Characterization of Mycobacterium tuberculosis isolated from cancer patients with suspected tuberculosis infection in Egypt: identification, prevalence, risk factors and resistance pattern

Abstract

Clin Microbiol Infect 2012; 18: E438–E445 Abstract Data are sparse on Mycobacterium tuberculosis infection among patients with cancer in Egypt. We sought to detect the presence of tuberculosis (TB) disease among patients with malignant conditions and suspected TB and to study the main risk factors. Also, we compared different diagnostic procedures and detected the antimicrobial susceptibility of M. tuberculosis isolates against rifampin and isoniazid. One hundred patients were included in this study, all of them had malignant conditions and were suspected by the clinicians of having TB. Identification of M. tuberculosis in different specimens was performed by smear microscopy, followed by Lowenstein–Jensen medium and Mycobacterium growth indicator tube (MGIT) cultures and artus® real‐time PCR. In addition, an indirect MGIT anti‐TB susceptibility test was carried out against rifampin and isoniazid. A total of 76% of studied cases were found to be TB positive. The frequencies of TB‐positive cases in the bronchogenic, haematological and solid tumour malignancy groups were 21%, 25% and 30%, respectively. Significant differences between pulmonary and extrapulmonary TB in different malignancy groups were recorded. Real‐time PCR showed the highest overall diagnostic efficiency. Multidrug‐resistance of M. tuberculosis to both rifampin and isoniazid was detected in 28.6% of examined isolates. Infection in cancer patients with TB was significantly more often recorded among elderly patients and those suffering from poverty. Pulmonary TB is more common than extrapulmonary TB in patients with malignancy. Real‐time PCR is the most accurate and rapid method for TB diagnosis. MGIT‐rifampin resistance may be used as a reliable marker for detection of multidrug‐resistant TB. Diagnosis and instituting treatment course for active or latent TB infection are crucial before starting anticancer therapy.

Risk of tuberculosis in patients with solid cancers and haematological malignancies: a systematic review and meta-analysis

“…Furthermore, several studies were excluded because they expressed TB cases among cancer patients as a proportion (cumulative incidence) rather than an incidence rate, with no adjustment for the time at risk [16,37,38]. Two studies were excluded after full-text review because they reported the risk of TB in cancer patients with an increased pre-test probability of having TB (based on the assessment of clinicians [39] or chest radiographic abnormalities suspicious for TB [40]). Another study was excluded because TB was diagnosed simultaneously with cancer in the majority of cases [41].…”

Simultaneous Detection of <b><i>Mycobacterium tuberculosis</i></b> and Atypical Mycobacteria by DNA-Microarray in Egypt

“…Over the last decade, several studies were conducted regarding the burden of M. tuberculosis, its genetic diversity, and drug resistance to antimycobacterial drugs in Egypt [ 12 , 13 , 14 , 15 ]. However, very few studies have reported the clinical existence of NTM in Egypt [ 16 , 17 ].…”

Comparison of the Diagnostic Performance of Two Real-Time PCR Systems for the Detection of Mycobacterium tuberculosis in Clinical Samples

“…Bu kiti güvenle kullanılabi-leceğini önermişlerdir. Benzer bir çalışmada da klinik örnekte MTB suşlarının moleküler olarak tespit edilmeside kültür göre artus ® M. tuberculosis PCR Kit kullanılmasının doğru ve hızlı bir yön-tem olarak rapor edilmiştir (18) . Bu çalışmada klinik örneklerde kültür bulguları ile artus ® MTB-PCR bulguları karşılaştırıldığında; duyarlılık %72, özgüllük %56, PPN %62, NPN %66 olarak belirlendi ve istatistiksel açıdan fark yoktu (p>0.05).…”