Modern methods for species identification of thermophilic bacteria of Campylobacter species

2021 ◽  
Vol 1 (11) ◽  
pp. 27-34
Author(s):  
Svetlana A. Makavchik ◽  
◽  
Lubov I. Smirnova ◽  
Aleksandr A. Sukhinin ◽  
Vladimir A. Kuzmin ◽  
...  
Keyword(s):  
Thermophilic Bacteria ◽  
Test Material ◽  
Clinical Samples ◽  
Biological Method ◽  
Chain Reactions ◽  
Defibrinated Horse Blood ◽  
Study Results ◽  
Bacteriological Method ◽  
Causative Agents ◽  
Campylobacter Species

Emergent thermophilic Campylobacter hepaticus is the causative agent of Spotty Liver Disease (SLD) in laying hens. C. hepaticus is difficult to cultivate because commercial media for the isolation and cultivation of Campylobacter contain cefoperazone, which inhibits many isolates of the C. hepaticus species. Campylobacter was isolated using modified Preston broth, incubated at 37 °C under microaerophilic conditions for 7 days and then subcultured onto selective Preston agar, erythritol agar with Oxoid selective additives and 5–7% defibrinated horse blood. Commercial test systems (API Campy) were used for identification. The use of the classical bacteriological diagnostic method, which is considered the 'gold' standard, is limited due to the difficulties of cultivation. The identification of new Campylobacter species requires revision of phenotypic identification algorithms. Specific primers for the identification of new Campylobacter species also need to be developed. In our studies, using the KAM-BAC kit, we detected Campylobacter jejuni DNA in clinically healthy birds. Consequently, the carriage of Campylobacter is massive. 30 samples of test material were examined using the molecular-biological method, and 60 samples using the bacteriological method. Analyzing the results of Campylobacter detection, it should be noted that thermophilic Campylobacteria were isolated from 60 clinical samples by the bacteriological method in 5,0% (3 Campylobacter cultures), and from 30 samples by the molecular-biological method in 27,0% (8 positive samples). Based on the analysis of the study results, it is necessary to conduct an in-depth study of the natural sources of Campylobacter hepaticus distribution, virulence factors, pathogenesis and mechanisms of infections caused by these emergent pathogens. The most promising research in the study of the causative agents of Campylobacteriosis in birds will be based on the application of innovative genomic technologies based on multiplex polymerase chain reactions and genome sequencing of Campylobacter hepaticus.

PATTERNS OF ANTIMICROBIAL RESISTANCE AMONG MAJOR BACTERIAL PATHOGENS ISOLATED FROM CLINICAL SAMPLES IN TWO TERTIARY’S HOSPITALS, IN SANA'A, YEMEN

2021 ◽  
Author(s):  
Huda Zaid Al-Shami ◽  
Muhamed Ahmed Al-Haimi ◽  
Omar Ahmed Esma’il Al-dossary ◽  
Abeer Abdulmahmood Mohamed Nasher ◽  
Mohammed Mohammed Ali Al-Najhi ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibiotic Resistance ◽  
Antimicrobial Resistance ◽  
Peer Review ◽  
Bacterial Pathogens ◽  
University Hospital ◽  
Clinical Samples ◽  
Isolation And Identification ◽  
Hemolytic Streptococcus ◽  
Study Results

