scholarly journals Investigation of Antimicrobial Susceptibility in Enterobacteriaceae Species Isolated From Blood Cultures

ANKEM Dergisi ◽  
2020 ◽  
Author(s):  
Tuğba Kula Atik ◽  
Berrin Uzun
2020 ◽  
Vol 75 (11) ◽  
pp. 3218-3229
Author(s):  
Stefano Mancini ◽  
Elias Bodendoerfer ◽  
Natalia Kolensnik-Goldmann ◽  
Sebastian Herren ◽  
Kim Röthlin ◽  
...  

Abstract Background Rapid antimicrobial susceptibility testing (RAST) of bacteria causing bloodstream infections is critical for implementation of appropriate antibiotic regimens. Objectives We have established a procedure to prepare standardized bacterial inocula for Enterobacterales-containing clinical blood cultures and assessed antimicrobial susceptibility testing (AST) data generated with the WASPLabTM automated reading system. Methods A total of 258 blood cultures containing Enterobacterales were examined. Bacteria were enumerated by flow cytometry using the UF-4000 system and adjusted to an inoculum of 106 cfu/mL. Disc diffusion plates were automatically streaked, incubated for 6, 8 and 18 h and imaged using the fully automated WASPLabTM system. Growth inhibition zones were compared with those obtained with inocula prepared from primary subcultures following the EUCAST standard method. Due to time-dependent variations of the inhibition zone diameters, early AST readings were interpreted using time-adjusted tentative breakpoints and areas of technical uncertainty. Results and conclusions Inhibition zones obtained after 18 h incubation using an inoculum of 106 cfu/mL prepared directly from blood cultures were highly concordant with those of the EUCAST standard method based on primary subcultures, with categorical agreement (CA) of 95.8%. After 6 and 8 h incubation, 89.5% and 93.0% of the isolates produced interpretable results, respectively, with CA of >98.5% and very low numbers of clinical categorization errors for both the 6 h and 8 h readings. Overall, with the standardized and automated RAST method, consistent AST data from blood cultures containing Enterobacterales can be generated after 6–8 h of incubation and subsequently confirmed by standard reading of the same plate after 18 h.


Author(s):  
Mokshanand Fhooblall ◽  
Fikile Nkwanyana ◽  
Koleka P. Mlisana

Background: There are presently many non-culture-based methods commercially available to identify organisms and antimicrobial susceptibility from blood culture bottles. Each platform has its benefits and limitations. However, there is a need for an improved system with minimal hands-on requirements and short run times.Objectives: In this study, the performance characteristics of the FilmArray® BCID Panel kit were evaluated to assess the efficiency of the kit against an existing system used for identification and antimicrobial susceptibility of organisms from blood cultures.Methods: Positive blood cultures that had initially been received from hospitalised patients of a large quaternary referral hospital in Durban, South Africa were processed as per routine protocol at its Medical Microbiology Laboratory. Positive blood cultures were processed on the FilmArray BCID Panel kit in parallel with the routine sample processing. Inferences were then drawn from results obtained.Results: Organism detection by the FilmArray BCID panel was accurate at 92.6% when organisms that were on the repertoire of the kit were considered, compared to the combination methods (reference method used in the study laboratory). Detection of the antimicrobial resistance markers provided by the panel and reference method demonstrated 100% consistency. Blood cultures with a single organism were accurately identified at 93.8% by FilmArray, while blood cultures with more than one organism were identified at 85.7%.Conclusion: The FilmArray BCID Panel kit is valuable for detection of organisms and markers of antibiotic resistance for an extensive range of organisms.


2019 ◽  
Author(s):  
FRANK CHINOWAITA ◽  
Wendy Chaka ◽  
Tinashe K Nyazika ◽  
Tendai C Maboreke ◽  
Inam Chitsike ◽  
...  

Abstract Introduction: Cancer and sepsis comorbidity is a major public health problem in most parts of the world including Zimbabwe. The microbial aetiologies of sepsis and their antibiograms vary with time and locations. Knowledge on local microbial aetiologies of sepsis and their susceptibility patterns is critical in guiding empirical antimicrobial treatment choices. Methods: This was a descriptive cross sectional study which determined the microbial aetiologies of sepsis from blood cultures of paediatric and adult cancer patients obtained between July 2016 and June 2017. The TDR-X120 blood culture system and TDR 300B auto identification machine were used for incubation of blood culture bottles and identification plus antimicrobial susceptibility testing, respectively. Results: A total of 142 participants were enrolled; 50 (35.2%) had positive blood cultures with 56.0% gram positive, 42.0% gram negative bacteria and 2.0% yeast isolates. Most common isolates were Coagulase Negative Staphylococcus (CoNS) (22.0%), Escherichia coli (16.0%), Klebsiella pneumoniae (14.0%), Enterococcus faecalis (14.0%) and Staphylococcus aureus (8.0%) in all cancer patients. These isolates were similar in both haematological and solid cancers. Amikacin and meropenem showed 85.7% and 95.2% activity respectively against all gram negative isolates while vancomycin and linezolid were effective against 96.2% and 100.0% of all gram positive isolates respectively. Ten (66.7%) isolates of E. coli and K. pneumoniae were extended spectrum β-lactamase (ESBL) positive and the same proportion was observed on methicillin resistance among Staphylococcus species. Conclusions: The major microbial aetiologies of sepsis among patients with cancer in Zimbabwe were CoNS, E. coli, K. pneumoniae, E. faecalis and S. aureus. Most isolates were resistant to commonly used empirical antibiotics and there was high level of ESBL and methicillin resistance carriage. A nationwide survey on microbial aetiologies of sepsis and their susceptibility patterns would assist in the guidance of effective sepsis empiric antimicrobial treatment among patients with cancer.


2019 ◽  
Vol 38 (9) ◽  
pp. 1665-1670 ◽  
Author(s):  
Carlos Sánchez-Carrillo ◽  
Paula Pescador ◽  
Rosa Ricote ◽  
Julia Fuentes ◽  
Carmen Losada ◽  
...  

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