Microbiological characteristics of bloodstream infections in a reference hospital in northeastern Brazil

Abstract Routine blood culture is used for the detection of bloodstream infections by aerobic and anaerobic bacteria and by common pathogenic yeasts. A retrospective study was conducted in a public hospital in Maceió-AL, by collecting data of all medical records with positive blood cultures. Out of the 2,107 blood cultures performed, 17% were positive with Staphylococcus coagulase negative (51.14%), followed by Staphylococcus aureus (11.21%) and Klebsiella pneumoniae (6.32%). Gram-positive bacteria predominated among positive blood cultures, highlighting the group of Staphylococcus coagulase-negative. While Gram-negative bacteria had a higher number of species among positive blood cultures.

Resumo A cultura sanguínea de rotina é usada para a detecção de infecções na corrente sanguínea por bactérias aeróbias e anaeróbias e por leveduras patogênicas comuns. Estudo retrospectivo realizado em hospital público de Maceió-AL, por meio da coleta de dados de todos os prontuários com culturas sanguíneas positivas. Das 2.107 culturas sanguíneas realizadas, 17% foram positivas com Staphylococcus coagulase negativo (51,14%), seguido por Staphylococcus aureus (11,21%) e Klebsiella pneumoniae (6,32%). As bactérias Gram-positiva predominaram entre as culturas de sangue positivas, destacando-se o grupo das Staphylococcus coagulase-negativo. Enquanto as bactérias Gram-negativas apresentaram um número maior de espécies entre as culturas de sangue positivas.

Microbiological characteristics of bloodstream infections in a reference hospital in northeastern Brazil / Características microbiológicas de infecções da corrente sanguínea em hospital de referência no nordeste do Brasil

Abstract Routine blood culture is used for the detection of bloodstream infections by aerobic and anaerobic bacteria and by common pathogenic yeasts. A retrospective study was conducted in a public hospital in Maceió-AL, by collecting data of all medical records with positive blood cultures. Out of the 2,107 blood cultures performed, 17% were positive with Staphylococcus coagulase negative (51.14%), followed by Staphylococcus aureus (11.21%) and Klebsiella pneumoniae (6.32%). Gram-positive bacteria predominated among positive blood cultures, highlighting the group of Staphylococcus coagulase-negative. While Gram-negative bacteria had a higher number of species among positive blood cultures.

Resumo A cultura sanguínea de rotina é usada para a detecção de infecções na corrente sanguínea por bactérias aeróbias e anaeróbias e por leveduras patogênicas comuns. Estudo retrospectivo realizado em hospital público de Maceió-AL, por meio da coleta de dados de todos os prontuários com culturas sanguíneas positivas. Das 2.107 culturas sanguíneas realizadas, 17% foram positivas com Staphylococcus coagulase negativo (51,14%), seguido por Staphylococcus aureus (11,21%) e Klebsiella pneumoniae (6,32%). As bactérias Gram-positiva predominaram entre as culturas de sangue positivas, destacando-se o grupo das Staphylococcus coagulase-negativo. Enquanto as bactérias Gram-negativas apresentaram um número maior de espécies entre as culturas de sangue positivas.

Microbiological characteristics of bloodstream infections in a reference hospital in northeastern Brazil.

Routine blood culture is used for the detection of bloodstream infections by aerobic and anaerobic bacteria and by common pathogenic yeasts. A retrospective study was conducted in a public hospital in Maceió-AL, by collecting data of all medical records with positive blood cultures. Out of the 2,107 blood cultures performed, 17% were positive with Staphylococcus coagulase negative (51.14%), followed by Staphylococcus aureus (11.21%) and Klebsiella pneumoniae (6.32%). Gram-positive bacteria predominated among positive blood cultures, highlighting the group of Staphylococcus coagulase-negative. While Gram-negative bacteria had a higher number of species among positive blood cultures.

Dietary ethanol extract of mango increases antioxidant activity of pork.

