scholarly journals Rapid and reliable identification of Gram-negative bacteria and Gram-positive cocci by deposition of bacteria harvested from blood cultures onto the MALDI-TOF plate

2015 ◽  
Vol 15 (1) ◽  
Author(s):  
Simona Barnini ◽  
Emilia Ghelardi ◽  
Veronica Brucculeri ◽  
Paola Morici ◽  
Antonella Lupetti
Keyword(s):  
Blood Cultures ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Reliable Identification ◽  
Maldi Tof ◽  
Gram Positive Cocci

Rapid demonstration of septic or infectious arthritis due to Gram-negative bacteria

1992 ◽  
Vol 50 (1) ◽  
pp. 686-687
Author(s):  
Jacob S. Hanker ◽  
Paul R. Gross ◽  
Beverly L. Giammara
Keyword(s):  
Chronic Arthritis ◽  
Blood Cultures ◽  
Gram Negative Bacteria ◽  
Infectious Arthritis ◽  
Bacterial Arthritis ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

Blood cultures are positive in approximately only 50 per cent of the patients with nongonococcal bacterial infectious arthritis and about 20 per cent of those with gonococcal arthritis. But the concept that gram-negative bacteria could be involved even in chronic arthritis is well-supported. Gram stains are more definitive in staphylococcal arthritis caused by gram-positive bacteria than in bacterial arthritis due to gram-negative bacteria. In the latter situation where gram-negative bacilli are the problem, Gram stains are helpful for 50% of the patients; they are only helpful for 25% of the patients, however, where gram-negative gonococci are the problem. In arthritis due to gram-positive Staphylococci. Gramstained smears are positive for 75% of the patients.

scholarly journals Trends of Bloodstream Infections in a University Greek Hospital during a Three-Year Period: Incidence of Multidrug-Resistant Bacteria and Seasonality in Gram-negative Predominance

2017 ◽  
Vol 66 (2) ◽  
pp. 171-180 ◽  
Author(s):  
Fevronia Kolonitsiou ◽  
Matthaios Papadimitriou-Olivgeris ◽  
Anastasia Spiliopoulou ◽  
Vasiliki Stamouli ◽  
Vasileios Papakostas ◽  
...  
Keyword(s):  
Bloodstream Infections ◽  
Multidrug Resistant ◽  
Blood Cultures ◽  
Diffusion Method ◽  
Resistant Bacteria ◽  
Gram Negative Bacteria ◽  
Multidrug Resistant Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Carbapenem Resistant

The aim of the study was to assess the epidemiology, the incidence of multidrug-resistant bacteria and bloodstream infections’ (BSIs) seasonality in a university hospital. This retrospective study was carried out in the University General Hospital of Patras, Greece, during 2011–13 y. Blood cultures from patients with clinical presentation suggestive of bloodstream infection were performed by the BacT/ALERT System. Isolates were identified by Vitek 2 Advanced Expert System. Antibiotic susceptibility testing was performed by the disk diffusion method and E-test. Resistance genes (mecA in staphylococci; vanA/vanB/vanC in enterococci; blaKPC/blaVIM/blaNDM in Klebsiella spp.) were detected by PCR. In total, 4607 (9.7%) blood cultures were positive from 47451 sets sent to Department of Microbiology, representing 1732 BSIs. Gram-negative bacteria (52.3%) were the most commonly isolated, followed by Gram-positive (39.5%), fungi (6.6%) and anaerobes bacteria (1.8%). The highest contamination rate was observed among Gram-positive bacteria (42.3%). Among 330 CNS and 150 Staphylococcus aureus, 281 (85.2%) and 60 (40.0%) were mecA-positive, respectively. From 113 enterococci, eight were vanA, two vanB and two vanC-positives. Of the total 207 carbapenem-resistant Klebsiella pneumoniae (73.4%), 202 carried blaKPC, four blaKPC and blaVIM and one blaVIM. A significant increase in monthly BSIs’ incidence was shown (R2: 0.449), which may be attributed to a rise of Gram-positive BSIs (R2: 0.337). Gram-positive BSIs were less frequent in spring (P < 0.001), summer (P < 0.001), and autumn (P < 0.001), as compared to winter months, while Gram-negative bacteria (P < 0.001) and fungi (P < 0.001) were more frequent in summer months. BSIs due to methicillin resistant S. aureus and carbapenem-resistant Gram-negative bacteria increased during the study period. The increasing incidence of BSIs can be attributed to an increase of Gram-positive BSI incidence, even though Gram-negative bacteria remained the predominant ones. Seasonality may play a role in the predominance of Gram-negative’s BSI.

scholarly journals Bacteriological Profile and their Susceptibility Pattern in Neonatal Intensive Care Unit at Tertiary Care Hospital in Wah

