Identification of tigecycline- and vancomycin-resistant Staphylococcus aureus strains among patients with urinary tract infection in Iran

Abstract

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the major causes of hospital- and community-acquired infections worldwide. Although S. aureus rarely accounts for urinary tract infections (UTI), untreated UTI can lead to several complications. For decades vancomycin has been used for the treatment of MRSA infections. This study was performed to assess the in vitro activity of vancomycin, tigecycline, linezolid and quinupristin/dalfopristin against MRSA isolates from UTI patients. Thirty MRSA strains from 54 S. aureus isolates were isolated from patients with UTI. The antimicrobial susceptibility patterns of the strains were determined by the Kirby-Bauer disk diffusion and broth microdilution methods. PCR assays were used to detect the vanA gene. The MRSA isolates resistant to vancomycin were confirmed using the broth microdilution method. The results revealed that the MRSA isolates were 100% susceptible to linezolid and quinupristin/dalfopristin but 93.3% susceptible to vancomycin and tigecycline respectively. The broth microdilution method confirmed two MRSA strains (6.6%) to be resistant to vancomycin and tigecycline. The study identified vancomycin resistance among the MRSA isolates from UTI patients. This vancomycin resistance in MRSA isolates poses a challenge in managing S. aureus infections. Our study's results highlight the need to correctly identify patients in whom last-resort therapy such as linezolid and quinupristin/dalfopristin should be administered.

Prevalence and Associated Factors of Methicillin Resistance Staphylococcus aureus (MRSA) Among Urinary Tract Infection Suspected Patients Attending at Arba Minch General Hospital, Southern Ethiopia

“…The overall proportion of MRSA among study participants was 43.4% [95% CI (35.0, 47.0)] which was slightly higher than the study conducted in India. 30 However, this finding was lower than that of the study reported from Debre Markos University, Ethiopia 28 and from other country studies like; Nepal with a prevalence of 82.0%, 31 Iran with a prevalence of 55.6%, 32 and 64.3% reported from Nigeria. 33 This difference in isolation rate of MRSA could be due to the isolation technique (multiple screens) and there might be specific risk factors which are not assessed by this study that might decrease the proportion of MRSA among S. aureus in the current study, sample collection method (they used more than one clinical specimen), variation in study participants (since they collected from patients with a confirmed UTI whereas this study is from UTI suspected participants only).…”

Emergence of CC8/ST239- SCCmec III/t421 tigecycline resistant and CC/ST22-SCCmec IV/t790 vancomycin resistant Staphylococcus aureus strains isolated from wound: A two-year multi-center study in Tehran, Iran

“…Similarly, a previous study conducted by Zorgani et al in Libya indicated resistance to tigecycline in 3.6% of their S. aureus isolates tested [24]. In an experiment performed by Yousefi et al on 54 S. aureus isolated from urinary tract infections, 6.6% isolates were found to be resistant to tigecycline [25]. These observations were also supported by findings from Canada, USA, Honduras, El Salvador, France, Germany, Italy, Poland, Nigeria, China, and Taiwan [21].…”

<p>Molecular Characterization, Drug Resistance and Virulence Analysis of Constitutive and Inducible Clindamycin Resistance <em>Staphylococcus aureus</em> Strains Recovered from Clinical Samples, Tehran – Iran</p>

“…However, different resistance rates to tigecycline among S. aureus isolates are reported in Libya (3.6%), 25 Turkey (2%), 26 and Iran (6.6%). 9 Recently published data from Asian countries indicated a low prevalence of resistance to fusidic acid (<10%). 27,28 We found a low prevalence (4.7%) of resistance to fusidic acid among our isolates carrying fusB (3 isolates), and fusC (1 isolate) genes.…”

“…[3][4][5][6] Due to emerging simultaneous resistance to several antibacterial agents, the choice of chemotherapeutic options and treatment of serious infections caused by S. aureus has become problematic. [7][8][9] Although various antibiotics such as vancomycin, linezolid, and quinupristin-dalfopristin may be considered as drugs of choice, S. aureus strains with reduced susceptibility and resistance to these agents also emerged. Therefore, the use of macrolide-lincosamide-streptogramin B (MLSB) antibiotics as an alternative approach to treating such infections was taken into consideration.…”