Ethanol extract of mango seeds (EEMS) are composed of several polyphenolic compounds with considerable in vitro antioxidant activity that can be used in pig feed and may contribute positively to meat quality characteristics. The aim of this study was to evaluate the effect of EEMS as a source of antioxidants in growing-finishing pig diets on meat quality, lipid stability, sulfhydryl groups non-proteinaceous (SG-NP), total phenolic compounds, total antioxidant potential and total antioxidant activity of meat after 1 and 7 days of refrigeration storage. Thirty-two (60-day-old) barrows, weighing 20.20 ±â€¯1.34 kg, were used in a randomized block design consisting of eight animals with four treatment regimens. Treatments consisted of: Control = no dietary antioxidant; butylated hydroxytoluene (BHT) = diet with 200 ppm BHT; EEMS200 = diet with 200 ppm EEMS; EEMS400 = diet with 400 ppm EEMS. At 145 days of age and average weight of 95.47 ±â€¯6.19 kg, the animals were slaughtered and loin samples were collected and frozen before for qualitative analysis and evaluation of the effect of subsequent storage for 1 or 7 days at 8 °C on lipid stability, SG-NP, phenolic compounds, total antioxidant capacity and total antioxidant activity Meat from animals fed EEMS400 diet showed lower cooking loss (P < 0.0001) and higher non-protein sulfhydryl groups, phenolic compounds and total antioxidant activity at both 1 and 7 days of storage (P < 0.0001) compared to the other treatments. Greater antioxidant capacity was observed at 1 day storage in the meat of animals that consumed EEMS regardless of concentration when compared to the control group (P < 0.01). The dietary inclusion of EEMS to pig diets is more effective at 400 ppm in improving meat quality after cooking and antioxidant parameters of pork.

Survival and prognostic factors in patients with oral squamous cell carcinoma.

BACKGROUND: This study aimed to evaluate sociodemographic and clinical factors influencing overall survival (OS) in patients with oral squamous cell carcinoma (OSCC). MATERIAL AND METHODS: Medical charts of 547 patients with OSCC from a public hospital in northeastern Brazil seen between 1999 and 2013 were evaluated. Survival analysis was performed using the Kaplan-Meier method. The influence of age, sex, ethnicity, clinical stage, anatomical location, type of treatment, and comorbidities on the patients' prognosis was evaluated. Cox proportional hazards regression model was used to identify independent prognostic factors. RESULTS: The 5-year OS was 39%. Multivariate analysis showed that age < 40 years (HR = 2.20; 95%CI: 1.02-4.72) and a single treatment modality (HR = 1.91; 95%CI: 1.37-2.67) were associated with a poor prognosis, while early clinical stage resulted in better outcomes (HR = 0.38; 95%CI: 0.25-0.58). CONCLUSIONS: OSCC patients in advanced clinical stages, diagnosed at a younger age, and submitted to a single therapeutic modality have a poorer prognosis.

[Management of transient radicular pain after receiving an epidural blood patch for headaches due to spontaneous intracranial hypotension]. / Radiculalgia transitoria tras administración de parche hemático epidural en la cefalea por hipotensión intracraneal espontánea, conducta a seguir.

Spontaneous intracranial hypotension headache is an uncommon disease that resolves spontaneously in most of the cases and in a short period of time. The initial treatment should be symptomatic. In some patients the symptomatology is extremely disabling, and in these cases both the diagnosis and treatment may be performed by an epidural blood patch. A 49-year-old Caucasian woman, with no previous record of epidural or intrathecal puncture, consulted in the Emergency Department complaining of a 9-day history of frontal headache and diplopia, along with nausea and vomiting. The patient was diagnosed with spontaneous intracranial hypotension headache. Considering the symptomatology and the uncontrolled pain, the Pain Unit of our hospital performed an epidural blood patch. In the first 24h the patient reported a remarkable relief of both headache and diplopia but developed a left lumbar radiculopathy that was treated successfully with supportive measures. Transient lumbar radiculopathy is a common and acceptable event secondary to the use of epidural blood patch as a treatment for spontaneous intracranial hypotension headache.

Predicting the potential invasion suitability of regions to cassava lacebug pests (Heteroptera: Tingidae: Vatiga spp.).

