Infecciones graves de huesos, articulaciones y tejidos blandos adquiridas en la comunidad / Severe community-acquired bone, joint, and soft tissue infections

Introducción: Las infecciones de huesos, articulaciones y partes blandas, no solo han tenido una incidencia creciente en los últimos años en el Hospital Pediátrico Universitario Paquito González Cueto de Cienfuegos, sino también una evolución más grave. Objetivo: Describir aspectos clínicos y epidemiológicos de las infecciones graves de tejidos blandos, huesos y articulaciones. Métodos: Se revisó la base de datos computadorizada del Departamento de Estadística del Hospital Pediátrico Paquito González, para identificar todos los egresos de la Unidad de Cuidados Intensivos Pediátricos, con diagnóstico de celulitis o absceso de tejidos blandos, fascitis, miositis, osteomielitis, sepsis severa y shock séptico, en el periodo de enero de 2009 a diciembre de 2019. Se estudiaron las siguientes variables: localización de la infección de piel y tejidos blandos, grupo de edad, año del egreso y sitio de origen de la sepsis. Resultados: No hubo diferencias en la incidencia entre los grupos de edad. La celulitis de los miembros fue la forma clínica más frecuente. Se encontró una incidencia creciente de las infecciones de tejidos blandos. Las infecciones de huesos y articulaciones, representaron el segundo sitio de origen más frecuente de sepsis grave y el shock séptico. Conclusiones: Ha habido un aumento de las infecciones de piel y tejidos blandos que requieren ingreso en la unidad de cuidados intensivos del citado hospital en los últimos 11 años. Estas infecciones de conjunto con las infecciones de huesos y articulaciones, constituyen un problema de salud puesto que provocan sepsis grave y shock séptico con una incidencia significativa(AU)

Introduction: Infections of bones, joints and soft parts have not only had an increasing incidence in recent years at ¨Paquito González Cueto¨ University Pediatric Hospital in Cienfuegos, but also a more serious evolution. Objective: Describe clinical and epidemiological aspects of severe soft tissues, bones and joints infections. Methods: The computerized database of the Department of Statistics of ¨Paquito González¨ Pediatric Hospital was reviewed to identify all discharges from the Pediatric Intensive Care Unit with a diagnosis of cellulite or soft tissue abscess, fasciitis, myositis, osteomyelitis, severe sepsis and septic shock, in the period from January 2009 to December 2019. The following variables were studied: location of skin and soft tissue infection, age group, year of discharge, and sepsis origin location. Results: There were no differences in the incidence between age groups. Limb cellulite was the most common clinical form. An increasing incidence of soft tissue infections was found. Bone and joint infections represented the second most frequent origin location of severe sepsis and septic shock. Conclusions: There has been an increase in skin and soft tissue infections that require admission to the intensive care unit of the aforementioned hospital in the last 11 years. These infections, together with bone and joint infections, constitute a health problem since they cause severe sepsis and septic shock with a significant incidence(AU)

Mechanisms of pyroptosis induced by meticillin-resistant Staphylococcus aureus in macrophages / 国际药学研究杂志

Objective: To evaluate the effect of meticillin-resistant Staphylococcus aureus(MRSA)on the pyroptosis of bone-marrow derived macrophages(BMDM)and investigate the mechanism of MRSA-induced pyroptosis in macrophages. Methods: The BMDM were triggered by the combination of lipopolysaccharide(LPS, 100 ng/ml)with adenosine-triphosphate(ATP, 3 mmol/L)or nigericin(Ng, 10 mmol/L)or treated with MRSA(multiplicity of infection 200, MOI 200)alone to induce pyroptosis in vitro. The cell morphology examination and lactate dehydrogenase(LDH)assay were applied to evaluate the cytotoxicity. The expression of pro- inflammatory cytokines, the interleukin(IL)- 1β, IL- 6 and tumor-necrosis factor(TNF)-α was detected by ELISA. The cleaved caspase-1 and mature IL-1β in the cells and released into the supernatant were detected by Western blotting. The signal pathway for the induction of pyroptosis by MRSA was investigated via the transfection of lentivirus- mediated short- hairpin RNA(shRNA)into the BMDM. Results: The treatment of BMDM with LPS/ATP, LPS/nigericin or MRSA alone caused cytotoxicity and up-regulated the expression of pro-inflammatory cytokines, IL-1β, IL-6 and TNF-α, as well as the caspase-1 activation and mature Zl-1β (P<0.01). After silencing NLRP3 or NLRC4, the expression of IL-1β induced by MRSA was significantly lessened(P< 0.01). Conclusion: MRSA could induce BMDM pyroptosis probably via activating NLRP3 inflammasome or NLRC4 inflammasome.