Background and objectives: At the present time, antimicrobial resistance (AMR) is a major public health hazard, with antimicrobial resistance bacteria increasing exponentially. This study estimates the epidemiological profiles and antimicrobial resistance of Gram-positive bacteria (GPB) and Gram-negative bacteria (GNB)  isolated from clinical samples among patients admitted to two University hospitals in Sana'a city for one year (2019). Methods: This was a retrospective study of clinical samples of patients collected from January 1, 2019 to December 30, 2019. All samples were appraised to determine presence of infectious agents using standard methods for isolation and identification of bacteria and yeasts from clinical samples of patients admitted to Al-Gumhouri University Hospital and Al-Kuwait University Hospital in Sana'a city. Antibiotic resistance was done using Kirby-Bauer disc diffusion methods. Results:  2,931 different pathogenic bacteria were detected from 24,690 different clinical specimens. The samples had an overall detection rate of 11.9% (2931/24,690). Among the bacterial pathogens isolated from clinical samples, 52.4% (n=1536) had GPB and 41.2% (n=1207) had GNB. The predominant GNB isolates were E.coli (22.04%), Klebsiella spp (6.03%), Pseudomonas aeruginosa (7.1%), Acinetobacter baumannii (1.46%), Enterobacter spp. (1.09%), Citrobacter spp. (1.16%), respectively. Among the GPB, S.aureus was the most common (26.3%), Coagulase-negative Staphylococcus (8.1%), Non-hemolytic Streptococcus (9.1%), Other alpha-hemolytic Streptococcus (3.9%), Streptococcus pyogenes (1.9%), and Streptococcus pneumoniae (0.5% ). A high rate of antibiotic resistance was recorded for sulfamethoxazole/trimethoprim (85.5%), ceftazidime (81.07%), ampicillin (70.4%), cefuroxime (66.4%). Conclusions:  The current study results revealed that the rate of resistance between GNB and GPB is associated with the incidence of different infections in patients attending two major tertiary hospitals in Sana'a city is very high. These results indicate ongoing screening and follow-up programs to detect antibiotic resistance, and also suggest the development of antimicrobial stewardship programs in Sana'a, Yemen.                     Peer Review History: Received: 9 September 2021; Revised: 11 October; Accepted: 23 October, Available online: 15 November 2021 Academic Editor:  Dr. A.A. Mgbahurike, University of Port Harcourt, Nigeria, [email protected] UJPR follows the most transparent and toughest ‘Advanced OPEN peer review’ system. The identity of the authors and, reviewers will be known to each other. This transparent process will help to eradicate any possible malicious/purposeful interference by any person (publishing staff, reviewer, editor, author, etc) during peer review. As a result of this unique system, all reviewers will get their due recognition and respect, once their names are published in the papers. We expect that, by publishing peer review reports with published papers, will be helpful to many authors for drafting their article according to the specifications. Auhors will remove any error of their article and they will improve their article(s) according to the previous reports displayed with published article(s). The main purpose of it is ‘to improve the quality of a candidate manuscript’. Our reviewers check the ‘strength and weakness of a manuscript honestly’. There will increase in the perfection, and transparency.  Received file:                Reviewer's Comments: Average Peer review marks at initial stage: 6.0/10 Average Peer review marks at publication stage: 7.5/10 Reviewers: Rima Benatoui, Laboratory of Applied Neuroendocrinology, Department of Biology, Faculty of Science, Badji Mokhtar University Annaba, BP12 E L Hadjar–Algeria, [email protected] Dr. Wadhah Hassan Ali Edrees, Hajja University, Yemen, [email protected] Rola Jadallah, Arab American University, Palestine, [email protected] Similar Articles: PREVALENCE OF PSEUDOMONAS AERUGINOSA (P. AERUGINOSA) AND ANTIMICROBIAL SUSCEPTIBILITY PATTERNS AT A PRIVATE HOSPITAL IN SANA'A, YEMEN EVALUATION OF ANTIBACTERIAL RESISTANCE OF BIOFILM FORMS OF AVIAN SALMONELLA GALLINARUM TO FLUOROQUINOLONES

scholarly journals A Systematic Review on Psychological and Biological Mediators Between Adversity and Psychosis: Potential Targets for Treatment

2019 ◽  
Author(s):  
Luis Alameda ◽  
Victoria Rodriguez ◽  
Ewan Carr ◽  
Monica Aas ◽  
Giulia Trotta ◽  
...  
Keyword(s):  
Systematic Review ◽  
Clinical Samples ◽  
Traditional Treatment ◽  
Affective Dysregulation ◽  
Cognitive Behavioural ◽  
Study Results ◽  
Registration Number ◽  
Meta Analyses ◽  
Competing Pathways

