Comparison of the reliability of Gram-negative and Gram-positive flags of the Sysmex UF-5000 with manual Gram stain and urine culture results

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Dietmar Enko ◽  
Ingeborg Stelzer ◽  
Michael Böckl ◽  
Wolfgang J. Schnedl ◽  
Andreas Meinitzer ◽  
...  
Keyword(s):  
Predictive Value ◽  
Urine Culture ◽  
Youden Index ◽  
Gram Stain ◽  
Gram Positive ◽  
Urine Sediment ◽  
Gold Standard Method ◽  
Gram Negative ◽  
Tract Infections ◽  
Culture Positive

AbstractObjectivesRecently, the fully automated flow cytometry-based UF-5000 (Sysmex Corboration, Kobe, Japan) urine sediment analyzer was developed providing bacteria (BACT) info flags for more accurate bacterial discrimination of urinary tract infections (UTIs). This study aimed to compare the reliability of the UF-5000 BACT-info flags with manual Gram stain and urine culture as the gold standard method.MethodsA total of 344 urine samples were analyzed on the UF-5000 and compared with manual microscopic Gram stain and urine cultures. Agreement was assessed by Cohen’s kappa (κ) analysis. The Youden index was used to determine the optimal BACT and white blood cell (WBC) cut-off points for discriminating positive and negative urine cultures.ResultsOverall 98/344 (28.5%) samples were urine culture positive at a cut-off of ≥105 CFU/mL. “Gram-negative?” UF-5000 BACT-Info flags showed a better concordance of 25/40 (62.5%) with urine culture compared to Gram stain with 30/50 (60%). The results for UF-5000 discrimination of Gram-positive and Gram-negative microorganisms demonstrated a substantial (κ = 0.78) and fair (κ = 0.40) agreement with urine culture. Optimal cut-off points detecting positive urine cultures were 135 BACT/µL (sensitivity [SE]: 92.1%, specificity [SP]: 85.4%, positive predictive value [PPV]: 71%, negative predictive value [NPV]: 96%) and 23 WBC/µL (SE: 73.5%, SP: 84.1%, PPV: 65%, NPV: 89%).ConclusionsThe UF-5000 analyzer (Sysmex) is a reliable diagnostic tool for UTI screening. The displayed BACT-Info flags allow a quick diagnostic orientation for the clinician. However, the authors suggest verifying the automated Gram categories with urine culture.

scholarly journals Comparing the Performance of the New Fully Automated Urine Particle Analyzer UF-5000 with UF-1000i and Gram Stain in Predicting Bacteria Growth Patterns in Women with Uncomplicated Urinary Tract Infections

2020 ◽  
Author(s):  
Stephen Shei-Dei Yang ◽  
Chun-Chun yang ◽  
Yi-Shen Chen ◽  
Shangjen chang
Keyword(s):  
Urinary Tract ◽  
Urine Analysis ◽  
Growth Patterns ◽  
Gram Stain ◽  
Gram Positive ◽  
Gram Negative ◽  
Bacterial Patterns ◽  
Tract Infections ◽  
Sensitivity Specificity ◽  
Gram Positive Cocci

Abstract BackgroudTo compare the performance of the new flow cytometer UF-5000 with UF-1000i (Sysmex, Kobe, Japan) and Gram stain in predicting the bacterial patterns in urine samples MethodsWomen with symptoms suggestive of urinary tract infection were enrolled. Mid-stream urine sample was collected for gram staining, urine analysis and urine culture. Bacterial patterns were classified though UF1000i (none, cocci bacteria or rods/mixed growth), UF-5000 (none, cocci, rods or mixed growth) and Gram stain. Results Among the 102 samples, there were 10 gram-positive cocci, 2 gram-positive bacilli, 66 gram-negative rods, and 24 mixed growth. The sensitivity/specificity of the UF-1000i was 81.8/91.1% for gram-negative rods and 23.5/96.9% for cocci/mixed. The sensitivity/specificity of the UF-5000 was 80.0/88.2% for gram negative rods and 70.0/86.5% for gram-positive cocci.ConclusionsThe UF-5000 demonstrated the good sensitivity and specificity for Gram-negative bacilli bacteria and demonstrated an improved sensitivity for detecting Gram-positive cocci.

