A case of neonatal bloodstream infection caused by Salmonella enterica subsp .enterica Serovar Worthington Strain / 中华检验医学杂志

The patient was a 6-day-and-19-hours-old girl. On March 31, 2023, she was admitted to Chongqing University JiangJin Hospital with symptoms of yellow skin staining for 3 days and fever for 6 hours. On April 1st, the Medicine Laboratory reported a critical value in blood cultures: Gram-negative bacilli, which were identified as Salmonella through mass spectrometry and biochemical tests. It was classified as non A-F group Salmonella due to negative AF and Vi serotyping results. Subsequent serum agglutination test after subculture showed O13, 23 Hz, l, w, and further results by analysis using the sequences of the 16S rRNA and gyrB genes confirmed it as Salmonellaenterica subsp. enterica Serovar Worthington Strain, consistent with the serum agglutination test result. After receiving a 14-day course of Ampicillin/Sulbact treatment for infection control, the patient′s health condition improved she was discharged from the hospital. The identification of Salmonella requires simultaneous bacterial biochemical identification and serological tests ser to ensure accurate results and provide reliable basis for etiological diagnosis.

Optimizing the number of blood cultures for lower and middle income countries: a large scale study in a public sector tertiary care teaching hospital of Southern India

Background: Blood culture is widely accepted as the gold standard investigation for the diagnosis of blood stream infections (BSI). The number of blood cultures collected has a considerable impact on the organism isolation. This study aims to optimize the number of blood cultures needed, for an optimal diagnostic yield in BacT/ALERT VIRTUO system mainly in a resource limited setting. Methods: All the blood cultures (BCs) obtained in BacT/Alert bottles per patient during a 24-h period were included as ‘one episode’ and categorized as single bottle, 1-set (2 aerobic bottles), 2 sets and 3 sets. BC bottles were incubated in the BacT/ALERT VIRTUO (bioMérieux) for a period of five days. Bottles flagged positive were subjected to Gram staining and culture plating. Colonies grown were identified by MALDI-TOF MS, VITEK MS, bioMérieux. Results: Cumulative positivity rate increased (21.7%, 41.4%, 56.1%, 60.6%) and pathogen isolation rate increased (10.3%, 21.8%, 30.4% and 33.8%) progressively when collected in single bottle, 1, 2 and 3 sets respectively. The pathogen detection rate for GNB and GPC were 45.1% and 42.6% respectively with one bottle and this got upsurged to 85.6% and 98.9% for GNB and 83.6% and 98.2% for GPC when collected in ?1 set and ?2 sets respectively. Conclusions: Two BC sets over a 24-h period can detect approximately 98% of the pathogens with a cumulative positivity rate of 60% and hence it is a justifiable alternative approach to the standard practice of 3-sets of BCs.

Application and Prospect of Nanopore Sequencing Technology in Etiological Diagnosis of Blood Stream Infection / 中国医学科学院学报

Blood stream infection (BSI),a blood-borne disease caused by microorganisms such as bacteria,fungi,and viruses,can lead to bacteremia,sepsis,and infectious shock,posing a serious threat to human life and health.Identifying the pathogen is central to the precise treatment of BSI.Traditional blood culture is the gold standard for pathogen identification,while it has limitations in clinical practice due to the long time consumption,production of false negative results,etc.Nanopore sequencing,as a new generation of sequencing technology,can rapidly detect pathogens,drug resistance genes,and virulence genes for the optimization of clinical treatment.This paper reviews the current status of nanopore sequencing technology in the diagnosis of BSI.

BRICS report of 2021: The distribution and antimicrobial resistance profile of clinical bacterial isolates from blood stream infections in China / 中华临床感染病杂志

