Rapid bacterial identification by MALDI-TOF MS directly from blood cultures and rapid susceptibility testing: A simple approach to reduce the turnaround time of blood cultures

Abstract Antimicrobial treatment of patients with bloodstream infections (BSI) is time-sensitive. In an era of increasing antimicrobial resistance, rapid detection and identification of bacteria with antimicrobial susceptibility are critical for targeted therapy early in the disease course. This study describes the performance of a rapid method for identifying and testing antimicrobial susceptibility of Gram-negative bacteria performed directly from blood culture bottles in a routine microbiology laboratory. A total of 284, 120, and 24 samples were analyzed by rapid identification (Rid), rapid susceptibility testing (RAST), and rapid broth microdilution for polymyxin B (rMIC), respectively, and compared with standard methods. Our protocol was able to identify 93% of isolates at the species level using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). We obtained 100% agreement for RAST compared to the standard method and 96% agreement for rMIC. Our protocol has proven to be an excellent tool for rapid identification of Gram-negative bacilli causing BSIs. It can also be used in microbiology laboratory routine along with RAST and faster polymyxin microdilution, especially for carbapenemase-producing bacteria, allowing for rapid, simple, accurate, and cost-effective diagnosis.

Bacterias aisladas en hemocultivos positivos en lactantes bajo 90 días de edad ingresados por fiebre al Hospital Exequiel González Cortés entre 2014 y 2016 / Positive blood cultured isolated bacteria in children under 90 days old admitted for fever in Hospital Exequiel González Cortés between 2014 and 2016

INTRODUCCIÓN: En neonatos y lactantes bajo 90 días de vida la fiebre constituye un signo clínico relevante ya que puede corresponder a una infección bacteriana grave, por lo que se toman hemocultivos de forma rutinaria y el paciente es hospitalizado. Aún no existe una recomendación respecto al tiempo de observación necesario una vez internado el paciente. OBJETIVO: Describir las bacterias aisladas en hemocultivos de lactantes bajo 90 días de vida hospitalizados por fiebre y el tiempo de detección de crecimiento microbiano en los mismos. ¨MÉTODO: Estudio descriptivo, retrospectivo. Se revisaron hemocultivos positivos tomados entre 2014 y 2016 en neonatos y lactantes < 90 días de edad. Se obtuvieron las identificaciones, tiempo de positividad de las bacterias, así como datos clínicos, de laboratorio y demográficos. RESULTADOS: Se identificaron 172 hemocultivos positivos, 51 cumplían los criterios de inclusión. De éstos, 21 microorganismos fueron patógenos (Escherichia coli: 10, Streptococcus agalactiae: 3, Streptococcus pyogenes: 3, otros: 5) y 30 se consideraron contaminación, principalmente Staphylococcus coagulasa negativa. En relación al total de la muestra, la mediana del tiempo de positividad fue de 10 h. A las 24 h de cultivo se detectó crecimiento bacteriano en 94% de la muestra. CONCLUSIÓN: Las bacterias patógenas aisladas en los hemocultivos de pacientes < 90 días de edad, que ingresaron con fiebre, corresponden principalmente a bacilos gramnegativos y estreptococos. Todos los patógenos aislados fueron detectados antes de 24 h de incubación.

BACKGROUND: Fever in infants younger than 90 days may reflect a serious bacterial infection, so blood cultures (BC) are taken routinely and the patient is hospitalized. The observation time to detect occult bacteremia is not well established. AIM: To describe type and positivity time of isolated bacteria in blood cultures in infants under 90 days admitted for fever. METHODS: Retrospective, descriptive study. Positive blood cultures taken between 2014-2016 in young infants admitted for fever were included. Identification and time of positivity of each bacteria, clinical, laboratory and demographic data were recorded. Demographic variables and the clinical outcome was obtained. RESULTS: There were 172 positive blood cultures, only 51 met inclusion criteria. Of these, 21 microorganisms were pathogenic (Escherichia coli: 10, Streptococcus agalactiae: 3, Streptococcus pyogenes: 3, others: 5) and 30 were considered contamination, mainly coagulase negative Staphylococcus. In relation to the total sample, the median time of positivity was 10 hrs. At 24 hours of culture, bacterial growth was detected in 94% of the sample. CONCLUSION: The pathogenic bacteria isolated in the blood cultures of patients younger than 90 days who were admitted with fever correspond mainly to Gram negative bacilli and streptococci. All isolated pathogens were detected before 24 h of incubation.