Cassava (Manihot esculenta Crantz) is one of the most important staple crops for small farmers in the tropics, feeding about 800 million people worldwide. It is currently cultivated in South and Central America, Africa and Asia. The genus Vatiga is widespread throughout the Neotropical region. Its species are sympatric and feed exclusively on cassava. The main objectives of this paper are: (1) to assess the potential distribution of Vatiga, one of the most relevant pests of cassava; (2) to project the resulting models onto the world; (3) to recognize areas with suitable and optimal climates (and thus, high probability) for future colonization, and (4) to compare this model with the harvested area of cassava analyzing the climatic variables required by both the host and the pest species. Species distribution models were built using Maxent (v3.3.3k) with bioclimatic variables from the WorldClim database in 2.5 arc min resolution across the globe. Our model shows that Vatiga has the potential to expand its current distribution into other suitable areas, and could invade other regions where cassava is already cultivated, e.g., Central Africa and Asia. Considering the results and the high host specificity of Vatiga, its recent appearance in Réunion Island (Africa) poses a serious threat, as nearby areas are potentially suitable for invasion and could serve as dispersal routes enabling Vatiga to reach the continent. The present work may help prevention or early detection of Vatiga spp. in areas where cassava is grown.

¿Quién soy yo? con la palabra, enfermeros supervisores de un hospital privado de Belo Horizonte / No disponible

En este artículo se pretende comprender cómo los enfermeros-supervisores de un gran hospital privado ubicado en Belo Horizonte construyen su identidad. Para ello, se realizó un estudio de caso descriptivo y analítico que incluyó a nueve enfermeros-supervisores. La recolección de datos se llevó a cabo a través de entrevistas con guión semiestructurado y el análisis mediante la técnica de análisis de contenido, que abarcó las siguientes unidades de análisis: la percepción de los enfermeros-supervisores en cuanto al nuevo método de gestión implantado en el hospital; el trabajo cotidiano de los enfermeros-supervisores; la formación en enfermería y la práctica profesional; los requisitos de un enfermero ideal para el puesto de gestión, y las expectativas de carrera de los enfermeros-supervisores. Los resultados mostraron que el nuevo modo de gestión adoptado por el hospital se caracterizó como un espacio significativo de reconfiguración de identidad de los enfermeros-supervisores, en particular, por poner de relieve el desnivel entre la formación académica y la práctica cotidiana del trabajo (AU)

This paper aims to understand how supervisor-nurses of a big private hospital in Belo Horizonte build their professional identity. In order to do that, a descriptive analytical case study was carried out in which nine supervisor nurses were included. Data were collected through semi-structured interviews and the analysis by means of the content analysis technique. The analysis focused on: the supervisor nurses’ perception concerning the new management procedure used at the hospital; supervisor-nurses’ routine at work; nursing education and professional practice; qualifications of an ideal nurse for the management position; and supervisor-nurses’ carrier expectations. The results showed that the new management strategy used by the hospital was considered a significant space for the supervisor-nurses’ identity reconfiguration, especially because it demonstrates a disharmony between academic instruction and daily practice at work (AU)

Validation of an analytical method for the determination of cadmium (Cd) in fish by atomic absorption spectrometry with electrothermal atomisation.

The validation of an analytical method was carried out for the determination of cadmium (Cd) in fish. The method was based on sample digestion in a microwave oven and subsequent reading using an atomic absorption spectrometer with a graphite furnace. The factorial design of experiments was applied to assess method ruggedness using the methodology of Box et al. [Box GEP, Hunter WG, Hunter JS. 1978. Statistics for experiments: an introduction to design, data analysis and model building. New York (NY): Wiley], studying the influence of sample mass, volume and concentration of acid used for sample digestion and the volume of modifier used. To study the possible matrix effect in the determination of Cd, the standard addition method was also performed. The results were treated using the OLS method. For the normality test a homoskedastic distribution was observed for the developed method and the results were adjusted to the statistical model proposed. F-tests and Student's t-tests indicated that there was no matrix effect on the calibration curve between the concentration range 1.0-10.0 µg Cd l(-1). Parameters such as selectivity, precision, decision limit, detection capability and limit of quantification were established by the method of standard addition to blank samples. The limit of quantification was 6.8 µg kg(-1). Accuracy, which was evaluated by using a certified reference material, was 107.0%. The recovery of the spiked analyte was 93.69% for the concentration of 50 µg kg(-1). Precision was defined by the coefficient of variation observed (Horrat value), estimated in terms of repeatability and reproducibility, and the values were below the limit, which is 2.0. The validation procedure confirmed the suitability of the method.

Method validation for the determination of total mercury in fish muscle by cold vapour atomic absorption spectrometry.