2020 ◽  
Vol 24 (3) ◽  
pp. 219-224
Author(s):  
Saba Mushtaq ◽  
Sohail Ashraf ◽  
Lubna Ghazal ◽  
Rida Zahid ◽  
Basharat Hussain ◽  
...  
Keyword(s):  
Intensive Care Unit ◽  
Intensive Care ◽  
Neonatal Intensive Care Unit ◽  
Neonatal Sepsis ◽  
Neonatal Intensive Care ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Blood Samples ◽  
Gram Negative ◽  
Gram Positive Cocci

Introduction: Neonatal sepsis is a clinical syndrome characterized by multiple symptoms and signs of infection during the first month of life. The objective of this study is to determine the frequency of commonly isolated bacteria from patients of neonatal sepsis and their susceptibility patterns in POF hospital at Wah. Methods: This cross-sectional study was carried out in POF Hospital Neonatal intensive care unit and Microbiology laboratory from January 2018 to December 2019. The blood samples of patients suspected with neonatal sepsis were processed as per standard methodology. Results: Out of ninety blood samples, fifty-one (56.7%) yielded the growth of Gram-negative rods and thirty-nine (43.3%) yielded Gram-positive cocci. Among Gram-positive bacteria, coagulase-negative staphylococci were the most common pathogen isolated from 53.8% cases followed by methicillin-resistant Staphylococcus aureus (15.3%). Among Gram-negative bacteria, Klebsiella pneumoniae (54.90%) was the most frequently identified bacteria followed by Serratia marcescens (27.45%). The Gram-positive cocci were the most susceptible to linezolid (100%) followed by vancomycin (87.2%). The Gram-negative rods depict remarkable resistance to ciprofloxacin (92.2%), gentamicin (100%), and meropenem (54.9%). Conclusions: The study concluded a predominance of Gram-negative bacteria as a causative agent of neonatal sepsis in our setup. The bacterial isolates are highly resistant to commonly prescribed oral as well as injectable antibiotics. Implementation of infection control policies is a dire need to combat the grave situation of increasing antibiotic resistance.

scholarly journals Evaluation of Verigene Blood Culture Test Systems for Rapid Identification of Positive Blood Cultures

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Jae-Seok Kim ◽  
Go-Eun Kang ◽  
Han-Sung Kim ◽  
Hyun Soo Kim ◽  
Wonkeun Song ◽  
...  
Keyword(s):  
Blood Culture ◽  
Resistance Genes ◽  
Rapid Identification ◽  
Blood Cultures ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Single Strain ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Susceptibility Tests

The performance of molecular tests using the Verigene Gram-Positive and Gram-Negative Blood Culture nucleic acid tests (BC-GP and BC-GN, resp.; Naosphere, Northbrook, IL, USA) was evaluated for the identification of microorganisms detected from blood cultures. Ninety-nine blood cultures containing Gram-positive bacteria and 150 containing Gram-negative bacteria were analyzed using the BC-GP and BC-GN assays, respectively. Blood cultures were performed using the Bactec blood culture system (BD Diagnostic Systems, Franklin Lakes, NJ, USA) and conventional identification and antibiotic-susceptibility tests were performed using a MicroScan system (Siemens, West Sacramento, CA, USA). When a single strain of bacteria was isolated from the blood culture, Verigene assays correctly identified 97.9% (94/96) of Gram-positive bacteria and 93.8% (137/146) of Gram-negative bacteria. Resistance genesmecAandvanAwere correctly detected by the BC-GP assay, while the extended-spectrumβ-lactamase CTX-M and the carbapenemase OXA resistance gene were detected from 30 cases cultures by the BC-GN assay. The BC-GP and BC-GN assays showed high agreement with conventional identification and susceptibility tests. These tests are useful for rapid identification of microorganisms and the detection of clinically important resistance genes from positive Bactec blood cultures.

Ocena działania olejku majerankowego wobec bakterii beztlenowych

2018 ◽  
Vol 19 (4) ◽  
Author(s):  
Anna Kędzia ◽  
Andrzej W. Kędzia ◽  
Henry O. Meissner ◽  
Joanna Wiśniewska
Keyword(s):  
Essential Oil ◽  
Anaerobic Bacteria ◽  
Geographic Origin ◽  
Antimicrobial Properties ◽  
Green Plant ◽  
Gram Negative Bacteria ◽  
Tannerella Forsythia ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Cocci