Behavior on Blood Collection from Patients by Nurses for Culture at the Microbiology Laboratory of Mahosot Hospital, Vientiane Capital / Lao Medical Journal

Background and rationale@#Infections caused by bacteria are significant public health problems and the roots of much illness and death in Laos. Hemoculture is the gold standard for the diagnosis of septicemia and the aetiological agents. However, the result of blood culture depend on many factors, from the collection of blood by nurses until completing and reporting the laboratory analysis. The process of blood collection by nurses plays an important role for optimizing culture yields in the laboratory and the result will be more accurate with a lower contamination rate, if performed using strict sterilized techniques. Correct blood collection and culture practices will also reduce the risks of needle-stick injuries and harm.@*Objective@#To study behavior on blood collection from patients by nurses for culture at Microbiology Laboratory of Mahosot Hospital, Vientiane Capital.@*Methodology@#The study was descriptive, cross-sectional quantitative study to the nurses who were performing blood collection for culture and who answered questionnaires. The reported behavior of the nurses was also compared to that observed by the researcher. Data entered into the Excel and analyzed with STATA.@*Results@#The majority of the study nurses were female (92%) with a mean age of 33 years, a mid-level of nursing study (82.4%), and with an average duration of working of 7 years. The awareness of nurses about the importance of blood collection technique for culture was in the range from 43.3% and 30.0% rating as high and intermediate respectively. Right attitude towards accurate practices was 27.0%. The reported correct practice of blood collection by the nurses was 38% however the correspondent figure by observation was only 12%. Older age, longer work experience, better work knowledge, attitude were significantly associated with correct blood collection procedures (P-value <0.05).@*Conclusion@#The techniques and knowledge of the nurses for collecting blood cultures remains low due to lack of knowledge, techniques, procedures and methods to collect and deliver samples. Therefore, adequate and regular trainings are urgently needed.

Embolismos sépticos pulmonares y sistémicos como forma de presentación de la endocarditis infecciosa / Septic pulmonary and systemic embolisms as form of presentation of infective endocarditis

Introducción: A partir de los años 50, la presentación clínica clásica de la endocarditis infecciosa ha variado. Debido al uso de antibióticos, drogas ilícitas, catéteres venosos, etc., las manifestaciones tradicionales no son frecuentes. Objetivo: Presentar un caso con endocarditis infecciosa y comentar las manifestaciones embolígenas, así como las medidas preventivas con las nuevas técnicas. Caso clínico: Enfermo con insuficiencia renal crónica, diabético, hipertenso, con catéter venoso central, que presentó, después de una sección de hemodiálisis; escalofríos intensos, fiebre de 39,5 0C, cefalea intensa, toma del estado general, dolor torácico intenso punzante, tos, expectoración con sangre roja rutilante, disnea, soplo regurgitante holosistólico. Se le realizó ecocardiograma dópler que muestra múltiples vegetaciones pequeñas, hemocultivos positivos a estafilococos dorado. Fue tratado según los resultados del antibiograma durante 6 semanas y resolvió su extrema gravedad. Conclusiones: La endocarditis infecciosa puede tener manifestaciones muy diferentes al de décadas anteriores; puede aparecer como cuadro agudo fulminante por manifestaciones embólicas y sépticas múltiples(AU)

Introduction: Since the 1950s, the classical clinical presentation of infectious endocarditis (E.I) has varied. Due to the use of antibiotics, illicit drugs, venous catheters, traditional manifestations are not frequent. Objectives: To review the embolic presentation of endocarditis and pecify the preventive measures with the new techniques. Clinical case: A patient with chronic renal insufficiency, diabetic, hypertensive, with central venous catheter, intense chills, fever of 39.5 ° C, intense headache, general state, severe chest pain, cough, expectoration with bright red blood, dyspnea, holosystolic regurgitant murmur, after a section of hemodialysis. Doppler echocardiogram was performed, visualizing multiple small vegetation's, positive blood cultures to golden staphylococci, treatment according to antibiograms for 6 weeks, at the end of which the extreme severity was resolved. Comments: Infective endocarditis can have a very different behavior from previous decades; it can appear as an acute fulminating disease due to embolic, septic, multiple manifestations(AU)