The Diagnostic Value of Gram Stain for Initial Identification of the Etiologic Agent of Peritonitis in Capd Patients

1997 ◽  
Vol 17 (3) ◽  
pp. 269-272 ◽  
Author(s):  
Dinoráh A. Bezerra ◽  
Mario B. Silva ◽  
Jaqueline S.T. Caramori ◽  
Maria F. Sugizaki ◽  
Teruê Sadatsune ◽  
...  
Keyword(s):  
Predictive Value ◽  
Medical Center ◽  
Single Agent ◽  
Etiologic Agent ◽  
Initial Diagnosis ◽  
Gram Stain ◽  
Gram Positive ◽  
Dialysis Unit ◽  
Gram Negative ◽  
Gram Positive Cocci

Objective To evaluate the effectiveness of the Gram stain in the initial diagnosis of the etiologic agent of peritonitis in continuous ambulatory peritoneal dialysis (CAPD). Design Retrospective study analyzing the sensitivity (S), specificity (SS), positive predictive value (+PV), and negative predictive value (-PV) of the Gram stain relating to the results of cultures in 149 episodes of peritonitis in CAPD. The data were analyzed in two studies. In the first, only the cases with detection of a single agent by Gram stain were taken (Study 1). In the second, only the cases with two agents in Gram stain were evaluated (Study 2). Setting Dialysis Unit and Laboratory of Microbiology of a tertiary medical center. Patients Sixty-three patients on regular CAPD who presented one or more episodes of peritonitis from May 1992 to May 1995. Results The positivity of Gram stain was 93.2% and the sensitivity was 95.7%. The values of S, SS, +PV, and -PV were respectively: 94.9%, 53.5%, 68.3%, and 90.9% for gram -positive cocci and 83.3%, 98.8%, 95.2%, and 95.6% for gram-negative bacilli. The association of grampositive cocci plus gram -negative bacilli were predictive of growth of both in 6.8%, growth of gram -positive cocci in 13.7%, and growth of gram -negative bacilli in 72.5%. Conclusions The Gram stain is a method of great value in the initial diagnosis of the etiologic agent of peritonitis in CAPD, especially for gram-negative bacilli.

Screening of presumptive urinary tract infections by the automated urine sediment analyser sediMAX

2015 ◽  
Vol 53 (s2) ◽  
Author(s):  
Andrea Tessari ◽  
Nicoletta Osti ◽  
Marino Scarin
Keyword(s):  
Urinary Tract ◽  
Urinary Tract Infections ◽  
Predictive Value ◽  
Urine Culture ◽  
False Negative ◽  
False Negative Rate ◽  
Urine Samples ◽  
Indwelling Catheter ◽  
Urine Sediment ◽  
Tract Infections

AbstractUrinary tract infections (UTI) are among the most common bacterial infections and urine samples represent a large proportion of the specimens processed in clinical microbiology laboratories, up to 80% of which, however, yield negative results. Automated microscopy is widely used for urine sediment analysis and has recently been evaluated in a few studies for bacteriological screening of urine samples, achieving high levels of performance.We present a study in which urine samples from both inpatients and outpatients, with either clean-catch or indwelling catheter urine samples, were screened for UTI by urine culture, as the reference method, and the automated urine analyser sediMAX, for the detection of bacteria, leukocytes and yeasts.In total, 3443 urine samples were evaluated. When a single algorithm was adopted for sediMAX to screen the total patient population, 96.4% sensitivity, 75.4% specificity, 57.8% positive predictive value, and 98.4% negative predictive value were found. However, for male outpatients and all patients with indwelling catheter other algorithms were necessary to improve performances. Altogether, with sediMAX false negative rate was 2.4% and false positive rate was 27.6%. In addition, 54% of the investigated samples could have avoided urine culture.After the identification of specific algorithms for different patient subgroups, the automated urine analyser sediMAX can be reliably employed in the screening of UTI.

