scholarly journals Epidemiology and Risk Factors for Carbapenem-Resistant Klebsiella Pneumoniae and Subsequent MALDI-TOF MS as a Tool to Cluster KPC-2-Producing Klebsiella Pneumoniae, a Retrospective Study

2020 ◽  
Vol 10 ◽  
Author(s):  
Lili Fang ◽  
Heping Xu ◽  
Xiaoying Ren ◽  
Xun Li ◽  
Xiaobo Ma ◽  
...  
Keyword(s):  
Risk Factors ◽  
Retrospective Study ◽  
Klebsiella Pneumoniae ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Carbapenem Resistant ◽  
Tof Ms

scholarly journals Overestimated discriminatory power of MALDI-TOF mass spectrometry for typing of carbapenem-resistant Klebsiella pneumoniae clones

2019 ◽  
Vol 147 ◽  
Author(s):  
Fei Jiang ◽  
Ziyan Kong ◽  
Chen Cheng ◽  
Haiquan Kang ◽  
Bing Gu ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Taxonomic Diversity ◽  
Discriminatory Power ◽  
Adjusted Rand Index ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Carbapenem Resistant ◽  
Typing Methods ◽  
Sequence Types ◽  
Tof Ms

Abstract Homology surveillance of carbapenem-resistant Klebsiella pneumoniae (CRKP) is critical to monitor and prevent outbreaks of nosocomial infections. In the present study, a matrix-assisted laser desorption/ionisation-time of flight (MALDI-TOF MS)-based method was evaluated as a rapid tool for typing CRKP in comparison with pulsed-field gel electrophoresis (PFGE) and multi locus sequence typing (MLST). Drug-resistant phenotypes and genotypes of 44 CRKP isolates were detected by microdilution broth method and polymerase chain reaction, and typed by PFGE, MLST and MALDI-TOF MS. Simpson's Index of Diversity was used to evaluate taxonomic diversity, Adjusted Rand Index (ARI) for congruence between the typing methods and Wallace coefficients (W) for the ability of either method to predict each other. Forty-four CRKP isolates of 15 sequence types (STs) produced either NDM-1 (n = 16), NDM-5 (n = 9) or KPC-2 (n = 19) carbapenemases. PFGE differentiated these isolates into 16 distinct types, and two deoxyribonucleic acid profiles were assigned to ST337 and ST11, respectively. MALDI-TOF MS failed to clearly delineate between clusters on dendrograms based on principal components analysis and main spectrum profile. The chosen parameters resulted in a maximum ARI of 0.310 (95% CI 0.088–0.531) between MALDI-TOF MS typing and the PFGE reference, indicating a low ability of the former to correctly identify related isolates. Likewise, the maximum W coefficient of 0.367 (95% CI 0.203–0.532) showed that MALDI-TOF MS had a lower predictive power than PFGE. We conclude that MALDI-TOF MS lacks the discriminatory power necessary for clone assignment of CRKP isolates and consequently cannot be considered as a rapid and creditable method for this purpose.

scholarly journals High index of suspicion for brucellosis in a highly cosmopolitan city in southern China

2019 ◽  
Author(s):  
Hai-Yan Ye ◽  
Fan-Fan Xing ◽  
Jin Yang ◽  
Simon Kam-Fai Lo ◽  
Ricky Wing-Tong Lau ◽  
...  
Keyword(s):  
Risk Factors ◽  
Southern China ◽  
Clinical Specimen ◽  
Guangdong Province ◽  
Human Brucellosis ◽  
Brucella Strain ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Chest Wall Abscess ◽  
Tof Ms

