BACKGROUND: We evaluated the reliability and accuracy of the combined use of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) bacterial identification and Vitek 2 antimicrobial susceptibility testing (AST) for bacteria from positive blood culture bottles. METHODS: Direct identification and AST were performed in parallel to the standard methods in monomicrobial positive blood culture bottles. In total, 254 isolates grown on aerobic and/or anaerobic bottles were identified with MALDI-TOF Vitek MS (bioMerieux, France), and 1,978 microorganism/antimicrobial agent combinations were assessed. For isolates from anaerobic bottles, an aliquot of the culture broth was centrifuged, washed, and filtered through a nylon mesh. For isolates from aerobic/pediatric bottles, a lysis step using 9.26% ammonium chloride solution and 2% saponin solution was included. RESULTS: The overall correct identification rate was 81.8% (208/254) and that for gram-positive/gram-negative isolates was 73.9%/92.6%, respectively, and it was 81.8%, 87.6%, and 57.9% for isolates from aerobic, anaerobic, and pediatric bottles, respectively. Identification was not possible in 45 cases, and most of these isolates were streptococci (N=14) and coagulase-negative staphylococci (N=11). Misidentification occurred only in one case. Compared with standard methods, direct AST showed 97.9% (1,936/1,978) agreement with very major error of 0.25%, major error of 0.05%, and minor error of 1.8%. CONCLUSIONS: This simple and cost-effective sample preparation method gives reliable results for the direct identification and AST of bacteria. For the identification of streptococci and coagulase-negative staphylococci, the method should be further improved.
Adult ; Ammonium Chloride/chemistry ; Anti-Infective Agents/*pharmacology ; Child ; Gram-Negative Bacteria/drug effects/*isolation & purification/metabolism ; Gram-Positive Bacteria/drug effects/*isolation & purification/metabolism ; Humans ; Reagent Kits, Diagnostic ; Saponins/chemistry ; *Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization

The aim of this study was to identify the risk factors associated with severe bacterial infection (SBI) in multiple myeloma (MM) patients during treatment with bortezomib-based regimens. A total of 98 patients with MM were evaluated during 427 treatment courses. SBI occurred in 57.1% (56/98) of the patients and during 19.0% (81/427) of the treatment courses. In the multivariate analysis for the factors associated with the development of SBI in each treatment course, poor performance status (Eastern Cooperative Oncology Group ≥ 2, P < 0.001), early course of therapy (≤ 2 courses, P < 0.001), and pretreatment lymphopenia (absolute lymphocyte count < 1.0 × 10(9)/L, P = 0.043) were confirmed as independent risk factors. The probability of developing SBI were 5.1%, 14.9%, 23.9% and 59.5% in courses with 0, 1, 2, and 3 risk factors, respectively (P < 0.001). In conclusion, we identified three pretreatment risk factors associated with SBI in each course of bortezomib treatment. Therefore, MM patients with these risk factors should be more closely monitored for the development of SBI during bortezomib-based treatment.
Adult ; Aged ; Aged, 80 and over ; Antineoplastic Combined Chemotherapy Protocols/therapeutic use ; Bacterial Infections/*complications/microbiology ; Bortezomib/*administration & dosage ; Female ; Gram-Negative Bacteria/isolation & purification ; Gram-Positive Bacteria/isolation & purification ; Humans ; Lymphocyte Count ; Lymphopenia/*therapy ; Male ; Middle Aged ; Multiple Myeloma/complications/*drug therapy/mortality ; Multivariate Analysis ; Proportional Hazards Models ; Retrospective Studies ; Risk Factors ; Stem Cell Transplantation ; Survival Rate ; Transplantation, Homologous