A method was validated for the determination of total Hg in fish muscle using continuous flow cold vapour atomic absorption (CVAAS) after microwave digestion in closed vessels. The method was validated according to European Union Regulations 333/2007 and 657/2002, considering the maximum level for the metal in fish, established by European Union regulation 1881/2006. The procedure for determining linear range, selectivity, recovery, precision, trueness, decision limit (CCα), detection capability (CCß), measurement uncertainty and robustness of the method is reported. The results of the validation process demonstrate the method fulfils the provisions of the Commission Regulation. The selectivity study indicated that there was no matrix effect on the calibration curve between the concentration range of 1.0 and 30.0 µg Hg l(-1). The mean recovery calculated at six levels of fortification was in the range of 94-104%. The limit of detection (LOD) and limit of quantification (LOQ) values were 4.90 and 15.7 µg kg(-1), while the CCα and CCß values were 0.517 and 0.533 mg kg(-1), respectively, for the maximum contaminant level of 0.500 mg kg(-1). The relative expanded measurement uncertainty of the method was 0.055 mg kg(-1). The method was not affected by slight variations of some critical factors (ruggedness minor changes) as sample mass and volume of the HNO(3) and H(2)O(2) used in the digestion step. The method allowed accurate confirmation analyses of the CRM DORM 3. In fact, the Z-scores attained in a proficiency test round were well below the reference value of 2.0, proving the excellent performance of the laboratory.

Increase of core temperature induced by corticotropin-releasing factor and urocortin: a comparative study.

This study compared the ability of CRF and UCN1 to induce a thermoregulatory response when centrally injected into rats. The effects of antipyretic drugs and CRF receptor antagonists (CRF1 and CRF2) on the temperature (T) changes induced by these peptides were also investigated. Rectal (rT) and tail skin (T(sk)) temperatures were measured with a thermistor probe while body (bT) temperature was measured with a battery-operated biotelemetry transmitter in male Wistar rats (200 g) every 30 min over a period of 6h, after intracerebroventricular (i.c.v.) injection of 1 nmol of either CRF or UCN1. Rats were pre-treated with indomethacin (2 mg kg⁻¹, i.p.) or celecoxib (5 mg kg⁻¹, p.o.), dexamethasone (0.5 mg kg⁻¹, s.c.), astressin (a CRF1/CRF2 antagonist, 7 nmol, i.c.v.) or antalarmin (a CRF1 antagonist, 20 mg kg⁻¹, i.p.). The increase in body temperature induced by CRF was accompanied by a reduction in T(sk) while the response induced by UCN1 was accompanied by an elevation in T(sk). Indomethacin or celecoxib did not change the increases in rT caused by either CRF or UCN1. Although dexamethasone attenuated the increase in rectal temperature in response to CRF, dexamethasone did not modify the response induced by UCN1. Astressin blocked the UCN1-induced hyperthermia and reduced CRF-induced fever. Antalarmin did not modify the hyperthermia in response to UCN1, but reduced the fever evoked by CRF. This study demonstrated that CRF by acting on the CRF1 receptor induces a prostaglandin-independent fever which seems to depend, at least in part, on the synthesis of other mediators while UCN1 acts on the CRF2 receptor, promoting a hyperthermic response which seems to be independent on synthesis/release of any mediator.

Cyclic fatigue of NiTi rotary instruments in a simulated apical abrupt curvature.

AIM: To evaluate the cyclic fatigue resistance of five NiTi rotary systems in an abrupt apical curvature. METHODOLOGY: Cyclic fatigue testing was performed in stainless-steel artificial canals with a 2-mm radius of curvature and an angle of curvature of 90 degrees constructed to the dimensions of the instruments tested. The middle of the simulated curvature was 2.5 mm from the tip of the instrument that was placed at full working length. All instruments were new and 25 mm in length. Ten ProTaper Universal F2 (Dentsply Maillefer, Ballaigues, Switzerland); FlexMaster (VDW, Munich, Germany) tip size 25, taper 0.06; Mtwo (Sweden & Martina, Padova, Italy) tip size 25, taper 0.06; ProFile tip size 25, taper 0.06 from Dentsply Maillefer (Ballaigues, Switzerland); and ProFile tip size 25, taper 0.06 from Dentsply Tulsa (Tulsa, OK, USA) were rotated passively at 300 rpm until fracture occurred, and the number of cycles to failure (NCF) recorded. Length of the fractured tip was measured. Data were analysed by one-way anova and Tukey HSD test to determine any statistical difference amongst groups. RESULTS: Mtwo had the highest fatigue resistance compared to the other instruments (NCF 124 +/- 25) (P < 0.001); there was no statistical difference between ProFile from the two different brands, although ProFile from Maillefer had the higher fatigue life (NCF 75 +/- 10) compared to ProFile from Tulsa (NCF 66 +/- 10). No difference was registered between FlexMaster (NCF 53 +/- 5) and ProFile from Tulsa; ProTaper F2 had a significantly (P < 0.001) lower fatigue life compared to the other instruments tested (NCF 29 +/- 5). CONCLUSIONS: Lifespan registered for the instruments tested in an apical abrupt curvature was Mtwo > ProFile from Maillefer > ProFile from Tulsa > FlexMaster > ProTaper.

