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1.
Arq. bras. med. vet. zootec. (Online) ; 72(4): 1571-1575, July-Aug. 2020. tab, ilus
Article in English | LILACS, VETINDEX | ID: biblio-1131505

ABSTRACT

O objetivo deste estudo foi realizar a caracterização genética de Staphylococcus spp. resistentes a meticilina isolados de suínos. Foram coletadas 30 amostras de swab nasal de suínos, abatidos em um frigorífico com Serviço de Inspeção Federal. Os isolados foram submetidos a análises macro e microscópicas que, em seguida, para detectar a resistência bacteriana, foram submetidos a ensaios fenotípicos da sensibilidade aos antimicrobianos. Posteriormente, as amostras resistentes a oxacilina, foram submetidas à reação em cadeia pela polimerase (PCR) para verificar a presença do gene mecA. Das 30 amostras analisadas, foram isolados 12 (40%) Staphylococcus spp. coagulase positiva, e 18 (60%) coagulase negativa, e, dentre os isolados, 26 (86,66%) foram resistentes a oxacilina sendo possível detectar o gene mecA em seis (23%) amostras. Este estudo evidencia a presença de genes de resistência em microrganismos comuns a microbiota de animais de produção que podem ser transmitidos ao homem. Além de chamar a atenção para a frequência e quantidade de antimicrobianos aos quais estes animais são expostos durante toda sua vida, podendo ser considerado um problema para a saúde única.(AU)


Subject(s)
Animals , Swine/microbiology , Methicillin-Resistant Staphylococcus aureus/genetics , Nasal Cavity/microbiology , Refrigeration/veterinary , Polymerase Chain Reaction/veterinary , Preliminary Data
2.
Rev. chil. infectol ; 37(1): 37-44, feb. 2020. tab, graf
Article in Spanish | LILACS | ID: biblio-1092720

ABSTRACT

Resumen Introducción: Staphylococcus aureus es uno de los patógenos con mayor prevalencia en el mundo, asociado a una alta tasa de mortalidad y un rápido desarrollo de resistencia a los antimicrobianos. A pesar de su patogenicidad, su seguimiento epidemiológico en México es escaso. Objetivo: Analizar la epidemiología molecular local y determinar el origen clonal de cepas resistentes a meticilina (RM) aisladas de pacientes internados en el Hospital Central "Dr. Ignacio Morones Prieto". Métodos: Se llevó a cabo un estudio prospectivo de corte transversal, de julio a diciembre de 2016. La caracterización de las cepas se realizó mediante genotipificación Spa, la determinación por RPC punto final de la frecuencia de genes de virulencia específicos y su antibiograma. Resultados: A partir de estos datos, se obtuvo que la prevalencia de S. aureus RM fue de 25,7%, destacando la presencia del tipo Spa t895 en 76% de las cepas resistentes y un patrón similar de susceptibilidad a antimicrobianos. Conclusión: Los resultados de este estudio indican que la prevalencia regional de SARM no se ha modificado en los últimos 10 años y proporcionan información valiosa del origen clonal y los factores de virulencia de las cepas de S. aureus aisladas en la región.


Abstract 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.


Subject(s)
Humans , Staphylococcal Infections/microbiology , Staphylococcal Infections/epidemiology , Methicillin-Resistant Staphylococcus aureus/classification , Methicillin-Resistant Staphylococcus aureus/drug effects , Methicillin-Resistant Staphylococcus aureus/genetics , Microbial Sensitivity Tests , Prevalence , Cross-Sectional Studies , Prospective Studies , Virulence Factors/genetics , Genotype , Mexico/epidemiology , Anti-Bacterial Agents/pharmacology
3.
Rev. Soc. Bras. Med. Trop ; 53: e20200244, 2020. tab, graf
Article in English | ColecionaSUS, LILACS, ColecionaSUS, SES-SP | ID: biblio-1136857

ABSTRACT

Abstract INTRODUCTION: Contaminated hospital environments contribute to the transmission of microorganisms associated with healthcare. Contaminated surfaces handled by patients or healthcare professionals are a source of microorganism transmission by hand. Methicillin-resistant Staphylococcus bacteria are among the main agents responsible for increasing healthcare-associated infections in Brazil and worldwide. METHODS: The objective of this study was to screen and characterize methicillin-resistant Staphylococcus spp. on surfaces near patients in an intensive care unit. Microbiological samples, collected from ten beds in an intensive care unit with five sampling sites, were inoculated into a methicillin-resistant Staphylococcus aureus chromogenic medium. MALDI-TOF and PCR analyses were used to identify the bacteria. Antimicrobial susceptibility was determined using the disk diffusion test. The presence of the mecA gene was investigated using PCR. RESULTS: We observed that 44 out of the 50 sampling sites presented grown isolates in the methicillin-resistant Staphylococcus aureus medium. The incidence of isolated microorganisms on the right side rail, left side rail, tables, infusion pump keypad, and cardiac monitor were 18.8 %, 36.7 %, 10.9 %, 2.4 %, and 31 %, respectively. The 42 isolates included in this study were identified as coagulase-negative Staphylococcus. All of these microorganisms were multidrug-resistant and mecA gene-positive. CONCLUSIONS: This study identified the presence of methicillin-resistant coagulase-negative Staphylococcus on the beds of an intensive care unit, providing evidence for the necessity of assertive actions to decrease the risk of healthcare-associated infections at the site.


