scholarly journals Phenotypic profile of priority multiresistant Аcinetobacter baumannii sequence types (ST 1167, ST 944, ST 208)

2022 ◽  
Vol 98 (6) ◽  
pp. 639-647
Author(s):  
O. S. Fedotova ◽  
Yu. A. Zakharova ◽  
A. V. Ostapchuk ◽  
U. A. Bazhanova ◽  
A. A. Zakharov
Keyword(s):  
Test Panel ◽  
Biochemical Tests ◽  
Phenotypic Properties ◽  
Genetic Method ◽  
Phenotypic Profile ◽  
Typing Methods ◽  
Phenotypic Methods ◽  
Multiresistant Strains ◽  
Hospital Acquired ◽  
Sequence Types

Introduction. About 1,000,000 cases of infections caused by Acinetobacter spp. per year are registered globally, making up 1.8% of all the cases of hospital-acquired infections. In compliance with long-term studies carried out in in this country and abroad, Acinetobacter baumannii is a clinically important representative of the Acinetobacter genus. Intraspecific typing of microorganisms is an integral part of a clinical microbiologist's contribution to scoring the outbreaks of purulent-septic infections within the sphere of HAI surveillance. Most of the practicing microbiological laboratories cannot use genotypic typing methods because of their high costs.Objective. Developing a test panel for intraspecific identification of A. baumannii sequence types (ST 1167, ST 944, ST 208) based on their phenotypic properties.Materials and methods. Intraspecific membership of 74 A. baumannii strains obtained from four multipurpose health settings of a large industrial centre was studied using a genetic method (multilocus sequence typing) and a suite of phenotypic methods (biochemical tests, biofilmogenous capacity, growth inhibition zones to antibacterial drugs, sensitivity to aniline dyes, disinfectants and Acinetobacter bacteriophage) was studied.Results. Phenotypic features of three predominant A. baumannii sequence types (ST 1167, 944, 208) were determined.Discussion. An efficacious economy set of differentiating tests allowing identification of intraspecific features of A. baumannii multiresistant strains was сreated.Conclusion. The test panel will enable the laboratories that cannot use sequencing methods to conduct intraspecific differentiation of common A. baumannii sequence types as part of microbiological monitoring.

scholarly journals Molecular Typing of Hospital-Acquired Staphylococcus aureus Isolated from Isfahan, Iran

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Seyed Asghar Havaei ◽  
Fahimeh Ghanbari ◽  
Ali Asghar Rastegari ◽  
Amir Azimian ◽  
Farzad Khademi ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Molecular Typing ◽  
Diffusion Method ◽  
Biochemical Tests ◽  
Spa Typing ◽  
Disk Diffusion Method ◽  
Type Iv ◽  
Typing Methods ◽  
Hospital Acquired ◽  
Spa Type

Background. Staphylococcus aureus (S. aureus) is one of the most common pathogens that cause hospital- and community-acquired infections in the world. The use of molecular typing methods is essential for determining the origin of the strains, their clonal relations, and also in epidemiological investigations. The purpose of this study was to determine the prevalence of antibiotic resistant S. aureus isolates and using spa, agr, and SCCmec typing to determine the dominant types in Iran. Material and Method. Fifty isolates of S. aureus were collected from January to May 2010. S. aureus identification was performed by biochemical tests. Disk diffusion method was employed to assess the sensitivity of S. aureus strains to antibiotics and then genetic analysis of bacteria was performed using SCCmec, agr, and spa typing. Results. S. aureus resistance to tetracycline, cefoxitin, clindamycin, ciprofloxacin, gentamicin, Cot: cotrimoxazole, levofloxacin, rifampin, and vancomycin were found to be 36%, 18%, 12%, 12%, 22%, 6%, 6%, and 0%, respectively. The results of this study showed that 16% of the isolates were resistant to methicillin (MRSA) and the majority of isolates were SSC mec type IV. In addition spa and agr typing revealed agr typeI and spa type t7688 to be the most predominant. Conclusion. In this study, spa typing showed 100% reliability and the t7688 spa type had a frequency of 26% compared to the frequency of 0.0% in the Ridom SpaServer. The frequency of t304 spa type was higher than the global average.

