79. The pyomelanin biosynthetic pathway was determined and presented a particular architecture concerning the peripheral (tyrB, phhB and hpd) and central (hmgB, hmgC and hmgR) metabolic pathway genes. The identification of a distant HmgA homologue, probably without dioxygenase activity, could explain pyomelanin production. Virulence determinants involved with adherence (csuA/BABCDE and a T5bSS-carrying genomic island), and iron uptake (basABCDEFGHIJ, bauABCDEF and barAB) were characterised. MAIN CONCLUSION: There is a biosynthetic pathway compatible with the pyomelanin production observed in persistent A. baumannii IC-5 strains.


Assuntos
Infecções por Acinetobacter/microbiologia , Acinetobacter baumannii/efeitos dos fármacos , Acinetobacter baumannii/genética , Vias Biossintéticas/genética , Melaninas , Acinetobacter baumannii/isolamento & purificação , Antibacterianos/farmacologia , Eletroforese em Gel de Campo Pulsado , Humanos , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Pandemias , beta-Lactamases
7.
PLoS One ; 15(10): e0240143, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33007026

RESUMO

Vibrio parahaemolyticus is responsible for seafood-borne gastroenteritis worldwide. Isolates of V. parahaemolyticus from clinical samples (n = 54) and environmental samples (n = 38) in Huzhou were analyzed by serological typing, virulence gene detection, antibiotic resistance testing, and pulsed-field gel electrophoresis (PFGE) for molecular typing. O3:K6 was the main serotype and tlh+tdh+trh- was the most frequently detected virulence genotype in clinical strains. O2:Kut was the main serotype and tlh+tdh-trh- was the most frequently detected virulence genotype in environmental strains. Antibiotic resistance testing indicated that the isolates were highly resistant to ampicillin (90.76%), followed by gentamicin and tetracycline. Following the restriction enzyme NotI digestion, the 91 strains yielded 81 PFGE patterns, and 16 clones had similarity values of > 85.00%, indicating a high level of diversity. Finally, there may be cross-contamination between freshwater and seawater products, so it is necessary to strengthen supervision of food processing.


Assuntos
Microbiologia Ambiental , Vibrio parahaemolyticus/genética , Vibrio parahaemolyticus/isolamento & purificação , China , Análise por Conglomerados , DNA Bacteriano/genética , Farmacorresistência Bacteriana/genética , Eletroforese em Gel de Campo Pulsado , Genes Bacterianos , Humanos , Filogenia , Sorotipagem , Vibrio parahaemolyticus/classificação , Virulência/genética
8.
BMC Infect Dis ; 20(1): 693, 2020 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-32962640

RESUMO

BACKGROUND: Pseudomonas aeruginosa is a Gram-negative bacteria responsible for infections in immunocompromised patients and is one of the most common causes of nosocomial infections particularly in intensive care and burn units. We aimed to investigate the population structure of P. aeruginosa strains isolated from patients at different hospital wards. METHODS: We analysed the possible presence of P. aeruginosa epidemic or endemic strains in hospitals of the selected region. A genotyping analysis was performed for P. aeruginosa isolates (n = 202) collected from patients of eleven hospitals in north-western Poland. Collections of P. aeruginosa were genotyped using pulsed-field gel electrophoresis (PFGE). Phenotypic screening for antibiotic susceptibility was performed for the common antimicrobial agents. RESULTS: Pseudomonas aeruginosa isolates were distributed among 116 different pulsotype groups. We identified 30 groups of clonally related strains, each containing from 2 to 17 isolates and typed the obtained 13 unique patterns, designated as A, D, E, J, K, M, N, Ó, P, T, X, AC, AD, and AH. The two largest clusters, D and E, contained 17 and 13 isolates, respectively. Strains of these groups were continuously isolated from patients at intensive care units and burn units, indicating transmission of these strains. CONCLUSIONS: In this study, we demonstrate the clonal relatedness of P. aeruginosa strains and their constant exchange in hospitals over a period of 15 months. The obtained results indicate a predominantly non-clonal structure of P. aeruginosa.