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical bacterial isolates from bloodstream infections in China in 2021.Methods:The clinical bacterial strains isolated from blood culture from member hospitals of Blood Bacterial Resistant Investigation Collaborative System (BRICS) were collected during January 2021 to December 2021. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical Laboratory Standards Institute (CLSI). WHONET 5.6 was used to analyze data.Results:During the study period, 11 013 bacterial strains were collected from 51 hospitals, of which 2 782 (25.3%) were Gram-positive bacteria and 8 231 (74.7%) were Gram-negative bacteria. The top 10 bacterial species were Escherichia coli (37.6%), Klebsiella pneumoniae (18.9%), Staphylococcus aureus (9.8%), coagulase-negative Staphylococci (6.3%), Pseudomonas aeruginosa (3.6%), Enterococcus faecium (3.6%), Acinetobacter baumannii (2.8%), Enterococcus faecalis (2.7%), Enterobacter cloacae (2.5%) and Klebsiella spp (2.1%). The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative Staphylococcus aureus were 25.3% and 76.8%, respectively. No glycopeptide- and daptomycin-resistant Staphylococci was detected; more than 95.0% of Staphylococcus aureus were sensitive to ceftobiprole. No vancomycin-resistant Enterococci strains were detected. The rates of extended spectrum B-lactamase (ESBL)-producing isolated in Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis were 49.6%, 25.5% and 39.0%, respectively. The prevalence rates of carbapenem-resistance in Escherichia coli and Klebsiella pneumoniae were 2.2% and 15.8%, respectively; 7.9% of carbapenem-resistant Klebsiella pneumoniae was resistant to ceftazidime/avibactam combination. Ceftobiprole demonstrated excellent activity against non-ESBL-producing Escherichia coli and Klebsiella pneumoniae. Aztreonam/avibactam was highly active against carbapenem-resistant Escherichia coli and Klebsiella pneumoniae. The prevalence rate of carbapenem-resistance in Acinetobacter baumannii was 60.0%, while polymyxin and tigecycline showed good activity against Acinetobacter baumannii (5.5% and 4.5%). The prevalence of carbapenem-resistance in Pseudomonas aeruginosa was 18.9%. Conclusions:The BRICS surveillance results in 2021 shows that the main pathogens of blood stream infection in China are gram-negative bacteria, in which Escherichia coli is the most common. The MRSA incidence shows a further decreasing trend in China and the overall prevalence of vancomycin-resistant Enterococci is low. The prevalence of Carbapenem-resistant Klebsiella pneumoniae is still on a high level, but the trend is downwards.

Bacterial Profile Of Blood Culture And Their Anti-Microbial Susceptibility Pattern In Pediatric Patients Of A Tertiary Care Hospital

Introduction: Blood stream infection are very common in the pediatric age group and these are one of the common causes of morbidity and mortality in children. In developing countries ,the rate of blood stream infection in children is about 20-50%.The present study was undertaken to determine the etiological agents causing blood stream infection and their antibiotic susceptibility pattern in pediatric patients. Patients with bacteremia may have either a transient bacteremia or persistent bacteremia which can be self-limited without development of focal infection or sequelae or may progress to a more serious fatal infection or toxic effects. The present study in a hospital basedMethodology: single centred, Observational study, of 3 years. Blood sample were collected in BacTec bottle and standard microbiological protocol were applied for the isolation identification of bacteria strains. Antimicrobial susceptibility test was performed by the Kirby Bauer Disc Diffusion Method as per CLSI 2019 guidelines. Out of total 350 bloodResults: samples received for culture,87(23.14%)were culture positive, out of which 42/87(48.27%) were Gram positive organisms and 39/87(44.82%) were Gram-negative organisms and 6 /87(6.89%) were candida spp. The most common organism was Staphylococcus aureus(31.03%) the predominant organism followed by Klebsiella pneumoniae(21.83%) and Streptococcus pneumoniae (9.19%), Escherichia coli, Enterobacter cloacae each (5.74%). All Gram positive bacteria were susceptibile to vancomycin, teicoplanin and linezolid. 11/27(40.74% )of Staphylococcus aureus were Methicillin resistant Staphylococcus aureus (MRSA) strains. All Gram negative bacteria were susceptibility to amikacin, Colistin,Tigecycline. Staphylococcus aureus is the leading cause ofConclusion: childhood septicemia in this locale, has been decline in susceptibility of the pathogens to common antibiotics which ultimately stresses on the need for continuous screening and surveillance for antibiotic resistance in the pediatric ward and calls for increased efforts to ensure more rational use of these drugs.

Disseminated cryptococcosis caused by Cryptococcus neoformans a case report and review / 中国热带医学

