scholarly journals Study on Molecular Profiles of Staphylococcus aureus Strains: Spectrometric Approach

Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 4894
Author(s):  
Michał Złoch ◽  
Paweł Pomastowski ◽  
Ewelina Maślak ◽  
Fernanda Monedeiro ◽  
Bogusław Buszewski
Keyword(s):  
Staphylococcus Aureus ◽  
Culture Conditions ◽  
Strain Typing ◽  
Major Health Problem ◽  
Matrix Type ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Molecular Profiles ◽  
The Impact ◽  
Tof Ms

Staphylococcus aureus remains a major health problem responsible for many epidemic outbreaks. Therefore, the development of efficient and rapid methods for studying molecular profiles of S. aureus strains for its further typing is in high demand. Among many techniques, matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI TOF MS) represents a timely, cost-effective, and reliable strain typing approach, which is still rarely used due to insufficient knowledge about the impact of sample preparation and analysis conditions on the molecular profiles and strain classification efficiency of S. aureus. The aim of this study was to evaluate the effect of the culture conditions and matrix type on the differentiation of molecular profiles of various S. aureus strains via the MALDI TOF MS analysis and different computational methods. The analysis revealed that by changing the culture conditions, matrix type, as well as a statistical method, the differentiation of S. aureus strains can be significantly improved. Therefore, to accelerate the incorporation of the MALDI-based strain typing in routine laboratories, further studies on the standardization and searching of optimal conditions on a larger number of isolates and bacterial species are of great need.

scholarly journals Relationships among intramammary health, udder and teat characteristics, and productivity of extensively managed ewes

2021 ◽  
Vol 99 (4) ◽  
Author(s):  
Ryan M Knuth ◽  
Whitney C Stewart ◽  
Joshua B Taylor ◽  
Bledar Bisha ◽  
Carl J Yeoman ◽  
...  
Keyword(s):  
Future Research ◽  
Morphometric Traits ◽  
Maldi Tof Ms ◽  
Microbial Species ◽  
Maldi Tof ◽  
Microbial Invasion ◽  
Lactation Stage ◽  
The Impact ◽  
Culture Positive ◽  
Tof Ms

Abstract Mastitis is an economically important disease and its subclinical state is difficult to diagnose, which makes mitigation more challenging. The objectives of this study were to screen clinically healthy ewes in order to 1) identify cultivable microbial species in milk, 2) evaluate somatic cell count (SCC) thresholds associated with intramammary infection, and 3) estimate relationships between udder and teat morphometric traits, SCC, and ewe productivity. Milk was collected from two flocks in early (<5 d) and peak (30 to 45 d) lactation to quantify SCC (n = 530) and numerate cultivable microbial species by culture-based isolation followed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS; n = 243) identification. Within flock and lactation stage, 11% to 74% (mean = 36%) of samples were culture positive. More than 50 unique identifications were classified by MALDI-TOF MS analysis, and Bacillus licheniformis (18% to 27%), Micrococcus flavus (25%), Bacillus amyloliquefaciens (7% to 18%), and Staphylococcus epidermidis (26%) were among the most common within flock and across lactation stage. Optimum SCC thresholds to identify culture-positive samples ranged from 175 × 103 to 1,675 × 103 cells/mL. Ewe productivity was assessed as total 120-d adjusted litter weight (LW120) and analyzed within flock with breed, parity, year, and the linear covariate of log10 SCC (LSCC) at early or peak lactation. Although dependent on lactation stage and year, each 1-unit increase in LSCC (e.g., an increase in SCC from 100 × 103 to 1,000 × 103 cells/mL) was predicted to decrease LW120 between 9.5 and 16.1 kg when significant. Udder and teat traits included udder circumference, teat length, teat placement, and degree of separation of the udder halves. Correlations between traits were generally low to moderate within and across lactation stage and most were not consistently predictive of ewe LSCC. Overall, the frequencies of bacteria-positive milk samples indicated that subclinical mastitis (SCM) is common in these flocks and can impact ewe productivity. Therefore, future research is warranted to investigate pathways and timing of microbial invasion, genomic regions associated with susceptibility, and husbandry to mitigate the impact of SCM in extensively managed ewes.