Assuntos
Infecção Hospitalar/microbiologia , Farmacorresistência Bacteriana/efeitos dos fármacos , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/genética , Antibacterianos/farmacologia , Eletroforese em Gel de Campo Pulsado , Técnicas de Genotipagem , Hospitais , Humanos , Unidades de Terapia Intensiva , Testes de Sensibilidade Microbiana , Polônia , Pseudomonas aeruginosa/isolamento & purificação
9.
Int J Food Microbiol ; 335: 108859, 2020 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-32947147

RESUMO

In this study, 205 Salmonella enterica serovar Corvallis strains were obtained from humans and foods from Guangdong, Guangxi, and Shanghai in China from 2009 to 2017 to assess drug resistance and molecular epidemiology. These isolates displayed high rates of resistance to sulfisoxazole (94.15%) and tetracycline (77.56%). Surprisingly, the rate of resistance to ciprofloxacin reached 21.46%. Moreover, 63.9% of the strains displayed multidrug resistance. Detection of quinolone genes showed that 97.56% of the strains had single mutations (T57S) in parC. The plasmid-mediated quinolone resistance (PMQR) genes qnrS, aac(6')-Ib-cr, and qnrB, were also detected. The extended spectrum ß-lactamase (ESBLS) gene that was most common among the isolates was blaTEM-1 (18.05%). These S. Corvallis isolates are the first to date, that have been reported to possess blaCTX-M-55 or blaNDM-5. Additionally, 95.61% of isolates were biofilm producers. The streptomycin resistance rate was higher in strong biofilm producers (87.50%) than in moderate (37.93%) and weak (26.49%) biofilm producers. Pulsed-field gel electrophoresis (PFGE) showed that some strains from different sources had the same genotype. These isolates may be transmitted to humans through food and therefore the monitoring of these isolates should be strengthened in China.


Assuntos
Farmacorresistência Bacteriana Múltipla/genética , Quinolonas/farmacologia , Salmonella enterica/efeitos dos fármacos , Salmonella enterica/genética , beta-Lactamases/genética , Animais , Antibacterianos/farmacologia , Biofilmes/crescimento & desenvolvimento , Galinhas/microbiologia , China , Eletroforese em Gel de Campo Pulsado , Microbiologia de Alimentos , Humanos , Testes de Sensibilidade Microbiana , Plasmídeos/genética , Prevalência , Salmonella enterica/isolamento & purificação , Sorogrupo
10.
PLoS One ; 15(8): e0236807, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32760141

RESUMO

Listeria monocytogenes is the etiological agent of listeriosis, a major foodborne disease and an important public health concern. Contamination of meat with L. monocytogenes occurs frequently at the slaughterhouse. Our aims were; 1) to investigate the distribution of L. monocytogenes in the processing areas of four swine slaughterhouses; 2) to describe the diversity of L. monocytogenes strains by pulsed-field gel electrophoresis; 3) to identify persistent L. monocytogenes strains and describe their distribution; 4) to investigate the associations between persistence of strains and their following characteristics: detection in food isolates, detection in human clinical isolates, and the presence of benzalkonium chloride (BAC) resistance genes. Various operation areas within the four swine slaughterhouses were sampled on four occasions. A total of 2496 samples were analyzed, and L. monocytogenes was successfully isolated from 243 samples. The proportion of positive samples ranged from 32 to 58% in each slaughterhouse and from 24 to 68% in each operation area. Fifty-eight different pulsotypes were identified and eight pulsotypes, present in samples collected during 4 visits, were considered persistent. The persistent pulsotypes were significantly more likely to be detected in food (P < 0.01, exact χ²) and human clinical cases (P < 0.01, exact χ²), respectively. Among pulsotypes harboring the BAC bcrABC resistance cassette or the emrE multidrug transporter gene, 42.8% were persistent compared to 4.5% for pulsotypes without these resistance genes (P < 0.01, exact χ²). Our study highlights the importance of persistent L. monocytogenes strains in the environmental contamination of slaughterhouses, which may lead to repeated contamination of meat products. It also shows that the presence of disinfectants resistance genes is an important contributing factor.


