Use of Limulus Lysate for Detecting Gram-Negative Neonatal Meningitis

PEDIATRICS ◽  
1976 ◽  
Vol 58 (1) ◽  
pp. 105-109
Author(s):  
Donald Dyson ◽  
George Cassady
Keyword(s):  
Bacterial Meningitis ◽  
Rapid Detection ◽  
Newborn Infants ◽  
Blood Cultures ◽  
Neonatal Meningitis ◽  
Gram Positive ◽  
Specific Test ◽  
Gram Negative ◽  
Gram Negative Organisms ◽  
Limulus Test

The Limulus, lysate test was evaluated as a method for rapid detection of neonatal gram-negative bacterial meningitis. A total of 208 CSF samples were collected from 145 newborn infants suspected of having meningitis. Initial samples from all six babies with culture-proven gram-negative bacterial meningitis had positive Limulus tests within 30 minutes of incubation. Samples from 14 infants with gram-negative organisms isolated only in blood and/or urine, as well as from four neonates with gram-positive organisms in CSF cultures and from 13 with gram-positive organisms in blood cultures all yielded negative Limulus tests. Thus, of 37 newborn infants with bacteria demonstrated in systemic cultures, only those six with gram-negative organisms in CSF had positive CSF Limulus tests. The CSF Limulus test was shown to be a rapid, reliable, and specific test for the detection of neonatal gram-negative bacterial meningitis.

The Causative Organisms of Bacterial Meningitis and their Antimicrobial Resistance Profiles in Iranian Children in 2011-2016

2020 ◽  
Vol 20 (2) ◽  
pp. 229-236
Author(s):  
Sepideh Keshavarz Valian ◽  
Shima Mahmoudi ◽  
Babak Pourakbari ◽  
Maryam Banar ◽  
Mohammad Taghi Haghi Ashtiani ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Bacterial Meningitis ◽  
Medical Center ◽  
Blood Cultures ◽  
Gram Positive ◽  
Gram Negative ◽  
Number Of Patients ◽  
Resistance Patterns ◽  
Iranian Children ◽  
Surgery Department

Objective: The study aimed to describe the identity and antimicrobial resistance patterns of the causative agents of bacterial meningitis in children referred to Children’s Medical Center (CMC) Hospital, Tehran, Iran. Methods: This retrospective study was performed at CMC Hospital during a six-year period from 2011 to 2016. The microbiological information of the patients with a diagnosis of bacterial meningitis was collected and the following data were obtained: patients’ age, sex, hospital ward, the results of CSF and blood cultures, and antibiotic susceptibility profiles of isolated organisms. Results: A total of 118 patients with bacterial meningitis were admitted to CMC hospital. Sixty-two percent (n=73) of the patients were male. The median age of the patients was ten months (interquartile range [IQR]: 2 months-2 years) and the majority of them (n=92, 80%) were younger than two years of age. The highest number of patients (n=47, 40%) were admitted to the surgery department. Streptococcus epidermidis was the most frequent isolated bacterium (n=27/127, 21%), followed by Klebsiella pneumoniae (n=20/127, 16%), and Staphylococcus aureus (n=16/127, 12.5%). Blood culture was positive in 28% (n=33/118) of patients. Ampicillin-sulbactam and imipenem were the most effective antibiotics against Gram-negative bacteria isolated from CSF cultures. In the case of Gram-positive organisms, ampicillinsulbactam, vancomycin, and linezolid were the best choices. Imipenem was the most active drug against Gram-negative blood pathogens. Also, ampicillin and vancomycin had the best effect on Gram-positive bacteria isolated from blood cultures. Conclusion: Results of this study provide valuable information about the antibiotic resistance profiles of the etiologic agents of childhood meningitis, which can be used for prescription of more effective empirical therapies.

scholarly journals 194. Description of Positive Blood Culture Results not Identified by Verigene Informs Empiric Antibiotic Selection

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S116-S117
Author(s):  
Connor Deri ◽  
Whitney Nesbitt ◽  
George Nelson ◽  
Jessica Keefe
Keyword(s):  
Antibiotic Therapy ◽  
Resistance Mechanism ◽  
Bloodstream Infections ◽  
Blood Cultures ◽  
Aerobic Bacteria ◽  
Gram Positive ◽  
Antibiotic Selection ◽  
Gram Negative ◽  
Empiric Antibiotic ◽  
Gram Negative Organisms