Bacterial infection is an important cause of death in patients with liver cirrhosis. The aim of this study was to investigate the clinical characteristics and prognostic impact of bacterial infection in hospitalized patients with alcoholic liver disease (ALD). We retrospectively analyzed data from 409 patients consecutively admitted to a tertiary referral center with ALD diagnosis. Of a total of 544 admissions, 133 (24.4%) cases presented with bacterial infection, of which 116 were community-acquired whereas 17 were hospital-acquired. The common types of infection were pneumonia (38%), biliary tract infection (17%), soft tissue infection (12%), and spontaneous bacterial peritonitis (9%). Diabetes, serum Na <135 mM/L, albumin <2.5 g/dL, C-reactive protein > or =20 mg/L, systemic inflammatory response syndrome (SIRS) positivity were independently associated with bacterial infection in patients with ALD. Overall 30-day and 90-day mortalities in patients with bacterial infection were significantly (P < 0.001) higher than those without infection (22.3% vs. 5.1% and 32.3% vs. 8.2%, respectively). Furthermore, bacterial infection (HR, 2.2; 95% CI, 1.049-4.579, P = 0.037), SIRS positivity (HR, 2.5; 95% CI, 1.240-4.861, P = 0.010), Maddrey's discriminant function score > or =32 (HR, 2.3; 95% CI, 1.036-5.222, P = 0.041), and hemoglobin <12 g/dL (HR, 2.4; 95% CI, 1.081-5.450, P = 0.032) were independent predictors of short-term mortality. In conclusion, bacterial infection and SIRS positivity predicted short-term prognosis in hospitalized patients with ALD. A thorough evaluation at admission or on clinical deterioration is required to detect possible infection with prompt management.
Adult ; Aged ; Bacterial Infections/complications/*diagnosis/mortality ; C-Reactive Protein/analysis ; Candida/isolation & purification ; Female ; Gram-Negative Bacteria/isolation & purification ; Gram-Positive Bacteria/isolation & purification ; Hemoglobins/analysis ; Hospitalization ; Humans ; Linear Models ; Liver Diseases, Alcoholic/complications/*diagnosis ; Male ; Middle Aged ; Patients ; Prognosis ; Proportional Hazards Models ; Retrospective Studies ; Risk Factors ; Serum Albumin/analysis ; Sodium/blood ; Survival Analysis ; Systemic Inflammatory Response Syndrome/complications/diagnosis ; Tertiary Care Centers

OBJECTIVETo explore the distribution and antibiotic resistance of pathogens in lesions of diabetic foot osteomyelitis (DFO) and analyze the risk factors causing osteomyelitis.

METHODSA total of 372 patients with diabetic foot infections hospitalized between January 2011 and December 2014, including 203 with osteomyelitis (OM group) and 169 without osteomyelitis (non-OM group), were examined for the distribution and antibiotic resistance profile of the pathogens in the wounds. Logistic regression analysis was used to analyze the risk factors causing osteomyelitis.

RESULTSGram-negative bacteria were the predominant pathogens (53.7%) in the infected wounds in OM group, whereas Gram-positive bacteria were the most frequently found (56.7%) in non-OM group (P=0.001). Among the Gram-positive bacteria, Staphylococcus was the dominating flora (35.1%). The resistance rate to oxacillin and cefoxitin of the isolated bacteria in OM group (64.9% and 68.5%, respectively) was significantly higher than that in non-OM group (29.2% and 32.6%, respectively; P<0.05). Among the gram-negative bacteria, Enterobacteriaceae was the dominating flora (62.4%), with a higher resistance rate to Cefepime and Aztreonam in OM group (30.1% and 38.6%, respectively) than in non-OM group (15.1% and 22.2%, respectively; P<0.05). Logistic regression analysis indicated that the infection by multi-drug resistant bacteria and an wounds area >4 cm(2) were the risk factors for osteomyelitis in patients with diabetic foot infections (P<0.05).

CONCLUSIONIn addition to an empirical anti-infection therapy, clinicians should choose specific antibiotics against Gram-negative bacteria according to the microbial spectrum and antibiotic resistance of pathogens in patients with DFO; patients with diabetic foot infections by multi-drug resistant bacteria and those with a wound area exceeding 4 cm(2) are exposed to an increased risk of osteomyelitis.