AbstractVarious psychological and biological pathways have been proposed as mediators between childhood adverse events (CA) and psychosis. A systematic review of the evidence in this domain is needed. The aim of this work is to systematically review the evidence on psychological and biological mediators between CA and psychosis across the psychosis spectrum. This systematic review followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines (registration number: CRD42018100846). Articles published between 1979 and July 2019 were identified through a literature search in OVID (PsychINFO; Medline and Embase). The evidence by each analysis and each study results are presented by group of mediator categories found in the review. The percentage of total effect mediated was calculated. 47 studies were included, with a total of 79,668 from general population (GP) and 3,189 from clinical samples. The quality of studies was judged as “fair”. Our results showed (i) solid evidence of mediation between CA and psychosis by negative cognitive schemas about the self, the world, and others (NS); by dissociation and other PTSD symptoms; (ii) evidence of al mediation through an affective pathway (affective dysregulation, anxiety, and depression) in GP; (iii) lack of studies exploring biological mediators. To conclude, we found evidence suggesting that various overlapping and not competing pathways contribute partially to the link between adversity and psychosis. Experiences of adversity, along with relevant mediators such as PTSD and mood related symptoms and NS, should be routinely assessed in patients with psychosis. Targeting such mediators through cognitive behavioural aproaches using trauma-focused therapy and/or pharmacological means could be a useful addition to the traditional treatment of positive symptoms.

scholarly journals Antimicrobial Effect of Acacia Nilotica Extracts on Endodontic Microorganisms

2019 ◽  
Author(s):  
Adel Alobaid ◽  
Abdalla Fadul ◽  
Reem Alqahtani ◽  
Norah Alqahtani
Keyword(s):  
Antimicrobial Effect ◽  
Acacia Nilotica ◽  
Clinical Isolates ◽  
Test Material ◽  
Clinical Samples ◽  
Zone Of Inhibition ◽  
Isolation And Identification ◽  
Linear Effect ◽  
Incomplete Removal ◽  
Endodontic Infections

Introduction: Acacia nilotica is widely used in traditional medicine as an anti-inflammatory and anti-bacterial agent. Endodontic irrigations exhibit lot of disadvantages with incomplete removal of bacteria. Sodium Hypochlorite (NaOCl) is the prototype irrigation against primary endodontic infections, while 2% chlorhexidine gluconate (CHX) is the best for secondary endodontic infections. Aim: This study aims to examine the antimicrobial effect of Acacia nilotica against clinical isolates of endodontic microorganisms compared to traditional(NaOCl and CHX). Materials and Methods: A total of 12 random clinical samples were collected for bacterial isolation and identification. Clinical isolates were identified as (Streptococcus viridans& staphylococcus aureus). A well identified candida albicans was also used. Acacia nilotica bark was collected, washed, dried and then grounded to fine powder. Specimens were percolated in methanol, filtrated, and concentrated for crude extract. Autoclaved Mueller Hinton media were used for antimicrobial sensitivity test. Microorganisms were inoculated and test material was loaded as original and 50% for 24h. Antibacterial activity was measured by zone of inhibition Results: All tested agents showed an excellent zone of inhibition against all microorganisms tested with their original concentration. Acacia nilotica showed excellent ZOI with more linear effect in both concentrations against S. viridans and S. aureus. Conclusion: Acacia nilotica has shown an excellent zone of inhibition in both original and 50% concentration, therefore, it may be an excellent substitute or adjunct irrigation solution of hebetic origin in endodontics. We recommend taking this material to the next level as an endodontic irrigant. Key words : Antimicrobial, Acacia Nilotica, Extracts , Endodontic, Microorganisms

COMPARATIVE STUDY OF E-STRIP AND VITEK 2 FOR VANCOMYCIN MIC FOR STAPHYLOCOCCUS AUREUS AT TERTIARY CARE CENTER

2021 ◽  
pp. 8-10
Author(s):  
Gauri Thakare ◽  
Sonal Chavan ◽  
Sharmila Raut ◽  
Rajani Tore ◽  
Ravindra Khadse
Keyword(s):  
Staphylococcus Aureus ◽  
Comparative Study ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Care Center ◽  
Tertiary Care ◽  
Test Material ◽  
Methicillin Resistant ◽  
Study Results ◽  
Vitek 2 ◽  
Strip Test