@#Abstract: To analyze the clinical, therapeutic and laboratory characteristics of disseminated cryptococcosis caused by Cryptococcus neoformans invading the blood stream in patient with liver cirrhosis and splenectomy. A 30-year-old male underwent splenectomy plus pericardial devascularization due to "splenomegaly and hypersplenism" in March in 2016. The patient had intermittent fever after operation for many times, and successively accompanied with back pain, left lower limb abscess and right hip pain. The highest body temperature was 39 ℃. CT and MRI revealed the lung lesion and multiple bone destruction. During that period, the effect of antibiotics was not good. On April 19th, 2017, Gram's stain, India ink stain, API 32C, Vitek 2 Compact, ribosomal ITS and IGS sequence analysis were performed to identify the strain isolated from the pus and blood stream. The serum of the patient was detected for cryptococcal antigen. Antifungal susceptibility test was used to determine drug sensitivity and minimum inhibitory concentration (MIC). The Cryptococcus neoformans isolated from fresh pus specimen showed a prominent, thick capsule after India ink stain. The colonies isolated from pus and blood stream were identified Cryptococcus neoformans using API 32C, Vitek 2 Compact, and sequence analysis of rDNA ITS and IGS. Cryptococcal capsule antigen was positive. The minimal inhibitory concentrations of 5-Flucytosine, amphotericin B, fluconazole, itriconazole, voriconazole against the isolate were <4 μg/mL, <0.5 μg/mL, 4 μg/mL, ≤0.25 μg/mL, 0.125 μg/mL respectively. The patient was initially treated with intravenous amphotericin B and flucytosine. After anti-Cryptococcus treatment for two months, the patient clinically improved, and the lesions were reduced on a follow-up CT scan. The patient made a full functional recovery after treatment for six months. Cryptococcosis has hidden onset, atypical clinical symptoms and lack of specificity. Blood stream is the main channel for Cryptococcus to spread and involve many organs of the whole body, including skin, bone and so on. Therefore, early use of blood culture to monitor blood flow dissemination, actively removing the primary focus and cutting off the infection route in time and carrying out effective anti-Cryptococcus treatment are conducive to the patient's early recovery.

Gut microbiota and hematological malignancies / 国际肿瘤学杂志

In recent years, driven by metagenomics sequencing technology, it has been found that compositional changes and diversity changes of gut microbiota are related to the occurrence of hematological malignancies. Gut microbiota affects the development of the hematopoietic system and the risk stratification of hematological malignancies. Microbial translocation plays an important role in and blood stream infection. Gut microbiota imbalance and blood stream infection affect the therapeutic effect of hematological malignancies. Probiotics and fecal microbiota transplant can restore the diversity of gut microbiota.

Candidemia: características en los adultos mayores / Candidemia: characteristics in elderly patients

Resumen Introducción: La candidemia es una micosis sistémica asociada a los cuidados de la salud de elevada morbimortalidad. Los adultos mayores presentan las tasas más altas y la información en esta población es escasa. Objetivos: Describir las características de las candidemias en los adultos mayores, identificar factores asociados a mortalidad y evaluar la utilidad de un score predictor. Métodos: Estudio retrospectivo de las candidemias en adultos mayores en un hospital de la ciudad de Buenos Aires. Se analizaron todos los episodios en pacientes mayores de 60 años en un período de ocho años. Resultados: Se incluyeron 59 episodios. La co-morbilidad más frecuente fue diabetes mellitus. El principal sitio de origen fue infección asociada a catéter (45%). Sólo 17% presentó un Candida score mayor a 2,5. La mortalidad global a las 48 h fue 20% y a 15 días 49%. Las variables asociadas a mortalidad fueron: shock, asistencia respiratoria mecánica (ARM), plaquetopenia, insuficiencia renal y leucocitosis (rango p < 0,0001-0,006). En el análisis multivariado el shock fue la única variable independiente asociada a mortalidad (HR 4,02 [IC 95% 1,18-13,72], p = 0,026). Conclusiones: La mitad de los adultos mayores con candidemia falleció en los primeros 15 días. Shock, ARM, plaquetopenia, insuficiencia renal y leucocitosis fueron factores asociados a mortalidad. El score predictor de uso habitual no fue útil en esta población.

Abstract Background: Candidemia is a nosocomial bloodstream infection and an important cause of comorbidity and mortality. Elderly patients present the highest rates of candidemia but data about this population is scarce. Aims: To describe characteristics of candidemia in elderly patients, to identify risk factors associated with mortality and to evaluate the usefulness of a predictive score. Methods: A retrospective observational study of candidemia in elderly patients from a tertiary care hospital was carried out. We analyzed all Candida bloodstream infections during an eight-year period in patients older than 60 years. Results: Fifty-nine episodes were included. Diabetes was the most frequent comorbidity. Most candidemia were catheter related infections (45%). Only 17% of patients had a Candida score > 2.5. Overall mortality at 48 hours was 20%, and at 15 days was 49%. Mortality-related factors were shock, assisted mechanical ventilation, thrombocytopenia, renal failure and leukocytosis (p range < 0.0001-0.006). On multivariate analysis septic shock was independently associated with mortality (HR 4.02 [CI 95% 1.18-13.72] p = 0.026). Conclusions: Nearly half of patients with candidemia died during the first fifteen days. Shock, assisted mechanical ventilation, thrombocytopenia, renal failure, and leukocytosis were factors associated with mortality. The predictive score was not useful in this population.

