Genotypic Diversity among Isoniazid-Resistant Isolates of <i>Mycobacterium tuberculosis</i> from Rashid Hospital in Dubai, United Arab Emirates

Abstract

Objective: To perform molecular fingerprinting for strain relatedness among isoniazid-resistant Mycobacterium tuberculosis isolates recovered from tuberculosis (TB) patients in the United Arab Emirates (UAE). Materials and Methods: Thirty-two consecutive isoniazid-resistant M. tuberculosis strains isolated from TB patients (4 natives and 28 expatriates) at Rashid Hospital, Dubai, UAE were analyzed. The typing was carried out by touchdown double-repetitive-element PCR (DRE-PCR). The status of R463 or L463 polymorphism and the presence of S315T mutation in the katG gene were also determined for isolates exhibiting cluster pattern in DRE-PCR. Results: All the 32 isolates (28 from expatriate patients and 4 from UAE nationals) exhibited 21 distinct patterns in DRE-PCR with 20 of 32 isolates exhibiting unique patterns and the remaining 12 exhibiting cluster ‘A’ pattern. All the isolates (19 of 19) yielding two or more DNA fragments in DRE-PCR were unique strains. The genotypic heterogeneity among 10 of the 12 cluster isolates was suggested by the varying susceptibility of these isolates to anti-TB drugs, presence of R463 or L463 polymorphism in the katG gene and the presence or absence of S315T mutation in the katG gene. Conclusion: The genotypic diversity among isoniazid-resistant M. tuberculosis isolates mostly recovered from expatriate patients indicates that most expatriates were infected with a unique strain imported, most likely, from their country of origin and that their latent infection was reactivated in UAE.

Extensive transmission of isoniazid resistant M. tuberculosis and its association with increased multidrug-resistant TB in two rural counties of eastern China: A molecular epidemiological study

“…This could be explained by the maintenance of the 30%~40% catalase-peroxidase activity in the INH resistant strain with the katG 315 Thr mutation [5,6] compared to other mutations related to drug resistance. Consequently, this allele was suspected as the cause of some earlier reported outbreaks [26-28] of INH resistant TB in specific areas and populations. Furthermore, the current study observed that in a cluster containing strains with different drug resistance profile and resistance conferring mutations, the INH resistance was caused by this mutation.…”

Current Status and the Epidemiology of Malaria in the Middle East Region and Beyond

“…The expatriates mostly originate from poor/developing countries of south/southeast Asia (e.g., India, Pakistan, Afghanistan, Nepal, Bangladesh, Sri Lanka, and Philippines) and Africa (e.g., Ethiopia, Sudan and Nigeria) where many infectious diseases such as malaria, tuberculosis, taeniasis etc. are endemic [4,5,[14][15][16][17][18][19][20]. The number of malaria cases reported from the countries from which most of the expatriates working in GCC countries originate and the number of expatriates from these countries presently living in GCC countries are provided in Table 2.…”

“…As stated above, many countries in the Middle East Region, particularly GCC countries have a large expatriate population [14,[16][17][18][19][39][40][41][42]. Many expatriates originate from malaria endemic countries such as Sudan, Ethiopia and Nigeria in Africa and India, Pakistan, Afghanistan, Bangladesh and Philippines in Asia.…”

Infectious diseases in the Arabian Peninsula and Egypt

“…In the GCC countries, expatriate workers from countries with a high prevalence of TB contribute to the occurrence of new cases and sustained TB transmission [2–5]. In Saudi Arabia, the TB incidence rate among expatriates doubles that for Saudi nationals and most non‐Saudi patients originate from countries with high TB endemicity [5,6].…”