PURPOSE: Comparative Study done for Vancomycin susceptibility in Methicillin Resistant Staphylococcus aureus (MRSA) in two methods Vitek-2 and E-strip test. MATERIAL AND METHOD: Vancomycin susceptibility testing was performed on these Methicillin Resistant Staphylococcus aureus (MRSA) isolates by two methods viz. Vitek 2 & E- strip Test. RESULT: A total of 10680 various specimens were received and processed in laboratory. 210 samples were S. aureus amongst which 76 were MRSAs. Pus was the predominant sample followed by endotracheal secretions, blood, and sputum. All the strains of MRSA found susceptible to vancomycin (MIC≤ 2µg/ ml) by both the methods. Maximum specimens by both the methods had MICs of 1.0 µg/ ml. CONCLUSION: In the present study results of Vitek and E-strip were almost comparable. In the advanced era of automation and computerized technology with manpower compromised labs, Vitek could be a better option for vancomycin MIC.

scholarly journals Development of a national neonatal intensive care unit-specific antimicrobial stewardship programme in Canada: protocol for a cohort study

BMJ Open ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. e043403
Author(s):  
Joseph Y. Ting ◽  
Ashley Roberts ◽  
Peter Tilley ◽  
Joan L Robinson ◽  
Michael S Dunn ◽  
...  
Keyword(s):  
Intensive Care ◽  
Antimicrobial Stewardship ◽  
Neonatal Intensive Care ◽  
Very Low Birth Weight ◽  
Multidrug Resistant ◽  
Clinical Samples ◽  
Antimicrobial Use ◽  
University Of British Columbia ◽  
Study Results ◽  
Adverse Neonatal Outcomes

IntroductionEarly empiric treatment with broad-spectrum antimicrobials is common in neonatal intensive care units (NICU) due to the non-specific clinical presentation of infection. However, excessive and inappropriate antimicrobial use can lead to the emergence of drug-resistant organisms and adverse neonatal outcomes. This study aims to develop and implement a nationwide NICU-specific antimicrobial stewardship programme (ASP) to promote judicious antimicrobial use and control the emergence of multidrug-resistant organisms (MDROs) in Canada.Methods and analysisOur study population will include all very low-birth-weight neonates admitted to participating tertiary NICU in Canada. Based on the existing limited literature, we will develop consensus on NICU antimicrobial stewardship interventions to enhance best practices. Using an expanded Canadian Neonatal Network (CNN) platform, we will collect data on antimicrobial use and the susceptibility of organisms identified in clinical samples from blood and cerebrospinal fluid over a period of 2 years. These data will be used to provide all NICU stakeholders with benchmarked centre-adjusted antimicrobial use and MDRO prevalence reports. An ASP plan will be developed at both individual unit and national levels in the subsequent years. Knowledge translation strategies will be implemented through the well-established Evidence-based Practice for Improving Quality methodology.Ethics and disseminationEthics for the study has been granted by the University of British Columbia Children’s & Women’s Research Ethics Board (H19-02490) and supported by CNN Executive Committee. The study results will be disseminated through national organisations and open access peer-reviewed publications.Trial registration numberNCT04388293.

IMPROVEMENT OF BACTERIAL RHINOSINUSITIS DIAGNOSTIC PROCEDURES

2020 ◽  
Vol 65 (8) ◽  
pp. 496-500
Author(s):  
V. A. Shmylenko ◽  
A. P. Bondarenko ◽  
O. E. Trotsenko
Keyword(s):  
Unique Feature ◽  
Pneumococcal Infection ◽  
Sampling Technique ◽  
Diagnostic Procedures ◽  
Clinical Samples ◽  
Non Invasive ◽  
Test Sensitivity ◽  
Diagnostic Capability ◽  
Bacteriological Method ◽  
Pneumococcal Antigen

The research included evaluation of express-diagnosis capability of immunochromatographic assay (ICA) Binax NOW (Alere, Inc., USA) for diagnosis of the rhinosinusitis caused by to detect the Streptococcus pneumoniae antigen directly in clinical samples. The unique feature of the method included obtaining samples with an electric suction machine in order to evaluate aspirate from deep parts of the nasal cavity. Diagnostic capability of the Binax NOW was determined in a comparative study using classical bacteriological method in 100 clinical samples. Pneumococcus was isolated in 16 patients (16±3,7%) via bacteriological method. ICA utilization allowed to reveal pneumococcal antigen in 20 cases (20±4,0%). ICA test sensitivity equaled 87,5%, specificity - 92,9%. Obtained results allow us to recommend ICA for identification of pneumococcal infection in patients with sinusitis for practicing physicians. The advantages of the evaluated method were fast results (for up to 15 min) and possibility of non-invasive sampling technique of clinical specimens.

