Diversity of aminoglycoside modifying enzymes and 16S rRNA methylases in Acinetobacter baumannii and Acinetobacter nosocomialis species in Iran; wide distribution of aadA1 and armA.

PURPOSE: Acinetobacter baumannii-calcoaceticus complex (ABC) make a great burden on health-care systems due to hospital-acquired infections and antibacterial resistance. Aminoglycoside in combination with other antibacterials used as treatment options. However, ABC species overcome this class of antibacterials in different ways. This study provides a comprehensive report on the distribution of aminoglycoside modifying enzymes (AMEs) and 16S rRNA methylase in Acinetobacter baumannii and Acinetobacter nosocomialis isolated from various provinces in Iran. METHODS: During six month of study, from eight referral centers in seven provinces across the country, Iran, 178 A. baumannii and 43 A. nosocomialis isolates were collected. The minimum inhibitory concentration of amikacin, gentamicin, netilmicin, kanamycin and tobramycin were measured by microbroth dilution method. AMEs and 16S rRNA methylase variants were sought by PCR. RESULTS: High rates of resistance were seen in all centers. MIC50 and MIC90 for all A. baumannii and A. nosocomialis isolates from different centers were > 512 mg/L. The most frequent AME was ant(3″)-Ia (aadA1) in both of A. baumannii (74.1%) and A. nosocomialis (86%). armA was detected in A. baumannii and A. nosocomialis at the frequency of 41.6% and 67.4%, respectively. rmtA, B, C, D, aac(3)-Ia (aacC1) and aac(6')-Im were not detected, neither in A. baumannii nor A. nosocomialis. Moreover, aac(6')-Ih was only found in A. baumannii isolates. The distribution of some of the ARGs was limited to a definite center. CONCLUSION: The overall high-level carriage of ARGs in Acinetobacter species may limited usage of this class of antibacterials as a treatment option.

Concurrent effects of ABCB1 C3435T, ABCG2 C421A, and XRCC1 Arg194Trp genetic polymorphisms with risk of cancer, clinical output, and response to treatment with imatinib mesylate in patients with chronic myeloid leukemia.

There are a paucity and contradicted data about the impact of concurrent heredity of polymorphic genes and risk of chronic myeloid leukemia (CML). In the present study, the concurrent effects of three polymorphisms affecting the integrity of DNA consist of ABCB1 C3435T, ABCG2 C421A, and XRCC1 Arg194Trp on development of chronic myeloid leukemia were studied. Furthermore, the role of these polymorphisms in clinical and laboratory outcomes of patients was evaluated. In this case-control study, 70 CML patients and 140 healthy individuals were enrolled in the study. The clinical features of patients such as phase of disease and response to treatment and laboratory data before and after treatment with imatinib mesylate were collected. ABCB1 C3435T, ABCG2 C421A, and XRCC1 Arg194Trp single nucleotide polymorphisms were evaluated by restriction fragment length polymorphism-polymerase chain reaction. The T allele of ABCB1 C3435T, T allele of XRCC1 Arg194Trp, and C allele of ABCG2 C421A polymorphisms were significantly higher in patients than controls. TT genotype of ABCB1 and TT genotype of XRCC1 were associated with higher risk of chronic myeloid leukemia development. CC421 ABCG2/TT3435 ABCB1 and CC421 ABCG2/TT27157 XRCC1 were also correlated with a higher risk of CML. Patients with C allele of ABCB1 had poor cytogenetic response, and correlation of CC421 ABCG2/TT3435 ABCB1 diplotype with accelerated phase of CML was significant. Patients with CC421 ABCG2/TT3435 ABCB1 and CC421 ABCG2/TT27157 XRCC1 diplotypes might be at higher risk to rapid and severe development of CML and have weaker response to treatments with imatinib.