Limits...
Antimicrobial resistance characteristics and fitness of Gram-negative fecal bacteria from volunteers treated with minocycline or amoxicillin.

Kirchner M, Mafura M, Hunt T, Abu-Oun M, Nunez-Garcia J, Hu Y, Weile J, Coates A, Card R, Anjum MF - Front Microbiol (2014)

Bottom Line: A yearlong study was performed to examine the effect of antibiotic administration on the bacterial gut flora.Following amoxicillin administration, an increase in the proportion of amoxicillin resistant E. coli and a three-fold increase in the levels of bla TEM gene carriage was observed, an effect not observed in the other two treatment groups.Although there were no unique characteristics associated with plasmids from persistent or transient isolates, PM assays showed transient isolates had greater adaptability to a range of antiseptic biocides and tetracycline; characteristics which were lost in some, but not all persistent isolates.

View Article: PubMed Central - PubMed

Affiliation: Department of Bacteriology, Animal and Plant Health Agency Addlestone, UK.

ABSTRACT
A yearlong study was performed to examine the effect of antibiotic administration on the bacterial gut flora. Gram-negative facultative anaerobic bacteria were recovered from the feces of healthy adult volunteers administered amoxicillin, minocycline or placebo, and changes determined in antimicrobial resistance (AMR) gene carriage. Seventy percent of the 1039 facultative anaerobic isolates recovered were identified by MALDI-TOF as Escherichia coli. A microarray used to determine virulence and resistance gene carriage demonstrated that AMR genes were widespread in all administration groups, with the most common resistance genes being bla TEM, dfr, strB, tet(A), and tet(B). Following amoxicillin administration, an increase in the proportion of amoxicillin resistant E. coli and a three-fold increase in the levels of bla TEM gene carriage was observed, an effect not observed in the other two treatment groups. Detection of virulence genes, including stx1A, indicated not all E. coli were innocuous commensals. Approximately 150 E. coli collected from 6 participants were selected for pulse field gel electrophoresis (PFGE), and a subset used for characterisation of plasmids and Phenotypic Microarrays (PM). PFGE indicated some E. coli clones had persisted in volunteers for up to 1 year, while others were transient. Although there were no unique characteristics associated with plasmids from persistent or transient isolates, PM assays showed transient isolates had greater adaptability to a range of antiseptic biocides and tetracycline; characteristics which were lost in some, but not all persistent isolates. This study indicates healthy individuals carry bacteria harboring resistance to a variety of antibiotics and biocides in their intestinal tract. Antibiotic administration can have a temporary effect of selecting bacteria, showing co-resistance to multiple antibiotics, some of which can persist within the gut for up to 1 year.

No MeSH data available.


Related in: MedlinePlus

The percentage of isolates carrying the most common antibiotic resistance associated genes detected during the study. A total of 1039 isolates were tested, 413 of these isolates were collected from volunteers given a placebo, 378 from those given amoxicillin and 248 from those given minocycline.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4269195&req=5

Figure 1: The percentage of isolates carrying the most common antibiotic resistance associated genes detected during the study. A total of 1039 isolates were tested, 413 of these isolates were collected from volunteers given a placebo, 378 from those given amoxicillin and 248 from those given minocycline.

Mentions: The most frequently detected genes in all species are shown in Figure 1. All these genes were more frequently associated with E. coli. The exception to this was the gene encoding the AmpC-type enzyme CMY, which was detected in 64% of the Citrobacter spp. (C. freundii, C. braakii, C. youngae, and C. koseri). Overall i.e., from all time points in the study, 36.9% of all isolates had a MDR genotype (see Methods for definition); while approximately 50% of all the E. coli tested had an MDR genotype.


Antimicrobial resistance characteristics and fitness of Gram-negative fecal bacteria from volunteers treated with minocycline or amoxicillin.

Kirchner M, Mafura M, Hunt T, Abu-Oun M, Nunez-Garcia J, Hu Y, Weile J, Coates A, Card R, Anjum MF - Front Microbiol (2014)

The percentage of isolates carrying the most common antibiotic resistance associated genes detected during the study. A total of 1039 isolates were tested, 413 of these isolates were collected from volunteers given a placebo, 378 from those given amoxicillin and 248 from those given minocycline.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4269195&req=5

Figure 1: The percentage of isolates carrying the most common antibiotic resistance associated genes detected during the study. A total of 1039 isolates were tested, 413 of these isolates were collected from volunteers given a placebo, 378 from those given amoxicillin and 248 from those given minocycline.
Mentions: The most frequently detected genes in all species are shown in Figure 1. All these genes were more frequently associated with E. coli. The exception to this was the gene encoding the AmpC-type enzyme CMY, which was detected in 64% of the Citrobacter spp. (C. freundii, C. braakii, C. youngae, and C. koseri). Overall i.e., from all time points in the study, 36.9% of all isolates had a MDR genotype (see Methods for definition); while approximately 50% of all the E. coli tested had an MDR genotype.

Bottom Line: A yearlong study was performed to examine the effect of antibiotic administration on the bacterial gut flora.Following amoxicillin administration, an increase in the proportion of amoxicillin resistant E. coli and a three-fold increase in the levels of bla TEM gene carriage was observed, an effect not observed in the other two treatment groups.Although there were no unique characteristics associated with plasmids from persistent or transient isolates, PM assays showed transient isolates had greater adaptability to a range of antiseptic biocides and tetracycline; characteristics which were lost in some, but not all persistent isolates.

View Article: PubMed Central - PubMed

Affiliation: Department of Bacteriology, Animal and Plant Health Agency Addlestone, UK.

ABSTRACT
A yearlong study was performed to examine the effect of antibiotic administration on the bacterial gut flora. Gram-negative facultative anaerobic bacteria were recovered from the feces of healthy adult volunteers administered amoxicillin, minocycline or placebo, and changes determined in antimicrobial resistance (AMR) gene carriage. Seventy percent of the 1039 facultative anaerobic isolates recovered were identified by MALDI-TOF as Escherichia coli. A microarray used to determine virulence and resistance gene carriage demonstrated that AMR genes were widespread in all administration groups, with the most common resistance genes being bla TEM, dfr, strB, tet(A), and tet(B). Following amoxicillin administration, an increase in the proportion of amoxicillin resistant E. coli and a three-fold increase in the levels of bla TEM gene carriage was observed, an effect not observed in the other two treatment groups. Detection of virulence genes, including stx1A, indicated not all E. coli were innocuous commensals. Approximately 150 E. coli collected from 6 participants were selected for pulse field gel electrophoresis (PFGE), and a subset used for characterisation of plasmids and Phenotypic Microarrays (PM). PFGE indicated some E. coli clones had persisted in volunteers for up to 1 year, while others were transient. Although there were no unique characteristics associated with plasmids from persistent or transient isolates, PM assays showed transient isolates had greater adaptability to a range of antiseptic biocides and tetracycline; characteristics which were lost in some, but not all persistent isolates. This study indicates healthy individuals carry bacteria harboring resistance to a variety of antibiotics and biocides in their intestinal tract. Antibiotic administration can have a temporary effect of selecting bacteria, showing co-resistance to multiple antibiotics, some of which can persist within the gut for up to 1 year.

No MeSH data available.


Related in: MedlinePlus