Introduction: Over the past decades, prevalence of biofilm-forming Staphylococcus aureus strains has significantly increased in urinary tract infections. The aim of this study was to investigate prevalence of biofilm forming and adhesion encoding genes and to analyze distribution of different agr and spa types in S. aureus isolates. Methodology: In the present study, 75 S. aureus isolates obtained from patients with urinary tract infections were examined for susceptibility to antimicrobial agents. Adhesion, biofilm, and spa encoding genes were detected by PCR screening; agr types were determined using multiplex PCR. Results: Among the 75 isolates, 72% were biofilm producers and 28% were non-biofilm producers. Notably, the ability to produce biofilm was higher among MRSA strains ompared to MSSA strains. The most prevalent biofilm forming gene was icaD (77.3%), followed by icaA (76%), icaB (57.3%) and icaC (50.7%). Adhesion genes clfA, clfB, fnbB, can, fnbA, ebp and bap were detected in 94.7%, 92%, 68%, 64%, 64%, 60% and 5.3% of the isolates, respectively. The spa types t426 and t7789 were found among the non-MDR isolates. It was found that t790, t084, t7789 and t325 spa types were biofilm producers, while t426 and t1339 spa types were non-biofilm producers. Conclusion: Biofilm encoding genes icaD and spa type t790 and agr type III were the most prevalent factors among MDR biofilm producer isolates. The study emphasized that identification of genes and characterization of molecular types involved in biofilm formation should be considered.

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Background: Treatment for infections caused by Methicillin-Resistant Staphylococcus aureus (S. aureus) is one of the main concerns of public health. Objectives: The aim of this study was to investigate the prevalence of toxin, enterotoxin, and resistant encoding genes and analyze the distribution of different SCCmec types. The prevalence of integron was also determined in S. aureus isolates obtained from patients with urinary tract infections (UTIs). Methods: In the present study, 126 MRSA isolates obtained from patients with UTI were examined for susceptibility to antimicrobial agents. Genes encoding integrase, resistance, toxin, and SEs were detected by the polymerase chain reaction (PCR) screening. The SCCmec types were determined using the multiplex PCR. Integrase positive strains were evaluated for determination of integron classes using PCR-restriction fragment length polymorphism assay. Results: From 126 MRSA isolates studied, 107 isolates (84.9%) were multi-drug resistant. The most prevalent genes in isolates under study was aac (6´)-Ie/aph (2˝) (50%) followed by tet (M) (47.6%), msr (A) (38.1%), aph (3´)-IIIa (25.4%), erm (A) (23%), ant (4´)-Ia (16.7%), erm (B) (14.3%), msr (B) (9.5%), and erm (C) (7.1%). Staphylococcal enterotoxins sea, sec, see, sed, seg, seb, and sei were detected in 27%, 20.6%, 16.7%, 14.3%, 11.1%, 7.1%, and 5.6% of the isolates, respectively. The results revealed that 126 MRSA isolates fell in the SCCmec type III (37.3%), SCCmec type I (23%), SCCmec type II (14.3%), SCCmec type IV (13.5%), and SCCmec type V (11.9%). Class 1 and 2 integrons were commonly found in 34.1% and 14.3% of the isolates, respectively. Seven isolates (5.6%) were observed to carry class 1 and 2 integrons, simultaneously. Conclusions: The current findings showed that identification and screening of integrons and SCCmec elements as reservoirs that should be considered for various resistance genes to consume proper antibiotic and perform a systematic surveillance.

Background: Infections caused by Staphylococcus aureus strains are a major public health challenge worldwide, especially in specialized burn hospitals. Infections caused by S. aureus account for more than 50% of burn-related deaths. Objectives: Since data on characteristics of these isolates are not sufficient, the current study aimed to assess the prevalence of resistance to antibacterial agents and to analyze the distribution of biofilm, and adhesion encoding genes among S. aureus strains isolated from burn patients in Motahari Hospital, Tehran, Iran. Methods: A total of 83 S. aureus strains were collected from burn wounds of patients admitted to a referral burn center in Tehran for 10 months. In vitro antibacterial susceptibility of isolates was evaluated using the Kirby-Bauer disk diffusion method. Strains were subjected to polymerase chain reaction (PCR) to determine the presence of nucA, mecA, ebps, cna, bbp, fnbA, fnbB, clfA, and clfB genes. Results: The highest frequency of resistance was found to cephalexin and cefoxitin (87.9%), followed by clindamycin (75.9%), erythromycin (72.3%), and ciprofloxacin (60.2%). Five resistance patterns were identified in which cephalexin, cefoxitin, clindamycin, erythromycin, and ciprofloxacin had the most predominant resistance profile (36.1%). Biofilm gene detection indicated a markedly high prevalence of cna (74.7%), clfB (54.2%), clfA (50.6%), fnbA (42.1%), ebp (13.2%), and fnbB (12%). Six different biofilm genetic patterns were identified, wherein clfA, clfB, fnbA, ebp, and cna (30.1%), clfA, clfB, fnbA, fnbB, ebp, and cna (12%), and clfA, clfB, and cna (8.4%) were the top three most frequently identified patterns. Conclusions: The prevalence of biofilm encoding genes, which are associated with multidrug resistance in S. aureus strains isolated from burn patients, is high. Therefore, identification of epidemiology, molecular characteristics, and biofilm management of S. aureus infection in burn units would be helpful.