Susceptibilidad a meticilina y vancomicina en Staphylococcus aureus aislados de hemocultivos / Susceptibility to methicillin and vancomycin in Staphylococcus aureus isolated from blood cultures

Para determinar la susceptibilidad a meticilina y vancomicina en cepas de Staphylococcus aureus aisladas de hemocultivos, se analizaron los registros de pacientes ingresados en las Unidades de Cuidados Intensivos del Servicio Autónomo Hospital Universitario de Maracaibo durante el período enero 2011-diciembre 2015. Se procesaron 35.341 hemocultivos; 5.072 (14,35%) fueron positivos; en 455 (8,97%) se aislaron 96 cepas de Staphylococcus aureus (21,09%), de las cuales, 78 (81,25%) fueron resistentes y 18 (18,75%), sensibles a meticilina. Todos los aislados resultaron sensibles a vancomicina. El 61,45% de las cepas expresó multirresistencia. No se encontró diferencia estadísticamente significativa en la frecuencia de aislamiento de Staphylococcus aureus por año, edad y sexo del paciente (p > 0,05); pero si según el tipo de unidad y la presencia de co-resistencia antimicrobiana (p < 0,05). Los elevados niveles de resistencia a meticilina y la evidencia de fenotipos sensibles a vancomicina con valores elevados de concentración inhibitoria mínima (> 1 µg/ml), demandan la vigilancia sistemática del patrón de susceptibilidad antimicrobiana a fin de guiar a los clínicos para elegir la terapia empírica adecuada, contribuyendo al reforzamiento continuo de las precauciones estándar y al establecimiento de las políticas locales de administración y regulación del uso de antimicrobianos

To determine susceptibility to methicillin and vancomycin in blood-isolated strains of Staphylococcus aureus isolated from blood cultures, patient records entered in the Intensive Care Units of the Autonomous Hospital University Service of Maracaibo were analyzed during the period January 2011-December 2015. 35,341 blood cultures were processed; 5.072 (14,35%) were positive; in 455 (8.97%)96 strains of Staphylococcus aureus (21.09%) were isolated, of which 78 (81.25%) were resistant and 18 (18.75%), sensitive to methicillin. All isolates were sensitive to vancomycin. 61.45% of the strains expressed multi-resistance. No statistically significant difference in the frequency of isolation of Staphylococcus aureus per year, age and sex of the patient (p > 0.05) was found; but if according to the type of unit and the presence of antimicrobial co-resistance (p ˂ 0.05). The high levels of methicillin resistance and the evidence of vancomycin-sensitive phenotypes with high minimum inhibitory concentration values (>1 µg/ml), require systematic monitoring of the antimicrobial susceptibility pattern in order to guide clinicians to choose appropriate empirical therapy, contributing to the continuous strengthening of standard precautions and the establishment of local policies for the administration and regulation of the use of antimicrobials

Hemocultivos en recién nacidos: optimizando la toma de muestra y su rendimiento / Blood cultures in newborns: optimizing sample collection and performance

Resumen La solicitud de hemocultivos en la atención médica es frecuente, especialmente en las Unidades de Neonatologia, donde se realiza en forma rutinaria frente a la sospecha de sepsis precoz o tardia. Este documento tiene como objetivo estandarizar la técnica de obtención de muestra con la finalidad de aumentar su rendimiento y establecer criterios de cómo interpretar un hemocultivo positivo.

The request of blood cultures in medical care is frequent, especially in Neonatal Units, where it is performed routinely in case of suspected early or late sepsis. The purpose of this document is to standardize the sampling technique in order to increase its performance and establish criteria to interpret a positive blood culture.

Detection of the mecA gene and identification of Staphylococcus directly from blood culture bottles by multiplex polymerase chain reaction

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.

