scholarly journals The persistance of drug resistant Escherichia coli strains in the majority faecal flora of calves

1984 ◽  
Vol 93 (3) ◽  
pp. 547-557 ◽  
Author(s):  
M. Hinton ◽  
P. D. Rixson ◽  
Vivien Allen ◽  
A. H. Linton
Keyword(s):  
Escherichia Coli ◽  
Drug Resistance ◽  
Resistance Index ◽  
The Other ◽  
Antibacterial Drug ◽  
Drug Resistant ◽  
Faecal Flora ◽  
Resistance Determinants ◽  
Veterinary School ◽  
Antibacterial Drug Resistance

SummaryTwo groups of calves, one of three and the other of two animals, were purchased in markets and reared initially on a commercial veal unit for 1 month and 4 months respectively. They were then moved to the Veterinary School, Langford, and kept for a further 6 and 4 months respectively. The animals were sampled weekly and a continual turnover in the strains forming the majority Escherichia coli faecal flora was demonstrated for all calves. Antibacterial-drug resistance, as measured by an Antibiotic Resistance Index (ARI), increased after arrival on the veal unit and persisted at high levels during the whole of their stay. After moving to Langford the ARI fell. Initially there was a reduction in the average number of resistance determinants per resistant strain and then, after a delay of up to 8 weeks, by an increase in the proportion of isolates that were fully sensitive. The source of the sensitive strains was not ascertained, although their appearance was not associated specifically with either weaning or turning out to pasture.

scholarly journals The persistence of drug resistant Escherichia coli in the intestinal flora of healthy broiler chicks

1982 ◽  
Vol 89 (2) ◽  
pp. 269-278 ◽  
Author(s):  
M. Hinton ◽  
Z. A. M. Al-Chalaby ◽  
Vivien Allen ◽  
A. H. Linton
Keyword(s):  
Escherichia Coli ◽  
Intestinal Flora ◽  
Broiler Chicks ◽  
Antibacterial Drug ◽  
Multiple Resistance ◽  
Drug Resistant ◽  
Gut Flora ◽  
Faecal Flora ◽  
Antibacterial Drugs ◽  
E Coli

SUMMARYAntibacterial drugs (oxytetracycline, streptomycin and sulphonamides) were included in the drinking water of healthy broiler chicks from the sixth to the twentieth day of life to select a resistant gut flora. On the twenty-first day the birds were divided into three groups and reared in separate rooms until 100 days of age. One group was housed in cages with wire floors while the others were reared on litter. Faeces from adult hens were added regularly to the litter of one of these groups to determine its effect on the gut flora of the chicks.The ecology of Escherichia coli was studied using O-serotyping, biotyping and antibacterial drug resistogram typing. The proportion of E. coli in the dominant faecal flora resistant to two to four antibacterial drugs increased with time to reach a peak several days after the drugs were withdrawn. Thereafter, the level of drug resistance in the E. coli declined equally in all three groups. The majority of organisms with multiple resistance were derived from biotypes of O-serotypes initially resistant to only one drug and were identified before the drugs were administered. The decline in the level of resistance in the dominant faecal flora after the fourth week was due to the appearance of either new O-serotypes or new biotypes of O-serotypes previously shown to be multiply resistant, and which were either sensitive or resistant to only one drug. It is probable that these new strains were derived from the food since several O-serotypes appeared simultaneously in all three groups of birds.

scholarly journals On the Mechanism of Berberine–INF55 (5-Nitro-2-phenylindole) Hybrid Antibacterials

2014 ◽  
Vol 67 (10) ◽  
pp. 1471 ◽  
Author(s):  
Naveen K. Dolla ◽  
Chao Chen ◽  
Jonah Larkins-Ford ◽  
Rajmohan Rajamuthiah ◽  
Sakthimala Jagadeesan ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Antibacterial Activity ◽  
Multidrug Resistance ◽  
Inhibitory Activity ◽  
Antibacterial Drug ◽  
Antibacterial Mechanism ◽  
Antibacterial Effects ◽  
Antibacterial Drug Resistance

Berberine–INF55 hybrids are a promising class of antibacterials that combine berberine and the NorA multidrug resistance pump inhibitor INF55 (5-nitro-2-phenylindole) together in one molecule via a chemically stable linkage. Previous studies demonstrated the potential of these compounds for countering efflux-mediated antibacterial drug resistance but they didn’t establish whether the compounds function as originally intended, i.e. with the berberine moiety providing antibacterial activity and the attached INF55 component independently blocking multidrug resistance pumps, thereby enhancing the activity of berberine by reducing its efflux. We hypothesised that if the proposed mechanism is correct, then hybrids carrying more potent INF55 pump inhibitor structures should show enhanced antibacterial effects relative to those bearing weaker inhibitors. Two INF55 analogues showing graded reductions in NorA inhibitory activity compared with INF55 were identified and their corresponding berberine–INF55 hybrids carrying equivalent INF55 inhibitor structures synthesised. Multiple assays comparing the antibacterial effects of the hybrids and their corresponding berberine–INF55 analogue combinations showed that the three hybrids all show very similar activities, leading us to conclude that the antibacterial mechanism(s) of berberine–INF55 hybrids is different from berberine–INF55 combinations.