Anti-Bacterial Agents ; Cephalosporins ; Diabetic Foot ; microbiology ; Drug Resistance, Multiple, Bacterial ; Gram-Negative Bacteria ; classification ; isolation & purification ; Gram-Positive Bacteria ; classification ; isolation & purification ; Humans ; Osteomyelitis ; microbiology ; Risk Factors ; Wound Infection ; microbiology

Neonatal sepsis remains one of the most important causes of death and co-morbidity in very-low-birth-weight (VLBW) infants. The aim of this study was to determine the current incidences of early-onset sepsis (EOS) and late-onset sepsis (LOS), the distribution of pathogens, and the impact of infection on co-morbidities in VLBW infants. We analyzed the data including sepsis episode from 2,386 VLBW infants enrolled in Korean Neonatal Network from January 2013 to June 2014. We defined EOS as a positive blood culture occurring between birth and 7 days of life and LOS after 7 days of life. Sepsis was found in 21.1% of VLBW infants. The risk of sepsis was inversely related to birth weight and gestational age. EOS was found in only 3.6% of VLBW infants, however the mortality rate was as high as 34.1%. EOS was associated with the increased odds for bronchopulmonary dysplasia and intraventricular hemorrhage. The vast majority of EOS was caused by Gram-positive organisms, particularly coagulase-negative staphylococci (30.6%). LOS developed in 19.4% of VLBW infants with a 16.1% mortality rate. Pathogens in LOS were dominated by coagulase-negative staphylococci (38.3%). Twenty-five percent and fifty percent of first LOS episode occurred after 12 days and 20 days from birth, respectively. Younger and smaller VLBW infants showed the earlier occurrence day for the 25% of first LOS episode. This study provides a recent nationwide epidemiology of sepsis in VLBW infants in Korea. Based on this study, successful strategies to reduce infections would improve survival and reduce morbidity.
Coagulase/metabolism ; Databases, Factual ; Gestational Age ; Gram-Negative Bacteria/isolation & purification ; Gram-Positive Bacteria/isolation & purification ; Humans ; Incidence ; Infant, Newborn ; *Infant, Very Low Birth Weight ; Kaplan-Meier Estimate ; Republic of Korea/epidemiology ; Risk Factors ; Sepsis/*epidemiology/microbiology/mortality ; Staphylococcus/enzymology/isolation & purification

This study aims at trying to establish a novel method of sterility test for injections based on biothermodynamics, in order to overcome the deficiencies of routine sterility tests such as long detecting cycle, low sensitivity and prone to misjudgments. A biothermodynamics method was adopted to rapidly detect the microorganism contamination of injections by monitoring the heat metabolism during the growth of microbe. The growth rate equal to or greater than zero and the heat power difference of P(i) and P(0) with three folds higher than the noise of baseline were chosen as indexes to study the heat change rule of microbe. In this way, the effectiveness of the new method to detect strains required by conventional sterility test or in injection samples was also investigated. Results showed that the Gram-positive bacteria, Gram-negative bacteria and fungi demanded by sterility testing methodology could be detected by biothermodynamics method within 10 hours, with the sensitivity lower than 100 CFU x mL(-1). Meanwhile, this method was successfully applied to the sterility test of Compound Yinchen injection (FFYC), Shuanghuanglian powder injection (SHL) and Compound Triamcinolone injection (TAND) which were sterilized with different degrees. Therefore, the biothermodynamics method, with advantages of fast detection and high sensitivity, could be a complementary solution for conventional sterility tests.
Anti-Inflammatory Agents ; administration & dosage ; chemistry ; Drug Contamination ; Drugs, Chinese Herbal ; administration & dosage ; chemistry ; Fungi ; isolation & purification ; Gram-Negative Bacteria ; isolation & purification ; Gram-Positive Bacteria ; isolation & purification ; Hot Temperature ; Injections ; Microbiological Techniques ; methods ; Sensitivity and Specificity ; Sterilization ; Triamcinolone ; administration & dosage ; chemistry

OBJECTIVETo investigate the incidence of nosocomial infections of extremely premature infants and to explore the risk factors and strategies for infection control.