Assessment of two-site blood cultures practice in pediatric patients / 中华实用儿科临床杂志

Objective To evaluate the effect of two-site blood cultures on detection rate in pediatric patients.Methods The data were retrospectively analyzed of 1 985 hospitalized children with blood cultures from January 2013 to February 2015 in Department of Infectious Diseases,Beijing Children's Hospital,Capital Medical University,including blood culture collection,the administration of antibiotics prior to obtaining blood cultures and positive condition of blood culture.It was divided into 3 stages according to blood culture collection.Blood culture of a single bottle referred to the blood culture in an aerobic bottle.Double bottles transition stage referred to two blood samples taken from the same skin puncture point and the aerobic bottle culture was carried out at the same time.Two-site blood cultures referred to two blood samples taken from the different skin puncture point and the aerobic bottle culture was carried out at the same time.The interval time between the two blood cultures should be less than 5 minutes.The positive rates of three stages were analyzed by Pearson x2 test.The change tendency of positive rates in three stages were analyzed by Cochran-Armitage test.Bilateral P ＜ 0.05 was considered as statistically significant difference in all test analysis.Results More than 80％ of the children in the three stages were given antibiotics.There was no significant difference in the true positive rate (x2 =1.343,P ＞ 0.05).There was no significant difference in the change tendency of positive rates (P ＞ 0.05).False-positive strains were common for coagulase-negative staphylococci.In terms of false positive rate,blood culture of single bottle was higher than two-site blood culture (x2 =6.051,P ＜ 0.05).Conclusion For children (non-neonates),two-site blood cultures can reduce the false positive rate of blood culture and play a role in distinguishing between true positives and false positives in blood culture.

Progress in the rapid identification techniques for pathogenic microorganisms from blood culture positive specimens / 中华检验医学杂志

It takes at least 48 hours for traditional identification of pathogens from blood stream infection.Therefore, a rapid identification is vital for optimizing antimicrobial therapy and improving the prognosis of patients.In recent years, the intelligentialized Gram staining based on convolutional neural network has been applied to automatically interpret the species of pathogens in positive smear and the matrix -assisted laser desorption/ionization time of flight mass spectrometry ( MALDI TOF-MS) can quickly identify pathogens.Furthermore, Peptide nucleic acid fluorescence in situ hybridization (PNA FISH)is applicable to the rapid identification of pathogens from positive bacteria liquid .Powered by morphokinetic cellular analysis (MCA) and fluorescence in situ hybridization (FISH), the Accelerate Pheno system can directly identify pathogens from positive blood cultures and determine MIC of pathogens to antibiotics .The above-mentioned methods can provide a direct , rapid and accurate identification of pathogens from positive blood culture bottles without subculture .

Analyzed the distribution of pathogenic spectra and antibiotic resistance by isolating from 4 238 blood cultures / 国际检验医学杂志

Objective To explore the distribution features of pathogenic spectra and antibiotic resistance of the isolates from blood cultures in hospital from June 2012 to June 2016.Methods A total of 4 238 blood samples from June 2012 to June 2016 were evaluated by BD Bactec FX-200,the identification results were used for retrospective analysis.Results A total of 455 positive pathogens were isolated from 4 238 blood cultures sample,the positive rate was 10.74％,Gram-positive accounts for 38.02％,Gram-negative bacilli accounts for 60.00％,Fungi accounts for 1.98％.Positive pathogens were distributed in newborn baby and middle-older patients,accounting for 6.78％ and 76.17％respectively.Which the Enterobacteriaceae accounting for 54.10％,the major consists were Escherichia coli and Klebsiellapneumoniae;Non-fermentative bacterial which consists of Pseudomonas aeruginosa and Acinetobacterbaumannii accounting for 2.90％.The major pathogens in Gram-positive cocci was Staphylococcus,accounting for 25.87％.Enterobacteriaceae were more sensitive to Meropenem,Imipenem and so all.Non-fermentative bacterial were more sensitive to Piperacillin/Tazobactam.Staphylococcus were more sensitive to Vancomycin and Linezolid.Streptococcus were sensitive to Vancomycin.Conclusion Combined with the distribution features of pathogenic spectra and antibiotic resistance,clinicians should pay attention to use of drugs reasonably to enhance the cure rate of bacteremia and Fungalemia.