Introduction. Sweet majoram (Origanum majorana L.), green plant from family Lamiaceae is common used in traditional medicine. Herba majoranae containing from 1 to 3.5% essential oil. The main components of the oil depend on the geographic origin of the plant and include: terpinen-4-ol, α-terpineol, terpinene, γ-terpinene, cis-sabinene hydrate, p-cymene, triterpenic acid, phenolic acid, flavonoids glycosides, tanins, diterpenoids and triterpenoids. The oil is used for treatment of lung diseases, spleen, kidneys, hepatitis, alimentary tract and headaches. It has antiemetic, anticancer, antioxidant and antimicrobial properties. Aim. The aim of the study was to determine the susceptibility of anaerobic bacteria isolated from oral cavity to majoram oil. Material and methods. A total of 57 anaerobic bacteria belonging to the genus of Porphyromonas (4 strains), Prevotella (9), Bacteroides (11), Parabacteroides (1), Tannerella (2), Fusobacterium (7), 11 strains of Gram-positive cocci, 12 strains of Gram-positive rods and 6 reference strains were tested. Investigation was carried out using the plate dilution technique in Brucella agar supplemented with 5% defibrynated sheep blood, menadione and hemine. Inoculum containing 106 CFU per spot was seeded with Steers replicator upon the agar with various oil concentrations as well as upon that no majoram oil (Semifarm, Elbląg). The concentrations oil were: 0.06, 0.12, 0.25, 0.5, 1.0 and 2.0 mg/ml. The plate were incubated in anaerobic conditions, in anaerobic jars for 48 hours in 37°C. Minimum inhibitory concentration (MIC) was interpreted as the lowest concentrations oil inhibiting the growth of strains of anaerobes. Results and discussion. The results of investigations indicated that the from Gram-negative bacteria belonging to the genus of Bacteroides uniformis, Tannerella forsythia and Bacteroides vulgatus were the most susceptible to the essential oil (MIC <0.06-0.5 mg/ml). But the 89% strains from genus of Prevotella was sensitive to 2.0 mg/ml and more. Tested oil was less active against the strains from genera of Fusobacterium. MIC of the strains were in ranges 1.0-> 2.0 mg/ml. The rods from the genera Prevotella bivia, Prevotella buccalis, Prevotella loescheii, Bacteroides fragilis, Parabacteroides distasonis and Fusobacterium nucleatum were the lowest sensitive (MIC > 2.0 mg/ml). The oil was very active vs. Gram-positive cocci. MIC for 50% this strains was in ranges < 0.06-0.25 mg/ml. But the Gram-positive rods were less sensitive. The growth of the strains were inhibited by concentrations in ranges 1.0-> 2.0 mg/ml (without Actinomyces viscosus – MIC 1.0 mg/ml). It appears that Gram-positive anaerobic bacteria were more susceptible to majoram oil than Gram-negative rods. Conclusions. The most susceptible to majoram oil from Gram-negative bacteria were rods of Bacteroides uniformis, Tannerella forsythia and Bacteroides vulgatus. The oil was very active against Gram-positive cocci and rods. The Gram-negative anaerobes were less susceptible to majoram oil than Gram-positive anaerobes.

Gram staining v1

2021 ◽  
Author(s):  
lydiariver not provided
Keyword(s):  
Cell Walls ◽  
Group B Streptococcus ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Staining ◽  
Acetone Treatment ◽  
Gram Negative Organisms ◽  
Group B ◽  
Gram Positive Cocci

Gram staining is one of the first techniques used for the identification of group B Streptococcus agalactiae and one would expect to see gram-positive cocci under the microscope. The technique consists of applying a series of colorants and bleaches (acetone), which interact with the lipids of the membranes of gram-positive and gram-negative bacteria. The cell walls of gram-positive organisms retain the dye after acetone treatment and appear purple in color, whereas gram-negative organisms become discolored after acetone treatment and appear pink.

Early Quantitative Determination of Serum Procalcitonin Can Help Distinguishing Strains of Different Bloodstream Infections in Patients with Hematologic Diseases

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 3703-3703
Author(s):  
Xiaofeng Luo ◽  
Jinhua Ren ◽  
Zhizhe Chen ◽  
Ting Yang ◽  
Jianda Hu
Keyword(s):  
Quantitative Determination ◽  
Bloodstream Infection ◽  
Large Population ◽  
Bloodstream Infections ◽  
Blood Cultures ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Hematologic Diseases ◽  
Fungi Infection

