SensiGram as a modified Gram staining procedure with higher sensitivity for detection of Gram-negative bacteria in blood culture

Author(s):  
O. Melter ◽  
L. Abdulla ◽  
M. Harwill ◽  
V. Vaniš ◽  
M. Pavlíková ◽  
...  
Author(s):  
Jacob S. Hanker ◽  
Dale N. Holdren ◽  
Kenneth L. Cohen ◽  
Beverly L. Giammara

Keratitis and conjunctivitis (infections of the cornea or conjunctiva) are ocular infections caused by various bacteria, fungi, viruses or parasites; bacteria, however, are usually prominent. Systemic conditions such as alcoholism, diabetes, debilitating disease, AIDS and immunosuppressive therapy can lead to increased susceptibility but trauma and contact lens use are very important factors. Gram-negative bacteria are most frequently cultured in these situations and Pseudomonas aeruginosa is most usually isolated from culture-positive ulcers of patients using contact lenses. Smears for staining can be obtained with a special swab or spatula and Gram staining frequently guides choice of a therapeutic rinse prior to the report of the culture results upon which specific antibiotic therapy is based. In some cases staining of the direct smear may be diagnostic in situations where the culture will not grow. In these cases different types of stains occasionally assist in guiding therapy.


2019 ◽  
Vol 10 (1) ◽  
pp. 38
Author(s):  
Aliyah Siti Sundari ◽  
Ni Nyoman Purwani ◽  
Anita Kurniati

Mangrove sediment is a habitat for various bacteria, one of them is amylolytic bacteria which has the potential to produce amylase enzyme. Amylase enzyme has many benefits in industry, textiles and medical. The mangrove ecosystem area has special soil characteristics, which have the opportunity to have microorganism diversity, one of which is the mangrove ecosystem in the Wonorejo region, Surabaya. This study aims to obtain potential amylolytic bacteria from potential amylolytic isolates derived from mangrove sediment. Soil bacteria were isolated in Starch media for 2% agar and tested with Lugol’s Iodine reagents to measure their amylolytic index. Character isolates observed included colony morphology, Gram staining, and motility. Of the 27 isolates found there were 3 isolates with the highest index values in their activity, namely isolates A.7, A.27 and A.64. Characterization results showed that isolates A.7 and A.64 were Gram negative bacteria, and isolates A.27 were Gram positive bacteria. And the motility results for the three isolates were negative, with the results of a positive catalase test.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 4564-4564
Author(s):  
Marek Seweryn ◽  
Urszula Jarosz ◽  
Malgorzata Krawczyk-Kulis ◽  
Miroslaw Markiewicz ◽  
Grzegorz Helbig ◽  
...  

Abstract Abstract 4564 Background: Infectious complications remain an important cause of morbidity and mortality in the early phase after hematopoietic stem cell transplantation (HSCT). Aim: The aim of this study was to assess the frequency of positive blood cultures and its potential correlation with different studied parameters in large patient population studied in the first 30 days after HSCT. Material and methods: 431 patients at median age of 47 years (range 18–85) transplanted between 2009–2011 for hematological and non-hematological malignancies were included in our analysis. There were 242 males and 189 females. Results: The indications for autologous and allogeneic HSCT were following: AML – 105 (24%), NHL – 86 (20%), MM – 75 (17,5%), HL – 48 (11%), ALL – 40 (9%), MDS – 17 (4%), AA – 15 (3,5%), CML – 12 (2,8%), PNH – 11 (2,6%), connective tissue diseases – 5 (1,2%), CLL – 3 (0,7%) and other – 14 (3,2%). The following transplant procedures were performed: ABCT – 213 (49%), ABMT – 3 (0,7%), alloBCT – 56 (13%), alloBMT – 21 (5%), URDBCT – 87 (20%), URDBMT – 51 (12%). Pre-transplant ATG and anti-CD52 antibody were used in 142 (33%) and 5 (1.2%) patients, respectively. Amongst 431 transplanted patients, 495 blood cultures were collected; range 0–8 (median 1). Eighty seven blood samples were positive (17,6%). The following pathogens were detected: gram-positive bacteria in 48% (n=42), gram-negative bacteria in 38% (n=33), fungi in 1% (n=1) and both G(+) and G(−) bacteria in 13%(n=11). The gram-positive bacteria included: Staphylococcus epidermidis: 21 (50%), Micrococcus spp: 4 (9%), Enterococcus faecium: 3 (7%), Enterococcus faecalis: 3 (7%), Streptococcus haemolyticus: 3 (7%). The following gram-negative bacteria were found: Enterobacter cloacae: 10 (30%), Escherichia coli: 7 (21%), Pseudomonas aeruginosa: 5 (15%), Klebsiella pneumonia: 5 (15%). Candida albicans was detected only in one case. The use of ATG was associated with higher number of total blood draw and positive blood cultures. No significant correlation was found between the specific pathogen and the use of ATG. Male gender was associated with significantly higher number of blood sampling and with tendency to higher number of positive blood cultures. The type of conditioning regimen, the source of stem cell and the donor origin (auto vs sibling vs unrelated) did not influence the number of positive blood culture. There was tendency to higher number of blood intake, but not positive blood culture in patients transplanted in NR if compared to PR or CR. Conclusions: Positive blood cultures were positive in about 20% of patients after HSCT. Only pre-transplant ATG use was associated with the higher number of positive blood culture. Disclosures: No relevant conflicts of interest to declare.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Andrea Nebbioso ◽  
Oluwakemi F. Ogundipe ◽  
Ernestina Carla Repetto ◽  
Calorine Mekiedje ◽  
Hugues Sanke-Waigana ◽  
...  