Inocuidad, prevención y riesgos de los probióticos / Probiotics: innocuousness, prevention and risks

Los probióticos son microorganismos vivos que cuando son administrados en cantidades adecuadas confieren beneficios a la salud del huésped. Su empleo es muy amplio en todas las edades, y los episodios adversos asociados con ellos, incluyendo casos de sepsis, que hagan suponer un riesgo real y manifiesto de invasión del torrente sanguíneo o algún tipo de contagio son muy infrecuentes. Sin embargo, algunos profesionales de la salud manifiestan dudas respecto de su inocuidad. Esta revisión revela que la incidencia de sepsis por probióticos, principalmente lactobacilos y bifidobacterias, evaluada en casuísticas numerosas a lo largo de decenios usando métodos de biología molecular o cultivos, es muy baja: del orden de 0,021% en algunas estadísticas y podría llegar hasta 1 caso/1.000.000 de habitantes. Estos datos son importantes teniendo en cuenta el empleo masivo de diversas especies y cepas, sin restricciones de ninguna especie y en todas las edades. Algunos estudios que comunican otros efectos adversos tienen problemas de diseño que ponen en duda su validez. Por el contrario, se ha demostrado que los probióticos ejercen efectos positivos estimulando la inmunidad innata y adquirida, en el tratamiento de la atopia y eccema y en la prevención de la enterocolitis necrosante en sujetos tan vulnerables como los prematuros.

Probiotics have been defined as live microorganisms which, when ingested in adequate numbers, confer health benefits to the host. They are currently consumed without any age restrictions and adverse effects such as sepsis, a marker of the risk of invasion of the bloodstream, are extremely infrequent. However, some health professionals express doubts about probiotics being truly innocuous. This review discusses the incidence of sepsis secondary to probiotics use, mainly lactobacilli and bifidobacteria, evaluated through molecular biology or classic culture techniques, showing that sepsis in large numbers of individuals along decennia is extremely low, of the order of 0,02% en some centers or as low as 1 case/million population in France. These data are important considering the use different species and strains of these microorganisms. Few studies which have reported other adverse effects but many of these have problems with their design that cast doubt about the validity of their results. On the contrary, it has been shown that probiotic microorganisms exert positive stimulatory effects on innate and acquired immunity, with decrease of the manifestations of atopy and eczema. These positive effects are further evidenced by the beneficial effects of many species of probiotics in preventing necrotizing enterocolitis in patients as functionally labile as premature-born babies.

Bacterial profile of blood stream infections and their antibiograms.

Background: Blood culture provides essential information for the evaluation of a variety of diseases like endocarditis, pneumonia, and pyrexia of unknown origin particularly, in patients with suspected sepsis. Septicaemia is one of the leading causes of neonatal mortality along with perinatal hypoxia. Objectives: To study the bacterial flora of blood stream infections in adults & pediatric patients including neonates. To study the risk factors and duration of incubation for obtaining positive cultures. To study their antibiotic resistant pattern and compare results with those of other investigators in this field. Methods: This prospective study was conducted in the department of microbiology, Narayana medical college and hospital, Nellore over a period of six months, from March 2014 to September 2014. During the six months period, 200 samples received from various departments were processed and relevant findings were noted. Results: Out of 200 blood samples growth was obtained in 34 samples (17%). Among them Gram positive bacteria were 11 (5.5%). Gram negative bacilli were 23 (11.6%). Among the gram positive bacteria maximum resistance was seen with methicillin and imipenum. No resistance was seen with vancomycin and erythromycin. Most of gram negative bacilli were multidrug resistant. Maximum resistance was seen with piperacillin, amikacin, ceftizoxime and amoxyclav. Conclusion: Early diagnosis & appropriate treatment of bacterial infections can make difference between life & death. It would reduce mortality from septicaemia, reduce time & improve patient management.