scholarly journals MODERN APPROACHES TO TREATMENT OF PSEUDOMONAS AERUGINOSA VENTILATOR-ASSOCIATED PNEUMONIA (LITERATURE REVIEW)

2019 ◽  
Vol 72 (5) ◽  
pp. 892-896
Author(s):  
Olha A. Poda ◽  
Tetyana O. Kryuchko ◽  
Inna N. Nesina ◽  
Olha Ya. Tkachenko ◽  
Nataliia V. Kuzmenko
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Causative Agent ◽  
Optimal Dose ◽  
Correct Choice ◽  
Antibacterial Drug ◽  
Controversial Issues ◽  
Ventilator Associated Pneumonia ◽  
Scientific Investigations ◽  
Multiresistant Strains ◽  
Hospital Acquired

Introduction: Nowadays anti-microbial therapy of ventilator-associated pneumonia caused by is one of the most topical issue as a consequence of widespread multiresistant strains of causative agent and their biological peculiarity of actively formation of resistance to new antibacterial drugs. The aim is to describe modern approaches to therapy of ventilator-associated pneumonia causative agent of which is presented by Pseudomonas aureginosa . Materials and methods: An analysis and summing up of results of scientific investigations described in medical publications concerning the issues of therapy of ventilatorassociated pneumonia caused by Pseudomonas aureginosa was done. Conclusions: Despite the development of modern approaches to anti-microbial therapy of ventilator-associated pneumonia caused by Pseudomonas aeruginosa, which are also concerned with such controversial issues as correct choice of antibacterial drug, its optimal dose, and duration of this therapy, the problem of treatment of hospital-acquired infections of respiratory airways caused by Pseudomonas aeruginosa has been discussable yet and requires the further study.

scholarly journals Emergence and spread of vancomycin resistance among enterococci in Europe

2008 ◽  
Vol 13 (47) ◽  
Author(s):  
G Werner ◽  
T M Coque ◽  
A M Hammerum ◽  
R Hope ◽  
W Hryniewicz ◽  
...  
Keyword(s):  
Population Analysis ◽  
Vancomycin Resistance ◽  
Vancomycin Resistant Enterococcus ◽  
Phenotypic Marker ◽  
Vancomycin Resistant Enterococci ◽  
Distinct Subpopulation ◽  
Typing Methods ◽  
Vancomycin Resistant ◽  
Hospital Acquired ◽  
Animal Strains

Vancomycin-resistant enterococci (VRE) first appeared in the late 1980s in a few European countries. Nowadays, six types of acquired vancomycin resistance in enterococci are known; however, only VanA and to a lesser extent VanB are widely prevalent. Various genes encode acquired vancomycin resistance and these are typically associated with mobile genetic elements which allow resistance to spread clonally and laterally. The major reservoir of acquired vancomycin resistance is Enterococcus faecium; vancomycin-resistant Enterococcus faecalis are still rare. Population analysis of E. faecium has revealed a distinct subpopulation of hospital-acquired strain types, which can be differentiated by molecular typing methods (MLVA, MLST) from human commensal and animal strains. Hospital-acquired E. faecium have additional genomic content (accessory genome) including several factors known or supposed to be virulence-associated. Acquired ampicillin resistance is a major phenotypic marker of hospital-acquired E. faecium in Europe and experience has shown that it often precedes increasing rates of VRE with a delay of several years. Several factors are known to promote VRE colonisation and transmission; however, despite having populations with similar predispositions and preconditions, rates of VRE vary all over Europe.

scholarly journals Strain Typing and the Ecological Structure of Escherichia coli