Bacteriological Profile And Antibiotic Susceptibility Pattern Of The Isolates Among The Neonatal Septicemia In Northeast India

Background: Bacterial resistance to antibiotics was a global problem. Multidrug-resistant bacteria causing neonatal septicemiaswere increasing in the world. It was difficult to compare the bacterial profile and antibiotic susceptibility pattern of the isolatesamong the neonatal septicemia between countries because the epidemiology of neonatal septicemia was extremely variable.Objective: Timely identification of bacterial profile and antibiotic susceptibility pattern of the isolates among the neonatalsepticemias are essential to guide the clinicians regarding both the empirical and definitive treatments of neonatal septicemia.Materials and Methods: Based on the AIIMS protocol 2014 of neonatal sepsis-World Health Organization newborn CC,an operational definition of clinically diagnosed neonatal septicemia was established for the selection of participants inthe study for blood culture and sensitivity test (CST). Hence, in this study, blood CST was done only among the selectedpatients for clinically diagnosed neonatal septicemia as recommended in the National Committee for Clinical LaboratoryStandards.Results: This study observed that there was a shift from the predominance of Gram-negative organisms to Gram-positiveorganisms, especially Staphylococcus aureus. Acinetobacter and Citrobacter were emerging organisms.In this study,aminoglycosides and fluoroquinolones were sensitive to organisms, especially in Gram-negative organisms. Imipenem andmeropenem were also sensitive in both Gram-positive and Gram-negative organisms. Imipenem was more sensitive toorganisms than meropenem. Tobramycin, doxycycline, gatifloxacin, and chloramphenicol were more sensitive to organismsthan erythromycin, azithromycin, and clindamycin.Conclusion: Early clinical diagnosis and prompt initiation of empirical antimicrobials therapy to patients of pending culturesensitivity reports for definitive therapy may be life-saving. Hence, periodic surveillance for bacteriological profile and antibioticsusceptibility pattern of the isolates among the neonatal septicemia for appropriate choice of antimicrobials for empirical therapycan be outlined and reevaluated in a timely manner to save the life of 5 million neonatal deaths a year, with 98% occurringin developing countries and limited resource rural areas. This study concluded that empiric therapy for clinically diagnosedneonatal septicemia should cover both Gram-negative and Gram-positive organisms. Hence, the combination of one antibioticfrom each of the following two groups, (1) Imipenam/piperacillin/cefotaxime and (2) amikacin/gentamicin/netilmicin, can beincluded as an initial therapy for neonatal septicemia.

Spectrum of Microorganisms Causing Blood Stream Infection and the Antibiotic Sensitivity Pattern among Gram Negative Organisms: A Study from a Tertiary Care Centre in Bihar

Introduction: Incidence of Blood stream infection (BSI) is onthe rise and so is the increasing drug resistance amongdifferent organisms causing BSI. The trend of such infectionand the antibiotic sensitivity pattern may vary from region toregion.Materials and Methods: This study was conducted with thesame aim in which about 240 blood culture and sensitivityresults were noted from the records and were analysed to seethe current trend in this region. Our focus was mainly on Gramnegative organisms, as they have been found to causeincreased number of BSI.Results: Escherichia coli was the main Gram negativeorganism, and Staphylococcus aureus along with Coagulasenegative Staphylococcus (CoNS) were the main gram positiveorganisms isolated. Candida albicans was also found in four ofthe cases. The antibiotic sensitivity pattern of gram negativeisolates showed more than 90% susceptibility to higherantibiotics, whereas the susceptibility to other antibiotics werefound to be variable.Conclusion: E. coli is the main GNB causing the infectionfollowed by K. pneumoniae and P. aeruginosa. Increasingtrend of drug resistance is being noted by GNBs against mostcommonly used antibiotics.

