Luciferase Reporter Mycobacteriophage (LRP) Assays for Diagnosis of Antibiotic Resistant Mycobacterium tuberculosis

(http://www.nih.gov/researchmatters/march2009/03092009tuberculosis.htm)(http://www.biochem.wisc.edu/faculty/rayment/lab/gallery.aspx)

Clare Bruggeman

General TB Information

WHO reported 9.9 million incident cases of TB in 2008.

TB is treatable, yet it killed 2.3 million people in 2008.

TB diagnostic tools are old-fashioned. Goal is to develop an inexpensive,

rapid and accurate tool to diagnose TB, MDR TB and XDR TB.

Pulmonary Tuberculosis

Primary Infection in the Lungs

Cough Coughing up blood Chest pain

http://www.path.cam.ac.uk/partIB_pract/P09/

Symptoms of TuberculosisTB in Other Organs Kidney

Blood in urine Brain

Headache and fever

Spine Extreme

Curvature of the spine

http://www.merck.com/mmhe/sec17/ch193/ch193a.htmlhttp://www.path.cam.ac.uk/partIB_pract/P09/

Diagnosis and Treatment Although TB is less common in developed

countries, there are a few highly burdened countries that have 80% of the reported TB cases (WHO 2009 Report).

DOTS-Directly Observed Therapy TB can be treated if patients adhere to a

strict, multi-drug regimen. 6-12 months of antibiotic treatment Attempting to prevent the spread of

multi-drug resistant strains.

Acid-Fast Stain (DOTS)

http://pathmicro.med.sc.edu/infectious%20disease/mycobacterial%20diseases.htm

Fails to identify 30-50% of active cases

BACTEC and MGIT

Luciferase Reporter Mycobacteriophages

1. Find a mycobacteriophage that infects M. tuberculosis

2. Genetically engineer the mycobacteriophage to contain luciferase.

3. Infect the cultured sputum sample with the phage.4. If viable mycobacteria are present, light is

produced in the presence of D-luciferin.5. If the light does not diminish when the

mycobacteria are treated with an antibiotic, then the mycobacteria are resistant.

6. Measure Relative Light Units (RLU) with a luminometer.

Banaiee et al. (2001)

Luciferase

http://www.lifesci.ucsb.edu/~biolum/chem/

Construction of the mycobacteriophage

Schematic of phAE39 and phAE40 DNA. Constructed in the E. coli cosmid pYUB216, then inserted into TM4 mycobacteriophage.

ColE1 = ORI Ap = Amp (selectable marker for E. coli).Phsp60 = promoter Fflux = firefly luciferase (Jacobs 1993)

Banaiee et al. (2001)

NTM = Nontuberculosis mycobacterium

MTC = M. tuberculosis complex

Banaiee et al. (2001)

Banaiee et al. (2001)

Only really changing the detection method and maybe the culture media.

Conclusions: LRP has the potential to be the rapid and affordable method that

developing countries need to diagnose active TB, MDR TB and XDR TB.

76% of positive smears were identified with LRP If contamination is minimized and both solid and liquid media

methods are used, LRP efficiency increases to 97%. 94% sensitivity and 100% specificity to MTC(agreement between

BACTEC and LRP) LRP determination of drug resistance was possible within 2-4 days

Concern: Phage resistant TB strains or phages with too broad of a host range.

Banaiee et al. (2001)

Kumar et al. (2008)

Had evidence that a temperate phage (compared to a lytic phage) might have increased light output (i.e. better sensitivity).

Collected phage samples near a tuberculosis sanatorium in India

Che12 was a likely candidate (formed turbid plaques on a lawn of M. smegmatis).

Kumar et al. (2008)

+ -

M. smegmatisM. tuberculosis

Kumar et al. (2008)

Conclusions Che12 infects M. smegmatis and M. tuberculosis.

▪ In the lab you can work with the safer M. smegmatis Che12 integrates with the host genome. phAETRC16 had increased and sustained light

output Che12 is the first true temperate phage that

infects M. tuberculosis. Hope that Che12 will be useful for assays and

vaccine construction because of the sustained light production.

Kumar et al. (2008)

Final Conclusions

“The LRP assay appears to be the most consistently accurate test” (Minion and Pai, 2010).

But the method is still slow, requires non-contaminated samples, and uses up antibiotics during susceptibility tests.

ReferencesMinion, J., and M. Pai. 2010. “Bacteriophage assays for rifampicin resistance detection in

Mycobacterium tuberculosis: updated meta-analysis.” Int J Tuberc Lung Dis 14 (8): 941-951.

WHO.int. 2010. The World Health Organization. 29 October 2010. <http://www.who.int/en >.

CDC.gov. 2010. The Center for Disease Control and Prevention. 29 October 2010. <http://www.cdc.gov >.

“Hypersensitivity.” 2010. Practical Pathology Class Website. Department of Pathology,

University of Cambridge. 29 October 2010. <http://www.path.cam.ac.uk/partIB_pract/P09/ >.

Kumar, V., P. Loganathan, G. Sivaramakrishnan, J. Kriakov, A. Dusthakeer, B. Subramanyam, J. Chan, W. Jacobs Jr. and N. Paranji Rama. 2008. “Characterization of temperate phage Che 12 and construction of a new tool for diagnosis of tuberculosis.” Tuberculosis 88, 616-623.

Banaiee, N., M. Bobadilla-del-Valle, S. Bardarov Jr., P. F. Riska, P. M. Small, A. Ponce-de-Leon, W. Jacobs Jr., G. F Hatfull and J. Sifuentes-Osornio. 2001. “Luciferase Reporter Mycobacteriophages for Detection, Identification, and Antibiotic Susceptibility Testing of Mycobacterium tuberculosis in Mexico.” J Clin Microbiol 39 (11), 3883-3888.

Gali, N. J. Dominquez, S. Blanco, C. Prat, F. Alcaide, P. Coll, V. Ausina and the Mycobacteria Research Group of Barcelona. 2006. “Use of a mycobacteriophage-based assay for rapid assessment of susceptibilities of Mycobacterium tubersulosis isolates to isoniazid and influence of resistance level on assay performance.” J Clin Microbiol 44(1) 201-205.

Jacobs, W. R. Jr, R. G. Barletta, R. Udani, J. Chan, G. Kalkut, G. Sosne, T. Kieser, G. Sarkis, G. Hatfull, B. Bloom. 1993. “Rapid Assessment of Drug Susceptibilites of Mycobacterium tuberculosis by Means of Luciferase Reporter Gene.” Science, New Series 260 (5109) 819-22.