Investigation of the antibiotic resistance of staphylococcus species isolated from foods

2021 ◽  
Vol 67 (2) ◽  
pp. 3372-3382
Author(s):  
Brigitta Horváth ◽  
Ferenc Peles ◽  
Judit Gasparikné Reichardt ◽  
Edit Pocklán ◽  
Rita Sipos ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Methicillin Resistance ◽  
Multidrug Resistant ◽  
Farm Animals ◽  
The European Union ◽  
Methicillin Resistant ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Tof Ms

The presence of methicillin-resistant Staphylococcus aureus (MRSA) strains in the food chain has been confirmed by several studies in the European Union, but there are only limited data available in Hungary. The objective of the present study was to investigate the antibiotic resistance of Staphylococcus strains isolated from foods, using classical microbiological, molecular biological methods and the MALDI-TOF-MS technique, as well as the multi-locus sequence typing (MLST) of antibiotic resistant strains. During the study, 47 coagulase-positive (CPS) and 30 coagulase-negative (CNS) Staphylococcus isolates were collected. In the course of the MALDI-TOF-MS investigations, all CPS isolates (n=47) were found to be S. aureus species, while 8 different species were identified in the case of the CNS strains. Methicillin resistance was confirmed in two S. aureus strains, one of which had a sequence type not yet known, while the other MRSA strain was type ST398, which is the most common type of MRSA strain isolated from farm animals in the EU/EEA. (The abbreviation “MRSA” is often used in common parlance, but occasionally in the literature to denote “multidrug-resistant Staphylococcus aureus”. In the authors’ manuscript - the methicillin-resistant pathogen is correctly designated as such. Ed.)

Élelmiszerekből izolált staphylococcus fajok antibiotikum rezisztencia vizsgálata

2021 ◽  
Vol 67 (2) ◽  
pp. 3361-3371
Author(s):  
Brigitta Horváth ◽  
Ferenc Peles ◽  
Judit Gasparikné Reichardt ◽  
Edit Pocklán ◽  
Rita Sipos ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Tof Ms

A methicillin-rezisztens Staphylococcus aureus (MRSA) törzsek élelmiszerláncban előforduló jelenlétét számos tanulmány igazolta az Európai Unióban, azonban Magyarországon kevés adat áll rendelkezésünkre ezzel kapcsolatban. Jelen vizsgálat célja az élelmiszerekből izolált Staphylococcus törzsek antibiotikum rezisztenciá-jának vizsgálata klasszikus mikrobiológiai, molekuláris biológiai módszerekkel és MALDI-TOF-MS technikával, továbbá az antibiotikum rezisztens törzsek multilókusz szekvencia tipizálása (MLST). A vizsgálat során 47 koaguláz-pozitív (CPS) és 30 koaguláz-negatív Staphylococcus (CNS) izolátumot gyűjtöttünk. A MALDI-TOF-MS vizsgálat során minden CPS izolátum (n=47) S. aureus fajnak bizonyult, míg a CNS törzsek esetében 8 különböző fajt azonosítottunk. Két S. aureus törzs esetében állapítottunk meg methicillin-rezisztenciát, amelyek közül az egyik izolátum eddig még nem ismert szekvencia típusba, míg a másik MRSA törzs az ST398 típusba tartozott, amely a mezőgazdasági haszonállatokból izolált MRSA törzsek leggyakoribb típusa az EU/EGT területén. (Az „MRSA” rövidítést köznapi szóhasználatban, de esetenként a szakirodalomban is gyakran a „multirezisztens Staphylococcus aureus” megjelölésére használják. A szerzők kéziratában - helyesen a methicillin-rezisztens kórokozót jelölik így. A Szerk.)

scholarly journals Characterization of Staphylococcus aureus Isolates From Cases of Clinical Bovine Mastitis on Large-Scale Chinese Dairy Farms

2020 ◽  
Vol 7 ◽  
Author(s):  
Kangjun Liu ◽  
Luyao Tao ◽  
Jianji Li ◽  
Li Fang ◽  
Luying Cui ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cluster Analysis ◽  
Antimicrobial Resistance ◽  
Large Scale ◽  
Bovine Mastitis ◽  
Dairy Farms ◽  
Clinical Mastitis ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Tof Ms