Assuntos
Microbiologia de Alimentos , Listeria monocytogenes/fisiologia , Listeriose/diagnóstico , Carne/microbiologia , Matadouros , Animais , Compostos de Benzalcônio/farmacologia , Farmacorresistência Bacteriana/genética , Eletroforese em Gel de Campo Pulsado , Manipulação de Alimentos , Humanos , Listeria monocytogenes/efeitos dos fármacos , Listeria monocytogenes/isolamento & purificação , Listeriose/microbiologia , Testes de Sensibilidade Microbiana , Sorogrupo , Suínos
11.
BMC Infect Dis ; 20(1): 621, 2020 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-32831057

RESUMO

BACKGROUND: We aimed to describe an outbreak of cutaneous abscesses caused by Panton-Valentine leukocidin (PVL)-producing methicillin-susceptible Staphylococcus aureus (MSSA) among gold mine workers. METHODS: In February 2018, we retrospectively reviewed a random sample of 50 medical records from 243 cases and conducted face-to-face interviews using a structured questionnaire. Pus aspirates were sent to the National Institute for Communicable Diseases from prospectively-identified cases (November 2017-March 2018). Nasopharyngeal swabs were collected during a colonisation survey in February 2018. Staphylococcus aureus isolates were screened with a conventional PCR for lukS/F-PV. Pulsed-field gel electrophoresis (PFGE) was performed to determine the genetic relatedness among the isolates. A sample of isolates were selected for whole genome sequencing (WGS). We conducted an assessment on biological risks associated with mining activities. RESULTS: From January 2017 to February 2018, 10% (350/3582) of mine workers sought care for cutaneous abscesses. Forty-seven medical files were available for review, 96% were male (n = 45) with a mean age of 43 years (SD = 7). About 52% (24/46) were involved in stoping and 28% (13/47) worked on a particular level. We cultured S. aureus from 79% (30/38) of cases with a submitted specimen and 14% (12/83) from colonisation swabs. All isolates were susceptible to cloxacillin. Seventy-one percent of S. aureus isolates (30/42) were PVL-PCR-positive. Six PFGE clusters were identified, 57% (21/37) were closely related. WGS analysis found nine different sequence types. PFGE and WGS analysis showed more than one cluster of S. aureus infections involving closely related isolates. Test reports for feed and product water of the mine showed that total plate counts were above the limits of 1000 cfu/ml, coliform counts > 10 cfu/100 ml and presence of faecal coliforms. Best practices were poorly implemented as some mine workers washed protective clothing with untreated water and hung them for drying at the underground surface. CONCLUSIONS: PVL-producing MSSA caused an outbreak of cutaneous abscesses among underground workers at a gold mining company. To our knowledge, no other outbreaks of PVL-producing S. aureus involving skin and soft tissue infections have been reported in mining facilities in South Africa. We recommend that worker awareness of infection prevention and control practices be strengthened.


Assuntos
Abscesso/microbiologia , Dermatopatias/epidemiologia , Infecções dos Tecidos Moles/epidemiologia , Infecções Estafilocócicas/epidemiologia , Staphylococcus aureus/patogenicidade , Adulto , Toxinas Bacterianas/metabolismo , Surtos de Doenças , Eletroforese em Gel de Campo Pulsado , Exotoxinas/metabolismo , Feminino , Ouro , Humanos , Leucocidinas/metabolismo , Masculino , Meticilina/farmacologia , Pessoa de Meia-Idade , Mineradores , Estudos Retrospectivos , Dermatopatias/microbiologia , Infecções dos Tecidos Moles/microbiologia , África do Sul/epidemiologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/genética , Staphylococcus aureus/metabolismo
12.
Zhonghua Yu Fang Yi Xue Za Zhi ; 54(8): 849-853, 2020 Aug 06.
Artigo em Chinês | MEDLINE | ID: mdl-32842314

RESUMO

Objective: To identify the epidemic clones of MRSA isolates at a hospital in shanghai. Methods: A total of 72 MRSA isolates have been isolated from a second grade hospital between 2017 and 2018, including 32 CA-MRSA isolates, 13 HA-MRSA isolates and 26 MRSA isolates from environment. In this study, MLST and PFGE typing methods were used to analyze the molecular epidemiology of the MRSA isolates. Results: A total of 72 MRSA isolates have been obtained including 46 isolates from clinical specimens, 26 isolates from environments. The 46 MRSA isolates from clinical specimens consisted of 33 CA-MRSA (community-acquired MRSA) and 13 HA-MRSA (hospital-acquired MRSA). Furthermore, these patients infected with MRSA isolates were mostly distributed in the department of geriatrics (34.8%, 16/46), internal medicine (26.1%, 12/46) and surgery (26.1%, 12/46). MLST typing results showed that ST764 was predominant in isolates from both clinical specimens and hospital environments. Furthermore, PFGE typing results showed that most ST764 MRSA had high homolog (>90%). Conclusion: ST764 MRSA isolates might spread in community, hospital and environments. Therefore, continuous monitoring of MRSA and its variation may be useful in understanding the involvement of epidemic clone, and in searching new strategies to control MRSA infection.