Procalcitonin and C-reactive protein in differantiating to contamination from bacteremia

Procalcitonin (PCT) and C-reactive protein (CRP) are important biological markers used in the diagnosis of severe infections. The aim of this study was to evaluate the consistency of blood culture with PCT and CRP in differentiating contamination and non-bacteremia from true bacteremia. In this study blood samples were obtained from 809 febrile patients and analyzed using BACTEC 9120 system. All of positive blood cultures were performed Gram staining. The microorganisms were identified with conventional methods and automated systems. Antibiotic susceptibility tests were made by disc diffusion. PCT levels were analyzed by mini VIDAS device and PCT kit. PCT and CRP levels were analyzed with blood cultures in same times. Kruskal Wallis test, Mann-Whitney U test, Spearman's rho test and ROC curve were used for statistical analyses. The bacteremia group was found to be significantly different from non-bacteremia group and contamination group in terms of both PCT and CRP (p<0.0001). The p values of PCT and CRP in differentiating bacteremia from non-bacteremia were p<0.001 for PCT, p=0.002 for CRP and in differentiating bacteremia from contamination were p<0.001 for PCT, p<0.001 for CRP. PCT is a more useful marker than CRP in the differentiating of true bacteremia from contamination according to the results of this study.

Shigella boydii Bacteremia in an Ederly Patient with No Underlying Disease / 대한임상미생물학회지

Shigella bacteremia is rare, occurring mainly in children. Shigella species often cause diarrhea or gastrointestinal inflammation in humans and are rarely associated with bacteremia. This report describes an unusual case of Shigella boydii bacteremia in an 84-year-old patient visiting our hospital after experiencing nausea, vomiting, and febrile sensation for 2 days. Peripheral blood cultures revealed S. boydii and 16S rDNA sequence analysis produced the same result. However, the organism was not isolated from the patient's stool. She was started on ciprofloxacin, to which this organism is sensitive, and was subsequently discharged with instructions to complete a 14-day course of ciprofloxacin. Shigellosis is usually a self-limiting enteric disease. However, in contrast to its isolation from both blood and stool, isolation of the organism from blood only is associated with a high mortality rate. As is frequently pointed out, blood cultures should be obtained from elderly or immunocompromised patients with acute febrile gastroenteritis to detect infection caused by enteric pathogens, including Shigella.

Análisis de la monitorización de cinco indicadores de calidad del hemocultivo en un hospital universitario en Chile 2009-2011 / Quality indicators for blood culture: three years of monitoring at a university hospital in Chile

Blood culture is considered the "gold standard" for the diagnosis of bacteremia, critical condition with high morbidity and mortality. Because of its importance, it is estimated that the blood culture is a critical test that requires close monitoring on the quality with which the process is performed. The objective of this work is to show the results of the monitoring carried out during the past three years, of 5 quality indicators of blood cultures in the laboratory of the Hospital Clínico de la Pontificia Universidad Católica de Chile, considering pre-analytical, analytical and post-analytical aspects. In the 3 years monitored the mean contamination was 0,7%, 46% of adult bottles had adequate volume, match between Gram stain with final identification was 99.4%, 100% of correct participations were achieved in surveys of external quality control and Gram staining notification before 1 hour was 88.7%. With regard to proposed aims, in 2011 the laboratory complies with all, except the percentage of bottles with appropriate volume of blood inoculated. This indicator is very low and should be corrected as soon as possible since it is known that it is an important condition for optimum performance of blood cultures.

El hemocultivo es el "estándar de oro" para el diagnóstico de bacteriemia, condición grave de alta morbi-mortalidad. Por esto, se estima que el hemocultivo es un examen crítico, que requiere monitorización de su calidad. El objetivo de este trabajo es mostrar los resultados de la monitorización de 3 años de 5 indicadores de calidad del hemocultivo implementados en nuestro hospital. El porcentaje promedio de contaminación de las botellas para hemocultivo fue 0,7%, el porcentaje de botellas de adultos con volumen adecuado fue 46%, la concordancia de la tinción de Gram con la identificación final correspondió a 99,4%, el 100% de las participaciones en encuestas de control de calidad externo fueron correctas y 88,7% de los avisos de valores de alerta de la tinción de Gram fueron realizados antes de 1 hora. En el año 2011 se cumplió con las metas propuestas por el laboratorio para todos los indicadores, excepto con el porcentaje de botellas con volumen apropiado de sangre. Este último, se encuentra muy por debajo de la meta y debe ser mejorado a la brevedad, ya que el volumen de sangre cultivada es el factor más importante para obtener un rendimiento óptimo del hemocultivo.

