scholarly journals MALDI-TOF MS for rapid detection and differentiation between Tet(X)-producers and non-Tet(X)-producing tetracycline-resistant Gram-negative bacteria

Virulence ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 77-88
Author(s):  
Zi-Jian Zheng ◽  
Ze-Hua Cui ◽  
Qiu-Yue Diao ◽  
Xin-Qing Ye ◽  
Zi-Xing Zhong ◽  
...  
2015 ◽  
pp. 83 ◽  
Author(s):  
Atqah AbdulWahab ◽  
Saad Taj-Aldeen ◽  
Emad B. ibrahim ◽  
Eman Talaq ◽  
Marawan Abu-Madi ◽  
...  

Author(s):  
T. V. Priputnevich ◽  
A. R. Melkumyan ◽  
L. A. Lyubasovskaya ◽  
V. V. Muravieva ◽  
E. N. Ilina ◽  
...  

Aim. Comparative evaluation of species identification of microorganisms by MALDI-TOF mass-spectrometry and automatic biochemical analyzer VITEK2 Compact30. Materials and methods. Species identification of18 400 isolates of microorganisms (staphylococci, streptococci, enterococci, enterobacteria, nonfermenting gram-negative bacteria, lactobacilli, anaerobes, yeast fungi, neisseriae), isolated from vagina of pregnant and non-pregnant women and from newborns, was carried out. Identification of the isolated microorganisms was carried out by automatic bac-teriologic analyzer VITEK2 Compact30 (BioMerieux, France) and MALDI-TOF-MS analysis method on AutoflexIII (Bruker Daltonics, Germany) mass-spectrometer. Results. Comparative identification of 2005 isolates of microorganisms was carried out. Sequencing of ribosomal RNA was used as a reference method. Authenticity of species identification my MALDI-TOF-MS analysis method was: for staphylococci (95.8%), enterococci (97.5%), enterobacteria (98.4%), nonfermenting gram-negative bacteria (93.6%), P-hemolytic staphylococci (93.8%), lactobacilli (92.8%), yeast fungi (99.9%). Conclusion. Introduction of MALDI-TOF-MS analysis technology into practical work of microbiological laboratories exceeds previously used methods of microbiological testing in terms of speed, cost and authenticity of identification of a wide spectrum of microorganisms.


2018 ◽  
Vol 151 (2) ◽  
pp. 143-153
Author(s):  
Seon Young Kim ◽  
Jeong Su Park ◽  
Yun Ji Hong ◽  
Taek Soo Kim ◽  
Kiho Hong ◽  
...  

2019 ◽  
Vol 8 (3) ◽  
pp. 83-90
Author(s):  
Homrani Mounia ◽  
Dalache Fatiha ◽  
Bouzouina Mohammed ◽  
Nemmiche Said ◽  
Homrani AbdelKader

This study reports the isola on of Lactobacilli from Four (n=04) typical Apis Mellifeca raw honey samples collected from different regions in Algeria and the evalua on of their an bacterial ac vi es against Gram-negative bacteria. The isolation of Lactobacilli was performed using different media. Isolates were identified  firrstly by catalase test, Gram staining and cells morphology, and confirmed by MALDI-TOF-MS. An bacterial activities of Bacterial cultures of selected Lactobacilli and their cell free supernatants were tested by agar spot assays and agar well diffusion assay. A total of eighteen (n=18) bacteria isolated from honey samples were presump vely iden ed as Lac- tobacillus spp. based on their posi ve Gram reactions, absence of catalase and their rod shape. MALDI-TOF MS iden ca on confirmed that all isolates were classified as Lactobacillus genus, but the results for their species were inconclusive with uncertainty between, Lactobacillus pentosus, Lactobacillus plantarum and Lactobacillus paraplantarum. Isolates exhibited an microbial activity with inhibition zone diameters ranging from 11 ± 1.41 mm to 17.5 ± 0.71 mm. 6 on 11 Lactobacilli Supernatants demonstrated inhibitory ac vity against all target bacteria. This study reveals the existence of Lactobacilli in Algerian raw Honeys. These Lactobacilli possess an bacterial properties against Gram-negative bacteria, often responsible of human infections, and can be a favorable substitute to antibiotics.


2022 ◽  
Vol 82 ◽  
Author(s):  
Y. M. Davies ◽  
L. S. Franco ◽  
F. B. Barbosa ◽  
C. L. Vanin ◽  
V. T. M. Gomes ◽  
...  