Clinical features and prognosis of children with hematological malignancies after chemotherapy with Stenotrophomonas maltophilia blood stream infection / 白血病·淋巴瘤

Objective To investigate the clinical features and prognosis of children with hematological malignancies after chemotherapy accompanied with Stenotrophomonas maltophilia blood stream infection (BSI). Methods The clinical data and antimicrobial susceptibility test of 25 hospitalized children with hematological malignancies who were diagnosed as Stenotrophomonas maltophilia BSI in the Department Pediatric Hematology of Fujian Medical University Union Hospital from January 2013 to May 2018 were analyzed retrospectively. Results A total of 25 children, including 18 males and 7 females with the median age 4 (1-11) years old were diagnosed as hematological malignancies and all received chemotherapy. The frequent risk factors of Stenotrophomonas maltophilia BSI in children with hematological malignancies included prior carbapenem antibiotic for more than 1 week (80％, 20/25), and neutropenia for more than 1 week (68％,17/25) and indwelling central venous catheter (48％, 12/25). Clinically, the main manifestations included neutropenia with fever after chemotherapy; however, anti-pseudomonas cephalosporin/carbicillin antibiotic combined with vancomycin and anti-fungal therapies were ineffective. Drug susceptibility test showed that all strains were sensitive to compound sulfamethoxazole, levofloxacin and minocycline. Before blood culture report, 3 patients died of septic shock, pulmonary hemorrhage and respiratory failure; after blood culture report, the treatment regimens were adjusted to compound sulfamethoxazole combined with cefoperazone sodium and sulbactam sodium (200-260 mg·kg-1·d-1) or levofloxacin anti-infective. Finally, 18 patient was cured, 2 patients died of the bad efficacy of underlying diseases, and 2 patients died of pulmonary hemorrhage. The overall fatality rate was 28％ (7/25) and the related mortality rate caused by Stenotrophomonas maltophilia BSI was 20％ (5/25). Conclusion Stenotrophomonas maltophilia BSI in children with hematological malignancies after chemotherapy has a high fatality rate, and better basic disease control and appropriate antibacterial therapy are the key to improve the prognosis.

A Case of Chryseobacterium hominis Isolated from Human Blood Drawn Through Peripherally Inserted Central Catheter

Chryseobacterium hominis is non-fermenting Gram-negative rod that was first identified as a novel species in 2007. Here, we report the first clinical case of C. hominis bacteremia, which was confirmed by MALDI-TOF MS and 16S rRNA gene sequencing. A 16-year-old boy diagnosed with acute lymphoblastic leukemia was hospitalized for three months. Two sets of blood culture test through a peripherally inserted central catheter (PICC), which was inserted a month ago, was performed when his white blood cell count declined and he had a high fever. Colonies of medium sizes that looked round, mucoid, sticky, and grayish on blood and chocolate agar plates were observed. Identification of bacteria using the VITEK MALDI-TOF MS system (BioMérieux, France) was not successful and the VITEK 2 system (BioMérieux, USA) indicated Sphingomonas paucimobilis, with a questionable level of confidence (92%). However, Microflex LT Biotyper (Bruker Daltonics, Germany) showed C. homins (log score: 1.81) and sequence of 16S rRNA showed a 100% identity with C. hominis. Piperacillin-tazobactam was administered since the isolate was susceptible to piperacillin-tazobactam but C. hominis showed growth in the next four follow-up culture of blood drawn through PICC. The fever subsided only after PICC was changed. The clinical prognosis and antimicrobial susceptibility test of C. hominis should be further studied.

Antibiotic resistance pattern in intensive care unit of a tertiary care teaching hospital

Background: Antimicrobials are a major class of drugs prescribed in Intensive Care Unit (ICU). Widespread use of empirical antibiotic therapy has facilitated the emergence of drug resistance, since empirical therapy is very often initiated at the outset, even before culture and sensitivity reports are available. The problem of drug resistance is on a rise, therefore, this study was planned to assess the drug resistance and sensitivity patterns of the blood isolates recovered from ICU.Methods: An observational- prospective study was conducted in the Tertiary care teaching hospital over a period of twelve months to assess antibiotic resistance and sensitivity pattern. A total of 104 consecutive patients receiving antibiotics in the ICU and having blood cultures with significant growth were included in the study. Blood sample was collected and after obtaining a culture growth, the identification and antimicrobial sensitivity testing was done.Results: Blood stream infection by Gram-negative bacteria (50.96%) was more common than Gram-positive bacteria (49.04%). Coagulase negative Staphylococci (CoNS) was the predominant single blood culture isolate (35.58%). Klebsiella pneumoniae (13.46%), Escherichia coli (12.50%), Acinetobacter baumannii complex (7.69%) were commonly isolated gram negative organisms. Gram positive isolates were resistant to beta lactams in maximum patients whereas Tigecycline, Linezolid, Daptomycin, Vancomycin, Nitrofurantoin and Teicoplanin were sensitive against them. Common gram negative isolates were sensitive to Colistin and Tigecycline but resistant to most of the antibiotics.Conclusions: A preponderance of gram negative bacteria over gram positive bacteria was noted with a higher degree of resistance to most of the first line antimicrobial agents.