Subject(s)
Humans , Staphylococcal Infections , Methicillin-Resistant Staphylococcus aureus/genetics , Staphylococcus/genetics , Bacterial Proteins , Brazil , Microbial Sensitivity Tests , Methicillin Resistance , Hospitals , Intensive Care Units , Anti-Bacterial Agents/pharmacology
4.
Rev. Soc. Bras. Med. Trop ; 53: e20200431, 2020. tab, graf
Article in English | ColecionaSUS, LILACS, ColecionaSUS, SES-SP | ID: biblio-1136795

ABSTRACT

Abstract INTRODUCTION: Methicillin-resistant Staphylococcus aureus (MRSA) is a common pathogen causing healthcare-associated infections. Owing to the restricted use of beta-lactams in MRSA infections, non-beta-lactam antimicrobials are required for treatment. However, MRSA can develop resistance mechanisms to non-beta-lactam antimicrobials, which reduces viable treatment options. Here, we evaluated the antimicrobial susceptibility and resistance genes of MRSA isolated from hospitalized patients in South Brazil. METHODS: The antimicrobial susceptibilities of hospital MRSA (217) isolates were determined by disk diffusion or microdilution methods. Additionally, the presence of 14 resistance genes and SCCmec typing was performed by PCR. RESULTS: Among the antimicrobials tested, we observed high erythromycin (74.2%), ciprofloxacin (64.5%), and clindamycin (46.1%) resistance rates and complete susceptibility to linezolid and vancomycin. Seventeen different patterns of MRSA antimicrobial resistance were observed, of which 42.9% represented multidrug resistance. Among erythromycin-resistant MRSA, 53.4%, 45.3%, 37.9%, 13.0%, and 6.8% carried ermA, msrA, msrB, ermC, and ermB genes, respectively. Among clindamycin-resistant MRSA, 83%, 17%, 10%, 4%, and 2% carried ermA, ermC, ermB, linA, and linB genes, respectively. Among gentamicin-resistant MRSA, 96.8%, 83.9%, and 9.7% carried aac(6')/aph(2''), aph(3')-IIIa, and ant(4')-Ia genes, respectively. Among tetracycline-resistant MRSA, 6.5% and 93.5% carried tetK and tetM genes, respectively. Lastly, among trimethoprim/sulfamethoxazole-resistant MRSA, 13.3% and 100% carried dfrA and dfrG genes, respectively. The SCCmec type IV isolates were detected more frequently, whereas the SCCmec type III isolates exhibited higher multidrug resistance. CONCLUSIONS: The study data provides information regarding the MRSA resistance profile in South Brazil that is associated with the clinical conditions of patients and can contribute to clinical decision-making.


Subject(s)
Humans , Methicillin-Resistant Staphylococcus aureus/genetics , Anti-Infective Agents , Staphylococcal Infections/drug therapy , Brazil , Microbial Sensitivity Tests , Hospitals , Anti-Bacterial Agents/pharmacology
5.
Braz. j. infect. dis ; 23(2): 134-138, Mar.-Apr. 2019. tab, graf
Article in English | LILACS | ID: biblio-1039223

ABSTRACT

ABSTRACT 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.


Subject(s)
Humans , Cross Infection/microbiology , Community-Acquired Infections/microbiology , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Methicillin-Resistant Staphylococcus aureus/genetics , Intensive Care Units/statistics & numerical data , Staphylococcal Infections/genetics , Staphylococcal Infections/microbiology , Brazil , Virulence Factors/isolation & purification , Virulence Factors/genetics , Equipment and Supplies, Hospital/microbiology , Methicillin-Resistant Staphylococcus aureus/pathogenicity , Genotype
6.
J. oral res. (Impresa) ; 8(1): 30-36, feb. 28, 2019. ilus, tab
Article in English | LILACS | ID: biblio-1145264

ABSTRACT

Objectives: To study the prevalence of methicillin resistant Staphylococcus aureus (MRSA) in saliva samples of pre-surgical oral squamous cell carcinoma (OSCC) patients along with their resistance pattern to other antibiotics. Methods: Saliva samples of OSCC patients were collected and processed for isolation of MRSA. Staphylococcus aureus isolates were primarily identified using standard microbiological methods like biochemical assays, specialized media and latex agglutination test. Confirmation of MRSA strains was done by growing the isolates on MRSA agar and by using PCR to amplify two MRSA specific genes. All the isolated Staphylococcus aureus strains were subjected to antibiotic sensitivity tests. Results: A total of 17 Staphylococcus aureus strains were isolated from 50 saliva samples of pre-surgical OSCC patients of which 13 were confirmed to be MRSA. These MRSA strains were also found to be mostly resistant to other commonly used antibiotics. Univariate analysis revealed that most patients with MRSA infections had a prior history of hospitalization and surgery. Also, it was confirmed that patients with other comorbidities and infections were more prone to having MRSA present in the saliva. Conclusion: The majority of Staphylococcus aureus isolates from the saliva of OSCC patients were MRSA, and were resistant to several other commonly used antibiotics.