Abstract Microbiological studies of the sanitary and health status of psittacine birds that will be reintroduced is important in evaluating whether these animals act as carriers of pathogenic agents to other animals and humans. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a faster and more accurate method to identify bacteria than conventional microbiology methods. The aim of this study was to evaluate the health status of psittacines housed in captivity, by assessment of Gram-negative bacteria from fecal microbiota through MALDI- TOF MS identification. The results indicate high frequency of Gram-negative bacteria in feces (96.5%), especially from the Enterobacteriaceae family (88.7%). The most prevalent bacteria were Escherichia coli (39.0%), Proteus vulgaris (12.2%), Klebsiella spp. (12.1%) and Raoultella ornithinolytica (8.7%). Proteus hauseri, Citrobacter spp., Morganella morgannii, Providencia rettgeri, Enterobacter spp. and Escherichia hermannii were isolated with lower frequency. . All these agents are potentially pathogenic for parrots and can cause systemic infections in other animals and humans. These findings reinforce that MALDI- TOF MS proved to be a rapid and accurate method of identification of the microorganism and evaluation of the health status of psittacines, providing relevant data to assist decision-making regarding the sanitary protocols in wildlife centers, and possible future reintroduction of wild birds.


2019 ◽  
Vol 57 (8) ◽  
pp. 1271-1279 ◽  
Author(s):  
Maximilian Kittel ◽  
Peter Findeisen ◽  
Beniam Ghebremedhin ◽  
Thomas Miethke ◽  
Alexander Grundt ◽  
...  

Abstract Background The increasing number of multi-drug resistant (MDR) bacteria provides enormous challenges for choosing an appropriate antibiotic therapy in the early phase of sepsis. While bacterial identification has been greatly accelerated by the introduction of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), the antibiotic susceptibility testing (AST) remains time-consuming. Here, we present a rapid susceptibility testing method for testing Gram-negative bacteria, exemplarily validated for Escherichia coli and Klebsiella spp. Methods Gram-negative isolates (E. coli and Klebsiella spp.) were either taken as single colonies from agar plates (n=136) or directly extracted and identified from positive blood cultures (n=42) using MALDI-TOF MS. Bacteria were incubated in glucose-supplemented Luria broths (LBs) each containing one antibiotic (ceftazidime, piperacillin, imipenem and ciprofloxacin), routinely used to classify Gram-negative bacteria in Germany. To determine susceptibility the dynamics of glucose utilization in bacterial suspensions were quantitatively measured in the presence or absence of antibiotics designated liquid-AST (L-AST). Results The L-AST can be run on clinical-chemistry analyzers and integrated into laboratory routines. It yields critical resistance information within 90–150 min downstream of a MS-based identification. The results showed a high concordance with routine susceptibility testing, with less than 1% very major errors (VME) and 3.51% major errors (ME) for 178 assessed isolates. Analysis of turnaround time (TAT) for 42 clinical samples indicated that L-AST results could be obtained 34 h earlier than the routine results. Conclusions As exemplified for E. coli and Klebsiella spp., L-AST provides substantial acceleration of susceptibility testing following MALDI-TOF MS identification. The assay is a simple and low-cost method that can be integrated into clinical laboratory to allow for 24/7 AST. This approach could improve antibiotic therapy.


2018 ◽  
Vol 159 (1) ◽  
pp. 23-30
Author(s):  
Emese Juhász ◽  
Miklós Iván ◽  
Júlia Pongrácz ◽  
Katalin Kristóf

Abstract: Introduction: Glucose non-fermenting Gram-negative bacteria are ubiquitous environmental organisms. Most of them are identified as opportunistic, nosocomial pathogens in patients. Uncommon species are identified accurately, mainly due to the introduction of matrix-assisted laser desorption-ionization time of flight mass spectrometry (MALDI-TOF MS) in clinical microbiology practice. Most of these uncommon non-fermenting rods are isolated from lower respiratory tract samples. Their significance in lower respiratory tract infections, such as rules of their testing are not clarified yet. Aim: The aim of this study was to review the clinical microbiological features of these bacteria, especially their roles in lower respiratory tract infections and antibiotic treatment options. Method: Lower respiratory tract samples of 3589 patients collected in a four-year period (2013–2016) were analyzed retrospectively at Semmelweis University (Budapest, Hungary). Identification of bacteria was performed by MALDI-TOF MS, the antibiotic susceptibility was tested by disk diffusion method. Results: Stenotrophomonas maltophilia was revealed to be the second, whereas Acinetobacter baumannii the third most common non-fermenting rod in lower respiratory tract samples, behind the most common Pseudomonas aeruginosa. The total number of uncommon non-fermenting Gram-negative isolates was 742. Twenty-three percent of isolates were Achromobacter xylosoxidans. Beside Chryseobacterium, Rhizobium, Delftia, Elizabethkingia, Ralstonia and Ochrobactrum species, and few other uncommon species were identified among our isolates. The accurate identification of this species is obligatory, while most of them show intrinsic resistance to aminoglycosides. Resistance to ceftazidime, cefepime, piperacillin-tazobactam and carbapenems was frequently observed also. Conclusions: Ciprofloxacin, levofloxacin and trimethoprim-sulfamethoxazole were found to be the most effective antibiotic agents. Orv Hetil. 2018; 159(1): 23–30.


Sign in / Sign up

Export Citation Format

Share Document