Peripheral venous catheter related blood stream infection in intensive care unit

Background: Peripheral venous catheter related blood stream infections (PVC-BSI) are a common cause of morbidity and mortality in hospitals. Most of the catheter related blood stream infections occurs due to lack of proper aseptic measures. This study points out the risk factors microbial profile and antimicrobial susceptibility of isolates associated with PVC-BSI. The common organisms causing Catheter related BSI are Staphylococcus aureus (41.1%), and Klebsiella species (17.6%) followed by CONS and Enterococcus species. Objective of present study was to isolate and identify the organisms causing PCV-BSI, perform antimicrobial sensitivity testing of isolated organisms and to identify the associated risk factors and preventive measures that should be used.Methods: The study was conducted over a period of one year from August 2015 to July 2016 in the Department of Microbiology. Study group comprised of all the patients with peripheral venous catheterization who developed signs and symptoms of septicemia after 48 hrs of insertion of PVC. These patients were followed up from the time of catheterization till discharge. Peripheral venous catheter tip was collected under aseptic condition along with peripheral blood samples from a site other than the catheterized one. Samples were collected from patients at any point of time who developed signs and symptoms of septicemia after 48 hrs of catheter insertion. The length of time for which the PVC was in place was recorded.Results: In total, 87 cases were included in the study with mean catheter duration of 4.8 days accounting for 418 catheter days. Out of these 87 cases, 17 cases developed PVC-BSI (19.5%) and 34 cases developed colonization (24.1%). Staphylococcus species (41.1%) was the most common isolate.

La espectrometría de masas MALDI-TOF en el laboratorio de microbiología clínica / MALDI-TOF mass spectrometry in clinical microbiology laboratories

Los métodos fenotípicos empleados para la identificación de microorganismos dependen de procesos metabólicos que requieren de tiempos de incubación mínimos para alcanzar resultados confiables. La espectrometría de masas MALDI-TOF (desorción/ionización láser asistida por una matriz con detección de masas por tiempo de vuelo) se ha instaurado como una metodología relevante para la identificación de microorganismos mediante el análisis de proteínas, a través de la creación de un espectro de masas específico de género y especie. En esta revisión, se presenta MALDI-TOF MS como una tecnología precisa para la identificación de bacterias, levaduras, mohos, en incluso de virus ,que además, permite la reducción del tiempo para obtener un resultado de identificación, que puede impactar los costos de atención y duración de la estancia hospitalaria. La identificación de microorganismos directamente de muestras biológicas y la detección de mecanismos de resistencia a antimicrobianos, prometen un mayor impacto clínico y epidemiológico con el desarrollo e implementación de esta tecnología en los laboratorios de microbiología clínica.

Phenotypic methods used for the identification of microorganisms depend on metabolic processes that require minimum incubation times to achieve reliable results. For this reason, MALDI-TOF MS (Matrix Assisted Laser Desorption/Ionization Mass Spectrometry) has been established as a relevant methodology for the identification of microorganisms using analysis of proteins, through the creation of a mass spectrum specific for genus and species. In the present review, MALDI TOF MS is presented as an accurate technology for identifying bacteria, yeasts, molds and viruses; Its use allows reduction of the time to obtain an identification result, which may impact the costs of care and length of hospital stay. The identification of microorganisms directly from biological samples and the detection of mechanisms of antimicrobial resistance, promise an additional clinical and epidemiological impact with the development and implementation of this technology in clinical microbiology laboratories.

Clinical features of community-acquired bloodstream infection due to Gram-negative bacilli in patients with liver cirrhosis / 中华肝脏病杂志

