We investigated the phylogenetic diversity of the bacterial isolates, as well as the minimum inhibitory concentration (MIC) of OTC, the occurrence of major OTC-resistant genes and multiple-antibiotic resistance in the isolates.\n\nMethods and Results:\n\nShrimps were collected from culture ponds, and the homogenates of whole bodies were plated on tryptic soy agar supplemented PPAR inhibitor with or without OTC. Percentages of OTC-resistant bacteria were 0 center dot 3-52 center dot 1% in white-leg samples and 0 center dot
008-22 center dot 3% in black tiger samples. Analyses of 16S rDNA sequences indicated that most OTC-resistant isolates were closely related to Aeromonas spp. and Lactococcus garvieae. MICs of OTC were 4-128 mu g ml-1 in the OTC-resistant aeromonads and 128-256 mu g ml-1 in OTC-resistant L. garvieae. OTC resistance was found to be conferred by the genes tet(A), tet(C), tet(D), tet(E), tet(M) and tet(S), detected either singly or in pairs. No resistance to ceftazidime, imipenem or chloramphenicol was observed in any
isolate.\n\nConclusions:\n\nBoth species of shrimp are associated with OTC-resistant bacteria, occasionally at high densities exceeding 106 cfu g-1. The associated bacteria, P5091 predominantly Lactococcus and Aeromonas genera, are potential pathogens and are reservoirs of a variety of OTC-resistant genes.\n\nSignificance and Impact of the Study:\n\nCultured shrimps can be vehicle to carry OTC-resistant bacteria to domestic and foreign consumers via the food chain. Very low populations of OTC-resistant bacteria observed in the several ponds suggest that levels of the resistant bacteria are artificially high and should be reduced in farmed shrimps.”
“Phenotypic Epigenetic Reader Do inhibitor variability in populations of cells has been linked to evolutionary robustness to stressful conditions.
A remarkable example of the importance of cell-to-cell variability is found in bacterial persistence, where subpopulations of dormant bacteria, termed persisters, were shown to be responsible for the persistence of the population to antibiotic treatments. Here, we use microfluidic devices to monitor the induction of fluorescent proteins under synthetic promoters and characterize the dormant state of single persister bacteria. Surprisingly, we observe that protein production does take place in supposedly dormant bacteria, over a narrow time window after the exit from stationary phase. Only thereafter does protein production stop, suggesting that differentiation into persisters fully develops over this time window and not during starvation, as previously believed. In effect, we observe that exposure of bacteria to antibiotics during this time window significantly reduces persistence. Our results point to new strategies to fight persistent bacterial infections.