Abstract Background Bloodstream infections are a leading cause of mortality amongst hospitalized patients. Optimizing time to pathogen identification and receipt of appropriate antibiotic therapy significantly decreases mortality, morbidity, and length of hospitalization. Rapid diagnostic tests, such as Verigene, assist in the early identification of bacteria and resistance determinants from positive blood cultures; however, Verigene assays are limited to the detection of 13 gram-positive and 9 gram-negative bacteria. Methods The purpose of this study was to describe gram-negative and gram-positive aerobic bacteria identified from positive blood cultures with no Verigene target detected and to use the susceptibilities to create an antibiogram to assist in empiric antibiotic selection. A total of 2325 positive blood cultures resulted between January 2017 and October 2018 underwent Verigene testing. Results Of the 2325 isolates, 383 (16.5%), had no Verigene organism or resistance mechanism detected. Of these, there were 239 (62.4%) gram-positive isolates, 141 (36.8%) gram-negative isolates, and 3 yeast isolates with 96 unique organisms. Seventy-six (19.8%) of the organisms identified by standard culture, but not Verigene testing, are included on Verigene panel. We analyzed nine common antibiotics active against gram-negative organisms to determine percent susceptibilities against the isolated aerobic pathogens: amikacin (92.1%), cefepime (93.5%), ceftazidime (94.0%), ceftriaxone (79.7%), ciprofloxacin (88.5%), gentamicin (91.9%), levofloxacin (86.9%), piperacillin–tazobactam (83.8%), and tobramycin (85.5%). Additionally, four antibiotics active against gram-positive organisms were analyzed for gram-positive susceptibilities: cefotaxime (91.8%), ceftriaxone (98.1%), levofloxacin (82.5%), and vancomycin (91.8%). Conclusion The results of this study provide clinicians with antibiotic susceptibilities against organisms that were not identified through Verigene to better guide timely and appropriate antibiotic therapy against gram-negative and gram-positive aerobic bacteria. Disclosures All authors: No reported disclosures.

scholarly journals Time to positivity of neonatal blood cultures: fast and furious?

2011 ◽  
Vol 60 (4) ◽  
pp. 446-453 ◽  
Author(s):  
Khadija Guerti ◽  
Helena Devos ◽  
Margareta M. Ieven ◽  
Ludo M. Mahieu
Keyword(s):  
Incubation Time ◽  
Early Onset ◽  
Late Onset ◽  
Blood Cultures ◽  
Gram Positive ◽  
Suspected Sepsis ◽  
Gram Negative ◽  
Late Onset Sepsis ◽  
Neonatal Blood ◽  
Gram Negative Organisms

The aim of this study was to determine the time to positivity (TTP) of neonatal blood cultures, to investigate differences between early onset versus late-onset sepsis, and non-proven versus proven sepsis, and to examine differences in TTP by organism type using a retrospective observational study at the Neonatal Intensive Care Unit, Antwerp University Hospital, Belgium. The subjects were 1828 neonates with suspected sepsis who were treated with antimicrobials for at least 3 days. The TTP was recorded for all episodes of suspected sepsis in an approximately 6.5 year period. A total of 2916 blood cultures were collected, of which 437 (15 %) became positive. The overall TTP was 21.33 h (Q1–Q3 13.17–32.46). The difference between the median TTP in early onset versus late-onset sepsis was 0.83 h (22.00 versus 21.17 h, P=0.75). The median TTP for Gram-negative organisms was 11.17 h (Q1–Q3 8.84–15.67), whereas the median TTP for Gram-positive organisms was 23.59 h (Q1–Q3 15.29–34.58, P<0.001). In Gram-positive isolates, the median TTP for coagulase-negative staphylococci (CNS) was 26.67 h (Q1–Q3 19.00–38.17), whereas the median TTP for non-CNS was 12.83 h (Q1–Q3 10.50–18.17, P<0.001). The median TTP in proven sepsis was 20.17 h (Q1–Q3 13.00–30.37), whereas it was 29.67 h (Q1–Q3 21.17–50.63, P<0.001) in non-proven sepsis. TTP of neonatal blood cultures was significantly shorter for Gram-negative organisms. We suggest shortening the total incubation time of neonatal blood cultures to a maximum of 3 days. However, blood cultures collected in infants <72 h of age might require a longer incubation time. According to our results, it may be safe to narrow the antimicrobial spectrum to solely target Gram-positive bacteria when the culture is still negative after 48 h, and to cease antimicrobial therapy when the culture is still negative after 72 h in clinically well infants.