Objetivos: Estudiar la prevalencia de Staphylococcus aureus resistente a la meticilina (MRSA) en muestras de saliva prequirúrgicas de pacientes con carcinoma oral de células escamosas (COCE) junto con su patrón de resistencia a otros antibióticos. Métodos: Se recolectaron muestras de saliva de pacientes con COCE y se procesaron para el aislamiento de SARM. Los aislamientos de Staphylococcus aureus se identificaron principalmente mediante métodos microbiológicos estándar, como los análisis bioquímicos, los medios especializados y la prueba de aglutinación con látex. La confirmación de las cepas de SARM se realizó cultivando los aislados en agar SARM y utilizando PCR para amplificar dos genes específicos de SARM. Todas las cepas aisladas de Staphylococcus aureus se sometieron a pruebas de sensibilidad a los antibióticos. Resultados: Se aislaron un total de 17 cepas de Staphylococcus aureus a partir de 50 muestras de saliva de pacientes prequirúrgicos con COCE, de los cuales solo se confirmó que 13 eran SARM. También se encontró que estas cepas de SARM son resistentes a otros antibióticos de uso común. El análisis univariado reveló que la mayoría de los pacientes con infecciones por SARM tenían antecedentes previos de hospitalización y cirugía. Además, se confirmó que los pacientes con otras comorbilidades e infecciones eran más propensos a las infecciones por SARM. Conclusión: la mayoría de los aislamientos de Staphylococcus aureusde la saliva de los pacientes con OSCC fueron MRSA y fueron resistentes a varios otros antibióticos de uso común.


Subject(s)
Humans , Male , Female , Adult , Middle Aged , Aged , Aged, 80 and over , Young Adult , Staphylococcus/isolation & purification , Drug Resistance, Microbial , Methicillin-Resistant Staphylococcus aureus/genetics , Squamous Cell Carcinoma of Head and Neck , Mouth/microbiology , Saliva , DNA, Bacterial/genetics , Prevalence , Anti-Bacterial Agents
7.
Rev. Soc. Bras. Med. Trop ; 52: e20190095, 2019. tab, graf
Article in English | LILACS | ID: biblio-1013299

ABSTRACT

Abstract 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.


Subject(s)
Humans , Staphylococcus aureus/drug effects , Staphylococcus aureus/genetics , Methicillin Resistance , Virulence Factors/genetics , Methicillin-Resistant Staphylococcus aureus/genetics , Anti-Bacterial Agents/pharmacology , Staphylococcal Infections/epidemiology , Staphylococcus aureus/isolation & purification , Staphylococcus aureus/classification , Virulence/genetics , Brazil/epidemiology , Microbial Sensitivity Tests , Molecular Epidemiology , Tertiary Care Centers , Hospitals, Public
8.
Braz. j. infect. dis ; 22(6): 487-494, Nov.-Dec. 2018. tab, graf
Article in English | LILACS | ID: biblio-984020

ABSTRACT

ABSTRACT Background: The rate of methicillin-resistant Staphylococcus aureus (MRSA) among the total of S. aureus isolates decreased to 35.3% in 2017 in China. It is unclear whether the molecular characteristics of S. aureus isolates have changed as the rate decreased. Objective: This study aimed to investigate the molecular characteristics and virulence genes profile of S. aureus isolates causing bloodstream infection and analyze the correlation between the prevalence rates of the common sequence types and MRSA. Methods: A total of 112 S. aureus strains from eight hospitals of four cities, including 32 MRSA isolates, were identified and evaluated through multilocus sequence typing, spa typing, and determination of virulence genes. Results: Twenty-five STs were identified, of which ST5 (21.4%) was the most prevalent, whereas the prevalence of ST239 correlated with the rate of MRSA among all S. aureus isolates. Forty-six spa types were identified, of which t2460 (14.3%) was the most common. clfa, hla, seb, fnbA and hlb were the prevailing virulence genes. 81.3% MRSA and 45.0% methicillin-sensitive S. aureus (MSSA) isolates harbored six or more tested virulence genes. ST5-t2460, seldom noted in bloodborne S. aureus isolates in China, was the most common clone. The prevalence of harboring six or more virulence genes in ST5-t2460 and ST188-t189 were 93.8% and 8.3%, respectively. Conclusion: ST5-t2460 was the most common clone in S. aureus causing bloodstream infection followed by ST188-t189, which had never been noted in China before. Moreover, ST5-t2460 harbored more virulence genes than ST188-t189, and the prevalence of ST239 clone decreased with the proportion of MRSA among all S. aureus isolates.