Assuntos
Infecções Comunitárias Adquiridas , Infecção Hospitalar/epidemiologia , Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas/epidemiologia , Antibacterianos , China/epidemiologia , Eletroforese em Gel de Campo Pulsado , Humanos , Meticilina , Testes de Sensibilidade Microbiana , Epidemiologia Molecular , Tipagem de Sequências Multilocus
13.
PLoS One ; 15(7): e0234475, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32663215

RESUMO

BACKGROUND: Neisseria meningitidis is a significant cause of morbidity and mortality worldwide. Meningococcal isolates have a highly dynamic population structure and can be phenotypically and genetically differentiated into serogroups and clonal complexes. The aim of this study was to describe the phenotypic and genotypic characteristics of invasive isolates recovered in Colombia from 2013 to 2016. METHODOLOGY: A total of 193 invasive isolates were analyzed. Phenotypic and genotypic characteristics were determined by serotyping, antimicrobial susceptibility testing, pulsed-field gel electrophoresis (PFGE) and whole-genome sequencing. RESULTS: Based on the results, meningococcal serogroups C, B and Y were responsible for 47.9%, 41.7%, and 9.4% of cases, respectively, and the distribution of serogroups B and C changed over time. Fifteen clonal groups and 14 clonal complexes (cc) were identified by PFGE and genome sequencing. The main clonal group included serogroup B isolates with sequence type (ST)-9493 and its four single-locus variants, which has only been identified in Colombian isolates. The clonal population structure demonstrates that the isolates in this study mainly belong to four clonal complexes: ST-11 cc, ST-32 cc, ST-35 cc and ST-41/44 cc. Thirty-eight penA alleles were identified, but no correlation between MICs and specific sequences was observed. CONCLUSION: This study shows that most meningococcal isolates recovered from patients with invasive meningococcal disease in Colombia are strains associated with distinct globally disseminated hyperinvasive clones.


Assuntos
Infecções Meningocócicas/epidemiologia , Infecções Meningocócicas/genética , Neisseria meningitidis/genética , Adolescente , Adulto , Técnicas de Tipagem Bacteriana/métodos , Criança , Pré-Escolar , Colômbia/epidemiologia , Eletroforese em Gel de Campo Pulsado/métodos , Feminino , Genótipo , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Neisseria meningitidis/isolamento & purificação , Neisseria meningitidis/patogenicidade , Sorogrupo , Sorotipagem
14.
BMC Infect Dis ; 20(1): 472, 2020 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-32616018

RESUMO

BACKGROUND: Carbapenem-resistant hypervirulent Klebsiella pneumoniae strains have recently come into existence worldwide; however, researchers in northeast China are not aware of their clinical features and molecular characteristics. METHODS: Here, the molecular and virulent characteristics of 44 carbapenem-resistant K. pneumoniae (CRKP) isolates collected from January 2015 to December 2017 were studied. Multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE) were carried out to define the clonal relatedness among the isolates. PCR and capsular serotyping of the virulence-associated genes, as well as biofilm formation and serum complement-mediated killing assays, were employed to determine the virulent potential. The genomic features and associated mobile genetic elements of JmsCRE57 were detected by whole genome sequencing. RESULTS: The only positive isolate was JmsCRE57, which belonged to the ST375 serotype K2 that expressed uge, mrkD, fimH, kpn, aerobactin and rmpA virulence-associated genes and showed strong biofilm formation and serum sensitivity. Sequencing results showed that the JmsCRE57 genome mainly consisted of a circular chromosome, three antimicrobial resistant plasmids and a virulent plasmid. The antimicrobial resistant plasmid expressing blaKPC-2, blaCTX-M-15, aph(3″)-Ib, aph(6)-Id, qnrB1, aac(3)-IIa, aac(6')-Ib-cr, blaOXA-1, blaTEM-1B, catB4, sul2, dfrA14 and blaSHV-99. The virulent plasmid belonged to the IncHI1B group, which is mainly composed of mucoid phenotype genes and siderophore-associated genes. The remaining CRKP strains that expressed uge, fimH, mrkD and kpn virulence-associated genes were not successfully typed. CONCLUSION: Our results provide new insights on the epidemiology of carbapenem-resistant K2 hypervirulent K. pneumoniae ST375 and CRKP ST76 strains in northeast China, which may help control their future outbreaks.