Abstract Background Infectious diseases account for the third most common cause of neonatal deaths. Globally, antibiotic resistance (ABR) has been increasingly challenging neonatal sepsis treatment, with 26 to 84% of gram-negative bacteria resistant to third-generation cephalosporins. In sub-Saharan Africa, limited evidence is available regarding the neonatal microbiology and ABR. To our knowledge, no studies have assessed neonatal bacterial infections and ABR in Central-African Republic (CAR). Therefore, this study aimed to describe the pathogens isolated and their specific ABR among patients with suspected antibiotic-resistant neonatal infection admitted in a CAR neonatal unit. Methods This retrospective cohort study included neonates admitted in the neonatal unit in Bangui, CAR, from December 2018 to March 2020, with suspected antibiotic-resistant neonatal infection and subsequent blood culture. We described the frequency of pathogens isolated from blood cultures, their ABR prevalence, and factors associated with fatal outcome. Results Blood cultures were positive in 33 (26.6%) of 124 patients tested (17.9% for early-onset and 46.3% for late-onset infection; p = 0.002). Gram-negative bacteria were isolated in 87.9% of positive samples; with most frequently isolated bacteria being Klebsiella pneumoniae (39.4%), Escherichia coli (21.2%) and Klebsiella oxytoca (18.2%). All tested bacteria were resistant to ampicillin. Resistance to third-generation cephalosporins was observed in 100% of tested Klebsiella pneumoniae, 83.3% of isolated Klebsiella oxytoca and 50.0% of tested Escherichia coli. None of the tested bacteria were resistant to carbapenems. Approximately 85.7 and 77.8% of gram-negative tested bacteria were resistant to first-line (ampicillin-gentamicin) and second-line (third-generation cephalosporins) treatments, respectively. In hospital mortality, adjusted for blood culture result, presence of asphyxia, birth weight and sex was higher among neonates with positive blood culture (adjusted relative risk [aRR] = 2.32; 95% confidence interval [CI] = 1.17–4.60), male sex (aRR = 2.07; 95% CI = 1.01–4.26), asphyxia (aRR = 2.42; 95% CI = 1.07–5.47) and very low birth weight (1000–1499 g) (aRR = 2.74; 95% CI = 1.3–5.79). Conclusion Overall, 77.8% of confirmed gram-negative neonatal infections could no longer effectively be treated without broad-spectrum antibiotics that are not routinely used in sub-Saharan Africa referral hospitals. Carbapenems should be considered an option in hospitals with surveillance and antibiotic stewardship.


2019 ◽  
Vol 25 (5) ◽  
pp. 502-507 ◽  
Author(s):  
Zenith Khashim ◽  
Seán Fitzgerald ◽  
Ramanathan Kadirvel ◽  
Daying Dai ◽  
Karen M Doyle ◽  
...  

Background Bacteria and bacterial components have been associated with the activation of coagulation factors and initiating the blood clot formation. The aim of this study was to investigate whether bacterial populations are present in clots retrieved from patients that have suffered a large vessel occlusion acute ischemic stroke (AIS). Materials and methods Clot samples were collected from 20 AIS patients who underwent clot retrieval with mechanical thrombectomy. Patient clinical demographic details were noted. Expression of bacterial 16S rDNA was analyzed by standard and real-time polymerase chain reaction (PCR). Gram staining was performed to identify Gram-positive and Gram-negative bacteria. Results Both the real-time and standard PCR demonstrated no expression of 16S rDNA in any of the 20 clots samples from AIS patients. Gram staining results showed no expression of Gram-positive or Gram-negative bacteria present in the clot samples. Conclusion Our current study found no bacteria populations in the clots of AIS patients.


2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Jae-Seok Kim ◽  
Go-Eun Kang ◽  
Han-Sung Kim ◽  
Hyun Soo Kim ◽  
Wonkeun Song ◽  
...  

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.


2021 ◽  
Author(s):  
lydiariver not provided

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.


2020 ◽  
Vol 69 (4) ◽  
pp. 503-508
Author(s):  
KONG-YANG WU ◽  
TONG-XIANG YANG

In this work, an exploratory study was conducted to examine Gram staining based on the capillary tube. Each Gram staining step for all bacterial strains tested was completed in capillary tubes. The results showed that different Gram staining morphologies were clearly visible in the capillary tubes. The results presented here demonstrated that the improved method could effectively distinguish between Gram-positive and Gram-negative bacteria, and only small volumes of reagents were required in this method. Collectively, this efficient method could rapidly and accurately identify the types of bacteria. Therefore, our findings could be used as a useful reference study for other staining methods.


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