Genetic diversity of healthcare-associated methicillin-resistant Staphylococcus aureus isolates from Southern Iran

Exploring the virulence potential of immune evasion cluster genes in methicillin-resistant Staphylococcus aureus from cancer patients

Methicillin-resistant Staphylococcus aureus (MRSA) is accountable for a plethora of infections, ranging from minor cutaneous manifestations to grave metastatic conditions. The dissemination of MRSA among cancer patients poses a substantial public health hazard on a global scale. This study explores the association between MRSA and bacteriophage-encoded immune evasion cluster (IEC) genes. This investigation employed a total of 168 pathogenic MRSA collected from 38 cancer and 130 non-cancer patients. A cefoxitin disc diffusion method followed by PCR analysis was used to identify the mecA gene. In this study, we employed singleplex and multiplexed PCR techniques to detect specific IEC genes. No association (p = 0.98) was observed between the sex and age of patients and MRSA isolates. However, MRSA isolates demonstrated a notable association (p = 0.01) with pus samples in non-cancer patients and skin swabs in cancer patients. The resistance profiles of MRSA strains from cancer and non-cancer patients did not show significant differences (p > 0.05). Notably, the sea gene was found to be more prevalent in MRSA isolates from cancer patients, displaying a significant association (p = 0.03). Additionally, this study identified two novel and distinct combinations of IEC types, namely V1 (sea, chp, scn) and V2 (sea, scn). Cancer patients had higher multidrug resistance and toxin gene abundance than non-cancer patients. The identification of two novel IEC patterns underscores the urgent need to control MRSA dissemination in hospitals and monitor emerging clones.

Staphylococcus aureus Bacteremia in Hospitalized Patients and Associated Factors: A Cross-sectional Study from Mashhad, Iran

Background: Staphylococcus aureus is an important cause of resistant infection with high mortality and morbidity. Objectives: We aimed to evaluate the clinical characteristics and comorbidities of patients with S. aureus infection to define the predictors of adverse outcomes. Methods: In this cross-sectional study, patients (aged ≥ 15 years) with positive S. aureus blood cultures were included. Their demographic and clinical characteristics were recorded, and their association with the main adverse outcomes (methicillin-resistant S. aureus [MRSA], infective endocarditis, source of infection, and the final outcome were analyzed using SPSS software version 16. Results: The male-to-female ratio was 54/51. The mean age was 55.13 years (women: 58.45 ± 20.4 and men: 53.6 ± 17.6). Of 105 cases analyzed, 40% had hospital-, 25.7% community-, and 34.3% healthcare-associated bacteremia. The median duration of hospital admission was 13 days. Thirty-two percent had MRSA, differently based on the source of infection (P = 0.029). Twenty-eight patients had infective endocarditis, differently based on the source of infection, prosthetics, considerable foci of infection, and receipt of blood and its derivatives (P < 0.05). Most patients with neurological and end-stage renal disease (both P = 0.001) did not have infective endocarditis. Finally, 61.9% of the patients were discharged with good condition, 38.1% died, and 9% left the hospital before diagnosis of the foci. Conclusions: Vascular catheters and cardiovascular diseases, including hypertension, are among the most common factors associated with S. aureus bacteremia, and it is necessary to carefully examine the presence of these factors, as well as infective endocarditis in these patients.