Assuntos
Enterobacteriáceas Resistentes a Carbapenêmicos/genética , Enterobacteriáceas Resistentes a Carbapenêmicos/patogenicidade , Surtos de Doenças , Infecções por Klebsiella/epidemiologia , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/patogenicidade , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/uso terapêutico , Enterobacteriáceas Resistentes a Carbapenêmicos/isolamento & purificação , Carbapenêmicos/uso terapêutico , China/epidemiologia , Eletroforese em Gel de Campo Pulsado , Feminino , Humanos , Infecções por Klebsiella/sangue , Infecções por Klebsiella/tratamento farmacológico , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/imunologia , Klebsiella pneumoniae/isolamento & purificação , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Tipagem de Sequências Multilocus , Plasmídeos/genética , Sorogrupo , Sorotipagem , Virulência/genética , Sequenciamento Completo do Genoma , Adulto Jovem
15.
Mikrobiyol Bul ; 54(2): 235-245, 2020 Apr.
Artigo em Turco | MEDLINE | ID: mdl-32723279

RESUMO

Rhizobium radiobacter, which is found in nature and causes tumorigenic plant diseases can lead to opportunistic infections, especially in people with underlying diseases. In our study, endophthalmitis that observed in ten patients caused by R.radiobacter bacteria after intravitreal ranibizumab injection in Ophthalmology Clinic were examined microbiologically. Vitreous fluid samples of 13 patients who received intravitreal ranibizumab injection were sent to the Microbiology Laboratory from Van Yuzuncu Yil University Faculty of Medicine's Ophthalmology Clinic for microbiological examination in December 21, 2016. Samples were examined under microscope after staining with Gram and cultured with 5% sheep blood agar and Eosin Methylene Blue (EMB) agar. The culture plates were incubated for 18-24 hours at 37°C in 5% CO2. At the end of this period, catalase, oxidase, and urease tests were performed on the colonies. The identification and antibiotic susceptibility tests of microorganisms growing in vitreous fluid samples were performed using BD Phoenix (Becton Dickinson, USA), Vitek 2 Compact (BioMerieux, France), and Vitek MS (BioMerieux, France) systems. In addition, 16S rDNA sequence analysis was performed and the pulsed field gel electrophoresis (PFGE) method was used to determine the clonal relationship between the isolates. After growing in cultures (one day after the procedure), culture samples were collected from the objects, medical tools and equipment, hands of healthcare staff and a new injection solution in the area where the procedure was performed. R.radiobacter was isolated in 10 of the vitreous fluid samples of 13 patients, and no bacterial growth was detected in 3. The microorganisms were found to be gram-negative bacilli, non-fermenter, motile, catalase/oxidase/urease positive, in compliance with R.radiobacter. All isolates were identified as R.radiobacter by BD Phoenix (Becton Dickinson, USA), Vitek 2 Compact (BioMerieux, France), and Vitek MS (BioMerieux, France) (database v2.0) systems. R.radiobacter isolates were found to be resistant to ampicillin, amoxicillin/clavulanate, trimethoprim/ sulfamethoxazole, cefotaxime and ceftazidime; susceptible to cefuroxime, cefepime, amikacin, gentamicin, imipenem, meropenem, ciprofloxacin, levofloxacin and piperacillin/tazobactam. The isolates were identified as R.radiobacter by 16S rDNA sequence analysis. PFGE showed that all isolates had the same band profile. R.radiobacter isolates with the same band profile likely revealed that the contamination was from the same source. However, the growth of R.radiobacter was not detected in the cultures made from the objects, medical instruments and supplies, the hands of healthcare professionals and the new injection solution in the area where the procedure was performed, and the source of the agent could not be determined. The results have shown that intravitreal injection procedure carries a risk for R.radiobacter infection. Disinfection and antisepsis conditions, before and during the procedure, is important for the prevention of such infections. This study is the first epidemic outbreak report of endophthalmitis caused by the same strain of R.radiobacter and the second article in which R.radiobacter was reported as the cause of endophthalmitis after intravitreal injection.