Mastite bovina causada por Staphylococcus spp. resistentes à meticilina: revisão de literatura / Bovine mastitis caused by Staphylococcus spp. methicillin-resistant: literature review

Staphylococcus spp. são os micro-organismos mais relacionados a casos de mastite bovina. Algumas cepas destes micro-organismos têm apresentado fatores de virulência como genes de resistência a antimicrobianos com destaque para a resistência à meticilina que é um problema de saúde pública. Esta revisão de literatura tem o objetivo de compilar dados sobre a mastite bovina causada por Staphylococcus spp. resistente à meticilina (MRS). Apesar desse antimicrobiano não ser comumente utilizado no tratamento das mastites, a frequência de casos de infecção da glândula mamária causada por MRS tem variado entre 1,34 a 47,6%. Acredita-se que o contato dos humanos com animais positivos para MRS e vice-versa favoreça a transmissão deste patógeno entre as espécies, contribuindo para a variação nas taxas de infecção. A detecção de MRS pode ser realizada por meio de provas fenotípicas, moleculares ou sorológicas e as medidas de controle devem contemplar a identificação dos casos, segregação dos animais, estudo epidemiológico da fonte de infecção do rebanho, além da constante limpeza e higienização do ambiente de confinamento, equipamentos e utensílios de ordenha. Casos de mastite ocasionados por esse patógeno assumem relevância para a saúde pública, pois a ingestão de leite e/ou derivados contaminados podem desencadear a transferência de MRS para seres humanos. Com isso, é necessário um alerta constante quanto à vigilância epidemiológica em fazendas leiteiras.(AU)

The most related microorganism in cases of bovine mastitis are Staphylococcus spp. Some strains of these microorganisms have shown virulence factors like antibiotic resistance genes, such as the resistance to methicillin, which represents a public health problem. This literature review aims to compile data related to bovine mastitis caused by Staphylococcus spp. Methicillin-resistant (MRS). Despite this antimicrobial not be commonly used in the treatment of mastitis, the frequency of cases of infection of the mammary gland caused by MRS has ranged from 1.34 to 47.6%. It is believed that the contact of humans with animals positive for MRS and vice versa favors the transmission of this pathogen among species, contributing to the variation in infection rates. MRS detection can be performed by phenotypic tests, molecular tests or serological tests and control measures must be taken such as the identification of cases, animal segregation, epidemiological study of the infection source of herd and the constant cleanliness and hygiene of the confined environment, equipment and milking utensils. Mastitis cases caused by this pathogen are of great relevance to public health because the ingestion of contaminated and/or derived from milk may trigger the transfer of MRS for human. Thus, a constant warning is required on the epidemiological surveillance in dairy farms.(AU)

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)

Caracterización de aislamientos nosocomiales de S. aureus en muestras purulentas en un hospital ortopédico en Cuba / Characterization of nosocomial isolates of S. aureus purulent samples in an orthopedic hospital in Cuba / Caractérisation des isolats nosocomiaux de S. aureus à partir des échantillons purulents dans un service d'orthopédie à Cuba