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 Linearized esculentin-2EM shows pH dependent antibacterial activity with an alkaline optimum

2021 ◽  
Author(s):  
Erum Malik ◽  
David A. Phoenix ◽  
Timothy J. Snape ◽  
Frederick Harris ◽  
Jaipaul Singh ◽  
...  
Keyword(s):  
Helical Structure ◽  
Food Preservation ◽  
Forming Process ◽  
Gram Positive ◽  
Gram Negative ◽  
Bacterial Membranes ◽  
Gram Positive Bacteria ◽  
Alkaline Conditions ◽  
Ph Dependent ◽  
Gram Negative Organisms

AbstractHere the hypothesis that linearized esculentin 2EM (E2EM-lin) from Glandirana emeljanovi possesses pH dependent activity is investigated. The peptide showed weak activity against Gram-negative bacteria (MLCs ≥ 75.0 μM) but potent efficacy towards Gram-positive bacteria (MLCs ≤ 6.25 μM). E2EM-lin adopted an α-helical structure in the presence of bacterial membranes that increased as pH was increased from 6 to 8 (↑ 15.5–26.9%), whilst similar increases in pH enhanced the ability of the peptide to penetrate (↑ 2.3–5.1 mN m−1) and lyse (↑ 15.1–32.5%) these membranes. Theoretical analysis predicted that this membranolytic mechanism involved a tilted segment, that increased along the α-helical long axis of E2EM-lin (1–23) in the N → C direction, with −  < µH > increasing overall from circa − 0.8 to − 0.3. In combination, these data showed that E2EM-lin killed bacteria via novel mechanisms that were enhanced by alkaline conditions and involved the formation of tilted and membranolytic, α-helical structure. The preference of E2EM-lin for Gram-positive bacteria over Gram-negative organisms was primarily driven by the superior ability of phosphatidylglycerol to induce α-helical structure in the peptide as compared to phosphatidylethanolamine. These data were used to generate a novel pore-forming model for the membranolytic activity of E2EM-lin, which would appear to be the first, major reported instance of pH dependent AMPs with alkaline optima using tilted structure to drive a pore-forming process. It is proposed that E2EM-lin has the potential for development to serve purposes ranging from therapeutic usage, such as chronic wound disinfection, to food preservation by killing food spoilage organisms.

scholarly journals 1554. Epidemiology of Adult Bacterial Hand Infections at Two Urban Hospitals

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S777-S778
Author(s):  
Arsheena Yassin ◽  
Christine Stavropoulos ◽  
Krystina L Woods ◽  
Jiashan Xu ◽  
Justin Carale ◽  
...  
Keyword(s):  
New York ◽  
Staphylococcus Aureus ◽  
Antibiotic Regimen ◽  
Gram Positive ◽  
Gram Negative ◽  
Streptococcus Species ◽  
Urban Hospitals ◽  
Haemophilus Parainfluenzae ◽  
Empiric Antibiotic ◽  
Gram Negative Organisms

Abstract Background Hand infections represent a major source of morbidity, which can result in hand stiffness and amputation. Early appropriate empiric antibiotic regimen may reduce the associated morbidity, hence the importance to examine local epidemiology. The aim of this study was to define the current epidemiology of adult hand infections at two urban hospitals in New York City. Methods We performed a double center, retrospective study of adult patients hospitalized from March 2018 to May 2020. Patients with positive cultures associated with the hand infections were included. Retrospectively, 100 patients were reviewed. Data on baseline demographic, clinical, surgical, microbiology, and treatment parameters were collected. Results Of the 100 patients, 76% were male, with median age of 47.5 years (35, 58.25) and average C-reactive protein (CRP) of 50.66 mg/L (± 64.64) on admission (see Table 1). Previous hospitalization within 1 year (38%), previous surgical procedures (39%) and recent IV medication use (26%) were common. 130 bacterial isolates were identified (see Table 2). The most frequent organisms were Gram-positive, with Methicillin susceptible Staphylococcus aureus (MSSA, 25.38%), Streptococcus species (20.08%), and Methicillin resistant Staphylococcus aureus (MRSA, 15.38%) being the most common. Gram-negative organisms were infrequent, with Haemophilus parainfluenzae (3.85%), Enterobacter cloacae (3.85) and Pseudomonas aeruginosa (3.08%) being the most prevalent. Of the 100 patients, 27% had polymicrobial infections, associated with trauma (6%), illicit IV use (6%) and unknown (7%) etiologies. Table 1: Baseline demographics and co-morbid conditions Table 2: Types and numbers of organisms in relation to etiologies Conclusion Within our population, the most common organisms associated with hand infections were Gram-positive, with Staphylococcus aureus and Streptococcus species being the most prevalent. Gram-negative pathogens were infrequently isolated. The results within this study can provide guidance to clinicians on assessing the appropriate empiric antibiotic regimen in patients with hand infections, and can serve as a basis for further studies identifying risk factors associated with isolation of organisms associated with hand infections. Disclosures All Authors: No reported disclosures

scholarly journals Evaluation of MicroScan Bacterial Identification Panels for Low-Resource Settings