THE EFFECT OF SALMINE ON BACTERIA

1958 ◽  
Vol 4 (2) ◽  
pp. 65-71 ◽  
Author(s):  
Thomas D. Brock
Keyword(s):  
Sodium Chloride ◽  
Gram Negative Bacteria ◽  
Bacteriostatic Activity ◽  
Bactericidal Action ◽  
Gram Stain ◽  
Gram Positive ◽  
Gram Negative ◽  
Bacterial Surface ◽  
Bactericidal Effects

The bacteriostatic and bactericidal effects of salmine on various bacteria have been studied. Salmine has more bacteriostatic activity against Gram-positive than against Gram-negative bacteria. It is bactericidal in water but not in broth, and this bactericidal action occurs against both Gram-positive and Gram-negative bacteria. It has been shown that salmine causes agglutination of washed suspensions of certain bacteria and this agglutination is not correlated directly with the Gram stain. Salmine causes an increase in the turbidity of washed cells of all bacteria, Gram-positive and Gram-negative, and differs in this respect from the solutes sodium chloride and glucose, which affect only Gram-negative species.A comparison has been made of the effects of salmine and polymyxin and it has been concluded that salmine may also act by attachment to the bacterial surface.

A New Screening Approach For Fast And Accurate Prediction Of Positive And Negative Urine Cultures By SediMAX Compared With The Standard Urine Culture

2021 ◽  
Vol 1 (1) ◽  
pp. 46-55
Author(s):  
Massimo Pieri ◽  
Flaminia Tomassetti ◽  
Paola Cerini ◽  
Roberta Felicetti ◽  
Lucia Ceccaroni ◽  
...  
Keyword(s):  
Blood Cell ◽  
Bacterial Infections ◽  
Urine Culture ◽  
Screening Method ◽  
Significant Proportion ◽  
Bacterial Count ◽  
Urine Samples ◽  
Screening Methods ◽  
Urine Sediment ◽  
Tract Infections

Urinary tract infections (UTI) are the most frequent bacterial infections, and the detection of infection in urine samples is expensive and time-consuming. Also, in laboratories a significant proportion of samples processed yield negative results. For this, screening methods represent an important improvement towards the final UTI diagnosis. SediMAX is an automated microscopy, easier to use in laboratories due to its basic procedure and it is widely used for urine sediment analysis. In our study, we evaluated the performance of SediMAX, applying some screening parameters, compared with the gold standard methods, urine culture, to identify all the positive cases for UTI. We analysed 1185 urine samples from our daily laboratory routine. The basis of our screening model was to establish a cut-off for bacterial count (BACT), as 300 bacteria/µL in order to avoid missing positive cases. However, the sensitivity and the specificity achieved were not enough to identify all UTI infection in urine samples. So, in addition to BACT we have considered other parameters, such as White Blood Cell (WBC), Red Blood Cell (RBC), Yeasts (YEST), Age and Nitrates (NIT). The second screening method reached a sensitivity of 100%, that could be reliably employed in detect of UTIs.

scholarly journals Evaluation of MRSASelect™Chromogenic Medium for the Early Detection of Methicillin-ResistantStaphylococcus aureusfrom Blood Cultures

2013 ◽  
Vol 24 (4) ◽  
pp. e113-e116 ◽  
Author(s):  
Kanchana Manickam ◽  
Andrew Walkty ◽  
Philippe RS Lagacé-Wiens ◽  
Heather Adam ◽  
Barbara Swan ◽  
...  
Keyword(s):  
Early Detection ◽  
Antimicrobial Therapy ◽  
Predictive Value ◽  
Turnaround Time ◽  
Blood Cultures ◽  
Gram Stain ◽  
Chromogenic Medium ◽  
Gram Positive ◽  
Microbiological Methods ◽  
Gram Positive Cocci