OBJETIVO: caracterizar microbiológicamente los aislamientos de Staphylococcus aureus recuperados a partir de muestras purulentas tomadas a pacientes con infecciones asociadas a la atención sanitaria en el Hospital Ortopédico Docente "Fructuoso Rodríguez" de enero a mayo de 2014. MÉTODO: estudio descriptivo realizado en el Hospital Ortopédico Docente "Fructuoso Rodríguez" de enero a mayo de 2014 en el que se analizaron 134 muestras de pacientes hospitalizados. El procesamiento de las muestras se realizó por métodos microbiológicos convencionales, y en aquellas donde se recuperó S. aureus se determinó la susceptibilidad antimicrobiana por el método de Bauer Kirby y de E-test para vancomicina. RESULTADOS: En 41,0 % de los aislamientos se identificó S. aureus. El 52,7 % de estos se obtuvieron de heridas quirúrgicas. Se encontró que 50,9 % de los aislamientos de S. aureus fueron meticillin resistentes. No se encontró ninguna cepa resistente a vancomicina. Los aislamientos de S. aureus meticillin resistentes resultaron ser significativamente más resistentes que los de S. aureus meticillin sensibles para eritromicina y las tetraciclinas (tetraciclina y doxiciclina). CONCLUSIONES: S. aureus resultó el microorganismo más encontrado en las muestras purulentas estudiadas. En los aislamientos hospitalarios S. aureus predominó en las heridas quirúrgicas lo cual está en correspondencia con la literatura revisada. La mitad de los aislamientos estudiados resultaron ser S. aureus meticillin resistentes. Todos los antimicrobianos testados, con excepción de vancomicina, mostraron mayores porcentajes de resistencia en los aislamientos meticillin resistentes que en los meticillin sensibles lo que representa un aumento en la estadía hospitalaria y en el costo de la atención médica en aquellos pacientes con S. aureus meticillin resistentes.

OBJECTIVE: microbiologically characterize isolates of Staphylococcus aureus recovered from purulent samples to patients with infections associated with health care at "Fructuoso Rodríguez" Teaching Orthopedic Hospital from January to May 2014. METHOD: a descriptive study was conducted at "Fructuoso Rodríguez" Teaching Orthopedic Hospital from January to May 2014 in which 134 samples from hospitalized patients were analyzed. Sample processing was performed by conventional microbiological methods and for those samples where S. aureus was recovered, antimicrobial susceptibility by the Kirby Bauer method and E-test was determined for vancomycin. RESULTS: 41.0 % of S. aureus isolates were identified. 52.7 % of these were obtained from surgical wounds. It was found that 50.9 % of the isolates were meticillin-resistant S. aureus. No vancomycin resistant strain was found. The isolates of meticillin-resistant S. aureus were significantly more resistant than S. aureus meticillin sensitive to erythromycin and tetracyclines (tetracycline and doxycycline). CONCLUSIONS: S. aureus was the microorganism most found in the purulent samples studied. In hospital S. aureus isolates predominated in the surgical wound which is in line with the literature reviewed. Half of the studied isolates proved meticillin-resistant S. aureus. All antimicrobials tested except vancomycin, showed higher percentages of meticillin resistance in isolates resistant to meticillin sensitive in which an increase in the hospital stay and cost of care for patients with S. aureus meticillin resistant.