Abstract Background: Brucellosis is one of the most widespread zoonosis in the world. In China, 90% of human brucellosis occurs in six northern agricultural provinces. However, there is a recent increase in the trend of human brucellosis in southern provinces with limited cases reported in the literature. Our study aims to describe the clinical features and epidemiology of brucellosis in a tertiary hospital in southern China. Methods: A retrospective case series of brucellosis was conducted between January 1, 2014 and October 31. 2018. Cases were identified based on positive Brucella serology by tube agglutination test, or positive culture from clinical specimen identified by Vitek 2 and MALDL-TOF MS. Clinical details of brucellosis including patients’ occupation, risk factors, and complications were analyzed. Clinical characteristics between patients from Guangdong and other provinces were also compared. Results: A total of 13 cases of laboratory-confirmed brucellosis were identified. 7 (53.8%) of the patients were male, 6 (46.2%) were female, with age ranging from 29 to 73 years old (median age: 51 years). Five patients (38.5%) were from Guangdong province, while the remaining patients (61.5%) were from other provinces. The commonest risk factors of acquisition were consumption of undercooked meat and goat placenta. Patients from Guangdong province were found to be more likely to have prior placenta consumption and handling of animal meat. The commonest clinical presentations were fever, osteoarticular pain, urinary symptoms, splenomegaly, and lymphadenopathy. Spondylodiscitis/ peripheral joint arthritis (5 patients, 38.5%) was the most prevalent complication, while extra-osteoarticular complications including abdominal aortitis, hepatosplenic abscess, chest wall abscess, and epididymo-orchitis were observed in 4 other patients. Furthermore, it was demonstrated that MALDI-TOF MS is reliable in Brucella identification after additional of reference spectra with standard Brucella strain. Conclusions: Brucellosis, previously thought to be only found in northern China, is now increasingly seen in highly cosmopolitan part of southern China. MALDI-TOF MS in hospitals in China should include reference spectra with standard Brucella strain to aid bacterial identification in routine clinical practice. In addition to tuberculosis, typhoid fever and typhus, brucellosis should be considered in patients with fever of unknown origin in this locality.

scholarly journals 2155. Accelerated Confirmation of Porin Loss in Carbapenem-Resistant Enterobacterales: A MALDI-TOF Mass Spectrometry-Based Approach

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S731-S731
Author(s):  
Carlos Correa-Martinez ◽  
Evgeny A Idelevich ◽  
Karsten Becker
Keyword(s):  
Mass Spectrometry ◽  
Molecular Weight ◽  
Gold Standard ◽  
Sodium Dodecylsulfate ◽  
Resistant Bacteria ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Carbapenem Resistant ◽  
Sds Page ◽  
Tof Ms

Abstract Background The accurate identification of carbapenem resistance mechanisms is decisive for the appropriate selection of antibiotic regimens. Numerous methods can detect carbapenemase-producing carbapenem-resistant bacteria (CPCR). However, non-CPCR (NCPCR) are routinely assumed to display porin loss as a diagnosis of exclusion. No further confirmatory tests are performed since the gold standard (sodium dodecylsulfate polyacrylamide gel electrophoresis, SDS–PAGE) is laborious and time consuming. We propose a test for rapid and easy detection of porin loss by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Methods Clinical meropenem-resistant Enterobacterales strains (10 CPCR, 10 NCPCR) and control strains recommended by EUCAST (5 carbapenemase-producing, one with porin loss, one-negative control) were analyzed. Membrane proteins were extracted by successive centrifugation of bacterial suspensions (McFarland 0.5) and addition of ethanol, formic acid and acetonitrile. MALDI-TOF MS of the protein extracts was performed on a 96-spot target (Bruker Daltonics, Germany). Peaks between 35 and 40 kDa were analyzed for the presence of porins and compared with the bands observed in the SDS–PAGE of the protein extracts. Results Within the molecular weight range of 35–40 kDa, the MALDI-TOF MS-based method revealed peaks in all CPCR isolates corresponding to those observed in the carbapenemase-producing control strains. In contrast, the control strain with porin loss as well as all CNCR isolates showed a lower quantity of peaks in this range. All peaks observed correlated with the bands observed in the SDS–PAGE of the protein extracts at the corresponding molecular weight (Figure 1). Conclusion Yielding results that reliably correspond to the current gold standard, we propose a method for accelerated detection of porin loss as an alternative to the diagnosis of exclusion usually made in routine settings. With a processing time of approximately 20 minutes, the method can be easily implemented in the clinical setting. Applying this MALDI-TOF MS-based approach, valuable information will be provided about a resistance mechanism that otherwise remains unexplained. Disclosures All authors: No reported disclosures.

scholarly journals Occurrence of the p019 gene in the blaKPC-harbouring plasmids: adverse clinical impact for direct tracking of KPC-producing Klebsiella pneumoniae by MALDI-TOF MS

2021 ◽  
Author(s):  
Eva Gato ◽  
Ignacio Pedro Constanso ◽  
Bruno Kotska Rodiño-Janeiro ◽  
Paula Guijarro-Sánchez ◽  
Tyler Alioto ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Computational Analysis ◽  
Direct Detection ◽  
Clinical Impact ◽  
Mass Peak ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Direct Tracking ◽  
Geographical Locations ◽  
Tof Ms