Culture-negative Endocarditis Caused by <i>Bartonella henselae</i> / 日本心臓血管外科学会雑誌

There is <i>Bartonella henselae</i> (<i>B. henselae</i>) leads to cat-scratch disease and causes infective endocarditis, but shows as negative in blood cultures. We performed aortic valve replacement in a patient with aortic valve infective endocarditis which was regative on blood cultures. The patient had a contact history with a cat prior to admission. Thus, we suspected <i>B. henselae </i>and made a definitive diagnosis by PCR method and Warthin-Starry (WS) stain. A correct diagnosis was possible by detailed history taking and the use of appropriate antibiotics.

Direct inoculation on Phoenix panels for identification and antimicrobial susceptibility from positive BACTEC cultures: First study from India.

Purpose: This was a prospective study planned in a super-specialty hospital in Delhi to reduce turnaround times of identification-susceptibility results of positive blood cultures. Materials and Methods: One hundred consecutive single morphology non-duplicate cultures were inoculated on Becton Dickinson Phoenix™ panels by growth recovered directly from liquid BACTEC™ media and after pure growth on solid media. Results: Complete concordance was observed in 72.4% of gram-negative and 45.8% of gram-positive isolates. For gram-negative isolates, categorical agreement (CA) was >83% and essential agreement (EA) was >96% among all antibiotics tested, very major errors (VME) were 0.13%, major errors (ME) 0.54%, and minor errors (MiE) were 3.01%. For gram-positive isolates, VME was 0.73%, 1.10% MiE and no ME. It was observed that average time from receipt of specimen to release of reports was 30:34 h and 32 h for gram-negative and gram-positive isolates if reports of "Direct" panels were to be released. Conclusions: By direct panel inoculation, a decrease of at least 18-20 h in turnaround time was observed compared with the standard method. This helps early change to effective antibiotic therapy and also reduces the expenditure incurred for a patient's hospital stay by average Rs 20,000 ($443) per day.

Can we predict which patients with community-acquired pneumonia are likely to have positive blood cultures? / 世界急诊医学杂志（英文）

BACKGROUND: Blood cultures (BC ) are commonly ordered during the initial assessment of patients with community-acquired pneumonia (CAP), yet their yield remains low. Selective use of BC would allow the opportunity to save healthcare resources and avoid patient discomfort. The study was to determine what demographic and clinical factors predict a greater likelihood of a positive blood culture result in patients diagnosed with CAP. METHODS: A structured retrospective systematic chart audit was performed to compare relevant demographic and clinical details of patients admitted with CAP, in whom blood culture results were positive, with those of age, sex, and date-matched control patients in whom blood culture results were negative. RESULTS: On univariate analysis, eight variables were associated with a positive BC result. After logistic regression analysis, however, the only variables statistically significantly associated with a positive BC were WBC less than 4.5 x 109/L [likelihood ratio (LR): 7.75, 95％ CI=2.89-30.39], creatinine >106 μmol/L (LR: 3.15, 95％CI=1.71-5.80), serum glucose<6.1 mmol/L (LR: 2.46, 95％CI=1.14-5.32), and temperature > 38 °C (LR: 2.25, 95％ CI =1.21-4.20). A patient with all of these variables had a LR of having a positive BC of 135.53 (95％ CI=25.28-726.8) compared to patients with none of these variables. CONCLUSIONS: Certain clinical variables in patients with CAP admitted to hospitals do appear to be associated with a higher probability of a positive yield of BC, with combinations of these variables increasing this likelihood. We have identified a subgroup of CAP patients in whom blood cultures are more likely to be useful.