Subject(s)
Humans , Staphylococcus aureus/genetics , Staphylococcus aureus/pathogenicity , Virulence/genetics , Bacteremia/virology , Phenotype , Microbial Sensitivity Tests , Virulence Factors/genetics , Methicillin-Resistant Staphylococcus aureus/genetics , Methicillin-Resistant Staphylococcus aureus/pathogenicity , Molecular Typing , Multilocus Sequence Typing , Genotype
9.
J. pediatr. (Rio J.) ; 94(4): 380-389, July-Aug. 2018. tab, graf
Article in English | LILACS | ID: biblio-954633

ABSTRACT

Abstract Objective: Staphylococcus aureus is responsible for a large number of infections in pediatric population; however, information about the behavior of such infections in this population is limited. The aim of the study was to describe the clinical, epidemiological, and molecular characteristics of infections caused by methicillin-susceptible and resistant S. aureus (MSSA-MRSA) in a pediatric population. Method: A cross-sectional descriptive study in patients from birth to 14 years of age from three high-complexity institutions was conducted (2008-2010). All patients infected with methicillin-resistant S. aureus and a representative sample of patients infected with methicillin-susceptible S. aureus were included. Clinical and epidemiological information was obtained from medical records and molecular characterization included spa typing, pulsed-field gel electrophoresis (PFGE), and multilocus sequence typing (MLST). In addition, staphylococcal cassette chromosome mec (SCCmec) and virulence factor genes were detected. Results: A total of 182 patients, 65 with methicillin-susceptible S. aureus infections and 117 with methicillin-resistant S. aureus infections, were included in the study; 41.4% of the patients being under 1 year. The most frequent infections were of the skin and soft tissues. Backgrounds such as having stayed in day care centers and previous use of antibiotics were more common in patients with methicillin-resistant S. aureus infections (p ≤ 0.05). Sixteen clonal complexes were identified and methicillin-susceptible S. aureus strains were more diverse. The most common cassette was staphylococcal cassette chromosomemec IVc (70.8%), which was linked to Panton-Valentine leukocidin (pvl). Conclusions: In contrast with other locations, a prevalence of infections in children under 1 year of age in the city could be observed; this emphasizes the importance of epidemiological knowledge at the local level.


Resumo Objetivo: O Staphylococcus aureus é responsável por um grande número de infecções na população pediátrica; contudo, as informações sobre o comportamento dessas infecções nessa população são limitadas. O objetivo do estudo foi descrever as características clínicas, epidemiológicas e moleculares de infecções causadas por Staphylococcus aureus suscetíveis e resistentes à meticilina (MSSA-MSRA) em uma população pediátrica. Método: Um estudo transversal descritivo foi realizado em pacientes entre 0 e 14 anos de idade de três instituições de alta complexidade (2008-2010). Todos os pacientes infectados com S. aureus resistentes à meticilina e uma amostra representativa de pacientes infectados com S. aureus suscetíveis à meticilina foram incluídos. As informações clínicas e epidemiológicas foram obtidas de prontuários médicos, e a caracterização molecular incluiu tipagem spa, Eletroforese em Gel de Campo Pulsado (PFGE) e Tipagem de sequências multilocus (MLST). Além disso, o Cassete Cromossômico Estafilocócico mec (SCCmec) e genes de fatores de virulência foram detectados. Resultados: 182 pacientes, 65 com infecções por S. aureus suscetíveis à meticilina e 117 com infecções por S. aureus resistentes à meticilina, foram incluídos no estudo; 41,4% dos pacientes com menos de um ano de idade. As infecções mais frequentes foram da pele e dos tecidos moles. Os históricos como internações em centros de atendimento e o uso prévio de antibióticos foram mais comuns em pacientes com infecções por S. aureus resistentes à meticilina (p ≤ 0,05). Dezesseis complexos clonais foram identificados, e as cepas de S. aureus suscetíveis à meticilina foram mais diversificadas. O cassete mais comum foi o Cassete Cromossômico Estafilocócicomec IVc (70,8%), relacionado à leucocidina de panton-valentine (pvl). Conclusões: Em comparação a outros locais, observamos uma prevalência de infecções em crianças com menos de um ano de idade na cidade; o que enfatiza a importância de conhecer a epidemiologia em nível local.


Subject(s)
Humans , Male , Female , Infant, Newborn , Infant , Child, Preschool , Child , Adolescent , Skin Diseases, Infectious/microbiology , Staphylococcal Infections/microbiology , Soft Tissue Infections/microbiology , Virulence Factors/genetics , Methicillin-Resistant Staphylococcus aureus/genetics , Skin Diseases, Infectious/diagnosis , Staphylococcal Infections/diagnosis , Cross-Sectional Studies , Electrophoresis, Gel, Pulsed-Field , Soft Tissue Infections/diagnosis , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Multilocus Sequence Typing
10.
Rev. Soc. Bras. Med. Trop ; 51(3): 361-363, Apr.-June 2018. graf
Article in English | LILACS | ID: biblio-1041462

ABSTRACT

Abstract INTRODUCTION: The pathogenic versatility of Staphylococcus aureus is attributed to various virulence genes, including enterotoxins and hemolysins. METHODS: Here, the virulence genes in 177 nosocomial MRSA strains in Porto Alegre, Brazil were detected by PCR. RESULTS: The overall prevalence rates were as follows: sea, 4.5%; pvl, 18.6%; tst, 27.7%; hla, 87.6%; and hld, 90.4%. No strain contained all tested genes. However, there was frequent coexistence of tst with pvl and hla with hld (40.7% and 26.6%, respectively). CONCLUSIONS: Horizontal transfer of virulence genes is very common in S. aureus, as suggested by the frequent coexistence of several virulence genes.


