scholarly journals Pharmacophore and ligand-guided screening of antibacterial leads targeting antibiotic resistance factor in Gram-negative bacteria

2018 ◽  
Vol 13 ◽  
Author(s):  
Abi Sofyan Ghifari
Author(s):  
Ganiyat Shitta ◽  
Olufunmilola Makanjuola ◽  
Olusolabomi Adefioye ◽  
Olugbenga Adekunle Olowe

Background: Extended Spectrum Beta Lactamase (ESBL) production in gram negative bacteria confers multiple antibiotic resistance, adversely affecting antimicrobial therapy in infected individuals. ESBLs result from mutations in β-lactamases encoded mainly by the bla TEM,bla SHVand bla CTX-Mgenes. The prevalence of ESBL producing bacteria has been on the increase globally especially its upsurge among isolates from community-acquired infections. Aim: To determine ESBL prevalence and identify ESBL genes among clinical isolates in Osun State, Nigeria. Material and Methods: A cross-sectional study was carried out from August 2016 –July 2017 in Osun State, Nigeria. Three hundred and sixty Gram negative bacteria recovered from clinical samples obtained from both community and healthcare associated infections were tested. They included147 Escherichia coli(40.8%), 116 Klebsiella spp(32.2%), 44 Pseudomo-nas aeruginosa(12.2%) and23 Proteus vulgaris (6.4%) isolates. Others were Acinetobacter baumannii, Serratia rubidae, Citrobacter spp, Enterobacter spp and Salmonella typhi. Disk diffusion antibiotic susceptibility testing was carried out, isolates were screened for ESBL production and confirmed using standard laboratory procedures. ESBLs resistance genes were identified by Polymerase Chain Reaction (PCR). Results: All isolates demonstrated multiple antibiotic resistance. Resistance to ampicillin, amoxicillin with clavulanate and erythromycin was 100%, whereas resistance to Imipenem was very low (5.0%). : Overall prevalence of ESBL producers was 41.4% with Klebsiellaspp as the highest ESBL producing Enterobacteriacaea. ESBL producers were more prevalent among the hospital pathogens than community pathogens, 58% vs 29.5% (p=0.003). ESBL genes were detected in all ESBL producers with the blaCTX-Mgene predominating (47.0%) followed by blaTEM(30.9%) and blaSHVgene was the least, 22.1%. The blaCTX-Mgene was also the most prevalent in the healthcare pathogens (62%) but it accounted for only 25% in those of community origin. Conclusion: A high prevalence of ESBL producing gram negative organisms occurs both in healthcare and in the community in our environment with the CTX-M variant predominating. Efforts to control spread of these pathogens should be addressed.


2018 ◽  
Vol 69 (8) ◽  
pp. 1410-1421 ◽  
Author(s):  
Hajnalka Tóth ◽  
Adina Fésűs ◽  
Orsolya Kungler-Gorácz ◽  
Bence Balázs ◽  
László Majoros ◽  
...  

Abstract Background Increasing antibiotic resistance may reciprocally affect consumption and lead to use of broader-spectrum alternatives; a vicious cycle that may gradually limit therapeutic options. Our aim in this study was to demonstrate this vicious cycle in gram-negative bacteria and show the utility of vector autoregressive (VAR) models for time-series analysis in explanatory and dependent roles simultaneously. Methods Monthly drug consumption data in defined daily doses per 100 bed-days and incidence densities of gram-negative bacteria (Escherichia coli, Klebsiella spp., Pseudomonas aeruginosa, and Acinetobacter baumannii) resistant to cephalosporins or to carbapenems were analyzed using VAR models. These were compared to linear transfer models used earlier. Results In case of all gram-negative bacteria, cephalosporin consumption led to increasing cephalosporin resistance, which provoked carbapenem use and consequent carbapenem resistance and finally increased colistin consumption, exemplifying the vicious cycle. Different species were involved in different ways. For example, cephalosporin-resistant Klebsiella spp. provoked carbapenem use less than E. coli, and the association between carbapenem resistance of P. aeruginosa and colistin use was weaker than that of A. baumannii. Colistin use led to decreased carbapenem use and decreased carbapenem resistance of P. aeruginosa but not of A. baumannii. Conclusions VAR models allow analysis of consumption and resistance series in a bidirectional manner. The reconstructed resistance spiral involved cephalosporin use augmenting cephalosporin resistance primarily in E. coli. This led to increased carbapenem use, provoking spread of carbapenem-resistant A. baumannii and consequent colistin use. Emergence of panresistance is fueled by such antibiotic-resistance spirals.


Author(s):  
T.F. Stepanova ◽  
L.V. Kataeva ◽  
A.P. Rebeshchenko ◽  
Le Thanh Hai ◽  
Khu Thi Khanh Dung ◽  
...  

The results of studies of resistance to antibiotics microflora isolated from mucous pharynx and rectum of patients intensive care unit newborns of National Hospital of Pediatrics, Hanoi are presented. It is shown that gram-negative bacteria isolated from children have a high resistance to penicillins, cephalosporins and carbapenem. Antibiotic resistance of bacteria isolated from children receiving treatment in «pure» block did not differ from sustainability of the strains, selected from children in «dirty» block.


1995 ◽  
Vol 20 (5) ◽  
pp. 308-311 ◽  
Author(s):  
Aurora Fernández-Astorga ◽  
María Joseé Hijarrubia ◽  
María Hernández ◽  
Ines Arana ◽  
Ester Suñen

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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