METHODThere were 118 extremely premature infants who were confirmed to have nosocomial infection in neonatal intensive care unit of the authors' hospital from January 2008 to December 2012. Their data of the infection rate, risk factors and clinical characteristics were retrospectively analyzed.

RESULTDuring the study, nosocomial infection occurred in 78 extremely premature infants 129 times. The nosocomial infection rate was 66.10%. The rate of ventilator-associated pneumonia (VAP) was 1.43% (35/2 452). The catheter related blood stream infection (CRBSI) rate was 0.35% (16/4 613). There were 74 (57.36%) cases of pneumonia, which was the most common nosocomial infection of extremely premature infants. There were 35 cases of VAP, which accounted for 47.30% of pneumonia. The next was sepsis, 48 cases. Seventy-four (74/90, 82.22%) strains of isolates were Gram-negative bacteria, which accounted for the highest proportion, followed by Gram-positive (12 strains), fungus (4 strains); Klebsiella pneumonia is the most common pathogens of nosocomial infection in extremely premature infants. The isolation rates of Klebsiella pneumonia with positive extended-spectrum beta-lactamases (ESBL) were 90.91% (20/22) , universally resistant to cephalosporins. Single-factor analysis showed that the body weight, mechanical ventilation, umbilical vein catheterization, central venous catheter, parenteral nutrition and hospitalization time were risk factors for nosocomial infections in extremely preterm infants. Logistic regression analysis showed that length of hospitalization (OR = 1.024, P = 0.043) and central venous catheterization (OR = 6.170, P = 0.041) were independent risk factors of nosocomial infection.

CONCLUSIONExtremely preterm infants were at higher risk of nosocomial infection. It is important to identify the high risk factors for nosocomial infections in extremely premature infants. To shorten time for mechanical ventilation, central venous catheterization and hospitalization days would be conducive to reducing the morbidity of nosocomial infection.

Birth Weight ; Catheterization, Central Venous ; adverse effects ; Cross Infection ; epidemiology ; microbiology ; Female ; Gram-Negative Bacteria ; isolation & purification ; Gram-Positive Bacteria ; isolation & purification ; Humans ; Incidence ; Infant, Extremely Premature ; Infant, Newborn ; Infant, Premature, Diseases ; epidemiology ; microbiology ; Intensive Care Units, Neonatal ; Logistic Models ; Male ; Pneumonia, Ventilator-Associated ; epidemiology ; microbiology ; Respiration, Artificial ; adverse effects ; Retrospective Studies ; Risk Factors ; Sepsis ; epidemiology ; microbiology

OBJECTIVETo investigate the distribution and drug-resistance of bacteria in the lower respiratory tract in patients with tuberculosis and severe pneumonia receiving invasive mechanical ventilation.

METHODSThe clinical data, lower respiratory tract infection pathogens and bacterial drug sensitivity were analyzed in 208 patients receiving invasive mechanical ventilation for tuberculosis and severe pneumonia.

RESULTSA total of 355 pathogenic microbial strains were obtained from the patients, among which 281 (79.2%) strains were Gram-negative bacteria, 62 (17.5%) were fungi, and 12 (3.4%) were Gram-positive bacteria. Mixed infections were found in 68 cases (19.2%). The sensitivity rates of meropenem, imipenem and amikacin were over 60% for Gram-negative bacteria, and those of teicoplanin, vancomycin, and fusidic acid were 100% for Gram-positive bacteria.

CONCLUSIONThe main pathogenic bacteria are Gram-negative bacteria, fungi and Gram-positive bacteria in the lower respiratory tract of patients with tuberculosis and severe pneumonia receiving mechanical ventilation. Meropenem, imipenem and amikacin are effective antibiotics for lower respiratory tract infections, and multi-drug resistance is frequent in these patients, which urges appropriate use of the antibiotics.