Genotyping of methicillin-resistant Staphylococcus aureus isolates obtained in the Northeast region of Brazil

Methicillin-resistant Staphylococcus aureus (MRSA) is a major agent of hospital infections worldwide. In Brazil, a multiresistant MRSA lineage (ST239-SCCmecIIIA), the so-called Brazilian epidemic clone (BEC), has predominated in all regions. However, an increase in nosocomial infections caused by non-multiresistant MRSA clones has recently been observed. In the present study, 45 clinical isolates of MRSA obtained from a university hospital located in Natal city, Brazil, were identified by standard laboratory methods and molecularly characterized using staphylococcal chromosome cassette mec (SCCmec) typing and pulsed-field gel electrophoresis. Antimicrobial susceptibility testing was carried out using CLSI methods. The MRSA isolates studied displayed a total of 8 different pulsed-field gel electrophoresis patterns (types A to H) with predominance (73 percent) of pattern A (BEC-related). However, MRSA harboring SCCmec type IV were also identified, 3 (7 percent) of which were genetically related to the pediatric clone - USA800 (ST5-SCCmecIV). In addition, we found a considerable genetic diversity within BEC isolates. MRSA displaying SCCmecIV are frequently susceptible to the majority of non-β-lactam antibiotics. However, emergence of multiresistant variants of USA800 was detected.

Genotyping of methicillin-resistant Staphylococcus aureus isolates obtained in the Northeast region of Brazil.

Methicillin-resistant Staphylococcus aureus (MRSA) is a major agent of hospital infections worldwide. In Brazil, a multiresistant MRSA lineage (ST239-SCCmecIIIA), the so-called Brazilian epidemic clone (BEC), has predominated in all regions. However, an increase in nosocomial infections caused by non-multiresistant MRSA clones has recently been observed. In the present study, 45 clinical isolates of MRSA obtained from a university hospital located in Natal city, Brazil, were identified by standard laboratory methods and molecularly characterized using staphylococcal chromosome cassette mec (SCCmec) typing and pulsed-field gel electrophoresis. Antimicrobial susceptibility testing was carried out using CLSI methods. The MRSA isolates studied displayed a total of 8 different pulsed-field gel electrophoresis patterns (types A to H) with predominance (73%) of pattern A (BEC-related). However, MRSA harboring SCCmec type IV were also identified, 3 (7%) of which were genetically related to the pediatric clone--USA800 (ST5-SCCmecIV). In addition, we found a considerable genetic diversity within BEC isolates. MRSA displaying SCCmecIV are frequently susceptible to the majority of non-beta-lactam antibiotics. However, emergence of multiresistant variants of USA800 was detected.

Staphylococcus aureus e estafilococos coagulase negativosresistentes à vancomicina em um Hospital Universitário Brasileiro / Vancomycin-resistant Staphylococcus aureus and coagulase-negative staphylococci in a Brazilian University Hospital