2010 ◽  
Vol 93 (3) ◽  
pp. 974-984 ◽  
Author(s):  
David M Gordon
Keyword(s):  
Escherichia Coli ◽  
Intestinal Tract ◽  
Domestic Animals ◽  
Seasonal Patterns ◽  
Strain Typing ◽  
E Coli ◽  
Hospital Acquired Infections ◽  
Typing Methods ◽  
The Many ◽  
Hospital Acquired

Abstract Escherichia coli is a commonly encountered commensal of the lower intestinal tract of humans and other mammals. Strains of the species are responsible for a significant amount of human morbidity and mortality each year. Consequently, numerous efforts attempt to track the movement of hospital-acquired infections, determine the source of a foodborne disease outbreak, or investigate the seasonal patterns of pathogen abundance in domestic animals. All of these endeavors require that the isolates acquired be differentiated from each other in some manner. This review briefly describes some of the commonly used molecular typing methods for E. coli. However, the main aim of the review is to describe the many levels, from the species to individual strains, at which E. coli can be considered, and to contend that a hierarchical approach to strain typing may often reveal patterns that are not obvious when a typing scheme is simply designed to differentiate isolates.

scholarly journals Bacteriological Monitoring of Inanimate Surfaces and Equipment in Some Referral Hospitals in Assiut City, Egypt

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Entsar H. Ahmed ◽  
Hebat-Allah M. Hassan ◽  
Nahla M. El-Sherbiny ◽  
Asmaa M. A. Soliman
Keyword(s):  
Essential Element ◽  
Public Health Problem ◽  
Hospital Environment ◽  
Coagulase Negative Staphylococcus ◽  
Biochemical Tests ◽  
Nosocomial Pathogens ◽  
Environmental Surfaces ◽  
Significant Difference ◽  
Referral Hospitals ◽  
Hospital Acquired

Hospital-acquired infections represent a serious public health problem in all countries. It is clear that monitoring of the hospital environment is an essential element in the control and a part of the policy for preventing nosocomial infections. It allows a better understanding of the microbial ecology for the purpose of conducting preventive and corrective actions. The aims of this work were to determine the percentage of bacterial contamination of environmental samples and to identify potential nosocomial pathogens isolated from environments of seven referral hospitals from 2009 to 2015. By using the swab technique, 12863 samples were collected. Qualitative and quantitative cultures were performed. The organisms were primarily identified by colony morphology, microscopy of Gram stain, and standard biochemical tests. 25.6% of total samples showed contamination (93% was monomicrobial and 7.0% was polymicrobial). The predominant species was coagulase-negative staphylococcus (CNS) (32%), followed by methicillin-resistant S. aureus (MRSA) (26%) and then K. pneumonia (10.6%). The percentage of contamination varied among the covered hospitals and according to the year of monitoring with highly statistically significant difference (p value<0.001). Direct contact with environmental surfaces or equipment transmits the majority of nosocomial infection. Major nosocomial pathogens have been identified. Hospital managers and healthcare bodies must be aware of the reality of the concept of environmental bacterial tanks and the need for respect of biocleaning procedures and choice of biocleaning tools.

EXTENDED STUDY OF SERRATIA IN A DIAGNOSTIC BACTERIOLOGY LABORATORY

1966 ◽  
Vol 12 (1) ◽  
pp. 99-103 ◽  
Author(s):  
R. M. Hotz ◽  
V. R. Dowell Jr.
Keyword(s):  
Polymyxin B ◽  
Biochemical Tests ◽  
Diagnostic Laboratory ◽  
Extended Study ◽  
Clinical Specimens ◽  
Hospital Acquired Infections ◽  
Noticeable Increase ◽  
Routine Identification ◽  
Hospital Acquired ◽  
Antibiotic Agents

The incidence of Serratia in clinical material received in a general hospital diagnostic laboratory was studied. Initially the morphologic features, biochemical characteristics, chromogenesis, and antibiotic susceptibility of 21 isolates were examined. On the basis of these studies certain cultural and biochemical tests were selected for routine identification of Serratia.Serratia isolated from various types of clinical specimens received during a 4-year period (1960–1964) were recorded. Most of the Serratia were nonchromogenic except on a special medium. The cultures were resistant to a number of antibiotic agents, particularly penicillin, polymyxin B, and the tetracyclines. A higher incidence of Serratia in sputum than in throat and nasopharyngeal cultures was observed. There was a noticeable increase in the overall incidence of Serratia isolates over the 4-year period. This may be a reflection of hospital acquired infections.

