Analysis of ROP signaling in the leaf epidermis of mutant tomato with low-energy ion beam.

The importance of the ROP small GTPase signaling pathway in the regulation of cellular polarity growth in eukaryotes has been thoroughly studied. In this study, we examined the LeROP small GTPase (related to Arabidopsis thaliana genome LeROP GTPase in tomato) signaling of cell polarity growth in the mutant (M-1) tomato. Interestingly, we detected expansive growth of epidermis cells in M-1, in which the leaves appeared slightly lobed shaped. However, we observed jigsaw puzzle shaped and deeply lobed shaped leaves in wild-type leaf epidermis cells. The t-test showed significant difference (P < 0.05). Based on previous studies of the AtROP gene in Arabidopsis leaf epidermis cells, we hypothesized that the growth of mutant M-1 tomato leaf epidermis cell is related to AtROP gene signal transmission. The results of reverse transcription-polymerase chain reaction showed the expression of LeROP2, LeROP4, and LeROP7 in M-1 mutants were stronger than in wild-type cells. At the flowering stage, LeROP2 GTPase showed no expression in wild-type cells, but was expressed in mutant cells. This study revealed a link between the low-energy ion beam and the ROP GTPase signaling pathway in tomato. In addition, the ROP gene changes analyzed suggest a new mechanism for mutations following low-energy ion beam implantation.

Molecular basis of high-level ciprofloxacin resistance in Neisseria gonorrhoeae strains from Shandong Province, China.

In the study, the ciprofloxacin resistance rate was 100%. High-level ciprofloxacin resistance rate was 63.55%. Sixteen different mutation patterns involved in the formation of ciprofloxacin resistance were identified. The most prevalent were patterns P7 (25.2%), P8 (15.0%), P9 (11.2%), P1 (10.3%), and P5 (10.3%). All of the 107 NG isolates analyzed for mutations in the study have demonstrated a change of Ser-91 → Phe in the gyrA gene, and all except one have demonstrated a change in position 95 of the amino acid sequence. All of the 68 high-level QRNG isolates had double mutations in gyrA gene combined with a single or two mutations in parC gene. It is most important that a new mutation site of Ile-97 → Met in gyrA and a new mutation of Leu-106 → Ile in parC were found in the study, both leading to high-level ciprofloxacin resistance (MIC values, 8 µg/mL, 32 µg/mL, respectively). Therefore, we confim that gyrA mutations are necessary for the fluoroquinolone resistance phenotype and parC mutations are correlated intimately with high-level fluoroquinolone resistance. In China fluoroquinolone resistance in Neisseria gonorrhoeae strains is very serious and the new mutation sites in the fluoroquinolone resistance-determining regions emerge more and more quickly. Hence, in China fluoroquinolones, which are used to treat gonorrhoea presently, should be substituted by a new antibiotics.

Molecular basis of high-level ciprofloxacin resistance in Neisseria gonorrhoeae strains from Shandong Province, China

In the study, the ciprofloxacin resistance rate was 100%. High-level ciprofloxacin resistance rate was 63.55%. Sixteen different mutation patterns involved in the formation of ciprofloxacin resistance were identified. The most prevalent were patterns P7 (25.2%), P8 (15.0%), P9 (11.2%), P1 (10.3%), and P5 (10.3%). All of the 107 NG isolates analyzed for mutations in the study have demonstrated a change of Ser-91 → Phe in the gyrA gene, and all except one have demonstrated a change in position 95 of the amino acid sequence. All of the 68 high-level QRNG isolates had double mutations in gyrA gene combined with a single or two mutations in parC gene. It is most important that a new mutation site of Ile-97 → Met in gyrA and a new mutation of Leu-106 → Ile in parC were found in the study, both leading to high-level ciprofloxacin resistance (MIC values, 8 µg/mL, 32 µg/mL, respectively). Therefore, we confim that gyrA mutations are necessary for the fluoroquinolone resistance phenotype and parC mutations are correlated intimately with high-level fluoroquinolone resistance. In China fluoroquinolone resistance in Neisseria gonorrhoeae strains is very serious and the new mutation sites in the fluoroquinolone resistance-determining regions emerge more and more quickly. Hence, in China fluoroquinolones, which are used to treat gonorrhoea presently, should be substituted by a new antibiotics.(AU)

Molecular basis of high-level ciprofloxacin resistance in Neisseria gonorrhoeae strains from Shandong Province, China

In the study, the ciprofloxacin resistance rate was 100%. High-level ciprofloxacin resistance rate was 63.55%. Sixteen different mutation patterns involved in the formation of ciprofloxacin resistance were identified. The most prevalent were patterns P7 (25.2%), P8 (15.0%), P9 (11.2%), P1 (10.3%), and P5 (10.3%). All of the 107 NG isolates analyzed for mutations in the study have demonstrated a change of Ser-91 → Phe in the gyrA gene, and all except one have demonstrated a change in position 95 of the amino acid sequence. All of the 68 high-level QRNG isolates had double mutations in gyrA gene combined with a single or two mutations in parC gene. It is most important that a new mutation site of Ile-97 → Met in gyrA and a new mutation of Leu-106 → Ile in parC were found in the study, both leading to high-level ciprofloxacin resistance (MIC values, 8 µg/mL, 32 µg/mL, respectively). Therefore, we confim that gyrA mutations are necessary for the fluoroquinolone resistance phenotype and parC mutations are correlated intimately with high-level fluoroquinolone resistance. In China fluoroquinolone resistance in Neisseria gonorrhoeae strains is very serious and the new mutation sites in the fluoroquinolone resistance-determining regions emerge more and more quickly. Hence, in China fluoroquinolones, which are used to treat gonorrhoea presently, should be substituted by a new antibiotics.