Infecções hospitalares por Methicillin-Resistant S. aureus (MRSA) e Methicillin-Resistant Coagulase-Negative Staphylococci (MRCoNS) estão entre as mais frequentes mundialmente, justificando um aumento significativo no uso de vancomicina. Com o objetivo de avaliar a presença de estafilococos resistentes aos glicopeptídeos em pacientes em uso terapêutico desse antimicrobiano, internados no Hospital de Clínicas da Universidade Federal de Uberlândia, Uberlândia MG, foi realizado um estudo longitudinal prospectivo incluindo 41 pacientes, 21 adultos e 20 crianças, entre dezembro de 2000 e março de 2002. O monitoramento microbiológico foi realizado por meio de swabs coletados a partir da cavidade bucal e reto e cultivo primário em Ágar Manitol Salgado acrescido de 6 mg/mL de oxacilina. Amostras selecionadas foram testadas quanto à sensibilidade aos glicopeptídeos pelas técnicas de gel difusão e diluição em ágar e a análise de heterorresistência, pela semeadura utilizando inóculo correspondente à escala 0,5 de McFarland (108 UFC/mL) e análise do perfil populacional. Um único paciente, nefropata em programa de hemodiálise apresentou-se colonizado com uma amostra do fenótipo Vancomycin-Intermediate S. aureus (VISA) (CIM = 8 miug/mL) e em doze, foram isoladas amostras de estafilococos heterorresistentes, correspondendo oito hVISA e quatro hVICoNS. O estudo do perfil populacional, confirmou a presença de subpopulações de células resistentes, sendo seis hVISA e duas hVICoNS. A presença de amostras heterorresistentes à vancomicina pode representar um risco potencial no futuro.

Methicillin-resistant Staphylococcus aureus (MRSA) and Methicillin-resistant Coagulase-negative Staphylococci (MRCoNS) are among the most frequent hospital infections around the world, and are associated with a significant rise in the use of vancomycin. In order to assess the presence of staphylococci resistant to glycopeptides in patients taking this antibiotic in Uberlândia Federal University Hospital, Uberlândia (MG, Brazil), a prospective longitudinal study of 41 patients (21 adults and 20 children) was performed between December 2000 and March 2002. Microbiological monitoring was carried out by means of swabs collected from the oral cavity and rectum, screened by culturing in Salt Mannitol Agar plus 6 ?g/mL oxacillin. Selected samples were tested for susceptibility to glycopeptides, by the techniques of gel diffusion and dilution in agar, and for heteroresistance, by seeding with an inoculum at a density of 0.5 on the McFarland scale (108 CFU/mL) and performing a population analysis profile (PAP). A single nephropathy patient was colonized with a strain of vancomycin intermediate S. aureus (VISA) phenotype (MIC = 8 miug/mL). In twelve patients, heteroresistant staphylococci were isolated, corresponding to eight hVISA and four hVICoNS. The PAP study confirmed the presence of six hVISA and two hVICoNS. The presence of heteroresistant vancomycin samples may pose a potential risk in the future.

Influence of cyclic torsional loading on the fatigue resistance of K3 instruments.

AIM: To evaluate the influence of cyclic torsional loading on the flexural fatigue resistance and torsional properties of rotary NiTi instruments. METHODOLOGY: Twelve sets of new K3 instruments, sizes 20, 25 and 30 with an 0.04 taper, and sizes 20 and 25 with an 0.06 taper, were torsion tested until rupture, to establish their mean values of maximum torque and angular deflection. Twelve new K3 instruments of each of the following dimensions, size 30, 0.04 taper and sizes 20 and 25 with 0.06 taper, were tested to failure by rotation bending in a fatigue test device. Cyclic torsional loading was performed in 20 cycles from zero angular deflection to 180 degrees and then return to zero applied torque. After cyclic loading, the same number of instruments were tested until rupture in torsion and flexural fatigue. Data obtained were subjected to a one way analysis of variance (anova) at 95% confidence level. RESULTS: Cyclic torsional loading caused no significant differences in maximum torque or in maximum angular deflection of the instruments analysed, but comparative statistical analysis between measured NCF values of new and previously cycled K3 instruments showed significant differences for all tested instrument. Longitudinal cracks, that is, cracks apparently parallel to the long axis of the instruments cycled in torsion was observed. CONCLUSIONS: Cyclic torsional loading experiments in new K3 rotary endodontic instruments showed that torsional fatigue decreased the resistance of these instruments to flexural fatigue, although it did not affect their torsional resistance.

Dimensional characterization and mechanical behaviour of K3 rotary instruments.