OBJECTIF: le but de ce travail est de caractériser du point de vue microbiologique les isolats de Staphylococcus aureus prélevés des échantillons purulents de patients affectés par des infections associées aux soins de santé du service d'orthopédie de l'hôpital universitaire "Fructuoso Rodríguez" depuis janvier jusqu'à mai 2014. MÉTHODES: une étude descriptive de 134 échantillons de patients hospitalisés à l'hôpital universitaire "Fructuoso Rodríguez" a été réalisée depuis janvier jusqu'à mai 2014. L'analyse de ces échantillons a été effectuée par des méthodes microbiologiques conventionnelles. La susceptibilité antimicrobienne a été définie par la méthode de Kirby Bauer et le test de sensibilité à la vancomycine dans les échantillons où le S. aureus a été récupéré. RÉSULTATS: le S. aureus a été identifié dans 41 % des isolats. Une partie (52.7 %) a été obtenue des blessures chirurgicales. On a trouvé que 50.9 % des isolats de S. aureus étaient résistants à la méticilline, tandis qu'aucune souche résistante à la vancomycine n'a été trouvée. Les isolats de S. aureus résistant à la méticilline étaient significativement plus résistants que les isolats de S. aureus sensibles à la méticilline pour l'érythromycine et les tétracyclines (tétracycline et doxicilline). CONCLUSIONS: le Staphylococcus aureus a été le microorganisme le plus souvent trouvé dans les échantillons purulents étudiés. Concernant les isolats hospitaliers, le S. aureus a été en majorité surtout dans les blessures chirurgicales, ce qui est en correspondance avec la littérature révisée. La moitié des isolats analysés ont mis en évidence un Staphylococcus aureus résistant à la méticilline. Tous les antimicrobiens testés, à l'exception de la vancomycine, ont montré des pourcentages de résistance beaucoup plus hauts dans les isolats résistants à la méticilline que dans les isolats sensibles à la méticilline. Ceci a résulté en une augmentation du séjour hospitalier et du coût des soins de santé des patients touchés par S. aureus résistant à la méticilline.

Crecimiento bacteriano en la úlcera del pie diabético previo al uso de Heberprot-P / Bacterial growth in diabetic foot ulcer prior to Heberprot-P

OBJETIVO: determinar el comportamiento del crecimiento microbiológico en las úlceras de pie diabético, previo al uso del Heberprot-P. MÉTODOS: estudio descriptivo mediante la revisión de las historias clínicas de 52 pacientes, incluidos en los ensayos clínicos fase I y II del Heberprot-P en la úlcera de pie diabético. Se tomaron 63 muestras y se consideró el estudio microbiológico realizado en cualquier momento de su evolución, en el período de estudio. RESULTADOS: cuatro muestras resultaron negativas y 29 positivas a Staphylococcus aureus meticillin resistente, que fue el germen más frecuentemente cultivado, por lo que un tercio de los pacientes requirió tratamiento antimicrobiano. CONCLUSIONES: se recomienda realizar estudio microbiológico a todos los pacientes con úlcera de pie diabético, previo al uso de Heberprot-P aun cuando no existan evidencias clínicas de infección local.

OBJECTIVE: to determine the microbiological growth behavior in diabetic foot ulcers, pre Heberprot-P. METHODS: descriptive study was conducted by reviewing the medical records of 52 patients enrolled in Heberprot-P clinical trials phase I and II of diabetic foot ulcer. 63 samples were taken and microbiological study was considered at any point in its evolution in the study period. RESULTS: four samples were negative and 29 positive to Staphylococcus aureus meticillin resistant, which was the most frequently cultivated germ, so that one third of the patients required antibiotic treatment. CONCLUSIONS: microbiological study is recommended to all patients with diabetic foot ulcer, prior to the use of Heberprot-P even when there is no clinical evidence of local infection.

Analysis on drug resistance in 78 strains of meticillinˉresistant Staphylococcus aureus / 国际检验医学杂志

Objective To analyze the drug resistance characteristics of 78 strains of meticillin-resistant Staphylococcus aureus (MRSA)for guiding rational use of antibiotics in clinic.Methods 78 strains of MRSA were collected in our hospital from Septem-ber 2013 to March 2014;their antimicrobial susceptibility test and the drug resistant gene were detected by the MIC method and PCR respectively.Results The resistance of MRSA to erythromycin was more than 90%,which to tetracycline and clindamycin was close to 90%,which to quinolones was more than 70%,which to aminoglycosides was more than 50%,which to trimethoprim and sulphame-thoxazole,nitrofurantoin and rifampicin was lower;no strains were resistant to tigecycline,quinupristin/dalfopristin, vancomycin,linezolid;77 strains of MRSA were positive for mecA gene.Conclusion The drug resistance rate of isolated MRSA in our hospital is roughly the same with that reported,but which still has difference among different departments;clinic should select drugs according to the drug susceptibility test results for preventing aggravation of MRSA drug resistance.

Multidrug-resistant Enterobacteriaceae including metallo-β-lactamase producers are predominant pathogens of healthcare-associated infections in an Indian teaching hospital.