Objective@#o investigate the features of pathogenic bacteria for community-acquired bloodstream infection due to Gram-negative bacilli in patients with liver cirrhosis and optimal therapeutic strategy.@*Methods@#A retrospective analysis was performed for the clinical data of patients with liver cirrhosis who were admitted to 302 Hospital of PLA due to community-acquired bloodstream infection from January 2010 to December 2015, and a statistical analysis was performed for their clinical features, pathogenic bacteria, and results of drug sensitivity test. The Pearson chi-square test was used for comparison of rates, and the Wilcoxon rank sum test was used for comparison of ranked data.@*Results@#A total of 240 patients (including 178 male patients) with liver cirrhosis caused by various reasons were enrolled, with a mean age of 51.7 ± 11.1 years, an overall clinical remission rate of 80.42%, and an ineffective/mortality rate of 19.58%. The patients who used sensitive antibiotics within 12 hours after the onset of community-acquired bloodstream infection achieved a significantly higher improvement rate than those who used such drugs at more than 12 hours after onset (88.2% vs 58.1%, P < 0.001). The improvement rate achieved by the application of sensitive antibiotics at more than 12 hours after onset decreased with the increase in the Child-Pugh grade (P < 0.05). A total of 245 strains of Gram-negative bacilli were isolated, among which the six most common ones were 135 strains of Escherichia coli (55.1%), 62 strains of Klebsiella pneumoniae (25.3%), 16 strains of Aeromonas (6.5%), 4 strains of non-typhoidal Salmonella (1.6%), 3 strains of Enterobacter cloacae (1.2%), and 2 strains of Acinetobacter baumannii (0.8%). These Gram-negative bacilli had the highest sensitivity to meropenem (98.5%), followed by imipenem (97.9%), amikacin (97.5%), piperacillin/tazobactam (94.7%), cefmetazole (93.7%), and cefoperazone/sulbactam (93%). Different bacteria had different sensitivities to antibiotics.@*Conclusion@#Once community-acquired bloodstream infection occurs in patients with liver cirrhosis, highly sensitive antibiotics should be used as early as possible. Cefoperazone/sulbactam, piperacillin/tazobactam, imipenem, and meropenem can be used as first-line empirical antibiotics, and drug combination should be considered when necessary.

A clinical study of elderly chemotherapy patients with malignant hematopathy combined with blood stream infection / 中国中西医结合急救杂志

Objective To analyze the pathogenesis and clinical characteristics of blood stream infection (BSI) occurring after chemotherapy in elderly patients with hematological malignancies hospitalized in this hospital, and to evaluate the role of procalcitonin (PCT) level in judging the pathogenic type of bacteria in BSI. Methods Thirty-nine elderly patients with malignant hematopathy were admitted to the Department of Hematologic Oncology of Shanxi Province Coal Center Hospital from June 2015 to June 2017, after admission they were treated with chemotherapy, then they were complicated with blood stream infection, and their clinical data were retrospectively analyzed; the clinical efficacy, the pathogenic factor of BSI occurring during chemotherapy, infection sites, pathogenesis, the different levels of PCT of bacterial types in BSI, etc. were observed. Results Thirty-nine cases of BSI were all in the stage of agranulocytosis, the proportion of relapsed and refractory re-induction remission chemotherapy was significantly higher than that of initial induction remission and consolidation intensive therapy [51.3% (20/39) vs. 28.2% (11/39), 20.5% (8/39)]. The BSI in 29 patients was controlled and 10 cases with BSI were dead. Clear infection sites sequences were respiratory tract (37 case times), digestive tract (25 case times) and anus periphery (10 case times); 39 pathogenic strains were isolated from the blood cultures, including the gram positive (G+) bacteria accounting for 43.6% (17/39), gram negative (G-) bacteria 53.8% (21/39) and fungi 2.6% (1/39). At the high level of PCT, the detection rate of G- bacteria was high, the PCT levels of isolated G- bacteria such as Escherichia coli, Aerobacter cloacae, Pseudomonas aeruginosa, Klebsiella pneumoniae, Acinetobacter bauman from high to low in turn were 12.82 (9.91 - 15.73), 10.19 (7.17 - 12.21), 10.01 (7.85 - 12.28), 9.68 (7.95 - 11.41), 8.12 (7.12 - 9.12) μg/L respectively; at the low level of PCT, the detection rate of G+bacteria was high, PCT levels of isolated G+bacteria such as methicillin-resistant Staphylococcus aureus, Enterococcus faecium, Streptococcus pneumoniae, Hemolytic streptococcus from high to low in turn were 6.87 (4.12 - 9.62), 2.78 (2.17 - 3.39), 1.31 (0.42 - 2.20), 1.05 (0.39 - 1.71) μg/L respectively. The positive predictive value of PCT for the diagnosis of G- bacterial BSI was higher than that for the G+bacterial BSI (90.1% vs. 78.3%). Conclusions In elderly patients with hematological malignancies, after chemotherapy, they are accompanied by BSI that is closely related to granulocyte count; PCT level has a suggestive effect on different types of bacteria as pathogen of BSI and the high level of PCT indicates a greater possibility that the BSI is due to G- bacterial infection.