Diagnostics ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 349
Author(s):  
Sien Ombelet ◽  
Alessandra Natale ◽  
Jean-Baptiste Ronat ◽  
Olivier Vandenberg ◽  
Liselotte Hardy ◽  
...  
Keyword(s):  
Bacterial Species ◽  
Ease Of Use ◽  
Bacterial Identification ◽  
Gram Positive ◽  
Gram Negative ◽  
Low Resource Settings ◽  
Low Resource ◽  
Bacillus Spp ◽  
Gram Negative Organisms ◽  
Instructions For Use

Bacterial identification is challenging in low-resource settings (LRS). We evaluated the MicroScan identification panels (Beckman Coulter, Brea, CA, USA) as part of Médecins Sans Frontières’ Mini-lab Project. The MicroScan Dried Overnight Positive ID Type 3 (PID3) panels for Gram-positive organisms and Dried Overnight Negative ID Type 2 (NID2) panels for Gram-negative organisms were assessed with 367 clinical isolates from LRS. Robustness was studied by inoculating Gram-negative species on the Gram-positive panel and vice versa. The ease of use of the panels and readability of the instructions for use (IFU) were evaluated. Of species represented in the MicroScan database, 94.6% (185/195) of Gram-negative and 85.9% (110/128) of Gram-positive isolates were correctly identified up to species level. Of species not represented in the database (e.g., Streptococcus suis and Bacillus spp.), 53.1% out of 49 isolates were incorrectly identified as non-related bacterial species. Testing of Gram-positive isolates on Gram-negative panels and vice versa (n = 144) resulted in incorrect identifications for 38.2% of tested isolates. The readability level of the IFU was considered too high for LRS. Inoculation of the panels was favorably evaluated, whereas the visual reading of the panels was considered error-prone. In conclusion, the accuracy of the MicroScan identification panels was excellent for Gram-negative species and good for Gram-positive species. Improvements in stability, robustness, and ease of use have been identified to assure adaptation to LRS constraints.

Leukocyte Lactate Dehydrogenase in Bacterial Meningitis

PEDIATRICS ◽  
1974 ◽  
Vol 54 (1) ◽  
pp. 27-33
Author(s):  
David W. Powers ◽  
Elia M. Ayoub
Keyword(s):  
Lactate Dehydrogenase ◽  
Bacterial Meningitis ◽  
Newborn Infants ◽  
Neonatal Meningitis ◽  
Subdural Effusion ◽  
Upper Limit ◽  
Ldh Activity ◽  
Initiation Of Therapy ◽  
Peripheral Leukocytes ◽  
Normal Controls

Lactate dehydrogenase (LDH) was assayed in peripheral leukocytes of 32 children with bacterial meningitis, nine children with nonbacterial meningitis, and 24 age-matched, healthy controls. Leukocyte LDH activity in patients with bacterial meningitis was significantly higher than in patients with nonbacterial meningitis (p &lt; 0.01) and normal controls (p &lt; 0.001). Eighty-eight percent of the patients with bacterial meningitis had leukocyte LDH values exceeding, 150 units/106 WBC, the upper limit of normal value for controls. Nitroblue tetrazolium (NBT) dye tests performed on 23 patients with bacterial meningitis were elevated in ten patients (43%). The elevation of leukocyte LDH activity in patients with bacterial meningitis appears to be independent of the number of circulating granulocytes or the presence of bacteremia. A major factor which appeared to influence the leukocyte LDH activity was the duration of adequate antibiotic therapy. Sequential determinations showed a return of the LDH values to normal approximately ten days after the initiation of therapy. A rise in leukocyte LDH was encountered in two patients with subdural effusion. The finding of significantly elevated leukocyte LDH values in three newborn infants with neonatal meningitis and sepsis suggests that this test may be of value in the diagnosis of neonatal sepsis.

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