ABSTRACT
Objective To evaluate the effectiveness of MGIT liquid medium fluorescence instrument manual interpretation method for rapid detection of Mycobacterium. Methods Two hundred sputa with newly diagnosed tuberculosis patients were collected from October 2008 to January 2009 in the district hospitals in Shanghai. Of these 200 sputa, 67 sputa were positive AFB, 133 were negative. All the sputa were isolated by L-J, BacT / Alert 3D system and MGIT liquid medium methods. Results Of the 200 sputa specimens,105(52. 5% ) were isolated as Mycobacterium strains. The positive culture rate of the MGIT, BacT/Alert 3D and L-J method was 49. 5% ( 99/200 ), 48. 0% (96/200) and 45.0% ( 90/200), respectively. The MGIT culture positive rate was significantly higher than that of L-J method (x2 = 5.40, P = 0. 020 1 ). Of the 133 sputa with negative AFB, the positive culture rate was 24. 8% ( 33/133 ), 23. 3% ( 31/133 ) and 18. 8% (25/133) with MGIT, BacT/Alert 3D and L-J method, respectively. The MGIT culture positive rate with the AFB negative sputum was significantly higher than that of L-J method (x2 = 5. 33, P = 0. 020 9 ).The median time of detection with MGIT, BacT/Alert 3D system and L-J method was 11 days, 15 days and 22 days, respectively. Comparing the median time of detection of MGIT with BacT/Alert 3D, the difference was statistically significant ( Z = 3.414 ,P ＜ 0. 01 ). Comparing the median time of detection of MGIT with L-J method, the difference was statistically significant (Z =7.083,P＜0. 01).Conclusions MGIT liquid medium manual method is a rapid detection method of Mycobacterium with a high positive detection rate, and do not need expensive equipment This method may suitable to resource limited medical institutions due to its low cost and short round time.
ABSTRACT
Objective To investigate the prevalence and risk factor of Ofloxacin resistance among the tuberculosis patients in Shanghai.Methods Totally 447 isolates resistant to anyone of first-line drug (Isoniazid,Rifampicin,Streptomycin and Ethambutol) and 151 randomly selected isolates susceptible to all above drugs were collected from district tuberculosis(TB) hospitals in Shanghai during 2009 to 2010.All 598 isolates were subject to Ofloxacin sensitive test.Logistic regression analysis was conducted to determine risk factors of Ofloxacin resistance.DNA sequencing was applied to study the mutation characteristics in gyrA and gyrB among Ofloxacin resistant isolates.Results Seventy-two(16.1%) of the 447 drug-resistant isolates were found resistant to Ofloxacin,and the Ofloxacin resistant rate among multiple drug-resistant (MDR) isolates was 39.6%(44/111).Ofloxacin resistance was also found in 4(2.6%) of the 151 drug sensitive isolates.Logistic regression analysis showed that first-line drug-resistance MDR(resistant to at least rifampin and isoniazid) and poly-drug resistance(resistance to two or more first-line drugs but not MDR) had significant effect on Ofloxacin resistance(OR = 19.5、5.6,95% CI:6.4 - 59.4、1.7 - 18.1,all P＜ 0.05);re-treatment(OR = 2.3,95 % CI:1.2 -4.0,P＜ 0.05),and a higher age(OR = 1.03,95 % CI:1.0 1 - 1.05,P＜ 0.05)were also significantly associated with Ofloxacin resistance.Resistance mutations in the gyrA and gyrB genes were detected in 62 of 76(81.6%) isolates with phenotypic Ofloxacin-resistance. Conclusions The Ofloxacin resistance rate in Shanghai MDR-TB patients is significantly higher than the pan-susceptible TB patients.Risk factors of ofloxacin resistance are MDR,poly-resistant,retreated patients,age.Among them,MDR has the highest strength of association.