Early detection of the bloodstream infection bacteria based on MALDI-TOF MS / 解放军医学杂志

Objective To establish a clinical method for early detection of the bloodstream infection bacteria based on matrix-assisted laser ionization time of flight mass spectrometry (MALDI-TOF MS).Methods After consulting the Laboratory Information System statistics and domestic related literature,We chose 10 kinds of bacteria (Escherichia coli.,Pseudomonas aeruginosa,Acinetobacter baumannii,Klebsiella pneumoniae,Enterococcus faecium,Enterococcus faecalis,Staphylococcus aureus and Staphylococcus epidermidis,Proteus mirabilis,Streptococcus pneumoniae) as target.The MALDI-TOF MS was established using simulated bacterial infection blood samples.From March to May 2017,33 blood samples of suspected sepsis patients from Emergency Department,General Hospital of PLA,were tested.Results The MALDI-TOF MS whose detecting sensitivity was 100CFU/ml had the same negative detection rate with the blood culture (27cases/27cases,100％).Besides the 2 samples of Morganella morganii infection and Staphylococcus hominis infection were out of the range,the results of the remaining 4 positive samples were consistent (100％).Conclusion Compared to the blood culture and biochemical identification,MALDI-TOF MS can rapidly detect 10 kinds of bloodstream infection bacteria with high sensitivity and high accuracy.

Diagnostic value of procalcitonin detection in Candida bloodstream infection / 中华急诊医学杂志

Objective To discuss the clinical application value of serum procalcitonin(PCT) in patients with Candida bloodstream infection.Methods The data of 783 hospitalized patients of Tianjin Medical University General Hospital including blood culture and serum PCT test were retrospectively analyzed,and the medical records of patients with Candida or bacterial bloodstream infection were evaluated by univaxiate and multivariate logistic regression analysis.The comparison of PCT value were carried out among the different blood culture groups using the Mann-Whitney U test.A receiver operating characteristic(ROC) curve was used to determine the diagnostic performance of the PCT.Results The PCT was 0.21 (0.06,1.02) ng/mL in the 510 patients with negative blood culture,but in 121 patients with Candida infection and 152 patients with bacteria infections,the PCT levels were 1.15 (0.38,6.85) ng/ mL and 2.34 (0.77,15.12) ng/mL,respectively.There were statistically significant differences in PCT levels among three groups(P＜0.05).According to ROC,when the value of PCT was 0.355 ng/mL,the sensitivity was 76.9％,and the specificity was 60.8％ with 0.726 area under the curve (AUC) (P＜0.01) for the identification of Candida infection by blood cultures.Conclusions Serum PCT levels have a certain diagnostic value for Candida bloodstream infection.In critically ill patients with factors associated with candidemia,the combination of clinical symptoms with PCT as an adjuvant diagnostic marker and other laboratory findings can be used to make a prompt and effective initiation of antifungal therapy.

Multidisciplinary Intestinal Rehabilitation for Short Bowel Syndrome in Adults: Results in a Korean Intestinal Rehabilitation Team

PURPOSE: Intense multidisciplinary team effort is required for the intestinal rehabilitation of patients afflicted with the short bowel syndrome (SBS). These include enteral and parenteral nutrition (PN) support, monitoring of complications related to treatment, and considering further medical or surgical options for intestinal adaptation. METHODS: In the Intestinal Rehabilitation Team (IRT) at the Samsung Medical Center, we have experienced 20 cases of adult SBS requiring multidisciplinary intestinal rehabilitation. This study is a retrospective review of the collected medical records. RESULTS: Of the 20 subjects treated, 12 patients were male and 8 patients were female. At the time of referral to the IRT, the mean age was 51.5 years, and the mean body weight was 50.1 kg, which was 90% of the usual body weight. The diseases or operative managements preceding massive bowel resection were malignancy in 11 cases, cardiac surgery in 2 cases, trauma in 2 cases and one case, each of tuberculosis, corrosive esophagitis, atrial fibrillation, simultaneous pancreas and kidney transplantation, and perforated appendicitis. Of these, there were 14 survivals and 6 mortalities. The fatalities were attributed to progression of disease, intestinal failure-associated liver disease, and sepsis (unrelated to intestinal failure) (2 cases each). Among the 14 surviving patients, 8 patients have been weaned off PN, whereas 6 are still dependent on PN (mean PN dependence 36%). CONCLUSION: This paper reports the results of multidisciplinary intestinal rehabilitation of adult short bowel patients treated at the Samsung Medical Center. Further studies are required to improve survival and enteral tolerance of these patients.