Objective To investigate the relationship between the phenotypes and the patterns of genetic mutations in the corresponding resistance genes (rpoB, katG, inhA, ahpC, rrs, rpsL, embB and gyrA) in resistant Mycobacterium tuberculosis (MTB) isolates. Methods Rifampicin-resistant gene (rpoB), isoniazid-resistant genes (katG, inhA, ahpC), streptomycin-resistant genes (rrs, rpsL), ethambutol-resistant gene (embB) and quinolinone-resistant gene (gyrA) were amplified by PCR with sequence-specific primers, then mutants screened by single-stranded conformation polymorphism (SSCP) were sequenced. Results rpoB mutation with predominant Ser450Trp pattern was 94. 9% (56/59) in 59 rifampicin-resistant isolates;katG mutation rate was 38. 9% (35/90) and the main pattern was Ser315Thr, but only 3 inhA mutants and no ahpC mutation were determined in 90 isoniazid-resistant isolates;gyrA mutation with main Asp94Gly then Ala90Val pattern was 82.4% (28/34) in 34 quinolinone-resistant isolates;the total mutation rate was 77.4% in 31 streptomycin-resistant isolates, of which 15 isolates mutated in rrs with main pattern A514C or A1041G, 10 isolates mutated in rpsL Lys88Arg;and embB mutation with main Met306Val accounted for 19.4% (6/31) in 31 ethambutol-resistant isolates. Conclusions The results showed that resistance of resistant MTB may be complicated, and DNA sequencing-based mutation analysis could efficiently detect the molecular makers such as rpoB, katG, gyrA, rrs, rpsL and embB in resistant MTB isolates. Meanwhile, it is notable that the rpoB mutation pattern in our isolates is different from previous report, further effort are needed to confirm the characteristics. The spectrum of potential resistance-related mutations in MTB clinical isolates may lay substantial foundation for the rapid molecular diagnosis and rational use of drug to MTB patients.

Objective:To analyze variant patterns and characteristics of focal physiological uptake (FPU) in the tongue on 18F-fluorodeoxyglucose (FDG) PET/CT imaging in patients without a history of oral tumor surgery and radiotherapy. Methods:A total of 6 233 consecutive patients who underwent routine whole-body PET/CT scan between January 2013 and December 2017 in the First Hospital of Shanxi Medical University were investigated retrospectively, and 324 patients with a history of oral surgery and radiotherapy were excluded, the remaining 5 909 patients (3 418 males, 2 491 females, age range: 2-95 (average: 58) years) were enrolled. A part of the patients underwent local PET/CT scan and CT scan with diagnostic dose, covering the oral cavity on mouth-opening position. The morphological characteristics of FPU patterns were analyzed, and the maximum standardized uptake value (SUV max) was measured. Results:Seventy-six FPUs in 76 patients (49 males, 27 females, age range: 40-83 (average 64) years) identified by routine whole-body PET/CT scan were confirmed by clinical examination from a specialist in stomatology or follow-up for more than 6 months. Forty-one of the 76 patients subsequently underwent local PET/CT scan and diagnostic CT scan on mouth-opening position. The incidence of FPU in the tongue was 1.29%(76/5 909). The FPU patterns could be classified into three types: type Ⅰ with FDG uptake involved only anterior part of the tongue body in the midline (near the tip of the tongue), which showed as a " dotted" shape( n=68; 1.15%, 68/5 909); type Ⅱ with FDG uptake involved mainly middle part of the genioglossus muscle, which showed as a " bar-shorted" shape ( n=5; 0.08%, 5/5 909); type Ⅲ with FDG uptake involved large part of the tongue body and the genioglossus, which showed as a " T" shape( n=3; 0.05%, 3/5 909). The SUV max in patients with type Ⅰ and type Ⅱ were 5.53(4.53, 7.30), 19.50(17.10, 22.74) respectively. The SUV max in 3 patients with type Ⅲ were 23.34, 27.50 and 35.14, respectively. Conclusion:In patients without a history of oral tumor surgery and radiotherapy, the FPU in the tongue has its specific pattern, and PET/CT scan on mouth-opening position helps to reveal the detailed features.