scholarly journals Molecular typing of bacteria for epidemiological surveillance and outbreak investigation / Molekulare Typisierung von Bakterien für die epidemiologische Überwachung und Ausbruchsabklärung

2016 ◽  
Vol 67 (4) ◽  
pp. 199-224 ◽  
Author(s):  
Werner Ruppitsch
Keyword(s):  
Molecular Typing ◽  
Pathogenic Bacteria ◽  
Animal Health ◽  
Epidemiological Surveillance ◽  
Healthcare Facilities ◽  
Microbial Infections ◽  
Molekulare Typisierung ◽  
Outbreak Investigations ◽  
Typing Methods ◽  
Phenotypic Methods

SummaryConstant confrontations with microbial threats pose major challenges to human and animal health, agricultural and food production, and public safety. Identifying pathogenic bacteria (species) and tracking strains (by series of well-characterized isolates) to their sources are especially important in outbreak investigations. Compared to the identification of the species, the identification of the source and spread of microbial infections represents a major—and many times futile—challenge. This is due to the multitude of ways microorganisms can occur and spread within healthcare facilities and in the community; how, when, and where they can contaminate the complex nutrition chain, leading to natural and man-made outbreaks.Typing is the characterization of isolates or strains below species or subspecies level. Typing of bacterial isolates is an essential procedure to identify the microbe causing the illness or to track down an outbreak to the suspected source. In the genomic era, the introduction of molecular methods has largely replaced phenotypic methods and “molecular epidemiology” has emerged as a new discipline. The current molecular typing methods can be classified into three categories: (a) PCR-based methods, (b) DNA fragment analysis-based methods, and (c) DNA sequence-based methods, including the new exciting era of high-throughput genome sequencing.

scholarly journals Rapid determination of hospital-acquired meticillin-resistant Staphylococcus aureus lineages

2007 ◽  
Vol 56 (5) ◽  
pp. 614-619 ◽  
Author(s):  
Joshua D. Cockfield ◽  
Smriti Pathak ◽  
Jonathan D. Edgeworth ◽  
Jodi A. Lindsay
Keyword(s):  
Staphylococcus Aureus ◽  
Large Scale ◽  
Rapid Determination ◽  
Control Strategies ◽  
Antibiotic Resistance Genes ◽  
Epidemiological Studies ◽  
Typing Methods ◽  
Mrsa Strains ◽  
Hospital Acquired

Multilocus sequence typing (MLST) and multi-strain microarray analysis have shown that most human Staphylococcus aureus strains belong to ten dominant clonal complexes (CCs) or lineages, each with unique surface architecture. Meticillin-resistant S. aureus (MRSA) strains currently belong to six of these lineages (CC1, CC5, CC8, CC22, CC30 and CC45), each of which has independently acquired mobile genetic elements (MGEs) carrying antibiotic resistance genes. MLST and microarrays are expensive and time consuming methods for routine determination of S. aureus lineage. A restriction-modification (RM) test has now been developed that is rapid, simple, inexpensive and accurately determines lineage of hospital-acquired MRSA. The RM test is based on three PCRs for hsdS gene variants, as hsdS genes likely control the independent evolution of S. aureus lineages. The RM test correctly identified 102 MRSA isolates as belonging to one of the six lineages/CCs. Real-time MRSA typing can be used to identify and track changes in local MRSA outbreaks, and provide support for targeting infection control strategies. Simple and accurate typing methods will also support large scale epidemiological studies, and could lead to greater understanding of the carriage, spread and virulence of different MRSA lineages.

scholarly journals Genomic insights into methicillin-resistant Staphylococcus aureus spa type t899 isolates belonging to different sequence types