MALDI-TOF MS has recently been used for the direct detection of KPC-producing isolates by analysis of the 11,109 Da mass peak representing the P019 protein. In this study we evaluate the presence of the 11,109 Da mass peak in a collection of 435 unduplicated K. pneumoniae clinical isolates. The prevalence of the P019 peak in the blaKPC K. pneumoniae isolates was 49.2% (32/65). The 11,109 Da mass peak was not observed in any of the other carbapenemase (319) or non carbapenemase producers (116). Computational analysis of the presence of the p019 gene was performed in the aforementioned carbapenemase-producing K. pneumoniae isolates fully characterized by WGS and in a further collection of 1,649 K. pneumoniae genomes included in EuSCAPE. Herein, we have demonstrated that the p019 gene is not exclusively linked to the pKpQil plasmid, but it is present in the following plasmids: IncFIB(K)/IncFII(K)/ColRNAI, IncFIB(pQil), IncFIB(pQil)/ColRNAI, IncFIB(pQil)/IncFII(K), IncFIB(K)/IncFII(K) and IncX3. Besides, we have proven the independent movement of the Tn4401 and the ISKpn31, of which the p019 gene is a component. The absence of the p019 gene was obvious in Col440I, Col(pHAD28), IncFIB(K)/IncX3/IncFII(K), IncFIB(K)/IncFII(K) plasmids. In addition, we also observed another plasmid in which neither Tn4401 nor ISKpn31 was found, IncP6. In the EuSCAPE, the occurrence of p019 varied from 0% to 100% among the different geographical locations. The adverse clinical impact of the diminished prevalence of the p019 gene within the plasmid encoding KPC-producing Klebsiella pneumoniae puts forward the need for reconsideration when applying this technique in a clinical setting.

scholarly journals High index of suspicion for brucellosis in a highly cosmopolitan city in southern China

2019 ◽  
Author(s):  
Hai-Yan Ye ◽  
Fan-Fan Xing ◽  
Jin Yang ◽  
Simon Kam-Fai Lo ◽  
Ricky Wing-Tong Lau ◽  
...  
Keyword(s):  
Risk Factors ◽  
Southern China ◽  
Clinical Specimen ◽  
Case Series ◽  
Guangdong Province ◽  
Human Brucellosis ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Chest Wall Abscess ◽  
Tof Ms

Abstract Background: Brucellosis is one of the most widespread zoonosis in the world. In China, 90% of human brucellosis occurs in six northern agricultural provinces. However, there is a recent increase in the trend of human brucellosis in southern provinces with limited cases reported in the literature. Our study aims to describe the clinical features and epidemiology of brucellosis in a tertiary hospital in southern China. Methods: A retrospective case series of brucellosis was conducted between January 1, 2014 and October 31. 2018. Cases were identified based on positive Brucella serology by tube agglutination test, or positive culture from clinical specimen identified by Vitek 2 and MALDL-TOF MS. Clinical details of brucellosis including patients’ occupation, risk factors, and complications were analyzed. Clinical characteristics between patients from Guangdong and other provinces were also compared. Results: A total of 13 cases of laboratory-confirmed brucellosis were identified. 7 (53.8%) of the patients were male, 6 (46.2%) were female, with age ranging from 29 to 73 years old (median age: 51 years). 5 patients (38.5%) were from Guangdong province, while the remaining patients (61.5%) were from other provinces. The commonest risk factors of acquisition were consumption of undercooked meat and goat placenta. Patients from Guangdong province were found to be more likely to have prior placenta consumption. The commonest clinical presentations were fever, osteoarticular pain, urinary symptoms, splenomegaly, and lymphadenopathy. Spondylodiscitis/ peripheral joint arthritis (5 patients, 38.5%) was the most prevalent complication, while extra-osteoarticular complications including abdominal aortitis, hepatosplenic abscess, chest wall abscess, and epididymo-orchitis were observed in 4 other patients. Furthermore, it was demonstrated that MALDI-TOF MS is reliable in Brucella identification after additional of reference spectra with standard Brucella strain.Conclusions: Brucellosis, previously thought to be only found in northern China, is now increasingly seen in highly cosmopolitan part of southern China. MALDI-TOF MS in hospitals in China should include reference spectra with standard Brucella strain to aid bacterial identification in routine clinical practice. In addition to tuberculosis, typhoid fever and typhus, brucellosis should be considered in patients with fever of unknown origin in this locality.