Purpose: A study was carried out in an Indian teaching hospital in 2009 to detect the rate of surgical site infections (SSI) and peripheral vascular access site infections. Materials and Methods: The study was a point-prevalence study involving over 300 patients. The presence of infection was determined according to the CDC criteria. Swabs were taken from the infected sites and identification and sensitivity were carried out using VITEK® 2 automated system. Characterisation of β-lactamase was carried out at ARRML, Colindale, London. Results: The rate of SSI was 15% for the clean and clean-contaminated categories while that for the dirty contaminated category was 85% (NNIS risk index 0). Cultures yielded definite or probable pathogens from 64% (9/14) of the patients with SSI. In 1/3 rd of the cultures, Staphylococcus aureus was grown and the rest had Enterobacteriaceae, either extended-spectrum β-lactamase (ESBL) producers or Amp-C hyperproducers and, alarmingly, three isolates were positive for newly recognised New Delhi metallo-β-lactamase-1 (NDM-1). In medicine, 87% (n = 99) of the patients had a peripheral IV access device, 55% developed associated phlebitis/infection and, in seven, probable pathogens were isolated (Candida species and Escherichia coli producing ESBL and NDM-1, respectively, Staphylococcus aureus and Enterococcus faecium). All ESBL and metallo-β-lactamase producers were resistant to multiple classes of antimicrobials, the latter being sensitive only to colistin and tigecycline. The study also found that all post-operative patients were on antibiotics, 92% on IV [213 defined daily doses (DDD)/100 post-op patients] limited mainly to the third-generation cephalosporins (26%) and aminoglycosides (24%) and imidazole derivatives (30%). In medicine, 83% (n = 82) were on IV antibiotics (123 DDD/100 bed-days), limited mainly to the third-generation cephalosporins (74%). Conclusion: Indiscriminate use of antibiotics is a major problem predisposing patients to harm by multi-resistant pathogens. Carbapenems were in little use in this hospital, but the selection pressure exerted by cephalosporins and other unrelated classes was sufficient to select NDM-1-producing strains due to co-selection, suggesting a role of single plasmid carrying resistance genes to multiple classes.

Colonización por Staphylococcus aureus resistentea meticilina en las manos de individuosde la comunidad / Hand colonization by methicillin-resistant Staphylococcus aureus (MRSA) in the community

En la última década han sido cada vez más frecuentes los informes de infecciones causadas porcepas de Staphylococcus aureus resistente a meticilina asociadas a la comunidad (CA-MRSA,por Community-associated methicillin-resistant S. aureus). La colonización juega un papelimportante en la epidemiología de tales infecciones. Sin embargo, los estudios de colonizaciónse han centrado principalmente en el ambiente hospitalario y se han hecho muy pocos en lacomunidad. En este trabajo se investigó la frecuencia de colonización por S. aureus en generaly por MRSA en las manos de individuos de la población general no relacionados con el área dela salud, empleando métodos fenotípicos y moleculares. Se obtuvieron mediante hisopado 800muestras de las manos de otros tantos individuos. Se halló colonización por Staphylococcusaureus en 65 muestras (8,1%) y por MRSA en 5 (0,63%). Las 5 cepas de MRSA presentaban elcasete cromosómico mec (SCCmec) de los tipos IV o V, típicamente relacionados con CA-MRSA.Nuestro trabajo evidenció la colonización de las manos por MRSA en individuos de la comunidad,lo cual constituye un importante factor de riesgo, no solo por su asociación con el desarrolloulterior de infecciones, sino también por el potencial de diseminar este microorganismo a lapoblación general.