Assuntos
Agrobacterium tumefaciens , Antibacterianos , Surtos de Doenças , Infecções por Bactérias Gram-Negativas , Injeções Intravítreas , Agrobacterium tumefaciens/classificação , Agrobacterium tumefaciens/efeitos dos fármacos , Agrobacterium tumefaciens/genética , Agrobacterium tumefaciens/isolamento & purificação , Antibacterianos/administração & dosagem , Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Eletroforese em Gel de Campo Pulsado , Infecções por Bactérias Gram-Negativas/epidemiologia , Infecções por Bactérias Gram-Negativas/microbiologia , Humanos , Injeções Intravítreas/efeitos adversos , Testes de Sensibilidade Microbiana , RNA Ribossômico 16S/genética , Ranibizumab/administração & dosagem , Turquia/epidemiologia
16.
J Med Microbiol ; 69(8): 1079-1088, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32729813

RESUMO

Introduction. Linezolid-resistant (LZR) Staphylococcus capitis has recently emerged in our hospital, and its potential resistance mechanisms are still not clear.Aim. This study aimed to investigate the epidemiology, clinical and genetic characteristics, resistance mechanisms and biofilm formation capacity of LZR S. capitis isolated from patients at Huashan Hospital, Shanghai, PR China between 2012 and 2018.Methodology. Strains were subjected to antimicrobial susceptibility testing (AST) with antibiotics using the broth microdilution method according to the Clinical and Laboratory Standards Institute (CLSI) guidelines. The presence of cfr, optrA and poxtA, as well as mutations in the 23S ribosomal (r)RNA and ribosomal proteins, was investigated using PCR and sequencing techniques. The genetic relationship between isolates was analysed using pulsed-field gel electrophoresis (PFGE) and whole-genome sequencing (WGS). Biofilm biomasses were detected by using crystal violet staining.Results. Twenty-one LZR S. capitis strains displayed MICs of 32-512 µg ml-1. All LZR strains showed G2576T and C2104T mutations in the 23S rRNA V region. Besides G2576T and C2104T, no base mutations were detected in the V region. The cfr was detected in 12 strains, while optrA and poxtA were not amplified in 21 S. capitis strains. PFGE showed that the LZR S. capitis strains belonged to a single clone. The phylogenetic tree showed that 20 LZR S. capitis strains were highly similar to LNZR-1, isolated from Harbin (located in the north of China) in 2013, which showed resistance to linezolid.Conclusions. In this research, cfr-negative strains displayed linezolid MICs of 32 µg ml-1. In comparison, cfr-positive strains exhibited linezolid MICs of 128-512 µg ml-1, indicating that high levels of linezolid resistance appear to be related to the presence of cfr. The outbreak of LZR S. capitis in our hospital needs to be monitored closely.


Assuntos
Antibacterianos/farmacologia , Linezolida/farmacologia , Infecções Estafilocócicas/epidemiologia , Staphylococcus capitis/efeitos dos fármacos , Adulto , Idoso , Idoso de 80 Anos ou mais , Biofilmes/crescimento & desenvolvimento , China/epidemiologia , DNA Bacteriano/isolamento & purificação , Farmacorresistência Bacteriana/genética , Eletroforese em Gel de Campo Pulsado , Feminino , Humanos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Mutação , Oxazolidinonas/farmacologia , RNA Ribossômico 23S/genética , Infecções Estafilocócicas/microbiologia , Staphylococcus capitis/genética , Staphylococcus capitis/fisiologia , Sequenciamento Completo do Genoma , Adulto Jovem
17.
BMC Infect Dis ; 20(1): 511, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32669095