2021 ◽  
Author(s):  
Henok Ayalew Tegegne ◽  
Ivana Koláčková ◽  
Martina Florianová ◽  
Pierre Wattiau ◽  
Tereza Gelbíčová ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Phylogenic Tree ◽  
Methicillin Resistant ◽  
Surveillance Studies ◽  
Virulence Markers ◽  
Knowing That ◽  
Routine Basis ◽  
Typing Methods ◽  
Sequence Types ◽  
Insight Into

Methicillin-resistant Staphylococcus aureus (MRSA) presenting the spa type t899 is commonly associated with sequence type (ST) 9, but also increasingly linked to ST398. This study provides a genomic insight into the diversity of t899 isolates using cgMLST, SNP-based phylogeny and the description of selected antimicrobial resistance and virulence markers. The SNP-based phylogenic tree showed that isolates sharing the same spa type (t899) but different STs highly diverged in their core and accessory genomes, revealing discriminant antimicrobial-resistant (AMR) and virulence markers. Our results highlighted that, in a surveillance context where only spa typing is used, an additional multiplex PCR for the detection of the tet(M), sak and seg genes would valuably allow to distinguish ST9 from ST398 isolates on a routine basis. Importance This study showed the genetic diversity and population structure of S. aureus presenting the same spa type t899 but belonging to different STs. Our findings revealed that these isolates vary deeply in their core and accessory genomes, contrary to what is regularly inferred from studies using spa typing only. Given that identical spa types can be associated with different STs, and knowing that spa typing only is not appropriate for S. aureus isolates that underwent major recombination events which include the passage of the spa gene (such as in t899-positive MRSA), the combination of both MLST and spa typing methods is recommended. However, spa typing only is still largely used in surveillance studies and basic characterization. Our data suggest that additional markers, such as tet(M), sak and seg genes, could be implemented in an easy and cheap manner in order to identify S. aureus lineages with a higher accuracy.

scholarly journals Pneumococcal pspA Sequence Types of Prevalent Multiresistant Pneumococcal Strains in the United States and of Internationally Disseminated Clones

2000 ◽  
Vol 38 (10) ◽  
pp. 3663-3669 ◽  
Author(s):  
Bernard Beall ◽  
Giovanni Gherardi ◽  
Richard R. Facklam ◽  
Susan K. Hollingshead
Keyword(s):  
United States ◽  
Cell Wall ◽  
Structural Gene ◽  
Gel Electrophoresis ◽  
Gene Diversity ◽  
The United States ◽  
Pulsed Field Gel Electrophoresis ◽  
Restriction Profiles ◽  
Multiresistant Strains ◽  
Sequence Types

In a recent genotypic survey of β-lactam-resistant pneumococci recovered in different areas of United States during 1997, eight clonal types that each represented 3 to 40 isolates accounted for 134 of 144 isolates (G. Gherardi, C. Whitney, R. Facklam, and B. Beall, J. Infect. Dis. 181:216–229, 2000). We determined the degree ofpspA gene diversity among these 134 isolates and for 11 previously characterized internationally disseminated multiresistant strains. Thirty-four different pspA restriction profiles were determined for an amplicon encompassing the variable portion of the structural gene that encodes the surface-exposed domain of PspA and a variable-length proline-rich putative cell wall-associated domain. These restriction profiles closely correlated with those of 33 different pspA sequence types of an approximately 230-residue region corresponding to residues 182 to 410 of the strain Rx1 PspA. These residues encompass a 100-residue clade-defining region known to contain cross-protective epitopes for which 17 sequence types were found. Distinct, conserved pspA sequence types were found for the majority of strains within seven of the eight U.S. clonal types assessed, while one pulsed-field gel electrophoresis type was represented by isolates of three distinct PspA clades. Sequence typing of pspA provides an added level of specificity in the subtyping of isolates and is a necessary first step in determining the components needed in a PspA vaccine which could elicit effective cross-protective coverage.

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