scholarly journals Application of MALDI-TOF MS to assess clinical characteristics, risk factors, and outcomes associated with anaerobic bloodstream infection: a retrospective observational study

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Tsuyoshi Watanabe ◽  
Yuki Hara ◽  
Yusuke Yoshimi ◽  
Waka Yokoyama-kokuryo ◽  
Yoshiro Fujita ◽  
...  
Keyword(s):  
Risk Factors ◽  
Hospital Mortality ◽  
Multivariate Logistic Regression Analysis ◽  
Bloodstream Infections ◽  
Gram Positive ◽  
Accurate Identification ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Independent Risk Factors ◽  
Tof Ms

Abstract Background Correctly identifying anaerobic bloodstream infections (BSIs) is difficult. However, a new technique, matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), enables more accurate identification and appropriate treatment. Anaerobic BSIs identified by MALDI-TOF MS were retrospectively analyzed to determine the clinical and microbiological features and patient outcomes based on the anaerobic genera or group. Methods Medical records of patients with anaerobic BSIs were used to conduct a single-center retrospective cohort study from January 2016 to December 2020 in Nagoya, Japan. Multivariate logistic regression analysis was performed to determine the independent risk factors for in-hospital mortality. Results Of the 215 patients with anaerobic BSIs, 31 had multiple anaerobic organisms in the blood culture, including 264 total episodes of anaerobic BSIs. Bacteroides spp. were isolated the most (n = 74), followed by gram-positive non-spore-forming bacilli (n = 57), Clostridium spp. (n = 52), gram-positive anaerobic cocci (GPAC) (n = 27), and gram-negative cocci (n = 7). The median patient age was 76 years; 56.7% were male. The most common focal infection site was intra-abdominal (36.7%). The in-hospital mortality caused by anaerobic BSIs was 21.3%, and was highest with Clostridium spp. (36.5%) and lowest with GPAC (3.7%). Age, solid tumors, and Clostridium spp. were independent risk factors for in-hospital mortality. Conclusions We identified current anaerobic BSI trends using MALDI-TOF MS and reported that mortality in patients with anaerobic BSIs patients was highest with Clostridium spp. infections.

scholarly journals An improved MALDI-TOF MS data analysis pipeline for the identification of carbapenemase-producing Klebsiella pneumoniae

2021 ◽  
Author(s):  
Eva Gato ◽  
Ignacio Pedro Constanso ◽  
Ana Candela ◽  
Fátima Galán ◽  
Bruno Kotska Rodiño-Janeiro ◽  
...  
Keyword(s):  
Data Analysis ◽  
Klebsiella Pneumoniae ◽  
Operating Procedure ◽  
Standard Operating Procedure ◽  
Resistant Bacteria ◽  
Analysis Pipeline ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Data Analysis Pipeline ◽  
Tof Ms

The increasing emergence of carbapenemase-producing Klebsiella pneumoniae (CPK) is a global health alarm. Rapid methods that require minimum sample preparation and rapid data analysis are urgently required. MALDI-TOF MS has recently been used by clinical laboratories for identification of antibiotic resistant bacteria; however, discrepancies have arisen regarding biological and technical issues. The aim of this study was to standardize an operating procedure and data analysis for identification of CPK by MALDI-TOF MS. To evaluate this approach, a series of 162 K. pneumoniae (112 CPK and 50 non CPK), were processed in the MALDI BioTyper system (Bruker Daltonik, Germany) following a standard operating procedure. The study was conducted in two stages, the first denominated the “Reproducibility stage” and the second, “CPK identification”. The first stage was designed to evaluate the biological and technical variation associated with the entire analysis of CPK and the second stage, to assess the final accuracy of MALDI-TOF for the identification of CPK. Therefore, we present an improved MALDI-TOF MS data analysis pipeline using neural network analysis implemented in Clover MS data analysis software (Clover Biosoft, Spain), that is designed to reduce variability, guarantee inter-laboratory reproducibility and maximize the information selected from the bacterial proteome. Using the Random Forest (RF) algorithm, 100% of CPK producing isolates were correctly identified when all the peaks in the spectra were selected as input features and TIC normalization was applied. Thus, we have demonstrated that real-time direct tracking of CPK is possible using MALDI-TOF MS.

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