Subject(s)
Humans , Virulence/genetics , Virulence Factors/genetics , Methicillin-Resistant Staphylococcus aureus/pathogenicity , Polymerase Chain Reaction , Cross-Sectional Studies , Methicillin-Resistant Staphylococcus aureus/genetics
11.
Braz. j. infect. dis ; 22(2): 99-105, Mar.-Apr. 2018. tab, graf
Article in English | LILACS | ID: biblio-951629

ABSTRACT

ABSTRACT Introduction: Staphylococcus spp. - both S. aureus, including methicillin-resistant strains (MRSA) and coagulase negative staphylococci (CoNS) - are relevant agents of healthcare-associated infections. Therefore, the rapid recognition of MRSA and methicillin-resistant CoNS from blood stream infections is critically important for patient management. It is worth noting that inappropriate empiric therapy has been associated with higher in-hospital mortality. Material and methods: In this study we evaluated a multiplex polymerase chain reaction (multiplex PCR) standardized to detect Staphylococcus spp., S. aureus, and mecA gene-encoded oxacillin resistance directly from blood culture bottles. A total of 371 blood cultures with Gram-positive microorganisms confirmed by Gram-stain were analyzed. Results from multiplex PCR were compared to phenotypic characterization of isolates. Results: Staphylococcus aureus was detected in 85 (23.0%) blood cultures and CoNS in 286 (77.0%). There was 100% agreement between phenotypic and multiplex PCR identification. Forty-three (50.6%) of the 85 S. aureus carried the mecA gene and among the 286 CoNS, 225 (78.7%) were positive for the mecA gene. Conclusions: The multiplex PCR assay developed here was found to be sensitive, specific, rapid, and showed good agreement with the phenotypic results besides being less expensive. This PCR method could be used in clinical laboratories for rapid identification and initiation of specific and effective treatment, reducing patient mortality and morbidity. Furthermore, this method may reduce misuse of antimicrobial classes that are more expensive and toxic, thus contributing to the selection of antibiotic-resistant Staphylococcus spp.


Subject(s)
Humans , Bacterial Proteins/genetics , Blood/microbiology , Bacteremia/diagnosis , Penicillin-Binding Proteins/genetics , Methicillin-Resistant Staphylococcus aureus/genetics , Multiplex Polymerase Chain Reaction , Oxacillin/pharmacology , Staphylococcal Infections/diagnosis , Staphylococcus aureus/isolation & purification , Staphylococcus aureus/drug effects , Bacterial Proteins/isolation & purification , DNA, Bacterial/genetics , Bacteremia/microbiology , Penicillin-Binding Proteins/isolation & purification , Blood Culture , Anti-Bacterial Agents/pharmacology
12.
Rev. chil. infectol ; 35(1): 7-14, 2018. tab, graf
Article in Spanish | LILACS | ID: biblio-899771

ABSTRACT

Resumen Desde el inicio de la era antimicrobiana se han ido seleccionando gradualmente cepas de Staphylococcus aureus resistentes a antimicrobianos de amplio uso clínico. Es así como en 1960 se describen en Inglaterra las primeras cepas resistentes a meticilina, y algunos años después son informadas en hospitales de Chile. Actualmente, S. aureus resistente a penicilinas antiestafilocóccicas es endémico en los hospitales de nuestro país y del mundo, siendo responsable de una alta morbimortalidad. La resistencia es mediada habitualmente por la síntesis de una nueva transpeptidasa, denominada PBP2a o PBP2' que posee menos afinidad por el β-lactámico, y es la que mantiene la síntesis de peptidoglicano en presencia del antimicrobiano. Esta nueva enzima se encuentra codificada en el gen mecA, a su vez inserto en un cassette cromosomal con estructura de isla genómica, de los cuales existen varios tipos y subtipos. La resistencia a meticilina se encuentra regulada, principalmente, por un mecanismo de inducción de la expresión del gen en presencia del β-lactámico, a través de un receptor de membrana y un represor de la expresión. Si bien se han descrito mecanismos generadores de resistencia a meticilina mec independientes, son categóricamente menos frecuentes.


Staphylococcus aureus isolates resistant to several antimicrobials have been gradually emerged since the beginning of the antibiotic era. Consequently, the first isolation of methicillin-resistant S. aureus occurred in 1960, which was described a few years later in Chile. Currently, S. aureus resistant to antistaphylococcal penicillins is endemic in Chilean hospitals and worldwide, being responsible for a high burden of morbidity and mortality. This resistance is mediated by the expression of a new transpeptidase, named PBP2a or PBP2', which possesses lower affinity for the β-lactam antibiotics, allowing the synthesis of peptidoglycan even in presence of these antimicrobial agents. This new enzyme is encoded by the mecA gene, itself embedded in a chromosomal cassette displaying a genomic island structure, of which there are several types and subtypes. Methicillin resistance is mainly regulated by an induction mechanism activated in the presence of β-lactams, through a membrane receptor and a repressor of the gene expression. Although mec-independent methicillin resistance mechanisms have been described, they are clearly infrequent.


