How to Manage Infections Caused by Antibiotic Resistant Gram-negative Bacteria - EBMT Educational Meeting from the Severe Aplastic Anaemia and Infectious Diseases Working Parties, Naples, Italy, 2014

2015 ◽  
Vol 16 (999) ◽  
pp. 1-1 ◽  
Author(s):  
Małgorzata Mikulska
Author(s):  
NА Gordinskaya ◽  
EV Boriskina ◽  
DV Kryazhev

Introduction: A large number of infectious processes are associated with opportunistic microorganisms. The phenotype of antibiotic resistance of such pathogens is multidrug-resistant strains with the presence of various β-lactamases. Our objective was to determine the phenotypic and genotypic features of antibiotic resistance of staphylococci, enterobacteria, and non-fermenting Gram-negative bacteria – the cause of infectious diseases in patients of various health facilities of Nizhny Novgorod. Material and methods: Using classical microbiological methods and molecular genetic studies, we analyzed 486 strains of microorganisms isolated from the upper respiratory tract, intestines, urine, and wound discharge of patients in 2019–2020. In all isolates, the phenotype of antibiotic resistance was determined by the disco-diffusion method (Bioanalyse, Turkey) and using the Multiscan FC spectrophotometer (ThermoScientific, Finland) with Microlatest tablets (PLIVA-Lachema, Czech Republic), along with molecular features of resistance mechanisms by PCR on the CFX96 device (BioRad, USA) using AmpliSens kits (Russia). Results and discussion: The results showed that the most prevalent causative agents of infectious diseases (40.7 %) were Gram-negative bacteria, of which Enterobacteriaceae and non-fermenting bacteria accounted for 27.1 % and 13.6 % of cases, respectively. Staphylococci were isolated in 37.6 % of patients: S. aureus and coagulase-negative staphylococci induced 13.4 % and 24.2 % of cases, respectively. The analysis of antibiotic resistance of the isolates showed a high level of antimicrobial resistance in all hospitals, regardless of the isolation locus. The phenotype of methicillin-resistant strains was found in 26.3 % and 37.9 % of S. aureus and coagulase-negative staphylococci, respectively; the mecA gene was found in 89.0 % of methicillin-resistant staphylococci. The highest number of antibiotic-resistant strains among Gram-negative microorganisms was observed in K. pneumoniae, A. baumannii, and P. aeruginosa. We established that 61.7 % of K. pneumoniae, 75.1 % of A. baumannii, and 58.2 % of P. aeruginosa were resistant to carbapenems. The results of molecular genetic studies confirmed the presence of serine carbapenemases KPC and OXA groups in all multidrug-resistant K. pneumoniae and A. baumannii; genes of the metallo-β-lactamase of VIM group were found in 40.9 % strains of P. aeruginosa. The production of numerous β-lactamases and the presence of determinants of antibiotic resistance in the genome determine the virulent properties of opportunistic microorganisms. Conclusion: The antibiotic resistance of opportunistic microorganisms is the cause of developing a chronic infectious process. Today, a wide spread of antibiotic-resistant infectious agents is a serious public health problem, which determines the need for constant microbiological monitoring and studies of molecular mechanisms of resistance to identify the most potent antibiotics and to determine the ways of eradication of multidrug-resistant strains.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shira Mandel ◽  
Janna Michaeli ◽  
Noa Nur ◽  
Isabelle Erbetti ◽  
Jonathan Zazoun ◽  
...  

AbstractNew antimicrobial agents are urgently needed, especially to eliminate multidrug resistant Gram-negative bacteria that stand for most antibiotic-resistant threats. In the following study, we present superior properties of an engineered antimicrobial peptide, OMN6, a 40-amino acid cyclic peptide based on Cecropin A, that presents high efficacy against Gram-negative bacteria with a bactericidal mechanism of action. The target of OMN6 is assumed to be the bacterial membrane in contrast to small molecule-based agents which bind to a specific enzyme or bacterial site. Moreover, OMN6 mechanism of action is effective on Acinetobacter baumannii laboratory strains and clinical isolates, regardless of the bacteria genotype or resistance-phenotype, thus, is by orders-of-magnitude, less likely for mutation-driven development of resistance, recrudescence, or tolerance. OMN6 displays an increase in stability and a significant decrease in proteolytic degradation with full safety margin on erythrocytes and HEK293T cells. Taken together, these results strongly suggest that OMN6 is an efficient, stable, and non-toxic novel antimicrobial agent with the potential to become a therapy for humans.


Author(s):  
L.V. Kataeva ◽  
A.P. Rebeshchenko ◽  
T.F. Stepanova ◽  
O.V. Posoiuznykh ◽  
Le Thanh Hai ◽  
...  

We studied the microflora structure and resistance gathered from the biomaterial of patients and the environment objects of various departments at the National hospital of Pediatrics in Hanoi. 140 clinical samples of biomaterials from 74 patients treated in the intensive care unit, the infectious diseases and the gastroenterology departments were studied. A systematic approach including microbiological, epidemiological and statistical research methods was used in carrying out the study. Bacteria of the Enterobacteriaceae family (38.5 per cent) prevailed in the biomaterial of intensive care unit patients. Nonfermentative Gram-negative bacteria (46.5 per cent) occupied the leading positions in the infectious diseases department and Gram-positive bacteria (39.3 per cent) were in the gastroenterology department. Gram-positive flora (60.2 per cent in the intensive care unit and 50.7 per cent in the infectious diseases department) prevailed in the microflora structure gathered from hospital environment objects. We identified the prevalence of bacteria of the genus Enterobacteriaceae and non-fermentative Gram-negative bacteria with a wide spectrum of resistance in the departments of the National Hospital of Pediatrics.


Antibiotics ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 162 ◽  
Author(s):  
Monica Francesca Blasi ◽  
Luciana Migliore ◽  
Daniela Mattei ◽  
Alice Rotini ◽  
Maria Cristina Thaller ◽  
...  

Sea turtles have been proposed as health indicators of marine habitats and carriers of antibiotic-resistant bacterial strains, for their longevity and migratory lifestyle. Up to now, a few studies evaluated the antibacterial resistant flora of Mediterranean loggerhead sea turtles (Caretta caretta) and most of them were carried out on stranded or recovered animals. In this study, the isolation and the antibiotic resistance profile of 90 Gram negative bacteria from cloacal swabs of 33 Mediterranean wild captured loggerhead sea turtles are described. Among sea turtles found in their foraging sites, 23 were in good health and 10 needed recovery for different health problems (hereafter named weak). Isolated cloacal bacteria belonged mainly to Enterobacteriaceae (59%), Shewanellaceae (31%) and Vibrionaceae families (5%). Although slight differences in the bacterial composition, healthy and weak sea turtles shared antibiotic-resistant strains. In total, 74 strains were endowed with one or multi resistance (up to five different drugs) phenotypes, mainly towards ampicillin (~70%) or sulfamethoxazole/trimethoprim (more than 30%). Hence, our results confirmed the presence of antibiotic-resistant strains also in healthy marine animals and the role of the loggerhead sea turtles in spreading antibiotic-resistant bacteria.


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