Bovine mastitis is a prevalent disease that causes serious economic problems globally in the dairy industry. Staphylococcus aureus is an important pathogen of bovine mastitis. This study was conducted to characterize S. aureus isolates from clinical bovine mastitis cases in large-scale dairy herds in China. S. aureus was isolated from 624 clinical mastitis cases and confirmed by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). In total, 62 S. aureus isolates were obtained. Cluster analysis, genetic diversity, quantification of biofilm formation, antimicrobial resistance, and detection of virulence genes were performed on these isolates of S. aureus. Eight isolates harbored the mecA gene and were sensitive to oxacillin. MALDI-TOF MS cluster analysis revealed that the 62 isolates were divided into three major clusters (I, II, III) and eight main groups (A–H) at the distance level of 700. The agr II was the most prevalent (56.5%). The 62 S. aureus isolates were assigned to seven spa types. The most common spa type was t529(58.1%), followed by t2196 (14.5%), t518 (14.5%), t571(6.5%), t034 (3.2%), t2734 (1.6%), and t730 (1.6%). Five STs were identified from seven representative isolates as follows: ST630/CC8, ST97/CC97, ST50, ST398, and ST705. All isolates had the ability to form biofilm. Antimicrobial resistance was most frequently observed to ciprofloxacin (29%), followed by penicillin (24.2%), and streptomycin (9.6%). All isolates harbored the fnbA, clfB (100%), icaA, and icaD genes. This study provides the basis for the development of bovine mastitis prevention program on large-scale dairy farms.

Tracing the pathogen Staphylococcus aureus on laboratory ants using physical preconcentration coupled ZnO nanoparticle assisted MALDI-TOF MS

The Analyst ◽  
2012 ◽  
Vol 137 (2) ◽  
pp. 357-364 ◽  
Author(s):  
Judy Gopal ◽  
Hui-Fen Wu ◽  
Chia-Hsun Lee ◽  
Muthu Manikandan
Keyword(s):  
Staphylococcus Aureus ◽  
Zno Nanoparticle ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Tof Ms

scholarly journals MDRSA: A Web Based-Tool for Rapid Identification of Multidrug Resistant Staphylococcus aureus Based on Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry

2021 ◽  
Vol 12 ◽  
Author(s):  
Chia-Ru Chung ◽  
Zhuo Wang ◽  
Jing-Mei Weng ◽  
Hsin-Yao Wang ◽  
Li-Ching Wu ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Rapid Identification ◽  
Antibiotics Resistance ◽  
Web Tool ◽  
Web Based ◽  
Ionization Time ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Flight Mass Spectrometry ◽  
Tof Ms

As antibiotics resistance on superbugs has risen, more and more studies have focused on developing rapid antibiotics susceptibility tests (AST). Meanwhile, identification of multiple antibiotics resistance on Staphylococcus aureus provides instant information which can assist clinicians in administrating the appropriate prescriptions. In recent years, matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has emerged as a powerful tool in clinical microbiology laboratories for the rapid identification of bacterial species. Yet, lack of study devoted on providing efficient methods to deal with the MS shifting problem, not to mention to providing tools incorporating the MALDI-TOF MS for the clinical use which deliver the instant administration of antibiotics to the clinicians. In this study, we developed a web tool, MDRSA, for the rapid identification of oxacillin-, clindamycin-, and erythromycin-resistant Staphylococcus aureus. Specifically, the kernel density estimation (KDE) was adopted to deal with the peak shifting problem, which is critical to analyze mass spectra data, and machine learning methods, including decision trees, random forests, and support vector machines, which were used to construct the classifiers to identify the antibiotic resistance. The areas under the receiver operating the characteristic curve attained 0.8 on the internal (10-fold cross validation) and external (independent testing) validation. The promising results can provide more confidence to apply these prediction models in the real world. Briefly, this study provides a web-based tool to provide rapid predictions for the resistance of antibiotics on Staphylococcus aureus based on the MALDI-TOF MS data. The web tool is available at: http://fdblab.csie.ncu.edu.tw/mdrsa/.

scholarly journals Staphylococcus aureus and Pseudomonas aeruginosa in Tubotympanic Chronic Suppurative Otitis Media Patients in Purwokerto, Indonesia

2020 ◽  
Vol 12 (4) ◽  
pp. 340-348
Author(s):  
Daniel Joko Wahyono ◽  
Anton Budhi Darmawan ◽  
Leader Alfason ◽  
Reinhard Simbolon ◽  
Siwi Pramatama Mars Wijayanti ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Otitis Media ◽  
Antimicrobial Susceptibility ◽  
Chronic Suppurative Otitis Media ◽  
Molecular Tools ◽  
Suppurative Otitis Media ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Tof Ms