Subject(s)
Bacterial Proteins/genetics , Genetic Structures/genetics , Penicillin-Binding Proteins/genetics , Methicillin-Resistant Staphylococcus aureus/genetics , Bacterial Proteins/drug effects , Molecular Structure , Chromosomes, Bacterial/drug effects , Penicillin-Binding Proteins/drug effects , Methicillin-Resistant Staphylococcus aureus/drug effects , Genes, Bacterial/drug effects , Methicillin/pharmacology , Methicillin/chemistry , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry
13.
Mem. Inst. Oswaldo Cruz ; 112(11): 790-792, Nov. 2017. graf
Article in English | LILACS | ID: biblio-1040563

ABSTRACT

Staphylococcus aureus subsp. aureus, commonly referred as S. aureus, is an important bacterial pathogen frequently involved in hospital- and community-acquired infections in humans, ranging from skin infections to more severe diseases such as pneumonia, bacteraemia, endocarditis, osteomyelitis, and disseminated infections. Here, we report the complete closed genome sequence of a community-acquired methicillin-resistant S. aureus strain, USA400-0051, which is a prototype of the USA400 clone.


Subject(s)
Humans , Staphylococcal Infections/virology , DNA, Viral/genetics , Genome, Bacterial/genetics , Methicillin-Resistant Staphylococcus aureus/genetics , Community-Acquired Infections/microbiology
14.
Mem. Inst. Oswaldo Cruz ; 112(9): 647-649, Sept. 2017. tab
Article in English | LILACS | ID: biblio-1040577

ABSTRACT

CC398 is a livestock-associated Staphylococcus aureus. However, it has also been isolated from humans with no previous contact with livestock. A surveillance of methicillin-resistant S. aureus colonisation among children attending public day care centres and hospitals in Niterói and Rio de Janeiro, Brazil, between 2011 and 2013, resulted in the isolation of six cases of CC398 from individuals with no previous exposure to livestock. These isolates showed a high frequency of the erm(C) gene (4/6, 66.7%) with induced resistance to clindamycin, and a relatively high frequency of SEs and lukS/lukF genes. These results suggest the emergence of a non-LA-CC398 in Brazil.


Subject(s)
Humans , Child , Staphylococcal Infections/microbiology , Methicillin-Resistant Staphylococcus aureus/genetics , Nasal Mucosa/microbiology , Brazil , Child Day Care Centers , Genotype
15.
Braz. j. infect. dis ; 21(2): 185-189, Mar.-Apr. 2017. tab
Article in English | LILACS | ID: biblio-1039190

ABSTRACT

Abstract Staphylococcus aureus is an important cause of bloodstream infections. Therefore, the main purpose of this work was to characterize a collection of 139 S. aureus isolates from bloodstream infections in two public hospitals in relation to their antimicrobial susceptibility profile, staphylococcal cassette chromosome mec types, and clonal relationship. Methicillin resistance and resistance to other 12 agents were accessed by the disk diffusion test. Minimum inhibitory concentration to mupirocin was also determined. The SCCmec types were accessed by multiplex PCR, and the clonal relationship was determined by pulsed field gel electrophoresis method and restriction modification system characterization. Besides, multilocus sequence typing was performed for representative methicillin-resistant S. aureus isolates. The military hospital showed a dissemination of the New York/Japan (USA100/ST5/CC5/SCCmecII) lineage associated to multidrug resistance, including mupirocin resistance, and the teaching hospital presented polyclonal and non-multidrug resistant MRSA isolates. Complete substitution of the Brazilian endemic clone by other lineages was found in both hospitals. These findings can highlight differences in policy control and prevention of infections used in the hospitals and a change in the epidemiological profile of MRSA in Brazilian hospitals, with the replacement of BEC, a previously well-established clone, by other lineages.


Subject(s)
Humans , Staphylococcal Infections/microbiology , Methicillin-Resistant Staphylococcus aureus/drug effects , Anti-Bacterial Agents/pharmacology , Brazil , DNA, Bacterial/genetics , Bacterial Typing Techniques , Mupirocin/pharmacology , Electrophoresis, Gel, Pulsed-Field , Disk Diffusion Antimicrobial Tests , Methicillin-Resistant Staphylococcus aureus/genetics , Multilocus Sequence Typing , Genotype , Hospitals, Public
16.
Mem. Inst. Oswaldo Cruz ; 112(1): 79-80, Jan. 2017.
Article in English | LILACS | ID: biblio-841753

ABSTRACT

Alarmingly, the isolation of methicillin-resistant Staphylococcus aureus (MRSA) has been increasing among patients with cystic fibrosis (CF). During a previous molecular characterisation of MRSA isolates obtained from patients with CF from Rio de Janeiro, Brazil, one isolate was identified as the ST398 clone, a livestock-associated (LA) MRSA. In this study, we report the draft genome sequence of an LA-MRSA ST398 clone isolated from a patient with CF.