RESUMO

BACKGROUND: Salmonella enterica subsp. enterica serovar Typhimurium infections continue to be a significant public health threat worldwide. The aim of this study was to investigate antibiotic resistance among 147 S. Typhimurium isolates collected from patients in Henan, China from 2006 to 2015. METHODS: 147 S. Typhimurium isolates were collected from March 2006 to November 2015 in Henan Province, China. Antimicrobial susceptibility testing was performed, and the resistant genes of ciprofloxacin, cephalosporins (ceftriaxone and cefoxitin) and azithromycin were detected and sequenced. Clonal relationships were assessed by multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE). RESULTS: Of the 147 isolates, 91.1% were multidrug resistant (MDR), with 4.1% being resistant to all antibiotic classes tested. Of concern, 13 MDR isolates were co-resistant to the first-line treatments cephalosporins and ciprofloxacin, while three were also resistant to azithromycin. Seven PFGE patterns were identified among the 13 isolates. All of the isolates could be assigned to one of four main groups, with a similarity value of 89%. MLST assigned the 147 isolates into five STs, including two dominant STs (ST19 and ST34). Of the 43 ciprofloxacin-resistant isolates, 39 carried double gyrA mutations (Ser83Phe, Asp87Asn/Tyr/Gly) and a single parC (Ser80Arg) mutation, including 1 isolate with four mutations (gyrA: Ser83Phe, Asp87Gly; parC: Ser80Arg; parE: Ser458Pro). In addition, 12 isolates not only carried mutations in gyrA and parC but also had at least one plasmid-mediated quinolone resistance (PMQR) gene. Among the 32 cephalosporin-resistant isolates, the most common extended-spectrum ß-lactamase (ESBL) gene was blaOXA-1, followed by blaCTX-M, blaTEM-1, and blaCMY-2. Moreover, the mphA gene was identified in 5 of the 15 azithromycin-resistant isolates. Four MDR isolates contained ESBL and PMQR genes, and one of them also carried mphA in addition. CONCLUSION: The high level of antibiotic resistance observed in S. Typhimurium poses a great danger to public health, so continuous surveillance of changes in antibiotic resistance is necessary.


Assuntos
Antibacterianos/uso terapêutico , Azitromicina/uso terapêutico , Cefalosporinas/uso terapêutico , Ciprofloxacino/uso terapêutico , Farmacorresistência Bacteriana Múltipla/genética , Infecções por Salmonella/tratamento farmacológico , Infecções por Salmonella/epidemiologia , Salmonella/genética , Sorogrupo , Adolescente , Adulto , Criança , Pré-Escolar , China/epidemiologia , Eletroforese em Gel de Campo Pulsado , Feminino , Humanos , Lactente , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Tipagem de Sequências Multilocus , Infecções por Salmonella/microbiologia , Adulto Jovem
18.
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
19.
PLoS One ; 15(5): e0233313, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32421705

RESUMO

INTRODUCTION: Knowledge of within-patient dynamics of resistance plasmids during outbreaks is important for understanding the persistence and transmission of plasmid-mediated antimicrobial resistance. During an outbreak of a Klebsiella pneumoniae carbapenemase-producing (KPC) K. pneumoniae, the plasmid and chromosomal dynamics of K. pneumoniae within-patients were investigated. METHODS: During the outbreak, all K. pneumoniae isolates of colonized or infected patients were collected, regardless of their susceptibility pattern. A selection of isolates was short-read and long-read sequenced. A hybrid assembly of the short-and long-read sequence data was performed. Plasmid contigs were extracted from the hybrid assembly, annotated, and within patient plasmid comparisons were performed. RESULTS: Fifteen K. pneumoniae isolates of six patients were short-read whole-genome sequenced. Whole-genome multi-locus sequence typing revealed a maximum of 4 allele differences between the sequenced isolates. Within patients 1 and 2 the resistance gene- and plasmid replicon-content did differ between the isolates sequenced. Long-read sequencing and hybrid assembly of 4 isolates revealed loss of the entire KPC-gene containing plasmid in the isolates of patient 2 and a recombination event between the plasmids in the isolates of patient 1. This resulted in two different KPC-gene containing plasmids being simultaneously present during the outbreak. CONCLUSION: During a hospital outbreak of a KPC-producing K. pneumoniae isolate, plasmid loss of the KPC-gene carrying plasmid and plasmid recombination was detected within the isolates from two patients. When investigating outbreaks, one should be aware that plasmid transmission can occur and the possibility of within- and between-patient plasmid variation needs to be considered.


Assuntos
Resistência Microbiana a Medicamentos/genética , Klebsiella pneumoniae/genética , Plasmídeos/genética , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Enterobacteriáceas Resistentes a Carbapenêmicos/genética , Infecção Hospitalar/epidemiologia , DNA Bacteriano/genética , Surtos de Doenças , Eletroforese em Gel de Campo Pulsado/métodos , Humanos , Infecções por Klebsiella/epidemiologia , Klebsiella pneumoniae/isolamento & purificação , Klebsiella pneumoniae/patogenicidade , Testes de Sensibilidade Microbiana/métodos , Tipagem de Sequências Multilocus/métodos , beta-Lactamases/genética , beta-Lactamases/metabolismo
20.
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
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