Community-associated methicillin-resistant Staphylococcus aureus infections (CA-MRSA) havebeen reported with increasing frequency during the past decade. Colonization plays an importantrole in the epidemiology of such infections. However, colonization studies have focused mostlyon hospital settings and only a few have been carried out in communities. This was a study of thefrequency of hand colonization by S. aureus in generaland by CA-MRSA, by means of phenotypical andmolecular methods, in 800 adults from the communitywho had no relationship with the health area.Staphylococcus aureus colonization was found in 65individuals (8.1%) and MRSA was present in 5 (0.63%).The 5 MRSA strains were found to have mecchromosomic cassettes (SCCmec) of either type IV orV, typical of CA-MRSA. Our study provides evidence ofCA-MRSA colonization in the hands of individuals fromthe community. This constitutes an important riskfactor, not only by its association with subsequentinfections, but also for the risk of dissemination of thismicroorganism to the general population.

Meticillin-resistant Staphylococcus Isolates in Staphylococcus auricularis and Staphylococcus hominis and Their Drug Resistance / 中华医院感染学杂志

OBJECTIVE To investigate the prevalence of meticillin-resistant Staphylococcus (MRS) isolates in Staphylococcus auricularis and S. hominis and detect their drug resistance. METHODS MRS isolates were detected by cefoxitin disc test and susceptibilities were tested by agar dilution method. RESULTS 94.7% and 91.7% MRS isolates were in S. auricularis and S. hominis. MRS strains were resistant to most of antimicrobial agents. There were no isolates resistant to vancomycin and teicoplanin. CONCLUSIONS MRS isolates are highly prevalent in S. auricularis and S. hominis with resistance to most of antimicrobial agents.

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.

In Vitro Monitoring and Analysis of Drug-Resistance of Gram-positive cocci / 中华医院感染学杂志

OBJECTIVE To investigate drug-resistance status of Gram-positive cocci in the local region and offer scientific basis for reasonable usage of antibiotics.METHODS 336 strains of Gram-positive cocci were isolated from all kinds of specimens from Jan 2003 to Dec 2007 in the local hospital.Organisms were cultivated and identified complying with National Operation Procedure of the Clinical Laboratory.Drug sensitivity test was performed with K-B methods.RESULTS Among the 336 strains,Staphylococcus aureus(SAU) ranked the top,accounting for 45.8%;then the coagulase-negative Staphylococcus(CNS) accounting for 23.2%;Enterococcus faecalis ranked the third,accounting for 18.2%;the detection rate of meticillin-resistant Staphylococcus aureus(MRSA) was 31.8%;that of meticillin-resistant coagulase-negative Staphylococcus(MRCNS) was 35.9%.The results of drug sensitivity test showed the Gram-positive cocci were resistant to the many antibiotics in different degrees except for 100% sensitive to vancomycin.CONCLUSIONS Hospital should attach importance to supervise the drug-resistance of Gram-positive cocci and prevent the dissemination and epidemic of drug resistant strains.

Rapid Identification of Staphylococcus aureus in Positive Blood Culture Bottles by Loop-mediated Isothermal Amplification / 中华医院感染学杂志

OBJECTIVE To establish a method of loop-mediated isothermal amplification(LAMP) for detecting Staphylococcus aureus in positive blood culture bottles.METHODS Genomic DNA in 293 positive blood culture bottles was extracted by guanidine hydrochloride and benzenemethanol,then genes ssa and mecA were amplified by LAMP to identify S.aureus.Finally,the results of LAMP were compared with the results of traditional method.RESULTS Twenty-two strains of S.aureus were detected in 293 positive blood culture bottles by LAMP method.Compared with traditional method,the sensitivity and specificity of LAMP method were both 100%,respectively,the detection could be finished in an hour.CONCLUSIONS The LAMP-based assay is simple,rapid,sensitive and specific which can be used to detect S.aureus in positive blood culture bottles rapidly.