Cambios en la distribución de especies de Candida aislados de hemocultivos: en pacientes del Servicio Autónomo Hospital Universitario de Maracaibo, Venezuela / Changes in tje distribution of Candida species isolated from the hemocultures of patients in the Service Autónomo Hospital Universitario de Maracaibo, Venezuela

Se estudió la epidemiología de Candidemias en el Servicio Autónomo Hospital Universitario de Maracaibo (SAHUM), analizándose 78 episodios de Candidemia entre Enero 2007 y Marzo 2010, procedentes de 70 pacientes de ambos sexos y edades entre 15 días y 88 años, hospitalizados en diferentes servicios de SAHUM, de cuyos hemocultivos se aisló Candida sp en el Centro de Referéncia Bacteriológica (CRB) de esa institución. Para la identificación de especies se usó el medio cromogénico Brilliance Candida Agar y Vitek-YBC en el CRB. Adicionalmente, los cultivos fueron evaluados por el método tradicional en el Laboratorio de Micología de la Universidad del Zulia. Las características de los pacientes se tomaron de fichas del CRB. La mediana de la edad de los pacientes fue 17 años. Hubo 8 aislamientos secuenciales. La frecuencia de las especies de Candida fue: C. parapsilosis 51,28%, C. tropicalis 15,38%, C. guilliermondii 11,54%, C. albicans 10,26% C. famata 6,41%, C. glabrata 3,85% y C. krusei 1,28%. El Chi cuadrado indicó que los niños en los servicios no UCI tienen mayor probabilidad de adquirir Candidemias. Se observó un cambio en la frecuencia de especies, por lo tanto se requiere una vigilancia epidemiológica permanente en SAHUM

The epidemiology of candidemia in the Servicio Autónomo Hospital Universitario de Maracaibo (SAHUM) was studied. From January 2008 to March 2010, 78 candidemia episodes from 70 patients were analyzed. Ages ranged from 15 days to 80 years old. Patients were hospitalized in different wards at SAHUM. Candida spp was isolated in blood cultures processed at the Bacteriology Reference Center (CRB). For species identification, chromogenic Brilliance Candida Agar and Vitek-YBC were used. Additionally, the cultures were evaluated by traditional methods at the Mycology Laboratory, University of Zulia. Patients’ characteristics were obtained from the CRB register. The median patients’ age was 17 years old. Eight sequential isolates were obtained. The following Candida species were found:, C. parapsilosis 51.28%, C. tropicalis 15.38%, C. guilliermondii 11.54%, C. albicans 10.26%, C. famata 6.41%, C. glabrata 3.85% and Candida krusei 1.28%. X²showed that children in non-ICU wards were more likely to have candidemia. A change in the frequency of the species isolated was observed; for this reason, a permanent surveillance system is required

Clinical and microbiological characteristics of bloodstream infections in a tertiary hospital in Maceió, Alagoas, Brazil

We observed the clinical and microbiological characteristics of several stages of bloodstream infections (BSI), as well as the mortality attributed to it in a tertiary hospital in the northeast of Brazil (in the city of Maceió, Alagoas). A prospective cohort of 143 patients who had at least one positive blood culture was enrolled in the study. Their clinical evolution was followed up for 30 days from October 2005 to December 2006. The relation among the qualitative variables was verified through Chi-square test. The significance level was 5 percent. The statistical package adopted was SPSS 15.0 for Windows. Up to the thirtieth day, 30.1 percent of the patients presented bacteremia and 69.9 percent developed sepsis.Among these, 20.3 percent developed severe sepsis and 10.5 percent septic shock. The mortality attributed to it was 37.8 percent. In bacteremia, sepsis, severe sepsis, and septic shock conditions, mortality rates were 9.3 percent, 50 percent, 65.5 percent, and 84.6 percent, respectively. Respiratory (32.2 percent) and urinary (14 percent) sources and the ones related to central venous catheter (14 percent) were prevalent. In the wards 55.12 percent of the cases developed sepsis, whereas in the intensive care units, the rate was 87.69 percent (p < 0.05). Chronic renal failure, diabetes melitus, and neuropathy were present in 21.7 percent, 26.6 percent, and 29.4 percent of the cases, respectively. Coagulase-negative Staphylococcus (25.9 percent), Staphylococcus aureus (21 percent), and Klebsiella pneumoniae (14 percent) were the most present microorganism in the sample. The high morbidity and mortality rates in this study are attributed to the lack of knowledge on BSI characteristics and on instituted protocols for detection and treatment in early stages.