scholarly journals Rapid diagnostic susceptibility testing of bacteria and fungi from clinical samples using silicon gratings

2019 ◽  
Author(s):  
Heidi Leonard ◽  
Christopher Heuer ◽  
Daniel Weizmann ◽  
Naama Massad-Ivanir ◽  
Sarel Halachmi ◽  
...  
Keyword(s):  
Susceptibility Testing ◽  
Clinical Samples ◽  
Bacteria And Fungi

scholarly journals Phenotypic detection of Carbapenamase among Klebsiella pneumoniae isolated from clinical samples using modified Hodged test

2020 ◽  
Vol 13 (3) ◽  
pp. 135-140
Author(s):  
HauwaYakubu ◽  
Mahmud Yerima Iliyasu ◽  
Asma’u Salisu ◽  
Abdulmumin Ibrahim Sulaiman ◽  
Fatima Tahir ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Susceptibility Testing ◽  
University Teaching ◽  
Diffusion Method ◽  
Clinical Samples ◽  
Beta Lactam ◽  
Beta Lactamases ◽  
Beta Lactam Antibiotics ◽  
Microbiological Techniques ◽  
Tract Infections

Carbapenemases are microbial enzymes that confer resistance to virtually all available beta-lactam antibiotics and the most frequent carbapenemases are the Klebsiella pneumoniae Carbapenamase (KPC). Detection of carbapenemases is a significant infection control strategy as the enzymes are often associated with extensive antimicrobial resistance, therapeutic failures and mortality associated with infectious diseases. A total of 400 clinical samples were collected from different groups of patients in Abubakar Tafawa Balewa University Teaching Hospital, Bauchi, Nigeria and 118 K. pneumoniae were isolated using standard microbiological techniques. The isolates were subjected to antibiotic susceptibility testing by Kirby-Bauer disc diffusion method, then screened for Carbapenamase production using modified Hodge test. The results indicated that the isolates were resistant to Ampicillin (61.9%), Ceftriaxone (50.8%) and Ceftazidime (50.8%), then Ciprofloxacin (54.2%), but predominantly sensitive to Imipenem (66.9%), Eterpenem (60.2%) and Meropenem (65.3%). It was found that 38 (32.2%) of the isolates phenotypically shows the presence of Carbapenamase, with highest frequency of (40.7%) among patients, mainly adult females with cases of Urinary Tract Infections (UTIs) and the least from wound (11.8%).This study revealed that the isolates produced other beta-lactamases than KPC or variants of Carbapenamase that cannot be detected by modified Hodge test, thus shows low resistance to carbapenems. Therefore further studies is needed to genotypically confirm the presence of KPC in these isolates.

Occurrence of Non-Fermenting Gram-Negative Bacilli and Their In Vitro Susceptibility Pattern by Vitek 2 at a Tertiary Care Teaching Hospital – An Observational Study

2021 ◽  
Vol 8 (8) ◽  
pp. 429-434
Author(s):  
Atit Dineshchandra Shah ◽  
Urvashi Natubhai Limbachia ◽  
Bhavin K. Prajapati ◽  
Lata Patel ◽  
Dharati Tusharbhai Shah ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Multidrug Resistance ◽  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Tertiary Care ◽  
Carbapenem Resistance ◽  
Antimicrobial Susceptibility Testing ◽  
Clinical Samples ◽  
Gram Negative ◽  
Vitek 2

BACKGROUND Non fermenting gram-negative bacilli (NFGNB) are a group of heterogenous, aerobic and non-sporing saprophytic bacteria, found as commensals in humans and other animals primarily causing opportunistic healthcare-associated infections. They are innately resistant to many antibiotics and are known to acquire resistance by various mechanisms. They pose a particular difficulty for the healthcare community because multidrug resistance is common and increasing among them and a number of strains have now been identified that exhibit pan drug resistance. This study was conducted to isolate and identify various non-fermenter gram negative bacilli (NFGNB), to study their antibiotic sensitivity pattern and their clinical significance from various clinical samples. METHODS A study was undertaken from March 2019 to February 2020 to isolate NFGNB from various clinical samples received for culture and sensitivity in the department of microbiology in a tertiary care hospital, Ahmedabad. Non lactose fermenting colonies on MacConkey agar plates were further processed by Vitek 2 to identify them and to study their antimicrobial susceptibility testing (AST). RESULTS A total of 2010 NFGNB were isolated from various clinical samples and their AST was evaluated by Vitek 2. Pseudomonas aeruginosa (52.7 %) and Acinetobacter baumannii (36.5 %) were the most common NFGNB isolated. Carbapenem resistance was 93 % for Acinetobacter species and 61 % for Pseudomonas species. CONCLUSIONS Accurate and rapid identification and antimicrobial susceptibility testing of NFGNB help in early initiation of appropriate antimicrobial therapy and proper management of patients thereby help in reducing emergence of MDR strains of NFGNB, mortality and overall hospital stay. KEYWORDS NFGNB – Non-Fermenting Gram-Negative Bacilli, Multidrug Resistance, Pan Drug Resistance, Carbapenem Resistance