Antimicrobial Resistance and Staphylococcal Cassette Chromosome mec Genotype of Meticillin-resistant Staphylococcus aureus from Lower Respiratory Tract / 中华医院感染学杂志

OBJECTIVE To investigate antimicrobial resistance and molecular epidemiology profiles of meticillin-resistant Staphylococcus aureus(MRSA)sampled from lower respiratory tract.METHODS Totally 107 MRSA strains were isolated from lower respiratory tract specimens at Shanghai Pulmonary Hospital between Dec 2005 and Dec 2006.PVL genes were detected by PCR.The genotypes of SCCmec were identified by multiplex PCR.The antimicrobial resistance of MRSA were tested by Kirby-Bauer agar dilution.We also performed the homology of 32 MRSA strains using pulsed-field gel electrophoresis(PFGE).RESULTS All of the 107 MRSA strains were negative in the PVL locus detection and the most frequent SCCmec types were type Ⅲ(81.3%),the others including type Ⅱ(15.9%),type Ⅳ(2.8%),type Ⅰ and type Ⅴ were not found in this group.Those 3 different types of SCCmec were all resistant to ?-lactam antibiotics,less resistant to rifampin,and susceptible to vancomycin,teicoplanin and daptomycin.The resistant rate of those 3 types were different to the non-?-lactam antimicrobial drugs such as trimethoprim/sulfamethoxazole,clindamycin,erythromycin,gentamicin,levofloxacin,and tetracycline,the resistant rate in the types Ⅱ and Ⅲ was significantly higher than the type Ⅳ.PFGE analyses assorted the 32 MRSA strains into 4 PFGE patterns:pulsotype A(25 strains),including subtypes A1(17strains),A2(1 strain)and A3(7 strains);pulsotype B(5 strains),pulsotype C(1 strain),and pulsotype D(1 strain).CONCLUSIONS This study does not found positive PVL locus in the MRSA strains in our hospital,the most frequent SCCmec types are type Ⅲ and some are type Ⅱ.PFGE presented that there are outbreaks of MRSA in ICU ward and TB ward No 5 at that time and the pandemic strains are subtypes A1 and A3,most of these MRSA strains are multiple resistant,which deserves attention from both the clinical staff and infection-control department of the hospital.

Antibiotic Resistance of Staphylococcus Isolated from Burn Patient Wounds / 中华医院感染学杂志

OBJECTIVE To study the antibiotic resistance of Staphylococcus isolated from the burn patient wounds. METHODS The sensitivity to 14 common antimicrobial agents was deteded by K-B method. MRSA and MRCNS were detected by cefoxitin disk;the inducible resistance to clindamycin was detected by D-test. RESULTS There were 378 strains of Staphylococcus isolated from the burn patient wounds. The isolation rates of Staphylococcus epidermidis,S. aureus and S. haemolyticus were 43.1%,41.6% and 11.1%. Antibiotic resistance rate to vancomycin,teicoplanin,minocycline,rifapin and nitrofurantoin was 0.0-19.0%,the resistance rate to other antibiotics was 54.1-100.0%. The detection rate of MRSA was 81.5%,the detection rate of MRCNS among S. epidermidis and S. haemolyticus was 55.6% and 66.7%. The total positive rate of D-test was 48.2% in Staphylococcus which were sensitive to clindamycin but resistant to erythromycin. The positive rate of S. aureus,S. epidermidis and S. haemolyticus were 49.1%,44.2% and 57.1%. CONCLUSIONS Staphylococcus are ones of the important pathogens which make burn wound infection happen and the antimicrobial resistance is increasingly severe. The high positive results of MRSA and D-test make great trouble to therapy,and that should have taken more attention of clinic.

Drug Resistance in ICU by Meticillin-resistant Staphylococcus aureus Infection and Effect of Linezolid / 中华医院感染学杂志

OBJECTIVE To explore the drug resistance of the infection caused by meticillin-resistant Staphylococcus aureus(MRSA) in ICU and the effect of linezolid in the treatment on MRSA.METHODS The collection of sputum,blood,urine,cerebrospinal fluid,the top and local drainage of central venous needle in 3 years(2006 to 2009) in ICU was carried out,and the bacteriological culture and drug susceptibility testing were executed.Fifteen cases of MRSA infection patients were treated with linezolid.RESULTS There were 72 cases of MRSA infection in 3 years in ICU,most of them were drug-resistant.The sensitivity for MRSA infection was high to 100% by used with vancomycin,teicoplanin and linezolid.The trend of MRSA infection in ICU had increased in the past 3 years.The efficiency and recovery rates of linezolid group(73.3% and 33.3%,respectively) were higher than the vancomycin group(66.7% and 28.6%,respectively)(P