INTRODUCTION:Staphylococcus aureusbacteremia is associated with considerable morbidity and mortality. In theory, reducing the turnaround time in reporting of methicillin-resistantS aureus(MRSA) among patients with bactermia could assist with the rapid optimization of antimicrobial therapy.OBJECTIVE: To evaluate the sensitivity and specificity of MRSASelect(Bio-Rad Laboratories, USA), a chromogenic medium, in the early detection of MRSA from blood cultures growing Gram-positive cocci in clusters, and to confirm that routine use of this medium would, in fact, reduce turnaround time for MRSA identification.METHODS: The present study was conducted at three microbiology laboratories in Manitoba. Between April 2010 and May 2011, positive blood cultures with Gram-positive cocci in clusters visualized on Gram stain were subcultured to both MRSASelectand routine media. MRSA isolates were identified using conventional microbiological methods from routine media and using growth with the typical colony morphology (pink colony) on MRSASelectmedium.RESULTS: A total of 490 blood cultures demonstrating Gram-positive cocci in clusters on Gram stain were evaluated.S aureuswas recovered from 274 blood cultures, with 51S aureusisolates (51 of 274 [18.6%]) identified as MRSA. MRSASelectmedium had a sensitivity of 98%, a specificity of 100%, a positive predictive value of 100% and a negative predictive value of 99.8% for the recovery and identification of MRSA directly from positive blood culture bottles. In addition, use of MRSASelectmedium was found to improve turnaround time in the detection of MRSA by almost 24 h relative to conventional methods.DISCUSSION: These data support the utility of MRSASelectmedium for the rapid identification of MRSA from positive blood cultures. Further clinical studies are warranted to determine whether the improvement in turnaround time will result in a measurable reduction in suboptimal antimicrobial therapy and/or improvement in patient outcome.

scholarly journals Clinical, Epidemiological and Bacteriological Profile of Culture Positive Urinary Tract Infections in Febrile Children – A Cross Sectional Study

2021 ◽  
Vol 8 (10) ◽  
pp. 522-526
Author(s):  
Bhavani Shankar Rokkam ◽  
Chowdary Babu Menni ◽  
Ramu Pedada ◽  
Deepak Kumar Alikana
Keyword(s):  
Urinary Tract Infection ◽  
Urinary Tract ◽  
Tract Infection ◽  
Urinary Tract Infections ◽  
Urine Culture ◽  
Signs And Symptoms ◽  
Cross Sectional ◽  
Bacteriological Profile ◽  
Tract Infections ◽  
Culture Positive

BACKGROUND Urinary tract infections (UTI) constitute a common cause of morbidity in infants and children. When associated with abnormalities of urinary tract, they may lead to long-term complications including renal scarring, loss of function and hypertension. Most urinary tract infections remain undiagnosed if investigations are not routinely performed to detect them. Prompt detection and treatment of urinary tract infections and any complicating factors are important. The objective of the study is to know the clinical, epidemiological and bacteriological profile (i.e. clinical signs and symptoms, age, sex, family history, associated urinary tract abnormalities, & causative organisms) of urinary tract infections in febrile children with culture positive urinary tract infection. METHODS This descriptive, cross sectional observational study was conducted at outpatient clinics of our “child health clinics” between May 2016 and April 2017 (one year). All children aged 0 to 12 years with culture positive urinary tract infections were included in this study to evaluate the clinical, epidemiological and bacteriological profile. RESULTS A total of 69 children with culture positive urinary tract infections were included in this study. Out of 69 children included in this study, 36 (52.2 %) were females and 33 (47.8 %) were males. Overall female preponderance was seen and the M: F ratio was 0.9:1. But during first year of life in our study group we had more boys (10, 14.49 %) affected with urinary tract infection than girls. 49.3 % of urinary tract infections in the present study belonged to lower socio-economic status. Most common organism causing urinary tract infection in our group was E. coli (56.5 %). Fever (100 %), anorexia or refusal of feeds (52.2 %), dysuria (46.4 %), vomiting (46.4 %) and abdominal pain (39.1 %) were the predominant clinical manifestations observed in our study. CONCLUSIONS Urinary tract infection is a common medical problem in children and it should be considered as a potential cause of fever in children. As febrile children with urinary tract infection usually present with non-specific signs and symptoms, urine culture should be considered as a part of diagnostic evaluation. KEYWORDS Urinary Tract Infections (UTI), Febrile Children, Bacteriological Profile, Urine Culture