Mixed mould species in laboratory cultures of respiratory specimens: how should they be reported, and what are the indications for susceptibility testing?: Table 1

2011 ◽  
Vol 64 (6) ◽  
pp. 543-545 ◽  
Author(s):  
J Purcell ◽  
J McKenna ◽  
P Critten ◽  
D W Denning ◽  
I A Hassan
Keyword(s):  
Clinical Microbiology ◽  
Susceptibility Testing ◽  
Positive Culture ◽  
Invasive Disease ◽  
Clinical Samples ◽  
Transplant Recipients ◽  
Patient Case ◽  
Tertiary Centre ◽  
Risk Patients ◽  
Respiratory Specimens

AimsTo investigate how clinical microbiology laboratories should report and interpret mixed mould isolates including Aspergillus species from clinical samples and the criteria for susceptibility testing of the isolates.MethodsRetrospectively collected data from our laboratory information system of moulds isolated between January 2005 and December 2007. Patient case notes were also reviewed.ResultsA total of 502 isolates (from 273 patients) were found. 20 patients with clinical diagnosis of a probable fungal infection had mixed Aspergillus species.ConclusionsIn most instances, the isolation of Aspergillus species from non-sterile sites does not represent clinical disease, but only colonisation/contamination. However, for high-risk patients including transplant recipients, a positive culture is associated with invasive disease. Our tertiary centre routinely reports single fungal isolates and mixed cultures with appropriate comments, and those considered significant will also have susceptibility testing carried out. The correlation of culture results with clinical features can differentiate between invasive disease and contamination.

scholarly journals A Biosensor Platform for Rapid Antimicrobial Susceptibility Testing Directly From Clinical Samples

2011 ◽  
Vol 185 (1) ◽  
pp. 148-153 ◽  
Author(s):  
Kathleen E. Mach ◽  
Ruchika Mohan ◽  
Ellen Jo Baron ◽  
Mei-Chiung Shih ◽  
Vincent Gau ◽  
...  
Keyword(s):  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Antimicrobial Susceptibility Testing ◽  
Clinical Samples

scholarly journals Detecting Azole-Antifungal Resistance in Aspergillus fumigatus by Pyrosequencing

2020 ◽  
Vol 6 (1) ◽  
pp. 12 ◽  
Author(s):  
Mireille H. van der Torre ◽  
Lilyann Novak-Frazer ◽  
Riina Rautemaa-Richardson
Keyword(s):  
Dna Sequencing ◽  
Susceptibility Testing ◽  
Simultaneous Detection ◽  
Drug Susceptibility ◽  
Turnaround Time ◽  
Fungal Species ◽  
Antifungal Resistance ◽  
Diagnostic Methods ◽  
Resistance Testing ◽  
Clinical Samples

Guidelines on the diagnosis and management of Aspergillus disease recommend a multi-test approach including CT scans, culture, fungal biomarker tests, microscopy and fungal PCR. The first-line treatment of confirmed invasive aspergillosis (IA) consists of drugs in the azole family; however, the emergence of azole-resistant isolates has negatively impacted the management of IA. Failure to detect azole-resistance dramatically increases the mortality rates of azole-treated patients. Despite drug susceptibility tests not being routinely performed currently, we suggest including resistance testing whilst diagnosing Aspergillus disease. Multiple tools, including DNA sequencing, are available to screen for drug-resistant Aspergillus in clinical samples. This is particularly beneficial as a large proportion of IA samples are culture negative, consequently impeding susceptibility testing through conventional methods. Pyrosequencing is a promising in-house DNA sequencing method that can rapidly screen for genetic hotspots associated with antifungal resistance. Pyrosequencing outperforms other susceptibility testing methods due to its fast turnaround time, accurate detection of polymorphisms within critical genes, including simultaneous detection of wild type and mutated sequences, and—most importantly—it is not limited to specific genes nor fungal species. Here we review current diagnostic methods and highlight the potential of pyrosequencing to aid in a diagnosis complete with a resistance profile to improve clinical outcomes.