Anti-Bacterial Agents ; pharmacology ; Drug Resistance, Bacterial ; Gram-Negative Bacteria ; isolation & purification ; Gram-Positive Bacteria ; isolation & purification ; Humans ; Microbial Sensitivity Tests ; Pneumonia, Bacterial ; microbiology ; Respiration, Artificial ; Respiratory Tract Infections ; microbiology ; Tuberculosis ; microbiology

BACKGROUND: Microbiological laboratories seek technologically innovative solutions to cope with large numbers of samples and limited personnel and financial resources. One platform that has recently become available is the Kiestra Total Laboratory Automation (TLA) system (BD Kiestra B.V., the Netherlands). This fully automated sample processing system, equipped with digital imaging technology, allows superior detection of microbial growth. Combining this approach with matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MS) (Bruker Daltonik, Germany) is expected to enable more rapid identification of pathogens. METHODS: Early growth detection by digital imaging using Kiestra TLA combined with MS was compared to conventional methods (CM) of detection. Accuracy and time taken for microbial identification were evaluated for the two methods in 219 clinical blood culture isolates. The possible clinical impact of earlier microbial identification was assessed according to antibiotic treatment prescription. RESULTS: Pathogen identification using Kiestra TLA combined with MS resulted in a 30.6 hr time gain per isolate compared to CM. Pathogens were successfully identified in 98.4% (249/253) of all tested isolates. Early microbial identification without susceptibility testing led to an adjustment of antibiotic regimen in 12% (24/200) of patients. CONCLUSIONS: The requisite 24 hr incubation time for microbial pathogens to reach sufficient growth for susceptibility testing and identification would be shortened by the implementation of Kiestra TLA in combination with MS, compared to the use of CM. Not only can this method optimize workflow and reduce costs, but it can allow potentially life-saving switches in antibiotic regimen to be initiated sooner.
Automation, Laboratory ; Candida albicans/genetics/*isolation & purification ; Disk Diffusion Antimicrobial Tests ; Gram-Negative Bacteria/genetics/*isolation & purification ; Gram-Positive Bacteria/genetics/*isolation & purification ; Humans ; RNA, Ribosomal, 16S/chemistry/genetics ; Retrospective Studies ; Sequence Analysis, RNA ; *Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization

BACKGROUND/AIMS: Diversion colitis is the inflammation of the excluded segment of the colon in patients undergoing ostomy. It has been suggested that a change in colonic flora may lead to colitis; however, direct evidence for this disease progression is lacking. The aim of this study was to evaluate the relationship between the severity of diversion colitis and the composition of colonic bacteria. METHODS: We used culture methods and polymerase chain reaction to analyze the colonic microflora of patients who underwent rectal cancer resection with or without diversion ileostomy. In the diversion group, we also evaluated the severity of colonoscopic and pathologic colitis before reversal. RESULTS: This study enrolled 48 patients: 26 in the diversion group and 22 in the control group. Significant differences were observed between the two groups in the levels of Staphylococcus (p=0.038), Enterococcus (p<0.001), Klebsiella (p<0.001), Pseudomonas (p=0.015), Lactobacillus (p=0.038), presence of anaerobes (p=0.019), and Bifidobacterium (p<0.001). A significant correlation between the severity of colitis and bacterial composition was only observed for Bifidobacterium (p=0.005, correlation coefficient=-0.531). CONCLUSIONS: The colonic microflora differed significantly between the diversion and control groups. Bifidobacterium was negatively correlated with the severity of diversion colitis.
Aged ; Aged, 80 and over ; Case-Control Studies ; Colitis/*microbiology ; Colon/*microbiology ; Female ; Gram-Negative Bacteria/isolation & purification ; Gram-Positive Bacteria/isolation & purification ; Humans ; Ileostomy ; Male ; Middle Aged ; Polymerase Chain Reaction ; Pouchitis/*microbiology ; Prospective Studies ; Rectal Neoplasms/microbiology/surgery