Subject(s)
Humans , Staphylococcal Infections/microbiology , Cystic Fibrosis/microbiology , Methicillin-Resistant Staphylococcus aureus/genetics , DNA, Bacterial , Genome, Bacterial
17.
Braz. j. infect. dis ; 20(6): 525-533, Nov.-Dec. 2016. tab, graf
Article in English | LILACS | ID: biblio-828162

ABSTRACT

ABSTRACT The spread of pandemic Staphylococcus aureus clones, mainly methicillin-resistant S. aureus (MRSA), must be kept under surveillance to assemble an accurate, local epidemiological analysis. In Ecuador, the prevalence of the USA300 Latin American variant clone (USA300-LV) is well known; however, there is little information about other circulating clones. The aim of this work was to identify the sequence types (ST) using a Multiple-Locus Variable number tandem repeat Analysis 14-locus genotyping approach. We analyzed 132 S. aureus strains that were recovered from 2005 to 2013 and isolated in several clinical settings in Quito, Ecuador. MRSA isolates composed 46.97% (62/132) of the study population. Within MRSA, 37 isolates were related to the USA300-LV clone (ST8-MRSA-IV, Panton-Valentine Leukocidin [PVL] +) and 10 were related to the Brazilian clone (ST239-MRSA-III, PVL−). Additionally, two isolates (ST5-MRSA-II, PVL−) were related to the New York/Japan clone. One isolate was related to the Pediatric clone (ST5-MRSA-IV, PVL−), one isolate (ST45-MRSA-II, PVL−) was related to the USA600 clone, and one (ST22-MRSA-IV, PVL−) was related to the epidemic UK-EMRSA-15 clone. Moreover, the most prevalent MSSA sequence types were ST8 (11 isolates), ST45 (8 isolates), ST30 (8 isolates), ST5 (7 isolates) and ST22 (6 isolates). Additionally, we found one isolate that was related to the livestock associated S. aureus clone ST398. We conclude that in addition to the high prevalence of clone LV-ST8-MRSA-IV, other epidemic clones are circulating in Quito, such as the Brazilian, Pediatric and New York/Japan clones. The USA600 and UK-EMRSA-15 clones, which were not previously described in Ecuador, were also found. Moreover, we found evidence of the presence of the livestock associated clone ST398 in a hospital environment.


Subject(s)
Humans , Male , Female , Infant, Newborn , Infant , Child, Preschool , Child , Adolescent , Adult , Middle Aged , Aged , Aged, 80 and over , Young Adult , Staphylococcal Infections/microbiology , Staphylococcus aureus/genetics , Bacterial Toxins/genetics , Exotoxins/genetics , Leukocidins/genetics , Anti-Bacterial Agents/pharmacology , Staphylococcus aureus/isolation & purification , Staphylococcus aureus/classification , DNA, Bacterial , Microbial Sensitivity Tests , Prevalence , Virulence Factors/genetics , Ecuador , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Methicillin-Resistant Staphylococcus aureus/classification , Methicillin-Resistant Staphylococcus aureus/genetics , Multilocus Sequence Typing , Genotype
18.
Rev. chil. infectol ; 33(4): 410-418, ago. 2016. ilus, tab
Article in Spanish | LILACS | ID: biblio-830111

ABSTRACT

Introduction: Bacterial resistance is a global concern for public health. Reports of antimicrobial resistance, including that against methicillin, have increased in strains of coagulase positive Staphylococcus (CPS) isolated from pets, however in Chile this information is limited. Objectives: To determine the antimicrobial susceptibility profiles and to detect the mecA gene in CPS strains isolated from cats in Chile. Materials and Methods : 134 samples were obtained from healthy cats and cats with skin lesions. These strains were characterized in their coagulase production and identified by BBL Crystal kit. The antimicrobial susceptibility was determined by Kirby Bauer method against 12 antimicrobials, including oxacillin. All strains were subjected to PCR to detect the mecA gene. Results: 72 CPS strains were isolated, including S. aureus and S. intermedius. Antimicrobial resistance against at least one drug was detected in strains from both healthy cats (75%) and from cats with skin lesions (87.5%). The mecA gene was detected in eight methicillin-resistant strains and also in three sensitive strains, being in general multi-resistant. Discussion: These results highlight the role of pets as reservoirs of bacterial resistance, and their potential impact on national public health.


Introducción: La resistencia bacteriana constituye un tema de preocupación para la salud pública mundial. Últimamente han aumentado los reportes de resistencia a antimicrobianos, incluida meticilina, en cepas de Staphylococcus coagulasa positiva (SCP) aisladas desde mascotas. Sin embargo, en Chile esta información es escasa. Objetivos: Determinar el perfil de susceptibilidad antimicrobiana y detectar el gen mecA en cepas de SCP aisladas desde gatos en Chile. Materiales y Métodos: Se obtuvieron 134 muestras desde gatos sanos y con lesiones dermatológicas. Las cepas fueron caracterizadas en su producción de coagulasa e identificadas mediante kit BBL Crystal. La susceptibilidad antimicrobiana se determinó mediante el método de Kirby Bauer ante 12 antimicrobianos, incluida oxacilina. Todas las cepas fueron sometidas a RPC para la detección del gen mecA. Resultados: 72 cepas de SCP fueron aisladas, incluyendo S. aureus y S. intermedius. Se detectó resistencia antimicrobiana a al menos un antimicrobiano en cepas de gatos sanos (75%) y de gatos con lesiones cutáneas (87,5%). El gen mecA fue detectado en ocho cepas resistentes a meticilina y en tres cepas sensibles, siendo en general multi-resistentes. Discusión: Estos resultados destacan el rol de las mascotas como reservorios de resistencia bacteriana y su potencial impacto en la salud pública.