scholarly journals 1756. Prediction of Bloodstream Infection Prior to Onset of Symptoms by Plasma Metagenomic Sequencing in Pediatric Patients With Relapsed or Refractory Malignancy (PREDSEQ)

2018 ◽  
Vol 5 (suppl_1) ◽  
pp. S60-S60 ◽  
Author(s):  
Kathryn Goggin ◽  
Yuki Inaba ◽  
Veronica Gonzalez-Pena ◽  
Kim J Allison ◽  
Ka Lok Chan ◽  
...  
Keyword(s):  
High Risk ◽  
Bloodstream Infection ◽  
Pediatric Patients ◽  
Clinical Samples ◽  
Metagenomic Sequencing ◽  
Research Support ◽  
Documented Infection ◽  
Risk Patients ◽  
Bacteria And Fungi ◽  
Refractory Malignancy

Abstract Background Patients undergoing treatment for relapsed or refractory malignancies are at high risk of life-threatening bloodstream infection (BSI). A predictive screening test for BSI might allow pre-emptive therapy, but no validated test is currently available. We tested the hypothesis that plasma metagenomic next generation pathogen sequencing (NGS) would predict BSI before the onset of attributable symptoms. Methods We enrolled 31 pediatric patients receiving for treatment relapsed or refractory malignancy in an IRB-approved prospective cohort study (PREDSEQ) of predictive sequencing. Episodes of febrile neutropenia or documented infection were collected prospectively from the medical record. BSI was defined according to NHSN criteria. Control Samples were defined as samples collected ≥7 clear days before or after any fever or documented infection. Residual clinical samples were stored for NGS; after filtering human sequences, reads were aligned to a curated pathogen database, and organisms above a predefined threshold were reported (Karius Inc., Redwood City, CA). Only bacteria and fungi were included in this analysis. Results A total of 11 BSI episodes occurred in 9 participants (Table 1) during the study period. Predictive sensitivity of NGS in the 2 days before onset of infection (n = 9) was 78% (95% CI 45–94%), and diagnostic sensitivity on the day of infection (n = 11) was 82% (95% CI 52–95%). Specificity of NGS for development of fever or infection within 7 days (n = 16) was 81% (95% CI 57–93%). NGS was positive up to 6 days prior to onset of BSI. In samples collected before or during documented infections, NGS also identified additional bacteria and fungi that were not detected by standard clinical testing. Conclusion Plasma NGS shows promise for the detection of BSI prior to onset of symptoms in high-risk patients. Disclosures K. Goggin, Karius Inc.: Investigator, Research support. K. L. Chan, Karius Inc.: Employee, Salary. D. Hollemon, Karius Inc.: Employee, Salary. A. Ahmed, Karius, Inc.: Employee, Salary. D. Hong, Karius, Inc.: Employee, Salary. R. Hayden, Roche Molecular: Scientific Advisor, Consulting fee. Abbott Molecular: Scientific Advisor, Consulting fee. Quidel: Scientific Advisor, Consulting fee. C. Gawad, Karius Inc.: Investigator, Research support. J. Wolf, Karius Inc.: Investigator, Research support.

scholarly journals A review of the current state of antimicrobial susceptibility test methods for Brachyspira

2017 ◽  
Vol 63 (6) ◽  
pp. 465-474 ◽  
Author(s):  
D.G.R.S. Kulathunga ◽  
J.E. Rubin
Keyword(s):  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Treatment Plan ◽  
Laboratory Data ◽  
Test Methods ◽  
Clinical Samples ◽  
Antimicrobial Susceptibility Test ◽  
Future Directions ◽  
Diagnostic Strategies ◽  
Current State

The re-emergence of swine dysentery (Brachyspira-associated muco-haemorrhagic colitis) since the late 2000s has illuminated diagnostic challenges associated with this genus. The methods used to detect, identify, and characterize Brachyspira from clinical samples have not been standardized, and laboratories frequently rely heavily on in-house techniques. Particularly concerning is the lack of standardized methods for determining and interpreting the antimicrobial susceptibility of Brachyspira spp. The integration of laboratory data into a treatment plan is a critical component of prudent antimicrobial usage. Therefore, the lack of standardized methods is an important limitation to the evidence-based use of antimicrobials. This review will focus on describing the methodological limitations and inconsistencies between current susceptibility testing schemes employed for Brachyspira, provide an overview of what we do know about the susceptibility of these organisms, and suggest future directions to improve and standardize diagnostic strategies.

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