BACKGROUND: Chronic Suppurative Otitis Media (CSOM) causes hearing impairment and frequently occurred in low-income country where medical care and personal hygiene are poor. Staphylococcus aureus and Pseudomonas aeruginosa are the most common cause of CSOM. We investigated prevalence and antimicrobial susceptibility of S. aureus and P. aeruginosa from tubotympanic CSOM patients in tertiary hospital, Purwokerto, Indonesia in 2016-2017.METHODS: Ear swab specimens were collected from patients with tubotympanic CSOM. S. aureus and P. aeruginosa were isolated and identified by culture, matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), and molecular tools. Antimicrobial susceptibility testing was performed using the disk diffusion method.RESULTS: Out of ear swabs from 34 patients with tubotympanic CSOM, P. aeruginosa and S. aureus were identified in 35%patients. No Methicillin-resistant S. aureus (MRSA) strain was found from the ear swabs of the patients with tubotympanic CSOM. Bacterial identification using the MALDI-TOF MS was concordantly with culture and molecular tools. All S. aureus isolates showed full susceptibility to cefoxitin and trimethoprim-sulphamethoxazole. Resistance to tetracycline was common with only 64% of S. aureus strains being susceptible. Meanwhile, all P. aeruginosa strains were susceptible to cefepime, cetazidime, meropenem, gentamicin, and tobramycin.CONCLUSION: S. aureus and P. aeruginosa are found in patients with tubotympanic CSOM and still susceptible to different antibiotic agents. MALDI-TOF MS demonstrate rapid, accurate and robust to detect S. aureus and P. aeruginosa.KEYWORDS: Staphylococcus aureus, Pseudomonas aeruginosa, chronic tubotympanic suppurative otitis media

scholarly journals Mass Spectrometry Proteotyping-Based Detection and Identification of Staphylococcus aureus, Escherichia coli, and Candida albicans in Blood

2021 ◽  
Vol 11 ◽  
Author(s):  
Nahid Kondori ◽  
Amra Kurtovic ◽  
Beatriz Piñeiro-Iglesias ◽  
Francisco Salvà-Serra ◽  
Daniel Jaén-Luchoro ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Candida Albicans ◽  
Blood Cultures ◽  
Blood Samples ◽  
Maldi Tof Ms ◽  
E Coli ◽  
Maldi Tof ◽  
Detection And Identification ◽  
Tof Ms

Bloodstream infections (BSIs), the presence of microorganisms in blood, are potentially serious conditions that can quickly develop into sepsis and life-threatening situations. When assessing proper treatment, rapid diagnosis is the key; besides clinical judgement performed by attending physicians, supporting microbiological tests typically are performed, often requiring microbial isolation and culturing steps, which increases the time required for confirming positive cases of BSI. The additional waiting time forces physicians to prescribe broad-spectrum antibiotics and empirically based treatments, before determining the precise cause of the disease. Thus, alternative and more rapid cultivation-independent methods are needed to improve clinical diagnostics, supporting prompt and accurate treatment and reducing the development of antibiotic resistance. In this study, a culture-independent workflow for pathogen detection and identification in blood samples was developed, using peptide biomarkers and applying bottom-up proteomics analyses, i.e., so-called “proteotyping”. To demonstrate the feasibility of detection of blood infectious pathogens, using proteotyping, Escherichia coli and Staphylococcus aureus were included in the study, as the most prominent bacterial causes of bacteremia and sepsis, as well as Candida albicans, one of the most prominent causes of fungemia. Model systems including spiked negative blood samples, as well as positive blood cultures, without further culturing steps, were investigated. Furthermore, an experiment designed to determine the incubation time needed for correct identification of the infectious pathogens in blood cultures was performed. The results for the spiked negative blood samples showed that proteotyping was 100- to 1,000-fold more sensitive, in comparison with the MALDI-TOF MS-based approach. Furthermore, in the analyses of ten positive blood cultures each of E. coli and S. aureus, both the MALDI-TOF MS-based and proteotyping approaches were successful in the identification of E. coli, although only proteotyping could identify S. aureus correctly in all samples. Compared with the MALDI-TOF MS-based approaches, shotgun proteotyping demonstrated higher sensitivity and accuracy, and required significantly shorter incubation time before detection and identification of the correct pathogen could be accomplished.

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