Subject(s)
Animals , Bacterial Proteins/genetics , Cats/microbiology , Polymerase Chain Reaction/veterinary , Penicillin-Binding Proteins/genetics , Methicillin-Resistant Staphylococcus aureus/genetics , Microbial Sensitivity Tests , Chile , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Genes, Bacterial/drug effects , Genes, Bacterial/genetics , Anti-Bacterial Agents/pharmacology
19.
Rev. Soc. Bras. Med. Trop ; 49(1): 51-56, Jan.-Feb. 2016. graf
Article in English | LILACS | ID: lil-776534

ABSTRACT

Abstract INTRODUCTION: Methicillin-resistant Staphylococcus aureus (MRSA) is a nosocomial pathogen in community settings. MRSA colonized individuals may contribute to its dissemination; the risk of MRSA infection is increased in human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS) patients, although the prevalence of colonization in this group is not well established. The present study addressed this issue by characterizing MRSA isolates from HIV/AIDS patients and their healthcare providers (HCPs) to determine whether transmission occurred between these two populations. METHODS: A total of 24 MRSA isolates from HIV-infected patients and five from HCPs were collected between August 2011 and May 2013. Susceptibility to currently available antimicrobials was determined. Epidemiological typing was carried out by pulsed-field gel electrophoresis, multilocus sequence typing, and Staphylococcus cassette chromosome (SCCmec) typing. The presence of heterogeneous vancomycin-intermediate Staphylococcus aureus (hVISA) and heterogeneous daptomycin-resistant Staphylococcus aureus (hDRSA) was confirmed by population analysis profile. Isolates characterized in this study were also compared to isolates from 2009 obtained from patients at the same hospital. RESULTS: A variety of lineages were found among patients, including ST5-SCCmecII and ST30-SCCmecIV. Two isolates were Panton-Valentine leukocidin-positive, and hVISA and hDRSA were detected. MRSA isolates from two HCPs were not related to those from HIV/AIDS patients, but clustered with archived MRSA from 2009 with no known relationship to the current study population. CONCLUSIONS: ST105-SCCmecII clones that colonized professionals in 2011 and 2012 were already circulating among patients in 2009, but there is no evidence that these clones spread to or between HIV/AIDS patients up to the 7th day of their hospitalization.


Subject(s)
Humans , Staphylococcal Infections , HIV Infections/microbiology , Cross Infection/transmission , Infectious Disease Transmission, Professional-to-Patient/statistics & numerical data , Methicillin-Resistant Staphylococcus aureus/genetics , Anti-Bacterial Agents/pharmacology , Staphylococcal Infections/microbiology , Microbial Sensitivity Tests , Cross Infection/microbiology , Bacterial Typing Techniques , Electrophoresis, Gel, Pulsed-Field , Molecular Epidemiology , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Multilocus Sequence Typing , Tertiary Care Centers
20.
Article in English | WPRIM | ID: wpr-48263

ABSTRACT

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) are important pathogens causing nosocomial infections in Korean hospitals. This study aimed to investigate the epidemiological and genetic diversity of clinical S. aureus isolates in healthcare settings from 2001 to 2008. METHODS: Samples and data were obtained from 986 individuals as part of the National Antimicrobial Surveillance Project, involving 10 regions nationwide. Molecular typing studies, including multilocus sequence typing (MLST) and staphylococcal cassette chromosome mec (SCCmec) typing were performed, and a representative clone of Korean MRSA was classified by combinational grouping using a DiversiLab (DL; bioMérieux, France) repetitive element polymerase chain reaction (rep-PCR) system. RESULTS: Nine Korean MRSA clones (KMRSA-1 to -9) were identified by analysis of genetic backgrounds and molecular characteristics. KMRSA-1 to -3, expressing clonal complex (CC) 5 (carrying SCCmec II), CC8 (carrying SCCmec III), and CC72 (carrying SCCmec IV) were spread nationwide. In contrast, KMRSA-6 was highly prevalent in Gyeongsangnam-do, and KMRSA-4 was highly prevalent in Jeollanam-do and Jeollabuk-do. CONCLUSIONS: Epidemic KMRSA clones were genetically similar to major clones identified from the USA, with the exception of KMRSA-2, which had the SCCmec III type. Our results provide important insights into the distribution and molecular genetics of MRSA strains in Korea and may aid in the monitoring of MRSA spread throughout the country.


Subject(s)
Bacterial Proteins/genetics , DNA, Bacterial/genetics , Electrophoresis, Gel, Pulsed-Field , Hospitals , Humans , Methicillin-Resistant Staphylococcus aureus/genetics , Multilocus Sequence Typing , Multiplex Polymerase Chain Reaction , Prevalence , Republic of Korea/epidemiology , Staphylococcal Infections/diagnosis
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