scholarly journals Antibiotics Resistance Profile of Uropathogens Isolated from Al Buraimi Hospital, Sultanate of Oman

2017 ◽  
Vol 10 (1) ◽  
pp. 98
Author(s):  
Mansoor Khalid ◽  
Maryam Khalifa Al Naimi ◽  
Hafiz Ghulam Murtaza Saleem ◽  
Muhammad Muqeet Ullah ◽  
Ahmed Yar Mohammed Dawood Al Baloshi
Keyword(s):  
Urine Samples ◽  
Diffusion Method ◽  
Antibiotics Resistance ◽  
Sultanate Of Oman ◽  
Gram Positive ◽  
Klebsiella Species ◽  
Gram Negative ◽  
Resistance Profile ◽  
Positive Urine ◽  
Tract Infections

BACKGROUND: Urinary tract infections (UTIs) is a worldwide problem of all age groups and gender. Emerging resistance to antibiotics making difficult in the choice of treatment and management of UTI cases. This study sought to determine the gender wise prevalence of common uropathogens from UTI patients and the resistance profile of uropathogens against commonly used antibiotics.METHOD: This cross sectional study was conducted in Al Buraimi Hospital, Sultanate of Oman. The data of UTI patients visited hospital was analyzed for the isolation of uropathogens from positive urine culture and antimicrobial sensitivity test was performed by disc diffusion method. Descriptive statistics was used to analyze the data using SPSS 21.0 and Microsoft Excel.RESULT: Total 4,480 urine samples were analyzed for isolation of uropathogens and significant bacteriuria were found in total 846 (19%) samples. Overall 728 (86%) Gram-negative and 118 (14%) Gram positive uropathogens were isolated from total (846) positive urine samples and the highest prevalence of isolates was observed in females 542(74%) than males 186(26%). E.coli was found the highest prevalent (50.3%) uropathogens followed by Klebsiella species (13.9%), Pseudomonas (6.3%), A.baumannii (4%), E.Cloacae (2.2%), Proteus species (1.4%), Citrobacter species (1.2%), M. morgani (0.3%) and Serratia species (0.1%). The highest (34.3%) antibiotic resistance was noticed in E.coli against Nalidixic Acid, however, susceptiblity was found against Ceftriaxone, Ceftazidime, Ciprofloxacin and Nitrofurantoin among female and males.CONCLUSION: Overall, β- lactam antibiotics, Cephalosporins, Fluroquiolones, Macrobids would be the first line of drugs and the most effective for the empirical treatment of Gram-negative and Gram-positive uropathogens; however Aminoglycosides, Carbapenems and Polymyxin could be used for the treatment of UTI infections as the second choice.

scholarly journals Evaluation of BacterioScan 216Dx in Comparison to Urinalysis as a Screening Tool for Diagnosis of Urinary Tract Infections in Children

2019 ◽  
Vol 57 (9) ◽  
Author(s):  
Ferdaus Hassan ◽  
Heather Bushnell ◽  
Connie Taggart ◽  
Caitlin Gibbs ◽  
Steve Hiraki ◽  
...  
Keyword(s):  
Urinary Tract Infection ◽  
Urinary Tract ◽  
Tract Infection ◽  
Predictive Value ◽  
Screening Tool ◽  
Urine Culture ◽  
Antibiotic Use ◽  
Urine Samples ◽  
Maldi Tof ◽  
Tract Infections

