Abstract:
The present study aimed to identify and to characterize multi
drug resistant Mycobacterium tuberculosis among tuberculous
patients in Khartoum state using Lowenstein Jensen Proportion
method and polymerase chain reaction technique(PCR).
One hundred and thirty ZN positive sputum specimens were
collected from patients with tuberculosis referred to different
T.B. centers in Khartoum state (88 specimens from National
Health Center, 42 specimens from Abu Anga and El shaab
hospitals).
All sputum samples were cultivated on Lj medium .119 (91.5%)
samples of AFB-positive showed characteristic growth of
Mycobacterium tuberculosis,while 5 isolates showed typical
growth of MOTTs and 6 speciemens showed no growth.
Different biochemical tests were selected , these include
catalase ,nitrate ,TCH and PNB,the results of these tests revealed
the following,124(100%)isolates showed negative for catalase at
68 ْC while 122(93.3%) positive at RT,108(87%) were nitrate
positive ,107(86.2%) showed resistance to TCH and 119(95.9%)
were sensitive to PNB.
Sixty five isolates were selected randomly and subjected to
PCR,the result revealed that fifty six of the isolates showed
typical band of 123bp,with sensitivity of 91% comparing with
cultur technique.
The result of antibiotics susceptibility testing using proportion
conventional method revealed that 30 (23%) of the speciemens
were Rifampicin resistant, 35 (26.9%) were Isoniazid resistant
and 28 (21.5%) were resistant for both drugs (MDR). In contrast,
PCR assay for drug resistance showed that a resistant rate of 20
(15.3%) for Rifampicin, 30 (23%) for Isoniazid and 15 (11.5%)
for both drugs (MDR).
In conclusion; the rapid specific PCR for the identification of
MDR M.tuberculosis, can substitute the hazardous slow
conventional methods. However, multiplex and nested PCR will
provide accurate reliable results.