Further studies on the use of chicken embryo infections for the study of drug resistance in Eimeria tenella

Parasitology ◽  
1976 ◽  
Vol 73 (3) ◽  
pp. 275-282 ◽  
Author(s):  
H. D. Chapman
Keyword(s):  
Drug Resistance ◽  
Drug Concentration ◽  
Chicken Embryo ◽  
The Other ◽  
Cross Resistance ◽  
Drug Resistant ◽  
Mutagenic Agent ◽  
Development Of Resistance ◽  
Drug Concentrations ◽  
Resistant Lines

Infections in the chicken embryo have been used to study the development of drug resistance in an embryo adapted strain of E. tenella. Resistance was developed to decoquinate, clopidol and robenidine by serially passaging this strain, but evidence for the development of resistance to amprolium was inconclusive. Resistance to decoquinate developed more readily than to the other drugs. Attempts to increase resistance to clopidol, robenidine and amprolium by increasing the sporozoite inoculum and by the use of a mutagenic agent were unsuccesful. No cross-resistance was found between the 4 drugs.Drug resistant lines of the Houghton strain (H) of E. tenella, made resistant to the 4 anticoccidial drugs by passage in chickens, were found to be resistant when evaluated using chicken embryo infections. Lines made resistant to decoquinate were not controlled by any concentration of this drug, suggesting that resistance, once developed, was absolute and not dependent on drug concentration. Lines made resistant to robenidine, clopidol and amprolium, however, were controlled by higher drug concentrations suggesting that in this case resistance was dependent on drug concentration.

scholarly journals Regulatory opportunities to encourage technology solutions to antibacterial drug resistance

2011 ◽  
Vol 66 (9) ◽  
pp. 1945-1947 ◽  
Author(s):  
R. Finch ◽  
M. Blaser ◽  
O. Carrs ◽  
G. Cassell ◽  
N. Fishman ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Antibacterial Drug ◽  
Antibacterial Drug Resistance

scholarly journals Multiple Mechanisms Synergistically Induce Pseudomonas Aeruginosa Multiple Drug Resistance

2021 ◽  
Author(s):  
Lulu Yang ◽  
Fangyan Jiao ◽  
Ousman Bajinka ◽  
Khalid A Abdelhalim ◽  
Guojun Wu ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Drug Resistance ◽  
Multiple Drug Resistance ◽  
Multiple Drug ◽  
Antibacterial Drug ◽  
Sequencing Analysis ◽  
Drug Resistant ◽  
Carbapenem Resistant ◽  
Resistant Genes ◽  
Epidemiological Characteristics

Abstract Background: This study was designed to detect the molecular epidemiological characteristics and resistant mechanism of carbapenem resistant Pseudomonas aeruginosa (CRPA) which provide reference for the prevention and treatment of hospital CRPA infection. Methods: 34 strains of CRPA from 2018 to 2019 were isolated and their resistance to 13 commonly used antibiotics was detected using TDR-300B Plus VitEK-2 compact automatic bacterial identification instrument. Then carbapenemase production was detected using Carbe NP test. The efflux pumps MexA and outer membrane protein OprD proteins were detected using RT-PCR and class Ⅰ integron carried with drug-resistant genes were detected using PCR and sequences analysis. Results: Among 34 strains of CRPA, 22 strains were multiple drug resistance (MDR) and 5 strains were extensively drug-resistant (XDR). The results of class Ⅰ integron carried drug-resistant gene sequencing analysis showed the class Ⅰ integron mainly carried aminoglycoside or quinolone antibacterial drug resistant genes. Conclusion: Multiple mechanisms play an important role in the formation and development of MDR or XDR resistance.

Transferred drug-resistance in Eimeria maxima

Parasitology ◽  
1975 ◽  
Vol 71 (3) ◽  
pp. 385-392 ◽  
Author(s):  
L. P. Joyner ◽  
C. C. Norton
Keyword(s):  
Drug Resistance ◽  
The Other ◽  
Drug Resistant ◽  
Resistance Factors ◽  
Eimeria Maxima ◽  
Series Of Experiments ◽  
Resistant Strains ◽  
Drug Resistant Strains

A series of experiments is described in which two drug-resistant strains of Eimeria maxima were passaged together in untreated chicks. The resultant oocysts were then inoculated into chicks treated with both drugs. When strains resistant to methyl benzoquate and sulphaquinoxaline or clopidol and sulphaquinoxaline were used the resultant infections were not controlled by the double treatment, indicating the acquisition of resistance factors by one strain from the other. When strains resistant to clopidol and methyl benzoquate were used the phenomenon was not observed.

scholarly journals Opportunities for Overcoming Mycobacterium tuberculosis Drug Resistance: Emerging Mycobacterial Targets and Host-Directed Therapy

2019 ◽  
Vol 20 (12) ◽  
pp. 2868 ◽  
Author(s):  
Eveline Torfs ◽  
Tatiana Piller ◽  
Paul Cos ◽  
Davie Cappoen
Keyword(s):  
Drug Resistance ◽  
Mycobacterium Tuberculosis ◽  
Antibiotic Susceptibility ◽  
Treatment Options ◽  
The Other ◽  
Adjunctive Treatment ◽  
Lung Pathology ◽  
Drug Resistant ◽  
Novel Treatment ◽  
Novel Targets

The ever-increasing incidence of drug-resistant Mycobacterium tuberculosis infections has invigorated the focus on the discovery and development of novel treatment options. The discovery and investigation of essential mycobacterial targets is of utmost importance. In addition to the discovery of novel targets, focusing on non-lethal pathways and the use of host-directed therapies has gained interest. These adjunctive treatment options could not only lead to increased antibiotic susceptibility of Mycobacterium tuberculosis, but also have the potential to avoid the emergence of drug resistance. Host-directed therapies, on the other hand, can also reduce the associated lung pathology and improve disease outcome. This review will provide an outline of recent opportunities.

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