ABSTRACTUrinalysis (UA) has routinely been used as a screening tool prior to urine culture set up. BacterioScan 216Dx is an FDA-cleared semiautomated system to detect bacterial growth in urine. The aim of this study was to evaluate 216Dx in comparison to UA for diagnosis of urinary tract infection (UTI) in children. Clean-catch, unpreserved urine samples from children aged <18 years were tested by 216Dx, and positive urine samples in media were processed for direct bacterial identification by matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) mass spectrometry. Sensitivity and specificity of 216Dx and urinalysis (UA) were determined against urine culture. Of 287 urine samples obtained from children (median age, 108 months), 44.0% and 56.0% were UA positive and negative, respectively, while 216Dx detected 27% and 73% as positive and negative, respectively. Compared to culture, the overall sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 216Dx versus UA were 92.1% versus 97.3%, 82.7% versus 63.8%, 44.8% versus 29.1%, and 98.6% versus 99.3%, respectively. Among 216Dx true-positive (TP) samples (n= 35), 77.0% were successfully identified directly from broth by MALDI-TOF. Among urine samples that were identified as contaminated by culture (n= 127; 44%), the 216Dx detected 93 (73.0%) as negative while UA detected 69 (54.0%) as negative. Although the sensitivities of 216Dx and UA are comparable, the specificity of 216Dx was higher than that of UA. The 216Dx can be used as an alternative/adjunct screening tool to UA to rule out urinary tract infection (UTI) in children. Compared to culture, the faster turnaround time (3 hours) of 216Dx has the potential to reduce unnecessary antibiotic use and improve patient management.

scholarly journals Automated Interpretation of Blood Culture Gram Stains by Use of a Deep Convolutional Neural Network

2017 ◽  
Vol 56 (3) ◽  
Author(s):  
Kenneth P. Smith ◽  
Anthony D. Kang ◽  
James E. Kirby
Keyword(s):  
Neural Network ◽  
Blood Culture ◽  
Convolutional Neural Network ◽  
Clinical Laboratory ◽  
Clinical Microbiology Laboratory ◽  
Proof Of Concept ◽  
Gram Stain ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Cocci

ABSTRACTMicroscopic interpretation of stained smears is one of the most operator-dependent and time-intensive activities in the clinical microbiology laboratory. Here, we investigated application of an automated image acquisition and convolutional neural network (CNN)-based approach for automated Gram stain classification. Using an automated microscopy platform, uncoverslipped slides were scanned with a 40× dry objective, generating images of sufficient resolution for interpretation. We collected 25,488 images from positive blood culture Gram stains prepared during routine clinical workup. These images were used to generate 100,213 crops containing Gram-positive cocci in clusters, Gram-positive cocci in chains/pairs, Gram-negative rods, or background (no cells). These categories were targeted for proof-of-concept development as they are associated with the majority of bloodstream infections. Our CNN model achieved a classification accuracy of 94.9% on a test set of image crops. Receiver operating characteristic (ROC) curve analysis indicated a robust ability to differentiate between categories with an area under the curve of >0.98 for each. After training and validation, we applied the classification algorithm to new images collected from 189 whole slides without human intervention. Sensitivity and specificity were 98.4% and 75.0% for Gram-positive cocci in chains and pairs, 93.2% and 97.2% for Gram-positive cocci in clusters, and 96.3% and 98.1% for Gram-negative rods. Taken together, our data support a proof of concept for a fully automated classification methodology for blood-culture Gram stains. Importantly, the algorithm was highly adept at identifying image crops with organisms and could be used to present prescreened, classified crops to technologists to accelerate smear review. This concept could potentially be extended to all Gram stain interpretive activities in the clinical laboratory.

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