scholarly journals Fatal Human Meningoencephalitis due to Halicephalobus Nematodes, Germany

2015 ◽  
Vol 2 (2) ◽  
Author(s):  
Camelia-Maria Monoranu ◽  
Wolfgang Müllges ◽  
Marc Keppler ◽  
Klaus Brehm ◽  
Sarah L. Ondrejka ◽  
...  
Keyword(s):  
Post Mortem ◽  
Healthy Human ◽  
Histopathological Findings ◽  
Chain Reactions ◽  
Polymerase Chain Reactions ◽  
Causative Agents ◽  
Polymerase Chain

Abstract Infections with Halicephalobus nematodes, causative agents of severe meningoencephalitis in horses, have rarely been reported in humans. In this study, the clinical, serological, cytokine, and histopathological findings of a rapidly progressive and eventually fatal meningoencephalitis in a previously healthy human are described. The helminth was finally diagnosed by specific polymerase chain reactions from post mortem tissue.

scholarly journals Measurement of Ribosomal RNA Turnover In Vivo by Use of Deuterium-Labeled Glucose

2009 ◽  
Vol 55 (10) ◽  
pp. 1824-1833 ◽  
Author(s):  
Julien Defoiche ◽  
Yan Zhang ◽  
Laurence Lagneaux ◽  
Ruth Pettengell ◽  
Andrea Hegedus ◽  
...  
Keyword(s):  
Ribosomal Rna ◽  
Clinical Studies ◽  
Method Development ◽  
Lymphocytic Leukemia ◽  
Clinical Samples ◽  
Excision Biopsy ◽  
Rna Turnover ◽  
Dna Labeling ◽  
Study Results

Abstract Background: Most methods for estimation of rates of RNA production are not applicable in human in vivo clinical studies. We describe here an approach for measuring ribosomal RNA turnover in vivo using [6,6-2H2]-glucose as a precursor for de novo RNA synthesis. Because this method involves neither radioactivity nor toxic metabolites, it is suitable for human studies. Methods: For method development in vitro, a lymphocyte cell line (PM1) was cultured in the presence of [6,6-2H2]-glucose. RNA was extracted, hydrolyzed enzymatically to ribonucleosides, and derivatized to either the aldonitrile tetra-acetate or the pentafluoro triacetate derivative of the pentose before GC-MS. We identified optimum derivatization and analysis conditions and demonstrated quantitative incorporation of deuterium from glucose into RNA of dividing cells. Results: Pilot clinical studies demonstrated the applicability of this approach to blood leukocytes and solid tissues. A patient with chronic lymphocytic leukemia received [6,6-2H2]-glucose (1 g/kg) orally in aliquots administered every 30 min for a period of 10 h. When we analyzed CD3– B cells that had been purified by gradient centrifugation and magnetic-bead adhesion, we observed deuterium enrichment, a finding consistent with a ribosomal RNA production rate of about 7%/day, despite the slow division rates observed in concurrent DNA-labeling analysis. Similarly, in 2 patients with malignant infiltration of lymph nodes, administration of [6,6-2H2]-glucose (by intravenous infusion for 24 h) before excision biopsy allowed estimation of DNA and RNA turnover in lymph node samples. Conclusions: Our study results demonstrate the proof-of-principle that deuterium-labeled glucose may be used to analyze RNA turnover, in addition to DNA production/cell proliferation, in clinical samples.

scholarly journals Genetic survey of alveolar and cystic echinococcoses in Romania: first molecular evidence of Echinococcus multilocularis in humans in the country

2017 ◽  
Vol 54 (3) ◽  
pp. 189-198 ◽  
Author(s):  
V. Šnábel ◽  
C. Calma ◽  
S. O. Georgescu ◽  
S. Cavallero ◽  
S. D’Amelio ◽  
...  
Keyword(s):  
Echinococcus Multilocularis ◽  
Mandatory Reporting ◽  
Clinical Samples ◽  
Molecular Evidence ◽  
Intermediate Hosts ◽  
Nucleotide Substitutions ◽  
European Variant ◽  
North Eastern ◽  
Causative Agents ◽  
Western Romania