Detection of Resistant Gene from MRSA and MRSH Isolates / 中华医院感染学杂志

OBJECTIVE To investigate the prevalence of the antimicrobial and disinfectant-resistant genes from the clinical isolates of meticillin-resistant Staphylococcus aureus(MRSA) and meticillin-resistant Staphylococcus haemolyticus(MRSH).METHODS The identification and antimicrobial susceptibility test of MRSA and MRSH isolates were determined by MicroScan auto SCAN4.PCR was used for detecting antimicrobial and disinfectant-resistant genes.The minimal inhibitory concentration(MIC)and minimal bactericidal concentration(MBC)of benzalkonium bromide to staphylococci that carried qacA/B gene were determined by broth dilution method.RESULTS The positive rates of qacA/B,aac(6′)/aph(2″),aph(3′)-Ⅲ,ant(4′,4″),TEM,erm,and tetM from 24 MRSH strains were 37.5%,87.5%,33.3%,29.2%,95.8%,and 94.4%;and 91.7%.respectively,and 30.6%,91.7%,72.2%,8.3%,100%,94.4% and 91.7%,respectively.The MIC of benzalkonium bromide for MRSH and MRSA were both 32-128 mg/L,MBC for MRSH was 256-512 mg/L and for MRSA was 512-1024 mg/L.The MIC and MBC of benzalkonium bromide for standard strain ATCC25923 were 16 mg/L and 32mg/L,respectively.CONCLUSIONS Antimicrobial and disinfectant-resistant genes are commonly prevalent in MRSA and MRSH isolates.

Distribution and Drug-resistance of Staphylococcus aureus in Intensive Care Unit / 中华医院感染学杂志

OBJECTIVE To investigate the resistance of Staphylococcus aureus,includ MRSA and MSSA,to antimicrobial agents in intensive care unit(ICU),and to provide basis for clinical therapy.METHODS K-B disk diffusion method was used to determine the drug susceptibility of 171 strains of S.aureus,and meticillin-resistant S.aureus(MRSA) was detected by using the disk diffusion method according to NCCLS/CLSI.RESULTS In ICU,S.aureus was isolated mostly from the respiratory tract,urine tract and blood.MRSA made up 57.89%.For MRSA and MSSA,no resistance against vancomycin and norvancomycin was observed.The resistance rates of MRSA to other agents were as follows: chloramphenicol 20.45%,and minocycline 20.45%.While the resistance rates of MSSA to other agents were as follows:cefazolin 6.25%,and amikacin 6.25%,minocycline 9.38%.CONCLUSIONS MRSA shows the multidrug resistance.Pathogenic monitoring,keeping the patients apart,rational utilization of antibiotics,medical facility sterilization strictly and intensive hand hygiene are very important to prevent MRSA infection.

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.

Antibiotic Resistance in Meticillin-resistant Staphylococcus and Antibiotics Usage / 中华医院感染学杂志

OBJECTIVE To investigate antibiotic resistance and antibiotics usage of meticillin-resistant Staphylococcus(MRS) and provide reference evidence in antibiotics using.METHODS Antibiotic susceptibility test was performed by biological assay system of VITEK-2.Design questionnaires to get the message of the categories,days,effects of antibacterial drug used.RESULTS Drug sensitive ratio to vancomycin,nitrofurantoin,quinupristin-dalfopristin,linezolid were all over 90.00%.The resistant ratios to some antibacterials in MRS were higher than in meticillin-sensitive Staphylococcus(MSS).The categories of antibacterials used after Staphylococcus species detection were more than before.63.01% patients′ medication was determined by antibiotic susceptibility test.Staphylococcus isolated ratio was 43.75% after antibacterial drug used.CONCLUSIONS The status of MRS is very serious.We should pay more attention to the identification and report of resistant strains and it is important to supervise Staphylococcus efficiently and medication by antibiotic susceptibility test.