Elementos de interés clínico en la microbiología molecular de Staphylococcus aureus / Elements of clinical interest in the molecular microbiology of Staphylococcus aureus

El Staphylococcus aureus es uno de los microorganismos de mayor importancia en la asistencia médica, emergente en la comunidad y en el medio hospitalario. El objetivo de este trabajo es presentar una actualización sobre los elementos de interés clínico de la microbiología molecular del Staphylococcus aureus. Para confeccionar esta revisión se utilizaron las bases de datos de Scielo, HINARI, Pubmed-Medline y bibliografías disponibles sobre el tema y los descriptores empleados fueron: Staphylococcus aureus, resistencia a la meticilina, genes, epidemiología molecular, virulencia y la combinación entre ellos. Se revisaron los elementos que determinan sus factores de virulencia, la resistencia antimicrobiana, la versatilidad de estrategias patogénicas, la capacidad de sobrevivir en diferentes condiciones, la evolución y virulencia de los procesos que produce. Igualmente se abordó el diagnóstico de la resistencia, las técnicas de diagnóstico molecular, con sus utilidades, limitaciones, ventajas y desventajas y los estudios de estos temas en los últimos años en Cuba, pues circulan cepas de Staphylococcus aureus resistentes a la meticilina, pero no se conoce la situación real. Se recomienda la conveniencia y necesidad de organizar y armonizar estudios clínicos, epidemiológicos y microbiológicos, que puedan mostrar cuál es la situación actual de este microorganismo y sus infecciones, que aporten datos de su evolución molecular, para evaluar la tendencia de la situación encontrada, que permitan decisiones para el desarrollo de programas de vigilancia y control y revitalicen los medios y métodos de diagnóstico. Resulta importante el conocimiento actualizado del tema, la interpretación de nuevos resultados y el intercambio científico(AU)

Staphylococcus aureus is one of the most important microorganisms in medical care, emerging in the community and in the hospital environment. The objective of this work is to present an update on the elements of clinical interest of the molecular microbiology of Staphylococcus aureus. To make this review, the databases of Scielo, HINARI, Pubmed-Medline and bibliographies available on the subject were used and the descriptors used were: Staphylococcus aureus, methicillin resistance, genes, molecular epidemiology, virulence and the combination between them. We reviewed the elements that determine its virulence factors, antimicrobial resistance, the versatility of pathogenic strategies, the ability to survive in different conditions, the evolution and virulence of the processes it produces. Likewise, the diagnosis of resistance, molecular diagnostic techniques, with their utilities, limitations, advantages and disadvantages, and the studies of these subjects in recent years in Cuba were addressed, since methicillin-resistant strains of Staphylococcus aureus circulate, but not the real situation is known. It is recommended the convenience and need to organize and harmonize clinical, epidemiological and microbiological studies, which can show what is the current situation of this microorganism and its infections, that provide data of its molecular evolution, to evaluate the tendency of the situation found, that allow decisions for the development of surveillance and control programs and revitalize the means and methods of diagnosis. Current knowledge of the subject, interpretation of new results and scientific exchange is important(AU)

Detection of Antibiotics-resistant Genes in Meticillin-resistant Staphylococcus aureus / 中华医院感染学杂志

OBJECTIVE To investigate the antimicrobial-resistant genes in meticillin-resistant Staphylococcus aureus(MRSA).METHODS Forty strains of MRSA were clinically isolated.Nine kinds of antimicrobial-resistant genes were analyzed by polymerase chain reaction(PCR).RESULTS The positive rates of mecA,aac(6′)/aph(2′)and tetM were all 100.0%.The positive rates of ermA/B/C,aph(3′)-Ⅲ,qacA/B,PVL and ant(4′,4″) were 82.5%,67.5%,45.0%,10.0% and 2.5%,respectively.CONCLUSIONS There are higher positive percentages of relevant resistance genes in MRSA isolates clinically.MRSA can induce clone transmition in hospital which should pay,and attention to the disinfection and isolation.

Meticillin-resistant Staphylococcus haemolyticus and Resistance in 103 Isolates of S.haemolyticus / 中华医院感染学杂志

OBJECTIVE To investigate the prevalence of meticillin-resistant Staphylococcus haemolyticus(MRSH)and resistance in S.haemolyticus isolates. METHODS MRSH was detected by cefoxitin disc test and susceptibilities were tested by agar dilution method. RESULTS There were 86.4% of MRSH isolates.MRSH was highly resistant to penicillin,cefazolin,cefuroxime,ceftriaxone,tetracycline,ciprofloxacin,and clindamycin.The resistance rate to amikacin,rifampicine and chloramphenicol was 16.9%,11.2% and 28.1%,respectively.All isolates were susceptible to vancomycin and teicoplanin.Except for tetracycline,amikacin,rifampicin,and chloramphenicol,the resistant rate to other antimicrobial agents was significantly higher in MRSH than in MSSH. CONCLUSIONS MRSH is mostly occupied in S.haemolyticus isolates and resistant to most of antimicrobial agents.More attention should be paid to survey and detect these strains.

Analysis of drug resistance of meticillin-resistant staphylococcus / 中国基层医药

Objective To analyze distribution and drug resistance of MRSA separated,to probe into a treat method for MRSA infection and offer scientific gist for reasonable use of clinical antibiotic. Methods 568 MRSA separated from clinic were measured and a drug sensitivity test was performed by means of Kirby-Bautr agar diffusion method. Results 370 individual plants were filtered, the rate of inspection was 65.1%. MRSA was 36.2 % among them,MRSCON was 77.5% ,the drug resistance of MRSA to quinolones(21% ～48% ) was below MRSCON(84 %～89 % ). The drug resistance of MRSA and MRSCON obviously excelled MSSA and MSSCON ( P＜0.05 ). VRS was undiscovered. Conclusion Severe infection caused by MRS should choose vancomycin resistant enterococci to cure at fist. Staphylococcus was one of primary pathogenic bacterium caused infection in hospital, MRS had multiple drug resistance and measure range about drug resistance should be extended, which would advance the cognition about the drug resistance of antibiotic and cut off the transmitted path, reduce the drug resistance of bacteria and the infection rate in hospital.

Analysis of the Epidemic Tendency of Methicillin-Resistant Staphylococcus aureus at a Hospital / 中国康复理论与实践

@#ObjectiveTo analysis the epidemic tendency of the methicillin-resistant Staphylococcus aureus(MRSA).MethodsClinical data of patients from August 2004 to August 2005 were analyzed retrospectively.Results62 Staphylococcus aureus were isolated,and the MRSA isolated rate was 59%.The MRSA patients tended to complex infection.ConclusionThe infection caused by MRSA is serious.It is necessary to take effective measures to control the MRSA prevalence.

Distribution and Drug-resistant Analysis of Staphylococcus spp in Nosocomial Infections / 中华医院感染学杂志

OBJECTIVE To analyze infection state and drug resistance feature of Staphylococcus spp with a view of offering references for controlling and treating infection led by it.METHODS Totally 652 strains of Staphylococcus isolated from patients with infection were identified and their drug resistance was analyzed.RESULTS From them 204 strains were Staphylococcus aureus and 448 strains were coagulase negative Staphylococcus detected and the isolating rate of MRSA and MRCNS were respectively accounted for 55.4% and 84.6%.The most common coagulase negative Staphylococcus strains were S.haemolyticus and S.epidermidis.The drug-resistant rates of MRS were higher transparently than MSS.CONCLUSIONS Staphylococcus are one of the main pathogens leading to nosocomial infections.As a result, it is very important to use antibiotics properly for infection control and nosocomial infection management.