AIM: To correlate the mechanical behaviour in torsion, bending and fatigue tests of K3 instruments with their dimensional characteristics. METHODOLOGY: Instrument length, tip angle, distance between blades (pitch length) and the diameter at each millimetre from the tip of sizes 20, 25 and 30, 0.04 taper and sizes 20 and 25, 0.06 taper K3 rotary instruments were measured in an optical microscope equipped with digital micrometers. The cross-sectional area at 3 mm from the tip of the same instruments was determined using digital image analysis of scanning electron microscopy images. Maximum torque and angular deflection, as well as bending moment at 45 degrees were measured according to specification of ISO 3630-1. Fatigue resistance of instruments size 30, 0.04 taper, and sizes 20 and 25, 0.06 taper was determined in a fatigue test bench device. RESULTS: The analysed instruments presented no uniformity in the distance between adjacent blades, but the measured diameters at each millimetre from the tip were regular, showing compliance with manufacturing standards. Torque and bending moment of the tested instruments increased significantly with diameter and cross-sectional area at 3 mm from the instrument tip. The fatigue resistance of the instruments showed a tendency to decrease as the diameter of the instruments increased. CONCLUSIONS: The bending moment at 45 degrees and the torsional resistance of K3 instruments can be predicted using instrument diameter and cross-sectional area at 3 mm from the tip. Fatigue resistance decreased as the instrument diameter increased.

Hospital surface contamination in wards occupied by patients infected with MRSA or MSSA in a Brazilian university hospital

The hospital environment, especially surfaces, represents a secondary reservoir for pathogens such as Staphylococcus aureus. The present study was carried out at the Hospital de Clínicas da Universidade Federal de Uberlândia (HC-UFU) in Brazil, from January to August 2004, with the aim of qualitatively and quantitatively assessing the presence of S. aureus on surfaces touched by hands (bed rail, bedside table and door handle), on the floor and in the air, in wards where the patients were infected or not infected with this organism. Twenty-six wards with at least one infected patient and 26 wards with uninfected patients were investigated. Surfaces and air were sampled during bedmaking, by means of sterile 10cm2 adhesive tapes and 90mm-diameter exposed culture plates, respectively. Cultures were carried out on Egg Yolk Salt Agar, containing 7.5% NaCl and 1% egg yolk, and colonies identified by lecithinase and coagulase tests and Gramstain. About 50% of the wards were S. aureus contaminated, without significant differences between the groups (46.1% in the infected patient wards versus 53.8% in controls); the correlation between counts of the pathogen on the surfaces and in the air was 66.7%. Inspite of the fact that these bacteria were frequently present in the assessed wards, the microbial density waslow (less than 1 CFU/cm2). The association between environmental contamination and the epidemiology of S. aureus nosocomial infections is complex and thus further investigations are needed to reach a better understanding of this relationship.

Molecular characterization of methicillin-resistant Staphylococcus aureus disseminated in a home care system.

OBJECTIVE: To study colonization with methicillin-resistant Staphylococcus aureus in a home care service during a 4-month period. DESIGN: Prospective study. SETTING: A home care service located in Rio de Janeiro, Brazil. PARTICIPANTS: Patients admitted to the home care service during this period, their household contacts, and health care workers (HCWs). METHODS: Swab specimens from the anterior nares were collected from each patient in the 3 groups at admission. Screening was repeated every 7 days. MRSA was detected using a mecA probe, and the clonality of isolates was evaluated by molecular methods, primarily pulsed-field gel electrophoresis. RESULTS: Of the 59 study patients, 9 (15.3%) had MRSA colonization detected; these cases of colonization were classified as imported. Only 1 (2.0%) of the 50 patients not colonized at admission became an MRSA carrier (this case of colonization was classified as autochthonous). Two (0.9%) of 224 household contacts and 16 (7.4%) of 217 HCWs had MRSA colonization. Cross-transmission from patient to HCW could be clearly demonstrated in 8 cases. The great majority of MRSA isolates belonged to the Brazilian epidemic clone. CONCLUSIONS: MRSA colonization was common in the home care service analyzed. The fact that the majority of MRSA isolates obtained were primarily of nosocomial origin (and belonged to the so-called Brazilian epidemic clone) substantiated our findings that all but 1 patient had already been colonized before admission to the home care service. Only cross-transmission from patients to healthcare workers could be verified. On the basis of these results, we believe that a control program built on admission screening of patients for detection of MRSA carriage could contribute to the overall quality of care.