Abstract High procalcitonin (PCT) levels are strongly associated with systemic bacterial infections. PCT is produced in response to bacterial endotoxin and inflammatory cytokines. Few studies are available in the literature on PCT ability to distinguish different strains of bloodstream infections in patients with hematologic diseases. The aim of the present study was to explore the value of determining serum PCT values early, i.e., as soon as blood cultures are positive, in a large population of patients with hematologic diseases. Patients with hematologic diseases admitted to the hematology department of our hospitalfrom January 2013 to March 2016 who had bloodstream infections were retrospectively analyzed. Patients whose blood samples were collected for simultaneous blood culture and PCT test were enrolled in the study, and they were divided into agranulocytosis and non-agranulocytosis groups. Automatic microbial analyzer was used to identify all strains, and PCT levels were analyzed with an automatic electrochemiluminescence system. The relationship between PCT levels and the strains in bloodstream infections was analyzed and compared, and the diagnostic efficacy of PCT was evaluated using the receiver operating characteristic (ROC) curve. A total of 494 bloodstream infection cases that fulfilled the inclusion criteria were included in the study, involving 312 cases of bloodstream infection with single Gram-negative, 146 cases with single Gram-positive, 12 cases with single fungi, 19 cases with polymicrobes, and 5 cases identified as contaminated specimens. Unpaired t-test was used for data analysis. PCT levels for single Gram-negative infection (15.17±2.11 ng/ml) were significantly higher than those for Gram-positive infection (3.30 ± 0.93 ng/ml) (P<0.0001), or those for single fungi infection (0.22 ± 0.04 ng/ml) (P<0.0001). PCT levels for single Gram-positive infection were also significantly higher than those in single fungi infection (P<0.01). In the agranulocytosis group, which included 403 cases, the PCT levels in the single Gram-negative infection (14.14 ± 2.13 ng/ml) were significantly higher than those in single Gram-positive (2.49 ± 0.73 ng/ml) (P<0.0001), or in single fungi infection (0.24 ± 0.04 ng/ml) (P<0.0001). The PCT levels in the single Gram-positive bacterial infection were also significantly higher than those in single fungi infection (P<0.01). In the single Gram-negative bacteria bloodstream infection, we further found that the PCT levels in Enterobacteriaceae infection (17.00 ± 3.04 ng/ml) were significantly higher than those in nonfermentative Gram-negatives infection (6.49 ± 1.50 ng/ml) (P<0.01). ROC analysis was performed on monomicrobial blood cultures. ROC of single Gram-negative and Gram-positive infections revealed that the area under the curve (AUC) was 0.687, the best cut-off value was 0.58 ng/ml, the sensitivity was 60.81% and specificity was 71%. ROC of single Gram-negative and fungi infections revealed that the AUC was 0.795, the best cut-off value was 0.42 ng/ml, the sensitivity was 67% and specificity was 100%. ROC of single Gram-positive and fungi infections revealed that the AUC was 0.6, the best cut-off value was 0.44 ng/ml, the sensitivity was 37% and specificity was 100%. In the non-agranulocytosis group, we only found that the PCT levels in the single Gram-negative infection were significantly higher than those in single Gram-positive infection (P<0.05). In summary, early serum PCT quantitative determination can be used as a routine test to help to distinguish Gram-negative bacteria, Gram-positive bacteria, or fungi bloodstream infections in patients with hematologic diseases. These findings will be of great clinical value to select appropriate antibiotics for patients with hematologic diseases and bloodstream infections. Figure Figure. Disclosures No relevant conflicts of interest to declare.

scholarly journals A Prospective Evaluation of Two Rapid Phenotypical Antimicrobial Susceptibility Technologies for the Diagnostic Stewardship of Sepsis

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Cesira Giordano ◽  
Elena Piccoli ◽  
Veronica Brucculeri ◽  
Simona Barnini
Keyword(s):  
Antimicrobial Susceptibility ◽  
Multidrug Resistant ◽  
Rapid Identification ◽  
Blood Cultures ◽  
Gram Positive ◽  
Gram Negative ◽  
Maldi Tof Ms ◽  
Gram Positive Bacteria ◽  
Maldi Tof ◽  
Tof Ms

Rapid identification of bloodstream pathogens by MALDI-TOF MS and the recently introduced rapid antimicrobial susceptibility testing (rAST) directly from positive blood cultures allow clinicians to promptly achieve a targeted therapy, especially for multidrug resistant microorganisms. In the present study, we propose a comparison between phenotypical rASTs performed in light-scattering technology (Alfred 60AST, Alifax®) and fluorescencein situhybridization (Pheno™, Accelerate) directly from positive blood cultures, providing results in 4–7 hours. Blood samples from 67 patients admitted to the Azienda Ospedaliero-Universitaria Pisana were analyzed. After the direct MALDI-TOF MS identification, the rAST was performed at the same time both on Alfred 60AST and Pheno. Alfred 60AST provided qualitative results, interpreted in terms of clinical categories (SIR). Pheno provided identification and MIC values for each antibiotic tested. Results were compared to the broth microdilution assay (SensiTitre™, Thermo Fisher Scientific), according to EUCAST rules. Using Alfred 60AST, an agreement was reached, 91.1% for Gram-negative and 95.7% for Gram-positive bacteria, while using Pheno, the agreement was 90.6% for Gram-negative and 100% for Gram-positive bacteria. Both methods provided reliable results; Alfred 60AST combined with MALDI-TOF MS proved itself faster and cheaper. Pheno provided identification and MIC determination in a single test and, although more expensive, may be useful whenever MIC value is necessary and where MALDI-TOF MS is not present.

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