Summary Cystic echinococcosis (CE) and alveolar echinococcosis (AE) are considered as one of the most important zoonotic diseases in Romania, where they are subject to mandatory reporting. To obtain more knowledge about the genetic diversity of Echinococcus causative agents of these diseases, 11 isolates from humans and ungulate intermediate hosts from the two regions of Romania were genotyped using mitochondrial markers. In clinical samples of five patients from north-eastern Romania (Iasi, Botosani, Vaslui counties), Echinococcus multilocularis was identified as causal agent by cox1 sequence analysis. To the best of our knowledge this finding presents the first molecular evidence of E. multilocularis in humans from Romania. Only two cases of AE in patients were previously documented in the country by serological methods. In our four patients the most widespread European variant E5 of E. multilocularis was recorded, whereas in isolate from Vaslui county three nucleotide substitutions were detected as compared to the most related E5 haplotype. One of these mutations (411T/G) matched N1 and N2 haplotypes described previously from North America. In six CE samples retrieved from western Romania (Caras-Severin and Timis counties), two human isolates were diagnosed as Echinococcus canadensis G7, one as E. granulosus s.s. G1 and one as E. granulosus s.s. G3 using atp6 and rrnS sequencing. In ungulates, the cattle isolate was allocated to E. granulosus s.s. G1 and pig isolate to E. canadensis G7. The two G7 findings in humans reinforced the recent view that G7 was underestimated as compared to the E. granulosus s.s. regarding human CE threat that can be further employed for identifying sources of infections and establishing suitable preventive measures.

scholarly journals Characteristics of Species Composition of Causative Agents in Infective Endocarditis

2020 ◽  
pp. 48-51
Author(s):  
H. Filonenko ◽  
A. Avetyan ◽  
D. Kramarenko ◽  
A. Salamanina ◽  
O. Guryeva ◽  
...  
Keyword(s):  
Infective Endocarditis ◽  
Species Composition ◽  
Treatment Algorithm ◽  
Study Groups ◽  
Coagulase Negative Staphylococcus ◽  
Study Results ◽  
Causative Agents ◽  
The Difference ◽  
Group 2 ◽  
Group 1

  Introduction. The frequency of infective endocarditis (IE) in children with congenital heart disease (CHD) is 15– 140 times higher than that in the overall population and varies from 2 to 18% according to different authors. The aim. To define the main groups of causative agents of infective endocarditis in children and adults in order to build up an antibiotic treatment algorithm. Materials and methods. The analysis of examination findings and treatment outcomes in 124 patients was conducted from 2014 to 2019. These patients received medical treatment at the Ukrainian Children`s Cardiac Center (UCCC), Kyiv. The patients were divided into two groups by age: group 1 included children aged from 6 days to 18 years (62 [50.0%]), group 2 comprised adults aged from 18 to 79 years (62 [50.0%]). Results and discussion. Forty-nine isolates were recovered from 124 patients during the analysis of microbiological study results. The frequency of bacterial IE causative agents was 26 (41.9%) in group 1, and 17 (27.4%) in group 2. Comparative analysis of the spectrum of IE pathogens revealed differences in the two study groups. Coagulase-negative staphylococcus was the most common causative agent in group 1 (46.7% of all isolated strains; n = 12) and in group 2 (44.4%; n = 8). Staphylococcus aureus in children was detected in 5 (8.1%) cases, whereas in adults only in 2 (11.1%) cases. Pathogens of the Enterococcus spp. family (E. faecalis) were recovered in both study groups: in 6.5% (n = 2) and 16.6% (n = 3) of the patients, respectively. Gram-negative flora was detected in 3 (9.7%) patients of group 1 and, in 2 (11.1%) patients of group 2. Fungal flora was more commonly found in children (7 [22.6%] cases represented by the Candida family), whereas in adults only 1 (5.6%) case represented by the Mucor family was revealed. Conclusions. Etiological structure of the infective endocarditis pathogens in both groups was represented mainly by gram-positive bacteria, with S. epidermidis (24.5%) being the most essential. The changes were revealed in the species composition of the pathogens in group 1 with fungal microflora dominance: Candida parapsilosis in 9.7%, C. albicans and C. famata in 6.5% of the total number of plated cultures in this group. The difference in surgical operations due to possible IE in both groups was established based on the specific features of operations determined by the age factor.

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